Boltzmann equation analysis of electron swarm behaviour in methane

Ohmori, Y; Kitamori, K.; Shimozuma, M.; Tagashira, Hiroaki

doi:10.1088/0022-3727/19/3/013

Cited by 73 publications

(18 citation statements)

References 38 publications

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“…Similar good agreement was found in the case of CH 4 discussed in a previous paper [14]. Although the cross-sections used in the present work may not guarantee the completeness established by the so called swarm method as usually required in gas discharge and plasma physics [77][78][79][80][81], figures 2 to 4 show that in the low E/N range relevant for the present work (drift fields E/N~<20Td near the photocathode), our calculations give sufficiently accurate drift parameters. In particular, they reproduce well known characteristic effects very sensitive to cross-sections, namely the anisotropy of diffusion when electrons drift under an electric field [36,[82][83][84][85], and negative differential conductivity [81,[86][87][88][89][90].…”

Section: Electron Drift Parameters In Xe Ne and Xe-ch 4 And Ne-ch 4supporting

confidence: 87%

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures

Escada¹,

Dias²,

Rachinhas³

et al. 2010

J. Phys. D: Appl. Phys.

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Abstract. The extraction efficiency f for the photoelectrons emitted from a CsI photocathode into gaseous Xe-CH 4 and Ne-CH 4 mixtures is investigated by Monte Carlo simulation. The results are compared with earlier calculations in Ar-CH 4 mixtures and in the pure gases Xe, Ar, Ne and CH 4 . The calculations examine the dependence of f on the density-reduced electric field E/N in the 0.1-40 Td range, on the incident photon energy E ph in the 6.8-9.8 eV (183-127 nm) VUV range and on the mixture composition. Results calculated for irradiation of the photocathode with a Hg(Ar) lamp are compared with experimental measurements for this lamp. To test the electron scattering cross-sections used in the simulations, electron drift parameters in Xe, Ne and their mixtures with CH 4 are also presented and compared with available experimental data.

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Section: Electron Drift Parameters In Xe Ne and Xe-ch 4 And Ne-ch 4supporting

confidence: 87%

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures

Escada¹,

Dias²,

Rachinhas³

et al. 2010

J. Phys. D: Appl. Phys.

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“…The computational procedure is the same as that in Date et al 14 ͓there are editorial errors in Eqs. ͑8͒ and ͑9͒ of the paper; however, the results are valid͔, and the six-term approximation applied to the present analysis has been validated by Yachi et al 16 The electron collision cross sections for methane were taken from Ohmori et al 19 …”

Section: ͑12͒mentioning

confidence: 77%

Time-of-flight observation of electron swarm in methane

Hasegawa¹,

Date²,

Yoshida³

et al. 2009

Journal of Applied Physics

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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 / N͒ 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 r ͒ is determined for methane gas. The result is compared with the mean-arrival-time drift velocity ͑W 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 r and W m at high E / Ns ͑above 200 Td͒ is clearly ascertained in the experimental and theoretical investigations, which is attributable to the occurrence of ionization events.

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“…The (e, CH 4 ) dissociative attachment cross section is large and extended in energy [Ohmori et al, 1986], ranging from 10 to 100 eV. Peak values are at ∼20 eV with a value of 1.6 × 10 −20 m 2 and progressively decreased to about 1 × 10 −20 m 2 at 100 eV.…”

Section: Saturation Via Intrinsic Chemistrymentioning

confidence: 98%

Martian dust devil electron avalanche process and associated electrochemistry

et al. 2010

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[1] Mars' dynamic atmosphere displays localized dust devils and larger, global dust storms. Based on terrestrial analog studies, electrostatic modeling, and laboratory work, these features will contain large electrostatic fields formed via triboelectric processes. In the low-pressure Martian atmosphere, these fields may create an electron avalanche and collisional plasma due to an increase in electron density driven by the internal electrical forces. To test the hypothesis that an electron avalanche is sustained under these conditions, a self-consistent atmospheric process model is created including electron impact ionization sources and electron losses via dust absorption, electron dissociation attachment, and electron/ion recombination. This new model is called the Dust Devil Electron Avalanche Model (DDEAM). This model solves simultaneously nine continuity equations describing the evolution of the primary gaseous chemical species involved in the electrochemistry. DDEAM monitors the evolution of the electrons and primary gas constituents, including electron/water interactions. We especially focus on electron dynamics and follow the electrons as they evolve in the E field driven collisional gas. When sources and losses are self-consistently included in the electron continuity equation, the electron density grows exponentially with increasing electric field, reaching an equilibrium that forms a sustained time-stable collisional plasma. However, the character of this plasma differs depending upon the assumed growth rate saturation process (chemical saturation versus space charge). DDEAM also shows the possibility of the loss of atmospheric methane as a function of electric field due to electron dissociative attachment of the hydrocarbon. The methane destruction rates are presented and can be included in other larger atmospheric models.Citation: Jackson, T. L., W. M. Farrell, G. T. Delory, and J. Nithianandam (2010), Martian dust devil electron avalanche process and associated electrochemistry,

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Boltzmann equation analysis of electron swarm behaviour in methane

Cited by 73 publications

References 38 publications

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures

Time-of-flight observation of electron swarm in methane

Martian dust devil electron avalanche process and associated electrochemistry

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Boltzmann equation analysis of electron swarm behaviour in methane

Cited by 73 publications

References 38 publications

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH4 and Ne–CH4 mixtures

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH4 and Ne–CH4 mixtures

Time-of-flight observation of electron swarm in methane

Martian dust devil electron avalanche process and associated electrochemistry

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A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures

A Monte Carlo study of photoelectron extraction efficiency from CsI photocathodes into Xe–CH₄ and Ne–CH₄ mixtures