Constraints on ion velocity distributions from fusion product spectroscopy
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.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE; USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344; NA0003525; NA0003856
- OSTI ID:
- 1890757
- Report Number(s):
- LLNL-JRNL-844882
- Journal Information:
- Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 12 Vol. 62; ISSN 0029-5515
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- IAEA
- Language:
- English
Similar Records
A Perturbative Solution for Nonlinear Stratified Upwelling over a Frictional Slope
Fluid and drift-kinetic description of a magnetized plasma with low collisionality and slow dynamics orderings. II. Ion theory