Imaging with the invisible light
arXiv:physics/0703176 · doi:10.1016/j.nima.2007.07.098 10.1016/j.nima.2007.11.002
Abstract
We describe a UV photo-detector with single photon(electron) counting and imaging capability. It is based on a CsI photocathode, a GEM charge multiplier and a self triggering CMOS analog pixel chip with 105k pixels at 50 micron pitch. The single photoelectron produced by the absorption of a UV photon is drifted to and multiplied inside a single GEM hole. The coordinates of the GEM avalanche are reconstructed with high accuracy (4 micron rms) by the pixel chip. As a result the map of the GEM holes, arranged on a triangular pattern at 50micron pitch, is finely imaged.
6 pages, 14 figures, presented at the 11th Vienna Conference on Instrumentation VIC 2007, submitted to Nuclear Instruments and Methods A