A simple physical phantom for an intercomparison exercise on 241Am activity determination in the skull

Area of Science:

• Nuclear physics
• Medical physics
• Radiological protection

Background:

• Accurate determination of Americium-241 (241Am) activity in the skull is crucial for radiological protection.
• Existing phantoms may not fully represent the complexities of human skull composition for 241Am measurements.
• The EURADOS intercomparison exercise (2011-13) required a standardized phantom for reliable activity assessment.

Purpose of the Study:

• To design and prepare a simple hemispherical phantom for the EURADOS intercomparison exercise on 241Am activity determination in the skull.
• To create a voxelized representation of the phantom for simulation purposes.
• To validate the phantom design through comparison with real measurement data.

Main Methods:

• A three-part hemispherical phantom was constructed, simulating bone and soft tissues.
• Americium-241 (241Am) was deposited onto the bone-substituting component.
• A voxel representation of the phantom was prepared for computational modeling.
• Simulated measurement spectra were compared with those from the physical phantom.

Main Results:

• The designed phantom successfully mimics bone and soft tissue components relevant to 241Am deposition.
• The voxel representation accurately reflects the physical phantom's geometry and composition.
• Spectra from real measurements of the physical phantom showed good agreement with simulation results.

Conclusions:

• The developed hemispherical phantom and its voxel model are suitable for the EURADOS intercomparison exercise.
• The phantom provides a reliable tool for standardizing and improving 241Am activity determination in skull phantoms.
• The validated phantom and its digital counterpart will be supplied to intercomparison participants.