| Autor: |
M.R. Sene, D.J.S. Findlay, N.P. Hawkes |
| Rok vydání: |
1987 |
| Předmět: |
|
| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 254:591-599 |
| ISSN: |
0168-9002 |
| Popis: |
Measurements have been made of afterpulses induced by light from a blue LED in EMI 9823B, Hamamatsu R1250, Mullard XP2041 and RCA 8854 fast linear-focussed photomultiplier tubes. The RCA and Hamamatsu tubes were found to produce significantly fewer afterpulses than the EMI and Mullard tubes. More detailed measurements of the Hamamatsu R1250 indicated that the total number of afterpulses is proportional to the magnitude of the initial flash and consists of two components. The first component is independent of the wavelength of the initial light flash, arises from ionization of residual gas in the phototube and can be effectively suppressed by gating the photomultiplier. The second component is wavelength-dependent, dominates the first component at short wavelengths, and cannot be significantly reduced by gating. It is possibly due to fluorescence of the phototube glass envelope or excitation of a metastable state of the photocathode. Similar components were found to contribute to afterpulsing in the RCA 8854 PMT. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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