Abstract
We have proposed the possibility of a cost-efficient way to improve the detector performance for water Cherenkov detectors, by reflecting the usually lost light falling between ...photo-detectors onto the other side of the tank with retro-reflectors. Using a detector simulation based on optical measurements of retro-reflectors, we developed a convolutional neural network-based reconstruction algorithm. Here we report on the reconstruction performance for ring events in the energy scale expected for atmospheric and accelerator neutrinos under various candidate detector configurations.
Abstract
Hyper-Kamiokande detector is proposed as a next generation underground water Cherenkov detector in Japan, and is planned to be an order of magnitude bigger than its predecessor, ...Super-Kamiokande. In order to further improve the detector capabilities in both low and high energy sectors, the multi-PMT modules instrumented with multiple 3-inch PMTs are being developed, in addition to the improved high quantum efficiency 20-inch PMTs. We developed a moveable laser system that can illuminate different positions on the photocathode to measure the characterization of the 3-inch PMTs as a function of the position on the photocathode.
Abstract
Hyper-Kamiokande is the next generation large-scale water Cherenkov detector. In Hyper-Kamiokade and Intermediate Water Cherenkov Detector for its long baseline project with J-PARC neutrino ...beam, use of multi-PMT, which is made by combination of 3-inch PMTs, is being considered. As part of multi-PMT development, we measured the characteristics of the 3-inch PMT including the temperature dependence of dark noise rate. The dark noise rate is important characteristic for detection of low energy events including neutron tagging. In addition, since PMT is generally susceptible to the magnetic field, we confirmed the photon detection efficiency in the condition where the magnetic field was applied.
The Double Chooz is a reactor neutrino experiment which measures the last unknown neutrino mixing angle
θ
13
. The Double Chooz experiment uses two identical detectors placed at sites far and near ...from Chooz reactor cores. The detector uses 390 low-background and high performance 10-in. Photo-Multiplier Tubes (PMTs) to detect scintillation light from gadolinium loaded liquid scintillator. In order to test and characterize the PMTs and to tune operation parameter, we developed two types of PMT test system and evaluated 400
PMTs before installation. Those PMTs fulfilled our requirements and half of them were installed in the far detector in 2009 and physics data have been successfully taken since 2011.
We carried out a study of neutrino detection at the experimental fast reactor JOYO using a 0.76
tons gadolinium loaded liquid scintillator detector. The detector was set up on the ground level at ...24.3
m from the JOYO reactor core of 140
MW thermal power. The measured neutrino event rate from reactor on–off comparison was 1.11±1.24(stat.)±0.46(syst.)
events/day. Although the statistical significance of the measurement was not enough, backgrounds in such a compact detector at the ground level were studied in detail and MC simulations were found to describe the data well. A study for improvement of the detector for future such experiments is also shown.
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