[en] LET dependence of highly sensitive Al₂O₃:C and CaF₂:Mn thermoluminescence (TL) dosemeters was investigated using glow curve analysis to determine the efficiencies of TL light production for alpha particle and neutron irradiation relative to gamma exposure. No high temperature peak, nor significant change of glow curve shape were found after irradiation by high LET (alpha and neutron) radiation. Gamma sensitivity of Al₂O₃:C as compared to CaF₂:Mn was 6:1. However the relative TL efficiency for alpha particle irradiation of Al₂O₃:C was a factor of ten lower as compared to that of CaF₂:Mn. Neutron sensitivity was found to be similar for the two materials. (author)

[en] The aim of this work was to determine important dosimetric characteristics of several types of the most interesting tissue-equivalent thermoluminescent detectors (TLDs). Special attention was given to the determination of energy dependence for medium and low energy X rays. The following types of TLDs were investigated: (a) two new types based on lithium borate: Li₂B₄O₇:Cu,In and Li₂B₄O₇:Cu,In,Ag; (b) two types of the recently developed highly sensitive LiF:Mg,Cu,P material: TLD-700H and GR 200A and (c) two well known types of LiF:Mg,Ti detectors: TLD-100 and TLD-700. In order to determine their photon energy response characteristics, TLDs previously calibrated with ¹³⁷Cs gamma rays were simultaneously irradiated with X ray beams in the range of effective energies between 33 and 116 keV. Measured energy responses (relative to air), normalised to those to ¹³⁷Cs photons were compared with calculated data. Although the deviations of the measured data from the 'theoretical' predictions are different for all the investigated TLDs, there is no large difference in 'tissue-equivalency' between them. (author)

[en] Photon energy spectra at different depths in water irradiated with a ⁶⁰Co source were evaluated using a pair of dosemeters: a CaF₂:Mn dosemeter with a large energy dependence in comparison with water and a Fricke dosemeter which is practically water-equivalent. The basis of the spectra evaluations are the photon fluence spectra as a function of depth in water calculated by Seltzer. The ratios of dose readings of CaF₂ (relative to those obtained by an unscreened ⁶⁰Co source) and the results obtained by a Fricke dosemeter, giving Fricke-to-CaF₂ correction factors, were compared with water-to-CaF₂ correction factors calculated using Burlin's cavity theory. The results enabled the evaluation of the quality of the ⁶⁰Co source used. For estimated spectra, the experimental values of water-to-CaF₂ correction factors were in very good agreement with the values calculated using cavity theory. (author)

[en] The radiation doses absorbed by various organs of patients (gonads, chest, thyroid and the lens of the eye) were measured at the body surface of patients during computerised tomography (CT) examinations of the head. According to our earlier energy response studies with X ray irradiations, the TL responses of LiF TLDs have the lowest energy dependence and hence LiF:Mg,Ti TLD discs (produced in Poland) and TLD-700 (Harshaw) were used for measurements of the dose. Approximately 600 TLD discs and 200 TLD-700 were used in this study for surface organ dose measurements on 54 patients of different sex and age. The highest dose measured in this study (71.10 mGy) was delivered to the eye lens during a CT examination of the head. (author)

[en] Croatian Radiation Protection Association (CRPA) was formed as an independent association in 1991, and since 1992 it is a member of the International Radiation Protection Association (IRPA). CRPA organises regular national symposia with international participation, and takes part in organisation of regional IRPA congresses. The members of CRPA take part also in international and European congresses. In this paper we analyse the participation of Croatian authors in national symposia and international congresses in the period from 1992 to 2002. The number of papers in proceedings of the national symposia is rather constant (about 60), while at the First symposium in 1992 it was slightly higher (68). The fraction of papers by Croatian authors was also the highest at the First Symposium (∼ 90%), while at the following symposia it varied between 70% and 80%. Although the analysed period is rather short, one can see slight changes in the research topics. Radioecology, including radon and related topics, was the most frequent research area (36% of all papers) at the national CRPA symposia 1992-1998, followed by the biological effects of radiation and radiation protection in medicine (24%), dosimetry, methods and instrumentation (21%), general topics (11%) and radioactive waste (7%). The distribution of topics at the Fifth symposium is: 27% radioecology and radon, 30% biological and medical topics, as well as professional and public exposure, 24% dosimetry, 14% general topics and 5% non-ionising radiations. In this Symposium we have separate sections for non-ionising radiations and public exposure, although several papers on these subjects were presented already at the previous symposia. (author)

[en] The abstracts of the presentations at the IRPA Regional Congress on Radiation Protection in Central Europe: Radiation Protection and Health are presented in this book of abstracts. The Congress was structured into nine sessions: 1. General aspects of radiation protection; 2. Basic physical effects; 3. Biological effects of radiation; 4. Radiation protection in medicine; 5. Radiation protection and environment; 6. Radiation protection at workplaces; 7. Radiation dosimetry; 8. Instrumentation and methods; 9. Non-ionising radiation

[en] To calculate dose in water from the results of doses measured by different dosemeters, dosemeter-to-water correction factors have to be used. A critical parameter in the calculation is the ratio of mass energy absorption coefficients, which in the case of dosimetry systems with a different energy dependence in comparison with water, strongly depend on the spectral characteristics of the photon radiation. For the evaluation of spectra in water, that pair of dosemeters with different energy dependences could be used. In this work, photon energy spectra at different depths in water irradiated with ⁶⁰Co source were evaluated using a pair of dosemeters: CaF₂:Mn dosemeter with a large energy dependence in comparison with water and Fricke dosemeter which is practically water equivalent. The basis of the spectra evaluation are the photon fluence spectra as a function of depth in water calculated by Seltzer. The ratios of dose readings of CaF₂ (relative to those obtained by an unscreened ⁶⁰Co source) and the results obtained by Fricke dosemeter, giving Fricke-to-CaF₂ correction factors, were compared with water-to-CaF₂ correction factors calculated using the Burlin's cavity theory. The results enabled the evaluation of the quality of the ⁶⁰Co source used. For estimated spectra, the experimental values of water-to-CaF₂ correction factors were in very good agreement with the values calculated using cavity theory. (author)

[en] Task of EURADOS Working Group 3 (WG3) is the coordination of research projects for the correct measurement of ambient dose equivalent H*(10), dose rate and radioactivity concentrations from artificial sources on top of the natural environmental radiation for different release scenarios. For these aims in addition to continuous collection of information on the situation in environmental dose monitoring in Europe the group organised more intercomparisons for gamma spectroscopic systems as well as for passive dosimeters. These intercomparisons aimed the harmonisation of area dose rate measurements of radiation monitoring stations in Europe. A major key aspect of the group activities is the work of many WG3 members in two EUROMET Joint Research Projects entitled 'Metrology for radiological early warning networks in Europe - METROERM' (2014-2017) and 'Metrology for mobile detection of ionising radiation following a nuclear or radiological incident - PREPAREDNESS' (2017-2020). The objectives of the upcoming project are: development of unmanned mobile detection systems for the remote measurement of dose rates and radioactivity concentrations based on drones and helicopters; development and validation of transportable air-sampling systems for quick information on radioactive contamination levels in air; to investigate the metrological relevance of 'crowd monitoring' data on dose rate; procedures to measure dose rates of contaminated areas by passive dosimeters; to ensure uptake and knowledge transfer about new instrumentation and procedures to decision makers and dosimetry services. (author).

[en] Thermoluminescent (TL) properties of irradiated sage, starch and egg powder were investigated in order to identify irradiation treatment. Glow curves were recorded and readout parameters established. The TL response in the dose range 1 to 10 kGy and fading characteristics show that sage and egg powder are potential TL detectors. The TL response of starch irradiated above 1 kGy does not depend on irradiated food. (author). 12 refs.; 1 tab.; 3 figs

[en] Precise dosimetric calibration of the radiation field of the Gammacell irradiator has been carried out. For measuring spatial dose distribution a cavity ionization chamber in conjunction with a Farmer dosimeter and CaF₂ thermoluminescent dosimeters were used. The results make possible the calculation of doses received by samples of different sizes and shapes. (author) 10 refs.; 4 figs.; 1 tab