A phoswich detector for high-energy neutrons

Area of Science:

• Nuclear Instrumentation
• Radiation Detection
• Astroparticle Physics

Background:

• Aircraft and spacecraft are exposed to complex radiation fields including neutrons, gamma rays, and protons.
• Accurate measurement of neutron energy spectra is vital for assessing radiation hazards in these environments.
• Existing detectors may struggle to discriminate between different radiation types.

Purpose of the Study:

• To develop and validate a phoswich detector for measuring neutron energy spectra.
• To achieve effective discrimination between neutrons, gamma rays, and protons.
• To assess the detector's performance in simulated and actual flight conditions.

Main Methods:

• Utilized a phoswich detector designed for neutron energy spectrum measurement.
• Particle discrimination capabilities were tested at the HIMAC facility.
• Detector response functions were simulated using MCNPX code.
• Neutron response was measured using quasi-mono-energetic neutrons from a p-Li reaction.
• Conducted test flights at altitudes of 6.5 and 8.5 km over Japan.

Main Results:

• Demonstrated excellent particle discrimination capabilities, separating neutrons from gamma rays and protons.
• Validated detector response functions through both simulation and experimental measurements.
• Successfully performed high-altitude flight measurements to assess real-world performance.

Conclusions:

• The developed phoswich detector is a capable instrument for measuring neutron energy spectra in aerospace radiation environments.
• The detector's ability to discriminate between radiation types is a significant advantage.
• Flight measurements confirm the detector's suitability for monitoring cosmic radiation.