bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porcelain Slices as a Stable Thermoluminescence Dosemeter up to 500 oC
Authors: Stoneham D. , Green T.H. , Voice E. 
Published: February 2017

Abstract
Porcelain slices have been used as a dosemeter to measure low gamma doses at 300 oC in the Prototype Fast Reactor at Dounreay. At the 1980 Toulouse Conference Aitken, Bussel and Voice reported the use of the 430 oC peak of natural fluorite to measure the gamma flux at 250 oC and comparisons were first made against this technique. By using porcelain slices cut into sections 7 mm square and 200 µm thick and encapsulated in aluminium, it is possible to measure the gamma flux up to a temperature of 500 oC. The sensitivity changes induced in the 100 oC peak (the so-called pre-dose effect) enable minimum dose evaluations to 10 mGy ± 10% to be made. This sensitivity change is activated by post-irradiation heating to 600 oC; at 300 oC only 4% of this change has been activated, but at 500 oC, 25% change is observed. This limits the temperatures at which exposure can be made although higher temperatures are possible if lower accuracy is acceptable. There is no detectable loss due to thermal fading. Allowance is made for irradiation at elevated temperature by laboratory tests using a 60Co source. An added advantage with this technique is that after suitable thermal treatment, the slices can be re-used.
Thermoluminescence in Sintered CaB4O7:Dy and CaB4O7:Eu
Authors: Fukuda Y. , Mizuguchi K. , Takeuchi N. 
Published: February 2017

Abstract
TL in sintered CaB4O7 doped with activators, such as Eu, Dy and also Pb and Cu, has been investigated. For a heating rate of 20 oC.min-1, the TL glow peaks can be roughly grouped into three temperature regions: (I) 75~110 oC, (II) 170~190 oC, and (III) 255~275 oC. Their emission spectra depend on the activator and its valence. The activators release to the luminescence in the following way: Eu2+ to 440 nm, Dy3+ to 480 and 580 nm, Pb2+ to 275 nm, and Cu+ to 540 nm, respectively. Thermally stimulated current (TSC) was observed corresponding to all the temperatures at which TL glow peaks were observed. This indicates that the thermally released charge carriers recombine with the luminescent centres through conduction or/and valence bands, and not by a tunnelling process. All the TL glow peaks showed no supralinearity before they saturated at an exposure of about 2.58 C.kg-1 (104 R). Peaks appearing at the temperature regions II and III retained memories of irradiation for a storage period of 6 months in the dark at room temperature.
The Determination of Gamma Doses due to Capture and Inelastic Scattering Processes in a Trunk Phantom Irradiated with 15 MeV Neutrons
Authors: Reulein W. , Kühn H. 
Published: February 2017

Abstract
The aim of these investigations was to improve gamma dose determination with Geiger-Müller counters. The required values of the responses of the detector for neutrons and gamma rays were taken from the literature. The time discrimination of the signals, a method used to discriminate neutron and gamma radiation in neutron response measurements, makes possible the determination of the gamma doses caused by (n,n'?) processes. The experiments were performed with an accelerator in pulse mode. The radiation time was selected to be as small as possible to reduce the build-up of thermal neutrons in the phantom during irradiation. The pause time was chosen to allow the decrease of thermal neutrons produced after moderation. The different gamma spectra emitted by (n,n'?) and (n,?) processes were considered in calculating the gamma dose. In the centre of the trunk of the water phantom, the H?(n,n'?)/H?(n,?) ratio is given by 2.0 ± 0.2.
A Facility to Produce Collimated Neutron Beams at the Legnaro Laboratories
Authors: Colautti P. , Talpo G. , Tornielli G. 
Published: February 2017

Abstract
The 7 MV Van de Graaff and the 16 MV Tandem accelerators at the Legnaro National Laboratories can be used to produce fast neutron fluxes of moderate intensity, ranging in energy from 1 MeV to 50 MeV. A W-polyethylene-Pb cylindrical collimator has been constructed in order to produce a collimated neutron beam, with well defined dose and microdose characteristics for radiobiological experiments. The collimator can be assembled in different configurations allowing both for different thicknesses and different beam apertures. Dosimetric measurements have been made with a d(4.5)+Be source. These demonstrate sharp beam edges with attenuation behind the shield of 20% with the 15 cm collimator and 1.5% with the 50 cm collimator.
Patient Dosimetry and Staff Protection at the Clatterbridge High Energy Neutron Facility
Authors: Blake S.W. , Finch J. , Bonnett D.E. , Shaw J.E. 
Published: February 2017

Abstract
The Clatterbridge High Energy Neutron Facility was designed to provide a neutron beam comparable to an X ray beam generated by a modern linear accelerator in terms of both dose distribution and patient positioning. This has been achieved using a cyclotron which accelerates protons to 62 MeV, and an isocentric treatment unit incorporating a variable collimator. Neutrons are generated by the interaction of the proton beam with a beryllium target situated in the treatment head. The neutron beam is described in terms of the beam parameters measured for routine clinical use. Where relevant, they are compared with those of an 8 MV X ray beam. The neutron and X ray beams are also compared by means of treatment plans produced for the two beams. Finally, the dose equivalent to radiographic staff caused by the neutron activation of the treatment machine and room are presented and discussed. These are found to be comparable with that measured at other facilities employing neutron beams with similar energies.
Neutron Physics Studies Relating to Cancer Therapy on the Clatterbridge Cyclotron
Authors: Crout N.M.J. , Fletcher J.G. , Scott M.C. , Taylor G.C. 
Published: February 2017

Abstract
Both neutron spectrum and microdosimetric measurements have been made in a water phantom exposed to different field size therapy beams from the 62 MeV Clatterbridge cyclotron. The neutron spectrum measurements have been made using an NE213 detector and the procedures for measuring the response functions necessary for unfolding are described. The results of measurements both in air and in phantom are presented. The spectrum measurements show very significant in-beam hardening with depth into the phantom, and the microdosimetric measurements are consistent with this finding.
Thermoluminescent LiF:Cu,Mg,P for Gamma Ray Dosimetry in Mixed Fast Neutron-Gamma Radiation Fields
Authors: Horowitz Y.S. , Shachar B.B. 
Published: February 2017

Abstract
In thermoluminescent dosimetry (TLD), the relative TL response, ?n?, of fast neutrons to gamma rays usually lies betwen 0.05 to 0.3. Recently, several groups have reported on the development of a new TL material, LiF:Cu,Mg,P, with a gamma ray TL sensitivity ~20 times greater than LiF:Mg,Ti (TLD-100, Harshaw-Filtrol). We have measured the relative TL response of LiF:Cu,Mg,P to 252Cf fast neutrons (E = 2.5 MeV). Neutron dosimetry was carried out using the polycarbonate technique, and, for comparison purposes, the neutron irradiations were also carried out simultaneously on pairs of LiF:Mg,Ti (TLD-700, H/F) and CaF:Tm (TLD-300, H/F) dosemeters. The following results were obtained; (1) ?(LiF:Cu,Mg,P) = 0.011 ± 0.01; (2) ?(TLD-700)/?(LiF:Cu,Mg,P) ( 5:1; and, (3) ?(TLD-300)/?(LiF:Cu,Mg,P) ( 4:1. Estimation of the TL signal was carried out using cmputerised glow curve deconvolution (CGCD). These results establish LiF:Cu,Mg,P as the 'tissue-equivalent' TL material least sensitive to fast neutrons discovered to date and suggest that LiF:Cu,Mg,P can serve as an excellent discriminator for gamma ray dose measurement in fast neutron - gamma ray radiation fields.
Dispersion of 226Ra in a Contaminated Environment
Authors: de Bettencourt A.O. , Texeira M.M.G.R. , Madruga M.J. , Faisca (INVITED) M.C. 
Published: February 2017

Abstract
A radium salts extraction factory was established in Portugal in 1908 in the northeastern part of the country. It was abandoned in the forties and is now in ruins. Wastes (mainly sands) highly contaminated with 226Ra were left near these ruins. Measurements were performed to evaluate the extent of the contamination due to the dispersion of radium around this site, using portable Gieger tube equipment as well as by gamma spectrometry analyses of soil samples. Vertical profiles of soil were taken to a depth of about 40 cm, and 5 cm sections were analysed by gamma spectrometry to evaluate the vertical distribution of 226Ra and 210Pb. Some soil characteristics, such as pH, organic matter and exchangeable calcium and radium were also analysed. The dispersion of radium seems to be mostly due to the removal of contaminated wastes by mechanical means, although some leaching may have occurred. Laboratory experiments were also conducted on sandy and agricultural soils to study the leaching of 226Ra and 210Pb with rainwater and to help explain the results obtained in the field study. The observed influence of different parameters on this leaching are briefly discussed. Vegetables grown on these soils (mainly cabbage) were analysed for their content of 226Ra and 210Pb in order to calculate concentration factors. For 226Ra, these range from about 7 x 10-3 to 7 x 10-2. For 210Pb, they range from about 10-3 to 2 x 10-2.
Investigations of the Properties of an Instrument for In Situ Exhalation Measurements
Authors: Aldenkamp F.J. , Put L.W. , de Meijer R.J. 
Published: February 2017

Abstract
Experimental investigations on the properties of an instrument for in situ measurements of the radon exhalation rate revealed several unexpected results. The measurements were based on determining the growth of the activity in a measuring volume. Exhalation rates are often determined from the initial linear increase of the activity; this investigation, however, indicates that such a determination may not be reliable in the case of porous materials like gypsum and soil. The investigations also revealed that the results depend on a number of parameters such as temperature and aerosol conditions.
Environmental Radiation Survey Around a Coal-Fired Power Plant Site
Authors: Battaglia A. , Bramati L. 
Published: February 2017

Abstract
For siting of a coal-fired power station in the Apulia region, ENEL (Ente Nazionale Energia Elettrica) carried out an environmental impact evaluation. Owing to the natural radioactivity in the coal and in the ash, the local authorities required an investigation of the environmental radioactivity in the area. Measurements on the radiation level, of radioactivity concentrations in soil and of radon concentration in the air were carried out at selected points on the basis of the expected atmospheric diffusion and ash disposal. At some points higher than normal radiation levels and some disequilibrium in the natural uranium decay products were observed due to hydrogeological events in the soils near the coast. A comparison is made of the radiological impact by the power plant operation and the impact due to the natural radiation environment.
Preliminary Measurements of Indoor Radon in Ljubljana, Yugoslavia
Authors: Kobal I. , Vavpotic J. , Burger J. , Stegnar P. 
Published: February 2017

Abstract
In Ljubljana, the capital of Slovenia, one of six Yugoslav republics, 28 houses were selected according to their size, age and construction material, as sampling points to measure indoor air 222Rn concentrations. Air samples were taken every three months and analysed for 222Rn. Radon was isolated from air contained in a 1.2 dm3 sampling glass ampoule, transferred to a scintillation cell and counted. In some homes radon was measured under different microclimatic conditions. In addition outdoor air was surveyed in winter during a temperature inversion when increased radon concentration is expected in a mass of stagnant polluted air. The results obtained have not been quantitatively elaborated. They merely show a preliminary picture of indoor radon levels in Ljubljana and as such are a good base for a planned nationwide radon monitoring programme.
Sources of Technologically Enhanced Natural Radioactivity and Their Impact in Slovenia (Yugoslavia)
Authors: Brajnik D. , Krizman M. , Kobal I. , Stegnar P. 
Published: February 2017

Abstract
The environmental impact of a uranium mine and several other sources of technologically enhanced natural ratioactivity such as coal fired power plants, coal mines, production of phosphoric acid, phosphate fertilisers and titanium dioxide contributing to the radioactive pollution in Slovenia has been studied. The main contribution to the individual dose is caused by inhalation of radon and its daughters in the vicinity of the uranium mine. Other sources contribute mainly to the radioactive pollution of the river Sava and its underground water.
Modelling of the Electron and Ion Kinetics in Cylindrical Proportional Counters
Authors: Ségur P. , Pérès I. , Boeuf J.P. , Barthe (INVITED) J. 
Published: February 2017

Abstract
This paper gives an overview of the state of the art in the modelling of electron and ion kinetics in proportional counters. Three specific points are emphasised. First, we determine, by using an accurate solution of the Boltzmann equation, the electron transport parameters (ionisation coefficient, drift velocity, diffusion coefficient) in methane over a very large range of values of the ratio electric field upon pressure. We then calculate the gas gain of the counter by using our calculated data. The calculation of this gas gain is generally based on the assumption that the ionisation coefficient and other transport paraments, at a given location in space, depend only on the value of the local electric field (equilibrium assumption). In a proportional counter, the electric field can present large spatial variations over distances of the order of one or a few electron mean free paths (especially for low gas pressure) and the equilibrium assumption can become questionable. The second objective of this work is to investigate the importance of these non-equibibrium effects. The existence of space charge fields in the counter can greatly affect its gain. In order to estimate the magnitude of these effects, self-consistent calculations based on a macroscopic description (continuity and momentum transfer equations) of the electron and ion kinetics coupled with Poisson equation are carried out. We show how such calculations make possible the determination of the onset and the importance of space charge effects in the counter.
Quality Factor, Concepts and Issues
Authors: Sinclair (INVITED) W.K. 
Published: February 2017

Abstract
Three issues in quality factor assignment arise from Report 40 of the ICRU. These include the validity of the observation of high RBE values for high-LET radiation at low doses, the question of reference radiation, X or ? rays, and the 'effective' quality factor in the body compared with the nominal value of Q. On the first item, high values of RBE at low doses are becoming generally accepted, see a recent report from the NCRP. On the second, a survey of past recommendations of both ICRP and NCRP indicate that both organisations have, for protection purposes, always set all low-LET radiations equal to 1 and accepted the differences (of 2-3 times) between them. However, for radiobiological purposes high energy ? rays are to be preferred as the reference radiation. Third, the 'effective quality factor' or radiation weighting factor, WR, for a variety of whole body exposure circumstances can be estimated from HE = WR S wTDT where the effective dose equivalent is the summation of tissue weighting factors wT, times the absorbed dose DT for the organ, multiplied by an average 'radiation weighting factor' WR. WR values can be calculated for a variety of exposure circumstances and are always less than Q. Maximum values, for fission neutrons for example, are not greatly less however. These issues are under further consideration by the ICRP.
The Effect of Dynamic Disordering Upon Thermostimulated Processes in TLD Ionic Crystals
Authors: Tale I. , Tale V. , Nagornyi A. 
Published: February 2017

Abstract
Annealing of radiation defects has been studied by means of the fractional glow technique in KC1-Tl and CaF2 crystals in the temperature range where the ionic motion arises. A novel model of dynamic disordering for describing the kinetics of thermostimulated luminescence is proposed, taking into account the fluctuational changes of the trap spatial structure and their energetics during the relaxation process due to the interaction with mobile ions and/or vacancies.
Neutron Dosimetry with SSNTDs and Spark Counting Evaluation
Authors: Schmidt W.F.O. 
Published: February 2017

Abstract
A new system consisting of polypropylene spheres 25 cm in diameter and SSNTDs as central detectors is presented. The behaviour of these spheres for different neutron spectra is well known. The SSNTD foil in use is Makrofol KG (0.01 mm, Bayer). Two platelets of natural uranium (U(nat) 16x13 mm2 in size (thickness 0.25 mm) serve as radiators in contact with the foil, which is fixed in a commercial dia-frame (inner dimensions 36x24 mm2). The foils are etched in KOH (28%, 60 oC, 2 h) and evaluated with a spark counter. The system is cheap, robust, insensitive to water and shocks and does not depend on electrical supply. Readings are completely insensitive to accompanying photons. Doses may be measured from 0.01 mSv to 1000 Sv. The system is designed for area neutron survey at various neutron facilities up to energies of 14 MeV.
Simultaneous Measurement of Angle of Incidence and Energy in Fast Neutron Fields by CR-39
Authors: Guldbakke S. , Pitt E. , Scharmann A. , Simmer R. 
Published: February 2017

Abstract
Commercial American Acrylics CR-39 (dosimetry grade), partly covered with polypropylene radiators of increasing thickness (step radiator) has been irradiated with monoenergetic neutrons (0.565 - 5 MeV) in parallel beams at various angles of incidence. The step rise has been varied with neutron energy, the maximum thickness of the step-radiator exceeding the maximum recoil proton energy range. The CR-39 detectors have been etched electrochemically and evaluated by a semi-automatic image analysing system (Leitz Autoscope P). By varying the radiator thickness the track density increases up to a saturation track density. The ratio of saturation track density of uncovered CR-39 depends on the angle of incidence. The knowledge of the saturation radiator thickness combined with the angle of incidence allows, on the other hand, the neutron energy to be estimated.
Beta Dosimetry Using Thin TL Detectors
Authors: Fellinger J. , Schmidt P. , Hübner K. 
Published: February 2017

Abstract
A personnel dosemeter for routine dosimetry in mixed beta-gamma fields requires a thin, nearly tissue-equivalent detector with a high sensitivity and with a high mechanical resistance. A special TL sandwich detector has been designed for application in beta dosimetry. It consists of two TL sensitive layers (TLD 1 and TLD 2) separated by a material with poor thermal conductivity. In consequence of the poor thermal conductivity of the separating layer the temperatures of TLD 1 and TLD 2 are different during the evaluation process. The TLD 1 layer shows an excellent beta sensitivity (about 75% for 14C beta rays related to 90Sr/90Y). Information about the radiation field can be obtained by using the relation of the detector readings of TLD 1 and TLD 2. The production of the TL sandwich detector is described, and the dosimetric properties in different beta fields are represented and discussed.
Individual Dosimetry Using Electret Detectors
Authors: Dörschel B. , Prokert K. , Seifert H. , Stoldt C. 
Published: February 2017

Abstract
Electret dosemeters are designed as small air-filled ionisation chambers in which one of the electrodes is replaced by an electret. The dosemeter readout expressed as the difference in the electret voltage measured before and after the irradiation is proportional to the absorbed dose in the chamber gas. The application of such electret detectors to individual dosimetry requires knowledge of their energy and angular dependence as well as of their dynamic range and measurement accuracy. The dosimetric properties of electret ionisation chambers containing corona-charged PTFE electrets are described. Conclusions about their applicability in individual dosimetry in photon fields are drawn.
A TL Technique for On-Plate Measurement of Doses Below 1 Microgray
Authors: Benkö L. 
Published: February 2017

Abstract
The TL response of CaSO4:Dy to extremely low beta doses delivered by samples of environmental origin was investigated. Taking into account the main factors limiting the precision of measurements below about 5 µGy, a special TL technique was developed. The heating chamber and the PM assembly are placed in a 20 cm thick iron shield. 0.1 g of CaSO4:Dy is spread on the heating plate, constituting a 1.5 cm diam. phosphor layer. The phosphor, heated to 350 oC, can be re-used with no change in sensitivity at low doses. Replacing the PM tube with a container filled with 4 g of sample (soil, pottery clay) or CaSO4:Dy (for background correction), on-plate exposures are made overnight. For calibrations and quick checks, K2CO3 and NBL reference standards with specified U and Th content are used. This technique enables highly reliable measurements to be performed at doses as low as 0.1 µGy. Some of the results relating to isotope dependence, build-up of spurious TL and possible applications in TL dating are also presented.
Accident Dosimetry Using Environmental Materials Collected from Regions Downwind of Chernobyl: A Preliminary Evaluation
Authors: Hütt G. , Brodski L. , Bailiff I.K. , Göksu Y. , Haskell E. , Jungner H. , Stoneham D. 
Published: February 2017

Abstract
Environmental materials including bricks, tiles porcelain fixtures and a variety of other ceramic objects were collected in July, 1990, and August, 1991, from indoor and outdoor locations in the town of Pripyat, situated 3 km NW of the Chernobyl nuclear power plant. The samples were distributed to a number of laboratories to investigate their suitability for thermoluminescence dosimetry and for measurement of gamma ray doses with samples deemed suitable, using pre-dose, fine-grain and quartz inclusion thermoluminescence techniques. In the most heavily exposed region of Pripyat, values ranged from near background (" 0.1 Gy) in the most shielded interior locations of apartment buildings to a maximum of 0.6 Gy directly behind closed windows, while exterior values ranged from 1.7 to 2.3 Gy for samples located at least 1 m above ground level.
Eight Years Application of Computerised Glow Curve Analysis at the Rossendorf Nuclear Research Centre
Authors: Sahre P. , Schönmuth Th. 
Published: February 2017

Abstract
Since 1983 computerised glow curve analysis has been carried out at the Rossendorf Nuclear Research Centre. The application fields, the methods developed and the results obtained are: (1) Skin dose determination in beta/gamma fields. The glow curve of a fast, directionally heated thick TL detector is deconvoluted into contributions of standard glow curves for beta and gamma irradiation of known depth dose distribution. Doses in tissue depths from 0.05 mm to 1.6 mm are obtainable. (2) Fading reduction. The evaluation of only the separated main peak yields the fading-independent dose and, additionally, the evaluation of the separated low temperature peak gives an indication of the time elapsed since a single high exposure. (3) High range exposure. For exposures of CaSO4:Dy detectors to doses from 0.1 kGy to 5 kGy the saturation effects can be reduced by deconvolution of the glow curve into up to five Gaussian peaks. The dose is obtained from two or more peak areas as well as from the ratio of peak height and location.