Publication Date:
2019-07-12
Description:
Rotational and fine-structure transitions between the low rotational levels of the OH radical in its X 2Pi state have been observed in absorption in the laboratory. It has thus been possible to measure the frequencies of these transitions directly. The observations were made with tunable far-infrared radiation generated by mixing two chosen CO2 laser frequencies in a metal-insulator-metal diode; the far-infrared difference frequency was radiated from the diode's whisker antenna. The measurements have an accuracy of a few hundred kHz. They both confirm and improve on the best previous estimates, which were obtained by extrapolation of laser magnetic resonance data.
Keywords:
ATOMIC AND MOLECULAR PHYSICS
Type:
Astrophysical Journal, Part 1 (ISSN 0004-637X); 307; 410-413
Format:
text
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