Kinetic analysis of gamma-ray-generating reactions for fuel ion and energetic particle diagnostics of D-T fusion plasma - art. no. 024801

摘要

In D-T fusion plasma seeded with a small amount of Li-6, monochromatic 0.429-, 0.478- and 0.981-MeV gamma rays are produced in the Li-6 + D and Li-6 + T nuclear reactions. In the present paper we investigate these processes in the appropriate plasma kinetic model. The non-Maxwellian tails of deuteron and triton distribution functions created due to nuclear elastic scattering of D-T alpha-particles by fuel ions are found to enhance crucially production of the diagnostic gamma rays. This result can be considered as the first explicit demonstration that in a fusion plasma the role of suprathermal reaction channels induced by energetic knock-on ions can become comparable with (or even dominate) that of thermal ones. Possibilities of fuel ion and alpha-particle diagnostics using the reaction-produced gamma rays are also discussed. It is pointed out for the first time that the behavior of alpha-particles during slowing-down could be diagnosed by detecting 0.981-MeV alpha-rays emitted in a nuclear reaction between knock-on tritons and Li-6 admixture ions.