Synchrotron radiation shielding design and ICRP radiological protection quantities

Area of Science:

• Medical Physics
• Radiation Protection
• Particle Accelerator Technology

Background:

• Radiological protection relies on quantities defined by ICRP and ICRU.
• Protection quantities, such as effective dose, have evolved since the 1980s, impacting conversion coefficients.
• Synchrotron radiation shielding requires accurate dose assessment using appropriate conversion factors.

Purpose of the Study:

• To evaluate the impact of different ICRP photon dose conversion coefficient versions on synchrotron radiation shielding calculations.
• To compare effective dose equivalent (ICRP 51) and effective dose (ICRP 74, 116) conversion coefficients.
• To determine if the choice of ICRP version influences shielding design decisions for experimental enclosures.

Main Methods:

• Calculated synchrotron radiation shielding using three ICRP photon dose conversion coefficient sets (ICRP 51, 74, 116).
• Modeled radiation leakage from a bending magnet, undulator, and wiggler sources with energies up to 500 keV.
• Assessed shielding effectiveness against a design criterion of <0.5 µSv/h radiation leakage.

Main Results:

• Higher calculated dose rates were observed using the older ICRP Publication 51 coefficients.
• The percentage differences in calculated dose rates decreased with the addition of shielding.
• The selection of ICRP conversion coefficients did not alter the final shielding decision for the experimental enclosure.

Conclusions:

• The evolution of ICRP dose conversion coefficients has a quantifiable effect on initial dose rate calculations.
• For the specific shielding scenario studied, the choice of ICRP version did not compromise the final shielding design.
• This highlights the importance of using updated ICRP recommendations while confirming robustness in shielding design.