physicsworld--2020-10-15--Pathways to scalable quantum technologies - Physics World

This episode of the Physics World Weekly podcast features interviews with two leaders in the race to build practical quantum @ @ @ @ @ director of Australia ’ s Centre of Excellence for Quantum Computation and Communication Technology .
@ @ @ @ @ early work on fabricating solar cells kindled a passion for building electronic devices that she @ @ @ @ @ research group at the University of New South Wales that is building solid-state quantum computing @ @ @ @ @ .
Jelena Vučković is Professor of Electrical Engineering and by courtesy , professor of Applied @ @ @ @ @ There , she leads the Nanoscale and Quantum Photonics Lab and focuses on using impurities @ @ @ @ @ devices .
Vučković talks about the challenges involved in creating scalable quantum computers and also @ @ @ @ @ engineers and physicists play in the development of quantum technologies .
Vučković and Simmons are @ @ @ @ @ 2020 Virtual Conference , which is being held on 19—22 October .

This episode of the Physics World Weekly podcast features interviews with two leaders in the race to build practical quantum computers.
Michelle Simmons is director of Australia’s Centre of Excellence for Quantum Computation and Communication Technology. She talks about how her early work on fabricating solar cells kindled a passion for building electronic devices that she now pursues by leading a research group at the University of New South Wales that is building solid-state quantum computing devices at the atomic scale.
Jelena Vučković is Professor of Electrical Engineering and by courtesy, professor of Applied Physics at Stanford University. There, she leads the Nanoscale and Quantum Photonics Lab and focuses on using impurities in diamond to create quantum devices. Vučković talks about the challenges involved in creating scalable quantum computers and also reflects on the roles that engineers and physicists play in the development of quantum technologies.
Vučković and Simmons are plenary speakers at the Quantum 2020 Virtual Conference, which is being held on 19—22 October.


physicsworld--2020-10-15--Air-breathing rocket engines: the future of space flight - Physics World

The pursuit , exploration and utilization of the space environment can be misinterpreted as a luxury .
History portrays space as an exclusive domain for global powers looking to demonstrate their prowess through technological marvels , or the stage for far-off exploration and scientific endeavour with little impact on daily life .
However , the benefits of space are already woven into our everyday routines and provide utilities and resources on which the society has grown dependent .
If these were suddenly to disappear and the world were to experience just “ a day without space ” , the consequences @ @ @ @ @ @ @ biggest space-based resource is the satellites we ’ ve put in orbit around the Earth .
Communication satellites provide global connectivity and the means to transmit live television around the world .
We can remotely watch international events and sporting spectacles in real time , thanks to this space-borne infrastructure .
Earth observation is also of growing importance , letting us monitor and assess our natural habitat and climate , which in turn enables us to optimize agricultural land use , to predict and intervene in national disasters , to organize relief efforts @ @ @ @ @ @ @ navigation and timing ( PNT ) satellites provide valuable location data for drivers and outdoor enthusiasts , while their timing signals are also used to timestamp and co-ordinate global cash withdrawals and financial transactions .
Satellites provide platforms for science and technology , and they can give universities access to orbital experimentation .
Companies are learning to rapidly develop technology through prototypes placed in orbit , while research into space weather using in-orbit instruments provides improved understanding and forecasting to protect our Earth-bound power grids from solar storms .
The utilization of space @ @ @ @ @ @ @ .
A new vision for the future is starting to emerge that will feature even more innovative uses of space , ranging from space-based manufacturing and energy production to global Internet connectivity .
Space-debris management is also receiving greater focus alongside lunar and Martian exploration , and even space tourism .
While some of these new innovations may sound like they are confined to the realm of science fiction , there are already companies furthering the technology to turn them into reality .
One of the fundamental challenges associated with exploring and working @ @ @ @ @ @ @ there , starts down here .
Escaping Earth ’ s gravity and achieving orbit is technically difficult , operationally complex and financially exclusive .
The tide is turning , however , and the world is in the midst of a transformational era in the history of spaceflight .
An activity once limited to governments and national space agencies is now witnessing a flourish of innovation led by entrepreneurial private companies such as Rocket Lab , Virgin Orbit and SpaceX , the latter of which was in the global spotlight as watched the US @ @ @ @ @ @ @ the International Space Station and then return them safely earlier this year .
By optimizing conventional rocket technology , these firms are rapidly reducing the cost of space access and generating launch capacity .
This in turn is creating opportunities for new space operators and is beginning to initiate a virtuous circle , in which reduced launch costs and increased flight rates create additional commercial opportunities and more demand for launch services .
Indeed , the investment bank Morgan Stanley estimates that the global space market will be worth $ 1 trillion per @ @ @ @ @ @ @ could significantly reduce launch costs even further , it will be limited if the global space-access industry remains focused on optimizing conventional rocket technology , which was first used in the mid-20th century .
That ’ s why we here at Reaction Engines in the UK ( see box below ) are developing the Synergetic Air Breathing Rocket Engine ( SABRE ) – what we think will be the next generation of space-propulsion technology .
Our aim is to enable horizontally launched reusable space vehicles that are affordable , reliable and responsive , @ @ @ @ @ @ @ and regular frequency .
Conventional rocket vehicles are propelled by a fuel ( liquid hydrogen , kerosene or methane ) and an oxidizer ( liquid oxygen ) carried within the vehicle body .
When the fuel and oxidizer combust , mass is projected out of the back of the rocket , creating thrust .
However , this approach – and especially the use of heavy on-board liquid oxygen – is constrained by Tsiolkovsky ’ s rocket equation .
It basically tells us that everything carried on board a vehicle has a penalty in @ @ @ @ @ @ @ and structural mass of the vehicle , needed to get it off the ground .
In other words , this approach hampers mission performance , mission payload and mission time .
SABRE , on the other hand , is a hybrid air-breathing rocket engine .
During the atmospheric segment of its ascent , it will use oxygen from the atmosphere instead of carrying it inside the vehicle , before switching to on-board oxygen upon leaving the atmosphere .
A SABRE-powered launch vehicle will therefore have lower mass for a given payload than a @ @ @ @ @ @ @ can be traded for systems that will enable reusability and aircraft-like traits , such as wings , undercarriage and thermal-protection systems – all the features needed to fly the same vehicle over and over again , achieving hundreds of launches .
Reusability will not only drive down the cost of the launch .
SABRE-powered launch vehicles will also take off like aircraft instead of launching vertically like conventional rocket vehicles .
As a result , they will introduce faster turnaround times , higher vehicle utilization rates and more responsive launches .
They will @ @ @ @ @ @ @ return-to-base scenarios .
The design of SABRE-powered launch vehicles will also allow more rapid set-up and simpler launch facilities compared with current vehicle designs .
At Reaction Engines , we think these characteristics are far beyond what we see from even the most advanced expendable systems currently available – and that they therefore will unlock the full virtuous cycle for space access and the greater potential of the space economy .
The key element within SABRE is its unique , high-performance thermal-management system , which relies on fundamental thermodynamics to extract , redirect @ @ @ @ @ @ @ ( Mach 5 ) airstream as it enters the engine .
One of the most important parts of this system is the precooler , which was therefore one of the first pieces of SABRE technology to be developed .
The speed of existing air-breathing engines is limited by their ability to handle and exploit the energy contained within high-Mach air streams .
To create thrust from an air-breathing engine you have to increase the speed of the air that passes through it .
Counterintuitively , you also have to slow the air down @ @ @ @ @ @ @ the internal machinery can apply work into the airflow before accelerating it from the back of the engine .
However , when fast-moving air slows down , it rapidly heats up as kinetic energy is converted into thermal energy .
For example , these temperatures can reach over 1000 °C when slowing a Mach 5 air stream .
At such high temperatures , it is not possible to maintain the integrity of conventional engine components – quite simply , they melt .
Together , SABRE ’ s thermal management system and the precooler @ @ @ @ @ @ @ When high-Mach air enters SABRE , it is first slowed down by the intake of the engine through a series of shockwaves created by the geometry of the engine ’ s components .
As this happens the air rapidly heats up , but is then passed into the precooler where its temperature is reduced to manageable levels .
The precooler has been designed to create heat transfer between the air stream and an internal fluid medium ( cryogenic helium ) .
Geometry , fluid properties , and thermal and mechanical effects have all @ @ @ @ @ @ @ extraction of heat from the air stream .
With the air stream suitably cooled , it can now enter the heart of the engine , where it goes through a cycle involving compression , combustion , regeneration and , ultimately , expansion through the engine ’ s nozzle thereby creating propulsive force .
The air stream ’ s thermal energy , which has been transferred to the precooler fluid , is also used to drive the internal components of the engine .
The precooler can cool high mass-flow airstreams from temperatures above 1000 @ @ @ @ @ @ @ milliseconds , within a compact and low-weight design .
It is formed from over 42 km of tubing , the walls of which are thinner than a human hair – thereby providing an enormous area for heat-transfer between the air and cooling medium .
Putting it to the test In 2012 Reaction Engines manufactured a fully operational precooler and tested it more than 700 times , verifying the ability to take ambient air down to cryogenic temperatures .
This prototype unit saw more test time than an already operational prospective SABRE precooler , @ @ @ @ @ @ @ the Hot Heat Exchanger ( HTX ) test campaign , which was designed to subject the precooler to a range of high-temperature conditions representative of high-Mach flight .
Carried out in 2019 , the testing took place at a specially constructed facility at the Colorado Air and Space Port near Denver in the US .
The test set-up featured a conventional fighter aircraft engine running on full afterburner in order to create the high-mass air flow and high-temperature conditions a SABRE precooler will experience in flight after stagnating ( or slowing down ) @ @ @ @ @ @ @ test campaigns were conducted , with each achieving a higher equivalent Mach number .
The final round of tests saw both the precooler and test equipment pushed to their limits , and successfully deliver the ultimate Mach 5 test objective – it demonstrated that the precooler could quench airflow temperatures in excess of 1000 °C in less than 50 milliseconds .
The tests showed the precooler ’ s ability to successfully cool airflow at speeds much higher than the operational limit of any jet-engine-powered aircraft in history .
It ran at over twice @ @ @ @ @ @ @ one and a half times the conditions of the SR71 Blackbird .
This remarkable precooler technology is , therefore , not only key to the SABRE engine but also offers propulsion solutions for high-Mach and hypersonic aircraft that remain within the atmosphere .
What comes next ?
Since the successful HTX test campaign , the next phase of SABRE testing is now under way in its “ core engine campaign ” , which aims to validate the performance of the air-breathing core .
This part of SABRE is responsible for recycling the thermal @ @ @ @ @ @ @ engine ’ s internal components .
It is also where the incoming air is compressed , mixed with hydrogen fuel and then burnt within the engine ’ s combustion systems prior to being expanded through its nozzle .
This stage will prove the viability of SABRE ’ s entire thermodynamic cycle and will be a landmark moment when it is demonstrated for the first time .
While the precise timings of this latest phase of the test campaign have been hit by the COVID-19 restrictions imposed in the UK , an extensive design @ @ @ @ @ @ @ with the UK and European space agencies , which will enable the programme to swiftly progress once the restrictions are reduced .
And while the COVID-19 pandemic has undoubtedly impacted both the global aerospace sector and the operation of manufacturing and R & D facilities in the UK , there remains robust demand in the commercial space-launch sector .
Reaction Engines can already see a number of possibilities where applications of SABRE-class engines might be used in launch-vehicle architectures , and we are working with partners across the space industry to understand how @ @ @ @ @ @ @ fore .
Despite being originally conceived as an engine for enabling low-cost space access , it ’ s now clear that SABRE technology could provide benefits beyond the space industry .
That ’ s why Reaction Engines is also developing spin-out applications of the technology with other industry partners .
In the aerospace sector , SABRE ’ s thermal-management capability and heat-exchanger technology could boost the efficiency of next-generation commercial aircraft engines and systems , as well as high-Mach and hypersonic aircraft .
At a time when the aerospace industry must demonstrate resilience @ @ @ @ @ @ @ paradigm shifts and challenging decarbonization targets , SABRE technology could help by providing a range of efficiency improvements and cost savings for current and future aircraft concepts .
Reaction Engines is investigating how SABRE technology could benefit other sectors too .
Motorsport , industrial processes and the energy industry are all areas where intelligent thermal management , such as that at the heart of SABRE , could bring about significant change .
Reaction Engines is keen to adapt and deploy its technology into these industries to make them more efficient , more sustainable @ @ @ @ @ @ @ It is clear that the space industry is going through a period of significant innovation and rapid development .
Innovative new commercial entrants have lowered the cost of space access , which has in turn opened up further commercial opportunities in space .
As the industry develops and the demand for ultra-low-cost access to space increases , we believe that there will be a need for the kind of revolutionary leap forward in propulsion that SABRE and its thermal-management systems represent .

Physics World, where it appeared under the headline "Eliminating the boundary between sky and space". Members of the Institute of Physics can enjoy the full issue Taken from the October 2020 issue of, where it appeared under the headline "Eliminating the boundary between sky and space". Members of the Institute of Physics can enjoy the full issue via the Physics World app
Reusable vehicles are vital to make access to space more affordable, but conventional rocket engines have their limits. Oliver Nailard describes how UK firm Reaction Engines hopes to revolutionize space access with a new class of propulsion system, the Synergetic Air Breathing Rocket Engine (SABRE)
(Courtesy: Reaction Engines)
The pursuit, exploration and utilization of the space environment can be misinterpreted as a luxury. History portrays space as an exclusive domain for global powers looking to demonstrate their prowess through technological marvels, or the stage for far-off exploration and scientific endeavour with little impact on daily life. However, the benefits of space are already woven into our everyday routines and provide utilities and resources on which the society has grown dependent. If these were suddenly to disappear and the world were to experience just “a day without space”, the consequences would be evident to all.
Our biggest space-based resource is the satellites we’ve put in orbit around the Earth. Communication satellites provide global connectivity and the means to transmit live television around the world. We can remotely watch international events and sporting spectacles in real time, thanks to this space-borne infrastructure. Earth observation is also of growing importance, letting us monitor and assess our natural habitat and climate, which in turn enables us to optimize agricultural land use, to predict and intervene in national disasters, to organize relief efforts, and more besides.
Position, navigation and timing (PNT) satellites provide valuable location data for drivers and outdoor enthusiasts, while their timing signals are also used to timestamp and co-ordinate global cash withdrawals and financial transactions. Satellites provide platforms for science and technology, and they can give universities access to orbital experimentation. Companies are learning to rapidly develop technology through prototypes placed in orbit, while research into space weather using in-orbit instruments provides improved understanding and forecasting to protect our Earth-bound power grids from solar storms.
The utilization of space is set to become more important still. A new vision for the future is starting to emerge that will feature even more innovative uses of space, ranging from space-based manufacturing and energy production to global Internet connectivity. Space-debris management is also receiving greater focus alongside lunar and Martian exploration, and even space tourism.
While some of these new innovations may sound like they are confined to the realm of science fiction, there are already companies furthering the technology to turn them into reality.
SABRE unleashed A concept image of Reaction Engine’s Synergetic Air Breathing Rocket Engine (SABRE). (Courtesy: Reaction Engines)
Affordable space access
One of the fundamental challenges associated with exploring and working in space is that whatever is up there, starts down here. Escaping Earth’s gravity and achieving orbit is technically difficult, operationally complex and financially exclusive.
The tide is turning, however, and the world is in the midst of a transformational era in the history of spaceflight. An activity once limited to governments and national space agencies is now witnessing a flourish of innovation led by entrepreneurial private companies such as Rocket Lab, Virgin Orbit and SpaceX, the latter of which was in the global spotlight as watched the US Commercial Crew Programme launched American astronauts to the International Space Station and then return them safely earlier this year. By optimizing conventional rocket technology, these firms are rapidly reducing the cost of space access and generating launch capacity. This in turn is creating opportunities for new space operators and is beginning to initiate a virtuous circle, in which reduced launch costs and increased flight rates create additional commercial opportunities and more demand for launch services. Indeed, the investment bank Morgan Stanley estimates that the global space market will be worth $1 trillion per year by 2040.
The global space-access industry will be limited if it remains focused on optimizing conventional rocket technology, which was first used in the mid-20th century
While this cycle could significantly reduce launch costs even further, it will be limited if the global space-access industry remains focused on optimizing conventional rocket technology, which was first used in the mid-20th century. That’s why we here at Reaction Engines in the UK (see box below) are developing the Synergetic Air Breathing Rocket Engine (SABRE) – what we think will be the next generation of space-propulsion technology. Our aim is to enable horizontally launched reusable space vehicles that are affordable, reliable and responsive, and can be launched at a high and regular frequency.
SABRE versus conventional rockets
Conventional rocket vehicles are propelled by a fuel (liquid hydrogen, kerosene or methane) and an oxidizer (liquid oxygen) carried within the vehicle body. When the fuel and oxidizer combust, mass is projected out of the back of the rocket, creating thrust. However, this approach – and especially the use of heavy on-board liquid oxygen – is constrained by Tsiolkovsky’s rocket equation. It basically tells us that everything carried on board a vehicle has a penalty in the form of the additional propellant, and structural mass of the vehicle, needed to get it off the ground. In other words, this approach hampers mission performance, mission payload and mission time.
SABRE, on the other hand, is a hybrid air-breathing rocket engine. During the atmospheric segment of its ascent, it will use oxygen from the atmosphere instead of carrying it inside the vehicle, before switching to on-board oxygen upon leaving the atmosphere. A SABRE-powered launch vehicle will therefore have lower mass for a given payload than a conventional rocket vehicle. This mass benefit can be traded for systems that will enable reusability and aircraft-like traits, such as wings, undercarriage and thermal-protection systems – all the features needed to fly the same vehicle over and over again, achieving hundreds of launches.
Reusability will not only drive down the cost of the launch. SABRE-powered launch vehicles will also take off like aircraft instead of launching vertically like conventional rocket vehicles. As a result, they will introduce faster turnaround times, higher vehicle utilization rates and more responsive launches. They will be able to undertake safe abort and return-to-base scenarios. The design of SABRE-powered launch vehicles will also allow more rapid set-up and simpler launch facilities compared with current vehicle designs.
At Reaction Engines, we think these characteristics are far beyond what we see from even the most advanced expendable systems currently available – and that they therefore will unlock the full virtuous cycle for space access and the greater potential of the space economy.
The precooler
The key element within SABRE is its unique, high-performance thermal-management system, which relies on fundamental thermodynamics to extract, redirect and utilize the enthalpy of a hypersonic (Mach 5) airstream as it enters the engine. One of the most important parts of this system is the precooler, which was therefore one of the first pieces of SABRE technology to be developed.
The speed of existing air-breathing engines is limited by their ability to handle and exploit the energy contained within high-Mach air streams. To create thrust from an air-breathing engine you have to increase the speed of the air that passes through it. Counterintuitively, you also have to slow the air down when you reach high speeds so that the internal machinery can apply work into the airflow before accelerating it from the back of the engine.
However, when fast-moving air slows down, it rapidly heats up as kinetic energy is converted into thermal energy. For example, these temperatures can reach over 1000 °C when slowing a Mach 5 air stream. At such high temperatures, it is not possible to maintain the integrity of conventional engine components – quite simply, they melt.
Quick cooling Hot airstreams can be cooled from 1000 °C to ambient temperatures within 50 ms by SABRE’s precooler. (Courtesy: Reaction Engines)
Together, SABRE’s thermal management system and the precooler provide a solution to this problem. When high-Mach air enters SABRE, it is first slowed down by the intake of the engine through a series of shockwaves created by the geometry of the engine’s components. As this happens the air rapidly heats up, but is then passed into the precooler where its temperature is reduced to manageable levels. The precooler has been designed to create heat transfer between the air stream and an internal fluid medium (cryogenic helium). Geometry, fluid properties, and thermal and mechanical effects have all been considered so as to maximize the extraction of heat from the air stream.
With the air stream suitably cooled, it can now enter the heart of the engine, where it goes through a cycle involving compression, combustion, regeneration and, ultimately, expansion through the engine’s nozzle thereby creating propulsive force. The air stream’s thermal energy, which has been transferred to the precooler fluid, is also used to drive the internal components of the engine.
The precooler can cool high mass-flow airstreams from temperatures above 1000 °C to ambient in less than 50 milliseconds, within a compact and low-weight design. It is formed from over 42 km of tubing, the walls of which are thinner than a human hair – thereby providing an enormous area for heat-transfer between the air and cooling medium.
Putting it to the test
In 2012 Reaction Engines manufactured a fully operational precooler and tested it more than 700 times, verifying the ability to take ambient air down to cryogenic temperatures. This prototype unit saw more test time than an already operational prospective SABRE precooler, and performed impeccably throughout.
Next came the Hot Heat Exchanger (HTX) test campaign, which was designed to subject the precooler to a range of high-temperature conditions representative of high-Mach flight. Carried out in 2019, the testing took place at a specially constructed facility at the Colorado Air and Space Port near Denver in the US. The test set-up featured a conventional fighter aircraft engine running on full afterburner in order to create the high-mass air flow and high-temperature conditions a SABRE precooler will experience in flight after stagnating (or slowing down) a Mach 5 airstream.
Three hot test campaigns were conducted, with each achieving a higher equivalent Mach number. The final round of tests saw both the precooler and test equipment pushed to their limits, and successfully deliver the ultimate Mach 5 test objective – it demonstrated that the precooler could quench airflow temperatures in excess of 1000 °C in less than 50 milliseconds.
The tests showed the precooler’s ability to successfully cool airflow at speeds much higher than the operational limit of any jet-engine-powered aircraft in history. It ran at over twice the operational conditions of Concorde and over one and a half times the conditions of the SR71 Blackbird. This remarkable precooler technology is, therefore, not only key to the SABRE engine but also offers propulsion solutions for high-Mach and hypersonic aircraft that remain within the atmosphere.
Testing, testing The precooler was put through a series of high-temperature tests using an engine from a conventional fighter aircraft. (Courtesy: Reaction Engines)
What comes next?
Since the successful HTX test campaign, the next phase of SABRE testing is now under way in its “core engine campaign”, which aims to validate the performance of the air-breathing core. This part of SABRE is responsible for recycling the thermal energy extracted through the precooler into the engine’s internal components. It is also where the incoming air is compressed, mixed with hydrogen fuel and then burnt within the engine’s combustion systems prior to being expanded through its nozzle. This stage will prove the viability of SABRE’s entire thermodynamic cycle and will be a landmark moment when it is demonstrated for the first time.
While the precise timings of this latest phase of the test campaign have been hit by the COVID-19 restrictions imposed in the UK, an extensive design process has already been conducted in conjunction with the UK and European space agencies, which will enable the programme to swiftly progress once the restrictions are reduced. And while the COVID-19 pandemic has undoubtedly impacted both the global aerospace sector and the operation of manufacturing and R&D facilities in the UK, there remains robust demand in the commercial space-launch sector. Reaction Engines can already see a number of possibilities where applications of SABRE-class engines might be used in launch-vehicle architectures, and we are working with partners across the space industry to understand how these capabilities can be brought to the fore.
Technology spinout
Despite being originally conceived as an engine for enabling low-cost space access, it’s now clear that SABRE technology could provide benefits beyond the space industry. That’s why Reaction Engines is also developing spin-out applications of the technology with other industry partners.
In the aerospace sector, SABRE’s thermal-management capability and heat-exchanger technology could boost the efficiency of next-generation commercial aircraft engines and systems, as well as high-Mach and hypersonic aircraft. At a time when the aerospace industry must demonstrate resilience in the face of COVID-19, technological paradigm shifts and challenging decarbonization targets, SABRE technology could help by providing a range of efficiency improvements and cost savings for current and future aircraft concepts.
Reaction Engines is investigating how SABRE technology could benefit other sectors too. Motorsport, industrial processes and the energy industry are all areas where intelligent thermal management, such as that at the heart of SABRE, could bring about significant change. Reaction Engines is keen to adapt and deploy its technology into these industries to make them more efficient, more sustainable, and better for the environment.
It is clear that the space industry is going through a period of significant innovation and rapid development. Innovative new commercial entrants have lowered the cost of space access, which has in turn opened up further commercial opportunities in space.
As the industry develops and the demand for ultra-low-cost access to space increases, we believe that there will be a need for the kind of revolutionary leap forward in propulsion that SABRE and its thermal-management systems represent.
Reaction Engines Reaction Engines is a UK company founded in 1989 by the propulsion engineers Alan Bond, Richard Varvill and John Scott Scott. They had previously worked together on the RB545 engine, which was destined for use on the Horizontal Takeoff and Landing (HOTOL) system – a space plane concept developed by British Aerospace and Rolls-Royce – in the late 1980s. After HOTOL was cancelled, the team formed Reaction Engines to evolve the HOTOL and RB545 concepts into the SABRE engine class, which the company continues to develop. After years of fundamental technology development, a UK government grant of £60m in 2015 – coupled with investment from BAE Systems, Rolls-Royce and Boeing HorizonX – has enabled Reaction Engines to grow and transition from research into design and demonstration. Based at the Culham Science Centre in Oxfordshire, the company is working alongside the UK Space Agency, European Space Agency and other organizations in the UK and Europe, to develop SABRE.


physicsworld--2020-10-15--Why physics-based firms benefit from green-strings-attached economic-recovery measures - Physics Wor

Why physics-based firms benefit from green-strings-attached economic-recovery measures - Physics World

Climate change is a “ defining factor ” in the long-term prospects of businesses .
So said Larry Fink – boss of leading asset-management firm Blackrock – in an open letter he wrote to chief executives around the world in January , shortly before COVID-19 hit pandemic levels .
What ’ s interesting is that as the world emerges from lockdown and governments look to restart their economies with stimulus packages , many are taking the opportunity to attach “ green strings ” to their support .
The world ’ s greenest pandemic bailout initiative so far is the European @ @ @ @ @ @ @ Unlike many national COVID-19 support schemes , EU member states that want funds must show they will use the money in line with Europe ’ s Green Deal to eliminate net greenhouse-gas emissions .
The UK has its own Green Recovery Programme , which seeks to drive investment in low-carbon innovation , infrastructure and industries , supporting sectors that increase job creation and decarbonization .
Such programmes essentially involve providing financial support with green caveats attached , which is great news for the “ clean technology ” sector .
However , any such @ @ @ @ @ @ @ may take several years to get to market .
What ’ s more , falling profits and reduced business confidence following COVID-19 will lead to companies cutting their spending on research and development , unless appropriate support and encouragement are in place .
That ’ s why I was delighted to see , here in the UK , chancellor Rishi Sunak increase the Research and Development Expenditure Credit ( RDEC ) from 12 % to 13 % to help businesses invest in R & D .
More significantly , the UK government is @ @ @ @ @ @ @ refine the scheme to make it more effective at stimulating growth and investment – something that I and others on the Business Innovation and Growth ( BIG ) group of the Institute of Physics ( IOP ) have been pushing since it was set up in 2018 .
The BIG group and the IOP ’ s policy team will be responding to the consultation by reminding the UK government how physics-based firms can take a lot longer to develop especially as scaling up prototype products and processes is risky and expensive .
But @ @ @ @ @ @ @ a sustained competitive advantage and often export globally .
They also encourage basic science , develop patents , employ talented people and boost manufacturing .
Given the emphasis on green technology in the post-COVID future , I was therefore pleased that several of this year ’ s IOP business award winners , which I was involved in selecting , are exactly the kind of clean-tech companies we need .
They included Hirst Magnetic Instruments , a research-led company founded in 1938 that develops and makes equipment to test , measure and produce magnets @ @ @ @ @ @ @ focuses on the growing market for magnetic-material characterization , which is vital for improving the efficiency of motors in electric vehicles .
Hirst ’ s materials equipment and magnetizers are supporting materials testing in China and the production lines of companies in the electric-vehicle supply chain .
Meanwhile , one company to win an IOP business start-up award this year was QLM Technology , which is developing low-power tunable-diode LIDAR gas-imaging systems based on infrared single-photon detection .
Its prototypes have produced some amazing camera images that show parts-per-million levels of methane in @ @ @ @ @ @ @ to 200 m. Methane is the second most important greenhouse gas – being roughly 30 times more potent at trapping heat than carbon dioxide – and there are over a million gas and oil-well pads around the world , which are leaking much more than they should .
QLM ’ s low cost , accurate and robust devices are exactly what ’ s needed for widespread emissions monitoring and meaningful regulation .
Indeed , the company is already developing products for industry leaders such as Ametek , BP and the National Grid , @ @ @ @ @ @ @ next year .
Perhaps the most intriguing of the IOP ’ s start-up winners was FeTu , a company set up in 2016 by chief executive Jonathan Fenton , whose Fenton Turbine seems the closest we have got so far to the ideal , closed-cycle reversible heat engine first imagined by thermodynamics pioneer Nicolas Carnot in 1824 .
The turbine , the firm claims , could replace compressors , air conditioners , fridges , vacuum pumps and heat pumps with efficiency savings across the board .
It sounds like a “ too-good-to-be-true ” @ @ @ @ @ @ @ out to prove that ’ s not the case , with some remarkable results .
The turbine is complex to describe but the first version – a “ bare-shaft ” unit – cuts the energy cost of compressing gases like air by 25 % , with the result proven in independent tests carried out by researchers at the University of Bath .
That ’ s promising for FeTu given that 10 % of all electricity used by companies in Europe goes on compressing air – roughly 80 terawatt hours consumption per year .
@ @ @ @ @ @ @ open-cycle ” variant of the company ’ s turbine can , when configured to act as a heat pump , be as efficient as air-conditioning units and refrigerators – despite using just air as the working fluid .
It therefore has great environmental potential given that conventional “ phase-change ” refrigerants are some 2500 times more potent than carbon dioxide as greenhouse gases .
FeTu says it is making good progress with customers where the energy saving and environmental advantages are clear .
It is also developing a “ closed-cycle ” variant of @ @ @ @ @ @ @ improvements in store .
As many of the IOP ’ s award winners illustrate , plenty of these clean-tech innovations are firmly rooted in physics .
I believe that research and development will be critical to ensure both economic and social recovery from the impacts of COVID-19 , enabling us to build a greener , healthier and more resilient world .
The IOP ’ s business award winners are therefore well placed to contribute to that endeavour .

Physics World, where it appeared under the headline "Green strings attached".. Members of the Institute of Physics can enjoy the full issue Taken from the October 2020 issue of, where it appeared under the headline "Green strings attached".. Members of the Institute of Physics can enjoy the full issue via the Physics World app
Solving many of today’s environmental problems will require advanced technological solutions, says James McKenzie
Greener futures Economic recovery will go hand in hand with cleaner technology. (Courtesy: iStock/Ratsanai)
Climate change is a “defining factor” in the long-term prospects of businesses. So said Larry Fink – boss of leading asset-management firm Blackrock – in an open letter he wrote to chief executives around the world in January, shortly before COVID-19 hit pandemic levels. What’s interesting is that as the world emerges from lockdown and governments look to restart their economies with stimulus packages, many are taking the opportunity to attach “green strings” to their support.
The world’s greenest pandemic bailout initiative so far is the European Commission’s €750bn recovery package. Unlike many national COVID-19 support schemes, EU member states that want funds must show they will use the money in line with Europe’s Green Deal to eliminate net greenhouse-gas emissions. The UK has its own Green Recovery Programme, which seeks to drive investment in low-carbon innovation, infrastructure and industries, supporting sectors that increase job creation and decarbonization.
As governments look to restart their economies with stimulus packages, many are taking the opportunity to attach “green strings” to their support
Such programmes essentially involve providing financial support with green caveats attached, which is great news for the “clean technology” sector. However, any such clean-tech improvements will not happen overnight and may take several years to get to market. What’s more, falling profits and reduced business confidence following COVID-19 will lead to companies cutting their spending on research and development, unless appropriate support and encouragement are in place.
That’s why I was delighted to see, here in the UK, chancellor Rishi Sunak increase the Research and Development Expenditure Credit (RDEC) from 12% to 13% to help businesses invest in R&D. More significantly, the UK government is currently holding a consultation on how to refine the scheme to make it more effective at stimulating growth and investment – something that I and others on the Business Innovation and Growth (BIG) group of the Institute of Physics (IOP) have been pushing since it was set up in 2018.
The BIG group and the IOP’s policy team will be responding to the consultation by reminding the UK government how physics-based firms can take a lot longer to develop especially as scaling up prototype products and processes is risky and expensive. But, once established, such firms have a sustained competitive advantage and often export globally. They also encourage basic science, develop patents, employ talented people and boost manufacturing.
Innovation in action
Given the emphasis on green technology in the post-COVID future, I was therefore pleased that several of this year’s IOP business award winners, which I was involved in selecting, are exactly the kind of clean-tech companies we need.
They included Hirst Magnetic Instruments, a research-led company founded in 1938 that develops and makes equipment to test, measure and produce magnets. Headed by John Dudding, it focuses on the growing market for magnetic-material characterization, which is vital for improving the efficiency of motors in electric vehicles. Hirst’s materials equipment and magnetizers are supporting materials testing in China and the production lines of companies in the electric-vehicle supply chain.
Meanwhile, one company to win an IOP business start-up award this year was QLM Technology, which is developing low-power tunable-diode LIDAR gas-imaging systems based on infrared single-photon detection. Its prototypes have produced some amazing camera images that show parts-per-million levels of methane in the atmosphere measured at distances of up to 200 m. Methane is the second most important greenhouse gas – being roughly 30 times more potent at trapping heat than carbon dioxide – and there are over a million gas and oil-well pads around the world, which are leaking much more than they should.
QLM’s low cost, accurate and robust devices are exactly what’s needed for widespread emissions monitoring and meaningful regulation. Indeed, the company is already developing products for industry leaders such as Ametek, BP and the National Grid, with plans to deliver industry-ready products early next year.
Perhaps the most intriguing of the IOP’s start-up winners was FeTu, a company set up in 2016 by chief executive Jonathan Fenton, whose Fenton Turbine seems the closest we have got so far to the ideal, closed-cycle reversible heat engine first imagined by thermodynamics pioneer Nicolas Carnot in 1824. The turbine, the firm claims, could replace compressors, air conditioners, fridges, vacuum pumps and heat pumps with efficiency savings across the board.
It sounds like a “too-good-to-be-true” technology, but Fenton has sensibly set out to prove that’s not the case, with some remarkable results. The turbine is complex to describe but the first version – a “bare-shaft” unit – cuts the energy cost of compressing gases like air by 25%, with the result proven in independent tests carried out by researchers at the University of Bath. That’s promising for FeTu given that 10% of all electricity used by companies in Europe goes on compressing air – roughly 80 terawatt hours consumption per year.
As many of the IOP’s award winners illustrate, plenty of these clean-tech innovations are firmly rooted in physics
What’s more, an “open-cycle” variant of the company’s turbine can, when configured to act as a heat pump, be as efficient as air-conditioning units and refrigerators – despite using just air as the working fluid. It therefore has great environmental potential given that conventional “phase-change” refrigerants are some 2500 times more potent than carbon dioxide as greenhouse gases. FeTu says it is making good progress with customers where the energy saving and environmental advantages are clear. It is also developing a “closed-cycle” variant of the same machine with even greater efficiency improvements in store.
As many of the IOP’s award winners illustrate, plenty of these clean-tech innovations are firmly rooted in physics. I believe that research and development will be critical to ensure both economic and social recovery from the impacts of COVID-19, enabling us to build a greener, healthier and more resilient world. The IOP’s business award winners are therefore well placed to contribute to that endeavour.


physicsworld--2020-10-15--Excitement grows over mysterious signal in dark-matter detector - Physics World

In June of this year , physicists working on the XENON1T dark-matter detector announced the measurement of a curious signal in their experiment — which comprises 2 tonne of ultrapure xenon .
The signal had a statistical significance of 3.5σ or less , which is well below the 5σ level that is usually required for a discovery in particle physics .
In a preprint published at the time , the team suggested that the signal – an excess in low-energy electron recoil events – could have three explanations .
The most mundane is that it was caused by contamination of @ @ @ @ @ @ @ A more intriguing explanation , they said , is that the signal is the detection of hypothetical particles called axions that could be emitted the Sun .
The third possibility is that the excess is caused by neutrinos interacting with the xenon in an unexpected way – which would also be very interesting .
Now , the original preprint has been published in Physical Review D and over in Physical Review Letters , five theoretical papers put forth a wide range of tantalizing explanations for the excess .
Working in Japan , Fuminobu @ @ @ @ @ @ @ Yin say that the signal could be related to a hypothetical axionlike particle ( ALP ) with a mass of a few keV/c2 that interacts with electron .
As well as explaining the XENON1T signal , such an ALP could be a constituent of dark matter and its existence could explain an anomaly in the observed cooling of white dwarf and red giant stars .
Meanwhile in Germany , Andreas Bally , Sudip Jana , and Andreas Trautner reckon the mystery signal could be the work of a hypothetical gauge boson that mediates @ @ @ @ @ @ @ electrons .
A paper written by Nicole Bell et al .
makes the case for a “ relatively low-mass luminous dark matter candidate , ” as the source of the excess .
They suggest that this dark-matter particle could enter the detector in a “ light state ” and be scattered into a “ heavy state ” that would decay by emitting a photon .
This photon would then interact with an electron in the detector to create the observed signal .
Another dark-matter proposal comes from Bartosz Fornal and colleagues who suggest @ @ @ @ @ @ @ a boost of energy from the galactic centre and collide with XENON1T electrons .
The fifth idea comes from Joseph Bramante and Ningqiang Song in Canada , who argue that the signal could come from the scattering of a type of dark matter that is a thermal relic from the early universe .
They can ’ t all be right , and it will be very interesting to see if a similar signal shows up in future dark-matter experiments .

Inside XENON1: the bottom array of photomultiplier tubes and the copper structure that creates the electric drift field. (Courtesy: XENON1T collaboration)
In June this year, physicists working on the XENON1T dark-matter detector announced the measurement of a curious signal in their experiment – which comprises 2 tonne of ultrapure xenon. The signal had a statistical significance of 3.5σ or less, which is well below the 5σ level that is usually required for a discovery in particle physics.
In a preprint published at the time, the team suggested that the signal – an excess in low-energy electron recoil events – could have three explanations. The most mundane is that it was caused by contamination of the ultrapure xenon by radioactive tritium.
A more intriguing explanation, they said, is that the signal is the detection of hypothetical particles called axions that could be emitted the Sun. The third possibility is that the excess is caused by neutrinos interacting with the xenon in an unexpected way – which would also be very interesting.
Now, the original preprint has been published in Physical Review D and over in Physical Review Letters, five theoretical papers put forth a range of tantalizing explanations for the excess.
Axionlike particle
Working in Japan, Fuminobu Takahashi, Masaki Yamada and Wen Yin say that the signal could be related to a hypothetical axion-like particle (ALP) with a mass of a few keV/c2 that interacts with electrons. As well as explaining the XENON1T signal, such an ALP could be a constituent of dark matter and its existence could explain an anomaly in the observed cooling of white dwarf and red giant stars.
Meanwhile, in Germany, Andreas Bally, Sudip Jana and Andreas Trautner reckon the mystery signal could be the work of a hypothetical gauge boson that mediates a new interaction between solar neutrinos and electrons.
A paper written by Nicole Bell et al. makes the case for a “relatively low-mass luminous dark-matter candidate” as the source of the excess. They suggest that this dark-matter particle could enter the detector in a “light state” and be scattered into a “heavy state” that would decay by emitting a photon. This photon would then interact with an electron in the detector to create the observed signal.
Galactic boost
Another dark-matter proposal comes from Bartosz Fornal and colleagues who suggest that otherwise sluggish cold-dark-matter particles could get a boost of energy from the galactic centre and collide with XENON1T electrons.
The fifth idea comes from Joseph Bramante and Ningqiang Song in Canada, who argue that the signal could come from the scattering of a type of dark matter that is a thermal relic from the early universe.
They can’t all be right, and it will be very interesting to see if a similar signal shows up in future dark-matter experiments.


physicsworld--2020-10-16--Sodium nanofluid helps extract heavy oil - Physics World

With the world ’ s reserves of light oil diminishing , oil companies are increasingly turning to heavier varieties – which make up 70 % of global oil reserves – to meet rising energy demands .
Existing extraction technologies for heavy oil are , however , inefficient , expensive and damaging to the environment in ways that extend beyond the CO emissions produced when the oil is eventually burned .
A team of researchers from the University of Houston in the US have now developed an alternative method that uses an inexpensive , non-toxic sodium-based nanofluid to extract heavy oil @ @ @ @ @ @ @ 80 % in laboratory tests .
Reserves of heavy oil – so-called because it has a viscosity of more than 100 centipoise , or cP – and extra-heavy oil , with a viscosity of more than 10 000 cP , are currently being exploited in several areas , notably Canada and Venezuela .
The high viscosities of these grades of oils make them difficult to recover , and two main technologies are currently used to do it .
The first relies on extracting oil from surface sands using hot water and air bubbles @ @ @ @ @ @ @ as n-pentane or n-heptane .
This method has been used for decades , but it requires large quantities of water and is thus not suitable for all locations .
Since most heavy oil resources are located below the surface , the second , in situ , recovery method is more common .
In recent years , researchers have developed both thermal and non-thermal variants of these in situ techniques .
The former , which include cold production with sands , vapour extraction , chemical injection and “ flooding ” the oil with steam @ @ @ @ @ @ @ of oil formations .
The problem is that these techniques are limited to shallow layers and relatively light ( < 200 cP ) viscous oils .
While thermal methods like in-situ combustion and steam flooding can recover oil with higher viscosities ( potentially more than 70 % ) , they are only economically viable when oil formations are thick .
Producing the steam they require also consumes fuel such as natural gas , leading to additional CO emissions .
To overcome these challenges , researchers have begun to explore alternative techniques , including @ @ @ @ @ @ @ are not yet mainstream , and so far the nanomaterials developed have only played a secondary role – for example , modifying the flow behaviour ( rheology ) of crude oil or being used as catalysts to upgrade crude oil during steaming processes .
A team led by Zhifeng Ren , who is director of the Texas Center for Superconductivity at the University of Houston ( TcSUH ) , has now used a sodium ( Na ) nanofluid to recover over 80 % of extra-heavy oil ( with a viscosity of over 400 @ @ @ @ @ @ @ a laboratory experiment .
The researchers made this nanofluid by using a hand-held blender to mix commercially-available bulk sodium chunks with silicone oil .
This non-reactive solvent is necessary because ( as we all remember from chemistry classes at school ) sodium reacts very strongly when it comes into contact with water .
When the researchers do add water to their sodium nanofluid , it reacts according to the formula 2Na + 2H 0 – > 2NaOH + H .
The substantial amount of heat produced in this reaction generates steam , which @ @ @ @ @ @ @ oil in a way that is similar to older steam flooding techniques – with the advantage that the sodium reaction is relatively easy to control and can be kick-started in situ simply by adding water .
The sodium nanomaterials also dissipate once the reaction is complete , which means that the oil is not damaged by adsorbing the sodium .
Finally , the technique does not use any fossil fuels to generate steam or hot water , thereby reducing the direct CO emissions from the oil-extraction process .
“ Based on these advantages @ @ @ @ @ @ @ could become a game-changing technology for recovery of oil of any viscosity , as well as a milestone in using nanotechnology to solve oil-recovery problems in the petroleum industry , ” Ren and colleagues say .
The researchers note that by mixing their sodium nanoparticles in silicone oil , the particles dispersed throughout the simulated reservoir before coming into contact with water .
This dispersion has the effect of triggering smaller chemical reactions across a larger area .
The team says it may also be possible to disperse the sodium nanoparticles in other @ @ @ @ @ @ @ , or even to mix them with polymers or surfactants for a higher oil recovery rate .
As a final benefit , the researchers note that one of their reaction ’ s products , NaOH ( sodium hydroxide ) , is routinely employed in oil fields to spark a different reaction that also reduces oil viscosity – a technique known as alkaline flooding .
The other reaction product , H , could be used for gas flooding – another common oil recovery technique – as well as for upgrading the heavy oil via @ @ @ @ @ @ @ is detailed in Materials Today Physics .

Zhifeng Ren, director of the Texas Center for Superconductivity at UH. Credit: University of Houston
With the world’s reserves of light oil diminishing, oil companies are increasingly turning to heavier varieties – which make up 70% of global oil reserves – to meet rising energy demands. Existing extraction technologies for heavy oil are, however, inefficient, expensive and damaging to the environment in ways that extend beyond the CO 2 emissions produced when the oil is eventually burned. A team of researchers from the University of Houston in the US have now developed an alternative method that uses an inexpensive, non-toxic sodium-based nanofluid to extract heavy oil from reservoirs, with an efficiency of 80% in laboratory tests.
Reserves of heavy oil – so-called because it has a viscosity of more than 100 centipoise, or cP – and extra-heavy oil, with a viscosity of more than 10 000 cP, are currently being exploited in several areas, notably Canada and Venezuela. The high viscosities of these grades of oils make them difficult to recover, and two main technologies are currently used to do it. The first relies on extracting oil from surface sands using hot water and air bubbles, then diluting it with solvents such as n-pentane or n-heptane. This method has been used for decades, but it requires large quantities of water and is thus not suitable for all locations.
Since most heavy oil resources are located below the surface, the second, in situ, recovery method is more common. In recent years, researchers have developed both thermal and non-thermal variants of these in situ techniques. The former, which include cold production with sands, vapour extraction, chemical injection and “flooding” the oil with steam, can be used for thin layers of oil formations. The problem is that these techniques are limited to shallow layers and relatively light (< 200 cP) viscous oils.
Alternative techniques sought
While thermal methods like in-situ combustion and steam flooding can recover oil with higher viscosities (potentially more than 70%), they are only economically viable when oil formations are thick. Producing the steam they require also consumes fuel such as natural gas, leading to additional CO 2 emissions.
To overcome these challenges, researchers have begun to explore alternative techniques, including some that use nanomaterials. Such approaches are not yet mainstream, and so far the nanomaterials developed have only played a secondary role – for example, modifying the flow behaviour (rheology) of crude oil or being used as catalysts to upgrade crude oil during steaming processes.
80% recovery efficiency
A team led by Zhifeng Ren, who is director of the Texas Center for Superconductivity at the University of Houston (TcSUH), has now used a sodium (Na) nanofluid to recover over 80% of extra-heavy oil (with a viscosity of over 400 000 cP) from sand packs in a laboratory experiment. The researchers made this nanofluid by using a hand-held blender to mix commercially-available bulk sodium chunks with silicone oil. This non-reactive solvent is necessary because (as we all remember from chemistry classes at school) sodium reacts very strongly when it comes into contact with water.
When the researchers do add water to their sodium nanofluid, it reacts according to the formula 2Na + 2H 2 0 –> 2NaOH + H 2 . The substantial amount of heat produced in this reaction generates steam, which then reduces the viscosity of the heavy oil in a way that is similar to older steam flooding techniques – with the advantage that the sodium reaction is relatively easy to control and can be kick-started in situ simply by adding water. The sodium nanomaterials also dissipate once the reaction is complete, which means that the oil is not damaged by adsorbing the sodium. Finally, the technique does not use any fossil fuels to generate steam or hot water, thereby reducing the direct CO 2 emissions from the oil-extraction process.
“Based on these advantages, we anticipate that the sodium nanofluid could become a game-changing technology for recovery of oil of any viscosity, as well as a milestone in using nanotechnology to solve oil-recovery problems in the petroleum industry,” Ren and colleagues say.
Side benefits
The researchers note that by mixing their sodium nanoparticles in silicone oil, the particles dispersed throughout the simulated reservoir before coming into contact with water. This dispersion has the effect of triggering smaller chemical reactions across a larger area. The team says it may also be possible to disperse the sodium nanoparticles in other solvents, such as pentane and kerosene, or even to mix them with polymers or surfactants for a higher oil recovery rate.
As a final benefit, the researchers note that one of their reaction’s products, NaOH (sodium hydroxide), is routinely employed in oil fields to spark a different reaction that also reduces oil viscosity – a technique known as alkaline flooding. The other reaction product, H 2 , could be used for gas flooding – another common oil recovery technique – as well as for upgrading the heavy oil via a hydrogenation reaction.
The new technique is detailed in Materials Today Physics.


physicsworld--2020-10-16--Very high-energy electrons could treat tumours deep within the body - Physics World

Very high-energy electrons ( VHEEs ) , typically defined as those above 40 MeV , provide a potential new radiotherapy modality with dosimetric advantages .
Beams of such electrons penetrate deep into the patient , enabling treatment of deep-seated tumours that photon-based irradiation may not reach .
Speaking at the Medical Physics & Engineering Conference ( MPEC ) , Louie Hancock from the University of Manchester described the recent resurgence in interest in VHEE radiotherapy .
“ Over the last couple of decades , new linac designs mean that it ’ s now possible to produce roughly 200 MeV electrons @ @ @ @ @ @ @ whereas before it might have taken 20 metres or so , ” he explained .
“ This has spurred interest in using these VHEEs for treating deep-seated tumours.
” Hancock noted that a linac-based VHEE treatment system should be compact enough to fit into a hospital bunker .
“ It ’ s much cheaper to put a machine in an existing bunker than to build a new building , ” he pointed out .
“ I expect that VHEEs will probably be more expensive than photons to produce , but cheaper than protons.
@ @ @ @ @ @ @ systems available , there are electron accelerators for research use , such as the high-gradient X-band linac at CERN ’ s CLEAR facility , for example , and the CLARA electron accelerator at Daresbury Laboratory .
In the meantime , Monte Carlo simulations can provide insight into VHEE treatments without having to actually build a machine .
Depth–dose curves show that , as well as delivering dose deep inside a patient , VHEEs should also be extremely resilient to changes in patient geometry .
To confirm this , Hancock performed a back-of-the-envelope calculation @ @ @ @ @ @ @ a cylindrical 5 cm tumour in its centre .
He simulated treatment of the tumour by rotating a beam around the target , and then introduced a cavity above the tumour ( a 5 cm sphere of bone or air ) to calculate its impact on the tumour dose .
For treatments simulated using 1.3 MeV X-rays , the introduction of an air bubble resulted in hot spots of about 15 % , while an unexpected bony region led to cold spots of about 10 % .
For 250 MeV VHEEs , while @ @ @ @ @ @ @ they were only of about 2 % .
“ In this simple situation , VHEE appears to be nearly an order of magnitude more resilient to unexpected homogeneities when compared with X-rays , ” said Hancock .
But will this advantage translate to patients ?
To find out , Hancock and colleagues examined a clinical case , comparing treatment plans for VHEE and volumetric-modulated arc therapy ( VMAT ) .
VHEE treatment planning is a highly complex process , with millions of variables creating a huge optimization problem .
As such , the @ @ @ @ @ @ @ treatment planning system for VHEEs that incorporates various tools to create a full planning workflow .
This includes organ identification using Slicer 3D software , Monte Carlo dose calculations using Geant4 , and then optimization of the generated dose profiles with Python software written by Hancock .
Using their VHEE code , the researchers created a treatment plan for a patient with cervical cancer , which included two large target sites to irradiate and many nearby organs to avoid .
They compared this with a VMAT plan creating using Monaco .
The two @ @ @ @ @ @ @ , while nearby organs ( the sigmoid colon , bowel and bladder ) received slightly less dose from VHEE than VMAT .
For organs further from the tumour , VHEE conferred significant dosimetric advantages , particularly to the femoral heads where it reduced the delivered dose from 35 to 15 Gy .
“ We achieved coverage of all of the tumour with VHEEs , so can say for sure that these electrons are capable of treating a large tumour deep inside the patient , ” said Hancock .
“ We could also see @ @ @ @ @ @ @ with the VMAT plan.
” To examine the impact of geometric changes , the team re-simulated the treatment plans with the rectal cavity filled with air instead of water .
The error between the two VHEE plans was roughly 0.15 Gy , while for the X-ray plans it was about 0.7 Gy .
“ In the simple water phantom , we saw a dose error nearly an order of magnitude lower with VHEEs , now we ’ ve seen this effect in silico in an actual patient case , ” explained Hancock .
@ @ @ @ @ @ @ will be to repeat the analysis with lung and brain cases , and “ move towards putting real things in real beams ” .
The real thing is the MARVIN human head-and-neck phantom , while the real beams will be delivered by CLARA at Daresbury and CLEAR at CERN .
These two facilities provide a wide span of electron energies and will enable VHEE measurements in realistic environments .
Initial experiments using a 45 MeV electron beam at CLARA to irradiate MARVIN demonstrated a near-uniform dose over a large area inside the phantom @ @ @ @ @ @ @ currently on hold due to the pandemic .
Hancock concluded that the clinical test case , using the team ’ s VHEE treatment planning software , demonstrates that VHEE radiotherapy has the ability to treat tumours that are both deep and large .
“ VHEE might well also be more insensitive to inhomogeneities and changes in patient geometry than photons , which I think is likely to be clinically beneficial , ” he added .

Researchers are using the CLARA electron accelerator at the Daresbury Laboratory to study the potential of very high-energy electrons for radiotherapy. (Courtesy: STFC)
Very high-energy electrons (VHEEs), typically defined as those above 40 MeV, provide a potential new radiotherapy modality with dosimetric advantages. Beams of such electrons penetrate deep into the patient, enabling treatment of deep-seated tumours that photon-based irradiation may not reach.
Speaking at the Medical Physics & Engineering Conference (MPEC), Louie Hancock from the University of Manchester described the recent resurgence in interest in VHEE radiotherapy. “Over the last couple of decades, new linac designs mean that it’s now possible to produce roughly 200 MeV electrons in about two to three metres, whereas before it might have taken 20 metres or so,” he explained. “This has spurred interest in using these VHEEs for treating deep-seated tumours.”
Hancock noted that a linac-based VHEE treatment system should be compact enough to fit into a hospital bunker. “It’s much cheaper to put a machine in an existing bunker than to build a new building,” he pointed out. “I expect that VHEEs will probably be more expensive than photons to produce, but cheaper than protons.”
While there are currently no clinical systems available, there are electron accelerators for research use, such as the high-gradient X-band linac at CERN’s CLEAR facility, for example, and the CLARA electron accelerator at Daresbury Laboratory. In the meantime, Monte Carlo simulations can provide insight into VHEE treatments without having to actually build a machine.
Depth–dose curves show that, as well as delivering dose deep inside a patient, VHEEs should also be extremely resilient to changes in patient geometry. To confirm this, Hancock performed a back-of-the-envelope calculation for a simple block of water containing a cylindrical 5 cm tumour in its centre. He simulated treatment of the tumour by rotating a beam around the target, and then introduced a cavity above the tumour (a 5 cm sphere of bone or air) to calculate its impact on the tumour dose.
For treatments simulated using 1.3 MeV X-rays, the introduction of an air bubble resulted in hot spots of about 15%, while an unexpected bony region led to cold spots of about 10%. For 250 MeV VHEEs, while hot and cold spots were seen, they were only of about 2%. “In this simple situation, VHEE appears to be nearly an order of magnitude more resilient to unexpected homogeneities when compared with X-rays,” said Hancock.
But will this advantage translate to patients? To find out, Hancock and colleagues examined a clinical case, comparing treatment plans for VHEE and volumetric-modulated arc therapy (VMAT).
VHEE treatment planning is a highly complex process, with millions of variables creating a huge optimization problem. As such, the team at Manchester has developed an open-source treatment planning system for VHEEs that incorporates various tools to create a full planning workflow. This includes organ identification using Slicer 3D software, Monte Carlo dose calculations using Geant4, and then optimization of the generated dose profiles with Python software written by Hancock.
Using their VHEE code, the researchers created a treatment plan for a patient with cervical cancer, which included two large target sites to irradiate and many nearby organs to avoid. They compared this with a VMAT plan creating using Monaco. The two plans delivered identical dose to the target, while nearby organs (the sigmoid colon, bowel and bladder) received slightly less dose from VHEE than VMAT. For organs further from the tumour, VHEE conferred significant dosimetric advantages, particularly to the femoral heads where it reduced the delivered dose from 35 to 15 Gy.
“We achieved coverage of all of the tumour with VHEEs, so can say for sure that these electrons are capable of treating a large tumour deep inside the patient,” said Hancock. “We could also see that the low-dose background was reduced compared with the VMAT plan.”
To examine the impact of geometric changes, the team re-simulated the treatment plans with the rectal cavity filled with air instead of water. The error between the two VHEE plans was roughly 0.15 Gy, while for the X-ray plans it was about 0.7 Gy. “In the simple water phantom, we saw a dose error nearly an order of magnitude lower with VHEEs, now we’ve seen this effect in silico in an actual patient case,” explained Hancock.
The next step, he said, will be to repeat the analysis with lung and brain cases, and “move towards putting real things in real beams”. The real thing is the MARVIN human head-and-neck phantom, while the real beams will be delivered by CLARA at Daresbury and CLEAR at CERN. These two facilities provide a wide span of electron energies and will enable VHEE measurements in realistic environments.
Preliminary simulations for planned experiments using a 45 MeV electron beam at CLARA to irradiate MARVIN demonstrated a near-uniform dose over a large area inside the phantom. Hancock noted that the study is currently on hold due to the pandemic — although there is a potential to perform these experiments in Q1 2021.
Hancock concluded that the clinical test case, using the team’s VHEE treatment planning software, demonstrates that VHEE radiotherapy has the ability to treat tumours that are both deep and large. “VHEE might well also be more insensitive to inhomogeneities and changes in patient geometry than photons, which I think is likely to be clinically beneficial,” he added.


physicsworld--2020-10-16--Celebrating Emmy Noether, Sameera Moussa, Caroline Bleeker, Toshiko Yuasa and other inspiring women

Celebrating Emmy Noether, Sameera Moussa, Caroline Bleeker, Toshiko Yuasa and other inspiring women in science - Physics World

Tuesday was Ada Lovelace Day , which celebrates achievements of women in science , technology , engineering and maths ( STEM ) .
Named after the 19th-century polymath Ada Lovelace , the annual initiative also seeks to engage with the challenges of attracting more women into STEM careers and supporting career development .
Nature ’ s On Your Wavelength blog celebrated with a piece by Ankita Anirban about five inspiring female physicists .
Perhaps the most intriguing of the biographies is that of the Egyptian nuclear physicist Sameera Moussa , who some believe was murdered in 1952 to prevent Egypt @ @ @ @ @ @ @ also tales of wartime daring .
The Dutch physicist and entrepreneur Caroline Bleeker , for example hid Jewish people from Nazi occupiers in her factory .
And when it was raided in 1944 , she managed to usher them to safety .
After the war , her factory produced the world ’ s first complete phase contrast microscopes .
Meanwhile in wartime Berlin , the Japanese physicist Toshiko Yuasa developed a double-focussing beta spectrometer that she carried on her back through Siberia to Japan when she was expelled from Germany by the Soviet @ @ @ @ @ @ @ important mathematician you ’ ve never heard of is a new book from the Canadian children ’ s author Helaine Becker .
Illustrated by Kari Rust , the book was commissioned by Lisa Lyons Johnston , president and publisher of Kids Can Press .
Lyons Johnston became aware of the remarkable life and work of Noether when she joined the Emmy Noether Council at the Perimeter Institute for Theoretical Physics .
“ Boys and girls , men and women , need to see more women in physics and science , ” says Lyons @ @ @ @ @ @ @ frustrating that people haven ’ t heard of her .
I wanted people to know more about Emmy , who is a remarkable person in her own right , and also an inspiration for girls.
” You can read more about the book here .

Emmy Noether: a new book celebrates the life of the mathematician. (Courtesy: Kids Can Press)
Tuesday was Ada Lovelace Day, which celebrates achievements of women in science, technology, engineering and maths (STEM). Named after the 19th-century polymath Ada Lovelace, the annual initiative also seeks to engage with the challenges of attracting more women into STEM careers and supporting career development.
Nature’s On Your Wavelength blog celebrated with a piece by Ankita Anirban about five inspiring female physicists. Perhaps the most intriguing of the biographies is that of the Egyptian nuclear physicist Sameera Moussa, who some believe was murdered in 1952 to prevent Egypt from developing nuclear weapons.
There are also tales of wartime daring. The Dutch physicist and entrepreneur Caroline Bleeker, for example hid Jewish people from Nazi occupiers in her factory. And when it was raided in 1944, she managed to usher them to safety. After the war, her factory produced the world’s first complete phase contrast microscopes.
Meanwhile in wartime Berlin, the Japanese physicist Toshiko Yuasa developed a double-focussing beta spectrometer that she carried on her back through Siberia to Japan when she was expelled from Germany by the Soviet army.
Emmy Noether: The most important mathematician you’ve never heard of is a new book from the Canadian children’s author Helaine Becker. Illustrated by Kari Rust, the book was commissioned by Lisa Lyons Johnston, president and publisher of Kids Can Press. Lyons Johnston became aware of the remarkable life and work of Noether when she joined the Emmy Noether Council at the Perimeter Institute for Theoretical Physics.
“Boys and girls, men and women, need to see more women in physics and science,” says Lyons Johnston. “It’s so frustrating that people haven’t heard of her. I wanted people to know more about Emmy, who is a remarkable person in her own right, and also an inspiration for girls.”
You can read more about the book here.


physicsworld--2020-10-17--Software tool for MRI predicts motor development disorders in preterm babies - Physics World

A new software quantification tool has been developed by researchers in the US for analyzing white-matter abnormalities in very preterm babies .
This magnetic resonance imaging ( MRI ) biomarker can predict motor development risks , including cerebral palsy , in a much more objective way than existing diagnostic tools .
Today , most children born extremely prematurely ( earlier than 30 weeks of gestation ) survive .
However , nearly 70 % of these very preterm infants show abnormalities in the white matter of their brains .
Furthermore , half of very prematurely born children develop minor motor abnormalities @ @ @ @ @ @ @ cerebral palsy ( CP ) .
CP is a group of permanent neurological disorders that affect movement , posture , and balance .
It is the most common physical disability in children .
Even though the last three decades have brought improved survival and care for extremely preterm babies , they are about 50 times more likely to develop CP than full-term babies .
Improved care for these children has not translated into fewer disabilities , since most children with CP are diagnosed at 1–2 years of age and conventional neuroimaging is subjective @ @ @ @ @ @ @ accurately predict CP .
Yet , identifying biomarkers of CP at an early stage of life could significantly increase the quality of life for both affected patients and their families .
Early intervention by physical and occupational therapy could take advantage of early neuroplasticity and mitigate symptoms such as tremors , stiff muscles , or difficulty performing precise movements .
To address these issues , a group of researchers led by Nehal Parikh , a neonatologist at the Perinatal Institute , Cincinnati Children ’ s Hospital Medical Center , has been developing better @ @ @ @ @ @ @ to improve outcome prediction .
They have developed an algorithm that can analyze structural MRI scans of preterm infants to predict their risk of motor development abnormalities based on spotting and quantifying brain defects .
Parikh ’ s team targeted diffuse white matter abnormality ( DWMA ) , the most common finding in premature infants .
It appears on a brain MRI scan as areas with increased signal intensity .
Early evidence suggests these abnormalities are associated with inflammation-initiating illnesses and may represent areas of increased fluid in the brain ’ s wiring @ @ @ @ @ @ @ on visual analysis of the MRI data .
“ Manual tracing of DWMA regions within the brain is highly subjective and produces poor reliability and reproducibility , ” explains Parikh .
“ It is clear that we need a better tool for diagnostics .
I started working with computer scientists to come up with an algorithm that can segment these lesions.
” In the study , the team enrolled very prematurely born infants and performed brain structural MRI scans at the term-equivalent age .
These images were fed into an algorithm created using @ @ @ @ @ @ @ a very preterm infant brain .
“ Since it was not possible to create a gold standard manual brain atlas for DWMA , Lili He , a computer scientist in my lab , decided to use a synthetic one to train the algorithm .
I drew out the respective brain regions manually , ” explains Parikh .
The resulting algorithm could detect signal intensity and location of normal white matter , gray matter , and cerebrospinal fluid and isolate DWMA regions based on their different signal intensity and spatial information with an accuracy @ @ @ @ @ @ @ the ground truth .
Critics might say that the algorithm represents a computer simulation trained on a synthetic brain model that is not relevant to a real patient .
However , it can already predict clinical outcomes relevant to patients and their families .
Indeed , the team correlated their results with cognitive and language scores of their cohort at the age of two ; and motor scores at three years of age .
“ The results correlated very nicely , ” says Parikh .
“ It showed that DWMA volume was predictive @ @ @ @ @ @ @ years of age , independent of other conventional MRI and other known predictors.
” The team is now working on implementing a deep learning approach to improve the DMWA region identification .
In addition , Parikh is planning to work with leading MRI vendors to implement the algorithm into their consoles to allow for the earliest diagnostics possible .
“ Ideally , when the MRI scan is complete , our algorithm would do its job within seconds and provide a value for diffuse white matter abnormality , ” he says .
“ If @ @ @ @ @ @ @ would be referred for aggressive early intervention therapies and/or research trials of novel interventions.
” Manon Benders , a neonatologist at the Wilhelmina Children ’ s hospital , UMC Utrecht , foresees a big future for this research as a decision-support tool .
“ It is very important since obtaining the most accurate prognosis as early as possible is essential in order to inform the child ’ s family adequately.
” “ Moreover , beginning the intervention therapy even before the onset of clinical symptoms of cerebral palsy or adverse motor outcomes is @ @ @ @ @ @ @ brain ’ s plasticity is highest in the first few months after birth , ” she adds .
These research is described in Scientific Reports .

MRI biomarker: objectively segmented diffuse white matter abnormality (red) in the periventricular white matter displayed in sagittal (A), coronal (B), and axial orientations (C) in a 26 weeks’ gestation very preterm infant. (Courtesy: Nehal Parikh)
A new software quantification tool has been developed by researchers in the US for analyzing white-matter abnormalities in very preterm babies. This magnetic resonance imaging (MRI) biomarker can predict motor development risks, including cerebral palsy, in a much more objective way than existing diagnostic tools.
Today, most children born extremely prematurely (earlier than 30 weeks of gestation) survive. However, nearly 70% of these very preterm infants show abnormalities in the white matter of their brains. Furthermore, half of very prematurely born children develop minor motor abnormalities, and up to 10% develop cerebral palsy (CP).
CP is a group of permanent neurological disorders that affect movement, posture, and balance. It is the most common physical disability in children. Even though the last three decades have brought improved survival and care for extremely preterm babies, they are about 50 times more likely to develop CP than full-term babies. Improved care for these children has not translated into fewer disabilities, since most children with CP are diagnosed at 1–2 years of age and conventional neuroimaging is subjective and not sensitive on its own to accurately predict CP.
Early intervention
Yet, identifying biomarkers of CP at an early stage of life could significantly increase the quality of life for both affected patients and their families. Early intervention by physical and occupational therapy could take advantage of early neuroplasticity and mitigate symptoms such as tremors, stiff muscles, or difficulty performing precise movements.
To address these issues, a group of researchers led by Nehal Parikh, a neonatologist at the Perinatal Institute, Cincinnati Children’s Hospital Medical Center, has been developing better diagnostic tools using advanced imaging risk factors to improve outcome prediction. They have developed an algorithm that can analyze structural MRI scans of preterm infants to predict their risk of motor development abnormalities based on spotting and quantifying brain defects.
Fully automated detection
Parikh’s team targeted diffuse white matter abnormality (DWMA), the most common finding in premature infants. It appears on a brain MRI scan as areas with increased signal intensity. Early evidence suggests these abnormalities are associated with inflammation-initiating illnesses and may represent areas of increased fluid in the brain’s wiring.
Current tools to assess DWMA rely on visual analysis of the MRI data. “Manual tracing of DWMA regions within the brain is highly subjective and produces poor reliability and reproducibility,” explains Parikh. “It is clear that we need a better tool for diagnostics. I started working with computer scientists to come up with an algorithm that can segment these lesions.”
In the study, the team enrolled very prematurely born infants and performed brain structural MRI scans at the term-equivalent age. These images were fed into an algorithm created using a probabilistic brain atlas constructed specifically for a very preterm infant brain.
“Since it was not possible to create a gold standard manual brain atlas for DWMA, Lili He, a computer scientist in my lab, decided to use a synthetic one to train the algorithm. I drew out the respective brain regions manually,” explains Parikh. The resulting algorithm could detect signal intensity and location of normal white matter, gray matter, and cerebrospinal fluid and isolate DWMA regions based on their different signal intensity and spatial information with an accuracy greater than 95% when compared with the ground truth.
Towards clinical translation
Critics might say that the algorithm represents a computer simulation trained on a synthetic brain model that is not relevant to a real patient. However, it can already predict clinical outcomes relevant to patients and their families. Indeed, the team correlated their results with cognitive and language scores of their cohort at the age of two; and motor scores at three years of age. “The results correlated very nicely,” says Parikh. “It showed that DWMA volume was predictive of standardized developmental scores up to three years of age, independent of other conventional MRI and other known predictors.”
The team is now working on implementing a deep learning approach to improve the DMWA region identification. In addition, Parikh is planning to work with leading MRI vendors to implement the algorithm into their consoles to allow for the earliest diagnostics possible.
“Ideally, when the MRI scan is complete, our algorithm would do its job within seconds and provide a value for diffuse white matter abnormality,” he says. “If this value was abnormal, the child would be referred for aggressive early intervention therapies and/or research trials of novel interventions.”
Manon Benders, a neonatologist at the Wilhelmina Children’s hospital, UMC Utrecht, foresees a big future for this research as a decision-support tool. “It is very important since obtaining the most accurate prognosis as early as possible is essential in order to inform the child’s family adequately.”
“Moreover, beginning the intervention therapy even before the onset of clinical symptoms of cerebral palsy or adverse motor outcomes is also crucial, particularly given that the brain’s plasticity is highest in the first few months after birth,” she adds.
These research is described in Scientific Reports.


physicsworld--2020-10-19--Astronomers propose telescope to monitor Betelgeuse dimming - Physics World

An international team of astronomers has proposed a telescope to monitor the bright star Betelgeuse to provide clues about the cause of its sudden drop in brightness .
The Betelgeuse Scope concept – which is anticipated to cost about $ 0.4m – would use twelve off-the-shelf 10 cm-aperture telescopes secured to a radio telescope dish to provide detailed , nightly observations of the supergiant star .
Betelgeuse ’ s “ great dimming ” began late last year and changed the naked-eye appearance of the constellation Orion .
With it continuing to enthral astronomers , theories have emerged to explain why @ @ @ @ @ @ @ A leading contender is that the star ’ s surface churned out an immense dust cloud that hid some of its famously ruddy light .
To closely scrutinize this “ mass-loss ” activity , researchers will need frequent , high-resolution views of the roiling surface of the star , which are difficult to acquire with most telescopes right now , but possible via interferometry by connecting several telescopes as if they were one instrument .
The team is building a prototype of the Betelgeuse Scope that would be placed on a University of @ @ @ @ @ @ @ now seeking funding for the final telescope .
“ If successful , we will bring it to a larger antenna [ of ] 12 m or more to increase the interferometer array size , ” says astronomer Narsireddy Anugu from the University of Arizona , who is leading the project .
By using relatively inexpensive instruments affixed to the structure of an already-constructed radio telescope , the final Betelgeuse Scope system should be cheaper than a more complex , conventional arrangement .
“ It also saves money by using the pointing and tracking @ @ @ @ @ @ @ adds Anugu .
“ So we don ’ t have to build it for all the individual amateur optical telescopes.
” Graham Harper , an astrophysicist at the University of Colorado who has studied Betelgeuse and is not associated with the Betelgeuse Scope , says that if the proposal is successful then it would be “ a major step forward ” beyond existing observations .
“ Coordinating major observatories to look at a common object is difficult enough , even for one-off events , but for systematic monitoring of a couple of sources @ @ @ @ @ @ @ says .
“ The idea of a dedicated Betelgeuse Scope is a really nice one , because it attempts to address this problem.
” According to Harper , the proposed telescope would also glean information about Betelgeuse ’ s surface temperature .
“ They should be able to determine how the surface temperatures change with time across the stellar surface , ” he adds .
“ This would help tell us exactly where the interesting phenomena are occurring , for example shock waves , outbursts and ejections .
”

Star struck: Betelgeuse’s sudden drop in brightness, dubbed the “great dimming”, has enthralled astronomers since it was first observed late last year (Courtesy: ESO/M Montargès et al.)
An international team of astronomers has proposed a telescope to monitor the bright star Betelgeuse to provide clues about the cause of its sudden drop in brightness. The Betelgeuse Scope concept – which is anticipated to cost about $0.4m – would use twelve off-the-shelf 10 cm-aperture telescopes secured to a radio telescope dish to provide detailed, nightly observations of the supergiant star.
Betelgeuse’s “great dimming” began late last year and changed the naked-eye appearance of the constellation Orion. With it continuing to enthral astronomers, theories have emerged to explain why Betelgeuse’s glow has plummeted. A leading contender is that the star’s surface churned out an immense dust cloud that hid some of its famously ruddy light. To closely scrutinize this “mass-loss” activity, researchers will need frequent, high-resolution views of the roiling surface of the star, which are difficult to acquire with most telescopes right now, but possible via interferometry by connecting several telescopes as if they were one instrument.
The idea of a dedicated Betelgeuse Scope is a really nice one Graham Harper
The team is building a prototype of the Betelgeuse Scope that would be placed on a University of Arizona 6.1 m radio antenna and are now seeking funding for the final telescope. “If successful, we will bring it to a larger antenna [of] 12 m or more to increase the interferometer array size,” says astronomer Narsireddy Anugu from the University of Arizona, who is leading the project. By using relatively inexpensive instruments affixed to the structure of an already-constructed radio telescope, the final Betelgeuse Scope system should be cheaper than a more complex, conventional arrangement. “It also saves money by using the pointing and tracking of the existing radio antenna,” adds Anugu. “So we don’t have to build it for all the individual amateur optical telescopes.”
A step forward
Graham Harper, an astrophysicist at the University of Colorado who has studied Betelgeuse and is not associated with the Betelgeuse Scope, says that if the proposal is successful then it would be “a major step forward” beyond existing observations. “Coordinating major observatories to look at a common object is difficult enough, even for one-off events, but for systematic monitoring of a couple of sources it is totally impractical,” he says. “The idea of a dedicated Betelgeuse Scope is a really nice one, because it attempts to address this problem.” Read more Astronomers plan huge neutrino observatory in the Pacific Ocean
According to Harper, the proposed telescope would also glean information about Betelgeuse’s surface temperature. “They should be able to determine how the surface temperatures change with time across the stellar surface,” he adds. “This would help tell us exactly where the interesting phenomena are occurring, for example shock waves, outbursts and ejections.”


physicsworld--2020-10-19--Accretion, not colliding spaghetti, flares-up as star is devoured by black hole - Physics World

An extremely bright flare , originating from a star being devoured by a supermassive black hole , has been observed in a galaxy 215 million light-years away – making this the nearest tidal disruption event ( TDE ) ever seen .
The event was spotted by an international team of astronomers , headed by Matt Nicholl at the University of Birmingham .
They caught the event well before its climax using instruments at the European Southern Observatory ( ESO ) in Chile .
For the first time , the observations allowed astronomers to connect the characteristic brightening of these events @ @ @ @ @ @ @ .
If a star wanders too close to the supermassive black hole at the centre of its galaxy , it can experience tidal forces that exceed the gravitational forces holding the star together .
As a result , the star will be dramatically shredded into thin streams of debris , through the process of spaghettification .
During these TDEs , stellar remnants will flare , emitting large amounts of light .
Currently , there are two competing theories for these surges in brightness : either they occur as material accretes onto the black @ @ @ @ @ @ @ collisions between spaghettified streams .
Although astronomers are now discovering several TDEs every year , they have yet to determine which of these theories is best .
The main problem is that as the stars disintegrate , their colliding streams , combined with strong inflows and outflows of gas , make for a messy debris geometry which is incredibly difficult to disentangle .
In September 2019 , the ESO ’ s Very Large Telescope and New Technology Telescope each spotted a new surge in brightness in a spiral galaxy .
Through further calculations @ @ @ @ @ @ @ the flash originated from a supermassive black hole as large as 1 million solar masses , as it devoured a star with a similar mass to the Sun .
Over six months , the instruments recorded the event across multiple regions of the electromagnetic spectrum as its brightness grew and faded .
Owing to its proximity , Nicholl and colleagues were able to identify the TDE well before its peak brightness .
This allowed them to capture the whole process unfolding , well before the geometry of the debris became too convoluted to @ @ @ @ @ @ @ blueshift of key absorption lines in the stellar debris , Nicholl ’ s team showed that the origin of the TDE ’ s early optical emission was dominated by an outflow of bright material , with speeds reaching roughly 10,000 km/s .
Then , after around 30 days , the outflow underwent a sudden transition : first cooling , and then contracting .
Overall , the size and mass of the outflow remained consistent with the high ratio between optical and -ray emissions observed by the team , as well as in many @ @ @ @ @ @ @ that the outflow was more likely to have been powered by black hole accretion , instead of collisions between spaghettified streams of debris .
With the upcoming launch of ESO ’ s Extremely Large Telescope , now scheduled for first light in 2025 , the team ’ s findings will provide researchers with key guidance as they uncover increasingly fainter and more rapidly evolving TDEs .
The research is described in a paper in Monthly Notices of the Royal Astronomical Society .

Flare up: artist’s impression of a star in the foreground experiencing spaghettification as is sucked in by a supermassive black hole. (Courtesy: ESO/M Kornmesser)
An extremely bright flare, originating from a star being devoured by a supermassive black hole, has been observed in a galaxy 215 million light-years away – making this the nearest tidal disruption event (TDE) ever seen. The event was spotted by an international team of astronomers, headed by Matt Nicholl at the University of Birmingham. They caught the event well before its climax using instruments at the European Southern Observatory (ESO) in Chile. For the first time, the observations allowed astronomers to connect the characteristic brightening of these events with rapid outflows of material from stars.
If a star wanders too close to the supermassive black hole at the centre of its galaxy, it can experience tidal forces that exceed the gravitational forces holding the star together. As a result, the star will be dramatically shredded into thin streams of debris, through the process of spaghettification. During these TDEs, stellar remnants will flare, emitting large amounts of light.
Colliding spaghetti
Currently, there are two competing theories for these surges in brightness: either they occur as material accretes onto the black hole; or they result from earlier collisions between spaghettified streams. Although astronomers are now discovering several TDEs every year, they have yet to determine which of these theories is best. The main problem is that as the stars disintegrate, their colliding streams, combined with strong inflows and outflows of gas, make for a messy debris geometry which is incredibly difficult to disentangle.
In September 2019 the ESO’s Very Large Telescope and New Technology Telescope each spotted a new surge in brightness in a spiral galaxy. Through further calculations, Nicholl’s team concluded that the flash originated from a supermassive black hole as large as 1 million solar masses, as it devoured a star with a similar mass to the Sun.
Over six months, the instruments recorded the event across multiple regions of the electromagnetic spectrum as its brightness grew and faded. Owing to its proximity, Nicholl and colleagues were able to identify the TDE well before its peak brightness. This allowed them to capture the whole process unfolding, well before the geometry of the debris became too convoluted to untangle.
Sudden transition
By tracking changes in the blueshift of key absorption lines in the stellar debris, Nicholl’s team showed that the origin of the TDE’s early optical emission was dominated by an outflow of bright material, with speeds reaching roughly 10,000 km/s. Then, after around 30 days, the outflow underwent a sudden transition: first cooling, and then contracting.
Overall, the size and mass of the outflow remained consistent with the high ratio between optical and -ray emissions observed by the team, as well as in many TDEs from previous studies. This suggested that the outflow was more likely to have been powered by black hole accretion, instead of collisions between spaghettified streams of debris.
With the upcoming launch of ESO’s Extremely Large Telescope, now scheduled for first light in 2025, the team’s findings will provide researchers with key guidance as they uncover increasingly fainter and more rapidly evolving TDEs.
The research is described in a paper in Monthly Notices of the Royal Astronomical Society.