Bayesian inference of ion velocity distribution function from laserinduced fluorescence spectra
Abstract
The velocity distribution function is a statistical description that connects particle kinetics and macroscopic parameters in manybody systems. Laserinduced fluorescence (LIF) spectroscopy is utilized to measure the local velocity distribution function in spatially inhomogeneous plasmas. However, the analytic form of such a function for the system of interest is not always clear under the intricate factors in nonequilibrium states. Here, we propose a novel approach to select the valid form of the velocity distribution function based on Bayesian statistics. We formulate the Bayesian inference of ion velocity distribution function and apply it to LIF spectra locally observed at several positions in a linear magnetized plasma. We demonstrate evaluating the spatial inhomogeneity by verifying each analytic form of the local velocity distribution function. Our approach is widely applicable to experimentally establish the velocity distribution function in plasmas and fluids, including gases and liquids.
 Publication:

Scientific Reports
 Pub Date:
 October 2021
 DOI:
 10.1038/s41598021001384
 arXiv:
 arXiv:2110.10998
 Bibcode:
 2021NatSR..1120810T
 Keywords:

 Physics  Plasma Physics;
 Condensed Matter  Statistical Mechanics;
 Physics  Data Analysis;
 Statistics and Probability
 EPrint:
 Sci Rep 11, 20810 (2021)