Magnetic Field Measurement in Magnetized Laser Plasmas Using Zeeman Broadening Diagnostics

The Zeeman effect has been used to measure the magnetic field in high energy density plasmas. The measurements are difficult when the field orientation is fluctuating in the plasma volume or when the line broadening due to the high plasma density and temperature surpasses the Zeeman splitting. Based on an idea proposed by Tessarin et al. (2011), we implemented a solution to this problem to the field measurement in magnetized laser plasmas. Time resolved spectra were obtained at the Nevada Terawatt Facility for plasmas created by 20 J, 1 ns Leopard laser pulses in the azimuthal magnetic field produced by the 0.6 MA Zebra pulsed power generator. The time history of the components of the Al III 4s ²S_1/2 - 4p ²P_1/2,3/2 doublet were recorded via optical streak camera (approximately 400 ns frame) at various locations along the magnetic field radius. In these measurements the Zeeman splitting was not resolved, but the magnetic field strength can be measured from the difference between the widths of the line profiles.