IEC 61331-1: A new setup for testing lead free X-ray protective clothing

Area of Science:

• Medical Physics
• Radiation Protection
• Materials Science

Background:

• Lead-free protective clothing may exhibit different secondary radiation (SR) characteristics compared to lead-based materials, potentially impacting attenuation properties.
• The international standard IEC 61331-1:2014 uses the
• inverse broad beam geometry
• (IBG) method, recently updated to IBG*.
• Unspecific partial irradiation in the IBG* method can lead to inaccuracies in evaluating lead equivalence values (LEVs).

Purpose of the Study:

• To introduce and validate an alternative measurement setup, the
• modified broad beam geometry
• (BBG*), for evaluating protective clothing materials.
• To address the limitations of the IBG* method in accurately assessing LEVs, particularly for materials with significant SR contributions.
• To compare the performance of the proposed BBG* method against the established IBG* standard.

Main Methods:

• The BBG* setup was tested using Monte Carlo simulations and radiation measurements.
• Comparative analysis was performed against the IBG* method.
• Several lead-composite and lead-free protective materials were included in the study.

Main Results:

• Simulations indicated reduced SR collection efficiency with IBG* compared to BBG*.
• Materials with high SR content showed up to 8% higher LEVs when assessed with BBG* versus IBG*.
• Differences between BBG* and IBG* were generally below 3% (0.25 mm LEV) and 1% (0.50 mm LEV) for most commercially available materials, but discrepancies can lead to heavier clothing in specific cases.

Conclusions:

• The proposed BBG* setup demonstrates effective SR collection and meets IEC standard specifications for energy response.
• The BBG* method provides more accurate LEV assessments, especially for materials generating significant secondary radiation.
• Implementation of the BBG* method into the IEC standard is recommended for improved accuracy in protective clothing evaluation.