Pressure broadening of the NO"2 hyperfine multiplet at 93 GHz - Meier, D. (Elsevier)
Line shapes of the hyperfine NO"2 26(1,25)〈-25(2,24) rotational transition have been measured at pressures below 3 torr with a bridge spectrometer originally designed for direct absolute absorption studies. The multiplet consists of six lines with δF=δJ=δN=1 in the vicinity of 93,445 MHz. The same line-broadening parameter of 3.7 MHz/torr and the same maximum absorption of 1.8x10^-^5 cm^-^1 have been found for all 6 lines. The maximum absorption of the strongly overlapped multiplet at a pressure of 10 torr was measured to be 1.06x10^-^4 cm^-^1, in good agreement with the theoretical value. The interference effect of the overlapping lines turns out to be below 10%, so that a simple superposition of lorentzian shapes is a good approximation for this case. The remaining difference can be compensated for by the introduction of an overlap parameter for each line.
http://linkinghub.elsevier.com/retrieve/pii/0022-4073(78)90082-1
Keywords: U