Constraints on ion velocity distributions from fusion product spectroscopy
Name
22ja023_full.pdf
Size
1.98 MB
Format
Adobe PDF
Checksum (MD5)
2763243a96a0c8bbbeda4ae68ed67134
Author(s)
Crilly, A.J.
Appelbe, B.D.
Mannion, O.M.
Taitano, W.
Hartouni, E.P.
Moore, A.S.
Gatu Johnson, Maria
Chittenden, J.P.
Date Issued
March 2022
Journal
Nuclear Fusion
Publisher
IOP
Abstract
Recent inertial confinement fusion experiments have shown primary fusion spectral moments which are incompatible with a Maxwellian velocity distribution description. These results show that an ion kinetic description of the reacting ions is necessary. We develop a theoretical classification of non-Maxwellian ion velocity distributions using the spectral moments. At the mesoscopic level, a monoenergetic decomposition of the velocity distribution reveals there are constraints on the space of spectral moments accessible by isotropic distributions. General expressions for the directionally dependent spectral moments of anisotropic distributions are derived. At the macroscopic level, a distribution of fluid element velocities modifies the spectral moments in a constrained manner. Experimental observations can be compared to these constraints to identify the character and isotropy of the underlying reactant ion velocity distribution and determine if the plasma is hydrodynamic or kinetic.
Description
Submitted for publication in Nuclear Fusion
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1741-4326/ac90d5
