Single-UV-photon 2-D imaging with multi-GEM detectors

• Autor(a) principal: Maia, J. M.
• Data de Publicação: 2007
• Outros Autores: Mörmann, D., Breskin, A., Chechik, R., Veloso, J. F. C. A., Santos, J. M. F. dos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/4362
• topic: Single-UV-photon imaging; Gaseous imaging detector; Gaseous photomultipliers; Gas electron multiplier

The main goal being the construction of large-area, low-cost position-sensitive micropattern gaseous photomultipliers (GPMs) based on gas electron multipliers (GEM) cascades, we have studied the single-photon imaging capabilities of a 4-GEM GPM with a reflective CsI-photocathode deposited on the top surface of the 1st GEM. The charge readout was performed with a simple/economic Wedge and Strip (W&S) readout electrode, using pulses induced through a resistive electrode. We have demonstrated the feasibility of single-photon imaging GPM with sub-millimeter resolution; single-photon spatial resolutions as small as ~150 [mu]m (FWHM), i.e. ~65 [mu]m (RMS), were measured in Ar/5%CH4 gas mixture at atmospheric pressure.