Two-dimensional temperature spatial profiles and gradients in laser-heated plasmas relevant to MagLIF
Abstract
We present measurements of two-dimensional temperature spatial profiles from magnetized and unmagnetized plasma experiments performed at Z relevant to the pre-heat stage of Magnetized Liner Inertial Fusion. The D gas fill was doped with a trace amount of Ar for spectroscopy purposes and time-integrated spatially resolved spectra and narrowband images were collected in both experiments. Individual analysis of the spatially resolved spectra recovers temperature profiles Te(z) that are resolved along the axial direction of laser propagation but spatially integrated along the instrument's line-of-sight. By including both the spectrum and image data in a multi-objective analysis, we have extracted two-dimensional electron temperature distributions Te(r,z). The results indicate that, by inhibiting radial thermal conduction, the magnetic field increased Te, the axial extent of the laser heating, and the magnitude of the radial temperature gradients. Comparisons with simulations reveal that the simulations over-predict the extent of the laser heating and under-predict the temperature. Temperature gradient scale lengths extracted from the measurements also permit an assessment of the importance of nonlocal heat transport.
This work was supported by Contract 157018 with Sandia National Laboratories.- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- 2020
- Bibcode:
- 2020APS..DPPC09005C