Hole misalignment and gain performance of Gaseous Electron Multipliers

Erik Brücken, Jouni Heino, Timo Hildén, Matti Kalliokoski, Vladyslav Litichevskyi, Raimo Turpeinen, Dezső Varga

Research output: Contribution to journalArticleScientificpeer-review


It is well known and has been shown that the gain performance of Gaseous Electron Multipliers (GEM) depends on the size of the holes. With an optical scanner it is possible to measure the dimensions of the holes, and to predict the performance of GEMs. However, the gain prediction of GEMs that are manufactured with a double mask etching technique is not straightforward. With the hole size information alone, it is not possible to make precise prediction of the gain. We show that the alignment of the photo-masks between the two sides of the GEM foils plays a crucial role. A misalignment of a few microns can lower the gain substantially. The study is performed by using the Helsinki high definition optical scanner for quality control of GEM foils, and this will show its true potential.
Original languageEnglish
Article number165271
JournalNuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
Number of pages11
Publication statusPublished - 21 Jun 2021
MoE publication typeA1 Journal article-refereed

Fields of Science

  • GEM
  • Double-mask
  • Gain prediction
  • HD optical scanning
  • Quality control
  • 114 Physical sciences

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