Charge exchange recombination spectroscopy for α particles colliding with hydrogen atoms.

The intensities of charge exchange recombination spectroscopy (CXRS) of α particles colliding with the hydrogen atoms in the neutral beam injection (NBI) are calculated by solving the rate equations including electron collision processes in the quasi-static state approximation. The effects of electron collision processes on the CXRS signals for He⁺(n=4→3) at λ=468.6nm in various plasma conditions are discussed, and it is found that these effects can increase the CXRS signals by 50% for electron density n_e≥10¹⁵cm^-3. However, their importance decreases with the increasing of NBI energy. For the short pulse of NBI, the influences of electron collision processes can be neglected for n_e≤10¹⁴cm^-3. Furthermore, the spectra of He⁺(n→n') are present for the plasma conditions of HT-7 tokamak. [ABSTRACT FROM AUTHOR]