Ultrafast measurements of ion temperature in high-energy-density plasmas by nuclear resonance fluorescence

Abstract

Doppler broadening of characteristic emission lines by nuclear resonance fluorescence (NRF) is proposed as an ultrafast method for actively measuring the ion temperature in plasmas. For 6Li plasmas with an areal density of 1 g cm-2 and an ion temperature of 10 keV, a collimated ultrafast gamma-ray pulse with a spectral density of 100 photons/keV at a resonance energy of 3.56 MeV can generate one NRF photon and has an emission spectral width of approximately 6 keV. This method provides a new experimental tool for high-energy-density physics, including inertial confinement fusion and experimental astrophysics.