Measurement tolerance analysis of solar radiation

Energy Technology Data Exchange (ETDEWEB)

Cimo, J.; Maderkova, L.; Horak, J.; Igaz, D.; Pasztorova, S. [Department of Biomereorlogy and Hydrology, Slovak Agriculture University, Nitra (Slovakia)

2012-07-01

Solar radiant energy is bane and almost the only one source of heat for Earth 's surface and for atmosphere, and almost the only one source of energy for physical processes. Solar energy is one of the most available and the most ecological energy source. Currently the firm Kipp and Zonen belongs to prominent producer of sensors for measuring of global radiation. These sensors are the most used in our country and also in network of meteorological measurements of WMO. Therefore the two types of measuring sensors for global radiation (pyranometer PMP6, CMP 11) in comparison with calculation method Savin-Angstrom are analysed. (author)

Dosimetry of low-energy beta radiation

International Nuclear Information System (INIS)

Borg, J.

1996-08-01

Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

International Nuclear Information System (INIS)

Famiano, M.A.

1997-01-01

A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time (∼1 micros to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, 137 Cs gamma rays, and electrons from a 90 Sr/ 90 Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired

Calorimeter with capacitance transducer for measurement of SHF radiation power

International Nuclear Information System (INIS)

Kiselev, V.A.; Linnik, A.F.; Onishchenko, I.N.; Uskov, V.V.

2005-01-01

A calorimeter of simple design for measuring total energy of microwave radiation is described. It operates in the energy range of 0.5 J to 6 kJ; water is used as the absorbing material. A capacitive probe is applied to measure changes in the water volume. The energy absorption factor of electromagnetic radiation in the range of 3-60 GHz is at least 0.9. The calorimeter is insensitive to radiation field nonuniformity over the absorber volume. The calorimeter is intended for measuring the radiation energy of beam plasma generators and generators with dielectric structure. Its design makes it possible to simultaneously measure the radiation energy and monitor the beam current [ru

Solar and infrared radiation measurements

CERN Document Server

Vignola, Frank; Michalsky, Joseph

2012-01-01

The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

Measurement of NdFeB permanent magnets demagnetization induced by high energy electron radiation

Energy Technology Data Exchange (ETDEWEB)

Temnykh, Alexander B. [Wilson Lab, Cornell University, LEPP, Ithaca, NY 14850 (United States)], E-mail: abt6@cornell.edu

2008-03-11

Demagnetization of NdFeB permanent magnets has been measured as function of radiation dose induced by high energy electrons. The magnet samples were of different intrinsic coercive forces, {approx_equal}12 and {approx_equal}20KOe, dimensions and direction of magnetization. 5 GeV electron beam from 12 GeV Cornell Synchrotron was used as a radiation source. A calorimetric technique was employed for radiation dose measurement. Results indicated that depending on the sample intrinsic coercive force, shape and direction of magnetization the radiation dose causing 1% of demagnetization of the sample varies from 0.0765{+-}0.005Mrad to 11.3{+-}3.0Mrad, i.e., by more than a factor of 100. Experimental data analysis revealed that demagnetization of the given sample induced by radiation is strongly correlated with the sample demagnetizing temperature. This correlation was approximated by an exponential function with two parameters obtained from the data fitting. The function can be used to predict the critical radiation dose for permanent magnet assemblies like undulator magnets based on its demagnetizing temperature. The latter (demagnetization temperature) can be determined at the design stage from 3-D magnetic modeling and permanent magnet material properties.

Intercomparison of Environmental Nuclear Radiation Measuring

Institute of Scientific and Technical Information of China (English)

GAO; Fei; NI; Ning; HOU; Jin-bing; SONG; Ming-zhe

2015-01-01

In 2015,Radiation Metrology Division of China Institute of Atomic Energy organized an environmental monitoring of nuclear radiation measuring intercomparison,and 9laboratories attended.The intercomparison included environmental level dosemeters and protection level

Radiation energy calibrating system and method

International Nuclear Information System (INIS)

Jacobson, A.F.

1980-01-01

A radiation energy calibrating system and method which uses a pair of calibrated detectors for measurements of radiation intensity from x-ray tubes for a non-invasive determination of the electrical characteristics; I.E., the tube potential and/or current

Measurement of solar radiation at the Earth's surface

Science.gov (United States)

Bartman, F. L.

1982-01-01

The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

Radiation detector device for measuring ionizing radiation

International Nuclear Information System (INIS)

Brake, D. von der.

1983-01-01

The device contains a compensating filter circuit, which guarantees measurement of the radiation dose independent of the energy or independent of the energy and direction. The compensating filter circuit contains a carrier tube of a slightly absorbing metal with an order number not higher than 35, which surrounds a tubular detector and which carries several annular filter parts on its surface. (orig./HP) [de

Radiation of transient high-current arcs: energy measurements in the optical range

International Nuclear Information System (INIS)

Bauchire, J M; Hong, D; Rabat, H; Riquel, G

2012-01-01

When no protection is used, the radiation emitted by a high-power electric arc can be dangerous for the eyes and the skin of a person. To ensure effective protection, it is first necessary to know the energy emitted by such arcs. The aim of our work was to experimentally determine the energy emitted by high-current (from 4 to 40 kA) transient arcs, for two different (10 cm and 2 m) lengths and for electrodes in copper or steel. These experiments enabled the radiative energy of the arcs to be quantified and also showed the influence of metal vapors in the spectral distribution of the radiation.

Low energy background radiation in India

International Nuclear Information System (INIS)

Gopinath, D.V.

1980-01-01

Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

Radiation energy detector and analyzer

International Nuclear Information System (INIS)

Roberts, T.G.

1981-01-01

A radiation detector array and a method for measuring the spectral content of radiation. The radiation sensor or detector is an array or stack of thin solid-electrolyte batteries. The batteries, arranged in a stack, may be composed of independent battery cells or may be arranged so that adjacent cells share a common terminal surface. This common surface is possible since the polarity of the batteries with respect to an adjacent battery is unrestricted, allowing a reduction in component parts of the assembly and reducing the overall stack length. Additionally, a test jig or chamber for allowing rapid measurement of the voltage across each battery is disclosed. A multichannel recorder and display may be used to indicate the voltage gradient change across the cells, or a small computer may be used for rapidly converting these voltage readings to a graph of radiation intensity versus wavelength or energy. The behavior of the batteries when used as a radiation detector and analyzer are such that the voltage measurements can be made at leisure after the detector array has been exposed to the radiation, and it is not necessary to make rapid measurements as is now done

Atmospheric Radiation Measurement Program plan

International Nuclear Information System (INIS)

1990-02-01

In order to understand energy's role in anthropogenic global climate change, significant reliance is being placed on General Circulation Models (GCMs). A major goal is to foster the development of GCMs capable of predicting the timing and magnitude of greenhouse gas-induced global warming and the regional effects of such warming. The Atmospheric Radiation Measurement (ARM) Program will contribute to the Department of Energy goal by improving the treatment of cloud radiative forcing and feedbacks in GCMs. Two issues will be addressed: the radiation budget and its spectral dependence and the radiative and other properties of clouds. The experimental objective of the ARM Program is to characterize empirically the radiative processes in the Earth's atmosphere with improved resolution and accuracy. A key to this characterization is the effective treatment of cloud formation and cloud properties in GCMs. Through this characterization of radiative properties, it will be possible to understand both the forcing and feedback effects. 19 refs., 4 figs., 2 tabs

Radiation monitoring in high energy research facility

International Nuclear Information System (INIS)

Miyajima, Mitsuhiro

1975-01-01

In High Energy Physics Research Laboratory, construction of high energy proton accelerator is in progress. The accelerator is a cascaded machine comprising Cockcroft type (50 keV), linac (20 MeV), booster synchrotron (500 MeV), and synchrotron (8-12 GeV). Its proton beam intensity is 1x10 13 photons/pulse, and acceleration is carried out at the rate of every 2 minutes. The essential problems of radiation control in high energy accelerators are those of various radiations generated secondarily by proton beam and a number of induced radiations simultaneously originated with such secondary particles. In the Laboratory, controlled areas are divided into color-coded four regions, red, orange, yellow and green, based on each dose-rate. BF 3 counters covered with thick paraffin are used as neutron detectors, and side-window GM tubes, NaI (Tl) scintillators and ionization chambers as γ-detectors. In red region, however, ionization chambers are applied to induced radiation detection, and neutrons are not monitored. NIM standards are adopted for the circuits of all above monitors considering easy maintenance, economy and interchangeability. Notwithstanding the above described systems, these monitors are not sufficient to complete the measurement of whole radiations over wide energy region radiated from the accelerators. Hence separate radiation field measurement is required periodically. An example of the monitoring systems in National Accelerator Laboratory (U.S.) is referred at the last section. (Wakatsuki, Y.)

Measurement of the diffuse atmospheric and cosmic γ-radiation in the energy range 1-10 MeV by a balloon carried Compton-telescope

International Nuclear Information System (INIS)

Lichti, G.

1975-01-01

The operation and design of a low-energy γ-compton telescope, developed and constructed at the Max-Planck-Institut fuer extraterrestrische Physik, are reported on. For energies of about 1 MeV, the telescope has an energy resolution of 30% (FWHM) and an angular resolution of +- 20 0 . In spite of the low efficiency of only about 0.5%, the vertical γ-flux could be measured for the first time in two balloon flights, and the extragalactic origin of the diffuse component of the cosmic γ-radiation could be demonstrated. The energy spectrum of this radiation was measured. The result is compared with measurements of other experiments, and theoretical models to describe the origin of this radiation are discussed. (orig.) [de

Measurements of internal stresses in bond coating using high energy x-rays from synchrotron radiation source

CERN Document Server

Suzuki, K; Akiniwa, Y; Nishio, K; Kawamura, M; Okado, H

2002-01-01

Thermal barrier coating (TBC) techniques enable high temperature combustion of turbines made of Ni-base alloy. TBC is made of zirconia top coating on NiCoCrAlY bond coating. The internal stresses in the bond coating play essential role in the delamination or fracture of TBC in service. With the X-rays from laboratory equipments, it is impossible to measure nondestructively the internal stress in the bond coating under the top coating. synchrotron radiations with a high energy and high brightness have a large penetration depth as compared with laboratory X-rays. Using the high energy X-rays from the synchrotron radiation, it is possible to measure the internal stress in the bond coating through the top coating. In this study, the furnace, which can heat a specimen to 1473 K, was developed for the stress measurement of the thermal barrier coatings. The internal stresses in the bond coating were measured at the room temperature, 773 K, 1073 K and 1373 K by using the 311 diffraction from Ni sub 3 Al with about 73...

Radiation dose measurements

International Nuclear Information System (INIS)

1960-01-01

About 200 scientists from 28 countries and 5 international organizations met at a symposium on radiation dosimetry held by the International Atomic Energy Agency in June 1960. The aim of the symposium was not so much the description of a large number of measuring instruments as a discussion of the methods used, with special emphasis on those problems which had become important in the context of recent developments, such as the measurement of mixed or very large doses

Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

Science.gov (United States)

Aydın, Güral; Usta, Metin; Oktay, Adem

2018-06-01

Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

Errors in measuring absorbed radiation and computing crop radiation use efficiency

International Nuclear Information System (INIS)

Gallo, K.P.; Daughtry, C.S.T.; Wiegand, C.L.

1993-01-01

Radiation use efficiency (RUE) is often a crucial component of crop growth models that relate dry matter production to energy received by the crop. RUE is a ratio that has units g J -1 , if defined as phytomass per unit of energy received, and units J J -1 , if defined as the energy content of phytomass per unit of energy received. Both the numerator and denominator in computation of RUE can vary with experimental assumptions and methodologies. The objectives of this study were to examine the effect that different methods of measuring the numerator and denominator have on the RUE of corn (Zea mays L.) and to illustrate this variation with experimental data. Computational methods examined included (i) direct measurements of the fraction of photosynthetically active radiation absorbed (f A ), (ii) estimates of f A derived from leaf area index (LAI), and (iii) estimates of f A derived from spectral vegetation indices. Direct measurements of absorbed PAR from planting to physiological maturity of corn were consistently greater than the indirect estimates based on green LAI or the spectral vegetation indices. Consequently, the RUE calculated using directly measured absorbed PAR was lower than the RUE calculated using the indirect measures of absorbed PAR. For crops that contain senesced vegetation, green LAI and the spectral vegetation indices provide appropriate estimates of the fraction of PAR absorbed by a crop canopy and, thus, accurate estimates of crop radiation use efficiency

Radiation practices and radiation measurements

International Nuclear Information System (INIS)

2008-03-01

The guide presents the principal requirements on accuracy of radiation measurements and on the approval, calibration and operating condition inspections of radiation meters, together with requirements for dosimetric services measuring the individual radiation doses of workers engaged in radiation work (approved dosimetric services). The Guide also sets out the definitions of quantities and units used in radiation measurements. The radiation protection quantities used for assessing the harmful effects of radiation and for expressing the maximum values for radiation exposure (equivalent dose and effective dose) are set out in Guide ST 7.2. This Guide concerns measurements of ionizing radiation involved in radiation practices, the results of which are used for determining the radiation exposure of workers engaged in radiation work and members of the public, and of patients subject to the use of radiation in health services, or upon the basis of which compliance with safety requirements of appliances currently in use and of their premises of use or of the workplaces of workers is ensured. The Guide also concerns measurements of the radon concentration of inhaled air in both workplaces and dwellings. The Guide does not apply to determining the radiation exposure of aircrews, determination of exposure caused by internal radiation, or measurements made to protect the public in the event of, or in preparation for abnormal radiation conditions

On output measurements via radiation pressure

DEFF Research Database (Denmark)

Leeman, S.; Healey, A.J.; Forsberg, F.

1990-01-01

It is shown, by simple physical argument, that measurements of intensity with a radiation pressure balance should not agree with those based on calorimetric techniques. The conclusion is ultimately a consequence of the circumstance that radiation pressure measurements relate to wave momentum, while...... calorimetric methods relate to wave energy. Measurements with some typical ultrasound fields are performed with a novel type of hydrophone, and these allow an estimate to be made of the magnitude of the discrepancy to be expected between the two types of output measurement in a typical case....

Neutron measuring instruments for radiation protection

International Nuclear Information System (INIS)

Heinzelmann, M.; Schneider, W.; Hoefert, M.; Kuehn, H.; Jahr, R.; Wagner, S.; Piesch, E.

1979-09-01

The present report deals with selected topics from the field of neutron dosimetry for radiation protection connected with the work of the subcommittee 6802 in the Standards Committee on Radiology (NAR) of the German Standards Institute (DIN). It is a sort of material collection. The topics are: 1. Measurement of the absorbed-energy dose by a) ionization chambers in fields of mixed radiation and b) recoil-proton proportional counting tubes. 2. Measurement of the equivalent dose, neutron monitors, combination methods by a) rem-meters, b) recoil-proton counting tubes, c) recombination method, tissue-equivalent proportional counters, activation methods for high energies in fields of mixed radiation, d) personnel dosimetry by means of ionization chambers and counting tubes, e) dosimetry by means of activation methods, nuclear track films, nonphotographic nuclear track detectors and solid-state dosimeters. (orig./HP) [de

Measurement of the energy and power radiated by a pulsed blackbody x-ray source

International Nuclear Information System (INIS)

Chandler, Gordon Andrew; McDaniel, Dillon Heirman; Jorgenson, Roy E.; Warne, Larry Kevin; Dropinski, Steven Clark; Hanson, Donald L.; Johnson, William Arthur; York, Mathew William; Lewis, D.F.; Korde, R.; Haslett, C.L.; Wall, D.L.; Ruggles, Laurence E.; Ramirez, L.E.; Stygar, William A.; Porter, John Larry Jr.; McKenney, John Lee; Bryce, Edwin Anthony; Cuneo, Michael Edward; Torres, Jose A.; Mills, Jerry Alan; Leeper, Ramon Joe; McGurn, John Stephen; Fehl, David Lee; Spielman, R. B.; Pyle, John H.; Mazarakis, Michael Gerrassimos; Ives III, Harry Crockett; Seamen, Johann F.; Simpson, Walter W.

2006-01-01

We have developed a diagnostic system that measures the spectrally integrated (i.e. the total) energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP) diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38 x 38 square array of 10-(micro)m-diameter pinholes in a 50-(micro)m-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of ∼1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999)RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode's output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation) the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and--on every shot--provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects) of the sensitivity of an array-diode combination is presented

Automatic actinometric system for diffuse radiation measurement

Science.gov (United States)

Litwiniuk, Agnieszka; Zajkowski, Maciej

2015-09-01

Actinometric station is using for measuring solar of radiation. The results are helpful in determining the optimal position of solar panels relative to the Sun, especially in today's world, when the energy coming from the Sun and other alternative sources of energy become more and more popular. Polish climate does not provide as much energy as in countries in southern Europe, but it is possible to increase the amount of energy produced by appropriate arrangement of photovoltaic panels. There is the possibility of forecasting the amount of produced energy, the cost-effectiveness and profitability of photovoltaic installations. This implies considerable development opportunities for domestic photovoltaic power plants. This article presents description of actinometric system for diffuse radiation measurement, which is equipped with pyranometer - thermopile temperature sensor, amplifier AD620, AD Converter ADS1110, microcontroller Atmega 16, SD card, GPS module and LCD screen.

Detection and measurement of ionizing radiation

International Nuclear Information System (INIS)

Anon.

1990-01-01

All detection or measurement of radiation rests in the possibility of recognizing the interactions of radiation with matter. When radiation passes through any kind of material medium, all or a portion of its energy is transferred to this medium. This transferred energy produces an effect in the medium. In principle, the detection of radiation is based on the appearance and the observation of this effect. In theory, all of the effects produced by radiation may be used in detecting it: in practice, the effects most commonly employed are: (1) ionization of gases (gas detectors), or of some chemical substance which is transformed by radiation (photographic or chemical dosimeters); (2) excitations in scintillators or semiconductors (scintillation counters, semiconductor counters); (3) creation of structural defects through the passage of radiation (transparent thermoluminescent and radioluminescent detectors); and (4) raising of the temperature (calorimeters). This study evaluates in detail, instruments based on the ionization of gases and the production of luminescence. In addition, the authors summarize instruments which depend on other forms of interaction, used in radiation medicine and hygiene (radiology, nuclear medicine)

Measurement of the energy distribution of parametric X-ray radiation from a double-crystal system

International Nuclear Information System (INIS)

Mori, Akira; Hayakawa, Yasushi; Kidokoro, Akio; Sato, Isamu; Tanaka, Toshinari; Hayakawa, Ken; Kobayashi, Kouji; Ohshima, Hisashi

2006-01-01

A parametric X-ray radiation (PXR) generator system was developed at the Laboratory for Electron Beam Research and Applications (LEBRA) at Nihon University; this PXR generator system is a tunable wavelength and quasi-monochromatic X-ray source constructed as one of the advanced applications of the LEBRA 125-MeV electron linear accelerator. The PXR beam which has characteristic of energy distribution. The theoretical values of energy distribution obtained at the output port were calculated to be approximately 300 eV and 2 keV at the central X-ray energies of 7 keV and 20 keV, respectively. In order to investigate the energy distribution, several measurements of the X-ray energy were carried out. The X-ray absorption of known materials and that of thin aluminum has been evaluated based on analyses of images taken using an imaging plate. The X-ray energy was deduced base on the identification of the absorption edges, and the energy distribution was estimated based on measurements using aluminum step method. In addition, an X-ray diffraction method using a perfect silicon crystal was employed, and spectra were measured using a solid state detector (SSD). The results of these experiments agreed with the calculated results. In particular, the well-defined absorption edges in the X-ray images and the typical rocking curves obtained by the measurement of the X-ray diffraction indicated that the distribution has a high-energy resolution

Radiation Dose Measurement Using Chemical Dosimeters

International Nuclear Information System (INIS)

Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

2010-01-01

The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

Radiation from silver films bombarded by low-energy electrons

International Nuclear Information System (INIS)

Chung, M.S.; Callcott, T.A.; Kretschmann, E.; Arakawa, E.T.

1980-01-01

Emission spectra from Ag films irradiated by low energy electrons (20-1500 eV) have been measured, and the results compared with theory. For relatively smooth films, two peaks in the spectra are resolved. One at 3.73 eV, the volume plasmon energy, is attributed to transition radiation and/or bremsstrahlung. The second, at about 3.60 eV, is very sensitive to surface roughness in both position and magnitude and is produced by roughness-coupled radiation from surface plasmons. For rough films, the roughness-coupled radiation dominates the emission. In addition to spectral shapes, the polarization of the radiation and its intensity as a function of electron energy were measured. The experimental results are compared with new calculations of roughness-coupled emission which account for most of our observations. They indicate that high wavevector roughness components play the dominant role in the emission process. (orig.)

Dosimetry of high energy radiation

CERN Document Server

Sahare, P D

2018-01-01

High energy radiation is hazardous to living beings and a threat to mankind. The correct estimation of the high energy radiation is a must and a single technique may not be very successful. The process of estimating the dose (the absorbed energy that could cause damages) is called dosimetry. This book covers the basic technical knowledge in the field of radiation dosimetry. It also makes readers aware of the dangers and hazards of high energy radiation.

Centralizing and decentralizing the system for unifying measurements on ionizing-radiation characteristics (medium-energy photon and charged-particle radiometry and spectrometry)

International Nuclear Information System (INIS)

Bregadze, Yu.I.; Stepanov, E.K.

1993-01-01

Ionizing-radiation applications have gradually defined the physical quantities needed to describe radiation sources, radiation as such, and interactions with matter. The optimum unit system has not yet been defined, since new regularities appear during research on the interactions of radiation with matter, and new relationships are being discovered between the radiation characteristics and the observed effects. There are 13 state primary standards in the measurement of ionizing radiation. Several of the standards reproduce the same unit but for different forms of radiation, while special standards reproduce units under special conditions. The present article discusses the various approaches to centralizing and decentralizing systems of supporting unified measurements for various ionizing-radiation characteristics. The three basic physical quantities used to characterize radioactive sources -- radionuclide activity, external particle emission, and particle energy -- are addressed separately. 10 refs

Split energy level radiation detection

International Nuclear Information System (INIS)

Barnes, G.T.

1986-01-01

This patent describes an energy discriminating radiation detector comprising: (a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range; (b) a second element comprising a second material different in kind from the first material and of a kind which is preferentially responsive to penetrative radiation of second energy range extending higher than the first energy range. The element is positioned to receive radiation which has penetrated through a portion of the first element; and (c) a filter of penetrative radiation interposed between the first and second elements

Measuring the spectra of low-energy X radiation of heavy-current nanosecond discharge in the diode of relativistic electron beam generator

International Nuclear Information System (INIS)

Aranchuk, L.E.; Bogolyubskij, S.L.; Volkov, G.S.

1986-01-01

Results of measuring the absolute energy spectrum of pulsed x-radiation of plasma produced by ''Triton'' REB generator (I∼200 kA, τ 1/2 ∼60 ns) are presented. Vacuum photoemission detectors are used to record 0.1-1 keV quanta. The mehod of Ross filters in combimation with detectors with specially selected characteristics was used in 1-20 keV energy interval. The measured radiation power in the E≥1.3 keV area exceeds 10 6 W and in 0.1-1 keV area it is of the order of 3x10 9 W

Measurement of ion energy by a calorimetric method

Energy Technology Data Exchange (ETDEWEB)

Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Bunak, Suwat

1996-12-01

In calorimetric method, ion energy is determined based on the temperature changes during radiation of an absorbing material, radiation current and heat capacity of the calorimeter. This method is convenient and its measuring procedures are simple as well as the measuring apparatus. Here, the temperature changes of the calorimeter during {sup 14}N ion beam radiation were determined. The temperature increased linearly when irradiated with {sup 14}N{sup 3+}, 8.3 MeV or {sup 14}N{sup 2+}, 6 MeV, but not linearly for {sup 14}N{sup 1+}, 3.6 MeV, resulting in a comparatively large error. Thus, the measurement of ion energy by calorimetric method was found available as a convenient method for an accelerator having an energy stability less than 10{sup -3}. Especially this method seems to be useful for low-energy ion accelerator or ion injecting apparatus. (M.N.)

Measurements of neutron radiation in aircraft

International Nuclear Information System (INIS)

Vukovic, B.; Poje, M.; Varga, M.; Radolic, V.; Miklavcic, I.; Faj, D.; Stanic, D.; Planinic, J.

2010-01-01

Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21 o to 58 o ; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was H n =5.9 μSv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of H f =1.4 μSv/h.

Measurements of neutron radiation in aircraft

Energy Technology Data Exchange (ETDEWEB)

Vukovic, B.; Poje, M.; Varga, M.; Radolic, V.; Miklavcic, I. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Faj, D. [Clinical Hospital Osijek (Croatia); Stanic, D. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Planinic, J., E-mail: planinic@ffos.h [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia)

2010-12-15

Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21{sup o} to 58{sup o}; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was H{sub n}=5.9 {mu}Sv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of H{sub f}=1.4 {mu}Sv/h.

Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

International Nuclear Information System (INIS)

Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

2005-01-01

CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

Radiation Measured for Chinese Satellite SJ-10 Space Mission

Science.gov (United States)

Zhou, Dazhuang; Sun, Yeqing; Zhang, Binquan; Zhang, Shenyi; Sun, Yueqiang; Liang, Jinbao; Zhu, Guangwu; Jing, Tao; Yuan, Bin; Zhang, Huanxin; Zhang, Meng; Wang, Wei; Zhao, Lei

2018-02-01

Space biological effects are mainly a result of space radiation particles with high linear energy transfer (LET); therefore, accurate measurement of high LET space radiation is vital. The radiation in low Earth orbits is composed mainly of high-energy galactic cosmic rays (GCRs), solar energetic particles, particles of radiation belts, the South Atlantic Anomaly, and the albedo neutrons and protons scattered from the Earth's atmosphere. CR-39 plastic nuclear track detectors sensitive to high LET are the best passive detectors to measure space radiation. The LET method that employs CR-39 can measure all the radiation LET spectra and quantities. CR-39 detectors can also record the incident directions and coordinates of GCR heavy ions that pass through both CR-39 and biosamples, and the impact parameter, the distance between the particle's incident point and the seed's spore, can then be determined. The radiation characteristics and impact parameter of GCR heavy ions are especially beneficial for in-depth research regarding space radiation biological effects. The payload returnable satellite SJ-10 provided an excellent opportunity to investigate space radiation biological effects with CR-39 detectors. The space bio-effects experiment was successfully conducted on board the SJ-10 satellite. This paper introduces space radiation in low Earth orbits and the LET method in radiation-related research and presents the results of nuclear tracks and biosamples hitting distributions of GCR heavy ions, the radiation LET spectra, and the quantities measured for the SJ-10 space mission. The SJ-10 bio-experiment indicated that radiation may produce significant bio-effects.

System for determining absorbed dose and its distribution for high-energy electron radiation

International Nuclear Information System (INIS)

Hegewald, H.; Wulff, W.

1977-01-01

Taking into account the polarization effect, the dose determination for high-energy electron radiation from particle accelerators depends on the knowledge of the energy dependence of the mass stopping power. Results obtained with thermoluminescent dosemeters agree with theoretical values. For absorbed dose measurements the primary energy of electron radiation has been determined by nuclear photoreactions, and the calculation of the absorbed dose from charge measurements by means of the mass stopping power is described. Thus the calibration of ionization chambers for high-energy electron radiation by absolute measurements with the Faraday cage and chemical dosemeters has become possible. (author)

Calorific energy deposited by gamma radiations in a test reactor. Calorimetric measurements and calculations

International Nuclear Information System (INIS)

Mecheri, K.-F.

1977-01-01

The purpose of this work was to determine the calorific energy deposited by gamma radiations in the experimental devices irradiated in the test reactors of the Grenoble Nuclear Study Centre. A theoretical study briefly recalls to mind the various sorts of nuclear reactions that occur in a reactor, from the special angle of their ability to deposit calorific energy in the materials. A special study with the help of a graphite calorimeter made it possible to show the possible effect of the various parameters intervening in this energy absorption: the nature of the materials, their geometry, the spectrum of the incident gamma rays and the fact that the variation of this spectrum is due to the position of the measuring point with respect to the reactor core or to the presence of structures around the measuring instrument. The results of the calculations made with the help of the Mercury IV and ANISN codes are compared with those of the determinations in order to ascertain that very are adapted to the forecasts of energy deposition in the various materials. The conclusion was reached that in order to calculate with accuracy the depositifs of gamma energy in the experimental devices, it is necessary either to introduce the build-up calculation for the low energy photons, in the Mercury IV calculation code or to associate the DOT code to the ANISN calculation code [fr

Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

International Nuclear Information System (INIS)

2004-01-01

ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. E max > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

The radiation budget of stratocumulus clouds measured by tethered balloon instrumentation: Variability of flux measurements

Science.gov (United States)

Duda, David P.; Stephens, Graeme L.; Cox, Stephen K.

1990-01-01

Measurements of longwave and shortwave radiation were made using an instrument package on the NASA tethered balloon during the FIRE Marine Stratocumulus experiment. Radiation data from two pairs of pyranometers were used to obtain vertical profiles of the near-infrared and total solar fluxes through the boundary layer, while a pair of pyrgeometers supplied measurements of the longwave fluxes in the cloud layer. The radiation observations were analyzed to determine heating rates and to measure the radiative energy budget inside the stratocumulus clouds during several tethered balloon flights. The radiation fields in the cloud layer were also simulated by a two-stream radiative transfer model, which used cloud optical properties derived from microphysical measurements and Mie scattering theory.

Pressing problems of measurement of ionizing radiations

International Nuclear Information System (INIS)

Fominykh, V.I.; Yudin, M.F.

1993-01-01

The current system for ensuring the unity of measurements in the Russian Federation and countries of the former Soviet Union ensures a high quality of dosimetric, radiometric, and spectrometric measurements in accordance with the recommendations of the Consulative Committee on Standards for Measurements of Ionizing Radiations of the International Bureau of Weights and Measures (IBWM), International Organization on Radiological Units (ICRU), International Commission on Radiological Protection (ICRP), International Organization on Legislative Metrology (IOLM), International Atomic Energy Agency (IAEA), World Health Organization (WHO), etc. Frequent collation of the national primary and secondary standards of Russia with those of IBWM and the leading national laboratories of the world facilitate mutual verification of the measurements of ionizing radiations. The scope of scientific and scientific-technical problems that can be solved by using ionizing radiations has expanded significantly in recent years. In this paper the authors consider some pressing problems of the metrology of ionizing radiations which have arisen as a result of this expansion. These include the need for unity and reliability of measurements involved in radiation protection, the measurement of low doses involving low dose rates, ensuring the unity of measurements when monitoring the radiological security of the population, the need for more uniformity on an international scale regarding the basic physical quantities and their units for characterizing radiation fields, determination of the accuracy of measurement of the radiation dose absorbed by an irradiated tissue or organ, and the development of complex standards for ionizing radiations. 5 refs., 1 tab

Shielding Design and Leaking Measurement for the High Energy Radiation Room

International Nuclear Information System (INIS)

Chu, Sung Sil

1979-01-01

An optimum shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV , are presented. We obtained following results by comparison between the p recalculating values and actual survey after complete installation of radio generating units. 1. The precalculating values of protective barrier are 5 times more protective than that of actual measurement. 2. The dose rate during exposure are 2-10 mR /hr at out of the door and the control room. 3. The exposure doses for occupationally persons are relatively low levels, the average values of exposure dose is 10-50 mR per month. 4. The foul smelling and ozone gas production from long exposure of cancer patients cannot be eliminated when the room is ill ventilated

Moderate Image Spectrometer (MODIS) Fire Radiative Energy: Physics and Applications

Science.gov (United States)

Kaufman, Y.

2004-01-01

MODIS fire channel does not saturate in the presence of fires. The fire channel therefore is used to estimate the fire radiative energy, a measure of the rate of biomass consumption in the fire. We found correlation between the fire radiative energy, the rate of formation of burn scars and the rate of emission of aerosol from the fires. Others found correlations between the fire radiative energy and the rate of biomass consumption. This relationships can be used to estimates the emissions from the fires and to estimate the fire hazards.

Radiative corrections to high-energy neutrino scattering

International Nuclear Information System (INIS)

Rujula, A. de; Petronzio, R.; Savoy-Navarro, A.

1979-01-01

Motivated by precise neutrino experiments, the electromagnetic radiative corrections to the data are reconsidered. The usefulness is investigated and the simplicity demonstrated of the 'leading log' approximation: the calculation to order α ln (Q/μ), α ln (Q/msub(q)). Here Q is an energy scale of the overall process, μ is the lepton mass and msub(q) is a hadronic mass, the effective quark mass in a parton model. The leading log radiative corrections to dsigma/dy distributions and to suitably interpreted dsigma/dx distributions are quark-mass independent. The authors improve upon the conventional leading log approximation and compute explicitly the largest terms that lie beyond the leading log level. In practice this means that the model-independent formulae, though approximate, are likely to be excellent estimates everywhere except at low energy or very large y. It is pointed out that radiative corrections to measurements of deviations from the Callan-Gross relation and to measurements of the 'sea' constituency of nucleons are gigantic. The QCD inspired study of deviations from scaling is of particular interest. The authors compute, beyond the leading log level, the radiative corrections of the QCD predictions. (Auth.)

The response of film badge dosemeters to high energy photon radiation

International Nuclear Information System (INIS)

Playle, T.S.

1988-12-01

The sites of the earlier magnox reactor power stations at Berkeley and Bradwell in the United Kingdom are subject to 6 MeV photon radiation from the coolant gas. Since 1966 the Central Electricity Generating Board has included in its film badge personal dosimetry procedures an algorithm for applying a correction for over-response to high energy photon radiation. The correction is based on laboratory irradiations using a source of pure 6 MeV photon radiation. Recently, the opportunity arose to evaluate the response of the film badges at locations around the Berkeley reactors where spectrum-dependent dose equivalent rates had been measured. This report compares the response of the film badge in these characterised radiation environments with the response measured in the calibration laboratory. It is concluded that in the location where measurements were made, the high energy enhancement of measured dose was obscured by the effects of low energy scattered radiation, and it is considered that this will be the case for all practical situations on the power station site. There is therefore no advantage in using the 6 MeV correction factors for routine film badge dosimetry in these locations. (author)

Radiation measurement

International Nuclear Information System (INIS)

Go, Sung Jin; Kim, Seung Guk; No, Gyeong Seok; Park, Myeong Hwan; Ann, Bong Seon

1998-03-01

This book explains technical terms about radiation measurement, which are radiation, radiation quantity and unit such as prefix of international unit, unit for defence purposes of radiation, coefficient of radiation and interaction, kinds and principles of radiation detector, ionization chamber, G-M counter, G-M tube, proportional counter, scintillation detector, semiconductor radiation detector, thermoluminescence dosimeter, PLD, others detector, radiation monitor, neutron detector, calibration of radiation detector, statistics of counting value, activation analysis and electronics circuit of radiation detector.

Measuring scatter radiation in diagnostic x rays for radiation protection purposes

International Nuclear Information System (INIS)

Panayiotakis, George; Vlachos, Ioannis; Delis, Harry; Tsantilas, Xenophon; Kalyvas, Nektarios; Kandarakis, Ioannis

2015-01-01

During the last decades, radiation protection and dosimetry in medical X-ray imaging practice has been extensively studied. The purpose of this study was to measure secondary radiation in a conventional radiographic room, in terms of ambient dose rate equivalent H*(10) and its dependence on the radiographic exposure parameters such as X-ray tube voltage, tube current and distance. With some exceptions, the results indicated that the scattered radiation was uniform in the space around the water cylindrical phantom. The results also showed that the tube voltage and filtration affect the dose rate due to the scatter radiation. Finally, the scattered X-ray energy distribution was experimentally calculated. (authors)

A unified approach to deconvolution radiation spectra measured by radiochromic films

CERN Document Server

Stancic, V; Ljubenov, V

2002-01-01

A method for the evaluation of energy distribution of a radiation source on the basis of measured space distribution of deposited energy is proposed. The measured data were obtained by using radiochromic films. Mathematical modeling is defined as a Fredholm integral equation inversion problem. Negative solutions were treated as an additional condition expressed through undefined energy group boundaries, caused by virtue of the physical phenomenon of statistical uncertainty. Examples are given of the electron source and neutron radiation field.

Radiation versus radiation: nuclear energy in perspective

International Nuclear Information System (INIS)

Gonzalez, A.J.; Anderer, J.

1989-01-01

This paper seeks to provide a proper perspective on radiation exposures from nuclear energy. Instead of comparing these exposures with other pollutants, natural and man-made, it assesses the radiation doses that result from the human environment and from the entire fuel cycle associated with nuclear generated electricity. It explores radiation versus radiation, not only in terms of absolute levels but, more importantly, of the enormous variability characterizing many radiation sources. The quantitative findings and their implications are meant to contribute to a balanced understanding of the radiological impact of nuclear energy, and so to help to bridge the information gap that is perceived to exist on this issue. The 1988 Unscear report and its seven scientific annexes provide an authoritative and dispassionate factual basis for examining radiation levels from all sources, natural and man-made. It is the main source for this paper. (author)

Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

Energy Technology Data Exchange (ETDEWEB)

Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.

1992-03-01

The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.

Environmental Gamma Radiation Measurements in Baskil District

International Nuclear Information System (INIS)

Canbazoglu, C.

2008-01-01

In this study, we have determined environmental gamma radiation dose rate in Baskil district which has very high granite content in its geographical structure. Gamma radiation dose rate measurements were achieved by portable radiation monitoring equipment based on the energy range between 40 keV and 1.3 MeV. The measurements were performed on asphalt and soil surface level and also one meter above the ground surface. The gamma dose rate was also performed inside and outside of buildings over the district. The dose rates were found to be between 8.46μR/h and 34.66 μR/h. Indoor and outdoor effective dose rate of the gamma radiation exposure has been calculated to be 523μSv/y and 196μSv/y, respectively

An overview of global solar radiation measurements in Ghardaia area, south Algeria

Energy Technology Data Exchange (ETDEWEB)

Gairaa, Kacem; Bakelli, Yahia [Applied Research Unit for Renewables Energies, Ouargla Road, Ghardaia (Algeria)

2011-07-01

This paper presents an overview of actual solar radiation data measurements in Ghardaia site (32.360 N, 3.810 W, 450 m above MSL). Global solar radiation and surface temperatures were measured and analyzed for one complete year from 1 January-31December 2005. The data thus recorded are compared with corresponding data of the 22-year average of NASA's surface meteorology and solar energy-model. Hourly, daily and monthly solar radiation was made from five-minute recorded by EKO Pyranometer. The highest measured daily and monthly mean solar radiation was found to be 369 and 326 (W/m2), and the highest five minute averaged solar radiation values up to 1268 (W/m2) were observed in the summer season from May to September, and the yearly average daily energy input was 21.83 (MJ/m2/day). Besides the global solar radiation, the daily and monthly average temperature variations are discussed. The collected data indicate that Ghardaia has a strong potential for solar energy applications.

Dark information of black hole radiation raised by dark energy

Science.gov (United States)

Ma, Yu-Han; Chen, Jin-Fu; Sun, Chang-Pu

2018-06-01

The "lost" information of black hole through the Hawking radiation was discovered being stored in the correlation among the non-thermally radiated particles (Parikh and Wilczek, 2000 [31], Zhang et al., 2009 [16]). This correlation information, which has not yet been proved locally observable in principle, is named by dark information. In this paper, we systematically study the influences of dark energy on black hole radiation, especially on the dark information. Calculating the radiation spectrum in the existence of dark energy by the approach of canonical typicality, which is reconfirmed by the quantum tunneling method, we find that the dark energy will effectively lower the Hawking temperature, and thus makes the black hole has longer life time. It is also discovered that the non-thermal effect of the black hole radiation is enhanced by dark energy so that the dark information of the radiation is increased. Our observation shows that, besides the mechanical effect (e.g., gravitational lensing effect), the dark energy rises the stored dark information, which could be probed by a non-local coincidence measurement similar to the coincidence counting of the Hanbury-Brown-Twiss experiment in quantum optics.

Radiation effects, nuclear energy and comparative risks

International Nuclear Information System (INIS)

Gopinath, D.V.

2007-01-01

Nuclear energy had a promising start as an unlimited, inexpensive and environmentally benign source of energy for electricity generation. However, over the decades its growth was severely retarded due to concerns about its possible detrimental effects on the well-being of mankind and the environment. Since such concerns are essentially due to the gigantic magnitude of radioactivity and ionizing radiations associated with nuclear energy, this article starts with a comprehensive account of effects of the ionizing radiation on living systems. Quantitative description of types of radiation exposure and their varied effects is given. The origin, type and magnitude of mutagenic effects of radiation are described. The concept of radiation risk factors, basis for their evaluation and their currently accepted values are presented. With this background, origin and magnitude of radioactivity and associated ionizing radiations in nuclear reactors are presented and the elaborate measures to contain them are described. It is recognized that notwithstanding all the measures taken in the nuclear industry, certain amount of radiation exposure, however small, is inevitable and the values, based on the experience world over, are presented. Estimated health risk due to such exposures is evaluated. For a comparative analysis, risks in other options of electricity generation such as hydel and fossil-fuelled plants are described. It is seen that on an overall basis, the nuclear option is no more risky than the other commonly employed options, and is in fact, significantly less. Lastly, since every option of electricity generation entails some risk, the case of 'no addition of electricity, and its impact on the society are considered. Based on the analysis of extensive data provided by UNDP on the human development parameters for different countries in the world, it is shown that at least for developing countries, any option of addition of electricity would be far more desirable than the

Online radiation dose measurement system for ATLAS experiment

International Nuclear Information System (INIS)

Mandic, I.; Cindro, V.; Dolenc, I.; Gorisek, A.; Kramberger, G.; Mikuz, M.; Bronner, J.; Hartet, J.; Franz, S.

2009-01-01

In experiments at Large Hadron Collider, detectors and electronics will be exposed to high fluxes of photons, charged particles and neutrons. Damage caused by the radiation will influence performance of detectors. It will therefore be important to continuously monitor the radiation dose in order to follow the level of degradation of detectors and electronics and to correctly predict future radiation damage. A system for online radiation monitoring using semiconductor radiation sensors at large number of locations has been installed in the ATLAS experiment. Ionizing dose in SiO 2 will be measured with RadFETs, displacement damage in silicon in units of 1-MeV(Si) equivalent neutron fluence with p-i-n diodes. At 14 monitoring locations where highest radiation levels are expected the fluence of thermal neutrons will be measured from current gain degradation in dedicated bipolar transistors. The design of the system and tests of its performance in mixed radiation field is described in this paper. First results from this test campaign confirm that doses can be measured with sufficient sensitivity (mGy for total ionizing dose measurements, 10 9 n/cm 2 for NIEL (non-ionizing energy loss) measurements, 10 12 n/cm 2 for thermal neutrons) and accuracy (about 20%) for usage in the ATLAS detector

Techniques for radiation measurements: Micro-dosimetry and dosimetry

International Nuclear Information System (INIS)

Waker, A. J.

2006-01-01

Experimental Micro-dosimetry is concerned with the determination of radiation quality and how this can be specified in terms of the distribution of energy deposition arising from the interaction of a radiation field with a particular target site. This paper discusses various techniques that have been developed to measure radiation energy deposition over the three orders of magnitude of site-size; nano-meter, micrometer and millimetre, which radiation biology suggests is required to fully account for radiation quality. Inevitably, much of the discussion will concern the use of tissue-equivalent proportional counters and variants of this device, but other technologies that have been studied, or are under development, for their potential in experimental Micro-dosimetry are also covered. Through an examination of some of the quantities used in radiation metrology and dosimetry the natural link with Micro-dosimetric techniques will be shown and the particular benefits of using Micro-dosimetric methods for dosimetry illustrated. (authors)

A large area transition radiation detector to measure the energy of muons in the Gran Sasso underground laboratory

International Nuclear Information System (INIS)

Barbarito, E.; Bellotti, R.; Cafagna, F.; Castellano, M.; De Cataldo, G.; De Marzo, C.; Favuzzi, C.; Fusco, P.; Giglietto, N.; Guarnaccia, P.; Mazziotta, M.N.; Mongelli, M.; Montaruli, T.; Perchiazzi, M.; Raino, A.; Sacchetti, A.; Spinelli, P.

1995-01-01

We have designed and built a transition radiation detector of 36 m 2 area in order to measure the residual energy of muons penetrating in the Gran Sasso cosmic ray underground laboratory up to the TeV region. It consists of three adjacent modules, each of 2x6 m 2 area. Polystyrene square tubes, filled with a argon-carbon dioxide gas mixture, and polyethylene foam layers are used as proportional detectors and radiators respectively. We cover such a large surface with only 960 channels that provide adequate energy resolution and particle tracking for the astroparticle physics items to investigate. The detector has been calibrated using a reduced size prototype in a test beam. Results from one module exposed to cosmic rays at sea level are shown. (orig.)

Radiation measurement of civil air flight

International Nuclear Information System (INIS)

Winter, M.

1999-01-01

In order to aquire knowledge of the radiation exposure of civil aircrew members in common flight altitudes, it was necessary to develop a practicable measurement system. Radiation exposure was hereby estimated by using the ACREM-System, which is patented by the Austrian Research Centres Seibersdorf (OEFZS). Total Equivalent Dose could be estimated in a simple way by combining a measured component of the radiation field in flight altitudes and the results of simulation with LUIN 94 particle transport code (Keran O'Brian). To verify the results of the measurement system, a tissue equivalent proportional counter (TEPC) was used. Because of the difficult measurement conditions in cargo airplanes, special attention had to be taken to make the measurement equipment easy to use and transport. Special software has been developed to automate the measurement and the evaluation of the large amount of collected data. Measurements in standard calibration photon fields for the characterization of the equipment could be performed at the Primary Dosimetry Laboratory for Austria at the Austrian Research Centre (OEFZS) in Seibersdorf. Additional measurements were performed at Physikalisch Technische Bundesanstalt Braunschweig (PTB, Germany) and Paul Scherer Institute (PSI, Switzerland) to determine the reponse of the instruments to high energy photon and standard neutron fields. (author)

Radiative energy losses from a high-current air-blast arc

International Nuclear Information System (INIS)

Strachan, D.C.; Lidgate, D.; Jones, G.R.

1977-01-01

The importance of total radiation losses from high-current arcs burning in highly accelerated air flows representative of conditions existing in commercial gas-blast switchgear has been investigated. Such losses have been measured both in the high-pressure region upstream of a shaped orifice, where gas velocities are low, and in the region downstream where velocities become supersonic and pressure conditions approach ambient. The dominance of upstream electrode vapor as the source of plasma radiation losses is demonstrated and the importance of radiated losses within the arc energy balance is examined using measured values of axial electric field. For upstream electrodes of elkonite (sintered copper/tungsten) as used in high-power gas-blast circuit breakers, it is shown that some 30--40% of the electrical energy input upstream of the orifice is lost as radiation, while downstream this figure becomes 10--20%. The effect of reservoir pressure on arc electric fields is examined and the contribution to this effect of radiation losses is quantified

Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling

Energy Technology Data Exchange (ETDEWEB)

Gueymard, Christian A. [Solar Consulting Services, P.O. Box 392, Colebrook, NH 03576 (United States); Myers, Daryl R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401-3305 (United States)

2009-02-15

The solar renewable energy community depends on radiometric measurements and instrumentation for data to design and monitor solar energy systems, and develop and validate solar radiation models. This contribution evaluates the impact of instrument uncertainties contributing to data inaccuracies and their effect on short-term and long-term measurement series, and on radiation model validation studies. For the latter part, transposition (horizontal-to-tilt) models are used as an example. Confirming previous studies, it is found that a widely used pyranometer strongly underestimates diffuse and global radiation, particularly in winter, unless appropriate corrective measures are taken. Other types of measurement problems are also discussed, such as those involved in the indirect determination of direct or diffuse irradiance, and in shadowband correction methods. The sensitivity of the predictions from transposition models to inaccuracies in input radiation data is demonstrated. Caution is therefore issued to the whole community regarding drawing detailed conclusions about solar radiation data without due attention to the data quality issues only recently identified. (author)

Control of the radiation environment and the worker in high-energy facilities

International Nuclear Information System (INIS)

Stevenson, G.R.

1993-01-01

The philosophy behind the prediction, measurement, monitoring and limitation by access control of the radiation hazard in high-energy accelerator facilities is compared with that which could be employed for controlling similar hazards due to cosmic radiation in civil aircraft flights. Special mention is made of computer simulations of the radiation environment as a means of predicting necessary control measures, of the reliability and integration of radiation measuring devices into control procedures and of the relevance of different access control procedures. (author)

An Experiment in Radiation Measurement Using the Depron Instrument

Science.gov (United States)

Benghin, Victor V.; Nechaev, Oleg Y.; Zolotarev, Ivan A.; Amelyushkin, Alexander M.; Petrov, Vasiliy L.; Panasyuk, Milhail I.; Yashin, Ivan V.

2018-02-01

Most of the radiation measurements have been made onboard spacecraft flying along orbits with an inclination of up to 51.6 degrees. Due to the prospect of manned missions at orbits with larger inclinations, it is advisable to conduct preliminary detailed dosimetry measurements at a high-inclination orbit; due to its polar orbit, the Lomonosov satellite provides good opportunities for such study. We chose a method of cosmic radiation dosimetry based on semiconductor detectors. This method is widely used onboard spacecraft, including full-time radiation monitoring onboard the International Space Station (ISS). It should be noted that not only did the charged particles contribute significantly in the dose equivalent, but also did the neutrons. Semiconductor detectors have low sensitivity to neutron radiation and are not sufficient for detecting the expected flux of neutrons. We add a thermal neutron counter to the proposed device in order to provide an opportunity for estimation of neutron flux variations along the satellite trajectory. Thus, the design of the instrument DEPRON (Dosimeter of Electrons, PROtons and Neutrons) was determined. DEPRON is intended for registration of the absorbed doses and linear energy transfer spectra for high-energy electrons, protons and nuclei of space radiation, as well as registration of thermal neutrons. The present paper provides a brief description of the DEPRON instrument. Its calibration results and the first mission results of background radiation measurements are also presented.

High energy particle accelerators as radiation Sources

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

1997-12-31

Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

Online radiation dose measurement system for ATLAS experiment

Energy Technology Data Exchange (ETDEWEB)

Mandic, I.; Cindro, V.; Dolenc, I.; Gorisek, A.; Kramberger, G. [Jozef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Mikuz, M. [Jozef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Faculty of Mathematics and Physics, University of Ljubljana (Slovenia); Bronner, J.; Hartet, J. [Physikalisches Institut, Universitat Freiburg, Hermann-Herder-Str. 3, Freiburg (Germany); Franz, S. [CERN, Geneva (Switzerland)

2009-07-01

In experiments at Large Hadron Collider, detectors and electronics will be exposed to high fluxes of photons, charged particles and neutrons. Damage caused by the radiation will influence performance of detectors. It will therefore be important to continuously monitor the radiation dose in order to follow the level of degradation of detectors and electronics and to correctly predict future radiation damage. A system for online radiation monitoring using semiconductor radiation sensors at large number of locations has been installed in the ATLAS experiment. Ionizing dose in SiO{sub 2} will be measured with RadFETs, displacement damage in silicon in units of 1-MeV(Si) equivalent neutron fluence with p-i-n diodes. At 14 monitoring locations where highest radiation levels are expected the fluence of thermal neutrons will be measured from current gain degradation in dedicated bipolar transistors. The design of the system and tests of its performance in mixed radiation field is described in this paper. First results from this test campaign confirm that doses can be measured with sufficient sensitivity (mGy for total ionizing dose measurements, 10{sup 9} n/cm{sup 2} for NIEL (non-ionizing energy loss) measurements, 10{sup 12} n/cm{sup 2} for thermal neutrons) and accuracy (about 20%) for usage in the ATLAS detector

Application of a universal optic data link for radiation measurements

International Nuclear Information System (INIS)

Komatsu, T.; Takada, E.

2002-01-01

Optic Data Link (ODL) is a device to convert electric and optic signals to each other, which is used for the field of optical communications. We examined the possibility to apply ODLs to radiation measurements. The effect of ODLs on energy and timing resolution has been investigated. From the results, fundamental applicability of ODLs to radiation measurements has been demonstrated. (author)

Calculation of radiative corrections to virtual compton scattering - absolute measurement of the energy of Jefferson Lab. electron beam (hall A) by a magnetic method: arc project

International Nuclear Information System (INIS)

Marchand, D.

1998-11-01

This thesis presents the radiative corrections to the virtual compton scattering and the magnetic method adopted in the Hall A at Jefferson Laboratory, to measure the electrons beam energy with an accuracy of 10 4 . The virtual compton scattering experiments allow the access to the generalised polarizabilities of the protons. The extraction of these polarizabilities is obtained by the experimental and theoretical cross sections comparison. That's why the systematic errors and the radiative effects of the experiments have to be controlled very seriously. In this scope, a whole calculation of the internal radiative corrections has been realised in the framework of the quantum electrodynamic. The method of the dimensional regularisation has been used to the treatment of the ultraviolet and infra-red divergences. The absolute measure method of the energy, takes into account the magnetic deviation, made up of eight identical dipoles. The energy is determined from the deviation angle calculation of the beam and the measure of the magnetic field integral along the deviation

Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

International Nuclear Information System (INIS)

Szabó, J.; Pálfalvi, J.K.

2012-01-01

The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008–2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

Energy Technology Data Exchange (ETDEWEB)

Szabo, J., E-mail: julianna.szabo@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary); Palfalvi, J.K. [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary)

2012-12-01

The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008-2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

Bunch Length Measurements using Coherent Radiation

CERN Document Server

Ischebeck, Rasmus; Barnes, Christopher; Blumenfeld, Ian; Clayton, Chris; Decker, Franz Josef; Deng, Suzhi; Hogan, Mark; Huang Cheng Kun; Iverson, Richard; Johnson, Devon K; Krejcik, Patrick; Lu, Wei; Marsh, Kenneth; Oz, Erdem; Siemann, Robert; Walz, Dieter

2005-01-01

The accelerating field that can be obtained in a beam-driven plasma wakefield accelerator depends on the current of the electron beam that excites the wake. In the E-167 experiment, a peak current above 10kA will be delivered at a particle energy of 28GeV. The bunch has a length of a few ten micrometers and several methods are used to measure its longitudinal profile. Among these, autocorrelation of coherent transition radiation (CTR) is employed. The beam passes a thin metallic foil, where it emits transition radiation. For wavelengths greater than the bunch length, this transition radiation is emitted coherently. This amplifies the long-wavelength part of the spectrum. A scanning Michelson interferometer is used to autocorrelate the CTR. However, this method requires the contribution of many bunches to build an autocorrelation trace. The measurement is influenced by the transmission characteristics of the vacuum window and beam splitter. We present here an analysis of materials, as well as possible layouts ...

Measurement of radiative lifetime in atomic samarium using ...

Indian Academy of Sciences (India)

2014-02-08

Feb 8, 2014 ... gations of radiative lifetime measurement of odd-parity energy level at ... introduced by an electronic delay generator between the two ... cascade repopulation and depopulation, Zeeman and hyperfine quantum beats [6]. The.

Space weather effects measured in atmospheric radiation on aircraft

Science.gov (United States)

Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Wieman, S. R.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, L. D.; Mertens, C. J.; Xu, X.; Wiltberger, M. J.; Wiley, S.; Teets, E.; Shea, M. A.; Smart, D. F.; Jones, J. B. L.; Crowley, G.; Azeem, S. I.; Halford, A. J.

2016-12-01

Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Since 2013 Space Environment Technologies (SET) has been conducting observations of the atmospheric radiation environment at aviation altitudes using a small fleet of six instruments. The objective of this work is to improve radiation risk management in air traffic operations. Under the auspices of the Automated Radiation Measurements for Aerospace Safety (ARMAS) and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) projects our team is making dose rate measurements on multiple aircraft flying global routes. Over 174 ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the radiation environment resulting from Galactic Cosmic Rays (GCRs), Solar Energetic Protons (SEPs), and outer radiation belt energetic electrons. The real-time radiation exposure is measured as an absorbed dose rate in silicon and then computed as an ambient dose equivalent rate for reporting dose relevant to radiative-sensitive organs and tissue in units of microsieverts per hour. ARMAS total ionizing absorbed dose is captured on the aircraft, downlinked in real-time, processed on the ground into ambient dose equivalent rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users. Dose rates from flight altitudes up to 56,700 ft. are shown for flights across the planet under a variety of space weather conditions. We discuss several space weather

Neutron dose measurements with the GSI ball at high energy accelerators

International Nuclear Information System (INIS)

Fehrenbacher, G.; Gutermuth, F.; Radon, T.; Kozlova, E.

2005-01-01

Full text: At high energy particle accelerators the production of neutron radiation dominates radiation protection. For the radiation survey at accelerators there is a need for reliable detection systems (passive radiation monitors), which can measure the dose for a wide range of neutron energies independently on the beam pulse structure of the produced radiation. In this work a passive neutron dosemeter for the measurement of the ambient dose equivalent is presented. The dosemeter is suitable for measurements of the emerging neutron radiation at accelerators for the whole energy range up to about 10 GeV. The dosemeter consists of a polyethylene sphere, TL elements (pairs of TLD600/700) and an additional lead layer (PE/Pb) in neutron fields at high energy accelerators is investigated in this work. Results of dose measurements which were performed in realistic neutron fields at the high energy accelerator SPS at CERN (CERF facility) and in Cave A at the heavy ion synchrotron SIS at GSI are presented. The results of these measurements are compared with the expected dose values from the neutron spectra determined for the measurement positions at CERF and in Cave A (FLUKA) and with the dosemeter response derived by the calculated response functions (FLUKA) folded with the neutron spectra. The comparisons show that the additional lead layer in the PE/Pb-sphere improves significantly the response of the dosemeter. The response of the PE/Pb-sphere is 40 to 50 % higher at CERF and Cave A in comparison to the bare PE-sphere. At CERF the dose values of the PE/Pb-sphere is about 25 % lower than the expected dose value, whilst for Cave A, a rather good agreement was found (2 % deviation). (author)

Measurement of Gamma-ray Energy Spectrum According to Temperature Variation Using a Fiber-Optic Radiation Sensor Based on YSO:Ce Crystal

Energy Technology Data Exchange (ETDEWEB)

Jeon, H.; Yoo, W. J.; Shin, S. H.; Jang, J. S.; Kim, J. S.; Kwon, G.; Lee, D. E.; Jang, K. W.; Lee, B. [BK21 Plus Research Institute of Biomedical Engineering, Konkuk University, Chungju (Korea, Republic of)

2015-05-15

As an alternative to conventional radiation detectors, various fiber-optic radiation sensors (FORSs) have been investigated for gamma-ray monitoring because of their various desirable advantages, such as their small sensing volume, substantial flexibility, remote operation, ability to make real-time measurement, and immunity to high electromagnetic interference. In general, the basic principle of a radiation detection using scintillators is to measure the scintillating light signals generated from the interactions between the scintillators and the radiations. To measure gamma-ray, the inorganic scintillators used in the FORS should have some properties, such as high atomic material, high light yields, fast decay time, high density, and high stopping power. For these reasons, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal has been introduced as a promising scintillator in various radiation sensor applications. According to the recent studies, however, LYSO:Ce crystal is impossible to be applied in high-temperature conditions because it serves the fluctuations of its light yields with the temperature variation (i.e., thermosluminescence). In this study, to obtain gamma-ray energy spectra by measuring scintillating light signals emitted from the scintillators in high-temperature conditions, we first fabricated an FORS system using various inorganic scintillator crystals and then evaluated the light yields of each inorganic scintillator. As a promising scintillator for use in high-temperature conditions, a cerium-doped yttrium orthosilicate (YSO:Ce) crystal was selected and evaluated its thermal property according to the elevated temperature up to 300 .deg. C. We fabricated an FORS using inorganic scintillator and an optical fiber bundle. To select an adequate scintillator to apply in high-temperature conditions, the gamma-ray energy spectra were obtained by using four kinds of inorganic scintillators. From the experimental results, we selected YSO

Pulse-by-pulse energy measurement at the Stanford Linear Collider

International Nuclear Information System (INIS)

Blaylock, G.; Briggs, D.; Collins, B.; Petree, M.

1992-01-01

The stanford Linear Collider (SLC) collides a beam of electrons and positrons at 92 GeV. It is the first colliding linac, and produces Z 0 particles for High-Energy Physics measurements. The energy of each beam must be measured to one part in 10 4 on every collision (120 Hz). An Energy Spectrometer in each beam line after collision produces two stripes of high-energy synchrotron radiation with critical energy of a few MeV. The distance between these two stripes at an imaging plane measures the beam energy. The Wire- Imaging Synchrotron Radiation Detector (WISRD) system comprises a novel detector, data acquisition electronics, readout and analysis. The detector comprises an array of wires for each synchrotron stripe. The electronics measure secondary emission charge on each wire of each array. A Macintosh II (using THINK C, THINK Class Library) and DSP coprocessor (using ANSI C) acquire and analyze the data, and display and report the results for SLC operation

Pulse-by-pulse energy measurement at the Stanford Linear Collider

Science.gov (United States)

Blaylock, G.; Briggs, D.; Collins, B.; Petree, M.

1992-01-01

The Stanford Linear Collider (SLC) collides a beam of electrons and positrons at 92 GeV. It is the first colliding linac, and produces Z(sup 0) particles for High-Energy Physics measurements. The energy of each beam must be measured to one part in 10(exp 4) on every collision (120 Hz). An Energy Spectrometer in each beam line after the collision produces two stripes of high-energy synchrotron radiation with critical energy of a few MeV. The distance between these two stripes at an imaging plane measures the beam energy. The Wire-Imaging Synchrotron Radiation Detector (WISRD) system comprises a novel detector, data acquisition electronics, readout, and analysis. The detector comprises an array of wires for each synchrotron stripe. The electronics measure secondary emission charge on each wire of each array. A Macintosh II (using THINK C, THINK Class Library) and DSP coprocessor (using ANSI C) acquire and analyze the data, and display and report the results for SLC operation.

A compact low energy multibeam gamma-ray densitometer for pipe-flow measurements

International Nuclear Information System (INIS)

Tjugum, Stein-Arild; Frieling, Joop; Johansen, Geir Anton

2002-01-01

A compact low-energy multibeam gamma-ray densitometer for oil/water/gas pipe-flow measurement has been built at the University of Bergen. The instrument consists of one Am-241 source and three detectors, all collimated and embedded in the pipe wall. Only the 59.5 keV radiation energy of the source is utilized. Two of the detectors measure transmitted radiation across the pipe flow, and one measure scattered radiation at a 90 degree sign angle. The purpose of the multibeam measurement geometry is to acquire flow regime information and to reduce the flow regime dependency of the gas volume fraction (GVF) measurements. The measurement of scattered radiation enables the dual modality densitometry (DMD) measurement principle to be exploited. Its basic principle is to combine the measurement of scattered and transmitted radiation in order to obtain salinity independent GVF measurements. The salinity dependency is otherwise strongly significant when using low-energy radiation. It is also possible to measure the salinity by using this principle. The instrument is a laboratory prototype, and it has been used for characterising the measurement principle and to test different detector alternatives. The testing of the instrument includes static tests on plastic phantoms, tests on simulated water/gas flow and three phase flow loop tests. Both the multibeam measurement principle and the DMD principle have been verified to provide valuable information. This paper presents the physics behind, experimental results and an evaluation of the system

Characterization of CERN-EU high energy reference radiation fields with recombination chamber

International Nuclear Information System (INIS)

Golnik, N.

1998-01-01

The CERN-EU reference radiation field facility (called CERFF) is available behind a shielding of high-energy particles beam at CERN since 1993. At present the parameters of the radiation from beam target are well investigated, however, there are still some serious doubts concerning contribution of low-LET concurrent radiation. This paper presents an experimental procedure for determination of the contribution from the concurrent radiation by measuring the absorbed dose and recombination index of radiation quality at different beam intensities. Additionally, the values of H * (10) were measured in several measuring locations. Measurements were performed with a REM-2 recombination chamber and compared with those obtained by using a HANDI-TEPC instrument. (author)

Evaluation of long-term global radiation measurements in Denmark and Sweden

DEFF Research Database (Denmark)

Skalík, Lukáš; Lulkovičová, Otília; Furbo, Simon

The climate, especially global radiation is one of the key factors influencing the energy yield of solar energy systems. In connection with planning and optimization of energy efficient buildings and solar energy systems it is important to know the climate data of the area where the buildings...... of the atmosphere, increased duration of periods without clouds and/or combination of both these effects. Twenty years of measurements from a climate station in Lyngby, Denmark show that the global radiation increase is almost 3.5 kWh/m2 per year, corresponding to a growth of 7 % for the last 20 years. The global....../systems are located. This study is based on yearly and monthly values of global radiation based on measurements from a climate station placed on the roof of building 119 at Technical University of Denmark in Kgs. Lyngby, from different Danish climate stations runned by Danish Meteorological Institute and from...

Measuring thyroid uptake with hand-held radiation monitors

International Nuclear Information System (INIS)

Deschamps, M.

1987-04-01

With the use of Iodine 123, 125 and 131 and some compounds of Technetium-99 m, a fraction of the isotopes can be trapped in the thyroid of the technicians. We used the hand-held radiation contamination or survey meters of the nine (9) Nuclear medicine departments we visited to see if they were adequate for the evaluation of thyroid uptake of the users. Measurements on a neck-phanton helped us to determine a minimum detectable activity for each isotope. We were then able to check if the measurements of investigations and action levels were possible. None of the hand-held radiation monitors are completely satisfactory for the measure of thyroid uptake of the user. We discuss a class of equipment capable of measuring radiation emissions at the investigation level. Measurement at the action level is possible with meters having scintillation or proportional probes but none of them permits the discrimination in energy required for a quantitative evaluation of the radioisotopes used

A study on radiation safety measures for the use of high-energy beta-ray sources in medical fields

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Woo; Yang, Jeong Seon; Kim, Hyeon Jo [Cheju National Univ., Cheju (Korea, Republic of)

2000-12-15

The scope of this study consists of : an investigation of the current application status of medical radioisotopes, Sr-90, Ho-166, Re-188, which emit beta-rays of energy greater than 1.5 Mev, analyses of the environments under which the above isotopes are used, estimation of personal radiation doses by using the MCNP-4C computer code for the situations in which high radiation doses might be probable, review of the USA's regulations related to safe use of the radioisotopes, investigation of past over-expose cases reported in the internet, analysis of the current domestic regulations, suggestion of safety measures necessary for the use of the radioisotopes.

High energy radiation detector

International Nuclear Information System (INIS)

Vosburgh, K.G.

1975-01-01

The high energy radiation detector described comprises a set of closely spaced wedge reflectors. Each wedge reflector is composed of three sides forming identical isoceles triangles with a common apex and an open base forming an equilateral triangle. The length of one side of the base is less than the thickness of the coat of material sensitive to high energy radiation. The wedge reflectors reflect the light photons spreading to the rear of the coat in such a way that each reflected track is parallel to the incident track of the light photon spreading rearwards. The angle of the three isosceles triangles with a common apex is between 85 and 95 deg. The first main surface of the coat of high energy radiation sensitive material is in contact with the projecting edges of the surface of the wedge reflectors of the reflecting element [fr

Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

International Nuclear Information System (INIS)

Osterhuber, R.; Condreva, K.

1998-01-01

Incoming, background cosmic radiation constantly fluxes through the earth's atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters' worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location

Solar Radiation Measurement Using Raspberry Pi and Its Modelling Using Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Priya Selvanathan Shanmuga

2016-01-01

Full Text Available The advent of solar energy as the best alternative to traditional energy sources has led to an extensive study on the measurement and prediction of solar radiation. Devices such as pyranometer, pyrrheliometer, global UV radiometer are used for the measurement of solar radiation. The solar radiation measuring instruments available at Innovation Center, MIT Manipal were integrated with a Raspberry Pi to allow remote access to the data through the university Local Area Network. The connections of the data loggers and the Raspberry Pi were enclosed in a plastic box to prevent damage from the rainfall and humidity in Manipal. The solar radiation data was used to validate an Artificial Neural Network model which was developed using various meterological data from 2011-2015.

INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

Directory of Open Access Journals (Sweden)

Alexandru Dan Toma

2013-07-01

Full Text Available The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categories of instruments used to measure the transmission of solar radiation through Earth's atmosphere: instruments that measure radiation from the entire sky and instruments that measure only direct solar radiation. Within each of these categories, instruments can be further subdivided into those that measure radiation over a broad range of wavelengths and those that measure only specific wavelengths.

Spectroscopic and bolometric measurements of radiation loss in DIVA

International Nuclear Information System (INIS)

Shiho, Makoto; Odajima, Kazuo; Sugie, Tatsuo; Maeda, Hikosuke; Kasai, Satoshi

1977-11-01

Radiation loss due to low- and high-z impurities in DIVA (JFT-2a) was measured by means of a calibrated 3m grazing incidence vacuum monochromater and a calibrated pyroelectric detector. The following results were obtained: 1) Radiation loss power due to low-z impurities becomes insignificant by using clean surfaces for the vacuum wall. 2) Radiation loss power due to pseudo continuum from high-z impurities has influence on the energy balance of the confined plasma. 3) The divertor reduces the radiation loss by a factor of about 3. (auth.)

Radiation doses by radiation diagnostics at the border of a hospital. Calculation model for Nuclear Energy Law regulations

International Nuclear Information System (INIS)

Shapiro, B.; Thijssen, T.; De Jong, R.

2000-01-01

According to the Nuclear Energy Law in the Netherlands radiation doses at the border of a specific institute (e.g. hospitals) must be determined which can not simply be done by measurements. In this article a model calculation for radiation diagnostics is described

Energy balance in processes of transition radiation

International Nuclear Information System (INIS)

Vladimirov, S.V.; Tsytovich, V.N.

1985-01-01

The authors consider the transition radiation arising when a charged particle crosses an interface between two nonabsorbing media. It is shown that energy balance is observed under these circumstances. The fulfillment of energy balance in transition radiation for nonabsorbing media is rigorously demonstrated. This allows one to find the energy of the transition radiation from the change in the energy of the intrinsic field of the charge and the work of forces for volume waves, which in a number of cases of complicated configurations may prove to be considerably simpler than a direct calculation of the radiation power. For surface waves, a calculation of the work of forces enables one to determine the radiation power directly

Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

CERN Document Server

García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

Density measurement using gamma radiation - theory and application

International Nuclear Information System (INIS)

Springer, E.K.

1979-01-01

There are still widespread uncertainties about the use and safety of gamma radiation in industries. This paper describes, by the example of radiometric density measurement, the theory of gamma radiation. The differences and advantages of both types of detectors, the ionization chamber and the scintillation counter, are discussed. The degree of accuracy which can be expected from the radiometric density meter will be defined, and the inter-relationship: source strength - measuring range - measuring length(normally the pipe diameter) in relation to the measuring accuracy required will be explained in detail. The use of radioactive material requires the permission of the Atomic Energy Board. The formalities involved to receive a user's licence and the implementations of safety standards set by the local authorities are discussed in depth [af

High-energy outer radiation belt dynamic modeling

International Nuclear Information System (INIS)

Chiu, Y.T.; Nightingale, R.W.; Rinaldi, M.A.

1989-01-01

Specification of the average high-energy radiation belt environment in terms of phenomenological montages of satellite measurements has been available for some time. However, for many reasons both scientific and applicational (including concerns for a better understanding of the high-energy radiatino background in space), it is desirable to model the dynamic response of the high-energy radiation belts to sources, to losses, and to geomagnetic activity. Indeed, in the outer electron belt, this is the only mode of modeling that can handle the large intensity fluctuations. Anticipating the dynamic modeling objective of the upcoming Combined Release and Radiation Effects Satellite (CRRES) program, we have undertaken to initiate the study of the various essential elements in constructing a dynamic radiation belt model based on interpretation of satellite data according to simultaneous radial and pitch-angle diffusion theory. In order to prepare for the dynamic radiation belt modeling based on a large data set spanning a relatively large segment of L-values, such as required for CRRES, it is important to study a number of test cases with data of similar characteristics but more restricted in space-time coverage. In this way, models of increasing comprehensiveness can be built up from the experience of elucidating the dynamics of more restrictive data sets. The principal objectives of this paper are to discuss issues concerning dynamic modeling in general and to summarize in particular the good results of an initial attempt at constructing the dynamics of the outer electron radiation belt based on a moderately active data period from Lockheed's SC-3 instrument flown on board the SCATHA (P78-2) spacecraft. Further, we shall discuss the issues brought out and lessons learned in this test case

Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

Energy Technology Data Exchange (ETDEWEB)

Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

1986-08-01

The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs.

Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

International Nuclear Information System (INIS)

Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

1986-08-01

The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs

DCARR: a spectrograph for measuring low-energy x rays

International Nuclear Information System (INIS)

Anon.

1978-01-01

DCARR, the Differential Critical Angle Reflection Refraction detector system, is described. This detector was designed to measure low-energy x rays, 500 to 5000 eV, with a high degree of resolution, 250 eV. DCARR was developed because these low-energy measurements are of interest in the diagnostics of x-radiation in nuclear tests and available equipment could not make measurements at this low an energy in field tests. DCARR is a versatile piece of equipment that can also be used as a laboratory tool, such as in measuring the low-energy x rays emitted by lasers and various x-ray machines

Fundamental radiation effect on polymers energy transfer from radiation to polymer

International Nuclear Information System (INIS)

Seguchi, T.

2007-01-01

Polymer modification as cross-link, chain scission, and graft-polymerization by radiation is initiated by the quantum energy transferred from radiation to polymers. The active species for chemical reactions are produced through ionization or activation of polymer molecules for any radiation source. The energy transfer occurs mainly by ionic interaction between radiation and polymer molecule, and the contribution from the collision interaction is miner. The radiation of electromagnetic wave as X-ray or γ-ray generates the energetic electron which induces ionic interaction with polymer molecule. The energy loss profile along the penetration to polymer material is much different among the radiation sources of EB, γ-ray, and ion beams in the macroscopic mechanism. In this article, the behavior of single event, that is, the event induced by one electron, γ-ray, ion, and neutron is described by the macroscopic mechanism and by the microscopic mechanism. (authors)

Experimental microdosimetry in high energy radiation fields

International Nuclear Information System (INIS)

Spurny, F.; Bednar, J.; Vlcek, B.; Bottollier-Depois, J.-F.; Molokanov, A.G.

2000-01-01

To determine microdosimetric characteristics in the beams and fields of high energy panicles with the goal, also, to compare the classical method of experimental microdosimetry, a tissue equivalent low pressure proportional counter (TEPC) with the linear energy transfer (LET) spectrometer based on a chemically etched polyallyldiglycolcarbonate as a track etched detector (TED). To test the use of TED LET spectrometer in the conditions, where the use or TEPC is not possible (high energy charged particle beams at high dose rates). The results obtained with the TEPC NAUSICAA were used in this work to compare them with other data. This TEPC measures directly the linear energy in the interval between 0.15 and 1500 keV/μm in tissue, the low gas pressure (propan based TE mixture) permits to simulate a tissue element of about 3 μm. It can be used in the fields with instantaneous dose equivalent rates between 1 μSv/hour and 1 mSv/ hour. TED LET spectrometer developed to determine LET spectra between 10 and 700 keV/μm in tissue. Primarily, track-to-bulk etch rate ratios are determined through the track parameters measurements, the spectra of these ratios are convened to LET spectra using the calibration curve established by means of heavy charge panicles. The critical volume of thi spectrometer is supposed to be a few nm. There is no limit of use for the dose rate, the background tracks limit the lowest threshold to about 1 mSv, the overlapping of tracks (the highest one) to 100 mSv. Both experimental microdosimetry methods have been used in on board aircraft radiation fields, in on-Earth high energy radiation reference fields, and in the beams of protons with energies up to 300 MeV (Dubna, Moscow, Loma Linda). First, it should be emphasized, that in all high energy radiation fields studied, we concentrated our analysis on the region, where both methods overlap, i.e. between 10 and 1000 keV/μm in tissue. It should be also stressed, that the events observed in this region

CREAM for high energy composition measurements

CERN Document Server

Seo, E S; Allison, P S; Beatty, J J; Choi, M J; Conklin, N B; Coutu, S; DuVernois, M A; Ganel, O; Kim, K C; Lee, M H; Liu, L; Lutz, L; Maestro, P; Marrocchesi, P S; Minnick, S A; Min, K W; Mognet, S I; Nutter, S; Park, H; Schindhelm, E; Song, C; Swordy, S; Wu, J; Yang, J

2003-01-01

Ground-based indirect measurements have shown that the cosmic-ray allparticle spectrum extends many orders of magnitude beyond the energy thought possible for supernova acceleration. Our balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment is capable of extending direct measurements of cosmic-rays to the supernova energy scale of 1015 eV in a series of Ultra Long Duration Balloon (ULDB) flights. Identification of Z = 1 - 26 particles will be made with a timing-based charge detector and a pixelated silicon charge detector. Energy measurements will be made with a transition radiation detector and a tungsten/scintillating fiber calorimeter. The instrument has been tested with various particles in accelerated beams at the CERN SPS. The first flight is planned to be launched from Antarctica in December 2004.

Energy and carbon balances in cheatgrass, an essay in autecology. [Shortwave radiation, radiowave radiation

Energy Technology Data Exchange (ETDEWEB)

Hinds, W.T.

1975-01-01

An experiment to determine the fates of energy and carbon in cheatgrass (Bromus tectorum L.) was carried out on steep (40/sup 0/) north- and south-facing slopes on a small earth mound, using many small lysimeters to emulate swards of cheatgrass. Meteorological conditions and energy fluxes that were measured included air and soil temperatures, relative humidity, wind speed, incoming shortwave radiation, net all-wave radiation, heat flux to the soil, and evaporation and transpiration separately. The fate of photosynthetically fixed carbon during spring growth was determined by analysis of the plant tissues into mineral nutrients, crude protein, crude fat, crude fiber, and nitrogen-free extract (NFE) for roots, shoots, and seeds separately. (auth)

Atmospheric radiation measurement program facilities newsletter, June 2002.; TOPICAL

International Nuclear Information System (INIS)

Holdridge, D. J.

2002-01-01

greenhouse gas studies. These instruments will provide more accurate, detailed global observations of weather and atmospheric parameters that will, in turn, improve the accuracy and quality of weather forecasts. A satellite-based instrument is cost-effective because it can provide continuous global measurements, eliminating isolated yet costly weather balloon releases. Aqua, launched from Vandenberg Air Force Base in California (Figure 2), carries six state-of-the-art instruments that measure various water vapor parameters: (1) AIRS, which measures atmospheric temperature and humidity, land and sea surface temperatures, cloud properties, and radiative energy flux; (2) Advanced Microwave Sounding Unit, which measures atmospheric temperature and humidity during both cloudy and cloud-free periods; (3) Advanced Microwave Scanning Radiometer, which measures cloud properties, radiative energy flux, precipitation rates, land surface wetness, sea ice, snow cover, sea surface temperature, and wind fields; (4) Clouds and the Earth's Radiant Energy System, which measures radiative energy flux; (5) Humidity Sounder for Brazil, which measures atmospheric humidity by using a passive scanning microwave radiometer; and (6) Moderate Resolution Imaging Spectroradiometer, which measures cloud properties, radiative energy flux, aerosol properties, land cover and land use change, vegetation dynamics, land surface temperature, fire occurrence, volcanic effects, sea surface temperature, ocean color, snow cover, atmospheric temperature and humidity, and sea ice. The data-gathering capabilities of the Aqua instruments will provide an unprecedented view of atmosphere-land interactions (Figure 3). The availability of more frequent, more accurate global measurements of important atmospheric parameters will both improve our capabilities for short-term weather forecasting and lead to a better understanding of climate variability and climate change. Simultaneous measurements of many parameters will allow

Development of radiation detection and measurement system - Development of scintillation radiation sensor

Energy Technology Data Exchange (ETDEWEB)

Kang, Hee Dong; Kim, Wan [Kyungpook National University, Taegu (Korea); Kim, Do Sung [Taegu University, Taegu (Korea)

2000-03-01

We have been fabricated CsI(Tl) scintillation crystals and plastic scintillators for radiation-based measuring equipment. CsI (Tl) single crystals doped with thallium as an activator were grown using the Czochralski method. The crystal structure of grown CsI(Tl) was bcc, and it was confirmed that its lattice constant was 4,568 A. The spectral range of luminescence of CsI(Tl) was 350 {approx} 700 nm independent of thallium concentration, and the fast component of the luminescence was decreased with increasing thallium concentration. The energy resolution of CsI(Tl) scintillator doped with 0.1 mole% thallium was about 9% for 137 Cs {gamma}-rays. The relation formula of {gamma}-ray energy versus energy resolution was ln(FWHM%)=-0.705ln({epsilon})+6.75. The radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation dosage, and the irradiated crystals were colored reddish. The radiation induced absorption bands appeared around 355, 425, 520 and 555 nm, and their energy level were about 3.50, 2.88, 2.39 and 2.21 eV. Plastic scintillators were fabricated thermal polymerization method. Those were polymerizing at 120 deg. C, during 72 hours, and annealing at 75 deg. C, during 24 hours. When the concentration of 1st solute was 1.5 wt% and concentration of 2nd solute was 0.01 wt%, the characteristics of scintillation were very excellent. Also 3.0 wt% tetraphenyl lead were loaded to improve the detection efficiency of {gamma}-ray. The range of emission spectrum was 400 {approx} 450nm, and the central peak was 415 nm. The radiation damage was not appear under 1*10{sup 3}Gy, but the color of plastic scintillator was changed to brown, over 1*10{sup 4}Gy exposured. 84 refs., 39 figs. (Author)

Surface dose measurements under stretched, perforated thermoplast sheets and under protective wound dressings for high energy photon radiation

International Nuclear Information System (INIS)

Staudenraus, J.; Christ, G.

2000-01-01

Patient fixation masks made of perforated thermoplast sheets are widely used in radiotherapy. These masks in particular serve to immobilize the head and neck region during radiation treatment. We placed samples made of differently stretched, perforated mask material on the surface of a white polystyrene (RW3) phantom and measured for high energy photon beams from Co-60 radiation up to 25 MV bremsstrahlung the dose increase resulting from the build-up under the hole and bridge areas. Depending on the energy of the incident beam and the thickness of the stretched mask material we observed a dose increase under the bridges at the phantom surface of 55% up to 140% compared to the dose without a layer of mask material. Under a hole the dose increase is almost half the value found under a bridge. However, deeper than 1 mm under the phantom surface this difference in dose increase under holes and bridges decreases to less than 10%. The mean dose increase under a perforated thermoplast sheet is lower than the dose increase under a homogeneous sheet made of the same material with the same mean thickness. Radiation induced skin lesions or an ulcerating tumour, respectively, may require a protective wound dressing under a patient fixation mask during radiation therapy. Choosing a thin hydrocolloid wound dressing the additional dose increase of the skin, compared to the dose increase due to the fixation mask, can be kept low. (orig.) [de

Ultraviolet light and infrared radiation. Measurement and hazard assessment

International Nuclear Information System (INIS)

Mayer, A.; Salsi, S.

1979-01-01

Ultraviolet, light and infrared radiation exists in many work places and can be dangerous in many ways, especially for the eyes. The INRS has developed a method and an apparatus for measuring on site or in a laboratory the spectral energy distribution of such radiation and the luminance of the source. With current knowledge of the effects of radiation on the eyes and by comparing readings taken and recommended limit values, it is possible to determine the risk levels at work places in the different wave ranges. Two examples of readings taken at a pot furnace in a crystal glass factory and at an MAG welding station are given and the appropriate protective measures described [fr

Measurement of activation yields for platinum group elements using Bremsstrahlung radiation with end-point energies in the range 11-14 MeV

Energy Technology Data Exchange (ETDEWEB)

Tickner, James, E-mail: james.tickner@csiro.a [CSIRO Process Science and Engineering, PMB 5, Menai, NSW 2234 (Australia); Bencardino, Raffaele; Roach, Greg [CSIRO Process Science and Engineering, PMB 5, Menai, NSW 2234 (Australia)

2010-01-15

Activation yields have been measured for (gamma,n) reactions of the elements Ru, Rh, Pd, Ir and Pt. Metallic foils of natural isotopic composition were irradiated using Bremsstrahlung radiation produced from an electron linear accelerator operated with electron beam energies in the range 11-14 MeV. Activation products, including both unstable ground states and metastates were measured using a high-purity germanium detector. Cross-sections were estimated from the yield data by assuming a simple two-parameter model for the shape of the cross-section with energy.

Measurement of activation yields for platinum group elements using Bremsstrahlung radiation with end-point energies in the range 11-14 MeV

International Nuclear Information System (INIS)

Tickner, James; Bencardino, Raffaele; Roach, Greg

2010-01-01

Activation yields have been measured for (γ,n) reactions of the elements Ru, Rh, Pd, Ir and Pt. Metallic foils of natural isotopic composition were irradiated using Bremsstrahlung radiation produced from an electron linear accelerator operated with electron beam energies in the range 11-14 MeV. Activation products, including both unstable ground states and metastates were measured using a high-purity germanium detector. Cross-sections were estimated from the yield data by assuming a simple two-parameter model for the shape of the cross-section with energy.

Solar energy R + D programme, 1979-1983. Project F: solar radiation data

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

Individual presentations report work in the following areas: production of test reference years for model simulation of solar systems and components; global radiation atlas for horizontal surfaces; radiation data on inclined surfaces; intensity thresholds and cumulative frequency curves; useful energy output from solar collectors; network comparison of pyranometers; measurements of turbidity, spectral radiation, etc.; satellite data. (LEW)

Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

International Nuclear Information System (INIS)

Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.

1992-03-01

The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth's atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy's Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described

Statistics for Radiation Measurement. Chapter 5

Energy Technology Data Exchange (ETDEWEB)

Lötter, M. G. [Department of Medical Physics, University of the Free State, Bloemfontein (South Africa)

2014-12-15

Measurement errors are of three general types: (i) blunders, (ii) systematic errors or accuracy of measurements, and (iii) random errors or precision of measurements. Blunders produce grossly inaccurate results and experienced observers easily detect their occurrence. Examples in radiation counting or measurements include the incorrect setting of the energy window, counting heavily contaminated samples, using contaminated detectors for imaging or counting, obtaining measurements of high activities, resulting in count rates that lead to excessive dead time effects, and selecting the wrong patient orientation during imaging. Although some blunders can be detected as outliers or by duplicate samples and measurements, blunders should be avoided by careful, meticulous and dedicated work. This is especially important where results will determine the diagnosis or treatment of patients.

Radiation measured for ISS-Expedition 12 with different dosimeters

International Nuclear Information System (INIS)

Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Weyland, M.

2007-01-01

Radiation in low Earth orbit (LEO) is mainly from Galactic Cosmic Rays (GCR), solar energetic particles and particles in South Atlantic Anomaly (SAA). These particles' radiation impact to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to investigate the LET spectrum for the radiation field and the influence of radiation on astronauts. At present, the best active dosimeters used for all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors; the best passive dosimeters are thermoluminescence dosimeters (TLDs) or optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation for space mission Expedition 12 (ISS-11S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the mission with these different dosimeters. This paper introduces the operation principles for these dosimeters, describes the method to combine the results measured by CR-39 PNTDs and TLDs/OSLDs, presents the experimental LET spectra and the radiation quantities

Radiofrequency (RF) radiation measurement for diathermy machine

International Nuclear Information System (INIS)

Rozaimah Abdul Rahim; Roha Tukimin; Mohd Amirul Nizam; Ahmad Fadzli; Mohd Azizi

2010-01-01

Full-text: Diathermy machine is one of medical device that use widely in hospital and clinic. During the diathermy treatment, high radiofrequency (RF) currents (shortwave and microwave) are used to heat deep muscular tissues through electromagnetic energy to body tissues. The heat increases blood flow, relieve pain and speeding up recovery. The stray RF radiation from the machine can exposes to unintended tissue of the patient, to the operator (physical therapist) and also can cause electromagnetic interference (EMI) effect to medical devices around the machine. The main objective of this study is to establish a database of the RF radiation exposure levels experienced by the operator and patient during the treatments. RF radiation (electric and magnetic field) produced by the diathermy machines were measured using special RF survey meters. The finding of this study confirms that radiation levels on the surface and near the applicator of the diathermy machine much more elevated due to the much closer distance to the source and they exceeding the occupational and general public exposure limit. The results also shows the field strengths drop very significantly when the distance of measurement increase. (author)

How to promote risk literacy of atomic energy and radiation in public

International Nuclear Information System (INIS)

Matsubara, Junko

2005-01-01

According to broad use of radiation and nuclear energy in our society we recognize that the promotion of risk literacy in public is urgently needed. Necessary topics as follows are explained and discussed. 1. view-points of micro-, macro- and human-world, 2.how to measure risks objectively, 3. why we need to consider nuclear/radiation risks, 4. nuclear/radiation safety measures, 5. how to protect ourselves from risks, and 6. needs to establish new system of comprehensive risk education in the future. (author)

Solar Radiation and Cloud Radiative Forcing in the Pacific Warm Pool Estimated Using TOGA COARE Measurements

Science.gov (United States)

Chou, Ming-Dah; Chou, Shu-Hsien; Zhao, Wenzhong

1999-01-01

The energy budget of the tropical western Pacific (TWP) is particularly important because this is one of the most energetic convection regions on the Earth. Nearly half of the solar radiation incident at the top of atmosphere is absorbed at the surface and only about 22% absorbed in the atmosphere. A large portion of the excess heat absorbed at the surface is transferred to the atmosphere through evaporation, which provides energy and water for convection and precipitation. The western equatorial Pacific is characterized by the highest sea surface temperature (SST) and heaviest rainfall in the world ocean. A small variation of SST associated with the eastward shift of the warm pool during El-Nino/Souther Oscillation changes the atmospheric circulation pattern and affects the global climate. In a study of the TWP surface heat and momentum fluxes during the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) Intensive observing period (IOP) from November 1992 to February have found that the solar radiation is the most important component of the surface energy budget, which undergoes significant temporal and spatial variation. The variations are influenced by the two 40-50 days Madden Julian Oscillations (MJOs) which propagated eastward from the Indian Ocean to the Central Pacific during the IOP. The TWP surface solar radiation during the COARE IOP was investigated by a number of studies. In addition, the effects of clouds on the solar heating of the atmosphere in the TWP was studied using energy budget analysis. In this study, we present some results of the TWP surface solar shortwave or SW radiation budget and the effect of clouds on the atmospheric solar heating using the surface radiation measurements and Japan's Geostationary Meteorological Satellite 4 radiance measurements during COARE IOP.

Nuclear energy and radiation

International Nuclear Information System (INIS)

Myers, D.K.; Johnson, J.R.

1980-01-01

Both the light water reactor and the Canadian heavy water reactor systems produce electricity cheaply and efficiently. They produce some fissionable byproducts, which can be recycled to extend energy sources many-fold. Besides the production of electrical power, the nuclear industry produces various radioistopes used for treatment of cancer, in diagnostic procedures in nuclear medicine, in ionization smoke detectors, and as radioactive tracers with various technological applications including the study of the mechanisms of life. The increment in environmental radiation levels resulting from operation of nuclear power reactors represents a very small fraction of the radiation levels to which we are all exposed from natural sources, and of the average radiation exposures resulting from diagnostic procedures in the healing arts. The total health hazard of the complete nuclear power cycle is generally agreed to be smaller than the hazards associated with the generation of an equal amount of electricity from most other currently available sources of energy. The hazards from energy production in terms of shortened life expectancy are much smaller in all cases than the resulting increase in health and life expectancy. (auth)

Radiation energy devaluation in diffusion combusting flows of natural gas

International Nuclear Information System (INIS)

Makhanlall, Deodat; Munda, Josiah L.; Jiang, Peixue

2013-01-01

Abstract: CFD (Computational fluid dynamics) is used to evaluate the thermodynamic second-law effects of thermal radiation in turbulent diffusion natural gas flames. Radiative heat transfer processes in gas and at solid walls are identified as important causes of energy devaluation in the combusting flows. The thermodynamic role of thermal radiation cannot be neglected when compared to that of heat conduction and convection, mass diffusion, chemical reactions, and viscous dissipation. An energy devaluation number is also defined, with which the optimum fuel–air equivalence for combusting flows can be determined. The optimum fuel–air equivalence ratio for a natural gas flame is determined to be 0.7. The CFD model is validated against experimental measurements. - Highlights: • Thermodynamic effects of thermal radiation in combusting flows analyzed. • General equation for second-law analyses of combusting flows extended. • Optimum fuel–air equivalence ratio determined for natural gas flame

Medical radiation dosimetry theory of charged particle collision energy loss

CERN Document Server

McParland, Brian J

2014-01-01

Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the worl...

An intercomparison of surface energy flux measurement systems used during FIFE 1987

International Nuclear Information System (INIS)

Nie, D.; Kanemasu, E.T.; Fritschen, L.J.; Weaver, H.L.; Smith, E.A.; Verma, S.B.; Field, R.T.; Kustas, W.P.; Stewart, J.B.

1992-01-01

During FIFE 1987, surface energy fluxes were measured at 22 flux sites by nine groups of scientists using different measuring systems. A rover Bowen ratio station was taken to 20 of the flux stations to serve as a reference for estimating the instrument-related differences. The rover system was installed within a few meters from the host instrument of a site. Using linear regression analysis, net radiation, Bowen ratio, and latent heat fluxes were compared between the rover measurements and the host measurements. The average differences in net radiation, Bowen ratio, and latent heat flux from different types of instruments can be up to 10, 30, and 20 percent, respectively. The Didcot net radiometer gave higher net radiation while the Swissteco type showed lower values, as compared to the corrected radiation energy balance system (REBS) model. The four-way components method and the Thornthwaite type give similar values to the REBS. The surface energy radiation balance systems type Bowen ratio systems exhibit slightly lower Bowen ratios and thus higher latent heat fluxes, compared to the arid zone evapotranspiration systems. Eddy correlation systems showed slightly lower latent heat flux in comparison to the Bowen ratio systems. It is recommended that users of the flux data take these differences into account. 11 refs

Measurement of the energy stored in alkalihalogenids by radiation defects

International Nuclear Information System (INIS)

Schrey, P.

1976-01-01

The energy stored in alkali-halogen crystals after X-ray irradiation is studied at 11 K. Using a heat flux calorimeter designed especially for this experiment, single crystals are irradiated and the energy release is recorded as the temperature is increased proportional to time from 10 K to 50 K. The energy release spectra are compared with relevant optical measurements and thus a relation between energy release and tempering of point defects is established. The energy release peaks can be assigned definitly to tempering stages of the Frenkel pairs. For explanation a simple model is proposed. (orig./HPOE) [de

Dose measurements in pulsed radiation fields with commercially available measuring components

International Nuclear Information System (INIS)

Friedrich, Sabrina; Hupe, Oliver

2016-01-01

Dose measurements in pulsed radiation fields with dosemeters using the counting technique are known to be inappropriate. Therefore, there is a demand for a portable device able to measure the dose in pulsed radiation fields. As a detector, ionisation chambers seem to be a good alternative. In particular, using a secondary standard ionisation chamber in combination with a reliable charge-measuring system would be a good solution. The Physikalisch-Technische Bundesanstalt (PTB) uses secondary standard ionisation chambers in combination with PTB-made measuring electronics for dose measurements at its reference fields. However, for general use, this equipment is too complex. For measurements on-site, a mobile special electronic system [Hupe, O. and Ankerhold, U. Determination of ambient and personal dose equivalent for personnel and cargo security screening. Radiat. Prot. Dosim. 121(4), 429-437 (2006)] has been used successfully. Still, for general use, there is a need for a much simpler but a just as good solution. A measuring instrument with very good energy dependence for H*(10) is the secondary standard ionisation chamber HS01. An easy-to-use and commercially available electrometer for measuring the generated charges is the UNIDOS by PTW Freiburg. Depending on the expected dose values, the ionisation chamber used can be selected. In addition, measurements have been performed by using commercially available area dosemeters, e.g. the Mini SmartION 2120S by Thermo Scientific, using an ionisation chamber and the Szintomat 6134 A/H by Automess, using a scintillation detector. (authors)

Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

Energy Technology Data Exchange (ETDEWEB)

LR Roeder

2008-12-01

The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

Atmospheric Radiation Measurement Program Plan

International Nuclear Information System (INIS)

1990-02-01

In order to understand energy's role in anthropogenic global climate change, significant reliance is being placed on General Circulation Models (GCMs). A major goal of the Department is to foster the development of GCMs capable of predicting the timing and magnitude of greenhouse gas-induced global warming and the regional effects of such warming. DOE research has revealed that cloud radiative feedback is the single most important effect determining the magnitude of possible climate responses to human activity. However, cloud radiative forcing and feedbacks are not understood at the levels needed for reliable climate prediction. The Atmospheric Radiation Measurement (ARM) Program will contribute to the DOE goal by improving the treatment of cloud radiative forcing and feedbacks in GCMs. Two issues will be addressed: the radiation budget and its spectral dependence and the radiative and other properties of clouds. Understanding cloud properties and how to predict them is critical because cloud properties may very well change as climate changes. The experimental objective of the ARM Program is to characterize empirically the radiative processes in the Earth's atmosphere with improved resolution and accuracy. A key to this characterization is the effective treatment of cloud formation and cloud properties in GCMs. Through this characterization of radiative properties, it will be possible to understand both the forcing and feedback effects. GCM modelers will then be able to better identify the best approaches to improved parameterizations of radiative transfer effects. This is expected to greatly improve the accuracy of long-term, GCM predictions and the efficacy of those predictions at the important regional scale, as the research community and DOE attempt to understand the effects of greenhouse gas emissions on the Earth's climate. 153 refs., 24 figs., 6 tabs

High Energy Ion Acceleration by Extreme Laser Radiation Pressure

Science.gov (United States)

2017-03-14

published in the internationally leading journal Physical Review Letters. We continued to progress this pionee 15.  SUBJECT TERMS ion therapy, heavy ion ...Thomson parabola spectrometer: To separate and provide a measurement of the charge -to-mass ratio and energy spectrum of the different ion species...AFRL-AFOSR-UK-TR-2017-0015 High energy ion acceleration by extreme laser radiation pressure Paul McKenna UNIVERSITY OF STRATHCLYDE VIZ ROYAL COLLEGE

Variation of the optical energy gap with {gamma}-radiation and thickness in Bi-thin films

Energy Technology Data Exchange (ETDEWEB)

Al-Houty, L.; Kassem, M.E.; Abdel Kader, H.I. [Qatar Univ., Doha (Qatar). Dept. of Physics

1995-02-01

The effect of {gamma}-radiation and thickness on the optical energy gap of Bi-thin films has been investigated by measuring their optical absorbance. The measurements were carried out on thermally evaporated films having thicknesses in the range 5-20 nm. Different {gamma}-radiation doses were used ranging from 0-300 Mrad. The optical energy gap as well as the absorption coefficient were found to be {gamma}-dose dependent. (author).

Variation of the optical energy gap with γ-radiation and thickness in Bi-thin films

International Nuclear Information System (INIS)

Al-Houty, L.; Kassem, M.E.; Abdel Kader, H.I.

1995-01-01

The effect of γ-radiation and thickness on the optical energy gap of Bi-thin films has been investigated by measuring their optical absorbance. The measurements were carried out on thermally evaporated films having thicknesses in the range 5-20 nm. Different γ-radiation doses were used ranging from 0-300 Mrad. The optical energy gap as well as the absorption coefficient were found to be γ-dose dependent. (author)

Nuclear energy - Radioprotection - Procedure for radiation protection monitoring in nuclear installations for external exposure to weakly penetrating radiation, especially to beta radiation

International Nuclear Information System (INIS)

2002-01-01

This International Standard specifies a procedure for radiation protection monitoring in nuclear installations for external exposure to weakly penetrating radiation, especially to beta radiation and describes the procedure in radiation protection monitoring for external exposure to weakly penetrating radiation in nuclear installations. This radiation comprises β - radiation, β + radiation and conversion electron radiation as well as photon radiation with energies below 15 keV. This International Standard describes the procedure in radiation protection planning and monitoring as well as the measurement and analysis to be applied. It applies to regular nuclear power plant operation including maintenance, waste handling and decommissioning. The recommendations of this International Standard may also be transferred to other nuclear fields including reprocessing, if the area-specific issues are considered. This International Standard may also be applied to radiation protection at accelerator facilities and in nuclear medicine, biology and research facilities

Instantaneous x-ray radiation energy from laser produced polystyrene plasmas for shock ignition conditions

International Nuclear Information System (INIS)

Shang, Wanli; Wei, Huiyue; Li, Zhichao; Yi, Rongqing; Zhu, Tuo; Song, Tianmin; Huang, Chengwu; Yang, Jiamin

2013-01-01

Laser target energy coupling mechanism is crucial in the shock ignition (SI) scheme, and x-ray radiation energy is a non-negligible portion of the laser produced plasma energy. To evaluate the x-ray radiation energy amount at conditions relevant to SI scheme, instantaneous x-ray radiation energy is investigated experimentally with continuum phase plates smoothed lasers irradiating layer polystyrene targets. Comparative laser pulses without and with shock spike are employed. With the measured x-ray angular distribution, full space x-ray radiation energy and conversion efficiency are observed. Instantaneous scaling law of x-ray conversion efficiency is obtained as a function of laser intensity and time. It should be pointed out that the scaling law is available for any laser pulse shape and intensity, with which irradiates polystyrene planar target with intensity from 2 × 10 14 to 1.8 × 10 15 W/cm 2 . Numerical analysis of the laser energy transformation is performed, and the simulation results agree with the experimental data

Radiation protection, measurements and methods

International Nuclear Information System (INIS)

1983-06-01

The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP) [de

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

Science.gov (United States)

Sohn, Jongdae; Lee, Jaejin; Min, Kyoungwook; Lee, Junchan; Lee, Seunguk; Lee, Daeyoung; Jo, Gyeongbok; Yi, Yu; Na, Gowoon; Kang, Kyung-In; Shin, Goo-Hwan

2018-05-01

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0°. 45°, and 90°, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from 350 keV to 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

Implantation of keV-energy argon clusters and radiation damage in diamond

DEFF Research Database (Denmark)

Popok, Vladimir; Samela, Juha; Nordlund, Kai

2012-01-01

We show that for impacting argon clusters, both mean projected ranges of the constituents and depths of radiation damage in diamond scale linearly with momentum. The same dependence was earlier found for keV-energy cluster implantation in graphite, thus suggesting the universality of this scaling...... law. For diamond, a good agreement for the value of displacement energy for the case of cluster impact is found by comparing the calculated target sputtering and experimentally measured depth of radiation damage....

Spectral measurements of gamma radiation streaming through ducts

International Nuclear Information System (INIS)

Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

1979-01-01

The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

Experimental research on electromagnetic radiation in inductive energy storage accelerator

International Nuclear Information System (INIS)

Zhong Jianzhong; Liu Lie; Li Limin; Wen Jianchun

2008-01-01

There exists strong electromagnetic radiation in inductive energy storage accelerators. In can destroy a measuring device at a distance. By repeated experiments, we found that it is a wide-spectrum electromagnetic wave with a main frequency of 75 MHz. The effector such as coaxial transmission line is effected strongly in short distance. The current in the coaxial transmission line can be measured in Rogowski coils. The strength of field in it is about 500 V/m and the peak current is 217 mA. The radiation source may be LC oscillating or electric exploding opening switch. Through the experimental research, we think it probably may be caused by the LC oscillating in the circuit when the switches conduct. And its strength is correlated to current change ratio. The change rate in secondary circuit is stronger than in primary circuit. So the radiation generated in secondary circuit is stronger than in primary circuit. It may be a reference for further research in inductive energy storage accelerators and shielding electromagnetic disturbing. (authors)

On the measurement of the surface energy budget over a land ...

Indian Academy of Sciences (India)

The measurement of surface energy balance over a land surface in an open area in Bangalore is reported. Measurements of all variables needed to calculate the surface energy balance on time scales longer than a week are made. Components of radiative fluxes are measured while sensible and latent heat fluxes are ...

High energy radiation from neutron stars

International Nuclear Information System (INIS)

Ruderman, M.

1985-04-01

Topics covered include young rapidly spinning pulsars; static gaps in outer magnetospheres; dynamic gaps in pulsar outer magnetospheres; pulse structure of energetic radiation sustained by outer gap pair production; outer gap radiation, Crab pulsar; outer gap radiation, the Vela pulsar; radioemission; and high energy radiation during the accretion spin-up of older neutron stars. 26 refs., 10 figs

Chambers nuclear energy and radiation dictionary

International Nuclear Information System (INIS)

Walker, P.M.B.

1992-01-01

This Dictionary is designed to make it easier for those who are concerned about nuclear power and radiation to learn more about nuclear energy and to come to an informed opinion. The first two of the 11 chapters which precede the dictionary proper describe the properties of the atomic nucleus which make nuclear energy possible and then the problems which have to be overcome in harnessing this energy. The next two chapters discuss the many different kinds of power stations which rely on fission and then the methods of fusion which may produce power in the next century. There are then two chapters on nuclear safety and on the production and enrichment of uranium fuel, together with methods for its eventual disposal. These are followed by a chapter on nuclear bombs of various kinds and one on how nuclear and other forms of radiation can be detected. There is then a chapter which relates the radiation resulting from nuclear fission to other kinds of radiation. The next chapter discusses some basic biology particularly cancer. Finally, the biological effects of radiation are described before comparing the amounts of man-made radiation to that which comes naturally from outer space and from the rocks beneath us. This then leads to the radiation limits which are determined by the various regulartory authorities and the kinds of evidence upon which their decisions are based. (Author)

Measurement of Gamma Radiation in an Automobile Mechanic ...

African Journals Online (AJOL)

imeh james

Nuclear Technology Centre, Nigeria Atomic Energy Commission, ... An in-situ measurement approach was adopted using RDS-200 Universal Survey Meter and a handheld ... the people living and working within the area are safe and are not exposed to high doses of radiation as a result .... battery works, panel beating e.t.c..

Enhancing radiative energy transfer through thermal extraction

Directory of Open Access Journals (Sweden)

Tan Yixuan

2016-06-01

Full Text Available Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a. In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics.

Radiative inflation and dark energy

International Nuclear Information System (INIS)

Di Bari, Pasquale; King, Stephen F.; Luhn, Christoph; Merle, Alexander; Schmidt-May, Angnis

2011-01-01

We propose a model based on radiative symmetry breaking that combines inflation with dark energy and is consistent with the Wilkinson Microwave Anisotropy Probe 7-year regions. The radiative inflationary potential leads to the prediction of a spectral index 0.955 S < or approx. 0.967 and a tensor to scalar ratio 0.142 < or approx. r < or approx. 0.186, both consistent with current data but testable by the Planck experiment. The radiative symmetry breaking close to the Planck scale gives rise to a pseudo Nambu-Goldstone boson with a gravitationally suppressed mass which can naturally play the role of a quintessence field responsible for dark energy. Finally, we present a possible extra dimensional scenario in which our model could be realized.

Radiation measurements at the Clark Special Economic Zone (former US military base)

International Nuclear Information System (INIS)

Duran, Emerenciana B.; Yulo-Nazarea, Teresa; Garcia, Teofilo Y.; De Vera, Cecile M.; Reyes, Rolando; Nato, Alejandro Q.; Asada, Antonio A.

1999-01-01

The Philippine Nuclear Research Institute (PNRI) measured radiation levels at the Clark Special Economic Zone (CSEZ) using a carbon gamma-ray spectrometric system (Exploration Gr-650) equipped with a Nal detector and global positioning system in 1998. The measurement covered approximately 131 km of CSEZ road network and generated 6875 data. Soil and water samples within the specified area were also collected for specific radionuclide activity analyses using high pressure germanium (HPGe) detector. The Health Physics Research Section (HPRS) of the PNRI has earlier established the average baseline level of absorbed dose rate received by the Filipino population due to primordial (naturally-occurring) radionuclides ( 238 U, 232 Th and 40 K) at 45 nGy h -1 (n = 1645 locations) with ranges from 5 to 74 nGy h-1. The estimated average absorbed dose rate in 23 countries by the United National Scientific Committee on the Effect of Atomic Radiation (UNSCEAR, 1982) was reported at 55 nGy h -1 . The average absorbed dose rate in air measured within CSEZ is 26.3 ± 6.68 nGy h -1 with ranges from 13.27 to 37.93 nGy h-1 . This average value is within the range of values observed in other parts of the country outside of CSEZ and hence can be attributed to natural source of radiation, not man-made sources. To confirm the above measurements, the contribution of man-made sources to the total dose rate measured was assessed further. Evaluation of natural and man-made sources of radiations is achieved through count rate ratio measurements of low energy, 35-350keV, (natural radiation) and high energy, 350-2800 keV, (anthropogenic radiation) spectra of gamma radiation. The ratios of low to high energy remained practically constant throughout the entire area monitored. Initial analyses of soil and water samples collected in areas of interest within the CSEZ for specific radionuclides using the HPGe detector indicated activity concentrations within baseline levels of these radionuclides

Ionizing radiation measurements on LDEF: A0015 Free flyer biostack experiment

Science.gov (United States)

Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Frigo, L. A.

1995-01-01

This report covers the analysis of passive radiation detectors flown as part of the A0015 Free Flyer Biostack on LDEF (Long Duration Exposure Facility). LET (linear energy transfer) spectra and track density measurements were made with CR-39 and Polycarbonate plastic nuclear track detectors. Measurements of total absorbed dose were carried out using Thermoluminescent Detectors. Thermal and resonance neutron dose equivalents were measured with LiF/CR-39 detectors. High energy neutron and proton dose equivalents were measured with fission foil/CR-39 detectors.

Study of the radiated energy loss during massive gas injection mitigated disruptions on EAST

Science.gov (United States)

Duan, Y. M.; Hao, Z. K.; Hu, L. Q.; Wang, L.; Xu, P.; Xu, L. Q.; Zhuang, H. D.; EAST Team

2015-08-01

The MGI mitigated disruption experiments were carried out on EAST with a new fast gas controlling valve in 2012. Different amounts of noble gas He or mixed gas of 99% He + 1% Ar are injected into plasma in current flat-top phase and current ramp-down phase separately. The initial results of MGI experiments are described. The MGI system and the radiation measurement system are briefly introduced. The characteristics of radiation distribution and radiation energy loss are analyzed. About 50% of the stored thermal energy Wdia is dissipated by radiation during the entire disruption process and the impurities of C and Li from the PFC play important roles to radiative energy loss. The amount of the gas can affect the pre-TQ phase. Strong poloidal asymmetry of radiation begins to appear in the CQ phase, which is possibly caused by the plasma configuration changes as a result of VDE. No toroidal radiation asymmetry is observed presently.

Radiation entropy influx as a measure of planetary dissipative processes

International Nuclear Information System (INIS)

Izakov, M.N.

1989-01-01

Dissipative processes including high flows of matter and energy occur at the planets. Radiation negentropy influx, resulting from difference of entropy fluxes of incoming solar and outgoing thermal radiation of the planet, is a measure of all these processes. Large share of radiation negentropy influx is spent in the vertical thermal fluxes which keep the planet temperature conditions. Next share of radiation negentropy consumption at the Earth is water evaporation. It's rest part is used for the dynamics, which is explained by the efficiency insignificant amount of heat engine, which generates movements in the atmosphere and ocean. Essentially higher share of radiation negentropy influx, than at the Earth, is spent at the Venus, where there are practically no water

Radiation Calibration Measurements

International Nuclear Information System (INIS)

Omondi, C.

2017-01-01

KEBS Radiation Dosimetry mandate are: Custodian of Kenya Standards on Ionizing radiation, Ensure traceability to International System (SI ) and Calibration radiation equipment. RAF 8/040 on Radioisotope applications for troubleshooting and optimizing industrial process established Radiotracer Laboratory objective is to introduce and implement radiotracer technique for problem solving of industrial challenges. Gamma ray scanning technique applied is to Locate blockages, Locate liquid in vapor lines, Locate areas of lost refractory or lining in a pipe and Measure flowing densities. Equipment used for diagnostic and radiation protection must be calibrated to ensure Accuracy and Traceability

Advances in absorbed dose measurement standards at the australian radiation laboratory

International Nuclear Information System (INIS)

Boas, J.F.; Hargrave, N.J.; Huntley, R.B.; Kotler, L.H.; Webb, D.V.; Wise, K.N.

1996-01-01

The applications of ionising radiation in the medical and industrial fields require both an accurate knowledge of the amount of ionising radiation absorbed by the medium in question and the capability of relating this to National and International standards. The most useful measure of the amount of radiation is the absorbed dose which is defined as the energy absorbed per unit mass. For radiotherapy, the reference medium is water, even though the measurement of the absorbed dose to water is not straightforward. Two methods are commonly used to provide calibrations in absorbed dose to water. The first is the calibration of the chamber in terms of exposure in a Cobalt-60 beam, followed by the conversion by a protocol into dose to water in this and higher energy beams. The other route is via the use of a graphite calorimeter as a primary standard device, where the conversion from absorbed dose to graphite to absorbed dose in water is performed either by theoretical means making use of cavity ionisation theory, or by experiment where the graphite calorimeter and secondary standard ionisation chamber are placed at scaled distances from the source of the radiation beam (known as the Dose-Ratio method). Extensive measurements have been made at Cobalt-60 at ARL using both the exposure and absorbed dose to graphite routes. Agreement between the ARL measurements and those based on standards maintained by ANSTO and NPL is within ± 0.3%. Absorbed dose measurements have also been performed at ARL with photon beams of nominal energy 16 and 19 MeV obtained from the ARL linac. The validity of the protocols at high photon energies, the validity of the methods used to convert from absorbed dose in graphite to absorbed dose in water and the validity of the indices used to specify the beams are discussed. Brief mention will also be made of the establishment of a calibration facility for neutron monitors at ARL and of progress in the development of ERP dosimetry

Advances in absorbed dose measurement standards at the australian radiation laboratory

Energy Technology Data Exchange (ETDEWEB)

Boas, J.F.; Hargrave, N.J.; Huntley, R.B.; Kotler, L.H.; Webb, D.V.; Wise, K.N. [Australian Radiation Laboratory, Yallambie, VIC (Australia)

1996-12-31

The applications of ionising radiation in the medical and industrial fields require both an accurate knowledge of the amount of ionising radiation absorbed by the medium in question and the capability of relating this to National and International standards. The most useful measure of the amount of radiation is the absorbed dose which is defined as the energy absorbed per unit mass. For radiotherapy, the reference medium is water, even though the measurement of the absorbed dose to water is not straightforward. Two methods are commonly used to provide calibrations in absorbed dose to water. The first is the calibration of the chamber in terms of exposure in a Cobalt-60 beam, followed by the conversion by a protocol into dose to water in this and higher energy beams. The other route is via the use of a graphite calorimeter as a primary standard device, where the conversion from absorbed dose to graphite to absorbed dose in water is performed either by theoretical means making use of cavity ionisation theory, or by experiment where the graphite calorimeter and secondary standard ionisation chamber are placed at scaled distances from the source of the radiation beam (known as the Dose-Ratio method). Extensive measurements have been made at Cobalt-60 at ARL using both the exposure and absorbed dose to graphite routes. Agreement between the ARL measurements and those based on standards maintained by ANSTO and NPL is within {+-} 0.3%. Absorbed dose measurements have also been performed at ARL with photon beams of nominal energy 16 and 19 MeV obtained from the ARL linac. The validity of the protocols at high photon energies, the validity of the methods used to convert from absorbed dose in graphite to absorbed dose in water and the validity of the indices used to specify the beams are discussed. Brief mention will also be made of the establishment of a calibration facility for neutron monitors at ARL and of progress in the development of ERP dosimetry.

High energy radiation in cancer treatment

Energy Technology Data Exchange (ETDEWEB)

NONE

1959-10-15

Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

High energy radiation in cancer treatment

International Nuclear Information System (INIS)

1959-01-01

Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

Application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

2003-01-01

This paper introduces the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 reader and GR-100 M chips on the measurement of hard X-ray pulse energy spectrum. The idea using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV) is discussed in details. Considering all the factors of the measuring surrounding, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device-high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

Radiation measurement practice for understanding statistical fluctuation of radiation count using natural radiation sources

International Nuclear Information System (INIS)

Kawano, Takao

2014-01-01

It is known that radiation is detected at random and the radiation counts fluctuate statistically. In the present study, a radiation measurement experiment was performed to understand the randomness and statistical fluctuation of radiation counts. In the measurement, three natural radiation sources were used. The sources were fabricated from potassium chloride chemicals, chemical fertilizers and kelps. These materials contain naturally occurring potassium-40 that is a radionuclide. From high schools, junior high schools and elementary schools, nine teachers participated to the radiation measurement experiment. Each participant measured the 1-min integration counts of radiation five times using GM survey meters, and 45 sets of data were obtained for the respective natural radiation sources. It was found that the frequency of occurrence of radiation counts was distributed according to a Gaussian distribution curve, although the obtained 45 data sets of radiation counts superficially looked to be fluctuating meaninglessly. (author)

Evaluation of the spectral distribution of X-ray beams from measurements on the scattered radiation

International Nuclear Information System (INIS)

Casnati, E.; Baraldi, C.

1980-01-01

Most of the phenomena activated by photons with energies below 100 keV show an apparent or real dependence on the quantum energy. Therefore, knowledge of the beam energy characteristics is of primary importance for interpretation of the irradiation results. The greatest difficulty arises from the high flux density of the beams usually employed which does not allow direct measurements of the beam. A method was developed which permits evaluation of the spectral distribution of the X-ray beam from a spectrometric measurement of the radiation scattered by a thin foil of a suitable metal. This makes possible a new and more rational approach to the measurement of X-rays in the energy range where the interaction parameters show a large photon energy dependence. The corrections required by the presence of some collateral effects, among which the most important is the coexistence of the coherent and incoherent scattering, must be evaluated. The knowledge of the spectral distribution is of immediate usefulness for studies of radiation damage in biological and other materials, for the calibration of radiation measuring instruments and for the improvement of the radiological instrumentation response which contributes to reducing the patient's dose. (H.K.)

Measurement of radiation shielding properties of polymer composites by using HPGe detector

International Nuclear Information System (INIS)

Gupta, Anil; Pillay, H.C.M.; Kale, P.K.; Datta, D.; Suman, S.K.; Gover, V.

2014-01-01

Lead is the most common radiation shield and its composite with polymers can be used as flexible radiation shields for different applications. However, lead is very hazardous and has been found to be associated with neurological disorders, kidney failure and hematotoxicity. Lead free radiation shield material has been developed by synthesizing radiation cross linked PDMS/Bi 2 O 3 polymer composites. In order to have a lead free radiation shield the relevant shielding properties such as linear attenuation, half value thickness (HVT) and tenth value thickness (TVT) have been measured by using HPGe detector. The present study describes the methodology of measurement of the shielding properties of the lead free shield material. In the measurement gamma energies such as 59.537 keV ( 241 Am), 122.061 keV and 136.474 keV ( 57 Co) are taken into consideration

Measurement of leakage and design for the protective barrier of the high energy radiation therapy room

International Nuclear Information System (INIS)

Chu, S.S.; Park, C.Y.

1981-01-01

The logical development of an optimum structural shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV are presented. We obtained following results by comparison in between the precalculating values and actual survey after complete installation of radiogenerating units. 1) The calculating formula for the protective barrier written in NCRP report no. 34(1970) was the most ideal and economic calculating methods for the construction of barrier and to determine thickness for the meeting requirements of the number of patients of 80-100 in daily treatment. 2) The precalculating values of protective barrier are 5 times more protective than that of actual measurement. It is depending on radiation workload and utilization the data most securely. 3) The dose rate during exposure are 2-10 mR/hr at out of the door and the control room. 4) The foul smelling and ozone gas production from long exposure of cancer patients cannot be estimated when the room is ill ventilated. (author)

Effects of low energy radiations on the stability of red palm oil

International Nuclear Information System (INIS)

Dzulkefly, K.; Zarida, Z.; Hamdan, S.

1999-01-01

Red palm oil (R-PO) is a new generation of cooking oil in which the carotenes are retained in the refined oil. In this study, the oxidative effects of low energy radiations (sunlight and ultra-violet radiation) on RPO were investigated. The red palm oil was exposed to sunlight and ultra-violet (UV) radiation for various time intervals. The concentrations of carotene, peroxide value (PV), conjugated diene value (CD) and free fatty acid (FFA) content were measured. The irradiation was also performed in the presence of antioxidant butylated hydroxytoluene (BHT). Results showed that carotene contents were significantly reduced as the irradiation doses increase. The destruction of carotenes were 23.9 % and 24.1 % respectively under sunlight and UV radiation after 5 hours exposure. Measurements of PV, CD and FFA have indicated that both UV and sunlight radiations caused deterioration of red palm oil. In the presence of antioxidant, the extent of deterioration of RPO and the destruction of carotene were suppressed. This study has shown that the natural antioxidant (carotenes and tocopherols) did not give complete protection to RPO against oxidative deterioration induced by low energy radiations. Additional antioxidant (BHT) was needed to suppress the oxidative deterioration of RPO. (Author)

Enhancing radiative energy transfer through thermal extraction

Science.gov (United States)

Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

2016-06-01

Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

Radiation and energy balance of lettuce culture inside a polyethylene greenhouse

International Nuclear Information System (INIS)

Frisina, V. de A.; Escobedo, J.F.

1999-01-01

The objective of this paper was to describe the radiation and energy balance, during the lettuce (Lactuca sativa, L. cv. Verônica) crop cycle inside a polyethylene greenhouse. The radiation and energy balance was made inside a tunnel greenhouse with polyethylene cover (100 mm) and in an external area, both areas with 35 m 2 . Global, reflected and net radiation, soil heat flux and air temperature (dry and humid) were measured during the crop cycle. A Datalogger, which operated at 1 Hz frequency, storing 5 minutes averages was utilized. The global (K↓) and reflected (K) radiations showed that the average transmission of global radiation (K↓in / K↓ex) was almost constant, near to 79.59%, while the average ratio of reflected radiation (Kin / Kex) was 69.21% with 8.47% standard-deviation. The normalized curves of short-wave net radiation, in relation to the global radiation (K*/ K↓), found for both environments, were almost constant at the beginning of cycle; this relation decreased in the final stage of culture. The normalized relation (Rn/ K↓) was bigger in the external area, about 12%, when the green culture covered the soil surface. The long-wave radiation balance average (L*) was bigger outside, about 50%. The energy balance, estimated in terms of vertical fluxes, showed that, for the external area, in average, 83.07% of total net radiation was converted in latent heat evaporation (LE), and 18% in soil heat flux (G), and 9.96% in sensible heat (H), while inside of the greenhouse, 58.71% of total net radiation was converted in LE, 42.68% in H, and 28.79% in G. (author) [pt

Thermoluminescent measurement in space radiation dosimetry

International Nuclear Information System (INIS)

Chen Mei; Qi Zhangnian; Li Xianggao; Huang Zengxin; Jia Xianghong; Wang Genliang

1999-01-01

The author introduced the space radiation environment and the application of thermoluminescent measurement in space radiation dosimetry. Space ionization radiation is charged particles radiation. Space radiation dosimetry was developed for protecting astronauts against space radiation. Thermoluminescent measurement is an excellent method used in the spaceship cabin. Also the authors mentioned the recent works here

Energy exchanges in a Central Business District - Interpretation of Eddy Covariance and radiation flux measurements (London UK)

Science.gov (United States)

Kotthaus, S.; Grimmond, S.

2013-12-01

Global urbanisation brings increasingly dense and complex urban structures. To manage cities sustainably and smartly, currently and into the future under changing climates, urban climate research needs to advance in areas such as Central Business Districts (CBD) where human interactions with the environment are particularly concentrated. Measurement and modelling approaches may be pushed to their limits in dense urban settings, but if urban climate research is to contribute to the challenges of real cities those limits have to be addressed. The climate of cities is strongly governed by surface-atmosphere exchanges of energy, moisture and momentum. Observations of the relevant fluxes provide important information for improvement and evaluation of modelling approaches. Due to the CBD's heterogeneity, a very careful analysis of observations is required to understand the relevant processes. Current approaches used to interpret observations and set them in a wider context may need to be adapted for use in these more complex areas. Here, we present long-term observations of the radiation balance components and turbulent fluxes of latent heat, sensible heat and momentum in the city centre of London. This is one of the first measurement studies in a CBD covering multiple years with analysis at temporal scales from days to seasons. Data gathered at two sites in close vicinity, but with different measurement heights, are analysed to investigate the influence of source area characteristics on long-term radiation and turbulent fluxes. Challenges of source area modelling and the critical aspect of siting in such a complex environment are considered. Outgoing long- and short-wave radiation are impacted by the anisotropic nature of the urban surface and the high reflectance materials increasingly being used as building materials. Results highlight the need to consider the source area of radiometers in terms of diffuse and direct irradiance. Sensible heat fluxes (QH) are positive

Design and testing of an innovative solar radiation measurement device

International Nuclear Information System (INIS)

Badran, Omar; Al-Salaymeh, Ahmed; El-Tous, Yousif; Abdala, Wasfi

2010-01-01

After review of studies conducted on the solar radiation measuring systems, a new innovative instrument that would help in measuring the accurate solar radiation on horizontal surfaces has been designed and tested. An advanced instrument with ease of use and high precision that would enable the user to take the readings in terms of solar intensity (W/m 2 ) has been tested. Also, the innovative instrument can record instantaneous readings of the solar intensities as well as the averages value of the solar radiation flux during certain periods of time. The instrument based in its design on being programmed by programmable interfacing controller (PIC). Furthermore, the power supply circuit is fed by the solar energy cells and does not need an external power source.

High energy radiation effects on the human body

International Nuclear Information System (INIS)

Kato, Kazuaki

1977-01-01

High-energy radiation injuries and their risks were recognized, information on low-energy radiation injuries was also arranged, and with these backgrounds, countermeasures against prevention of radiation injuries were considered. Redintegration of DNA and mutation by radiation were described, and relationship between radiation injuries and dose was considered. Interaction of high-energy radiation and substances in the living body and injuries by the interaction were also considered. Expression method of risk was considered, and a concept of protection dose was suggested. Protection dose is dose equivalent which is worthy of value at the point where the ratio to permissible dose distributed among each part of the body is at its maximum in the distribution of dose equivalent formed within the body when standard human body is placed at a certain radiation field for a certain time. Significance and countermeasures of health examination which is under an abligation to make radiation workers receive health check were thought, and problems were proposed on compensation when radiation injuries should appear actually. (Tsunoda, M.)

Relations between radiation risks and radiation protection measuring techniques

International Nuclear Information System (INIS)

Herrmann, K.; Kraus, W.

Relations between radiation risks and radiation protection measuring techniques are considered as components of the radiation risk. The influence of the exposure risk on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Based upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high exposure risk. As a consequence the following recommendations are presented: occupationally exposed persons with small exposure risk should be monitored using only a long-term desimeter (for instance a thermoluminescence desimeter). In the case of internal exposure, the surface and air contamination levels should be controlled so strictly that routine measurements of internal contamination need not be performed

The Global Energy Balance Archive (GEBA) version 2017: a database for worldwide measured surface energy fluxes

Science.gov (United States)

Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Folini, Doris; Schwarz, Matthias; Zyta Hakuba, Maria; Sanchez-Lorenzo, Arturo

2017-08-01

The Global Energy Balance Archive (GEBA) is a database for the central storage of the worldwide measured energy fluxes at the Earth's surface, maintained at ETH Zurich (Switzerland). This paper documents the status of the GEBA version 2017 dataset, presents the new web interface and user access, and reviews the scientific impact that GEBA data had in various applications. GEBA has continuously been expanded and updated and contains in its 2017 version around 500 000 monthly mean entries of various surface energy balance components measured at 2500 locations. The database contains observations from 15 surface energy flux components, with the most widely measured quantity available in GEBA being the shortwave radiation incident at the Earth's surface (global radiation). Many of the historic records extend over several decades. GEBA contains monthly data from a variety of sources, namely from the World Radiation Data Centre (WRDC) in St. Petersburg, from national weather services, from different research networks (BSRN, ARM, SURFRAD), from peer-reviewed publications, project and data reports, and from personal communications. Quality checks are applied to test for gross errors in the dataset. GEBA has played a key role in various research applications, such as in the quantification of the global energy balance, in the discussion of the anomalous atmospheric shortwave absorption, and in the detection of multi-decadal variations in global radiation, known as global dimming and brightening. GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible through the internet via http://www.geba.ethz.ch. Supplementary data are available at https://doi.org/10.1594/PANGAEA.873078.

Energy window selection for a radiation signal processing system

International Nuclear Information System (INIS)

Knoll, G.F.; Schrader, M.E.

1986-01-01

This invention provides an apparatus and method for selecting only meaningful information from signals produced by Anger-type radioisotope cameras producing positional information. It is an improvement in the means for determining energy threshold values as a function of radiation event positional information. The establishment of an energy threshold table begins by flooding the camera face with a uniform source of radiation and utilizing the pre-established spatial translation table to reposition detected radiation events according to their true spatial element coordinates. A histogram is compiled for each spatial element, the histogram comprising the number of radiation events occurring at several discrete energy levels. A peak centroid value is then determined for each element, and an initial energy window is set. Next, a specified region of the camera field of view is inspected to determine a target sum of radiation events to be accepted by each element, setting a standard for adjusting the energy windows of each element. Using this standard, the energy window for each element is progressively adapted so that each will accept nearly the same number of radiation events or counts in response to a flood or calibration image. Finally the energy window for each true spatial element is translated back to its apparent spatial element and incorporated into an energy threshold table accessible by the apparent spatial coordinates of each radiation event

"Atmospheric Radiation Measurement (ARM) Research Facility at Oliktok Point Alaska"

Science.gov (United States)

Helsel, F.; Ivey, M.; Hardesty, J.; Roesler, E. L.; Dexheimer, D.

2017-12-01

Scientific Infrastructure To Support Atmospheric Science, Aerosol Science and UAS's for The Department Of Energy's Atmospheric Radiation Measurement Programs At The Mobile Facility 3 Located At Oliktok Point, Alaska.The Atmospheric Radiation Measurement (ARM) Program's Mobile Facility 3 (AMF3) located at Oliktok Point, Alaska is a U.S. Department of Energy (DOE) site designed to collect data and help determine the impact that clouds and aerosols have on solar radiation. AMF3 provides a scientific infrastructure to support instruments and collect arctic data for the international arctic research community. The infrastructure at AMF3/Oliktok is designed to be mobile and it may be relocated in the future to support other ARM science missions. AMF3's present base line instruments include: scanning precipitation Radars, cloud Radar, Raman Lidar, Eddy correlation flux systems, Ceilometer, Balloon sounding system, Atmospheric Emitted Radiance Interferometer (AERI), Micro-pulse Lidar (MPL) Along with all the standard metrological measurements. In addition AMF3 provides aerosol measurements with a Mobile Aerosol Observing System (MAOS). Ground support for Unmanned Aerial Systems (UAS) and tethered balloon flights. Data from these instruments and systems are placed in the ARM data archives and are available to the international research community. This poster will discuss what instruments and systems are at the ARM Research Facility at Oliktok Point Alaska.

Development of dose monitoring system applicable to various radiations with wide energy ranges

International Nuclear Information System (INIS)

Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira

2006-01-01

A new radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with WIde energy raNges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high energy accelerator facilities. DARWIN is composed of a phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with 6 Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. DARWIN has the following features: (1) capable of monitoring doses from neutrons, photons and muons with energies from thermal energy to 1 GeV, 150 keV to 100 MeV, and 1 MeV to 100 GeV, respectively, (2) highly sensitive with precision, and (3) easy to operate with a simple graphical user-interface. The performance of DARWIN was examined experimentally in several radiation fields. The results of the experiments indicated the accuracy and rapid response of DARWIN for measuring dose rates from neutrons, photons and muons with wide energies. With these properties, we conclude that DARWIN will be able to play a very important role for improving radiation safety in high energy accelerator facilities. (author)

In situ composition measurements of Bunsen reaction solution by radiation probes

Energy Technology Data Exchange (ETDEWEB)

Kubo, Shinji; Nagaya, Yasunobu [Japan Atomic Energy Agency (Japan)

2010-07-01

Measuring equipments are integral to chemical process controls. A stable hydrogen production by the Iodine-Sulfur thermochemical water-splitting process is relatively difficult because of lack of existing in situ composition measurement techniques for multiple components and corrosive solution. Composition regulations of Bunsen reaction solution is particularly important, since a closed cycle system provided with this process causes that the many streams with different composition return to this section. Accordingly Bunsen solution becomes changeable composition. Radiation probes have a potential for applications to determine this multiple component solution while the non-contact approach avoids the corrosive issues. Moreover the probes have features of the promptness, contact-less and sequential use. Laboratory scale experiments to evaluate these possibilities of the measurement were conducted with use of simulated Bunsen solution, HIx solution and H{sub 2}SO{sub 4} solution, containing HI, I2, H{sub 2}SO{sub 4} and H{sub 2}O and sealed radiation sources. Radiations were counted, which were interacted with the solutions in various compositions around room temperature contained in vessels. For HIx solution, the obtained counting rates were correlated with hydrogen volume concentrations; moreover, the application of the Monte Carlo method suggests possibilities that the detector responses for HIx solution by the radiation probes are predictable. For H{sub 2}SO{sub 4} solution, iodine atoms had significant influences on the relationship between output values of two gamma-ray density meters, cesium source as higher energy and barium source as lower energy. This results suggest that the neutron ray probe, the gamma-ray probes of both lower energy and higher energy have possibilities to determine the composition of Bunsen solution of HIx and H{sub 2}SO{sub 4} solutions. (orig.)

S-factor for radiative capture reactions for light nuclei at astrophysical energies

Science.gov (United States)

Ghasemi, Reza; Sadeghi, Hossein

2018-06-01

The astrophysical S-factors of thermonuclear reactions, including radiative capture reactions and their analysis in the frame of different theoretical models, are the main source of nuclear processes. We have done research on the radiative capture reactions importance in the framework of a potential model. Investigation of the reactions in the astrophysical energies is of great interest in the aspect of astrophysics and nuclear physics for developing correct models of burning and evolution of stars. The experimental measurements are very difficult and impossible because of these reactions occurrence at low-energies. In this paper we do a calculation on radiative capture astrophysical S-factors for nuclei in the mass region A theoretical methods.

Role of radiation standards in peaceful uses of nuclear energy

International Nuclear Information System (INIS)

Mahant, A.K.; Sathian, V.; Joseph, L.

2009-01-01

Radiation standards play an acute role in all the peaceful applications of nuclear energy, which is not limited to generation of electrical power anymore. Radioactive sources are being used in a very wide variety of applications, which can be broadly classified as medicine, agriculture, industry and scientific research. All these applications involve the use of radiation in a well-controlled manner and hence require accurate characterization and quantification of the radiation. Radiation Standards Section of Radiation Safety Systems Division at BARC is the apex national laboratory for all the radiological quantities related to various types of radiation sources. The laboratory develops, maintains and disseminates the standards to the users of the radiation sources all over the country and some of the neighbouring countries viz. Nepal, Bangladesh, Sri Lanka and Myanmar with an essential objective to bring homogeneity in all radiological measurements and make them compatible with the international standards. Various services provided by the Radiation Standards Section have been briefly described in the following sections. (author)

Deviating measurements in radiation protection. Legal assessment of deviations in radiation protection measurements

International Nuclear Information System (INIS)

Hoegl, A.

1996-01-01

This study investigates how, from a legal point of view, deviations in radiation protection measurements should be treated in comparisons between measured results and limits stipulated by nuclear legislation or goods transport regulations. A case-by-case distinction is proposed which is based on the legal concequences of the respective measurement. Commentaries on nuclear law contain no references to the legal assessment of deviating measurements in radiation protection. The examples quoted in legal commentaries on civil and criminal proceedings of the way in which errors made in measurements for speed control and determinations of the alcohol content in the blood are to be taken into account, and a commentary on ozone legislation, are examined for analogies with radiation protection measurements. Leading cases in the nuclear field are evaluated in the light of the requirements applying in case of deviations in measurements. The final section summarizes the most important findings and conclusions. (orig.) [de

Biological effects of high-energy radiation

International Nuclear Information System (INIS)

Curtis, S.B.

1976-01-01

The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

The Global Energy Balance Archive (GEBA): A database for the worldwide measured surface energy fluxes

Science.gov (United States)

Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Hakuba, Maria Z.; Mystakidis, Stefanos; Arsenovic, Pavle; Sanchez-Lorenzo, Arturo

2017-02-01

The Global Energy Balance Archive (GEBA) is a database for the worldwide measured energy fluxes at the Earth's surface. GEBA is maintained at ETH Zurich (Switzerland) and has been founded in the 1980s by Prof. Atsumu Ohmura. It has continuously been updated and currently contains around 2500 stations with 500`000 monthly mean entries of various surface energy balance components. Many of the records extend over several decades. The most widely measured quantity available in GEBA is the solar radiation incident at the Earth's surface ("global radiation"). The data sources include, in addition to the World Radiation Data Centre (WRDC) in St. Petersburg, data reports from National Weather Services, data from different research networks (BSRN, ARM, SURFRAD), data published in peer-reviewed publications and data obtained through personal communications. Different quality checks are applied to check for gross errors in the dataset. GEBA is used in various research applications, such as for the quantification of the global energy balance and its spatiotemporal variation, or for the estimation of long-term trends in the surface fluxes, which enabled the detection of multi-decadal variations in surface solar radiation, known as "global dimming" and "brightening". GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible over the internet via www.geba.ethz.ch.

Photographic film dosimetry for high-energy accelerator radiation

International Nuclear Information System (INIS)

Komochkov, M.M.; Salatskaya, M.I.

1981-01-01

A technique for personnel photographic film dosimetry (PPFDN) of wide energy spectrum neutrons intended for measuring the effect of accelerating device radiation on personnel is described. Procedures of data measurement and processing as well as corrections to hadron contribution are presented. It is noted that the PPFDN method permits to measure a neutron dose equivalent for personnel in the range from 0.01 to 0.02 up to 100 rem, if the relativistic neutron contribution to a total dose does not exceed 5%. The upper limit of the measured dose reduced several times for a greater contribution of relativistic neutrons to the total dose [ru

Radiation damage measurements in room temperature semiconductor radiation detectors

International Nuclear Information System (INIS)

Franks, L.A.; Olsen, R.W.; James, R.B.; Brunett, B.A.; Walsh, D.S.; Doyle, B.L.; Vizkelethy, G.; Trombka, J.I.

1998-01-01

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI 2 ) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 10 p/cm 2 and significant bulk leakage after 10 12 p/cm 2 . CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 x 10 9 p/cm 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10 10 n/cm 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 x 10 10 α/cm 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 x 10 9 α/cm 2 . CT detectors show resolution losses after fluences of 3 x 10 9 p/cm 2 at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 x 10 10 n/cm 2 . Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10 12 p/cm 2 and with 1.5 GeV protons at fluences up to 1.2 x 10 8 p/cm 2 . Neutron exposures at 8 MeV have been reported at fluences up to 10 15 n/cm 2 . No radiation damage was reported under these irradiation conditions

A unique experiment. Measurement of radiation doses at Vinca

Energy Technology Data Exchange (ETDEWEB)

NONE

1960-07-15

For the first time in the history of the peaceful applications of atomic energy, an experiment was conducted to determine the exact levels of radiation exposure resulting from a reactor incident. The experiment was made at Vinca, Yugoslavia, wherein October 1958 six persons had been subjected to high doses of neutron and gamma radiation during a brief uncontrolled run of a zero-power reactor. One of them died but the other five were successfully treated at the Curie Hospital in Paris. In the case of four of them, the treatment involved the grafting of healthy bone marrow to counteract the effects of radiation on blood-forming tissues. It was recognized that if the effects produced on the irradiated persons could be related to the exact doses of radiation they had received, it would be possible to gain immensely valuable knowledge about the biological consequences of acute and high level radiation exposure on a quantitative basis. It was suggested to the Yugoslav authorities that a dosimetry experiment be conducted at Vinca. The most accurate modern techniques of dosimetry developed at the Oak Ridge National Laboratory were employed during the experiment. Simultaneous measurements of the neutron and gamma doses were made at points where the people had been located. At these points the effects of the radiation on the salt solution in the phantoms were studied. In particular, the energy distribution of the radiation was investigated.It was the ratio between the various components of the radiation that was of special interest in these measurements because this ratio itself would help in determining the exact doses. The dose of one of the components, viz. slow neutrons, had already been determined during the treatment of the patients. If the ratio of the components could be ascertained, the doses of the fast neutrons and gamma rays could also be established because the ratio would not be affected by the power level at which the reactor was operated

Measurement of high-energy electrons by means of a Cherenkov detector in ISTTOK tokamak

Energy Technology Data Exchange (ETDEWEB)

Jakubowski, L., E-mail: lech.Jjakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal); Malinowski, K.; Sadowski, M.J.; Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal)

2010-10-15

The paper concerns detectors of the Cherenkov radiation which can be used to measure high-energy electrons escaping from short-living plasma. Such detectors have high temporal (about 1 ns) and spatial (about 1 mm) resolution. The paper describes a Cherenkov-type detector which was designed, manufactured and installed in the ISTTOK tokamak in order to measure fast runaway electrons. The radiator of that detector was made of an aluminium nitride (AlN) tablet with a light-tight filter on its front surface. Cherenkov signals from the radiator were transmitted through an optical cable to a fast photomultiplier. It made possible to perform direct measurements of the runaway electrons of energy above 80 keV. The measured energy values and spatial characteristics of the recorded electrons appeared to be consistent with results of numerical modelling of the runaway electron generation process in the ISTTOK tokamak.

Towards a quantitative, measurement-based estimate of the uncertainty in photon mass attenuation coefficients at radiation therapy energies

Science.gov (United States)

Ali, E. S. M.; Spencer, B.; McEwen, M. R.; Rogers, D. W. O.

2015-02-01

In this study, a quantitative estimate is derived for the uncertainty in the XCOM photon mass attenuation coefficients in the energy range of interest to external beam radiation therapy—i.e. 100 keV (orthovoltage) to 25 MeV—using direct comparisons of experimental data against Monte Carlo models and theoretical XCOM data. Two independent datasets are used. The first dataset is from our recent transmission measurements and the corresponding EGSnrc calculations (Ali et al 2012 Med. Phys. 39 5990-6003) for 10-30 MV photon beams from the research linac at the National Research Council Canada. The attenuators are graphite and lead, with a total of 140 data points and an experimental uncertainty of ˜0.5% (k = 1). An optimum energy-independent cross section scaling factor that minimizes the discrepancies between measurements and calculations is used to deduce cross section uncertainty. The second dataset is from the aggregate of cross section measurements in the literature for graphite and lead (49 experiments, 288 data points). The dataset is compared to the sum of the XCOM data plus the IAEA photonuclear data. Again, an optimum energy-independent cross section scaling factor is used to deduce the cross section uncertainty. Using the average result from the two datasets, the energy-independent cross section uncertainty estimate is 0.5% (68% confidence) and 0.7% (95% confidence). The potential for energy-dependent errors is discussed. Photon cross section uncertainty is shown to be smaller than the current qualitative ‘envelope of uncertainty’ of the order of 1-2%, as given by Hubbell (1999 Phys. Med. Biol 44 R1-22).

Measurement and simulation of the radiation environment in the lower atmosphere for dose assessment

International Nuclear Information System (INIS)

Pioch, Christian Dieter

2012-01-01

Flying personnel is occupationally exposed to rather high radiation levels due to secondary cosmic radiation. Therefore, the radiation environment induced in the lower atmosphere by galactic and solar cosmic radiation was characterized by means of particle transport calculations using GEANT4. These calculations were validated with continuous measurements of the energy spectra of secondary neutrons with Bonner sphere spectrometers at the Zugspitze mountain and near the North Pole. The response of these instruments was determined with GEANT4 and for the first time experimentally verified at high neutron energies (244 and 387 MeV). Route doses for aircrews along typical long-haul flights were determined for galactic and solar cosmic radiation using most recent data on the magnetospheric field and primary cosmic radiation.

Radiation effects on integrated circuits used in high energy research

International Nuclear Information System (INIS)

Kanofsky, A.S.; Yost, B.; Farr, W.

1990-01-01

The authors report here on radiation effects on two amplifiers used in high energy experiments. These are standard devices that are produced by LeCroy. They describe each of the devices and the experimental techniques. Finally, they present and discuss the results of the measurements. 5 figs

Measuring and Controlling the Energy Spread in CEBAF

CERN Document Server

Krafft, G A; Dickson, R W; Kazimi, R; Lebedev, V A; Tiefenback, M G

2000-01-01

As compared to electron storage rings, one advantage of recirculating linear accelerators is that the beam properties at target are no longer dominated by the equilibrium between quantum radiative diffusion and radiation damping because new beam is continually injected into the accelerator. This allows the energy spread from a CEBAF-type machine to be relatively small; the measured energy spread from CEBAF at 4 GeV is less than 100 parts per million accumulated over times of order several days. In this paper, the various subsystems contributing to the energy spread of a CEBAF-type accelerator are reviewed, as well as the machine diagnostics and controls that are used in CEBAF to ensure that a small energy spread is provided during routine running. Examples of relevant developments are (1) stable short bunches emerging from the injector, (2) precision timing and phasing of the linacs with respect to the centroid of the beam bunches on all passes, (3) implementing 2 kHz sampling rate feedback systems for final ...

Ultraviolet radiation, measurements and safety evaluations for radiation protection purposes

International Nuclear Information System (INIS)

Witew, B.; Fischer, P.G.

1983-01-01

In order to evaluate the effects of ultraviolet radiation, one has to study that photobiologically effective radiation which induces a just measurable threshold reaction. For practical radiation protection, one has to determine the permissible duration of exposure at the end of which the threshold reaction is induced. This time limit is derived by means of spectral measurements and determination of radiation intensity. Detrimental photobiological effects can be avoided, and favourable effects optimized, by observing the time limit. Thus these measurements are used to determine the threshold at which the desired effects of ultraviolet radiation will be accompanied by unwanted effects or damage to persons, as for instance in the use of ultraviolet radiation for operating room sterilization, arc welding work, or cosmetic purposes. (orig.) [de

The application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

2001-01-01

This paper introduce the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 Reader and TLD-100M chips on the measurement of hard X-ray pulse energy spectrum. The idea, using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV), is discussed in details. Considering all the factors of the measuring surroundings, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device -high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

Development of transmission dose estimation algorithm for in vivo dosimetry in high energy radiation treatment

International Nuclear Information System (INIS)

Yun, Hyong Geun; Shin, Kyo Chul; Hun, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2004-01-01

In vivo dosimetry is very important for quality assurance purpose in high energy radiation treatment. Measurement of transmission dose is a new method of in vivo dosimetry which is noninvasive and easy for daily performance. This study is to develop a tumor dose estimation algorithm using measured transmission dose for open radiation field. For basic beam data, transmission dose was measured with various field size (FS) of square radiation field, phantom thickness (Tp), and phantom chamber distance (PCD) with a acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. By using regression analysis of measured basic beam data, a transmission dose estimation algorithm was developed. Accuracy of the algorithm was tested with flat solid phantom with various thickness in various settings of rectangular fields and various PCD. In our developed algorithm, transmission dose was equated to quadratic function of log(A/P) (where A/P is area-perimeter ratio) and the coefficients of the quadratic functions were equated to tertiary functions of PCD. Our developed algorithm could estimate the radiation dose with the errors within ±0.5% for open square field, and with the errors within ±1.0% for open elongated radiation field. Developed algorithm could accurately estimate the transmission dose in open radiation fields with various treatment settings of high energy radiation treatment. (author)

Darwin: Dose monitoring system applicable to various radiations with wide energy ranges

International Nuclear Information System (INIS)

Sato, T.; Satoh, D.; Endo, A.; Yamaguchi, Y.

2007-01-01

A new radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with Wide energy ranges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high-energy accelerator facilities. DARWIN is composed of a Phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with 6 Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. DARWIN has the following features: (1) capable of monitoring doses from neutrons, photons and muons with energies from thermal energy to 1 GeV, 150 keV to 100 MeV and 1 MeV to 100 GeV, respectively, (2) highly sensitive with precision and (3) easy to operate with a simple graphical user-interface. The performance of DARWIN was examined experimentally in several radiation fields. The results of the experiments indicated the accuracy and wide response range of DARWIN for measuring dose rates from neutrons, photons and muons with wide energies. It was also found from the experiments that DARWIN enables us to monitor small fluctuations of neutron dose rates near the background level because of its high sensitivity. With these properties, DARWIN will be able to play a very important role for improving radiation safety in high-energy accelerator facilities. (authors)

Measurement and detection of radiation

CERN Document Server

Tsoulfanidis, Nicholas

2015-01-01

This fourth edition reflects recent major developments that have occurred in radiation detector materials, systems, and applications. It continues to provide the most practical and up-to-date introduction to radiation detector technology, proper measurement techniques, and analysis of results for engineers and scientists using radiation sources. New chapters emphasize the expanded use of radiation detection systems in nuclear non-proliferation, homeland security, and nuclear medicine. The book also discusses the correct ways to perform measurements following current health physics procedures.

Individual Dosimetry for High Energy Radiation Fields

International Nuclear Information System (INIS)

Spurny, F.

1999-01-01

The exposure of individuals on board aircraft increased interest in individual dosimetry in high energy radiation fields. These fields, both in the case of cosmic rays as primary radiation and at high energy particle accelerators are complex, with a large diversity of particle types, their energies, and linear energy transfer (LET). Several already existing individual dosemeters have been tested in such fields. For the component with high LET (mostly neutrons) etched track detectors were tested with and without fissile radiators, nuclear emulsions, bubble detectors for both types available and an albedo dosemeter. Individual dosimetry for the low LET component has been performed with thermoluminescent detectors (TLDs), photographic film dosemeters and two types of electronic individual dosemeters. It was found that individual dosimetry for the low LET component was satisfactory with the dosemeters tested. As far as the high LET component is concerned, there are problems with both the sensitivity and the energy response. (author)

Role of visualization of nuclear radiation in public education on atomic energy. Visualization of natural nuclear radiation using a cloud chamber

International Nuclear Information System (INIS)

Kaneko, Junichi H.; Fujita, Fumiyuki; Narabayashi, Tadashi

2008-01-01

Nuclear radiation is indispensable tool, i.e., medical diagnostic systems and industrial nondestructive measurement systems, for our life. On the other hand, ordinary people sometimes have bad image for nuclear radiation. To improve this undesirable situation, many individuals and groups keep holding public educational meeting on nuclear radiation. For this purpose, visualization of natural nuclear radiation by a cloud chamber is very effective way; participants feel existence of nuclear radiation directly. In this talk, public educational activity of Hokkaido University and Japan Atomic Energy Society Hokkaido branch will be reported. (author)

Electron bunch length measurement with a wakefield radiation decelerator

Directory of Open Access Journals (Sweden)

Weiwei Li

2014-03-01

Full Text Available In this paper, we propose a novel method to measure the electron bunch length with a dielectric wakefield radiation (DWR decelerator which is composed of two dielectric-lined waveguides (DLWs and an electron spectrometer. When an electron beam passes through a DLW, the DWR is excited which leads to an energy loss of the electron beam. The energy loss is found to be largely dependent on the electron bunch length and can be easily measured by an electron spectrometer which is essential for a normal accelerator facility. Our study shows that this method has a high resolution and a great simplicity.

Online Radiation Dose Measurement System for ATLAS experiment

CERN Document Server

Mandić, I; The ATLAS collaboration

2012-01-01

Particle detectors and readout electronics in the high energy physics experiment ATLAS at the Large Hadron Collider at CERN operate in radiation field containing photons, charged particles and neutrons. The particles in the radiation field originate from proton-proton interactions as well as from interactions of these particles with material in the experimental apparatus. In the innermost parts of ATLAS detector components will be exposed to ionizing doses exceeding 100 kGy. Energetic hadrons will also cause displacement damage in silicon equivalent to fluences of several times 10e14 1 MeV-neutrons per cm2. Such radiation doses can have severe influence on the performance of detectors. It is therefore very important to continuously monitor the accumulated doses to understand the detector performance and to correctly predict the lifetime of radiation sensitive components. Measurements of doses are important also to verify the simulations and represent a crucial input into the models used for predicting future ...

Measurement of gamma radiation doses at the RA reactor by thermoluminescent dosemeters

International Nuclear Information System (INIS)

Prokic, M.

1974-01-01

This paper presents the procedures and gamma radiation doses measured at the exit from the horizontal experimental channel HK-5, vertical experimental channel VK-5 and in the thermal column of the RA reactor in Vinca. Measurement of gamma radiation dose in the mixed intense gamma and neutron radiation field was done by two types of thermoluminescent dosemeters, LiF (TLD-700) and CaF 2 (TLD-08). Gamma dose in the VK-5 was measured in the air and on the bottle filled with tissue-equivalent solution. Increase of the dose on the surface of the bottle was 2.3 compared to the gamma dose value in the air. Correction for the influence of neutrons having different energies was done by using the known sensitivity values of both TL dosemeter types for thermal, intermediate and fast neutrons. Results showed that the TLD-700 dosemeter contains 5 time more Li-6 isotopes (0.035%) than the declared value causing increased neutron sensitivity of this dosemeter. This paper includes numerical sensitivity data for neutrons of different energies for both types of TL dosemeters. Neutron sensitivity values for TLD-700 are related to LiF with 0.035% of Li-6 isotope. Result of measurement have also shown that the CaF 2 :Mn (TLD-08) thermoluminescent dosemeter is more suitable for gamma radiation dose measurements in mixed n-gamma fields with intensive neutron fluxes due to lower neutron sensitivity compared to TLD-700 [sr

Preliminary design of an energy-conversion unit of radiation-voltaic battery

International Nuclear Information System (INIS)

Yang Yuqing; Wang Guanquan; Hu Rui; Gao Hui; Liu Yebing; Zhang Huaming; Luo Shunzhong

2010-01-01

Based on the principle of radiation-voltaic effect, a preliminary energy-conversion unit of radiation-voltaic battery was designed. Three energy-conversion units were manufactured and their electric I-V properties under irradiation of solid sources of 63 Ni and 3 H were measured. The I-V curves were analyzed and some ideas for improvement were presented. It was found that the designed energy-conversion unit deteriorated dramatically under irradiation of 241 Am source. The best U oc and I sc gained under irradiation of 2.96 x 10 8 Bq 63 Ni were 0.267 V and 28.4 nA, and were 0.260 V and 62.8 nA under irradiation of a 5.09 x 10 9 Bq 3 H source. Further efforts are being made to improve the design. (authors)

Environmental radiation measurements using TLD in and around AERE, Dhaka

International Nuclear Information System (INIS)

Mollah, A.S.; Husain, S.R.; Rahman, M.M.

1986-01-01

The external background radiation level in and around the Atomic Energy Research Establishment (AERE) in Dhaka has been measured. The measurements were performed using lithium fluoride (LiF) thermoluminescence dosemeters (TLD-100) at 32 locations, all one metre above the ground. The annual average dose rate measured in the AERE environs was 1.74+-0.23 mGy.y -1 in air, based on analysis of thermoluminescence dosemeter data collected from 1982 to 1984. (author)

Black hole firewalls require huge energy of measurement

Science.gov (United States)

Hotta, Masahiro; Matsumoto, Jiro; Funo, Ken

2014-06-01

The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the original firewall paradox of Almheiri et al. [J. High Energy Phys. 02 (2013) 062] in quantum black holes. Though the late-time part of radiations emitted from the mirror is fully entangled with the early part, no firewall exists with a deadly, huge average energy flux in this model. This is because the high-energy entanglement structure of the discretized systems in almost maximally entangled states is modified so as to yield the correct description of low-energy effective field theory. Furthermore, the strong subadditivity paradox of firewalls is resolved using nonlocality of general one-particle states and zero-point fluctuation entanglement. Due to the Reeh-Schlieder theorem in quantum field theory, another firewall paradox is inevitably raised with quantum remote measurements in the model. We resolve this paradox from the viewpoint of the energy cost of measurements. No firewall appears, as long as the energy for the measurement is much smaller than the ultraviolet cutoff scale.

Status of radiation-based measurement technology

International Nuclear Information System (INIS)

Moon, B. S.; Lee, J. W.; Chung, C. E.; Hong, S. B.; Kim, J. T.; Park, W. M.; Kim, J. Y.

1999-03-01

This report describes the status of measurement equipment using radiation source and new technologies in this field. This report includes the development status in Korea together with a brief description of the technology development and application status in ten countries including France, America, and Japan. Also this report describes technical factors related to radiation-based measurement and trends of new technologies. Measurement principles are also described for the equipment that is widely used among radiation-based measurement, such as level measurement, density measurement, basis weight measurement, moisture measurement, and thickness measurement. (author). 7 refs., 2 tabs., 21 figs

Radiation flux measuring device

International Nuclear Information System (INIS)

Corte, E.; Maitra, P.

1977-01-01

A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

The Atmospheric Radiation Measurement Program May 2003 Intensive Operations Period Examining Aerosol Properties and Radiative Influences: Preface to Special Section

Science.gov (United States)

Ferrare, Richard; Feingold, Graham; Ghan, Steven; Ogren, John; Schmid, Beat; Schwartz, Stephen E.; Sheridan, Pat

2006-01-01

Atmospheric aerosols influence climate by scattering and absorbing radiation in clear air (direct effects) and by serving as cloud condensation nuclei, modifying the microphysical properties of clouds, influencing radiation and precipitation development (indirect effects). Much of present uncertainty in forcing of climate change is due to uncertainty in the relations between aerosol microphysical and optical properties and their radiative influences (direct effects) and between microphysical properties and their ability to serve as cloud condensation nuclei at given supersaturations (indirect effects). This paper introduces a special section that reports on a field campaign conducted at the Department of Energy Atmospheric Radiation Measurement site in North Central Oklahoma in May, 2003, examining these relations using in situ airborne measurements and surface-, airborne-, and space-based remote sensing.

Radiation protection at workplaces with increased natural radiation exposure in Greece: recording, monitoring and protection measures

International Nuclear Information System (INIS)

Potiriadis, C.; Koukoliou, V.

2002-01-01

Greek Atomic Energy Commission (GAEC) is the regulatory, advisory and competent authority on radiation protection matters. It is the authority responsible for the introduction of Radiation Protection regulations and monitoring of their implementation. In 1997, within the frame of its responsibilities the Board of the GAEC appointed a task group of experts to revise and bring the present Radiation Protection Regulations into line with the Basic Safety Standards (BSS) 96/29/Euratom Directive and the 97/43/Euratom Directive (on health protection of individuals against the dangers of ionising radiation in relation to medical exposure). Concerning the Title 7. of the new European BSS Directive, which refers to the Radiation Protection at work places with increased levels of natural radiation exposure, the Radiation Protection Regulations provides that the authority responsible for recording, monitoring and introducing protection measures at these places is the GAEC. Practices where effective doses to the workers due to increased natural radiation levels, may exceed 1mSv/y, have to be specified and authorised by the GAEC. The identification procedure is ongoing

Nuclear instrumentation for radiation measurement

International Nuclear Information System (INIS)

Madan, V.K.

2012-01-01

Nuclear radiation cannot be detected by human senses. Nuclear detectors and associated electronics facilitate detection and measurement of different types of radiation like alpha particles, beta particles, gamma radiation, and detection of neutrons. Nuclear instrumentation has evolved greatly since the discovery of radioactivity. There has been tremendous advancement in detector technology, electronics, computer technology, and development of efficient algorithms and methods for spectral processing to extract precisely qualitative and quantitative information of the radiation. Various types of detectors and nuclear instruments are presently available and are used for different applications. This paper describes nuclear radiation, its detection and measurement and associated electronics, spectral information extraction, and advances in these fields. The paper also describes challenges in this field

Measuring ionizing radiation with a mobile device

Science.gov (United States)

Michelsburg, Matthias; Fehrenbach, Thomas; Puente León, Fernando

2012-02-01

In cases of nuclear disasters it is desirable to know one's personal exposure to radioactivity and the related health risk. Usually, Geiger-Mueller tubes are used to assess the situation. Equipping everyone with such a device in a short period of time is very expensive. We propose a method to detect ionizing radiation using the integrated camera of a mobile consumer device, e.g., a cell phone. In emergency cases, millions of existing mobile devices could then be used to monitor the exposure of its owners. In combination with internet access and GPS, measured data can be collected by a central server to get an overview of the situation. During a measurement, the CMOS sensor of a mobile device is shielded from surrounding light by an attachment in front of the lens or an internal shutter. The high-energy radiation produces free electrons on the sensor chip resulting in an image signal. By image analysis by means of the mobile device, signal components due to incident ionizing radiation are separated from the sensor noise. With radioactive sources present significant increases in detected pixels can be seen. Furthermore, the cell phone application can make a preliminary estimate on the collected dose of an individual and the associated health risks.

Estimates of the generation of available potential energy by infrared radiation

Science.gov (United States)

Hansen, A. R.; Nagle, R. L.

1984-01-01

Data from the National Meteorological Center and net outgoing infrared radiation (IR) data measured by NOAA satellites for January 1977 are used to compute estimates of the spectral and spatial contributions to the net generation of available potential energy in the Northern Hemisphere due to infrared radiation. Although these estimates are necessarily crude, the results obtained indicate that IR causes destruction of both zonal and eddy available potential energy. The contributions from midlatitudes to the zonal and eddy generation are about -5.0 W/sq m and about -0.6 W/sq m, respectively. The eddy generation is due almost entirely to stationary wavenumbers one and two. Comparison with earlier studies and computation of Newtonian cooling coefficients are discussed.

ACREM: A new air crew radiation exposure measuring system

International Nuclear Information System (INIS)

Beck, P.; Duftschmid, K.; Kerschbaumer, S.; Schmitzer, C.; Strachotinsky, C.; Grosskopf, A.; Winkler, N.

1996-01-01

Cosmic radiation has already been discovered in 1912 by the Austrian Nobel Laureate Victor F. Hess. After Hess up to now numerous measurements of the radiation exposure by cosmic rays in different altitudes have been performed, however, this has not been taken serious in view of radiation protection.Today, with the fast development of modern airplanes, an ever increasing number of civil aircraft is flying in increasing altitudes for considerable time. Members of civil aircrew spending up to 1000 hours per year in cruising altitudes and therefore are subject to significant levels of radiation exposure. In 1990 ICRP published its report ICRP 60 with updated excess cancer risk estimates, which led to significantly higher risk coefficients for some radiation qualities. An increase of the radiation weighting factors for mean energy neutron radiation increases the contribution for the neutron component to the equivalent dose by about 60%, as compared to the earlier values of ICRP26. This higher risk coefficients lead to the recommendation of the ICRP, that cosmic radiation exposure in civil aviation should be taken into account as occupational exposure. Numerous recent exposure measurements at civil airliners in Germany, Sweden, USA, and Russia show exposure levels in the range of 3-10 mSv/year. This is significantly more than the average annual dose of radiation workers (in Austria about 1.5 mSv/year). Up to now no practicable and economic radiation monitoring system for routine application on board exits. A fairly simple and economic approach to a practical, active in-flight dosimeter for the assessment of individual crew exposure is discussed in this paper

Development of Nuclear Energy and Radiation Textbooks for Elementary School Students

International Nuclear Information System (INIS)

Han, E.; Choi, Y.; Yang, J.; Lee, S.

2015-01-01

The textbooks for elementary school students were developed to help future generations make value judgments based on appropriate information about nuclear energy and radiation. The themes and educational contents of the 13 lessons, to be delivered in one semester at elementary school level, were selected by the educational requirements of students, science teachers, and experts. The “Radiation and Life” textbook for elementary school students consists of the following chapters: – Chapter 1. What is nuclear energy and radiation?, – Chapter 2. Who discovered the nuclear energy and radiation?, – Chapter 3. Why is nuclear energy and radiation important?, – Chapter 4. Is nuclear energy and radiation dangerous?, – Chapter 5. Let’s learn about what to do when an accident occurs, – Chapter 6. How are nuclear energy and radiation used?, – Chapter 7. What is nuclear power generation?, – Chapter 8. Why is radiation used for food?, – Chapter 9. What is medical radiation?, – Chapter 10. What kind of irradiated products are in our daily lives?, – Chapter 11. What jobs are related to nuclear energy and radiation?, – Chapter 12. What are energies of future?, – Chapter 13. Concept of Talk-talk (a study review game). The general trend in recent educational curriculum development suppresses national education course organizations and authorities and expands the autonomy and authority of regions and schools. The derived textbook contents are expected to be helpful as first textbooks for the autonomous selection of education about nuclear energy and radiation for use in creative experiences developed at the school level. (author)

Preliminary analysis of surface radiation measurements recorded at the Nansen ice sheet (Antarctica)

International Nuclear Information System (INIS)

Bonafe', U.; Dalpane, E.; Georgiadis, T.; Pitacco, A.

1996-01-01

An experiment on radiation and surface energy balance was conducted during the 9. Italian expedition in Antarctica at the Nancen ice sheet, a glacier situated close to the Italian base at Terra Nova Bay, to correlate surface balances to the formation and development of katabatic winds. Measurements were taken by radiometers covering the whole spectra of solar and terrestrial emissions and by fast sensors of atmospheric wind velocity and humidity for the application of the eddy correlation technique. A preliminary analysis of the radiometric data collected in order to quantify the major components of radiative energy balance during the Antarctic summer in clear sky conditions is reported and discussed. The findings show the very low available energy (mean about 1 W/m 2 ), in terms of net radiation, for the physical processes such as sensible- and latent-heat fluxes. Long-wave radiation balance was applied to estimate the reliability of the Swinbank's parametrization, relative to general conditions of the atmosphere

Project and construction of a measurement system and nuclear radiations analysis

International Nuclear Information System (INIS)

Castro, R. B. de.

1983-01-01

A counting system was designed and built, aiming to: detect and measure nuclear radiations using a Geiger-Mueller counter; and to measure the amplitudes of pulses from either a proportional or a NaI detector. The results obtained of the Cs-137 and Co-60 energy spectra were compared with results obtained from other researches. (Author) [pt

Measurement assurance studies of high-energy electron and photon dosimetry in radiation-therapy applications

Energy Technology Data Exchange (ETDEWEB)

Ehrlich, M; Soares, C G [National Bureau of Standards, Washington, DC (USA)

1981-08-01

This is a brief review of surveys on the dosimetry of radiation-therapy beams by the National Bureau of Standards (NBS). Covered are the NBS ferrous-sulfate (Fricke) dosimetry service, a recently completed survey carried out with thermoluminescence dosimeters (TLD) on the dosimetry in cobalt-60 teletherapy beams, and plans for a TLD survey of dosimetry in high-energy bremsstrahlung beams.

Measurement assurance studies of high-energy electron and photon dosimetry in radiation-therapy applications

International Nuclear Information System (INIS)

Ehrlich, M.; Soares, C.G.

1981-01-01

This is a brief review of surveys on the dosimetry of radiation-therapy beams by the National Bureau of Standards (NBS). Covered are the NBS ferrous-sulfate (Fricke) dosimetry service, a recently completed survey carried out with thermoluminescence dosimeters (TLD) on the dosimetry in cobalt-60 teletherapy beams, and plans for a TLD survey of dosimetry in high-energy bremsstrahlung beams. (author)

Radiographic imaging system for high energy radiation

International Nuclear Information System (INIS)

Barrett, H.H.

1976-01-01

A radiographic imaging system for high energy radiation utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation interspersed among regions relatively opaque to such radiation is described. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

Radiographic imaging system for high energy radiation

International Nuclear Information System (INIS)

1975-01-01

A radiographic imaging system for high energy radiation is described utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation and interspersed among regions relatively opaque to such radiation. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

Spatio-temporal representativeness of ground-based downward solar radiation measurements

Science.gov (United States)

Schwarz, Matthias; Wild, Martin; Folini, Doris

2017-04-01

Surface solar radiation (SSR) is most directly observed with ground based pyranometer measurements. Besides measurement uncertainties, which arise from the pyranometer instrument itself, also errors attributed to the limited spatial representativeness of observations from single sites for their large-scale surrounding have to be taken into account when using such measurements for energy balance studies. In this study the spatial representativeness of 157 homogeneous European downward surface solar radiation time series from the Global Energy Balance Archive (GEBA) and the Baseline Surface Radiation Network (BSRN) were examined for the period 1983-2015 by using the high resolution (0.05°) surface solar radiation data set from the Satellite Application Facility on Climate Monitoring (CM-SAF SARAH) as a proxy for the spatiotemporal variability of SSR. By correlating deseasonalized monthly SSR time series form surface observations against single collocated satellite derived SSR time series, a mean spatial correlation pattern was calculated and validated against purely observational based patterns. Generally decreasing correlations with increasing distance from station, with high correlations (R2 = 0.7) in proximity to the observational sites (±0.5°), was found. When correlating surface observations against time series from spatially averaged satellite derived SSR data (and thereby simulating coarser and coarser grids), very high correspondence between sites and the collocated pixels has been found for pixel sizes up to several degrees. Moreover, special focus was put on the quantification of errors which arise in conjunction to spatial sampling when estimating the temporal variability and trends for a larger region from a single surface observation site. For 15-year trends on a 1° grid, errors due to spatial sampling in the order of half of the measurement uncertainty for monthly mean values were found.

Radiation ray measuring device

International Nuclear Information System (INIS)

Maekawa, Tatsuyuki; Ida, Masaki.

1997-01-01

The present invention provides a chained-radiation ray monitoring system which can be applied to an actual monitoring system of a nuclear power plant or the like. Namely, this device comprises a plurality of scintillation detectors. Each of the detectors has two light take-out ports for emitting light corresponding to radiation rays irradiated from the object of the measurement to optical fibers. In addition, incident light from the optical fiber by way of one of the light take-out optical ports is transmitted to the other of the ports and sent from the other optical port to the fibers. Plurality sets of measuring systems are provided in which each of the detectors are disposed corresponding to a plurality of objects to be measured. A signal processing device is (1) connected with optical fibers of plurality sets of measuring systems in conjunction, (2) detects the optical pulses inputted from the optical fibers to identify the detector from which the optical pulses are sent and (3) measures the amount of radiation rays detected by the identified detector. As a result, the device of the present invention can form a measuring system with redundancy. (I.S.)

A new system for measurement of the space radiation

International Nuclear Information System (INIS)

Pazmandi, T.; Apathy, I.; Deme, S.; Beaujean, R.

2001-01-01

The space radiation mainly consists of heavy charged particles (protons and heavier particles). Due to this fact its effective dose significantly differs from the physical dose. The recently used measuring equipment is not fully suitable to measure both quantities simultaneously. The combined device for measurement of mentioned values consists of an on board thermoluminescent dosimeter reader and a three axis silicon telescope as a linear energy transfer spectrometer. The paper deals with the main characteristics of the new system. This system can be applied for dosimetry of air-crew as well. (authors)

A study of build-up effects in high-energy radiation fields using a TEPC

Energy Technology Data Exchange (ETDEWEB)

Hoefert, M; Stevenson, G R [CERN, European Laboratory for Particle Physics, Geneva (Switzerland); Aroua, A [IAR, Institute for Applied Radiophysics, Lausanne (Switzerland); Sannikov, A V [IHEP, Institute for High-Energy Physics, Protvino (Russian Federation)

1995-09-04

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

A study of build-up effects in high-energy radiation fields using a TEPC

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.; Aroua, A.; Sannikov, A.V.

1995-01-01

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy - Part 4: Calibration of area and personal dosemeters in low energy X reference radiation fields

International Nuclear Information System (INIS)

2004-01-01

ISO 4037 consists of the following parts, under the general title X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy: Part 1: Radiation characteristics and production methods; Part 2: Dosimetry for radiation protection over the energy ranges from 8 keV to 1,3 MeV and 4 MeV to 9 MeV; Part 3: Calibration of area and personal dosemeters and the measurement of their response as a function of energy and angle of incidence; Part 4: Calibration of area and personal dosemeters in low energy X reference radiation fields. This part 4. of ISO 4037 gives guidelines on additional aspects of the characterization of low energy photon radiations. This part of ISO 4037 also describes procedures for calibration and determination of the response of area and personal dose(rate)meters as a function of photon energy and angle of incidence. This part of ISO 4037 concentrates on the accurate determination of conversion coefficients from air kerma to Hp(10) and H*(10) for the spectra of low energy photon radiations. As an alternative to the use of conversion coefficients, the direct calibration in terms of these quantities by means of appropriate reference instruments is described

Comprehension of radiation for RI license

International Nuclear Information System (INIS)

Guk, Jin Sun

2005-08-01

This book starts with theoretical nuclear energy which explains technical terms such as nuclear physics and chemistry, RI and utilization of radiation, radiochemistry and radiation chemistry, radiation biology. It also explains radiation measurements technology including radiation detector and measurements radiation measurements circuit, measuring of energy spectrum. Radiation protection monitoring for radiation protection. It deals with nuclear law, enforcement regulation and ordinance.

Radiation protection measures in the case of incidents and radiation accidents

International Nuclear Information System (INIS)

Herzberg, B.

1976-01-01

Measures to be taken in the case of radiation accidents connected with an unusually high radiation exposure to persons, the amounts of which exceed the limiting values, with depend on whether there has been an external or an internal exposure. In order to give further treatment in the case of whole-body or partial-body irradiation, it is necessary to estimate the exposure dose. In nuclear medicine the accident doses are generally low, i.e. acute radiation damage does not occur here, and immediate measures are not necessary. Therapeutic measures in the case of incorporation accidents are only necessary when the maximum amounts for the nuclide in question recommended by the ICRP has been reached or exceeded in the organism. However, decorporation measures ought to be carried out only by qualified radiation protection physicians. The type of radiation accident which occurs most frequently in nuclear medicine is radiation exposure as a result of contamination. If in the case of contamination of a person the measurement exceeds the radioactivity limit, the decontamination measures are necessary. In the present contribution, these measures for cases without injuries are described in detail. (orig./HP) [de

Calculating the diffuse solar radiation in regions without solar radiation measurements

International Nuclear Information System (INIS)

Li, Huashan; Bu, Xianbiao; Long, Zhen; Zhao, Liang; Ma, Weibin

2012-01-01

Correlations for calculating diffuse solar radiation can be classified into models with global solar radiation (H-based method) and without it (Non-H method). The objective of the present study is to compare the performance of H-based and Non-H methods for calculating the diffuse solar radiation in regions without solar radiation measurements. The comparison is carried out at eight meteorological stations in China focusing on the monthly average daily diffuse solar radiation. Based on statistical error tests, the results show that the Non-H method that includes other readily available meteorological elements gives better estimates. Therefore, it can be concluded that the Non-H method is more appropriate than the H-based one for calculating the diffuse solar radiation in regions without solar radiation measurements. -- Highlights: ► Methods for calculating diffuse solar radiation in regions without solar radiation measurements are investigated. ► Diffuse solar radiation models can be classified into two groups according to global solar radiation. ► Two approaches are compared at the eight meteorological stations in China. ► The method without global solar radiation is recommended.

Measurement uncertainty in broadband radiofrequency radiation level measurements

Directory of Open Access Journals (Sweden)

Vulević Branislav D.

2014-01-01

Full Text Available For the evaluation of measurement uncertainty in the measurement of broadband radio frequency radiation, in this paper we propose a new approach based on the experience of the authors of the paper with measurements of radiofrequency electric field levels conducted in residential areas of Belgrade and over 35 municipalities in Serbia. The main objective of the paper is to present practical solutions in the evaluation of broadband measurement uncertainty for the in-situ RF radiation levels. [Projekat Ministarstva nauke Republike Srbije, br. III43009

Measurement of continuous x-radiation and determination of the energy distribution function of high-energy electrons from an ECR plasma

International Nuclear Information System (INIS)

Bernhardi, K.

1980-01-01

Investigations were made on the x-radiation emitted by a plasma. The methods applied here represent a further development of experimental and numerical methods used hitherto for determining the bremsstrahlung emitted by a plasma, and makes possible a more precise determination of the high-energy electron component of a plasma

The simultaneous measurement of energy and linear polarization of the scattered radiation in resonant inelastic soft x-ray scattering

Energy Technology Data Exchange (ETDEWEB)

Braicovich, L., E-mail: lucio.braicovich@polimi.it; Minola, M.; Dellea, G.; Ghiringhelli, G. [CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133 (Italy); Le Tacon, M. [Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Moretti Sala, M.; Morawe, C.; Peffen, J.-Ch.; Yakhou, F.; Brookes, N. B. [European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043 (France); Supruangnet, R. [Synchrotron Light Research Institute, Nakhon Ratchasima (Thailand)

2014-11-15

Resonant Inelastic X-ray Scattering (RIXS) in the soft x-ray range is an element-specific energy-loss spectroscopy used to probe the electronic and magnetic excitations in strongly correlated solids. In the recent years, RIXS has been progressing very quickly in terms of energy resolution and understanding of the experimental results, but the interpretation of spectra could further improve, sometimes decisively, from a full knowledge of the polarization of incident and scattered photons. Here we present the first implementation, in a high resolution soft-RIXS spectrometer used to analyze the scattered radiation, of a device allowing the measurement of the degree of linear polarization. The system, based on a graded W/B{sub 4}C multilayer mirror installed in proximity of the CCD detector, has been installed on the AXES spectrometer at the ESRF (European Synchrotron Radiation Facility); it has been fully characterized and it has been used for a demonstration experiment at the Cu L{sub 3} edge on a high-T{sub c} superconducting cuprate. The loss in efficiency suffered by the spectrometer equipped with this test facility was a factor 17.5. We propose also a more advanced version, suitable for a routine use on the next generation of RIXS spectrometers and with an overall efficiency up to 10%.

Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory.

Science.gov (United States)

Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G

2013-05-31

The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

Nuclear energy and radiation protection law: no. 14 1987

International Nuclear Information System (INIS)

1987-01-01

The full text of Jordan's Nuclear Energy and Radiation Protection Law, no. 14 1987. The law's 39 articles govern all aspects organizing the utilization of nuclear energy and radiation protection activities in the country; including terms and conditions for licensing activities and personnel, and the import, export, and disposal of radioactive sources. The law establishes for the purpose of implementing its regulations, a consultative technical committee and a radiation protection board, both in the Ministry of Energy and Mineral Resources

Spectral and electronic measurements of solar radiation

International Nuclear Information System (INIS)

Suzuki, Mamoru; Hanyu, Mitsuhiro

1977-01-01

The spectral data of solar radiation are necessary if detailed discussion is intended in relation to the utilization of solar energy. Since those data have not been fully prepared so far, a measuring equipment developed in Electro-technical Laboratory to obtain those data is described. The laboratory is now continuing the measurement at the wavelength of 0.3 μm to 1.1 μm. The equipment employs the system to always calibrate with the standard light source, it can measure both the direct light of the sun only and the sun light including sky light, and it enables to obtain the value based on the secondary standard of spectral illumination intensity established by the laboratory. The solar spectral irradiance is determined with the current readings of photomultiplier in the standard light source and the sun-light measurements at a wavelength and with the spectral illumination intensity from the standard light source. In order to practice such measurement many times at various wavelengths, control of the equipment, data collection, computation, drawing and listing are performed by a microcomputer. As an example, the data on Sept. 10, 1976, are shown comparing the graphs at three different hours. It can be well observed that the transmissivity attenuates with shorter wavelength, and the transmissivity in near infra-red region changes greatly due to the absorption of radiation by water vapour. (Wakatsuki, Y.)

Use of Monte Carlo method in low-energy gamma radiation applications

International Nuclear Information System (INIS)

Sulc, J.

1982-01-01

Modelling based on the Monte Carlo method is described in detail of the interaction of low-energy gamma radiation resulting in characteristic radiation of the K series of a pure element. The modelled system corresponds to the usual configuration of the measuring part of a radionuclide X-ray fluorescence analyzer. The accuracy of determination of the mean probability of impingement of characteristic radiation on the detector increases with the number of events. The number of events was selected with regard to the required accuracy, the demand on computer time and the accuracy of input parameters. The results of a comparison of computation and experiment are yet to be published. (M.D.)

Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

Science.gov (United States)

Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

2002-01-01

Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

Absolute measurement of undulator radiation in the extreme ultraviolet

International Nuclear Information System (INIS)

Maezawa, H.; Kitamura, H.; Sasaki, T.; Mitani, S.; Osaka City Univ.; Suzuki, Y.; Kanamori, H.; Tamamushi, S.; Tokyo Univ.; Mikuni, A.; Tokyo Univ., Tanashi

1983-01-01

The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy #betta#, the field parameter K, and the angle of observation THETA in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula lambdasub(n)=lambda 0 /2n#betta# 2 (1+K 2 /2+#betta# 2 THETA 2 ), and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed. (orig.)

Laboratory investigation of fire radiative energy and smoke aerosol emissions

Science.gov (United States)

Charles Ichoku; J. Vanderlei Martins; Yoram J. Kaufman; Martin J. Wooster; Patrick H. Freeborn; Wei Min Hao; Stephen Baker; Cecily A. Ryan; Bryce L. Nordgren

2008-01-01

Fuel biomass samples from southern Africa and the United States were burned in a laboratory combustion chamber while measuring the biomass consumption rate, the fire radiative energy (FRE) release rate (Rfre), and the smoke concentrations of carbon monoxide (CO), carbon dioxide (CO2), and particulate matter (PM). The PM mass emission rate (RPM) was quantified from...

Radiation measurements and quality control

International Nuclear Information System (INIS)

McLaughlin, W.L.

1977-01-01

Accurate measurements are essential to research leading to a successful radiation process and to the commissioning of the process and the facility. On the other hand, once the process is in production, the importance to quality control of measuring radiation quantities (i.e., absorbed dose, dose rate, dose distribution) rather than various other parameters of the process (i.e. conveyor speed, dwell time, radiation field characteristics, product dimensions) is not clearly established. When the safety of the product is determined by the magnitude of the administered dose, as in radiation sterilization, waste control, or food preservation, accuracy and precision of the measurement of the effective dose are vital. Since physical dose measurements are usually simpler, more reliable and reproducible than biological testing of the product, there is a trend toward using standardized dosimetry for quality control of some processes. In many industrial products, however, such as vulcanized rubber, textiles, plastics, coatings, films, wire and cable, the effective dose can be controlled satisfactorily by controlling process variables or by product testing itself. In the measurement of radiation dose profiles by dosimetry, it is necessary to have suitable dose meter calibrations, to account for sources of error and imprecision, and to use correct statistical procedures in specifying dwell times or conveyor speeds and source and product parameters to achieve minimum and maximum doses within specifications. (author)

Monitoring Top-of-Atmosphere Radiative Energy Imbalance for Climate Prediction

Science.gov (United States)

Lin, Bing; Chambers, Lin H.; Stackhouse, Paul W., Jr.; Minnis, Patrick

2009-01-01

Large climate feedback uncertainties limit the prediction accuracy of the Earth s future climate with an increased CO2 atmosphere. One potential to reduce the feedback uncertainties using satellite observations of top-of-atmosphere (TOA) radiative energy imbalance is explored. Instead of solving the initial condition problem in previous energy balance analysis, current study focuses on the boundary condition problem with further considerations on climate system memory and deep ocean heat transport, which is more applicable for the climate. Along with surface temperature measurements of the present climate, the climate feedbacks are obtained based on the constraints of the TOA radiation imbalance. Comparing to the feedback factor of 3.3 W/sq m/K of the neutral climate system, the estimated feedback factor for the current climate system ranges from -1.3 to -1.0 W/sq m/K with an uncertainty of +/-0.26 W/sq m/K. That is, a positive climate feedback is found because of the measured TOA net radiative heating (0.85 W/sq m) to the climate system. The uncertainty is caused by the uncertainties in the climate memory length. The estimated time constant of the climate is large (70 to approx. 120 years), implying that the climate is not in an equilibrium state under the increasing CO2 forcing in the last century.

Smith-Purcell experiment utilizing a field-emitter array cathode measurements of radiation

CERN Document Server

Ishizuka, H; Yokoo, K; Shimawaki, H; Hosono, A

2001-01-01

Smith-Purcell (SP) radiation at wavelengths of 350-750 nm was produced in a tabletop experiment using a field-emitter array (FEA) cathode. The electron gun was 5 cm long, and a 25 mmx25 mm holographic replica grating was placed behind the slit provided in the anode. A regulated DC power supply accelerated electron beams in excess of 10 mu A up to 45 keV, while a small Van de Graaff generator accelerated smaller currents to higher energies. The grating had a 0.556 mu m period, 30 deg. blaze and a 0.2 mu m thick aluminum coating. Spectral characteristics of the radiation were measured both manually and automatically; in the latter case, the spectrometer was driven by a stepping motor to scan the wavelength, and AD-converted signals from a photomultiplier tube were processed by a personal computer. The measurement, made at 80 deg. relative to the electron beam, showed good agreement with theoretical wavelengths of the SP radiation. Diffraction orders were -2 and -3 for beam energies higher than 45 keV, -3 to -5 ...

Dosimetric And Fluence Measurements At Hadron Facilities For LHC Radiation Damage Studies

CERN Document Server

León-Florián, E

2001-01-01

Dosimetry plays an essential role in experiments assessing radiation damage and hardness for the components of detectors to be operated at the future Large Hadron Collider (LHC), CERN (European Laboratory for Particle Physics), Geneva, Switzerland. Dosimetry is used both for calibration of the radiation fields and estimate of fluences and doses during the irradiation tests. The LHC environment will result in a complex radiation field composed of hadrons (mainly neutrons, pions and protons) and photons, each having an energy spectrum ranging from a few keV to several hundreds of MeV or several GeV, even. In this thesis, are exposed the results of measurements of particle fluences and doses at different hadron irradiation facilities: SARA, πE1-PSI and ZT7PS used for testing the radiation hardness of materials and equipment to be used in the future experiments at LHC. These measurements are applied to the evaluation of radiation damage inflicted to various semiconductors (such as silicon) and electronics ...

Global solar energy radiation in relation with electricity supply in Romania

International Nuclear Information System (INIS)

Zoran, Maria

2001-01-01

Solar energy is one of the most viable source of renewable energy being both clean and nonpolluting. Spiraling energy use and other human activities have led to measurable effects upon the global environment and climatic changes. There is increasing international concern particularly in the areas of global warming owing to the increase of carbon dioxide (CO 2 ) in the atmosphere and of other greenhouse gases as sulfur dioxide (SO 2 ), oxides of nitrogen (NOx), hydrogen sulfide H 2 S, diethyl sulfide (DMS), chlorofluorocarbons (CFCs), methane CH 4 , as well in the effect of depletion of ozone (O 3 ) layer in the stratosphere. Climatological and global solar radiation analysis for some Romanian zones with great solar energy potential are presented. Remote sensing data provided by satellites are used for radiative fluxes monitoring and solar energy mapping as well as for solar energy use assessment. The realistic technical potential for solar energy applications in Romania is substantial, over 40000 TJyear -1 . As average energy global solar radiation in horizontal plane lies between 1100 and 1300 kWhm -2 year -1 , solar energy using for electrical power supply being a reliable alternative. More than one half of Romania's area has a range of insolation period between 1200 and 1500 hours year -1 , at an overall average daily irradiation of 1000 - 1200 kWh m -2 . The most favorable area in Romania is the North - Western part of Black Sea coast with an insolation period above 2300 hours year -1 . A small part 140 TJyear -1 are used profitably and almost 10% of the installed 10 6 m 2 of collector area, is still in operation. (author)

Ionizing radiation, nuclear energy and radiation protection for school

International Nuclear Information System (INIS)

Lucena, E.A.; Reis, R.G.; Pinho, A.S.; Alves, A.S.; Rio, M.A.P.; Reis, A.A.; Silva, J.W.S.; Paula, G.A. de; Goncalves Junior, M.A.

2017-01-01

Since the discovery of X-rays in 1895, ionizing radiation has been applied in many sectors of society, such as medicine, industry, safety, construction, engineering and research. However, population is unaware of both the applications of ionizing radiation and their risks and benefits. It can be seen that most people associate the terms 'radiation' and 'nuclear energy' with the atomic bomb or cancer, most likely because of warlike applications and the stealthy way radioactivity had been treated in the past. Thus, it is necessary to clarify the population about the main aspects related to the applications, risks and associated benefits. These knowledge can be disseminated in schools. Brazilian legislation for basic education provides for topics such as nuclear energy and radioactivity to high school students. However, some factors hamper such an educational practice, namely, few hours of class, textbooks do not address the subject, previous concepts obtained in the media, difficulty in dealing with the subject in the classroom, phobia, etc. One solution would be the approximation between schools and institutions that employ technologies involving radioactivity, which would allow students to know the practices, associated radiological protection, as well as the risks and benefits to society. Currently, with the increasing application of ionizing radiation, especially in medicine, it is necessary to demystify the use of radioactivity. (author)

Electromagnetic radiation from nuclear collisions at RHIC energies

CERN Document Server

Turbide, Simon; Frodermann, Evan; Heinz, Ulrich

2008-01-01

The hot and dense strongly interacting matter created in collisions of heavy nuclei at RHIC energies is modeled with relativistic hydrodynamics, and the spectra of real and virtual photons produced at mid-rapidity in these events are calculated. Several different sources are considered, and their relative importance is compared. Specifically, we include jet fragmentation, jet-plasma interactions, the emission of radiation from the thermal medium and from primordial hard collisions. Our calculations consistently take into account jet energy loss, as evaluated in the AMY formalism. We obtain results for the spectra, the nuclear modification factor (R_AA), and the azimuthal anisotropy (v_2) that agree with the photon measurements performed by the PHENIX collaboration at RHIC.

Development of a research reactor power measurement system using Cherenkov radiation

Energy Technology Data Exchange (ETDEWEB)

Salles, Brício M.; Mesquita, Amir Z., E-mail: briciomares@hotmail.com, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-11-01

Nuclear research reactors are usually located in open pools, to allow visibility to the core and bluish luminosity of Cherenkov radiation. Usually the thermal power released in these reactors is monitored by chambers that measure the neutron flux, as it is proportional to the power. There are other methods used for power measurement, such as monitoring the core temperature and the energy balance in the heat exchanger. The brightness of Cherenkov's radiation is caused by the emission of visible electromagnetic radiation (in the blue band) by charged particles that pass through an insulating medium (water in nuclear research reactors) at a speed higher than that of light in this medium. This effect was characterized by Pavel Cherenkov, which earned him the Nobel Prize for Physics in 1958. The project's objective is to develop an innovative and alternative method for monitoring the power of nuclear research reactors. It will be performed by analyzing and monitoring the intensity of luminosity generated by Cherenkov radiation in the reactor core. This method will be valid for powers up to 250 kW, since above that value the luminosity saturates, as determined by previous studies. The reactor that will be used to test the method is the TRIGA, located at Nuclear Technology Development Center (CDTN), which currently has a maximum operating power of 250 kW. This project complies with International Atomic Energy Agency (IAEA) recommendations on reactor safety. It will give more redundancy and diversification in this measure and will not interfere with its operation. (author)

Development of a research reactor power measurement system using Cherenkov radiation

International Nuclear Information System (INIS)

Salles, Brício M.; Mesquita, Amir Z.

2017-01-01

Nuclear research reactors are usually located in open pools, to allow visibility to the core and bluish luminosity of Cherenkov radiation. Usually the thermal power released in these reactors is monitored by chambers that measure the neutron flux, as it is proportional to the power. There are other methods used for power measurement, such as monitoring the core temperature and the energy balance in the heat exchanger. The brightness of Cherenkov's radiation is caused by the emission of visible electromagnetic radiation (in the blue band) by charged particles that pass through an insulating medium (water in nuclear research reactors) at a speed higher than that of light in this medium. This effect was characterized by Pavel Cherenkov, which earned him the Nobel Prize for Physics in 1958. The project's objective is to develop an innovative and alternative method for monitoring the power of nuclear research reactors. It will be performed by analyzing and monitoring the intensity of luminosity generated by Cherenkov radiation in the reactor core. This method will be valid for powers up to 250 kW, since above that value the luminosity saturates, as determined by previous studies. The reactor that will be used to test the method is the TRIGA, located at Nuclear Technology Development Center (CDTN), which currently has a maximum operating power of 250 kW. This project complies with International Atomic Energy Agency (IAEA) recommendations on reactor safety. It will give more redundancy and diversification in this measure and will not interfere with its operation. (author)

Measurement and detection of radiation

CERN Document Server

Tsoulfanidis, Nicholas

2011-01-01

This is an update of the standard textbook for the field of radiation measurement. It includes illustrative examples and new problems. The research and applications of nuclear instrumentation have grown substantially since publication of the previous editions. With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines, including nuclear nonproliferation, homeland security, and nuclear medicine. Continuing in the tradition of its bestselling predecessors, "Measurement and Detection of Radiation, Third Edition" illustrates the fundamentals of nuclear interactions and radiation detection with a multitude of examples and problems. It offers a clearly written, accessible introduction to nuclear instrumentation concepts. The following are new to the third edition: a new chapter on the latest applications of radiation detection, covering nuclear medicine, dosimetry, health physics, no...

Broadband Outdoor Radiometer Calibration Process for the Atmospheric Radiation Measurement Program

Energy Technology Data Exchange (ETDEWEB)

Dooraghi, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-09-01

The Atmospheric Radiation Measurement program (ARM) maintains a fleet of monitoring stations to aid in the improved scientific understanding of the basic physics related to radiative feedback processes in the atmosphere, particularly the interactions among clouds and aerosols. ARM obtains continuous measurements and conducts field campaigns to provide data products that aid in the improvement and further development of climate models. All of the measurement campaigns include a suite of solar measurements. The Solar Radiation Research Laboratory at the National Renewable Energy Laboratory supports ARM's full suite of stations in a number of ways, including troubleshooting issues that arise as part of the data-quality reviews; managing engineering changes to the standard setup; and providing calibration services and assistance to the full fleet of solar-related instruments, including pyranometers, pyrgeometers, pyrheliometers, as well as the temperature/relative humidity probes, multimeters, and data acquisition systems that are used in the calibrations performed at the Southern Great Plains Radiometer Calibration Facility. This paper discusses all aspects related to the support provided to the calibration of the instruments in the solar monitoring fleet.

Smith-Purcell experiment utilizing a field-emitter array cathode: measurements of radiation

International Nuclear Information System (INIS)

Ishizuka, H.; Kawamura, Y.; Yokoo, K.; Shimawaki, H.; Hosono, A.

2001-01-01

Smith-Purcell (SP) radiation at wavelengths of 350-750 nm was produced in a tabletop experiment using a field-emitter array (FEA) cathode. The electron gun was 5 cm long, and a 25 mmx25 mm holographic replica grating was placed behind the slit provided in the anode. A regulated DC power supply accelerated electron beams in excess of 10 μA up to 45 keV, while a small Van de Graaff generator accelerated smaller currents to higher energies. The grating had a 0.556 μm period, 30 deg. blaze and a 0.2 μm thick aluminum coating. Spectral characteristics of the radiation were measured both manually and automatically; in the latter case, the spectrometer was driven by a stepping motor to scan the wavelength, and AD-converted signals from a photomultiplier tube were processed by a personal computer. The measurement, made at 80 deg. relative to the electron beam, showed good agreement with theoretical wavelengths of the SP radiation. Diffraction orders were -2 and -3 for beam energies higher than 45 keV, -3 to -5 at 15-25 keV, and -2 to -4 in between. The experiment has thus provided evidence for the practical applicability of FEAs to compact radiation sources

A self-powered thin-film radiation detector using intrinsic high-energy current

Energy Technology Data Exchange (ETDEWEB)

Zygmanski, Piotr, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sajo, Erno, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States)

2016-01-15

Purpose: The authors introduce a radiation detection method that relies on high-energy current (HEC) formed by secondary charged particles in the detector material, which induces conduction current in an external readout circuit. Direct energy conversion of the incident radiation powers the signal formation without the need for external bias voltage or amplification. The detector the authors consider is a thin-film multilayer device, composed of alternating disparate electrically conductive and insulating layers. The optimal design of HEC detectors consists of microscopic or nanoscopic structures. Methods: Theoretical and computational developments are presented to illustrate the salient properties of the HEC detector and to demonstrate its feasibility. In this work, the authors examine single-sandwiched and periodic layers of Cu and Al, and Au and Al, ranging in thickness from 100 nm to 300 μm and separated by similarly sized dielectric gaps, exposed to 120 kVp x-ray beam (half-value thickness of 4.1 mm of Al). The energy deposition characteristics and the high-energy current were determined using radiation transport computations. Results: The authors found that in a dual-layer configuration, the signal is in the measurable range. For a defined total detector thickness in a multilayer structure, the signal sharply increases with decreasing thickness of the high-Z conductive layers. This paper focuses on the computational results while a companion paper reports the experimental findings. Conclusions: Significant advantages of the device are that it does not require external power supply and amplification to create a measurable signal; it can be made in any size and geometry, including very thin (sub-millimeter to submicron) flexible curvilinear forms, and it is inexpensive. Potential applications include medical dosimetry (both in vivo and external), radiation protection, and other settings where one or more of the above qualities are desired.

Radiation-tolerant, red-sensitive CCDs for dark energy investigations

International Nuclear Information System (INIS)

Roe, N.A.; Bebek, C.J.; Dawson, K.S.; Emes, J.H.; Fabricius, M.H.; Fairfield, J.A.; Groom, D.E.; Holland, S.E.; Karcher, A.; Kolbe, W.F.; Palaio, N.P.; Wang, G.

2007-01-01

We describe the development of thick (200-300 μm), fully depleted p-channel, charge-coupled devices (CCDs). The advantages of these CCDs relative to conventional thin, n-channel CCDs include: high quantum efficiency over a wide range of wavelengths, extending into the near-infrared; negligible fringing at long (∼900-1000 nm) wavelengths; improved radiation tolerance; and a small point-spread function controlled through the application of the bias voltage. These visible-to-near-infrared light detectors are good candidates for the next generation of large focal-plane mosaics under development for dark energy measurements. The Dark Energy Survey has selected these CCDs for the focal plane of a new camera being designed for the Blanco 4 m telescope at CTIO in Chile. They also meet all the requirements for the visible-light detectors for the SuperNova/Acceleration Probe, a satellite-based experiment designed to make precision measurements of dark energy

The measurement of alpha, beta and gamma radiations

International Nuclear Information System (INIS)

Burns, P.A.

1982-01-01

Detection methods for nuclear radiations are based on the processes of excitation and ionization of atoms in the detection medium by the passage of a charged particle. Detectors are usually of two types, those which produce a charge pulse following ionization of the medium and those which produce a burst of light photons which are then detected by a photomultiplier tube. By processing the electronic signals produced in suitable ways either the count rate of the source, the activity, or the dose equivalent to a person may be determined. In order to make these determinations it is necessary to understand the type of nuclear transformation of the radionuclide in question, the type and energy of the radiation being emitted and the processes involved when these radiations pass through the medium of the detector. Suitable choice of detectors and extrapolation from measured data to the quantity which is to be determined can then be made

Radiation measuring instrument

International Nuclear Information System (INIS)

Genrich, V.

1985-01-01

A highly sensitive and compactly structured radiation measuring instrument for detecting ionizing radiation, in particular for measuring dose rates and contamination. The laminar structure of the associated counter tube, using only a few, simple plastic parts and a highly elastic counter wire, makes it possible to use the simplest manufacturing techniques. The service life of the counter tube construction, which is completely and permanently sealed and filled with gas, is expected to be more than 12 years. The described counter tube can be adapted in optimal fashion to the available space in a pocket instrument if it is used in combination with a specialized high-voltage generator which is low in interference voltage and with a pulse evaluation circuit having a means of compensating for interference voltage

Basic concepts in dosimetry. A critical analysis of the concepts of ionizing radiation and energy imparted

International Nuclear Information System (INIS)

Carlson, G.A.

1978-01-01

The concepts of ionizing radiation and energy imparted defined by the ICRU in 1971 (Radiation Quantities and Units, Report 19, International Commission on Radiation Units and Measurements, Washington, D.C., 1971) are critically analyzed. It is found that the definitions become more consistent by changing them at two points. Charged particles with insufficient kinetic energy to ionize by collision but which are capable of initiating nuclear and elementary particle transformations are suggested to be classified as ionizing particles. In addition, the expressions ''the energy released'' or the ''energy expended'' in a nuclear or elementary particle transformation are suggested to be specified as ''the change in rest-mass energy of nuclei and elementary particles.'' Then the ionization caused by, for instance, nuclear reactions contributes to the energy imparted and the Q-value of an excitation or deexcitation of the electron structure, regarded as an elementary particle transformation, is zero

Secondary electrons monitor for continuous electron energy measurements in UHF linac

International Nuclear Information System (INIS)

Zimek, Zbigniew; Bulka, Sylwester; Mirkowski, Jacek; Roman, Karol

2001-01-01

Continuous energy measurements have now became obligatory in accelerator facilities devoted to radiation sterilization process. This is one of several accelerator parameters like dose rate, beam current, bean scan parameters, conveyer speed which must be recorded as it is a required condition of accelerator validation procedure. Electron energy measurements are rather simple in direct DC accelerator, where the applied DC voltage is directly related to electron energy. High frequency linacs are not offering such opportunity in electron energy measurements. The analyzing electromagnet is applied in some accelerators but that method can be used only in off line mode before or after irradiation process. The typical solution is to apply the non direct method related to control and measurements certain accelerator parameters like beam current and microwave energy pulse power. The continuous evaluation of electron energy can be performed on the base of calculation and result comparison with calibration curve

Investigation of Radiation Protection Methodologies for Radiation Therapy Shielding Using Monte Carlo Simulation and Measurement

Science.gov (United States)

Tanny, Sean

The advent of high-energy linear accelerators for dedicated medical use in the 1950's by Henry Kaplan and the Stanford University physics department began a revolution in radiation oncology. Today, linear accelerators are the standard of care for modern radiation therapy and can generate high-energy beams that can produce tens of Gy per minute at isocenter. This creates a need for a large amount of shielding material to properly protect members of the public and hospital staff. Standardized vault designs and guidance on shielding properties of various materials are provided by the National Council on Radiation Protection (NCRP) Report 151. However, physicists are seeking ways to minimize the footprint and volume of shielding material needed which leads to the use of non-standard vault configurations and less-studied materials, such as high-density concrete. The University of Toledo Dana Cancer Center has utilized both of these methods to minimize the cost and spatial footprint of the requisite radiation shielding. To ensure a safe work environment, computer simulations were performed to verify the attenuation properties and shielding workloads produced by a variety of situations where standard recommendations and guidance documents were insufficient. This project studies two areas of concern that are not addressed by NCRP 151, the radiation shielding workload for the vault door with a non-standard design, and the attenuation properties of high-density concrete for both photon and neutron radiation. Simulations have been performed using a Monte-Carlo code produced by the Los Alamos National Lab (LANL), Monte Carlo Neutrons, Photons 5 (MCNP5). Measurements have been performed using a shielding test port designed into the maze of the Varian Edge treatment vault.

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models

International Nuclear Information System (INIS)

Patrinos, A.A.; Renne, D.S.; Stokes, G.M.; Ellingson, R.G.

1991-01-01

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM's highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM's experimental approach, and recent activities within the ARM program

Radiation damage measurements in room-temperature semiconductor radiation detectors

CERN Document Server

Franks, L A; Olsen, R W; Walsh, D S; Vizkelethy, G; Trombka, J I; Doyle, B L; James, R B

1999-01-01

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI sub 2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 sup 1 sup 0 p/cm sup 2 and significant bulk leakage after 10 sup 1 sup 2 p/cm sup 2. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5x10 sup 9 p/cm sup 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from a moderated fission spectrum of neutrons after fluences up to 10 sup 1 sup 0 n/cm sup 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particles at fluences up to 1.5x10 sup 1 sup 0 alpha/cm sup 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5x10 sup 9 alpha/cm sup 2. CT detectors show resolution...

Introduction to meteorological measurements and data handling for solar energy applications. Task IV. Development of an isolation handbook and instrument package

Energy Technology Data Exchange (ETDEWEB)

None

1980-01-01

The following are covered: the Sun and its radiation, solar radiation and atmospheric interaction, solar radiation measurement methods, spectral irradiance measurements of natural sources, the measurement of infrared radiation, the measurement of circumsolar radiation, some empirical properties of solar radiation and related parameters, duration of sunshine, and meteorological variables related to solar energy. Included in appendices are manufacturers and distributors of solar radiation measuring instruments and an approximate method for quality control of solar radiation instruments. (MHR)

Radiation detection and measurement

International Nuclear Information System (INIS)

Knoll, G.F.

1979-01-01

The book is a complete, clear and up-to-date text that provides a basic review of instruments and methods of ionizing radiation. The text covers detailed discussion of all detector types introductory discussions of radiation sources, interactions, and counting statistics functional analysis of the electronics and pulse processing aspects of radiation detectors in instrumentation systems and consideration of shielding and background potentially vital in low-level counting. A total of 350 figures and approximately 900 references to current scientific literature is included. The book is largely intended as a textbook for a junior/senior or first-year graduate course in nuclear instrumentation and radiation measurements

Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

International Nuclear Information System (INIS)

Zhang, Long Jiang; Wu, Shengyong; Wang, Mei; Lu, Li; Chen, Bo; Jin, Lixin; Wang, Jiandong; Larson, Andrew C.; Lu, Guang Ming

2012-01-01

Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

A method for ultra-short pulse-shape measurements using far infrared coherent radiation from an undulator

International Nuclear Information System (INIS)

Geloni, G.; Saldin, E.L.; Schneidmiller, E.A.; Yurkov, M.V.

2004-01-01

In this paper, we discuss a method for non-destructive measurements of the longitudinal profile of sub-picosecond electron bunches for X-ray free electron lasers. The method is based on the detection of the coherent synchrotron radiation (CSR) produced by a bunch passing through an undulator. Coherent radiation energy within a central cone turns out to be proportional, per pulse, to the square modulus of the bunch form-factor at the resonant frequency of the fundamental harmonic. An attractive feature of the proposed technique is the absence of any apparent limitation which would distort measurements. Indeed, the radiation process takes place in vacuum and is described by analytical formulae. CSR propagates to the detector placed in vacuum. Since CSR energy is in the range up to a fraction of mJ, a simple bolometer is used to measure the energy with a high accuracy. The proposed technique is very sensitive and it is capable of probing the electron bunches with a resolution down to a few microns

Measurement and evaluation of the external radiation level at reactor Kartini

International Nuclear Information System (INIS)

Atok Suhartanto; Suparno

2013-01-01

Measurement and evaluation of external radiation level at reactor Kartini in 2012 has been done. The purpose of this activity is to know the external radiation level as a result of the radioactive or radiation source usage, toward the operational of limit condition. The measurement is using survey meter Inspector 11086, factor of calibration 0.991 mR/h, at 9 locations is: Control room area, Thermal column facilities, Demineralizer, Beamport radiography facilities, bulk shielding Deck, Subcritical facilities, Reactor hall, Deck reactor and on the surface of reactor water tank . The highest room average measurement result in 9 working areas for 12 months continuously are at the reactor tank location is between 13.05±1.09 (xlO -2 mSv/hour) to 16.80±1.40 (x10 -2 mSv/hour), and the lowest measurement result in 1 location (control room) is 0.02±0.005 (x10 -2 mSv/hour) to 0.035±0.009 (x10 -2 mSv/hour). The Kartini reactor is involved in the control area which has potentially contaminated and has radiation exposure at the level of 6 mSv/year. Radiation Protection Officer that work in interval will received radiation exposure dosage of 8.4 mSv/year. This dosage is still below the Below Dosage Value which is recommended by, BAPETEN decree No, 4, 2013 about Protection and Radiation Safety in Nuclear Energy Application at 20 mSv/year. The result of the evaluation above shows that the external radiation which occurred in each area is still below the operational of limit condition that is written on the Kartini reactor safety analysis report, on document number: C7/05/B2/LAK/2010, revision 7. So that the workplace is safe for work monitored. (author)

Radiation Load of Children by Chest Radiodiagnostic Measurements

International Nuclear Information System (INIS)

Nikodemova, D.; Vladar, M.; Ranogajec-Komor, M.; Horvathova, M.

1998-01-01

Radiodiagnostic examinations of children present particular importance from the radiation hygiene point of view. The estimation of the radiation load of pediatric patient is not easy, because of the lack of information about organ weighting factors for various ages of patients, as well as due to the differences in applied X-ray examination parameters. In the district of Slovak Republic, in which also the working Nuclear Power Plant Jaslovske Bohunice is included, efforts were done to estimate the radiation load of children to 15 years by chest radiodiagnostic examinations. The data of entrance surface doses were collected using measurements with TLD for 100 patients divided in 5 age categories at six radiodiagnostic departments. The calculations of the total absorbed dose were performed using the measured ESD values (entrance surface dose in mGy) integrated over the X-ray beam area, the conversion factors between the imparted energy and the dose-area product and the known irradiation parameters (kV, HVL, mass, etc.). The analysis of the obtained absorbed doses (E a ) as a function of age for chest PA radiodiagnostic examinations has shown, that the investigated Slovak radiodiagnostic centres use rather lower voltage techniques and the entrance surface doses are much higher than the proposed value of European Communities. (author)

A new system for the measurement of the space radiation

International Nuclear Information System (INIS)

Pazmandi, T.; Apathy, I.; Deme, S.; Beaujean, R.

2000-01-01

Radiation from space mainly consists of charged heavy particles (protons and heavier particles). Due to this fact, the effective dose significantly differs from the physical dose. Current measuring equipment is not fully suitable to measure both of the quantities simultaneously. A combined device for measurement of the mentioned values consists of an on-board thermoluminescence dosimeter reader and a three-axis silicon detector linear energy transfer spectrometer. This paper deals with the main characteristic of the new system. This system can be, applied for dosimetry of air crew as well. (authors)

KERMA-based radiation dose management system for real-time patient dose measurement

Science.gov (United States)

Kim, Kyo-Tae; Heo, Ye-Ji; Oh, Kyung-Min; Nam, Sang-Hee; Kang, Sang-Sik; Park, Ji-Koon; Song, Yong-Keun; Park, Sung-Kwang

2016-07-01

Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient's radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient's radiation exposure and acquisition of diagnostic images.

The possible direct use of satellite radiance measurements by the Atmospheric Radiation Measurement Program

International Nuclear Information System (INIS)

1993-03-01

The Atmospheric Radiation Measurement (ARM) Program is a major research program initiated by the Department of Energy to improve our understanding of radiative and cloud processes critical to predicting the Earth's climate and its changes. Central to this concept is the use of four to six intensively instrumented sites for long-term study and characterization of the processes of interest. The instrumentation suites will include ground-based, high-accuracy radiometers for measuring the short and longwave surface flux, as well as an extensive set of ground-and air-based instrumentation for characterizing the intervening atmospheric column. Satellite-based measurements are expected to play a very important role in providing top-of-the-atmosphere measurements. In this study, we examine the possibility of comparing ARM outputs directly with satellite measurements, thereby ensuring the independence of these two important data sets. Thus we focused on what do satellites really measure and how well do they measure it. On what can we do about the general lack of adequate visible channel calibration. On what is the best way for ARM to obtain near-real-time access to this unprocessed data. And on what is the optimum way for ARM to make use of satellite data

Infrared radiation in the energy balance of the upper atmosphere

International Nuclear Information System (INIS)

Gordiets, B.F.; Markov, M.N.

1977-01-01

The contribution of the infrared radiation to the energy balance of the Earth's upper atmosphere is discussed. The theoretical analysis has been carried out of the mechanisms of the transformation of the energy of outgoing particles and the ultraviolet-radiation of the Sun absorbed at the heights of Z >= 90 km into the infrared radiation. It is found out the the infrared radiation within the wave length range of 1.2-20 μ is more intensive that the 63 μ radiation of atomic oxygen and plays an important role in the general energy balance and the thermal regime of the thermosphere. It has been found out too that in the area of Z >= 120 km heights the radiation in the 5.3 μ NO band is the most intensive. This radiation is to be considered for the more accurate description of parameters of the atmosphere (temperature, density) conditioning the nature of the translocation of ionospheric sounds (ISS)

Characterization of a radiation detector for aircraft measurements

International Nuclear Information System (INIS)

Holanda M, L. de; Federico, C. A.; Caldas, L. V. E.

2014-08-01

Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

Characterization of a radiation detector for aircraft measurements

Energy Technology Data Exchange (ETDEWEB)

Holanda M, L. de; Federico, C. A.; Caldas, L. V. E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares, Av. Lineu Prestes 2242, Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil)

2014-08-15

Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

Science.gov (United States)

Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Characteristics and correlation of various radiation measuring methods in spatial radiation measurement

International Nuclear Information System (INIS)

Yoneda, Kazuhiro; Tonouchi, Shigemasa

1992-01-01

When the survey of the state of natural radiation distribution was carried out, for the purpose of examining the useful measuring method, the comparison of the γ-ray dose rate calculated from survey meter method, in-situ measuring method and the measuring method by sampling soil was carried out. Between the in-situ measuring method and the survey meter method, the correlation Y=0.986X+5.73, r=0.903, n=18, P<0.01 was obtained, and the high correlation having the inclination of nearly 1 was shown. Between the survey meter method and the measuring method by sampling soil, the correlation Y=1.297X-10.30, r=0.966, n=20 P<0.01 was obtained, and the high correlation was shown, but as for the dose rate contribution, the disparities of 36% in U series, 6% in Th series and 20% in K-40 were observed. For the survey of the state of natural radiation distribution, the method of using in combination the survey meter method and the in-situ measuring method or the measuring method by sampling soil is suitable. (author)

The use of remotely-sensed wildland fire radiation to infer the fates of carbon during biomass combustion - the need to understand and quantify a fire's mass and energy budget

Science.gov (United States)

Dickinson, M. B.; Dietenberger, M.; Ellicott, E. A.; Hardy, C.; Hudak, A. T.; Kremens, R.; Mathews, W.; Schroeder, W.; Smith, A. M.; Strand, E. K.

2016-12-01

Few measurement techniques offer broad-scale insight on the extent and characteristics of biomass combustion during wildland fires. Remotely-sensed radiation is one of these techniques but its measurement suffers from several limitations and, when quantified, its use to derive variables of real interest depends on an understanding of the fire's mass and energy budget. In this talk, we will review certain assumptions of wildland fire radiation measurement and explore the use of those measurements to infer the fates of biomass and the dissipation of combustion energy. Recent measurements show that the perspective of the sensor (nadir vs oblique) matters relative to estimates of fire radiated power. Other considerations for producing accurate estimates of fire radiation from remote sensing include obscuration by an intervening forest canopy and to what extent measurements that are based on the assumption of graybody/blackbody behavior underestimate fire radiation. Fire radiation measurements are generally a means of quantifying other variables and are often not of interest in and of themselves. Use of fire radiation measurements as a means of inference currently relies on correlations with variables of interest such as biomass consumption and sensible and latent heat and emissions fluxes. Radiation is an imperfect basis for these correlations in that it accounts for a minority of combustion energy ( 15-30%) and is not a constant as is often assumed. Measurements suggest that fire convective energy accounts for the majority of combustion energy and (after radiation) is followed by latent energy, soil heating, and pyrolysis energy, more or less in that order. Combustion energy in and of itself is not its potential maximum, but is reduced to an effective heat of combustion by combustion inefficiency and by work done to pyrolyze fuel (important in char production) and in moisture vaporization. The effective heat of combustion is often on the order of 65% of its potential

Physics of intense, high energy radiation effects

International Nuclear Information System (INIS)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-01-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the

Development of High Energy Particle Detector for the Study of Space Radiation Storm

Directory of Open Access Journals (Sweden)

Gyeong-Bok Jo

2014-09-01

Full Text Available Next Generation Small Satellite-1 (NEXTSat-1 is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

Quality assurance in field radiation measurements

International Nuclear Information System (INIS)

Howell, W.P.

1985-01-01

In most cases, an ion chamber radiation measuring instrument is calibrated in a uniform gamma radiation field. This results in a uniform ionization field throughout the ion chamber. Measurement conditions encountered in the field often produce non-uniform ionization fields within the ion chamber, making determination of true dose rates to personnel difficult and prone to error. Extensive studies performed at Hanford have provided appropriate correction factors for use with one type of ion chamber instrument, the CP. Suitable corrections are available for the following distinct measurement circumstances: (1) contact measurements on large beta and gamma sources, (2) contact measurements on small beta and gamma sources, (3) contact measurements on small-diameter cylinders, (4) measurements in small gamma beams, and (5) measurements at a distance from large beta sources. Recommendations are made for the implementation of these correction factors, in the interest of improved quality assurance in field radiation measurements. 12 references, 10 figures

The technique on handling radiation

International Nuclear Information System (INIS)

1997-11-01

This book describes measurement of radiation and handling radiation. The first part deals with measurement of radiation. The contents of this part are characteristic on measurement technique of radiation, radiation detector, measurement of energy spectrum, measurement of radioactivity, measurement for a level of radiation and county's statistics on radiation. The second parts explains handling radiation with treating of sealed radioisotope, treating unsealed source and radiation shield.

An investigation of build-up effects in high energy radiation fields using a Handi TEPC

International Nuclear Information System (INIS)

Aroua, A.; Sannikov, A.V.

1995-01-01

ICRP considers that a dose limit of 2 mSv close to the body surface of a pregnant woman will ensure a dose limit of 1 mSv to the foetus. This assumption depends on the energy spectrum and composition of the radiation fields, especially those containing high energy particles such as are found around particle accelerators or in aircraft. In this work the response of a tissue-equivalent proportional counter in radiation fields of different composition and energy was measured as a function of depth in cylindrical phantoms. The decrease in dose and dose equivalent at a phantom depth equivalent to that of a foetus was 10% in a typical high energy stray radiation field and 30% for neutrons from a Pu-Be source. It is concluded that it would be prudent in these cases to limit the exposure of a pregnant woman to 1 mSv in order to ensure that the dose to the foetus stays below the same limit. (Author)

X-ray fluorescence analysis of substance composition using two radiation sources of different energies

International Nuclear Information System (INIS)

Varvaritsa, V.P.; Martishchenko, L.G.

1980-01-01

An X-ray radiometric method of determining substance composition, based on using two fluxes of primary radiation with energies above absorption edge of the determined element, is suggested. The method permits to decrease matrix effect and to obtain linear dependence between the measuring results and the determined value (concentration). The method has the following advantages: 1) increased accuracy during analyzing substances of complex composition; 2) absence of necessity to know beforehand composition of the analyzed element and its variations; 3) simplicity of choice of primary radiation energies; 4) simplicity of equipment realization; 5) possibility of graduating the equipment directly in concentration units. The suggested method has been tested during measuring Zn concentration in samples, containing S, Ba, Ca and polyethylene, 109 Cd and 238 Pu have been used as sources [ru

Radiation safety aspects of high energy particle accelerators

International Nuclear Information System (INIS)

Subbaiah, K.V.

2007-01-01

High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

Application of microprocessors to radiation protection measurements

International Nuclear Information System (INIS)

Zappe, D.; Meldes, C.

1982-01-01

In radiation protection measurements signals from radiation detectors or dosemeters have to be transformed into quantities relevant to radiation protection. In most cases this can only be done by taking into account various parameters (e.g. the quality factor). Moreover, the characteristics of the statistical laws of nuclear radiation emission have to be considered. These problems can properly be solved by microprocessors. After reviewing the main properties of microprocessors, some typical examples of applying them to problems of radiation protection measurement are given. (author)

Semiconductor high-energy radiation scintillation detector

International Nuclear Information System (INIS)

Kastalsky, A.; Luryi, S.; Spivak, B.

2006-01-01

We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

Bridging the Radiative Transfer Models for Meteorology and Solar Energy Applications

Science.gov (United States)

Xie, Y.; Sengupta, M.

2017-12-01

Radiative transfer models are used to compute solar radiation reaching the earth surface and play an important role in both meteorology and solar energy studies. Therefore, they are designed to meet the needs of specialized applications. For instance, radiative transfer models for meteorology seek to provide more accurate cloudy-sky radiation compared to models used in solar energy that are geared towards accuracy in clear-sky conditions associated with the maximum solar resource. However, models for solar energy applications are often computationally faster, as the complex solution of the radiative transfer equation is parameterized by atmospheric properties that can be acquired from surface- or satellite-based observations. This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to combine the advantages of radiative transfer models designed for meteorology and solar energy applictions. A fast all-sky radiation model, FARMS-NIT, was developed to efficiently compute narrowband all-sky irradiances over inclined photovoltaic (PV) panels. This new model utilizes the optical preperties from a solar energy model, SMARTS, to computes surface radiation by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. For cloudy-sky conditions, cloud bidirectional transmittance functions (BTDFs) are provided by a precomputed lookup table (LUT) by LibRadtran. Our initial results indicate that FARMS-NIT has an accuracy that is similar to LibRadtran, a highly accurate multi-stream model, but is significantly more efficient. The development and validation of this model will be presented.

A method to detect ultra high energy electrons using earth's magnetic field as a radiator

Science.gov (United States)

Stephens, S. A.; Balasubrahmanyan, V. K.

1983-01-01

It is pointed out that the detection of electrons with energies exceeding a few TeV, which lose energy rapidly through synchrotron and inverse Compton processes, would provide valuable information on the distribution of sources and on the propagation of cosmic rays in the solar neighborhood. However, it would not be possible to measure the energy spectrum beyond a few TeV with any of the existing experimental techniques. The present investigation is, therefore concerned with the possibility of detecting electrons with energies exceeding a few TeV on the basis of the photons emitted through synchrotron radiation in the earth's magnetic field. Attention is given to the synchrotron radiation of electrons in the earth's magnetic field, detector response and energy estimation, and the characteristics of an ideal detector, capable of detecting photons with energies equal to or greater than 20 keV.

Measurement of the residual radiation intensity at the Hiroshima and Nagasaki atomic bomb sites. Penetration of weapons radiation: application to the Hiroshima and Nagasaki studies

Energy Technology Data Exchange (ETDEWEB)

Pace, N; Smith, R E; Ritchie, R H; Hurst, G S

1959-01-01

This document contains 2 reports. The first is on the measurement of residual radiation intensity at the Hiroshima and Nagasaki bomb sites, the second is on the penetration of weapons radiation at Hiroshima and Nagasaki. Separate abstracts have been prepared for each report for inclusion in the Energy Database. (DMC)

Spatial and energy distributions of skyshine neutron and gamma radiation from nuclear reactors on the ground-air boundary

Energy Technology Data Exchange (ETDEWEB)

Orlov, Y.; Netecha, M.E.; Vasiliev, A.P.; Avaev, V.N.; Vasiliev, G.A. [Research and Development Institute of Power Engineering, Moscow (Russian Federation); Zelensky, D.I.; Istomin, Y.L.; Cherepnin, Y.S. [Institute of Atomic Energy of the National Nuclear Center of the Republic of Kazakhstan, Semipalatinsk-21 (Kazakhstan); Nomura, Y. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2000-03-01

A set of measurements on skyshine radiation was conducted at two special research reactors. A broad range of detectors was used in the measurements to record neutron and gamma radiations. Dosimetric and radiometric field measurements of the neutrons and gamma quanta of the radiation scattered in the air were performed at distances of 50 to 1000 m from the reactor during different weather conditions. The neutron spectra in the energy range of 1 eV to 10 MeV and the gamma quanta spectra in the range of 0.1-10 MeV were measured. (author)

Radiation budget measurement/model interface

Science.gov (United States)

Vonderhaar, T. H.; Ciesielski, P.; Randel, D.; Stevens, D.

1983-01-01

This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments.

Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip

International Nuclear Information System (INIS)

Cho, Jennifer S; Taschereau, Richard; Olma, Sebastian; Liu Kan; Chen Yichun; Shen, Clifton K-F; Van Dam, R Michael; Chatziioannou, Arion F

2009-01-01

It has been observed that microfluidic chips used for synthesizing 18 F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18 F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e. electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18 F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18 F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18 F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge-coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, the calibration of a Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles.

Examination of spent fuel radiation energy conversion for electricity generation

Energy Technology Data Exchange (ETDEWEB)

Lee, Haneol; Yim, Man-Sung, E-mail: msyim@kaist.ac.kr

2016-04-15

Highlights: • Utilizing conversion of radiation energy of spent fuel to electric energy. • MCNPX modeling and experiment were used to estimate energy conversion. • The converted energy may be useful for nuclear security applications. • The converted energy may be utilized for safety applications through energy storage. - Abstract: Supply of electricity inside nuclear power plant is one of the most important considerations for nuclear safety and security. In this study, generation of electric energy by converting radiation energy of spent nuclear fuel was investigated. Computational modeling work by using MCNPX 2.7.0 code along with experiment was performed to estimate the amount of electric energy generation. The calculation using the developed modeling work was validated through comparison with an integrated experiment. The amount of electric energy generation based on a conceptual design of an energy conversion module was estimated to be low. But the amount may be useful for nuclear security applications. An alternative way of utilizing the produced electric energy could be considered for nuclear safety application through energy storage. Further studies are needed to improve the efficiency of the proposed energy conversion concept and to examine the issue of radiation damage and economic feasibility.

Radiation energy collector

Energy Technology Data Exchange (ETDEWEB)

Chao, Bei Tse; Rabl, A

1977-02-10

The invention deals with a concentrating solar collector. Collectors of this kind often have considerable natural convection losses which are due, among other facts, to the location of the energy absorber at the outlet with the heated surface of the absorber facing the inlet opening of the collector. According to the invention, the collector is designed in such manner that the absorber is located inside a space in such a way that the radiation emitted by the absorber is reflected back to the absorber with the aid of mirror surfaces. Various designs are described.

Unravelling radiative energy transfer in solid-state lighting

Science.gov (United States)

Melikov, Rustamzhon; Press, Daniel Aaron; Ganesh Kumar, Baskaran; Sadeghi, Sadra; Nizamoglu, Sedat

2018-01-01

Today, a wide variety of organic and inorganic luminescent materials (e.g., phosphors, quantum dots, etc.) are being used for lighting and new materials (e.g., graphene, perovskite, etc.) are currently under investigation. However, the understanding of radiative energy transfer is limited, even though it is critical to understand and improve the performance levels of solid-state lighting devices. In this study, we derived a matrix approach that includes absorption, reabsorption, inter-absorption and their iterative and combinatorial interactions for one and multiple types of fluorophores, which is simplified to an analytical matrix. This mathematical approach gives results that agree well with the measured spectral and efficiency characteristics of color-conversion light-emitting diodes. Moreover, it also provides a deep physical insight by uncovering the entire radiative interactions and their contribution to the output optical spectrum. The model is universal and applicable for all kinds of fluorophores.

Radiation detection and measurement concepts, methods and devices

CERN Document Server

McGregor, Douglas

2019-01-01

This text on radiation detection and measurement is a response to numerous requests expressed by students at various universities, in which the most popularly used books do not provide adequate background material, nor explain matters in understandable terms. This work provides a modern overview of radiation detection devices and radiation measurement methods. The topics selected in the book have been selected on the basis of the author’s many years of experience designing radiation detectors and teaching radiation detection and measurement in a classroom environment.

Radiation protection in nuclear energy. V.1

International Nuclear Information System (INIS)

1988-01-01

The conference was convened to provide a forum for the exchange of international views on the principles of radiation protection for regulators and practitioners, to highlight issues of current importance, to examine the problems encountered in applying the principles of radiation protection, and, where possible, to identify generic solutions. A special session entitled ''The dose-response relationship: implications for nuclear energy'', and a panel on ''Radiation protection education and training'' were included in the conference programme. Refs, figs and tabs

Radiation processing of liquid with low energy electron accelerator

International Nuclear Information System (INIS)

Makuuchi, Keizo

2003-01-01

Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

Radiation processing of liquid with low energy electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2003-02-01

Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

Medium-Energy Particle experiments (MEPs) for the Exploration of energization and Radiation in Geospace (ERG) mission

Science.gov (United States)

Kasahara, S.; Yokota, S.; Mitani, T.; Asamura, K.; Hirahara, M.; Shibano, Y.; Yamamoto, K.; Takashima, T.

2017-12-01

ERG (Exploration of energization and Radiation in Geospace) is the geospace exploration spacecraft, which was launched on 20 December 2016. The mission goal is to unveil the physics behind the drastic radiation belt variability during space storms. One of key observations is the measurement of ions and electrons in the medium-energy range (10-200 keV), since these particles excite EMIC, magnetosonic, and whistler waves, which are theoretically suggested to play significant roles in the relativistic electron acceleration and loss. Medium-Energy Particle experiments - electron analyser (MEP-e) measures the energy and the direction of each incoming electron in the range of 7 to 87 keV. The sensor covers 2π radian disk-like field-of-view with 16 detectors, and the solid angle coverage is achieved by using spacecraft spin motion. The electron energy is independently measured by an electrostatic analyser and avalanche photodiodes, enabling the significant background reduction. Medium-Energy Particle experiments - ion mass analyzer (MEP-i) measures the energy, mass, and charge state of the direction of each incoming ion in the medium-energy range (180 keV/q). MEP-i thus provides the velocity distribution functions of medium-energy ions (e.g., protons and oxygens), from which we can obtain significant information on local ion energization and pitch angle scattering in the inner magnetosphere. Heavy ion measurements can also play an important role to restrict global mass transport including the ionosphere and the plasmasheet. Here we show the technical approaches, data output, and highlights of initial observations.

The use of gamma radiation in fluid flow measurements

International Nuclear Information System (INIS)

Tjugum, S.A.; Johansen, G.A.

2000-01-01

The use of gamma radiation in densitometry measurements is a well known principle. These measurements are often used in the oil industry where there is a need for finding the gas fraction of an oil/water/gas flow. The traditional gamma densitometer has a simple construction, where the measured parameter is the attenuation of a single gamma beam. High reliability, robustness and the clamp-on possibility are advantages that this type of instruments offer. More information can be found by studying how radiation is scattered and absorbed by matter. This information is needed in new multiphase flow meters. Problems to be solved in these instruments are how to find volume fractions of more than two components, how to handle different flow regimes in non-homogeneous flow, and how to do measurements independent of the salinity of the water. The new technology involves multi-energy, multi-mode and multi-sensor systems. At the University of Bergen the focus has been on how to do flow regime and salinity independent measurements by using multi-sensor and multi-mode systems. This paper gives an overview of the different techniques, and presents the latest results within this field of research at the University of Bergen. (author)

Thermoluminescence of LiNaSo4: TI after exposure to radiation doses from electrons of different energies

International Nuclear Information System (INIS)

El-Kolaly, M.A.

2002-01-01

Lithium sodium sulphate doped by rare impurities (LiNaSO 4 : TI) has been locally prepared. Its Thermoluminescence properties (TL) have been performed from room temperature up to 300 degree C. The used heating rate was 5 degree C/sec. The samples were irradiated by electrons of different energies (5, 7, 9 and 13 MeV.). These samples were exposed to different duration to attain different radiation doses. It has been observed that the glow curves are consisted of four glow peaks at 75, 125, 225 and 250 degree C respectively. The first peak showed a linear dependence with electron radiation doses and can be used in radiation measurement. The irradiated impurities LiNaSO 4 : TI with energies higher than 5 MeV showed no appreciable change in the TL peak height. The obtained results will explore the probability of using such system (double sulphates doped by rare earth impurities) in the field of radiation measurements

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author)

Direct energy conversion of radiation energy in fusion reactor

Science.gov (United States)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned.

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S. [National Inst. for Fusion Science, Nagoya (Japan); Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-12-31

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-01-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author)

Exposure of Finnish population to ultraviolet radiation and radiation measurements

International Nuclear Information System (INIS)

Hoikkala, M.; Lappalainen, J.; Leszczynski, K.; Paile, W.

1990-01-01

This report is based on a survey of the literature on radiation risks involved in sunbathing and the use of solaria. The purpose of the report is to provide background information for the development of regulations on solaria and for informing the public about the risks posed by solaria and the sun. The report gives an overview of the properties and biological effects of ultraviolet radiation. The most important regulations and recommendations issued in various countries are presented. The connection between ultraviolet radiation and the risks of skin cancer is examined both on a general level and in reference to information obtained from the Finnish Cancer Registry. In Finland, the incidence of melanomas nearly tripled between 1960 and 1980. The most important cause is considered to be the population's increased exposure to the su's ultraviolet radiation. There are no reliable data on the connection between the use of solaria and the risks of skin cancer. It is estimated, however, that solaria account for less than 10 per cent of the skin cancer risk of the whole population. There are some difficult physical problems associated with the measurement of ultraviolet radiation emitted by both natural sources and solaria. A preliminary study of these problems has been undertaken by means of a survey of the available literature, supplemented by a review of measurements performed by the Finnish Centre For Radiation and Nuclear Safety. The estimated inaccuracy of the Optronic 742 spectroradiometer used by the Centre in the measurement of ultraviolet radiation emitted by the sun and solaria is about +-14%

Challenge of high energy radiation dosimetry and protection

International Nuclear Information System (INIS)

Nelson, W.R.; Jenkins, T.M.

1976-08-01

An accelerator health physicist can make contributions in many fields of science in addition to the various operational tasks that he is charged with. He can support others in his laboratory by designing shielding for new accelerators and storage rings, by consulting with experimenters on background radiation problems that they may encounter, by helping the high energy physicist select appropriate radiation sources for checking out his equipment, by providing him with low energy atomic and nuclear physics calculations, and many other ways. Most of all, he can perform and publish research using the many tools and techniques that are at his disposal at a high-energy accelerator laboratory

Physics of intense, high energy radiation effects.

Energy Technology Data Exchange (ETDEWEB)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-02-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic

Gamma radiation shielding and optical properties measurements of zinc bismuth borate glasses

International Nuclear Information System (INIS)

Yasaka, P.; Pattanaboonmee, N.; Kim, H.J.; Limkitjaroenporn, P.; Kaewkhao, J.

2014-01-01

Highlights: • 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 , (ZBB) glasses were prepared. • Radiation shielding and optical properties were investigated. • Higher 25 mol% of Bi 2 O 3 show better shielding property compared with concretes. • ZBB glasses can develop as a Pb-free radiation shielding material. - Abstract: In this work, the zinc bismuth borate (ZBB) glasses of the composition 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 (where x = 15, 20, 25 and 30 mol%) were prepared by the melt quenching technique. Their radiation shielding and optical properties were investigated and compared with theoretical calculations. The mass attenuation coefficients of ZBB glasses have been measured at different energies obtained from a Compton scattering technique. The results show a decrease of the mass attenuation coefficient, effective atomic number and effective electron density values with increasing of gamma-ray energies; and good agreements between experimental and theoretical values. The glass samples with Bi 2 O 3 concentrations higher than 25 mol% (25 and 30 mol%) were observed with lower mean free path (MFP) values than all the standard shielding concretes studied. These results are indications that the ZBB glasses in the present study may be developed as a lead-free radiation shielding material in the investigated energy range

Radiative lifetime measurements of rubidium Rydberg states

International Nuclear Information System (INIS)

Branden, D B; Juhasz, T; Mahlokozera, T; Vesa, C; Wilson, R O; Zheng, M; Tate, D A; Kortyna, A

2010-01-01

We have measured the radiative lifetimes of ns, np and nd Rydberg states of rubidium in the range 28 ≤ n ≤ 45. To enable long-lived states to be measured, our experiment uses slow-moving (∼100 μK) 85 Rb atoms in a magneto-optical trap (MOT). Two experimental techniques have been adopted to reduce random and systematic errors. First, a narrow-bandwidth pulsed laser is used to excite the target nl Rydberg state, resulting in minimal shot-to-shot variation in the initial state population. Second, we monitor the target state population as a function of time delay from the laser pulse using a short-duration, millimetre-wave pulse that is resonant with a one- or two-photon transition to a higher energy 'monitor state', n'l'. We then selectively field ionize the monitor state, and detect the resulting electrons with a micro-channel plate. This signal is an accurate mirror of the nl target state population, and is uncontaminated by contributions from other states which are populated by black body radiation. Our results are generally consistent with other recent experimental results obtained using a method which is more prone to systematic error, and are also in excellent agreement with theory.

Theory and practice of radiation

International Nuclear Information System (INIS)

2006-02-01

This book deals with theory of the atomic energy; nuclear physics, radiochemistry, radiation chemistry and radiobiology. Also it says about protection radiation, management of waste of radiation, dealing of radiation including measuring the radiation energy and a neutron content and explanation of the laws and ordinances of nuclear energy. This is a book of preparations for examinations.

Compound Semiconductor Radiation Detector

International Nuclear Information System (INIS)

Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

2005-01-01

In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

Whole-body dose and energy measurements in radiotherapy by a combination of LiF:Mg,Cu,P and LiF:Mg,Ti.

Science.gov (United States)

Hauri, Pascal; Schneider, Uwe

2018-04-01

Long-term survivors of cancer who were treated with radiotherapy are at risk of a radiation-induced tumor. Hence, it is important to model the out-of-field dose resulting from a cancer treatment. These models have to be verified with measurements, due to the small size, the high sensitivity to ionizing radiation and the tissue-equivalent composition, LiF thermoluminescence dosimeters (TLD) are well-suited for out-of-field dose measurements. However, the photon energy variation of the stray dose leads to systematic dose errors caused by the variation in response with radiation energy of the TLDs. We present a dosimeter which automatically corrects for the energy variation of the measured photons by combining LiF:Mg,Ti (TLD100) and LiF:Mg,Cu,P (TLD100H) chips. The response with radiation energy of TLD100 and TLD100H compared to 60 Co was taken from the literature. For the measurement, a TLD100H was placed on top of a TLD100 chip. The dose ratio between the TLD100 and TLD100H, combined with the ratio of the response curves was used to determine the mean energy. With the energy, the individual correction factors for TLD100 and TLD100H could be found. The accuracy in determining the in- and out-of-field dose for a nominal beam energy of 6MV using the double-TLD unit was evaluated by an end-to-end measurement. Furthermore, published Monte Carlo (M.C.) simulations of the mean photon energy for brachytherapy sources, stray radiation of a treatment machine and cone beam CT (CBCT) were compared to the measured mean energies. Finally, the photon energy distribution in an Alderson phantom was measured for different treatment techniques applied with a linear accelerator. Additionally, a treatment plan was measured with a cobalt machine combined with an MRI. For external radiotherapy, the presented double-TLD unit showed a relative type A uncertainty in doses of -1%±2% at the two standard deviation level compared to an ionization chamber. The type A uncertainty in dose was in

Computational methods for industrial radiation measurement applications

International Nuclear Information System (INIS)

Gardner, R.P.; Guo, P.; Ao, Q.

1996-01-01

Computational methods have been used with considerable success to complement radiation measurements in solving a wide range of industrial problems. The almost exponential growth of computer capability and applications in the last few years leads to a open-quotes black boxclose quotes mentality for radiation measurement applications. If a black box is defined as any radiation measurement device that is capable of measuring the parameters of interest when a wide range of operating and sample conditions may occur, then the development of computational methods for industrial radiation measurement applications should now be focused on the black box approach and the deduction of properties of interest from the response with acceptable accuracy and reasonable efficiency. Nowadays, increasingly better understanding of radiation physical processes, more accurate and complete fundamental physical data, and more advanced modeling and software/hardware techniques have made it possible to make giant strides in that direction with new ideas implemented with computer software. The Center for Engineering Applications of Radioisotopes (CEAR) at North Carolina State University has been working on a variety of projects in the area of radiation analyzers and gauges for accomplishing this for quite some time, and they are discussed here with emphasis on current accomplishments

High energy synchrotron radiation. A new probe for condensed matter research

International Nuclear Information System (INIS)

Schneider, J.R.; Bouchard, R.; Brueckel, T.; Lippert, M.; Neumann, H.B.; Poulsen, H.F.; Ruett, U.; Schmidt, T.; Zimmermann, M. von

1994-01-01

The absorption of 150 keV synchrotron radiation in matter is weak and, as normally done with neutrons, bulk properties are studied in large samples. However, the k-space resolution obtained with a Triple Crystal Diffractometer (TCD) for high energy synchrotron radiation is about one order of magnitude better than in high resolution neutron diffraction. The technique has been applied to measure the structure factor S(Q) of amorphous solids up to momentum transfers of the order of 32 A -1 , to study the intermediate range Ortho-II ordering in large, high quality YBa 2 Cu 3 O 6.5 single crystals and for investigations of the defect scattering from annealed Czochralski grown silicon crystals. Magnetic superlattice reflections have been measured in MnF 2 demonstrating the potential of the technique for high resolution studies of ground state bulk antiferromagnetism. Recently the question of two length scales in the critical scattering at the 100 K phase transition in SrTiO 3 was studied. At the PETRA storage ring, which serves as an accumulator for the HERA electron-proton-ring at DESY and which can be operated up to electron energies of 12 GeV, an undulator beam line is currently under construction and should be available in summer 1995. It opens up exciting new research opportunities for photon energies from about 20 to 150 keV. (orig.)

Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy.

Science.gov (United States)

Ebenau, Melanie; Radeck, Désirée; Bambynek, Markus; Sommer, Holger; Flühs, Dirk; Spaan, Bernhard; Eichmann, Marion

2016-08-01

Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm(3)) made from the commonly used plastic scintillator BC400. Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a (60)Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks' formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks' formula was determined to be kB = (12.3 ± 0.9) mg MeV(-1) cm(-2). The energy response was quantified relative to the response to (60)Co which is the common radiation quality for the calibration of therapy dosemeters. The observed energy dependence could be well explained with the

Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy

Energy Technology Data Exchange (ETDEWEB)

Ebenau, Melanie, E-mail: melanie.ebenau@tu-dortmunde.de; Sommer, Holger; Spaan, Bernhard; Eichmann, Marion [Fakultät Physik, Technische Universität Dortmund, Otto-Hahn Str. 4a, 44221 Dortmund (Germany); Radeck, Désirée; Bambynek, Markus [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Flühs, Dirk [Universitätsklinikum Essen, Hufelandstr. 55, 45147 Essen (Germany)

2016-08-15

Purpose: Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm{sup 3}) made from the commonly used plastic scintillator BC400. Methods: Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a {sup 60}Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks’ formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. Results: The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks’ formula was determined to be kB = (12.3 ± 0.9) mg MeV{sup −1} cm{sup −2}. Conclusions: The energy response was quantified relative to the response to {sup 60}Co which is the common radiation quality for the calibration of therapy dosemeters. The

Program controlled system for measuring and monitoring the electron coherent radiation spectrum of Yerevan synchrotron

International Nuclear Information System (INIS)

Adamyan, F.V.; Vartapetyan, G.A.; Galumyan, P.I.

1980-01-01

An automatic system for measurement, processing and control of energy spectrum of polarized photons realized at the Yerevan electron synchrotron is described. For measuring energy spectra of intensive high energy photon beams a pair spectrometer is used which comprises an aluminium target-converter, an analizing magnet and 2 telescopes of scintillation counters for electron-positron pairs registration. the procedure of spectra measurement by the pair spectrometer is reduced to determining the converted e + e - pairs yield at certain values of the H field intensity of the analizing magnet. An algorithm of the data express-processing for operative monitoring of peak energy stability of electron coherent radiation spectrum is given. The spectra measurement results obtained under real experimental conditions are presented

Polarization Property Measurement of the Long Undulator Radiation Using Cr/C Multilayer Polarization Elements

International Nuclear Information System (INIS)

Niibe, Masahito; Mukai, Mikihito; Shoji, Yoshihiko; Kimura, Hiroaki

2004-01-01

A rotating analyzer ellipsometry (RAE) system was developed with Cr/C multilayers that function as polarization elements for photon energy range of 110 - 280 eV. Polarization properties of a planar undulator change axisymmetrically in off-axial manner, and the second harmonic is more remarkable for the change. By using the RAE system, the polarization property of the second harmonic radiation from the NewSUBARU long undulator at the energy of 180 eV was examined. The degree of linear polarization of the on-axis radiation was over 0.996. The spatial distribution of the polarization azimuth was measured and was in fair agreement with the theoretical calculation. A peculiar behavior of the polarization property near the radiation peak of the second harmonic was observed by changing the height of the undulator gap

A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

International Nuclear Information System (INIS)

Tallentire, Alan; Miller, Arne; Helt-Hansen, Jakob

2010-01-01

The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement with a previously published value.

A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

DEFF Research Database (Denmark)

Tallentire, A.; Miller, Arne; Helt-Hansen, Jakob

2010-01-01

The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement...... with a previously published value....

Atmospheric Radiation Measurement (ARM) Climate Research Facility Management Plan

Energy Technology Data Exchange (ETDEWEB)

Mather, James [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-04-01

Mission and Vision Statements for the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Mission The ARM Climate Research Facility, a DOE scientific user facility, provides the climate research community with strategically located in situ and remote-sensing observatories designed to improve the understanding and representation, in climate and earth system models, of clouds and aerosols as well as their interactions and coupling with the Earth’s surface. Vision To provide a detailed and accurate description of the Earth atmosphere in diverse climate regimes to resolve the uncertainties in climate and Earth system models toward the development of sustainable solutions for the nation's energy and environmental challenges.

Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils

International Nuclear Information System (INIS)

Falciglia, Pietro P.; Puccio, Valentina; Romano, Stefano; Vagliasindi, Federico G.A.

2015-01-01

This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different 232 Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations. - Highlights: • We assess the effects of 232 Th contamination on performance of S/S treated soil. • We assess the γ-radiation shielding of the S/S materials as a function of energy. • We report a full testing protocol for assessing S/S resistance performance. • Emission energy influences the γ radiation shielding of the S/S. • Barite gives high γ-radiation shielding and low contaminant leaching

Device for converting electromagnetic radiation energy into electrical energy and method of manufacturing such a device

NARCIS (Netherlands)

2007-01-01

Device (10) for converting electromagnetic radiation energy into electrical energy, comprising at least a photovoltaic element (11) with a radiation-sensitive surface, wherein a covering layer (12) of a material comprising a silicon compound, to which a rare earth element has been added, is present

Measurement of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 high-altitude airplane

CERN Document Server

Goldhagen, P E; Kniss, T; Reginatto, M; Singleterry, R C; Van Steveninck, W; Wilson, J W

2002-01-01

Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the atmospheric ionizing radiation (AIR) project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (t...

Radiation dose rate measuring device

International Nuclear Information System (INIS)

Sorber, R.

1987-01-01

A portable device is described for in-field usage for measuring the dose rate of an ambient beta radiation field, comprising: a housing, substantially impervious to beta radiation, defining an ionization chamber and having an opening into the ionization chamber; beta radiation pervious electrically-conductive window means covering the opening and entrapping, within the ionization chamber, a quantity of gaseous molecules adapted to ionize upon impact with beta radiation particles; electrode means disposed within the ionization chamber and having a generally shallow concave surface terminating in a generally annular rim disposed at a substantially close spacing to the window means. It is configured to substantially conform to the window means to define a known beta radiation sensitive volume generally between the window means and the concave surface of the electrode means. The concave surface is effective to substantially fully expose the beta radiation sensitive volume to the radiation field over substantially the full ambient area faced by the window means

Unified limiting form of graviton radiation at extreme energies

CERN Document Server

Ciafaloni, Marcello; Coradeschi, Francesco; Veneziano, Gabriele

2016-01-01

We derive the limiting form of graviton radiation in gravitational scattering at transplanckian energies ($E\\gg M_P$) and small deflection angles. We show that --- owing to the graviton's spin 2 --- such limiting form unifies the soft- and Regge- regimes of emission, by covering a broad angular range, from forward fragmentation to deeply central region. The single-exchange emission amplitudes have a nice expression in terms of the transformation phases of helicity amplitudes under rotations. As a result, the multiple-exchange emission amplitudes can be resummed via an impact parameter $b$-space factorization theorem that takes into account all coherence effects. We then see the emergence of an energy spectrum of the emitted radiation which, being tuned on $\\hbar/R \\sim M_P^2/E \\ll M_P$, is reminiscent of Hawking's radiation. Such a spectrum is much softer than the one na\\"ively expected for increasing input energies and neatly solves a potential energy crisis. Furthermore, by including rescattering correction...

Electromagnetically driven radiative shocks and their measurements

International Nuclear Information System (INIS)

Kondo, K.; Watanabe, M.; Nakajima, M.; Kawamura, T.; Horioka, K.

2005-01-01

Experimental results on a generation of strong shocks in a compact pulse power device are reported. The characteristics of strong shocks are different from hydrodynamical shocks' because they depend on not only collisions but radiation processes. Radiative shocks are relevant to high energy density phenomena such as the explosions of supernovae. When initial pressure is lower than about 50 mtorr, an interesting structure is confirmed at the shock front, which might indicate a phenomenon proceeded by the radiative process. (author)

Limiting energy loss distributions for multiphoton channeling radiation

International Nuclear Information System (INIS)

Bondarenco, M.V.

2015-01-01

Recent results in the theory of multiphoton spectra for coherent radiation sources are overviewed, with the emphasis on channeling radiation. For the latter case, the importance of the order of resummation and averaging is emphasized. Limiting shapes of multiphoton spectra at high intensity are discussed for different channeling regimes. In some spectral regions, there emerges a correspondence between the radiative energy loss and the electron integrals of motion

Relations between radiation risks and radiation protection measuring techniques

International Nuclear Information System (INIS)

Herrmann, K.; Kraus, W.

1975-10-01

'Risk of damage' and 'exposure risk' are considered as components of the radiation risk. The influence of the 'exposure risk' on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Basing upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high 'exposure risk'. As a consequence the following recommendations are given for discussion: (a) occupationally exposed persons with small 'exposure risk' should be monitored using only a long-term dosimeter (for instance a thermoluminescence dosimeter), (b) in the case of internal exposure the surface and, if necessary, air contamination should be controlled so strictly that routine measurements of internal contamination need not be performed. (author)

Quality assurance in radiation measurement

International Nuclear Information System (INIS)

Noriah Mod Ali

2002-01-01

The achievement of traceability to recognize measurement standards for ionizing radiation posses special requirements. Methods of transferring reference standard to the working situation are devised through calibration and appropriate traceability, which optimize the accuracy attainable with the method of dose determination in routine use. Appropriate procedures are developed by the SSDL-MINT to establish accurate dose measurement in wide range of radiation fields such as in medicine, agriculture and industrial application. The status of work including effort towards ISO 9000 certification of SSDL dosimetry services will be summarized. (Author)

Neutron Measurements for Radiation Protection in Low Earth Orbit - History and Future

Science.gov (United States)

Golightly, M. J.; Se,pmes. E/

2003-01-01

The neutron environment inside spacecraft has been of interest from a scientific and radiation protection perspective since early in the history of manned spaceflight. With 1:.1e exception of a few missions which carried plutonium-fueled radioisotope thermoelectric generators, all of the neutrons inside the spacecraft are secondary radiations resulting from interactions of high-energy charged particles with nuclei in the Earth's atmosphere, spacecraft structural materials, and the astronaut's own bodies. Although of great interest, definitive measurements of the spacecraft neutron field have been difficult due to the wide particle energy range and the limited available volume and power for traditional techniques involving Bonner spheres. A multitude of measurements, however, have been made of the neutron environment inside spacecraft. The majority of measurements were made using passive techniques including metal activation fo ils, fission foils, nuclear photoemulsions, plastic track detectors, and thermoluminescent detectors. Active measurements have utilized proton recoil spectrometers (stilbene), Bonner Spheres eRe proportional counter based), and LiI(Eu)phoswich scintillation detectors. For the International Space Station (ISS), only the plastic track! thermoluminescent detectors are used with any regularity. A monitoring program utilizing a set of active Bonner spheres was carried out in the ISS Lab module from March - December 200l. These measurements provide a very limited look at the crew neutron exposure, both in time coverage and neutron energy coverage. A review of the currently published data from past flights will be made and compared with the more recent results from the ISS. Future measurement efforts using currently available techniques and those in development will be also discussed.

About Solar Radiation Intensity Measurements and Data Processing

Directory of Open Access Journals (Sweden)

MICH-VANCEA Claudiu

2012-10-01

Full Text Available Measuring the intensity of solar radiation is one of the directions of investigation necessary for the implementation of photovoltaic systems in a particular geographical area. This can be done by using specific measuring equipment (pyranometer sensors based onthermal or photovoltaic principle. In this paper it is presented a method for measuring solar radiation (which has two main components - direct radiation and diffuse radiation with sensors based on photovoltaic principle. Such data are processed for positioning solarpanels, in order their efficiency to be maximized.

X-ray energy-dispersive diffractometry using synchrotron radiation

International Nuclear Information System (INIS)

Buras, B.; Staun Olsen, J.; Gerward, L.

1977-03-01

In contrast to bremsstrahlung from X-ray tubes, synchrotron radiation is very intense, has a smooth spectrum, its polarization is well defined, and at DESY the range of useful photon energies can be extended to about 70 keV and higher. In addition the X-ray beam is very well collimated. Thus synchrotron radiation seems to be an ideal X-ray source for energy-dispersive diffractometry. This note briefly describes the experimental set up at DESY, shows examples of results, and presents the underlying 'philosophy' of the research programme. (Auth.)

Measuring space radiation shielding effectiveness

Directory of Open Access Journals (Sweden)

Bahadori Amir

2017-01-01

Full Text Available Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

Measuring space radiation shielding effectiveness

Science.gov (United States)

Bahadori, Amir; Semones, Edward; Ewert, Michael; Broyan, James; Walker, Steven

2017-09-01

Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

Vectorial and plane energy fluences - useful concepts in radiation physics

International Nuclear Information System (INIS)

Carlsson, C.A.

1977-06-01

The vectorial physical quantities describing the radiation field are defined in this report. The use of these quantities is rare in the radiation dosimetry literature since a knowledge of the directions of motion of the ionizing particle is often uninteresting when determining absorbed doses. However the plane energy fluence rate is a useful quantity in cases with plane irradiation geometries. The plane energy fluence rate is closely related to the vectorial energy fluence rate. The backscattering properties of a medium can be expressed in terms either of its albedo or its reflection-coefficient (backscatter-coefficient). These quantities are discussed in order to derive useful relations between the plane energy fluence and the energy fluence at points on an extended plane surface. Examples are also given of erroneous use of energy fluence instead of vectorial or plane energy fluence. The examples are taken from roentgen diagnostic examinations. To prevent further mistakes it could be valuable if the quantities of vectorial and plane fluences were introduced in text books in radiation dosimetry. Awaiting for this, this report may hopefully be useful. (E.R.)

The solar energy in Colombia, Atlas of solar radiation of Colombia

International Nuclear Information System (INIS)

Rodriguez P, F.

1995-01-01

This study was made by means of the Agreement inter-institutional subscribed between Mines Ministry and Energy, HIMAT and INEA and was published by CARBOCOL. In the evaluation of solar energy potential, the information of the radiometric net of the HIMAT taken in 203 stations distributed throughout all Country from 1980 until 1990, it was had in account. A meteorological station is an observation point where are located different instruments and equipment that serve to measure and study meteorological parameter as solar radiation (radiometer actinograph), Solar sheen (Campbell Stoke), Temperature (Thermograph), Moisture (hydrographer), Wind (Anemograph Anemometer) and Precipitation (Pluviograph)

Heat rejection efficiency research of new energy automobile radiators

Science.gov (United States)

Ma, W. S.; Shen, W. X.; Zhang, L. W.

2018-03-01

The driving system of new energy vehicle has larger heat load than conventional engine. How to ensure the heat dissipation performance of the cooling system is the focus of the design of new energy vehicle thermal management system. In this paper, the heat dissipation efficiency of the radiator of the hybrid electric vehicle is taken as the research object, the heat dissipation efficiency of the radiator of the new energy vehicle is studied through the multi-working-condition enthalpy difference test. In this paper, the test method in the current standard QC/T 468-2010 “automobile radiator” is taken, but not limited to the test conditions specified in the standard, 5 types of automobile radiator are chosen, each of them is tested 20 times in simulated condition of different wind speed and engine inlet temperature. Finally, regression analysis is carried out for the test results, and regression equation describing the relationship of radiator heat dissipation heat dissipation efficiency air side flow rate cooling medium velocity and inlet air temperature is obtained, and the influence rule is systematically discussed.

measurement of indoor background ionizing radiation in some

African Journals Online (AJOL)

Administrator

Measurement of the background ionizing radiation profile within the. Chemistry Research Laboratory and Physics Laboratory III all of the. University of Jos and their immediate neighbourhood were carried out. These science laboratories also harbour a number of active radiation sources. The radiation levels were measured ...

Development of nuclear energy and radiation textbooks for high school students

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok [Dept. of Education and Research, Korea Academy of Nuclear Safety, Seoul (Korea, Republic of)

2015-04-15

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort.

Development of nuclear energy and radiation textbooks for high school students

International Nuclear Information System (INIS)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok

2015-01-01

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort

The measurement of longwave radiation properties upon plastic films used in greenhouses

International Nuclear Information System (INIS)

Horiguchi, I.; Tani, H.; Sugaya, H.

1982-01-01

Due to the rising cost of heating oils in recent years, the subject of heat conservation on a greenhouse has become more important. In this aspect, the plastic films used for reducing heat losses must have low transmittance property for longwave radiation, also need to have low emissivity. The properties of plastic films which affect on the transfer of energy are important. The paper discusses the measurements of reflectance, transmittance, and emissivity of longwave radiation (thermal radiation) upon various plastic films used for crop protection in agriculture, particularly in a greenhouse. New measuring methods for reflectance and emissivity were presented, and the previous transmittance calculations (Hagiwara and Horiguchi, 1972) were improved by using newly obtained reflectance values. The transmittance values obtained from the present study are about 2-5 percent larger than the values obtained from the previous study. The reason for the discrepancy may be due to the negligence of the reflectance term in the previous calculation. (author)

U. S. Department of Energy Aerial Measuring Systems

Energy Technology Data Exchange (ETDEWEB)

J. J. Lease

1998-10-01

The Aerial Measuring Systems (AMS) is an aerial surveillance system. This system consists of remote sensing equipment to include radiation detectors; multispectral, thermal, radar, and laser scanners; precision cameras; and electronic imaging and still video systems. This equipment, in varying combinations, is mounted in an airplane or helicopter and flown at different heights in specific patterns to gather various types of data. This system is a key element in the US Department of Energy's (DOE) national emergency response assets. The mission of the AMS program is twofold--first, to respond to emergencies involving radioactive materials by conducting aerial surveys to rapidly track and map the contamination that may exist over a large ground area and second, to conduct routinely scheduled, aerial surveys for environmental monitoring and compliance purposes through the use of credible science and technology. The AMS program evolved from an early program, begun by a predecessor to the DOE--the Atomic Energy Commission--to map the radiation that may have existed within and around the terrestrial environments of DOE facilities, which produced, used, or stored radioactive materials.

U. S. Department of Energy Aerial Measuring Systems

International Nuclear Information System (INIS)

Lease, J.J.

1998-01-01

The Aerial Measuring Systems (AMS) is an aerial surveillance system. This system consists of remote sensing equipment to include radiation detectors; multispectral, thermal, radar, and laser scanners; precision cameras; and electronic imaging and still video systems. This equipment, in varying combinations, is mounted in an airplane or helicopter and flown at different heights in specific patterns to gather various types of data. This system is a key element in the US Department of Energy's (DOE) national emergency response assets. The mission of the AMS program is twofold--first, to respond to emergencies involving radioactive materials by conducting aerial surveys to rapidly track and map the contamination that may exist over a large ground area and second, to conduct routinely scheduled, aerial surveys for environmental monitoring and compliance purposes through the use of credible science and technology. The AMS program evolved from an early program, begun by a predecessor to the DOE--the Atomic Energy Commission--to map the radiation that may have existed within and around the terrestrial environments of DOE facilities, which produced, used, or stored radioactive materials

First Measurements of the Longitudinal Bunch Profile at SLAC Using Coherent Smith-Purcell Radiation at 28GeV

International Nuclear Information System (INIS)

Arnold, R.; Molloy, S.; Woods, M.; Kimmitt, M.F.; Blackmore, V.; Doucas, G.; Ottewell, B.; Perry, C.

2011-01-01

Coherent Smith-Purcell radiation has been demonstrated as a technique for measuring the longitudinal profile of charged particles bunches in the low to intermediate energy range. However, with the advent of the International Linear Collider, the need has arisen for a non-invasive method of measuring the bunch profile at extremely high energies. Smith-Purcell radiation has been used for the first time in the multi-GeV regime to measure the longitudinal profile of the 28GeV SLAC beam. The experiment has both successfully determined the bunch length, and has also demonstrated its sensitivity to bunch profile changes. The challenges associated with this technique, and its prospects as a diagnostic tool are reported here.

Size measurement of radioactive aerosol particles in intense radiation fields using wire screens and imaging plates

Energy Technology Data Exchange (ETDEWEB)

Oki, Yuichi; Tanaka, Toru; Takamiya, Koichi; Ishi, Yoshihiro; UesugI, Tomonori; Kuriyama, Yasutoshi; Sakamoto, Masaaki; Ohtsuki, Tsutomu [Kyoto University Research Reactor Institute, Osaka (Japan); Nitta, Shinnosuke [Graduate School of Engineering, Kyoto University, Kyoto (Japan); Osada, Naoyuki [Advanced Science Research Center, Okayama University, Okayama (Japan)

2016-09-15

Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of 11C-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. The size distribution for 11C-bearing aerosol particles was found to be ca. 70 μm in geometric mean diameter. The size was similar to that for 7Be-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.

Preliminary measurements of gamma radiation in Chilean Antarctic Stations

Energy Technology Data Exchange (ETDEWEB)

Stuardo B, E. (Comision Chilena de Energia Nuclear, Santiago. Dept. de Aplicaciones Nucleares)

1983-11-01

Natural and artificial gamma radiation, 1 m above the soil, is being investigated in 4 Chilean Antartic Stations. The measurements are performed with different types of TLD detectors. Preliminary results in the Tte. Marsh Station are reported and discussed. An average exposition of 3,5 ..mu..R/h was found during a 108 days period. This exposition corresponds to an annual dose of about 40 mrad, 8% of the annual dose limit for individual of the public. The presence of low energy artificial radioisotopes was not found.

Optical fiber radiation sensors: first in vivo measurements during orbital irradiation

International Nuclear Information System (INIS)

Gripp, S.; Bannach, B.; Muskalla, K.; Haesing, F.; Bueker, H.; Schmitt, G.

1995-01-01

Purpose: To investigate the applicability of doped optical fiber radiation sensors in clinical dosimetry. Methods: Ionizing radiation causes a dose depending discoloring in silica. When proper impurities (doping agents) are added, the radiation sensitivity may be increased to a range suited for clinical dosimetry. We performed in-vivo-measurements using a lead doped silica fiber (d TM ) in comparison to thermoluminescence detectors (TLDs). Results: The scattered radiation is easily detected with this sensor fiber. In contrast to TLDs the dose and doserate values are obtained immediately and setup errors can be recognized before irradiation is completed. The SD clearly depends on setup modifications due to the extent of disease. Other doping agents (GeP) provide better tissue equivalence and less energy dependence. Conclusions: Optical fibers are suitable for in vivo dosimetry purposes. Fiber sensors provide real time dose values, and the readout procedure is much easier compared to TLDs. These features may gain significance in quality assurance, conformal therapy, and intraoperative radiotherapy (IORT)

Measurement of Underwater Operational Noise Emitted by Wave and Tidal Stream Energy Devices.

Science.gov (United States)

Lepper, Paul A; Robinson, Stephen P

2016-01-01

The increasing international growth in the development of marine and freshwater wave and tidal energy harvesting systems has been followed by a growing requirement to understand any associated underwater impact. Radiated noise generated during operation is dependent on the device's physical properties, the sound-propagation environment, and the device's operational state. Physical properties may include size, distribution in the water column, and mechanics/hydrodynamics. The sound-propagation environment may be influenced by water depth, bathymetry, sediment type, and water column acoustic properties, and operational state may be influenced by tidal cycle and wave height among others This paper discusses some of the challenges for measurement of noise characteristics from these devices as well as a case study of the measurement of radiated noise from a full-scale wave energy converter.

A determination of the centre-of-mass energy at LEP2 using radiative two-fermion events

CERN Document Server

Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; llmendinger, T; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, D; Barker, G J; Baroncelli, A; Battaglia, M; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N; Benvenuti, A C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Buschbeck, Brigitte; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F; Chapkin, M; Charpentier, P; Checchia, P; Chierici, R; Chliapnikov, P V; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J; Gandelman, M; García, C; Gavillet, P; Gazis, E; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, B P; Kerzel, U; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Mazzucato, M; Mönig, K; Mulders, M; Nawrocki, K; Orava, R; Masik, J; Mastroyiannopoulos, N; Migliore, E; Matorras, F; Matteuzzi, C; Mazzucato, F; Nulty, R M; Moch, M; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Murray, W; Monge, R; Ouraou, A; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Olshevskii, A G; Palacios, J P; Navarria, Francesco Luigi; Onofre, A; Palka, H; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Paiano, S; Meroni, C; Mitaroff, W A; Mjörnmark, U; Moa, T; Mundim, L; Nicolaidou, R; Österberg, K; Oyanguren, A; Paganoni, M; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Pozdnyakov, V; Pukhaeva, N; Pullia, A; Rames, J; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Sander, C; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sisakian, A; Smadja, G; Smirnova, O; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J; Wilkinson, G; Winter, M; Witek1, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M

2006-01-01

Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.

Design and construction of a calorimeter for the measurement of radiation doses in a nuclear reactor

International Nuclear Information System (INIS)

Lugo R, J.F.

1979-01-01

The amount of energy deposited by the radiation in an absorber system, in radiation dose units was established, the Reactor Triga Mark III core of the Mexican Nuclear Center was used as radiation source. The calorimetric method was used, which gives us a direct measurement in energy units. The total dose was measured, that is, no difference was made between the different forms of radiation that operate with the system. A calorimeter was made with the following materials: stainless steel jacket, aluminium absorber material and thermometers of iron alloy. The calibration system was made for the heating and cooling technique, obtaining with the experimental data the value of the pseudo period constant. With that value and using the fit derived equation, the dose values were established for the G-21 position of the reactor core. It was established that the obtained dose is a function of the operation reactor time before the measurement, at the same a lot of propositions are presented in order to improve this technique, as for the used materials as to the obtaining the most fit equations. A comparison was made between the theoretical calculated dose and the experimentally obtained data with the calorimetric technique. (author)

A Self-Powered Thin-Film Radiation Detector Using Intrinsic High-Energy Current (HEC) (Author’s Final Version)

Science.gov (United States)

2016-09-08

of electromagnetic 85 pulse effects on cables and electrical devices4 and as a self - powered detector for in-core neutron flux measurement in nuclear...AFCEC-CX-TY-TP-2016-0003 A SELF - POWERED THIN-FILM RADIATION DETECTOR USING INTRINSIC HIGH-ENERGY CURRENT (HEC) (AUTHOR’S FINAL VERSION...14 -- 5 Oct 15 A self - powered thin-film radiation detector using intrinsic high-energy current (HEC) (Author’s Final Version) FA8051-15-P-0010

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

International Nuclear Information System (INIS)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon

2002-01-01

transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD(VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of 10cm in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the 30cm x 30cm 2 x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size 40 cm x 40 cm 2 and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The lead pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large field of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets reduced the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

2002-03-15

transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD(VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of 10cm in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the 30cm x 30cm{sup 2} x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size 40 cm x 40 cm{sup 2} and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The lead pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large field of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets reduced the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young

Photon detector for high energy measurements in the SELEX spectrometer (Fermilab experiment E781)

International Nuclear Information System (INIS)

Goncharenko, Yu.M.; Grachov, O.A.; Kurshetsov, V.F.; Landsberg, L.G.; Nurushev, S.B.; Vasil'ev, A.N.

1995-01-01

A possibility to use one- or two-photon lead glass detectors for high energy measurements in the SELEX spectrometer with E γ up to 500 GeV is studied. It is shown that a single photon detector equipped with radiation-resistant lead glass counters is applicable for the experiment discussed. It is concluded that for the best energy resolution in the case of Primakoff effect like π - = γ * → π - + γ the combined method would be used with weighted combination of direct E γ measurement in the Photon-3 detector and the π - beam energy precise measurement. 11 refs., 4 tabs., 17 figs

Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy.

Science.gov (United States)

Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S

2015-05-15

Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave-particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity.

Ground-based spectral measurements of solar radiation, (2)

International Nuclear Information System (INIS)

Murai, Keizo; Kobayashi, Masaharu; Goto, Ryozo; Yamauchi, Toyotaro

1979-01-01

A newly designed spectro-pyranometer was used for the measurement of the global (direct + diffuse) and the diffuse sky radiation reaching the ground. By the subtraction of the diffuse component from the global radiation, we got the direct radiation component which leads to the spectral distribution of the optical thickness (extinction coefficient) of the turbid atmosphere. The measurement of the diffuse sky radiation reveals the scattering effect of aerosols and that of the global radiation allows the estimation of total attenuation caused by scattering and absorption of aerosols. The effects of the aerosols are represented by the deviation of the real atmosphere measured from the Rayleigh atmosphere. By the combination of the measured values with those obtained by theoretical calculation for the model atmosphere, we estimated the amount of absorption by the aerosols. Very strong absorption in the ultraviolet region was recognized. (author)

Method and apparatus for determining accuracy of radiation measurements made in the presence of background radiation

International Nuclear Information System (INIS)

Horrocks, D.L.

1977-01-01

A radioactivity measuring instrument, and a method related to its use, for determining the radioactivity of a sample measured in the presence of significant background radiation, and for determining an error value relating to a specific probability of accuracy of the result are presented. Error values relating to the measurement of background radiation alone, and to the measurement of sample radiation and background radiation together, are combined to produce a true error value relating to the sample radiation alone