|Fast signals and single electron detection with MICROMEGAS photodetector|
|J. Derre, Y. Giomataris, P. Rebourgeard, H. Zaccone, J.P. Perroud, G. Charpak|
Abstract: ======== The performance of a new gaseous photodetector was investigated. It consists of a solid photocathode and a gas amplification structure of the MICROMEGAS type. Using a mixture of helium and isobutane at atmospheric pressure, a stable and high amplification gain close to 10^7 was achieved. Such a high gain and small fluctuations allowed the detection of single photoelectrons with a time resolution better than 700 ps. These performances are comparable with those obtained with the best photomultipliers.