Multiplate Shower Counter for High Energy Gamma Rays

Abstract

A type of total absorption photon counter was constructed and calibrated. It is a multiplate shower detector composed of seventeen 10‐mm‐thick sheets of plastic scintillator, sandwiched by sixteen 3‐mm‐thick sheets of lead. The total radiation length of the counter is 9.5 radiation lengths. The scintillation light produced in the plastic sheets is detected by four phototubes. The two counters constructed were calibrated by using electrons over the energy range from 60–600 MeV, and they showed the same characteristics. The energy response of the output pulse height from either counter is nearly proportional to the energy of incident electrons over the range studied, and the energy spread of the counter, defined by the full‐width of the distribution at the half‐maximum, ΔE over E, is about 30% at 600 MeV and proportional to E^−1/2.