Transient CARS spectroscopy of rotational transitions in H{sub 2}: the statistical dependences of the Doppler and collision dephasing

Journal Article · Mon Feb 28 00:00:00 EST 2005 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2005V035N02ABEH002896· OSTI ID:21470690

Arakcheev, V G; Valeev, A A; Morozov, V B; Olenin, A N; Tunkin, V G; Yakovlev, D V ^[1]

---

1. International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

The S{sub 0}(0) and S{sub 0}(1) rotational transitions in the H{sub 2} molecules are studied by the method of transient CARS spectroscopy at temperatures 296 and 80 K in a broad range of gas densities - from the density at which Doppler dephasing occurs to the density corresponding to collision dephasing. The slowest decay of the responses of the scattered probe pulse at the molar gas density {approx}0.2 amagat corresponds to the Dicke line narrowing. It is shown that the dephasing of the S{sub 0}(1) transition in the natural H{sub 2} mixture leads to a substantial discrepancy between the experimental results and the model of statistically independent perturbations of the rotational and translational motion of molecules at densities within a few tenths of amagat. This discrepancy becomes quite significant at liquid nitrogen temperature. At the same time, the dephasing of the S{sub 0}(0) transition better corresponds to this model, as well as the dephasing of the S{sub 0}(1) transition in the buffer He gas. The deviation from the model of statistically independent perturbations is described by introducing the correlation parameter. It is assumed that the features of the dephasing of the S{sub 0}(1) transition observed in the natural H{sub 2} mixture are mainly caused by resonance dephasing collisions. (papers devoted to the 250th anniversary of the moscow state university)

• OSTI ID: 21470690
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 35, Issue 2; Other Information: DOI: 10.1070/QE2005v035n02ABEH002896; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BUFFERS
COHERENT SCATTERING
COLLISIONS
CORRELATIONS
DENSITY
DISTURBANCES
DOPPLER EFFECT
ENERGY-LEVEL TRANSITIONS
HYDROGEN
LINE NARROWING
MOLECULES
RAMAN SPECTROSCOPY
RESONANCE
ROTATIONAL STATES
ELEMENTS
ENERGY LEVELS
EXCITED STATES
LASER SPECTROSCOPY
NONMETALS
PHYSICAL PROPERTIES
SCATTERING
SPECTROSCOPY