Influence of the Earth's magnetic field on large area photomultipliers
- INFN - National Inst. of Nuclear Physics, Section of Catania, CO Via Santa Sofia 64, 95123 Catania (Italy)
- Dept. of Physics and Astronomy of Catania, CO Via Santa Sofia 64, 95123 Catania (Italy)
The influence of the Earth's magnetic field on large area photomultipliers proposed for a future deep sea neutrino telescope was studied under the EU-funded KM3NeT design study. The aims were to evaluate variations in PMT performance in the Earth's magnetic field and to decide whether the use of magnetic shielding is necessary. Measurements were performed on three Hamamatsu PMTs: two 8-inch R5912 types, one of these with super-bi-alkali photocathode, and a 10-inch R7081 type with a standard bi-alkali photocathode. The various characteristics of the PMTs were measured while varying the PMT orientations with respect to the Earth's magnetic field, both with and without a mu-metal cage as magnetic shield. In the 8-inch PMTs the impact of the magnetic field was found to be smaller than that on the 10-inch PMT. The increased quantum efficiency in the 8 super-bi-alkali PMT almost compensated its smaller detection surface compared to the 10' PMT. No significant effects were measured upon transit time and the fraction of spurious pulses. (authors)
- OSTI ID:
- 22039856
- Resource Relation:
- Conference: ANIMMA 2011: 2. International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications, Ghent (Belgium), 6-9 Jun 2011; Other Information: Country of input: France; 10 refs.; IEEE Catalog Number: CFP1124I-CDR
- Country of Publication:
- United States
- Language:
- English
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