Abstract
Linestrengths, N-2-, Ar-, He- and self-broadening coefficients of acetylene have been measured at 296 K in the P branch of the v(4)+v(5) combination band for 25 rotational transitions. The effect of gas temperature is studied over 296-683 K for five transitions to allow the determination of the temperature dependent exponent n for N-2- and Ar-broadening coefficients. These measurements were performed using a continuous-wave quantum cascade laser (cw-QCL) operating over 1253-1310 cm(-1). Spectroscopic parameters were obtained by fitting absorption spectra using Voigt, Galatry and Rautian profiles. Linestrength and broadening results are compared with previous studies available in literature for the v(4)+v(5) combination band and other vibrational bands of acetylene. (C) 2014 Elsevier Ltd. All rights reserved.