Development of scintillation counter with ultra high time resolution and its application to research of fragment momentum distributions

The measurement of the time of flight of charged particles by a fast scintillation counter can give the accurate particle velocity that is important information for particle identification. In order to improve the resolution of particle identification, it is effective to improve the velocity resolution, namely, the time resolution of the scintillation counter. Recently, Hamamatsu Photonics Co., Ltd. developed a new type of ultra high speed photomultiplier tube. On the other hand, Eljen technology develops high-speed scintillators. In this study, we developed a scintillation counter with an extremely good time resolution by combining these two. As an application of the detector developed in this research, we consider the following. In this research, we aim to measure the momentum distribution of 15N produced in the one neutron removal reaction of 16N secondary beam using the developed counter.

In order to test the performance of this detector, we measured the time resolution using primary beams such as 132 Xe at 420A MeV and others at the HIMAC synchrotron accelerator facility at National Institute of Radiological Sciences. In the presentation we will report on the final results of this test experiment.