On feasibility of absolute measurements of ion temperature in D-3He fusion plasma

We investigate a possibility of using γ-ray-generating nuclear reactions for absolute measurements of bulk ion temperature in D-3He fusion plasma. Radiative capture processes between fuel ions and specific γ-ray modes of nuclear reactions induced by a small admixture of 6Li are examined for such an application. It is shown that ion temperature can be determined by comparative measurements of the respective γ-ray yields. An essential point of the method proposed is that any fluctuations of plasma parameters during the measurements do not affect accuracy of temperature probe. Nuclear reactions 3He(3He,γ)6Be and 6Li(3He,γp)8Be are suggested for diagnostics for the first time. Necessary data on reaction cross sections and Maxwellian rate parameters are calculated. (author)