X-ray generation by laser hole boring and channelling in dense plasma

We report on an experiment which aimed to investigate the sensitivity of X-ray radiation generation to the degree of laser channelling occurring in overdense plasma. Channelling is driven by the processes of relativistic self induced transparency (RSIT) [1] and radiation pressure hole boring (HB) [2] and enables the laser to interact with the target plasma volumetrically. X-rays are produced by electron acceleration in the fields generated, or via Bremsstrahlung due to interaction with the fields of the target atoms, and provide a useful diagnostic due to their penetration through the dense target, enabling the channelling dynamics to be probed. Investigation of laser hole-boring and channelling physics in dense plasma at the upper limits of intensities achievable today (~1021 Wcm-2) benchmarks models used to design future experiments at multi-petawatt lasers, for which radiation pressure driven effects will dominate the physics.