The hyperfine dependence of collisional relaxation of molecular spectra is a not widely known effect which can be observed only under particularly favorable circumstances. While the absence of such an effect was observed for various molecules, a variation of the collisional broadening parameter with the hyperfine quantum number F was observed only for CH3I. All these results are explained in the frame of a theoretical model showing that a hyperfine F-dependence of the relaxation parameters is not due to the negligible influence of nuclear spin interaction on the collisional dynamics, but to the F-dependence of the matrix elements of the multipole of the absorber involved in the collisional relaxation of the line. A recent experimental investigation allows an accurate validation of the theoretical model. (C) 2 001 Elsevier Science B.V. All rights reserved.
Hyperfine level dependence of the pressure broadening in molecular spectra
DI LIETO, ALBERTO;MINGUZZI, PAOLO;TONELLI, MAURO
2001-01-01
Abstract
The hyperfine dependence of collisional relaxation of molecular spectra is a not widely known effect which can be observed only under particularly favorable circumstances. While the absence of such an effect was observed for various molecules, a variation of the collisional broadening parameter with the hyperfine quantum number F was observed only for CH3I. All these results are explained in the frame of a theoretical model showing that a hyperfine F-dependence of the relaxation parameters is not due to the negligible influence of nuclear spin interaction on the collisional dynamics, but to the F-dependence of the matrix elements of the multipole of the absorber involved in the collisional relaxation of the line. A recent experimental investigation allows an accurate validation of the theoretical model. (C) 2 001 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
