Kinetic modeling of rotational nonequilibrium in chemical lasers. A comparison of three models applied to the Cl/sub 2//HI/He system

Journal Article · Tue Jan 01 04:00:00 EST 1980 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.327406· OSTI ID:5803136

Reuven, Y; Ben-Shaul, A; Baer, M

In this study three theoretical models which yield the temporal evolution of photon densities and population levels for a pulsed chemical laser are compared. The models are applied to the Cl/sub 2//HI/He chemical laser system. The simplest one is the well-known Boltzmann equilibrium model (BEQM) which assumes instantaneous rotational equilibrium throughout the lasing period. This assumption is removed in the detailed rotational nonequilibrium model (DRNM) which follows the time development of each vib-rotational population level separately. A third model, recently introduced by Baer, Top, and Alfassi, is an approximate rotational relaxation model (ARRM) which represents the rotational distribution in each vibrational level as a linear combination of three known functions with time-dependent coefficients. The main conclusions are as follows: (1) The BEQM is inadequate for providing the properties of a laser operating under low and intermediate inert-gas pressures. It can serve at most to derive an upper bound for the actual laser performance. (2) The ARRM provides very good estimates of total laser energy and efficiency as well as of more detailed properties, such as band intensities and the temporal behavior of the vibrational populations, for a wide range of pressures. (3) The use of the DRNM cannot be avoided if fine details, such as spectral distribution of output energy or rotational energy profiles, are required.

• Research Organization: Department of Theoretical Physics and Applied Mathematics, Soreq Nuclear Research Centre, Yavne, Israel
• OSTI ID: 5803136
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 51:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
BOLTZMANN EQUATION
CHEMICAL LASERS
CHLORINE
CRYOGENIC FLUIDS
DIFFERENTIAL EQUATIONS
ELEMENTS
ENERGY LEVELS
EQUATIONS
FLUIDS
HALOGEN COMPOUNDS
HALOGENS
HELIUM
HYDRIODIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IODINE COMPOUNDS
KINETICS
LASERS
MATHEMATICAL MODELS
NONMETALS
PULSES
RARE GASES
RELAXATION
TIME DEPENDENCE