COCHISE observations of argon Rydberg emission from 2 to 16 micrometers
By: W.T. Rawlins, A. Gelb, R.A. Armstrong
Contributors: Gelb, A.; Armstrong, R. A.
Series: AFGL-TR -- 83-0201; Environmental research papers -- no. 849; Environmental research papers (Hanscom AFB, Mass.) -- no. 849
Publisher: Optical Physics Division, Air Force Geophysics Laboratory, Air Force Systems Command, USAF
Published: 1983
Place of publication: Hanscomb AFB, Mass
Language: eng
Number of pages: 59
Subjects: Rydberg states; Atomic spectra; Argon; Observations; Infrared radiation; Infrared technology
Description: Infrared (2 to 16 micrometers emission from atomic Ar Rydberg atoms, excited in a coventional low-pressure microwave discharge plasma, has been observed in the cryogenic COCHISE facility. The observed spectrum is very complex but is identifiable using the detailed energy level structure and optical selection rules for Arl. Detailed transition probabilities for dipole-allowed transitions between 2 and 16 micrometers were estimated using the Coulomb approximation. Comparisons of observed and simulated spectra show that substantial LWIR emission (approx. 12 micrometers) arises from Rydberg states near the ionization limit. These states must have kinetically enchanced populations in order to account for the observed emission intensities. The results are interpreted in terms of a radiative collisional cascade sequence initiated by dissociative recombination of Ar2(+) with energetic electrons in the active discharge. The implications of these observations for atmospheric infrared signatures are discussed.
Notes: Title from cover.

"5 August 1983."

"Optical Physics Division project 2310."

Includes bibliographical references (P. 55-56).