B.S.T.J. Briefs: Excited Level Populations in High Current Density ArgonDischarges

Excited Level Populations in High Current Density Argon Discharges By R. C. M I L L E R , E. F. L A B t ' D A , and C. E. W E B B (Manuscript received N o v e m b e r 2, I960) Spontaneous emission intensities of AI and A l l in the range 2500 A to 11,500 A have been obtained from 2-mm diameter capillaries operated at filling pressures between 0.45 and 5.0 torr and currents up to 10 amperes. Only the A l l results at 0.0 torr and 5 amperes are rej>orted Fig. Level population in the 4p and 4p' configuration* of A l l in a capillary discharge. Capillary diameter = 2 mm, discharge current = 5 amps, filling pressure -- 0.6 T o r r . T h e value of electron mean energy £ was obtained from shielded double probe measurements and the absolute value scalc from Ladenburg-Keiche measurements.