Document Details

Document Type : Article In Journal 
Document Title :
Numerical investigation of the electron dynamic dependence on gas pressure in the breakdown of hydrogen by KrF laser radiation
Numerical investigation of the electron dynamic dependence on gas pressure in the breakdown of hydrogen by KrF laser radiation
 
Subject : physics 
Document Language : English 
Abstract : This paper presents a numerical investigation of the measurements that were carried out by Yagi et al. [12] to study the breakdown of molecular hydrogen induced by short laser of wavelength 248 nm and pulse duration 20 ns. The aim of the study is to give a detailed description of the physical processes which contributed to the breakdown of molecular hydrogen at focused intensities between 4 x 10(12) W/cm(2) and 8.0 x 10(12) W/cm(2) over gas pressure range extended from 150 to 7000 Torr. The applied computer simulation model is based on the numerical solution of the time dependent Boltzmann equation and a set of rate equations that describe the rate of change of the formed excited states population. The experimentally measured rate constants and cross-sections for the various physical processes involved in the model are used in the calculations. Provision is made for the electron impact ionization and photoionization of the excited states. The former process is incorporated parametrically in the calculation owing to the lack of quantitative description of this process. Computations are performed at each gas pressure. The calculated threshold intensities are found to be in good agreement with the experimentally measured ones, both showing a noticeable increase in the higher pressure region. Moreover, calculation of the electron energy distribution function (EEDF) and its parameters demonstrated the exact correlation between gas pressure and the physical processes responsible for determining the breakdown threshold intensity 
ISSN : 0030-3992 
Journal Name : OPTICS AND LASER TECHNOLOGY 
Volume : 44 
Issue Number : 7 
Publishing Year : 1433 AH
2012 AD 
Article Type : Article 
Added Date : Sunday, July 23, 2017 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
Yosr E. E. -D GamalGamal, Yosr E. E. -D InvestigatorDoctorategamaly@yahoo.co
Khaled A ElsayedElsayed, Khaled A ResearcherDoctorate 
M. A MahmoudMahmoud, M. A ResearcherDoctorate 

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