1. Photon detection efficiency measurements of the VERITAS Cherenkov telescope photomultipliers after four years of operation
- Author
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Thanh Huy Nguyen, N. Otte, Gregory Richards, and Eliza Gazda
- Subjects
Photomultiplier ,Physics - Instrumentation and Detectors ,Photon ,FOS: Physical sciences ,01 natural sciences ,Photocathode ,High Energy Physics - Experiment ,law.invention ,Telescope ,High Energy Physics - Experiment (hep-ex) ,Optics ,law ,0103 physical sciences ,Emission spectrum ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Instrumentation ,Mathematical Physics ,Cherenkov radiation ,Physics ,010308 nuclear & particles physics ,business.industry ,Instrumentation and Detectors (physics.ins-det) ,Sample (graphics) ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Sensitivity (electronics) - Abstract
The photon detection efficiency of two sets of R10560-100-20 superbialkali photomultiplier tubes from Hamamatsu were measured between 200 nm and 750 nm to quantify a possible degradation of the photocathode sensitivity after four years of operation in the cameras of the VERITAS Cherenkov telescopes. A sample of 20 photomultiplier tubes, which was removed from the telescopes was compared with a sample of 20 spare photomultiplier tubes, which had been kept in storage. It is found that the average photocathode sensitivity marginally increased below 300 nm and dropped by 10% to 30% above 500 nm. The average photocathode sensitivity folded with the Cherenkov spectrum emitted by particles in air showers, however, reveals a consistent detection yield of 18.9+/-0.2% and 19.1+/-0.2% for the sample removed from the telescope and the spare sample, respectively., 5 pages, 9 figures, submitted to JINST
- Published
- 2016