Time-of-flight observation of electron swarm in methane

Journal Article · Mon Jun 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3142322· OSTI ID:21352221

Hasegawa, H ^[1]; Date, H ^[2]; Yoshida, K ^[3]; Shimozuma, M ^[4]

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1. Tomakomai National College of Technology, Tomakomai 059-1275 (Japan)
2. Faculty of Health Sciences, Hokkaido University, Sapporo 060-0812 (Japan)
3. Kitami Institute of Technology, 090-8507 (Japan)
4. Hokkaido Institute of Technology, Sapporo 006-8585 (Japan)

This paper reports on the evolution of an isolated electron swarm, which is experimentally observed as spatial distributions at every moment. This observation is assumed to directly correspond to the conventional time-of-flight theory. We have measured the spatial distribution of electrons using a double-shutter technique in the drift tube, where a shutter electrode to collect electrons can be slid along the field (E/N) direction in order to capture a relative electron number at a certain range of location. As a typical parameter defined by this spatial distribution, the center-of-mass drift velocity (W{sub r}) is determined for methane gas. The result is compared with the mean-arrival-time drift velocity (W{sub m}) defined from the arriving electron number at fixed positions. We have also performed a theoretical analysis in which a Fourier transformed Boltzmann equation is solved to deduce both of the drift velocities from a dispersion relationship. The difference between W{sub r} and W{sub m} at high E/Ns (above 200 Td) is clearly ascertained in the experimental and theoretical investigations, which is attributable to the occurrence of ionization events.

• OSTI ID: 21352221
• Journal Information: Journal of Applied Physics, Vol. 105, Issue 11; Other Information: DOI: 10.1063/1.3142322; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOLTZMANN EQUATION
CAPTURE
CENTER-OF-MASS SYSTEM
DISPERSION RELATIONS
DRIFT TUBES
ELECTRODES
ELECTRONS
FOURIER TRANSFORMATION
IONIZATION
METHANE
PLASMA
PLASMA DIAGNOSTICS
SPATIAL DISTRIBUTION
TIME-OF-FLIGHT METHOD
ALKANES
DIFFERENTIAL EQUATIONS
DISTRIBUTION
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HYDROCARBONS
INTEGRAL TRANSFORMATIONS
INTEGRO-DIFFERENTIAL EQUATIONS
KINETIC EQUATIONS
LEPTONS
ORGANIC COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
TRANSFORMATIONS