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The individual monitoring service Seibersdorf uses two different passive dosemeter types based on thermo luminescence (TL) detectors for monitoring occupationally exposed persons in Austria. Whole body personal dosemeters for the personal dose equivalent quantities H p (10) and H p (0.07) worn on the trunk and dosemeters for the extremities for H p (0.07) worn on a finger or wrist. Both routine dosemeters were calibrated and tested in terms of the personal dose equivalent H p (3) assuming that the whole body dosemeter is worn on the chest (without or above a lead apron) and the modified ring/wrist dosemeter using a special strap worn on the forehead near the eyes (head band dosemeter). The test results show that it is possible to measure the dose quantity H p (3) with these dosemeters that were originally not designed for this dose quantity. Only changes in the dose calculation algorithm and in the choice of the reference radiation quality were necessary to fulfil the requirements given in international standards for passive dosemeters in a wide energy (20 keV–1.3 MeV) and angular range (0°–60°).

At the accredited PSI Calibration Laboratory neutron reference fields traceable to the national standards of the Physikalisch-Technische Bundesanstalt (PTB) in Germany are available for the calibration of ambient and personal dose equivalent (rate) meters and passive dosimeters. The photon contribution to the ambient dose equivalent in the neutron fields of the 252Cf and 241Am–Be sources was measured using various photon dose rate meters and active and passive dosimeters. Measuring photons from a neutron source usually involves considerable uncertainties due to the presence of neutron induced photons in the room, due to a non-zero neutron sensitivity of the photon detector, and last but not least due to the energy response of the photon detectors. Therefore eight independent detectors and methods were used to obtain a reliable estimate for the photon contribution of the two sources as an average of the individual methods. For the 241Am–Be source a photon contribution of approximately 4.9% was determined and for the 252Cf source a contribution of 3.6%.

Dosimetry studies are of increasing interest in diagnostic high-dose applications such as computed tomography especially for examinations of children. A routine CT scan protocol for paediatric head and neck imaging was investigated at a new multi-detector CT scanner using LiF:Mg,Cu,P thermoluminescence dosemeters (TLDs) and a 0.125 cm3 thimble ionization chamber. Calibrations of the detectors in terms of absorbed dose to water were carried out at the Dosimetry Laboratory Seibersdorf in standard radiation fields. The dosimetry method was validated in the spiral CT X-ray field by comparing TLD and ionization chamber measurement results in cylindrical PMMA phantoms. Absorbed dose results were within stated uncertainties. An anthropomorphic phantom representing a child of about 5 years was loaded with TLD chips at various organ and tissue positions in the head and neck region as well as at some critical organ locations. Organ dose values were calculated from TLD based average absorbed dose with about 5% total uncertainty, e.g. 22 mGy (eyes), 21 mGy (thyroid), 19 mGy (brain), 3.4 mGy (thymus), and 0.03 mGy (testes). For comparison purposes an effective dose of 1.9 mSv was estimated for the investigated paediatric CT examination based on ICRP-103 age-independent tissue-weighting factors.

This paper presents the results of an uncertainty assessment and a comparison study of dose algorithms for H(p)(10) and H(p)(0.07) used for evaluating a routine two-element thermoluminescent whole-body dosemeter. Due to the photon-energy response of the two different filtered LiF:Mg,Ti detector elements, the application of a dose algorithm is necessary to assess the relevant photon doses over the rated energy range with an acceptable energy dependence. A linear dose algorithm with two different sets of parameters was designed to assess the personal dose equivalent in the relevant quantity H(p)(10) and H(p)(0.07). Based on the experimental results from calibrations on the ISO water slab phantom, a detailed uncertainty analysis was performed by means of Monte-Carlo (MC) techniques and other analytical methods. The uncertainty contribution of the individual detector element signals was taken into special consideration. For this analysis, realistic energy and angular distributions were applied to calculate the dosemeter response. It is concluded that the MC method is an appropriate tool to perform uncertainty calculations. The possibility to assign arbitrary probability density functions to the input quantities, as well as to define a complex model function (dose algorithm) allows the simulation of irradiation conditions close to reality.

In August 2009, almost 1000 passive extremity dosemeters were irradiated at the Dosimetry Laboratory Seibersdorf as part of the EURADOS intercomparison IC2009. Forty-four European individual monitoring services participated, with a total of 59 dosimetry systems (46 finger ring, 4 finger tip and 9 wrist/ankle dosemeter systems). Additionally, finger-ring dosemeters from the Dosimetry Service Seibersdorf were irradiated in a non-competitive manner. Dosemeter irradiations on rod and pillar phantoms in four photon-radiation fields complying with the ISO standard 4037 were performed with personal dose equivalent values (H(p)(0.07)) ranging from 4 to 480 mSv. Traceability was established by using an air-kerma-calibrated monitor ionisation chamber together with the X-ray facility as well as a calibrated (137)Cs gamma radiation field with a collimated beam geometry. The ISO-tabulated conversion coefficients from air kerma free-in-air to H(p)(0.07) were applied, resulting in the main contribution to the expanded measurement uncertainties.

The energy and angular response of the MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) TL detectors inside the RADOS personal dosemeters to X-rays photons in the energy range 16–250 keV and incidence angles 0°, 30°, 40°, 50°, ± 60 ∘ and 137 Cs and 60 Co sources was measured. The irradiations were performed at the Dosimetry Laboratory of the Austrian Research Centers Seibersdorf. The dosemeters were centered on the front surface of the ISO water slab phantom ( 30 × 30 × 15 cm 3 ) and irradiated with reference photon radiation qualities N (the narrow spectrum series), and S–Cs and S–Co nuclide radiation qualities, specified in ISO 4037 (1999) . In addition, the energy response to photons of the dosemeter with MCP-N detectors has been calculated using the Monte Carlo transport code MCNP5. The simulation model of the personal dosemeter badge was set up according to the technical drawings. The results of simulations are in good agreement with measurements, except at the lowest (16 keV) photon energy. The results have confirmed that the RADOS personal dosemeter with MTS-N detectors (used by LADIS dosimetry service of the IFJ, Krakow) fulfils the requirements setup in the IEC 61066 (2006) technical recommendations for TL systems for personal dosimetry. These requirements are also fulfilled by the RADOS dosemeter equipped with highly sensitive MCP-N detectors.

This paper presents the results of a comparison of four different dose algorithms used for evaluating a two element TL routine whole body dosemeter. Due to the energy response of LiF:Mg,Ti detectors a dose algorithm is applied to assess the relevant dose over the rated energy range with an acceptable energy response. The discussed dose algorithms are designed to calculate the dose in terms of three different dose quantities. The first two algorithms are used to evaluate the dose quantity photon dose equivalent H x . This quantity was the legal quantity in Austria and Germany for the last decades. The other two algorithms are designed for reading out the dosemeter in terms of the dose quantities personal dose equivalents, H p (10) and H p (0.07). A huge number of individual dose values are recalculated and compared by statistical methods. In addition all dose values are analysed with respect to the ratio of the two detector readings which adds some spectral information to the dose values. This allows estimating the radiation quality (photon energy) for the different dose values.

The goal of this study is to characterize the 137 Cs and 60 Co nuclide calibration fields of the reference irradiation facility with collimated beam geometry as part of the Dosimetry Laboratory Seibersdorf. Air kerma along the main beam axis with source–detector distances up to 19 m and additionally lateral field profiles are investigated by comparing mainly ionization chamber measurements with MCNP Monte Carlo computer simulations. The scatter radiation contributions from various facility components including simulations with and without air environment are studied by detailed modeling of the facility. Relative differences between measured and simulated results are currently within about 1–2%, i.e., roughly two to three times of the total measurement uncertainties, but reasons due to scattering influences and further improvements in the model are discussed.

The Dosimetry Laboratory Seibersdorf was the irradiation laboratory for the IC2014 EURADOS intercomparison for individual monitoring. One hundred and twelve whole-body dosimetry systems with 30 dosemeters per dosimetry system participated in the intercomparison. In total, 2240 personal dosemeters were irradiated in photon reference radiation fields on the ISO water slab phantom in terms of personal dose equivalent Hp(10) and Hp(0.07). Two nuclide irradiation systems ((137)Cs and (60)Co gamma radiation) and a 320-kV X-ray radiation unit were used. The irradiation plan consisted of nine irradiation set-ups with five different ISO/IEC photon radiation qualities (S-Cs, S-Co, RQR 7, W-80 and W-150) and two different angles of radiation incidence (0° and 60°). Reference dose equivalent values were in the range of ∼1-500 mSv. Reference values were based on air kerma rate traceable to primary standard calibrations and appropriate conversion coefficients resulting in total expanded measurement uncertainties

This paper reports the results of a study using a commercial routine read out system with non-contact hot nitrogen heating and linear heating gas profiles. Glow curves of LiF:Mg,Ti as well as LiF:Mg,Cu,P were analysed for different linear heating rates beta from 1 to 30 degrees K s(-1). Different thermoluminescent detectors (TLDs) of different thicknesses (0.38-0.90 mm) were studied and compared. By means of the application of CGCD program considering kinetic parameters of the used TL-material the analysis of the peak temperature of the individual TL peaks lead to the approximation of the real heating profile T(chip)(t) in the TL chip. The real heating profile deviates strongly from linearity and can be characterised by the solution of a differential equation T(chip)(t) = F [T(gas)(t)]. The model of this equation is discussed in the paper. The difference between gas and chip temperatures are heating rate and chip thickness dependent and reach values of up to 100 degrees C (for thick detectors and fast heating rates). Especially for LiF:Cu,P, knowledge of the real chip temperature is essential, since read out shall be performed at the highest possible temperature, without destroying the dosimetric properties of the material. On the basis of this work, an optimisation of the readout parameters for LiF:Cu,P is possible.

The simulation of response of a new passive area dosemeter for measuring ambient dose equivalent H*(10) for photons has been performed using the Monte Carlo code MCNP and experimentally determined responses of LiF:Mg,Ti and LiF:Mg,Cu,P thermoluminescent (TL) detectors for hard-filtered X-ray spectra from 20 to 300 keV and for 137 Cs and 60 Co gamma radiation. Relative TL efficiency for both types of detectors, determined in experiments with bare detectors and similar Monte Carlo simulations, compared favourably with prediction of microdosimetric models for proposed microdosimetric target sizes in the range of 20-40 nm. The concluding verification experiment showed small deviations between measured and simulated dosemeter energy response values in the range of a few percent.

The photon energy response of different RADOS (Mirion Technologies) personal dosemeters with MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) thermoluminescence (TL) detectors was investigated. Three types of badges were applied. The irradiation with reference photon radiation qualities N (the narrow spectrum series), and S-Cs and S-Co nuclide radiation qualities, specified in ISO 4037 [International Organization for Standardization (ISO). X and gamma reference radiations for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy. ISO 4037. Part 1-4 (1999)], in the energy range of 16-1250 keV, were performed at the Dosimetry Laboratory Seibersdorf. The results demonstrated that a readout of a single MTS-N or MCP-N detector under the Al filter can be used to determine Hp(10) according to requirements of IEC 61066 [International Electrotechnical Commission (IEC). Thermoluminescence dosimetry systems for personal and environmental monitoring. International Standard IEC 61066 (2006)] for TL systems for personal dosimetry. The new RADOS badge with the experimental type of a holder (i.e. Cu/Al filters) is a very good tool for identifying the radiation quality (photon energy).

The AIT Austrian Institute of Technology coordinates the project MATSIM (MATROSHKA Simulation) in collaboration with the Vienna University of Technology and the German Aerospace Center, to perform FLUKA Monte Carlo simulations of the MATROSHKA numerical phantom irradiated under reference radiation field conditions as well as for the radiation environment at the International Space Station (ISS). MATSIM is carried out as co-investigation of the ESA ELIPS projects SORD and RADIS (commonly known as MATROSHKA), an international collaboration of more than 18 research institutes and space agencies from all over the world, under the science and project lead of the German Aerospace Center. During MATSIM a computer tomography scan of the MATROSHKA phantom has been converted into a high resolution 3-dimensional voxel model. The energy imparted and absorbed dose distribution inside the model is determined for various radiation fields. The major goal of the MATSIM project is the validation of the numerical model under reference radiation conditions and further investigations under the radiation environment at ISS. In this report we compare depth dose distributions inside the phantom measured with thermoluminescence detectors (TLDs) and an ionization chamber with FLUKA Monte Carlo particle transport simulations due to 60Co photon exposure. Further reference irradiations with neutrons, protons and heavy ions are planned. The fully validated numerical model MATSIM will provide a perfect tool to assess the radiation exposure to humans during current and future space missions to ISS, Moon, Mars and beyond.

The European Commission has funded within its 6th Framework Programme a three-year project (2005–2007) called CONRAD, COordinated Network for RAdiation Dosimetry . A major task of the CONRAD Work Package “ complex mixed radiation fields at workplaces ” was to organise a benchmark exercise in a workplace field at a high-energy particle accelerator where neutrons are the dominant radiation component. The CONRAD benchmark exercise took place at the Gesellschaft fur Schwerionenforschung mbH (GSI) in Darmstadt, Germany in July 2006. In this paper, the results of the spectrometry using four extended -range Bonner sphere spectrometers of four different institutes are reported. Outside Cave A the neutron spectra were measured with three spectrometers at six selected positions and ambient dose equivalent values were derived for use in the intercomparison with other area monitors and dosemeters. At a common position all three spectrometers were used to allow a direct comparison of their results which acts as an internal quality assurance. The comparison of the neutron spectra measured by the different groups shows very good agreement. A detailed analysis presents some differences between the shapes of the spectra and possible sources of these differences are discussed. However, the ability of Bonner sphere spectrometers to provide reliable integral quantities like fluence and ambient dose equivalent is well demonstrated in this exercise. The fluence and dose results derived by the three groups agree very well within the given uncertainties, not only with respect to the total energy region present in this environment but also for selected energy regions which contribute in certain strength to the total values. In addition to the positions outside Cave A one spectrometer was used to measure the neutron spectrum at one position in the entry maze of Cave A. In this case a comparison was possible to earlier measurements.

An intercomparison of radiation protection devices in a high-energy stray neutron field was held in the framework of the COordinated Network for Radiation Dosimetry [CONRAD, http://www.eurados.org/conrad/conrad_overview.htm ], financed by the European Commission. An irradiation hall of the GSI (Gesellschaft fur Schwerionenforschung, Darmstadt, Germany) was the facility selected for this benchmark experiment. The measurements were carried out outside the shielding barriers of this facility, while bombarding a thick carbon target with a beam of 400 MeV/u carbon ions. This paper describes the Monte Carlo simulations which were performed in order to characterize the radiation field at the measurement positions. Two codes were used for this purpose, namely FLUKA and MCNPX. Different approaches were adopted for the simulations and the results are compared and discussed. The results of the different simulations were in a satisfactory agreement. The comparisons with the measurements are discussed in Wiegel et al. [Intercomparison of radiation protection devices in a high-energy stray neutron field. Part II: Bonner sphere spectrometry. Radiat. Meas., 2008] and Silari et al. [Intercomparison of radiation protection devices in a high-energy stray neutron field. Part III: instrument response. Radiat. Meas., 2008].

The H p (10) energy response of the personal dosemeter Seibersdorf and its two different filtered LiF:Mg,Ti (TLD-100) thermoluminescence (TL) detectors are investigated. A close-to-reality simulation model of the personal dosemeter badge including the wrapped detector card was implemented with the MCNP Monte Carlo N-particle transport code. The comparison of measured and computationally calculated response using a semi-empirical TL efficiency function is carried out to provide information about the quality of the results of both methods, experiment and simulation. Similar to the experimental calibration conditions, the irradiation of dosemeters centred on the front surface of the International Organization for Standardization (ISO) water slab phantom is simulated using ISO-4037 reference photon radiation qualities with mean energies between 24 keV and 1.25 MeV and corresponding ISO conversion coefficients. The comparison of the simulated and measured relative H p (10) energy responses resulted in good agreement within some percent except for the filtered TL element at lower photon energies.

The gamma radiation fields of the reference irradiation facility of the Dosimetry Laboratory Seibersdorf with collimated beam geometry are used for calibrating radiation protection dosemeters. A close-to-reality simulation model of the facility including the complex geometry of a 60Co source was set up using the Monte Carlo code MCNP. The goal of this study is to characterise the radionuclide gamma calibration field and resulting air-kerma distributions inside the measurement hall with a total of 20 m in length. For the whole range of source-detector-distances (SDD) along the central beam axis, simulated and measured relative air-kerma values are within +/-0.6%. Influences on the accuracy of the simulation results are investigated, including e.g., source mass density effects or detector volume dependencies. A constant scatter contribution from the lead ring-collimator of approximately 1% and an increasing scatter contribution from the concrete floor for distances above 7 m are identified, resulting in a total air-kerma scatter contribution below 5%, which is in accordance to the ISO 4037-1 recommendations.

This paper provides results of computer simulation studies with the goal to analyse issues regarding radiation protection for personnel, patients and third persons involved in hadron therapy treatment. The treatment room and the patient are modelled by simple cylindrical geometries at incident proton energies of 250 MeV. Monte Carlo simulations of the energy and angular dependence of proton, neutron and photon radiation fields and resulting ambient dose equivalent distributions outside the shielding walls are performed. In order to investigate systematic uncertainties due to the shielding materials and inherent to the computer models, various concrete compositions, densities and water contents are modelled, and the influence of simulation parameters on the results obtained is determined. Generally, good agreement is found between results provided by MCNPX and FLUKA computer codes. Variations in neutron ambient dose attenuation from -50 to +/-30% are found due to varying concrete composition. Changes in the water content of the concrete in the order of 8% may cause variations up to 20%.