Time-resolved Spectroscopy for Temperature Profile Measurements of a Sheared Flow Stabilized Z-Pinch*

The ZaP-HD Flow Z-pinch device is designed to scale the sheared flow stabilized Z-pinch to high energy density conditions. ZaP-HD uses a tri-axial electrode configuration to decouple formation and compression power for a 50 cm long, 0.4 cm diameter hydrogen pinch. Plasma conditions can exceed temperatures of 1 keV and densities of 2e17 cm^-3, with lifetimes of 100 μs. The device is being used as a platform to develop a novel spatiotemporally resolved diagnostic to measure plasma temperatures throughout the pulse. ZaP-HD uses ion Doppler spectroscopy (IDS) to obtain radial profiles of temperature and velocity by measuring the emission profiles of carbon-III and carbon-V. The IDS system uses a detector which is only capable of making one measurement per plasma pulse.  Acquiring time-resolved profiles requires data collection at varying times over hundreds of pulses. To reduce the number of pulses needed to characterize the plasma conditions, a spectrometer is coupled to a Kirana ultra-fast framing camera to obtain up to 180 spectra at rate of 5e5 frames/s throughout the plasma lifetime. These data can elucidate the continuous evolution of the temperature profile at one axial location in the pinch from a single plasma pulse.