A NEW DOSE DETERMINATION METHOD FOR HP(3) AND DP LENS FOR BETA REFERENCE RADIATION QUALITIES.

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Computational Physics

Background:

• Accurate dose determination is crucial for radiation protection and calibration.
• Existing methods, like the ISO 6980 standard, have limitations in uncertainty for specific dose quantities.
• 90Sr/90Y beta sources are common reference fields for dosimeter calibration.

Purpose of the Study:

• To develop a novel Monte Carlo simulation-based method for reducing uncertainties in Hp(3) and Dp lens dose determination.
• To calculate conversion coefficients and factors using advanced simulation techniques.
• To improve the accuracy and applicability of dose determination in reference beta fields.

Main Methods:

• Utilized the EGSnrc Monte Carlo code for simulations.
• Calculated conversion coefficients from absorbed dose in air (Dair, det) to Hp(3; α) and Dp lens(α).
• Employed eye and head phantoms with Chinese characteristics for Dp lens calculations.

Main Results:

• Achieved uncertainty reductions of 7.7-52.8% for Hp(3; α) and 7.9-55.0% for Dp lens(α) compared to the ISO 6980 standard.
• Extended calculations to a wider range of irradiation conditions for conversion coefficients.
• Developed more suitable conversion factors for Chinese populations using specific phantoms.

Conclusions:

• The proposed Monte Carlo simulation method significantly reduces uncertainties in Hp(3) and Dp lens dose determination.
• The method provides more accurate and applicable dose conversion coefficients and factors.
• This advancement enhances the reliability of radiation dosimetry in 90Sr/90Y beta reference fields, particularly in China.