GEM Production at the FTD in Bonn

Philip Hauer; Markus Ball; Shania Müller; Dmitri Schaab; Tim Schüttler; Rui De Oliviera; Adam Drozd; Alexis Rodrigues; Bernhard Ketzer

arXiv · 2606.03295

GEM Production at the FTD in Bonn

Philip Hauer·Markus Ball·Shania Müller·Dmitri Schaab·Tim Schüttler·Rui De Oliviera·Adam Drozd·Alexis Rodrigues·Bernhard Ketzer

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Abstract

This manuscript describes the establishment of a local production line for 10 cm x 10 cm Gas Electron Multiplier (GEM) foils at the Forschungs- und Technologiezentrum Detektorphysik (FTD) at the university of Bonn. GEM foils are widely used in modern gaseous detectors, providing high-gain signal amplification and high-rate capability. Our fabrication process utilizes a double-mask photolithographic technique on 50 $\mu$m polyimide cladded on both sides with 5 $\mu$m copper. The chemical etching procedure that is required to achieve uniform hole geometries with outer hole diameters of 70 $\mu$m and inner hole diameters of 50 $\mu$m will be described. Quality control protocols, including semi-automated optical inspection and high-voltage leakage current tests, demonstrate that foils produced at our facility achieve uniform hole size distributions and leakage currents of less than 1 nA at 600 V in air with no discharge hotspots. These results confirm that the production chain is capable of delivering high-performance foils suitable for research and development purposes.

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Philip Hauer, Markus Ball, Shania Müller, Dmitri Schaab, Tim Schüttler, Rui De Oliviera, Adam Drozd, Alexis Rodrigues, Bernhard Ketzer. 2026-06-02. GEM Production at the FTD in Bonn. https://arxiv.org/abs/2606.03295

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