What we do
Discover how we support the defence and security of the UK.Discover more
Two eminent international teams of academics who worked on the world-leading Orion laser have published papers about their respective experiments in Nature Communications and Scientific Reports, both of which are highly acclaimed scientific publications.
The experiments led by Professor Gianluca Gregori (University of Oxford) and Dr Andy Higginbotham (previously at Oxford and now at the University of York), were undertaken as part of the Orion collaborative academic access programme. In addition to AWE scientists and facility staff, participants from many other institutions supported the experiments, including the UK’s STFC Rutherford Appleton Laboratory, French groups from the LULI Laboratory (CNRS), the CEA and the Observatoire de Paris (CNRS), and US researchers from the University of Michigan and Lawrence Livermore National Laboratory.
Supported by the MOD, the peer-reviewed academic access programme allows UK-led teams to work on Orion – a unique centre of excellence based at AWE – using the wider capabilities of the facility to pursue their collaborative academic research programmes. The application process is highly competitive and has been significantly oversubscribed since the first call for proposals in 2013.
A high energy density physics experimental facility, Orion allows scientists to study matter compressed to many times denser than solid and heated to millions of degrees without resorting to underground nuclear testing. This capability also allows Orion to recreate the extreme conditions found at, for example, the cores of the Earth and the Sun and within the atmospheres of stars. Experiments to understand the basic physics of these otherwise distant and inaccessible environments support the complex computer codes and models used in the deterrent programme, as well as expanding our understanding of the wider universe.
Concerning his experiment studying fundamental properties of silicon, Andy said: “The data quality we obtained at Orion is unprecedented. This has allowed us to gain deep insight into the response of silicon to rapid compression – a topic which has puzzled the scientific community for around two decades. We are very grateful to the Orion staff, whose tireless hard work in fielding this experiment was invaluable.”
Speaking about his experiment to investigate the physics of an unusual class of binary star, Gianluca said:
“The Orion campaign has provided a vital piece of the jigsaw in the understanding of how strong shock waves behave. There are always three key ingredients that need to be considered each time a shock occurs. First, the shock compresses the ambient medium and its density increases. Second, the temperature rises. Third, some of the stored energy is radiated away. “We were able to reproduce all of these elements in the experiment, making it a good replica of what is believed to occur when gas extracted from a main sequence star impacts the surface of a magnetised white dwarf – a phenomenon characteristic of an elusive binary system known as a cataclysmic variable.”
Commenting on the performance of Orion, he added:
“The quality of the data was impressive and well above what was previously possible, giving us access to quantities otherwise inaccessible in astronomical observations. I believe this work could stand as the ideal platform where astrophysics and laboratory communities meet to solve the enigmatic behaviour of cataclysmic variables.”
The results are expected to attract significant interest from the international community, which is vital to both future research and inspiring the next generation of scientists. It is also expected to encourage future collaborative applications to Orion as part of AWE’s successful academic access programme.