In neutral-beam-injection (NBI)-heated plasma, the emission spectra of the neutrons produced by D(d,n)3He and T(d,n)α fusion reactions are known to be distorted from Gaussian distribution functions in both the high and low energy sides along the NBI direction. This study shows that the effect of NBI heating can be applied to the central energy region, i.e., the 2.4 - 2.5MeV range in the D(d,n)3He neutron emission spectrum. Conventionally, the intense spectrum anisotropy appears via the anisotropy in the double-differential D(d,n)3He cross-section. Herein, we have shown the anisotropy in the neutron emission spectrum of the central energy range (2.4 - 2.5 MeV) due to the alteration of the neutron emission spectrum (2.4 - 2.5 MeV). Caused by the modification of the deuteron velocity distribution function is large enough to negate the anisotropy caused by the double-differential D(d,n)3He cross-section. An application of the anisotropy effect to fuel-ion ratio diagnostics is discussed, and the attendant degree of improvement is evaluated.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics