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Sample records for biological radiation dosimeter

  1. Radiation dosimeters

    International Nuclear Information System (INIS)

    A radiation dosimeter is a device, instrument or system that measures or evaluates, either directly or indirectly, the quantities exposure, kerma, absorbed dose or equivalent dose, or their time derivatives (rates), or related quantities of ionizing radiation. A dosimeter along with its reader is referred to as a dosimetry system. Measurement of a dosimetric quantity is the process of finding the value of the quantity experimentally using dosimetry systems. The result of a measurement is the value of a dosimetric quantity expressed as the product of a numerical value and an appropriate unit. To function as a radiation dosimeter, the dosimeter must possess at least one physical property that is a function of the measured dosimetric quantity and that can be used for radiation dosimetry with proper calibration. In order to be useful, radiation dosimeters must exhibit several desirable characteristics. For example, in radiotherapy exact knowledge of both the absorbed dose to water at a specified point and its spatial distribution are of importance, as well as the possibility of deriving the dose to an organ of interest in the patient. In this context, the desirable dosimeter properties will be characterized by accuracy and precision, linearity, dose or dose rate dependence, energy response, directional dependence and spatial resolution. Obviously, not all dosimeters can satisfy all characteristics. The choice of a radiation dosimeter and its reader must therefore be made judiciously, taking into account the requirements of the measurement situation

  2. Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter

    International Nuclear Information System (INIS)

    The final report is on the work carried out under the Agency research contract 3173/RB entitled ''Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter'', at the Clinical Hospital Centre ''Zvezdara'' in Belgrade, Yugoslavia. In co-operation and co-ordination dissemination with an international team of cytogeneticists under the IAEA CRP, the development of a suitable biological dosimetry system has been accomplished at the national institute to assist reliably in the absorbed radiation-dose assessment of accidentally-over-exposed personnel. The quantitative yield of asymmetrical chromosomal aberrations, such as dicentrics, rings and fragments consequent to exposure(s) to radiation overdose, help in such estimation of vital prognostic and radiation protection significance. This biological dosimeter system is particularly essential where the exposed person was not wearing any physical dosemeter during the accident. Prerequisite for implementation of an effective biological dosimetry is the availability of a reliable standard dose-response curve and an adherence to a protocol for lymphocytic chromosome analysis in first division phase of lymphocytes. The validation of the reported biological dosimeter is established through its successful analysis of a simulated over-exposure incident, with the associated error of less than 10%. Analytical cytogenetic methods for whole- and part-body acute exposures have been discussed. Part of the results have been reported in the publications under the CRP concerned

  3. Cytogenetic techniques as biological indicator and dosimeter of radiation damage

    International Nuclear Information System (INIS)

    Full text: The cytogenetic methods are established techniques for bio monitoring and bio dosimetry of professionally and accidentally exposed to ionizing radiation subjects. They are applied to continue the evaluation of the physical dosimetry and to consider the individual radiosensitivity. The results of cytogenetic monitoring and dosimetry of radiation exposed subjects carried out during the last 5 years in laboratory of Radiation Genetics, NCRRP is reported. Laboratory of Radiation genetics performs cytogenetic monitoring of low dose radiation professionally or medically exposed subjects: workers in Kozloduy NPP, radioactive waste repository workers, X-rays diagnostically exposed patients, and radiotherapy exposed as well. Three cytogenetic indicators are applied as the most sensitive indicators for human radiation exposure: analysis of micronuclei (MN), chromosomal aberrations (CA) and stable translocations (FISH). The optimized methodology for application of different cytogenetic techniques for radiation estimation is discussed

  4. Biological dosimeter for UV-radiation and alpha particles, based on DNA damages

    International Nuclear Information System (INIS)

    A bioluminescence method for determination of biologically relevant (DNA damaging) doses of UV-radiation and alpha particles is developed. The method is based on bacterial luminescence as a bio-marker regulated by the SOS system. Cultures of E. coli cells transformed with the plasmid pPSL1 which carries the lux gene under control of the col promotor, an SOS-controlling gene, is used. The lux gene encode the enzyme luciferase which takes part in the reaction, resulting in the emission of a visible light at 490 nm. The light output is measured by photomultiplier and one channel analyzer. SOS-response kinetic curves of bacteria, UV-irradiated and treated with alpha particles, are obtained. An assessment of the risk from solar UV-radiation is made. The method has the sensitivity required to be used as biological UV-dosimeter (author)

  5. Radiation-induced apoptosis in human lymphocytes: Potential as a biological dosimeter

    International Nuclear Information System (INIS)

    We have tested the possibility of using apoptosis (programmed cell death) in human peripheral blood lymphocytes as a short-term biological dosimeter. Lymphocytes isolated from whole blood were irradiated in culture with 250 kVp x-rays or 60Co gamma rays. Two assays were used to measure apoptosis in lymphocytes after irradiation: in situ terminal deoxynucleotidyl transferase assay and fluorescence analysis of DNA unwinding assay. Similar qualitative and quantitative results were produced by the assays, supporting the notion that the fluorescence analysis of DNA unwinding assay measured DNA fragmentation associated with apoptosis. Induction of apoptosis in lymphocytes irradiated in vitro was proportional to dose and could be detected following exposures as low as 0.05 Gy. Lymphocytes irradiated in vitro was proportional to dose and could be detected following exposures as low as 0.05 Gy. Lymphocytes from individual donors had reproducible dose responses. There was, however, variation between donors. X-ray and gamma-ray exposures induced similar levels of apoptosis at similar doses. The induction kinetics of apoptosis in vitro indicate a maximum is reached about 72 h after irradiation. In conclusion, the in vitro experimental evidence indicates that radiation-induced apoptosis in human lymphocytes has the kinetics, sensitivity, and reproductibility to be a potential biological dosimeter. 29 refs., 5 figs

  6. Miniature Active Space Radiation Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

  7. Investigation of the effect of ionizing radiation on gene expression variation by the 'DNA chips': feasibility of a biological dosimeter

    International Nuclear Information System (INIS)

    After having described the different biological effects of ionizing radiation and the different approaches to biological dosimetry, and introduced 'DNA chips' or DNA micro-arrays, the author reports the characterization of gene expression variations in the response of cells to a gamma irradiation. Both main aspects of the use DNA chips are investigated: fundamental research and diagnosis. This research thesis thus proposes an analysis of the effect of ionizing radiation using DNA chips, notably by comparing gene expression modifications measured in mouse irradiated lung, heart and kidney. It reports a feasibility study of bio-dosimeter based on expression profiles

  8. Radiation dosimeters for medical use

    International Nuclear Information System (INIS)

    The several personal radiation dosimeter types for medical use, which look like promising for this kind of application, as pMOS (RADFET) dosimeter, direct ion storage (DIS) dosimeters, thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters, are described, and their advantages and disadvantages are analyzed. The p-channel metal-oxide-semiconductor (pMOS) dosimetric transistors allow dose measurements in vivo in real time, and they are especially important for radiotherapy. Direct ion storage (DIS) dosimeters are a hybrid of ion chamber and floating gate MOSFETs (FGMOSFETs), show very high sensitivity. Radiative processes that happen during the exposure of crystal to radiation are classified as prompt luminescence or radioluminescence (RL). In the case of an emission during stimulation, this phenomenon is referred to thermoluminescence or optically stimulated luminescence depending on whether the stimulation source is heat or light. TL and OSL dosimeters are natural or synthetic materials, which the intensity of emitted light is proportional to the irradiation dose. (Author)

  9. Status of human chromosome aberrations as a biological radiation dosimeter in the nuclear industry

    International Nuclear Information System (INIS)

    It seems that the determination of peripheral lymphocyte chriomosome aberration levels is now firmly established as a means of biological dosimetry of great value in many phases of the nuclear industry. In the case of large external exposure it can provide valuable quantitative estimates, as well as information on dose distribution and radiation quality. In the case of routine occupational exposures the technique is more qualitative, but is of value particularly in resolving uncertainties as to whether suspected overexposures did in fact occur. Where workers accumulate burdens of internal emitters, aberration analysis provides a valuable, though at present quite qualitative indicator. In spite of the expense of cytogenetic analyses, they are of sufficient value to justify much more widespread application, particularly in high risk situations

  10. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

  11. Radiation sensitive polymer gel dosimeters

    International Nuclear Information System (INIS)

    Full text: Radiation sensitive gels are studied for their potential to retain a permanent 3D dose distribution for applications in radiotherapy. Co-monomers dissolved in a tissue-equivalent hydrogel undergo a polymerization reaction upon absorption of ionizing radiation. The polymer formed influences the local spin-spin relaxation time (T2) of the dosimeter that can be determined using magnetic resonance imaging (MRI). The relationship between T2 and the absorbed dose was studied for different initial chemical compositions. The aim was to find a model linking the changes in T2 with absorbed dose to the initial composition of the dosimeter. It is believed this will help designing new gel dosimeters having desired properties to minimize the uncertainty in the determination of the dose distribution. 1H, 13C nuclear magnetic resonance spectroscopy and FT-Raman spectroscopy were used to quantify the amount of monomers still remaining after the absorption of a given dose of radiation. This data is used to model the changes of T2 as a function of the absorbed dose. A model of fast exchange of magnetization between three proton pools was used, where the fraction of protons (fxH ) in the xth pool is obtained from the chemical composition of the dosimeter and the apparent T2 of each pool is determined for a given composition. Initially, the protons are contained in two pools; a mobile (mob), which contains the water protons and the monomers protons, and a gelatin (gela) proton pool. The mobile pool is partially depleted as polymer is formed, the protons are transferred into the polymer (pol) pool. In the figure, the experimental data along with the calculated values are plotted for three different monomer concentrations, with the gelatin concentration fixed. The model is seen to provide a good fit to the experimental data

  12. Cytologic-Biochemical Radiation Dosimeters in Man

    International Nuclear Information System (INIS)

    The result of radiation interacting with living tissue is the deposition of energy therein. This energy triggers numerous chemical reactions within the molecules of the target tissues. We have measured in man the results of some of these reactions at doses up to 300 rads: chromosome aberrations; alterations in the kinetics of specific human cell populations; changes in 37 biochemical constituents of serum and/or urine. The utilization of chromosomes as a biological dosimeter is partially perfected but there are numerous discrepancies in data between different laboratories. Etiocholanolone can be used to evaluate marrow injury before the white-cell count falls below 5000/mm3. Most biochemical dosimeters evaluated gave negative or inconsistent results. However, salivary amylase is a promising indicator of human radiation injury from doses as low as 100 rads. (author)

  13. Response of bacteriophage T7 biological dosimeter to dehydration and extraterrestrial solar UV radiation

    Science.gov (United States)

    Hegedüs, M.; Fekete, A.; Módos, K.; Kovács, G.; Rontó, Gy.; Lammer, H.; Panitz, C.

    2007-02-01

    The experiment "Phage and uracil response" (PUR) will be accommodated in the EXPOSE facility of the ISS. Bacteriophage T7/isolated T7 DNA will be exposed to different subsets of extreme environmental parameters in space, in order to study the Responses of Organisms to the Space Environment (ROSE). Launch into orbit is preceded by EXPOSE Experiment Verification Tests (EVT) to optimize the methods and the evaluation. Bacteriophage T7/isolated T7 DNA thin layers were exposed to vacuum ( 10-6Pa), to monochromatic (254 nm) and polychromatic (200-400 nm) UV radiation in air as well as in simulated space vacuum. Using neutral density (ND) filters dose-effect curves were performed in order to define the maximum doses tolerated. The effect of temperature fluctuation in vacuum was also studied. The structural/chemical effects on bacteriophage T7/isolated T7 DNA were analyzed by spectroscopic and microscopical methods. Characteristic changes in the absorption spectrum and in the electrophoretic pattern of phage/DNA have been detected indicating the damage of isolated and intraphage DNA. DNA damage was also determined by quantitative PCR (QPCR) using 555 and 3826 bp fragments of T7 DNA. We obtained substantial evidence that DNA lesions (e.g. strand breaks, DNA-protein cross-links, cyclobutane pirimidine dimers (CPDs) etc.) accumulate throughout exposure. Preliminary results suggest a synergistic action of space vacuum and UV radiation with DNA being the critical target.

  14. Study on multiple channel radiation dosimeter

    International Nuclear Information System (INIS)

    An intelligent radiation dosimeter, with multiple channel signal collection and data processing, storing, printing and display, has been developed. It can measure doses at six different positions at one time. The device consists of six micro-semiconductors. This dosimeter can be used in irradiation experiments by 60Co source, radiotherapeutic facilities and radiation processing

  15. Developing a biological dosimeter based on mitochondrial DNA

    International Nuclear Information System (INIS)

    Direct measurement of deoxyribonucleic acid (DNA) damage from ionizing radiation may be advantageous in determining radiation radiation exposures and assessing their effects on atomic radiation workers. The mitochondrial DNA molecule is one potential cellular DNA target which is: fully defined and sequenced; present in many copies per cell; not vital to cellular survival; and less subject to DNA repair than nuclear DNA. A method is described to isolate and analyse normal mitochondrial DNA. We describe the developments needed to determine DNA damage in mitochondrial DNA. The target is to make a biological dosimeter. (author). 6 refs., 3 figs

  16. Liquid polymers for using in a holographic ionizing radiation dosimeter

    International Nuclear Information System (INIS)

    Some liquid polymeric systems for using in the holographic ionizing radiation dosimeter are presented. It is shown that the action of radiation on polymers leads to the destruction of the polymeric chains or to perform them, the both processes being applied in radiation dosimetry. Some advantages of the holographic dosimeter are outlined comparatively with those common used. (author)

  17. The intelligence of dosimeter for ionization radiation

    International Nuclear Information System (INIS)

    The connection of dosimeter with microcomputer system is described, which has the functions of sampling, data handling, display and printing dose values in legal units of measurement. The accuracy and speed of measurement for dosimeters are also raised, thereby the dosimeters are made to have intelligence and the application range of dosimeter is enlarged

  18. Heater design for reading radiation dosimeters

    International Nuclear Information System (INIS)

    The nichrome heating element of a conventional dosimeter reading apparatus has been redesigned to include a flat-bottomed depression big enough to hold a thermoluminescent dosimeter. A thin glass plate is positioned in the recess on top of the dosimeter to retain it in the recess during the heating and reading process. This technique of securing the dosimeter in contact with the heating element avoids physical scratching or damage to the dosimeter

  19. Biological dosimeter for cellular damage and repair by ionizing radiation. Final technical progress report, May 1, 1993--April 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Cress, A.E.

    1998-06-30

    The authors have investigated the alteration of chromatin domains in Human T and B cells after ionizing radiation using three DNA specific dyes, Feulgen, Hoechst and 7-amino actinomycin D. Characterization and differentiation of T and B cells was accomplished using only 4 of a possible 32 image features with the CAS and Quaritex QX7 Digital Image Systems. Human B and T cells were irradiated with 1, 5 and 10 Gy and analyzed during a 1.5 hour recovery period. The chosen features detect a dose dependent change in DNA domains which can be observed as early as 1.5 hours after a 1Gv exposure. The results suggest that the ability of DNA specific dyes to stain chromatin can be used as an early sensitive indicator of DNA damage. The observed alteration of chromatin staining suggests that chromatin structure does observably change in a significant manner during a DNA repair interval. Since these alteration can be detected with DNA specific dyes that stain both AT rich, GC rich or total DNA, these data suggest that a global alteration of the chromatin is occurring after exposure to ionizing radiation.

  20. NRC TLD [thermoluminescent dosimeter] Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the second quarter of 1990

  1. Environmental gamma radiation monitoring at Visakhapatnam using Thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    The external background radiation levels at Visakhapatnam have been measured. The measurements were performed using CaSO4: Dy thermoluminescence dosimeters at 15 locations in and around Visakhapatnam at one meter above the ground. The range of annual average dose rate measured was 0.79-1.86 mGy/year in air based on the analysis of thermoluminescence dosimeters. Spot readings of the background radiation levels were taken using hand held radiation survey meter. (author)

  2. Marine radiation measured with personal dosimeter

    International Nuclear Information System (INIS)

    This measurement was conducted after the Fukushima Daiichi Nuclear Power Plant Accident to study preliminarily the influence of the Accident on the sea water radiation and to get the information like materials and methods to measure the marine radiation for coming authorized study. The integrating dosimeters used were for personal fitting, Aloka's MYDOSEminiE PDM-111 with the silicon P-N junction semiconductor detector and ECOTEST's TERRA MKS-05, a GM tube type. Measurement was done with PDM-111 placed in a water-resistant vessel set up at 1 m and 3 cm distances from the bottom at the maximal depth of 100 m of 10 sea spots in Kochi Prefecture. Radiation doses were found to be 0.04-0.07 mcSv/h at the bottom of 6-13 m depth, which varied with the configuration of the bed, and 0.03 mcSv/h in water at either depth of the average 16 m or at 1 m far from the bottom. The dose rates in water and at bottom were found to decrease with increase of the depth by the enough long time measurement at 25 m and 40 m. Further, the more distant from the land, the lower the rates: 0.03-0.04 mcSv/h, which was thought to be derived from the cosmic ray. Results with MKS-05 were found to be of similar tendency to those by PDM-111 above and to be less sensitive. Authorized studies on marine radiation should be conducted systematically within a nearest future. (T.T.)

  3. Tissue-Equivalent Radiation Dosimeter-On-A-Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many commercially available digital dosimeters are bulky and are unable to properly measure dose for space radiation. The complexity of space flight design requires...

  4. Tissue-Equivalent Radiation Dosimeter-On-A-Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Available digital dosimeters are bulky and unable to provide real-time monitoring of dose for space radiation. The complexity of space-flight design requires...

  5. Preliminary evaluation of implantable MOSFET radiation dosimeters

    International Nuclear Information System (INIS)

    In this paper, we report on measurements performed on a new prototype implantable radiation detector that uses metal-oxide semiconductor field effect transistors (MOSFETs) designed for in vivo dosimetry. The dosimeters, which are encapsulated in hermetically sealed glass cylinders, are used in an unbiased mode during irradiation, unlike other MOSFET detectors previously used in radiotherapy applications. They are powered by radio frequency telemetry for dose measurements, obviating the need for a power supply within each capsule. We have studied the dosimetric characteristics of these MOSFET detectors in vitro under irradiation from a 60Co source. The detectors show a dose reproducibility generally within 5% or better, with the main sources of error being temperature fluctuations occurring between the pre- and post-irradiation measurements as well as detector orientation. A better temperature-controlled environment leads to a reproducibility within 2%. Our preliminary in vitro results show clearly that true non-invasive in vivo dosimetry measurements are feasible and can be performed remotely using telemetric technology

  6. An ESR study on biological dosimeters: Human hair

    International Nuclear Information System (INIS)

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with ΔHpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (Gmean) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  7. An ESR study on biological dosimeters: Human hair

    Energy Technology Data Exchange (ETDEWEB)

    Colak, Seyda, E-mail: seyda@hacettepe.edu.t [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey); Ozbey, Turan [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey)

    2011-05-15

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with {Delta}Hpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G{sub mean}) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  8. The DL-alanine ESR dosimeter in the radiation processing

    International Nuclear Information System (INIS)

    In this paper, the basic dosimetric characters of the alanine/ESR dosimeter used in radiation processing is introduced and the method for preparing the dosimeter is discussed. An excellent linearity in the range of 102Gy --- 104Gy was observed. The linear correlation coefficient between the amplitude of the main peak of ESR signal and the correspondent dose is greater than 0.9999. A special instrument was designed for fixing the lower end of the sample tube. It improved the standard deviation from ±1.1% to ±0.45% and the linear relations between gain settings of the spectrometer were amended. The dispersivity of the signal amplitude for many of dosimeters with a dose of 1 KGy was studied and the standard deviation of the signals was ±0.55. The correction factor of dosimeters for the response value of the radiation temperature was 0.0021/0C. (author)

  9. Radiation measured with passive dosimeters in low Earth orbit

    Science.gov (United States)

    Zhou, D.; Semones, E.; Gaza, R.; Weyland, M.

    begin center Radiation Measured with Passive Dosimeters in Low Earth Orbit end center begin center D Zhou 1 2 E Semones 1 R Gaza 1 2 M Weyland 1 end center begin center 1 Johnson Space Center - NASA 2101 Nasa Road 1 Houston 77058 USA end center begin center 2 Universities Space Research Association 2101 Nasa Parkway Houston 77058 USA end center begin center Abstract end center The linear energy transfer LET of particles in low Earth orbit LEO is extended from sim 0 1 to sim 1000 keV mu m water The best passive dosimeters for the radiation measurement are thermoluminescence dosimeters TLDs or optically stimulated luminescence dosimeters OSLDs for low LET and CR-39 plastic nuclear track detectors PNTDs for high LET Radiation quantities fluence absorbed dose dose equivalent and quality factor were measured with the passive dosimeters composed of TLDs OSLDs and CR-39 PNTDs for STS-114 mission This paper introduces the operation principles for TLDs OSLDs and CR-39 PNTDs describes the method to combine the results measured by TLDs OSLDs and CR-39 PNTDs and presents the results measured by different dosimeters for different LET band and that combined for all LET

  10. Design, construction and characterization of a dosimeter for neutron radiation

    International Nuclear Information System (INIS)

    An individual dosimeter for neutron-gamma mixed field dosimetry was design and developed aiming monitoring the increasing number of workers potentially exposed to neutrons. The proposed dosimeter was characterized to an Americium-Beryllium source spectrum and dose range of radiation protection interest (up to 20 mSv). Thermoluminescent albedo dosimetry and nuclear tracks dosimetry, traditional techniques found in the international literature, with materials of low cost and national production, were used. A commercial polycarbonate, named SS-1, was characterized for solid state tack detector application. The chemical etching parameters and the methodology of detectors evaluation were determined. The response of TLD-600, TLD-700 and SS-1 were studied and algorithms for dose calculation of neutron and gamma radiation of Americium- Beryllium sources were proposed. The ratio between thermal, albedo and fast neutrons responses, allows analyzing the spectrum to which the dosimeter was submitted and correcting the track detector response to variations in the radiation incidence angle. The new dosimeter is fully characterized, having sufficient performance to be applied as neutron dosimeter in Brazil. (author)

  11. Ionizing radiation M.O.S. dosimeters: sensibility and stability

    International Nuclear Information System (INIS)

    This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 μm thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a Dox2 power law. The maximum sensitivity achieved (9,2 V/Gy for 2μm devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10-2 Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10-3 Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs

  12. Radiation dosimetry in FLASH tunnel using passive dosimeters

    International Nuclear Information System (INIS)

    Sophisticated electronic devices comprised of sensitive microelectronic components have been installed in the close proximity of the 720 MeV superconducting electron linear accelerator (linac) driving FLASH, the Free Electron Laser in Hamburg, presently in operation at DESY in Hamburg. Microelectronic chips are inherently vulnerable to ionising radiations, usually generated during routine operation of high-energy particle accelerator facilities like FLASH. Hence, in order to assess the radiation effect on microelectronic chips and to develop suitable mitigation strategy, it becomes imperative to characterise the radiation field in the FLASH environment. We have evaluated the neutron and gamma energy (spectra) and dose distributions at critical locations in the FLASH tunnel using superheated emulsion (bubble) detectors, GaAs light emitting diodes (LED), LiF-Thermoluminescence dosimeters (TLD) and radiochromic (Gafchromic EBT) films. This report highlights the application of the passive dosimeters for an accurate analysis of the radiation field in produced by high-energy electron linear accelerators. (orig.)

  13. Thermoluminescent dosimeter-direct reading dosimeter dose discrepancy: studies on the role of beta radiation fields

    International Nuclear Information System (INIS)

    Dosimetry studies pertaining to thermoluminescent dosimeter (TLD) and direct reading dosimeter (DRD) have been performed for photons, beta fields and mixed field of photons and beta particles. In lab conditions, for pure photon radiation fields, the doses estimated using DRD and TLD match within the acceptable limits whereas in the mixed fields of photons and high energy beta particles, it has been found that the DRD doses are always higher than the corresponding whole body doses estimated by the TLD. This is due to the fact that DRD responds to high energy beta particles and the typical response of the DRD to high energy beta particles is observed to be in the range of 15-30%. This may lead to TLD-DRD dose discrepancy at workplaces where the skin doses received by the radiation workers from high energy beta sources in a given monitoring period are significant. The paper also provides a comparison of three different TLD-DRD discrepancy identification criteria available in literature for exposure conditions with a significant dose due to beta radiations. In addition, estimate of threshold beta dose which may lead to discrepancy as per the criteria have been studied. The results reported in this paper would be helpful in understanding the discrepancy arising out of variable response of DRD to beta radiations and will be useful in resolving the discrepancy in such cases. (author)

  14. Dual calibrated dosimeter for simultaneous measurements of erythemal and vitamin D effective solar ultraviolet radiation.

    Science.gov (United States)

    Wainwright, L; Parisi, A V; Downs, N

    2016-04-01

    A miniaturized ultraviolet radiation (UV) dosimeter based on polyphenylene oxide (PPO) has been dual calibrated for both erythemal and vitamin D effective exposures (UVB 280 - 320nm) over extended periods up to five days. Optimal human health requires a balanced amount of UVB exposure as both too much and too little have different but serious potential health consequences. Dosimetry is an established method of measuring specific UV exposures to an object or subject. PPO dosimeters have previously been used to measure the erythemally effective UV exposure. An extension of this use is to dual calibrate the miniaturized dosimeter which will also enable measurement of vitamin D effective exposures. By calibration to the erythemal and vitamin D effective action spectra, PPO dosimeters were able to record both types of biologically effective exposure as both are active within the UVB waveband. Dose response tests were conducted in each season by exposure to solar UV with the corresponding dual calibrations made for each season. The calibration provided an R(2) of 0.95-0.99 for erythemal UV and an R(2) of 0.99 for vitamin D effective UV. The successful outcome of this testing has established that PPO is suitable for use as a long term, dual calibrated dosimeter provided the film is seasonally calibrated. This enables one dosimeter to provide two sets of exposure results. The combination of dual calibration and the long term exposure potential of PPO makes the PPO dosimeter more versatile and increases the scope of UV field research on erythemal UV and vitamin D effective UV in the future. PMID:26878218

  15. NRC TLD [thermoluminescent dosimeter] Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network is operated by the NRC in cooperation with participating states to provide continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. Ambient radiation levels result from naturally occurring radionuclides present in the soil, cosmic radiation constantly bombarding the earth from outer space, and the contribution, if any, from the monitored facilities and other man-made sources. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an usual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the first quarter of 1990. A complete listing of the site facilities monitored is included. In some instances, two power reactor facilities are monitored by the same set of dosimeters

  16. Dental enamel as an in vivo radiation dosimeter

    International Nuclear Information System (INIS)

    The determination of the radiation exposure history of the population has become increasingly important in the study of the effects of low-level radiation. The present work was started to try to obtain an in vivo dosimeter that could give an indication of radiation exposure. Dental enamel is the only living tissue which retains indefinitely its radiation history, and electron spin resonance measurements have shown that the radiation signal can be resolved down to about 10 cGy. Measurements on samples from the general population give radiation exposure estimates that are reasonable, and one measurement on a patient who had radiotherapy to the mouth area showed a good correlation with tumor dose.We believe that this is an important new indicator of radiation dose and taken together with exposure histories should provide important data for epidemiological studies as well as accidental exposures

  17. Evaluation of the radiation-sensitizer/protector and/or antioxidant efficiencies using Fricke and PAG dosimeters

    Science.gov (United States)

    Meesat, Ridthee; Jay-Gerin, Jean-Paul; Khalil, Abdelouahed; Lepage, Martin

    2009-05-01

    In this study, our aim is to assess the potential of Fricke and polyacrylamide gel (PAG) dosimeters to quantitatively evaluate the efficiency of potential radiation sensitizers/protectors and antioxidants. These compounds are of importance in radiotherapy as well as in disease prevention and promotion of health. The basic principle of the Fricke dosimeter is the radiation-induced oxidation of Fe2+ to Fe3+ in an aerated aqueous 0.4 M H2SO4. The production of ferric ions is most sensitive to the radical species produced in the radiolysis of water. Using this method, we observed that cystamine (one of the best of the known radioprotectors) can prevent oxydation of Fe2+ from reactive radiolysis species. However, one obvious disadvantage of the Fricke dosimeter is that it operates under highly acidic conditions (pH 0.46), which may degrade biological compounds. In contrast, the pH of the polyacrylamide gel (PAG) dosimeter is almost neutral, such that degradation of compounds is less probable. A change in R2-dose sensitivity was observed in the presence of radiosensitizers/radioprotectors and antioxidants. The protective effect of Trolox (a well-known antioxidant) and thiourea (a radioprotector) was readily observed using the PAG dosimeter. Incorporation of iodinated radiation sensitizers such as NaI and an iodine contrast agent led to a quantifiable sensitizer enhancement ratio. These studies suggest that the Fricke and the PAG dosimeters have the potential to evaluate the efficiency of radiation sensitizers/protectors and antioxidants.

  18. Development and evaluation of polycrystalline cadmium telluride dosimeters for accurate quality assurance in radiation therapy

    Science.gov (United States)

    Oh, K.; Han, M.; Kim, K.; Heo, Y.; Moon, C.; Park, S.; Nam, S.

    2016-02-01

    For quality assurance in radiation therapy, several types of dosimeters are used such as ionization chambers, radiographic films, thermo-luminescent dosimeter (TLD), and semiconductor dosimeters. Among them, semiconductor dosimeters are particularly useful for in vivo dosimeters or high dose gradient area such as the penumbra region because they are more sensitive and smaller in size compared to typical dosimeters. In this study, we developed and evaluated Cadmium Telluride (CdTe) dosimeters, one of the most promising semiconductor dosimeters due to their high quantum efficiency and charge collection efficiency. Such CdTe dosimeters include single crystal form and polycrystalline form depending upon the fabrication process. Both types of CdTe dosimeters are commercially available, but only the polycrystalline form is suitable for radiation dosimeters, since it is less affected by volumetric effect and energy dependence. To develop and evaluate polycrystalline CdTe dosimeters, polycrystalline CdTe films were prepared by thermal evaporation. After that, CdTeO3 layer, thin oxide layer, was deposited on top of the CdTe film by RF sputtering to improve charge carrier transport properties and to reduce leakage current. Also, the CdTeO3 layer which acts as a passivation layer help the dosimeter to reduce their sensitivity changes with repeated use due to radiation damage. Finally, the top and bottom electrodes, In/Ti and Pt, were used to have Schottky contact. Subsequently, the electrical properties under high energy photon beams from linear accelerator (LINAC), such as response coincidence, dose linearity, dose rate dependence, reproducibility, and percentage depth dose, were measured to evaluate polycrystalline CdTe dosimeters. In addition, we compared the experimental data of the dosimeter fabricated in this study with those of the silicon diode dosimeter and Thimble ionization chamber which widely used in routine dosimetry system and dose measurements for radiation

  19. Development and evaluation of polycrystalline cadmium telluride dosimeters for accurate quality assurance in radiation therapy

    International Nuclear Information System (INIS)

    For quality assurance in radiation therapy, several types of dosimeters are used such as ionization chambers, radiographic films, thermo-luminescent dosimeter (TLD), and semiconductor dosimeters. Among them, semiconductor dosimeters are particularly useful for in vivo dosimeters or high dose gradient area such as the penumbra region because they are more sensitive and smaller in size compared to typical dosimeters. In this study, we developed and evaluated Cadmium Telluride (CdTe) dosimeters, one of the most promising semiconductor dosimeters due to their high quantum efficiency and charge collection efficiency. Such CdTe dosimeters include single crystal form and polycrystalline form depending upon the fabrication process. Both types of CdTe dosimeters are commercially available, but only the polycrystalline form is suitable for radiation dosimeters, since it is less affected by volumetric effect and energy dependence. To develop and evaluate polycrystalline CdTe dosimeters, polycrystalline CdTe films were prepared by thermal evaporation. After that, CdTeO3 layer, thin oxide layer, was deposited on top of the CdTe film by RF sputtering to improve charge carrier transport properties and to reduce leakage current. Also, the CdTeO3 layer which acts as a passivation layer help the dosimeter to reduce their sensitivity changes with repeated use due to radiation damage. Finally, the top and bottom electrodes, In/Ti and Pt, were used to have Schottky contact. Subsequently, the electrical properties under high energy photon beams from linear accelerator (LINAC), such as response coincidence, dose linearity, dose rate dependence, reproducibility, and percentage depth dose, were measured to evaluate polycrystalline CdTe dosimeters. In addition, we compared the experimental data of the dosimeter fabricated in this study with those of the silicon diode dosimeter and Thimble ionization chamber which widely used in routine dosimetry system and dose measurements for radiation

  20. Intercomparison of radiation dosimeters for individual monitoring

    International Nuclear Information System (INIS)

    The Co-ordinated Research Programme on Intercomparison for Individual Monitoring was established to provide participants with an opportunity to assess (1) their ability to measure external photon radiation fields and (2) the potential impact of introduction of the new operational quantities on their dosimetry programmes. Twenty-four laboratories from 18 IAEA Member States and three international organizations, including the IAEA, participated. The results of phase II of the CRP are presented in this document, which includes a compilation of the presentations and conclusions from the meeting. Refs, figs and tabs

  1. New dosimeters for solar-flare radiations

    International Nuclear Information System (INIS)

    From the extensive investigations carried out since 1992 with the dosimetric ANPA-stack on 107 long-haul flights, it is possible to conclude that the cumulative dose per flight on a given route changes within less than 20% among different repeated routes, two different aircrafts (Boeings 747 and 767), and among different locations within the aircraft. In contrast to galactic cosmic rays, solar-flare radiation is totally unpredictable and extremely variable in terms of energy spectrum, intensity, direction, duration and starting time. Most of the dosimetric systems used to date for the galactic cosmic rays may not be appropriate for solar-flare-radiation dosimetry. For this reason, different dosimetric systems have been investigated for both the retrospective and prospective dosimetry of solar flares. While waiting for the rare solar flare to occur, these dosimetric systems could be used for the validation of the computer-estimated route doses and/or for dosimetry in space, where frequent measurements of solar-flare events are needed

  2. Development of semiconductor radiation sensors for portable alarm-dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-01-01

    We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

  3. Radiation dosimetry of polymer gel dosimeters using Raman microscopy

    International Nuclear Information System (INIS)

    Full text: For several years polyacrylamide gels (PAGs) have been used for radiation therapy gel dosimetry. More recently FT-Raman spectroscopy has provided direct measurements of the concentration of monomers, post-irradiation, as a function of absorbed radiation dose. Adapting this work to Raman microscopy is an attractive proposition as it may enable dose to be measured to spatial resolutions of one micron. The composition of the PAG dosimeter was 3% acrylamide, 3% N,N'- methylene-bis-acrylamide, 5% gelatin and 89% water by weight. The PAG was irradiated from one end of a quartz glass slide of dimensions, 8 mm γ 38 mm γ 0.2 mm using electrons from a 6 MeV linear accelerator. Raman spectra were obtained using a Renishaw Raman microprobe with a nominal resolution of one micron. A helium neon laser operating at 8 mW and 633 nm was used for excitation. The depth dose measurement using the Raman microprobe compared to a calibrated ion chamber is illustrated. Raman microscopy of PAG dosimeters shows great potential in determining dose distributions with high spatial resolution and may have potential in areas such as cardiovascular brachytherapy. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

  4. Chemical dosimeter system for mixed neutron and gamma radiation

    International Nuclear Information System (INIS)

    G-values for the Fricke dosimeter and the FeCu dosimeter have been calculated for moderated fission neutrons. By combining these two chemical dosimeters, the fast neutron and gamma doses can be measured separately in a mixed field. (author). 7 refs, 2 tabs

  5. Radiation-induced defects in magnesium lactate as ESR dosimeter

    CERN Document Server

    Hassan, G M; Takaki, S

    1999-01-01

    Magnesium lactate (Mg-lactate: (CH sub 3 CH(OH)COO) sub 2 Mg), magnesium lactate doped with lithium lactate (Mg(Li)-lactate) and nominal pure lithium lactate (CH sub 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate) were irradiated by gamma-rays to study radicals for materials of radiation dosimeter with electron spin resonance (ESR). Quartet spectra were ascribed to lactate radicals in Mg-lactate and Li(Mg)-lactate with the spectroscopic splitting factors (g-factor) of 2.0032+-0.004 and 2.0029+-0.004 and the intensity ratio of 1:3:3:1 due to the hyperfine coupling constants of (A/g beta) of 1.92+-0.06 and 1.82+-0.06 mT, respectively. The response to gamma-ray dose and the thermal stability as well as the effect of UV-illumination have been studied to establish this material as an ESR dosimeter. The number of free radicals per 100 eV (G-value) was obtained to be 1.15+-0.32, 1.35+-0.35, 0.46+-0.14 and 0.78+-0.24 for Mg-lactate, Mg(Li)-lactate, Li-lactate and Lie(Mg)-lactate, respectively. Thermoluminescenc...

  6. NRC [Nuclear Regulatory Commission] TLD [thermoluminescent dosimeter] direct radiation monitoring network

    International Nuclear Information System (INIS)

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the second quarter of 1989

  7. Evaluation of the radiation-sensitizer/protector and/or antioxidant efficiencies using Fricke and PAG dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Meesat, Ridthee; Jay-Gerin, Jean-Paul; Khalil, Abdelouahed; Lepage, Martin [Departement de medecine nucleaire et de radiobiologie, Faculte de medecine et des sciences de la sante, Universite de Sherbrooke, Sherbrooke (Quebec) J1H 5N4 (Canada)], E-mail: Martin.Lepage@USherbrooke.ca

    2009-05-01

    In this study, our aim is to assess the potential of Fricke and polyacrylamide gel (PAG) dosimeters to quantitatively evaluate the efficiency of potential radiation sensitizers/protectors and antioxidants. These compounds are of importance in radiotherapy as well as in disease prevention and promotion of health. The basic principle of the Fricke dosimeter is the radiation-induced oxidation of Fe{sup 2+} to Fe{sup 3+} in an aerated aqueous 0.4 M H{sub 2}SO{sub 4}. The production of ferric ions is most sensitive to the radical species produced in the radiolysis of water. Using this method, we observed that cystamine (one of the best of the known radioprotectors) can prevent oxydation of Fe{sup 2+} from reactive radiolysis species. However, one obvious disadvantage of the Fricke dosimeter is that it operates under highly acidic conditions (pH 0.46), which may degrade biological compounds. In contrast, the pH of the polyacrylamide gel (PAG) dosimeter is almost neutral, such that degradation of compounds is less probable. A change in R{sub 2}-dose sensitivity was observed in the presence of radiosensitizers/radioprotectors and antioxidants. The protective effect of Trolox (a well-known antioxidant) and thiourea (a radioprotector) was readily observed using the PAG dosimeter. Incorporation of iodinated radiation sensitizers such as NaI and an iodine contrast agent led to a quantifiable sensitizer enhancement ratio. These studies suggest that the Fricke and the PAG dosimeters have the potential to evaluate the efficiency of radiation sensitizers/protectors and antioxidants.

  8. The design and implementation of gamma radiation dosimeter based on LabVIEW

    International Nuclear Information System (INIS)

    The design of γ radiation dosimeter based on LabVIEW is introduced. The dosimeter uses G-M counter as the detector, and a microcontroller is used to process the γ radiation dose data. The processed data is then transferred to upper computer and an application program based on LabVIEW is designed so that the upper computer can monitor the real-time γ radiation dose. (authors)

  9. Development of prototype fiber optics dosimeter for remote radiation measurements

    International Nuclear Information System (INIS)

    Optical fiber dosimetry has been studied as an emerging method of monitoring radiation remotely in difficult to access and hazardous areas and is suitable for use in confined environments that may be inaccessible using existing dosimeters. Being light weight and non intrusive, optical fibers provide several advantages in the field of dosimetry like resistant to electromagnetic interferences. An extrinsic architecture, where the radiation-sensing component is spliced or coupled to an optical fiber, is employed in this work. A prototype single channel fiber optic based remote radiation measurement system with BaFBr:Eu sensor, which has a wide linear dose response, is developed at Radiological Safety Division, IGCAR. High sensitive BaFBr:Eu2+ storage phosphor of 10 mm dia and 4 mm thickness has been successfully synthesized using high temperature solid state diffusion route in a reducing atmosphere. Optical characteristics of the BaFBr:Eu pellet were studied by taking Photoluminescence (PL) and Photo stimulated luminescence (PSL) measurements. PL emission wavelength is measured to be 390 nm. The BaFBr:Eu is irradiated for various absorbed doses in a gamma chamber at 213 Gy/hr using 60Co standard source (BRIT make) available at RSD, IGCAR

  10. Biological effects of radiation

    International Nuclear Information System (INIS)

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  11. FlexyDos3D: a deformable anthropomorphic 3D radiation dosimeter: radiation properties

    DEFF Research Database (Denmark)

    De Deene, Yves; Skyt, Peter Sandegaard; Hill, Robin;

    2015-01-01

    registration software.A new three dimensional anthropomorphically shaped flexible dosimeter, further called 'FlexyDos3D', has been constructed and a new fast optical scanning method has been implemented that enables scanning of irregular shaped dosimeters. The FlexyDos3D phantom can be actuated and deformed...... during the actual treatment. FlexyDos3D offers the additional advantage that it is easy to fabricate, is non-toxic and can be molded in an arbitrary shape with high geometrical precision.The dosimeter formulation has been optimized in terms of dose sensitivity. The influence of the casting material and......Three dimensional radiation dosimetry has received growing interest with the implementation of highly conformal radiotherapy treatments. The radiotherapy community faces new challenges with the commissioning of image guided and image gated radiotherapy treatments (IGRT) and deformable image...

  12. A search for novel thermoluminescent radiation dosimeter media

    International Nuclear Information System (INIS)

    We describe two example pilot efforts to help define new thermoluminescent dosimeter media. The first concerns ZnS:Mn nanophosphors, prepared by chemical precipitation using zinc and sodium sulfate, doped with manganese sulfate at concentrations varying from 1 to 3 mol. The second concerns chemical vapor deposited diamond, produced as a thin film or as amorphous carbon on a single-crystal silicon substrate, each deposited under the same conditions, use being made of the hot filament-chemical vapor deposition (HFCVD) technique. The gas concentrations used were 1% CH4 in 99% H2 and 25% CH4 in 75% H2. Characterization of formations used FESEM, XRD and EDX. The nanophosphors consisted of particles of sizes in the range 85–150 nm, the thermoluminescence (TL)-based radiation detection medium giving rise to a single peaked glow curve of maximum yield at a temperature of 250 °C at a heating rate of 5 °C/s. The TL response increased linearly with radiation dose, ZnS doped to 2 mol of Mn being found the most sensitive. Regarding chemical vapor deposited (CVD) carbon, inappreciable TL was found for the resultant ball-like amorphous carbon films, graphite, and the silicon substrate, whereas CVD diamond films showed a promising degree of linearity with dose. For both the ZnS and diamond samples, TL signal fading was appreciable, being some 40% per day for ZnS and>50% per day for CVD films even under storage in the dark at room temperature, making it apparent that there is need to adjust parameters such as the size of nanoparticles. - Highlights: • ZnS:Mn nanophosphors and CVD diamond films as new TL dosimeter media. • The TL response of both increases linearly with radiation dose. • For ZnS:Mn doped to 2 moles of Mn is found to be the most sensitive. • For CVD diamond films there is a need to adjust parameters such as nanoparticles size

  13. Gamma radiation field extremity personal dosimeter. Calibration and implementation

    International Nuclear Information System (INIS)

    The purpose of this paper is to show the extremity dose equivalent-kerma conversion factors obtained theoretical and experimentally in arm and finger for normally incident gamma radiation. Extremity dosemeters, based on termoluminescent dosimeters (TLD) LiF7 (TLD-700, Harshaw), have been irradiated on designed as finger and arm phantoms. The finger phantom is been characterised as a solid cylinder made of polymethylmethacrylate (PMMA) 19mm diameter and 300mm height. The arm phantom is a cylinder 73mm external diameter with PMMA walls 2.5mm thick filled with water and 300mm height. There were used several radiation sources like Co-60 and Cs-137 from the Regional Reference Dosimetry Centre (CRR) of the National Atomic Energy Commission (CNEA) and from the Nuclear Regulatory Authority (ARN) of Argentina. In the same way RX wide spectrum irradiations were made in the ISO-4037 qualities W60, W110 and W200. At the same time the conversion factors have been theoretically obtained. In order to achieve this, the finger and arm phantoms have been modelled and the photon and electron transport have been done with the Monte Carlo code MCNP-4B. There was a good agreement between the theoretical and experimental results, showing a difference less than 8%. Also the experimental results have been compared with the published data available giving a difference less than 7%. In this work is shown the performance of the extremity dosimeter usually used by the exposed workers of the ARN. It has got a similar energy response in the range of W110-Co-60 (not more than 7%) with respect to the experimental results obtained. The dose equivalent-kerma conversion factors are going to be used in the dose equivalent evaluation of workers mainly hands exposed. Related with the incident energy several applied recommendations have been made. An application is presented in nuclear medicine experiences. In the case of a thyroid treatment with 131I, the external dose workers have been evaluated

  14. Investigation of detergent powder as gamma radiation dosimeter using ESR technique

    International Nuclear Information System (INIS)

    Detergent powder is one of the most commonly available laboratory materials, which is often used for decontamination. If radiation exposure induced free radicals in this matrix are measurable, it can potentially serve as a retrospective dosimeter under accidental conditions. Therefore work in the study of radiation induced radicals in the detergent powder by electron spin resonance (ESR), were initiated and evaluated for its potential as a ESR dosimeter at higher dose ranges. These results therefore suggest that detergent can be used as a possible dosimeter in programmes such as food preservation by irradiation (1 kGy - 10 kGy) and accidental dosimetry at lower dose levels (∼25 Gy)

  15. NASA Crew Personal Active Dosimeters (CPADs): Leveraging Novel Terrestrial Personal Radiation Monitoring Capabilities for Space Exploration

    Science.gov (United States)

    Leitgab, Martin; Semones, Edward; Lee, Kerry

    2016-01-01

    The NASA Space Radiation Analysis Group (SRAG) is developing novel Crew Personal Active Dosimeters (CAPDs) for upcoming crewed space exploration missions and beyond. To reduce the resource footprint of the project a COTS dosimeter base is used for the development of CPADs. This base was identified from evaluations of existing COTS personal dosimeters against the concept of operations of future crewed missions and tests against detection requirements for radiation characteristic of the space environment. CPADs exploit operations efficiencies from novel features for space flight personal dosimeters such as real-time dose feedback, and autonomous measuring and data transmission capabilities. Preliminary CPAD design, results of radiation testing and aspects of operational integration will be presented.

  16. A Medipix-Based Small Personal Space Radiation Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR effort will take the first step in improving the existing Medipix dosimeter technology in terms of advancing the technique now used to couple the actual...

  17. Extremity dosimeters characterization and calibration for beta radiation fields to evaluate the personal dose equivalent

    International Nuclear Information System (INIS)

    Two extremity personal dosimeters were type tested and calibrated to measure the personal dose equivalent, Hρ(d), at 0.07 mm depth, at beta particle fields from a 90 Sr+90 Y radiation source. One dosimeter is a graphite mixed CaSO4:Dy thermoluminescent (TL) detector in the Harshaw /Bicron Ext-Rad ring; the other is a LiF:Mg,Ti TL detector in a velcro ring. Type tests were carried out to verify the detection limit, linearity, and the angular dependence of both dosimeters. Dosimeters were used to evaluate the personal dose equivalent of operators who deal with 90 Sr+90 Y ophthalmic and dermatologic applicators at a beta therapy service. Results suggest that the CaSO4:Dy dosimeter is more reliable and adequate for measurements at beta radiation fields than the LiF:Mg,Ti dosimeter which shows a trend to subestimate the values of Hρ(0.07). Two extremity personal dosimeters were type tested. (author)

  18. Impact of the Fukushima nuclear accident on background radiation doses measured by control dosimeters in Japan.

    Science.gov (United States)

    Romanyukha, Alexander; King, David L; Kennemur, Lisa K

    2012-05-01

    After the 9.0 magnitude earthquake and subsequent massive tsunami on 11 March 2011 in Japan, several reactors at the Fukushima Daiichi Nuclear Power Plant suffered severe damage. There was immediate participation of U.S. Navy vessels and other United States Department of Defense (DoD) teams that were already in the area at the time of the disaster or arrived shortly thereafter. The correct determination of occupational dose equivalent requires estimation of the background dose component measured by control dosimeters, which is subsequently subtracted from the total dose equivalent measured by personal dosimeters. The purpose of the control dosimeters is to determine the amount of radiation dose equivalent that has accumulated on the dosimeter from background or other non-occupational sources while they are in transit or being stored. Given the release of radioactive material and potential exposure to radiation from the Fukushima Daiichi Nuclear Power Plant and the process by which the U.S. Navy calculates occupational exposure to ionizing radiation, analysis of pre- and post-event control dosimeters is warranted. Several hundred historical dose records from the Naval Dosimetry Center (NDC) database were analyzed and compared with the post-accident dose equivalent data of control dosimeters. As result, it was shown that the dose contribution of the radiation and released radiological materials from the Fukushima nuclear accident to background radiation doses is less than 0.375 μSv d for shallow and deep photon dose equivalent. There is no measurable effect on neutron background exposure. The latter has at least two important conclusions. First, the NDC can use doses measured by control dosimeters at issuing sites in Japan for determination of personnel dose equivalents; second, the dose data from control dosimeters prior to and after the Fukushima accident may be used to assist in dose reconstruction of non-radiological (non-badged) personnel at these locations

  19. On-line hybrid radiation dosimeter for the nuclear mobile robot (KAEROT/m2)

    International Nuclear Information System (INIS)

    The electronics of a mobile robot in nuclear facilities is required to satisfied the relibility to sustain survival in its radiation environment. To know how much radiation the robot has been encountered to replace sensitive electronic parts, a dosimeter to measure total accumulated does is necessary. Among many radiation dosimeters or detectors, semiconductor radiation sensors have advantages in terms of power requirements and their sizes over conventional detectors. This paper describes the use of the radiation-induced threshold voltage change of a commercial power pMOSFET as an accumulated radiation dose monitoring mean and that of the photo-current of a commercial PIN Diode as a dose-rate measurement mean. Commercial p-type power MOSFETs and PIN Diodes were tested in a Co-60 gamma irradiation facility to see their capabilities as radiation sensors. We found an inexpensive commercial power pMOSFET that shows good linearity in their threshold voltage shift with radiation dose and a PIN diode that shows good linearity in its photo-current change with dose-rate. According to these findings, a radiation hardened hybrid electronic radiation dosimeter for nuclear robots has been developed for the first time. This small hybrid dosimeter has also an advantage in the point of view of reliability improvement by using a diversity concept

  20. Considerations concerning the use of counting active personal dosimeters in pulsed fields of ionising radiation.

    Science.gov (United States)

    Ambrosi, Peter; Borowski, Markus; Iwatschenko, Michael

    2010-06-01

    Active personal electronic dosimeters (APDs) exhibit limitations in pulsed radiation fields, which cannot be overcome without the use of new detection technology. As an interim solution, this paper proposes a method by which some conventional dosimeters can be operated in a way such that, based on the basic knowledge about the pulsed radiation field, any dosimetric failure of the dosimeter is signalised by the instrument itself. This method is not applicable to all combinations of APD and pulsed radiation field. The necessary requirements for the APD and for the parameters of the pulsed radiation field are given in the paper. Up to now, all such requirements for APDs have not been tested or verified in a type test. The suitability of the method is verified for the use of one APD used in two clinical pulsed fields. PMID:20083488

  1. Calibration of personal dosimeters for photon radiation with respect to the personal dose equivalent Hp(10)

    International Nuclear Information System (INIS)

    The main steps of the calibration of personal dosimeters in terms of the personal dose equivalent Hp(10) are described. Special consideration is given to ISO photon reference radiations, conversion coefficients from air kerma to Hp(10), various calibration methods including an example of a routine calibration, and positioning of dosimeters for the calibration. In particular, radiation qualities used for measuring the response as a function of the photon energy and of the direction of the incident radiation in an intercomparison of a Co-ordinated Research Project of the IAEA are dealt with. (author)

  2. Introduction to radiation biology

    International Nuclear Information System (INIS)

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  3. NRC TLD [Nuclear Regulatory Commission thermoluminescent dosimeter] direct radiation monitoring network

    International Nuclear Information System (INIS)

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1989. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  4. NRC TLD [thermoluminescent dosimeter] Direct Radiation Monitoring Network: Progress report, October--December 1988

    International Nuclear Information System (INIS)

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1988. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 4 tabs

  5. Programmable Zone Dosimeter for Operational Monitoring and Measurement of External Gamma Radiation

    Science.gov (United States)

    Toledo, René; Osorio, Juan Fco.; López, Ernesto; Claro, Leodibel Pablo; Galván, José

    2002-08-01

    The ZONE DOSIMETER is a high technology portable device, designed on the base of strict quality requirements. It uses real-time digital techniques in order to enhance the quality of monitoring. The dosimeter measures the dose rate of external γ (gamma) radiation, which allows determining the dose of radiation to which the personal is exposed. In this manner, the accomplishment of the regulations of radiological protection and security in institutions where ionizing radiations are used is assured. The dosimeter is commercialized with a fixed pre-calibration; nevertheless, it is up to the user to obtain all the certifications required by the national legislations for its operation within the system of radiological security. It may also be used in Laboratories of Nuclear Medicine.

  6. Programmable zone dosimeter for operational monitoring and measurement of external gamma radiation

    International Nuclear Information System (INIS)

    The ZONE DOSIMETER is a high technology portable device, designed on the base of strict quality requirements. It uses real-time digital techniques in order to enhance the quality of monitoring. The dosimeter measures the dose rate of external γ (gamma) radiation, which allows determining the dose of radiation to which the personal is exposed. In this manner, the accomplishment of the regulations of radiological protection and security in institutions where ionizing radiations are used is assured. The dosimeter is commercialized with a fixed pre-calibration; nevertheless, it is up to the user to obtain all the certifications required by the national legislations for its operation within the system of radiological security. It may also be used in Laboratories of Nuclear Medicine

  7. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect

    International Nuclear Information System (INIS)

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter. (author)

  8. Novel composition of polymer gel dosimeters based on N-(Hydroxymethyl)acrylamide for radiation therapy

    International Nuclear Information System (INIS)

    A new composition of polymer gel dosimeters is developed based on radiation induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) for radiotherapy treatment planning. The dosimeters were irradiated by 10 MV photon beam of a medical linear accelerator at a constant dose rate of 600 cGy/min with doses up to 20 Gy. The polymerization occurs and increases with increasing absorbed dose. The dose response of polymer gel dosimeters was studied using nuclear magnetic imaging (NMR) for relaxation rate (R2) of water proton. Dose rate, energy of radiation and the stability of the polymerization after irradiation were investigated. No appreciable effects of these parameters on the performance of the novel gel dosimeters were observed. - Highlights: • This manuscript relates to polymer gel dosimeter for used in radiotherapy. • Polymer gel containing N-(Hydroxymethyl)acrylamide has been introduced. • Polymerization of NHMA gel increases gradually with increasing absorbed dose. • Response of NHMA gel was slightly affected by dose rate and energy of radiation

  9. The relationship between radiation-induced chemical processes and transverse relaxation times in polymer gel dosimeters

    International Nuclear Information System (INIS)

    The effects of ionizing radiation in different compositions of polymer gel dosimeters are investigated using FT-Raman spectroscopy and NMR T2 relaxation times. The dosimeters are manufactured from different concentrations of comonomers (acrylamide and N,N'-methylene-bis-acrylamide) dispersed in different concentrations of an aqueous gelatin matrix. Results are analysed using a model of fast exchange of magnetization between three proton pools. The fraction of protons in each pool is determined using the known chemical composition of the dosimeter and FT-Raman spectroscopy. Based on these results, the physical and chemical processes in interplay in the dosimeters are examined in view of their effect on the changes in T2. The precipitation of growing macroradicals and the scavenging of free radicals by gelatin are used to explain the rate of polymerization. The model describes the changes in T2 as a function of the absorbed dose up to 50 Gy for the different compositions. This is expected to aid the theoretical design of new, more efficient dosimeters, since it was demonstrated that the optimum dosimeter (i.e, with the lowest dose resolution) must have a range of relaxation times which match the range of T2 values which can be determined with the lowest uncertainty using an MRI scanner. (author)

  10. Uses of polymer-alanine film/ESR dosimeters in dosimetry of ionizing radiation

    International Nuclear Information System (INIS)

    Alanine ESR dosimetry is a reliable method, used in a various fields of ionizing radiation. The polymer-alanine film/ESR dosimeters of 0.3 -0.4 mm thickness were prepared and their dosimetric properties were studied for 60Co γ photons and 3 - 5 MeV electrons in the dose range from 20 Gy to 100 kGy. The results show that under normal conditions the alanine calibration curves are linear in the dose range from 100 Gy to 10kGy. The dose profiles at the electron radiation field were measured with the film alanine dosimeters. The polymer-alanine film dosimeters were used for ion implantation of 400 keV ion implantor. Their dose response and energy dependence were investigated initially. (Author)

  11. Copper doped borate dosimeters revisited

    International Nuclear Information System (INIS)

    We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu+ and Cu++) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu+ ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated technique in borate

  12. Copper doped borate dosimeters revisited

    Energy Technology Data Exchange (ETDEWEB)

    Alajerami, Y.S.M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Department of Medical Radiography, Al-Azhar University, Gaza Strip, Palestine (Country Unknown); Hashim, S., E-mail: suhairul@utm.my [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Oncology Treatment Centre, Sultan Ismail Hospital, 81100 Johor Bahru (Malaysia); Ghoshal, S.K. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mhareb, M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Saleh, M.A. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); National Atomic Energy Commission (NATEC), Sana' a (Yemen)

    2014-11-15

    We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu{sup +} and Cu{sup ++}) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu{sup +} ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated

  13. Measurement of scatter radiation on MDCT equipment using an OSL dosimeter

    International Nuclear Information System (INIS)

    The recent introduction of multi-detector row computed tomography (MDCT) has made it possible to scan the entire abdomen within approximately 10 sec in procedures such as interventional radiology computed tomography (IVRCT), which are associated with operator exposure. Therefore, anxious patients and patients who are not able to remain still can be examined with an assistant. In the present study, radiation exposure to the assistant was estimated, and the distribution of scattered radiation near the gantry was measured using an optically stimulated luminescence (OSL) dosimeter. Simultaneous measurements were obtained using a direct ion storage (DIS) dosimeter for reference. The maximum value of 1.47 mSv per examination was obtained at the point closest to the gantry's center (50 cm from the center at a height of 150 cm above the floor). In addition, scattered radiation decreased as the measurement point was moved further from the gantry's center, falling below the limit of detection (0.1 mSv or less) at 200 cm and at the sides of the gantry OSL dosimeters are also employed as personal dosimeters, permitting reliable values to be obtained easily. They were found to be an effective tool for the measurement of scattered radiation, as in the present study, helping to provide better understanding of the distribution of scattered radiation within the CT room. (author)

  14. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  15. Characterization and calibration of extremity dosimeters for beta radiation field in terms of mass and metallurgic individual equivalent dose

    International Nuclear Information System (INIS)

    Two extremity personal dosimeters were 'type tested' and calibrated to measure the personal dose equivalent, Hp(d), at 0.07 mm depth, at beta particle fields from a 90 Sr+90 Y radiation source. One dosimeter is a graphite mixed Ca SO4:Dy thermoluminescent (TL) detector in the Harshaw/Bicron Ext-Rad ring; the other is a LiF:Mg, Ti TL detector in a Velcro ring. The 'Type tests' were carried out to verify the detection limit, linearity, and angular dependence of both dosimeters. The calibrated dosimeters were used to evaluate the personal dose equivalent of operators who deal with 90 Sr + 90 Y ophthalmic and dermatological applicators at a beta therapy service. Results suggest that the Ca SO4:Dy dosimeter is more reliable and adequate for measurements at beta radiation fields than the LiF:Mg,Ti dosimeter which subestimates the values of Hp (0.07). (author)

  16. Testing and calibration of radiation dosimeters designed for astronauts during an EVA

    International Nuclear Information System (INIS)

    An active real-time dosimeter will be required for astronauts during extra vehicular activities (EVA). It must be capable of measuring and recording the dose rate and quality factor from galactic cosmic rays during ambient conditions. It must also record the dose and issue a warning to the astronaut during the initiation of a high intensity solar particle event (SPE). This dosimeter can be integrated into the new space suit configuration that is currently under design by National Aeronautics and Space Administration (NASA) or installed in a transportation rover or tool box. The National Space Biomedical Research Institute (NSBRI) is the administrative agency for this EVA initiative. The mission of NSBRI is to support NASA in understanding health concerns for astronauts during long term missions in space. It is a nonprofit agency dedicated to promoting research and dissemination of results through publications and scientific meetings. General specifications outlined by NASA are that the detectors should be tissue equivalent, omni-directional and capable of measuring ambient dose rates of 300 μGy/d for particles with LET ranging from 0.2 to 300 keV/μm. At the onset of a solar particle event the system must be capable of signaling an alarm at 0.05 mGy/min and at 10 mGy/min. Simultaneous measurements of the dose to the skin (surface) and blood forming organs (1 cm depth) must have a time resolution of 1 minute and a latency period less than 5 minutes. A Tissue Equivalent Proportional Counter (TEPC) gives details of the absorbed dose and dose rate. It can also provide direct information on the quality or type of the radiation field. The interior cavity of the detector is filled with tissue equivalent gas such that the density thickness, cm2/g, of the gas is equivalent to the density thickness of tissue with dimensions approaching the nucleus of a mammalian cell (1-5 μm). The motivation for this was that the proportional counter serves as a microdosimeter that can

  17. SU-E-T-368: Effect of a Strong Magnetic Field On Select Radiation Dosimeters

    International Nuclear Information System (INIS)

    Purpose: To determine the effect of a strong magnetic field on TLD-100, OSLD (Al2O2:C), and PRESAGE dosimetry devices. This study will help to determine which types of dosimeters can be used for quality assurance and in-vivo dosimetry measurements in a magnetic resonance imaginglinear accelerator (MRI-linac) system. Methods: The dosimeters were separated into two categories which were either exposed or not exposed to a strong magnetic field. In each category a set of dosimeters was irradiated with 0, 2, or 6 Gy. To expose the dosimeters to a magnetic field the samples in that category were place in a Bruker small animal magnetic resonance scanner at a field strength slightly greater than 2.5 T for at least 1 hour preirradiation and at least 1 hour post-irradiation. Irradiations were performed with a 6 MV x-ray beam from a Varian TrueBeam linac with 10×10 cm2 field at a 600 MU/min dose rate. The samples that received no radiation dose were used as control detectors. Results: The readouts of the dosimeters which were not exposed to a strong magnetic field were compared with the measurements of the dosimetry devices which were exposed to a magnetic field. No significant differences (less than 2% difference) in the performance of TLD, OSLD, or PRESAGE dosimeters due to exposure to a strong magnetic field were observed. Conclusion: Exposure to a strong magnetic field before and after irradiation does not appear to change the dosimetric properties of TLD, OSLD, or PRESAGE which indicates that these dosimeters have potential for use in quality assurance and in-vivo dosimetry in a MRI-linac. We plan to further test the effect of magnetic fields on these devices by irradiating them in the presence of a magnetic fields similar to those produced by a MRI-linac system. Elekta-MD Anderson Cancer Center Research Agreement

  18. Physico-chemical studies for strontium sulfate radiation dosimeter

    Directory of Open Access Journals (Sweden)

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  19. A wide-range dosimeter relatively insensitive to radiation quality: alanine

    International Nuclear Information System (INIS)

    A dosimeter based on the electron paramagnetic resonance measurement of radiation-produced free radicals in alanine has the advantages of small bulk, non destructive reading, good reproducibility, tissue equivalence for both photons and neutrons and a wide linearity range between 102 and 106 rads. This linearity results in a low sensitivity to the microscopic dose distribution. From the first measurements on different fast neutron beams the parameter a of Katz's mathematical model may be calculated and the latter used to predict the dosimeter response to any particle of known mass, charge and speed. Present and future applications of this dosimeter range from the link-up of γ dosimetries for source of quite different dose rates to the dosimetry of mixed γ+n fields (in-pile dosimetry for example)

  20. Influence of environmental factors on some high dose dosimeter responses in Yazd Radiation Processing Center

    International Nuclear Information System (INIS)

    In this paper attempt has been made to study the influence of temperature and UV light (exist in laboratory due to the fluorescent light or diffused sunlight) on some high dose dosimetry responses that are being used in Yazd Radiation Processing Center (YRPC). The CTA, FWT and B3 film dosimeters were used for this investigation. The correction of the read response of the dosimeters to the real absorbed dose values is very important especially while we need to measure the precise dose values in the medical devices and in foodstuff materials. Yazd city is near to the desert, and so temperature and UV light due to the sun are very different in compare to other cities. Therefore, we tried to investigate the temperature and UV light effects on the dosimeter response in different doses and obtain its variation as a function of temperature (up to ∼600C) and exposure time (up to ∼1 year), respectively

  1. Engineering design of dosimeter prototype based on graphite calorimetry for electron radiation dose measurement

    International Nuclear Information System (INIS)

    he engineering design of a dosimeter prototype based on graphite calorimetry for electron radiation dose measurement at electron energy of at most 300 keV and maximum dose of 60 kGy have been carried out. The graphite core is a cylinder shape with diameter and thickness of 30 mm and 2 mm respectively, surrounded by a guard ring made of the same graphite material. Dosimeter based on graphite calorimetry is equipped with a styrofoam for thermal insulation, temperature sensors and instrumentation based on micro controller. The characteristics of dosimeter based on graphite calorimetry are obtained by means of calculation and computer simulations using Penelope 2003 software and ANSYS computer program. The dosimeter based on graphite calorimetry has been designed to perform real time measurement of the average of absorbed and surface dose, it was expected that dosimeter based on graphite calorimetry can operate well. Compared with the cellulose tri acetate (CTA) dose measurement it gives relative differences of 18.9% and 9.1% at the experiments of energy variation and electron beam current alteration of the electron beam machine (EBM) respectively. (author

  2. Lymphocyte as a biological dosimeter : a different approach

    International Nuclear Information System (INIS)

    Chromosome aberration frequency as a measure of radiation exposure in human blood lymphocytes following a short term culture is well known and the technique is in use at several laboratories in the world to determine accidental exposures. Results of an entirely different approach to arrive at the exposure is presented. Time course of interphase death of human peripheral blood lymphocytes was followed for 6 days after exposure to cobalt-60 gamma radiation. Trypan blue dye exclusion method was used for scoring viable cells. Survival curves at 5 days post irradiation were exponential and had two components: an initial sensitive component representing a major sub-population of lymphocytes with a mean lethal dose (DO) of 75 rads and the other an apparently more resistant population with a Do of about 300 rads. The initial part of the survival curve which spans to about 100 rads reaching a survival level of 15 percent, can be used to read off the extent of exposure in accident cases. Although 60 percent of the initial lymphocytes survive in the unexposed control cultures, the method is sensitive to exposures of the order of 20 rads and reproducible results have been obtained. The response is independent of dose-rate from 65 rads/min to 65 rads/hour. Other aspects of the dosimetry system such as the neutron response, in vitro and in vivo correlation are discussed. (author)

  3. SU-D-213-06: Dosimetry of Modulated Electron Radiation Therapy Using Fricke Gel Dosimeter

    International Nuclear Information System (INIS)

    Purpose: Modulated electron radiation therapy (MERT) has been proposed as an effective modality for treatment of superficial targets. MERT utilizes multiple beams of different energies which are intensity modulated to deliver optimized dose distribution. Energy independent dosimeters are thus needed for quantitative evaluations of MERT dose distributions and measurements of absolute doses delivered to patients. Thus in the current work we study the feasibility of Fricke gel dosimeters in MERT dosimetry. Methods: Batches of radiation sensitive Fricke gel is fabricated and poured into polymethyl methacrylate cuvettes. The samples were irradiated in solid water phantom and a thick layer of bolus was used as a buildup. A spectrophotometer system was used for measuring the color changes (the absorbance) before and after irradiation and then we calculate net absorbance. We constructed calibration curves to relate the measured absorbance in terms of absorbed dose for all available electron energies. Dosimetric measurements were performed for mixed electron beam delivery and we also performed measurement for segmented field delivery with the dosimeter placed at the junction of two adjacent electron beams of different energies. Dose measured by our gel dosimetry is compared to that calculation from our precise treatment planning system. We also initiated a Monte Carlo study to evaluate the water equivalence of our dosimeters. MCBEAM and MCSIM codes were used for treatment head simulation and phantom dose calculation. PDDs and profiles were calculated for electron beams incident on a phantom designed with 1cm slab of Fricke gel. Results: The calibration curves showed no observed energy dependence with all studied electron beam energies. Good agreement was obtained between dose calculated and that obtained by gel dosimetry. Monte Carlo results illustrated the tissue equivalency of our Gel dosimeters. Conclusion: Fricke Gel dosimeters represent a good option for the dosimetric

  4. SU-D-213-06: Dosimetry of Modulated Electron Radiation Therapy Using Fricke Gel Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Gawad, M Abdel; Elgohary, M; Hassaan, M; Emam, M [Al Azhar University, Cairo Egypt (Egypt); Desouky, O [National center for radiation research and technology-Egyptian atomic energy, Cairo (Egypt); Eldib, A [Al Azhar University, Cairo Egypt (Egypt); Fox Chase Cancer Center, Philadelphia, PA (United States); Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2015-06-15

    Purpose: Modulated electron radiation therapy (MERT) has been proposed as an effective modality for treatment of superficial targets. MERT utilizes multiple beams of different energies which are intensity modulated to deliver optimized dose distribution. Energy independent dosimeters are thus needed for quantitative evaluations of MERT dose distributions and measurements of absolute doses delivered to patients. Thus in the current work we study the feasibility of Fricke gel dosimeters in MERT dosimetry. Methods: Batches of radiation sensitive Fricke gel is fabricated and poured into polymethyl methacrylate cuvettes. The samples were irradiated in solid water phantom and a thick layer of bolus was used as a buildup. A spectrophotometer system was used for measuring the color changes (the absorbance) before and after irradiation and then we calculate net absorbance. We constructed calibration curves to relate the measured absorbance in terms of absorbed dose for all available electron energies. Dosimetric measurements were performed for mixed electron beam delivery and we also performed measurement for segmented field delivery with the dosimeter placed at the junction of two adjacent electron beams of different energies. Dose measured by our gel dosimetry is compared to that calculation from our precise treatment planning system. We also initiated a Monte Carlo study to evaluate the water equivalence of our dosimeters. MCBEAM and MCSIM codes were used for treatment head simulation and phantom dose calculation. PDDs and profiles were calculated for electron beams incident on a phantom designed with 1cm slab of Fricke gel. Results: The calibration curves showed no observed energy dependence with all studied electron beam energies. Good agreement was obtained between dose calculated and that obtained by gel dosimetry. Monte Carlo results illustrated the tissue equivalency of our Gel dosimeters. Conclusion: Fricke Gel dosimeters represent a good option for the dosimetric

  5. Development of a fiber-optic dosimeter based on modified direct measurement for real-time dosimetry during radiation diagnosis

    International Nuclear Information System (INIS)

    For applying modified direct measurement, we developed a fiber-optic dosimeter (FOD) with two dosimeter probes to infer the entrance surface dose (ESD) at the center of an x-ray beam field without the obstruction of radiation imaging. The dosimeter probe of the FOD was fabricated by coupling a plastic scintillating fiber to a plastic optical fiber. Under varying exposure parameters, we measured the scintillating light signals using two dosimeter probes, which were placed at the center and the edge of the beam field, respectively, and compared the results with the absorbed doses obtained using a conventional semiconductor dosimeter. Various correlations between the two dosimeter probes according to the exposure parameters were obtained for measuring ESD using a new modified direct measurement approach during a medical imaging task. (paper)

  6. Assessment of radiation exposure of nuclear medicine staff using personal TLD dosimeters and charcoal detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, F.; Garcia-Talavera, M.; Pardo, R.; Deban, L. [Valladolid Univ., Dept. de Quimica Analitica, Facultad de Ciencias (Spain); Garcia-Talavera, P.; Singi, G.M.; Martin, E. [Hospital Clinico Univ., Servicio de Medicina Nuclear, Salamanca (Spain)

    2006-07-01

    Although the main concern regarding exposure to ionizing radiation for nuclear medicine workers is external radiation, inhalation of radionuclides can significantly contribute to the imparted doses. We propose a new approach to assess exposure to inhalation of {sup 131}I based on passive monitoring using activated charcoal detectors. We compared the inhalation doses to the staff of a nuclear medicine department, based on the measurements derived from charcoal detectors placed at various locations, and the external doses monitored using personal TLD dosimeters. (authors)

  7. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    Science.gov (United States)

    Britton, Jr.; Charles L.; Buckner, Mark A.; Hanson, Gregory R.; Bryan, William L.

    2011-04-26

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  8. Radiation biology for environment

    International Nuclear Information System (INIS)

    Environmental pollution problems such as the green-house effect by increase of CO2, acid rain caused by flue gases, and contamination of chemicals and pesticides in foods and water, have become serious in the world with the rapid development of industry and agriculture. To solve some of these problems, radiation treatment has being applied for the removal of the contaminants from flue gases and waste water from industrial plants. On the other hand, the contribution of radiation biology for these environmental pollution problems is not direct but it has contributed indirectly in many fields. This paper describes the contributions of radiation biology for environment in the following two topics: 1) control of insects and microorganisms, and 2) application of radiation for agricultural wastes

  9. A metal-oxide-semiconductor radiation dosimeter with a thick and defect-rich oxide layer

    International Nuclear Information System (INIS)

    Enhancing the density of defects in the oxide layer is the main factor in improving the sensitivity of a metal-oxide-semiconductor (MOS) radiation dosimeter. This paper reports a novel MOS dosimeter with a very thick and defect-rich oxide layer fabricated by MEMS technology. The category of defects in SiO2 and their possible effect on the radiation dose sensing was analyzed. Then, we proposed combining deep-reactive-ion etching, thermal oxidation and low pressure chemical vapor deposition to realize an oxide layer containing multiple and large interfaces which can increase defects significantly. The trench-and-beam structure of silicon was considered in detail. The fabrication process was developed for obtaining a thick and compact MEMS-made SiO2. Our devices were irradiated by γ-rays of 60Co at 2 Gy per minute for 2 h and a thermally stimulated current (TSC) method was used to determine the readout of the dosimeters. Results show that there is a peak current of about 450 nA, indicating a total TSC charge of 158 μC and sensitivity of 1.1 μC mm−3·Gy, which is 40 times the sensitivity of previous MOS dosimeters. (paper)

  10. Study of PIN diode based pocket dosimeter for gamma and beta radiation

    International Nuclear Information System (INIS)

    A pocket dosimeter, based on PN junction Si Semiconductor detector earlier was developed for the measurement of dose equivalent in the field of gamma and beta radiation. This dosemeter was insensitive to beta radiation which is primary requirement as a legal personal dosemeter from IEE standards. This dosemeter works on a high power 3V Li battery along with a micro power DC-DC converter to get 3.3V needed to power the circuit. It has a 6 digit LCD digital display along with battery low indication. It measures the dose range of 1- 99999 μSv. The photon energy dependence of the dosimeter from 60 keV to 1.2 MeV is ± 30% for gamma radiation and ± 40% for beta. Further work is in progress to bring beta response within acceptable limit and to display beta and gamma response separately as Hp (0.07) and Hp (10). (author)

  11. Application of electric personal dosimeter to environmental radiation on long term continuous measurement

    International Nuclear Information System (INIS)

    The radiation doses measured by Electric Personal Dosimeter (EPD) were compared with those by Radio-Photoluminescence Dosimeter (RPLD) in natural radiation environment. These two values were almost agreed and have a linear relationship with high correlation. However, the dose by EPD was higher than that by RPLD. The regression expression shows that the slope is a little higher than one, and this line does not pass through the zero dose point. In order to investigate the cause, the gamma ray irradiation was conducted. The result shows that the sensitivity of the EPDs were 4-11% higher than the expected dose. On the other hand, the dose rates varied from 0.019 μSv/h to 0.028 μSv/h in the lead box which has 10 cm thickness. As a result, it would be necessary that the sensitivity of each EPD is calibrated in order to obtain an accurate dose. (author)

  12. Three-dimensional radiation dosimetry for gamma knife using a gel dosimeter

    Science.gov (United States)

    Hussain, Kazi Muazzam

    The use of three-dimensional radiation dosimetry has been limited. With the use of water phantoms and ionization chambers, it has been possible to determine three dimensional dose distributions on a gross scale for cobalt 60 and linear accelerator sources. This method has been somewhat useful for traditional radiotherapy. There is, however, a need for more precise dosimetry, particularly with stereotactic radiosurgery. Most gamma knife facilities use either thermoluminescant dosimetry or film, neither of which provides three dimensional dose distributions. To overcome this limitation, we have developed a gel dosimetry system that relies on the production of a ferric ion-xylenol orange colored complex. This work demonstrates the use of laser light and a detector to quantify radiation-induced colorimetric changes in absorbance for the gel dosimeter. The absorbance has been reconstructed by the back projection technique to demonstrate the applicability of the gel dosimeter to gamma knife 3D-dose distributions.

  13. Evaluation of a locally manufactured polyester film (Garfilm-EM) as a dosimeter in radiation processing

    International Nuclear Information System (INIS)

    Locally manufactured 250 μm thick polyester film (Garfilm-EM) was evaluated spectrophotometrically for its dosimetric properties for use as a high dose radiation dosimeter. This film has good clarity, consistent thickness, scratch resistance and is easy to handle. Radiation induced changes in the absorption spectra were analyzed and 340 nm was chosen as the wavelength for absorption measurements. The reproducibility of the response for gamma rays of 60Co was found to be within ±2%. The effect of post irradiation storage time on the response was also investigated. From the studies carried out, Garfilm-EM has been found to have a good potential as a dosimeter to measure absorbed doses in the range 20 kGy-200 kGy due to its linear dose-response relationship. (author)

  14. Determination of transmission factors for beta radiation using Al 2O 3:C commercial OSL dosimeters

    Science.gov (United States)

    Pinto, T. N. O.; Caldas, L. V. E.

    2010-07-01

    In recent years, the optically stimulated luminescence (OSL) technique has been used in personal dosimetry, and aluminum oxide (Al 2O 3:C) has become a very useful material for this technique. The objective of this work was the determination of the transmission factors for beta radiation using Al 2O 3:C commercial dosimeters and the OSL method. The obtained results were similar to the transmission factors reported in the beta source calibration certificates.

  15. Calibration of routine dosimeters in radiation processing: Validation procedure for in-plant calibration

    Directory of Open Access Journals (Sweden)

    Šećerov Bojana Lj.

    2011-01-01

    Full Text Available The essential prerequisite of radiation dosimetry is to provide quality assurance and documentation that the irradiation procedure has been carried out according to the specification requirement of correct calibration of the chosen dosimetry system. At the Radiation Plant of the Vinča Institute of Nuclear Sciences we compared two recommended protocols of irradiation procedures in the calibration of dosimetry systems in radiation processing: (1 by irradiation of routine dosimeters (ethanol-chlorobenzene - ECB at the calibration laboratory and (2, by in-plant calibration with alanine transfer - dosimeters. The critical point for in-plant calibration is irradiation geometry, so we carefully positioned the phantom carrying both dosimeters in order to minimize dose gradients across the sample. The analysis of results obtained showed that the difference among determined absorbed doses for the construction of calibration curves between these two methods, (alanine vs. ECB, is less than 1%. The difference in combined standard uncertainty for each calibration procedure is 0.1%. These results demonstrate that our in-plant calibration is as good as calibration by irradiation at the calibration laboratory and validates our placement of the irradiation phantom during irradiation.

  16. Multimode optical fiber study for a new radiation dosimeter development

    Science.gov (United States)

    Badita, Eugenia; Stancu, Elena; Scarlat, Florea; Vancea, Catalin; Dumitrascu, Maria; Scarisoreanu, Anca

    2013-06-01

    This paper presents the experimental results on preliminary study of the physical proprieties of the multimode optical fiber in radiation field delivered by electron linear accelerator of the National Research and Development Institute for Laser, Plasma and Radiation Physics (INFLPR). This study is based on the physical degradation effect of the optical fiber due to electron beam exposure measured through dependence of the exposure dose in electron beam and radiation induced attenuation. Optical fiber attenuations were measured before, during and after electron beam exposure. Results show a greater attenuation for multimode optical fiber of lower wavelength.

  17. Integrative radiation systems biology.

    Science.gov (United States)

    Unger, Kristian

    2014-01-01

    Maximisation of the ratio of normal tissue preservation and tumour cell reduction is the main concept of radiotherapy alone or combined with chemo-, immuno- or biologically targeted therapy. The foremost parameter influencing this ratio is radiation sensitivity and its modulation towards a more efficient killing of tumour cells and a better preservation of normal tissue at the same time is the overall aim of modern therapy schemas. Nevertheless, this requires a deep understanding of the molecular mechanisms of radiation sensitivity in order to identify its key players as potential therapeutic targets. Moreover, the success of conventional approaches that tried to statistically associate altered radiation sensitivity with any molecular phenotype such as gene expression proofed to be somewhat limited since the number of clinically used targets is rather sparse. However, currently a paradigm shift is taking place from pure frequentistic association analysis to the rather holistic systems biology approach that seeks to mathematically model the system to be investigated and to allow the prediction of an altered phenotype as the function of one single or a signature of biomarkers. Integrative systems biology also considers the data from different molecular levels such as the genome, transcriptome or proteome in order to partially or fully comprehend the causal chain of molecular mechanisms. An example for the application of this concept currently carried out at the Clinical Cooperation Group "Personalized Radiotherapy in Head and Neck Cancer" of the Helmholtz-Zentrum München and the LMU Munich is described. This review article strives for providing a compact overview on the state of the art of systems biology, its actual challenges, potential applications, chances and limitations in radiation oncology research working towards improved personalised therapy concepts using this relatively new methodology. PMID:24411063

  18. Integrative radiation systems biology

    International Nuclear Information System (INIS)

    Maximisation of the ratio of normal tissue preservation and tumour cell reduction is the main concept of radiotherapy alone or combined with chemo-, immuno- or biologically targeted therapy. The foremost parameter influencing this ratio is radiation sensitivity and its modulation towards a more efficient killing of tumour cells and a better preservation of normal tissue at the same time is the overall aim of modern therapy schemas. Nevertheless, this requires a deep understanding of the molecular mechanisms of radiation sensitivity in order to identify its key players as potential therapeutic targets. Moreover, the success of conventional approaches that tried to statistically associate altered radiation sensitivity with any molecular phenotype such as gene expression proofed to be somewhat limited since the number of clinically used targets is rather sparse. However, currently a paradigm shift is taking place from pure frequentistic association analysis to the rather holistic systems biology approach that seeks to mathematically model the system to be investigated and to allow the prediction of an altered phenotype as the function of one single or a signature of biomarkers. Integrative systems biology also considers the data from different molecular levels such as the genome, transcriptome or proteome in order to partially or fully comprehend the causal chain of molecular mechanisms. An example for the application of this concept currently carried out at the Clinical Cooperation Group “Personalized Radiotherapy in Head and Neck Cancer” of the Helmholtz-Zentrum München and the LMU Munich is described. This review article strives for providing a compact overview on the state of the art of systems biology, its actual challenges, potential applications, chances and limitations in radiation oncology research working towards improved personalised therapy concepts using this relatively new methodology

  19. Development of electronic radiation dosimeter using commercial power pMOSFET

    Energy Technology Data Exchange (ETDEWEB)

    Lee, N.H.; Cho, J.W.; Kim, S.H. [Korea Atomic Energy Research Institute, Yusong, Taejon (Korea); Youk, G.U. [Inventors' Enterprise, Inc., IN (United States)

    2000-03-01

    When a metal oxide field effect transistor (MOSFET) is exposed to ionizing radiation, electron/hole pairs are generated in its oxide layer. The slow moving holes are trapped in the oxide layer of pMOSFET and appear as extra charges that change the characteristics of the transistor. The radiation-induced charges directly impact the threshold (turn-on) voltage of the transistor. This paper describes the use of the radiation-induced threshold voltage change of commercial power pMOSFETs as an accumulated radiation dose monitoring method. Two kinds of commercial p-type power MOSFETs were tested in a Co-60 gamma irradiation facility to see their capabilities as a radiation dosimeter. We found that the transistors showed good linearity in their threshold voltage shift characteristics with radiation dose. According to these results, a electronic radiation dosimeter using inexpensive commercial power pMOSFETs was developed for the first time. And these power pMOSFETs show good linearity in dose rate effect, room temperature annealing, and 100degC thermal annealing for 48 hours. (author)

  20. Development of electronic radiation dosimeter using commericial power pMOSFET

    International Nuclear Information System (INIS)

    When a metal oxide field effect transistor (MOSFET) is exposed to ionizing radiation, electron/hole pairs are generated in its oxide layer. The slow moving holes are trapped in the oxide layer of pMOSFET and appear as extra charges that change the characteristics of the transistor. The radiation-induced charges directly impact the threshold (turn-on) voltage of the transistor. This paper describes the use of the radiation-induced threshold voltage change of commercial power pMOSFET s as an accumulated radiation dose monitoring method. Two kinds of commercial p-type power MOSFETs were tested in a Co-60 gamma irradiation facility to see their capabilities as a radiation dosimeter. We found that the transistors showed good linearity in their threshold voltage shift characteristics with radiation dose. According to this results, a electronic radiation dosimeter using inexpensive commercial power pMOSFETs was developed for the first time. And these power pMOSFETs show good linearity in dose rate effect, room temperature annealing, and 100 .deg. C thermal annealing for 48hours

  1. Development of electronic radiation dosimeter using commercial power pMOSFET

    International Nuclear Information System (INIS)

    When a metal oxide field effect transistor (MOSFET) is exposed to ionizing radiation, electron/hole pairs are generated in its oxide layer. The slow moving holes are trapped in the oxide layer of pMOSFET and appear as extra charges that change the characteristics of the transistor. The radiation-induced charges directly impact the threshold (turn-on) voltage of the transistor. This paper describes the use of the radiation-induced threshold voltage change of commercial power pMOSFETs as an accumulated radiation dose monitoring method. Two kinds of commercial p-type power MOSFETs were tested in a Co-60 gamma irradiation facility to see their capabilities as a radiation dosimeter. We found that the transistors showed good linearity in their threshold voltage shift characteristics with radiation dose. According to these results, a electronic radiation dosimeter using inexpensive commercial power pMOSFETs was developed for the first time. And these power pMOSFETs show good linearity in dose rate effect, room temperature annealing, and 100degC thermal annealing for 48 hours. (author)

  2. Biological radiation effects

    International Nuclear Information System (INIS)

    The book covers all aspects of biological radiation effects and provides the fundamental basis for understanding the necessity of radiation protection as well as applications in radiotherapy. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are thoroughly discussed, taking into account modern developments and techniques. The effects on the human organism are reviewed, both from the point of view of applications in medicine as well as with regard to radiation hazards (teratogenic, gonadal and carcinogenic effects). It can be used by graduate students as an introduction and as a source book for all who want to become acquainted with this important field. It is an extended version of the original German book containing updated information and new material. (orig.) With 273 figs

  3. Radiation effects in frozen solutions of iron salts and solid state dosimeters at low temperatures

    International Nuclear Information System (INIS)

    Low temperature dosimetry is useful in space research, in the simulation of reactions that may take place in extraterrestrial icy-bodies, etc. In this paper we study the behavior of three different systems in order to evaluate if they can be used as dosimeters at low temperatures. The systems under study are 1) frozen solutions of iron salts, 2) crystals of LiF co-doped with Mg, Cu and P, and 3) crystals of CaSO4 doped with Dy. For the frozen solution the analysis was performed after melting by UV-spectroscopy and for the crystals the response was measured by thermoluminescence. The systems were irradiated with gamma radiation at different doses (from 10 to 2500 Gy), and at different temperatures (from 77 K to 298 K). Numerical simulations of the chemical reaction system reproduce the experimental effects produced by the irradiation in aqueous solutions of ferrous salt. The results with both the thermoluminescence dosimeters and the frozen iron aqueous solutions showed that the response of the dosimeters is a function of the temperature. At low radiation doses the response was linear. (Author)

  4. Management of radiation sources and personal dosimeters based on the optical identification using two-dimensional barcode

    International Nuclear Information System (INIS)

    For accurate and efficient radiation safety management in facilities using radioisotopes, two-dimensional barcode (2-DC) was applied to the optical identification of radiation sources and personal dosimeters. The mobile personal computer (PC) equipped with a barcode reader, which has imported inventory records from the pre-existing radiation management system, enabled us to finish inventory procedures for 170 2-DC-labelled radiation sources in as short as 20min by one person. Identification of 270 personal dosimeters in their monthly replacement procedures also successfully completed within 20 min by incorporating pre-labeled 2-DC to PC installed with inventory records of dosimeters and radiation workers. As equipments and software required for 2-DC are affordable, easy to operate, and potentially expandable, the introduction of 2-DC system may help to establish practically higher level of radiation management. (author)

  5. X-Ray energy dependence of the dose response of SIRAD radiation dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Tsang [City University of Hong Kong, Department of Physics and Materials Science, Kowloon Tong, Hong Kong (China); Butson, Martin J. [City University of Hong Kong, Department of Physics and Materials Science, Kowloon Tong, Hong Kong (China); Illawarra Cancer Care Centre, Department of Medical Physics, Crown St, Wollongong, NSW 2500 (Australia); Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, Gwyneville 2518, NSW (Australia); E-mail: martin.Butson@sesiahs.health.nsw.gov.au; Yu, Peter K.N. [City University of Hong Kong, Department of Physics and Materials Science, Kowloon Tong, Hong Kong (China)

    2007-07-15

    SIRADs (self-indicating instant radiation alert dosimeters) are designed to measure accident radiation doses. As the energy of radiation is usually unknown in such situations, a detector with a weak energy dependence of its response to dose would be ideal. We have studied the energy dependence of the dose response of SIRADs in the range from 50kVp to 10MV, which corresponds to photon equivalent energies from 25.5keV to 2.2MeV. The response to the same dose at 25.5keV is (29+/-4)%(+/-1s) lower than the response at 1.4MeV. The response to a dose slowly increases with radiation energy. This energy dependence is relatively weak in comparison with the dependence for radiographic films and similar in magnitude to the dependence for lithium fluoride thermoluminescence dosimeters. This energy dependence of the response diminishes the accuracy of dose assessments in radiation fields of unknown energy, but does not significantly compromise the core ability of the devices to provide visual estimates of radiation doses.

  6. Stored-fluorography mode reduces radiation dose during cardiac catheterization measured with OSLD dosimeter

    Science.gov (United States)

    Ting, Chien-Yi; Chen, Zhih-Cherng; Tang, Kuo-Ting; Liu, Wei-Chung; Lin, Chun-Chih; Wang, Hsin-Ell

    2015-12-01

    Coronary angiogram is an imperative tool for diagnosis of coronary artery diseases, in which cine-angiography is a commonly used method. Although the angiography proceeds under radiation, the potential risk of radiation exposure for both the patients and the operators was seldom noticed. In this study, the absorbed radiation dose in stored-fluorography mode was compared with that in cine-angiography mode by using optically simulated luminescent dosimeters to realize their effects on radiation dose. Patients received coronary angiogram via radial artery approach were randomized into the stored-fluorography group (N=30) or the cine-angiography group (N=30). The excluded criteria were: 1. women at pregnancy or on breast feeding, 2. chronic kidney diseases with glomerular filtration rate less than 60 mL/min. During the coronary angiogram, absorbed dose of the patients and the operator radiation exposure was measured with optically simulated luminescent dosimeter (OSLD). The absorbed dose of the patients in the stored-fluorography group (3.13±0.25 mGy) was apparently lower than that in the cine-angiography group (65.57±5.37 mGy; Pstatistical difference (P<0.001) was also found between the stored-fluorography group (0.09163 μGy) and the cine-angiography (0.6519μGy). Compared with traditional cine-angiography mode, the stored-fluorography mode can apparently reduce radiation exposure of the patients and the operator in coronary angiogram.

  7. Radiation-induced statistical uncertainty in the threshold voltage measurement of MOSFET dosimeters

    International Nuclear Information System (INIS)

    The results of a recent study on the limiting uncertainties in the measurement of photon radiation dose with MOSFET dosimeters are reported. The statistical uncertainty in dose measurement from a single device has been measured before and after irradiation. The resulting increase in 1/f noise with radiation dose has been investigated via various analytical models. The limit of uncertainty in the ubiquitous linear trend of threshold voltage with dose has been measured and compared to two nonlinear models. Inter-device uncertainty has been investigated in a group of 40 devices, and preliminary evidence for kurtosis and skewness in the distributions for devices without external bias has been observed

  8. The Development of an Individual Dosimeter for Measurement of High-Level Radiation Doses

    International Nuclear Information System (INIS)

    In connection with industry a dosimeter has been developed over the last few years which seems to be suited for general use in the measurement of high doses for radiation protection purposes. It consists of a phosphate glass and a filter. The case is water- and dust-proof and can be attached to an identity disc. The report gives values over the properties of the phosphate glass together with the results of tests on temperature and time response, the dependence on energy and direction of radiation and the influence of the dose rate. (author)

  9. Characteristics Of Dosimeter TL CaSO4:Dy Glass Capillaries For Environmental Radiation Dose Monitoring

    International Nuclear Information System (INIS)

    research on the characteristic of dosimeter TL CaSO4 : Dy glass capillaries for environmental dose radiation have been carried out. The results obtained are uniform response and reproducibility during three cycles consumption with average percentage standard deviation of 7.31 % and 5.45%. The response dose is linear and has a minimum detectable dose of 0.01 mGy, sunshine effect with non-penetrating light capsule of 4.65%, humidity effects is not significant by using non-penetrating light capsule. Radiation dose information during 30 days are fading 25%

  10. Miniaturized, low power FGMOSFET radiation sensor and wireless dosimeter system

    KAUST Repository

    Arsalan, Muhammad

    2013-08-27

    A miniaturized floating gate (FG) MOSFET radiation sensor system is disclosed, The sensor preferably comprises a matched pair of sensor and reference FGMOSFETs wherein the sensor FGMOSFET has a larger area floating gate with an extension over a field oxide layer, for accumulation of charge and increased sensitivity. Elimination of a conventional control gate and injector gate reduces capacitance, and increases sensitivity, and allows for fabrication using standard low cost CMOS technology. A sensor system may be provided with integrated signal processing electronics, for monitoring a change in differential channel current I.sub.D, indicative of radiation dose, and an integrated negative bias generator for automatic pre-charging from a low voltage power source. Optionally, the system may be coupled to a wireless transmitter. A compact wireless sensor System on Package solution is presented, suitable for dosimetry for radiotherapy or other biomedical applications.

  11. Commercial power silicon devices as possible routine dosimeters for radiation processing

    International Nuclear Information System (INIS)

    The use of silicon devices as possible radiation dosimeters has been investigated in this study. A bipolar power transistor in TO126 plastic packaging has been selected. Irradiations, with doses in the range from 50 Gy up to 5 kGy, have been performed at room temperature using different radiation sources (60Co g source, 2.5, 4 and 12 MeV electron accelerators). Few irradiations with g rays were also done at different temperatures. A physical parameter, T, related to the charge carrier lifetime, has been found to change as a function of irradiation dose. This change is radiation energy dependent. Long term stability of the electron irradiated transistors has been checked by means of a reliability test ('high temperature reverse bias', HTRB) at 150 deg. C for 1000 h. Deep level transient spectroscopy (DLTS) measurements have been performed on the irradiated devices to identify the recombination centres introduced by the radiation treatment. The results obtained confirm that these transistors could be used as routine radiation dosimeters in a certain dose range. More work needs to be done particularly with g rays in the low dose region (50-200 Gy) and with low energy electrons. (author)

  12. Characterization of a medical X-ray machine for testing the response of electronic dosimeters in pulsed radiation fields

    International Nuclear Information System (INIS)

    Electronic personal dosimeters (EPD) based on solid state detectors have been used for personnel monitoring for radiation protection purpose; their use has been extended to practices with pulsed radiation beams although their performance is not well known. Deficiencies in the EPD response in pulsed radiation fields have been reported; they were not detected before since type tests and calibrations of EPDs were established in terms of continuous X and gamma reference radiations. An ISO working group was formed to elaborate a standard for test conditions and performance requirements of EPDs in pulsed beams; the PTB/Germany implemented a special X-ray facility for generating the reference pulsed radiation beams. In this work, an 800 Plus VMI medical X-ray machine of the Dosimeter Calibration Laboratory of CDTN/CNEN was characterized to verify its feasibility to perform EPD tests. Characterization of the x-ray beam was done in terms of practical peak voltage, half-value layer, mean energy and air kerma rate. Reference dosimeters used for air kerma measurements were verified as far their metrological coherence and a procedure for testing EDPs was established. - highlights: • Electronic personal dosimeters (EPD) have been used for personnel monitoring. • EPD use has been extended to pulsed radiation beams. • Deficiencies in the EPD response in pulsed beams have been reported. • The feasibility of using a medical X-ray machine to perform EPD tests was studied. • Reference dosimeters were verified and EPD testing procedure was established

  13. Space-radiation dosimetry using CR-39 and TLD integrating dosimeters

    CERN Document Server

    Tawara, H; Nagamatsu, A

    2002-01-01

    Since the dose levels in space are significantly higher than those on the ground, accurate dosimetric measurements have strongly been required for the radiation protection of astronauts and cosmonauts engaged in long-term space flights. Passive dosimeters such as TLDs and nuclear track detectors have frequently been employed from the beginning of the history of the manned space flights. CR-39 plastic is currently the most common passive detector for measuring LET distributions of heavy-charged particles in space radiation fields. Although CR-39 and TLDs are integrating types, they are still promising as space radiation dosimeters. The combination of data from both detectors allows us to estimate total radiation doses over an extremely wide LET range of the order from 10 sup - sup 1 to 10 sup 4 keV/mu m. We compare the dosimetric results from CR-39/TLD aboard STS-84 and STS-91 to those from RRRD-III to discuss the accuracy of the dose measurements. We emphasize that the measurement of short-range high-LET part...

  14. Resistant and sensitive single-crystal diamond dosimeters for ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Trucchi, D.M., E-mail: daniele.trucchi@imip.cnr.it [CNR-IMIP, Via Salaria km 29.300, 00016 Monterotondo Scalo, Rome (Italy); Allegrini, P.; Bellucci, A.; Calvani, P. [CNR-IMIP, Via Salaria km 29.300, 00016 Monterotondo Scalo, Rome (Italy); Galbiati, A. [Solaris Photonics Ltd, 23 Almond Avenue, UB7 9 EL, London (United Kingdom); Girolami, M. [CNR-IFN, Via Cineto Romano 42, 00156 Rome (Italy)

    2013-08-01

    Diamond dosimeters for intense ionizing radiation were assembled by developing Ohmic contacts on single-crystal high-purity diamond films. Leakage electrical resistivity of the order of 10{sup 14} Ω cm was measured. Devices were tested with a low-intensity 17.48 keV X-ray beam to probe their maximum sensitivity and the minimum detectable dose-rate. Diamond detectors provided a linearity coefficient to X-ray dose-rate of 1.023±0.07, whose dependence on operative bias voltage is here analyzed.

  15. Development of prototype fiber optics dosimeter for remote radiation level measurements

    International Nuclear Information System (INIS)

    Measurement of radiation levels in difficult-to-access and hazardous areas, such as hot cells, high active source storage areas, require refined and sensitive remote radiation level measurement techniques. Optical fiber dosimetry has been studied as an emerging method of monitoring radiation remotely and is suitable for use in confined environments that may be inaccessible using existing conventional electronic dosimeters or radiation survey meters. Being light weight and nonintrusive, optical fibers based dosimeters provide several advantages in the field of remote radiation dosimetry and in-vivo medical applications. A prototype fiber optic dosimetry system with extrinsic architecture is designed and developed using optically stimulated luminescence (OSL) technique at Radiological Safety Division, Indira Gandhi Centre for Atomic Research. The fiber optic dosimetry system uses OSL material like BaFBr: Eu to detect radiation and a bifurcated optical cable to illuminate the sensor with the suitable light source and also to guide the light from the sensor to the detector. Indigenously developed hardware is used for pulse processing and application software of the system is developed in Microsoft Visual Basic.Net. This paper depicts the characterization of the dosimetric material, development of hardware and software for the system and calibration of the system using standard source. The system uses Advantech APAX 5570 base controller with suitable modular add-on cards for data acquisition and controlling. Indigenously developed electronics is used for processing the pulses from the sensor attached to the tip of the bifurcated optical cable. The acquisition of the counts from the electronic circuit and illumination and bleaching time for the sensor pellet is controlled by application software developed in VB.Net. The system is calibrated by irradiating the pellet with different absorbed doses. The system explores the possibility of remote radiation monitoring using

  16. Test of a remotely measuring radiation dosimeter model constructed with combination of a plastic scintillator and plastic optical fiber

    International Nuclear Information System (INIS)

    A real-time remotely measuring radiation dosimeter with a high spatial resolution is useful to monitoring radiation doses in a research irradiation chamber or a human phantom for radiation cancer treatment planning. This study presents the results of the performance test of a radiation dosimeter model which was constructed by attaching a small piece of plastic scintillator to one end of a plastic optical fiber and a current-type PMT the other end. The dosimeter model was inserted into an irradiation chamber loaded with about 222 TBq (6,000 Ci) of 60Co to measure the PMT currents at a number of points differently distance from the source. MCNPX simulations were conducted to calculate the energy deposited in the scintillator piece. A Farmer type ionization chamber and Alanine pellet dosimeter were employed to measure the absorbed dose rates at the same positions inside the irradiation chamber. Normalization is made for each data set with respect to the corresponding maximum value. The normalized distribution of the PMT current is compared with those of the calculated energy deposition and the measured dose rates, respectively to evaluate the accuracy of the dosimeter model measuring the dose rate as PMT current. The normalized distribution of the measured PMT current well coincides with those of the MCNPX-calculated deposited energy and the dose rates measured with a Farmer type ionization chamber and Alanine pellet dosimeters. An average calibration factor is obtained from the measured data to convert the measured PMT currents into the absorbed dose rates. When this average calibration factor is applied in the measured dose rate range 47 ∼ 1180 Gy h-1, the maximum error is estimated to be less than 7%, which is very comparable with deviations between the data measured with commercially available dosimeters

  17. Performance characteristics of CaSO4 :Dy based indigenous thermoluminescent dosimeters for environmental radiation monitoring

    International Nuclear Information System (INIS)

    Dysprosium doped calcium sulphate based Thermoluminescent Dosimeter (TLD) cards, generally used for personal dosimetry applications in India were redesigned and modified to suit the environmental gamma radiation monitoring applications. Characteristics of the new TLDs, necessary for environmental gamma radiation monitoring were studied and found to be satisfactory in every respect. The TLDs were field tested together with the calcium fluoride powder based capsule TLDs and the results were found to be very satisfactory. This report describes the design parameters, characteristics of the TLDs and results of comparison studies between the two systems that were carried out in all the DAE installations where the environmental gamma radiation monitoring is being carried out for more than three decades. (author)

  18. Biological radiation effects

    International Nuclear Information System (INIS)

    This work examines ionizing radiations: what they are, where they come from, their actions and consequences, finally the norms and preventive measures necessary to avoid serious contamination, whether the individual or the population in general is involved. Man has always been exposed to natural irradiation, but owing to the growing use of ionizing radiations both in medicine and in industry, not to mention nuclear tests and their use as an argument of dissuasion, the irradiation of human beings is increasing daily. Radioactive contamination does remain latent, apart from acute cases, but this is where the danger lies since the consequences may not appear until long after the irradiation. Of all biological effects due to the action of radioelements the genetic risk is one of the most important, affecting the entire population and especially the generations to come. The risk of cancer and leukemia induction plays a substantial part also since a large number of people may be concerned, depending on the mode of contamination involved. All these long-term dangers do not of course exclude the various general or local effects to which the individual alone may be exposed and which sometimes constitute a threat to life. As a result the use of ionizing radiations must be limited and should only be involved if no other process can serve instead. The regulations governing radioelements must be stringent and their application strictly supervised for the better protection of man. This protection must be not only individual but also collective since pollution exists in air, water and land passes to plants and animals and finally reaches the last link in the food chain, man

  19. Radiation-induced refraction artifacts in the optical CT readout of polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Warren G.; Jirasek, Andrew, E-mail: jirasek@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Wells, Derek M. [British Columbia Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2014-11-01

    Purpose: The objective of this work is to demonstrate imaging artifacts that can occur during the optical computed tomography (CT) scanning of polymer gel dosimeters due to radiation-induced refractive index (RI) changes in polyacrylamide gels. Methods: A 1 L cylindrical polyacrylamide gel dosimeter was irradiated with 3 × 3 cm{sup 2} square beams of 6 MV photons. A prototype fan-beam optical CT scanner was used to image the dosimeter. Investigative optical CT scans were performed to examine two types of rayline bending: (i) bending within the plane of the fan-beam and (ii) bending out the plane of the fan-beam. To address structured errors, an iterative Savitzky–Golay (ISG) filtering routine was designed to filter 2D projections in sinogram space. For comparison, 2D projections were alternatively filtered using an adaptive-mean (AM) filter. Results: In-plane rayline bending was most notably observed in optical CT projections where rays of the fan-beam confronted a sustained dose gradient that was perpendicular to their trajectory but within the fan-beam plane. These errors caused distinct streaking artifacts in image reconstructions due to the refraction of higher intensity rays toward more opaque regions of the dosimeter. Out-of-plane rayline bending was observed in slices of the dosimeter that featured dose gradients perpendicular to the plane of the fan-beam. These errors caused widespread, severe overestimations of dose in image reconstructions due to the higher-than-actual opacity that is perceived by the scanner when light is bent off of the detector array. The ISG filtering routine outperformed AM filtering for both in-plane and out-of-plane rayline errors caused by radiation-induced RI changes. For in-plane rayline errors, streaks in an irradiated region (>7 Gy) were as high as 49% for unfiltered data, 14% for AM, and 6% for ISG. For out-of-plane rayline errors, overestimations of dose in a low-dose region (∼50 cGy) were as high as 13 Gy for

  20. Use of MOSFET dosimeters to validate Monte Carlo radiation treatment calculation in an anthropomorphic phantom

    Science.gov (United States)

    Juste, Belén; Miró, R.; Abella, V.; Santos, A.; Verdú, Gumersindo

    2015-11-01

    Radiation therapy treatment planning based on Monte Carlo simulation provide a very accurate dose calculation compared to deterministic systems. Nowadays, Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) dosimeters are increasingly utilized in radiation therapy to verify the received dose by patients. In the present work, we have used the MCNP6 (Monte Carlo N-Particle transport code) to simulate the irradiation of an anthropomorphic phantom (RANDO) with a medical linear accelerator. The detailed model of the Elekta Precise multileaf collimator using a 6 MeV photon beam was designed and validated by means of different beam sizes and shapes in previous works. To include in the simulation the RANDO phantom geometry a set of Computer Tomography images of the phantom was obtained and formatted. The slices are input in PLUNC software, which performs the segmentation by defining anatomical structures and a Matlab algorithm writes the phantom information in MCNP6 input deck format. The simulation was verified and therefore the phantom model and irradiation was validated throughout the comparison of High-Sensitivity MOSFET dosimeter (Best medical Canada) measurements in different points inside the phantom with simulation results. On-line Wireless MOSFET provide dose estimation in the extremely thin sensitive volume, so a meticulous and accurate validation has been performed. The comparison show good agreement between the MOSFET measurements and the Monte Carlo calculations, confirming the validity of the developed procedure to include patients CT in simulations and approving the use of Monte Carlo simulations as an accurate therapy treatment plan.

  1. Development of a biological dosimeter for translocation scoring based on two-color fluorescence in situ hybridization of chromosome subsets

    International Nuclear Information System (INIS)

    Recently fluorescence in situ hybridization protocols have been developed which allow the paining of individual chromosomes using DNA-libraries from sorted human chromosomes. This approach has the particular advantage that radiation induced chromosome translocations can be easily detected, if chromosomes of distinctly different colors take part in the translocation event. To enhance the sensitivity of this approach two metaphase chromosome subsets A and B (A: chromosome 1, 2, 4, 8, 16; B: 3, 5, 9, 10, 13) were simultaneously painted in green and red color. Counterstaining of the chromosomes with DAPI resulted in a third subset which exhibited blue fluorescence only. Green-red, green-blue and red-blue translocation chromosomes could be easily detected after irradiation of lymphocyte cultures with 137Cs-γ-rays. Analyses of painted chromosomes can be combined with conventional GTG-banding analyses. This new biological dosimeter should become useful to monitor both long term effects of single irradiation events and the cumulative effects of multiple or chronic irradiation exposure. In contrast to translocation scoring based on the analysis of banded chromosomes, this new approach has the particular advantage that a rapid, automated scoring of translocations can now be envisaged. (author)

  2. Temperature and relative humidity dependence of radiochromic film dosimeter response to gamma electron radiation

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Puhl, J.M.; Miller, A.

    of both types. It is observed that for each new batch of film to be used for radiation processing, the effects of such parameters on response to both gamma rays and electrons should be investigated. It is also suggested that the films should be packaged under controlled atmospheric conditions......Nylon-base radiochromic films (FWT-60(TM) and FWT-460(TM)) are commercially-available, thin dosimeters that are widely used in radiation processing. These films cover the following ranges of absorbed dose: 2 x 10(3) to 5 x 10(4) Gy for FWT-60(TM) and 5x10(3) Gy to 105 Gy for FWT-460(TM). Based on...

  3. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  4. Franco-Russian comparison of mixed neutron and gamma radiation field dosimeters at the Silene reactor

    International Nuclear Information System (INIS)

    This paper gives the results of dosimetry measurements carried out in the Silene reactor at Valduc (France) with neutron and photon dosimeters in mixed neutron and gamma radiation fields, in the frame of a Franco-Russian comparison of dosimeters. Neutron dosimetry was supplied by passive semiconductors, activation detectors and nuclear track detectors. For photon dosimetry, thermoluminescent and passive semiconductor detectors were used. The experiments were located at 3 m from the reactor core, in free air and also at the front and back of a tissue-equivalent phantom. The pulse operating mode of the reactor was used to simulate a criticality accident with solid fissile material, while the free evolution mode simulated a criticality accident in a fissile solution. The photon absorbed dose showed a slight increase on entering the phantom compared to measurements in free air, probably due to backscattering by the phantom. At the rear of the phantom, the neutron kerma was four times lower than on the front, whereas the photon dose was only two times lower. The heterogeneity of dose inside the phantom was far greater for neutrons than for photons

  5. Proposed algorithm to angular radiation incidence correction of fast neutron track dosimeter

    International Nuclear Information System (INIS)

    Aiming to improve the dosimetry of workers potentially exposed to neutron radiation in Brazil, the Instituto de Pesquisas Energeticas e Nucleares - IPEN, a governmental Research Center, in association with PRO-RAD, a private Monitoring Service, designed and developed an individual dosimeter for gamma-neutron mixed field monitoring using the techniques of Thermoluminescent Albedo Dosimetry (TLAD) and Solid State Nuclear Track Dosimetry (SSNTD). Neutron doses are preferably estimated according to albedo neutrons dosimeter response. Track detectors are used just to high fast neutron doses confirmation. Thermoluminescent detectors Harshaw TLD-600 and TLD-700 were used to evaluate gamma and intermediate (albedo) neutrons doses. A commercial polycarbonate produced in Brazil, named SS-1, was used as track detector to measure fast neutrons doses. Previous study shown that SS-1 directional (angular) response presents a cosine behavior. Knowing the incidence angle, a correction factor, equal to the inverse of this angle's cosine, must be applied in the dose calculation algorithm. The ratio of fast and albedo neutrons responses could be considered constant as a function of dose, but decreases proportionally with increasing radiation incidence angle. This variation allows estimating the incidence angle and, then, correcting the fast neutrons dose response. An algorithm to directional incidence correction applied to Americium-Beryllium neutron sources and dose range of radiation protection interest (up to 20 mSv) was proposed based on these premises and considering that correction factor will be applied only if the ratio of fast and albedo neutron responses is below its average to normal incidence less 30% (∼ 200 tracks/cm2.nC). (author)

  6. External radiation monitoring in the environs of KAPS region using thermoluminescent dosimeters, 1986-2000

    International Nuclear Information System (INIS)

    This paper presents the results of gamma radiation background survey, over the past fourteen years, carried out using Thermoluminescent Dosimeters (TLDs), in the environs of Kakrapar Atomic Power Station (KAPS). The survey comprises of measurement of soil radioactivity, seven-year pre-operational radiation levels and a regular TLD monitoring survey after the power station became operational. The data were analysed to study long-term trends in the radiation levels of the region. It is observed that the average annual air dose in the Kakrapar region, before KAPS became operational, was in the range 387 - 649 μGy/y as monitored by TLDs. This agrees well with the dose estimated from the soil radioactivity data. The radiation levels monitored after the KAPS became operational are in the range of 475 - 645 μGy/y in the region within 5 -15 km radius. This points to the fact that there has been no detectable increase in the environmental radiation levels due to the KAPS operations. The details are discussed in the paper. (author)

  7. Towards a cumulative biological dosimeter based on chromosome painting and digital image analysis

    International Nuclear Information System (INIS)

    An approach for a long-term (cumulative) biological dosimeter is described, based on the idea that stem cells with irradiation-induced reciprocal translocations and their progeny would neither lose nor gain genetic material and thus should retain the same proliferative potential as non-irradiated cells. Rapid detection of chromosome translocations has become possible in irradiated human lymphocytes by a newly developed fluorescent in situ hybridization method called 'chromosome painting'. We have used this approach to score chromosome aberrations, including translocation events, in over 8000 chromosomes painted in lymphocytes from two patients exposed to an X-ray contrast medium containing Th-232 and from two age-matched control persons. The percentage of both the total fraction of aberrant painted chromosomes and of translocations was found significantly higher in exposed patients. A program was developed which can automatically determine the number of normal and aberrant painted chromosomes and classify evaluated cells as 'normal' or 'aberrant' within 1 to 2 seconds. (orig.)

  8. A cyanocobalamin dosimeter for monitoring gamma-radiation doses of 0.1-2 kGy

    Science.gov (United States)

    Maged, A. F.; Hamza, M. S. A.; Saad, E. A.

    1997-08-01

    A simple dosimeter is described for measuring gamma-ray doses useful for insect sterilization, seed-sprouting inhibition and food shelf-life extensions. The red aqueous solution of cyanocobalamin (B 12) before irradiation, assumes a stable yellow color when irradiated. It shows a linear response of absorbance decrease with the dose over the range of 0.1-2.0 kGy when the concentration of cyanocobalamin is equal 0.09 mM. The radiation-induced color is analyzed spectrophotometrically at the maximum absorption band (361 nm). The absorption spectra, dose response and post-irradiation stability of the dosimeter are discussed.

  9. Biological radiation effects

    International Nuclear Information System (INIS)

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed

  10. The fundamental radiation properties of normoxic polymer gel dosimeters: a comparison between a methacrylic acid based gel and acrylamide based gels

    International Nuclear Information System (INIS)

    Polymer gel dosimeters offer a wide range of applications in the three-dimensional verification of complex dose distributions such as in intensity-modulated radiotherapy. One of the major difficulties with polymer gel dosimeters is their sensitivity to oxygen, as oxygen inhibits the radiation-induced polymerization reaction. For several years, oxygen was removed from the gels by bubbling the sol with inert gases for several hours during the gel fabrication. Also, the gel had to be poured in containers with low oxygen permeability and solubility. Recently, it was found that these technical difficulties can easily be solved by adding an antioxidant to the gel. These gels are called 'normoxic' gels as they can be produced under normal atmospheric conditions. In this study several properties of polymer gel dosimeters have been investigated: the dose sensitivity, the temporal and spatial stability of the gel, the sensitivity of the dose response to temperature during irradiation and during MR imaging, the energy dependence and the dose-rate dependence. This study reveals that the normoxic polymer gel dosimeter based on methacrylic acid (nMAG) studied in this work has inferior radiation properties as compared to the polyacrylamide gelatine (PAG) gel dosimeters. It is shown that from the three different gel dosimeters investigated in this study, the nPAG gel dosimeter results in a less sensitive gel dosimeter but with superior radiation properties as compared to the nMAG gel dosimeter. The importance of investigating relevant radiation properties of gel dosimeters apart from the radiation sensitivity-prior to their use for dosimetric validation experiments-is illustrated and emphasized throughout this study. Other combinations of monomer and gelling agent may result in more reliable normoxic polymer gel dosimeters

  11. Sucrose as double-signal high-dose dosimeter for ionizing radiation

    International Nuclear Information System (INIS)

    A possibility to use chemically pure sucrose as double-signal (EPR+UV) dosimeter for high doses of gamma radiation was checked. Sucrose (as obtained) was irradiated in solid state and one part of the sample was analyzed by EPR and the second one by optical method. In a range 5-50 kGy both signals were linearly dependent on an absorbed dose. Additionally, a linear correlation between EPR and optical signal was observed. EPR signal (peak-to-peak amplitude) decreased slowly with time (some percent during the first 11 weeks). The decay was slightly dose depended. Optical signals were measured after dissolution of irradiated sucrose in triple distilled water. An absorption band with maximum at 263 nm was chosen as dosimetric signal. Its intensity increased slowly with time (about 5% during the first day). The heating procedure proposed in literature for UV signal stabilization was checked but it was not recommended for a routine use.

  12. Measurements of radon and thoron concentrations in high radiation background area using pin-hole dosimeter

    International Nuclear Information System (INIS)

    In present investigation, newly designed twin cup pin-hole dosimeter with LR-115 track detector has been used for the integrated measurements of radon and thoron in the environmental air of a high background radiation area in coastal Orissa. The twin cup dosimeters were calibrated before installation in the field. The calibration experiment was made in an inter calibration exercise at NIRS, Chiba, Japan. The resulting calibration factors were used to obtain the values of radon and thoron in the study area. Radon and thoron concentrations in the houses of study area were found to vary from 24 Bq/m3 to 98 Bq/m3 and 46 Bq/m3 to 689 Bq/m3, respectively. The indoor and outdoor gamma dose rates in the study area vary from 0.124 μGy/h to 0.257 μGy/h and 0.109 μGy/h to 0.361 μGy/h, respectively. The annual effective dose due to the exposure to indoor radon and progeny was found to vary from 0.70 mSv to 2.84 mSv with an average value of 1.73 mSv. However, the annual effective dose due to the exposure to thoron and progeny was found to vary from 1.16 mSv to 17.36 mSv with an average value of 7.36 mSv. Thoron concentration and gamma dose rate were found relatively higher in the area. - Highlights: • Results of a newly designed twin cup pin-hole dosimeter are reported in this paper. • Radon and thoron were measured in high background radiation area of India. • Concentration of thoron and resulting effective dose were found higher in the area. • The indoor and outdoor gamma dose rates were also relatively higher in the area. • The resulting dose to the people living in the area was estimated

  13. Two kinds of biological dosimeters applied to 131I-treated thyroid cancer patients

    International Nuclear Information System (INIS)

    dicentric numbers. The No.4 patient toke 131I two times; e.g., 3.7 GBq in 1997, and 3.7 GBq in 1998,and got the result of 0.043 dicentrics per cell. The formula Y = 2.62x10-2 D + 1.96 x 102 D2 (D=dose(Gy), Y=dicentric yield), was used and the biological dose evaluation is 0.53 Gy. Both methods showed relatively in accordance with the accuracy. The results once more showed that dicentric chromosome aberration is the mainstay and the sensitive method for the biological dosimeters, but it takes a lot of microscopic work and rather tedious procedures, and the TCR mutation assay is a speedy biological dosimeter, since the TCR results can be obtained within one day. However the TCR mutation assay is still considered as in the early stage of development, many experimental data have not been fully tested. (author)

  14. Two kinds of biological dosimeters applied to {sup 131}I-treated thyroid cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ming-Shia; Chen, Li-Hsiang [Health Physics Division, Institute of Nuclear Energy Research, Taiwan (China)

    2000-05-01

    long period (on more than 5 years) {sup 131}I treatment. But nevertheless the No.10 patient was taken {sup 131}I 27.5 GBq total activity still has the highest TCR rates and dicentric numbers. The No.4 patient toke {sup 131}I two times; e.g., 3.7 GBq in 1997, and 3.7 GBq in 1998,and got the result of 0.043 dicentrics per cell. The formula Y = 2.62x10{sup -2} D + 1.96 x 10{sup 2} D{sup 2} (D=dose(Gy), Y=dicentric yield), was used and the biological dose evaluation is 0.53 Gy. Both methods showed relatively in accordance with the accuracy. The results once more showed that dicentric chromosome aberration is the mainstay and the sensitive method for the biological dosimeters, but it takes a lot of microscopic work and rather tedious procedures, and the TCR mutation assay is a speedy biological dosimeter, since the TCR results can be obtained within one day. However the TCR mutation assay is still considered as in the early stage of development, many experimental data have not been fully tested. (author)

  15. Biology relevant to space radiation

    International Nuclear Information System (INIS)

    The biological effects of the radiations to which mankind on earth are exposed are becoming known with an increasing degree of detail. This knowledge is the basis of the estimates of risk that, in turn, fosters a comprehensive and evolving radiation protection system. The substantial body of information has been, and is being, applied to questions about the biological effects of radiation is space and the associated risk estimates. The purpose of this paper is not to recount all the biological effect of radiation but to concentrate on those that may occur as a result from exposure to the radiations encountered in space. In general, the biological effects of radiation in space are the same as those on earth. However, the evidence that the effects on certain tissues by the heaviest-charged particles can be interpreted on the basis of our knowledge about other high-LET radiation is equivocal. This specific question will be discussed in greater detail later. It is important to point out the that there are only limited data about the effects on humans of two components of the radiations in space, namely protons and heavy ions. Thus predictions of effects on space crews are based on experimental systems exposed on earth at rates and fluences that are higher than those in space and one the effects of gamma or x rays with estimates of the equivalent doses using quality factors

  16. Biologically efficient solar radiation

    OpenAIRE

    Grigalavicius, Mantas; Juzeniene, Asta; Baturaite, Zivile; Dahlback, Arne; Moan, Johan

    2013-01-01

    Solar ultraviolet (UV) radiation is the main source of vitamin D production and is also the most important environmental risk factor for cutaneous malignant melanoma (CMM) development. In the present study the relationships between daily or seasonal UV radiation doses and vitamin D status, dietary vitamin D intake and CMM incidence rates at different geographical latitudes were investigated. North-South gradients of 25-hydroxyvitamin D (25(OH)D) generation and CMM induction were calculated, b...

  17. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair

  18. Radiation-induced failures and degradation of wireless real-time dosimeter under high-dose-rate irradiation

    Science.gov (United States)

    Tsuchiya, K.; Kuroki, K.; Akiba, N.; Kurosawa, K.; Matsumoto, T.; Nishiyama, J.; Harano, H.

    2010-04-01

    Radiation-induced malfunction and degradation of electronic modules in certain operating conditions are described in this report. The cumulative radiation effects on Atmel AVR microcontrollers, and 2.4 GHz and 303 MHz wireless network devices were evaluated under gamma ray irradiation with dose rates of 100, 10 and 3 Gy/h. The radiation-induced malfunctions occurred at doses of 510+/-22 Gy for AVR microcontrollers, and 484+/-111 and 429+/-14 Gy for 2.4 GHz and 303 MHz wireless network devices, respectively, under a 100 Gy/h equivalent dose rate. The degradation of microcontrollers occurred for total ionizing doses between 400 and 600 Gy under X-ray irradiation. In addition, we evaluated the reliability of neutron dosimeters using a standard neutron field. One of the neutron dosimeters gave a reading that was half of the standard field value.

  19. Characteristics of OSL dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Akifumi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ito, Masashi [Nagase Landauer Co., Ltd., Tokyo (Japan)

    2001-02-01

    Optically Stimulated Luminescence (hereafter OSL) dosimeter system is the method for radiation dose measurements by detecting light emitted when the luminescence material, which is exposed to radiation, is stimulated with visible light. Recently, this system has been developed as an advanced method for personal radiation dosimetry and has already been adopted in some countries such as U.S.A., Canada and others. Some basic characteristics (linearity for dose, energy response, angular dependence, dose evaluation performance on mixed irradiation field, fading and so on) required for the practical application of the {alpha}-Al{sub 2}O{sub 3} OSL dosimeter were investigated. It is shown that the OSL dosimeter has excellent good enough to performance for the measurement of {gamma}, X and {beta} doses and is good enough for practical use as personal dosimeter. This paper describes the basic characteristics of the OSL dosimeter obtained by the investigation. (author)

  20. Measurement of the dose by dispersed radiation in a lineal accelerator using thermoluminescent dosimeters of CaSO4:Dy

    International Nuclear Information System (INIS)

    The thermoluminescence (Tl) is based on the principle of the luminescent in a material when is heated below their incandescence temperature. Is a technique very used in dosimetry that is based on the property that have most of the crystalline materials regarding the storage of the energy that they absorb when are exposed to the ionizing radiations. When this material has been irradiated previously, the radioactive energy that contains is liberated in form of light. In general, the principles that govern the thermoluminescence are in essence the same of those responsible for all the luminescent processes and, this way, the thermoluminescence is one of the processes that are part of the luminescence phenomenon. For this work, the dispersed radiation was measured in the therapy area of the lineal accelerator of medical use type Elekta, using thermoluminescent dosimeters of CaSO4:Dy + Ptfe developed and elaborated in the Universidad Autonoma Metropolitana, Unidad Iztapalapa. With the dosimeters already characterized and calibrated, we proceeded to measure the dispersed radiation being a patient in treatment. The results showed values for the dispersed radiation the order of a third of the dose received by the patient on the treatment table at 30 cm of the direct beam and the order of a hundredth in the control area (4 m of the direct beam, approximately). The conclusion is that the thermoluminescent dosimeters of CaSO4: Dy + Ptfe are appropriate to measure dispersed radiation dose in radiotherapy. (author)

  1. A high-precision, tissue-equivalent dosimeter for nuclear accident and radiation oncology applications based on optically stimulated luminescence (OSL) in Al2O3:C

    International Nuclear Information System (INIS)

    Injection molding is an important industrial technique for producing large quantities of identical polymer and polymer composite parts. Although alumina of any kind is abrasive and damaging to the steel molds, a technique was developed that reduces both the mold abrasion and the effective atomic number of the composite polymer dosimeter [Miller, S. 1996a. U.S. Patent No. 5,567,948, issued 22 October 1996; Miller, S. 1996b. U.S. Patent No. 5,569,927, issued 29 October 1996; Miller, S. 1998. U.S. Patent No. 5,731,590, issued 24 March 1998.]. Radiation oncology dose measurement applications would benefit from a large uniform batch of high-precision dosimeters (<2%, 1 sigma measurement precision). This new, high-precision dosimeter would eliminate the need to calibrate each dosimeter individually, as is currently the case with the thermoluminescence dosimeter measurements performed by the radiation oncology community

  2. Radiation physics, biophysics, and radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  3. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ''biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons

  4. Radiation biology of mosquitoes

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  5. Radiation biology and oncology

    International Nuclear Information System (INIS)

    Chinese hamster indicated (line CHO) were cultured under hypoxic conditions and their clonogenicity and cell cycle distributions were measured as a function of the gassing period. Cells cultured under 1000 ppM O2 exhibited a biphasic reduction in cell survival. Cell cycle analyses indicd that hypoxic cells traversed the cell cycle at a reduced rate depending on the level of oxygen tension. The radiosensitivity of CHO cells cultured under hypoxic conditions was also measured at 24 h intervals for 96 h. Radiation survival curves also indicated that the hypoxic cells traversed the cell cycle at slow rates, exhibiting a slightly increased radiosensitivity of the hypoxic cells at 24 h, followed by decreased radiosensitivity at 72 h. These results indicate that hypoxia induced a partial synchronization of cells which persisted over prolonged periods (i.e., up to six times the normal culture doubling time). To test whether the radiation-induced delay in cell progression is dependent on the level of cell survival, CHO cells were first exposed to nitrogen gas for a period of 1 h followed by x-irradiation under the same nitrogen gassing or under aerated conditions. The results indicated that for a given dose, the cell progression delay was considerably less for hypoxic cells. These findings suggest that radiation-induced cell progression delay is cell-survival dependent. In another study, interactions between x rays or alpha particles from plutonium and drugs [nitrogen mustard (NM), actinomycin D (AMD)] were measured using V79 cells. Cells were exposed to radiation first, followed by drug exposure for 1 h. The data indicated that there seems to be no significant difference between x-ray-NM and alpha-NM interactions. A study using AMD instead of NM indicated that drug treatment after alpha irradiation resulted in an increased steepening of the survival curve, suggesting that there is an interaction between alpha particles and AMD

  6. Radiation physics, biophysics, and radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.

    1992-05-01

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  7. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent

  8. The importance of fabric structure in the construction of 2D textile radiation dosimeters

    International Nuclear Information System (INIS)

    A range of fabrics was selected for examination as material for construction of 2D radiation dosimeters as a consequence of previously obtained results confirming the possibility of radiation dose measurement with the modified polyamide textiles. These fabrics were surface finished with either 2,3,5-triphenyltetrazolium chloride (TTC) or nitrotetrazolium blue chloride (NBT). Under UV light irradiation the fabrics change colour to reddish (TTC) or bluish (NBT). The tinge intensity depends on the absorbed dose, which was analysed through the reflectance of light measurements. Some parameters of the samples are discussed in this work, such as dose sensitivity, quasi-linear and dynamic dose response, which allowed the samples that were potentially attractive for 2D dosimetry to be selected. The textile samples were assessed in terms of 2D measurements with the application of a computer operated scanner. The accuracy of 2D measurements was found to depend on the type and structure of fabric and tinge distribution after irradiation as well as additional polymer finishing of the textiles.

  9. Development of chemical dosimeters

    International Nuclear Information System (INIS)

    A chemical dosimeter is a system that measures the energy by virtue of chemical changes from ionizing absorbed radiation produced unit when it is exposed to ionizing radiation. In all chemical dosimeters radiation induced chemical reaction produces at least one, initially absent species, which is properties long lived enough to determine its quantity or the change in the initial systems. Different types of chemical dosimeters were discussed such as aqueous, gaseous and solid, but the great consideration was given to aqueous systems because of their vital role in setting many processes.(Author)

  10. Biology with neutron radiation

    International Nuclear Information System (INIS)

    Neutron diffraction, elastic and inelastic neutron scattering experiments provide important information on the structure, interactions and dynamics of biological molecules. This arises from the unique properties of the neutron and of its interaction with matter. Coherent and incoherent neutron scattering amplitudes and cross-sections are very different for H and 2H (deuterium). Deuterium labelling by chemical or biochemical methods and H2O:2H2O exchange is the basis of high resolution crystallography experiments to locate functionally important H-atoms in protein molecules. It is also very important in low resolution crystallography and small angle scattering experiments to solve large complex structures, such as protein-nucleic acid complexes or biological membrane systems, by using contrast variation techniques. The energies of neutrons with a wavelength of the order of 1 - 10 A are similar to thermal energies and inelastic neutron scattering experiments have been done with different energy resolutions (≥∼ 1 μeV) to characterise the functional dynamics of proteins in solution and in membranes. (author)

  11. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples

    International Nuclear Information System (INIS)

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning. (paper)

  12. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples

    Science.gov (United States)

    Furuta, T.; Maeyama, T.; Ishikawa, K. L.; Fukunishi, N.; Fukasaku, K.; Takagi, S.; Noda, S.; Himeno, R.; Hayashi, S.

    2015-08-01

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning.

  13. Antioxidants and biological radiation protection

    International Nuclear Information System (INIS)

    Antioxidants and antioxidant enzymes, by combatting oxygen radical-mediated radiation-induced oxidative stress, may prevent the accumulation of damage involved in tumor initiation, promotion and progression, and thus serve to protect us against ionizing radiation. We are testing the possible role of dietary antioxidants, and other biological response modifiers, in determining individual radiation response. These experiments use the fluorescent protein beta-phycoerythrin as a target and biomolecular marker for radiation-induced oxidative stress. Antioxidants are ranked according to their radioprotectiveness by their ability to compete with beta-phycoerythrin for radiolytic oxygen radicals. Samples of blood serum from cancer patients have been analyzed using this technique. There is a trend towards decreasing antioxidant levels with increasing donor age, and this is consistent with data showing an increasing radiosensitivity with age. We are presently monitoring antioxidant and antioxidant enzyme levels in atomic radiation workers and the general public, in order to assess whether they influence individual radiosensitivity. Knowledge of this source of biological response modification will be useful in applying radiation protection practices to those individuals or groups most at risk, and for estimating individual risks associated with radiation exposure. (author)

  14. Antioxidants and biological radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Lenten, K.J.; Greenstock, C.L. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    1998-07-01

    Antioxidants and antioxidant enzymes, by combatting oxygen radical-mediated radiation-induced oxidative stress, may prevent the accumulation of damage involved in tumor initiation, promotion and progression, and thus serve to protect us against ionizing radiation. We are testing the possible role of dietary antioxidants, and other biological response modifiers, in determining individual radiation response. These experiments use the fluorescent protein beta-phycoerythrin as a target and biomolecular marker for radiation-induced oxidative stress. Antioxidants are ranked according to their radioprotectiveness by their ability to compete with beta-phycoerythrin for radiolytic oxygen radicals. Samples of blood serum from cancer patients have been analyzed using this technique. There is a trend towards decreasing antioxidant levels with increasing donor age, and this is consistent with data showing an increasing radiosensitivity with age. We are presently monitoring antioxidant and antioxidant enzyme levels in atomic radiation workers and the general public, in order to assess whether they influence individual radiosensitivity. Knowledge of this source of biological response modification will be useful in applying radiation protection practices to those individuals or groups most at risk, and for estimating individual risks associated with radiation exposure. (author)

  15. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

  16. Chromosome translocations as biological dosimeter identified by in situ fluorescent hybridization (FISH)

    International Nuclear Information System (INIS)

    Chromosomal aberration analysis in lymphocytes is used for dose assessment by workers overexposed to ionizing radiation. The conventional method is based on the dicentric metaphase chromosomes and/or micronucleus scoring, which gives thoroughly satisfactory results for accidental and recent exposures. Nevertheless, when evaluating acute doses occurring in the past or accidents where the time elapsed between exposure and analysis is unknown, the translocations scoring could be the method to use. This is because translocations retain the cell's reproductive potential so that they persist over time. For a long time the detection of translocations for dosimetric purposes was impractical as a routine method until situ fluorescent hybridization (FISH) techniques appeared. This method arising from molecular biology and applied to biological dosimetry has greatly simplified detection and although it is expensive, requiring special infrastructure, its availability is a sign of the state of development for these techniques in the region. The use of translocations scoring for biological dosimetry, as for the dicentric scoring, requires calibration curves for the different types of ionizing radiation. Therefore, the aim of this work was to prepare a dose-effect curve for Co-60 γ rays by chromosome translocations analysis. The study material was peripheral lymphocytes from a clinically healthy donor, irradiated and cultured in vitro and the detection of translocations in chromosomes 1, 2 and 4. The results showed a dose effect curve linear quadratic, accordingly with other authors

  17. Proton spectroscopic imaging of polyacrylamide gel dosimeters for absolute radiation dosimetry

    International Nuclear Information System (INIS)

    Proton spectroscopy has been evaluated as a method for quantifying radiation induced changes in polyacrylamide gel dosimeters. A calibration was first performed using BANG-type gel samples receiving uniform doses of 6 MV photons from 0 to 9 Gy in 1 Gy intervals. The peak integral of the acrylic protons belonging to acrylamide and methylenebisacrylamide normalized to the water signal was plotted against absorbed dose. Response was approximately linear within the range 0-7 Gy. A large gel phantom irradiated with three, coplanar 3x3cm square fields to 5.74 Gy at isocentre was then imaged with an echo-filter technique to map the distribution of monomers directly. The image, normalized to the water signal, was converted into an absolute dose map. At the isocentre the measured dose was 5.69 Gy (SD = 0.09) which was in good agreement with the planned dose. The measured dose distribution elsewhere in the sample shows greater errors. A T2 derived dose map demonstrated a better relative distribution but gave an overestimate of the dose at isocentre of 18%. The data indicate that MR measurements of monomer concentration can complement T2-based measurements and can be used to verify absolute dose. Compared with the more usual T2 measurements for assessing gel polymerization, monomer concentration analysis is less sensitive to parameters such as gel pH and temperature, which can cause ambiguous relaxation time measurements and erroneous absolute dose calculations. (author)

  18. Biological physics and synchrotron radiation

    International Nuclear Information System (INIS)

    This conference deals with the applications of synchrotron radiation to current problems in biology and medicine. Seven sessions take stock on the subject: sources and detectors; inelastic scattering and dynamics; muscle diffraction; reaction mechanisms; macromolecular assemblies; medical applications; imaging and spectroscopy. The document presents the papers abstracts. (A.L.B.)

  19. Biological physics and synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Filhol, J.M.; Chavanne, J. [European Synchrotron Radiation Facility, 38 - Grenoble (France); Weckert, E. [Hasylab at Desy, Hamburg (Germany)] [and others

    2001-07-01

    This conference deals with the applications of synchrotron radiation to current problems in biology and medicine. Seven sessions take stock on the subject: sources and detectors; inelastic scattering and dynamics; muscle diffraction; reaction mechanisms; macromolecular assemblies; medical applications; imaging and spectroscopy. The document presents the papers abstracts. (A.L.B.)

  20. Emerging frontiers in radiation biology

    International Nuclear Information System (INIS)

    Radiation biology owes its origin to the spectacular success in the treatment of human diseases by x-rays and radium, just after their respective discoveries in 1895-96. From the very inception it has attracted researchers from all disciplines of science. The target and hit theory developed by physicists, dominated the scene till the advent of radiation chemistry concepts which offered an entirely different perspective to the mechanisms involved in biological effects of radiations and their modification by endogenous and exogenous agents like radioprotectors and radiosensitisers including hyperthermia. The applied aspect of radiation biology mainly relates to radiation therapy of cancer which, in spite of its long existence, is still to achieve scientific perfection. Nevertheless, it did not wait -and fortunately so-, for its radiobiological rationality but continued its development to be the main modality for cancer treatment today. Several approaches are now being attempted to improve its efficacy by selectively damaging the cancerous cells while sparing the normal tissues and also by devising suitable predictive assays for radioresponse of different tumours to enable individualisation of treatment schedules. (author). 99 refs., 1 fig., 2 tabs

  1. SU-E-CAMPUS-T-02: Exploring Radiation Acoustics CT Dosimeter Design Aspects for Proton Therapy

    International Nuclear Information System (INIS)

    Purpose: Investigate the design aspects and imaging dose capabilities of the Radiation Acoustics Computed Tomography (RA CT) dosimeter for Proton induced acoustics, with the objective to characterize a pulsed pencil proton beam. The focus includes scanner geometry, transducer array, and transducer bandwidth on image quality. Methods: The geometry of the dosimeter is a cylindrical water phantom (length 40cm, radius 15cm) with 71 ultrasound transducers placed along the length and end of the cylinder to achieve a weighted set of projections with spherical sampling. A 3D filtered backprojection algorithm was used to reconstruct the dosimetric images and compared to MC dose distribution. First, 3D Monte Carlo (MC) Dose distributions for proton beam energies (range of 12cm, 16cm, 20cm, and 27cm) were used to simulate the acoustic pressure signal within this scanner for a pulsed proton beam of 1.8x107 protons, with a pulse width of 1 microsecond and a rise time of 0.1 microseconds. Dose comparison within the Bragg peak and distal edge were compared to MC analysis, where the integrated Gaussian was used to locate the 50% dose of the distal edge. To evaluate spatial fidelity, a set of point sources within the scanner field of view (15×15×15cm3) were simulated implementing a low-pass bandwidth response function (0 to 1MHz) equivalent to a multiple frequency transducer array, and the FWHM of the point-spread-function determined. Results: From the reconstructed images, RACT and MC range values are within 0.5mm, and the average variation of the dose within the Bragg peak are within 2%. The spatial resolution tracked with transducer bandwidth and projection angle sampling, and can be kept at 1.5mm. Conclusion: This design is ready for fabrication to start acquiring measurements. The 15 cm FOV is an optimum size for imaging dosimetry. Currently, simulations comparing transducer sensitivity, bandwidth, and proton beam parameters are being evaluated to assess signal-to-noise

  2. Advances in Physical and Biological Radiation Detectors. Proceedings of a Symposium on New Developments in Physical and Biological Radiation Detectors

    International Nuclear Information System (INIS)

    unsatisfactory, and saw an important role for the Agency in furthering international intercomparison studies. This would in particular help the developing countries who were not able to set up specialized standards laboratories, while providing a check for all Member States on the reliability of quoted measurements and their associated accuracies. The final section on biological dosimetry evidenced the growing interest in this topic. The use of physical dosimeters has certain shortcomings: it is, for example, difficult to determine the dose received by one part of the body from a reading of a dosimeter worn on another part. It is possible that biological changes in the body could be used as a direct measure of the radiation insult received, without the need for interpolating data obtained by physical dosimeters. Biological dosimetry is, however, already being used a a ''null indicator'' in cases of suspected high exposure. This section is rounded off by a brief discussion on general topics related to biological dosimetry. The Symposium was attended by 170 participants from 29 Member States and 5 international organizations. The papers are given in full together with the discussions

  3. Biological Research for Radiation Protection

    International Nuclear Information System (INIS)

    The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H2O2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H2O2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H2O2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect radiation or paraquat-induced damage) because such compounds are able to potentiate the cell-killing or cell protecting effects. Based on the above result, we suggest that the express regulation of theses genes have potentially importance for sensitizing the efficiency of radiation therapy of cancer or for protecting the radiation-induced damage of normal cells

  4. Biological Research for Radiation Protection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Gyu; Kim, Kug Chan; Jung, Il Lae; Choi, Yong Ho; Kim, Jin Sik; Moon, Myung Sook; Byun, Hee Sun; Phyo, Ki Heon; Kim, Sung Keun

    2005-04-15

    The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H{sub 2}O{sub 2}(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H{sub 2}O{sub 2})-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H{sub 2}O{sub 2}(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect radiation or paraquat-induced damage) because such compounds are able to potentiate the cell-killing or cell protecting effects. Based on the above result, we suggest that the express regulation of theses genes have potentially importance for sensitizing the efficiency of radiation therapy of cancer or for protecting the radiation-induced damage of normal cells.

  5. Delay of hair regrowth in mice as a possible biological dosimeter on the skin in cases of over-exposure

    International Nuclear Information System (INIS)

    In cases of partial body over-exposure, the dose estimation is often impossible without considerable error. The dose-effect relationship on the delay of hair regrowth and reduction in hair length of mice after irradiation were examined to investigate the possibility of hair growth as a biological dosimeter. Hairs on the dorsum skin of mice were shaved. Shaved areas were irradiated with a Sr-90/Y-90 β-ray source in the early anagen or midanagen stage of the hair cycle. Skin doses were from 0.5 Gy to 10 Gy. The time of hair regrowth and the length of hair was examined with the scaling loupe. The delay of hair regrowth was dose dependent, fitting the L-Q function. Reduction in hair length was less dose dependent. These findings were supported by the histological observations of mitosis and pycnosis in hair matrix cells. Dose estimation functions were derived from the dose-effect relationship curves. Hair regrowth delay is thought to be a sensitive biological dosimeter which can be applied as early as a few days after over-exposure. (4 figs.)

  6. Biophysical models in radiation biology

    International Nuclear Information System (INIS)

    Models serve a variety of purposes: to link physics and biology; to interpolate and extrapolate to dose regions where direct biological measurements of statistical significance are not feasible; to address basic mechanisms; to suggest new experiments designed to test hypotheses predicted by the model. In the past, the modeling arena has been dominated by dose-response curves for cell killing which have slowly but surely incorporated more and more of the biological factors that are known to be important. At the present time, the modelers urgently need to follow the revolution in the new biology as quantitative data become available. There are several areas involved: i. the relation between DNA strand breaks, initial breaks as measured by the premature chromosome condensation technique and cell lethality. ii. modeling of oncogenic transformation as a function of dose and of radiation quality. iii. modeling of oncogenic transformation as a function of oncogene activation. iv. modeling of oncogene activation and suppressor cell deletion as a function of radiation dose and radiation quality. (author)

  7. Measurement of radiation dose with BeO dosimeters using optically stimulated luminescence technique in radiotherapy applications

    International Nuclear Information System (INIS)

    The radiation dose delivered to the target by using different radiotherapy applications has been measured with the help of beryllium oxide (BeO) dosimeters to be placed inside the rando phantom. Three-Dimensional Conformal Radiotherapy (3DCRT), Intensity-Modulated Radiotherapy (IMRT) and Intensity-Modulated Arc Therapy (IMAT) have been used as radiotherapy application. Individual treatment plans have been made for the three radiotherapy applications of rando phantom. The section 4 on the phantom was selected as target and 200 cGy doses were delivered. After the dosimeters placed on section 4 (target) and the sections 2 and 6 (non-target) were irradiated, the result was read through the OSL technique on the Risø TL/OSL system. This procedure was repeated three times for each radiotherapy application. The doses delivered to the target and the non-target sections as a result of the 3DCRT, IMRT and IMAT plans were analyzed. The doses received by the target were measured as 204.71 cGy, 204.76 cGy and 205.65 cGy, respectively. The dose values obtained from treatment planning system (TPS) were compared to the dose values obtained using the OSL technique. It has been concluded that, the radiation dose can be measured with the OSL technique by using BeO dosimeters in medical practices. - Highlights: • BeO material is suitable to use as a detector in radiotherapy applications. • The measurements by using OSL technique were observed to close to the TPS results. • BeO can be used in medical dosimeter

  8. Radiation Measured with Different Dosimeters for ISS-Expedition 18-19/ULF2 on Board International Space Station during Solar Minimum

    Science.gov (United States)

    Zhou, Dazhuang; Gaza, R.; Roed, Y.; Semones, E.; Lee, K.; Steenburgh, R.; Johnson, S.; Flanders, J.; Zapp, N.

    2010-01-01

    Radiation field of particles in low Earth orbit (LEO) is mainly composed of galactic cosmic rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). GCR are modulated by solar activity, at the period of solar minimum activity, GCR intensity is at maximum and the main contributor for space radiation is GCR. At present for space radiation measurements conducted by JSC (Johnson Space Center) SRAG (Space Radiation Analysis Group), the preferred active dosimeter sensitive to all LET (Linear Energy Transfer) is the tissue equivalent proportional counter (TEPC); the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. For the method using passive dosimeters, radiation quantities for all LET can be obtained by combining radiation results measured with TLDs/OSLDs and CR-39 PNTDs. TEPC, TLDs/OSLDs and CR-39 detectors were used to measure the radiation field for the ISS (International Space Station) - Expedition 18-19/ULF2 space mission which was conducted from 15 November 2008 to 31 July 2009 - near the period of the recent solar minimum activity. LET spectra (differential and integral fluence, absorbed dose and dose equivalent) and radiation quantities were measured for positions TEPC, TESS (Temporary Sleeping Station, inside the polyethylene lined sleep station), SM-P 327 and 442 (Service Module - Panel 327 and 442). This paper presents radiation LET spectra measured with TEPC and CR-39 PNTDs and radiation dose measured with TLDs/OSLDs as well as the radiation quantities combined from results measured with passive dosimeters.

  9. A dosimetric evaluation of organs at risk in prostate radiation therapy using a MAGIC gel dosimeter

    International Nuclear Information System (INIS)

    Multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. In this work, we investigated MR-based MAGIC gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. Materials and Methods: A heterogeneous slab phantom including bones was made. Paired cubes in the phantom representing bladder and prostate and a cylindrical container representing rectum were filled with MAGIC gel and placed in the anthropomorphic pelvic phantom The phantom was irradiated with four beams as planned using a treatment planning system. Magnetic resonance transverse relaxation rate images were acquired and turned into dose distribution maps using a calibration curve. This calibration curve was obtained by linear fitting to R2 values of 4 test tubes against their given known doses. Image processing and data analysis were performed in MATLAB7 software. The gel dosimeter was validated using an ionization chamber. Dose maps and dose volume histograms were compared with dose distributions and dose volume histograms of the treatment planning system. Results: Mean distance-to-agreementand mean dose differencewere 2.98 mm and 6.2%, respectively, in the comparison of profiles obtained from ionization chamber and gel dosimetry. Mean relative difference of dose volume histograms between gel dosimetry and treatment planning system data were 3.04%, 10.4% and 11.7%, for prostate, bladder and rectum, respectively. Discussion and Conclusions: Gel dosimetry is a good method for three dimensional dosimetry although it has a low precision in high dose gradient regions. This method can be used for evaluation of complicated dose distribution accuracy in 3D conformal radiotherapy, especially in presence of heterogeneities.

  10. Radiation biology of low doses

    International Nuclear Information System (INIS)

    Present risk assessments and standards in radiation protection are based on the so-called linear no-threshold (LNT) dose - effect hypothesis, i.e., on a linear, proportional relationship between radiation doses and their effects on biological systems. This concept presupposes that any dose, irrespective of its level and time of occurrence, carries the same risk coefficient and, moreover, that no individual biological effects are taken into account. This contribution presents studies of low energy transfer (LET) radiation which deal with the risk of cancer to individual cells. According to the LNT hypothesis, the relationship for the occurrence of these potential effects should be constant over the dose range: successful repair, cell death, mutation with potential carcinogenesis. The results of the studies presented here indicate more differentiated effects as a function of dose application as far as damage to cellular DNA by ionizing radiation is concerned. At the same overall dose level, multiple exposures to low doses sometimes give rise to much smaller effects than those arising from one single exposure to the total dose. These adaptive effects of cells are known from other studies. The results of the study allow the conclusion to be drawn that non-linear relationships must be assumed to exist for the LET radiation considered. Correspondingly, the linear no-threshold hypothesis model should at least be reconsidered with respect to the low dose range in the light of recent biological findings. The inclusion of other topical research findings also could give rise to a new, revised, risk-oriented approach in radiological protection. (orig.)

  11. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  12. Biological imaging in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Grosu, A.L.; Wiedenmann, N.; Molls, M. [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie Klinikum rechts der Isar, Technical Univ. of Munich (Germany)

    2005-07-01

    The goal of this study was to discuss the value of integrating biological imaging (PET, SPECT, MRS etc.) in radiation treatment planning and monitoring. Studies in patients with brain tumors have shown that, compared to CT and MRI alone, the image fusion of CT/MRI and amino acid SPECT or PET allows a more correct delineation of gross tumor volume (GTV) and planning target volume (PTV). For FDG-PET, comparable results with different techniques are reported in the literature also for bronchial carcinoma, ear-nose-and-throat tumors, and cervical carcinoma, or, in the case of MRS, for prostate cancer. Imaging of hypoxia, cell proliferation, apoptosis, tumor angiogenesis, and gene expression leads to the identification of differently aggressive areas of a biologically inhomogeneous tumor mass that can be individually and more appropriately targeted using innovative IMRT. Thus, a biological, inhomogeneous dose distribution can be generated, the so-called dose painting. In addition, the biological imaging can play a significant role in the evaluation of the therapy response after radiochemotherapy. Clinical studies in ear-nose-and-throat tumors, bronchial carcinoma, esophagus carcinoma, and cervical carcinoma suggest that the sensitivity and specificity of FDG-PET for the therapy response are higher compared to anatomical imaging (CT and MRI). Clinical and experimental studies are required to define the real impact of these investigations in radiation treatment planning, and especially in the evaluation of therapy response. (orig.)

  13. Measurement of multi-slice computed tomography dose profile with the Dose Magnifying Glass and the MOSkin radiation dosimeter

    International Nuclear Information System (INIS)

    This study describes the application of two in-house developed dosimeters, the Dose Magnifying Glass (DMG) and the MOSkin dosimeter at the Centre for Medical Radiation Physics, University of Wollongong, Australia, for the measurement of CT dose profiles for a clinical diagnostic 16-slice MSCT scanner. Two scanner modes were used; axial mode and helical mode, and the effect of varying beam collimation and pitch was studied. With an increase in beam collimation in axial mode and an increase of CT pitch in helical mode, cumulative point dose at scanner isocentre decreased while FWHM increased. There was generally good agreement to within 3% between the acquired dose profiles obtained by the DMG and the film except at dose profile tails, where film over-responded by up to 30% due to its intrinsic depth dose dependence at low doses. -- Highlights: ► This study shows the CT beam profiles acquired with our institution's detectors. ► The DMG is a relative dosimeter calibrated to absolute MOSkin readings. ► There was good agreement between dose profiles acquired by the DMG and the film

  14. The influence of ambient temperature and time on the radiation response of Harwell Red 4034 PMMA dosimeters

    International Nuclear Information System (INIS)

    Previously we have reported the short term effects, if significant, of different dose rates and different irradiation temperatures on the radiation response characteristics of four different batches of Harwell Red 4034 PMMA dosimeters. Using dosimeters randomly selected from these same four batches we have extended the earlier work by investigating the effects of elevated temperatures, up to 50 deg. C imposed both during and after irradiation. Dosimeters were irradiated to known doses of 15 and 25 kGy at a dose rate of 1.5 Gy·s-1 and fixed temperatures of 30, 40 or 50 deg. C, then held at these temperatures for periods of 1, 24 and 48 hours prior to measurement. The data produced in these studies were compared with original Harwell 15 and 25 kGy calibration data for these batches, based on calibration irradiations carried out at temperatures of 20 to 25 deg. C. In agreement with previous studies, the short-term (1 hour) effects of elevated temperatures were small and only marginally significant, ± 3% maximum, at 30 and 40 deg. C, but in some cases larger, depending on batch, up to + 9 % at 50 deg. C. At 30 deg. C the long-term (24 and 48 hour) effects were insignificant, within ± 2%, but significant up to + 34%, at the higher temperatures, indicating the need for a special calibration protocol under these adverse temperature/time conditions. (author)

  15. EPR Study of Radiation-Induced Radicals in Gaba: A Possible Tissue Equivalent Dosimeter For Medical Applications

    International Nuclear Information System (INIS)

    Evaluation of radiation doses delivered by patients during the therapeutic sessions of cancer is of much importance, especially in cases of recently implemented techniques like IMRT and/or radiosurgery. EPR is one of radiation dosimetric techniques which characterized by its non-destructive evaluation of radiation doses delivered to the dosimeters. In the current study, gamma aminobutyric acid (GABA) is suggested as a possible radiation dosimeter for medical applications due to its bio-nature and its expected tissue-equivalency. EPR spectrum of GABA was recorded for the first time and some spectroscopic characteristics were studied including the effect of microwave power on the peak-to-peak signal intensity and the effect of modulation amplitude. The determined linear range in microwave dependence was found to be 1 mW and the calculated effective atomic number was found to be 6.87. The time dependence was studied over 18 days after irradiation and the decay over such period in signal amplitude was about 10 %.

  16. Development and application of extremity dosimeter using the thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    An extremity dosimeter using thermoluminescent dosimeters was developed for practical measurement of beta and gamma doses. This dosimeter is composed of three TL elements and some filters. The TL element is CaSO4(Tm) thin disc and the structure is a type of finger ring. The performance characteristics of this dosimeter was studied by irradiation data of standard sources. Minimum detectable amount of this dosimeter is about 100 mrem for both beta and gamma rays in the mixed radiation field. Also β-ray maximum energy could be estimated by the ratio of the thermoluminescences measured by two TLD discs in this dosimeter. This extremity dosimeter has been used in routine personnel monitoring since 1979 in PNC Tokai Works. (author)

  17. Measurement of environmental radioactivity using a cumulative gamma radiation dosimeter (1). A capability study

    International Nuclear Information System (INIS)

    The accident of Fukushima Dai-ichi Nuclear Power Plant (FDNPP) on 11 March 2011 dispersed radionuclides to large areas of northern Japan. Although the decontamination programs are completed in many residential areas, forest areas still have received less attention. Then, concerns for potentially contaminated forest products, such as mushrooms, timber, and litter-based composts are closed up with the progress of rehabilitation of the distressed areas. Possible discharges of radionuclides into drainage basins and or drifts from decomposed particles of plant debris in flowing water are also a large concern. These mean that more attentive on site survey is expected for each subject; however, due to the nature of the forest environment, the current method for the surveying is labor intensive, expensive, inapplicable, or potentially ineffective for such long-term purpose, and thus, needs for alternative method become greater. Here, we present the concept and results of trial measurements of an alternative method using a cumulative gamma radiation dosimeter (D-shuttle, Chiyoda Technol Corp., Japan) and a lead shield. The trials were conducted at our laboratory in Abiko, Chiba, where is one of the comparatively higher radionuclides-deposited area from the Fukushima accident. The targets of the trial measurements were cut boughs of a flowering cherry (Prunus x yedoensis cv. Somei Yoshino) and living trunks of a cedar (Cryptomeria japonica). Measurements using NaI and GM survey meters were carried out as a comparison. The D-shuttle demonstrated a good detection ability of the targeted radiation from the environment and a certain level of correlation (Pearson's r=0.28 - 0.59) between cumulative doses and the activity concentration of radiocesium, although such attributes were dependent on the measurement condition (e.g., air dose rate and shield). Even though further investigations (e.g., specific shielding effects of trees) are required to establish a specific

  18. External gamma radiation monitoring in the environs of KAPS region using thermoluminescent dosimeters, during the years 1986-2003

    International Nuclear Information System (INIS)

    This report discusses the results of gamma radiation-monitoring programme in the Kakrapar Atomic Power Station, situated near Surat, Gujrat. The monitoring, during the period 1986-2003, was carried out using thermoluminescent dosimeters at nineteen locations and covered the pre-operational period during 1986-1992 and operational period during 1992-2003. The report discusses the soil radioactivity contents in the region during the pre-operational period, prevalent gamma radiation levels and the comparison of these radiation levels during the period 1992-2003. Long term analyses on the data to assess the contribution of the power station to radiation levels in the environment of KAPS are discussed using correlation between the stack releases and thc doses recorded by TLD. Frequency distribution study and extreme value probability analysis, carried out on the data are also discussed in the report. (author)

  19. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    The efficient dose of ionizing radiation (I.R.), expressed in sievert is a weighting of the deposited energy (absorbed dose in grays) by factors that take into account the radiation hazard and tissues radiosensitivity. it is useful in radiation protection because it allows to add exposures to ionizing radiation of different nature. for low doses, it has no probabilistic value. The determinist effects of ionizing radiation are observed from thresholds of several hundred of milli sievert. The seriousness grows with the dose. The whole-body doses exceeding 8 Sv are always lethal. The radio-induced cancers are observed only for doses exceeding 100 to 200 mSv for adults, delivered at a self important dose rate. Their seriousness does not depend on the dose. Their appear fortuity (stochastic effect) with a various individual susceptibility, genetically determined. The number of eventual radio-induced cancers coming from the exposure of a high number of persons to low dose of ionizing radiation (<100 mSv) cannot be evaluated with a linear without threshold model. these models, however usually used, do not take into account the biological reality of cell defense mechanisms, tissues or whole body defense mechanisms, these one being different against low or high doses of ionizing radiation. Against low doses, the preponderant mechanism is the elimination of potentially dangerous damaged cells. Against high doses, the repair of damaged cells is imperative to preserve the tissue functions. It can lead to DNA repair errors (radio-induced mutations) and canceration. The radio-induced congenital malformations are effects with threshold. The radio-induced carcinogenesis in utero is a stochastic effect. The radio-induced hereditary congenital malformations have never been highlighted for man. (N.C.)

  20. Biology relevant to space radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M. [Oak Ridge National Lab., TN (United States)

    1997-04-30

    There are only very limited data on the health effects to humans from the two major components of the radiations in space, namely protons and heavy ions. As a result, predictions of the accompanying effects must be based either on (1) data generated through studies of experimental systems exposed on earth at rates and fluences higher than those in space, or (2) extrapolations from studies of gamma and x rays. Better information is needed about the doses, dose rates, and the energy and LET spectra of the radiations at the organ level that are anticipated to be encountered during extended space missions. In particular, there is a need for better estimates of the relationship between radiation quality and biological effects. In the case of deterministic effects, it is the threshold that is important. The possibility of the occurrence of a large solar particle event (SPE) requires that such effects be considered during extended space missions. Analyses suggest, however, that it is feasible to provide sufficient shielding so as to reduce such effects to acceptable levels, particularly if the dose rates can be limited. If these analyses prove correct, the primary biological risks will be the stochastic effects (latent cancer induction). The contribution of one large SPE to the risk of stochastic effects while undesirable will not be large in comparison to the potential total dose on a mission of long duration.

  1. Examination of external radiation exposure assessment method of plant incineration workers with electronic dosimeter in disaster area

    International Nuclear Information System (INIS)

    A large amount of radioactive materials were emitted by the Fukushima Daiichi Nuclear Power Plant accident that was caused by the Great East Japan Earthquake. Decontamination work has been continued to reduce the radioactive contamination in disaster area. The amount of decontamination waste is very large, and the volume is needed to be reduced by incineration process. Therefore, the assessment of radiation exposure level in incineration plants are indispensable. In this research, assessment of external exposure of plant workers was carried out by measuring air dose rate and integral dose of working environment with NaI scintillator and electronic dosimeters. (author)

  2. Delay of hair regrowth in mice as a possible biological dosimeter on the skin in case of over exposure

    International Nuclear Information System (INIS)

    The delay of hair regrowth of mice after irradiation was examined to investigate its possibility as a biological dosimeter in the cases of localized over exposure. Hairs on the dorsal skin of mice were shaved and irradiated with a 90Sr/90Y β-ray source in early anagen or midanagen stage of hair cycle. Skin doses were 0.5-10 Gy and 1-4 Gy, respectively. Hair regrowth was observed with a scaling loupe. Hair regrowth delay was dose dependent, fitting the linear-quadratic function and the linear function according to the stages of hair. Histological observations indicated that the hair matrix cells death was the main cause of hair regrowth delay in the midanagen stage. Dose estimation functions, derived from the dose-effect relationship curves, could be applied for the dosimetry of the skin over exposure. It could detect a dose over 1 Gy, and as early as a few days after the exposure. (author)

  3. Characterization of a new photo-fluorescent film dosimeter for high-radiation dose applications

    International Nuclear Information System (INIS)

    Characterization studies on one of the first versions of the Sunna fluorescent dosimeterTM have been published by Kovacs and McLaughlin. This present study describes testing results of a newer version of the dosimeter (Model γ, batch 0399-20). This dosimeter is a 1-cmx3-cm polymeric film of 0.5 mm thickness that emits a green fluorescence component at intensities almost linear with dose. The manufacturing method (injection molding) allows potential batch sizes on the order of a million while maintaining a signal precision on the order of ±1%. Studies include dose response, dose rate dependence, energy dependence, post-irradiation stability, environmental effects, and variation of response within a batch. Data for both food irradiation and sterilization dose levels were obtained. The results indicate that the green signal (0.3-250 kGy) works well for food irradiation dose levels, especially in refrigerated facilities that maintain tight temperature control. The green signal also works well in sterilization facilities because its irradiation temperature coefficient above room temperature is minimal at sterilization doses. If the user requires readout results in <22 h after room temperature irradiation, the user can either calibrate for a specific post-irradiation readout time(s) or simply heat the dosimeters in a small laboratory oven to quickly stabilize the signal

  4. Development of radiation biological dosimetry

    International Nuclear Information System (INIS)

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay

  5. Development of radiation biological dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay.

  6. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1949-11-16

    This paper discusses procedures for research on biological effects of radiation, using mouse tissue: activation trace analysis including methods and proceedures for handling samples before during and after irradiation; methods and procedures for ion exchange study; method of separation and recovery of copper, iron, zinc, cobalt, pubidium and cesium. Also included are studies of trace elements with radioactive isotopes: the distribution of cobalt 60, zinc 65, and copper 64 in the cytoplasm and nuclei of normal mice and those with tumors. 16 figs., 2 tabs.

  7. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    An important event of the year was the designation of our Laboratory as a Center for Radiological Research by the Dean of the Faculty of Medicine and Vice-President for Health Sciences. Center status acknowledges the size and importance of the research efforts in this area, and allows a greater measure of independence in administrative matters. While the name has changed from a Laboratory to a Center within the Medical School, the mission and charge remain the same. The efforts of the Center are a multidisciplinary mix of physics, chemistry, and biology, mostly at a basic level, with the admixture of a small proportion of pragmatic or applied research in support of radiation protection or radiation therapy. About a quarter of our funding, mostly individual research awards, could be regarded as in direct support of radiotherapy, with the remainder (an NCI program project grant and DOE grants) being in support of research addressing more basic issues. An important effort currently underway concerns ab-initio calculations of the dielectric response function of condensed water. This investigation has received the coveted designation, ''Grand Challenge Project,'' awarded by DOE to research work which represents ''distinct advance on a major scientific or engineering problem that is broadly recognized as important within the mission of the Department.''

  8. Measurement of personal dose equivalent of X and gamma radiation by ring dosimeter: Results of intercomparison measurements

    Directory of Open Access Journals (Sweden)

    Małgorzata Adamowicz

    2013-10-01

    Full Text Available Background: The aim of the study was to present the results of the interlaboratory comparisons for ring dosimeters and to confirm that the applied method is suitable for measuring the personal dose equivalent HP(0.07. In addition, calibration procedures used in dosimetric measurements in persons occupationally exposed to ionizing photon radiation X and γ were presented. Materials and Methods: Ring dosimeters made of flexible plastics with the diameter of approximately 20 mm, equipped with two thermoluminescence (TL detectors type MTS-N, were the subject of interlaboratory comparisons. Irradiated detectors were red out using a new manual TLD's reader (FIMEL, France. All TLD exposures were done for validation of TLD readers and were performed using the reference X-ray and γ beams with the ISO rod phantom. The methodology of performed exposures corresponded with the methods applied by the European Radiation Dosimetry Group (EURADOS, the European organizer of interlaboratory comparisons. Results: The energy, dose and angular characteristics of the ring dosimeter allowed to elaborate the formula for estimating and verifying the personal dose equivalent HP(0.07. The test was performed to check and confirm the correctness of the estimated characteristics. The test results were satisfactory, and thus the readiness to implement TLD reader in the used method and to participate in interlaboratory comparisons was confirmed. Conclusions: According to the requirements of the Polish Centre for Accreditation, the laboratory was participating in the interlaboratory comparison organized by EURADOS in terms of the personal dose equivalent HP(0.07. The result of the comparison was satisfactory, therefore the correctness of the testing procedure was confirmed. Med Pr 2013;64(5:631–637

  9. Biological research for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Gyu; Kim, Kug Chan; Shim, Hae Won; Oh, Tae Jeong; Park, Seon Young; Lee, Kang Suk

    2000-04-01

    The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by {gamma}-radiation and toxic agents, the standardization of human T-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in the hypoxanthine (guanine) phosphoribosyl transferase (HPRT) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods using reverse transcriptase has been developed to analyze the mutant gene induced by {gamma}-radiation and chemical (pentachlorophenol) agent exposure, and to investigate the point mutations in the HPRT gene locus of T-lymphocytes. The HPRT T-cell clonal assay revealed that it could not differentiate {gamma}-irradiation from pentachlorophenol, because the frequency of somatic mutations induced by both damaging agents increased in a dose-dependent manner. The analysis of DNA sequence alterations of HPRT mutant clones clearly showed that both damaging agents induced different mutational spectra in the HPRT locus of T-cells. The large deletions, which account for 75 percent of the analyzed mutants, are characteristic mutations induced by {gamma}-irradiation. By contrast, point mutations such as base substitutions and insertion, come up to 97 percent in the case of pentachlorophenol-treated cells. The point mutation frequencies at 190 base pair and 444 base pair positions are 3-6 folds as high as in those at other mutation positions. It may be that these mutation sites are hot spots induced by pentachlorophenol. These results suggest that the HPRT mutation spectrum can be used as a potential bio marker for assessing a specific environmental risk. (author)

  10. Biological research for radiation protection

    International Nuclear Information System (INIS)

    The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by γ-radiation and toxic agents, the standardization of human T-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in the hypoxanthine (guanine) phosphoribosyl transferase (HPRT) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods using reverse transcriptase has been developed to analyze the mutant gene induced by γ-radiation and chemical (pentachlorophenol) agent exposure, and to investigate the point mutations in the HPRT gene locus of T-lymphocytes. The HPRT T-cell clonal assay revealed that it could not differentiate γ-irradiation from pentachlorophenol, because the frequency of somatic mutations induced by both damaging agents increased in a dose-dependent manner. The analysis of DNA sequence alterations of HPRT mutant clones clearly showed that both damaging agents induced different mutational spectra in the HPRT locus of T-cells. The large deletions, which account for 75 percent of the analyzed mutants, are characteristic mutations induced by γ-irradiation. By contrast, point mutations such as base substitutions and insertion, come up to 97 percent in the case of pentachlorophenol-treated cells. The point mutation frequencies at 190 base pair and 444 base pair positions are 3-6 folds as high as in those at other mutation positions. It may be that these mutation sites are hot spots induced by pentachlorophenol. These results suggest that the HPRT mutation spectrum can be used as a potential bio marker for assessing a specific environmental risk. (author)

  11. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    This report firstly summarises information on the biological hazards of radiation and their relation to radiation dose, and hence estimates the biological risks associated with nuclear power production. Secondly, it describes the basis and present status of radiation protection standards in the nuclear power industry

  12. The influence of dose rate, irradiation temperature and post-irradiation storage conditions on the radiation response of Harwell Amber 3042 PMMA dosimeters

    International Nuclear Information System (INIS)

    The response of routine dosimeters is not independent of radiation dose rate, and environmental conditions such as humidity and temperature. In Harwell Amber 3042 dosimeters these influences are minimised by careful conditioning, and the use of special packaging material to maintain humidity. This paper describes studies carried out on the influences of irradiation dose rate and temperature, on two batches of dosimeters. Firstly, this paper gives gamma irradiation response data for dose rates of 6.1, 1.3 and 0.5 Gy·s-1 with irradiation temperatures of 20, 30, 40 and 50 deg. C. Dosimeters were irradiated, to doses of 3, 5, 7, 10 and 15 kGy. Secondly, this paper considers irradiation plus post irradiation storage temperatures, at a fixed dose rate of 1.5 Gy·s-1. Dosimeters were irradiated, to doses of 10 and 20 kGy; at temperatures of 30, 40 and 50 deg. C. The dosimeters were stored at these temperatures for 1, 24 and 48 hours before measurement. Results at both of the recommended measurement wavelengths, 603 nm and 651 nm, are presented. The choice of wavelength is discussed, in order to aid the optimum choice for the conditions prevailing. (author)

  13. Electron paramagnetic resonance radiation dosimetry: possible inorganic alternatives to the EPR/alanine dosimeter

    International Nuclear Information System (INIS)

    The intensity of the EPR spectrum of γ-irradiated L-α-alanine has been accepted by the International Atomic Energy Agency as a secondary standard for high-dose (10-100 000 Gy) dosimetry. The alanine dosimeter is not without its disadvantages, however, and in this article alternative EPR dosimeters are explored. These include SO3- in irradiated K2CH2(SO3)2 and CO2- in irradiated sodium formate (NaHCO2), both of which have some advantages over CH3CHCO2- in L-α-alanine. Using as a readout parameter the peak-to-peak excursion of the strongest line, these systems have a four-fold sensitivity advantage over alanine. The radicals SO3- and CO2- are, moreover, found in a wide variety of matrices, and it may be possible to find one in which they are even stronger. The need to discover a dosimeter material sensitive enough to function in the 'clinical' dose range (below 10 Gy) is emphasized. (author)

  14. Electron paramagnetic resonance radiation dosimetry: possible inorganic alternatives to the EPR/alanine dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Keizer, P.N.; Morton, J.R.; Preston, K.F. (National Research Council of Canada, Ottawa, ON (Canada). Steacie Inst. for Molecular Sciences)

    1991-10-07

    The intensity of the EPR spectrum of {gamma}-irradiated L-{alpha}-alanine has been accepted by the International Atomic Energy Agency as a secondary standard for high-dose (10-100 000 Gy) dosimetry. The alanine dosimeter is not without its disadvantages, however, and in this article alternative EPR dosimeters are explored. These include SO{sub 3}{sup -} in irradiated K{sub 2}CH{sub 2}(SO{sub 3}){sub 2} and CO{sub 2}{sup -} in irradiated sodium formate (NaHCO{sub 2}), both of which have some advantages over CH{sub 3}CHCO{sub 2}{sup -} in L-{alpha}-alanine. Using as a readout parameter the peak-to-peak excursion of the strongest line, these systems have a four-fold sensitivity advantage over alanine. The radicals SO{sub 3}{sup -} and CO{sub 2}{sup -} are, moreover, found in a wide variety of matrices, and it may be possible to find one in which they are even stronger. The need to discover a dosimeter material sensitive enough to function in the 'clinical' dose range (below 10 Gy) is emphasized. (author).

  15. A deployable in vivo EPR tooth dosimeter for triage after a radiation event involving large populations

    International Nuclear Information System (INIS)

    In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators. Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately 5 min, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care. -- Highlights: → Advances in radiation biodosimetry are needed for large-scale emergency response. → Radiation-induced radicals in tooth enamel can be measured using in vivo EPR. → A novel transportable spectrometer was applied in the laboratory and at remote sites. → The current

  16. A deployable in vivo EPR tooth dosimeter for triage after a radiation event involving large populations

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin B., E-mail: Benjamin.B.Williams@dartmouth.edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Section of Radiation Oncology, Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH (United States); Dong, Ruhong [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Flood, Ann Barry [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Clin-EPR, LLC, Lyme, NH (United States); Grinberg, Oleg [Clin-EPR, LLC, Lyme, NH (United States); Kmiec, Maciej; Lesniewski, Piotr N.; Matthews, Thomas P.; Nicolalde, Roberto J.; Raynolds, Tim [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Salikhov, Ildar K. [Clin-EPR, LLC, Lyme, NH (United States); Swartz, Harold M. [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Clin-EPR, LLC, Lyme, NH (United States)

    2011-09-15

    In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators. Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately 5 min, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care. -- Highlights: > Advances in radiation biodosimetry are needed for large-scale emergency response. > Radiation-induced radicals in tooth enamel can be measured using in vivo EPR. > A novel transportable spectrometer was applied in the laboratory and at remote sites. > The current instrument

  17. Nanotechnology in radiation oncology: The need for implantable nano dosimeters for in-vivo real time measurements

    Directory of Open Access Journals (Sweden)

    Abdulhamid Chaikh

    2015-01-01

    Full Text Available Rapidly advancing technology provides successive generations of irradiation techniques and modalities of cancer treatment in radiation oncology. Most of these techniques are able to deliver higher doses per fraction than the standard 2 Gy per day. The complexity of these new techniques involves hundreds of parameters for the delivery of each beam making quality assurance increasingly demanding. A direct assessment of the "final product", namely the absorbed dose, would be extremely useful if easy to obtain. Thus, a real need exists for dosimeters able to provide direct and real time measurements within the target volume. Nanotechnology is a relatively new field, and in some ways raises new technological aspirations, especially in the field of medical applications for cancer treatment. In this paper we argue the need for an implantable “nano-dosimeter” based on nanotechnology to monitor the delivered dose, combining all the ideal features such a future tool should have for quality assurance in radiation oncology.  

  18. Biological improvement of radiation resistance

    Energy Technology Data Exchange (ETDEWEB)

    Chun, K. J.; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J

    2000-08-01

    To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes.

  19. Biological improvement of radiation resistance

    International Nuclear Information System (INIS)

    To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes

  20. Doses and biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Basic values and their symbols as well as units of physical dosimetry are given. The most important information about biological radiation effects is presented. Polish radiation protection standards are cited. (A.S.)

  1. Radiation biology for pediatric radiologists

    International Nuclear Information System (INIS)

    The biological effects of radiation result primarily from damage to DNA. There are three effects of concern to the radiologist that determine the need for radiation protection and the dose principle of ALARA (As Low As Reasonably Achievable). (1) Heritable effects. These were thought to be most important in the 1950s, but concern has declined in recent years. The current ICRP risk estimate is very small at 0.2%/Sv. (2) Effects on the developing embryo and fetus include weight retardation, congenital anomalies, microcephaly and mental retardation. During the sensitive period of 8 to 15 weeks of gestation, the risk estimate for mental retardation is very high at 40%/Sv, but because it is a deterministic effect, there is likely to be a threshold of about 200 mSv. (3) Carcinogenesis is considered to be the most important consequence of low doses of radiation, with a risk of fatal cancer of about 5%/Sv, and is therefore of most concern in radiology. Our knowledge of radiation carcinogenesis comes principally from the 60-year study of the A-bomb survivors. The use of radiation for diagnostic purposes has increased dramatically in recent years. The annual collective population dose has increased by 750% since 1980 to 930,000 person Sv. One of the principal reasons is the burgeoning use of CT scans. In 2006, more than 60 million CT scans were performed in the U.S., with about 6 million of them in children. As a rule of thumb, an abdominal CT scan in a 1-year-old child results in a life-time mortality risk of about one in a thousand. While the risk to the individual is small and acceptable when the scan is clinically justified, even a small risk when multiplied by an increasingly large number is likely to produce a significant public health concern. It is for this reason that every effort should be made to reduce the doses associated with procedures such as CT scans, particularly in children, in the spirit of ALARA. (orig.)

  2. Radiation biology for pediatric radiologists

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Eric J. [Columbia University Medical Center, New York, NY (United States)

    2009-02-15

    The biological effects of radiation result primarily from damage to DNA. There are three effects of concern to the radiologist that determine the need for radiation protection and the dose principle of ALARA (As Low As Reasonably Achievable). (1) Heritable effects. These were thought to be most important in the 1950s, but concern has declined in recent years. The current ICRP risk estimate is very small at 0.2%/Sv. (2) Effects on the developing embryo and fetus include weight retardation, congenital anomalies, microcephaly and mental retardation. During the sensitive period of 8 to 15 weeks of gestation, the risk estimate for mental retardation is very high at 40%/Sv, but because it is a deterministic effect, there is likely to be a threshold of about 200 mSv. (3) Carcinogenesis is considered to be the most important consequence of low doses of radiation, with a risk of fatal cancer of about 5%/Sv, and is therefore of most concern in radiology. Our knowledge of radiation carcinogenesis comes principally from the 60-year study of the A-bomb survivors. The use of radiation for diagnostic purposes has increased dramatically in recent years. The annual collective population dose has increased by 750% since 1980 to 930,000 person Sv. One of the principal reasons is the burgeoning use of CT scans. In 2006, more than 60 million CT scans were performed in the U.S., with about 6 million of them in children. As a rule of thumb, an abdominal CT scan in a 1-year-old child results in a life-time mortality risk of about one in a thousand. While the risk to the individual is small and acceptable when the scan is clinically justified, even a small risk when multiplied by an increasingly large number is likely to produce a significant public health concern. It is for this reason that every effort should be made to reduce the doses associated with procedures such as CT scans, particularly in children, in the spirit of ALARA. (orig.)

  3. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 ± 1) Gy was measured for LD50 with Dose Rate of (0.44 ± 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 ± 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses

  4. Calibration of beta dosimeter and personal dosimeter

    International Nuclear Information System (INIS)

    This paper introduces ISO standard ISO 6980 which prepared especially for the calibration of beta dosimeter and personal dosimeter. The standard has three aspects including method of production of reference beta particle radiations, calibration fundamentals related to basic quantities characterizing the radiation field, and calibration of area and personal dosemters and the determination of their response as a function of beta radiation energy and angle of incidence. Here particular emphasis is placed on the determination of basic quantity of tissue absorbed dose at a depth of 0.07 mm in the tissue slab phantom and calibration procedure by mean of the calibration quantity of directional dose equivalent H'(0.07, Ω) and personal dose equivalent Hp (0.07, Ω). Finally, combined standard uncertainty for the determination of absorbed dose rate and component uncertainties of calibration is given as examples. (authors)

  5. Biological dosimetry by the radiation effects on the skin

    International Nuclear Information System (INIS)

    In cases of partial body over-exposure, the dose estimation with personal monitors or with reconstruction of exposed conditions is often impossible without considerable error. Clinical signs of irradiated skin, such as epilation or moist desquamation have been used as the indicators of doses in the radiological accidents, because each sign has the threshold dose. As hair growth is known to be sensitive to radiation, the dose-effect relationship of the delay of hair regrowth and the reduction in hair length of mice after irradiation were examined to investigate if they can be used as biological dosimeters. Hairs on the dorsal skin of 290 ICR mice (8 weeks old) were shaved and irradiated with a Sr-90/Y-90 β-ray source in the early anagen and the midanagen stages of the hair cycle. Skin doses were from 0.5 to 10 Gy. The time of hair regrowth and the hair length were examined with the scaling loupe. Dose-effect relationship of the delay of hair regrowth and reduction in hair length were both clearly dose dependent, fitting the L-Q or L function depending on the stage. Dose estimation functions were derived from the dose-effect relationship curves. The histological observations suggested that hair growth retardation caused by irradiation in midanagen might be due to the cell death and the depression of mitosis in the hair matrix cells. This dose estimation method was applied to the case who was over-exposed to X-ray on his hand and fingers. The findings showed that hair regrowth delay was a sensitive biological dosimeter in the case of partial body over-exposure, which could be applied as early as a few days after over-exposure. The method was simple and non-invasive to the exposed patient. (author)

  6. Calibration of CVD-diamond based dosimeter in high-power electron and x-ray radiation fields

    International Nuclear Information System (INIS)

    Results of a study of dosimetry characteristics of a prototype of the detector based on a polycrystalline diamond film (CVD-diamond) produced in NSC KIPT are summarized. The techniques of the detector calibration against the electron and X-ray radiation dose rate are developed. The conditions of calibration were studied by means of computer simulation. For determination of detector sensitivity to electron radiation, it was placed inside of a standard polystyrene phantom. An additional filter of electrons was used at measurement in the X-ray field. Every time detector irradiation was carried out together with the Harwell Red Perpex 4034 dosimeters, which registrations provided the calibration data. The measurements, executed at the LU-10, EPOS and LU-40 linacs of NSC KIPT, have demonstrated, that the values of detector sensitivity against each type of radiation are close and conform to ones obtained earlier for the low-intensity radiation fields. Considering significant radiation durability of the CVD-diamond, it enables its application in technological dosimetry.

  7. Verification of shielding effect by the water-filled materials for space radiation in the International Space Station using passive dosimeters

    Czech Academy of Sciences Publication Activity Database

    Kodaira, S.; Tolochek, R. V.; Ambrožová, Iva; Kawashima, H.; Yasuda, N.; Kurano, M.; Kitamura, H.; Uchihori, Y.; Kobayashi, I.; Hakamada, H.; Suzuki, A.; Kartsev, I. S.; Yarmanova, E. N.; Nikolaev, I. V.; Shurshakov, V. A.

    2014-01-01

    Roč. 53, č. 1 (2014), s. 1-7. ISSN 0273-1177 Institutional support: RVO:61389005 Keywords : space radiation dosimetry * water shield * dose reduction * passive dosimeters * CR-39 * TLD Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.358, year: 2014

  8. Ionizing radiation M.O.S. dosimeters: sensibility and stability; Dosimetres M.O.S. de rayonnements ionisants: sensibilite et stabilite

    Energy Technology Data Exchange (ETDEWEB)

    Gessinn, F.

    1993-12-01

    This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 {mu}m thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a D{sub ox}{sup 2} power law. The maximum sensitivity achieved (9,2 V/Gy for 2{mu}m devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10{sup -2} Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10{sup -3} Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs.

  9. Performance evaluation of lithium formate dosimeter

    International Nuclear Information System (INIS)

    Lithium formate dosimeter system is being developed for the dose range 50-1250 Gy. The performance of this dosimeter for use in radiation processing dosimetry was investigated by carrying out dose mapping in product box of Food Package Irradiator and comparing the doses measured by the system with that of Fricke dosimeters placed at identical positions in the product box. It is clear that the maximum difference between the dose values measured by Fricke and lithium formate dosimeters for identical dosimeter position was found to be ± 8 %. As the maximum difference between the dose values measured by lithium formate dosimeters and Fricke dosimeters for identical dosimeter position is within ± 10% (1σ), this dosimetry system qualifies for radiation processing dosimetry as per the limits specified by International Dose Assurance Services of IAEA

  10. Radioisotopes and ionizing radiations in biological research

    International Nuclear Information System (INIS)

    This book deals with the use of radioisotopes and ionizing radiations in the various aspects of biological research. The following topics were presented: labelled compounds; conformation-function relationships of hormonal polypeptides and their spectroscopic study; neutron scattering and neutron diffraction for biological studies; high resolution autoradiography; radioimmunoassay; nuclear medicine; transfer of excitation energy in photosynthesis; radioagronomy; radiation preservation of food

  11. Thermoluminescent Dosimeter as the Gamma Component of a Nuclear Accident Dosimeter

    International Nuclear Information System (INIS)

    Various types of gamma dosimeters have been employed as the gamma-measuring component of accident dosimeters. These have included various types of glass dosimeters, film, chemical dosimeters and polymerization dosimeters. The thermoluminescent dosimeter has notable advantages over these other types. The wide range of the thermoluminescent dosimeter permits it to be used both as a daily monitor for radiation protection purposes and as an accident dosimeter. This concept eliminates the need for special instrumentation for accident dosimeters and allows the well-calibrated instrumentation in daily use to be utilized in the accident dosimeter system. Commonly, the thermoluminescent dosimeter's inherent range is from 5 mr to 100 000 r, with a reproducibility of ± 10%. A single-type calcium fluoride dosimeter and associated readout equipment has been designed and manufactured to cover 5 mr to 5000 r. Readout of the dosimeter is accomplished by heating the phosphor and measuring the light output. Six decade readout instruments are available and completely automated systems have been designed. None of the readout equipment requires more than 20 seconds per dosimeter. Another advantage of the thermoluminescent dosimeter is the low neutron response. The neutron response will vary with the type of container and the type of phosphor. One type of calcium fluoride dosimeter has a neutron response of 0.27 x 10-9 rad per n/cm2. Two physical forms of the thermoluminescent dosimeter are considered. The first is an internally heated evacuated dosimeter contained in a glass envelope. This dosimeter is about 3/8-in diam.x 2½-in long. The second type consists of a small-bore glass tube with the phosphor sealed inside. This dosimeter is 0.8-mm diam. x 6-mm long. Energy response correction shields have been designed for both types of dosimeter. (author)

  12. Determination of effective dose in anisotropic gamma radiation fields: application of dosimeters calibrated in terms of Hp(10)

    International Nuclear Information System (INIS)

    In this presentation authors deals with determination of effective dose in anisotropic gamma radiation fields. It was conclude that: - Straightforward application of Hp(10) as surrogate for E may not work under certain conditions; - Partial data on behavior of E and Hp(10) for different dosimeters allow to estimate E/Hp(10) conversion coefficients for any particular composite source; - In practical situations, anisotropy of workplace fields may be measured by six- collimator device assessing contribution to a dose from six orthogonal directions; - Reasonably conservative conversion coefficients may be assessed for given energy spectrum and degree of anisotropy of workplace fields; - For strongly anisotropic fields multiple dosimetry approach gives the best estimate of E comparing to plain Hp(10) readouts or integral conversion coefficients

  13. Biology responses to low dose radiation

    International Nuclear Information System (INIS)

    Biology responses to low dose radiation is the most important problem of medical radiation and radiation protection. The especial mechanism of low dose or low dose rate induced cell responses, has been found independent with linear no-threshold model. This article emphasize to introduce low dose or low dose rate induced biology responses of adaptive response, by-effect, super-sensitivity and genomic instability. (authors)

  14. Thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    A dosimeter of the type in which two plates of plastics material are bonded together with a layer of thermoluminescent material trapped between is described. The device is made by sprinkling granular thermoluminescent material over areas of a plastics plate which has adhesive on it, removing excess material and then applying a second layer of plastics material over the first layer, and over the thermoluminescent material, and bonding it to complete the dosimeter. (author)

  15. Response of STFZ diode as on-line gamma dosimeter in radiation processing

    International Nuclear Information System (INIS)

    In this work, it is presented the results obtained with this rad-hard STFZ silicon diode as a high-dose gamma dosimeter. This device is a p+/n/n+ junction diode, made on FZ Si wafer manufactured by Okmetic Oyj., Vantaa, Finland and processed by the Microelectronics Center of Helsinki University of Technology. The results obtained about the photocurrent registered and total charge accumulated on the diode as a function of the total absorbed dose are presented. The diodes' response showed a significant saturation effect for total absorbed doses higher than approximately 15 kGy. To reduce this effect, some STFZ samples have been pre-irradiated with gamma rays at accumulated dose of 700 kGy in order to saturate the trap production in the diode's sensitive volume. (author)

  16. Portable personal digital dosimeter

    International Nuclear Information System (INIS)

    The specifications, circuit structure and operating mechanism of a new protable personal digital dosimeter have been presented. The ingenious designs and high ratio of performance price make it an ideal monitoring apparatus for the personnel working at the environment of X and γ radiation

  17. Polyamide woven fabrics with 2,3,5-triphenyltetrazolium chloride or nitro blue tetrazolium chloride as 2D ionizing radiation dosimeters

    International Nuclear Information System (INIS)

    The development of flat woven fabric-based ionizing radiation 2D dosimeters is reported in this work. Polyamide fabric was surface modified with radiation-sensitive 2,3,5-triphenyltetrazolium chloride (TTC) or nitro blue tetrazolium chloride (NBT). These samples responded to gamma radiation of 60Co through a colour change: red and blue for TTC and NBT, respectively. The tinge intensity was observed to depend on the absorbed dose, which allowed for the reflectance of light (R) measurements and calculation of the calibration parameters: dose range, quasi-linear range, threshold dose and sensitivity. Oxygen was shown to be an important factor determining the dose response of the samples. For this reason, a range of additional modifications to the TTC- and NBT-polyamide fabric was proposed which lead to a decrease in the threshold dose and increase in the sensitivity to irradiation of the samples. For instance, a dosimeter made of polyamide fabric modified with 10 g/dm3 TTC, 0.5 mol/dm3 tert-butyl alcohol, 7.5% gelatine hydrogel at pH 10 (vacuum packed) showed the lowest dose threshold (50 Gy), dose range up to 2.8 kGy and the highest sensitivity to irradiation (−0.0396%/Gy) among the compositions studied. In consequence, this dosimeter was examined in terms of response to inhomogeneous irradiation from a 192Ir brachytherapy radiation source. The relative dose distribution profiles across the source's longitudinal axis were calculated. This showed potential of the textile dosimeters for 2D dose distribution measurements; however, further modifications towards improvement of the dosimeter's low dose response can be considered.

  18. Nanodosimetry, from radiation physics to radiation biology.

    Science.gov (United States)

    Grosswendt, B

    2005-01-01

    In view of the fact that early damage to genes and cells by ionising radiation starts with the early damage to segments of the DNA, it is a great challenge to radiation research to describe the general behaviour of ionising radiation in nanometric target volumes (nanodosimetry). After summarising basic aspects of nanodosimetry, an overview is given about its present state. As far as experimental procedures are concerned, main emphasis is laid on single-ion counting and single-electron counting methods, which use millimetric target volumes filled with a low-pressure gas to simulate nanometric target volumes at unit density. Afterwards, physical principles are discussed, which can be used to convert experimental ionisation cluster-size distributions into those caused by ionising radiation in liquid water. In the final section, possibilities are analysed of how to relate parameters derived from the probability of cluster-size formation in liquid water to parameters derived from radiobiological experiments. PMID:16381675

  19. Nanodosimetry, from radiation physics to radiation biology

    International Nuclear Information System (INIS)

    In view of the fact that early damage to genes and cells by ionising radiation starts with the early damage to segments of the DNA, it is a great challenge to radiation research to describe the general behaviour of ionising radiation in nano-metric target volumes (nanodosimetry). After summarising basic aspects of nanodosimetry, an overview is given about its present state. As far as experimental procedures are concerned, main emphasis is laid on single-ion counting and single-electron counting methods, which use millimetric target volumes filled with a low-pressure gas to simulate nano-metric target volumes at unit density. Afterwards, physical principles are discussed, which can be used to convert experimental ionisation cluster-size distributions into those caused by ionising radiation in liquid water. In the final section, possibilities are analysed of how to relate parameters derived from the probability of cluster-size formation in liquid water to parameters derived from radiobiological experiments. (authors)

  20. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    Proton radiation provides significant dosimetric advantages when compared with gamma radiation due to its superior energy deposition characteristics. Although the physical aspects of proton radiobiology are well understood, biological and clinical endpoints are understudied. The current practice to assume the relative biological effectiveness of low linear energy transfer (LET) protons to be a generic value of about 1.1 relative to photons likely obscures important unrecognised differentials in biological response between these radiation qualities. A deeper understanding of the biological properties induced by proton radiation would have both radiobiological and clinical impact. This article briefly points to some of the literature pertinent to the effects of protons on tissue-level processes that modify disease progression, such as angiogenesis, cell invasion and cancer metastasis. Recent findings hint that proton radiation may, in addition to offering improved radio-therapeutic targeting, be a means to provide a new dimension for increasing therapeutic benefits for patients by manipulating these tissue-level processes. (authors)

  1. Angular dependence of dose sensitivity of nanoDot optically stimulated luminescent dosimeters in different radiation geometries

    Energy Technology Data Exchange (ETDEWEB)

    Jursinic, Paul A., E-mail: pjursinic@wmcc.org [West Michigan Cancer Center, 200 North Park Street, Kalamazoo, Michigan 49007 (United States)

    2015-10-15

    Purpose: A type of in vivo dosimeter, an optically stimulated luminescent dosimeter, OSLD, may have dose sensitivity that depends on the angle of incidence of radiation. This work measures how angular dependence of a nanoDot changes with the geometry of the phantom in which irradiation occurs and with the intrinsic structure of the nanoDot. Methods: The OSLDs used in this work were nanoDot dosimeters (Landauer, Inc., Glenwood, IL), which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x-rays. NanoDots with various intrinsic sensitivities were irradiated in numerous phantoms that had geometric shapes of cylinders, rectangles, and a cube. Results: No angular dependence was seen in cylindrical phantoms, cubic phantoms, or rectangular phantoms with a thickness to width ratio of 0.3 or 1.5. An angular dependence of 1% was observed in rectangular phantoms with a thickness to width of 0.433–0.633. A group of nanoDots had sensitive layers with mass density of 2.42–2.58 g/cm{sup 3} and relative sensitivity of 0.92–1.09 and no difference in their angular dependence. Within experimental uncertainty, nanoDot measurements agree with a parallel-plate ion chamber at a depth of maximum dose. Conclusions: When irradiated in cylindrical, rectangular, and cubic phantoms, nanoDots show a maximum angular dependence of 1% or less at an incidence angle of 90°. For a sample of 78 new nanoDots, the range of their relative intrinsic sensitivity is 0.92–1.09. For a sample of ten nanoDots, on average, the mass in the sensitive layer is 73.1% Al{sub 2}O{sub 3}:C and 26.9% polyester. The mass density of the sensitive layer of a nanoDot disc is between 2.42 and 2.58 g/cm{sup 3}. The angular dependence is not related to Al{sub 2}O{sub 3}:C loading of the nanoDot disc. The nanoDot at the depth of maximum dose has no more angular dependence than a parallel-plate ion chamber.

  2. Angular dependence of dose sensitivity of nanoDot optically stimulated luminescent dosimeters in different radiation geometries

    International Nuclear Information System (INIS)

    Purpose: A type of in vivo dosimeter, an optically stimulated luminescent dosimeter, OSLD, may have dose sensitivity that depends on the angle of incidence of radiation. This work measures how angular dependence of a nanoDot changes with the geometry of the phantom in which irradiation occurs and with the intrinsic structure of the nanoDot. Methods: The OSLDs used in this work were nanoDot dosimeters (Landauer, Inc., Glenwood, IL), which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x-rays. NanoDots with various intrinsic sensitivities were irradiated in numerous phantoms that had geometric shapes of cylinders, rectangles, and a cube. Results: No angular dependence was seen in cylindrical phantoms, cubic phantoms, or rectangular phantoms with a thickness to width ratio of 0.3 or 1.5. An angular dependence of 1% was observed in rectangular phantoms with a thickness to width of 0.433–0.633. A group of nanoDots had sensitive layers with mass density of 2.42–2.58 g/cm3 and relative sensitivity of 0.92–1.09 and no difference in their angular dependence. Within experimental uncertainty, nanoDot measurements agree with a parallel-plate ion chamber at a depth of maximum dose. Conclusions: When irradiated in cylindrical, rectangular, and cubic phantoms, nanoDots show a maximum angular dependence of 1% or less at an incidence angle of 90°. For a sample of 78 new nanoDots, the range of their relative intrinsic sensitivity is 0.92–1.09. For a sample of ten nanoDots, on average, the mass in the sensitive layer is 73.1% Al2O3:C and 26.9% polyester. The mass density of the sensitive layer of a nanoDot disc is between 2.42 and 2.58 g/cm3. The angular dependence is not related to Al2O3:C loading of the nanoDot disc. The nanoDot at the depth of maximum dose has no more angular dependence than a parallel-plate ion chamber

  3. Performance characteristics of newly modified CaSO4. Dy based indigenous thermoluminescent dosimeters for environmental radiation monitoring

    International Nuclear Information System (INIS)

    Environmental gamma radiation monitoring around the nuclear installations in India is being carried out for over three decades. This programme was essentially based on powder based Thermoluminescent Dosimeters (TLDs) using naturally occurring calcium fluoride (Fluorite) powder. Being powder based, it was labor intensive and to cater to the increasing demand for monitoring new stations, it was necessary to go for automatic TLD reader system. This was achieved by modifying the TLD cards suitably and using the automated PC based TLD badge TLD reader system indigenously developed and being used for personal dosimetry in India. This paper discusses the modifications that were carried out to make the TLDs suitable for environmental gamma monitoring using TLDs. Performance characterisation of the TLDs like accuracy, precision and energy dependence etc were carried out to see the efficacy of the system for use in the environmental gamma radiation monitoring. In addition, inter-comparison with the existing TLD system, both deployed simultaneously in the field was also carried out. It was found that the new TLD exhibit the accuracy of 89-96% of the various delivered doses in the laboratory while the precision was observed to be within 4% for all the doses delivered. The gamma radiation levels as measured using two TLD systems were found to match very well with each other. The paper also discusses the results. (author)

  4. Personal neutron dosimeter

    International Nuclear Information System (INIS)

    Objective: To introduce the principle, structure and character of a new personal neutron dosimeter. Methods: In combination with relative documents, the dosimeter datum measured on neutron and γ rays emitted by 241Am-Be source, when 6LiF (Mg, Cu, P) and 7LiF(Mg, Cu, P) are disposed, are evaluated. Results: Its measurement results showed good linear relationship and can be repeated. The sensitivity of neutron detection is 0.72 times of 60Co γ rays and this result is similar to that to be reported previously. Conclusion: The measurement results of this dosimeter has been satisfied with the requirement of personal dose measurement in n or n-γ radiation field under 4.4 MeV energy

  5. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  6. Sand as in situ TL dosimeter in radiation hygienisation of sewage sludge

    International Nuclear Information System (INIS)

    Recently, we have investigated the thermoluminescence (TL) properties of the sand, collected from the sewage sludge, after various extensive cleansing procedures. In the present studies, the sand separated from the sludge was used to estimate irradiation dose to sludge at Sludge Hygienisation Research Irradiator (SHRI), Vadodara, India. A dose vs TL response calibration curve was established for the 220 deg. C TL peak for the hydrogen peroxide (H2O2)-treated and HF-treated sludge sand samples collected from the unirradiated batch. This was used to estimate the dose absorbed in the corresponding batch of the irradiated sludge. Similar curve was plotted for the 370 deg. C TL peak for the HF-treated sand samples for its application as an in-situ dosimeter. Using this method, the absorbed dose rate delivered to the sludge during irradiation at SHRI was estimated to be 0.49 ± 0.02 kGy per hour. Also, the saturation levels of the TL response curves for these peaks are reported here. (author)

  7. Radiation biology in cancer research

    International Nuclear Information System (INIS)

    This book contains the proceedings of a symposium held in February and March 1979. The publication of the book in early 1980 represents a timely appearance of the 40 scientific presentations and conference summary from a rather large meeting. The papers are organized into six categories ranging from basic biophysics of radiation damage to new methods and combinations in radiation therapy of human malignancies. This organization, going from the basic mechanisms of radiation damage to new therapy applications, is a logical one, and the relatively large emphasis on papers in the first category is a refreshing change for a symposium of this sort. The quality of editing, production, and illustrations is high

  8. Radiation sterilization of biological tissues

    International Nuclear Information System (INIS)

    After years of neglect, the value of sterile non-viable (allograft) tissue grafts in transplant surgery is now being recognised. Sterilization using γ-radiation is now becoming the method of choice for a wide range of tissues in a spectrum of Human Tissues banks throughout the world. The radiation treatment can initiate physical and chemical damage in the tissues. Where necessary methods of protection have been developed. Examples are given of the successful utilization of radiation for tissue sterilization and use. (author)

  9. Radiation biology of medical imaging

    CERN Document Server

    Kelsey, Charles A; Sandoval, Daniel J; Chambers, Gregory D; Adolphi, Natalie L; Paffett, Kimberly S

    2014-01-01

    This book provides a thorough yet concise introduction to quantitative radiobiology and radiation physics, particularly the practical and medical application. Beginning with a discussion of the basic science of radiobiology, the book explains the fast processes that initiate damage in irradiated tissue and the kinetic patterns in which such damage is expressed at the cellular level. The final section is presented in a highly practical handbook style and offers application-based discussions in radiation oncology, fractionated radiotherapy, and protracted radiation among others. The text is also supplemented by a Web site.

  10. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    This annual report contains a summary of our current research. Some highlights include: experimental microdosimetry, track structure, extension of the Dual Radiation Action model to be time dependent, experiments showing that the reverse dose-rate effect for onogenic transformation, first rated for neutrons, has also been observed for charged particles of intermediate LET, an analysis of low dose-rate, research in hyperthermia, studies in molecular cloning, low dose rate studies, experimental studies on high LET, and molecular studies on DNA. 42 figs., 11 tabs

  11. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

  12. Cell-phone interference with pocket dosimeters

    International Nuclear Information System (INIS)

    Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag. (note)

  13. Impact of Radiation Biology on Fundamental Insights in Biology

    Science.gov (United States)

    Setlow, Richard B.

    1982-07-27

    Research supported by OHER [Office of Health and Environmental Research] and its predecessors has as one of its major goals an understanding of the effects of radiation at low doses and dose rates on biological systems, so as to predict their effects on humans. It is not possible to measure such effects directly. They must be predicted from basic knowledge on how radiation affects cellular components such as DNA and membranes and how cells react to such changes. What is the probability of radiation producing human mutations and what are the probabilities of radiation producing cancer? The end results of such studies are radiation exposure standards for workers and for the general population. An extension of these goals is setting standards for exposure to chemicals involved in various energy technologies. This latter problem is much more difficult because chemical dosimetry is a primitive state compared to radiation dosimetry.

  14. A design of a personal dosimeter based on a new TL material CaSO4:Dy,P for use in photon-beta radiation fields

    International Nuclear Information System (INIS)

    A personal dosimeter containing TL elements, KCT-300, based on a new TL material CaSO4:Dy,P was developed to be used in measurement of Hp(10) and Hp(0.07) in photon-beta radiation fields. The performance requirements provided by ANSI were adopted as a design criteria. The MCNPX Monte Carlo code was utilized to obtain design parameters affecting dosimeter response and successfully functioned as a desk-top design tool predicting dosimeter responses upon change of parameters. The fundamental response functions of the new TL dosimeter were acquired from experiments in the reference radiation field established in the Korea Atomic Energy Research Institute. The personal dosimeter designed in this study, KCT-300PB3, consists of three areas: the window area, the energy information area and the energy compensation area. The energy compensation area was designed to give a measurement of deep dose Hp(10) incurred by Photons with energy ranging from 54 to 662 keV. The shallow dose Hp(0.07) was calculated by applying an average shallow dose conversion factor of those photons to the deep dose determined. Consequently it was not necessary to resolve quality of photon beyond 54keV. To compensate for overkill of low energy photons by the front filter, a hole of 1.3 mm in diameter was placed on the front primary filter. By tapering entrance of hole at 60 .deg. angle, response of the energy compensation area for photons ranging from 54 to 662 keV with incidence angles below 60 .deg. met the isodirectional criteria specified in the ANSI N13.11 within ±6%. The energy information area was designed to focus on low energy X-rays below 54keV which wee easy to be identified. As a consequence, chances of wrong identification of photon energy in either X-rays or X-rays/137Cs gamma mixed field followed by large deviations in the evaluated doses were inherently reduced. The energy compensation area and the energy information area were designed to shield at least 96% of 90Sr/90Y beta particles

  15. Biologically weighted measurement of UV radiation in space and on earth with the biofilm technique

    Science.gov (United States)

    Rettberg, P.; Horneck, G.

    Biological dosimetry has provided experimental proof of the high sensitivity of the biologically effective UVB doses to changes in atmospheric ozone and has thereby confirmed the predictions from model calculations. The biological UV dosimeter 'biofilm' whose sensitivity is based on dried spores of B. subtilis as UV target weights the incident UV radiation according to its DNA damaging potential. Biofilm dosimetry was applicated in space experiments as well as in use in remote areas on Earth. Examples are long-term UV measurements in Antarctica, measurements of diurnal UV profiles parallel in time at different locations in Europe, continuous UV measurements in the frame of the German UV measurement network and personal UV dosimetry. In space biofilms were used to determine the biological efficiency of the extraterrestrial solar UV, to simulate the effects of decreasing ozone concentrations and to determine the interaction of UVB and vitamin D production of cosmonauts in the MIR station.

  16. Areas of research in radiation chemistry fundamental to radiation biology

    International Nuclear Information System (INIS)

    Among all the environmental hazards to which man is exposed, ionizing radiation is the most thoroughly investigated and the most responsibly monitored and controlled. Nevertheless, because of the importance of radiation in modern society from both the hazard as well as the utilitarian standpoints, much more information concerning the biological effects induced and their modification and reversal is required. Together with radiation physics, an understanding of radiation chemistry is necessary for full appreciation of biological effects of high and low energy radiations, and for the development of prophylactic, therapeutic and potentiating methods and techniques in biological organisms. The necessity of understanding the chemistry of any system, biological or not, that is to be manipulated and controlled, is so obvious as to make trivial a statement to that effect. If any natural phenomenon is to be put to our use, surely the elements of it must be studied and appreciated fully. In the preliminary statements of the various panels of this general group, the need for additional information on the basic radiation chemistry concerned in radiation-induced biological effects pervades throughout

  17. Evaluation of personal integrating dosimeters

    International Nuclear Information System (INIS)

    The objective of this work is to analyze the different types of dosimeters present in the international market that are used to provide personal dose monitoring, specifically for external gamma and beta radiation, Hp(10) and Hp (0,07), as well as to add comments of advances in the field of passive and operative dosimetry, and the changes that are being produced in the regulating policy in other countries regarding the use of this devices. The technical specification of each dosimeter has been extracted of different catalogues of products. To conclude, the importance has been stressed in a proper selection of dosimeters with its advantages and disadvantages before its use. (author)

  18. M10.6.4: Design and manufacturing of AMC radiation dosimeter

    CERN Document Server

    Makowski, D

    2010-01-01

    This report outlines progress in the development of radiation monitoring module designed according to the AMC standard. We have designed gamma and neutron radiation monitoring module dedicated for xTCA-based LLRF control system. The research shows that SRAM memory chip can be used as a neutron fluence detector. For gamma measurement RadFET detector was applied. Triple modular redundancy was involved to enhance the reliability of the module firmware to SEEs. The detector provides measured gamma and neutron dose rate as typical IPMI sensors. The measured radiation doses can be read via PCIe or Serial interfaces and archived in external database.

  19. Performance testing of extremity dosimeters

    International Nuclear Information System (INIS)

    The Health Physics Society Standing Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance. The draft standard has been evaluated by testing the performance of existing processors of extremity dosimeters against the standard's proposed criterion. The proposed performance criterion is: absolute value of B + S ≤ 0.35, where B is the bias (calculated as the average of the performance quotients) of 15 dosimeter measurements and S is the standard deviation of the performance quotients. Dosimeter performance was tested in seven irradiation categories: low-energy photons (general and accident dosimetry), high-energy photons (general and accident dosimetry), beta particles, neutrons, and a mixture category. Twenty-one types of extremity dosimeters (both finger ring and wrist/ankle dosimeters) were received from 11 processors. The dosimeters were irradiated by the Pacific Northwest Laboratory (PNL) to specific dose levels in one or more of the seven categories as specified in the draft standard and were returned to the processors. The processors evaluated the doses and returned the results to PNL for analysis. The results were evaluated against the performance criterion specified in the draft standard. The results indicate that approximately 60% of both the finger ring and the wrist/ankle dosimeters met the performance criterion. Two-thirds of the dosimeters that did not meet the performance criterion had large biases (ranging from 0.25 to 0.80) but small standard deviations (less than 0.15). 21 refs., 3 figs., 20 tabs

  20. Sensitometry of the response of a new radiochromic film dosimeter to gamma radiation and electron beams

    Science.gov (United States)

    McLaughlin, W. L.; Yun-Dong, Chen; Soares, C. G.; Miller, A.; Van Dyk, G.; Lewis, D. F.

    1991-04-01

    A new radiation-sensitive imaging material, called GafChromic™ Dosimetry Media, offers advances in high-dose radiation dosimetry and high-resolution radiography for gamma radiation and electrons. The potential uses in radiation processing, radiation sterilization of medical devices, population control of insects by irradiation, food irradiation, blood irradiation for organ-transplant immuno-suppression, clinical radiography, and industrial radiography have led to the present sensitometric study over the breadth of the wide dynamic range of this new routine detector and imaging material, namely, absorbed doses from 10 Gy to 5 × 10 4 Gy. The thin-coated film is colorless before irradiation, and registers a deep-blue image upon irradiation, with two absorption bands at about 650 nm (major band) and 600 nm (minor band). The response to electrons, in terms of increase in absorbance per unit absorbed dose, is the same as that to gamma radiation within the estimated uncertainty of the measurements (± 5%, 95% confidence level). The spatial resolving power is > 1200 lines/mm. After the first 24 hours, the image is stable over many months (within ± 5% in absorbance), however, the system should be irradiated and analyzed at approximately the temperatures used during calibration, because of temperature dependence during irradiation and readout, and temperatures greater than 55°C should be avoided.

  1. Biological responses to ionizing radiation

    International Nuclear Information System (INIS)

    Post-nuclear war local and global fall-out distribution and levels are discussed in relation to fission products and neutron activation radionuclides. Tables are presented of the sensitivities of the major ecosystems to ionising radiations, of the sensitivity of dormant seed, of small animals and birds, and of the main factors affecting plant sensitivity to radiation. Representative bioconcentration factors for Co, Cs and Sr for various species are listed, together with whole-body dose estimates to marine biota from 10,000 MT nuclear war. Internal doses, and pathways to humans are discussed. It is concluded that the direct effects of fallout on humans would far exceed the indirect effects resulting from destruction or disturbance of ecological systems. (UK)

  2. Review of Fricke gel dosimeters

    International Nuclear Information System (INIS)

    The innovation of adding a gel matrix to the traditional Fricke dosimeter to stabilize geometric information established the field of gel dosimetry for radiation therapy. A discussion of Fricke gels provides an overview of the issues that determine the dose response of all gel dosimeters in general. In this paper we review some of the features of Fricke systems to illustrate these issues and, in addition, to motivate renewed clinical interest in Fricke gels

  3. Measurement of effective dose in clinic radiation diagnosis with TL dosimeters developed in Mexico

    International Nuclear Information System (INIS)

    At the moment the radiation diagnosis is one of the main causes of exposition to the ionizing radiations, and in many of the cases the limits to the limits of dose established by the Commission the International of Radiological safety are not applied. In this work the results obtained in the measurement of the effective dose with dosemeters Tl of LiF:Mg,Cu, P+PTFE developed in the National Institute of Nuclear Investigations (ININ), in patients to studies of clinical radiation diagnosis of urography and hysterosalpingography. The effective dose was considered in gonads, breasts and thyroid. Whereas in the radiologist physician the dose was measured in crystalline, thyroid and hands, in this work ware made whole body measurements in addition. The results showed that the dose received by patients is equivalent with the results reported in Literature; in the case of the radiologist physician, the dose considered in the made studies is below the limits recommended for POE

  4. Evaluation of photoneutron dose for prostate cancer radiation therapy by using optically stimulated luminescence dosimeter (OSLD)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Ah [Dept. of Oncology, Catholic University of Korea Incheon St.Mary,s HospitaL, Incheon (Korea, Republic of); Back, Geum Mun; Kim, Yeon Soo; Son, Soon Yong; Choi, Kwan Woo [Asan Medical Center, Seoul (Korea, Republic of); Yoo, Beong Gyu [Dept. of Radiological Science, Wonkwang Health Science University, Iksan (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Science, Beakseok Culture University, Cheonan (Korea, Republic of); Jung, Jae Hong [Dept. of Oncology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Kim, Ki Won [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Min, Jung Whan [Dept. of Radiological Science, Shingu University, Sungnam (Korea, Republic of)

    2014-06-15

    This study is to provide basic information regarding photoneutron doses in terms of radiation treatment techniques and the number of portals in intensity-modulated radiation therapy (IMRT) by measuring the photoneutron doses. Subjects of experiment were 10 patients who were diagnosed with prostate cancer and have received radiation treatment for 5 months from September 2013 to January 2014 in the department of radiation oncology in S hospital located in Seoul. Thus, radiation treatment plans were created for 3-Dimensional Conformal Radiotherapy (3D-CRT), Volumetric-Modulated Arc Radiotherapy (VMAT), IMRT 5, 7, and 9 portals. The average difference of photoneutron dose was compared through descriptive statistics and variance analysis, and analyzed influence factors through correlation analysis and regression analysis. In summarized results, 3D-CRT showed the lowest average photoneutron dose, while IMRT caused the highest dose with statistically significance (p <.01). The photoneutron dose by number of portals of IMRT was 4.37 ± 1.08 mSv in average and statistically showed very significant difference among the number of portals (p <.01). Number of portals and photoneutron dose are shown that the correlation coefficient is 0.570, highly statistically significant positive correlation (p <.01). As a result of the linear regression analysis of number of portals and photoneutron dose, it showed that photoneutron dose significantly increased by 0.373 times in average as the number of portals increased by 1 stage. In conclusion, this study can be expected to be used as a quantitative basic data to select an appropriate IMRT plans regarding photoneutron dose in radiation treatment for prostate cancer.

  5. Evaluation of photoneutron dose for prostate cancer radiation therapy by using optically stimulated luminescence dosimeter (OSLD)

    International Nuclear Information System (INIS)

    This study is to provide basic information regarding photoneutron doses in terms of radiation treatment techniques and the number of portals in intensity-modulated radiation therapy (IMRT) by measuring the photoneutron doses. Subjects of experiment were 10 patients who were diagnosed with prostate cancer and have received radiation treatment for 5 months from September 2013 to January 2014 in the department of radiation oncology in S hospital located in Seoul. Thus, radiation treatment plans were created for 3-Dimensional Conformal Radiotherapy (3D-CRT), Volumetric-Modulated Arc Radiotherapy (VMAT), IMRT 5, 7, and 9 portals. The average difference of photoneutron dose was compared through descriptive statistics and variance analysis, and analyzed influence factors through correlation analysis and regression analysis. In summarized results, 3D-CRT showed the lowest average photoneutron dose, while IMRT caused the highest dose with statistically significance (p <.01). The photoneutron dose by number of portals of IMRT was 4.37 ± 1.08 mSv in average and statistically showed very significant difference among the number of portals (p <.01). Number of portals and photoneutron dose are shown that the correlation coefficient is 0.570, highly statistically significant positive correlation (p <.01). As a result of the linear regression analysis of number of portals and photoneutron dose, it showed that photoneutron dose significantly increased by 0.373 times in average as the number of portals increased by 1 stage. In conclusion, this study can be expected to be used as a quantitative basic data to select an appropriate IMRT plans regarding photoneutron dose in radiation treatment for prostate cancer

  6. Application of the Sunna dosimeter film in gamma and electron beam radiation processing

    DEFF Research Database (Denmark)

    Kovács, A.; Baranyai, M.; Wojnárovits, L.; McLaughlin, W.L.; Miller, S.D.; Miller, A.; Fuochi, P.G.; Lavalle, M.; Slezsak, I.

    effect on the response of the film below 1 kGy. The film can be applied both in gamma and electron fields, although its response to the two types of radiation is somewhat different. No significant effects of UV light and humidity have been found, and effects of irradiation temperature are only...... significant in the case of OSL analysis for doses above 5 kGy. The applicability of two types of Sunna films in electron and gamma radiation processing is discussed in the paper. (C) 2000 Elsevier Science Ltd. All rights reserved....

  7. Metal alloy oxides, ceramics, glass as thermoluminescent dosimeters for radiation process control

    International Nuclear Information System (INIS)

    Metal alloy oxides, ceramics, glass and various papers (carton, filter paper, typewriting paper) have been investigated as possible thermoluminescent (TL) detectors or indicators for gamma and electron radiation technology process control. Results show that there is a good correlation between TL response and absorbed dose in the range 0.1 Gy-15 kGy. A large variety of materials readily available can be used for rate ratio determination, for mapping of radiation fields, and for dose monitoring, using the packaging material (e.g. cardboard) as a dose indicator. (author). 14 refs, 6 figs, 1 tab

  8. Effect of the ionizing radiation on alanine solution for a dosimeter application

    International Nuclear Information System (INIS)

    The amino acid alanine is well known as a dosimetric detector material for high level dosimetry. Its application is based on the formation of radicals by ionising radiation. In this study the effect of several parameters such as: the ionising radiation, the concentration, the dose on the pH, conductivity and the oscillotitrometric answer of Lalanine solution was investigated. The results show that there is a significant production of new species. The formation of these species increases upon increasing dose. The comparison between the repeatability of the used techniques led us to choose of the system alanine/pH and the alanine/conductivity as the most adapted. (Author)

  9. DEGRO 2009. Radiation oncology - medical physics - radiation biology. Abstracts

    International Nuclear Information System (INIS)

    The special volume of the journal covers the abstracts of the DEGRO 2009 meeting on radiation oncology, medical physics, and radiation biology, covering the following topics: seldom diseases, gastrointestinal tumors, radiation reactions and radiation protection, medical care and science, central nervous system, medical physics, the non-parvicellular lung carcinomas, ear-nose-and throat, target-oriented radiotherapy plus ''X'', radio-oncology - young academics, lymphomas, mammary glands, modern radiotherapy, life quality and palliative radiotherapy, radiotherapy of the prostate carcinoma, imaging for planning and therapy, the digital documentation in clinics and practical experiences, NMR imaging and tomography, hadrons - actual status in Germany, urinal tract oncology, radiotoxicity

  10. Biological consequences of radiation: risk factors

    International Nuclear Information System (INIS)

    This publication is a syllabus of a course on Radiation Protection. The publication offers an overview of the biological radiation effects at cellular level. For that purpose, different forms of cancers and their incidence are first discussed; structure and functioning of normal cells are considered and an introduction in genetics is given. Finally, an overview is presented of the character of tissue damage after high-dose irradiation. (G.J.P.)

  11. Thermoluminescence dosimeter

    Science.gov (United States)

    Zendle, Robert

    1985-01-01

    A thermoluminescence dosimeter having a very small rate of decline of sensitivity during subsequent uses after heating is disclosed. The dosimeter includes a detector crystal and a glass enclosure in which the detector crystal is located. The glass enclosure is air tight and is filled with a super dry inert fill gas. The inert fill gas is nonreactive with the detector crystal when the detector crystal is heated to thermoluminescence. The fill gas is selected from the group consisting of air, nitrogen, and argon, suitable admixed with 5 to 25 percent helium. The detector crystal consists essentially of calcium fluoride. The fill gas is preferably contained at a subatmospheric pressure in the glass enclosure.

  12. Dosimeter calibration facilities and methods at the Radiation Measurement Laboratory of the Centre d'etudes nucleaires, Grenoble

    International Nuclear Information System (INIS)

    At the Centre d'etudes nucleaires, Grenoble, the Radiation Measurement Laboratory, which forms part of the Environmental Protection and Research Department, serves the entire Centre for purposes of dosimetry and the calibration of dose meters. The needs of radiation protection are such that one must have facilities for checking periodically the calibration of radiation-monitoring instruments and developing special dosimetry techniques. It was thought a good idea to arrange for the dosimetry and radiation protection team to assist other groups working at the Centre - in particular, the staff of the biology and radiobiology laboratories - and also bodies outside the framework of the French Commissariat a l'energie atomique. Thus, technical collaboration has been established with, for example, Grenoble's Centre hospitalier universitaire (university clinic), which makes use of the facilities and skills available at the Radiation Measurement Laboratory for solving special dosimetry problems. With the Laboratory's facilities it is possible to calibrate dose meters for gamma, beta and neutron measurements

  13. Studies about space radiation promote new fields in radiation biology

    International Nuclear Information System (INIS)

    Astronauts are constantly exposed to space radiation of various types of energy with a low dose-rate during long-term stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Studies about biological the effects at a low dose and a low dose-rate include various aspects of microbeams, bystander effects, radioadaptive responses and hormesis which are important fields in radiation biology. In addition, space radiations contain high linear energy transfer (LET) particles. In particular, neutrons may cause reverse effectiveness at a low dose-rate in comparison to ionizing radiation. We are also interested in p53-centered signal transduction pathways involved in the cell cycle, DNA repair and apoptosis induced by space radiations. We must also study whether the relative biological effectiveness (RBE) of space radiation is affected by microgravity which is another typical component in space. To confirm this, we must prepare centrifuge systems in an International Space Station (ISS). In addition, we must prepare many types of equipment for space experiments in an ISS, because we cannot use conventional equipment from our laboratories. Furthermore, the research for space radiation might give us valuable information about the birth and evolution of life on the Earth. We can also realize the importance of preventing the ozone layer from depletion by the use of exposure equipment to sunlight in an ISS. For these reasons, we desire to educate space researchers of the next generation based on the consideration of the preservation of the Earth from research about space radiation. (author)

  14. Characterization of OSL commercial dosimeters using a hand phantom, in standard beta radiation beams

    International Nuclear Information System (INIS)

    In this study, a hand phantom was developed and tested with Al2O3:C detectors (nanodots, Landauer) and the optically stimulated luminescence (OSL) technique. This paper shows the results of a characterization study of Al2O3:C detectors at the hand phantom, to simulate operations at a nuclear medicine service. The OSL detectors were exposed to standard beta radiation beans of the beta secondary standard system of the Calibration Laboratory at IPEN, with 90Sr + 90Y, 85Kr and 147Pm sources. The detectors were optically treated prior each reutilization. The results obtained show that for monitoring of workers exposed to beta radiation, the technique and the material are useful, but the energy dependence of the OSL response of Al2O3: C has to be taken into consideration. (author)

  15. Sugars as double-signal high dose dosimeters of ionizing radiation. Preliminary results

    International Nuclear Information System (INIS)

    Preliminary results of investigation of some sugars (maltose, saccharose, commercial sugar) as sensor materials for a high dose dosimetry of ionizing radiation are presented. An advantage of using sugars consists in fact that ionizing radiation creates in them two kind of signals: colour centers (spectrophotometric read-out) and paramagnetic centers (read-out by EPR method). This allows to chose more convenient - in particular conditions a method of analysis and more exactly to estimate uncertainties connected with analytical procedures. The results indicate saccharose as better than others dosimetric material with a threshold at ∼ 100 Gy for the EPR method and ∼ 5 Gy for the optical one. The investigation reveals a high discrepancy of physicochemical parameters and generally a low quality of Polish grocery sugar. (author)

  16. Evaluation of radiation exposure in interventional radiology (IR) using active personal dosimeters (APD)

    International Nuclear Information System (INIS)

    Increased awareness of high personal dose exposure of medical staff in interventional radiology (IR) demands an assessment of radiation protection procedures. Mandatory dose monitoring systems do not allow to relate dose to specific actions of the staff as they just accumulate a total dose per month. Doses of head and limbs are expected to be high as those body parts which are not protected by the lead apron. We decided to use a measuring system by Unfors, RaySafe i2 which is built for real- time- dosimetry of scattered radiation in pulsed X-ray fields. An increased dose of the body side closer to the X-ray source (left body side) was detected. This is due to the position and the posture of the radiologist during intervention. Separating the phases of digital subtraction angiography (DSA) from those of fluoroscopy allowed not only to list the separate accumulated doses, but showed as well a big difference in dose rate. The measurements revealed the need of an improvement of common radiation protection, especially while DSA.

  17. Result of the investigation on performance of new type dosimeters

    International Nuclear Information System (INIS)

    We investigate the new type dosimeter to prepare for renewal of the present TLD in the near future. We hope the new dosimeter to be able to adopt to a radiation working environment in the ODC's radiation control area and be more useful to carry out the personal exposure monitoring. The objects of investigation are TLD, OSL dosimeter, Glass dosimeter, Electric pocket dosimeter and Solid state track detector. And this report have made using technical data presented by each maker. As a result of investigation, we recognize that The TLD's performance is so good that we can continue to use for personal exposure monitoring even if it is compared with other recently new type dosimeter. If we pursue the rationalization and convenience in the operation of dosimeter more and more, then we will recommend the electric pocket dosimeter positively. We recognize obviously that the electric pocket dosimeter can provide us available function and good artificial operation. (author)

  18. Characterization of a gamma radiation dosimeter based of glass doped with copper

    International Nuclear Information System (INIS)

    Commercial sodo-calcic silicate glass was studied by thermo luminescence in order to evaluate its potential like material sensitive to the gamma radiation for dosimetric application. We have examined in particular the effect of doping glass copper ion exchange C U-N A for different concentrations technique and multiple conditions of doping on luminescent thermo sensitivity on a very wide range of doses ranging from 10 mGy up to 100 kGy. We have also tried to explain the origin of thermoluminescence observed by exploiting the doped and non-doped samples EPR spectra.

  19. Taurine-EVA copolymer-paraffin rods dosimeters for EPR high-dose radiation dosimetry

    OpenAIRE

    Maghraby Ahmed M.; Mansour A; Abdel-Fattah A. A.

    2014-01-01

    Taurine/EPR rods (3 × 10 mm) have been prepared by a simple technique in the laboratory where taurine powder was mixed with a molten mixture of paraffin wax and an ethylene vinyl acetate (EVA) copolymer. The binding mixture EVA/Paraffin does not present interference or noise in the EPR signal before or after irradiation. The rods show good mechanical properties for safe and multi-use handling. An EPR investigation of radiation induced radicals in taurine rods revealed that there are two types...

  20. Radiation biology in Canada 1962-63

    International Nuclear Information System (INIS)

    A survey of the research projects in radiation biology being carried out in Canada during the fiscal year 1962-63. The report includes the names of the investigators, their location, a brief description of the projects and information on the financial support being provided. A classification of the projects into areas of specific interest is also included. (author)

  1. Notions of radiation chemistry in biological systems

    International Nuclear Information System (INIS)

    The present paper examines some aspects of the direct and indirect biological radiation effects: pair formation, free radicals, superoxide ion, hydrogen peroxide, hydroxyl radical, oxygen singlet together with the endogen radioprotector mechanisms of organisms and the ways in which an improved radioresistance of biochemical systems can be achieved. (author)

  2. Biological indicators for radiation dose assessment

    International Nuclear Information System (INIS)

    After an introductory report on the present level of practical experience in using biological indicator systems to identify and assess doses from radiation exposures, the state of the art in the field of biochemical, cytological and immunological indicators was presented as a basis for discussions in working groups. With reference to the type of radiation - gamma radiation, electrons, neutrons - the question was examined how and to which extent body doses could be evaluated on the basis of results from biological indicator systems. The indicator systems were examined and evaluated in working groups under the aspects of practical use, validity of results and demand of research according to uniform criteria. These were, among others, dose effect relationship, detection limit, reproducibility and specificity, interference factors, stress and reasonable inconvenience of the examined person, earliest possible availability of results and the maximum time needed to identify a biological effect after radiation exposure, as well as the possible maximum number of persons examined from a population group of radiation exposed individuals. The results of the working groups discussions were compiled and summarized in recommendations. (orig./MG)

  3. Performance characteristics and commissioning of MOSFET as an in-vivo dosimeter for high energy photon external beam radiation therapy

    International Nuclear Information System (INIS)

    Aim: In vivo dosimetry is an essential tool of quality assurance programmes in radiotherapy. In fact, the assessment of the final uncertainty between the prescribed dose and the dose actually delivered to the patient is an effective way of checking the entire dosimetric procedure. Metal oxide semiconductor field effect transistors (MOSFETs) have recently been proposed for use in radiation therapy. The purpose of this work is to study the performance characteristics and to carry out the commissioning of MOSFET as an in-vivo dosimeter for high-energy photon external beam radiation therapy. Material and Methods: Characterization and commissioning of low sensitivity TN502RD and high sensitivity TN1002RD MOSFETs for entrance and exit dosimetry respectively for application in in-vivo dosimetry in radiotherapy was carried out. The MOSFETs were characterized in terms of reproducibility, short-term constancy, long-term constancy, linearity, angular dependence, energy dependence, source to skin distance (SSD) dependence and field size dependence. Results: The reproducibility of standard sensitivity MOSFET is about 1.4 % (1 SD) and 1.98 % (1 SD) for high sensitivity detectors. The linearity of both MOSFETs was excellent (R2 = 0.996). The response of MOSFETs varies linearly for square fields from 3 x 3 cm2 to 30 x 30 cm2. For beam incidence ranging from ± 45o the MOSFET response varies within ± 3 %. Commissioning of both MOSFETs was carried out in terms of entrance dose calibration factor, exit dose calibration factor, SSD correction factor, field size correction factor, wedge correction factor and shielding tray correction factor. The average calibration factor for low and high sensitivity MOSFET detectors is 0.9065 cGy/mV and 0.3412 cGy/mV respectively. The average SSD correction factors are quite small and vary between 0.968 and 1.027 for both types of detectors for the range of clinical SSDs from 80 cm to 120 cm. The field size correction factor varies from 1.00 to 1

  4. Breast cancer biology for the radiation oncologist

    International Nuclear Information System (INIS)

    This is the first textbook of its kind devoted to describing the biological complexities of breast cancer in a way that is relevant to the radiation oncologist. Radiation Oncology has long treated breast cancer as a single biological entity, with all treatment decisions being based on clinical and pathologic risk factors. We are now beginning to understand that biological subtypes of breast cancer may have different risks of recurrence as well as different intrinsic sensitivity to radiotherapy. Multi-gene arrays that have for years been used to predict the risk of distant recurrence and the value of systemic chemotherapy may also have utility in predicting the risk of local recurrence. Additionally, the targeted agents used to treat breast cancer may interact with radiotherapy in ways that can be beneficial or undesirable. All of these emerging issues are extensively discussed in this book, and practical evidence-based treatment recommendations are presented whenever possible.

  5. Breast cancer biology for the radiation oncologist

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Jonathan [Northwestern Univ., Chicago, IL (United States). Dept. of Radiation Oncology; Small, William [Loyola Univ. Chicago, Maywood, IL (United States). Stritch School of Medicine, Cardianl Bernardin Cancer Center; Woloschak, Gayle E. (ed.) [Northwestern Univ. Feinberg, Chicago, IL (United States). School of Medicine

    2015-10-01

    This is the first textbook of its kind devoted to describing the biological complexities of breast cancer in a way that is relevant to the radiation oncologist. Radiation Oncology has long treated breast cancer as a single biological entity, with all treatment decisions being based on clinical and pathologic risk factors. We are now beginning to understand that biological subtypes of breast cancer may have different risks of recurrence as well as different intrinsic sensitivity to radiotherapy. Multi-gene arrays that have for years been used to predict the risk of distant recurrence and the value of systemic chemotherapy may also have utility in predicting the risk of local recurrence. Additionally, the targeted agents used to treat breast cancer may interact with radiotherapy in ways that can be beneficial or undesirable. All of these emerging issues are extensively discussed in this book, and practical evidence-based treatment recommendations are presented whenever possible.

  6. Response of an implantable MOSFET dosimeter to 192Ir HDR radiation.

    Science.gov (United States)

    Fagerstrom, Jessica M; Micka, John A; DeWerd, Larry A

    2008-12-01

    New in vivo dosimetry methods would be useful for clinical HDR brachytherapy. An implantable MOSFET Dose Verification System designed by Sicel Technologies, Inc. was examined for use with 192Ir HDR applications. This investigation demonstrated that varying the dose rate from 22 to 84 cGy/min did not change detector response. The detectors exhibited a higher sensitivity to 192Ir energies than 60Co energies. A nonlinear accumulated dose effect was characterized by three third-order polynomials fit to data from detectors placed at three different distances from the source. The detectors were found to have minimal rotational angular dependence. A strong longitudinal angular dependence was found when the detector's copper coil and electronics assembly were aligned between the MOSFETs and incident radiation. This orientation showed a 16% decrease in response relative to other orientations tested. PMID:19175130

  7. Response of an implantable MOSFET dosimeter to {sup 192}Ir HDR radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fagerstrom, Jessica M.; Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2008-12-15

    New in vivo dosimetry methods would be useful for clinical HDR brachytherapy. An implantable MOSFET Dose Verification System designed by Sicel Technologies, Inc. was examined for use with {sup 192}Ir HDR applications. This investigation demonstrated that varying the dose rate from 22 to 84 cGy/min did not change detector response. The detectors exhibited a higher sensitivity to {sup 192}Ir energies than {sup 60}Co energies. A nonlinear accumulated dose effect was characterized by three third-order polynomials fit to data from detectors placed at three different distances from the source. The detectors were found to have minimal rotational angular dependence. A strong longitudinal angular dependence was found when the detector's copper coil and electronics assembly were aligned between the MOSFETs and incident radiation. This orientation showed a 16% decrease in response relative to other orientations tested.

  8. Operation of Personal Electronic Dosimeters at NRCN

    International Nuclear Information System (INIS)

    In the recent years, electronic personal dosimeters (EPD's) are increasingly being used at NRCN, replacing the old direct reading dosimeters that are still widely used. The most significant advantage of the new dosimeters is the real time alarm in a radiation field exceeding a pre-determined threshold. The EPD dosimeters are more precise and can measure γ, β and x rays of a wide range of energies. In addition, the electronic dosimeters collects and stores the reading at a fixed pattern (every 10 seconds) and keeps the data until it is downloaded from the dosimeter. This feature gives the ability to build a personal time-dependent exposure report for each worker who carries this device and to analyze, identify and measure the exact dose, time and duration of any exposure event he was involved in. Designing and building a personal electronic dosimeter became possible as a result of the massive technological improvements of semi conductor detectors and the minimization processes of microprocessors and low energy electronic devices. The main purpose for personal electronic dosimeters was to monitor on-line doses for radiation workers.A special reader device enables to download data and upload operational settings of the dosimeters. By means of this communication channel, one can save the data acquired by the dosimeter, clear the dosimeter memory and set the dosimeter operational parameters. There are two possible working patterns. The first is to read and set all the dosimeters at a central point, normally a dosimetry laboratory (single reader) and the second and more expensive one, is to build a network of readers covering the plant for obtaining on-line communication

  9. Study on the angular dependence of personal exposure dosimeter - Focus on thermoluminescent dosimeter and photoluminescent dosimeter

    International Nuclear Information System (INIS)

    Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of ±90o at an interval scale of 15o from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0o to -90o, respectively. Therefore, PLDs have a lower angular dependence than TLDs.

  10. Study on the angular dependence of personal exposure dosimeter - Focus on thermoluminescent dosimeter and photoluminescent dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kyung-Rae [Department of Radiological Technology, Gwangju Health College University (Korea, Republic of); Department of Nuclear Engineering, Chosun University (Korea, Republic of); Kweon, Dae Cheol [Department of Radiologic Science, Shin Heung College University (Korea, Republic of); Chung, Woon-Kwan, E-mail: wkchung@chosun.ac.kr [Department of Nuclear Engineering, Chosun University (Korea, Republic of); Goo, Eun-Hoe [Department of Diagnostic Radiology, Seoul National University Hospital (Korea, Republic of); Department of Physics, Soonchunhyang University (Korea, Republic of); Dieter, Kevin [Department of Physical Therapy, Gwangju Health College University (Korea, Republic of); Choe, Chong-Hwan [Department of White Memorial Medical Center (United States)

    2011-02-15

    Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of {+-}90{sup o} at an interval scale of 15{sup o} from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0{sup o} to -90{sup o}, respectively. Therefore, PLDs have a lower angular dependence than TLDs.

  11. Dose verification of a clinical intensity-modulated radiation therapy eye case by the magnetic resonance imaging of N-isopropylacrylamide gel dosimeters

    International Nuclear Information System (INIS)

    In this study, N-isopropylacrylamide (NIPAM) polymer gel, together with magnetic resonance imaging (MRI), was used to measure the relative three-dimensional (3D) dose distribution of an intensity-modulated radiation therapy (IMRT) eye case. The gels were enclosed in cylindrical acrylic vessels with 10 cm outer diameter and 10 cm length. The gels were subsequently irradiated by delivering 5 Gy of a prescribed dose with a 6 MV linear accelerator using five fields. The 3D maps of the proton relaxation rate R2 were obtained using a 1.5 T MRI system correlated with the dose. The treatment planning system (TPS) data and NIPAM gel dosimeter data were compared with the experimental results in the form of relative dose distributions, including isodose curves, dose profiles, and gamma index maps. Results indicated that the linear relationship of the R2—dose for NIPAM gel dosimeters reached 0.999 within the dose range of 0 Gy to 12 Gy. Comparison of planar dose distributions among the gel dosimeters and TPS showed that the isodose lines corresponded to selected planes in the axial plane. For the 50% to 110% dose analysis, the maximum dose differences varied from 4.04% to 13.53%. Gamma evaluation of the planar dose profile resulted in pass rates of 96.84%, 83.16%, and 53.42% when the acceptance criteria of 3%/3 mm, 2%/2 mm, and 1%/1 mm, respectively, were used in the axial plane. Overall, the results showed that NIPAM polymer gel dosimeters can serve as a high-resolution, accurate, 3D tool for IMRT dose distribution verification. - Highlights: • 3D dose distribution of irradiated NIPAM gels. • High-resolution, accurate, 3D tool for IMRT dose distribution verification. • Study the dosimetric characteristics of NIPAM gels in conjunction with MRI

  12. Scanning of flat textile-based radiation dosimeters: Influence of parameters on the quality of results

    International Nuclear Information System (INIS)

    Flat woven polyamide textiles were chosen for modification with nitro blue tetrazolium chloride (NBT) or 2,3,5-triphenyltetrazolium chloride (TTC). Such samples change colour from white to blue (NBT) or red (TTC) if exposed to ionizing radiation or UV light. When inhomogenously irradiated, a clear pattern of the absorbed dose distribution is visible to the naked eye. Performance of quantitative 2D analysis with the aid of a flat-bed document scanner was proposed. Most importantly, the application of a scanner is an easy method for the assessment of irradiated samples. Therefore, scanning parameters such as resolution, sharpness, scanning reproducibility and sample preparation were assessed in this work; and optimal parameters were chosen. The cause of uncertainty in the measurements is discussed. - Highlights: • 2D textile dosimetry analysis with the aid of a flat-bed scanner is shown. • Scanning parameters and reproducibility were assessed in this work. • Optimal scanning parameters were chosen. • Cause of uncertainty in the measurements is discussed

  13. Radiation-induced change of optical property of hydroxypropyl cellulose hydrogel containing methacrylate compounds: As a basis for development of a new type of radiation dosimeter

    International Nuclear Information System (INIS)

    Hydrogels with matrix of a cellulose derivative, hydrogel of hydroxpropyl cellulose (HPC), containing two of methacrylate compounds (2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) dimethacrylate (9G)) were irradiated with 60Co γ-rays. The gels become white with irradiation, and thus, could be candidates of a new type of radiation dosimeter utilized in radiation therapy because the gels become white with irradiation and can be confirmed directly by human eyes even at low doses of 1–2 Gy. Radiation-induced change of optical properties, haze value and UV–vis absorption spectrum, of the irradiated gels was measured. Dose response of the white turbidity appearance was different for different compositions of the methacrylate compounds as well as for different dose rates. The degree of the radiation-induced white turbidity was quantified by measuring haze value, showing linear dose response in low dose region (<2 Gy). We also analyzed the gels with a UV–vis spectrometer and HEMA- and 9G-rich gels gave different spectral shapes, indicating that there are at least two mechanisms leading to the white turbidity. In addition, dose rate dependence was smaller for 9G-rich gels than HEMA-rich gels in the range of 0.015–1.5 Gy/min. - Highlights: • White turbidity appeared even at 1 or 2 Gy of 60Co γ-ray irradiation. • Haze could be used as an index of the degree of white turbidity. • UV–vis spectroscopy indicated multiple mechanisms leading to white turbidity

  14. Study of combinations of TL/OSL single dosimeters for mixed high/low ionization density radiation fields

    International Nuclear Information System (INIS)

    In this paper we discuss and compare the potential application of combined OSL/TL measurements using 6LiF:Mg,Ti (TLD-600 is enriched of isotope 6Li which has a high cross-section for the reaction with slow neutrons) or 7LiF:Mg,Ti ( TLD-700 is enriched of 7Li isotope) and TLD-100 (natural isotopic composition) detectors. The OSL/TL duel readout of LiF:Mg,Ti as an ionization density discriminator avoids some of the difficulties inherent to the various types of discrimination mixed-field passive dosimeters, and in addition has several advantages. The preferential excitation of OSL compared to TL following high ionization density (HID) alpha irradiation, naturally explained via the identification of OSL with the “two-hit” F2 or F3 center, whereas the major component of composite TL glow peak 5 is believed to arise from a ''one-hit'' complex defect. This evidence allows near-total discrimination between HID radiation and low-ionization density (LID) radiation. Beta and alpha particle irradiations were carried out with 90Sr/90Y (∼500 keV average energy) and 241Am sources (4.7 MeV) respectively and neutron irradiations were carried out at the PTB (Germany) (En = 5 MeV) and RARAF (Columbia University, USA) (En = 6 MeV) accelerator facilities. The highest values of the FOM obtained was ∼30 for neutron/gamma discrimination and ∼110 for alpha/gamma discrimination using OSL/TL – peak 5 measurements in TLD-700. -- Highlights: ► The increased response of OSL compared to TL following HID irradiation is observed. ► This evidence is explained via the identification of OSL with the ''two-hit'' F2 centers. ► The potential application of combined OSL/TL in discrimination dosimetry is discussed. ► The values of FOM were 110 for alpha/gamma and 30 for neutron/gamma discrimination

  15. Measurements of cosmic radiation doses in civil aircraft by pocket dosimeter (II). Results for international air lines

    International Nuclear Information System (INIS)

    Next to previous results for domestic airlines, the present ones concerned international lines. The measurement was done in about 70 international flights from December 1992-September 2000, using Aloka PDM-101 semiconductor electronic pocket dosimeter worn at the breast position. In some cases, dose rate was also measured by intermittent reading. The integrating dose was found to increase with the time of flight and dose rate change reflected the pattern of flight. Data are preliminary but it was thought that the pocket dosimeter can provide the whole dose and dose rate which are the sum of ionizing and neutron components. (K.H.)

  16. Biological indicators for radiation exposure. Thymidine concentration in human serum as 'biological dosemeter'?

    International Nuclear Information System (INIS)

    The in vivo test of blood from partial and whole-body irradiated patients revealed no strict differences in radiosensitivity in correlation to the dose, only tendencies for radiation-effects. The serum thymidine concentration appeared to be also dependent on non-investigated factors, such as diseases and previous therapies. Therefore, the suitability of thymidine concentration in blood as a 'biochemical dosimeter' could not be demonstrated. (orig.)

  17. Radon and radiation biology of the lung

    International Nuclear Information System (INIS)

    The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

  18. Biological effects of synchrotron radiation on crops

    Institute of Scientific and Technical Information of China (English)

    唐掌雄; 董保中; 等

    1996-01-01

    The sensitivity of germinating seeds of barley,winter wheat and spring one to synchrotron ultraviolet radiation is barley>winter wheat and spring one.But when dry seeds of the three crops are irradiated by 3.5-22keV X-rays,the sequence of their sensitivity to radiation can be changed.for irradiation of 0.6-3keV ultra soft X-rays,0.40-0.90 of the seedlings of the first generation appear mutation of striped chlorophyll defect.This biological effect has never been found for irradiation of other rays.

  19. ESR/L-alanine system as a proposed standard dosimeter for electron-beam irradiations

    International Nuclear Information System (INIS)

    The ESR/L-alanine system is a promising dosimeter, as it is characterized by high precision, stable dosimetric response, low value of G(freeradical) and non-toxicity. The scattering and absorption of γ radiation and fast electrons are equivalent for the system, for soft biological tissues, and for water. The possibility of further standardizations of the alanine dosimeter has now been proposed, not only as previously for γ radiation, but also for high-energy electron beam processing which brings high dose rates and side-effect problems. On the basis of the experimental results it seems reasonable to propose a new and more precise approximation of the functional shape describing the response of the L-alanine dosimeter and to express it directly by the radiation chemical yield of free radicals. (author)

  20. ESR/L-alanine system as a proposed standard dosimeter for electron-beam irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Panta, P.P.; Strzelczak-Burlinska, G.; Tomasinski, Z. (Institute of Nuclear Chemistry and Technology, Warsaw (Poland))

    1989-01-01

    The ESR/L-alanine system is a promising dosimeter, as it is characterized by high precision, stable dosimetric response, low value of G{sub (free} {sub radical)} and non-toxicity. The scattering and absorption of {gamma} radiation and fast electrons are equivalent for the system, for soft biological tissues, and for water. The possibility of further standardizations of the alanine dosimeter has now been proposed, not only as previously for {gamma} radiation, but also for high-energy electron beam processing which brings high dose rates and side-effect problems. On the basis of the experimental results it seems reasonable to propose a new and more precise approximation of the functional shape describing the response of the L-alanine dosimeter and to express it directly by the radiation chemical yield of free radicals. (author).

  1. A study of the fractionation dose on the radiation response of Harwell Red-Perspex PMMA dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Hosni, F., E-mail: ali_hosni2001@yahoo.fr [Unite de Recherche Maitrise des Techniques Nucleaires a Caractere Pacifique, Centre National des Sciences et Technologie Nucleaires, 2020 Sidi-Thabet (Tunisia); Farah, K. [Unite de Recherche Maitrise des Techniques Nucleaires a Caractere Pacifique, Centre National des Sciences et Technologie Nucleaires, 2020 Sidi-Thabet (Tunisia); ISTLS, 12 Rue, Abdallah Ibn Ezzoubeier 4000, Universite de Sousse (Tunisia); Mejri, A. [Unite de Recherche Maitrise des Techniques Nucleaires a Caractere Pacifique, Centre National des Sciences et Technologie Nucleaires, 2020 Sidi-Thabet (Tunisia); Khayat, A. [Institut National des Sciences Appliquees et de Technologie de Tunis, Centre Urbain Nord, BP 676, 1080 Tunis Cedex (Tunisia); Chtourou, R. [Centre de Recherche et des Technologies de l' Energie, Hammam-Lif 2050 (Tunisia); Hamzaoui, A.H. [Centre National de Recherche en Sciences des Materiaux, Hammam-Lif 2050 (Tunisia)

    2012-11-01

    The present paper reports the results of the study on the effect of the fractionation dose on the response of Red-Perspex dosimeter. Several experiments were carried out by combining the two factors: number of fractionation and storage time between fractions. Dosimeters were irradiated by gamma-rays to total doses of 10 and 40 kGy. These doses were delivered as single fraction, as well as in five fractions separated by different intervals of time: 1, 24 h and stored at 10 or 40 Degree-Sign C between successive irradiation. Three batches of Red-Perspex dosimeters (KS, GB, and EB) were used in this study. The relative specific response of dosimeters indicates a marked dependence of the number of fractionation and storage time. It was found that response variations due to dose fractionation can reach 18% in particular at high storage time and high temperatures. The dose fractionation effect has been found to be dependent of the batches. The obtained results allowed us to determine the necessary corrections for estimating doses with high accuracy.

  2. Feasibility of smartphone diaries and personal dosimeters to quantitatively study exposure to ultraviolet radiation in a small national sample

    DEFF Research Database (Denmark)

    Køster, Brian; Søndergaard, Jens; Nielsen, Jesper B; Allen, Martin; Bjerregaard, Mette; Olsen, Anja; Bentzen, Joan

    2015-01-01

    studies and of smartphones as a data collection tool. MATERIALS AND METHODS: Participants were sent a dosimeter which they wore for 7 days, received a short diary questionnaire by text message each day and subsequently a longer questionnaire. Correlation between responses from questionnaire, smartphone...

  3. Organ point dose measurements in clinical multi slice computed tomography (MSCT) examinations with the MOSkin™ radiation dosimeter

    International Nuclear Information System (INIS)

    This study reports on the application of the MOSkin™ dosimeter in MSCT imaging for the real-time measurement of absorbed organ point doses in a tissue-equivalent female anthropomorphic phantom. MOSkin™ dosimeters were placed within the phantom to measure absorbed point organ doses for 2 commonly applied clinical scan protocols, namely the renal calculus scan and the pulmonary embolus scan. Measured organ doses in the imaged field of view were found to be in the dose range 4.7–9.5 mGy and 16.2–27.4 mGy for the renal calculus scan and pulmonary scan protocols respectively. For the derivation of effective dose, using the more recent ICRP 103 tissue weighting factors (wT) compared to that of the ICRP 60 wT resulted in a difference in the derived effective dose by up to 0.8 mSv (−20%) in the renal calculus protocol and up to 1.8 mSv (18%) in the pulmonary embolus protocol. This difference is attributed to the reduced radiosensitivity of the gonads and the increased radiosensitivity of breast tissue in the latest ICRP 103 assigned wT. The results of this study show that the MOSkin™ dosimeter is a useful real-time tool for the direct assessment of organ doses in clinical MSCT examinations. -- Highlights: •The MOSkin™ dosimeter was used to measure CT organ point doses. •Effective doses varied depending on ICRP 60 or 103 wT factors used in the derivation. •The results show that the MOSkin™ dosimeter is a useful real-time clinical dosimetry tool

  4. Biological Sensors for Solar Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André P. Schuch

    2011-04-01

    Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

  5. Mexican gems as thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10-2 to 102 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

  6. Development of colored alumilite dosimeter

    CERN Document Server

    Obara, K; Yagi, T; Yokoo, N

    2003-01-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50 approx 100 degC), high gamma-ray radiation (approx 1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10 approx 100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to b...

  7. Ionizing radiation effects on biological macromolecules

    International Nuclear Information System (INIS)

    Ionizing radiation is one of the main environmental factors for life, particularly for human beings. The primary effects of ionizing radiation produce the perturbation of biomacromolecules functionality (DNA and proteins). This effect occurs by direct action and by the indirect way of water molecules radiolysis. These primary effects result in a cascade of biochemical and biological consequences that may finally influence the general functions of the organism. In the last five decades the research activity in this field was focused on the detailed description of the effects on DNA molecules and their biochemical and biological consequences. The reason for this is the importance of the integrity of DNA for the cell life evolution, especially for the cell recovery processes or for the programmed cell death after irradiation. These aspects have main applications in very important fields as radioprotection and radiotherapy. In the present paper the mechanisms of ionizing radiation action at the molecular level will be reviewed, with focus on the protein level effects. Although comparatively a lower number of results was reported concerning the effects of ionizing radiation on the proteins, during the last years this field was reconsidered in the context of a new research trend in the field of genomics and proteomics. The structural changes which occur most often in the proteins are the breaks of chemical links, the chemical moieties ionization (for instance, the oxidation of the proteins) and the inter - protein new links (cross-linking). These changes result in a gradual loss of protein functionality, influencing particularly the ionic transport, the signal transduction across the membrane or intermolecular recognition processes of antibody-antigen type. Some studies on the ion artificial channels (as gramicidin and amphotericin) incorporated in model membranes (BLM-s or liposomes) describe structural and functional changes of the peptides after the exposure to

  8. Calibrating pen dosimeters with and without a phantom

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Cescon, Claudinei T.; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: ctcescon@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Thirty one direct reading dosimeters (pen dosimeters) were calibrated and tested in standard beams of gamma radiation, with and without the use of a phantom. The calibration was performed with a Co-60 source and tested with a Cs-137 source. The dose-response curves of the pen dosimeters and their calibration factors for a Co-60 source, with and without the use of a phantom were obtained. The results show the need to calibrate the pen dosimeters with a phantom. (author)

  9. Radiation biology: a century of hopes and disappointments

    International Nuclear Information System (INIS)

    In the history of science, radiation biology will rank perhaps as the most popular subject to have attracted researchers from many disciplines of basic as well as applied sciences. Apart from the excitement arising in clinics relating to radiation treatment of cancers the tragedies in Hiroshima and Nagasaki brought numerous scientists together to investigate the harmful biological effects of ionizing radiation. It is then radiation biology picked up a great momentum. It started developing in two different directions what may be called basic radiation biology and radiation biology applied to radiotherapy of cancer. While great strides were being made in basic radiation biology trying to understand the biological effects of radiation and mechanisms thereof, clinical aspect remained confined mainly to the medical fraternity where empiricalism became the rule

  10. Biological research for the radiation protection

    International Nuclear Information System (INIS)

    The work scope of 'Biological Research for the Radiation Protection' had contained the research about polyamine effect on cell death triggered ionizing radiation, H2O2 and toxic agents. In this paper, to elucidate the role of polyamines as mediator in lysosomal damage and stress(H2O2)- induced apoptosis, we utilized α-DiFluoroMethylOrnithine (DFMO), which inhibited ornithine decarboxylase and depleted intracellular putrescine, and investigated the effects of polyamine on the apoptosis caused by H2O2, ionizing radiation and paraquat. We also showed that MGBG, inhibitor of polyamine biosynthesis, treatment affected intracellular redox steady states, intracellular ROS levels and protein oxidation. Thereafter we also investigated whether MGBG may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation or H2O2 because such compounds are able to potentiate the cell-killing effects. In addition, ceruloplasmin and thioredoxin, possible antioxidant proteins, were shown to have protective effect on radiation- or H2O2(or chemicals)-induced macromolecular damage or cell death

  11. Junction-FET dosimeter

    International Nuclear Information System (INIS)

    The performance of a new junction-FET dosimeter and its application to the beam profile measurement are presented. One of the two junction FET's making up an astable multivibrator is used as a small-size (approx.0.4x0.4 mm) high-level dose detector. The irradiated dose can be estimated by the amount of the decrease of the oscillator period of the multivibrator. The distinct advantages in its small size and superior resistive property to radiation effect enable us to measure the cross-sectional profile of the electron beam from a linac with high spatial resolution of about 0.4 mm

  12. Biological effect of low dose radiation

    International Nuclear Information System (INIS)

    This document describes the recent findings in studies of low dose radiation effect with those by authors' group. The low dose radiation must be considered in assessment of radiation effects because it induces the biological influence unexpected hitherto; i.e., the bystander effect and genetic instability. The former is a non-targeted effect that non-irradiated cells undergo the influence of directly irradiated cells nearby, which involves cell death, chromosome aberration, micronucleus formation, mutation and carcinogenesis through cellular gap junction and/or by signal factors released. Authors' group has found the radical(s) possessing as long life time as >20 hr released from the targeted cells, a possible mediator of the effect; the generation of aneuploid cells as an early carcinogenetic change; and at dose level <10 Gy, activation of MAPK signal pathway leading to relaxation of chromatin structure. The genetic instability means the loss of stability where replication and conservation of genome are normally maintained, and is also a cause of the late radiation effect. The group has revealed that active oxygen molecules can affect the late effect like delayed cell death, giant cell formation and chromosome aberration, all of which lead to the instability, and is investigating the hypothesis that the telomere instability resulted from the abnormal post-exposure interaction with its nuclear membrane or between chromatin and nuclear matrix, is enhanced by structural distortion of nuclear genes. As well, shown is the possible suppression of carcinogenesis by p53. The group, to elucidate the mechanism underlying the low dose radiation effect, is conducting their studies in consideration of the sequential bases of physical, chemical and biological processes. (R.T.)

  13. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  14. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  15. Department of Radiation and Environmental Biology - Overview

    International Nuclear Information System (INIS)

    Full text: In the year 2000 we completed our study of the genotoxic influence of occupational exposure to pesticides on human cells, and their susceptibility to radiation in particular. Examining blood samples from four countries: Greece, Hungary, Poland and Spain we found that exposure to pesticides usually resulted in an increased susceptibility to the UV-C radiation, although statistical significance could only be concluded for inhabitants of Poland. In Spain, exposure to pesticides was proved to impair the lymphocyte DNA repair capability, while for the Polish group this repair capability appeared enhanced in people exposed to pesticides (see the research reports below). The possible influence of lifestyle or particular diet on the observed national differences would probably be worth analyzing. We also investigate the biological effectiveness of therapeutic beams (neutrons and X-rays). Experimental part of such study, concerning neutrons of different mean energies, is over and the results are now being processed. Our work covers hot issues of environmental and radiation biology making us research partners to many domestic and foreign scientific institutions. Our proficiency in the field is also reflected by membership in various expert boards (e.g. evaluating research applications for the Fifth EU Framework Programme for RTD and Demonstration Activities in the field 'Environment and Health', lecturing in the 2000 NATO IOS Life Science Books). We have entered the 5th EU Programme Scheme within the EXPAH project starting January 1, 2001. (author)

  16. Miniature personal UV solar dosimeter

    Science.gov (United States)

    Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr.

    1981-01-01

    Small light-powered meter measures accumulated radiation in ultraviolet or other selected regions. Practical advantages are device's low cost, small size, accuracy, and adaptability to specific wave-band measurements. Medical applications include detection of skin cancer, vitamin D production, and jaundice. Dosimeter also measures sunlight for solar energy designs, agriculture and meteorology, and monitors stability of materials and environmental and occupational lighting.

  17. II. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1948-05-24

    With the completion of the 184 inch cyclotron in Berkeley and the successful construction of a deflector system, it was possible to bring the 190 Mev deuteron and the 380 Mev alpha beams out into the air and to begin a study of the effects of high-energy deuteron beams by direct irradiation of biological specimens. The direct biological use of deuteron beams was attempted earlier in Berkeley by Marshak, MacLeish, and Walker in 1940. These and other investigators have been aware for some time of the potential usefulness of high energy particle beams for radio-biological studies and their suitability for biological investigations. R.R. Wilson advanced the idea of using fast proton beams to deliver radiation and intervening tissues. R.E. Zirkle pointed out that such particle beams may be focused or screened until a cross-section of the beam is small enough to study effects of irradiation under the microscope on single cells or on parts of single cells. This article gives an overview of the radiological use of high energy deuteron beams, including the following topics: potential uses of high energy particle beams; experiments on the physical properties of the beam; lethal effect of the deuteron beam on mice.

  18. Recent developments on electronic dosimeters

    International Nuclear Information System (INIS)

    Potential replacements of the aging Film and TLD by passive and active electronic dosimetry systems are emerging. Such devises offer, at equally high dosimetric performance, additional features, such as direct readout and dose rate warnings. Today, a large number of electronic dosimeters is commercially available, but only very few comply with international standards and national requirements. Nevertheless, the first electronic dosimetry systems for photon and beta radiation have recently been approved for legal dosimetry. In neutron dosimetry, research projects on electronic dosimeters are still going on and some devices are already commercially available. (author)

  19. The shelf life of dyed polymethylmethacrylate dosimeters

    International Nuclear Information System (INIS)

    The long-term stability of the radiation response of Harwell Red 4034 and Amber 3042 Perspex Dosimeters has been monitored for more than 15 years, and the resulting data used in the justification of their shelf-life specifications

  20. Brachytherapy dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [i3N, Physics Department, University of Aveiro (Portugal); Castro, I.F.C. [i3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Veloso, J.F.C.A. [i3N, Physics Department, University of Aveiro (Portugal)

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40–50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25–100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  1. Brachytherapy dosimeter with silicon photomultipliers

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F. C.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40-50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25-100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  2. Biological aspects of radiation in nuclear medicine

    International Nuclear Information System (INIS)

    Radiotherapy with unsealed radionuclides differs from external radiotherapy with regard to the radiation quality and energy range, the regional dose uniformity and the time course of irradiation regimen. External radiotherapy is planned precisely and can be applied to a target volume independently from blood flow during a course of irradiation fractions. In contrary, administered radiopharmaceuticals distribute according to their pharmacokinetic properties and generate a continuous irradiation corresponding to the effective halflife. The resulting dose rates are approximately 1 Gy/min and 1 Gy/h, respectively. The bio-kinetics of radiopharmaceuticals involves cellular accumulation and retention with highly variable affinity to specific organs that can be modulated as well. A remarkable dose gradient is found at the edge of volumes with enhanced uptake. The biological effect of an irradiation with decreasing intensity can be compared with the radiation effect caused by conventional fractionation with 2 Gy a day in external beam therapy by means of the linear-quadratic model. However, the experimental validation of this translation is still under investigation. Radionuclide therapy is usually performed in several cycles some month apart. This procedure fails to meet external radiotherapy. The vision of a combined external-internal radiotherapy requires efforts for a common dosimetry approach both in vitro and in vivo with a physical and biological verification of the results. (orig.)

  3. Decontamination of biological ferment by gamma radiation

    International Nuclear Information System (INIS)

    Biological ferment is a product obtained from pure yeast (Saccharomyces cerevisiae) culture by a suitable technological process and employed to increase the size and porosity of the baker's products. Foods containing high microorganisms count indicate that Good Manufacturing Practices were not applied. The aim of this study was to observe the viability of Dry Biological Ferment after the radiation process using different doses of 60Co gamma rays and different storage times. Dry baker's yeast Saccharomyces cerevisiae samples were purchased from a local supermarket in Sao Paulo (Brazil) and irradiated at IPEN in a Gammacell source at 0.5, 1.0, 2.0 and 3.0 kGy doses (dose-rate of 3.51 kGy/h) at room temperature (25 deg C). The fluorescent method was performed to observe the viability of yeast cells. The viability decrease with the increase of the radiation dose, as shown: the amount of the viable cell found in the non-irradiated samples (control) at 0 day was 87.2%; 30 days 67.7%; 60 days 77.4% and 90 days 60.1%. With 1.0 kGy at 0 day was 61.4%; 30 days 22.7%; 60 days 56.9% and 90 days 24.2%. With 3.0 kGy at 0 day was 57.00%; at the next periods the most of the cells become not viable. (author)

  4. Decontamination of biological ferment by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sabundjian, Ingrid T.; Salum, Debora C.; Silva, Priscila V.; Furgeri, Camilo; Duarte, Renato; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: villavic@ipen.br

    2007-07-01

    Biological ferment is a product obtained from pure yeast (Saccharomyces cerevisiae) culture by a suitable technological process and employed to increase the size and porosity of the baker's products. Foods containing high microorganisms count indicate that Good Manufacturing Practices were not applied. The aim of this study was to observe the viability of Dry Biological Ferment after the radiation process using different doses of {sup 60}Co gamma rays and different storage times. Dry baker's yeast Saccharomyces cerevisiae samples were purchased from a local supermarket in Sao Paulo (Brazil) and irradiated at IPEN in a Gammacell source at 0.5, 1.0, 2.0 and 3.0 kGy doses (dose-rate of 3.51 kGy/h) at room temperature (25 deg C). The fluorescent method was performed to observe the viability of yeast cells. The viability decrease with the increase of the radiation dose, as shown: the amount of the viable cell found in the non-irradiated samples (control) at 0 day was 87.2%; 30 days 67.7%; 60 days 77.4% and 90 days 60.1%. With 1.0 kGy at 0 day was 61.4%; 30 days 22.7%; 60 days 56.9% and 90 days 24.2%. With 3.0 kGy at 0 day was 57.00%; at the next periods the most of the cells become not viable. (author)

  5. The late biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Full text: The principal objective of the symposium was to review the current status of understanding of the late biological effects of ionizing radiation from external and internal sources. A second objective was to critically evaluate information obtained from epidemiological studies of human population groups as well as from animal experimentation in order to provide a solid scientific basis upon which problems of current concern, such as radiation protection standards and risk-benefit analysis, could be deliberated. Eighty-one papers were presented in 10 sessions which covered epidemiological studies of late effects in human populations exposed to internal and/or external ionizing radiation; quantitative and qualitative data from animal experimentation of late effects; methodological problems and modern approaches; factors influencing susceptibility or expression of late radiation injury; comparative evaluation of late effects induced by radiation and other environmental pollutants, and problems of risk assessment. In addition, there were two evening sessions for free discussion of problems of interpreting animal data, and of the epidemiological studies of occupationally exposed populations. Reports on atomic bomb survivors showed that these epidemiological studies are providing dependable data, such as dose-related excess infant mortality. The reports also revealed the need for consensus in the method employed in the interpretation of data. That was also the case with studies on occupationally exposed populations at Hanford plant, where disparate results were presented on radiation-induced neoplasia among radiation workers. These data are, however, considered not so significant in relative terms when compared to risks involved in other industries. It was recommended that national registry systems for the dosimetry and medical records of radiation workers be established and co-ordinated internationally in order to facilitate reliable epidemiological

  6. Department of Radiation and Environmental Biology - Overview

    International Nuclear Information System (INIS)

    Full text:The year 1999 we devoted mainly to the activities concerning our basic research, and requirements and expectations of three research projects. The environmental project from the European Community was supporting our research in the issues of human monitoring of occupational exposure to pesticides. The two other radiobiology projects from the State Committee of Research were supporting our search on the biological efficiency and its enhancement of radio-therapeutic sources of various LET radiation. We succeeded fruitful co-operation with colleagues from Academy of Mining and Metallurgy that let us go faster with modernization of our laboratory by automation of our methods for screening cytogenetic damages. A lot of efforts were paid to modify our work by automatic reports of the coordinates of aberrant metaphases, and to make a smooth work of our new and own metaphase finder. We are sure that our new and unique research tool will not only enhance the accuracy and speed of measurements, but will also be useful for the purpose of the retrospective biological dosimetry of absorbed doses. We have applied fluorescent in situ hybridization (FISH) for cytogenetic studies of biological effects induced by neutrons. Now, we are looking forward to apply this technique in a combination with the DNA damage measures done by SCGE assay, to our research on mechanisms of the induction and repair, or interaction of the lesions induced by genotoxic agents. Understanding of the regulation of these processes could be a good goal for the new century to come. (author)

  7. Microwave radiation: biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1981-01-01

    The thermal effects of microwave radiation are well recognized and are discussed with particular reference to cataractogenesis; the possibility of an association cannot be questioned. Postulated nonthermal effects comprise an asthenic syndrome, and for the most part the disturbances lie within clinical norms and tolerances, and are reversible. World opinion on safe exposure levels for microwave radiation is varied, and this had led to national standards disparate by three to four orders of magnitude. The US and UK exposure standard of 10 mW/cm/sup 2/ was determined over two decades ago; the possibility of a change to a more restrictive level, in line with other countries, in the near future is examined. It is concluded that such a change, without scientific rationale, is not justified. Some biological implications of the microwave radiation from the solar power satellite are considered in terms of precautions to be taken by personnel working in the vicinity of the rectenna, effects on cardiac pacemakers, and any potential effects on birds. 14 references.

  8. QA programme based on clinical dosimeter with diamond detector

    International Nuclear Information System (INIS)

    The devices with ionizing chambers as the primary converters are traditionally used for dosimetry of the ionizing radiation in medicine and beam therapy. The application of the semiconductor detectors based on silicon is limited due to the high energy dependence of detection sensitivity, small radiation resource, dependence of the sensitivity on ambient temperature. Among the solid detectors, the diamond detectors are the most similar to the ionizing chambers as the carbon atomic number is close to the effective atomic number of air and biological tissue. The clinical dosimeter DKDa-01-'IPTP' based on the natural diamond detector was developed at the Institute in Physical and Technical Problems with the purpose of absolute and relative measurements in radiotherapy beams. The known properties of natural diamond detector provide high registration sensitivity, high radiation resistance and independence of the sensitivity on temperature, pressure. The small sensitive volume of the detector (1-6 mm3) allows measuring relative dose distributions with high spatial resolution. If calibrated in terms of absorbed dose to water in a Co-60 beam, the clinical dosimeter DKDa-01-'IPTP' provides determination of the absorbed dose to water of photon and electron beams in the radiotherapy dose rate and energy ranges without any additive corrections usually required during the ionizing chamber measurement. The relative error of these dose determinations is within ±2% that includes inherent features of the natural diamond detector (small energy dependence and dose rate dependence). The clinical dosimeter DKDa-01-'IPTP' was tested for the absolute measurements of proton radiation dose rate in the medical phasotron beam at the Joint Institute for Nuclear Research (JINR, Dubna). At the beginning, the dosimeter was calibrated in terms of absorbed dose to water against the secondary standard of gamma radiation absorbed dose to water (Co-60). The measurements were carried out at different

  9. Tests of health physics detectors and dosimeters to 6 and 9 MeV gamma-radiation

    International Nuclear Information System (INIS)

    The CEA health physicists working group on standardization and testing of detectors for the measurements of external exposure has set up and calibrated a capture #betta# beam. 6 and 9 MeV energies were obtained by means of Ti and Ni targets. These beams made it possible to determine the response of a number of detectors and dosimeters used in health physics to these energy ranges. Most generally, these tests showed that at 6 or 9 MeV the responses of instruments calibrated with 60Co #betta#-rays could vary as much as a factor 2 when compared to the maximun of the absorbed dose in a human body

  10. Comparison of electronic digital alarm dosimeter with TLD

    International Nuclear Information System (INIS)

    Control of exposure of radiation workers on day to day basis has been made easy by use of semiconductor based electronic digital dosimeter. Additional dose constraints of 10 mSv for occupational radiation workers have made it essential to use such type of digital personal monitoring devices. In addition to conventional ionisation chamber based direct reading dosimeters, additional 35 semiconductor based digital dosimeters model MGP DMC 2000 S were used for the monitoring of personal exposure of radiation workers in a spent fuel reprocessing plant. Though better least count and good performance over a wide range of dose rate are claimed by the manufacture, before making use of such dosimeter on large scale, validation of its performance is required to be checked. In this paper, an effort is made to determine the performance of digital dosimeters, by exposing these digital dosimeters in combination with TLDs at different radiation levels and obtained results were compared and analysed

  11. Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

    International Nuclear Information System (INIS)

    An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

  12. External gamma radiation monitoring in the environs of Kaiga Generating Station (KGS), using thermoluminescent dosimeters, during the period 1989-2003

    International Nuclear Information System (INIS)

    This publication reports the results of external gamma radiation monitoring using Thermoluminescent Dosimeters (TLDs), in the environs of Kaiga Generating Station (KGS) during its preoperational survey between October 1989 and June 1998. The report also presents quarterly and annual values of air dose during the operational phase of the station between July 1998 and Dec. 2003 around the environmcnt of KGS. The results of TLD analysis, during the period October 1989-June 1998, indicate that the average annual air dose for the locations monitored, was 502± 91 μGy/a. The general background of the environs around Kaiga during the operational period, i.e. July 1998 and Dec. 2003, between 2.3 km. to 32km. has been found to be 509±74 μGy/a. The report discusses the methodology and different analyses carried out. (author)

  13. 2.3.1 Biological Effects of Ionizing Radiations

    Science.gov (United States)

    Kaul, A.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Subsection '2.3.1 Biological Effects of Ionizing Radiations' of the Section '2.3 Biological Effects' of the Chapter '2 Radiation and Biological Effects' with the comtents:

  14. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  15. Proceedings of the symposium on molecular biology and radiation protection

    International Nuclear Information System (INIS)

    The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually

  16. European Society for Radiation Biology 21. annual meeting

    International Nuclear Information System (INIS)

    The volume contains about 100 abstracts of lectures presented to the conference covering a large variety of topics like: Radiobiology as a base for radiotherapy, radiation carcinogenesis and cellular effects, late and secondary effects of radiotherapy, radioprotection and radiosensitization, heavy ions in radiobiology and space research, microdosimetry and biological dosimetry, radiation effects on the mature and the developing central nervous system, DNA damage and repair and cellular mutations, the imact of radiation on the environment, free radicals in radiation biology

  17. Evaluation of DNA dosimetry to assess ozone-mediated variability of biologically harmful radiation in Antarctica

    NARCIS (Netherlands)

    George, AL; Peat, HJ; Buma, AGJ

    2002-01-01

    In this study we investigated the use of a DNA dosimeter to accurately measure changes in ultraviolet B radiation (UVBR; 280-315 nm) under Antarctic ozone hole conditions. Naked DNA solution in quartz tubes was exposed to ambient solar radiation at Rothera Research Station, Antarctica, between Octob

  18. Activities in biological radiation research at the AGF

    International Nuclear Information System (INIS)

    The AGF is working on a wide spectrum of biological radiation research, with the different scientific disciplines contributing different methodologies to long-term research projects. The following fields are studied: 1. Molecular and cellular modes of action of radiation. 2. Detection and characterisation of biological radiation damage, especially in humans. 3. Medical applications of radiation effects. 4. Concepts and methods of radiation protection. The studies will lead to suggestions for radiation protection and improved radiotherapy. They may also contribute to the development of environmental protection strategies. (orig./MG)

  19. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed

  20. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  1. Taurine as a biological dosimeter. Its determination in physiological samples by reversed phase high-performance liquid chromatography

    International Nuclear Information System (INIS)

    Taurina, which is the metabolic end-product of cysteine shows a dose dependent change in urinary excretion after radiation exposure. The results of whole body gamma irradiated rats with doses of CO-60 ranging from 100 cGy to 800 cGy are expressed as percent increase of taurine in urine in the first 48 hours postirradiation and confirm the existence of a linear relationship. (author)

  2. Approving of personal dosimeter services

    International Nuclear Information System (INIS)

    The Swedish regulation SSI FS 98:5 requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The regulation also includes certain specific dosimeter requirements, which are based on those presented in the Technical Recommendations by the European Commission (Report EUR 14852 EN, 1994). All services have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) at one radiation quality. The test was performed in the interval 0.2 mSv to 100 mSv at three different dose equivalents unknown to the system owner. The 11 services operating in Sweden at the moment use 5 different types of dosimeters. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosimeters. The dosimeters were irradiated to a personal dose equivalent of about 1 mSv at three photon energies and at four angles (0, 20, 40 and 60 deg. resp. ) both vertically and horizontally rotated. Only 2 of the services determine Hp(0.07) for beta and gamma radiation and were tested for this quantity. The test results for Hp(10) are all except two within the trumpet curve. For the unique systems it is shown that the uncertainty related to angular response at a specified energy is within the required ±40 % except for the lowest X-ray quality at 40 kV. The response is more dependent on photon energy than on the direction of the photon radiation and the choice of radiation quality for the calibration is of great importance for the system performance

  3. Behavior of reusable dosimeters in personnel monitoring

    International Nuclear Information System (INIS)

    Besides an individual calibration, reusable dosimeters, like TLD, need a further periodical control because of the possibility of ageing effects and defects intervening by use. Both calibration and periodical control can consist in verifying that the response of the dosimeters to a determined dose lies between two fixed limits. The alternative method, based on the attribution of a calibration factor to each sensitive element of every dosimeter, has become practically possible using a computer for the management of the control. This technique has the following advantages: better monitoring of the long-term dosimeters behavior; possibility to establish a precise ratio between the signals of two different elements in order to provide more information about the type and energy of the radiation; optimized utilisation of the dosimeters by a more selective exclusion. The registration, besides the calibration factors, of the accumulated dose and the number of use of each dosimeter allows to study the correlation between these quantities and the ageing effects. The results obtained by monitoring the behavior of 3000 dosimeters will be presented and discussed

  4. Ionizing radiation for sterilization of medical products and biological tissues

    International Nuclear Information System (INIS)

    The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products. (S.K.K.)

  5. Department of Radiation and Environmental Biology - Overview

    International Nuclear Information System (INIS)

    Full text: The year 2001 started for us with new demanding tasks connected with participation in a new research project performed in collaboration with a excellent teams from six countries under the 5th EU the Quality of Life Programme. The aim of the project EXPAH is to propose methods of molecular epidemiology for the risk assessment of exposure to polycyclic aromatic hydrocarbons in the air. The exploration of cause-effect relationships for carcinogenic agents will be based on the study of exogenous and endogenous influence on DNA damage in exposed population, and will determine the relationship between biomarkers of exposure, effects and susceptibility in the exposed populations. Analysis of this damage is carried out using highly specialising multidisciplinary techniques brought together by seven laboratories specialised in chemical, biochemical and biological techniques for analysing DNA damage and repair, together with access to populations exposed to environmental pollution and experience in collecting samples. In the year 2001 all the members of the department put much effort in co-organizing 12. Meeting of the Maria Sklodowska-Curie Polish Radiation Research Society. The Meeting was held in the September in Cracow and rewarded hard work of everybody with many applauding comments for the high scientific and organization level. Our parallel activities were concentrated on arrangement and preparation of the forthcoming Course on Human Monitoring for Genetic Effects proposed to us by the Alexander Hollaender Committee of the International Environmental Mutagenesis Society. The Alexander Hollaender ''HUMOGEF'' Course will concentrate on the commonly measured biomarkers (chromosome aberrations; micronuclei; DNA damage), but others (p53 protein levels; metabolic genotypes) will also be addressed. Scientists of international standing from the fields of toxicology, molecular biology, cytogenetics, mutation, and epidemiology, will present and discuss the state

  6. Measurement of individual doses of radiation by personal dosimeter is important for the return of residents from evacuation order areas after nuclear disaster.

    Science.gov (United States)

    Orita, Makiko; Hayashida, Naomi; Taira, Yasuyuki; Fukushima, Yoshiko; Ide, Juichi; Endo, Yuuko; Kudo, Takashi; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    To confirm the availability of individual dose evaluation for the return of residents after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP), we evaluated individual doses of radiation as measured by personal dosimeters in residents who temporarily stayed in Evacuation Order Areas in Kawauchi village, which is partially located within a 20 km radius of the FNPP. We also compared individual doses with the external radiation doses estimated from the ambient dose rates and with doses estimated from the concentrations of radionuclides in the soil around each individual's house. Individual doses were significantly correlated with the ambient doses in front of the entrances to the houses (r = 0.90, pradionuclides in soil samples ranged from 0.03 to 23.42 mSv/y. The individual doses were moderately correlated with external effective doses in the backyards (r = 0.38, pradionuclides and the decontamination of contaminated soil. Long-term follow-up of individual doses as well as internal-exposure doses, environmental monitoring and reconstruction of infrastructure are needed so that residents may return to their hometowns after a nuclear disaster. PMID:25806523

  7. Development of colored alumilite dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yagi, Toshiaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yokoo, Noriko [Radiation Application Development Association, Tokai, Ibaraki (Japan)

    2003-03-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50{approx}100 degC), high gamma-ray radiation ({approx}1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10{approx}100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to be approximately 1MGy which is too low to monitor the RH equipment for the ITER. In addition, these conventional dosimeters do not involve sufficient radiation resistance against the high gamma-ray radiation as well as are not easy handling and low cost. Based on the above backgrounds, a new dosimeter with bleaching of an azo group dye to be applied to a radiation monitor has been developed for high gamma-ray radiation use. The colored alumilite dosimeter is composed of the azo group dye (-N=N-) in an anodic oxidation layer of aluminum alloy (Al{sub 2}O{sub 3}). It can monitor the radiation dose by measuring the change of the bleaching of azo dye in the Al{sub 2}O{sub 3} layer due to gamma-ray irradiation. The degree of bleaching is measured as the change of hue (color) and brightness based on the Munsell's colors with a three dimensional universe using spectrophotometer. In the tests, the dependencies such as colors, anodized layer thickness, type of azo

  8. The Calvet calorimetric dosimeter

    International Nuclear Information System (INIS)

    This report describes a dosimeter based on the conduction calorimetry principle, and designed to operate in swimming-pool type nuclear reactors. The properties of the apparatus are as follows: 1 - the measurement is independent of the specific heat of the calorimetric elements; 2 - each calorimetric element is fitted with an electrical calibration; 3 - the apparatus is made up of two independent calorimetric elements; 4 - the nature of the calorimetric elements makes it possible to analyse the radiation received; 5 - the measurable intensities of the absorbed radiation vary from 4 to 4000 M/rads per hour; 6 - the sensitive part of the apparatus is fitted inside a cylinder 5 cm high and 2 cm in diameter. One pre-production unit made up of graphite and beryllium cores has been tried out in the reactor Siloe with radiation intensities of about 1 to 2 watts per gram. It absorbed an accumulated dose of 1.2*1O12 rads without any weaknesses appearing. (authors)

  9. Radiation effects analysis in a group of interventional radiologists using biological and physical dosimetry methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, M., E-mail: WEMLmirapas@iqn.upv.e [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montoro, A.; Almonacid, M. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Ferrer, S. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Barquinero, J.F. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Tortosa, R. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Verdu, G. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Rodriguez, P. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Barrios, L.L. [Department of Physiology and Cellular Biology, Unit of Cellular Biology (UAB) (Spain); Villaescusa, J.I. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain)

    2010-08-15

    Interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation, which extend during all their professional activities. These exposures can derive, due to the effects of direct and scattered radiation, in deterministic effects (radiodermitis, aged skin, cataracts, telangiectasia in nasal region, vasocellular epitelioms, hands depilation) and/or stochastic ones (cancer incidence). A methodology has been proposed for estimating the radiation risk or detriment from a group of six exposed interventional radiologists of the Hospital Universitario La Fe (Valencia, Spain), which had developed general exposition symptoms attributable to deterministic effects of ionizing radiation. Equivalent doses have been periodically registered using TLD's and wrist dosimeters, H{sub p}(10) and H{sub p}(0.07), respectively, and estimated through the observation of translocations in lymphocytes of peripheral blood (biological methods), by extrapolating the yield of translocations to their respective dose-effect curves. The software RADRISK has been applied for estimating radiation risks in these occupational radiation exposures. This software is based on transport models from epidemiological studies of population exposed to external sources of ionizing radiation, such as Hiroshima and Nagasaki atomic bomb survivors [UNSCEAR, Sources and effects of ionizing radiation: 2006 report to the general assembly, with scientific annexes. New York: United Nations; 2006]. The minimum and maximum average excess ratio for skin cancer has been, using wrist physical doses, of [1.03x10{sup -3}, 5.06x10{sup -2}], concluding that there is not an increased risk of skin cancer incidence. The minimum and maximum average excess ratio for leukemia has been, using TLD physical doses, of [7.84x10{sup -2}, 3.36x10{sup -1}], and using biological doses, of [1.40x10{sup -1}, 1.51], which is considerably higher than incidence rates, showing an

  10. Development of a personal digital dosimeter

    International Nuclear Information System (INIS)

    A compact size personal dosimeter was developed using electronic parts mainly available locally with the aim of having a low cost dosimeter capable of operating in local ambient conditions with ease of maintenance. Besides, the use of CMOS IC's reduces power consumption considerably. The dosimeter has a measuring range of 0-9999 mR using 7 segment LED display clearly readable even in the illuminated area. It is also equipped with alarm system to monitor presentable dose accumulation, dose rate at each 1 mR, saturation of GM detector at high level dose and the radiation surpassing levels selectable in steps of 2.5, 10 and 25 mR/hr. The dosimeter has a size of 7.4x12x3 cm3 with a weight of 300 g and is powered with four 1.2 V AAA size rechargeable Ni-Cd batteries with an energy capacity of 180 Ah each. A miniature GM tube for gamma and X-ray measurement is used as radiation detector. The results of performance testing and calibration show that the dosimeter can measure a dose rate up to 2.5 R/hr with an error less than of +-20% in energy range of 100-1330 keV. Using Cs-137 standard calibration source, the accuracy and precision of the dosimeter at dose limit of 2.5 R/hr are +-14% and 3% respectively. The dosimeter can be continuously operated for 7 hours with fully charged batteries at 300 mW power consumption, while at the lowest operational battery voltage of 4.53 V the dosimeter shows an error less than +-15%

  11. A Paradigm Shift in Low Dose Radiation Biology

    Directory of Open Access Journals (Sweden)

    Z. Alatas

    2015-08-01

    Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

  12. Biological dosimetry to determine the UV radiation climate inside the MIR station and its role in vitamin D biosynthesis

    Science.gov (United States)

    Rettberg, P.; Horneck, G.; Zittermann, A.; Heer, M.

    1998-11-01

    The vitamin D synthesis in the human skin, is absolutely dependent on UVB radiation. Natural UVB from sunlight is normally absent in the closed environment of a space station like MIR. Therefore it was necessary to investigate the UV radiation climate inside the station resulting from different lamps as well as from occasional solar irradiation behind a UV-transparent quartz window. Biofilms, biologically weighting and integrating UV dosimeters successfully applied on Earth (e.g. in Antarctica) and in space (D-2, Biopan I) were used to determine the biological effectiveness of the UV radiation climate at different locations in the space station. Biofilms were also used to determine the personal UV dose of an individual cosmonaut. These UV data were correlated with the concentration of vitamin D in the cosmonaut's blood and the dietary vitamin D intake. The results showed that the UV radiation climate inside the Mir station is not sufficient for an adequate supply of vitamin D, which should therefore be secured either by vitamin D supplementat and/or by the regular exposure to special UV lamps like those in sun-beds. The use of natural solar UV radiation through the quartz window for `sunbathing' is dangerous and should be avoided even for short exposure periods.

  13. Study of coloured poly(methylmethacrylate) films with bromothymol blue as dosimeter for application in gamma radiation

    International Nuclear Information System (INIS)

    The radiosterilization is a industrial technique whose application is increasing in the Brazil. Aiming the use in gamma dosimetry poly(methylmethacrylate) films (PMMA) colored with bromothymol blue acid-base indicator are investigate and properties related to ionizing radiation are studied. The samples were irradiated with Co60 doses between 15 and 100 kGy and the radiation effects on the optical properties were evaluated for spectrophotometric analysis. In this work, will show the characteristic-response of the films in terms of changes in the absorption spectrum due radiation, the dose-response correlation, Analysis of Variance (ANOVA) and will describe stability studies. (author)

  14. AINSE conference on radiation biology and chemistry. Conference handbook

    International Nuclear Information System (INIS)

    The conference handbook contains 60 oral and poster presentations dealing with recent advances in radiation chemistry applied to biological studies, radiopharmaceuticals, radiosensitizers as well as to solid state chemical physics

  15. AINSE conference on radiation biology and chemistry. Conference handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The conference handbook contains 60 oral and poster presentations dealing with recent advances in radiation chemistry applied to biological studies, radiopharmaceuticals, radiosensitizers as well as to solid state chemical physics.

  16. Current research in Canada on biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    A survey of current research in Canada on the biological effects of ionizing radiation has been compiled. The list of projects has been classified according to structure (organizational state of the test system) as well as according to the type of effects. Using several assumptions, ballpark estimates of expenditures on these activities have been made. Agencies funding these research activities have been tabulated and the break-down of research in government laboratories and in academic institutions has been designated. Wherever possible, comparisons have been made outlining differences or similarities that exist between the United States and Canada concerning biological radiation research. It has been concluded that relevant research in this area in Canada is inadequate. Wherever possible, strengths and weaknesses in radiation biology programs have been indicated. The most promising course for Canada to follow is to support adequately fundamental studies of the biological effects of radiation. (auth)

  17. Human · mouse genome analysis and radiation biology. Proceedings

    International Nuclear Information System (INIS)

    This issue is the collection of the papers presented at the 25th NIRS symposium on Human, Mouse Genome Analysis and Radiation Biology. The 14 of the presented papers are indexed individually. (J.P.N.)

  18. Solar ultraviolet radiation incident upon reef snorkelers determined by consideration of the partial immersion of dosimeters in the natural ocean environment

    International Nuclear Information System (INIS)

    Reef snorkelling is potentially a high-risk activity for persons visiting tropical and sub-tropical waters due to possible overexposure to solar ultraviolet radiation (UVR). Measurements and modelled estimates of the UVR received by human subjects are presented for a 10° latitudinal gradient of Australia's Great Barrier Reef and some Melanesian Islands (15°S to 25°S). A technique is described to measure the erythemally effective UVR received by the neck and the lower back. Measurements were made by application of a hybrid in-air and submerged calibration for polysulphone dosimeters. Measured exposures were used to model UVR exposure distributions at a number of popular snorkelling sites. A total of 11 snorkelling trials were held between 29 September 2009 and 26 January 2010. Exposures measured to the back and expressed relative to the horizontal plane ambient UVR have shown there to be some variation in the UVR distribution, with the neck receiving the greatest proportion of ambient UVR (0.56 ± 0.14 (1σ)), followed by the lower back (0.36 ± 0.14 (1σ)). Similarly high UVR exposures were determined at neck and lower back sites for different seasons, different times of day and over the latitudinal range of the study

  19. Current research in Radiation Biology and Biochemistry Division

    International Nuclear Information System (INIS)

    The Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay has been engaged in research in the frontier areas of (i) radiation biology related to tumour therapy and injury caused by free radicals; (ii) molecular basis of diseases of physiological origin; (iii) molecular aspects of chemical carcinogenesis and (iv) structure of genome and genome related functions. The gist of research and development activities carried out in the Division during the last two years are documented

  20. Comparative study of sensitivity of different albedo dosimeters and readout corrections at the U-400 cyclotron

    International Nuclear Information System (INIS)

    In this work we studied sensitivity of different albedo dosimeters placed in different positions with respect to the U-400M cyclotron: in the experimental area and behind the shield. It was shown that the ratio of albedo dosimeters (AD) and combined personal dosimeters (KID) to that of DVGN-01 dosimeters is constant within 25%. This allows us to use results obtained earlier with AD and KID dosimeters for the readout correction of the DVGN-01 dosimeters being used in the personal radiation monitoring. Values of correction coefficients for DVGN-01 behind the U-400M shield are obtained

  1. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved

  2. Biological effect of radiation on human

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae [and others

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved.

  3. Radiation, chemical and biological protection. Mass destruction weapons

    International Nuclear Information System (INIS)

    In this text-book mass destruction weapons and radiation, chemical and biological protection are reviewed. The text-book contains the following chapter: (1) Mass destruction weapons; (2) Matter and material; (3) Radioactive materials; (4) Toxic materials; (5) Biological resources; (6) Nuclear energetic equipment; Appendices; References.

  4. Biological effects of high energy radiations

    International Nuclear Information System (INIS)

    The author present the first results obtained by the determination of the survival of germ cells of mice exposed to X- and γ-radiation, to 400-600 MeV neutron beams, and irradiation by negative pions. (HSI)

  5. Small Active Radiation Monitor

    Science.gov (United States)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the

  6. Biophysical interpretation on the biological actions of radiations

    International Nuclear Information System (INIS)

    It is known that nuclear radiations such as alpha, beta, gamma, x-rays and neutron, proton and other heavy ion beams have many different actions on living cells; as killing, delaying growth, abnormal cell divisions and various genetical mutations and chromosomal aberrations. This document describes the mechanisms and kinetics of biological effects of ionizing radiation

  7. Enhancements in biologically effective ultraviolet radiation following volcanic eruptions

    Science.gov (United States)

    Vogelmann, A. M.; Ackerman, T. P.; Turco, R. P.

    1992-01-01

    A radiative transfer model is used to estimate the changes in biologically effective radiation (UV-BE) at the earth's surface produced by the El Chichon (1982) and Mount Pinatubo (1991) eruptions. It is found that in both cases surface intensity can increase because the effect of ozone depletion outweighs the increased scattering.

  8. Early mechanisms in radiation-induced biological damage

    International Nuclear Information System (INIS)

    An introduction to the mechanisms of radiation action in biological systems is presented. Several questions about the nature of the radiation damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical

  9. European activities in space radiation biology and exobiology

    Energy Technology Data Exchange (ETDEWEB)

    Horneck, G. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany)

    1996-12-31

    In view of the space station era, the European Space Agency has initiated a review and planning document for space life sciences. Radiation biology includes dosimetry of the radiation field and its modification by mass shielding, studies on the biological responses to radiation in space, on the potential impact of space flight environment on radiation effects, and assessing the radiation risks and establishing radiation protection guidelines. To reach a better understanding of the processes leading to the origin, evolution and distribution of life, exobiological activities include the exploration of the solar system, the collection and analysis of extraterrestrial samples and the utilization of space as a tool for testing the impact of space environment on organics and resistant life forms. (author)

  10. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    Radiation induced carcinogenesis and mutagenesis form the main risk to health from exposure to low levels of radiation. This risk effects can be at least qualitatively understood by considering the effects of radiation on cell DNA. Whilst exposure to high levels of radiation results in a number of identifiable effects, exposure to low levels of radiation may result in effects which only manifest themselves after many years. Risk estimates for low levels of radiation have been derived on the basis of a number of assumptions. In the case of uranium mine workers a major hazard arises from the inhalation of radon daughters. Whilst the correlation between radon daughter exposure and lung cancer incidence is well established, the numerical value of the risk factor is the subject of controversy. ICRP 50 gives a value of 10 cases per 106 person-years at risk per WLM (range 5-15 x 10-6 PYR-1 WLM-1). The effect of smoking on lung cancer incidence rates amongst miners is also controversial. Nevertheless, smoking by miners should be discouraged

  11. Radiation chemistry of biologically compatible polymers

    International Nuclear Information System (INIS)

    Full text: Poly (2-hydroxy ethyl methacrylate) [PHEMA] and poly (2-ethoxy ethyl methacrylate) [PEEMA] are of biomedical and industrial interest due to their biocompatibility with living tissue. In this paper the effect of high energy radiation on these polymers is reported. PHEMA and PEEMA have similar molecular structures to poly (methyl methacrylate)[PMMA], and the γ irradiation of this polymer is well understood. Hence the radiation chemistry of PMMA is used as model system for the the analysis of the radiation chemistry of these polymers. The mechanism of the radiation induced chemistry of the polymers has been investigated using a range of techniques including electron spin resonance spectroscopy (ESR) to establish free radical pathways, GC to identify small molecule volatile products, NMR to identify small molecule radiation products and Gel Permeation Chromatography (GPC) to determine molecular weight changes. Whilst much of the major part of the radiation chemistry can be attributed to similar reactions which can be observed in PMMA, there are a number of new radicals which are present as a result of the influence of the side chain interactions which reduces the mobility of the polymer chain

  12. Radiation chemistry of biologically compatible polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.J. T.; Pomery, P.J.; Saadat, G.; Whittaker, A.K. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry

    1996-12-31

    Full text: Poly (2-hydroxy ethyl methacrylate) [PHEMA] and poly (2-ethoxy ethyl methacrylate) [PEEMA] are of biomedical and industrial interest due to their biocompatibility with living tissue. In this paper the effect of high energy radiation on these polymers is reported. PHEMA and PEEMA have similar molecular structures to poly (methyl methacrylate)[PMMA], and the {gamma} irradiation of this polymer is well understood. Hence the radiation chemistry of PMMA is used as model system for the the analysis of the radiation chemistry of these polymers. The mechanism of the radiation induced chemistry of the polymers has been investigated using a range of techniques including electron spin resonance spectroscopy (ESR) to establish free radical pathways, GC to identify small molecule volatile products, NMR to identify small molecule radiation products and Gel Permeation Chromatography (GPC) to determine molecular weight changes. Whilst much of the major part of the radiation chemistry can be attributed to similar reactions which can be observed in PMMA, there are a number of new radicals which are present as a result of the influence of the side chain interactions which reduces the mobility of the polymer chain.

  13. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  14. The influence of dose rate, irradiation temperature and post-irradiation storage conditions on the radiation response of Harwell Gammachrome YR PMMA dosimeters

    International Nuclear Information System (INIS)

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

  15. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  16. Request for Travel Funds for Systems Radiation Biology Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos-Hoff, Mary Helen [NYU School of Medicine

    2014-03-22

    The 3rd International Systems Radiation Biology Workshop brought together the major European, US and Japanese research programs on radiation risk as well as selected experts representing systems biological approaches to discuss how the new methodologies could be best exploited for low dose research. A significant part of the workshop was devoted to discussions organised as breakout group sessions. To facilitate discussions number of participants was limited to 60 persons. To achieve the goals of this symposium in this international conference, support from DOE is vital. Hence, this proposal requested support in the amount of $15,000 to cover the travel expenses of international experts and radiation biology scientists from the United States. This supporting mechanism was clearly identified to the selected US participants as a conference support award from the DOE (See attached PDF). The workshop was an outstanding opportunity to strengthen interactions between leading experts in the emerging areas of radiation sciences, and will also provide opportunities for younger scientists to meet with experts and discuss their results. This workshop was designed to endorse active engagement in international collaboration. A major objective of this conference was to effectively communicate research results, in order to ensure that current thinking reflects sound science of radiation biology. Further, this international event addressed the use and success of scientific initiatives in radiation biology for policymakers, standard-setters, and the general public.

  17. Biological monitoring of radiation using indicators

    International Nuclear Information System (INIS)

    KAERI and INP(Poland) have been carried out parallel study and joint experiments on the major topics according to MOU about their cooperative project. The experimental materials were T-4430 clones. Main results of the cooperative project were made on response of TSH mutation to low LET radiation, response of TSH mutation to neutrons, response of TSH to mixed irradiation with different radiations and synergism between radiation and environmental factors such as photo period and diurnal temperature difference. Both institutes have established wide variety of research techniques applicable to tradescantia study through the cooperation. These result of research can make the role of fundamental basis for the better relationship between Korea and Poland. (author). 46 refs., 11 tabs., 31 figs

  18. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    International Nuclear Information System (INIS)

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described

  19. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1994-05-01

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described.

  20. Theoretical and experimental radiation effectiveness of the free radical dosimeter alanine to irradiation with heavy charged particles

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Olsen, K. J.

    1985-01-01

    Dose-response characteristics have been measured for the crystalline amino acid L-.alpha.-alanine irradiated with ion beams of 6 and 16 MeV protons, 20 MeV .alpha. particles, 21 MeV7Li ions, 64 MeV16O ions, and 80 MeV32S ions. The experimental radiation effectiveness (RE) with reference to low......-LET radiations of 60Co .gamma. rays, 4 and 16 MV X rays, and 6, 10, and 20 MeV electrons was compared with theoretical RE values derived from a model based on track structure theory of heavy charged particles. The ion beams covered a range in initial LET of 27-20,200 MeVcm2/g, and the experimental RE decreased...

  1. Environmental gamma monitoring in high background radiation areas of Orissa using CaSO4:Dy TL dosimeters

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides are the major contributor to the total effective dose of ionizing radiation received by the population. In India, there are quite a few monazite sand bearing placer deposits causing high background radiation along its long coastline. Chatrapur, Orissa is one of the high background areas of India. The beach sand of this area contains natural mineral Monazite abundantly. Maximum and minimum dose were found 1202. 1 μGy in spring and 483.8 μGy in monsoon at Port School and Gopalpur respectively. In spring, summer, monsoon and winter season the dose ranges were observed 1202.1-520.3, 1154.7-503.6, 1066.3-483.8 and 1141.7-508.5 μG respectively. (author)

  2. KCl:Eu2+ as a solar UV-C radiation dosimeter.Optically stimulated luminescence and thermoluminescence analyses

    Institute of Scientific and Technical Information of China (English)

    I.Aguirre de Cáarcer; H.L.D'Antoni; M.Barboza-Flores; V.Correcher; F.Jaque

    2009-01-01

    The KCl:Eu2+ system response to UV-C was investigated by analyzing the optically stimulated luminescence (OSL) and thertoo-luminescence (TL) signal produced by ultraviolet light exposure at room temperature.It was found that after UV-C irradiation,OSL was produced on a wide band of visible wavelengths with decay time that varied by several orders of magnitude depending on the Eu2+ aggregation state.In spite of the low intensity of solar UV-C reaching the Earth's surface in Madrid (40° N,700 m a.s.l.),it was possible to measure the UV-C radiation dose at 6:48 solar time by using the TL response of the KCl:Eu2+ system and differentiate it from the ambient beta radiation dose.

  3. Measurement of environmental radiation doses around PINSTECH (Pakistan Institute of Nuclear Science and Technology) using thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    Measurement of radiation doses around nuclear research reactors is an essential requirement to protect the environment and general public from harmful effects of radiation. To ensure safe operation of Pakistan Institute of Nuclear Science and Technology (PINSTECH) nuclear facilities, assessment of background radiation levels and ambient doses has been started before the criticality of the 5 MW Pakistan Research Reactor (PARR-1) in early sixties. In the present study, ambient dose rate levels were measured around PINSTECH by using TLD-200 (G-2 cards) installed at 15 different locations for a period from 2002-2010. The mean dose rates averaged over nine years for individual locations ranged from 0.14 +- 0.011 to 0.19 +- 0.028 mu Svh/sup -1/ with a cumulative mean value of 0.175 +- 0.02 uSv/hr. The seasonal variation between peak summer and peak winter was found to be 0.1 +- 0.002 uSv/hr. The results were found lower than world average values and are safe for general public residing around PINSTECH. (author)

  4. Exposure dose and personal dosimeter

    International Nuclear Information System (INIS)

    The concept of measuring the occupational exposure dose and of its management is explained. The Law Concerning Prevention from Radiation Hazards enacted in Japan in 1957, has been the basis of radiation protection with modifications like the incorporation of ICRP recommendations. Three sorts of radiological quantity (dose) are defined as physical, protective and practical ones. As well, the administrative quantity regards the protective quantity as the practical one. Thereby, the practical 1 cm dose equivalent is administrative effective dose, comparable to the protective effective dose limit. The practical dose equivalent subjected to measurement in the aligned and expanded radiation field involves 3 states of ambient, directional and personal ones. The personal dose equivalent is defined to be at d depth in the human body by ICRP but actually in the International Commission on Radiation Units and Measurement (ICRU) tissue equivalent slab phantom, and pragmatically measured with a personal dosimeter. Two kinds of radiation effects are known as deterministic and stochastic. The purpose of radiation protection is to suppress the former effect and to set the acceptable level for the latter, for which the equivalent dose limit and effective dose limit, respectively, are defined. Personal exposure dose of a man working at the aligned and expanded radiation field is measured with a survey-meter. Passive-type personal dosimeters have functions of the dose quantification, energy detection, discrimination of radiation sort and 1 cm/70 mc-m dose equivalent calculation. Total personal dose/y of a man must undergo the evaluation and acceptance from aspects of administrative effective dose limit defined. (T.T.)

  5. The biological bases of radiation protection

    International Nuclear Information System (INIS)

    Radiation protection is based on a large number of human data collected during the past 80 years. For dose levels of a few hundred rads, risks can be evaluated very accurately. Yet it is difficult to derive from them the risks due to low doses because of the uncertainty on the dose-effect relationship. In the practice, pessimistic assumptions are used, which involves an over-estimation of risks. However, even in these unfavorable conditions, risks associated to occupational activities implying radiation exposure seem to be less important than in most industries. Radiation protection has played a historical and essential part in the quantitative assessment of risks and opened a new era of occupational medicine and environmental health investigations. Many substances, such as radiations, are mutagenic and/or carcinogenic at very low doses, and in many cases human exposure cannot be avoided. Therefore, a policy advocating refusal of any risk whatsoever and absolute safety will lure with unattainable and misleading prospects. The only method is to assess the quantitative importance of the various risks in order to decide how far a damage may be tolerable in the various cases when exposure cannot be avoided

  6. Radiation biology: Major advances and perspectives for radiotherapy

    International Nuclear Information System (INIS)

    At the beginning of the 21. century, radiation biology is at a major turning point in its history. It must meet the expectations of the radiation oncologists, radiologists and the general public, but its purpose remains the same: to understand the molecular, cellular and tissue levels of lethal and carcinogenic effects of ionizing radiation in order to better protect healthy tissues and to develop treatments more effective against tumours. Four major aspects of radiobiology that marked this decade will be discussed: technological developments, the importance of signalling and repair of radiation-induced deoxyribonucleic acid (DNA) damage, the impact of individual factor in the response to radiation and the contribution of radiobiology to better choose innovative therapies such as proton-therapy or stereotactic body radiation therapy (SBRT). A translational radiobiology should emerge with the help of radiotherapists and radiation physicists and by facilitating access to the new radio and/or chemotherapy modalities. (authors)

  7. CaF2:Dy and CaF2 crystal-based UV dosimeters

    International Nuclear Information System (INIS)

    Background/aims: Monitoring of ultraviolet (UV) exposure in humans is important, since UV has been implicated in the pathogenesis of skin cancer, skin ageing and immunosuppression. Biological and physical dosimeters are being developed to measure occupational and environmental UV radiation exposure. We studied the UV-dependent thermoluminescence in CaF2:Dy and CaF2 crystals and report on the development of a small personal UV dosimeter based on the thermoluminescent phenomenon. Methods. CaF2:Dy or CaF2 was sensitized to UV by heating for 1-3 h to 750-950 deg. C on different supports (porcelain, steel, preheated steel, silicon, chromium, manganese, iron, cobalt, nickel, copper, Fe2O3, Fe3O4). Sensitized crystals were irradiated with UV of different energies and wavelengths. Thermoluminescence of irradiated crystals was measured at different temperatures. Results: Maximal sensitivity of the crystals to UV was obtained after preheating to 900 deg. C on steel and manganese supports. Sensitivity could be improved further by prolonging heating time. CaF2:Dy and CaF2 were most sensitive to short-wave UVC and UVB radiation. Based on these findings we have constructed personal UVB and UVC dosimeters. Conclusion: Development of personal UVC and UVB dosimeters based on UV-indued thermoluminescence in CaF2:DY and CaF2 crystals is feasible. CaF2:Dy and CaF2 crystals are not sensitive enough to long-wave UV radiation to be used for construction of UVA dosimeters. (au) 21 refs

  8. Radiation biology of human tumour xenografts

    International Nuclear Information System (INIS)

    The radiation response of human tumour xenografts can be measured with sufficient accuracy using cell survival in vitro and tumour growth delay in vivo as endpoints. There is evidence that radiation response of xenografts mirrors clinical radioresponsiveness of corresponding tumours in patients. Thus xenografts may have a significant potential in experimental radiotherapeutic research, e.g. in development of in vitro and in vivo predictive assays of clinical radioresponsiveness. There are at least three main disadvantages with xenografts as models for human cancer. Firstly, volume doubling time is usually shorter for xenografts than for tumours in patients. Secondly, the haematological system and vascular network of xenografts originate from the host. Thirdly, host defence mechanisms may be active against xenografts. These disadvantages may limit the usefulness of xenografts as models for human cancer in some types of radiobiological studies. (author)

  9. Kevlar® as a Potential Accident Radiation Dosimeter for First Responders, Law Enforcement and Military Personnel.

    Science.gov (United States)

    Romanyukha, Alexander; Trompier, François; Benevides, Luis A

    2016-08-01

    Today the armed forces and law enforcement personnel wear body armor, helmets, and flak jackets composed substantially of Kevlar® fiber to prevent bodily injury or death resulting from physical, ballistic, stab, and slash attacks. Therefore, there is a high probability that during a radiation accident or its aftermath, the Kevlar®-composed body armor will be irradiated. Preliminary study with samples of Kevlar® foundation fabric obtained from body armor used by the U.S. Marine Corps has shown that all samples evaluated demonstrated an EPR signal, and this signal increased with radiation dose. Based on these results, the authors predict that, with individual calibration, exposure at dose above 1 Gy can be reliably detected in Kevlar® samples obtained from body armor. As a result of these measurements, a post-event reconstruction of exposure dose can be obtained by taking various samples throughout the armor body and helmet worn by the same irradiated individual. The doses can be used to create a whole-body dose map that would be of vital importance in a case of a partial body or heterogeneous exposure. PMID:27356056

  10. Biological Sensors for Solar Ultraviolet Radiation

    OpenAIRE

    André P. Schuch; Teiti Yagura; Kazuo Makita; Hiromasa Yamamoto; Carlos F.M. Menck

    2011-01-01

    Solar ultraviolet (UV) radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage...

  11. Spectroscopic Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Analysis of Phase I test data demonstrates that the Photogenics Spectroscopic Dosimeter will detect neutron energies from 0.8 up to 600 MeV. The detector...

  12. Radiation carcinogenesis: Epidemiology and biological significance

    International Nuclear Information System (INIS)

    Epidemiologic studies of populations exposed to radiation have led to the identification of a preventable cause of cancer, but in the long run perhaps the most important contribution of radiation studies will be to provide insights into the basic processes of human carcinogenesis. In this volume, key investigators of major epidemiologic projects summarize their observations to date, including information to help assess the effects of low-level exposures. Experimentalists and theorists emphasize the relevance of laboratory and epidemiologic data in elucidating carcinogenic risks and mechanisms in man. This volume was prepared with several objectives in mind: (a) organize and synthesize knowledge on radiation carcinogenesis through epidemiologic and experimental approaches; (b) illustrate and explore ways of utilizing this information to gain insights into the fundamental mechanisms of cancer development; (c) stimulate the formation of hypotheses suited to experimental or epidemiologic testing, theoretical modeling, and multidisciplinary approaches; and (d) identify recent advances that clarify dose-response relationships and the influence of low-dose exposures, provide leads to carcinogenic mechanisms and host-environmental interactions, and suggest strategies for future research and preventive action

  13. Systems biology perspectives on the carcinogenic potential of radiation

    International Nuclear Information System (INIS)

    This review focuses on recent experimental and modeling studies that attempt to define the physiological context in which high linear energy transfer (LET) radiation increases epithelial cancer risk and the efficiency with which it does so. Radiation carcinogenesis is a two-compartment problem: ionizing radiation can alter genomic sequence as a result of damage due to targeted effects (TE) from the interaction of energy and DNA; it can also alter phenotype and multicellular interactions that contribute to cancer by poorly understood non-targeted effects (NTE). Rather than being secondary to DNA damage and mutations that can initiate cancer, radiation NTE create the critical context in which to promote cancer. Systems biology modeling using comprehensive experimental data that integrates different levels of biological organization and time-scales is a means of identifying the key processes underlying the carcinogenic potential of high-LET radiation. We hypothesize that inflammation is a key process, and thus cancer susceptibility will depend on specific genetic predisposition to the type and duration of this response. Systems genetics using novel mouse models can be used to identify such determinants of susceptibility to cancer in radiation sensitive tissues following high-LET radiation. Improved understanding of radiation carcinogenesis achieved by defining the relative contribution of NTE carcinogenic effects and identifying the genetic determinants of the high-LET cancer susceptibility will help reduce uncertainties in radiation risk assessment

  14. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  15. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    Energy Technology Data Exchange (ETDEWEB)

    Orton, C [Wayne State University, Grosse Pointe, MI (United States); Borras, C [Radiological Physics and Health Services, Washington, DC (United States); Carlson, D [Yale University School of Medicine, New Haven, CT (United States)

    2014-06-15

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  16. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    International Nuclear Information System (INIS)

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  17. BGRT: Biologically guided radiation therapy - The future is fast approaching!

    International Nuclear Information System (INIS)

    Rapid advances in functional and biological imaging, predictive assays, and our understanding of the molecular and cellular responses underpinning treatment outcomes herald the coming of the long-sought goal of implementing patient-specific biologically guided radiation therapy (BGRT) in the clinic. Biological imaging and predictive assays have the potential to provide patient-specific, three-dimensional information to characterize the radiation response characteristics of tumor and normal structures. Within the next decade, it will be possible to combine such information with advanced delivery technologies to design and deliver biologically conformed, individualized therapies in the clinic. The full implementation of BGRT in the clinic will require new technologies and additional research. However, even the partial implementation of BGRT treatment planning may have the potential to substantially impact clinical outcomes

  18. The development of high sensitive electron spin resonance (ESR) dosimeter

    International Nuclear Information System (INIS)

    This report introduces light metal ion-organic compound such as lactates, acetate and phosphate to a series of new ESR dosimeter materials. Their ESR spectra and sensitivities to radiation dose are obtained. (author)

  19. Miniature Space Dosimeter Based on Semiconductor Oxides Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro and Clemson University have teamed for a miniature, ultra low power, space radiation dosimeter. We project this unit, "MicroRad", to be 50X...

  20. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed. PMID:25722878

  1. Advances in the biological effects of terahertz wave radiation

    Institute of Scientific and Technical Information of China (English)

    Li Zhao; Yan-Hui Hao; Rui-Yun Peng

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  2. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    The 'hit theory' developed in 1920s to explain the actions of ionizing radiation on cells and organisms was purely physical, and its limitation was its inadequacy to address the contemporary findings such as the oxygen enhancement of radiobiological damage, and the increased radio- sensitivity of dividing compared to non-dividing cells. The textbooks written prior to 1970s did not either refer at all to oxygen as a radiosensitizer, or had mentioned it only in a passing manner; yet 'oxygen effect' was emerging as the central dogma in radiation biology. The oxygen effect in radiation biology is highly interdisciplinary encompassing atomic physics (i.e. interaction of photon with matter), radiation chemistry (formation of reactive oxygen species), molecular signalling, gene expression and genetic alterations in cells (mutation, cancer) or the cell death (apoptosis, necrosis, mitotic catastrophe, etc.). Cell death in higher organisms is now recognized as the precursor of possible error-free cell replacement repair. (author)

  3. Dose-rate and humidity effects upon the gamma-radiation response of nylon-based radiachromic film dosimeters

    International Nuclear Information System (INIS)

    At dose-rates typical for 60Co gamma irradiation sources, the radiation response of hexahydroxyethyl pararosaniline cyanide/ 50μm nylon radiachromic films is dependent upon dose-rate as well as upon the moisture content of the films, or the relative humidity of the surrounding atmosphere, respectively. Under equilibrium moisture conditions, the response measured at 606 nm 24 hours after end of irradiation shows its highest dose-rate dependence at about 32 % r.h. A decrease in dose-rate from 2.8 to 0.039 Gy.s-1 results in a decrease in response by 17%. At higher humidities, the sensitivity of the film as well as the rate dependence decreases and at 86% r.h. no discernible dose-rate effect could be found. At lower humidities than 32% a flat maximum in response follows. At nominal 0% r.h. a second absorption band at 412 nm appears which is converted completely to an additional 606 nm absorption by exposure to a humid atmosphere. After that procedure the resultant response is somewhat lower than but shows almost the same dose-rate dependence as at 32% r.h. or else to eliminate the dose-rate effect by an extrapolation procedure based on the fact that the rate dependence vanishes at zero dose. (author)

  4. Measurement of individual doses of radiation by personal dosimeter is important for the return of residents from evacuation order areas after nuclear disaster.

    Directory of Open Access Journals (Sweden)

    Makiko Orita

    Full Text Available To confirm the availability of individual dose evaluation for the return of residents after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP, we evaluated individual doses of radiation as measured by personal dosimeters in residents who temporarily stayed in Evacuation Order Areas in Kawauchi village, which is partially located within a 20 km radius of the FNPP. We also compared individual doses with the external radiation doses estimated from the ambient dose rates and with doses estimated from the concentrations of radionuclides in the soil around each individual's house. Individual doses were significantly correlated with the ambient doses in front of the entrances to the houses (r = 0.90, p<0.01, in the backyards (r = 0.41, p<0.01 and in the nearby fields (r = 0.80, p<0.01. The maximum cumulative ambient doses in the backyards and fields around the houses were 6.38 and 9.27 mSv/y, respectively. The maximum cumulative individual dose was 3.28 mSv/y, and the median and minimum doses were 1.35 and 0.71 mSv/y. The estimated external effective doses from concentrations of artificial radionuclides in soil samples ranged from 0.03 to 23.42 mSv/y. The individual doses were moderately correlated with external effective doses in the backyards (r = 0.38, p<0.01 and in the fields (r = 0.36, p<0.01; however, the individual doses were not significantly correlated with the external effective doses in front of the entrances (r = 0.01, p = 0.92. Our study confirmed that individual doses are low levels even in the evacuation order area in Kawauchi village, and external effective dose levels are certainly decreasing due to the decay of artificial radionuclides and the decontamination of contaminated soil. Long-term follow-up of individual doses as well as internal-exposure doses, environmental monitoring and reconstruction of infrastructure are needed so that residents may return to their hometowns after a nuclear disaster.

  5. Development of personal thermo-luminescence dosimeter and its application

    International Nuclear Information System (INIS)

    A new personal thermo-luminescence(TL) dosimeter LiF:Mg,Cu,Na,Si which can measure a radiation dose to personnel and material has been developed on the basis of the principle of a thermo-luminescence generation from a luminescent material, which is proportional to the absorbed radiation dose by heating to this material. This new TL dosimeter, which was made of LiF by adding a small fraction of Mg, Cu, Na and Si as an activator, showed a higher sensitivity in radiation detection by two times than the conventional foreign-made TL dosimeter LiF:Mg,Cu,P. Therefore, because of the fine characteristics of this new TL dosimeter in measuring the radiation dose regardless the radiation type, the intensity of radiation energy and direction of radiation incidence, it can be successfully utilized as a personal radiation dosimeter of radiation workers and patients for radiation diagnosis and therapy as well as an environmental radiation doimeter around the nuclear facility

  6. Automated Calibration of Dosimeters for Diagnostic Radiology

    International Nuclear Information System (INIS)

    Calibration of dosimeters for diagnostic radiology includes current and charge measurements, which are often repetitive. However, these measurements are usually done using modern electrometers, which are equipped with an RS-232 interface that enables instrument control from a computer. This paper presents an automated system aimed to the measurements for the calibration of dosimeters used in diagnostic radiology. A software application was developed, in order to achieve the acquisition of the electric charge readings, measured values of the monitor chamber, calculation of the calibration coefficient and issue of a calibration certificate. A primary data record file is filled and stored in the computer hard disk. The calibration method used was calibration by substitution. With this system, a better control over the calibration process is achieved and the need for human intervention is reduced. the automated system will be used in the calibration of dosimeters for diagnostic radiology at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene. (Author)

  7. Water equivalence of polymer gel dosimeters

    International Nuclear Information System (INIS)

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Zeff), electron density (ρe), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μen/ρ) and total stopping power (S/ρ)tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close (en/ρ for all polymer gels were in close agreement (tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  8. Radiation physics, biophysics and radiation biology. Progress report, October 1, 1980-September 30, 1981

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for the 29 papers in this progress report which deal with radiobiological physics, the biological effects of ionizing radiations, and the modification of these effects by chemical and pharmacological agents

  9. Selfcalibrated alanine/EPR dosimeters. A new generation of solid state/EPR dosimeters

    International Nuclear Information System (INIS)

    Alanine/EPR dosimeters are well established as secondary, reference dosimeters for high-energy radiation. However, there are various sources of uncertainty in the evaluation of absorbed dose. This arises primarily from the necessity to calibrate each EPR spectrometer and each batch of dosimeters before their use. In order to overcome this disadvantage, a new generation alanine/EPR dosimeter has been developed, and its possibilities as a radiation detector are reported. Principally, it is a mixture of alanine, some quantity of EPR active substance, and a binding material. The EPR active substance, acting as an internal EPR standard, is chosen to have EPR parameters which are independent of the irradiation dose. The simultaneous recording of the spectra of both the sample and the standard under the same experimental conditions and the estimation of the ratio Ialanine/IMn as a function of the absorbed dose strongly reduces the uncertainties. The response of these dosimeters for 60Co γ-radiation exhibits excellent linearity and reproducibility in the range of absorbed dose, 102 - 5 x 104 Gy. (author)

  10. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 ± 0.3 to 111 ± 7.4 KBq/m3 equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m3, this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author)

  11. Optical Fibre Dosimeter for SASE FEL Undulators

    CERN Document Server

    Körfer, M

    2003-01-01

    Single pass Free Electron Lasers (FELs) based on self-amplified spontaneous emission (SASE) are developed for high brightness and short wavelength applications. They use permanent magnet undulators which are radiation sensitive devices. During accelerator commissioning beam losses can appear anywhere along the undulator line. To avoid damage of the permanent magnets due to radiation, an optical fibre dosimeter system can be used. The increase of absorption caused by ionizing radiation is measured in radiation sensitive optical fibers. The dose system enables relatively fast particle loss tuning during accelerator operation and allows the monitoring of the accumulated dose. Dose measurements in narrow gaps which are inaccessible for any other (online) dosimeter type become possible. The electromagnetic insensitivity of optical fibre sensor is an advantage of applications in strong magnetic undulator fields. At each location the light absorption is measured by using an optical power-meter. The dynamic range is ...

  12. Sterilization of biological tissues with ionizing radiation

    International Nuclear Information System (INIS)

    On June 1994, the National Institute of Nuclear Research (ININ) and the South Central Hospital for High Specialty of PEMEX (HCSAE) began a joint work with the finality to obtain radio sterilized amniotic membranes for to be used as cover (biological bandage) in burnt patients. Subsequently the Chemistry Faculty of UNAM and the National Institute of Cardiology began to collaborate this last with interest on cardiac valves for graft. Starting from 1997, the International Atomic Energy Agency (IAEA) supports this project (MEX/7/008) whose main objective is to set up the basis to establish in Mexico a Radio sterilized Tissue Bank (amniotic membranes, skin, bones, tendons, cardiac valves, etc.) to be used with therapeutic purposes (grafts). The IAEA support has consisted in the equipment acquisition which is fundamental for the Tissue Bank performance such as an experimental irradiator, laminar flow bell, lyophilizer, vacuum sealer and special knives for tissues. Also visits to Mexico of experts have been authorized with the aim of advising to the personnel which participate in the project and scientific visits of this personnel to another tissue banks (Sri Lanka and Argentine). The establishment in Mexico of a Tissue bank will be a great benefit because it will have availability of distinct tissues for grafts and it will reduce the synthetic materials importation which is very expensive. (Author)

  13. Biological indicators for radiation absorbed dose: a review

    International Nuclear Information System (INIS)

    Biological dosimetry has an important role to play in assessing the cumulative radiation exposure of persons working with radiation and also in estimating the true dose received during accidents involving external and internal exposure. Various biodosimetric methods have been tried to estimate radiation dose for the above purposes. Biodosimetric methods include cytogenetic, immunological and mutational assays. Each technique has certain advantages and disadvantages. We present here a review of each technique, the actual method used for detection of dose, the sensitivity of detection and its use in long term studies. (author)

  14. Flow-cytometry techniques in radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, K.F.; Hale, M.L.

    1988-01-01

    Considerable evidence exists that all blood cells are derived from HSC. These cells are of interest to radiobiologists because they are highly sensitive to low doses of ionizing radiation. Hematopoietic stem cells (HSC) are present in the marrow at a concentration of approximately 2-3 HSC per 1000 nucleated marrow cells. In the past, only clonogenic assays requiring 8-13 days and ten irradiated recipient rodents were available for assaying HSC. Because of the importance of HSC in the post-irradiation syndrome, the authors developed a new rapid method based on flow cytometry not only to assay but also to purify and characterize HSC. This new method makes extensive use of non-clonal antibodies conjugated to fluorescent phycobiliproteins through the sulfhydryls of the hinge region of the IgG molecule. An optical bench arrangement with a dye laser and an argon laser was used for dual excitation of the phycobiliprotein-monoclonal antibody conjugates and various cellular and DNA probes. Using 4', 6-diamidino 2-phenylindole dihydrochloride (DAP) exclusion to identify viable cells, it was possible to follow regeneration of post-irradiated rat marrow HSC.

  15. Spatial interpolation of biologically effective UV radiation over Poland

    Science.gov (United States)

    Walawender, J.; Ustrnul, Z.

    2010-09-01

    The ultraviolet(UV) radiation plays an important role in the Earth-Atmosphere System. It has a positive influence on both human health and natural environment but it may also be very harmful if UV exposure exceeds "safe" limits. For that reason knowledge about spatial distribution of biologically effective UV doses seems to be crucial in minimization or complete elimination of the negative UV effects. The main purpose of this study is to find the most appropriate interpolation method in order to create reliable maps of the biologically effective UV radiation over Poland. As the broadband UV measurement network in Poland is very sparse, erythemaly weighted UV radiation data reconstructed from homogeneous global solar radiation records were used. UV reconstruction model was developed in Centre of Aerology (Institute of Meteorology and Water Management) within COST Action 726 - ‘Long term changes and climatology of UV radiation over Europe'. The model made it possible to reconstruct daily erythemal UV doses for 21 solar radiation measurement stations in the period 1985 - 2008. Mapping methodology included the following processing steps: exploratory spatial data analysis, verification of additional variables, selection and parameterization of interpolation model, accuracy assessment and cartographic visualization. Several different stochastic and deterministic interpolation methods along with various empirical semivariogram models were tested. Multiple regression analysis was performed in order to examine statistical relationship between UV radiation and additional environmental variables such as: elevation, latitude, stratospheric ozone content and cloud cover. The data were integrated, processed and visualized within GIS environment.

  16. Department of Radiation and Environmental Biology - Overview

    International Nuclear Information System (INIS)

    Full text: The year 1998 might again be called as the ''Comet Year''. The rain of bolides expected in the sky resembles pictures of DNA damages in shapes, numbers, mysterious processes and sometimes challenges to detect them. It was in this year that we detected, in a fluorescent light under the microscope, another ''shinning star'' a long time expected translocation induced by neutrons and then transferred to its glitter through fluorescence in situ hybridization technic. The year was filled in with measurements and brought plenty of scientific events that are partly reflected in the following pages; strong will and hard work to maintain research standards equal to technologically advanced partners in Europe and in other parts of the World; the USA, Sth Korea. We mainly devoted the year 1998 to the activities concerning our basic research, and requirements and expectations of various Committees in the issues of three research projects. We gather results on genotoxicity of pesticides, occupational exposures, and also the importance of life styles as factors affecting the levels of damage induced in human cells. We have also succeeded to go faster with modernization of our methodology by transferring the single cell ''Comet Assay'' to the routine work for the analysis of DNA damage induced by UV and X-rays radiation and for the studies on individual variability in the damage repair capacity. On January 13th we installed a new powerful RTG machine. Polish Atomic Energy supported this investment. And this was really the meaningful celebration of 100 anniversary of the discovery of POLONIUM and RADIUM. So, now, before a new therapeutic tool will be used in routine applications for radiotherapy, we with our new beautiful and powerful roentgen machine are deeply involved in the exploration of the strength of radiotherapeutic efficiency of sources and schedules. With the use of gene mutations in TSH-assay, we have finally established good dose response curves for

  17. Biological effects of space radiation and development of effective countermeasures

    Science.gov (United States)

    Kennedy, Ann R.

    2014-04-01

    As part of a program to assess the adverse biological effects expected from astronauts' exposure to space radiation, numerous different biological effects relating to astronauts' health have been evaluated. There has been major focus recently on the assessment of risks related to exposure to solar particle event (SPE) radiation. The effects related to various types of space radiation exposure that have been evaluated are: gene expression changes (primarily associated with programmed cell death and extracellular matrix (ECM) remodeling), oxidative stress, gastrointestinal tract bacterial translocation and immune system activation, peripheral hematopoietic cell counts, emesis, blood coagulation, skin, behavior/fatigue (including social exploration, submaximal exercise treadmill and spontaneous locomotor activity), heart functions, alterations in biological endpoints related to astronauts' vision problems (lumbar puncture/intracranial pressure, ocular ultrasound and histopathology studies), and survival, as well as long-term effects such as cancer and cataract development. A number of different countermeasures have been identified that can potentially mitigate or prevent the adverse biological effects resulting from exposure to space radiation.

  18. Further approaches to biological indicators of radiation injury

    International Nuclear Information System (INIS)

    Despite of the decades-long investigations, the search for proper biological indicator of radiation injuries did not result in techniques fulfilling all the requirements. So far, the most reliable assay is the dicentric chromosome aberration analysis. New developments have been made recently on a cytogenetic technique, the micronucleus assay, and for local injuries on the application of thermography

  19. Thermal effects of laser radiation in biological tissue.

    OpenAIRE

    Cummins, L; Nauenberg, M.

    1983-01-01

    A theoretical model is presented that simulates the thermal effects of laser radiation incident on biological tissue. The multiple scattering and absorption of the laser beam and the thermal diffusion process in the tissue are evaluated by a numerical technique that is well suited for microcomputers. Results are compared with recent empirical observations.

  20. Studies to validate the measurement of translocation frequency in peripheral blood lymphocytes by GTG-banding and chromosome painting for biological dosimetry

    International Nuclear Information System (INIS)

    The wide use of radiation sources for medical, industrial, agricultural, research and military purposes increases the public concern and associated risks of overexposure. Biological dosimeters plays a important role in circumstances where physical dosimetry either unavailable or gives ambiguous dose estimates based upon biological indicators. Among various biological indicators, cytogenetic indicators have become routine tools for dose assessment and its biological effect

  1. The interaction between Terahertz radiation and biological tissue

    International Nuclear Information System (INIS)

    Terahertz (THz) radiation occupies that region of the electromagnetic (EM) spectrum between approximately 0.3 and 20 THz. Recent advances in methods of producing THz radiation have stimulated interest in studying the interaction between radiation and biological molecules and tissue. Given that the photon energies associated with this region of the spectrum are 2.0x10-22 to 1.3x10-20 J, an analysis of the interactions requires an understanding of the permittivity and conductivity of the medium (which describe the bulk motions of the molecules) and the possible transitions between the molecular energy levels. This paper reviews current understanding of the interactions between THz radiation and biological molecules, cells and tissues. At frequencies below approximately 6 THz, the interaction may be understood as a classical EM wave interaction (using the parameters of permittivity and conductivity), whereas at higher frequencies, transitions between different molecular vibrational and rotational energy levels become increasingly important and are more readily understood using a quantum-mechanical framework. The latter is of particular interest in using THz to probe transitions between different vibrational modes of deoxyribonucleic acid. Much additional experimental work is required in order to fully understand the interactions between THz radiation and biological molecules and tissue. (author)

  2. Radiation physics, biophysics and radiation biology. Progress report, December 1, 1984-November 30, 1985

    International Nuclear Information System (INIS)

    This is the annual progress report for the Radiological Research Laboratory, Department of Radiology, Columbia University. The report consists of 17 individual reports plus an overall summary. Reports survey research results in neutron dosimetry, microdosimetry of electron beams and x-radiation, development of theoretical models for biological radiation effects and induction of oncogenic transformations. Individual abstracts were also prepared for each paper

  3. Biological dosimetry in case of combined radiation injuries

    International Nuclear Information System (INIS)

    The state of biological dosimetry methods and prospects for their development are considered. Attention is paid to biological indicators of radiation injuries caused by nuclear weapons. It is noted, that determination of the number of lymphocytes in the blood in case of combined radiation injuries should be concerned with great care and in each case the analysis results should reffered to critically and supported by the data from other investigations. Promissing are the methods related to dermination of reticulocyte number in the peripheral blood within the irradiation dose range, causing bone marrow form of radiation syndrome, method of leukocyte adhesion and some other methods based on the change of biophysical caracteristics of cell membranes. To increase the information efficiency it is necessary to combine these methods with the methods, based on genetic change registration, and to develop a combined method

  4. Thermoluminescence slab dosimeter

    International Nuclear Information System (INIS)

    In 1953 F. Daniels et al. used the property of thermoluminescence in dosimetry for the first time. Since then, numerous thermoluminescence dosimeter (TLD) have been developed. 2D TLD was investigated for the first time in 1972 by P Broadhead. However, due to excessive fading, difficulties with handling and the time required for measurements, development stalled. At the current time, the majority of TLD are used in small scale, localized dosimetry with a wide dynamic range and personal dosimeters for exposure management. Urushiyama et. al. have taken advantage of the commoditization of charge-coupled devices (CCD) cameras in recent years -making large area, high resolution imaging easier- to introduce and develop a 2D TLD. It is expected that these developments will give rise to a new generation of applications for 2D thermoluminescence (TL) dosimetry. This paper introduces the ''TL Slab Dosimeter'' developed jointly by Urushiyama et. al. and our team, its measurement system and several typical usage scenarios. (author)

  5. Countermeasures for space radiation induced adverse biologic effects

    Science.gov (United States)

    Kennedy, A. R.; Wan, X. S.

    2011-11-01

    Radiation exposure in space is expected to increase the risk of cancer and other adverse biological effects in astronauts. The types of space radiation of particular concern for astronaut health are protons and heavy ions known as high atomic number and high energy (HZE) particles. Recent studies have indicated that carcinogenesis induced by protons and HZE particles may be modifiable. We have been evaluating the effects of proton and HZE particle radiation in cultured human cells and animals for nearly a decade. Our results indicate that exposure to proton and HZE particle radiation increases oxidative stress, cytotoxicity, cataract development and malignant transformation in in vivo and/or in vitro experimental systems. We have also shown that these adverse biological effects can be prevented, at least partially, by treatment with antioxidants and some dietary supplements that are readily available and have favorable safety profiles. Some of the antioxidants and dietary supplements are effective in preventing radiation induced malignant transformation in vitro even when applied several days after the radiation exposure. Our recent progress is reviewed and discussed in the context of the relevant literature.

  6. Ultrashort relativistic electron bunches and spatio-temporal radiation biology

    Science.gov (United States)

    Gauduel, Y. A.; Faure, J.; Malka, V.

    2008-08-01

    The intensive developments of terawatt Ti:Sa lasers permit to extend laser-plasma interactions into the relativistic regime, providing very-short electron or proton bunches. Experimental researches developed at the interface of laser physics and radiation biology, using the combination of sub-picosecond electron beams in the energy range 2-15 MeV with femtosecond near-IR optical pulses might conjecture the real-time investigation of penetrating radiation effects. A perfect synchronization between the particle beam (pump) and optical beam at 820 nm (probe) allows subpicosecond time resolution. This emerging domain involves high-energy radiation femtochemistry (HERF) for which the early spatial energy deposition is decisive for the prediction of cellular and tissular radiation damages. With vacuum-focused intensities of 2.7 x 1019 W cm-2 and a high energy electron total charge of 2.5 nC, radiation events have been investigated in the temporal range 10-13 - 10-10s. The early radiation effects of secondary electron on biomolecular sensors may be investigated inside sub-micrometric ionisation, considering the radial direction of Gaussian electron bunches. It is shown that short range electron-biosensor interactions lower than 10 A take place in nascent track structures triggered by penetrating radiation bunches. The very high dose delivery 1013 Gy s-1 performed with laser plasma accelerator may challenge our understanding of nanodosimetry on the time scale of molecular target motions. High-quality ultrashort penetrating radiation beams open promising opportunities for the development of spatio-temporal radiation biology, a crucial domain of cancer therapy, and would favor novating applications in nanomedicine such as highly-selective shortrange pro-drug activation.

  7. Intercomparison of extremity dosimeters in beta, photon and medical realistic fields. Performance of ring dosimeters in typical medical fields

    International Nuclear Information System (INIS)

    The EURADOS Working Group 9 is presently coordinating research activities on the assessment of occupational exposures at workplaces in therapeutic and diagnostic radiology as well as in nuclear medicine. A recent literature review showed that extremity doses, especially in nuclear medicine and interventional radiology, can be quite high. However, the use of extremity dosimeters in hospitals is still not very common. Furthermore, there is very little information on the performance of these dosimeter s in typical medical fields. Within this framework, EURADOS organized an intercomparison of ring dosimeters aimed at assessing the technical capabilities of available extremity dosimeter s and focusing on their performance at workplaces with potentially high extremity doses. 24 services from 16 European countries participated in the intercomparison. The dosimeter s represented in this study are used to monitor over 30,000 workers. The dosimeter s were exposed to reference photon (137Cs) and beta (147Pm, 85Kr and 90Sr/90Y) fields as well as to realistic interventional radiology (direct and scattered radiation) and nu clear medicine fields (99mTc and 18F). This report presents the main results of the intercomparison. It is shown that most dosimeters provided satisfactory measurements of Hp(0.07) for photon radiation, both in reference and realistic fields. However, only four dosimeter s fulfilled the requirements given by the trumpet curves for all tested radiation qualities. The main difficulties were found for the measurement of low energy beta radiation. A clear correlation between filter and detector thickness and response to beta particles was found, thus highlighting the need for appropriate dosimeter design for these fields. Finally, the results also showed a general under response of detectors to 18F, which was attributed to the difficulties of the dosimetric systems to measure the positron contribution to the dose. (author)

  8. Investigation of the energy dependence of dosimeters

    International Nuclear Information System (INIS)

    This paper reports on the results of investigations of the energy dependence of the detectors in the VA-J-18, 27012 (M 2300), DRG-01 and DKS-05 dosimeters. Each of the dosimeters is provided with several ionization chambers; one of the ionization chambers with a volume of ca 600-1000 cm3 is designated for measuring low radiation levels, i.e., for monitoring the quality of radiation shields. The investigations were made on reference units reproducing the unit of the exposure dose, the exposure dose rate, and the energy flux of x-ray and gamma radiation. The parameters of the instruments examined are presented. The instruments can be used as reference means of measurements and the error of dosimetric measurements can be reduced as the reliability of the instruments has been increased

  9. Standardisation and Validation of Cytogenetic Markers to Quantify Radiation Absorbed Dose

    Directory of Open Access Journals (Sweden)

    Venkatachalam Perumal

    2011-02-01

    Full Text Available The amounts of radiation exposure received by radiation workers are monitored generally by physical dosimeters like thermoluminescence dosimeter (TLD and film badge. However, in practice the over-exposure recorded by physical dosimeters need to be confirmed with biological dosimeters. In addition to confirming the dose recorded by physical dosimeters, biological dosimeters play an important role in estimating the doses received during accidental exposures. Exposure to high levels of radiation induces certain  biochemical, biophysical, and immunological changes (biomarkers in a cell. Measurement of these changes are generally precise but cannot be effectively used to assess the dose, as the level of these changes return to normalcy within hours to months after exposure. Thus, among various biological indicators, cytogenetic indicators are considered practical and reliable for dose estimation. The paper highlights the importance and establishment of biodosimetry facility using genetic markers such as the sensitive dicentric chromosomes, rapid micronucleus assay and stable translocations measured using fluorescence in situ hybridisation and GTG banding for retrospective dose estimation. Finally, the development of gH2AX assay, as a potential marker of triage dosimeter, is discussed.Defence Science Journal, 2011, 61(2, pp.125-132, DOI:http://dx.doi.org/10.14429/dsj.61.832

  10. 5. Conference cycle. The radiations and the Biological Sciences

    International Nuclear Information System (INIS)

    Nuclear technologies and their development have influenced many aspects of modern life. Besides used for electricity production nuclear technologies are applied in many other fields, especially in biological sciences. In genetics and molecular biology they enable research resulting in increased food production and better food preservation. Usage in material sciences lead to new varieties of plastics or improved characteristics. Nuclear applications are used in pe troleum industries and in forecasting geothermic power. Radiobiology and radiotherapy enable diagnosis and therapy of several diseases, e.g. cancer. Nuclear technologies also contribute to preserve the environment. They offer methods to analyse as well as decrease the environmental impacts. The 5. conference cyle entitled 'The Radiations and the Biological Sciences' aims to inform students of biological sciences about new nuclear technologies applied in their field of interest

  11. Diffusion measurement in ferrous infused gel dosimeters

    International Nuclear Information System (INIS)

    Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye and Ferrous sulphate, Gelatin and Xylenol orange dye in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. Ionizing radiation causes oxidation of Fe2+ ion to Fe3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours after irradiation. Materials and methods: 25 m M sulphuric acid, 0.4 mm ferrous ammonium sulphate, 0.2 mm xylenol orange dye and 1% by weight agarose in distilled water named Agarose and Xylenol orange dye and 0.1 mm ferrous ammonium sulphate, 0.1 mm xylenol orange dye, 50 mm sulphuric acid and 5% by weight gelatin in distilled water named Gelatin and Xylenol orange dye are used as two gel dosimeters. All chemicals were supplied by Sigma Ald ridge Company, Germany. The gels were poured in Perspex casts and were irradiated to a beam of X ray from linear accelerators or X ray machine. Results: In this study diffusion coefficients of Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters have been measured through a computer program for different temperature. The ferric ion diffusion coefficient (D) for the Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters were measured as (1.19.±0.03) x 10-2 cm2.hr -1 and (0.83±0.03) x 10-2 cm2.hr-1 respectively at room temperature. Conclusion: For both dosimeters the diffusion coefficients decreased with gel storage temperatures down to 6 digC. Gelatin and Xylenol orange dye dosimeters have advantage of lower diffusion coefficient for a specified temperature

  12. Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyunjun; Kim, Chankyu; Kim, Yewon; Kim, Giyoon; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information.

  13. Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

    International Nuclear Information System (INIS)

    There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information

  14. An approved personal dosimetry service based on an electronic dosimeter

    International Nuclear Information System (INIS)

    At the Second Conference on Radiation Protection and Dosimetry a paper was presented which, in part, announced the development of an electronic dosimeter to be undertaken in the UK by the National Radiological Protection Board (NRPB) and Siemens Plessey Controls Ltd. This dosimeter was to be of a standard suitable for use as the basis of an approved personal dosimetry service for photon and beta radiations. The project has progressed extremely well and dosimeters and readers are about to become commercially available. The system and the specification of the dosimeter are presented. The NRPB is in the process of applying for approval by the Health and Safety Executive (HSE) to operate as personal monitoring service based on this dosimeter. As part of the approval procedure the dosimeter is being type tested and is also undergoing an HSE performance test and wearer trials. The tests and the wearer trials are described and a summary of the results to date presented. The way in which the service will be organized and operated is described and a comparison is made between the running of the service and others based on passive dosimeters at NRPB

  15. Biological imaging in radiation therapy: role of positron emission tomography

    International Nuclear Information System (INIS)

    In radiation therapy (RT), staging, treatment planning, monitoring and evaluation of response are traditionally based on computed tomography (CT) and magnetic resonance imaging (MRI). These radiological investigations have the significant advantage to show the anatomy with a high resolution, being also called anatomical imaging. In recent years, so called biological imaging methods which visualize metabolic pathways have been developed. These methods offer complementary imaging of various aspects of tumour biology. To date, the most prominent biological imaging system in use is positron emission tomography (PET), whose diagnostic properties have clinically been evaluated for years. The aim of this review is to discuss the valences and implications of PET in RT. We will focus our evaluation on the following topics: the role of biological imaging for tumour tissue detection/delineation of the gross tumour volume (GTV) and for the visualization of heterogeneous tumour biology. We will discuss the role of fluorodeoxyglucose-PET in lung and head and neck cancer and the impact of amino acids (AA)-PET in target volume delineation of brain gliomas. Furthermore, we summarize the data of the literature about tumour hypoxia and proliferation visualized by PET. We conclude that, regarding treatment planning in radiotherapy, PET offers advantages in terms of tumour delineation and the description of biological processes. However, to define the real impact of biological imaging on clinical outcome after radiotherapy, further experimental, clinical and cost/benefit analyses are required. (topical review)

  16. DEGRO 2009. Radiation oncology - medical physics - radiation biology. Abstracts; DEGRO 2009. Radioonkologie - Medizinische Physik - Strahlenbiologie. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    The special volume of the journal covers the abstracts of the DEGRO 2009 meeting on radiation oncology, medical physics, and radiation biology, covering the following topics: seldom diseases, gastrointestinal tumors, radiation reactions and radiation protection, medical care and science, central nervous system, medical physics, the non-parvicellular lung carcinomas, ear-nose-and throat, target-oriented radiotherapy plus ''X'', radio-oncology - young academics, lymphomas, mammary glands, modern radiotherapy, life quality and palliative radiotherapy, radiotherapy of the prostate carcinoma, imaging for planning and therapy, the digital documentation in clinics and practical experiences, NMR imaging and tomography, hadrons - actual status in Germany, urinal tract oncology, radiotoxicity.

  17. Evaluations of properties and review applications of some chemical dosimeters

    International Nuclear Information System (INIS)

    A chemical dosimeter is one of the most important methods used to measure radiation doses via a chemical reaction caused by the ionizing radiation. It is a system that measures the dose rate by chemical changes when it is exposed to ionizing radiation. This interaction produces changes in the chemical properties of the material that used as dosimeter as well as change in color. In all chemical dosimeters radiation induced chemical reaction produces new species, which its properties long lived enough to determine its quantity or the change in the initial system. This study discussed some different types of chemical dosimeters such as aqueous, gaseous and solid, the great consideration was given to aqueous systems because of their vital role in many applications. The dose rate of gamma cell was measured by using Fricke dosimeter found that dose rate about 0.909 Gy/sec while the theoretical dose rate was 0.910 Gy/sec, which confirms the suitability of Fricke dosimeter for this calibration. (Author)

  18. Alanine dosimeter for practical use using polyethylene as binder

    Energy Technology Data Exchange (ETDEWEB)

    Tateishi, Tsuneo (Japan Radioisotope Association, Tokyo (Japan)); Kobayashi, Toshikazu; Iso, Katsuaki; Sone, Yasuhiro; Mamuro, Tetsuo

    1992-02-01

    Alanine dosimeters were manufactured using polyethylene as a binder and their characteristics were studied with the intention of developing cheap dosimeter for practical routine use having high precision in a dose range of 0.1-100 kGy. The effects of temperature and humidity during storage after irradiation on fading of the ESR response, which is proportional to radiation-induced free radicals in alanine, and the influence of ESR measurement conditions on the ESR response were investigated in detail. As the results, it was confirmed that practical dosimetry of satisfactorily high precision is possible with the manufactured dosimeters by following appropriate measurement procedures. (author).

  19. Alanine EPR dosimeter response in proton therapy beams

    International Nuclear Information System (INIS)

    We report a series of measurements directed to assess the suitability of alanine as a mailable dosimeter for dosimetry quality assurance of proton radiation therapy beams. These measurements include dose-response of alanine at 140 MeV, and comparison of response vs energy with a parallel plate ionization chamber. All irradiations were made at the Harvard Cyclotron Laboratory, and the dosimeters were read at NIST. The results encourage us that alanine could be expected to serve as a mailable dosimeter with systematic error due to differential energy response no greater than 3% when doses of 25 Gy are used. (Author)

  20. Alanine dosimeter for practical use using polyethylene as binder

    International Nuclear Information System (INIS)

    Alanine dosimeters were manufactured using polyethylene as a binder and their characteristics were studied with the intention of developing cheap dosimeter for practical routine use having high precision in a dose range of 0.1-100 kGy. The effects of temperature and humidity during storage after irradiation on fading of the ESR response, which is proportional to radiation-induced free radicals in alanine, and the influence of ESR measurement conditions on the ESR response were investigated in detail. As the results, it was confirmed that practical dosimetry of satisfactorily high precision is possible with the manufactured dosimeters by following appropriate measurement procedures. (author)

  1. A new design of TLD dosimeter card for personnel monitoring

    International Nuclear Information System (INIS)

    The personnel monitoring service for the occupationally exposed radiation workers to the external radiation is carried out in India by using Personnel Monitoring Film and Thermo-Luminescent Dosimeter (TLD) systems. The TLD system of monitoring in India is based on three dosimeter discs of CaSO4:Dy in Teflon matrix clipped on nickel plated aluminium card. TLD system besides having other technical advantages over film has got the advantage of reusability. The contact heating system based on electrical resistance limits the useful life of the Teflon based TL dosimeters hence increasing the cost per readout. The hot gas heating system along with the sandwiching of TLD-Teflon discs in stainless steel plates gives the TL dosimeter card a very large life i.e. it can be used for more than 100 cycles of reuse thus bringing down the cost of monitoring considerably. (author)

  2. Effects of UV and microwave radiation on biological material

    International Nuclear Information System (INIS)

    For the present study, ten publications on the effect of UV radiation were analyzed. In vitro tests were carried out with one biological substance and seven different human or animal organs and biocytocultures. In vivo, three bacterial strains were irradiated and four irradiation experiments were carried out on mice. As to the effect of microwave radiation, eleven publications were analyzed. In vitro tests were carried out with one biological substance and three animal organs. In vivo, one bacterial strain was irradiated and eight irradiation experiments were carried out on different types of animals. The study's aim was to obtain a survey on biochemical changes of the organisms. Phenomenological changes were given only when the corresponding articles contained further investigation results. Behavioral changes were not taken into account. The results published by the authors of the original papers were compiled in a kind of dictionary. All relevant data are listed in a defined order. (orig.)

  3. Biological effects of low-intensity millimetric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Betskiy, O.V.; Putvinskiy, A.V.

    1986-10-01

    The authors discuss a possible role of strong absorption of millimetric (MM) waves by water molecules in the primary mechanism of the reaction of biological systems to MM irradiation. Data are given on the interaction of MM radiation with simple aqueous systems. Primary attention is given to the phenomenon of convective mixing of aqueous solutions under the effect of low-intensity MM waves (1 ... 10 mW/cm/sup 2/). 12 references, 6 figures.

  4. A view of future solid dosimeter

    International Nuclear Information System (INIS)

    It would be almost impossible to measure directly the exposure as defined. The concept of charged particle equilibrium has been introduced to estimate the exposure. At the equilibrium, the total kinetic energy of electrons coming into a region is equal to that going out of it. In such a state, therefore, an exposure equivalent to that as defined can be determined from the total number of ions existing in the region. A solid dosimeter, which can only measure a relative exposure, has to be calibrated against a ionization chamber to provide an estimated absolute exposure. A quantity called kerma has been defined for indirect ionizing radiation. This quantity may also serve well if applied to direct ionizing radiation. Detailed studies have not been made on the effect of a strong electric and/or magnetic field on a solid dosimeter. No technique is available to measure the energy spectrum of single burst-like radiation. Such technique would serve for dosimetry. EED may be applied to measure the intensity of synchrotron orbit radiation. A practical technique for transient dosimetry may also be developed in the future. New dosimeters are also expected to be developed which will be effective for a mixed neutron-X-ray field. (Nogami, K.)

  5. Radiation processing of biological tissues for nuclear disaster management

    International Nuclear Information System (INIS)

    A number of surgical procedures require tissue substitutes to repair or replace damaged or diseased tissues. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Allograft tissues provide an excellent alternative to autografts. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. However, the risk of infectious disease transmission via tissue allografts is a major concern. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Radiation processing has well appreciated technological advantages and is the most suitable method for sterilization of biological tissues. Radiation processed biological tissues can be provided by the tissue banks for the management of injuries due to a nuclear disaster. A nuclear detonation will result in a large number of casualties due to the heat, blast and radiation effects of the weapon. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone grafts can be employed for repairing fracture defects, filling in destroyed regions of bone, management of open fractures and joint injuries. Radiation processed tissues have the potential to repair or reconstruct damaged tissues and can be of great assistance in the treatment of injuries due to the nuclear weapon. (author)

  6. Advances in radiation biology: Radiosensitization in DNA and living cells

    Science.gov (United States)

    Lacombe, S.; Sech, C. Le

    2009-06-01

    One fundamental goal of radiation biology is the evolution of concepts and methods for the elaboration of new approaches and protocols for the treatment of cancers. In this context, the use of fast ions as ionizing particles offers the advantage of optimizing cell killing inside the tumor whilst preserving the surrounding healthy tissues. One extremely promising strategy investigated recently is the addition of radiosensitizers in the targeted tissue. The optimization of radiotherapy with fast ions implies a multidisciplinary approach to ionizing radiation effects on complex living systems, ranging from studies on single molecules to investigations of entire organisms. In this article we review recent studies on ion induced damages in simple and complex biological systems, from DNA to living cells. The specific aspect of radiosensitization induced by metallic atoms is described. As a fundamental result, the addition of sensitizing compounds with ion irradiation may improve therapeutic index in cancer therapy. In conclusion, new perspectives are proposed based on the experience and contribution of different communities including Surface Sciences, to improve the development of radiation biology.

  7. Radiation Biology: A Handbook for Teachers and Students

    International Nuclear Information System (INIS)

    Knowledge of the radiobiology of normal tissues and tumours is a core prerequisite for the practice of radiation oncology. As such the study of radiobiology is mandatory for gaining qualification as a radiation oncologist in most countries. Teaching is done partly by qualified radiobiologists in some countries, and this is supplemented by teaching from knowledgeable radiation oncologists. In low and middle income (LMI) countries the teachers are often radiation oncologists and/or medical physicists. In Europe, a master's course on radiobiology is taught jointly by a consortium of five European Universities. This is aimed at young scientists from both Western and Eastern Europe, training in this discipline. Recently the European Society for Therapeutic Radiology and Oncology (ESTRO) initiated the launch of a radiobiology teaching course outside Europe (Beijing, 2007; Shanghai, 2009). Radiation protection activities are governed by many regulations and recommendations. These are based on knowledge gained from epidemiological studies of health effects from low as well as from high dose radiation exposures. Organizations like the International Commission on Radiological Protection (ICRP) have put a lot of effort into reviewing and evaluating the biological basis to radiological protection practices. Personnel being trained as future radiation protection personnel should have a basic understanding of the biological and clinical basis to the exposure limitations that they are subject to and that they implement for industrial workers and the public at large. It is for these reasons that aspects of Radiobiology related to protection issues are included in this teaching syllabus. In LMI countries, many more teachers are needed in radiobiology, and the establishment of regional training centres or special regional training courses in radiobiology, are really the only options to solve the obvious deficit in knowledge of radiobiology in such countries. Radiobiology teaching

  8. Recall of Personal Dosimeters Not Presently in Use

    CERN Multimedia

    SC Unit

    2008-01-01

    The Dosimetry Service requests all persons who do not require access to radiation areas in the foreseeable future to return their personal dosimeter to the Dosimetry Service. This concerns, for example, experimental physicists whose beam time is over until 2009, or persons whose work profile has changed and therefore no longer need regular access to radiation areas. When regular access to radiation areas is needed again at a later date, a new dosimeter can be attributed if the prerequisites (medical fitness certificate, RP course) are met. This recall will allow personal dosimeters to be attributed to personnel who will soon be working in newly created radiation areas at the LHC. Thank you for your understanding and collaboration. Thomas Otto on behalf of the Dosimetry Service Radiation Protection Group

  9. Evaluation of the implementation and use of active personal dosimeters for neutrons in Brazil

    International Nuclear Information System (INIS)

    This work was conducted through of a field research based on a questionnaire sent to users of active personal dosimeters. A retrospective study of the last six years was also carried out of the services in the Neutron Metrology Laboratory (2008-2013) referent to the active personal dosimeters, taking into consideration the standards ISO-8529-3 and IEC-61526. The active personal dosimeters are defined as any instrument of individual monitoring with direct reading capacity, used by individuals exposed to ionizing radiation fields. Through research was verified that the active personal dosimeters work associated with other dosimeter types. Considering all dosimeters declared in the questionnaire, only two dosimeters (MGP brand Dmc 2000-GN model and the brand ATOMTEX model AT2503A) have conformity declaration with the international standard IEC-61526: 2005 reported by the manufacturers. (author)

  10. New Scientific Pearl about Biologic Effect of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. A. Alamdaran

    2008-01-01

    Full Text Available Soon after the discovery of X-ray by Rontgen in 1895, it became evident that radiation can cause some somatic damage to tissues. The hazards of X-ray exposure were clearly known when many large hospitals had radiology departments. The greatest increased in knowledge about X-ray risks had accrued from the dropping of the two atomic bombs in Japan in 1945 and some other atomic accident. For example, among the Japanese bomb survivors from Hiroshima and Nagasaki, there have been about 400 extra cancer deaths. These were the origin of radiology personnel and people fear from radiation exposure and resistant in against simple X-ray exam (radiophobia. However, new scientific data on the effects radiation on survivors, especially about biologic effect of ionizing rays, background radiation exposure, amount of endogenous radiation, hormosis phenomenon and comparison radiation risk with other risk over lifetime are still being continuously revised and risk estimates updated. Fundamentally, this risk is much"nlower than whatever already estimated and it is insignificant in diagnostic domain. Better perception of physician from these instances help to prevent of false radiophobia and to make proper use of diagnostic and therapeutic advantages of ionizing beam.

  11. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

  12. Biological effects of radiation and health risks from exposure to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    The very fact that ionizing radiation produces biological effects is known from many years. The first case of injury reported by Sir Roentgen was reported just after a few months after discovery of X-rays in 1895. As early as 1902, the first case of X-ray induced cancer was reported in the literature. Early human evidence of harmful effects as a result of exposure to radiation in large amounts existed in the 1920s and 1930s, based upon the experience of early radiologists, miners exposed to airborne radioactivity underground, persons working in the radium industry, and other special occupational groups. The long-term biological significance of smaller, repeated doses of radiation, however, was not widely appreciated until relatively recently, and most of our knowledge of the biological effects of radiation has been accumulated since World War II. The mechanisms that lead to adverse health effects after exposure to ionizing radiation are still not fully understood. Ionizing radiation has sufficient energy to change the structure of molecules, including DNA, within the cells of the body. Some of these molecular changes are so complex that it may be difficult for the body's repair mechanisms to mend them correctly. However, the evidence is that only a small fraction of such changes would be expected to result in cancer or other health effects. The most thoroughly studied individuals for the evaluation of health effects of ionizing radiation are the survivors of the Hiroshima and Nagasaki atomic bombings, a large population that includes all ages and both sexes.The Radiation Effects Research Foundation (RERF) in Japan has conducted followup studies on these survivors for more than 50 years. An important finding from these studies is that the occurrence of solid cancers increases in proportion to radiation dose. More than 60% of exposed survivors received a dose of radiation of less than 100 mSv (the definition of low dose used by the BEIR VII report). (author)

  13. Angular energy response of personnel thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    The angular energy dependence of the response of two commercial thermoluminescent dosimeter systems was investigated. The first personnel dosimeter investigated was the Radi-Guard which is a multi-area LiF (TLD-700) locked in Teflon matrix and incorporated with a PB-2 holder developed by Teledyne Isotopes. The second one was the BG-7 which is comprised of two LiF (TLD-700) chips developed by Harshaw, but the TH-2 holder was fabricated at National Tsing Hua University. The angle of incidence was varied from perpendicular to parallel for 90Sr-90Y β radiation, 241Am and 60Co γ radiation. Experimental results are presented and discussed

  14. IAEA activities related to radiation biology and health effects of radiation

    International Nuclear Information System (INIS)

    The IAEA is involved in capacity building with regard to the radiobiological sciences in its member states through its technical cooperation programme. Research projects/programmes are normally carried out within the framework of coordinated research projects (CRPs). Under this programme, two CRPs have been approved which are relevant to nuclear/radiation accidents: (1) stem cell therapeutics to modify radiation-induced damage to normal tissue, and (2) strengthening biological dosimetry in IAEA member states. (note)

  15. A silicon diode dosimeter with a memory

    International Nuclear Information System (INIS)

    An integrating dosimeter using a silicon diode has been developed which can be used to check the calibration of radiation therapy treatment units at remote facilities by mail. The dose reading is retained indefinitely in a battery-operated CMOS digital counter. The accuracy of the device is at least +-0.6% standard deviation, as determined by 60Co irradiations over a two month period. (orig.)

  16. Radiation damage and repair in cells and cell components. Part 2. Physical radiations and biological significance. Final report

    International Nuclear Information System (INIS)

    The report comprises a teaching text, encompassing all physical radiations likely to be of biological interest, and the relevant biological effects and their significance. Topics include human radiobiology, delayed effects, radiation absorption in organisms, aqueous radiation chemistry, cell radiobiology, mutagenesis, and photobiology

  17. Investigating On Colour Stability Conditions Of Postirradiation Radiochromic Film Dosimeter

    International Nuclear Information System (INIS)

    B3 dosimeter is a thin film with average thickness of 0.0194 mm, which is supplied by the Gex company, the United States. This dosimeter was influenced by many factors: light, temperature, humidity during and after irradiation process. In fact, B3 film dosimeters will be stable under certain conditions such as tightly sealed packs, controlled irradiation and stored temperature after irradiated. Therefore, investigation of the stability effect of postirradiated B3 film dosimeters on the heating temperature, heating time and storing time is carried out before the absorbed dose is read and followed standard reading procedures. When exposed to ionizing radiation, the dosimeters change from colorless to colour. The absorbed doses are read on a Genesys 20 spectrophotometer at a wavelength of 544 nm. Absorbed dose range is investigated from 0.55 to 80 kGy. Experimental results were indicated that colour stability of the postirradiated dosimeters at a temperature of 65 ± 3 oC for 30 minutes and keeping them in desiccator for 5 minutes before read out. Under these conditions, colour stability of B3 film dosimeter has maintained for 3 months. (author)

  18. [Thermoluminescence Slab Dosimeter].

    Science.gov (United States)

    Shinsho, Kiyomitsu; Koba, Yusuke; Tamatsu, Satoshi; Sakurai, Noboru; Wakabayashi, Genichiro; Fukuda, Kazusige

    2013-01-01

    In 1953 F. Daniels et al. used the property of thermoluminescence in dosimetry for the first time. Since then, numerous TLD have been developed. 2D TLD was investigated for the first time in 1972 by P Broadhead. However, due to excessive fading, difficulties with handling and the time required for measurements, development stalled. At the current time, the majority of TLD are used in small scale, localized dosimetry with a wide dynamic range and personal dosimeters for exposure management. Urushiyama et. al. have taken advantage of the commoditization of CCD cameras in recent years--making large area, high resolution imaging easier--to introduce and develop a 2D TLD. It is expected that these developments will give rise to a new generation of applications for 2D TL dosimetry. This paper introduces the "TL Slab Dosimeter" developed jointly by Urushiyama et. al. and our team, its measurement system and several typical usage scenarios. PMID:24893451

  19. Complex systems of biological interest stability under ionising radiations

    International Nuclear Information System (INIS)

    This PhD work presents the study of stability of molecular systems of biological interest in the gas phase after interaction with ionising radiations. The use of ionising radiation can probe the physical chemistry of complex systems at the molecular scale and thus consider their intrinsic properties. Beyond the fundamental aspect, this work is part of the overall understanding of radiation effects on living organisms and in particular the use of ionizing radiation in radiotherapy. Specifically, this study focused on the use of low-energy multiply charged ions (tens of keV) provided by the GANIL (Caen), which includes most of the experiments presented. In addition, experiments using VUV photons were also conducted at synchrotron ELETTRA (Trieste, Italy). The bio-molecular systems studied are amino acids and nucleic acid constituents. Using an experimental crossed beams device allows interaction between biomolecules and ionising radiation leads mainly to the ionization and fragmentation of the system. The study of its relaxation dynamics is by time-of-flight mass spectrometry coupled to a coincidences measurements method. It is shown that an approach combining experiment and theory allows a detailed study of the fragmentation dynamics of complex systems. The results indicate that fragmentation is generally governed by the Coulomb repulsion but the intramolecular rearrangements involve specific relaxation mechanisms. (author)

  20. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1992--November 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ``biological fingerprint`` of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  1. New Neutron Dosimeter

    CERN Multimedia

    2001-01-01

    CERN has been operating an Individual Dosimetry Service for neutrons for about 35 years. The service was based on nuclear emulsions in the form of film packages which were developed and scanned in the Service. In 1999, the supplier of theses packages informed CERN that they will discontinue production of this material. TIS-RP decided to look for an external service provider for individual neutron dosimetry. After an extensive market survey and an invitation for tender, a supplier that met the stringent technical requirements set up by CERN's host states for personal dosimeters was identified. The new dosimeter is based on a track-etching technique. Neutrons have the capability of damaging plastic material. The microscopic damage centres are revealed by etching them in a strong acid. The resulting etch pits can be automatically counted and their density is proportional to dose equivalent from neutrons. On the technical side, the new dosimeter provides an improved independence of its response from energy and th...

  2. Type testing of the SDM2000 personal dosimeter

    CERN Document Server

    LiuZhengShan; Deng Chang Ming; Guo Zhan Jie; Zhang Zhi Yong

    2001-01-01

    The results of the performance of a new type of personal dosimeter, the SDM2000 Personal Dosimeter made by China Institute for Radiation Protection is presented. Tests were performed on radiological performance including radiation energy, incidence angular, beta radiation, neutron radiation, accuracy of alarm levels, relative intrinsic error, overload, response time, linearity, retention of reading. There are also tests on the effects of a variety of environmental factors, such as temperature, humidity, external magnetic fields, electrostatic discharge, external electromagnetic fields. Other characteristics tested were dropping test, vibration test and battery life. The test results were compared with the relevant requirements of three standards: CIRP standard: Q/DSC1-92, National standard: GB/T 13161-91, IEC standard: IEC1283. In general, the performance of the SDM2000 personal dosimeter was found to be quite acceptable; it meets most of the relevant requirements of the three standards

  3. Type testing of the SDM2000 personal dosimeter

    International Nuclear Information System (INIS)

    The results of the performance of a new type of personal dosimeter, the SDM2000 Personal Dosimeter made by China Institute for Radiation Protection is presented. Tests were performed on radiological performance including radiation energy, incidence angular, beta radiation, neutron radiation, accuracy of alarm levels, relative intrinsic error, overload, response time, linearity, retention of reading. There are also tests on the effects of a variety of environmental factors, such as temperature, humidity, external magnetic fields, electrostatic discharge, external electromagnetic fields. Other characteristics tested were dropping test, vibration test and battery life. The test results were compared with the relevant requirements of three standards: CIRP standard: Q/DSC1-92, National standard: GB/T 13161-91, IEC standard: IEC1283. In general, the performance of the SDM2000 personal dosimeter was found to be quite acceptable; it meets most of the relevant requirements of the three standards

  4. Biological effects of low level exposures to chemicals and radiation

    International Nuclear Information System (INIS)

    In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the immune response' was presented as well as 'Cellular adaptation as an important response during chemical carcinogenesis'. The final presentation was devoted to biostatistical considerations when designing studies that address issues associated with the biological responses to low doses of chemicals and radiation, as well as issues in interpretation of the findings from such studies

  5. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Science.gov (United States)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  6. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    International Nuclear Information System (INIS)

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders

  7. Biological dosimetry of ionizing radiation in the high dose range

    International Nuclear Information System (INIS)

    The report reviews briefly methods of dose evaluation after exposure to high doses of ionizing radiation. Validation of two methods also is described: micronucleus (Mn) frequency estimation according Muller and Rode and premature chromosome condensation (PCC) combined with painting of 3 pairs of chromosomes in human lymphocytes. According to Muller and Rode, micronucleus frequency per binucleated cells with at least one Mn linearly increases with dose up to 15 Gy and is suitable end-point for biological dosimetry. These authors, however, examined cells from only one donor. The data reported below were obtained for 5 donors; they point to a considerable individual variation of thus measured response to irradiation. Due to the high degree of inter-donor variability, there is no possibility to apply this approach in biological dosimetry in the dose range 5 - 20 Gy gamma 60Co radiation. A linear response up to 10 Gy was observed only in the case of certain donors. In contrast, determination of the dose-effect relationship with the PCC method gave good results (small inter-individual variation, no plateau effect up to dose 10 Gy), so that with a calibration curve it could be used for dose estimation after exposure to doses up to 10 Gy of X or gamma 60Co radiation. (author)

  8. Advances in microbeam technologies and applications to radiation biology.

    Science.gov (United States)

    Barberet, P; Seznec, H

    2015-09-01

    Charged-particle microbeams (CPMs) allow the targeting of sub-cellular compartments with a counted number of energetic ions. While initially developed in the late 1990s to overcome the statistical fluctuation on the number of traversals per cell inevitably associated with broad beam irradiations, CPMs have generated a growing interest and are now used in a wide range of radiation biology studies. Besides the study of the low-dose cellular response that has prevailed in the applications of these facilities for many years, several new topics have appeared recently. By combining their ability to generate highly clustered damages in a micrometric volume with immunostaining or live-cell GFP labelling, a huge potential for monitoring radiation-induced DNA damage and repair has been introduced. This type of studies has pushed end-stations towards advanced fluorescence microscopy techniques, and several microbeam lines are currently equipped with the state-of-the-art time-lapse fluorescence imaging microscopes. In addition, CPMs are nowadays also used to irradiate multicellular models in a highly controlled way. This review presents the latest developments and applications of charged-particle microbeams to radiation biology. PMID:25911406

  9. Radiation physics, biophysics, and radiation biology: Progress report, December 1, 1987-November 30, 1988

    International Nuclear Information System (INIS)

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiation therapy. At the current level of funding, approximately one quarter of the research of the Laboratory could be regarded as in support of radiotherapy, with the remainder addressing more basic issues. The new initiatives have been in two directions. First, there has been an increased emphasis on research in radiation chemistry, inasmuch as this subject which involves the study of free radicals and fast radiation chemistry processes starts to bridge the gap between physics and biology, between the initial deposition of radiant energy and its final expression in terms of biological consequences. Second, the emphasis in the biological research has moved towards studies at the molecular level, with the appointment of new members of staff with expertise in this area. Individual chapters were processed separately for the data base

  10. The high dose response and functional capability of the DT-702/Pd lithium fluoride thermoluminescent dosimeter.

    Science.gov (United States)

    Lawlor, Tyler M; Talmadge, Molly D; Murray, Mark M; Nelson, Martin E; Mueller, Andrew C; Romanyukha, Alexander A; Fairchild, Gregory R; Grypp, Matthew D; Williams, Anthony S

    2015-05-01

    The United States Navy monitors the dose its radiation workers receive using the DT-702/PD thermoluminescent dosimeter, which consists of the Harshaw 8840 holder and the four-element Harshaw 8841 card. There were two main objectives of this research. In the first objective, the dosimeters were exposed to 100 Gy using electron and x-ray beams and found to respond approximately 30-40% lower than the delivered dose. No significant effect on the under-response was found when dose rate, radiation type, dosimeter position on the phantom, and dosimeter material were varied or when the card was irradiated while enclosed in its holder. Since the current naval policy is to remove from occupational use any thermoluminescent dosimeter with an accumulated deep dose equivalent of 0.05 Sv or greater, the functionality of the dosimeter was also investigated at deep dose equivalents of 0.05, 0.15, and 0.25 Sv using 60Co and 137Cs sources as the second main objective. All dosimeters were annealed following exposure and then exposed to 5.0 mSv from a 90Sr source. In all cases, the dosimeters responded within 3% of the delivered dose, indicating that the dosimeters remained functional as defined by naval dosimetry requirements. However, the anneal time required to clear the thermoluminescent dosimeter's reading was found to increase approximately as the cube root with the delivered dose. PMID:25811149

  11. Radiochromic blue tetrazolium film dosimeter

    International Nuclear Information System (INIS)

    The colourless radiochromic chloride salt of blue tetrazolium (BT2+) is reduced radiolytically to the deep violet-coloured formazan. Dosimeter films of this radiation sensor can be produced by dissolving polyvinyl alcohol (PVA) in a heated aqueous solution of the salt, and, upon cooling, by casting the solution on a horizontal glass plate. In the present development, the resulting flexible transparent film is readily stripped from the plate, with a thickness of 0.045 mm. Upon irradiation with gamma rays or electron beams, a permanent image is produced with a broad absorption band in the visible spectrum. The radiation response is approximately a linear function in terms of the increase in optical absorbance (ΔA) measured at λmax 552 nm wavelength versus absorbed dose (D) over the range 5 to 50 kGy. The radiochromic image has a relatively high spatial resolution and can be used to register dose distributions and beam profiles. The value of ΔA shows a gradual increase for the first 24 hours after irradiation but is stable thereafter. The variation of response with irradiation temperature is negligible over the temperature range -20 deg. C to +30 deg. C, but displays a pronounced positive temperature dependence at higher temperatures. The response to gamma radiation shows negligible dose-rate dependence as long as the radiochromic sensor concentration in the PVA matrix is sufficiently high (> 6 % by weight). (author)

  12. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1991--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.

    1992-05-01

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  13. The application of Sunna dosimeter film for process control at industrial gamma- and electron beam irradiation facilities

    Science.gov (United States)

    Kovács, A.; Baranyai, M.; Fuochi, P. G.; Lavalle, M.; Corda, U.; Miller, S.; Murphy, M.; O'Doherty, J.

    2004-09-01

    The Sunna dosimeter was introduced for dose determination in the dose range of 50-300 kGy by measuring optically stimulated luminescence. The usefulness of the dosimeter film has already been shown in food irradiation for routine process control. The aim of the present study was to check the performance of the Sunna dosimeter film for process control in radiation sterilization under industrial processing conditions, i.e. at high activity gamma irradiators and at high energy electron beam facilities. To ensure similar irradiation conditions during calibration and routine irradiation "in-plant calibration" was performed by irradiating the Sunna dosimeters together with ethanol-monochlorobenzene transfer standard and alanine reference standard dosimeters. The Sunna dosimeters were then irradiated together with the routine dosimeter of the actual plant during regular production runs and the absorbed doses measured by the different dosimeters agreed within ±2%(1 σ).

  14. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  15. Calibration and performance testing of electronic personal dosimeters (EPD)

    International Nuclear Information System (INIS)

    In modern radiation protection practices, active personal dosimeters are becoming absolutely necessary operational tools for satisfying the ALARA principle. The aim of this work was to carry out calibration and performance testing of ten electronic personal dosimeters (EPD) used for the individual monitoring. The EPDs were calibrated in terms of operation radiation protection quantity, personal dose equivalent, Hp (10). Calibrations were carried out at three of x-ray beam qualities described in ISO 4037 namely 60, 100 and 150 kV in addition to Cs-137 gamma ray quality. The calibrations were performed using polymethylmethacrylate (PMMA) phantom with dimensions 20*20*15 cm3. Conversion coefficient Hp (10)/K air for the phantom was also calculated. The response and linearity of the dosimeter at the specified energies were also tested. The EPDs tested showed that the calibration coefficient ranged from 0.60 to 1.31 and an equivalent response for the specified energies that ranged from 0.76 to 1.67. The study demonstrated the possibility of using non standard phantom for calibrating dosimeters used for individual monitoring. The dosimeters under study showed a good response in all energies except the response in quality 100 kV. The linearity of the dosimeters was within ±15%, with the exception of the quality 100 kV where this limit was exceeded.(Author)

  16. Mayak Film Dosimeter Response Studies, Part I: Measurements

    International Nuclear Information System (INIS)

    The Mayak Worker Dosimetry study is a joint Russian/US project to evaluate doses received by workers at the Mayak Production Association facilities from 1948-1972. A key investigation in this project is the characterization of responses of the three types of film dosimeters used to monitor workers during this time period. Experimental irradiations of the dosimeters were performed in the radiation calibration laboratories at the National Research Center for Environment and Health (GSF) in Munich, Germany. The irradiations used photon sources from X-ray beams with ten different energy distributions and with 60Co and 137Cs isotopic gamma sources. Irradiations were performed with the dosimeters on phantoms and free-in-air. The dosimeters and phantoms were also positioned at varying angles to the radiation beam. The result of the experiments was a thorough characterization of the dosimeter response as a function of photon energy and as a function of angle for energy and angular ranges that cover the conditions encountered in the Mayak workplaces. The characterization data were then available for use in developing correction factors which could be applied to worker dosimeter readings to provide a more accurate assessment of worker dose and estimates of doses to organs

  17. Alternative statistical methods for cytogenetic radiation biological dosimetry

    CERN Document Server

    Fornalski, Krzysztof Wojciech

    2014-01-01

    The paper presents alternative statistical methods for biological dosimetry, such as the Bayesian and Monte Carlo method. The classical Gaussian and robust Bayesian fit algorithms for the linear, linear-quadratic as well as saturated and critical calibration curves are described. The Bayesian model selection algorithm for those curves is also presented. In addition, five methods of dose estimation for a mixed neutron and gamma irradiation field were described: two classical methods, two Bayesian methods and one Monte Carlo method. Bayesian methods were also enhanced and generalized for situations with many types of mixed radiation. All algorithms were presented in easy-to-use form, which can be applied to any computational programming language. The presented algorithm is universal, although it was originally dedicated to cytogenetic biological dosimetry of victims of a nuclear reactor accident.

  18. Biological dosimetry of ionizing radiation by chromosomal aberration analysis

    International Nuclear Information System (INIS)

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical, and cytogenetic data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable. In this case, the study ol chromosomal aberrations, normally dicentric chromosomes, in peripheral lymphocytes can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using dicentric chromosomes analysis, X-rays at 300 kVp, 114 rad/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y =α + β1D + β2D 2 , where Y is the number of dicentrics per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 14 refs

  19. Biological rhythms for rehabilitation of radiation damage of population

    International Nuclear Information System (INIS)

    Considerable disturbances in biological eurhythmycal structure of redoracu were discovered for people living in Borodulikha area of the Semipalatinsk test site. The deep desynchronise may result in a development of the cardiovascular, bronco-pulmonary, endocrine, oncologic, neuro psychic diseases. A method to correct the biological eurhythmycal structure was developed. Homeopathic doses of melatonin ('rhythm driver' managing the most regenerating and immune systems) and uthynol (promoting production of dehydroepiandrosterone of maternal prehormone of 27 hormones) were used to provide the general correction. The endocrine diseases are not practically subjected to the homeopathic correction. The sub correction was sometimes carried out after 5 months. The developed methods of rehabilitation of the radiation damages are unique, since they allow performing the homeopathic correction using the acupuncture monitoring

  20. Cerenkov Radiation: A Multi-functional Approach for Biological Sciences

    Directory of Open Access Journals (Sweden)

    Xiaowei eMa

    2014-02-01

    Full Text Available Cerenkov radiation (CR has been used in various biological research fields, which has aroused lots of attention in recent years. Combining optical imaging instruments and most of nuclear medicine imaging or radiotherapy probes, the CR was developed as a new imaging modality for biology studies, called Cerenkov luminescence imaging (CLI. On the other hand, it was novelly used as an internal excitation source to activate some fluorophores for energy transfer imaging. However, it also has some shortages such as relatively weak luminescence intensity and low penetration in tissue. Thus some scientific groups demonstrated to optimize the CLI and demonstrated it to three-dimension tomography. In this article, we elaborate on its principle, history, and applications and discuss a number of directions for technical improvements. Then concluded some advantages and shortages of CR and discuss some prospects of it.

  1. Biological efficiency of interaction between various radiation and chemicals

    International Nuclear Information System (INIS)

    This research project has been carried out jointly with INP (Poland) to develop technologies to assess the biological efficiency of interaction between radiation and chemicals. Through the cooperative project, KAERI and INP have established wide variety of bioassay techniques applicable to radiation bioscience, human monitoring, molecular epidemiology and environmental science. The joint experiment, in special, made it possible to utilize the merits of both institutes and to upgrade and verify KAERI's current technology level. All results of the cooperative research will be jointly published in high standard scientific journals listed in the Science Citation Index (SCI), which can make the role of fundamental basis for improving relationship between Korea and Poland. Research skills such as Trad-MCN assay, SCGE assay, immunohistochemical assay and molecular assay developed through joint research will be further elaborated and will be continuously used for the collaboration between two institutes

  2. Radiation exposure and the woman worker: biological and legal parameters

    International Nuclear Information System (INIS)

    The interpretation of federal and state legislation and regulations concerning the radiation protection of women in the workplace has not been a clear and straightforward procedure. On one hand, the safety of all workers, independent of sex, imposes a specific directive for the enforcement of working standards in general. On the other hand, must allowance be made in setting radiation standards for the particular biological characteristics of workers, some of whom are women. Title VII of the Civil Rights Act provides equal employment opportunity for women and is now being enforced. All legal questions aside, men and women are decidedly different in one aspect; only women can conceive and carry a fetus and studies have shown that, in humans, the most radiosensitive stage of the fetus is during the first trimester of pregnancy. Possible legal and socio-economic aspects of questions posed by the employment of women by the nuclear industry are considered

  3. Inner-shell ionization and biological radiations effects

    International Nuclear Information System (INIS)

    Biological effects of K-ionizations followed by Auger cascades have been much studied to elucidate mechanisms of cell inactivation and DNA repair and to develop therapeutic applications. Experiments performed with incorporated radionuclides (125I) or incorporated elements (Br, I, P) photoionized in the K-shell using synchrotron radiation all displayed a K + Auger enhancement. The interest in K-ionization rose again when recent works suggested that K-ionizations in C, N, 0 atoms of DNA could be the primary physical events responsible for cell death induced by heavy ions. Photoabsorption experiments at the C-K threshold support this hypothesis. (authors)

  4. Stochastic Effects in Computational Biology of Space Radiation Cancer Risk

    Science.gov (United States)

    Cucinotta, Francis A.; Pluth, Janis; Harper, Jane; O'Neill, Peter

    2007-01-01

    Estimating risk from space radiation poses important questions on the radiobiology of protons and heavy ions. We are considering systems biology models to study radiation induced repair foci (RIRF) at low doses, in which less than one-track on average transverses the cell, and the subsequent DNA damage processing and signal transduction events. Computational approaches for describing protein regulatory networks coupled to DNA and oxidative damage sites include systems of differential equations, stochastic equations, and Monte-Carlo simulations. We review recent developments in the mathematical description of protein regulatory networks and possible approaches to radiation effects simulation. These include robustness, which states that regulatory networks maintain their functions against external and internal perturbations due to compensating properties of redundancy and molecular feedback controls, and modularity, which leads to general theorems for considering molecules that interact through a regulatory mechanism without exchange of matter leading to a block diagonal reduction of the connecting pathways. Identifying rate-limiting steps, robustness, and modularity in pathways perturbed by radiation damage are shown to be valid techniques for reducing large molecular systems to realistic computer simulations. Other techniques studied are the use of steady-state analysis, and the introduction of composite molecules or rate-constants to represent small collections of reactants. Applications of these techniques to describe spatial and temporal distributions of RIRF and cell populations following low dose irradiation are described.

  5. American Society for Radiation Oncology (ASTRO) Survey of Radiation Biology Educators in U.S. and Canadian Radiation Oncology Residency Programs

    International Nuclear Information System (INIS)

    Purpose: To obtain, in a survey-based study, detailed information on the faculty currently responsible for teaching radiation biology courses to radiation oncology residents in the United States and Canada. Methods and Materials: In March-December 2007 a survey questionnaire was sent to faculty having primary responsibility for teaching radiation biology to residents in 93 radiation oncology residency programs in the United States and Canada. Results: The responses to this survey document the aging of the faculty who have primary responsibility for teaching radiation biology to radiation oncology residents. The survey found a dramatic decline with time in the percentage of educators whose graduate training was in radiation biology. A significant number of the educators responsible for teaching radiation biology were not fully acquainted with the radiation sciences, either through training or practical application. In addition, many were unfamiliar with some of the organizations setting policies and requirements for resident education. Freely available tools, such as the American Society for Radiation Oncology (ASTRO) Radiation and Cancer Biology Practice Examination and Study Guides, were widely used by residents and educators. Consolidation of resident courses or use of a national radiation biology review course was viewed as unlikely by most programs. Conclusions: A high priority should be given to the development of comprehensive teaching tools to assist those individuals who have responsibility for teaching radiation biology courses but who do not have an extensive background in critical areas of radiobiology related to radiation oncology. These findings also suggest a need for new graduate programs in radiobiology.

  6. Effects of temperature and humidity during irradiation on the response of a film dosimeter

    International Nuclear Information System (INIS)

    A commercially available leuco dye containing polyvinyl butyral based film (FWT-63-02) has been investigated spectrometrically for its dosimetric characteristic and for its use as routine dosimeter in radiation processing for the absorbed dose range 0.1 to 10 kGy. The present study was carried out to evaluate the performance of dosimeter under different environmental conditions (i.e. effects of temperature and relative humidity during irradiation). The response was measured at peak wavelength of 600 nm as well as at a number of other wavelengths (550, 625, 640 and 650 nm). The dosimeter was found to show quite stable response up to a radiation chamber temperature of 40oC. The dosimeter also showed stable behaviour at low or moderate relative humidity conditions (< 76%) in the radiation chamber. The characteristics of the dosimeter are suitable for its possible application in radiation processing, food irradiation and sterilization applications. (author)

  7. Towards Space Exploration of Moon, Mars Neos: Radiation Biological Basis

    Science.gov (United States)

    Hellweg, Christine; Baumstark-Khan, Christa; Berger, Thomas; Reitz, Guenther

    2016-07-01

    Radiation has emerged as the most critical issue to be resolved for long-term missions both orbital and interplanetary. Astronauts are constantly exposed to galactic cosmic radiation (GCR) of various energies with a low dose rate. Primarily late tissue sequels like genetic alterations, cancer and non-cancer effects, i.e. cataracts and degenerative diseases of e.g. the central nervous system or the cardiovascular system, are the potential risks. Cataracts were observed to occur earlier and more often in astronauts exposed to higher proportions of galactic ions (Cucinotta et al., 2001). Predictions of cancer risk and acceptable radiation exposure in space are subject to many uncertainties including the relative biological effectiveness (RBE) of space radiation especially heavy ions, dose-rate effects and possible interaction with microgravity and other spaceflight environmental factors. The initial cellular response to radiation exposure paves the way to late sequelae and starts with damage to the DNA which complexity depends on the linear energy transfer (LET) of the radiation. Repair of such complex DNA damage is more challenging and requires more time than the repair of simple DNA double strand breaks (DSB) which can be visualized by immunofluorescence staining of the phosphorylated histone 2AX (γH2AX) and might explain the observed prolonged cell cycle arrests induced by high-LET in comparison to low-LET irradiation. Unrepaired or mis-repaired DNA DSB are proposed to be responsible for cell death, mutations, chromosomal aberrations and oncogenic cell transformation. Cell killing and mutation induction are most efficient in an LET range of 90-200 keV/µm. Also the activation of transcription factors such as Nuclear Factor κB (NF-κB) and gene expression shaping the cellular radiation response depend on the LET with a peak RBE between 90 and 300 keV/µm. Such LET-RBE relationships were observed for cataract and cancer induction by heavy ions in laboratory animals

  8. WE-E-BRE-03: Biological Validation of a Novel High-Throughput Irradiator for Predictive Radiation Sensitivity Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, TL; Martin, JA; Shepard, AJ; Bailey, AM; Nickel, KP; Kimple, RJ; Bednarz, BP [University of Wisconsin, Madison, WI (United States)

    2014-06-15

    Purpose: The large dose-response variation in both tumor and normal cells between individual patients has led to the recent implementation of predictive bioassays of patient-specific radiation sensitivity in order to personalize radiation therapy. This exciting new clinical paradigm has led us to develop a novel high-throughput, variable dose-rate irradiator to accompany these efforts. Here we present the biological validation of this irradiator through the use of human cells as a relative dosimeter assessed by two metrics, DNA double-strand break repair pathway modulation and intercellular reactive oxygen species production. Methods: Immortalized human tonsilar epithelial cells were cultured in 96-well micro titer plates and irradiated in groups of eight wells to absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy. High-throughput immunofluorescent microscopy was used to detect γH2AX, a DNA double-strand break repair mechanism recruiter. The same analysis was performed with the cells stained with CM-H2DCFDA that produces a fluorescent adduct when exposed to reactive oxygen species during the irradiation cycle. Results: Irradiations of the immortalized human tonsilar epithelial cells at absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy produced excellent linearity in γH2AX and CM-H2DCFDA with R2 values of 0.9939 and 0.9595 respectively. Single cell gel electrophoresis experimentation for the detection of physical DNA double-strand breaks in ongoing. Conclusions: This work indicates significant potential for our high-throughput variable dose rate irradiator for patient-specific predictive radiation sensitivity bioassays. This irradiator provides a powerful tool by increasing the efficiency and number of assay techniques available to help personalize radiation therapy.

  9. Hanford personnel dosimeter supporting studies FY-1981

    International Nuclear Information System (INIS)

    This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies

  10. Real-time optical fiber dosimeter probe

    Science.gov (United States)

    Croteau, André; Caron, Serge; Rink, Alexandra; Jaffray, David; Mermut, Ozzy

    2011-03-01

    There is a pressing need for a passive optical fiber dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiation therapy patients. An optical fiber probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on a dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5 Gy were performed. Net optical densities increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20 μm, respectively.

  11. Wallac automatic alarm dosimeter type RAD21

    International Nuclear Information System (INIS)

    The Automatic Alarm Dosimeter type RAD 21 is a batterypowered personal dosemeter and exposure rate alarm monitor, designed to be worn on the body, covering an exposure range from 0.1 to 999.9 mR and has an audible alarm which can be pre-set over the range 1 mR h-1 to 250 mR h-1. The instrument is designed to measure x- and γ radiation over the energy range 50 keV to 3 MeV. The facilities and controls, the radiation, electrical, environmental and mechanical characteristics, and the manual, have been evaluated. (U.K.)

  12. Physical and biological characterization of a seawater ultraviolet radiation sterilizer

    International Nuclear Information System (INIS)

    The physical and biological characterization of a seawater ultraviolet (UV) sterilizer is described. The physical characterization was performed using radiochromic dye films by evaluating the uniformity of the radiant exposure along each lamp, the effect of the radiation from one lamp on the array of adjacent lamps, and by measuring the UV radiation absorption of seawater with respect to distilled water. The biological characterization was performed by measuring the amount of reduction of bacteria in stored seawater after different filtration and UV treatments. Among the filtration methods tested, differential filtration (5, 3 and 0.45 μm filters connected in series) caused the highest bacterial reduction factor of 60%. UV radiant exposures of 212, 424, 636 and 848 J m-2 yielded bacteria reduction factors of 99.86, 99.969, 99.997 and 100%, respectively, for populations of Vibrio and Pseudomonas bacteria present in stored seawater. It is concluded that the system is useful for water disinfection when 1, 2 or 3 lamps are on; when 4 lamps are used the treated water becomes sterile. (author)

  13. Radiation degradation of carbohydrates and their biological activities for plants

    Energy Technology Data Exchange (ETDEWEB)

    Kume, T.; Nagasawa, N.; Matsuhashi, S. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment] [and others

    2000-03-01

    Radiation effects on carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to improve the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities such as anti-bacterial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Pectic fragments obtained from degraded pectin induced the phytoalexins such as glyceollins in soybean and pisatin in pea. The irradiated chitosan shows the higher elicitor activity for pisatin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. Kappa and iota carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa irradiated at 100 kGy. Some radiation degraded carbohydrates suppressed the damage of heavy metals on plants. The effects of irradiated carbohydrates on transportation of heavy metals have been investigated by PETIS (Positron Emitting Tracer Imaging System) and autoradiography using {sup 48}V and {sup 62}Zn. (author)

  14. Radiation degradation of carbohydrates and their biological activities for plants

    International Nuclear Information System (INIS)

    Radiation effects on carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to improve the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities such as anti-bacterial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Pectic fragments obtained from degraded pectin induced the phytoalexins such as glyceollins in soybean and pisatin in pea. The irradiated chitosan shows the higher elicitor activity for pisatin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. Kappa and iota carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa irradiated at 100 kGy. Some radiation degraded carbohydrates suppressed the damage of heavy metals on plants. The effects of irradiated carbohydrates on transportation of heavy metals have been investigated by PETIS (Positron Emitting Tracer Imaging System) and autoradiography using 48V and 62Zn. (author)

  15. Development of the exposure and access control dosimeter system for nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Si Young; Lee, B. J.; Kim, B. H.; Kim, J. S.; Lee, K. C.; Kang, B. H.; Kim, C. K.; Ham, C. S.; Kwon, K. C.; Park, W. M.; Kim, C. H.; Kim, J. T.; Koo, C. H.; Park, S. J.; Kim, T. W

    1999-12-01

    In this paper an electronic personal dosimeter(EPD) adopt in a PIN type silicon semiconductor as a radiation detector has been developed, designed and a prototype dosimeter has been manufactured. A series of performance test of this EPD on reference radiation field has been carried out. A dosimeter reader which reads the radiation dose from EPD and make a real time access control in connection with the entrance door to radiation controlled area has been developed, designed and manufactured. S/W program supporting hangul (Korean language) has been developed to operate the EPD and reader system with a personal computer. (author)

  16. Development of the exposure and access control dosimeter system for nuclear facilities

    International Nuclear Information System (INIS)

    In this paper an electronic personal dosimeter(EPD) adopt in a PIN type silicon semiconductor as a radiation detector has been developed, designed and a prototype dosimeter has been manufactured. A series of performance test of this EPD on reference radiation field has been carried out. A dosimeter reader which reads the radiation dose from EPD and make a real time access control in connection with the entrance door to radiation controlled area has been developed, designed and manufactured. S/W program supporting hangul (Korean language) has been developed to operate the EPD and reader system with a personal computer. (author)

  17. Continuing training program in radiation protection in biological research centers

    International Nuclear Information System (INIS)

    The use of ionizing radiation in biological research has many specific characteristics. A great variety of radioisotopic techniques involve unsealed radioactive sources, and their use not only carries a risk of irradiation, but also a significant risk of contamination. Moreover, a high proportion of researchers are in training and the labor mobility rate is therefore high. Furthermore, most newly incorporated personnel have little or no previous training in radiological protection, since most academic qualifications do not include training in this discipline. In a biological research center, in addition to personnel whose work is directly associated with the radioactive facility (scientific-technical personnel, operators, supervisors), there are also groups of support personnel - maintenance and instrumentation workers, cleaners, administrative personnel, etc. - who are associated with the radioactive facility indirectly. These workers are affected by the work in the radioactive facility to varying degrees, and they therefore also require information and training in radiological protection tailored to their level of interaction with the installation. The aim of this study was to design a specific training program in radiation protection to meet the different needs of all workers in a biological research center. This program aims to ensure compliance with the relevant national legislation and to minimize the possibility of radiological incidents and accidents in this kind of center. This study has involved contributions from six nationally and internationally recognized Spanish biological research centers that have active training programs in radiation protection, and the design of the program presented here has been informed by the teaching experience of the training staff involved. The training method is based on introductory and refresher courses for personnel in direct contact with the radioactive facility and also for indirectly associated personnel. The

  18. A Novel Biological Dosimetry Method for Monitoring Occupational Radiation Exposure in Diagnostic and Therapeutic Wards: From Radiation Dosimetry to Biological Effects

    OpenAIRE

    Heydarheydari, S.; Haghparast, A.; Eivazi, M.T.

    2016-01-01

    Background and Objective Professional radiation workers are occupationally exposed to long-term low levels of ionizing radiation. Occupational health hazards from radiation exposure, in a large occupational segment of the population, are of special concern. Biological dosimetry can be performed in addition to physical dosimetry with the aim of individual dose assessment and biological effects. Methods In this biodosimetry study, some hematological parameters have been examined in 40 exposed a...

  19. Vanguards of paradigm shift in radiation biology. Radiation-induced adaptive and bystander responses

    International Nuclear Information System (INIS)

    The risks of exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to high dose radiation, using a linear no-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. In other words, there are accumulated findings which cannot be explained by the classical ''target theory'' of radiation biology. The radioadaptive response, radiation-induced bystander effects, low-dose radio-hypersensitivity, and genomic instability are specifically observed in response to low dose/low dose-rate radiation, and the mechanisms underlying these responses often involve biochemical/molecular signals that respond to targeted and non-targeted events. Recently, correlations between the radioadaptive and bystander responses have been increasingly reported. The present review focuses on the latter two phenomena by summarizing observations supporting their existence, and discussing the linkage between them from the aspect of production of reactive oxygen and nitrogen species. (author)

  20. Health and biological effects of non-ionizing radiations

    International Nuclear Information System (INIS)

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 μT magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  1. Potential of biological images for radiation therapy of cancer

    International Nuclear Information System (INIS)

    Full text: Recent technical advances in 3D conformal and intensity modulated radiotherapy (3DCRT and IMRT) based, on patient-specific CT and MRI images, have the potential of delivering exquisitely conformal dose distributions to the target volume while avoiding critical structures. Emerging clinical results in terms of reducing treatment-related morbidity and increasing local control appear promising. Recent developments in imaging have suggested that biological images may further positively impact cancer diagnosis, characterization and therapy. While in the past radiological images are largely anatomical, the new types of images can provide metabolic, biochemical, physiological, functional and molecular (genotypic and phenotypic) information. For radiation therapy, images that give information about factors (e.g. tumor hypoxia, Tpot) that influence radiosensitivity and treatment outcome can be regarded as radiobiological images. The ability of IMRT to 'paint' (in 2D) or 'sculpt' (in 3D) the dose, and produce exquisitely conformal dose distributions begs the '64 million dollar question' as to how to paint or sculpt, and whether biological imaging may provide the pertinent information. Can this new approach provide 'radiobiological phenotypes' non-invasively, and incrementally improve upon the predictive assays of radiobiological characteristics such as proliferative activity (Tpot - the potential doubling time), radiosensitivity (SF2 - the surviving fraction at a dose of 2 Gy), energy status (relative to sublethal damage repair), pH (a possible surrogate of hypoxia), tumor hypoxia, etc. as prognosticator(s) of radiation treatment outcome. Important for IMRT, the spatial (geometrical) distribution of the radiobiological phenotypes provide the basis for dose distribution design to conform to both the physical (geometrical) and the biological attributes. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  2. Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

    Energy Technology Data Exchange (ETDEWEB)

    Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

    1987-01-01

    This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

  3. Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

    International Nuclear Information System (INIS)

    This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation

  4. Biological basis of combination therapy with radiation and bleomycin

    International Nuclear Information System (INIS)

    The biological basis for combination therapy with radiation and bleomycin (BLM) was studied on C2W cells growing in vitro. When BLM was added to the medium before or after irradiation, a potentiating effect was observed. The potentiation remained for 4-6 hours after irradiation. To make clear the mechanism, both type of repair from radiation damage (Elkind type and PLD) by BLM were examined. BLM didn't inhibit the Elkind type recovery but it did inhibit the repair of potentially lethal damage (PLD repair). Plateau phase C2W cells were irradiated, incubated at 370C for a various number of hours, then trypsinized for colony formation. PLD repair was inhibited when BLM was added immediately after irradiation. Based on such experimental results, we treated lung cancer with combination of radiation and BLM. BLM was injected intravenously within 30 minutes after irradiation. Although it seems too early to discuss the result of the combination therapy, it is very promising. (J.P.N.)

  5. Radioprotection, biological effects of the radiations and security in the handling of radioactive material

    CERN Document Server

    Teran, M

    2000-01-01

    The development of the philosophy of the radioprotection is dependent on the understanding of the effects of the radiation in the man. Behind the fact that the radiation is able to produce biological damages there are certain factors with regard to the biological effects of the radiations that determine the boarding of the radioprotection topics.

  6. Biology panel: coming to a clinic near you. Translational research in radiation biology

    International Nuclear Information System (INIS)

    The explosion of knowledge in molecular biology coupled with the rapid and continuing development of molecular techniques allow a new level of research in radiation biology aimed at understanding the processes that govern radiation damage and response in both tumors and normal tissues. The challenge to radiation biologists and radiation oncologists is to use this knowledge to improve the therapeutic ratio in the management of human tumors by rapidly translating these new findings into clinical practice. This panel will focus on both sides of the therapeutic ratio coin, the manipulation of tumor control by manipulating the processes that control cell cycle regulation and apoptosis, and the reduction of normal tissue morbidity by applying the emerging information on the genetic basis of radiosensitivity. Apoptosis is a form of cell death believed to represent a minor component of the clinical effects of radiation. However, if apoptosis is regulated by anti-apoptotic mechanisms, then it may be possible to produce a pro-apoptotic phenotype in the tumor cell population by modulating the balance between pro- and anti-apoptotic mechanisms by pharmacological intervention. Thus signaling-based apoptosis therapy, designed to overcome the relative resistance to radiation-induced apoptosis, may improve the therapeutic ratio in the management of human tumors. The explosion of information concerning cell cycle regulation in both normal and tumor cells has provided the opportunity for insights into the mechanism of action of chemotherapeutic agents that can act as radiosensitizers. The second talk will explore the hypothesis that the dysregulation of cell cycle checkpoints in some cancers can be exploited to improve the therapeutic index of radiation sensitizers, specifically the fluoropyrimidines which appear to act at the G1/S transition. Finally, efforts to increase tumor control will be translated into clinical practice only if such treatments do not increase the complication

  7. Continuing training program in radiation protection in biological research centers

    International Nuclear Information System (INIS)

    The use of ionizing radiation in biological research has many specific characteristics. A great variety of radioisotopic techniques involve unsealed radioactive sources, and their use not only carries a risk of irradiation, but also a significant risk of contamination. Moreover, a high proportion of researchers are in training and the labor mobility rate is therefore high. Furthermore, most newly incorporated personnel have little or no previous training in radiological protection, since most academic qualifications do not include training in this discipline. In a biological research center, in addition to personnel whose work is directly associated with the radioactive facility (scientific-technical personnel, operators, supervisors), there are also groups of support personnel The use of ionizing radiation in biological research has many specific characteristics. A great variety of radioisotopic techniques involve unsealed radioactive sources, and their use not only carries a risk of irradiation, but also a significant risk of contamination. Moreover, a high proportion of researchers are in training and the labor mobility rate is therefore high. Furthermore, most newly incorporated personnel have little or no previous training in radiological protection, since most academic qualifications do not include training in this discipline. In a biological research center, in addition to personnel whose work is directly associated with the radioactive facility (scientific-technical personnel, operators, supervisors), there are also groups of support personnel maintenance and instrumentation workers, cleaners, administrative personnel, etc. who are associated with the radioactive facility indirectly. These workers are affected by the work in the radioactive facility to varying degrees, and they therefore also require information and training in radiological protection tailored to their level of interaction with the installation. The aim of this study was to design a

  8. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1985-November 30, 1986

    International Nuclear Information System (INIS)

    This is the annual report of the Radiological Research Laboratory of the Department of Radiation Oncology, Columbia University. The bulk of the research of the Laboratory involves basic and fundamental aims, not confined to radiotherapy. Research carried out in the Laboratory covers the determination of microdosimetry quantities, computer simulation of particle tracks, determination of oncogenic transformation, and the transfection of DNA into cells. The Hallmark of the Laboratory is the interaction between physics and biology

  9. Radiation physics, biophysics and radiation biology. Progress report, October 1, 1982-November 1983

    International Nuclear Information System (INIS)

    A wide range of research is carried out at the Radiological Research Laboratory, from computer simulation of particle tracks to the determination of oncogenic transformation in mammalian cells. Mechanistic studies remain the central mission in an attempt to understand the biological action of ionizing radiations. Collaborative research is carried out on the use of radiosensitizers on chemosensitizers on the effect of hormones on oncogenic transformation and on cataractogenesis

  10. Anthracene dosimeter characterization under radiotherapy photons

    International Nuclear Information System (INIS)

    New radiotherapy techniques such as intensity-modulated radiation therapy and stereotactic radiosurgery have increased the need for dosimeters that can provide measurements in real time with high spatial resolution. Organic scintillation dosimeters are able to measure with accuracy small radiation fields and fields with high gradients, besides having advantages such as water and soft tissue equivalence and the possibility to be used in vivo. Anthracene is an organic scintillator crystal with the highest known scintillation efficiency among organic scintillation materials. The objective of this work is to characterize the anthracene as a dosimeter under radiotherapy photons energies, analysing its signal against average granulosity, intern capsule diameter, absorbed dose, absorbed dose rate, photon energy and its spatial resolution; with the last one analysed under three methods (edge spread function, line spread function and modulation transfer function). The photons energies used were 1.25 MeV (60Co), 0.661 MeV (137Cs) and X-rays (effective energies of 28.4; 46.5; 48.5; 94.0 e 106.0 keV). The scintillation detection system consisted of an optical fiber with one end attached to the anthracene capsule and the other to a photomultiplier tube maintained by power supply followed by an electrometer. Once Cerenkov radiation occurs in the optical fiber, it was removed from the total scintillation signal trough the subtraction of the signal, taken irradiating the optical fiber without the anthracene attached to one of its extremity. From results obtained, one can infer that the dosimeter signal increases proportionally with average granulosity and intern capsule diameter. The signal is linearly dependent of absorbed dose, linearly dependent of low photons energies and independent for high photons energies, as well as independent of the absorbed dose rate. From the spatial resolution values obtained it was possible to infer that the one obtained through modulation transfer

  11. Biological dose assessment of 15 victims in Haerbin radiation accident

    International Nuclear Information System (INIS)

    Full text: a) On July 5 and 8, 2005, Two patients with bone marrow suppression were successively hospitalized by the First Affiliated Hospital of Haerbin Medical University. Examination results showed that the patients seemed to get suspicious radiation disease. On July 13, 2005, a radioactive source was found in the patients' dwelling. The radiation source is Iridium-192 with 0.5 Ci(1.85 x 1010Bq) radioactivity. The radiation source is a metal bar which is a kind of radioactive industrial detection source for welding. The source is currently stored in the urban radioactive waste storehouse of Heilongjiang province. After finding the radioactive source on July 13, The Haerbin municipal government initiated an emergency response plan and developed medical rescue, radioactive source examination and case detection through organizing ministries involving health, environmental protection and public security. After receiving a report at 17:00 on July 14, 2005, Chinese Ministry of Health immediately sent experts to the spot for investigation, dose estimation and direction of patients' rescue. Health authority carried out physical examination twice on 113 residents within 30 meters to the source, among which 4 got radiation sickness, 5 showed abnormal hemotogram, and others showed no abnormal response. Of 4 patients with radiation sickness, one 81 year old patient has died of severe bone marrow form of sub acute radiation sickness coupled with lung infection and prostrate apparatus at 13:00 on Oct., 20. Two children have been treated in Beitaiping Road Hospital in Beijing, another patient has been treated in local hospital. b) Biological dosimetry using conventional chromosome aberration analysis in human peripheral blood lymphocytes has been shown as a reliable and useful tool in medical management of radiation accident victims. Peripheral blood lymphocytes of the victims were cultured using conventional culture medium with colchicine added at the beginning. Chromosome

  12. Low Level Laser Therapy: laser radiation absorption in biological tissues

    Science.gov (United States)

    Di Giacomo, Paola; Orlando, Stefano; Dell'Ariccia, Marco; Brandimarte, Bruno

    2013-07-01

    In this paper we report the results of an experimental study in which we have measured the transmitted laser radiation through dead biological tissues of various animals (chicken, adult and young bovine, pig) in order to evaluate the maximum thickness through which the power density could still produce a reparative cellular effect. In our experiments we have utilized a pulsed laser IRL1 ISO model (based on an infrared diode GaAs, λ=904 nm) produced by BIOMEDICA s.r.l. commonly used in Low Level Laser Therapy. Some of the laser characteristics have been accurately studied and reported in this paper. The transmission results suggest that even with tissue thicknesses of several centimeters the power density is still sufficient to produce a cell reparative effect.

  13. A Mathematical Model for Estimating Biological Damage Caused by Radiation

    CERN Document Server

    Manabe, Yuichiro; Bando, Masako

    2012-01-01

    We propose a mathematical model for estimating biological damage caused by low-dose irradiation. We understand that the Linear Non Threshold (LNT) hypothesis is realized only in the case of no recovery effects. In order to treat the realistic living objects, our model takes into account various types of recovery as well as proliferation mechanism, which may change the resultant damage, especially for the case of lower dose rate irradiation. It turns out that the lower the radiation dose rate, the safer the irradiated system of living object (which is called symbolically "tissue" hereafter) can have chances to survive, which can reproduce the so-called dose and dose-rate effectiveness factor (DDREF).

  14. A Mathematical Model for Estimating Biological Damage Caused by Radiation

    Science.gov (United States)

    Manabe, Yuichiro; Ichikawa, Kento; Bando, Masako

    2012-10-01

    We propose a mathematical model for estimating biological damage caused by low-dose irradiation. We understand that the linear non threshold (LNT) hypothesis is realized only in the case of no recovery effects. In order to treat the realistic living objects, our model takes into account various types of recovery as well as proliferation mechanism, which may change the resultant damage, especially for the case of lower dose rate irradiation. It turns out that the lower the radiation dose rate, the safer the irradiated system of living object (which is called symbolically ``tissue'' hereafter) can have chances to survive, which can reproduce the so-called dose and dose-rate effectiveness factor (DDREF).

  15. Radiation effects on biological molecules: Influence of the local environment

    International Nuclear Information System (INIS)

    Because it crystallizes with several different molecular environments (e.g. hydrated, anhydrous, and HCl), and in several slightly modified molecular forms, the amino acid proline has been chosen as a probe of possible local effects on the radiation chemistry of biological molecules. In all systems studied so far (proline, proline/sup ./H/sub 2/O, proline /sup ./HCl, hydroxyl-proline, thioproline, and oxoproline), evidence for the ''deamination'' radical has been detected. This product, shown to arise from the primary carboxyl anion in hydroxyproline, is probably the result of electron attack in the other cases, also from the α-carbon. Evidence for the other products is currently under analysis and is discussed along with a summary of the results

  16. Water equivalence of polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Sellakumar, P. [Bangalore Institute of Oncology, 44-45/2, II Cross, RRMR Extension, Bangalore-560 027 (India)]. E-mail: psellakumar@rediffmail.com; James Jebaseelan Samuel, E. [School of Science and Humanities, Vellore Institute of Technology, Vellore-632 014 (India); Supe, Sanjay S. [Kidwai Memorial Institute of Oncology, Hosur Road, Bangalore-560 027 (India)

    2007-07-15

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z{sub eff}), electron density ({rho}{sub e}), photon mass attenuation coefficient ({mu}/{rho}), photon mass energy absorption coefficient ({mu}{sub en}/{rho}) and total stopping power (S/{rho}){sub tot} of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close (<1%) to that of water except PAGAT, MAGAT and NIPAM which had the variation of 3%, 2% and 3%, respectively. The value of {mu}/{rho} and {mu}{sub en}/{rho} for all polymer gels were in close agreement (<1%) with that of water beyond 80keV. The value of (S/{rho}){sub tot} of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application.

  17. 13th AINSE radiation biology conference: conference handbook

    International Nuclear Information System (INIS)

    The forty one papers presented at this conference covered the areas of radiation induced lesions, apoptosis, genetics and radiobiological consequences of low level radiation exposure, clinical applications of radiation, mammalian cells radiosensitivity and radiation-activated proteins

  18. 2.3.2 Biological Effects of Non-Ionizing Radiations

    Science.gov (United States)

    Bernhardt, J. H.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Subsection '2.3.2 Biological Effects of Non-Ionizing Radiations' of the Section '2.3 Biological Effects' of the Chapter '2 Radiation and Biological Effects' with the contents:

  19. Measurement of the dose by dispersed radiation in a lineal accelerator using thermoluminescent dosimeters of CaSO{sub 4}:Dy; Medicion de la dosis por radiacion dispersa en un acelerador lineal usando dosimetros termoluminiscentes de CaSO{sub 4}:Dy

    Energy Technology Data Exchange (ETDEWEB)

    Chavez C, N.; Torijano, E.; Azorin, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Herrera, A. [ISSSTE, Hospital Nacional 20 de Noviembre, Eje 7 Sur Felix Cuevas Esq. Av. Coyoacan, Col. del Valle, 03229 Mexico D. F. (Mexico)

    2014-08-15

    The thermoluminescence (Tl) is based on the principle of the luminescent in a material when is heated below their incandescence temperature. Is a technique very used in dosimetry that is based on the property that have most of the crystalline materials regarding the storage of the energy that they absorb when are exposed to the ionizing radiations. When this material has been irradiated previously, the radioactive energy that contains is liberated in form of light. In general, the principles that govern the thermoluminescence are in essence the same of those responsible for all the luminescent processes and, this way, the thermoluminescence is one of the processes that are part of the luminescence phenomenon. For this work, the dispersed radiation was measured in the therapy area of the lineal accelerator of medical use type Elekta, using thermoluminescent dosimeters of CaSO{sub 4}:Dy + Ptfe developed and elaborated in the Universidad Autonoma Metropolitana, Unidad Iztapalapa. With the dosimeters already characterized and calibrated, we proceeded to measure the dispersed radiation being a patient in treatment. The results showed values for the dispersed radiation the order of a third of the dose received by the patient on the treatment table at 30 cm of the direct beam and the order of a hundredth in the control area (4 m of the direct beam, approximately). The conclusion is that the thermoluminescent dosimeters of CaSO{sub 4}: Dy + Ptfe are appropriate to measure dispersed radiation dose in radiotherapy. (author)

  20. Scientific projection paper on biologic effects of ionizing radiation

    International Nuclear Information System (INIS)

    There is widespread knowledge about the effects of radiation in human populations but the studies have had some limitations which have left gaps in our knowledge. Most populations have had exposure to high doses with little information on the effect of dose rate. The characteristics of the populations have been restricted by the location of the disaster, the occupational limitations, or the basic risks associated with the under-lying disease for which radiation was given. All doses have been estimated and such values are subject to marked variability particularly when they rely on sources of data such as hospital records. The biological data although extensive have several deficits in information. Which are the sites in which cancer is produced by irradiation and what are the cell types which are produced. The sensitivity of various tissues and organs are not similar and it is important to rank them according to susceptibility. This has been done in the past but the results are not complete for all cell types and organs. The temporal patterns for tumor development, the latent period, the period of expressed excess, the life-time risks need to be defined more precisely for the cancers. Many populations have not been followed long enough to express the complete risk