CHARGE EXCHANGE OBSERVATIONS AND ANALYSIS IN THE DITE TOKAMAK
Measurements of the enhancement of line intensities from Oxygen and Carbon ions during beam injection of hydrogen atoms into the DITE Tokamak have been made for neutral energies of 25 keV and beam powers up to 2 MW. Observations of the spectrum from O encompass the Lyman series in the X-UV region (1s-np, n < 9) and "TRIANGLE"n=1 transitions in the VUV and visible regions. The different selection rules for these transitions allow a differentiation between C/X and electron impact excitation of the different (n, l) states. Using theoretical cross-sections and a cascade model for C/X recombination in to hydrogenic ions, the concentrations of impurity nuclei (eg: O**8+) are determined from the "TRIANGLE"n=1 VUV lines. This analysis is unsuitable for the Lyman series which lack the C/X signature. Their intensity is determined primarily by the ionisation balance, and excitation from the ground state hydrogenic ion. L state mixing is considered. No indication of statistical repopulation of the sublevels is observed for n < 7.
Bibliographic Reference: WRITE TO THE LIBRARIAN, UKAEA, CULHAM LABORATORY, ABINGDON, OXON OX14 3DB (UK) MENTIONING REPORT CLM-P737, 1985
Record Number: 1989124038100 / Last updated on: 1987-01-01
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