Development of a multi-layer high-efficiency GEM-based neutron detector for spallation sources.

Area of Science:

• Neutron detection instrumentation
• Applied physics
• Materials science

Background:

• Current neutron detection relies heavily on Helium-3 (³He) gas detectors.
• Shortages of ³He and evolving experimental needs necessitate advanced neutron detection technologies.
• High neutron flux environments demand detectors with superior performance and durability.

Purpose of the Study:

• To develop and characterize a new neutron detector utilizing Gas Electron Multiplier (GEM) technology.
• To integrate boron layers as efficient neutron converters within the GEM detector.
• To evaluate the detector's performance, including efficiency and time resolution, under high neutron flux conditions.

Main Methods:

• Fabrication of a novel detector combining Gas Electron Multiplier (GEM) foils with multiple boron layers.
• Characterization of the detector's response to thermal and epithermal neutrons at the ISIS Pulsed Neutron and Muon Source.
• Analysis of detection efficiency and time resolution.

Main Results:

• The developed detector demonstrated a good response to thermal and epithermal neutrons.
• Achieved a neutron detection efficiency of 16% for neutrons with a wavelength of 1.8 Å (25 meV).
• The detector exhibits good time resolution and capability for 2D-resolved measurements.

Conclusions:

• The boron-loaded GEM detector presents a viable and efficient alternative to traditional Helium-3 detectors.
• Its high detection efficiency and good time resolution make it suitable for advanced neutron techniques, particularly those involving high neutron fluxes.
• The detector's 2D-resolved capability enhances its utility in techniques like neutron transmission measurements.