Köln 2025 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 31: Instrumentation VII
HK 31.1: Vortrag
Mittwoch, 12. März 2025, 15:45–16:00, SR Exp1A Chemie
The Stabilized Voltage Divider – A Rate-Capable HV-Scheme for GEMs — •Jakob Krauß1, Philip Hauer1, Karl Flöthner1, 2, Christian Honisch1, and Bernhard Ketzer1 — 1Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany — 2CERN, Geneva, Switzerland
GEM detectors are widely used as tracking detectors in modern particle physics experiments. Typically, stacks of multiple GEM foils are used to provide the required gain. For discharge-safe operation, the potentials of the electrodes are often generated through a resistor chain from a single input channel, and a large-valued resistor is used to limit the current in case of a shorted segment. When such a detector is subjected to high particle rates, of up to several MHz/cm2, the large number of charges moving inside the detector lead to non-negligible potential drops over the bias resistor. The performance of the detector is degraded, as the detector gain and efficiency are highly sensitive to the potentials, calling for improvements of the high-voltage scheme.
The newly developed Stabilized Voltage Divider (SVD) uses MOSFETs to provide the nominal potentials and limit the current in case of a short circuit in the GEMs, while having a low output impedance during normal operation. Strong emphasis was put on the adequate response of the SVD to discharges, minimizing the risk of damage to the detector’s GEMs and readout. Measurements demonstrating the resilience to discharges and the superior rate capability of the SVD will be presented.
Supported by BMBF.
Keywords: GEM; MPGD; Gaseous Detectors; High Voltage