Impact Broadening of Microwave Spectra

Abstract

structure separations 25 : AE lf2 =E(/=l)-£(/=2) = 7.1SkMc/sec, A£ M =£(/=l)-£(/=0) = 5.20 kMc/sec, we can calculate all the first-order gF (1), s and the secondorder E (2) 's of the N=l rotational level from Eqs. (3.9) and (3.10). The numerical values of g^( 1) and gF(=gF (0) +g> (1) ) thus calculated are shown in Table I. The signs and the orders of magnitude of g> (1), s are in agreement with the preliminary experimental values of Lichten and Brooks. 3,9 However, the absolute values of the calculated g> (1) 's are about a factor of 2 too large in almost all cases, This indicates that the first-order g> (1) 's do account for the discrepancies between gF (0), s 25 The fine-structure separations used here are the preliminary experimental results of Lichten and Brooks. One can also obtain a set of theoretical energy separations from Ref. 6. They are AJEI, 2 = 6.54 kMc/sec, AE 0 ,i = 4.10 kMc/sec. In view of the simple wave function used in Ref. 6, we use the experimental values here to calculate the &F (1), S.

Line mixing in the ν6 Q branches of self- and nitrogen-broadened methyl bromide

“…Comparison between experimental and calculated spectra for various Q branches is discussed in Section 4. Line-mixing effects modeled in the case of self-perturbed CH 3 Br, are also presented in the same section.…”

“…The line-mixing effects have been analyzed for CH 3 F perturbed by rare gas [5,6] using a dynamical model. A simple modelling of the ν 5 R Q 0 branch of CH 3 Cl perturbed by N 2 was proposed by Hartmann et al [7] and Frichot et al [8].…”

“…In the present work, nitrogen pressures up to about 1 atm were used. In such conditions, the usual Voigt or Lorentz line profiles can no longer correctly reproduce the experimental shape of the Q branches, because of line mixing [3,4]. Line mixing has been studied for various molecules as CO 2 , N 2 O, CH 4 .…”

“…It is also the primary organobromide species in the lower atmosphere. For these reasons, the infrared spectrum of CH 3 Br has been extensively studied in the 10 µm atmospheric window, where the fundamental ν 6 band occurs (see Refs. [1,2] and references therein).…”

“…In the present paper, a model similar to the one used for CH 3 Cl [9] was applied to calculate line mixing in the ν 6 R Q K and P Q K (K = 0 -6) branches of CH 3 Br perturbed by nitrogen and self perturbed.…”