Measurements of Heat Flux-Driven Anisotropic Electron Temperatures in Laser-Produced Plasmas*

Experiments at the Omega Laser Facility have utilized a single-beam gas-jet platform to infer anisotropic electron temperatures (T_∥ > T_⊥) in a low-density Nitrogen plasma (n_e = 5×10¹⁸ cm^-3). The temperature anisotropy exists on a nanosecond timescale while being driven by a 351 nm laser focused through a 200 μm distributed phase plate (I = 5×10¹⁴ W/cm²). Thomson-scattering analysis show the spectral density function changes relative to the axis of the laser beam. The temperature anisotropy is generated by the perpendicular heat conduction associated with the temperature gradient in that direction. Results from recent experiments using a larger 650 μm DPP to effectively remove the temperature gradient will be discussed.