Novel Boron Based Multilayer Thermal Neutron Detector

TL;DR

This paper presents a multilayer thermal neutron detector using natural Boron layers, which captures neutrons and detects resulting ionization in gas gaps, achieving efficiencies up to 12.5%.

Contribution

It introduces a novel multilayer Boron-based detector design with specific layer thicknesses and gas gap configurations for improved neutron detection.

Findings

Detector efficiency ranges from 2.9% to 12.5%.

Multiple layers increase detection efficiency.

The design effectively captures thermal neutrons.

Abstract

The detector contains four or more layers of natural Boron absorbing thermal neutrons. Thickness of a layer is 0.4 - 1.2 mg/cm2. The layers are deposited on one or on both sides of a metal surface used as contacts. Between the absorbing layers there are gas-filled gaps 3 - 6 mm thick. Electric field of 100 - 200 V/cm is applied to the gas-filled gaps. Natural Boron contains almost 20% of 10B isotope. When atoms of 10B capture a thermal neutron, nuclear reaction occurs, as a result of which two heavy particles - alpha particle and ion 7Li - from the thin absorber layer are emitted in opposing sides. One of the two particles penetrates into gas-filled gap between Boron layers and ionizes the gas. An impulse of electric current is created in the gas-filled gap actuated by the applied electric field. The impulse is registered by an electronic circuit. We have made and tested detectors containing from two to sixteen layers of natural Boron with an efficiency of thermal neutron registration from 2.9% to 12.5% accordingly.