Measurement of collision-induced shift and broadening of the ultraviolet transitions of OH

Abstract

Using a cw tunable laser, absorption measurements were made to determine for the first time the shift and broadening of the ultraviolet transitions of OH induced by collisions with molecular nitrogen and oxygen. Similar measurements were also made for collisions with air and inert gases He, Ne, Ar, and Kr. Both the shift and broadening due to these collisions were found to depend linearly upon pressures in the range from 50 Torr up to 1 atm. The homogeneous linewidth for the P 1(2) transition ofOH in ambient air is determined to be (0.20±0.OO5) em-I. Results with Ar and Kr show contributions not accounted for by the polarizability of the colliding species.

Pressure broadening calculations for OH in collisions with argon: Rotational, vibrational, and electronic transitions

“…6 these computed coefficients with the experimental measurements of Shirinzadeh at al. [11] and Kasyutich [13]. We see that there is quite good agreement for the three lines for which experimental measurements have been made.…”

“…Kessler et al [10] measured line broadening and shifting of a number of lines in the A -X (1,0) in atmospheric-pressure hydrogen-air combustion gases. Shirinzadeh et al [11] employed a narrow-band tunable uv laser to measure the pressure broadening width and shift at room temperature of one line in the A -X (0,0) band in collisions with a variety of collision partners, including Ar. Rea et al [12] employed a rapidly scanned narrow-band laser and carried out a shock tube study of collisional broadening of lines in this band by Ar and N 2 at 2000 K. Kasyutich [13] has employed sum-frequency generation of two diode lasers (one frequency doubled) to measure room-temperature pressure broadening widths and shifts for several lines near the band origin of the A -X (0,0) band in collisions with a number of collision partners, including Ar.…”

“…The OH angular momentum j is the value for the lower level. Also plotted (solid points) are experimental measurements of the broadening and shifting of transitions by Kasyutich[13] (Q 1 transitions) and Shirinzadeh at al [11]. (P…”

Pressure Broadening and Temperature Dependence of Microwave and Far Infrared Rotational Lines in OH Perturbed by N2, O2, and Ar

“…In 1963 it became the first free radical to be identified by radioastronomy in the interstellar medium (3). In the 1980s it was detected in the far infrared (FIR) waves (4,5) as well as in electronic transitions in the ultraviolet part of the spectrum (6). Although this system has been the subject of intensive studies, its profile parameters have nevertheless been explored only poorly both experimentally and theoretically.…”

Application of a laser induced fluorescence model to the numerical simulation of detonation waves in hydrogen–oxygen–diluent mixtures

“…The 2γ and n parameters were taken from available data [44,47,48,49,50] for the OH radical (0,0) band because of the lack of data for the (1,0) band. The rotational level dependence of the collisional broadening coefficient studied by Kessler et al…”