Measurements of linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene in the ν4+ν5 combination band using a cw quantum cascade laser

- Various spectroscopic parameters of acetylene are measured for ν4+ν5 band.
- Linestrengths, N2-, Ar-, He- and self-broadening coefficients are reported.
- Voigt, Galatry and Rautian line profiles are used to simulate the spectra.
- Heated cell measurements (296-683 K) were carried out for five rotational transitions.
- Collisional narrowing coefficients and dynamic friction coefficients are reported.

Linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene have been measured at 296 K in the P branch of the ν4+ν5 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 N2- 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 ν4+ν5 combination band and other vibrational bands of acetylene.