Optimizing non-Pb radiation shielding materials using bilayers

Area of Science:

• Materials Science
• Medical Physics
• Radiation Protection

Background:

• Traditional lead (Pb) shielding materials pose weight and toxicity concerns for radiation shielding garments.
• Developing effective non-Pb alternatives is crucial for improving the safety and comfort of personnel working with ionizing radiation.

Purpose of the Study:

• To demonstrate that non-Pb radiation shielding material weight can be minimized.
• To achieve this by structuring materials as bilayers of metal-powder-embedded elastomer layers.

Main Methods:

• Utilized Monte Carlo (MC) calculations and experimental measurements to assess attenuation properties of non-Pb metal bilayers.
• Studied x-ray energy range from 30-150 keV using metals chosen for cost, non-toxicity, and complementary photoelectric absorption.
• Employed EGSnrc user code cavity.cpp for spectral calculations and calibrated beams at the Institute for National Measurement Standards for air kerma attenuation measurements.

Main Results:

• The low-Z (atomic number) upstream/high-Z downstream metal bilayer configuration significantly enhanced attenuation compared to the reverse order.
• Determined optimal metal percentages within each bilayer for specific x-ray radiation beam qualities.
• Achieved substantial x-ray attenuation with non-Pb materials.

Conclusions:

• Appropriate selection of two complementary metal-embedded elastomer layers can reduce radiation shielding garment weight by up to 25% compared to lead-based garments.
• These non-Pb materials provide equivalent radiation attenuation.
• This offers a promising avenue for lighter and safer radiation shielding solutions.