ISO 4037:2019 VALIDATION OF RADIATION QUALITIES BY MEANS OF HALF-VALUE LAYER AND HP(10) DOSIMETRY.

Radiation qualities were characterised and validated at the fully automated X-ray calibration facility of the Individual Monitoring Service at Helmholtz Zentrum München by using half-value layer and Hp(10) dosimetry approaches specified in the updated ISO 4037:2019 standard. As the ISO 4037 contains a somewhat vague description of the half-value layer procedure, we extended it to be more constrained and thus less subjective in its implementation. We specify both the measurement and data analysis steps performed in order to provide reproducible half-value layer results and compare the results with the Hp(10) dosimetry-based validation approach specified in the ISO 4037 as an alternative for field validation. Finally, we discuss the implications of our results and the extended procedure on validation and the recent changes to the ISO 4037.

SIMULATION OF OSL AND TLD DOSEMETER RESPONSE FOR THE DEVELOPMENT OF NEW EXTREMITY DOSEMETERS.

The individual monitoring service at the Helmholtz Zentrum München is currently developing a new eye lens dosemeter to be integrated in radiation protection glasses and a new ring dosemeter using a new BeOSL detector element for extremity dosimetry developed by Dosimetrics. In the design process for the new eye lens dosemeter, MCNP6 Monte Carlo simulations were used to model the energy and angular response of new dosemeters before ordering the expensive tools for injection molding. This study describes the simulation of the dosemeter and detector, and the involved calculations do obtain the response in terms of the radiation protection quantity Hp(3). Simulations were carried out also for existing whole body dosemeters and TLD rings in order to verify the MC tools. With the final dosemeter prototypes becoming available earlier this year, all MC models could be verified and show very good agreement with experimental data.

A FULLY AUTOMATED SECONDARY STANDARD X-RAY CALIBRATION FACILITY FOR PERSONAL DOSEMETERS.

The individual monitoring service at the Helmholtz Zentrum München has extended the calibration facilities provided at the Munich IAEA/WHO secondary standard dosimetry laboratory with a new fully automated X-ray calibration facility for the calibration of personal dosemeters according to the ISO 4037 standard series. This work describes the X-ray irradiation system and the automated dosemeter transport system as well as the measurements performed to characterize the photon fields and to ascertain conformity to the ISO standard. Standard uncertainties of the radiation quantities provided by the system are given together with a discussion of some of the problems that are encountered in fulfilling the requirements of a matched field according to the latest drafts of the ISO 4037-1 standard.