Photomultiplier tube performance of the WCDA++ in the LHAASO experiment
| Autor: | Khuram Tariq, Z. K. Zeng, Dong Liu, Hengying Zhang, Xiurong Li, Y. H. Yu, Cheng Liu, Cunfeng Feng |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Nuclear and High Energy Physics Photomultiplier 010308 nuclear & particles physics Dynamic range Cherenkov detector business.industry Voltage divider Signal Width High voltage 01 natural sciences law.invention Air shower Optics law 0103 physical sciences 010306 general physics business Instrumentation Dark current |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 958:162079 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2019.04.033 |
| Popis: | In the Large High Altitude Air Shower Observatory (LHAASO), the main physics objective of the water Cherenkov detector array (WCDA) is to survey the sky for gamma-ray sources in the energy range of 100 GeV to 30 TeV. In order to extend the dynamic range of the WCDA, a 1.5-inch photomultiplier tube (PMT) is placed aside the 8-inch PMT in each cell of the WCDA. All of these 1.5-inch PMTs (900 in total) consist of the WCDA dynamic extended system (WCDA++). These PMTs are required to maintain linearity within four orders of magnitude. The performance of the 1.5-inch PMTs with a specially designed bi-readout voltage divider is tested with a PMT test system. Accordingly, the effects of the working high voltage and signal width on the dynamic range of the PMTs are studied. The test results show that the dynamic range with a 5% non-linearity for a driven signal width of 5.5 ns is more than 200 kPEs (photoelectrons). The dark noise count rate is less than 200 Hz for a 1 mV threshold at a PMT gain of 2 × 1 0 5 . These results confirm that the PMT performance meets the WCDA++ requirements. |
| Databáze: | OpenAIRE |
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