MONSTA

Measurement Of Neutrons with Scintillators in The Atmosphere



Instrument

PING - Phoswich Instrument for Neutrons and Gammas

The instrument PING has been developed in the PhD thesis of Esther M. Dönsdorf. The instrument PING (Phoswich Instrument for Neutrons and Gammas) is a so called Phoswich detector which consists of a separate cylindrical sensor head and the electronics box. The main objective of this detector is to determine the intensity of neutrons and gamma rays. The sensor head is composed of two dissimilar scintillators optically coupled to each other and to a common PMT. For this setup a combination of a fast plastic scintillator BC412 and a slow inorganic scintillator CsI(Na) is used. The pulses from the two scintillators will be separated by applying pulse shape analysis. These two different scintillator materials have been chosen because BC412 is hydrogen rich and thus the cross section for fast neutrons is relatively high and CsI(Na) has a high cross section for gamma radiation. Currently the design of the BC412 is to determine the flux of 1-100 MeV neutrons and of the CsI(Na) to register gamma rays between 363 keV and 32 MeV. Although the instrument is mainly designed to distinguish between gamma rays and neutrons it is also sensitive to charged particles.