X-RAY-LINE POLARIZATION SPECTROSCOPY IN LASER-PRODUCED PLASMAS

In this work, we show that x-ray-line polarization spectroscopy can be a powerful diagnostic to study laser-produced plasmas. Kinetic calculations are compared to experiments designed to probe the low-density plasma region (with a 1-ps laser pulse) and the overdense plasma (with a 400-fs laser pulse). We observe the transition from a ''pancakelike'' electron distribution function at low density to a ''beamlike'' electron distribution function in the overdense plasma. The results are in agreement with the calculations which indicate non-Maxwellian behavior and strong anisotropy due to nonlocal electron heat flow.