The SISWICH, a detector telescope with intrinsic calibration

Phoswich counters provide adequate energy resolution and particle identification up to atomic numbers Z=20, but calibration has proved difficult. To overcome this difficulty, a silicon-scintillator sandwich (SISWICH) has been built. This detector consists of a Si PIN photodiode glued to the front of a CsI(Tl) scintillator crystal. The signal coming from the PIN diode contains the energy deposited by the particle by direct ionization in the silicon, which is very fast, and the light output of the scintillator, which is slow. The direct component can be calibrated against a pulser. Since the energy loss of a particular particle has been measured, its energy is known, and this can be used to calibrate the signal from the scintillator