bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applicability of TLD-700 Detectors for Dosimetry in d(14)+Be Neutron Fields
Authors: Meissner P. , Bienek U. , Rassow J. 
Published: February 2017

Abstract
The glow curve of TLD-700 at higher temperatures has its main maximum at about 200 oC. At about 270 oC there is a much smaller second peak. These two peaks exhibit different LET dependences. For photons both peaks are supralinear. In this work the photon and neutron sensitivities for neutrons which were produced by bombarding a thick beryllium target with 14 MeV deuterons (d(14)+Be neutrons) and for gamma rays are determined in the dose range up to 2.1 Gy which is relevant for clinical neutron dosimetry. In addition the two peak method used for TLD-300 is transferred to TLD-700 and the accuracy of the dose determination is tested.
Experience in Neutron Dose Measurements with Mailable Pin Diodes
Authors: Reft C.S. , Kuchnir F.T. 
Published: February 2017

Abstract
We have investigated the performance characteristics of PIN diodes as neutron dosemeters. Data were obtained on dose response as a function of accumulated dose and neutron beam quality. We have studied fading characteristics at room temperature and developed a technique for partially annealing the radiation damage. After two years of experience with PIN diodes we tested them for their usefulness as mail dosemeters among the six neutron therapy facilites in the United States. Our results show that intercomparison of calibrated neutron beams is achievable with a precision of ±3%.
Radon Exhalation from the Soil
Authors: Keller G. , Schütz M. 
Published: February 2017

Abstract
The exhalation of radon from the soil is the main source for high radon concentration in dwellings. A study of the mechanism of exhalation, its dependence on various parameters and the entry points for radon in houses are presented. Electrostatic deposition of the radon daughter products on a surface barrier detector and subsequent analysis of the measured alpha spectra allows one to determine the exhalation rates of 222Rn and 220Rn directly from the soil. For a sampling time of two hours, the lower limit of detection of our equipment was found to be 0.3 x 10-3 Bq.m-2.s-1 for 222Rn. In the south-west part of Germany, the 222Rn exhalation rates from the soil vary approximately between 2 x 10-3 and 100 x 10-3 Bq.m-2.s-1. The water content of the investigated soil, its actual porosity and its radium content determine the radon migration through the pores. For example in regions with volcanic rocks the exhalation rates are up to 10 times higher than in sandstone areas. Some special constructive measures to reduce the entry of radon in buildings are proposed.
A Simple Model for Estimating the Mixing Depth from the Diurnal Variation of Atmospheric 222Rn Concentration
Authors: Fujinami N. , Esaka S. 
Published: February 2017

Abstract
A simple model is proposed for estimating the mixing depth from the diurnal variation of 222Rn concentration in surface air. The comparison is described between the mixing depth calculated with the model and that determined from observations of temperature profiles with rawinsondes, which indicates good agreement.
Uranium in Humans
Authors: Fisenne I.M. , Perry P.M. , Harley N.H. 
Published: February 2017

Abstract
Measurements of the environmental and metabolic behaviour of the naturally occurring radionuclides have provided necessary information on the behaviour of stable elements and have been useful analogues in the study of man-made radionuclides. Uranium has been studied primarily because of its role in the nuclear industry and its possible effects as a heavy metal in occupational exposure cases. There is abundant literature dealing with uranium studies in animals, and some literature on human studies with chronically ill patients. Relatively few data are available which document the uranium concentrations in humans under chronic, low level environmental conditions. Some recent bone measurements performed at the US Department of Energy, Environmental Measurements Laboratory are presented. For comparison, a summary of published information on uranium concentrations in blood, soft tissues and bones of humans is also presented. These data are selected to eliminate results from areas of known elevated natural radionuclide levels and occupational or controlled experimental exposure cases. From the measurements of the uranium concentration in bone from 12 countries, it is possible to derive a cumulative frequency distribution for the sampled populations.
The Flow and Diffusion of Radon Isotopes in Fractured Porous Media: Part 1, Finite Slabs
Authors: Schery S.D. , Holford D.J. , Wilson J.L. , Phillips F.M. 
Published: February 2017

Abstract
In the conventional equations used to describe gaseous transport of radon isotopes through fractured porous media the two processes responsible for radon movement are diffusion and pressure-driven flow (advection). Fractures in a porous medium can be especially effective for pressure-driven transport but lateral diffusion can be a strong mitigating influence. The interplay of diffusion and flow is examined for a fractured concrete slab and a fractured, high-diffusivity layer between a house and an underlying radium-rich medium. For underpressures common in houses, fractures only a fraction of a millimetre wide in concrete are important and often big enough to ensure flow transport of radon with small diffusive loss. In contrast, fractures several millimetres wide through high-diffusivity layers several metres thick such as sand may be unimportant for radon transport due to large lateral diffusive losses.
Comparison of Predicted and Measured Variations of Indoor Radon Concentration
Authors: Arvela H. , Voutilainen A. , Mäkeläinen I. , Castrén O. , Winqvist K. 
Published: February 2017

Abstract
Prediction of the variations of indoor radon concentration were calculated using a model relating indoor radon concentration to radon entry rate, air infiltration and meteorological factors. These calculated variations have been compared with seasonal variations of 33 houses during 1-4 years, with winter-summer concentration ratios of 300 houses and the measured dirunal variation. In houses with a slab in ground contact the measured seasonal variations are quite often in agreement with variations predicted for nearly pure pressure difference driven flow. The contribution of a diffusion source is significant in houses with large porous concrete walls against the ground. Air flow due to seasonally variable thermal convection within eskers strongly affects the seasonal variations within houses located thereon. Measured and predicted winter-summer concentration ratios demonstrate that, on average, the ratio is a function of radon concentration. The ratio increases with increasing winter concentration. According to the model the diurnal maximum caused by a pressure difference driven flow occurs in the morning, a finding which is in agreement with the measurements. The model presented can be used for differentiating between factors affecting radon entry into houses.
Preliminary Survey of Indoor Radon Concentrations in Portuguese Houses from High Natural Radioactivity Regions
Authors: Faisca M.C. , de Bettencourt A.O. 
Published: February 2017

Abstract
The exploration of uranium ore started in Portugal at the beginning of the century, firstly for the extraction of radium and later for uranium. Radium processing wastes, uranium tailings, and their possible use in buildings contribute significantly to the enhancement of radon levels. A screening survey of indoor radon concentrations is initiated in houses from the granitic region of Beira Alta, in particular in the surroundings of an abandoned radium salts factory, near the mine and chemical treatment installations of Urgeirica, and the town of Guarda. Passive detectors are exposed for periods of one to two months. The preliminary results of this survey programme are presented and discussed. Indoor levels up to the order of 3 x 103 Bq.m-3 have been detected at Urgeirica as well as near the old radium salts factory at Barracao. These concentrations are compared with results for houses from the town of Guarda and also for some houses from the region of Lisbon.
Radon in an Alum Shale Rich Norwegian Area
Authors: Stranden E. , Strand T. 
Published: February 2017

Abstract
Alum shale is known to contain enhanced levels of radium, and may thus be a source of enhanced radon concentrations. The Hedemarken area in the south-eastern part of Norway has, due to its high geological occurrence of alum shale, been the subject of an extensive study on indoor radon. Measurements of the activity concentration of soil and shale, radon exhalation from the ground and from geological samples, are reported, together with measurements of indoor radon concentrations in about 200 houses. In about 70 houses, the radon concentration exceeded 400 Bq.m-3, and the highest concentration (mean value for a house) was 5300 Bq.m-3. Radon exhalation measurements from the ground suggest that the alum shale areas generally should be classified as high radon risk areas.
The Search for Radon Sources, A Multidisciplinary Task
Authors: Surbeck H. 
Published: February 2017

Abstract
In a city in the Swiss Jura, well known for its watch industry, there are high 222Rn concentrations in many houses (up to 4 kBq.m-3 in living rooms). Clear 226Ra contamination is present in and near former workshops that had processed radium activated paint, but enhanced radon levels are also measured in houses free from any contamination; thus the origin of the radon problem in this city is by no means clear. The methods used to localise the radium sources, to reveal the origin (natural or artificial) and to study the radon transport to the houses are presented.
Strategies to Reduce Exposure to Indoor Radon
Authors: Castrén O. 
Published: February 2017

Abstract
Various possible national strategies are analysed as to their cost-effectiveness. The estimated cost per averted collective dose, irrespective of who is juridically responsible for the cost, is used as a measure of the rationality of the strategy. The results show that the most cost-effective strategy is to find the dwellings with the highest indoor radon concentrations and to reduce the radon entry into them from the ground. Preventing radon entry into new houses does not seem to be as cost-effective as repairing existing houses. This is mainly due to the cost and difficulty of identifying in advance the building sites where an unacceptable level of concentration will occur unless preventive measures are taken. The analysis also shows that random sampling cannot be recommended for performing large scale surveys in a country with large geographical differences in radon occurrence. The sampling density should be higher in areas with higher concentrations.
Radon Reduction Techniques for Finnish Small Houses
Authors: Lehtoviita T. 
Published: February 2017

Abstract
The general principles and design methods of developed radon gas reduction techniques for Finnish small houses are discussed. Most of these methods have been worked out since 1984 in the Laboratory of Structural Engineering and Building Physics at the Helsinki University of Technology in cooperation with the Ministry of the Environment, the Finnish Centre of Radiation and Nuclear Safety and private building material companies. This work has concerned basic research and some practical development projects concerning radon gas reduction methods for existing dwellings and new detached houses. The results have been very encouraging. As a result of these research projects reports and guidebooks have been published in which the developed reduction techniques are presented. Also a design method of groundbased structures based on radon classification of soil has been developed. This article is a review of the results achieved.
Radon Reduction in Homes: Research Phase to Operational Phase
Authors: Mardis H.M. , Guimond R.J. , Fisher E. 
Published: February 2017

Abstract
The United States Environmental Protection Agency's (USEPA) House Evaluation Program (HEP) is an on-going programme designed to transfer research findings on radon diagnostic and mitigation technologies to the general public. The HEP accomplishes this technology transfer by providing guidance and hands-on training to States, homeowners, and local contractors while conducting radon diagnostics and mitigation design planning in houses. An overview of the HEP is given and the programme's accomplishments and findings to date are discussed.
Towards an Ab Initio Evaluation of the Wave-Vector- and Frequency-Dependent Dielectric Response Function for Crystalline Water
Authors: Zaider M. , Fry J.L. , Orr D.E. 
Published: February 2017

Abstract
We describe an ab initio calculation of the properties of energy loss by electrons in crystalline water using its dielectric response function, e(q), ?), where q and ? are, respectively, the wave vector and frequency. The calculation was performed on a model system (cubic ice) in order to take advantage of its ordered structure (i.e. Bloch's theorem), but also because of evidence that liquid water in biological systems ('structured' water) contains residues with tetrahedral structure (i.e. ice) over time scales of at least 10-11 s. The main features of the calculation are: (a) e(q,w) is evaluated in the random phase approximation (we used the expression given by Ehrenreich and Cohen), (b) the crystal potential is expressed as a sum of water-molecule self-consistent potentials, and (c) wave functions are expanded using tight binding functions (ultimately employing a Gaussian base set). A total of seven states (bands), five occupied and two conduction, are considered. We report the band structure and the density of states of the crystal, as well as values of e(q,w) at selected values of q and w. Results are compared with energy loss measurements and with absorption spectra (XPS, UPS, and VUV data). The possibility of using an empirical combination of molecular potentials as a phenomenological Hamiltonian is also examined.
Determination of Photon and Neutron Dose Fractions with Tissue-Equivalent Proportional Counters
Authors: Schrewe U.J. , Schuhmacher H. , Brede H.J. , Dietze G. 
Published: February 2017

Abstract
The separation of dose fractions due to neutrons and photons by means of tissue-equivalent proportional counters was investigated for ten different neutron fields. Nearly monoenergetic neutrons of energies between 12 keV and 1.2 MeV were produced by 7Li(p,n)7Be and 3H(p,n)3He reactions using pulsed proton beams. Time-of-flight (TOF) techniques were applied to distinguish between prompt neutrons and prompt photons originating from the neutron source. Dose fractions caused by the room background radiation were separated and subtracted. The dose distributions, d(y), obtained for prompt neutrons could therefore be analysed in the whole range of lineal energies, y, which overlap with events from photons. The logarithm of y.d(y) was found to be proportional to the logarithm of y. The slopes depend only slightly on the neutron energy. The experimentally determined shape of the dose distribution was compared with theoretical ion yield spectra. A procedure for separating neutron-photon dose fractions is discussed which does not require TOF techniques.
Analysis of Biological Effectiveness of Heavy Ions Using Two Microdosimetric Approaches
Authors: Waligorski M.P.R. , Morstin K. , Bond V.P. , Baum J.W. 
Published: February 2017

Abstract
Experimental data on chromosome aberrations induced in CH2B2 mammalian cells by heavy ion beams were analysed using a hit-size effectiveness approach and a cellular track structure theory. The two approaches, based on rather incompatible premises, differ widely in their predictions of low level radiation risk from X ray or gamma ray fields, and in their predictions of RBE-LET dependences. Though for different reasons, both approaches suggest limitations in applying the present formulations of dose and of dose related RBE or Quality Factors in the low level region of interest in radiation protection.
RBE-LET Relationships for V79 Cells Irradiated with Low Energy Protons
Authors: Belli M. , Cera F. , Cherubini R. , Ianzini F. , Moschini G. , Sapora O. , Simone G. , Tabocchini M.A. , Tiveron P. 
Published: February 2017

Abstract
Mutation curves of V79 Chinese hamster cells irradiated with low energy proton beams of LET ranging from 10 to 34 keV.µm-1 have been studied in the dose range of 0.5 - 2.0 Gy and compared with that obtained using 200 kV X rays. A substantial difference in the number of induced mutants, at the same dose, has been found when comparing protons and X rays, protons being more effective. The relative biological effectiveness (RBE) for mutation, evaluated as the a/ax ratios, were found to be significantly higher than those expected using heavier particles, in agreement with the results recently obtained for survival. This finding is discussed in terms of general validity of the 'classical' RBE-LET relationship when different types of radiations are compared.
Radiobiological Effects of Intracellular 210Po Alpha Emissions: A Comparison with Auger Emitters
Authors: Howell R.W. , Narra V.R. , Rao D.V. , Sastry K.S.R. 
Published: February 2017

Abstract
A daughter product of 226Ra, 210Po, emits 5.3 MeV a particles. The kinetics of uptake, retention, and cytotoxicity of 210Po-citrate have been studied in Chinese hamster V79 cells. The survival of V79 cells is exponentially dependent on the absorbed dose to the cell nucleus, the mean lethal dose (D37) being 700 mGy. These results, when compared with those obtained for Auger electron emitters incorporated into the DNA of V79 cells, confirm that Auger cascades are as effective as high LET a particles in causing biological damage.
Role of Dy in the Thermoluminescence of CaSO4:Dy
Authors: Morgan M.D. , Stoebe T.G. 
Published: February 2017

Abstract
Building on recent models of the thermoluminescence (TL) process in CaSO4:Dy, work is undertaken to delineate more specifically the role of the Dy impurity in the TL process. Thermally stimulated currents observations show that the recombination mechanism for peak 3 is bimolecular while that for peak 1 is monomolecular. TL results clearly show that the absence of Dy removes the dosimetric peak 3 near 220 oC in this material. Apparently, only Dy impurity develops the appropriate SO4 --VCa centres needed for observation of these peaks. The peak-3-related centres are shown to be quite different in behaviour from that of the structurally similar peak-1 - related SO4 --VCa centres. These results emphasise the importance of Dy impurities in stabilising the TL process needed to observe the dosimetric peak in this system.
Dosimetric Properties of Carbon Loaded LiF Detectors for Beta Photon Extremity Dosimetry
Authors: Burgkhardt B. , Klipfel A. 
Published: February 2017

Abstract
The dosimetric properties of carbon loaded LiF detectors manufactured by Alnor and Vinten are presented in comparison with various LiF detectors. In particular, the beta and photon response, the residual reading after repeated annealing in the oven or reader as well as light sensitivity and fading are discussed. In comparison with LiF detectors of 240 mg.cm-2, LiF + C detectors indicate a photon response of only 2% and in finger rings irradiated on a finger phantom an unexpected high photon energy response. Regarding repeated use, oven annealing in air or N2 affects mainly Vinten LiF + 1%C by discoloration and reduces the 147Pm response of LiF + C detectors by between 1% and 6% per N2 annealing, whereas reader annealing in the Toledo and Alnor reader does not affect the relative beta response. The residual dose H0 of LiF + C remains sufficiently low after oven annealing, but increases for Alnor LiF + 4% C after reader annealing, which is therefore more suitable for Vinten LiF + 1% C. Spurious detector reading exceeds H0 and its standard deviation by a factor of 2 to 3.
Natural CaF2 and Na2B4O7 Thermoluminescence Detector Sensitive to Thermal Neutrons
Authors: Fratin L. , Cruz M.T. 
Published: February 2017

Abstract
A thermoluminescence detector (TLD) sensitive to thermal neutrons based on CaF2 (nat) bound with Na2B4O7 has been produced. A second TLD using NaCl as a binder was used to measure the gamma component in the neutron irradiation field. The production techniques were established. Three different grain sizes were used to study the sensitivity and reproducibility of the detectors produced. Tests for neutron fluence determination within the range of interest for radiation protection (1 - 10 x 108nth.cm-2) showed that the sensitivity of the detectors has to be increased to allow their use in personnel monitoring.
The Relative, Prompt, Fast Neutron Kerma to RPL Conversion Efficiency ?n/?gamma of SEI and Toshiba FD-P10-7 RPL Glass Dosemeters
Authors: Croft S. , Weaver D.R. 
Published: February 2017

Abstract
Recently we have reported the measurement of the fast neutron sensitivities of SEI and Toshiba FD-P10-7 RPL glass dosemeters over the energy range En = 0.2 MeV to 15 MeV. Here we analyse these measurements within the framework of kerma calculations in order to extract ?n(En)/??(60Co), the prompt, fast neutron kerma to RPL conversion efficiency relative to the gamma kerma to RPL conversion efficiency measured using 60Co gamma radiation. In order to do this, both the prompt and activation neutron kerma factors of the two dosemeter materials were generated. The measured RPL sensitivities were corrected for the effects of glass activation on the basis of the calculated activation kerma before the ?n(En/??(60Co) values were calculated. Thus the parameter obtained relates specifically to the prompt action of fast neutrons, and as such, sheds light on the sensitivity of SEI and FD-P10-7 glasses to heavily ionising particulate radiation. It was found the ?n(En)/??(60Co) varied with energy in a similar way for both dosemeter types. Over the neutron energy range studied, the ?n(En)/??(60Co) ratio averaged 0.19 for SEI glass and 0.17 for Toshiba FD-7 glass. These values are consistent with the RPL conversion efficiencies, reported by other workers, for heavy charged particles acting on RPL dosemeters of similar composition.
On the Use of TLD for Gamma Ray Dosimetry Evaluation in Mixed Fast Neutron and Gamma Ray Fields
Authors: Wang T-K. 
Published: February 2017

Abstract
Some assessments are provided on the use of thermoluminescence dosemeters (TLDs) for ? ray dosimetry evaluation in mixed (fast neutron-? ray) radiation fields. Dosimetry measurements and calculations were performed in three different experimental arrangements driven by 252Cf sources. Measurements were made with TLD-200, TLD-400 and TLD-700. Various corrections including the TLD neutron sensitivities and the general cavity theory f factors were applied to the measurements. Calculations were performed using diffusion code 2DB and discrete ordinate transport codes ANISN and DOT. Good agreement was found between TLD-200, TLD-400 and TLD-700 results. Generic deviations were found between calculated and measured results. Analyses showed that, due to the inaccuracies in standard computational schemes, calculations underestimate the measured results.
A New Development of Dyed ECE Tracks for Radiation Dosimetry
Authors: Sohrabi M. , Sadeghi Bajd S. 
Published: February 2017

Abstract
In a new development, high contrast red dyed ECE recoil tracks in polycarbonate and, partially, in CR39, have been successfully achieved at AEOI for radiation dosimetry. The principle incentive has been the provision of high contrast photon absorbing large dyed tracks on an unaffected bulk material for UV and/or IR spectrophotometry. The method consists of: (a) exposing the polymer to charged particles or neutrons, (b) ECE of tracks, (c) acid sensitisation, and (d) dyeing with a suitable dye. By investigation of the type, concentration, duration and temperature of acid and dye, optimised values of 20% by weight acrylic acid at 75 oC for 3.5 h for sensitisation and 3% by weight eosin bluish at 95 oC for 4 h dyeing provided nearly 100% dyeing efficiency. The optimisation results are also presented and discussed.