Calculation of Attenuation Parameter for Ir-192 Gamma Source in Shielding Materials

Area of Science:

• Nuclear Engineering
• Materials Science
• Radiation Physics

Background:

• Photon attenuation calculations are crucial for selecting appropriate shielding materials in irradiation facilities.
• High-energy gamma sources require effective shielding to ensure safety and operational integrity.

Purpose of the Study:

• To evaluate the radiation shielding effectiveness of clay-polyethylene mixtures and clay for high-energy gamma sources (Iridium-192).
• To compare the performance of these novel materials against ordinary concrete as a benchmark shielding material.

Main Methods:

• Monte Carlo simulation was employed to model and calculate photon attenuation.
• Linear attenuation coefficients (μ) were determined for ordinary concrete, clay, and clay-polyethylene mixtures.
• Simulations were validated against standard XCOM data for a 380 keV photon source.

Main Results:

• Calculated linear attenuation values for ordinary concrete closely matched XCOM data (within 0.44% for 380 keV).
• For the Ir-192 source, ordinary concrete showed higher attenuation coefficients than clay (15.5% higher) and clay-polyethylene (7.25% higher).
• Clay-polyethylene exhibited a 8.3% higher linear attenuation coefficient compared to pure clay.

Conclusions:

• A 10 cm thickness of clay and clay-polyethylene mixture is sufficient to attenuate 87% and 89% of photons from an Ir-192 source, respectively.
• The simulated linear attenuation coefficients for all three materials were consistently higher than XCOM values for 380 keV photons.
• Clay-based materials present a promising alternative for radiation shielding applications, offering comparable or improved performance in specific scenarios.