Radiative cooling instabilities in magnetized high-density plasmas.

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The student will be involved in experimental research at the MAGPIE pulsed power facility at Imperial College into physics of high energy density plasmas, with applications to Laboratory Astrophysics. This PhD project will focus on interactions of counter-streaming plasmas generated by x-ray driven ablation of targets. The dense and magnetised plasma formed at the collision of these plasmas is subject to the development of various radiative instabilities, such as nonlinear thin shell instability and Field's cooling instability, which are common in many astrophysical systems and in Inertial Confinement Fusion (ICF). Experiments will be performed using a recently developed by us experimental platform utilizing X-rays generated by wire array z-pinch implosions, with the plasma formed in a 10-50 T magnetic field of the pinch (Halliday et al, Physics of Plasmas, 29, 042107 (2022)). Variation of the target materials (Carbon, Si and high -Z metals) will allow controllable variation of the strength of the radiative cooling of the plasma flows and of the formed stagnation layer. Variations of the ablated target structure will also allow controlling wavelengths and amplitudes of the imposed perturbations, which will be initiating the instabilities and possibly transition to turbulence. A broad range of diagnostics will be used in these experiments, including laser interferometry imaging, Faraday rotation polarimetry, Thomson scattering and optical and x-ray spectroscopy. Experimental data will be compared with numerical simulations and will provide quantitative data for validation of ICF and Astrophysical computer codes.