Characterising high-flux x-ray emission in the highest intensity laser-matter interactions (plasma strand project)

Supervisors: K.Lancaster (University of York) and C.Ridgers (University of York)

Our ability to compress more laser energy into shorter duration pulses, has enabled a dramatic increase in the achievable laser intensity and thus the exploration of new regimes of light-matter interaction.  At the limit reached by state-of-the-art high power petawatt (PW) laser systems (1022Wcm-2) any matter in the laser focus is rapidly ionised to create a plasma where the electrons are rapidly accelerated to ultra-relativistic energies and novel ultra-relativistic plasma processes become important.  One such process is relativistic transparency where the relativistic mass increase of the electrons causes even solid density plasmas to become transparent.  Recent simulation work has shown that when this occurs bright, collimated x-ray bursts are emitted.  In addition the radiation pressure of the laser pulse is so strong in this ultra-relativistic plasma regime that the laser accelerates the whole target like a light sail, enabling the ions to reach GeV energies.  While the underlying physics of this new regime is almost completely unexplored in the laboratory the x-rays could be very useful for radiography of dense materials such as compressed inertial confinement cores and the ions could be used for novel fast ignition fusion schemes. This project will use state-of-the-art high power laser facilities to understand the processes of x-ray emission and ion acceleration in ultra-relativistic plasmas.

Our group has world-leading expertise in high intensity laser plasma interactions.  The student will be able to tap into this to design and lead experiments at world-leading laser facilities.  We have excellent links with the Central Laser Facility at the Rutherford Appleton Laboratory and the Center for Ultrafast Optical Science at the University of Michigan, home to the Vulcan PW and Hercules lasers respectively and expect to perform experiments on these at the highest intensities yet reached in laser-plasma interactions, enabling us to truly reach the ultra-relativistic plasma regime for the first time.

While the project will be based at the York Plasma Institute, experimental time is anticipated at national and international laser facilities.

The student will develop team-working and leadership skills working as part of an experimental team.  Bringing experiments to a successful conclusion will provide excellent development opportunities for problem-solving skills.

For further information please contact Kate Lancaster (kate.lancaster@york.ac.uk) or Christopher Ridgers (christopher.ridgers@york.ac.uk)