Evaluation of Phoswitch-type scintillation detector to distinguish low-energy charged particles

It is indispensable for describing the equation of state of nuclear matter that we clarify the property of atomic nuclei not only at standard density but also at low density. One of the theoretically predicted states at low nucleon density is a superfluid condensate of alpha particles. Identifying this state can help describing the equation of state, and therefore, much efforts to search for a condensate of alpha particles have been devoted.

Since a condensate of alpha particles decays by emitting multiple low-energy alpha particles, we can identify the condensate by detecting these decay particles. However, conventional detectors are not suitable for such measurements because these detectors are not useful to distinguish low-energy alpha particles from other charged particles. We need a new type of detector to solve this difficulty.

We develop a Phoswitch-type scintillation detector, in which a thin layer of scintillation material is fabricated on inorganic scintillation crystal with different time constants. This layer effectively works as a very thin transmission detector which low-energy particles can penetrate, and at the same time has sufficient detection efficiency. In the present talk, we will report details about this detector and its performance.