Title :
A measurement of the first Townsend coefficient as a function of the electric field for a TMAE-He mixture
Author :
Shuping, Zhang ; Bruyndonckx, P. ; Goldberg, M. ; Tavernier, S.
Author_Institution :
Interuniversity Inst. for High Energies, Vrije Univ., Brussels, Belgium
Abstract :
TMAE (tetrakis-dimethylamino-ethylene) has been widely used in photo-ionization detectors in the last decade. As a gas photocathode, it has one of the lowest ionization potentials of the organic compounds studied to date, a high quantum efficiency, and adequate vapor pressures at just above room temperatures. In order to understand the gas amplification mechanism of an avalanche chamber filled with a TMAE-based gas mixture operated at a low gas pressure, we have measured the first Townsend coefficient for a TMAE-He mixture with a parallel plate avalanche chamber. Based on this result, the gas amplification process in wire chambers operated at low gas pressure is discussed.<>
Keywords :
Townsend discharge; discharges (electric); electric fields; gas mixtures; helium; ionisation chambers; He; TMAE-He mixture; avalanche chamber; electric field; first Townsend coefficient; gas amplification; low pressure; parallel plate avalanche chamber; Anodes; Cathodes; Detectors; Electric variables measurement; Electrons; Ionization; Pollution measurement; Pressure measurement; Temperature; Wire;
Journal_Title :
Nuclear Science, IEEE Transactions on
