A variety of experimental techniques have been employed in a spectroscopic investigation of the strong visible chemiluminescence from the phosphine–nitrous oxide reaction system. Reaction was initiated by a fast electrical discharge in PH3/N2O mixtures over the pressure range 18–666 Torr. The predominant emission is a true continuum extending from a threshold wavelength at 3300 Å to beyond 1 μm. The results are consistent with the possible existence of a chemically formed (PO)2* exciplex molecule as the source of the visible continuum emission, but another molecular emitter containing only phosphorus and oxygen atoms, such as PO2, cannot be ruled out. Because of the possible use of this reaction system for a tunable, visible laser source, laser cavity tests and absorption and stimulated emission tests were carried out; these gave negative results. The photon yield from 3300 to 9000 Å was determined to vary linearly with pressure; a maximum yield of 8.5×10−3 was reached at the highest pressure investigated of 666 Torr. The broad spectral range of emission and low photon yield indicates that the ratio of stimulated emission to spontaneous emission did not exceed 0.02 at any wavelength shorter than 9000 Å.

New laser transitions at 15 wavelengths from 1.454 to 14.54 μ have been observed from eight metal atoms. A double-discharge technique has been employed for the production and excitation of metal atoms by dissociation of metal halides, alkyls, and carbonyls. The possibility of laser action on the Tl(I) 6s2 8p 2P01/2,3/2→6s2 7s 2S1/2 transitions at 6714 and 6550 A° is discussed.

New laser transitions at 24 wavelengths from 1.152–12.02 μ have been observed from nine metal atoms. Pulsed discharges have been employed for the production of the metal atoms by dissociation of metal halides, hydrides, and alkyls. This technique shows promise for application for pulsed chemical lasers based on electronic transitions in diatomic metal oxides and halides.

Hydrogen atoms are detected in situ in atmospheric pressure CH4 pyrolysis by three-photon ionization via two-photon resonance of the 2S <-IS transition at 243 nm. An expected deuterium isotope shift of 22.4 cm-1 is observed during CD4 pyrolysis. Similar resonant multiphoton ionization signals of H atoms and D atoms are also observed from thermal dissociation of H2 and D2, respectively. The ionization signals are converted into absolute concentration via the H2 «= 2H equilibrium. The detection sensitivity is estimated to be -10-9-10-8 mole fraction at 1-atm pressure.

Die starke Chemilu‐ mineszenz des Systems PH3/N2O im Sichtbaren wird nach Initiierung durch eine schnelle elektrische Entladung im Druckbereich 18‐666 Torr untersucht.