1. Characterization of the ETEL and HZC 3+ inch PMTs
R.Bormuth, L.Classen, O.Kalekin*, J.Reubelt, D.Samtleben, E.Visser for the KM3NeT Collaboration
VLVnT13, Stockholm, Sweden

2. KM3NeT Digital Optical Module (DOM)
31 ~3 inch photomultiplier tubes (PMTs) 17 inch glass sphere Digitized data: Time-over-Threshold (ToT) First DOM is operational in Antares since April 2013 (T.Michael, Deep-sea and deep- ice technology session)
O. Kalekin: ETEL and HZC PMTs

3. PMTs and test sites
Hamamatsu R (E.Leonora, G.Bourlis, this session)
This talk:
ET Enterprises Ltd (ETEL, UK)
D783KFLA, D793KFLA – 77 mm
104 pc 10 pc
D792KFLA – 86 mm
12 pc
HZC (China) XP53
7 pc mm
Test sites:
Hellenic Open University, Nikhef, LNS INFN Catania and ECAP
O. Kalekin: ETEL and HZC PMTs

4. KM3NeT specification for 3” PMTs
404nm: 25% min. – 28% typ. 470nm: 18% min. – 20% typ. HV for 3x106 gain: V Gain slope: 6.5 min. – 8.0 max. Transit Time Spread (TTS): 5.0ns max – 4.5ns typ. (FWHM) Dark count rate: 1.50 kHz max. – 1.25 kHz typ. Prepulses: 1% max. Delayed pulses: 3.5% max. Early afterpulses: 2% max. Late afterpulses: 10% max.
O. Kalekin: ETEL and HZC PMTs

5. Measurement setup For all measurements except QE In Nikhef
O. Kalekin: ETEL and HZC PMTs

6. QE measurement setup
In ECAP
O. Kalekin: ETEL and HZC PMTs

7. Dark rate
1.50 kHz max
D783
D792
D793
O. Kalekin: ETEL and HZC PMTs

8. Gain
Slope 6.5 min. – 8.0 max.
D783
D792
D793
O. Kalekin: ETEL and HZC PMTs

9. TTS
5.0 ns max (FWHM)
D783
D793
D792
O. Kalekin: ETEL and HZC PMTs

10. Delayed pulses
3.5% max
D783
D792
D793
O. Kalekin: ETEL and HZC PMTs

11. Late afterpulses
10% max
D783
D792
D793
O. Kalekin: ETEL and HZC PMTs

12. Quantum efficiency
404nm: 25% min. – 28% typ. 470nm: 18% min. – 20% typ.
D792
O. Kalekin: ETEL and HZC PMTs

13. D792: potential problems Internal reflective coating not plain
Inserting into support structure
External rubber coating:
more friction
not perfectly shaped
O. Kalekin: ETEL and HZC PMTs

14. HZC XP53
O. Kalekin: ETEL and HZC PMTs

15. HZC XP53 Dark rate: 1.50 kHz max. Late afterpulses: 10% max.
O. Kalekin: ETEL and HZC PMTs

16. Conclusions ETEL D792 PMTs: Meet KM3NeT specifications
Mechanical properties to be investigated
Detection efficiency / effective area to be measured
HZC XP53 PMTs:
Improvement of dark count rate, late afterpulses and gain needed
O. Kalekin: ETEL and HZC PMTs