N2-, H2-, and He-induced collisional broadening of the J = 24 ← 23 transition of HC3N located near 218.3 GHz at different temperatures

Abstract We report on experimental collisional relaxation of the J  = 24 ← 23 line of HC 3 14 N, located near 218.3 GHz, induced by nitrogen, hydrogen, and helium. The measurements were carried out at selected temperatures in the 235–350 K range using a video-type spectrometer. The foreign gas broadening parameters and their temperature dependences were determined assuming Voigt lineshape profiles and the usual T −n temperature law. The experimental broadening parameters are compared with results derived using the ATC collisional formalism.