No Arabic abstract
The Large High Altitude Air Shower Observatory (LHAASO) is planned to be built at Daocheng, Sichuan Province, China. The water Cherenkov detector array (WCDA), with an area of 78,000 m2 and capacity of 350,000 tons of purified water, is one of the major components of the LHAASO project. A 9-cell detector prototype array has been built at the Yangbajing site, Tibet, China to comprehensively understand the water Cherenkov technique and investigate the engineering issues of WCDA. In this paper, the rate and charge distribution of single-channel signals are evaluated using a full detail Monte Carlo simulation. The results are discussed and compared with the prototype array.
The Large High-Altitude Air Shower Observatory (LHAASO) is being built at Haizi Mountain, Sichuan province of China at an altitude of 4410 meters. One of its main goals is to survey the northern sky for very-high-energy gamma ray sources via its ground-based water Cherenkov detector array (WCDA). 900 8-inch photomultiplier tubes (PMTs) CR365-02-1 from Beijing Hamamatsu Photon Techniques INC. (BHP) are installed in the WCDA, collecting Cherenkov photons produced by air shower particles crossing water. The design of the PMT base with a high dynamic range for CR365-02-1, the PMT batch test system, and the test results of 997 PMTs are presented in this paper.
MEMPHYS (MEgaton Mass PHYSics) is a proposed large-scale water-Cherenkov experiment to be performed deep underground. It is dedicated to nucleon decay searches and the detection of neutrinos from supernovae, solar, and atmospheric neutrinos, as well as neutrinos from a future beam to measure the CP violating phase in the leptonic sector and the mass hierarchy. This paper provides an overview of the latest studies on the expected performance of MEMPHYS in view of detailed estimates of its physics reach, mainly concerning neutrino beams.
A scaler has been fabricated to count the signals from any radiation de- tector. It can count signals of frequency up to 140 kHz. Transistor Transistor Logic (TTL) is used in this scaler. In this article the details of the design, fabrication and operation processes of the scaler is presented.
The novel idea of water Cherenkov calorimeter made of water tanks as the next generation neutrino detector for nu factories and nu beams is investigated. A water tank prototype with a dimension of 1*1*13m^3 is constructed, its performance is studied and compared with a GEANT4 based Monte Carlo simulation. By using measured parameters of the water tank, including the light collection efficiency, attenuation length, angular dependent response etc, a detailed Monte Carlo simulation demonstrates that the detector performance is excellent for identifying neutrino charged current events while rejecting neutral current and wrong-flavor backgrounds.
The water at the proposed site of the CHIPS water Cherenkov detector has been studied to measure its attenuation length for Cherenkov light as a function of filtering time. A scaled model of the CHIPS detector filled with water from the Wentworth 2W pit, proposed site of the CHIPS deployment, in conjunction with a 3.2unit{m} vertical column filled with this water, was used to study the transmission of 405nm laser light. Results consistent with attenuation lengths of up to 100m were observed for this wavelength with filtration and UV sterilization alone.