Introduction

The Gd‐lined plastic scintillator system is designed to detect and discriminate gamma and neutrons emitted by radioactive sources to identify the presence of potential threats. The layout of the system is optimized for use in Radiation Portal Monitors for vehicle and cargo screening. Performances established in realistic tests have shown that the system meets or exceeds international standards for these applications.

Technical features

The detector consists of an assembly of plastic scintillator slabs coupled with photomultipliers (PMT) and separated by thin foils with gadolinium-oxide coating. The system is capable of simultaneously detecting  gamma and neutrons and to discriminate them based on the different interaction topology. The real time analysis of the PMT signals provides an estimate of the gamma and neutron rate incident on the detector. An increase of the rates, in particular for neutrons, is a direct indication of the presence of radioactive or nuclear material. This technology provides means to detect the presence of gamma and neutron sources such as Special Nuclear Materials with the sensitivity requested by international standards for Radiation Portal Monitors.

Possible Applications

• Gamma and neutron detection;
• Radiation detectors;
• Radiation portal monitors.

Advantages

• High sensitivity to gamma and neutrons over a broad energy range;
• Large detection surface/volume;
• Low neutron background and high discriminating power;
• Easily available components.