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Photon spectra in NPL standard monoenergetic neutron fields
N J Roberts1, A Bennett1, S S Cheema1
1National Physical Laboratory, Nuclear Metrology Group, Hampton Road, Teddington, Middx. TW11 0LW, United Kingdom.
Radiation Protection Dosimetry
|October 11, 2023
Summary
High Purity Germanium (HPGe) detectors measured photon spectra across various monoenergetic neutron fields. This data improved photon to neutron dose equivalent ratios, enhancing radiation dosimetry accuracy.
Area of Science:
- Nuclear physics
- Radiation detection and measurement
Background:
- Accurate photon and neutron dosimetry is crucial for radiation protection.
- Previous measurements at NPL using Geiger-Muller tubes and electronic personal dosemeters had limitations in determining photon to neutron dose equivalent ratios.
Purpose of the Study:
- To measure photon spectra in monoenergetic neutron fields using a High Purity Germanium (HPGe) detector.
- To improve the accuracy of photon to neutron dose equivalent ratios for radiation dosimetry.
Main Methods:
- Utilized a High Purity Germanium (HPGe) detector to measure photon spectra at NPL across six monoenergetic neutron fields (0.144 to 16.5 MeV).
- Characterized and modeled the HPGe detector to generate a response matrix.
- Unfolded measured pulse height spectra to derive photon fluence spectra.
Main Results:
- Successfully obtained photon fluence spectra in various monoenergetic neutron fields.
- The derived spectra allowed for the refinement of photon to neutron dose equivalent ratios.
- Demonstrated an improvement over earlier dosimetry work conducted with Geiger-Muller tubes and electronic personal dosemeters.
Conclusions:
- High Purity Germanium (HPGe) detectors are effective for measuring photon spectra in monoenergetic neutron fields.
- The improved photon to neutron dose equivalent ratios enhance the accuracy of radiation dosimetry.
- This work provides valuable data for radiation protection standards and instrument calibration.
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