2023, 40(1): 66-72.
doi: 10.11804/NuclPhysRev.40.2022108
Published:2023-03-20
Keywords:
silicon photomultiplier tube ,
gain ,
avalanche breakdown voltage ,
temperature characteristics ,
neutron detection
In order to fulfill the requirements of the engineering material diffraction spectrometer of China Spallation Neutron Source(CSNS), a new integrated and modular scintillator detector based on Silicon Photomultiplier(SiPM) readout is designed and constructed by the Neutron Detector Group of the CSNS. In this paper, the characteristics such as breakdown voltage, gain, temperature characteristics and dark count rate of Sensl MicroFJ-30035-TSV and Hamamatsu S13363-3050NE-16 model SiPM are tested. The results show that the performance of the two SiPM including the single-photon resolution, gain, dark count rate can meet the requirements of the scintillator detector. The gain of Sensl SiPM is higher than that of Hamamatsu SiPM in the same overbias and the latter is more sensitive to temperature. The temperature compensation coefficient of the Sensl and Hamamatsu SiPM are 22.0 and 53.6 mV/°C respectively, which will provide reference for the design of temperature compensation circuit of SiPM. The prototype of a scintillator detector based on the above two SiPM readout was developed and the detection efficiency of the detector has been tested on the BL09 of CSNS. The results show that the detection efficiency of detector equipped with Sensl SiPM or Hamamatsu SiPM is 76% and 68% for 2.8 Å neutrons, respectively. The results of this paper will provide reference for the selection of SiPM for the developed scintillator detector and other SiPM-based detectors.
2021, 38(2): 190-195.
doi: 10.11804/NuclPhysRev.38.2020058
Published:2021-06-20
Since neutron sensitive microchannel plates (nMCP) has high detection efficiency and the spatial resolution, combined with advanced readout electronics it can be a better choice for energy-resolved neutron imaging detectors. Compared with the matrix-doped nMCP, the nMCP based on Atomic Layer Deposition(ALD) has the advantages of less neutron sensitive material consumption and high secondary electron emission coefficient on the inner wall of the channel. Firstly, the typical neutron and gamma signal of natGd-doped nMCP were studied experimentally. Geant4 simulation and theoretical calculation were performed to optimize the pore diameter, wall thickness, bias angle and coating thickness of the coated 10B2O3 nMCP. It was shown that the thermal neutron detection efficiency was about 56% and the spatial resolution was about 22 μm when the coating thickness was 1 μm, the pore diameter was 10 μm, the wall thickness was 1 μm and the bias angle was 3°. The results are of great significance to the geometric parameter design of nMCP used as energy-resolved neutron imaging detectors at CSNS.