Development of high-gain gaseous photomultipliers for the visible spectral range

Abstract

We summarize the development of visible-sensitive gaseous photomultipliers, combining a semitransparent bi-alkali photocathode with a state-of-the-art cascaded electron multiplier. The latter has high photoelectron collection efficiency and a record ion blocking capability. We describe in details the system and methods of photocathode production and characterization, their coupling with the electron multiplier and the gaseous-photomultiplier operation and characterization in a continuous mode. We present results on the properties of laboratory-produced K${}_2$CsSb, Cs${}_3$Sb and Na${}_2$KSb photocathodes and report on their stability and QE in gas; K${}_2$CsSb photocathodes yielded QE values in Ar/CH${}_4$(95/5) above 30% at wavelengths of 360-400 nm. The novel gaseous photomultiplier yielded stable operation at gains of 10${}^5$, in continuous operation mode, in 700 Torr of this gas; its sensitivity to single photons was demonstrated. Other properties are described. The successful detection of visible light with this gas-photomultiplier pave ways towards further development of large-area sealed imaging detectors, of flat geometry, insensitive to magnetic fields, which might have significant impact on light detection in numerous fields.

22 pages, 12 figures, for submission to JINST

References in corpus (5)

• A concise review on THGEM detectors
• Advances in Gaseous Photomultipliers
• Ion backflow in the Micromegas TPC for the future linear collider
• Further progress in ion back-flow reduction with patterned gaseous hole-multipliers
• Advances in ion back-flow reduction in cascaded gaseous electron multipliers incorporating R-MHSP elements

Cited by in corpus (2)

• Further evaluation of a THGEM UV-photon detector for RICH - comparison with MWPC
• Measurement of the absolute Quantum Efficiency of Hamamatsu model R11410-10 photomultiplier tubes at low temperatures down to liquid xenon boiling point