Evaluation of 400 low background 10-in. photo-multiplier tubes for the Double Chooz experiment

Improved measurements of the neutrino mixing angle θ 13 with the Double Chooz detector

“…The boundaries of the NT, GC and Buffer are made of transparent acrylic vessels, while the Buffer volume is surrounded by a steel tank and optically separated from an outer layer described below. There are 390 low background 10-inch photomultiplier tubes (PMTs) [10,11] positioned on the inner surface of the buffer tank. Orientation and positions of the PMT assemblies and dimensions of the tank walls were verified by photographic survey.…”

Afterpulse measurements of R7081 photomultipliers for the Double Chooz experiment

“…For the two detectors a total of 780 PMTs + 23 spares were provided, about one half by German and the other half by Japanese groups. For a preselection and validation of the specifications of the 803 target PMTs two test setups were built: (A) at the "Max-Planck-Institut für Kernphysik" (MPIK) in Heidelberg in collaboration with the "RWTH Aachen University" [4] and (B) at the "Tokyo Institute of Technology" [5]. This article focuses on afterpulse measurements that have been performed with setup A.…”

Qualification tests of 474 photomultiplier tubes for the inner detector of the Double Chooz experiment

“…Each of the two inner detectors of Double Chooz will be observed by 390 photomultiplier tubes (PMTs) to record light pulses produced by neutrino-induced reactions inside the gadolinium-doped scintillator target volume. The tasks of testing and calibrating these PMTs were shared between German Figure 1: The PMT Hamamatsu R7081 and the base circuit used for Double Chooz (taken from [4] and [3]). R1, R2 = 2.5 MΩ; R3 = 180 kΩ; R4 = 1.02 MΩ; R5 = 1.5 MΩ; R6 = 1 MΩ; R7 = 499 kΩ; R8 = 300 kΩ; R9 = 360 kΩ; R10 = 430 kΩ; R11 = 680 kΩ; R12 = 910 kΩ; R13 = 750 kΩ; R20 = 10 kΩ; R21-R23 = 100 Ω; R24 = 49.9 Ω; C1-C3, C6 = 10nF; C4, C5 = 4.7 nF.…”