Study of laser produced plasma in a strong external magnetic field

Laser plasma interaction and plasma dynamics in strong magnetic fields was investigated at intensities of 10¹⁵-10¹⁹ W/cm². A pulsed power machine generated transverse and longitudinal magnetic fields of 50-300 T. The impact on laser targets due to eddy currents in a fast rising magnetic field, x-ray flux, and plasma from the coil load were studied. The formation of a thin plasma disc around the rod load was observed in the transverse B-field. The plasma disc expanded with a velocity of 250 km/s. Propagation of plasma in the transverse magnetic field after the end of the laser pulse was modelled with 2D MHD simulations. Laser plasma interaction with Si targets in the longitudinal B-field was studied by laser and x-ray spectral diagnostics. The plasma plume collimates in the magnetic field to a narrow jet 0.2-0.3 mm in diameter with a length of 3-4 mm and electron plasma density of (0.2-1.5)x10²⁰ cm^-3. Analysis of Si x-ray K-shell spectra shows a trend for the enhanced heating in the magnetic field.