TY  - JOUR
AB  - A potentially tissue-equivalent dosimeter based on lithium tetraborate co-doped with Cu and In was successfully synthesized in two steps melting process. Basic material properties were characterized using Differential scanning calorimetry, X-ray diffraction, and Fourier Transform Infrared Spectroscopy, the dosimetric properties using Thermoluminescence. The highest sensitivity was observed for dopant concentrations of 0.1% Cu and 0.5% In. Tmax-Tstop analysis revealed the existence of eight individual peaks in the composite TL glow curve, which was confirmed by computerized glow curve deconvolution. A linear dose-response was seen up to about 30 Gy, for higher doses saturation effects occurred. The minimum detectable dose was estimated at about 670 μGy. TL peaks, with peak temperature above 150 °C faded to values between 3.3 and 14.9% of the respective of initial values after 70 days storage.
AU  - El-Faramawy, N.*
AU  - Sabry, M.*
AU  - Farouk, S.*
AU  - El-Kinawy, M.*
AU  - Mafodda, A.
AU  - Woda, C.
C1  - 66589
C2  - 53221
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
TI  - Preliminary study of lithium tetraborate doped with Cu and in for external dosimetry.
JO  - Appl. Radiat. Isot.
VL  - 191
PB  - Pergamon-elsevier Science Ltd
PY  - 2023
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Luminescence dosimetry was applied in the former settlement of Metlino, Southern Urals, Russia as part of a full-scale study to validate the Techa River Dosimetry System (TRDS) 2016 for the upper Techa River region. The village, which was evacuated in 1956, was located 7 km downstream of the release point of liquid radioactive waste by the Mayak plutonium facility. Several brick samples were taken from north-eastern and south-eastern walls of the granary, facing the former Techa river shoreline and floodplain. Samples were all taken at the same height and measured at different depths into the brick. For the majority of brick samples, good Optically Stimulated Luminescence properties of the quartz grains were observed. In some cases, however, strong levels of sensitization and/or signal recuperation were encountered which necessitated adjustment in the measurement protocols. Anthropogenic doses in bricks varied from 1.5 to 6.6 Gy and the horizontal profiles along both walls showed significant variation, which is explained on a qualitative basis. A dose depth profile is observed for selected samples, which is different from the dose depth profile measured and simulated for samples from the north-western wall of the granary in previous studies. This is qualitatively explained by the differences in source configuration.
AU  - Woda, C.
AU  - Hiller, M.*
AU  - Ademola, J.A.*
AU  - Bugrov, N.G.*
AU  - Degteva, M.O.*
AU  - Napier, B.A.*
C1  - 67181
C2  - 53480
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
TI  - Luminescence dosimetry for evaluation of the external exposure in Metlino, upper Techa River valley, Southern Urals, Russia: Analysis of new results.
JO  - Appl. Radiat. Isot.
VL  - 193
PB  - Pergamon-elsevier Science Ltd
PY  - 2023
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - This paper compares trace element concentrations (Ca, K, Sr, Fe, Mn, Zn, Ni, Cu, Co and Cr) in 27 Sudanese medical plants determined in parallel by PIXE and ICP-OES to get information on which technique is preferable at different matrices and element concentrations. PIXE correlates well to ICP-OES for Sr, Mn, Ca, K, Zn and Fe determinations. ICP-OES seems to be the superior technique over PIXE when measuring low concentrated elements (chromium, cobalt, nickel and copper) in the medicinal plants.
AU  - Mubark Ebrahim, A.*
AU  - Etayeb, M.A.*
AU  - Khalid, H.*
AU  - Noun, M.*
AU  - Roumie, M.*
AU  - Michalke, B.
C1  - 31273
C2  - 34269
CY  - Oxford
SP  - 218-224
TI  - PIXE as a complement to ICP-OES trace metal analysis in Sudanese medicinal plants.
JO  - Appl. Radiat. Isot.
VL  - 90
PB  - Pergamon-elsevier Science Ltd
PY  - 2014
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - On the Nigerian Jos Plateau tin mining is extensively carried out in open pit style. Several types of materials occurring there (raw materials, waste, and soil) were analysed radiometrically. The geochemical host phases of the natural radionuclides were determined by a sequential extraction procedure according to the European BCR standard. It was found that especially easily mobilisable (228)Ra must be taken into consideration as a radioactive contaminant for the mining area.
AU  - Leopold, K.
AU  - Arogunjo, A.M.*
AU  - Giussani, A.
AU  - Höllriegl, V.
AU  - Oeh, U.
AU  - Veronese, I.*
AU  - Gerstmann, U.C.
C1  - 259
C2  - 26383
CY  - Oxford
SP  - 926-930
TI  - Inventory and geochemical host phases of natural radionuclides in tin mining materials from Nigeria.
JO  - Appl. Radiat. Isot.
VL  - 67
IS  - 5
PB  - Pergamon-Elsevier Science Ltd
PY  - 2009
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Radon and thoron decay products appear in two size modes: unattached and attached to aerosol particles. They deposit at different regions of the human respiratory tract causing different inhalation doses. A separate measurement of the concentration of both modes is realized by a new device based on a working level monitor and screen sampling. In addition, a new operation and evaluation procedure of the working level monitor is described to identify the thoron decay products (212)Pb and (212)Bi separately. First measurements reveal consistent results. The developments in measurement technique will enhance radon and thoron dose assessment.
AU  - Meisenberg, O.
AU  - Tschiersch, J.
C1  - 2089
C2  - 26964
CY  - Oxford
SP  - 843-848
TI  - Online measurement of unattached and total radon and thoron decay products.
JO  - Appl. Radiat. Isot.
VL  - 67
IS  - 5
PB  - Pergamon, Elsevier Science
PY  - 2009
SN  - 0969-8043
ER  - 

TY  - JOUR
AU  - Gerstmann, U.
C1  - 4162
C2  - 25129
SP  - 332-333
TI  - Comment on "Sequential determination of Pu and Am radioisotopes in environmental samples; a comparison of two separation procedures" by R. Jakopic, P. Tavcar and L. Benedik, Appl. Radiat. Isot. 65 (2007) 504-511.
JO  - Appl. Radiat. Isot.
VL  - 66
IS  - 3
PB  - Elsevier
PY  - 2008
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modelling for Radiation Safety (EMRAS) programme was established to improve modelling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.
AU  - Thiessen, K.M.*
AU  - Batandjieva, B.*
AU  - Andersson, K.G.*
AU  - Arkhipov, A.*
AU  - Charnock, T.W.*
AU  - Gallay, F.*
AU  - Gaschak, S.*
AU  - Golikov, V.*
AU  - Hwang, W.T.*
AU  - Kaiser, J.C.
AU  - Kamboj, S.*
AU  - Steiner, M.*
AU  - Tomás, J.*
AU  - Trifunovic, D.*
AU  - Yu, C.*
AU  - Zelmer, R.L.*
AU  - Zlobenko, B.*
C1  - 2296
C2  - 25795
SP  - 1741-1744
TI  - Improvement of modelling capabilities for assessing urban contamination: The EMRAS Urban Remediation Working Group.
JO  - Appl. Radiat. Isot.
VL  - 66
IS  - 11
PB  - Elsevier
PY  - 2008
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - After the nuclear reactor accident of Chernobyl, the "Integrated Measurement and Information System (IMIS) for Monitoring the Environmental Radioactivity and Detecting Emissions from Nuclear Plants was implemented in Germany. IMIS is a nationwide comprehensive measuring system which permanently monitors the radioactivity in all important environment media in the whole federal territory. At approximately 40 sites, the activity concentration of radioactive substances is measured in air and precipitations. At least 14 of them are responsible for trace monitoring of radionuclides in the air. The legal bases of IMIS prescribe regular inter-laboratory comparison analyses in cooperation with the Physikalisch-Technische Bundesanstalt (PTB), with the use of reference materials prepared by the Federal Coordinating Laboratories. In order to fulfil this requirement in the field of trace survey measurements in ground-level air, the Federal Office for Radiation Protection ("Bundesamt für Strahlenschutz", BfS) and the PTB have conducted a comparison with real, dust-loaded reference filters in 2005. The comparison was organized within the framework of a cooperation of trace survey stations from Austria, Germany and Switzerland. The paper describes the preparation of the real, dust-loaded reference filters, the procedure for spiking the filters with the activity standard solution containing (22)Na, (88)Y, (89)Sr, (90)Sr, (125)Sb, (133)Ba, (134)Cs, and (241)Am. Some results are discussed and conclusions are given.
AU  - Wershofen, H.*
AU  - Bieringer, J.*
AU  - Frenzel, S.*
AU  - Kanisch, G.*
AU  - Katzlberger, C.*
AU  - Steinkopff, T*
AU  - Tschiersch, J.
AU  - Völkle, H.*
C1  - 2373
C2  - 25477
SP  - 737-741
TI  - An inter-laboratory comparison of low-level measurements in ground-level aerosol monitoring.
JO  - Appl. Radiat. Isot.
VL  - 66
IS  - 6-7
PB  - Elsevier
PY  - 2008
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - From previous work, it is known that CO2− radicals in tooth enamel are induced by gamma as well as by UV-light exposure. The parameters of the EPR signal of the CO−2 radical were found to be independent of the source of exposure. However, it would be desirable for retrospective dosimetry to identify other characteristic features of the EPR spectrum of tooth enamel, which would allow differentiation between the two sources of exposure. In the present work, enamel of deciduous molars was exposed to γ-radiation from a 60Co-source and 254 nm UV-light from a low-pressure mercury lamp. The resulting EPR spectra were deconvoluted, and the native spectrum simulated from spectra of the CO−2 radical, and two further EPR lines. Both EPR signals of the native spectrum were located at g=2.0046, but were different in line shape and width. One was a 1 mT wide isotropic signal of Gaussian line shape while the other was a 0.7 mT wide axial signal of Lorentzian line shape. A comparable study of the amplitudes of the native and CO2− signals was done before and after γ- and UV-light exposure. While the native signals were found to be only slightly sensitive to γ-radiation, their amplitude increased significantly on UV-light exposure. Feasibilities are discussed to distinguish different radiation sources by exposure-induced alterations of the native EPR spectrum.
AU  - El-Faramawy, N.A.
C1  - 3695
C2  - 22474
SP  - 191-195
TI  - Comparison of gamma- and UV-light-induced EPR spectra of enamel from deciduous molar teeth.
JO  - Appl. Radiat. Isot.
VL  - 62
IS  - 2
PY  - 2005
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Enamel from 34 molars from 22 individuals in the general population are used to evaluate the background radiation in six cities in India. The estimation of the background dose for each tooth is evaluated using two EPR methods: the calibration-curve method and the additive-dose method. The variation of the estimated EPR dose with tooth position is investigated by using eight teeth taken from the same person. Contribution of the dental X-ray treatments to the enamel-absorbed dose was evaluated using another 17 teeth exposed from 1 to 10 times.
AU  - El-Faramawy, N.A.
C1  - 3696
C2  - 22475
SP  - 207-211
TI  - Estimation of radiation levels by EPR measurement of tooth enamel in Indian populations.
JO  - Appl. Radiat. Isot.
VL  - 62
IS  - 2
PY  - 2005
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  -  
      		
      	
      
      
      	ESR spectroscopy is currently taking root as a key technology in dosimetry, dating and imaging. In dosimetry, it competes with cytometry in the fields of biological dosimetry and retrospective dosimetry, leads in high-level reference and routine dosimetry, is high-ranking among the methods to identify radiation preserved foods, represents a method of choice to date geological, archaeological and paleontological materials back millions of years, and has demonstrated capacity for imaging. Further scientific and technological progress as predicted in the recent past (Appl. Radiat. Isot. 52 (2000) 1023) is reviewed here. Additionally, the review is expanded to include international reports and recommendations on ESR dosimetry and dose reconstruction, under way at the American Society for Testing and Materials (ASTM), the International Organisation of Standards (ISO), the International Atomic Energy Agency (IAEA) and the International Commission on Radiation Units and Measurements (ICRU). Emphasis is placed on interpretation of tooth enamel doses in terms of organ and effective doses, using CT-based virtual humans. The future of EPR spectroscopy for in situ dose measurements is noted, depicting a non-destructive in vivo dosimetry applicable directly to individuals, but also to hominid and animal fossils for direct dating.
      
      
      	 
AU  - Regulla, D.F.
C1  - 323
C2  - 22543
SP  - 117-127
TI  - ESR spectrometry: A future-oriented tool for dosimetry and dating.
JO  - Appl. Radiat. Isot.
VL  - 62
IS  - 2
PY  - 2005
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The aim of this paper is to analyze the lower limit of detection (LLD), linearity of dose response, variation of radiation sensitivity between different tooth enamel samples, and time/temperature stability of EPR biodosimetry in tooth enamel. The theoretical LLD is shown to be 0.46 mGy, which is far lower than the measured value of about 30 mGy. The main issues to lowering LLD are the differentiation of the radiation-induced component against the total EPR spectrum and the complex nature of the dose dependence of the EPR signal. The following questions are also discussed in detail: need for exfoliated or extracted teeth from persons of interest, accounting for background radiation contribution; conversion of tooth enamel absorbed dose to effective dose; accounting for internal exposure specifically from bone-seeking radionuclides. Conclusions on future development of EPR retrospective biodosimetry are made.
AU  - Romanyukha, A.A.*
AU  - Schauer, D.A.*
AU  - Thomas, J.A.*
AU  - Regulla, D.F.
C1  - 4544
C2  - 22544
SP  - 147-154
TI  - Parameters affecting EPR dose reconstruction in teeth.
JO  - Appl. Radiat. Isot.
VL  - 62
IS  - 2
PY  - 2005
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 11 molars, which were cut into two halves. One half of each tooth was irradiated in a 60Co beam to doses in the ranges of 30-100 mGy (5 samples), 100-300 mGy (5 samples), and 300-900 mGy (1 sample). Fourteen international laboratories participated in this intercomparison programme. A first analysis of the results and an overview of the essential features of methods applied in different laboratories are presented. The relative standard deviation of results of all methods was better than 27% for applied doses in the range of 79-704 mGy. In the analysis of the unirradiated tooth halves 8% of the samples were identified as outliers with additional absorbed dose above background dose.
AU  - Wieser, A.
AU  - Debuyst, R.*
AU  - Fattibene, P.*
AU  - Meghzifene, A.*
AU  - Onori, S.*
AU  - Bayankin, S.N.*
AU  - Blackwell, B.*
AU  - Brik, A.*
AU  - Bugay, A.*
AU  - Chumak, V.*
AU  - Ciesielski, B.*
AU  - Hoshi, M.*
AU  - Imata, H.*
AU  - Ivannikov, A.*
AU  - Ivanov, D.*
AU  - Junczewska, M.*
AU  - Miyazawa, C.*
AU  - Pass, B.*
AU  - Penkowski, M.*
AU  - Pivovarov, S.*
AU  - Romanyukha, A.*
AU  - Romanyukha, L.*
AU  - Schauer, D.*
AU  - Scherbina, O.*
AU  - Schultka, K.*
AU  - Shames, A.*
AU  - Sholom, S.*
AU  - Skinner, A.*
AU  - Skvortsov, V.*
AU  - Stepanenko, V.
AU  - Tielewuhan, E.*
AU  - Toyoda, S.*
AU  - Trompier, F.*
C1  - 1503
C2  - 22481
SP  - 163-171
TI  - The 3. International intercomparison on EPR tooth dosimetry: Part 1, general analysis.
JO  - Appl. Radiat. Isot.
VL  - 62
IS  - 2
PY  - 2005
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The radioisotopes of ruthenium (103Ru and 106Ru) are abundant fission products and represent a radiological risk for the population in case of nuclear accidents. Few biokinetic studies have been performed on humans up to now and consequently the current model recommended by ICRP for ruthenium is derived mainly by extrapolation from animal data. The stable isotope 101Ru and proton activation analysis have been used to study the biokinetics of Ru in blood plasma samples taken during 8 studies in three healthy volunteers. The results obtained demonstrated that complexed Ru (in the form of citrate Ru(IV) complexes) is cleared from blood plasma very rapidly (characteristic half time of 17+/-2 min), while inorganic Ru remains longer in the systemic circulation, and is transferred to other organs and/or excreted with a biological half time of 23+/-2h. Good reproducibility of the clearance curves indicated no evidence of inter- or intra-individual variability when the same Ru solution was injected in repeated experiments to different subjects.
AU  - Veronese, I.*
AU  - Giussani, A.*
AU  - Cantone, M.C.*
AU  - Birattari, C.*
AU  - Bonardi, M.*
AU  - Groppi, F.*
AU  - Höllriegl, V.
AU  - Roth, P.
AU  - Werner, E.
C1  - 1812
C2  - 21674
SP  - 7-13
TI  - Influence of the chemical form on the plasma clearance of ruthenium in humans.
JO  - Appl. Radiat. Isot.
VL  - 60
IS  - 1
PB  - Elsevier
PY  - 2004
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - There is much interest in understanding the biokinetics of zirconium in humans due to the potential radiological risk represented by the radionuclide 95Zr and by its daughter 95Nb. Despite the significance of zirconium, few data are available on the actual biokinetics of zirconium in humans. Accordingly the biokinetic model currently recommended by ICRP for this element is based mainly on data from animal experiments.
      
      	In this study, the use of the stable isotopes 90Zr and 96Zr as tracers has enabled the conduct of 6 biokinetic investigations in 3 healthy volunteers. These studies have provided new valuable information about intestinal absorption and kinetics in blood plasma of zirconium and have been used for the set-up of a more realistic compartmental model with possible applications for dosimetric purposes.
AU  - Veronese, I.*
AU  - Giussane, A.*
AU  - Cantone, M.C.*
AU  - Maggioni, T.*
AU  - Birattari, C.*
AU  - Groppi, F.*
AU  - Werner, E.
AU  - Roth, P.
AU  - Höllriegl, V.
C1  - 10350
C2  - 21093
SP  - 431-439
TI  - A re-evaluation of the biokinetics of zirconium in humans.
JO  - Appl. Radiat. Isot.
VL  - 58
IS  - 4
PY  - 2003
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Three different autoradiographical methods were tested for detection, localisation and quantification of radionuclides in hot particles deposited on air filters. With all methods, hot particles could successfully be localised on air filters. Two methods, a X-ray film technique and a digital autoradiography technique using a microchannel array detector, have been examined with particles of known activity and with particles on air filter samples of the Chernobyl area to be able to quantify the  activity in the hot particles consistently. The results obtained in this study suggest that the digital autoradiography system is a very useful tool having a high efficiency with a low measurement uncertainty and allowing short exposure times for extensive measurement tasks.
AU  - Yoschenko, V.I.*
AU  - Kashparov, V.A.*
AU  - Protsak, V.P.*
AU  - Tschiersch, J.
C1  - 22140
C2  - 20818
SP  - 95-102
TI  - Autoradiographical methods for the assessment of radionuclides in hot particles on filter samples.
JO  - Appl. Radiat. Isot.
VL  - 58
IS  - 1
PY  - 2003
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - After the end of atmospheric nuclear weapons tests and after the Chernobyl accident, the deposition characteristics of 137Cs changed from a predominant wet deposition to the present resuspension mechanism characterised by predominant dry deposition. To study the consequences of this change for deposition sampling, monthly deposition data from two collectors located at a distance of 600 m were compared from 1991 to 2000. On the average, the deposition rates differed by roughly a factor of two for 137Cs, whereas for the cosmogenic 7Be a difference was not detectable with statistical significance. Further, a “funnel” collector with a mostly dry surface collected on the long-term average 36% less of 137Cs, but 8% less of 7Be, than a “pot” collector with a continuously water-covered surface. Since for 137Cs deposition and the bulk deposition a similar behaviour was found, a stronger sensitivity of other resuspension-derived radionuclides against local and collector surface variations can generally be expected.
AU  - Rosner, G.
AU  - Winkler, R.
C1  - 21803
C2  - 19990
SP  - 823-829
TI  - Nuclide-dependent local and collector surface effects in samling of radioactive deposition to ground.
JO  - Appl. Radiat. Isot.
VL  - 55
IS  - 6
PY  - 2001
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The EPR dose response of tooth enamel was determined for human molars collected in Egypt. The influence of age, gender and residence of the tooth donors as well as tooth position and sample preparation on EPR sensitivity and its variability over the enamel samples was investigated. The EPR sensitivity and its variability were found to depend only on the sample preparation procedure. The variability in EPR sensitivity of enamel from Egyptian teeth was maximally 10% and the mean sensitivity was in good agreement with that of German teeth.
AU  - Wieser, A.
AU  - El-Faramawy, N.*
AU  - Meckbach, R.
C1  - 10349
C2  - 19841
SP  - 793-799
TI  - Dependencies of the radiation sensitivity of human tooth enamel in EPR dosimetry.
JO  - Appl. Radiat. Isot.
VL  - 54 
IS  - 5
PB  - Elsevier Science Ltd.
PY  - 2001
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - ESR spectroscopy represents a tool for quantitative radiation analysis that was developed somehow simultaneously for dating purposes in Japan and in Germany for high-level standardization, in the mid-seventies. Meanwhile, ESR dosimetry has reached an established metrology level. Present research fields of ESR dosimetry consider post-accident dose reconstruction in the environment, and biophysical dosimetry using human tissues. The latter promises a re-definition of radiation risk for chronicle exposure to be derived from individuals of the early nuclear facilities in Russia, and hopefully United States in the future. An attempt is made to sketch development and potential future of the ESR technique.
AU  - Regulla, D.F.
C1  - 21282
C2  - 19396
SP  - 1023-1030
TI  - From dating to biophysics: 20 years of progress in applied ESR spectroscopy.
JO  - Appl. Radiat. Isot.
VL  - 52
IS  - 5
PY  - 2000
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - This paper focuses on the opportunities to gain risk assessment information from populations exposed to ionizing radiation. Details are presented on the scale of the nuclear events in several areas within the former Soviet Union. An overview of the issues associated with dose reconstruction by electron paramagnetic resonance (EPR) is given. Principles and outline of the EPR tooth enamel dose assessment are described. Technical details, the latest achievements and the problems of each procedural step are analyzed. In addition, the present accuracy of the EPR dose reconstruction, its problems and cost are discussed.
AU  - Romanyukha, A.A.*
AU  - Desrosiers, M.F.*
AU  - Regulla, D.F.
C1  - 21283
C2  - 19397
SP  - 1265-1273
TI  - Current issues on EPR dose reconstruction in tooth enamel.
JO  - Appl. Radiat. Isot.
VL  - 52
IS  - 5
PY  - 2000
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - In dose reconstruction by EPR dosimetry with teeth various methods are applied to prepare tooth enamel samples and to evaluate the dosimetric signal. A comparison of seven frequently used methods in EPR dosimetry with tooth enamel was performed. The participating Institutes have applied their own procedure to prepare tooth enamel samples and to evaluate the dosimetric signal. The precision of the EPR measurement and the dependence of the estimated dosimetric signal with irradiation up to 1000 mGy were compared. The obtained results are consistent among the different methods. The reproducibility of the dosimetric signal and its estimated relation with the absorbed dose was found to be very close for the applied methods with one possible exception.
AU  - Wieser, A.
AU  - Onori, S.*
AU  - Aragno, D.*
AU  - Fattibene, P.*
AU  - Romanyukha, A.*
AU  - Ignatiev, E.*
AU  - Koshta, A.*
AU  - Skvortzov, V.*
AU  - Ivannikov, A.*
AU  - Stepanenko, V.*
C1  - 21353
C2  - 19469
SP  - 1059-1064
TI  - Comparison of sample preparation and signal evaluation methods for EPR analysis of tooth enamel.
JO  - Appl. Radiat. Isot.
VL  - 52
IS  - 5
PY  - 2000
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The complex conditions of irradiation in computed tomography (CT), involving highly-collimated X-ray beams, necessitate the use of specially-defined dose descriptors such as the computed tomography dose index (CTDI). When used in a weighted form (CTDIW), this concept can describe the absorbed dose from a single slice in standard head and body phantoms. The model can easily be extended to characterise patient exposure for a complete examination by means of the reference dose quantity dose-length product (DLP). Effective dose can also be estimated from DLP, when required.
AU  - Jessen, K.A.*
AU  - Shrimpton, P.C.*
AU  - Geleijns, J.*
AU  - Panzer, W.
AU  - Tosi, G.*
C1  - 20776
C2  - 18823
SP  - 165-172
TI  - Dosimetry for optimisation of patient protection in computed tomography.
JO  - Appl. Radiat. Isot.
VL  - 50
IS  - 1
PY  - 1999
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The precision of the thermoluminescent response of Harshaw micro-cube dosimeters (TLD-100), evaluated in both Harshaw thermoluminescent readers 5500 and 3500, for 1 Gy dose value, was investigated. The mean reproducibility for micro-cubes, pre-readout annealed at 100°C for 15 min, evaluated with the manual planchet reader 3500, is 0.61% (1 standard deviation). When micro-cubes are evaluated with the automated hot-gas reader 5500, reproducibility values are undoubtedly worse, mean reproducibility for numerically stabilised dosimeters being equal to 3.27% (1 standard deviation). These results indicate that the reader model 5500, or, at least, the instrument used for the present measurements, is not adequate for micro-cube evaluation, if precise and accurate dosimetry is required. The difference in precision is apparently due to geometry inconsistencies in the orientation of the imperfect micro-cube faces during readout, requiring careful and manual reproducible arrangement of the selected micro-cube faces in contact with the manual reader planchet.
AU  - Rossa, L.A.R. da*
AU  - Regulla, D.F.
AU  - Fill, U.A.
C1  - 20775
C2  - 18824
SP  - 573-577
TI  - Reproducibility study of TLD-100 micro-cubes at radiotherapy dose level.
JO  - Appl. Radiat. Isot.
VL  - 50
IS  - 3
PY  - 1999
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Series of monthly values of 137Cs and 7Be wet and dry deposition were measured with a wet-only and a dry-only collector each having an area of 2.25 m2. The results are presented for the period from November 1991 to May 1995. The behaviour of resuspended, Chernobyl-derived radiocesium is shown to be significantly different from that of cosmogenic 7Be and from that of global fallout 137Cs from nuclear weapons testing. The dry-to-total ratio of 0.65, the dry deposition velocity of 1.5 cm s−1, the close correlation to the total amount of solids collected and the absence of a correlation between activity deposition and amount of rainfall point to a strong similarity in the deposition behaviour of present radiocesium and that of stable elements of terrestrial origin such as Fe, Al, Ca, Mg etc.
AU  - Rosner, G.
AU  - Hötzl, H.
AU  - Winkler, R.
C1  - 20750
C2  - 17218
SP  - 1135-1139
TI  - Continuous Wet-only and Dry-only Deposition Measurements of 137Cs and 7 Be: an Indicator of their Origin.
JO  - Appl. Radiat. Isot.
VL  - 47
IS  - 9-10
PY  - 1996
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Irradiated egg shells exhibit a paramagnetic center at g = 2.0018. The center is stable up to temperatures of 150°C and against u.v. light. The center concentration as determined by electron paramagnetic resonance spectroscopy increases with absorbed dose. A dose range between 3 Gy-10 kGy was examined in which egg shells can serve as a dosimeter. Precision of measurement was found to be better than ± 10% on a 95% confidence level, for absorbed doses above 10 Gy. Egg shells are shown to be applicable for retrospective dosimetry after radiation accidents. | Irradiated egg shells exhibit a paramagnetic center at g = 2.0018. The center is stable up to temperatures of 150°C and against u.v. light. The center concentration as determined by electron paramagnetic resonance spectroscopy increases with absorbed dose. A dose range between 3 Gy-10 kGy was examined in which egg shells can serve as a dosimeter. Precision of measurement was found to be better than ±10% on a 95% confidence level, for absorbed doses above 10 Gy. Egg shells are shown to be applicable for retrospective dosimetry after radiation accidents.
AU  - Regulla, D.F.
AU  - Göksu, H.Y.
AU  - Vogenauer, A.
AU  - Wieser, A.
C1  - 39996
C2  - 38943
SP  - 371-373
TI  - Retrospective dosimetry based on egg shells.
JO  - Appl. Radiat. Isot.
VL  - 45
IS  - 3
PY  - 1994
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - As a result of EPR investigations on tooth enamel from radiation workers of the Russian nuclear facility 'Mayak' in South Ural, individual doses are reconstructed. The individual doses obtained range up to 3.89 Gy. It is shown that the reconstructed doses are unreasonable until very good agreement with the original personal doses as provided by the radiation protection authority. The findings first prove the applicability of EPR dosimetry on tooth enamel for a life-time including accident dose reconstruction of individuals as a basis for epidemiological studies.
AU  - Romanyukha, A.A.*
AU  - Regulla, D.F.
AU  - Vasilenko, E.K.*
AU  - Wieser, A.
C1  - 39993
C2  - 38936
SP  - 1195-1199
TI  - South ural nuclear workers: Comparison of individual doses from retrospective EPR dosimetry and operational personal monitoring.
JO  - Appl. Radiat. Isot.
VL  - 45
IS  - 12
PY  - 1994
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - During the TL- and ESR-Conference in Clemont-Ferrand in 1990 we initiated a second “Intercomparison project on ESR dating” in which 14 ESR groups participated. Each group was provided with two samples of a coral powder, one of which (Sample A) was a fossil coral with a mass spectrometric determined U/Th age. Sample B was a recent coral, irradiated with a definite γ-dose (checked by alanine dosimetry). In both cases the AD had to be determined (for sample A the U-content and age as well). Additionally, the chance of a calibration of γ-sources by alanine dosimeters was offered (GSF). The results show that (i) the γ-source calibration is better than ±5%, (ii) the mean value of the AD from sample A seems to agree with the expected AD but the mean AD value from sample B is overestimated, (iii) systematic errors occur due to the fitting procedure: the AD estimate depends on the maximum γ-dose used for the irradiation curve, (iv) the AD determination including the smallest systematic error gives correct values for sample B but too low values for sample A which may be caused by fading of the signal g = 2.0006.
AU  - Barabas, M.
AU  - Walther, R.
AU  - Wieser, A.
AU  - Radtke, U.
AU  - Grün, R.
C1  - 19683
C2  - 12811
SP  - 119-129
TI  - Second Interlaboratory-Comparison Project on ESR Dating.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - For some decades ferrous sulphate (Fricke) dosimetry was considered to be the method of choice for the calibration of therapy level dosimeters in terms of absorbed dose to water. Attempts to replace the Fricke by alanine/ESR dosimeters failed because of inadequate precision at the absorbed dose level of 40 Gy so far used for intercomparisons with Fricke dosimeters. The present paper, however, shows by a means of comparative measurements with ion chamber and thermoluminescent dosimeters that a coefficient of variation of lower than 0.5 % can be achieved for the alanine at the 30 Gy absorbed dose level. Together with further advantages of the alanine/ESR technique, e.g., its easy handling and reliability, this result is encouraging to use alanine as an alternative to Fricke dosimeters for the transfer of the quantity absorbed dose to water.
AU  - Feist, H.
AU  - Regulla, D.F.
AU  - Wieser, A.
C1  - 20474
C2  - 13682
SP  - 47-51
TI  - Is Alanine/ESR Dosimetry Now on Alternative to Ferrous Sulphate Dosimetry?.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - For some decades ferrous sulphate (Fricke) dosimetry was considered to be the method of choice for the calibration of therapy level dosimeters in terms of absorbed dose to water. Attempts to replace the Fricke by alanine/ESR dosimeters failed because of inadequate precision at the absorbed dose level of 40 Gy so far used for intercomparisons with Fricke dosimeters. The present paper, however, shows by a means of comparative measurements with ion chamber and thermoluminescent dosimeters that a coefficient of variation of lower than 0.5% can be achicved for the alanine at the 30 Gy absorbed dose level. Together with further advantages of the alanine/ESR technique, e.g., its easy handling and reliability, this result is encouraging to use alanine as an alternative to Fricke dosimeters for the transfer of the quantity absorbed dose to water. | For some decades ferrous sulphate (Fricke) dosimetry was considered to be the method of choice for the calibration of therapy level dosimeters in terms of absorbed dose to water. Attempts to replace the Fricke by alanine/ESR dosimeters failed because of inadequate precision at the absorbed dose level of 40 Gy so far used for intercomparisons with Fricke dosimeters. The present paper, however, shows by a means of comparative measurements with ion chamber and thermoluminescent dosimeters that a coefficient of variation of lower than 0.5% can be achieved for the alanine at the 30 Gy absorbed dose level. Together with further advantages of the alanine/ESR technique, e.g., its easy handling and reliability, this result is encouraging to use alanine as an alternative to Fricke dosimeters for the transfer of the quantity absorbed dose to water.
AU  - Feist, H.
AU  - Regulla, D.F.
AU  - Wieser, A.
C1  - 40309
C2  - 40000
SP  - 47-51
TI  - Is alanine/ESR dosimetry now an alternative to ferrous sulphate dosimetry?.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The IAEA has long been active in the field of high-dose standardization. In cooperation with the Gesellschaft für Umwelt und Gesundheit (GSF), Germany, an International Dose Assurance Service (IDAS) was established based on alanine/ESR dosimetry. This service operates over the range of 100 Gy to 100 kGy and is directed towards industrial radiation processing in IAEA Member States. In complements the IAEA/WHO TLD postal dose intercomparison service for dose assurance in hospital radiotherapy departments. Experience with the alanine high dose service suggests that the alanine dosimeter might provide superior performance to TLD in the therapy dose range.
      
      	Preliminary test measurements with the participation of GSF/Germany, Istituto Superiore di Sanità/Italy (both providing alanine dosimeters and their evaluation) and IAEA (providing) reference irradiations traceable to BIPM) seems to justify research efforts through an IAEA Coordinated Research Programme (CRP). This CRP, entitled “Therapy Level Dosimetry with the Alanine/ESR System” is presently under set-up. It will include general work common to all assigned/potential contract holders as well as some specific research topics in accordance to individual proposals of each participant.
      
      	 
AU  - Nette, H.P.
AU  - Onori, S.
AU  - Fattibene, P.
AU  - Regulla, D.F.
AU  - Wieser, A.
C1  - 19688
C2  - 12816
SP  - 7-11
TI  - Co-ordinated Research Efforts for Establishing an International Radiotherapy Dose Intercomparison Service based on the Alanine/ESR System.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The IAEA has long been active in the field of high-dose standardization. In cooperation with the Gesellschaft für Umwelt und Gesundheit (GSF), Germany, an International Dose Assurance Service (IDAS) was established based on alanine/ESR dosimetry. This service operates over the range of 100 Gy to 100 kGy and is directed towards industrial radiation processing in IAEA Member States. In complements the IAEA/WHO TLD postal dose intercomparison service for dose assurance in hospital radiotherapy departments. Experience with the alanine high dose service suggests that the alanine dosimeter might provide superior performance to TLD in the therapy dose range. Preliminary test measurements with the participation of GSF/Germany, Istituto Superiore di Sanità/Italy (both providing alanine dosimeters and their evaluation) and IAEA (providing) reference irradiations traceable to BIPM) seems to justify research efforts through an IAEA Coordinated Research Programme (CRP). This CRP, entitled "Therapy Level Dosimetry with the Alanine/ESR System" is presently under set-up. It will include general work common to all assigned/potential contract holders as well as some specific research topics in accordance to individual proposals of each participant.
AU  - Nette, H.P.*
AU  - Onori, S.*
AU  - Fattibene, P.*
AU  - Regulla, D.F.
AU  - Wieser, A.
C1  - 40238
C2  - 40016
SP  - IN1-IN2,7-11
TI  - Coordinated research efforts for establishing an in international radiotherapy dose intercomparison service based on the alanine/ESR system.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - It is shown that an international network of ESR dosimetry laboratories can exchange alanine samples for precise interlaboratory calibration in the absorbed dose range 0.01–100 kGy. For the experimental verification the alanine/ESR dosimetry laboratories and calibration centers of both the GSF-Forschungszentrum fur Umwelt und Gesundheit, Neuherberg, and the Istituto Superiore di Sanità (ISS), Rome, were mutually acting as a partial network. A blind test, together with the National Physical Laboratory (NPL), Teddington, UK, revealed agreement between the NPL administered doses and the doses reported by GSF and ISS within ±1%.
AU  - Regulla, D.F.
AU  - Bartolotta, A.
AU  - Deffner, U.
AU  - Onori, S.
AU  - Pantaloni, M.
AU  - Wieser, A.
C1  - 19681
C2  - 12809
SP  - 23-31
TI  - Calibration Network based on Alanine/ESR Dosimetry?.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - It is shown that an international network of ESR dosimetry laboratories can exchange alanine samples for precise interlaboratory calibration in the absorbed dose range 0.01-100 kCy. For the experimental verification the alanine/ESR dosimetry laboratories and calibration centers of both the CSF-Forschungszentrum fur Umwelt und Gesundheit, Neuherberg, and the Istituto Superiore di Sanita (ISS), Rome, were mutually acting as a partial network. A blind test, together with the National Physical Laboratory (NPL), Teddington, UK, revealed agreement between the NPL administered doses and the doses reported by GSF and ISS within ±1%. | It is shown that an international network of ESR dosimetry laboratories can exchange alanine samples for precise interlaboratory calibration in the absorbed dose range 0.01-100 kGy. For the experimental verification the alanine/ESR dosimetry laboratories and calibration centers of both the GSF-Forschungszentrum fur Umwelt und Gesundheit, Neuherberg, and the Istituto Superiore di Sanita (ISS), Rome, were mutually acting as a partial network. A blind test, together with the National Physical Laboratory (NPL), Teddington, UK, revealed agreement between the NPL administered doses and the doses reported by GSF and ISS within ±1%.
AU  - Regulla, D.F.
AU  - Bartolotta, A.
AU  - Deffner, U.
AU  - Onori, S.
AU  - Pantaloni, M.
AU  - Wieser, A.
C1  - 40252
C2  - 38892
SP  - 23-31
TI  - Calibration network based on alanine/ESR dosimetry.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The yield of radicals induced by ionizing radiation in the amino acid alanine and its quantification by ESR spectroscopy has proven excellent reproducibility. Those radicals trapped in the crystal lattice are prevented from recombination providing a thermally very stable system. This allows alanine to be applied as a transfer dosemeter. With paraffin-alanine probes ESR dosimetry can be performed with a standard deviation of ±0.5% in the dose range from 20 Gy up to 100 kGy. At 1 Gy dose level the error increases to ±6%. This dose level is three orders of magnitude higher than the calculated detection threshold for alanine with modern X-band ESR spectrometers. It was found that the poor standard deviation at the 1 Gy dose level, is not mainly produced by a bad signal-to-noise ratio but by a variable non-radiation induced ESR background signal from the alanine probes within a batch. In the present study the main sources of error for ESR dosimetry in the dose range below 20 Gy were analyzed. The influences of the production process, UV light and humidity upon the ESR background signal from paraffin-alanine probes were investigated. Measurements are shown indicating a second stable structure of the alanine radical at room temperature.
AU  - Wieser, A.
AU  - Lettau, C.
AU  - Fill, U.
AU  - Regulla, D.F.
C1  - 19673
C2  - 12775
SP  - 585-587
TI  - The Influence of Non-Radiation Induced ESR Background Signal from Paraffin-Allanine Probes for Dosimetry in the Radiation Therapy Dose Range.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Travertine precipitated from hyperalkaline paleo-groundwaters in Central Jordan appeared at first sight very suitable for dating by ESR and TL due to the presence of a g = 2.0036 ESR signal and 270°C TL peak. However the paleodose obtained by the additive dose method was found not to agree between TL and ESR, in spite of the fact that identical sample preparation, irradiation and heat treatment procedures were followed. The possibility of using the acid-insoluble silica residue is discussed for this particular type of travertine. | Travertine precipitated from hyperalkaline paleo-groundwaters in Central Jordan appeared at first sight very suitable for dating by ESR and TL due to the presence of a g = 2.0036 ESR signal and 270°C TL peak. However the paleodose obtained by the additive dose method was found not to agree between TL and ESR, in spite of the fact that identical sample preparation, irradiation and heat treatment procedures were followed. The possibility of using the acid-insoluble silica residue is discussed for this particular type of travertine.
AU  - Wieser, A.
AU  - Göksu, H.Y.
AU  - Regulla, D.F.
AU  - Fritz, P.J.
AU  - Vogenauer, A.
AU  - Clark, I.D.
C1  - 34073
C2  - 38910
SP  - 149-152
TI  - ESR and TL dating of travertine from Jordan: Complications in paleodose assessment.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The yield of radicals induced by ionizing radiation in the amino acid alanine and its quantification by ESR spectroscopy has proven excellent reproducibility. Those radicals trapped in the crystal lattice are prevented from recombination providing a thermally very stable system. This allows alanine to be applied as a transfer dosemeter. With paraffin-alanine probes ESR dosimetry can be performed with a standard deviation of ±0.5% in the dose range from 20 Gy up to 100 kGy. At 1 Gy dose level the error increases to ±6%. This dose level is three orders of magnitude higher than the calculated detection threshold for alanine with modern X-band ESR spectrometers. It was found that the poor standard deviation at the 1 Gy dose level, is not mainly produced by a bad signal-to-noise ratio but by a variable non-radiation induced ESR background signal from the alanine probes within a batch. In the present study the main sources of error for ESR dosimetry in the dose range below 20 Gy were analyzed. The influences of the production process, UV light and humidity upon the ESR background signal from paraffin-alanine probes were investigated. Measurements are shown indicating a second stable structure of the alanine radical at room temperature. | The yield of radicals induced by ionizing radiation in the amino acid alanine and its quantification by ESR spectroscopy has proven excellent reproducibility. Those radicals trapped in the crystal lattice are prevented from recombination providing a thermally very stable system. This allows alanine to be applied as a transfer dosemeter. With paraffin-alanine probes ESR dosimetry can be performed with a standard deviation of ±0.5% in the dose range from 20 Gy up to 100 kGy. At 1 Gy dose level the error increases to ±6%. This dose level is three orders of magnitude higher than the calculated detection threshold for alanine with modern X-band ESR spectrometers. It was found that the poor standard deviation at the 1 Gy dose level, is not mainly produced by a bad signal-to-noise ratio but by a variable non-radiation induced ESR background signal from the alanine probes within a batch. In the present study the main sources of error for ESR dosimetry in the dose range below 20 Gy were analyzed. The influences of the production process, UV light and humidity upon the ESR background signal from paraffin-alanine probes were investigated. Measurements are shown indicating a second stable structure of the alanine radical at room temperature.
AU  - Wieser, A.
AU  - Lettau, C.
AU  - Fill, U.A.
AU  - Regulla, D.F.
C1  - 40383
C2  - 40078
SP  - 59-65
TI  - The influence of non-radiation induced ESR background signal from paraffin-alanine probes for dosimetry in the radiotherapy dose range.
JO  - Appl. Radiat. Isot.
VL  - 44
IS  - 1-2
PY  - 1993
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The effect emerging when ionization chamber extension cables are in a radiation field is analyzed in terms of energy dependence and linearity of the response. In the region of 100 keV x-rays the effect reaches maximum values and for 137Cs radiation fields, minimum values. Linear behaviour was observed between 5 and 40 cm of irradiated extension cable length.
AU  - Caldas, L.V.E.
AU  - Regulla, D.F.
AU  - Pychlau, P.
C1  - 18919
C2  - 11291
SP  - 93-94
TI  - Ionization Chamber Extension Cables: Radiation Effects.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 1
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The effect emerging when ionization chamber extension cables are in a radiation field is analyzed in terms of energy dependence and linearity of the response. In the region of 100 keV x-rays the effect reaches maximum values and for 137Cs radiation fields, minimum values. Linear behaviour was observed between 5 and 40 cm of irradiated extension cable length.
AU  - Caldas, L.V.E.
AU  - Regulla, D.F.
AU  - Pychlau, P.J.
C1  - 42058
C2  - 36490
SP  - 93-94
TI  - Ionization chamber extension cables: Radiation effects.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 1
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AU  - Chu, S.
AU  - Wieser, A.
AU  - Feist, H.
AU  - Regulla, D.F.
C1  - 17920
C2  - 11383
SP  - 993-996
TI  - ESR/Alanine Dosimetry of High-energy Electrons in Radiotherapy.
JO  - Appl. Radiat. Isot.
VL  - 40
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Dosimetry with detectors of organic material and electron spin resonance (ESR) spectroscopy for readout has been developed metrologically at GSF for high-level photon radiation. The tissue-equivalent probes also appear appropriate for therapy-level dosimetry. Here, results of dose measurements are reported which were performed in a water phantom using high-energy electrons as produced by a linear accelerator. Firstly, the dose range of the ESR/alanine dosimetry system had to be extended down to around 1 Gy. On this basis the response of the alanine dosimeters was determined for electrons at different therapeutic dose levels from less than 0.5 Gy to 10 Gy. Finally depth-dose measurements were carried out for electrons with initial energies up to 21 MeV. Comparisons between ESR/alanine and ion chamber dosimetry were made performing depth-dose measurements in a water phantom to examine the agreement of both methods under field conditions.
AU  - Chu, S.
AU  - Wieser, A.
AU  - Feist, H.W.
AU  - Regulla, D.F.
C1  - 41907
C2  - 36500
SP  - 993-996
TI  - ESR/alanine dosimetry of high-energy electrons in radiotherapy.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Based on a literature survey, solid materials of crystalline, amorphous, sintered and ceramic origin were selected and investigated for dosimetric applicability up to 100 MGy at irradiation temperatures up to 200°C. The thermal stability of the radiation induced centers was studied by post-irradiation annealing. Metrologically, electron spin resonance (ESR) spectroscopy, optical spectroscopy and thermoluminescence analysis were used. The results as achieved with the investigated detector materials are considered in view of practicability. Limitations due to center instability and saturation effects are reported. | Based on a literature survey, solid materials of crystalline, amorphous, sintered and ceramic origin were selected and investigated for dosimetric applicability up to 100 MGy at irradiation temperatures up to 200°C. The thermal stability of the radiation induced centers was studied by post-irradiation annealing. Metrologically, electron spin resonance (ESR) spectroscopy, optical spectroscopy and thermoluminescence analysis were used. The results as achieved with the investigated detector materials are considered in view of practicability. Limitations due to center instability and saturation effects are reported.
AU  - Göksu, H.Y.
AU  - Wieser, A.
AU  - Waibel, A.
AU  - Vogenauer, A.
AU  - Regulla, D.F.
C1  - 33834
C2  - 36580
SP  - 905-909
TI  - Comparing measurements of free radicals, optical density and thermoluminescence in solids for high-level dosimetry.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Humic substances in aqueous solution undergo characteristics alterations when irradiated with light of wavelengths >290 nm. Humic substances subjected to a preliminary irradiation are less capable of generating reactive oxygen species. This effect is illustrated by changes in spectroscopic (u.v., ESR) and other physical properties of the samples.
AU  - Kotzias, D.
AU  - Beyerle-Pfnür, R.
C1  - 17545
C2  - 10474
SP  - 897-899
TI  - Characterization of Humic Substances by ESR Spectroscopy.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Humic substances in aqueous solution undergo characteristic alterations when irradiated with light of wavelengths > 290 nm. Humic substances subjected to a preliminary irradiation are less capable of generating reactive oxygen species. This effect is illustrated by changes in spectroscopic (u.v., ESR) and other physical properties of the samples. | Humic substances in aqueous solution undergo characteristic alterations when irradiated with light of wavelengths > 290 nm. Humic substances subjected to a preliminary irradiation are less capable of generating reactive oxygen species. This effect is illustrated by changes in spectroscopic (u.v., ESR) and other physical properties of the samples.
AU  - Kotzias, D.
AU  - Beyerle-Pfnür, R.
C1  - 41804
C2  - 36503
SP  - 897-899
TI  - Characterization of humic substances by ESR spectroscopy.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Alanine and radiochromic film dosimeters were irradiated with absorbed doses from 3 to 10 kGy at a 10 MeV electron accelerator under typical radiation processing conditions. The nominal doses were measured by graphite calorimeters and the dosimeters were irradiated in graphite phantoms. The dosimeters were calibrated by irradiation with 60Co photons.
      
      	The ratios of calorimeter to film and alanine dosimeter readings were generally within 0.99 ± 0.01 for 10 mm phantoms, but larger differences were observed for 20 mm phantoms. The discrepancies may be due to uncertainties in irradiation geometry, or in the stopping power ratios applied.
AU  - Miller, A.
AU  - Kovacs, A.
AU  - Wieser, A.
AU  - Regulla, D.F.
C1  - 17924
C2  - 11387
SP  - 967-969
TI  - Measurements with Alanine and Film Dosimeters for Industrial 10 MeV Electron Reference Dosimetry.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - For the standardization of radiation processing dosimetry on an international scale, and for further promotion of dosimetry as quality control measures in high-dose applied research and irradiation industry, the International Dose Assurance Service (IDAS) has been initiated in the framework of the high-dose standardization programme. IDAS is being provided on the basis of an Agreement between IAEA and its Member States. As a transfer standard the GSF-operated ESR/alanine dosimeter has been used for the service. The significance of IDAS and the major achievements made to date are discussed.
AU  - Nam, J.W.
AU  - Regulla, D.F.
C1  - 17923
C2  - 11386
SP  - 953-955
TI  - The Significance of the International Dose Assurance Service for Radiation Processing.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - Feasibility of dating caliche nodules by ESR and TL is investigated. For both methods the properties of the dating signal are described. Chemical composition as well as TL glow curves of caliches originating from different localities exhibit some differences. Due to the complexity of the TL glow curves, some samples required a special post-annealing procedure in order to resolve the main TL peak for age determination. Typical ESR calcite signals do not exist in caliche, therefore usefulness of the g = 2.0040 ESR signal is studied. The results of TL and ESR ages are found to be compatible except for two samples. Possible causes of the discrepancy in these samples are discussed. It is shown that, with proper treatment of the radiation-induced signals, it was possible to date caliche formations older than 350 ka, which is not achieveable with other methods like uranium series disequilibrium and/or radiocarbon dating.
AU  - Özer, A.M.
AU  - Wieser, A.
AU  - Göksu, H.Y.
AU  - Müller, P.
AU  - Regulla, D.F.
AU  - Erol, O.
C1  - 17925
C2  - 11388
SP  - 1159-1162
TI  - ESR and TL Age Determination of Caliche Nodules.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - In Norway, 1982, a fatal radiation accident occurred at a radioactive cobalt source used for radiation processing. There was a lack of realistic estimates on the victim's tissue or body doses up to his death. GSF was able to provide the first reliable dose values, upon request from Norwegian colleagues. Dosimetry was performed by ESR spectroscopy of long-lived radiation-induced radicals that could be measured in the heart tablets of the victim. The concentration of the free radicals proved, by proper calibration, to be proportional to dose. Procedures and dose results are reported; comparison is made with data from literature dealing with the same subject and also using TL as well as ESR. For biological relevance, the doses as determined from the tablets are converted into whole-body doses.
AU  - Regulla, D.F.
AU  - Deffner, U.
C1  - 17926
C2  - 11389
SP  - 1039-1043
TI  - Dose Estimation by ESR Spectroscopy at a Fatal Radiation Accident.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - In Norway, 1982, a fatal radiation accident occurred at a radioactive cobalt source used for radiation processing. There was a lack of realistic estimates on the victim's tissue or body doses up to his death. GSF was able to provide the first reliable dose values, upon request from Norwegian colleagues. Dosimetry was performed by ESR spectroscopy of long-lived radiation-induced radicals that could be measured in the heart tablets of the victim. The concentration of the free radicals proved, by proper calibration, to be proportional to dose. Procedures and dose results are reported; comparison is made with data from literature dealing with the same subject and also using TL as well as ESR. For biological relevance, the doses as determined from the tablets are converted into whole-body doses. | In Norway, 1982, a fatal radiation accident occurred at a radioactive cobalt source used for radiation processing. There was a lack of realistic estimates on the victim's tissue or body doses up to his death. GSF was able to provide the first reliable dose values, upon request from Norwegian colleagues. Dosimetry was performed by ESR spectroscopy of long-lived radiation-induced radicals that could be measured in the heart tablets of the victim. The concentration of the free radicals proved, by proper calibration, to be proportional to dose. Procedures and dose results are reported; comparison is made with data from literature dealing with the same subject and also using TL as well as ESP. For biological relevance, the doses as determined from the tablets are converted into whole-body doses.
AU  - Regulla, D.F.
AU  - Deffner, U.
C1  - 41997
C2  - 36493
SP  - 1039-1043
TI  - Dose estimation by ESR spectroscopy at a fatal radiation accident.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AU  - Regulla, D.F.
AU  - Scharmann, A.*
AU  - McLaughlin, W.L.*
C1  - 42671
C2  - 40289
SP  - VII-VIII
TI  - Preface.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - The energy response of alanine dosimeter probes with 20% paraffin admixtures for neutron energies between 0.6 and 15 MeV was determined experimentally using accelerator-produced monoenergetic neutrons. Theoretical considerations are made to estimate the energy dependence of the response relative to the response to photons. An optimum mixture of alanine and paraffin is derived which would give an energy-independent neutron tissue dose-response, if the kerma ratio were the only factor influencing the energy response. | The energy response of alanine dosimeter probes with 20% paraffin admixtures for neutron energies between 0.6 and 15 MeV was determined experimentally using accelerator-produced monoenergetic neutrons. Theoretical considerations are made to estimate the energy dependence of the response relative to the response to photons. An optimum mixture of alanine and paraffin is derived which would give an energy-independent neutron tissue dose-response, if the kerma ratio were the only factor influencing the energy response.
AU  - Schraube, H.
AU  - Weitzenegger, E.
AU  - Wieser, A.
AU  - Regulla, D.F.
C1  - 41202
C2  - 36509
SP  - 941-944
TI  - Fast neutron response of alanine probes.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - ESR spectroscopy of radiation induced free radicals in organic and inorganic solids has recently been accepted for photon dosimetry in the high-level dose range. With alanine as the commonly used dosimetric material, the ESR spectroscopy has proven reliable applicability for doses up to 0.5 MGy irradiation and storage temperatures up to 50°C. The upper detection limit is given by effects of saturation, respectively thermal instability of the radiation induced paramagnetic centres. For most solid materials saturation of the paramagnetic centres is reached at dose levels below or equal to 1 MGy. It was the subject of the present study to develop a dosimetric procedure that (a) allows for dosimetry at dose levels between, at least, 0.01 MGy and 0.1 GGy, (b) operates at irradiation temperature levels up to 250°C, and (c) is able to integrate the radiation dose over periods of up to 5 y. Among the different crystalline and amorphous materials investigated, crystalline quartz was found to match best the requirements. It is the E'1 centre in quartz that could be shown not to saturate up to absorbed doses of at least 50 MGy, and provide thermal stability up to at least 200°C for long periods of irradiation time.
AU  - Wieser, A.
AU  - Regulla, D.F.
C1  - 17921
C2  - 11384
SP  - 911-913
TI  - ESR Dosimetry in the "Gigarad" Range.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - GSF operates the only IAEA high-level dosimetry reference laboratory and, as a joint project with the IAEA, the International Dose Assurance Service (IDAS). Dosimetry is based on long-lived free radicals in organic alanine induced by ionizing radiation and readout by ESR spectroscopy. The thermal time response of the radical concentration in alanine is fairly constant after irradiation provided that the alanine samples are stored at temperatures below 50°C. By contrast, a positive temperature coefficient had earlier been found at GSF for the production rate of alanine radicals, for irradiation temperatures between 0 and 50°C. This effect has to be considered for reference dosimetry in radiation processing. Radiation processing is also of interest at irradiation temperatures below 0°C. The present study describes experiments on the influence of irradiation temperatures between +50 and -100°C. Comparison is made between the present and earlier results, in the overlapping temperature range. An empirical function is proposed for the temperature coefficient based on the experimental data.
AU  - Wieser, A.
AU  - Siegele, R.
AU  - Regulla, D.F.
C1  - 17922
C2  - 11385
SP  - 957-959
TI  - Influence of the Irradiation Temperature on the Free-radical Response of Alanine.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - ESR spectroscopy of radiation induced free radicals in organic and inorganic solids has recently been accepted for photon dosimetry in the high-level dose range. With alanine as the commonly used dosimetric material, the ESR spectroscopy has proven reliable applicability for doses up to 0.5 MGy irradiation and storage temperatures up to 50°C. The upper detection limit is given by effects of saturation, respectively thermal instability of the radiation induced paramagnetic centres. For most solid materials saturation of the paramagnetic centres is reached at dose levels below or equal to 1 MGy. It was the subject of the present study to develop a dosimetric procedure that (a) allows for dosimetry at dose levels between, at least, 0.01 MGy and 0.1 GGy, (b) operates at irradiation temperature levels up to 250°C, and (c) is able to integrate the radiation dose over periods of up to 5 y. Among the different crystalline and amorphous materials investigated, crystalline quartz was found to match best the requirements. It is the E1' centre in quartz that could be shown not to saturate up to absorbed doses of at least 50 MGy, and provide thermal stability up to at least 200°C for long periods of irradiation time. | ESR spectroscopy of radiation induced free radicals in organic and inorganic solids has recently been accepted for photon dosimetry in the high-level dose range. With alanine as the commonly used dosimetric material, the ESR spectroscopy has proven reliable applicability for doses up to 0.5 MGy irradiation and storage temperatures up to 50°C. The upper detection limit is given by effects of saturation, respectively thermal instability of the radiation induced paramagnetic centres. For most solid materials saturation of the paramagnetic centres is reached at dose levels below or equal to 1 MGy. It was the subject of the present study to develop a dosimetric procedure that (a) allows for dosimetry at dose levels between, at least, 0.01 MGy and 0.1 GGy, (b) operates at irradiation temperature levels up to 250°C, and (c) is able to integrate the radiation dose over periods of up to 5y.
AU  - Wieser, A.
AU  - Regulla, D.F.
C1  - 33842
C2  - 36530
SP  - 911-913
TI  - ESR dosimetry in the 'gigarad' range.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  - 

TY  - JOUR
AB  - GSF operates the only IAEA high-level dosimetry reference laboratory and, as a joint project with the IAEA, the International Dose Assurance Service (IDAS). Dosimetry is based on long-lived free radicals in organic alanine induced by ionizing radiation and readout by ESR spectroscopy. The thermal time response of the radical concentration in alanine is fairly constant after irradiation provided that the alanine samples are stored at temperatures below 50°C. By contrast, a positive temperature coefficient had earlier been found at GSF for the production rate of alanine radicals, for irradiation temperatures between 0 and 50°C. This effect has to be considered for reference dosimetry in radiation processing. Radiation processing is also of interest at irradiation temperatures below 0°C. The present study describes experiments on the influence of irradiation temperatures between +50 and -100°C. Comparison is made between the present and earlier results, in the overlapping temperature range. An empirical function is proposed for the temperature coefficient based on the experimental data. | GSF operates the only IAEA high-level dosimetry reference laboratory and, as a joint project with the IAEA, the International Dose Assurance Service (IDAS). Dosimetry is based on long-lived free radicals in organic alanine induced by ionizing radiation and readout by ESR spectroscopy. The thermal time response of the radical concentration in alanine is fairly constant after irradiation provided that the alanine samples are stored at temperatures below 50°C. By contrast, a positive temperature coefficient had earlier been found at GSF for the production rate of alanine radicals, for irradiation temperatures between 0 and 50°C. This effect has to be considered for reference dosimetry in radiation processing. Radiation processing is also of interest at irradiation temperatures below 0°C. The present study describes experiments on the influence of irradiation temperatures between +50 and -100°C. Comparison is made between the present and earlier results, in the overlapping temperature range. An empirical function is proposed for the temperature coefficient based on the experimental data.
AU  - Wieser, A.
AU  - Siegele, R.N.
AU  - Regulla, D.F.
C1  - 42601
C2  - 36426
SP  - 957-959
TI  - Influence of the irradiation temperature on the free-radical response of alanine.
JO  - Appl. Radiat. Isot.
VL  - 40
IS  - 10-12
PY  - 1989
SN  - 0969-8043
ER  -