Pressure-induced shift and broadening of acetylene lines in the region 6580-6600 cm(-1)

摘要

Highly accurate measurements of pressure shift and broadening parameters of acetylene absorption lines in the region 6580-6600 cm(-1) have been performed by tunable diode laser spectroscopy (TDLS). For these purposes the three channel spectrometer with distributed-feedback diode laser, operated at 1.53 mu m was used. The laser is generating pulses of 4-10 ms duration at a repetition frequency of 40 Hz. A temperature-stabilization system, using a thermoelectric cooling unit affords a temperature stability of the order of 10(-4) K in the temperature range from -15 to +50 degrees C. A three channels acquisition system ensured simultaneous real time recording of the sample gas absorption spectrum and of two spectral calibration signals (Fabry-Perot fringes and low-pressure reference lines). We have measured the pressure-induced self-shift and broadening coefficients for six lines of the R-branch in the v(1) + v(3) rotation-vibration band of acetylene (C2H2)-C-12. The self-shift coefficients have been determined for these lines in the wide pressure region. A non-linear behavior of the pressure dependence of the shift was observed. The temperature exponent it of pressure-induced broadening and shift are reported. (c) 2006 Elsevier B.V. All rights reserved.