Author:
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Languages : en
Pages :
Book Description
Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF3 + H2 chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth).
Numerical Investigation of the Pulsed NF3 + H2 Chemical Laser Using a Model which Includes Rotational Relaxation and Semi-classical Laser Equations
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF3 + H2 chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth).
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF3 + H2 chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth).
A Numerical Investigation of the Pulsed NF3+H2 Chemical Laser Using a Model which Includes Rotational Relaxation and Semi-classical Laser Equations
Author: John Rogers Creighton
Publisher:
ISBN:
Category :
Languages : en
Pages : 644
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 644
Book Description
ERDA Energy Research Abstracts
Author: United States. Energy Research and Development Administration. Technical Information Center
Publisher:
ISBN:
Category : Force and energy
Languages : en
Pages : 724
Book Description
Publisher:
ISBN:
Category : Force and energy
Languages : en
Pages : 724
Book Description
ERDA Energy Research Abstracts
Author: United States. Energy Research and Development Administration
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 724
Book Description
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 724
Book Description
Scientific and Technical Aerospace Reports
Nuclear Science Abstracts
ERDA Research Abstracts
Author: United States. Energy Research and Development Administration
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 716
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 716
Book Description
ERDA Energy Research Abstracts
Author: United States. Energy Research and Development Administration
Publisher:
ISBN:
Category : Energy conservation
Languages : en
Pages : 986
Book Description
Publisher:
ISBN:
Category : Energy conservation
Languages : en
Pages : 986
Book Description