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Development of a triple GEM UV-photon detector operated in pure CF4 for the PHENIX experiment

A. Kozlov·I. Ravinovich·L. Shekhtman·Z. Fraenkel·M. Inuzuka·I. Tserruya
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Abstract

Results obtained with a triple GEM detector operated in pure CF4 with and without a reflective CsI photocathode are presented. The detector operates in a stable mode at gains up to 10^4. A deviation from exponential growth starts to develop when the total charge exceeds ~ 4 10^6 e leading to gain saturation when the total charge is ~ 2 10^7 e and making the structure relatively robust against discharges. No aging effects are observed in the GEM foils after a total accumulated charge of ~ 10 mC/cm^2 at the anode. The ion back-flow current to the reflective photocathode is comparable to the electron current to the anode. However, no significant degradation of the CsI photocathode is observed for a total ion back-flow charge of ~ 7 mC/cm^2.

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A. Kozlov, I. Ravinovich, L. Shekhtman, Z. Fraenkel, M. Inuzuka, I. Tserruya. 2003-08-31. Development of a triple GEM UV-photon detector operated in pure CF4 for the PHENIX experiment. https://doi.org/10.1016/j.nima.2003.12.018

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