Application of laser resonance fluorescence for investigations of helium in a near-wall plasma

Use of laser resonance fluorescence (LRF) method for solution of problems related to the presence of helium in plasma is considered. Investigations were carried on at T-10 tokamak. General principles of measurements consist in optical pumping of one of transitions in HeI with the subsequent observation of responses in different lines. In optical pumping of the 23P → D3D transition 33P → 23S(λ=388.9 nm) and 33S → 23P(λ=706.5 nm) lines were observed. Observed evaluations of elementary process rates in helium atom agree well with theoretical evaluations