The developed ”Leopard” high resolution scanner measures the single electron response of MPGDs. Therefore it became possible to quantify the amplification of individual holes. A UV light source is focused on the MPGD surface and single photoelectron spectra is recorded in every pixel over the selected two dimensional region (map). This way the MPGD gain and the photoelectron yield is clearly separated and can be computed. The single photoelectron spectrum also provides information about the exact distribution shape of the low amplitude responses as well. The MPGD surface structure is well observable on the photoelectron map. As expected, the gain map fluctuates hole by hole, but it is constant around a given hole. This technology reveals the microstructure of photo-efficiency and local gain to quantitatively compare different MPGD geometries and thus provides a powerful tool for e.g. GEM quality assurance.
|Journal||Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|Publication status||Published - ápr. 1 2020|
ASJC Scopus subject areas
- Nuclear and High Energy Physics