Laboratory for Particle Properties (Phi-lab)
[English | Japanese]


We try to develop the high counting rate neutron detector for experiment of compound neucleus resonanse reaction. We evaluated the maximum counting rate of LiTA12 detector system which was developed by Hokkaido University and KEK. The LiTA12 detector system combines a segmented Li-glass scintillator and a multi-anode PMT. This detector can also detect neutrons with a high counting rate because the signal from each pixel is treated individually.
The LiTA12 detector can be used for experiment under neutron-flux level about 0.8Mcps/cm^2. However, this detector didn’t meet requirement for our final experiments to search CP-violation. We have a good candidate, Boron loaded liqued scintillator. This detector has shorter decay time than Liglass scintillator. In order to constructe the DAQ system, the photomultiplier tube (PMT) output signal from a boron-loaded liquid scintillator was analyzed.

It is more diffcult to control the neutron trajectry than charged particle, becaus the electromagnetic interaction is weak for non-charge particle. We have one solution, it is neutron mirror. The neutron mirror is made by thin layers of Niand Ti. Neutrons are reflected or tarnsmitted by these stacked metal layers. As the reflectance and transmittance are depending on the energy of incident neutrons and the thickness of the layers, we chage the condition for our research situation. Now we are developing these devices for our own experiment.