Study on the 241Am-Be neutron reference radiation field established at CAEP

Area of Science:

• Nuclear Physics
• Radiation Metrology
• Instrument Calibration

Background:

• The China Academy of Engineering Physics (CAEP) required a characterized neutron radiation field for instrument calibration.
• Existing facilities needed validation against established standards like ISO 8529.

Purpose of the Study:

• To evaluate the field characteristics of the 241Am-Be neutron reference radiation field at CAEP.
• To assess the instrument calibration capability within this established field.
• To ensure the field meets requirements for routine calibration and experiments.

Main Methods:

• Neutron energy spectrum analysis using multi-sphere spectrometer and Geant4 simulations.
• Quantity transmission verification via a precision long counter system between China Institute of Atomic Energy (CIAE) and CAEP.
• Calibration of three neutron dose rate meters from different manufacturers in both CAEP and CIAE fields.
• Uncertainty analysis of calibration factors for the calibrated instruments.

Main Results:

• The neutron radiation field at CAEP demonstrated acceptable room scatter, meeting ISO 8529 requirements.
• The measured neutron energy spectrum was deemed acceptable.
• The range and uncertainty of neutron ambient dose equivalent rate at CAEP were determined.
• Calibration factors and their uncertainties were found to be reasonable and reliable when validated across both fields.

Conclusions:

• The established 241Am-Be neutron radiation field at CAEP is suitable for routine calibration and experimental use.
• The field's characteristics and calibration capabilities have been successfully evaluated and validated.
• The study confirms the reliability of instruments calibrated within the CAEP neutron reference field.