Phototube response for a multielement Optical Module A
Phototube response for a multi-element Optical Module A. Mjös H. Löhner P. Lubberdink N. Kalantar A. B. C. KVI Groningen in collaboration with NIKHEF Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 1
Motivation Antares: 10” PM noise, trigger selectivity multi-PM configuration: 3” PM larger field of view, low Candidate: Photonis XP 53 x 2 (or modification) produced in large quantities, available for selection Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 2
Outline 3” XP 53 X 2 • PMT: Photonis • Test Setup • Light pulser • Analysis 3” XP 3330 • Measurements • Results • Future investigations Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 3
Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 4
Test Setup Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 5
LED Light pulser previous pulser Pylos, April 2007 light intensity variable by LED supply voltage, neutral-density filters present pulser H. Löhner - PM studies for multi-PM OM 6
charge vs. supply voltage XP 53 X 2 typ. spread in gain requires selection and sufficient dynamic range Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 7
surface sensitivity XP 53 X 2 at max. gain: 4 x 106 (1500 V) t 1 ns photocathode area Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 8
Time over threshold sufficient sensitivity Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 9
Charge spectrum XP 53 X 2 at max. gain: 4 x 106 (1500 V) s. p. e. dark rate typ. 5 k. Hz peak/valley 2. 4 charge threshold: 0. 25 s. p. e. Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 10
electronic noise / base design = 0. 11 m. V = 0. 05 m. V less critical threshold setting Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 11
10 stage tube: XP 3330 at gain: 4 x 106 (1100 V) peak/valley 2. 1 Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 12
Temperature dependence of dark rate XP 3330 at gain: 8 x 106 (1200 V) Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 13
Comparison should be improved Peak/valley 2. 79 0. 46 2. 4 Dark Noise (Hz) 1880 1078 5500 2. 1 3100 150 ideal solution: XP 53 X 2 with 10 stages; can be realized within 10 weeks (Photonis offer) Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 14
Summary • • Test setup for systematic measurements 3” PM XP 53 X 2 sensitive to s. p. e. at maximum gain Peak/valley = 2. 4 Position and angle-of-incidence dependence over cathode area within 10 % • Time spread over cathode area within 1 ns • Time-over-threshold analysis yields 4 ns/p. C 4 ns / s. p. e. • Improvement on dark noise: a) voltage-multiplying base for XP 53 X 2 (9 stage) (in progress at NIKHEF, prototype available) b) use 10 -stage PM: good results with XP 3330 (150 Hz) Ideal and viable solution: XP 53 X 2*(10 stage) Pylos, April 2007 H. Löhner - PM studies for multi-PM OM 15
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