Jv. Bozin et al., EXCITATION OF 2P LEVELS OF ARGON IN TOWNSEND DISCHARGES AT A HIGH-RATIO OF ELECTRIC-FIELD TO GAS-DENSITY, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 53(4), 1996, pp. 4007-4011
We have made measurements of the absolute emission intensities, i.e.,
excitation coefficients of 2p levels of argon atom, from 2p(1) to 2p(9
), by measuring intensities of light originating from 2p levels and de
caying to 2s levels. The excitation coefficients were obtained from th
e optical signal at the anode of Townsend Ar discharges, after correct
ion for the detector quantum efficiency. Measurements were done for wi
der ranges of E/N from 50 Td to 9 kTd, than previously reported. Compa
risons of our data with other experiments and calculations show differ
ent effects of collisional energy transfer for different 2p levels at
low E/N (pressure above 5 Torr). A comparison of the measured total ex
citation coefficient for 2p levels with the Boltzmann calculations of
electron excitation of 2p levels from the ground state and via cascadi
ng shows the influence of collisional quenching to Is levels at the lo
wer end of the E/N range and strong cascading from higher levels at hi
gh E/N.