Title :
A Monte Carlo study of backscattering effects in the photoelectron emission into CH4 and Ar-CH4 mixtures
Author :
Escada, J. ; Rachinhas, P.J.B.M. ; Dias, T.H.V.T. ; Lopes, J.A.M. ; Santos, F.P. ; Conde, C.A.N. ; Stauffer, A.D.
Author_Institution :
Dept. de Fisica, Coimbra Univ., Portugal
Abstract :
Monte Carlo simulation is used to investigate the backscattering and the transmission efficiency for the photoelectrons emitted from a CsI photocathode into CH4 and Ar-CH4 mixtures, for incident photons Eph in the 6.8-9.8 eV (183-127 nm) energy range and applied electric fields from E/N=0.1 Td to E/N=40 Td. Due to vibrational excitation of CH4, which starts at low electron impact energy, the addition of CH4 to a noble gas increases electron transmission and drift velocity. The dependence of the transmission efficiency in CH4 and Ar-CH4 mixtures on the reduced electric field E/N, incident photon energy Eph and mixture composition is analyzed, and results are compared with available experimental data.
Keywords :
Monte Carlo methods; gas scintillation detectors; ionisation chambers; photocathodes; 127 to 183 nm; 6.8 to 9.8 eV; Ar-CH4 mixtures; CsI photocathode; Monte Carlo simulation; backscattering effects; drift velocity; electron impact energy; electron transmission; incident photon energy; mixture composition; noble gas; photoelectron emission; photoelectron transmission efficiency; reduced electric field; vibrational excitation; Argon; Backscatter; Cathodes; Electron emission; Electron mobility; Gases; Ionization; Monte Carlo methods; Production; Solid scintillation detectors;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2004 IEEE
Print_ISBN :
0-7803-8700-7
Electronic_ISBN :
1082-3654
DOI :
10.1109/NSSMIC.2004.1462257
