The alpha (α) -particle and neutron emission spectra in a deuterium-tritium plasma accompanied with neutral-beam-injection (NBI) heating are evaluated in a consistent way by solving the Boltzmann-Fokker-Planck equations for deuteron, triton, and α -particle simultaneously. It is shown that owing to the existence of non-Maxwellian tail component in fuel-ion distribution function due to NBI and/or nuclear elastic scattering, the generation rate of the energetic (≥4 MeV) α -particle increases significantly. When 20 MW intense deuterium beam with 1 MeV beam-injection energy is injected into an 800 m3 plasma (Te =10 keV, ne =6.2× 1019 m-3), the enhancement of the fraction of the power carried by α -particles with energy above 4 (3.9) MeV to total α -particle power is almost twice (1.5 times) as much from the value for Gaussian distribution. A verification scenario for the modification of the emission spectrum by using the gamma (γ) -ray-generating B9 e (α,nγ) C 12 reaction is also presented.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics