Foreign-gas linewidth-broadening measurements in formaldehyde

Abstract
Line-broadening parameters corresponding to the collisional relaxation times T1 and T2 have been measured for the rotational transition 312 from 313 (28.975 GHz) of the astrophysical molecule CH2O when mixed to make dilute gas solutions with H2 and He. The method employed static absorption linewidth measurements with a high-resolution Stark spectrometer. Corrections necessary to account for instrumental and other lineshape distortion effects which arise with this technique are described. Results which disagree with those of some previous workers are presented.