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The recent statement on tissue reactions issued by the International Commission on Radiological Protection in April 2011 recommends a very significant reduction in the equivalent dose annual limit for the eye lens from 150 to 20 mSv y(-1); this has stimulated a lot of interest in eye lens dosimetry in the radiation protection community. Until now no conversion coefficients were available for the operational quantity Hp(3) for neutrons. The scope of the present work was to extend previous evaluations of H*(10) and Hp(10) performed at the PTB in 1995 to provide also Hp(3) data for neutrons. The present work is also intended to complete the studies carried out on photons during the last 4 y within the European Union-funded ORAMED (optimisation of radiation protection for medical staff) project.

In the framework of the ORAMED project (Optimization of RAdiation protection for MEDical staff), funded by the European Union Seventh Framework Programme, different studies were aimed at improving the quality of radiation protection in interventional radiology and nuclear medicine. The main results of the project were presented during a final workshop held in Barcelona in January 2011, the proceedings of which are available in the open literature. One of the ORAMED tasks was focused on the problem of eye-lens photon exposure of the medical staff, a topic that gained more importance especially after the ICRP decision to lower the limiting equivalent dose to 20 mSv per year. The present technical note has the scope, besides briefly summarising the physical reasons of the proposal and the practical implications, to provide, in tabular form, a set of air kerma to Hp(3) conversion coefficients based on the adoption of a theoretical cylindrical model that is well suited for reproduction of the mass and the shape of a human head.

In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.

Photons conversion coefficients from 20 keV to 100 MeV have been calculated with the voxel model NORMAN-05 using the MCNPX code. Both kerma approximation and electronic transport were employed and the results compared with published data. In the near future, ICRP group DOCAL will issue a new computational model, based on the GSF-GOLEM, which is intended to be the reference adult male voxel model for ICRP. NORMAN-05 well approximates the western-caucasian standard man characteristics, in terms of body height (176 cm) and mass (73 kg) and masses of the organs. It is not intended to substitute, or to be an alternative, to the future official ICRP voxel model, but thanks to its accuracy and its "standard man structure" can be useful to evaluate the intrinsic uncertainties associated with the dose quantities evaluated adopting different voxel models. For such reason data obtained with NORMAN-05 could be easily compared with those that will be derived from the future ICRP model.

'QUADOS', a concerted action of the European Commission, has promoted an intercomparison aimed at evaluating the use of computational codes for dosimetry in radiation protection and medical physics. This intercomparison was open to all users of radiation transport codes. Eight problems were selected for their relevance to the radiation dosimetry community, five of which involved photon and proton transport. This paper focuses on a discussion of lessons learned from the participation in solving the photon and charged particle problems. The lessons learned from the participation in solving the neutron problems are presented in a companion paper (in this issue).

QUADOS, a Concerted Action of the European Commission, has promoted an intercomparison aimed at evaluating the use of computational codes for dosimetry in radiation protection and medical physics. This intercomparison was open to all users of radiation transport codes. Eight problems were selected for their relevance to the radiation dosimetry community, five of which involved photon and proton transport. This paper focuses on the analysis of the photon and charged particle problems. The neutron problems were presented in a paper at the NEUDOS9 conference.

Abstract: Due to the need for accurate neutron spectrum measurements in environments characterized by very high neutron and photon fluence rates, such as medical LINACs and the target area of particle accelerators, many research groups have adopted gold activation detectors inside Bonner sphere based instruments. Consequently, several response matrices have been derived. Nevertheless, the validation of such functions with reference neutron fields is still a difficult task, due to the limited availability of high fluence rate calibration facilities. An Italian collaboration, coordinated by the Radiation Protection Group of the Frascati National Laboratories, calculated the response matrix of a commercial BSS equipped with gold foils (0.1mm diameter) and performed a validation experiment with a 252Cf source available at the ENEA-Bologna calibration laboratory. As a result, a spectrometric system with known accuracy is now available for workplace measurements. This work gives the details of the calculations, performed with MCNP, and shows the results of the validation experiment. [Copyright &y& Elsevier]

Abstract: This communication summarizes the results concerning the Monte Carlo (MC) modelling of Germanium detectors for the measurement of low energy photons arising from the “International comparison on MC modelling for in vivo measurement of Americium in a knee phantom” organized within the EU Coordination Action CONRAD (Coordinated Network for Radiation Dosimetry) as a joint initiative of EURADOS working groups 6 (computational dosimetry) and 7 (internal dosimetry). MC simulations proved to be an applicable way to obtain the calibration factor that needs to be used for in vivo measurements. [Copyright &y& Elsevier]