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

We investigate a possibility of using gamma-ray-generating nuclear reactions for absolute measurements of bulk ion temperature in D-He-3 fusion plasma. Radiative capture processes between fuel ions and specific gamma-ray modes of nuclear reactions induced by a small admixture of Li-6 are examined for such an application. It is shown that ion temperature can be determined by comparative measurements of the respective gamma-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 He-3(He-3,gamma)Be-6 and Li-6(He-3,gammap)Be-8 are suggested for diagnostics for the first time. Necessary data on reaction cross sections and Maxwellian rate parameters are calculated.