The most powerful lasers in the world – including those at the CLF – create some of the most extreme conditions in the universe, with temperatures many times hotter than the centre of the sun, and matter compressed to a thousand times solid density, in just a few billionths of a second. Such extreme conditions are difficult to predict due to the rapid flows of matter and energy and, because the laser light is so intense, whatever gets in its way will become ionized - creating a plasma. Predicting plasma dynamics is extremely complex because any electric current within the plasma has the effect of creating a magnetic field, this magnetic field in turn affects the electric current which in turn affects the magnetic field! The physics describing this is called magnetohydrodynamics and by combining it with the physics of light propagation and interaction, in a ‘radiation-magnetohydrodynamics’ simulation code, physicists can predict what will happen in laser experiments before they occur.
"Odin will be invaluable for the UK plasma physics community, as it will, for the first time, enable UK plasma physicists to make predictive simulations of “long-pulse” (intensity <1 × 1015 W/cm2) laser experiments."
Dr Robbie Scott, CLF Plasma Physics Group and STFC principle investigator on Odin project
A recent multi-institution (the Universities of Warwick and York, Imperial College London, the AWE and the STFC) collaboration has successfully been awarded £1M by EPSRC for the development of a 3D radiation-magnetohydrodynamics simulation code called “Odin”. The Odin code is crucial not only for experiment design purposes and the interpretation of experimental data, but also for performing theoretical predictions, diagnostic design and even multi-beam laser system design. For the world’s largest laser systems such predictive simulation capabilities are essential in order even to apply for experimental time.
The new simulation code Odin will provide a unique tool for the UK laser fusion, high energy density physics and laboratory astrophysics communities. It will also have important applications in other higher-intensity branches of laser-plasma physics such as ion and electron acceleration, x-ray sources, and fundamental research. This is because ultra-high-intensity (UHI) laser pulses are preceded by unwanted lower intensity laser light, which dictates the initial conditions for the UHI laser-plasma interaction. Odin will be able to accurately model the effects of this low-intensity laser light, providing researchers with the correct initial conditions for the UHI interaction resulting in a better understanding of the UHI interaction.
