Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-05-31
Abstract: Neutron-sensitive microchannel plates (nMCPs) have applications in neutron detection, including energy spectrum measurements, neutron-induced cross-sections, and neutron imaging. 10B-doped MCPs (B-MCPs) have attracted significant attention owing to their potential for exhibiting a high neutron detection efficiency over a large neutron energy range. Good spatial and temporal resolutions are useful for neutron energy-resolved imaging. However, their practical applications still face many technical challenges. In this study, a B-MCP with 10 mol% 10B was tested for its response to wide-energy neutrons from eV to MeV at the Back-n white neutron source at the China Spallation Neutron Source. The neutron detection efficiency was calibrated at 1 eV, which is approximately 300 times that of an ordinary MCP and indicates the success of 10B doping. The factors that caused the reduction in the detection efficiency were simulated and discussed. The neutron energy spectrum obtained using B-MCP was compared with that obtained by other measurement methods, and showed very good consistency for neutron energies below tens of keV. The response is more complicated at higher neutron energy, at which point the elastic and non-elastic reactions of all nuclides of B-MCP gradually become dominant. This is beneficial for the detection of neutrons, as it compensates for the detection efficiency of B-MCP for high-energy neutrons.
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology submitted time 2024-05-31
Abstract: Neutron resonance imaging (NRI) has recently emerged as an appealing technique for neutron radiography. Its complexity surpasses that of conventional transmission imaging, as it requires a high demand for both a neutron source and detector. Consequently, the progression of NRI technology has been sluggish since its inception in the 1980s, particularly considering the limited studies analyzing the neutron energy range above keV. The white neutron source (Back-n) at the China Spallation Neutron Source (CSNS) provides favorable beam conditions for the development of the NRI technique over a wide neutron energy range from eV to MeV. Neutron-sensitive microchannel plates (MCP) have emerged as a cutting-edge tool in the field of neutron detection owing to their high temporal and spatial resolutions, high detection efficiency, and low noise. In this study, we report the development of a 10B-doped MCP detector, along with its associated electronics, data processing system, and NRI experiments at the Back-n. Individual heavy elements such as gold, silver, tungsten, and indium can be easily identified in the transmission images by their characteristic resonance peaks in the 1-100 eV energy range; the more difficult medium-weight elements such as iron, copper, and aluminum with resonance peaks in the 1-100 keV energy range can also be identified. In particular, results in the neutron energy range of dozens of keV (Aluminum) are reported here for the first time.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2016-09-13
Abstract: Aging experiments of a novel type of large area MCP-PMT made by JUNO collaboration were conducted.In these aging experiments, the multi-photoelectron spectrum and single photoelectron spectrum were measured daily,as well as the MCP resistance of the second PMT before and after the experiment. Two PMTs were aged successivelyfor cross check. The first PMT was aged for 52 days, while the other one was aged for 84 days. In order to study the mechanism of the aging process, the high voltage on the second PMT was increased to accelerate its aging process when the cumulative output of charge from its anode was about 4 C. From our study, it can be known that large area MCP-PMT aging had a strong relationship with the related MCPs. In accordance with the PMT aging curve,a PMT aging model was setup and a general aging formula was given.
Peer Review Status:Awaiting Review