[en] Film+TLD and film or TLD Dosimetry have a certain delay in dose reporting, since the reports on occupational doses are usually available to the users within 40 days after the actual exposure. This is particularly important when the dose is received within the short-time interval or when the radiation source has some technical failures. For this reason, the additional monitoring is recommendable. The common Dosimetry service in Croatia is well established and the data available shows that over 80% of occupationally exposed persons are working in medical facilities, mainly with x-ray sources. Dosimetry services in the country are providing three types of dosemeters, film dosemeter badge, film+TLD dosemeter badge or plane TLD badge. We have decided to introduce the palette of digital pocket dosemeters to be used at different workplaces occupationally exposed to ionizing radiation. After the first experience with the ALARA 1G digital dosemeter it came out that this type of ionizing radiation measuring device is suitable for the various non-occupational purposes. After some technical improvement and with some telecommunication electronics this device is usable as a point environmental measuring station. This means that the probe of the record any change in normal environmental radiation field, send the data to the central station and to raise alarm if necessary. That is why we have made a prototype for environmental monitoring able to be connected to any kind of telecommunication net. (author)

[en] The monitor is intended for measurement of an exposition doze rate, an absorbed doze rate in air, an equivalent doze rate, estimation of average energy and speed of the pulses account of a spectrum registered x-ray and gamma-radiation. Is applied to the of control of radiation safety of installations, which are sources of x-ray and low energy gamma-radiation. A measurement ranges of a doze rate are 0.005-10 mR/h, 0.00005-0.1 mGy/h, 0.00005-0.1 mSv/h. A energy range of x-ray and gamma-radiation is 5-160 keV

[en] The Facility of Radiation Standard of the Japan Atomic Energy Research Institute (FRS-JAERI) is equipped with a thermal neutron calibration field in order to calibrate instruments for neutron dose measurement such as personnel dosemeter and surveymeter. The thermal neutron field is produced by using a neutron source which is placed in a graphite pile moderator. In case of calibrating a personnel dosemeter in this thermal neutron field, intermediate and fast neutrons (called as 'higher energy component') are mixed in the field, and they can accordingly affect the calibration result. Thus, by using Monte Carlo calculation techniques, neutron energy spectra in the calibration field were calculated, and the influence of the higher energy component to the calibration result was evaluated. The higher energy component in 'outside-pile thermal neutron irradiation field' was estimated as amount of 2% of the thermal neutron fluence, and it would be 10-14% of the dose equivalent due to thermal neutrons. The influence of the higher energy component depends on the energy response of personnel dosemeter. Especially in a case of neutron personnel dosemeters having an energy response even in the high energy region, the higher energy component should be taken into account to obtain a correct calibration result. In addition, in a case of on-phantom calibration of thermal neutron dosemeter, it can be concluded that the higher energy component have substantially no significant effect to the result. (author)

[en] In water calorimetry, in addition to the temperature increase due to beam energy deposition in water, unwanted thermal effects occur during and after calorimeter irradiation. This should be accounted for by applying proper corrections to the experimental results. In order to determine such corrections heat flow calculations were performed using the 'finite element' method. This method applies even to complex 3D geometries with not necessarily symmetric conditions. Some preliminary results of these calculations are presented together with a description of the analytical method for the evaluation of the correction factors that should be applied to the experimental results to account for the above thermal effects. (orig.)

No abstract available

[en] Panasonic thermoluminescent dosimeters (TLDs) are used as the photon dose assessment part of the personal nuclear accident dosimeter (PNAD) and may be used for the same purpose with the fixed nuclear accident dosimeter (FNAD). To demonstrate compliance with 10CFR835.1304 (and, its predecessor, DOE Order 5480.11), several sets of dosimeters were irradiated to photon doses above the upper limit of the DOELAP testing standard, DOE/EH-0026 and DOE/EH-0027. The upper range of the test was 10,000 rads, using both low energy (70 keV) and high energy (662 keV and 1,332 keV) sources. The testing indicated that the Panasonic TLD system is capable of meeting the requirements of 10CFR835.1304 and DOE Order 5480.11

[en] Routine dosimeters are often influenced by changing dose rates, and also environmental conditions such as humidity and temperature. In Harwell Gammachrome YR dosimeters these influences are minimised by a carefully controlled conditioning process, and the use of special packaging material to maintain these conditions. This paper describes studies carried out on the influences of irradiation dose rate and temperature on two batches of dosimeters. Firstly, this paper gives gamma irradiation response data for dose rates of 5.5, 1.1 and 0.5 Gy·s^-1 with irradiation temperatures of -20, 0, 10, 20 and 35 deg. C. Dosimeters were irradiated to doses of 0.1, 0.5, 1, 2 and 3 kGy. Secondly, this paper considers both, irradiation and post-irradiation storage temperatures, at a fixed dose rate of 1.4 Gy·s^-1. Dosimeters were irradiated to doses of 0.1 and 3 kGy; at temperatures of 30, 40 or 50 deg. C. The dosimeters were stored at these temperatures for 2, 24 and 48 hours before measurement. (author)

[en] The aim of this project is to develop a calorimeter for use in both electron and photon beams. The calorimeter should be more robust than the present NPL primary standard X-ray calorimeter and is designed to be sufficiently portable to enable measurements at clinical accelerators away from NPL. Although intended for therapy-level dosimetry, the new calorimeter can also be used for high-dose measurements at industrial facilities. The system consists of a front end (the calorimeter itself), means for thermal isolation and temperature control, and a measurement system based on thermistors in a DC Wheatstone bridge. The early part of the project focused on the development of a temperature control system sensitive enough to allow measurements of temperature rises of the order of 1 mK. The control system responds to the calorimeter, phantom and air temperatures and maintains the temperature of the calorimeter to within ± 0.2 mK over several hours. Initial operation at NPL in 6, 10 and 16 MV X-ray beams show that the system is capable of measurements of 1 Gy at 2 Gy/min with a random uncertainty of ± 0.5% (1 standard deviation). (author)

[en] Since 1985, the IAEA has been using alanine-ESR as a transfer dosimeter for its dose quality audit service, namely the International Dose Assurance Service. The alanine dosimeters are rod-type containing 70 wt% DL--α-alanine and 30 wt% polystyrene. We have two self-shielded gamma facilities for the calibration of the dosimetry system, where the temperature within the irradiation chamber can be controlled by a specially designed unit. A 4th order polynomial is fitted to the 16 data points in the dose range of 100 Gy to 50 kGy. The measured value of the irradiation temperature coefficient at two dose values (15 and 45 kGy) is 0.23 %/deg. C. Also, the ESR-response was followed for several dosimeters for about 8 months to study the post-irradiation effect. A value of 0.008 %/day was observed for the fading of the response for two dose values (15 and 45 kGy) and three irradiation temperatures (15, 27 and 40 deg. C). The effect of the analysis temperature on the ESR response was also studied. The combined relative uncertainty for the IAEA alanine-ESR dosimetry system is 1.5% (k=1). This includes that transferred from the primary laboratory for the dose rate measurements of the gamma facilities, dosimetry system calibration uncertainties, batch variability and uncertainty in the curve fitting procedure. This value however does not include the contribution due to the irradiation temperature correction which is applied when it differs from that during calibration; this component being specific for each dose measurement. (author)

[en] A detecting system for environmental neutrons has to be characterized by a very low inherent background. The details are reported of measuring the background of a ³He proportional counter in a polythene sphere in the Asse salt mine. A spherical counter with 40 mm ext. diameter, filled with 100 kPa ³He and 53 kPa Xe was used. The inherent background of the counter was found to be less then 1 nSv per 24 hours, being less than 1% of the natural neutron radiation level at the ground level. The ambient dose equivalent due to environmental neutrons was estimated at 100-200 nSv per 24 hours. A ³He proportional counter in a polythene sphere was thus found to be sufficiently sensitive to estimate the neutron component at environmental levels. (A.K.)