Time and position sensitive single photon detector for scintillator read-out

TL;DR

This paper presents a novel photon counting detector system capable of determining position, time, and intensity of photon flashes in scintillators, suitable for high-throughput neutron and gamma radiography applications.

Contribution

The development of a fast, position- and time-sensitive photon detector with pulse-height discrimination for combined neutron and gamma imaging systems.

Findings

Demonstrated effective position and time resolution in tests.

Implemented a pulse-height-to-time converter circuit for energy discrimination.

Showed suitability for automated cargo inspection systems.

Abstract

We have developed a photon counting detector system for combined neutron and gamma radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy gamma radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate gamma energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).