Photoelectron transmission efficiency in Ar-CH4 and Xe-CH4 mixtures: Experimental results

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Coelho, LCC (Author) Other; Lopes, JAM (Author) Other; Escada, J (Author) Other; Dias, THVT (Author) Other; dos Santos, JMF (Author) Other

Journal

Title: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT

Vol. 607

Pages: 587-590

ISSN: 0168-9002

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-003-GPN

DOI: 10.1016/j.nima.2009.06.009

Abstract (EN): The transmission efficiency of photoelectrons emitted from CsI photocathodes operated in Ar-CH4 and Xe-CH4 mixtures is experimentally investigated and compared to Monte Carlo simulation results: the ratio between the number of photoelectrons collected in the gas media and in vacuum is determined as a function of the pressure-reduced electric field E/p at the photocathode surface, for irradiation with the VUV photons from an Hg(Ar) lamp. The addition of a small percentage of CH4 to At and Xe results in a significant increase of the photoelectron transmission, in particular for electric fields below E/p similar to 1 V cm(-1) Torr(-1). Below E/p similar to 0.5 V cm(-1) Torr(-1) the transmission efficiency f in Ar-CH4 Mixtures reaches values higher than in pure CH4, going through a maximum in the range of 10-30% CH4. The addition of 5% and 20% CH4 to Xe increases f by a factor of about 2 and 3, respectively, when compared to pure Xe.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4