WorldWideScience

Sample records for incident radiation fields

  1. Radiation incidents in dentistry

    International Nuclear Information System (INIS)

    Lovelock, D.J.

    1996-01-01

    Most dental practitioners act as their own radiographer and radiologist, unlike their medical colleagues. Virtually all dental surgeons have a dental X-ray machine for intraoral radiography available to them and 40% of dental practices have equipment for dental panoramic tomography. Because of the low energy of X-ray equipment used in dentistry, radiation incidents tend to be less serious than those associated with other aspects of patient care. Details of 47 known incidents are given. The advent of the 1985 and 1988 Ionising Radiation Regulations has made dental surgeons more aware of the hazards of radiation. These regulations, and general health and safety legislation, have led to a few dental surgeons facing legal action. Because of the publicity associated with these court cases, it is expected that there will be a decrease in radiation incidents arising from the practice of dentistry. (author)

  2. The incidence of breast cancer following mantle field radiation therapy as a function of dose and technique

    International Nuclear Information System (INIS)

    Tinger, Alfred; Wasserman, Todd H.; Klein, Eric E.; Miller, Elizabeth A.; Roberts, Tracy; Piephoff, James V.; Kucik, Nancy A.

    1997-01-01

    Purpose: There is an increased incidence of breast cancer following mantle field radiation therapy for Hodgkin's disease (HD). We reviewed the experience at the Mallinckrodt Institute of Radiology (MIR) for radiation factors related to the development of breast cancer after mantle field radiation therapy for HD. Methods: The radiation therapy records of 152 women treated with mantle field irradiation for HD at MIR between 1966-1985 were reviewed for the development of breast cancer and treatment-related factors. All patients had a minimum of 5 years of follow-up. The treatment era (1966-1974 vs. 1975-1985), stage of HD, mediastinal dose, axillary dose, maximum dose from the anterior field (anterior d max dose), the anterior-posterior:posterior-anterior (AP:PA) ratio, age at the time of treatment, length of follow-up, and history of splenectomy were analyzed as possible contributing factors for the development of breast cancer. The observed number of breast cancers was compared to the expected number based on age-adjusted incidences from the Connecticut Tumor Registry. Results: Ten breast cancers occurred in the population. Eight involved an upper outer quadrant. In a multivariate analysis, the development of breast cancer was significantly associated with axillary dose. Patients in the early treatment era were at an increased risk for the development of breast cancer due to high anterior d max and breast doses from weighting the fields anteriorly on a low energy linear accelerator. The use of current radiation therapy techniques was not related to an increased risk of breast cancer with a median follow-up of 13 years. Conclusions: A high dose to the axilla and the anterior d max point is significantly associated with the development of breast cancer after mantle field irradiation for HD. Efforts to protect the breast from high doses will likely lessen the increased risk of breast cancer in women treated with radiation therapy for HD

  3. Acoustic radiation force due to arbitrary incident fields on spherical particles in soft tissue

    Energy Technology Data Exchange (ETDEWEB)

    Treweek, Benjamin C., E-mail: btreweek@utexas.edu; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F. [Applied Research Laboratories, The University of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029 (United States)

    2015-10-28

    Acoustic radiation force is of interest in a wide variety of biomedical applications ranging from tissue characterization (e.g. elastography) to tissue treatment (e.g. high intensity focused ultrasound, kidney stone fragment removal). As tissue mechanical properties are reliable indicators of tissue health, the former is the focus of the present contribution. This is accomplished through an investigation of the acoustic radiation force on a spherical scatterer embedded in tissue. Properties of both the scatterer and the surrounding tissue are important in determining the magnitude and the direction of the force. As these properties vary, the force computation shows changes in magnitude and direction, which may enable more accurate noninvasive determination of tissue properties.

  4. Workplace photon radiation fields

    International Nuclear Information System (INIS)

    Burgess, P.H.; Bartlett, D.T.; Ambrosi, P.

    1999-01-01

    The knowledge of workplace radiation fields is essential for measures in radiation protection. Information about the energy and directional distribution of the incident photon radiation was obtained by several devices developed by the National Radiation Protection Board, United Kingdom, by the Statens Stralskyddsinstitut, Sweden, together with EURADOS and by the Physikalisch-Technische Bundesanstalt, Germany. The devices are described and some results obtained at workplaces in nuclear industry, medicine and science in the photon energy range from 20 keV to 7 MeV are given. (author)

  5. RADIATION CONTAMINATION INCIDENT AT ISOLDE

    CERN Multimedia

    2000-01-01

    On 27 June 2000 three specialists were investigating a problem with the extraction electrode of the high-resolution separator (HRS) in Isolde. Whilst using an endoscope in order to have a closer look at the interior, they came into contact with radioactive dust and became contaminated. The level of contamination was low and the radiation dose received by the 3 persons was far below the effective dose limit given in the CERN Radiation Safety Manual and in the regulations of the Host States.According to the usual procedure, the Director General has set up a Fact-Finding Group and an Accident Board in order to advise him on the steps and decisions tobe taken following this incident and in particular to avoid a recurrence.

  6. Incidence and latency of radiation reactions

    International Nuclear Information System (INIS)

    Bentzen, S.M.; Thames, H.D.

    1989-01-01

    Like any other pathological condition, radiation reactions are characterized not only by their incidence (i.e. frequency) but also buy their latent period. The difference between latencies is the basis for the biologically and clinically important distinction between early and late radiation reactions. The authors conclude in this letter that a hazard-rate type of analysis does not allow separation of the effects of incidency and latency. The authors feel that a more adequate framework for analysis of latent-time distributions is provided bu the mixture model. Currenctly, the hydronephrosis data by Knowles and Trott are being reanalyzed using the model. (author). 8 refs.; 1 fig

  7. Radiation incident in oil well logging

    International Nuclear Information System (INIS)

    Lozada, J.A.

    1998-01-01

    On June 4th 1997 equipment failure and violation of approved procedures by a crew of workers initiated a series of events that resulted in the unnecessary exposure to neutron and gamma radiation, from a 666 GBq Am 241 Be source, of forty two workers from a well logging company in Venezuela. Due to the presence of dry mud or drilling fluids inside the logging tool, the nosepiece was screwed off the rest of the source holder; this piece was mistaken for the entire source holder thus leaving the source inside the tool. The tool was labelled for maintenance and electronic laboratory personal worked near the source for seven hours before they identify its presence. As soon as the incident was detected a contingency plan was implemented and the source could be retrieved from the tool and placed in its shipping container. The TLD badges indicate doses well below the annual limit of 20 mSv, and none of the workers involved in the incident seem to show serious health consequences from it. After the incident, in order to avoid the occurrence of similar situations, a better source and tool maintenance program was implemented, all the workers were re-trained, and area monitors were installed in all operations bases. (author)

  8. Discriminating electromagnetic radiation based on angle of incidence

    Science.gov (United States)

    Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

    2015-06-16

    The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

  9. Quantization of the Radiation Field

    Indian Academy of Sciences (India)

    Maxwell's equations, radiation field,quantization,Lamb shift. Avinash Khare. I briefly review the seminal 1927 paper of Dirac which emphasized the need for the quantization of the electromagnetic field and then showed how to carry it out. After mentioning few historical developments, I then point out some of the out- standing ...

  10. Scattering of Electromagnetic Radiation by Apertures: II. Oblique Incidence on the Slotted Plane for Parallel Polarization,

    Science.gov (United States)

    The report is the second in a series of investigations into the diffraction of electromagnetic radiation by apertures in conducting screens. Herein...is presented a technique for obtaining the fields everywhere for plane electromagnetic radiation incident obliquely on a slotted conducting plane. The

  11. Hawking radiation and interacting fields

    Science.gov (United States)

    Frasca, Marco

    2017-11-01

    Hawking radiation is generally derived using a non-interacting field theory. Some time ago, Leahy and Unruh showed that, in two dimensions with a Schwarzschild geometry, a scalar field theory with a quartic interaction gets the coupling switched off near the horizon of the black hole. This would imply that interaction has no effect on Hawking radiation and free theory for particles can be used. Recently, a set of exact classical solutions for the quartic scalar field theory has been obtained. These solutions display a massive dispersion relation even if the starting theory is massless. When one considers the corresponding quantum field theory, this mass gap becomes a tower of massive excitations and, at the leading order, the theory is trivial. We apply these results to Hawking radiation for a Kerr geometry and prove that the Leahy-Unruh effect is at work. Approaching the horizon the scalar field theory has the mass gap going to zero. We devise a technique to study the interacting scalar theory very near the horizon increasing the coupling. As these solutions are represented by a Fourier series of plane waves, Hawking radiation can be immediately obtained with well-known techniques. These results open a question about the behavior of the Standard Model of particles very near the horizon of a black hole where the interactions turn out to be switched off and the electroweak symmetry could be restored.

  12. Prostate cancer incidence in Australia correlates inversely with solar radiation.

    Science.gov (United States)

    Loke, Tim W; Seyfi, Doruk; Sevfi, Doruk; Khadra, Mohamed

    2011-11-01

    What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States. • To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia. • Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined. • Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades. •  There exists an association between less solar radiation and higher prostate cancer incidence in Australia. © 2011 THE AUTHORS. BJU

  13. Quantization of the Radiation Field

    Indian Academy of Sciences (India)

    physics, anyons and supersymmetric quantum mechanics. Keywords. Qua ntu m electrodynamics,. Maxwell's equations, radiation field,quantization,Lamb shift. Avinash Khare ... could only assume values which are integral multiples of a certain unit, i.e. ... choices one can make for A and if; , leaving E and B unchanged, are ...

  14. Quantization of the Radiation Field

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 8. Quantization of the Radiation Field. Avinash Khare. General Article Volume 8 Issue 8 August 2003 pp 10-16. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/08/0010-0016. Keywords.

  15. Limited-field radiation for bifocal germinoma

    International Nuclear Information System (INIS)

    Lafay-Cousin, Lucie; Millar, Barbara-Ann; Mabbott, Donald; Spiegler, Brenda; Drake, Jim; Bartels, Ute; Huang, Annie; Bouffet, Eric

    2006-01-01

    Purpose: To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation. Methods and Materials: This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers. Results: Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months). Conclusions: This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity

  16. Radiation produced by electrons incident on molecules

    International Nuclear Information System (INIS)

    Moehlman, G.R.

    1977-01-01

    The work described in this thesis deals with light intensity measurements of emission spectra (1850-9000 A) produced by a continuous or pulsed beam of monoenergetic electrons (0 - 2000 eV) incident on a variety of molecular gases like H 2 , D 2 , H 2 O, HCl, NH 3 and several hydrocarbons. The emission spectra are dominated by fluorescence from excited fragments produced via dissociative excitation, besides fluorescence from excited parent molecules themselves. The experimental results thus obtained are expressed in terms of emission cross sections and lifetimes

  17. Radiation protection aspects of the incident recovery

    International Nuclear Information System (INIS)

    Tibor, Bujtas; Arpad, Nenyei

    2006-01-01

    On the 10. April 2003 a serious accident occurred at PAKS nuclear power plant. The cleaning of fuel assemblies unloaded from the reactor of unit 2 was commencing under water in the fuel-cleaning equipment in the maintenance shaft number 1. There was no chain reaction in the cleaning tank but the fission products, accumulated in the previous operational time still produced a significant heat. Due to the inadequate cooling of the cleaning tank the assemblies overheated within a few hours. After opening the lid of the tank the entering cold water caused thermal shock and significant damage to the fuel assemblies. cladding of the fuel elements opened up and the uranium dioxide pellets got also damaged. The removal of the damaged fuel assemblies and the released debris must be managed. There are technical difficulties and radiation protection problems to reduce the radiation exposure of the workers as well as the minimization of the radioactive materials released into the environment. The description of the situation and the different actions are detailed. (N.C.)

  18. Ascertaining directionality information from incident nuclear radiation

    International Nuclear Information System (INIS)

    Archambault, Brian C.; Lapinskas, Joseph R.; Wang Jing; Webster, Jeffrey A.; McDeavitt, Sean; Taleyarkhan, Rusi P.

    2011-01-01

    Highlights: → Use of tensioned metastable fluids for detection of fast neutron radiation. → Monitored neutrons with 100% gamma photon blindness capability. → Monitored direction of incoming neutron radiation from special nuclear material emissions. → Ascertained directionality of neutron source to within 30 deg. and with 80% confidence with 2000 detection events at rate of 30-40 per second. → Conducted successful blind test for determining source of neutrons from a hidden neutron emitting source. → Compared results with MCNP5-COMSOL based multi-physics model. - Abstract: Unprecedented capabilities for the detection of nuclear particles via tailored resonant acoustic systems such as the acoustic tensioned metastable fluid detection (ATMFD) systems were assessed for determining directionality of incoming fast neutrons. This paper presents advancements that expand on these accomplishments, thereby increasing the accuracy and precision of ascertaining directionality information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on demand enlargement of the detector sensitive volume. Advances in the development of ATMFD systems were accomplished utilizing a combination of experimentation and theoretical modeling. Modeling methodologies include Monte-Carlo based nuclear particle transport using MCNP5 and multi-physics based assessments accounting for acoustic, structural, and electromagnetic coupling of the ATMFD system via COMSOL's multi-physics simulation platform. Benchmarking and qualification studies have been conducted with a 1 Ci Pu-Be neutron-gamma source. These results show that the specific ATMFD system used for this study can enable detection of directionality of incoming fast neutrons from the neutron source to within 30 o with 80% confidence; this required ∼2000 detection events which could be collected within ∼50 s at a detection rate of ∼30-40 per second. Blind testing was successfully

  19. The dielectric response to the magnetic field of electromagnetic radiation

    Science.gov (United States)

    Mukherjee, Shouvik; Mukhopadhyay, Sourabh; Datta, Prasanta Kumar

    2017-04-01

    Light-matter interaction in transparent dielectrics is revisited, including the magnetic force on bound charges in the Lorentz oscillator model. The parameter ranges of incident radiation and the medium on which the magnetic field of the electromagnetic radiation will have a significant effect are traced using Floquet theory. The analysis reveals that the threshold intensity for a significant response of the magnetic field of the radiation at the second harmonic of the incident radiation can be reduced to {10}12 {{W}}{{cm}}-2 for off resonant and even lower for resonant interaction. This phenomenon has already been observed indirectly in experiments [1, 2]. Induced magnetizing current due to the magnetic force is shown to originate from a modified dielectric response, which may be useful in future magneto-optic devices, solar energy harvesting, and studying the ultrafast dynamics in doped dielectrics.

  20. Graphene Field Effect Transistor for Radiation Detection

    Science.gov (United States)

    Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

    2016-01-01

    The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

  1. Medical management of three workers following a radiation exposure incident

    International Nuclear Information System (INIS)

    House, R.A.; Sax, S.E.; Rumack, E.R.; Holness, D.L.

    1992-01-01

    The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms

  2. Medical management of three workers following a radiation exposure incident

    Energy Technology Data Exchange (ETDEWEB)

    House, R.A.; Sax, S.E.; Rumack, E.R.; Holness, D.L. (Department of Occupational and Environmental Health, St. Michael' s Hospital, Toronto, Ontario (Canada))

    1992-01-01

    The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms.

  3. Learning from radiation incidents: the new OTHEA website

    International Nuclear Information System (INIS)

    Shaw, P V; Ely, S Y; Croueail, P; Bataille, C

    2010-01-01

    OTHEA is the name of a new website (www.othea.net), created by the Health Protection Agency (UK) and the Centre d'etude sur l'evaluation de la protection dans le domaine nucleaire (CEPN, France), and supported by several other stakeholders including national societies and associations. The website is bi-lingual (French and English) and the purpose is to share the lessons learnt from radiological incidents that have occurred in the industrial, medical, research and teaching, and other non-nuclear sectors. OTHEA contains a collection of incident reports, categorised according to the sector and the type of application, and a search facility. The reports can be freely downloaded and printed, for example for use in radiation protection training activities. To encourage dissemination, the incident reports have been made anonymous, i.e. any information that could identify a particular individual, organisation or site has been removed. Each report contains a brief summary of the incident, the radiological consequences, and the lessons learnt. The aim is not to capture every single incident, but to provide a range of reports selected according to the value of the lessons learnt. For OTHEA to be a long-term success, it needs to be sustained with new reports. Therefore users are encouraged to submit incident reports that can be considered for inclusion in OTHEA. This note summarises the background to OTHEA, and provides a description of the operating features and content at its launch in summer 2010. (note)

  4. Gravitational radiation resistance, radiation damping and field fluctuations

    International Nuclear Information System (INIS)

    Schaefer, G.

    1981-01-01

    Application is made of two different generalised fluctuation-dissipation theorems and their derivations to the calculation of the gravitational quadrupole radiation resistance using the radiation-reaction force given by Misner, Thorne and Wheeler (Gravitation (San Francisco: Freeman) ch 36,37 (1973)) and the usual tidal force on one hand and the tidal force and the free gravitational radiation field on the other hand. The quantum-mechanical version (including thermal generalisations) of the well known classical quadrupole radiation damping formula is obtained as a function of the radiation resistance. (author)

  5. Scattering by an electromagnetic radiation field

    OpenAIRE

    Bini, Donato; Geralico, Andrea

    2014-01-01

    Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term {\\it \\`a la} Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle's rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the elect...

  6. Magnetic field sensor for isotropically sensing an incident magnetic field in a sensor plane

    Science.gov (United States)

    Pant, Bharat B. (Inventor); Wan, Hong (Inventor)

    2001-01-01

    A magnetic field sensor that isotropically senses an incident magnetic field. This is preferably accomplished by providing a magnetic field sensor device that has one or more circular shaped magnetoresistive sensor elements for sensing the incident magnetic field. The magnetoresistive material used is preferably isotropic, and may be a CMR material or some form of a GMR material. Because the sensor elements are circular in shape, shape anisotropy is eliminated. Thus, the resulting magnetic field sensor device provides an output that is relatively independent of the direction of the incident magnetic field in the sensor plane.

  7. Wireless Phones Electromagnetic Field Radiation Exposure Assessment

    OpenAIRE

    A. D. Usman; W. F.W. Ahmad; M. Z.A.A. Kadir; M. Mokhtar

    2009-01-01

    Problem statement: Inadequate knowledge of electromagnetic field emitted by mobile phones and increased usage at close proximity, created a lot of skepticism and speculations among end users on its safety or otherwise. Approach: In this study, near field electromagnetic field radiation measurements were conducted on different brand of mobile phones in active mode using a tri-axis isotropic probe and electric field meter. Results: The highest electromagnetic field exposure was recorded when th...

  8. Graphene Field Effect Transistors for Radiation Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This is propose to develop Graphene Field Effect Transistor based Radiation Sensors (GFET-RS) for NASA Manned Spaceflight Missions anticipated in next several...

  9. Scattering by an electromagnetic radiation field

    Science.gov (United States)

    Bini, D.; Geralico, A.

    2012-02-01

    Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term à la Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle’s rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the electromagnetic wave, i.e., scalar (spin 0), massless spin (1)/(2) and electromagnetic (spin 1) fields, is studied too.

  10. Electromagnetic radiation field of an electron avalanche

    Science.gov (United States)

    Cooray, Vernon; Cooray, Gerald

    2012-11-01

    Electron avalanches are the main constituent of electrical discharges in the atmosphere. However, the electromagnetic radiation field generated by a single electron avalanche growing in different field configurations has not yet been evaluated in the literature. In this paper, the electromagnetic radiation fields created by electron avalanches were evaluated for electric fields in pointed, co-axial and spherical geometries. The results show that the radiation field has a duration of approximately 1-2 ns, with a rise time in the range of 0.25 ns. The wave-shape takes the form of an initial peak followed by an overshoot in the opposite direction. The electromagnetic spectrum generated by the avalanches has a peak around 109 Hz.

  11. 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

  12. Influence of radiation and non-radiation factors on pancreatic cancer incidence among Mayak PA workers

    Energy Technology Data Exchange (ETDEWEB)

    Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D. [Southern Ural Biophysics Institute (SUBI), Ozyorsk (Russian Federation); Syrchikov, V.A.; Grigoryeva, E.S. [Mayak Production Association (Mayak PA), Ozyorsk (Russian Federation)

    2006-07-01

    The finding of this nested case-control study suggests that high levels of 239 Pu incorporation (239 Pu body burden > 3.7), alcohol abuse and smoking were associated with increasing the risk of pancreatic cancer among Mayak PA workers chronically exposed to ionizing radiation. The contribution of non radiation factors (alcohol abuse and smoking) to pancreatic tumor incidence is greater (AR=51%) than 239 Pu incorporation kBq; AR = 7%). No significant effect of external gamma rays ({<=} 6.8 Gy), prior exposure to chemical agents, or chronic digestive diseases was found on the incidence of pancreatic tumor. Evaluation of the absorbed alpha-radiation pancreatic dose will permit to make more exact the 239 Pu risk estimation in the further extended study.

  13. Influence of radiation and non-radiation factors on pancreatic cancer incidence among Mayak PA workers

    International Nuclear Information System (INIS)

    Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D.; Syrchikov, V.A.; Grigoryeva, E.S.

    2006-01-01

    The finding of this nested case-control study suggests that high levels of 239 Pu incorporation (239 Pu body burden > 3.7), alcohol abuse and smoking were associated with increasing the risk of pancreatic cancer among Mayak PA workers chronically exposed to ionizing radiation. The contribution of non radiation factors (alcohol abuse and smoking) to pancreatic tumor incidence is greater (AR=51%) than 239 Pu incorporation kBq; AR = 7%). No significant effect of external gamma rays (≤ 6.8 Gy), prior exposure to chemical agents, or chronic digestive diseases was found on the incidence of pancreatic tumor. Evaluation of the absorbed alpha-radiation pancreatic dose will permit to make more exact the 239 Pu risk estimation in the further extended study

  14. Measurement of incident sound power using near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2009-01-01

    ; and it has always been regarded as impossible to measure the sound power that is incident on a wall directly. This paper examines a new method of determining this quantity from sound pressure measurements at positions on the wall using ‘statistically optimised near field acoustic holography’ (SONAH...

  15. Lessons Learnt from Past Incidents and Accidents in Radiation Oncology.

    Science.gov (United States)

    Knöös, T

    2017-09-01

    The purpose of this report is to review and compile what have been and can be learnt from incidents and accidents in radiation oncology, especially in external beam and brachytherapy. Some major accidents from the last 20 years will be discussed. The relationship between major events and minor or so-called near misses is mentioned, leading to the next topic of exploring the knowledge hidden among them. The main lessons learnt from the discussion here and elsewhere are that a well-functioning and safe radiotherapy department should help staff to work with awareness and alertness and that documentation and procedures should be in place and known by everyone. It also requires that trained and educated staff with the required competences are in place and, finally, functions and responsibilities are defined and well known. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  16. Using mortality data to estimate radiation effects on breast cancer incidence

    International Nuclear Information System (INIS)

    Hoel, D.G.; Dinse, G.E.

    1990-01-01

    In this paper we combine Japanese data on radiation exposure and cancer mortality with U.S. data on cancer incidence and lethality to estimate the effects of ionizing radiation on cancer incidence. The analysis is based on the mathematical relationship between the mortality rate and the incidence and lethality rates, as well as on statistical models that relate Japanese incidence rates to U.S. incidence rates and radiation risk factors. Our approach assumes that the risk of death from causes other than the cancer does not depend on whether or not the cancer is present, and among individuals with the cancer, the risk of death attributable to the cancer is the same in Japan and the U.S. and is not affected by radiation exposure. In particular, we focus on the incidence of breast cancer in Japanese women and how this incidence is affected by radiation risk factors. The analysis uses Japanese exposure and mortality data from the Radiation Effects Research Foundation study of atomic bomb survivors and U.S. incidence and lethality data from the Surveillance, Epidemiology, and End Results Registry. Even without Japanese incidence data, we obtain reasonable estimates of the incidence of breast cancer in unexposed Japanese women and identify the radiation risk factors that affect this incidence. Our analysis demonstrates that the age at exposure is an important risk factor, but that the incidence of breast cancer is not affected by the city of residence (Nagasaki versus Hiroshima) or the time since exposure

  17. Fiber optics in high dose radiation fields

    International Nuclear Information System (INIS)

    Partin, J.K.

    1985-01-01

    A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

  18. A solution algorithm for calculating photon radiation fields with the aid of the Monte Carlo method

    International Nuclear Information System (INIS)

    Zappe, D.

    1978-04-01

    The MCTEST program and its subroutines for the solution of the Boltzmann transport equation is presented. The program renders possible to calculate photon radiation fields of point or plane gamma sources. After changing two subroutines the calculation can also be carried out for the case of directed incidence of radiation on plane shields of iron or concrete. (author)

  19. An Evaluation of Departmental Radiation Oncology Incident Reports: Anticipating a National Reporting System

    International Nuclear Information System (INIS)

    Terezakis, Stephanie A.; Harris, Kendra M.; Ford, Eric; Michalski, Jeff; DeWeese, Theodore; Santanam, Lakshmi; Mutic, Sasa; Gay, Hiram

    2013-01-01

    Purpose: Systems to ensure patient safety are of critical importance. The electronic incident reporting systems (IRS) of 2 large academic radiation oncology departments were evaluated for events that may be suitable for submission to a national reporting system (NRS). Methods and Materials: All events recorded in the combined IRS were evaluated from 2007 through 2010. Incidents were graded for potential severity using the validated French Nuclear Safety Authority (ASN) 5-point scale. These incidents were categorized into 7 groups: (1) human error, (2) software error, (3) hardware error, (4) error in communication between 2 humans, (5) error at the human-software interface, (6) error at the software-hardware interface, and (7) error at the human-hardware interface. Results: Between the 2 systems, 4407 incidents were reported. Of these events, 1507 (34%) were considered to have the potential for clinical consequences. Of these 1507 events, 149 (10%) were rated as having a potential severity of ≥2. Of these 149 events, the committee determined that 79 (53%) of these events would be submittable to a NRS of which the majority was related to human error or to the human-software interface. Conclusions: A significant number of incidents were identified in this analysis. The majority of events in this study were related to human error and to the human-software interface, further supporting the need for a NRS to facilitate field-wide learning and system improvement

  20. An Evaluation of Departmental Radiation Oncology Incident Reports: Anticipating a National Reporting System

    Energy Technology Data Exchange (ETDEWEB)

    Terezakis, Stephanie A., E-mail: stereza1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Harris, Kendra M. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Ford, Eric [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); DeWeese, Theodore [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Santanam, Lakshmi; Mutic, Sasa; Gay, Hiram [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-03-15

    Purpose: Systems to ensure patient safety are of critical importance. The electronic incident reporting systems (IRS) of 2 large academic radiation oncology departments were evaluated for events that may be suitable for submission to a national reporting system (NRS). Methods and Materials: All events recorded in the combined IRS were evaluated from 2007 through 2010. Incidents were graded for potential severity using the validated French Nuclear Safety Authority (ASN) 5-point scale. These incidents were categorized into 7 groups: (1) human error, (2) software error, (3) hardware error, (4) error in communication between 2 humans, (5) error at the human-software interface, (6) error at the software-hardware interface, and (7) error at the human-hardware interface. Results: Between the 2 systems, 4407 incidents were reported. Of these events, 1507 (34%) were considered to have the potential for clinical consequences. Of these 1507 events, 149 (10%) were rated as having a potential severity of ≥2. Of these 149 events, the committee determined that 79 (53%) of these events would be submittable to a NRS of which the majority was related to human error or to the human-software interface. Conclusions: A significant number of incidents were identified in this analysis. The majority of events in this study were related to human error and to the human-software interface, further supporting the need for a NRS to facilitate field-wide learning and system improvement.

  1. Production of X-ray transition radiation with relativistic electrons propagating at grazing incidence

    CERN Document Server

    Couillaud, C

    2002-01-01

    This paper is concerned with the production of X-ray transition radiation when a relativistic electron crosses the interface between two media of different permittivities at the grazing incidence. The production yields are derived analytically when a thick interface is considered and are compared with those obtained when the electron crosses the interface at normal incidence. The production of X-ray photons having an energy between two photoabsorption edges or close to a photoabsorption edge is also investigated. The main features of the transition radiation produced are then exhibited and it is shown that the intensity can be increased by many orders of magnitude. We also show that, at grazing incidence, the backward transition radiation has an intensity close to the forward emission one, contrary to the normal incidence case. The production of quasi-monochromatic radiation is also presented. Finally, the production of X-ray transition radiation using a multilayer radiator is considered and compared in both ...

  2. Radiation Effects on Current Field Programmable Technologies

    Science.gov (United States)

    Katz, R.; LaBel, K.; Wang, J. J.; Cronquist, B.; Koga, R.; Penzin, S.; Swift, G.

    1997-01-01

    Manufacturers of field programmable gate arrays (FPGAS) take different technological and architectural approaches that directly affect radiation performance. Similar y technological and architectural features are used in related technologies such as programmable substrates and quick-turn application specific integrated circuits (ASICs). After analyzing current technologies and architectures and their radiation-effects implications, this paper includes extensive test data quantifying various devices total dose and single event susceptibilities, including performance degradation effects and temporary or permanent re-configuration faults. Test results will concentrate on recent technologies being used in space flight electronic systems and those being developed for use in the near term. This paper will provide the first extensive study of various configuration memories used in programmable devices. Radiation performance limits and their impacts will be discussed for each design. In addition, the interplay between device scaling, process, bias voltage, design, and architecture will be explored. Lastly, areas of ongoing research will be discussed.

  3. Recent developments in radiation field control technology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, C.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-03-01

    The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses.

  4. Recent developments in radiation field control technology

    International Nuclear Information System (INIS)

    Wood, C.J.

    1995-01-01

    The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses

  5. On quantization of the electromagnetic field in radiation gauge

    International Nuclear Information System (INIS)

    Burzynski, A.

    1982-01-01

    This paper contains a detailed description of quantization of the electromagnetic field (in radiation gauge) and quantization of some basic physical variables connected with radiation field as energy, momentum and spin. The dynamics of the free quantum radiation field and the field interacting with external classical sources is described. The canonical formalism is not used explicity. (author)

  6. Haemopoietic cell renewal in radiation fields

    Science.gov (United States)

    Fliedner, T. M.; Nothdurft, W.; Tibken, B.; Hofer, E.; Weiss, M.; Kindler, H.

    1994-10-01

    Space flight activities are inevitably associated with a chronic exposure of astronauts to a complex mixture of ionising radiation. Although no acute radiation consequences are to be expected as a rule, the possibility of Solar Particle Events (SPE) associated with relatively high doses of radiation (1 or more Gray) cannot be excluded. It is the responsibility of physicians in charge of the health of astronauts to evaluate before, during and after space flight activities the functional status of haemopoietic cell renewal. Chronic low level exposure of dogs indicate that daily gamma-exposure doses below about 2 cGy are tolerated for several years as far as blood cell concentrations are concerned. However, the stem cell pool may be severely affected. The maintenance of sufficient blood cell counts is possible only through increased cell production to compensate for the radiation inflicted excess cell loss. This behaviour of haemopoietic cell renewal during chronic low level exposure can be simulated by bioengineering models of granulocytopoiesis. It is possible to define a ``turbulence region'' for cell loss rates, below which an prolonged adaptation to increased radiation fields can be expected to be tolerated. On the basis of these experimental results, it is recommended to develop new biological indicators to monitor haemopoietic cell renewal at the level of the stem cell pool using blood stem cells in addition to the determination of cytokine concentrations in the serum (and other novel approaches). To prepare for unexpected haemopoietic effects during prolonged space missions, research should be increased to modify the radiation sensitivity of haemopoietic stem cells (for instance by the application of certain regulatory molecules). In addition, a ``blood stem cell bank'' might be established for the autologous storage of stem cells and for use in space activities keeping them in a radiation protected container.

  7. Particles in spherical electromagnetic radiation fields

    International Nuclear Information System (INIS)

    Mitter, H.; Thaller, B.

    1984-03-01

    If the time-dependence of a Hamiltonian can be compensated by an appropriate symmetry transformation, the corresponding quantum mechanical problem can be reduced to an effectively stationary one. With this result we investigate the behavior of nonrelativistic particles in a spherical radiation field produced by a rotating source. Then the symmetry transformation corresponds to a rotation. We calculate the transition probabilities in Born approximation. The extension to problems involving an additional Coulomb potential is briefly discussed. (Author)

  8. Radiation damage of polymers in ultrasonic fields

    International Nuclear Information System (INIS)

    Anbalagan, Poornnima

    2008-01-01

    Radiation damage has always been a topic of great interest in various fields of sciences. In this work, an attempt is made to probe into the effect of subthreshold ultrasonic waves on the radiation damage created by irradiation of deuterons in polymer samples wherein the polymer samples act as model systems. Two equal volumes of radiation damage were produced in a single polymer sample wherein a standing wave of ultrasound was introduced into one. Three polymers namely, Polycarbonate, Polymethylmethacrylate and Polyvinyl chloride were used in this work. Four independent techniques were used to analyze the irradiated samples and visualize the radiation damage. Interferometric measurements give a measure of the refractive index modulation in the irradiated sample. Polymers, being transparent, do not absorb in the visible region of the electromagnetic spectrum. UV-Vis absorption spectroscopy shows absorption peaks in the visible region in irradiated polymer samples. Ion irradiation causes coloration of polymers. The light microscope is used to measure the absorption of white light by the irradiated polymers. Positron annihilation spectroscopy is used to obtain a measure of the open volume created by irradiation in polymers. A comparison between the irradiated region and the region exposed to ultrasonic waves simultaneously with irradiation in a polymer sample shows the polymer specific influence of the ultrasonic standing wave. (orig.)

  9. Radiation damage of polymers in ultrasonic fields

    Energy Technology Data Exchange (ETDEWEB)

    Anbalagan, Poornnima

    2008-07-01

    Radiation damage has always been a topic of great interest in various fields of sciences. In this work, an attempt is made to probe into the effect of subthreshold ultrasonic waves on the radiation damage created by irradiation of deuterons in polymer samples wherein the polymer samples act as model systems. Two equal volumes of radiation damage were produced in a single polymer sample wherein a standing wave of ultrasound was introduced into one. Three polymers namely, Polycarbonate, Polymethylmethacrylate and Polyvinyl chloride were used in this work. Four independent techniques were used to analyze the irradiated samples and visualize the radiation damage. Interferometric measurements give a measure of the refractive index modulation in the irradiated sample. Polymers, being transparent, do not absorb in the visible region of the electromagnetic spectrum. UV-Vis absorption spectroscopy shows absorption peaks in the visible region in irradiated polymer samples. Ion irradiation causes coloration of polymers. The light microscope is used to measure the absorption of white light by the irradiated polymers. Positron annihilation spectroscopy is used to obtain a measure of the open volume created by irradiation in polymers. A comparison between the irradiated region and the region exposed to ultrasonic waves simultaneously with irradiation in a polymer sample shows the polymer specific influence of the ultrasonic standing wave. (orig.)

  10. Atmospheric impacts on climatic variability of surface incident solar radiation

    Directory of Open Access Journals (Sweden)

    K. C. Wang

    2012-10-01

    Full Text Available The Earth's climate is driven by surface incident solar radiation (Rs. Direct measurements have shown that Rs has undergone significant decadal variations. However, a large fraction of the global land surface is not covered by these observations. Satellite-derived Rs has a good global coverage but is of low accuracy in its depiction of decadal variability. This paper shows that daily to decadal variations of Rs, from both aerosols and cloud properties, can be accurately estimated using globally available measurements of Sunshine Duration (SunDu. In particular, SunDu shows that since the late 1980's Rs has brightened over Europe due to decreases in aerosols but dimmed over China due to their increases. We found that variation of cloud cover determines Rs at a monthly scale but that aerosols determine the variability of Rs at a decadal time scale, in particular, over Europe and China. Because of its global availability and long-term history, SunDu can provide an accurate and continuous proxy record of Rs, filling in values for the blank areas that are not covered by direct measurements. Compared to its direct measurement, Rs from SunDu appears to be less sensitive to instrument replacement and calibration, and shows that the widely reported sharp increase in Rs during the early 1990s in China was a result of instrument replacement. By merging direct measurements collected by Global Energy Budget Archive with those derived from SunDu, we obtained a good coverage of Rs over the Northern Hemisphere. From this data, the average increase of Rs from 1982 to 2008 is estimated to be 0.87 W m−2 per decade.

  11. Sci-Fri AM: Quality, Safety, and Professional Issues 06: An Evaluation of Incident Reporting and Learning using the Canadian National System for Incident Reporting – Radiation Treatment

    International Nuclear Information System (INIS)

    Montgomery, Logan; Kildea, John

    2016-01-01

    We report on the development and clinical deployment of an in-house incident reporting and learning system that implements the taxonomy of the Canadian National System for Incident Reporting – Radiation Treatment (NSIR-RT). In producing our new system, we aimed to: Analyze actual incidents, as well as potentially dangerous latent conditions. Produce recommendations on the NSIR-RT taxonomy. Incorporate features to divide reporting responsibility among clinical staff and expedite incident categorization within the NSIR-RT framework. Share anonymized incident data with the national database. Our multistep incident reporting workflow is focused around an initial report and a detailed follow-up investigation. An investigator, chosen at the time of reporting, is tasked with performing the investigation. The investigation feature is connected to our electronic medical records database to allow automatic field population and quick reference of patient and treatment information. Additional features include a robust visualization suite, as well as the ability to flag incidents for discussion at monthly Risk Management meetings and task ameliorating actions to staff. Our system was deployed into clinical use in January 2016. Over the first three months of use, 45 valid incidents were reported; 31 of which were reported as actual incidents as opposed to near-misses or reportable circumstances. However, we suspect there is ambiguity within our centre in determining the appropriate event type, which may be arising from the taxonomy itself. Preliminary trending analysis aided in revealing workflow issues pertaining to storage of treatment accessories and treatment planning delays. Extensive analysis will be undertaken as more data are accrued.

  12. Momentum of the Pure Radiation Field

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2007-01-01

    Full Text Available The local momentum equation of the pure radiation field is considered in terms of an earlier elaborated and revised electromagnetic theory. In this equation the contribution from the volume force is found to vanish in rectangular geometry, and to become nonzero but negligible in cylindrical geometry. Consequently the radiated momentum is due to the Poynting vector only, as in conventional electrodynamics. It results in physically relevant properties of a photon model having an angular momentum (spin. The Poynting vector concept is further compared to the quantized momentum concept for a free particle, as represented by a spatial gradient operator acting on the wave function. However, this latter otherwise successful concept leads to difficulties in the physical interpretation of known and expected photon properties such as the spin, the negligible loss of transverse momentum across a bounding surface, and the Lorentz invariance.

  13. Simulation of Solar Radiation Incident on Horizontal and Inclined Surfaces

    Directory of Open Access Journals (Sweden)

    MA Basunia

    2012-12-01

    Full Text Available A computer model was developed to simulate the hourly, daily and monthly average of daily solar radiation on horizontal and inclined surfaces. The measured hourly and daily solar radiation was compared with simulated radiation, and favourable agreement was observed for the measured and predicted values on clear days. The measured and simulated monthly averages of total (diffuse and beam daily solar radiation were compared and a reasonable agreement was observed for a number of stations in Japan. The simulation showed that during the rice harvesting season, September to October, there is a daily average of 14.7 MJ/m2 of solar irradiation on a horizontal surface in Matsuyama, Japan. There is a similar amount of solar radiation on a horizontal surface during the major rice harvesting season, November to December, in Bangladesh. This radiation can be effectively utilized for drying rough rice and other farm crops.

  14. Virtual radiation fields for ALARA determination

    Energy Technology Data Exchange (ETDEWEB)

    Knight, T.W.

    1995-12-31

    As computing power has increased, so too has the ability to model and simulate complex systems and processes. In addition, virtual reality technology has made it possible to visualize and understand many complex scientific and engineering problems. For this reason, a virtual dosimetry program called Virtual Radiation Fields (VRF) is developed to model radiation dose rate and cumulative dose to a receptor operating in a virtual radiation environment. With the design and testing of many facilities and products taking place in the virtual world, this program facilitates the concurrent consideration of radiological concerns during the design process. Three-dimensional (3D) graphical presentation of the radiation environment is made possible through the use of IGRIP, a graphical modeling program developed by Deneb Robotics, Inc. The VRF simulation program was designed to model and display a virtual dosimeter. As a demonstration of the program`s capability, the Hanford tank, C-106, was modeled to predict radiation doses to robotic equipment used to remove radioactive waste from the tank. To validate VRF dose predictions, comparison was made with reported values for tank C-106, which showed agreement to within 0.5%. Graphical information is presented regarding the 3D dose rate variation inside the tank. Cumulative dose predictions were made for the cleanup operations of tank C-106. A four-dimensional dose rate map generated by VRF was used to model the dose rate not only in 3D space but also as a function of the amount of waste remaining in the tank. This allowed VRF to predict dose rate at any stage in the waste removal process for an accurate simulation of the radiological conditions throughout the tank cleanup procedure.

  15. Virtual radiation fields for ALARA determination

    International Nuclear Information System (INIS)

    Knight, T.W.

    1995-01-01

    As computing power has increased, so too has the ability to model and simulate complex systems and processes. In addition, virtual reality technology has made it possible to visualize and understand many complex scientific and engineering problems. For this reason, a virtual dosimetry program called Virtual Radiation Fields (VRF) is developed to model radiation dose rate and cumulative dose to a receptor operating in a virtual radiation environment. With the design and testing of many facilities and products taking place in the virtual world, this program facilitates the concurrent consideration of radiological concerns during the design process. Three-dimensional (3D) graphical presentation of the radiation environment is made possible through the use of IGRIP, a graphical modeling program developed by Deneb Robotics, Inc. The VRF simulation program was designed to model and display a virtual dosimeter. As a demonstration of the program's capability, the Hanford tank, C-106, was modeled to predict radiation doses to robotic equipment used to remove radioactive waste from the tank. To validate VRF dose predictions, comparison was made with reported values for tank C-106, which showed agreement to within 0.5%. Graphical information is presented regarding the 3D dose rate variation inside the tank. Cumulative dose predictions were made for the cleanup operations of tank C-106. A four-dimensional dose rate map generated by VRF was used to model the dose rate not only in 3D space but also as a function of the amount of waste remaining in the tank. This allowed VRF to predict dose rate at any stage in the waste removal process for an accurate simulation of the radiological conditions throughout the tank cleanup procedure

  16. Observations of the diffuse UV radiation field

    Science.gov (United States)

    Murthy, Jayant; Henry, R. C.; Feldman, P. D.; Tennyson, P. D.

    1989-01-01

    Spectra are presented for the diffuse UV radiation field between 1250 to 3100 A from eight different regions of the sky, which were obtained with the Johns Hopkins UVX experiment. UVX flew aboard the Space Shuttle Columbia (STS-61C) in January 1986 as part of the Get-Away Special project. The experiment consisted of two 1/4 m Ebert-Fastie spectrometers, covering the spectral range 1250 to 1700 A at 17 A resolution and 1600 to 3100 A at 27 A resolution, respectively, with a field of view of 4 x .25 deg, sufficiently small to pick out regions of the sky with no stars in the line of sight. Values were found for the diffuse cosmic background ranging in intensity from 300 to 900 photons/sq cm/sec/sr/A. The cosmic background is spectrally flat from 1250 to 3100 A, within the uncertainties of each spectrometer. The zodiacal light begins to play a significant role in the diffuse radiation field above 2000 A, and its brightness was determined relative to the solar emission. Observed brightnesses of the zodiacal light in the UV remain almost constant with ecliptic latitude, unlike the declining visible brightnesses, possibly indicating that those (smaller) grains responsible for the UV scattering have a much more uniform distribution with distance from the ecliptic plane than do those grains responsible for the visible scattering.

  17. The Submicrosecond Structure of Lightning Radiation Fields

    Science.gov (United States)

    1983-01-01

    lighting Technology , NASA Conf. Pub. 2128 and x iA-RD-80-30, pp. 39-82, 1980. 11. C. E. Baum, E. L. Breen, F. L. Pitts, G. D. Sower, and M. E. Thomas, "The Measurement of Lightning Environmental Parameters Related to Interaction with Electronic Systems", IEEE Trans, on EMC, Vol. EMC-24, pp. 123-137, 1982. 12. CD. Weidman and E. P. Krider, "The Radiation Field Waveforms Produced by Intra- cloud Lightning Discharge Processes", J. Geo- phys. Res., Vol. 84, pp. 3159-3164, 1979. 13. W. Beasley, M. A. Uman, and P. L. Rustan, Jr.,

  18. Reference neutron radiations. Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2000-01-01

    ISO 8529 consists of the following parts, under the general title Reference neutron radiations: Part 1: Characteristics and methods of production; Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of response as a function of energy and angle of incidence. This Part 2. of ISO 8529 takes as its starting point the neutron sources described in ISO 8529-1. It specifies the procedures to be used for realizing the calibration conditions of radiation protection devices in neutron fields produced by these calibration sources, with particular emphasis on the corrections for extraneous effects (e.g., the neutrons scattered from the walls of the calibration room). In this part of ISO 8529, particular emphasis is placed on calibrations using radionuclide sources (clauses 4 to 6) due to their widespread application, with less details given on the use of accelerator and reactor sources (8.2 and 8.3). This part of ISO 8529 then leads to ISO 8529-3 which gives conversion coefficients and the general rules and procedures for calibration

  19. Spin and radiation in intense laser fields

    International Nuclear Information System (INIS)

    Walser, M.W.; Urbach, D.J.; Hatsagortsyan, K.Z.; Hu, S.X.; Keitel, C.H.

    2002-01-01

    The spin dynamics and its reaction on the particle motion are investigated for free and bound electrons in intense linearly polarized laser fields. Employing both classical and quantum treatments we analytically evaluate the spin oscillation of free electrons in intense laser fields and indicate the effect of spin-orbit coupling on the motion of the electron. In Mott scattering an estimation for the spin oscillation is derived. In intense laser ion dynamics spin signatures are studied in detail with emphasis on high-order harmonic generation in the tunneling regime. First- and second-order calculations in the ratio of electron velocity and the speed of light show spin signatures in the radiation spectrum and spin-orbit effects in the electron polarization

  20. Radiation effects in silicon and gallium arsenide solar cells using isotropic and normally incident radiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.

    1984-01-01

    Several types of silicon and gallium arsenide solar cells were irradiated with protons with energies between 50 keV and 10 MeV at both normal and isotropic incidence. Damage coefficients for maximum power relative to 10 MeV were derived for these cells for both cases of omni-directional and normal incidence. The damage coefficients for the silicon cells were found to be somewhat lower than those quoted in the Solar Cell Radiation Handbook. These values were used to compute omni-directional damage coefficients suitable for solar cells protected by coverglasses of practical thickness, which in turn were used to compute solar cell degradation in two proton-dominated orbits. In spite of the difference in the low energy proton damage coefficients, the difference between the handbook prediction and the prediction using the newly derived values was negligible. Damage coefficients for GaAs solar cells for short circuit current, open circuit voltage, and maximum power were also computed relative to 10 MeV protons. They were used to predict cell degradation in the same two orbits and in a 5600 nmi orbit. Results show the performance of the GaAs solar cells in these orbits to be superior to that of the Si cells.

  1. The Equivalent Uniform Dose as a severity metric for radiation treatment incidents

    International Nuclear Information System (INIS)

    Dunscombe, Peter B.; Iftody, Sandra; Ploquin, Nicolas; Ekaette, Edidiong U.; Lee, Robert C.

    2007-01-01

    In allocating resources within a risk management program, ideally we would like to know both the probabilities and consequences of potential incidents. We simulate, on a treatment planning computer, several commonly reported incidents in radiation treatment and explore their consequences for the EUDs of targets and organs at risk

  2. Radiation-reaction electromagnetic fields in metasurfaces, a complete description of their optical properties

    OpenAIRE

    Merano, Michele

    2018-01-01

    This paper derives the macroscopic electric and magnetic fields and the surface susceptibilities for a metasurface, starting from the microscopic scatterer distribution. It is assumed that these scatterers behave as electric and magnetic dipoles under the influence of the incident radiation. Interestingly not only the retarded electromagnetic fields from oscillating dipoles are relevant to pass from the microscopic to the macroscopic representation, but the advanced fields must be considered ...

  3. A method for characterizing photon radiation fields

    International Nuclear Information System (INIS)

    Whicker, J.J.; Hsu, H.H.; Hsieh, F.H.; Borak, T.B.

    1999-01-01

    Uncertainty in dosimetric and exposure rate measurements can increase in areas where multi-directional and low-energy photons (< 100 keV) exist because of variations in energy and angular measurement response. Also, accurate measurement of external exposures in spatially non-uniform fields may require multiple dosimetry. Therefore, knowledge of the photon fields in the workplace is required for full understanding of the accuracy of dosimeters and instruments, and for determining the need for multiple dosimeters. This project was designed to develop methods to characterize photon radiation fields in the workplace, and to test the methods in a plutonium facility. The photon field at selected work locations was characterized using TLDs and a collimated NaI(Tl) detector from which spatial variations in photon energy distributions were calculated from measured spectra. Laboratory results showed the accuracy and utility of the method. Field measurement results combined with observed work patterns suggested the following: (1) workers are exposed from all directions, but not isotropically, (2) photon energy distributions were directionally dependent, (3) stuffing nearby gloves into the glovebox reduced exposure rates significantly, (4) dosimeter placement on the front of the chest provided for a reasonable estimate of the average dose equivalent to workers' torsos, (5) justifiable conclusions regarding the need for multiple dosimetry can be made using this quantitative method, and (6) measurements of the exposure rates with ionization chambers pointed with open beta windows toward the glovebox provided the highest measured rates, although absolute accuracy of the field measurements still needs to be assessed

  4. Temperature field for radiative tomato peeling

    International Nuclear Information System (INIS)

    Cuccurullo, G; Giordano, L

    2017-01-01

    Nowadays peeling of tomatoes is performed by using steam or lye, which are expensive and polluting techniques, thus sustainable alternatives are searched for dry peeling and, among that, radiative heating seems to be a fairly promising method. This paper aims to speed up the prediction of surface temperatures useful for realizing dry-peeling, thus a 1D-analytical model for the unsteady temperature field in a rotating tomato exposed to a radiative heating source is presented. Since only short times are of interest for the problem at hand, the model involves a semi-infinite slab cooled by convective heat transfer while heated by a pulsating heat source. The model being linear, the solution is derived following the Laplace Transform method. A 3D finite element model of the rotating tomato is introduced as well in order to validate the analytical solution. A satisfactory agreement is attained. Therefore, two different ways to predict the onset of the peeling conditions are available which can be of help for proper design of peeling plants. Particular attention is paid to study surface temperature uniformity, that being a critical parameter for realizing an easy tomato peeling. (paper)

  5. Are passive smoking, air pollution and obesity a greater mortality risk than major radiation incidents?

    Directory of Open Access Journals (Sweden)

    Smith Jim T

    2007-04-01

    Full Text Available Abstract Background Following a nuclear incident, the communication and perception of radiation risk becomes a (perhaps the major public health issue. In response to such incidents it is therefore crucial to communicate radiation health risks in the context of other more common environmental and lifestyle risk factors. This study compares the risk of mortality from past radiation exposures (to people who survived the Hiroshima and Nagasaki atomic bombs and those exposed after the Chernobyl accident with risks arising from air pollution, obesity and passive and active smoking. Methods A comparative assessment of mortality risks from ionising radiation was carried out by estimating radiation risks for realistic exposure scenarios and assessing those risks in comparison with risks from air pollution, obesity and passive and active smoking. Results The mortality risk to populations exposed to radiation from the Chernobyl accident may be no higher than that for other more common risk factors such as air pollution or passive smoking. Radiation exposures experienced by the most exposed group of survivors of Hiroshima and Nagasaki led to an average loss of life expectancy significantly lower than that caused by severe obesity or active smoking. Conclusion Population-averaged risks from exposures following major radiation incidents are clearly significant, but may be no greater than those from other much more common environmental and lifestyle factors. This comparative analysis, whilst highlighting inevitable uncertainties in risk quantification and comparison, helps place the potential consequences of radiation exposures in the context of other public health risks.

  6. Calorie restriction reduces the incidence of radiation-induced myeloid leukemia and spontaneous tumor

    International Nuclear Information System (INIS)

    Yoshida, Kazuko

    1999-01-01

    The host-defense mechanisms against cancers are known to be modulated by changing the environmental factor(s). The spontaneous incidence of myeloid leukemia is about 1% in C3H/He mice, and the incidence increases up to 23.3% when a single dose of radiation, 3 Gy X-ray, is exposed to a whole-body. Since calorie restriction was known to reduce the incidence of spontaneous tumors, a question as to whether such radiation induced-increase of myeloid leukemia would be also decreased by calorie restriction, was aimed to answer to elucidate possible mechanism of radiation-induced myeloid leukemia. By the calorie restriction, the incidence of myeloid leukemia was significantly decreased; it was reduced to 7.9% and 10.7% when restriction was started before (6 weeks old) and after (10 weeks old) irradiation, respectively. In addition, the latent period of the myeloid leukemia in the groups for calorie restriction was significantly extended at a greater extent as compared with the control diet groups. Number of hematopoietic stem cells, the possible target cells for radiation-induced leukemias, in the groups for the calorie restriction demonstrated a significant decrease, especially in the spleen, as compared with that in the control, when the evaluation was made at the time of radiation exposure. Then, we examined whether the decreased number of target cells at the time of exposure is caused by the reduction of radiation-induced myeloid leukemia with caloric restriction. The third restricted groups were fed 65 kcal diet (restricted diet) for the first 4 weeks i.e. from 6 weeks to 10 weeks old, then, the mice were fed with control diet after radiation. The incidence of myeloid leukemia in this group was slightly decreased but did not show statistically significance. Therefore, the caloric restriction seems to be more effective in the promotion stage than the initiation stage on radiation-induced leukemogenesis. It is well known that C3H/He mice develop hepatoma spontaneously

  7. Calorie restriction reduces the incidence of radiation-induced myeloid leukemia and spontaneous tumor

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Kazuko [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    The host-defense mechanisms against cancers are known to be modulated by changing the environmental factor(s). The spontaneous incidence of myeloid leukemia is about 1% in C3H/He mice, and the incidence increases up to 23.3% when a single dose of radiation, 3 Gy X-ray, is exposed to a whole-body. Since calorie restriction was known to reduce the incidence of spontaneous tumors, a question as to whether such radiation induced-increase of myeloid leukemia would be also decreased by calorie restriction, was aimed to answer to elucidate possible mechanism of radiation-induced myeloid leukemia. By the calorie restriction, the incidence of myeloid leukemia was significantly decreased; it was reduced to 7.9% and 10.7% when restriction was started before (6 weeks old) and after (10 weeks old) irradiation, respectively. In addition, the latent period of the myeloid leukemia in the groups for calorie restriction was significantly extended at a greater extent as compared with the control diet groups. Number of hematopoietic stem cells, the possible target cells for radiation-induced leukemias, in the groups for the calorie restriction demonstrated a significant decrease, especially in the spleen, as compared with that in the control, when the evaluation was made at the time of radiation exposure. Then, we examined whether the decreased number of target cells at the time of exposure is caused by the reduction of radiation-induced myeloid leukemia with caloric restriction. The third restricted groups were fed 65 kcal diet (restricted diet) for the first 4 weeks i.e. from 6 weeks to 10 weeks old, then, the mice were fed with control diet after radiation. The incidence of myeloid leukemia in this group was slightly decreased but did not show statistically significance. Therefore, the caloric restriction seems to be more effective in the promotion stage than the initiation stage on radiation-induced leukemogenesis. It is well known that C3H/He mice develop hepatoma spontaneously

  8. Radiation doses from global fallout and cancer incidence among reindeer herders and Sami in Northern Finland.

    Science.gov (United States)

    Kurttio, Päivi; Pukkala, Eero; Ilus, Taina; Rahola, Tua; Auvinen, Anssi

    2010-11-01

    People in the Arctic regions are one of the most heavily exposed population from the global fallout from atmospheric atomic bomb testing of the 1950s and 1960s due to their diet rich in reindeer meat in which radionuclides accumulate. We estimated the effect of the radioactive fallout and ethnicity on the cancer incidence in Northern Finland. A cohort of the Arctic population in Finland (n=34,653) was identified through the Population Register Centre with grouping by reindeer herding status, ethnicity and radiation exposure. Annual average radiation doses, based on (137)Cs whole-body measurements, were assigned by birth year, gender and reindeer herder status. Incident cancer cases of a priori selected cancer types in the study cohort during 1971-2005 were identified from the Finnish Cancer Registry. A total of 2630 cancer cases were observed versus 3073 expected on the basis of incidence rates in Northern Finland (standardised incidence ratio (SIR) was 0.86 with 95% CI of 0.82 to 0.89). For the indigenous Sami people SIR was even lower, 0.60 (95% CI 0.50 to 0.71). None of the cancer sites was significantly associated with the lifetime cumulative radiation dose. The SIR for the combined group of radiation-related cancer sites increased with the cumulative radiation dose received before 15 years of age (p=0.004). Despite the low overall cancer incidence in the Arctic population and ethnic Sami people in Finland and lack of association between the lifetime cumulative radiation exposure from global radioactive fallout and cancer incidence, we found some indication of an increased cancer risk associated with radiation exposure received during childhood. Potential underestimation and misclassification of the radiation dose may affect the results and the findings should be interpreted with caution.

  9. Cutaneous microcirculation in preterm neonates: comparison between sidestream dark field (SDF) and incident dark field (IDF) imaging

    NARCIS (Netherlands)

    van Elteren, H. A.; Ince, C.; Tibboel, D.; Reiss, I. K. M.; de Jonge, R. C. J.

    2015-01-01

    Incident dark field imaging (IDF) is a new generation handheld microscope for bedside visualization and quantification of microcirculatory alterations. IDF is the technical successor of sidestream dark field imaging (SDF), currently the most used device for microcirculatory measurements. In

  10. Relationship of cancer incidence to terrestrial radiation and population density in Connecticut, 1935-1974

    International Nuclear Information System (INIS)

    Walter, S.D.; Meigs, J.W.; Heston, J.F.

    1986-01-01

    The relationship of cancer incidence to terrestrial radiation and population density was investigated. Cancer incidence was obtained using 40 years of age-standardized data from the Connecticut Tumor Registry, and environmental radiation was estimated using data from an airborne gamma radiation survey of the entire state. These variables were examined ecologically, using the 169 towns of the state as the analytic units in a weighted regression analysis. The study design involves a large population base in a state having relatively high terrestrial radiation exposure levels overall and reasonable variation in exposure between towns. For all cancer combined, only one of the eight sex-specific analyses by decade yielded a significant radiation regression coefficient, and this was negative. In the sex- and site-specific analyses, almost all the coefficients for radiation were not significantly different from zero. In contrast, significant positive relationships of cancer incidence with population density were found for all cancer, for cancer of the lung for both sexes, for stomach, colonic, and prostatic cancer for males, and for lymphomas, thyroid, breast, and ovarian cancer for females. Both the radiation and population density relationships were adjusted for socioeconomic status. Socioeconomic status was significantly negatively associated with stomach and lung cancer in males and with cervical cancer in females; it was also positively associated with lymphomas and breast cancer in females. A power calculation revealed that, despite the relatively large size of this study, there was only a small probability of detecting a radiation effect of the strength anticipated from previous estimates

  11. Vacuum radiation induced by time dependent electric field

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2017-04-01

    Full Text Available Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

  12. Vacuum radiation induced by time dependent electric field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo, E-mail: zhangbolfrc@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Zhang, Zhi-meng; Hong, Wei; He, Shu-Kai; Teng, Jian [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Gu, Yu-qiu, E-mail: yqgu@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China)

    2017-04-10

    Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED) will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

  13. Radiation, waves, fields. Causes and effects on environment and health

    International Nuclear Information System (INIS)

    Leitgeb, N.

    1990-01-01

    The book discusses static electricity, alternating electric fields, magnetostatic fields, alternating magnetic fields, electromagnetic radiation, optical and ionizing radiation and their hazards and health effects. Each chapter presents basic physical and biological concepts and describes the common radiation sources and their biological effects. Each chapter also contains hints for everyday behaviour as well as in-depth information an specific scientific approaches for assessing biological effects; the latter are addressed to all expert readers working in these fields. There is a special chapter on the problem of so-called 'terrestrial radiation'. (orig.) With 88 figs., 31 tabs [de

  14. Radiation environment impact assessment of field radionuclide migration test

    International Nuclear Information System (INIS)

    Guo Zede; Han Jingyin; Wang Zhiming; Han Bianlian; Jin Xiaojuan; Yan Yukui

    2000-01-01

    A field radionuclide migration test was carried out under natural and sprinkling conditions at CIRP's Field Test Site. Environment monitoring results indicated that the test did not cause any change of radiation environment quality in and around the test area. After test, contaminated soil in each test pits was retrieved and transported back in CIRP for other research work. All recovery rates of 60 Co, 134 Cs in each test pits is more than 99.99%. After recovery, residual 3 H in former natural test pits is kept in shallow soil and subjected to be evaporated into atmosphere; residual 3 H in other test pits after stopping sprinkling is kept in deep position of aerated zone and can not reach aqueous layer before fully decay. Since its short half life, 85 Sr had nearly fully decayed when the test was finished. Retrieving contaminated soil eliminates possibility of any incidents in future. It is concluded from the point of both total amount and concentrations, that residual radionuclides at the field test site can not cause any unacceptable effect on human and the environment

  15. Identifying Predictive Factors for Incident Reports in Patients Receiving Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Elnahal, Shereef M., E-mail: selnaha1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Blackford, Amanda [Department of Oncology Biostatistics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Smith, Koren; Souranis, Annette N.; Briner, Valerie; McNutt, Todd R.; DeWeese, Theodore L.; Wright, Jean L.; Terezakis, Stephanie A. [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2016-04-01

    Purpose: To describe radiation therapy cases during which voluntary incident reporting occurred; and identify patient- or treatment-specific factors that place patients at higher risk for incidents. Methods and Materials: We used our institution's incident learning system to build a database of patients with incident reports filed between January 2011 and December 2013. Patient- and treatment-specific data were reviewed for all patients with reported incidents, which were classified by step in the process and root cause. A control group of patients without events was generated for comparison. Summary statistics, likelihood ratios, and mixed-effect logistic regression models were used for group comparisons. Results: The incident and control groups comprised 794 and 499 patients, respectively. Common root causes included documentation errors (26.5%), communication (22.5%), technical treatment planning (37.5%), and technical treatment delivery (13.5%). Incidents were more frequently reported in minors (age <18 years) than in adult patients (37.7% vs 0.4%, P<.001). Patients with head and neck (16% vs 8%, P<.001) and breast (20% vs 15%, P=.03) primaries more frequently had incidents, whereas brain (18% vs 24%, P=.008) primaries were less frequent. Larger tumors (17% vs 10% had T4 lesions, P=.02), and cases on protocol (9% vs 5%, P=.005) or with intensity modulated radiation therapy/image guided intensity modulated radiation therapy (52% vs 43%, P=.001) were more likely to have incidents. Conclusions: We found several treatment- and patient-specific variables associated with incidents. These factors should be considered by treatment teams at the time of peer review to identify patients at higher risk. Larger datasets are required to recommend changes in care process standards, to minimize safety risks.

  16. Six categories of ionizing radiation quantities practical in various fields

    International Nuclear Information System (INIS)

    Zheng Junzheng; Zhuo Weihai

    2011-01-01

    This paper is the part of review on the evolvement of the systems for ionizing radiation quantities and units. In the paper, for better understanding and correct use of the relevant quantities of ionizing radiation, the major ionizing radiation quantities in various fields are divided into six categories. (authors)

  17. Beta radiation field of a 85Kr source

    International Nuclear Information System (INIS)

    Caldas, L.V.E.; David, J.

    1987-12-01

    The beta radiation field of a 85 Kr(3,7GBq) source utilized in industrial applications was determined, with the use of gamagraphy films, a scintillation detector, an extrapolation chamber and thermoluminescent (TL) dosemeters of CaSO 4 : Tm. Among other characteristics, the isodose curves of beta radiation and Bremsstrahlung radiation were obtained experimentally. (author) [pt

  18. RO-ILS: Radiation Oncology Incident Learning System: A report from the first year of experience.

    Science.gov (United States)

    Hoopes, David J; Dicker, Adam P; Eads, Nadine L; Ezzell, Gary A; Fraass, Benedick A; Kwiatkowski, Theresa M; Lash, Kathy; Patton, Gregory A; Piotrowski, Tom; Tomlinson, Cindy; Ford, Eric C

    2015-01-01

    Incident learning is a critical tool to improve patient safety. The Patient Safety and Quality Improvement Act of 2005 established essential legal protections to allow for the collection and analysis of medical incidents nationwide. Working with a federally listed patient safety organization (PSO), the American Society for Radiation Oncology and the American Association of Physicists in Medicine established RO-ILS: Radiation Oncology Incident Learning System (RO-ILS). This paper provides an overview of the RO-ILS background, development, structure, and workflow, as well as examples of preliminary data and lessons learned. RO-ILS is actively collecting, analyzing, and reporting patient safety events. As of February 24, 2015, 46 institutions have signed contracts with Clarity PSO, with 33 contracts pending. Of these, 27 sites have entered 739 patient safety events into local database space, with 358 events (48%) pushed to the national database. To establish an optimal safety culture, radiation oncology departments should establish formal systems for incident learning that include participation in a nationwide incident learning program such as RO-ILS. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  19. Electromagnetic field, excited by monodirected X-radiation pulse

    International Nuclear Information System (INIS)

    Zhemerov, A.V.; Metelkin, E.V.

    1994-01-01

    Parameters of electromagnetic field, generated in the atmosphere by monodirected pulse source of X radiation located at the altitude of approximately several kilometers have been estimated by the method of delayed potentials. The source radiation is directed towards the Earth surface. The conclusion was made that restricted areas of approximately 1 km with considerable pulse electromagnetic fields can be created on the Earth surface

  20. Adiabatic compression and radiative compression of magnetic fields

    International Nuclear Information System (INIS)

    Woods, C.H.

    1980-01-01

    Flux is conserved during mechanical compression of magnetic fields for both nonrelativistic and relativistic compressors. However, the relativistic compressor generates radiation, which can carry up to twice the energy content of the magnetic field compressed adiabatically. The radiation may be either confined or allowed to escape

  1. Leakage of an irradiator source: The June 1988 Georgia RSI [Radiation Sterilizers, Inc.] incident

    International Nuclear Information System (INIS)

    1990-02-01

    On June 6, 1988, operators of a pool irradiator in Decatur, Georgia, were prevented by a safety system from raising sources from the pool. Radiation levels of 60 millirem per hour at the surface of the pool water were found, indicative of a leak of one or more of the 252 Cs-137 source capsules used at the irradiator. A summary of the Incident Evaluation Task Force's First Interim Report has been prepared for person's needing an overview of the incident and lessons learned to date. This report provides a summary of Agreement States' views and recommendations on some of the issues raised by the incident

  2. Electromagnetic radiation by quark-gluon plasma in magnetic field

    OpenAIRE

    Tuchin, Kirill

    2012-01-01

    The electromagnetic radiation by quark-gluon plasma in strong magnetic field is calculated. The contributing processes are synchrotron radiation and one--photon annihilation. It is shown that in relativistic heavy--ion collisions at RHIC and LHC synchrotron radiation dominates over the annihilation. Moreover, it constitutes a significant part of all photons produced by the plasma at low transverse momenta; its magnitude depends on the plasma temperature and the magnetic field strength. Electr...

  3. Novel reference radiation fields for pulsed photon radiation installed at PTB.

    Science.gov (United States)

    Klammer, J; Roth, J; Hupe, O

    2012-09-01

    Currently, ∼70 % of the occupationally exposed persons in Germany are working in pulsed radiation fields, mainly in the medical sector. It has been known for a few years that active electronic dosemeters exhibit considerable deficits or can even fail completely in pulsed fields. Type test requirements for dosemeters exist only for continuous radiation. Owing to the need of a reference field for pulsed photon radiation and accordingly to the upcoming type test requirements for dosemeters in pulsed radiation, the Physikalisch-Technische Bundesanstalt has developed a novel X-ray reference field for pulsed photon radiation in cooperation with a manufacturer. This reference field, geared to the main applications in the field of medicine, has been well characterised and is now available for research and type testing of dosemeters in pulsed photon radiation.

  4. Recommendations for Nuclear Medicine Technologists Drawn from an Analysis of Errors Reported in Australian Radiation Incident Registers.

    Science.gov (United States)

    Kearney, Nicole; Denham, Gary

    2016-12-01

    When a radiation incident occurs in nuclear medicine in Australia, the incident is reported to the relevant state or territory authority, which performs an investigation and sends its findings to the Australian Radiation Protection and Nuclear Safety Agency. The agency then includes these data in its Australian Radiation Incident Register and makes them available to the public as an annual summary report on its website. The aim of this study was to analyze the radiation incidents included in these annual reports and in the publically available state and territory registers, identify any recurring themes, and make recommendations to minimize future incidents. A multidisciplinary team comprising a nuclear medicine technologist, a radiation therapist, and a diagnostic radiographer analyzed all nuclear medicine technology-, radiation therapy-, and diagnostic radiography-related incidents recorded in the Australian Radiation Incident Register and in the registers of New South Wales, Western Australia, Victoria, South Australia, and Tasmania between 2003 and 2015. Each incident was placed into 1 of 18 categories, and each category was examined to determine any recurring causes of the incidents. We analyzed 209 nuclear medicine incidents. Their primary cause was failure to comply with time-out protocols (85.6%). By analyzing both the causes and the rates of radiation incidents, we were able to recommend ways to help prevent them from being repeated. Information drawn from the Australian Radiation Incident Register and 5 state registers has revealed steps that can be taken by any nuclear medicine department to prevent repetition of the incidents that have already occurred. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  5. The Influence of the Solar Coronal Radiation on Coronal Plasma Structures, I: Determination of the Incident Coronal Radiation

    Science.gov (United States)

    Brown, Gerrard M.; Labrosse, Nicolas

    2018-02-01

    Coronal structures receive radiation not only from the solar disc, but also from the corona. This height-dependent incident radiation plays a crucial role in the excitation and the ionisation of the illuminated plasma. The aim of this article is to present a method for computing the detailed incident radiation coming from the solar corona, which is perceived at a point located at an arbitrary height. The coronal radiation is calculated by integrating the radiation received at a point in the corona over all of the corona visible from this point. The emission from the corona at all wavelengths of interest is computed using atomic data provided by CHIANTI. We obtain the spectrum illuminating points located at varying heights in the corona at wavelengths between 100 and 912 Å when photons can ionise H or He atoms and ions in their ground states. As expected, individual spectral lines will contribute most at the height within the corona where the local temperature is closest to their formation temperature. As there are many spectral lines produced by many ions, the coronal intensity cannot be assumed to vary in the same way at all wavelengths and so must be calculated for each separate height that is to be considered. This code can be used to compute the spectrum from the corona illuminating a point at any given height above the solar surface. This brings a necessary improvement to models where an accurate determination of the excitation and ionisation states of coronal plasma structures is crucial.

  6. SU-E-T-524: Web-Based Radiation Oncology Incident Reporting and Learning System (ROIRLS)

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, R; Palta, J; Hagan, M [Virginia Commonwealth University, Richmond, VA (United States); National Radiation Oncology Program (10P4H), Richmond, VA (United States); Grover, S; Malik, G [TSG Innovations Inc., Richmond, VA (United States)

    2014-06-01

    Purpose: Describe a Web-based Radiation Oncology Incident Reporting and Learning system that has the potential to improve quality of care for radiation therapy patients. This system is an important facet of continuing effort by our community to maintain and improve safety of radiotherapy.Material and Methods: The VA National Radiation Oncology Program office has embarked on a program to electronically collect adverse events and near miss data of radiation treatment of over 25,000 veterans treated with radiotherapy annually. Software used for this program is deployed on the VAs intranet as a Website. All data entry forms (adverse event or near miss reports, work product reports) utilize standard causal, RT process step taxonomies and data dictionaries defined in AAPM and ASTRO reports on error reporting (AAPM Work Group Report on Prevention of Errors and ASTROs safety is no accident report). All reported incidents are investigated by the radiation oncology domain experts. This system encompasses the entire feedback loop of reporting an incident, analyzing it for salient details, and developing interventions to prevent it from happening again. The operational workflow is similar to that of the Aviation Safety Reporting System. This system is also synergistic with ROSIS and SAFRON. Results: The ROIRLS facilitates the collection of data that help in tracking adverse events and near misses and develop new interventions to prevent such incidents. The ROIRLS electronic infrastructure is fully integrated with each registered facility profile data thus minimizing key strokes and multiple entries by the event reporters. Conclusions: OIRLS is expected to improve the quality and safety of a broad spectrum of radiation therapy patients treated in the VA and fulfills our goal of Effecting Quality While Treating Safely The Radiation Oncology Incident Reporting and Learning System software used for this program has been developed, conceptualized and maintained by TSG Innovations

  7. SU-E-T-524: Web-Based Radiation Oncology Incident Reporting and Learning System (ROIRLS)

    International Nuclear Information System (INIS)

    Kapoor, R; Palta, J; Hagan, M; Grover, S; Malik, G

    2014-01-01

    Purpose: Describe a Web-based Radiation Oncology Incident Reporting and Learning system that has the potential to improve quality of care for radiation therapy patients. This system is an important facet of continuing effort by our community to maintain and improve safety of radiotherapy.Material and Methods: The VA National Radiation Oncology Program office has embarked on a program to electronically collect adverse events and near miss data of radiation treatment of over 25,000 veterans treated with radiotherapy annually. Software used for this program is deployed on the VAs intranet as a Website. All data entry forms (adverse event or near miss reports, work product reports) utilize standard causal, RT process step taxonomies and data dictionaries defined in AAPM and ASTRO reports on error reporting (AAPM Work Group Report on Prevention of Errors and ASTROs safety is no accident report). All reported incidents are investigated by the radiation oncology domain experts. This system encompasses the entire feedback loop of reporting an incident, analyzing it for salient details, and developing interventions to prevent it from happening again. The operational workflow is similar to that of the Aviation Safety Reporting System. This system is also synergistic with ROSIS and SAFRON. Results: The ROIRLS facilitates the collection of data that help in tracking adverse events and near misses and develop new interventions to prevent such incidents. The ROIRLS electronic infrastructure is fully integrated with each registered facility profile data thus minimizing key strokes and multiple entries by the event reporters. Conclusions: OIRLS is expected to improve the quality and safety of a broad spectrum of radiation therapy patients treated in the VA and fulfills our goal of Effecting Quality While Treating Safely The Radiation Oncology Incident Reporting and Learning System software used for this program has been developed, conceptualized and maintained by TSG Innovations

  8. Female all cancer incidence in medical radiation workers in Latvia 1982-2002

    International Nuclear Information System (INIS)

    Matisane, L.; Carpenter, L.; Venables, K.

    2005-01-01

    Medical radiation workers belong to one of the oldest occupational groups exposed to external radiation. Since the various radiological protection recommendations have been introduced, now ths process has resulted in low-dose exposure, regular monitoring of exposure and establishment of national dose registration bodies. In order to provide additional information to studies on cancer incidence among medical radiation workers (specially female workers) and in order to assess all cancer incidence in female medical radiation workers in Latvia, a retrospective cohort study based on the National Dose Register was set up in Latvia. The study cohort consisted of all workers employed in health care, occupationally exposed to ionising radiation for more than one year in any of the public health care establishments in Latvia, except military ones, between 1 January 1972 and 1 January 2002 and who were registered in the National Dose Register of Latvia. The cohort consisted of 1416 female medical radiation workers either in hospitals or outpatient departments, or both. The cohort included diagnostic and therapeutic radiologists with predominantly medical qualification, it also included radiotechnologits, nurses, junior nurses, but it did not include academic, physicists and dentists. In all cases the calculated SIR was over than expected or close to expected. Several major differences in study design makes ir difficult to compare the results of this study with the results of the studies carried out in other countries

  9. Incidence of Second Malignancies Among Patients Treated With Proton Versus Photon Radiation

    International Nuclear Information System (INIS)

    Chung, Christine S.; Yock, Torunn I.; Nelson, Kerrie; Xu, Yang; Keating, Nancy L.; Tarbell, Nancy J.

    2013-01-01

    Purpose: Proton radiation, when compared with photon radiation, allows delivery of increased radiation dose to the tumor while decreasing dose to adjacent critical structures. Given the recent expansion of proton facilities in the United States, the long-term sequelae of proton therapy should be carefully assessed. The objective of this study was to compare the incidence of second cancers in patients treated with proton radiation with a population-based cohort of matched patients treated with photon radiation. Methods and Materials: We performed a retrospective cohort study of 558 patients treated with proton radiation from 1973 to 2001 at the Harvard Cyclotron in Cambridge, MA and 558 matched patients treated with photon therapy in the Surveillance, Epidemiology, and End Results (SEER) Program cancer registry. Patients were matched by age at radiation treatment, sex, year of treatment, cancer histology, and site. The main outcome measure was the incidence of second malignancies after radiation. Results: We matched 558 proton patients with 558 photon patients from the Surveillance, Epidemiology, and End Results registry. The median duration of follow-up was 6.7 years (interquartile range, 7.4) and 6.0 years (interquartile range, 9.3) in the proton and photon cohorts, respectively. The median age at treatment was 59 years in each cohort. Second malignancies occurred in 29 proton patients (5.2%) and 42 photon patients (7.5%). After we adjusted for sex, age at treatment, primary site, and year of diagnosis, proton therapy was not associated with an increased risk of second malignancy (adjusted hazard ratio, 0.52 [95% confidence interval, 0.32-0.85]; P=.009). Conclusions: The use of proton radiation therapy was not associated with a significantly increased risk of secondary malignancies compared with photon therapy. Longer follow-up of these patients is needed to determine if there is a significant decrease in second malignancies. Given the limitations of the study

  10. Separation of radiation from two sources from their known radiated sum field

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey

    2011-01-01

    This paper presents a technique for complete and exact separation of the radiated fields of two sources (at the same frequency) from the knowledge of their radiated sum field. The two sources can be arbitrary but it must be possible to enclose the sources inside their own non-intersecting minimum...

  11. Factors influencing the incidence of sinusitis in nasopharyngeal carcinoma patients after intensity-modulated radiation therapy.

    Science.gov (United States)

    Su, Yan-xia; Liu, Lan-ping; Li, Lei; Li, Xu; Cao, Xiu-juan; Dong, Wei; Yang, Xin-hua; Xu, Jin; Yu, Shui; Hao, Jun-fang

    2014-12-01

    The aim of the study was to investigate the incidence of sinusitis in nasopharyngeal carcinoma (NPC) patients before and after intensity-modulated radiation therapy (IMRT) and to analyze factors associated with the incidence of sinusitis following IMRT. We retrospectively analyzed 283 NPC patients who received IMRT in our hospital from March 2009 to May 2011. The diagnostic criteria for sinusitis are based on computed tomography (CT) or magnetic resonance imaging (MRI) findings. CT or MRI scans were performed before and after IMRT to evaluate the incidence of sinusitis. Factors influencing the incidence of sinusitis were analyzed by log-rank univariate and logistic multivariate analyses. Among the 283 NPC patients, 128 (45.2 %) suffered from sinusitis before radiotherapy. The incidence rates of sinusitis in patients with T1, T2, T3, and T4 NPC before radiotherapy were 22.6, 37.5, 46.8, and 61.3 %, respectively (χ 2 = 14.548, p = 0.002). Among the 155 NPC patients without sinusitis before radiotherapy, the incidence rates of sinusitis at the end of radiotherapy and at 1, 3, 6, 9, 12, and 18 months after radiotherapy were 32.9, 43.2, 61.3, 68.4, 73.5, 69.7, and 61.3 %, respectively (χ 2 = 86.461, p < 0.001). Univariate analysis showed that T stage, invasion of the nasal cavity, nasal irrigation, and radiation dose to the nasopharynx were associated with the incidence of sinusitis in NPC patients after IMRT (p = 0.003, 0.006, 0.002, and 0.020). Multivariate analysis showed that T stage, invasion of the nasal cavity, and nasal irrigation were influential factors for the incidence of sinusitis in NPC patients after IMRT (p = 0.002, 0.002, and 0.000). There was a higher incidence of sinusitis with higher T stage among NPC patients before radiotherapy, and the incidence of sinusitis in NPC patients after IMRT was high (45.2 %). The incidence of sinusitis increased rapidly within the first 3 months after IMRT, and the number of sinusitis cases peaked at 6-9 months after

  12. Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

    OpenAIRE

    Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

    2016-01-01

    A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates o...

  13. Comments on 'Cellular response to modulated radiation fields'

    International Nuclear Information System (INIS)

    Ross, C K; Klassen, N V

    2009-01-01

    The authors of a recent paper (Claridge Mackonis et al 2007 Phys. Med. Biol. 52 5469-82) measured cell survival in spatially modulated radiation fields. They claim to have identified two new types of radiation-induced bystander effect. We conclude that their claims are not supported by their data. (letter to the editor)

  14. Radiation from channeled positrons in a hypersonic wave field

    International Nuclear Information System (INIS)

    Mkrtchyan, A.R.; Gasparyan, R.A.; Gabrielyan, R.G.

    1987-01-01

    The radiation emitted by channeled positrons in a longitudinal or transverse standing hypersonic wave field is considered. In the case of plane channeling the spectral distribution of the radiation intensity is shown to be of a resonance nature depending on the hypersound frequency

  15. Conditions's considerations of the CT radiation field

    International Nuclear Information System (INIS)

    Andrade, Lucio das Chagas de; Peixoto, Jose Guilherme Pereira

    2013-01-01

    In obtaining the standardization of radiation fields in diagnostic radiology were established standards and qualities to X radiation beams, which are specified in terms of the tension in the tube, first CSR, additional filters, homogeneity coefficient or second CSR. The qualities recommended in CT (RQT), are established in IEC 61267, which is the reference for the establishment of beams in diagnostic radiology. (author)

  16. The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

    Science.gov (United States)

    Likar, A.; Razpet, N.

    2009-01-01

    The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

  17. 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

  18. Hawking radiation of a vector field and gravitational anomalies

    International Nuclear Information System (INIS)

    Murata, Keiju; Miyamoto, Umpei

    2007-01-01

    Recently, the relation between Hawking radiation and gravitational anomalies has been used to estimate the flux of Hawking radiation for a large class of black objects. In this paper, we extend the formalism, originally proposed by Robinson and Wilczek, to the Hawking radiation of vector particles (photons). It is explicitly shown, with the Hamiltonian formalism, that the theory of an electromagnetic field on d-dimensional spherical black holes reduces to one of an infinite number of massive complex scalar fields on 2-dimensional spacetime, for which the usual anomaly-cancellation method is available. It is found that the total energy emitted from the horizon for the electromagnetic field is just (d-2) times that for a scalar field. The results support the picture that Hawking radiation can be regarded as an anomaly eliminator on horizons. Possible extensions and applications of the analysis are discussed

  19. International cooperation in the field of radiation application

    International Nuclear Information System (INIS)

    Sato, Shoichi

    1993-01-01

    Bilateral and multilateral research cooperations have been implemented at TRCRE, JAERI, producing favourable results in the field of radiation application. Frameworks and some achievements are described and the significance of the international cooperation is discussed. (Author)

  20. Tomography of binomial states of the radiation field

    NARCIS (Netherlands)

    Bazrafkan, MR; Man'ko, [No Value

    2004-01-01

    The symplectic, optical, and photon-number tomographic symbols of binomial states of the radiation field are studied. Explicit relations for all tomograms of the binomial states are obtained. Two measures for nonclassical properties of these states are discussed.

  1. Effects of hypersonic field and anharmonic interactions on channelling radiation

    International Nuclear Information System (INIS)

    George, Juby; Pathak, Anand P; Goteti, L N S Prakash; Nagamani, G

    2007-01-01

    The effects of a hypersonic field on positron channelling radiation are considered. Anharmonic effects of the transverse potential induced by these longitudinal fields are incorporated and the wavefunction of the planar channelled positron is found by the solution of Dirac equation under the resonant influence of hypersound. An expression for the resonant frequency is estimated. The transition probabilities and the intensity of the channelling radiation are also calculated. It is found that the anharmonic effects change the spectral distributions considerably

  2. Ischemic heart disease in workers at Mayak PA: latency of incidence risk after radiation exposure.

    Directory of Open Access Journals (Sweden)

    Cristoforo Simonetto

    Full Text Available We present an updated analysis of incidence and mortality from atherosclerotic induced ischemic heart diseases in the cohort of workers at the Mayak Production Association (PA. This cohort constitutes one of the most important sources for the assessment of radiation risk. It is exceptional because it comprises information on several other risk factors. While most of the workers have been exposed to external gamma radiation, a large proportion has additionally been exposed to internal radiation from inhaled plutonium. Compared to a previous study by Azizova et al. 2012, the updated dosimetry system MWDS-2008 has been applied and methods of analysis have been revised. We extend the analysis of the significant incidence risk and observe that main detrimental effects of external radiation exposure occur after more than about 30 years. For mortality, significant risk was found in males with an excess relative risk per dose of 0.09 (95% CI: 0.02; 0.16 [Formula: see text] while risk was insignificant for females. With respect to internal radiation exposure no association to risk could be established.

  3. Radiation effects on relativistic electrons in strong external fields

    International Nuclear Information System (INIS)

    Iqbal, Khalid

    2013-01-01

    The effects of radiation of high energy electron beams are a major issue in almost all types of charged particle accelerators. The objective of this thesis is both the analytical and numerical study of radiation effects. Due to its many applications the study of the self force has become a very active and productive field of research. The main part of this thesis is devoted to the study of radiation effects in laser-based plasma accelerators. Analytical models predict the existence of radiation effects. The investigation of radiation reaction show that in laser-based plasma accelerators, the self force effects lower the energy gain and emittance for moderate energies electron beams and increase the relative energy spread. However, for relatively high energy electron beams, the self radiation and retardation (radiation effects of one electron on the other electron of the system) effects increase the transverse emittance of the beam. The energy gain decreases to even lower value and relative energy spread increases to even higher value due to high radiation losses. The second part of this thesis investigates with radiation reaction in focused laser beams. Radiation effects are very weak even for high energy electrons. The radiation-free acceleration and the simple practical setup make direct acceleration in a focused laser beam very attractive. The results presented in this thesis can be helpful for the optimization of future electron acceleration experiments, in particular in the case of laser-plasma accelerators.

  4. Radiating low back pain in general practice : Incidence, prevalence, diagnosis, and long-term clinical course of illness

    NARCIS (Netherlands)

    Spijker-Huiges, Antje; Groenhof, Feikje; Winters, Jan C.; van Wijhe, Marten; Groenier, Klaas H.; van der Meer, Klaas

    Objective. The aim of this study was to calculate the incidence and prevalence of radiating low back pain, to explore the long-term clinical course of radiating low back pain including the influence of radiculopathy (in a subsample of the study population) and non-radiating low back pain thereon,

  5. Radiation risk factors in incidence anortality among exposed individuals of East Kazakhstand m

    Directory of Open Access Journals (Sweden)

    Kazbek Apsalikov

    2014-01-01

    Full Text Available Introduction: Lengthy clinical and epidemiological studies at the Research Institute of Radiation Medicine and Ecology have discovered basic patterns of long-term effects from ionizing radiation in population groups exposed to radiation risk. Methodology for calculating injury from radiation risk factors has been developed and implemented to minimize the effects of the Semipalatinsk nuclear test site (SNTS. Material and methods: We analyzed materials from the database of the Scientific Medical Register that were exposed to radiation as a result of SNTS. We analyzed both male and female populations of the Abay, Beskaragai and Zhanasemei, Kokpekti (control areas of East-Kazakhstan region (EKR from 2008-2012. These populations were split into three groups allocated by the generation. The first group represented persons born from the period of 01/01/1930 -08/01/1949 and their children born from the period of 10/09/1949-12/31/1962. The second group were persons born after 01/01/1963. The third group served as the control and were persons who immigrated to these areas after 1990. Results: There was an increased incidence of cancer (21.5%, p < 0.000734, cardiovascular diseases (10.2%; respiratory problems (9.6%, gastrointestinal issues (9.1%, p < 0.00371-0.00679 in the first group. The effect of the radiation dose has not been fully stuided among the subjects in the second group.The major causes of excess mortality in the first group were neoplams (30.6%, hypertension (23.8%, and myocardial infarction (22.6%. The effects of radiation influenced mortality in the second group were 2-2.5 times lower than the first group.Conclusion: There is a correlation between the size of the radiation dose, the risk profile, and age at the moment of radiation exposure with trends of morbidity and mortality in the radiation exposed areas.

  6. Lightweight space radiator with leakage control by internal electrostatic fields

    International Nuclear Information System (INIS)

    Kim, H.; Bankoff, S.G.; Miksis, M.J.

    1991-01-01

    An electrostatic liquid film space radiator is proposed. This will employ an internal electrostatic field to prevent leakage of the liquid-metal coolant out of a puncture. This overcomes the major disadvantage of membrane radiators, which is their vulnerability to micrometeorite impacts. Calculations show that leaks of liquid lithium at 700 degree K can easily be stopped from punctures which are several mm in diameter, with very large safety factors. The basic idea lends itself to a variety of radiator concepts, both rotating and non-rotating. Some typical film thickness and pressure calculations in the presence of an electric field are shown

  7. Effects of ionizing radiation and steady magnetic field on erythrocytes

    International Nuclear Information System (INIS)

    Ivanov, S. P.; Galutzov, B. P.; Kuzmanova, M. A.; Markov, M. S.

    1996-01-01

    A complex biophysical test for studying the effects of ionizing and non-ionizing radiation has been developed. The following cell and membrane parameters have been investigated: cell size, cell shape, cell distribution by size, electrophoretic mobility, extent of hemolysis, membrane transport and membrane impedance. Gamma ray doses of 2.2 Gy and 3.3 Gy were used as ionizing radiation and steady (DC) magnetic field of 5-90 mT representing the non-ionizing radiation. Erythrocytes from humans and rats were exposed in vitro to both ionizing and non-ionizing radiation. In some experiments ionizing radiation was applied in vivo as well. Each of the simultaneously studied parameters have been found to change as a function of applied radiation. The proposed test allows an estimation of the changes in the elastic, rheological and electrical parameters of cells and biological membranes. Results indicate that ionizing radiation is significantly more effective in an in vivo application, while magnetic fields are more effective when applied in vitro. Surprisingly, steady magnetic fields were found to act as protector against some harmful effects of ionizing radiation. (authors)

  8. Conclusions from some unusual events in the field of ionizing radiation in the German Democratic Republic

    International Nuclear Information System (INIS)

    Schuettmann, W.; Koenig, W.

    1977-01-01

    In the GDR all unusual events in the field of ionizing radiation have been recorded and analysed since 1963. This is done by a central governmental institution, the National Board of Nuclear Safety and Radiation Protection established in 1962, and responsible for all relevant measures throughout the country. An unusual event is defined by radiation protection legislation as an event which deviates from the planned operation programme whether the incident has caused injury or not. The obligation to report such events rests on all licensed users, from users of X-ray machines to operators of reactors in research and nuclear power production. The listed events are continually assessed by the Board. The results of the assessment are evaluated in summary. There has not been a single event with a fatal outcome arising from ionizing radiation. Over the same period there were only seventeen occurrences which resulted in permanent injury to persons, mainly effected by acute external irradiation of parts of the body, especially of hands and forearms. Among the detected causes of unusual events described in detail, human failure predominates by far. Finally, conclusions are drawn from these results. The measures suggested all aim to reduce the frequency of radiation accidents and to minimize their consequences. The main measures concern ways of reducing human error in all fields of radiation protection. Among these, the education and training and the medical examination of radiation workers are discussed in somewhat more detail. (author)

  9. Gravitational radiation from preheating with many fields

    International Nuclear Information System (INIS)

    Jr, John T. Giblin; Price, Larry R.; Siemens, Xavier

    2010-01-01

    Parametric resonances provide a mechanism by which particles can be created just after inflation. Thus far, attention has focused on a single or many inflaton fields coupled to a single scalar field. However, generically we expect the inflaton to couple to many other relativistic degrees of freedom present in the early universe. Using simulations in an expanding Friedmann-Lemaître-Robertson-Walker spacetime, in this paper we show how preheating is affected by the addition of multiple fields coupled to the inflaton. We focus our attention on gravitational wave production — an important potential observational signature of the preheating stage. We find that preheating and its gravitational wave signature is robust to the coupling of the inflaton to more matter fields

  10. Gravitational radiation from preheating with many fields

    Energy Technology Data Exchange (ETDEWEB)

    Jr, John T. Giblin [Department of Physics, Kenyon College, 201 North College Road, Gambier, OH 43022 (United States); Price, Larry R.; Siemens, Xavier, E-mail: giblinj@kenyon.edu, E-mail: larry@gravity.phys.uwm.edu, E-mail: siemens@gravity.phys.uwm.edu [Center for Gravitation and Cosmology, Department of Physics, University of Wisconsin — Milwaukee, P.O. Box 413, Milwaukee, WI 53201 (United States)

    2010-08-01

    Parametric resonances provide a mechanism by which particles can be created just after inflation. Thus far, attention has focused on a single or many inflaton fields coupled to a single scalar field. However, generically we expect the inflaton to couple to many other relativistic degrees of freedom present in the early universe. Using simulations in an expanding Friedmann-Lemaître-Robertson-Walker spacetime, in this paper we show how preheating is affected by the addition of multiple fields coupled to the inflaton. We focus our attention on gravitational wave production — an important potential observational signature of the preheating stage. We find that preheating and its gravitational wave signature is robust to the coupling of the inflaton to more matter fields.

  11. Radiation-field mapping of insect irradiation canisters

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M.L.; McLaughlin, W.L.; Puhl, J.M. [National Inst. of Standards and Technology - PL, Gaithersburg, MD (United States). Ionizing Radiation Div.; Gomes, P. [United States Department of Agriculture, Riverdale, MD (United States). Animal and Plant Health Inspection Service

    1997-01-01

    Dosimetry methods developed at NIST for mapping ionizing radiation fields were applied to canisters used in {sup 137}Cs dry-source irradiators designed for insect sterilization. The method of mapping the radiation fields inside of these canisters as they cycled through the gamma-ray irradiators involved the use of radiochromic films, which increase in optical density proportionately to the absorbed dose. A dosimeter film array in a cardboard phantom was designed to simulate the average insect pupae density and to map the dose within the full volume of the canister; the calibrated films were read using a laser scanning densitometer. Previously used dosimetric methods did not allow for the spatial resolution that is possible with these films. Results indicate that this dose-mapping technique is a powerful method of evaluating a variety of radiation fields of commercial radiation sources, with promising applications as a means of dose validation and quality control. (Author).

  12. Electron trajectories in pulsed radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Einwohner, T.; Lippmann, B.A.

    1987-05-01

    The work reported here analyzes the dynamical behavior of an electron, initially at rest, when subjected to a radiation pulse of arbitrary, but integrable, shape. This is done by a general integration procedure that has been programmed in VAXIMA. Upon choosing a specific shape for the pulse, VAXIMA finds both the space-time trajectory and the four-momentum of the electron. These are obtained in analytic or numerical form - or both - at the choice of the user. Several examples of analytical and numerical solutions, for different pulse shapes, are given.

  13. Electron trajectories in pulsed radiation fields

    International Nuclear Information System (INIS)

    Einwohner, T.; Lippmann, B.A.

    1987-05-01

    The work reported here analyzes the dynamical behavior of an electron, initially at rest, when subjected to a radiation pulse of arbitrary, but integrable, shape. This is done by a general integration procedure that has been programmed in VAXIMA. Upon choosing a specific shape for the pulse, VAXIMA finds both the space-time trajectory and the four-momentum of the electron. These are obtained in analytic or numerical form - or both - at the choice of the user. Several examples of analytical and numerical solutions, for different pulse shapes, are given

  14. Has the incidence of radiation-induced bowel damage following treatment of uterine carcinoma changed in the last 20 years

    International Nuclear Information System (INIS)

    Allen-Mersh, T.C.; Wilson, E.J.; Hope-Stone, H.F.; Mann, C.V.

    1986-01-01

    Radiation-induced bowel damage occurred in 4.3% of patients treated primarily by irradiation for uterine carcinoma during the period 1962-1982. There has been a progressive rise in the incidence of radiation damage and radiation-induced rectovaginal fistula during this 20-year period. Radiation from intracavitary sources was a contributory factor in 92% of injured cases. The rising incidence of bowel damage in our patients may be due to an increase in the number of patients receiving a high rectal dose from the intracavitary source. There was a significantly (P<0.01) higher incidence of radiation injury in cases of cervical carcinoma compared to endometrical carcinoma. This was because cervical carcinoma tended to present at a more advanced stage than endometrial carcinoma and was more frequently treated with combined external and intracavitary irradiation. There was no significant increase in the incidence of complications among patients undergoing hysterectomy. (author)

  15. Applicability of ambient dose equivalent H*(d) in mixed radiation fields - a critical discussion

    International Nuclear Information System (INIS)

    Hajek, M.; Vana, N.

    2004-01-01

    For purposes of routine radiation protection, it is desirable to characterize the potential irradiation of individuals in terms of a single dose equivalent quantity that would exist in a phantom approximating the human body. The phantom of choice is the ICRU sphere made of 30 cm diameter tissue-equivalent plastic with a density of 1 g.cm-3 and a mass composition of 76.2 % O, 11.1 % C, 10.1 % H and 2.6 % N. Ambient dose equivalent, H*(d), was defined in ICRU report 51 as the dose equivalent that would be produced by an expanded and aligned radiation field at a depth d in the ICRU sphere. The recommended reference depths are 10 mm for strongly penetrating radiation and 0.07 mm for weakly penetrating radiation, respectively. As an operational quantity in radiation protection, H*(d) shall serve as a conservative and directly measurable estimate of protection quantities, e.g. effective dose E, which in turn are intended to give an indication of the risk associated with radiation exposure. The situation attains increased complexity in radiation environments being composed of a variety of charged and uncharged particles in a broad energetic spectrum. Radiation fields of similarly complex nature are, for example, encountered onboard aircraft and in space. Dose equivalent was assessed as a function of depth in quasi tissue-equivalent spheres by means of thermoluminescent dosemeters evaluated according to the high-temperature ratio (HTR) method. The presented experiments were performed both onboard aircraft and the Russian space station Mir. As a result of interaction processes within the phantom body, the incident primary spectrum may be significantly modified with increasing depth. For the radiation field at aviation altitudes we found the maximum of dose equivalent in a depth of 60 mm which conflicts with the 10 mm value recommended by ICRU. Contrary, for the space radiation environment the maximum dose equivalent was found at the surface of the sphere. This suggests that

  16. Applicability of Ambient Dose Equivalent H (d) in Mixed Radiation Fields - A Critical Discussion

    International Nuclear Information System (INIS)

    Vana, R.; Hajek, M.; Bergerm, T.

    2004-01-01

    For purposes of routine radiation protection, it is desirable to characterize the potential irradiation of individuals in terms of a single dose equivalent quantity that would exist in a phantom approximating the human body. The phantom of choice is the ICRU sphere made of 30 cm diameter tissue-equivalent plastic with a density of 1 g/cm3 and a mass composition of 76.2% O, 11.1% C, 10.1% H and 2.6% N. Ambient dose equivalent, H(d), was defined in ICRU report 51 as the dose equivalent that would be produced by an expanded and aligned radiation field at a depth d in the ICRU sphere. The recommended reference depths are 10 mm for strongly penetrating radiation and 0.07 mm for weakly penetrating radiation, respectively. As an operational quantity in radiation protection, H(d) shall serve as a conservative and directly measurable estimate of protection quantities, e.g. effective dose E, which in turn are intended to give an indication of the risk associated with radiation exposure. The situation attains increased complexity in radiation environments being composed of a variety of charged and uncharged particles in a broad energetic spectrum. Radiation fields of similarly complex nature are, for example, encountered onboard aircraft and in space. Dose equivalent was assessed as a function of depth in quasi tissue-equivalent spheres by means of thermoluminescent dosemeters evaluated according to the high-temperature ratio (HTR) method. The presented experiments were performed both onboard aircraft and the Russian space station Mir. As a result of interaction processes within the phantom body, the incident primary spectrum may be significantly modified with increasing depth. For the radiation field at aviation altitudes we found the maximum of dose equivalent in a depth of 60 mm which conflicts with the 10 mm value recommended by ICRU. Contrary, for the space radiation environment the maximum dose equivalent was found at the surface of the sphere. This suggests that skin

  17. Occurrence of BOOP outside radiation field after radiation therapy for small cell lung cancer

    International Nuclear Information System (INIS)

    Hamanishi, Tohru; Oida, Kazukiyo; Morimatu, Takafumi

    2001-01-01

    We report a case of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy for small cell lung cancer. A 74-year-old woman received chemotherapy and a total of 60 Gy of radiation therapy to the right hilum and mediastinum for small cell carcinoma of the suprahilar area of the right lung. Radiation pneumonitis developed within the radiation port 3 months after the completion of radiation therapy. She complained of cough and was admitted 7 months after completion of the radiation therapy. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the side contralateral to that receiving the radiation therapy. Bronchoalveolar lavage showed that the total cell count was increased, with a markedly increased percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid improvement of the symptoms and complete resolution of the radiographic abnormalities of the left lung. Although some cases of BOOP following radiation therapy for breast cancer have been reported, none of BOOP after radiation therapy for lung cancer have appeared in the literature. (author)

  18. Medical and policy considerations for nuclear and radiation accidents, incidents and terrorism.

    Science.gov (United States)

    Gale, Robert Peter

    2017-11-01

    The purpose of this review is to address the increasing medical and public concern regarding the health consequences of radiation exposure, a concern shaped not only by fear of another Chernobyl or Fukushima nuclear power facility accident but also by the intentional use of a nuclear weapon, a radiological dispersion device, a radiological exposure device, or an improved nuclear device by rogue states such as North Korea and terrorist organizations such as Al Qaeda and ISIS. The United States has the medical capacity to respond to a limited nuclear or radiation accident or incident but an effective medical response to a catastrophic nuclear event is impossible. Dealing effectively with nuclear and radiation accidents or incidents requires diverse strategies, including policy decisions, public education, and medical preparedness. I review medical consequences of exposures to ionizing radiations, likely concomitant injuries and potential medical intervention. These data should help haematologists and other healthcare professionals understand the principles of medical consequences of nuclear terrorism. However, the best strategy is prevention.

  19. Problems with ink skin markings for radiation field setups

    International Nuclear Information System (INIS)

    Endoh, Masaru; Saeki, Mituaki; Ishida, Yusei

    1982-01-01

    Ink skin markings are used in radiation therapy to aid in reproduction of treatment field setups or to indelibly outline field markings or tumors. We reported two cases of indelible ink skin for radiation field septa with minimal discomfort and dermatitis have been experienced for 6 months and above since end of radiotherapy. These indelible ink skin markings look like tattoo that will be big problems in the case of young female. We improved these problems by using of 10 percent silver nitrate instead of habitual skin ink. (author)

  20. A Study of Radiation Incidence Angle in Anteroposterior Cervical Vertebra Examination

    International Nuclear Information System (INIS)

    Jeung, Seung Woon; Lim, Cheong Hwan; Jung, Hong Ryang; Joo, Yeong Cheol; Park, Mi Ja; Han, Beon Hee

    2012-01-01

    cervical vertebra, OID, axis angle, and FID, all of them were shown to have correlations with the incidence angle (p<.01). Conclusively, it was shown that the incidence angle was measured differently from average length of cervical vertebra, OID, FID, and axis slope, as well as from age and sex. Therefore, it can be suggested that the anteroposterior radiation test for cervical vertebra should be conducted by different incidence angles based on age and sex. The data of this study may be used as reference in determining the incidence angle of cervical vertebra tests for the future.

  1. A Study of Radiation Incidence Angle in Anteroposterior Cervical Vertebra Examination

    Energy Technology Data Exchange (ETDEWEB)

    Jeung, Seung Woon; Lim, Cheong Hwan; Jung, Hong Ryang; Joo, Yeong Cheol; Park, Mi Ja [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Han, Beon Hee [Dept. of Radiological Science, Seonam University, Namwon (Korea, Republic of)

    2012-06-15

    of cervical vertebra, OID, axis angle, and FID, all of them were shown to have correlations with the incidence angle (p<.01). Conclusively, it was shown that the incidence angle was measured differently from average length of cervical vertebra, OID, FID, and axis slope, as well as from age and sex. Therefore, it can be suggested that the anteroposterior radiation test for cervical vertebra should be conducted by different incidence angles based on age and sex. The data of this study may be used as reference in determining the incidence angle of cervical vertebra tests for the future.

  2. Causes of incident visual field loss in a general elderly population: the Rotterdam study

    NARCIS (Netherlands)

    Skenduli-Bala, Elisa; de Voogd, Simone; Wolfs, Roger C. W.; van Leeuwen, Redmer; Ikram, M. Kamran; Jonas, Jost B.; Bakker, Douwe; Hofman, Albert; de Jong, Paulus T. V. M.

    2005-01-01

    To determine the incidence and causes of visual field loss (VFL) in a general elderly population. Central visual fields of both eyes were examined with suprathreshold perimetry in 3761 persons aged 55 years or older and free of VFL at baseline from the population-based Rotterdam Study. Goldmann

  3. A proposal how to take into account inhomogeneous radiation fields in radiation protection

    International Nuclear Information System (INIS)

    Tschurlovits, M.

    1996-01-01

    External radiation fields exposing the human body inhomogenously are not considered neither in radiation protection standards nor in recent ICRU recommendations, but appear frequently in practical radiation protection. A proposal to solve this question is given taking into account both a conceptual and a metrological approach. The proposal suggests that a mean over an area of about 100 cm 2 can be taken as reference area for compliance with limits in terms of effective dose. (author)

  4. Incident learning and failure-mode-and-effects-analysis guided safety initiatives in radiation medicine

    Directory of Open Access Journals (Sweden)

    Ajay eKapur

    2013-12-01

    Full Text Available By combining incident learning and process failure-mode-and-effects-analysis in a structure-process-outcome framework we have created a risk profile for our radiation medicine practice and implemented evidence-based risk mitigation initiatives focused on patient safety. Based on reactive reviews of incidents reported in our departmental incident-reporting system and proactive failure-mode-and-effects-analysis, high safety-risk procedures in our paperless radiation medicine process and latent risk factors were identified. Six initiatives aimed at the mitigation of associated severity, likelihood of occurrence and detectability risks were implemented. These were the standardization of care pathways and toxicity grading, pre-treatment-planning peer review, a policy to thwart delay-rushed processes, an electronic whiteboard to enhance coordination and the use of six-sigma metrics to monitor operational efficiencies. The effectiveness of these initiatives over a three year period was assessed using process and outcome specific metrics within the framework of the department structure. There has been a 47% increase in incident reporting, with no increase in adverse events. Care pathways have been used with greater than 97% clinical compliance rate. The implementation of peer review prior to treatment planning and use of the whiteboard have provided opportunities for proactive detection and correction of errors. There has been a twofold drop in the occurrence of high-risk procedural delays. Patient treatment start delays are routinely enforced on cases that would have historically been rushed. Z-scores for high risk procedures have steadily improved from 1.78 to 2.35. The initiatives resulted in sustained reductions of failure-mode risks as measured by a set of evidence-based metrics over a three year period. These augment or incorporate many of the published recommendations for patient safety in radiation medicine by translating them to clinical

  5. Super-Planckian far-field radiative heat transfer

    Science.gov (United States)

    Fernández-Hurtado, V.; Fernández-Domínguez, A. I.; Feist, J.; García-Vidal, F. J.; Cuevas, J. C.

    2018-01-01

    We present here a theoretical analysis that demonstrates that the far-field radiative heat transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field radiative heat transfer, we make use of the theory of fluctuational electrodynamics and derive a relation between the far-field radiative heat transfer and the directional absorption efficiency of the objects involved. Guided by this relation, and making use of state-of-the-art numerical simulations, we show that the far-field radiative heat transfer between highly anisotropic objects can largely overcome the black-body limit when some of their dimensions are smaller than the thermal wavelength. In particular, we illustrate this phenomenon in the case of suspended pads made of polar dielectrics like SiN or SiO2. These structures are widely used to measure the thermal transport through nanowires and low-dimensional systems and can be employed to test our predictions. Our work illustrates the dramatic failure of the classical theory to predict the far-field radiative heat transfer between micro- and nanodevices.

  6. Radiation exposure from medical field in France

    International Nuclear Information System (INIS)

    Scanff, P.; Aubert, B.; Donadieu, J.; Pirard, P.

    2006-01-01

    Full text of publication follows: The only nationwide survey on medical X-ray practices in France was carried out more than fifteen years ago and recent updated information about the nature and frequency of X-ray diagnostic procedures and associated doses is lacking. However, with the implementation of the European Directive 97/43, the knowledge of medical practices is necessary and the question of the population dose resulting from medical X-ray examinations is raised again. In order to provide French data concerning the medical exposure to ionizing radiation, the Institute for Radiation Protection and Nuclear Safety (I.R.S.N.) and the National Institute for Public Health Surveillance (I.n.V.S.) have created an observatory of medical exposure to ionizing radiation. A first study was carried out in order to evaluate the nature and frequency of X-ray diagnostic procedures in conventional radiology and computed tomography. Information about annual frequencies was collected from two main sources: the main health insurance company (C.N.A.M.-T.S. - private radiologists) and the national statistics of the health establishments (S.A.E. examinations realized in public and private hospitals) from the ministry of health. Relevant data concerning examinations in conventional radiology (C.R.) with dental radiology and computed tomography (CT) were collected for the year 2002. As these two main sources of data may overlap, two hypotheses were retained, named low hypothesis (l.h.) and high hypothesis (h.h.). Dose contribution of these exams per inhabitant was calculated from French values of dose from the diagnostic reference level (D.R.L.) campaign completed with data from the European Commission publication 118 and from the health protection agency (H.P.A.). In this study, 82 different examination types were identified for C.R., according to the new French nomenclature for medical examinations (C.C.A.M.). The first five examinations (in number) are respectively chest

  7. Radiation exposure from medical field in France

    Energy Technology Data Exchange (ETDEWEB)

    Scanff, P.; Aubert, B. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Fontenay-aux-Roses (France); Donadieu, J.; Pirard, P. [Institut de Veille Sanitaire, St Maurice (France)

    2006-07-01

    Full text of publication follows: The only nationwide survey on medical X-ray practices in France was carried out more than fifteen years ago and recent updated information about the nature and frequency of X-ray diagnostic procedures and associated doses is lacking. However, with the implementation of the European Directive 97/43, the knowledge of medical practices is necessary and the question of the population dose resulting from medical X-ray examinations is raised again. In order to provide French data concerning the medical exposure to ionizing radiation, the Institute for Radiation Protection and Nuclear Safety (I.R.S.N.) and the National Institute for Public Health Surveillance (I.n.V.S.) have created an observatory of medical exposure to ionizing radiation. A first study was carried out in order to evaluate the nature and frequency of X-ray diagnostic procedures in conventional radiology and computed tomography. Information about annual frequencies was collected from two main sources: the main health insurance company (C.N.A.M.-T.S. - private radiologists) and the national statistics of the health establishments (S.A.E. examinations realized in public and private hospitals) from the ministry of health. Relevant data concerning examinations in conventional radiology (C.R.) with dental radiology and computed tomography (CT) were collected for the year 2002. As these two main sources of data may overlap, two hypotheses were retained, named low hypothesis (l.h.) and high hypothesis (h.h.). Dose contribution of these exams per inhabitant was calculated from French values of dose from the diagnostic reference level (D.R.L.) campaign completed with data from the European Commission publication 118 and from the health protection agency (H.P.A.). In this study, 82 different examination types were identified for C.R., according to the new French nomenclature for medical examinations (C.C.A.M.). The first five examinations (in number) are respectively chest

  8. Synchrotron radiation in strongly coupled conformal field theories

    Science.gov (United States)

    Athanasiou, Christiana; Chesler, Paul M.; Liu, Hong; Nickel, Dominik; Rajagopal, Krishna

    2010-06-01

    Using gauge/gravity duality, we compute the energy density and angular distribution of the power radiated by a quark undergoing circular motion in strongly coupled N=4 supersymmetric Yang-Mills theory. We compare the strong coupling results to those at weak coupling, finding them to be very similar. In both regimes, the angular distribution of the radiated power is in fact similar to that of synchrotron radiation produced by an electron in circular motion in classical electrodynamics: the quark emits radiation in a narrow beam along its velocity vector with a characteristic opening angle α˜1/γ. To an observer far away from the quark, the emitted radiation appears as a short periodic burst, just like the light from a lighthouse does to a ship at sea. Our strong coupling results are valid for any strongly coupled conformal field theory with a dual classical gravity description.

  9. Radiative electron-atom collision in a strong laser field

    International Nuclear Information System (INIS)

    Faisal, F.H.M.

    1984-01-01

    The comment is concerned with certain current problems and prospects in the theory of electron-atom collision in a strong radiation field. High energy off-shell electron-photon excitation of atoms; low-energy e-atom radiative scattering; steady state input distribution; typical distribution; low energy phenomena; and extensions of the close coupling and the algebraic methods, are all discussed. (U.K.)

  10. Modern Classical Electrodynamics and Electromagnetic Radiation - Vacuum Field Theory Aspects

    OpenAIRE

    Bogolubov, N. N.; Prykarpatsky, A. K.

    2012-01-01

    The work is devoted to studying some new classical electrodynamics models of interacting charged point particles and related with them physical aspects. Based on the vacuum field theory no-geometry approach, developed in \\cite{BPT,BPT1}, the Lagrangian and Hamiltonian reformulations of some alternative classical electrodynamics models are devised. A problem closely related to the radiation reaction force is analyzed aiming to explain the Wheeler and Feynman reaction radiation mechanism, well ...

  11. IAEA programme in the field of radiation technology

    Science.gov (United States)

    Chmielewski, Andrzej G.; Haji-Saeid, Mohammad

    2005-07-01

    Radiation technologies applying gamma sources and electron accelerators for material modification are well-established processes. There are over 160 gamma industrial irradiators and 1300 electron industrial accelerators in operation worldwide. A new advancement in the field of radiation sources engineering is the development of high power direct e-/X conversion sources based on electron accelerators. Technologies to be developed beside environmental applications could be nanomaterials, structure engineered materials (sorbents, composites, ordered polymers, etc.) and natural polymers' processing. New products based on radiation-processed polysaccharides have already been commercialised in many countries of the East Asia and Pacific Region, especially in those being rich in natural polymers. Very important and promising applications concern environmental protection-radiation technology, being a clean and environment friendly process, helps to curb pollutants' emission as well. Industrial plants for flue gas treatment have been constructed in Poland and China. The pilot plant in Bulgaria using this technology has just started its operation. The Polish plant is equipped with accelerators of over 1 MW power, a breakthrough in radiation technology application. The industrial plant for wastewater treatment is under development in Korea and a pilot plant for sewage sludge irradiation has been in operation in India for many years. Due to recent developments, the Agency has restructured its programme and organized a Technical Meeting (TM) on "Emerging Applications of Radiation Technology for the 21st Century" at its Headquarters in Vienna, Austria, in April 2003, to review the present situation and possible developments of radiation technology to contribute to a sustainable development. This meeting provided the basic input to launch others in the most important fields of radiation technology applications: "Advances in Radiation Chemistry of Polymers" (Notre Dame, USA

  12. IAEA programme in the field of radiation technology

    International Nuclear Information System (INIS)

    Chmielewski, Andrzej G.; Haji-Saeid, Mohammad

    2005-01-01

    Radiation technologies applying gamma sources and electron accelerators for material modification are well-established processes. There are over 160 gamma industrial irradiators and 1300 electron industrial accelerators in operation worldwide. A new advancement in the field of radiation sources engineering is the development of high power direct e - /X conversion sources based on electron accelerators. Technologies to be developed beside environmental applications could be nanomaterials, structure engineered materials (sorbents, composites, ordered polymers, etc.) and natural polymers' processing. New products based on radiation-processed polysaccharides have already been commercialised in many countries of the East Asia and Pacific Region, especially in those being rich in natural polymers. Very important and promising applications concern environmental protection-radiation technology, being a clean and environment friendly process, helps to curb pollutants' emission as well. Industrial plants for flue gas treatment have been constructed in Poland and China. The pilot plant in Bulgaria using this technology has just started its operation. The Polish plant is equipped with accelerators of over 1 MW power, a breakthrough in radiation technology application. The industrial plant for wastewater treatment is under development in Korea and a pilot plant for sewage sludge irradiation has been in operation in India for many years. Due to recent developments, the Agency has restructured its programme and organized a Technical Meeting (TM) on 'Emerging Applications of Radiation Technology for the 21st Century' at its Headquarters in Vienna, Austria, in April 2003, to review the present situation and possible developments of radiation technology to contribute to a sustainable development. This meeting provided the basic input to launch others in the most important fields of radiation technology applications: 'Advances in Radiation Chemistry of Polymers' (Notre Dame, USA

  13. Effect of organ size and position on out-of-field dose distributions during radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Scarboro, Sarah B; White, Allen; Yaldo, Derek; Kry, Stephen F; Howell, Rebecca M [University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX (United States); Stovall, Marilyn; Smith, Susan A, E-mail: Rhowell@mdanderson.or [The University of Texas M D Anderson Cancer Center, Houston, TX (United States)

    2010-12-07

    Mantle field irradiation has historically been the standard radiation treatment for Hodgkin lymphoma. It involves treating large regions of the chest and neck with high doses of radiation (up to 30 Gy). Previous epidemiological studies on the incidence of second malignancies following radiation therapy for Hodgkin lymphoma have revealed an increased incidence of second tumors in various organs, including lung, breast, thyroid and digestive tract. Multiple other studies, including the Surveillance, Epidemiology and End Results, indicated an increased incidence in digestive tract including stomach cancers following mantle field radiotherapy. Assessment of stomach dose is challenging because the stomach is outside the treatment field but very near the treatment border where there are steep dose gradients. In addition, the stomach can vary greatly in size and position. We sought to evaluate the dosimetric impact of the size and variable position of the stomach relative to the field border for a typical Hodgkin lymphoma mantle field irradiation. The mean stomach dose was measured using thermoluminescent dosimetry for nine variations in stomach size and position. The mean doses to the nine stomach variations ranged from 0.43 to 0.83 Gy when 30 Gy was delivered to the treatment isocenter. Statistical analyses indicated that there were no significant differences in the mean stomach dose when the stomach was symmetrically expanded up to 3 cm or shifted laterally (medial, anterior or posterior shifts) by up to 3 cm. There was, however, a significant (P > 0.01) difference in the mean dose when the stomach was shifted superiorly or inferiorly by {>=}2.5 cm.

  14. Incidence of neural tube defects in the natural radiation coastal areas of Kerala

    International Nuclear Information System (INIS)

    Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

    2010-01-01

    All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district, stands out among the most prominent background radiation areas of the world. Natural deposit of monazite sand, containing Thorium (8-10%), Uranium (0.3%) and corresponding decay products, is the source of elevated background radiation, ranging from < 1 to 45 mGy/year. Wide variation in dose, due to the patchy and non-uniform distribution of Monazite sand, enables in built controls. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation (NLNR) areas. The study carried out since 1995 does not seem to implicate HLNR in the incidence of neural tube defects among newborns

  15. Incidence and predictors of Lhermitte’s sign among patients receiving mediastinal radiation for lymphoma

    International Nuclear Information System (INIS)

    Youssef, Bassem; Shank, JoAnn; Reddy, Jay P.; Pinnix, Chelsea C.; Farha, George; Akhtari, Mani; Allen, Pamela K.; Fanale, Michelle A.; Garcia, John A.; Horace, Patricia H.; Milgrom, Sarah; Smith, Grace Li; Nieto, Yago; Arzu, Isadora; Wang, He; Fowler, Nathan; Rodriguez, Maria Alma; Dabaja, Bouthaina

    2015-01-01

    To prospectively examine the risk of developing Lhermitte’s sign (LS) in patients with lymphoma treated with modern-era chemotherapy followed by consolidation intensity-modulated radiation therapy. We prospectively interviewed all patients with lymphoma who received irradiation to the mediastinum from July 2011 through April 2014. We extracted patient, disease, and treatment-related variables from the medical records of those patients and dosimetric variables from treatment-planning systems and analyzed these factors to identify potential predictors of LS with Pearson chi-square tests. During the study period 106 patients received mediastinal radiation for lymphoma, and 31 (29 %) developed LS. No correlations were found between LS and any of the variables examined, including total radiation dose, maximum point dose to the spinal cord, volume receiving 105 % of the dose, and volumes receiving 5 or 15 Gy. In this group of patients, treatment with chemotherapy followed by intensity-modulated radiation therapy led to 29 % developing LS; this symptom was independent of radiation dose and seemed to be an idiosyncratic reaction. This relatively high incidence could have resulted from prospective use of a structured interview

  16. Incidence and predictors of Lhermitte's sign among patients receiving mediastinal radiation for lymphoma.

    Science.gov (United States)

    Youssef, Bassem; Shank, JoAnn; Reddy, Jay P; Pinnix, Chelsea C; Farha, George; Akhtari, Mani; Allen, Pamela K; Fanale, Michelle A; Garcia, John A; Horace, Patricia H; Milgrom, Sarah; Smith, Grace Li; Nieto, Yago; Arzu, Isadora; Wang, He; Fowler, Nathan; Rodriguez, Maria Alma; Dabaja, Bouthaina

    2015-09-25

    To prospectively examine the risk of developing Lhermitte's sign (LS) in patients with lymphoma treated with modern-era chemotherapy followed by consolidation intensity-modulated radiation therapy. We prospectively interviewed all patients with lymphoma who received irradiation to the mediastinum from July 2011 through April 2014. We extracted patient, disease, and treatment-related variables from the medical records of those patients and dosimetric variables from treatment-planning systems and analyzed these factors to identify potential predictors of LS with Pearson chi-square tests. During the study period 106 patients received mediastinal radiation for lymphoma, and 31 (29 %) developed LS. No correlations were found between LS and any of the variables examined, including total radiation dose, maximum point dose to the spinal cord, volume receiving 105 % of the dose, and volumes receiving 5 or 15 Gy. In this group of patients, treatment with chemotherapy followed by intensity-modulated radiation therapy led to 29 % developing LS; this symptom was independent of radiation dose and seemed to be an idiosyncratic reaction. This relatively high incidence could have resulted from prospective use of a structured interview.

  17. Electromagnetic fields radiated from electrostatic discharges: Theory and experiment

    Science.gov (United States)

    Wilson, Perry F.; Ondrejka, Arthur R.; Ma, Mark T.; Ladbury, John M.

    1988-02-01

    The fields radiated by electrostatic discharges (ESD) are studied both theoretically and experimentally. The ESD spark is modeled theoretically as an electrically short, time dependent, linear dipole situated above an infinite ground plane. Experimentally, sparks of varying voltages are generated by a commercially available simulator and used to excite a number of targets including: (1) the extended inner conductor of a coaxial cable mounted in a ground plane, (2) direct discharges to a ground plane, (3) indirect radiation from a large metal plate, (4) a metal chair over a a ground plane, and (5) a metal trash can. Results show that relatively low-voltage sparks (2 to 4 kV) excite the strongest radiated fields. This suggests that the spark fields can pose a significant interference threat to electronic equipment into the gigahertz range.

  18. Radiation of Electron in the Field of Plane Light Wave

    International Nuclear Information System (INIS)

    Zelinsky, A.; Drebot, I.V.; Grigorev, Yu.N.; Zvonareva, O.D.; Tatchyn, R.

    2006-01-01

    Results of integration of a Lorentz equation for a relativistic electron moving in the field of running, plane, linear polarized electromagnetic wave are presented in the paper. It is shown that electron velocities in the field of the wave are almost periodic functions of time. For calculations of angular spectrum of electron radiation intensity expansion of the electromagnetic field in a wave zone into generalized Fourier series was used. Expressions for the radiation intensity spectrum are presented in the paper. Derived results are illustrated for electron and laser beam parameters of NSC KIPT X-ray generator NESTOR. It is shown that for low intensity of the interacting electromagnetic wave the results of energy and angular spectrum calculations in the frame of classical electrodynamics completely coincide with calculation results produced using quantum electrodynamics. Simultaneously, derived expressions give possibilities to investigate dependence of energy and angular Compton radiation spectrum on phase of interaction and the interacting wave intensity

  19. Topological magnetoelectric effects in microwave far-field radiation

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, M.; Kamenetskii, E. O.; Shavit, R. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

    2016-07-21

    Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

  20. Radiation reaction force and unification of electromagnetic and gravitational fields

    International Nuclear Information System (INIS)

    Lo, C.Y.; Goldstein, G.R.; Napier, A.

    1981-04-01

    A unified theory of electromagnetic and gravitational fields should modify classical electrodynamics such that the radiation reaction force is accounted for. The analysis leads to a five-dimensional unified theory of five variables. The theory is supported by showing that, for the case of a charged particle moving in a constant magnetic field, the radiation reaction force is indeed included. Moreover, this example shows explicitly that physical changes are associated with the fifth variable. Thus, the notion of a physical five-dimensional space should be seriously taken into consideration

  1. A comparison of the quality of image acquisition between the incident dark field and sidestream dark field video-microscopes

    NARCIS (Netherlands)

    E. Gilbert-Kawai; J. Coppel (Jonny); V. Bountziouka (Vassiliki); C. Ince (Can); D. Martin (Daniel)

    2016-01-01

    markdownabstract__Background__ The ‘Cytocam’ is a third generation video-microscope, which enables real time visualisation of the in vivo microcirculation. Based upon the principle of incident dark field (IDF) illumination, this hand held computer-controlled device was designed to address the

  2. A comparison of the quality of image acquisition between the incident dark field and sidestream dark field video-microscopes

    NARCIS (Netherlands)

    Gilbert-Kawai, Edward; Coppel, Jonny; Bountziouka, Vassiliki; Ince, Can; Martin, Daniel; Ahuja, V.; Aref-Adib, G.; Burnham, R.; Chisholm, A.; Clarke, K.; Coates, D.; Coates, M.; Cook, D.; Cox, M.; Dhillon, S.; Dougall, C.; Doyle, P.; Duncan, P.; Edsell, M.; Edwards, L.; Evans, L.; Gardiner, P.; Grocott, M.; Gunning, P.; Hart, N.; Harrington, J.; Harvey, J.; Holloway, C.; Howard, D.; Hurlbut, D.; Imray, C.; Jonas, M.; van der Kaaij, J.; Khosravi, M.; Kolfschoten, N.; Levett, D.; Luery, H.; Luks, A.; Martin, D.; McMorrow, R.; Meale, P.; Mitchell, K.; Montgomery, H.; Morgan, G.; Morgan, J.; Murray, A.; Mythen, M.; Newman, S.; O'Dwyer, M.; Pate, J.; Plant, T.; Pun, M.; Richards, P.; Richardson, A.; Rodway, G.; Simpson, J.; Stroud, C.; Stroud, M.; Stygal, J.; Symons, B.; Szawarski, P.; van Tulleken, A.; van Tulleken, C.; Vercueil, A.; Wandrag, L.; Wilson, M.; Windsor, J.; Basnyat, B.; Clarke, C.; Hornbein, T.; Milledge, J.; West, J.; Abraham, S.; Adams, T.; Anseeuw, W.; Astin, R.; Burdall, O.; Carroll, J.; Cobb, A.; Coppel, J.; Couppis, O.; Court, J.; Cumptsey, A.; Davies, T.; Diamond, N.; Geliot, T.; Gilbert-Kawai, E.; Gilbert-Kawai, G.; Gnaiger, E.; Haldane, C.; Hennis, P.; Horscroft, J.; Jack, S.; Jarvis, B.; Jenner, W.; Jones, G.; Kenth, J.; Kotwica, A.; Kumar, R. B. C.; Lacey, J.; Laner, V.; Mahomed, Z.; Moonie, J.; Mythen, P.; O'Brien, K.; Ruggles-Brice, I.; Salmon, K.; Sheperdigian, A.; Smedley, T.; Tomlinson, C.; Ward, S.; Wight, A.; Wilkinson, C.; Wythe, S.; Feelisch, M.; Hanson, M.; Moon, R.; Peters, M.

    2016-01-01

    Background: The 'Cytocam' is a third generation video-microscope, which enables real time visualisation of the in vivo microcirculation. Based upon the principle of incident dark field (IDF) illumination, this hand held computer-controlled device was designed to address the technical limitations of

  3. Relation between cancer incidence or mortality and external natural background radiation in Japan

    International Nuclear Information System (INIS)

    Ujeno, Y.

    1983-01-01

    Analysis was performed on the relationships between the organ dose-equivalent rate due to natural background radiation (mSv/a) and three parameters of cancer risk: the age-adjusted cancer incidence (patients x 10 5 persons x a -1 ) in 13 large areas, the standardized mortality ratio of cancers in 46 large areas, and the cancer mortality in the population aged more than 40 years old (cancer deaths x 10 5 persons x a -1 ) in 649 small areas. The age-adjusted liver cancer incidence in males fitted the exponential model significantly (p<0.01) and the relationship of stomach cancer mortality of aged males in small areas fitted the linear model significantly (p<0.05). No relationship was observed with regard to female cancer in either case. The relationships between the three parameters and various other cancers of both sexes were not statistically significant. (author)

  4. Linux malware incident response an excerpt from malware forensic field guide for Linux systems

    CERN Document Server

    Malin, Cameron H; Aquilina, James M

    2013-01-01

    Linux Malware Incident Response is a ""first look"" at the Malware Forensics Field Guide for Linux Systems, exhibiting the first steps in investigating Linux-based incidents. The Syngress Digital Forensics Field Guides series includes companions for any digital and computer forensic investigator and analyst. Each book is a ""toolkit"" with checklists for specific tasks, case studies of difficult situations, and expert analyst tips. This compendium of tools for computer forensics analysts and investigators is presented in a succinct outline format with cross-references to suppleme

  5. Causality of relationship between paternal radiation exposure and leukaemia incidence in the children of Sellafield workers

    International Nuclear Information System (INIS)

    Wheldon, T.E.; Mairs, R.J.; Barrett, A.

    1992-01-01

    In this letter the author comments on K.E. Baverstock's case (1991) against the likelihood of a causal relationship between reported leukemia incidence and paternal radiation dose in the children of Sellafield workers, and emphasizes the desirability of devising experimental tests of the germ-cell line damage hypothesis as well as the evaluation of its plausibility. Particular reference is made to the role played by dose-rates and by the two-hit model for childhood acute leukemia. (Letter to the Editor)

  6. Health status of grandchildren of subjects occupationally exposed to chronic radiation. Communication 3. Disease incidence

    International Nuclear Information System (INIS)

    Petrushkina, N.P.; Musatkova, O.B.

    1996-01-01

    The morbidity of 1557 grandchildren of subjects occupationally exposed to chronic radiation were analyzed. Three groups were singled out. Group 1 consisted of children whose grandfathers were exposed, group 2 of children grandmothers were exposed and group 3 of children whose both grandparent were exposed. Total morbidity level and morbidity structure for 13 classes of diseases and 60 nosological entities was assessed. The study showed that disease incidence in general, structure by disease and individual nosological entities, the share of frequently falling ill children, and health index in the test group corresponded to those in controls. Reliable differences were observed only for respiratory diseases, at the expense of acute respiratory diseases, which were frequent during the second-third years of life in children whose both grandparents were occupationally exposed to radiation [ru

  7. Maximal near-field radiative heat transfer between two plates

    Science.gov (United States)

    Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

    2013-09-01

    Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

  8. Numerical Calculation of Electric Fields in Housing Spaces due to Electromagnetic Radiation from Antennas for Mobile Communication

    Directory of Open Access Journals (Sweden)

    H.-P. Geromiller

    2004-01-01

    Full Text Available The influence of electromagnetic radiation from mobile antennas on humans is under discussion in various group of scientists. This paper deals with the impact of electromagnetic radiation in housing spaces. The space is assumed to be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetic transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source of radiation is considered to be far away from the housing, the radiation is regarded as a plane wave. Due to the high signal frequency and the ferroconcrete walls, 5 sides of the housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.

  9. SU-E-T-208: Incidence Cancer Risk From the Radiation Treatment for Acoustic Neuroma Patient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D [Kyung Hee University International Med. Serv., Seoul (Korea, Republic of); Chung, W [Kyung Hee University Hospital at Gangdong, Seoul, Seoul (Korea, Republic of); Shin, D [Kyung Hee University Hospital, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2014-06-01

    Purpose: The present study aimed to compare the incidence risk of a secondary cancer from therapeutic doses in patients receiving intensitymodulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Methods: Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their incidnece excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were estimated using the corresponding therapeutic doses measured at various organs by radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. Results: When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, normal liver, colon, bladder, prostate (or ovary), and rectum were measured. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A LAR were estimated that more than 0.03% of AN patients would get radiation-induced cancer. Conclusion: The tyroid was highest radiation-induced cancer risk after radiation treatment for AN. We found that LAR can be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

  10. Fog-82: A Cooperative Field Study of Radiation Fog.

    Science.gov (United States)

    Meyer, Michael B.; Garland Lala, G.; Jiusto, James E.

    1986-07-01

    The Cloud Physics Section of the Atmospheric Sciences Research Center-State University of New York at Albany conducted a cooperative field study (FOG-82) during the autumn of 1982 as part of an ongoing radiation-fog research program. A computer-controlled data-acquisition system consisting of sophisticated soil, surface, and boundary-layer sensors, as well as contemporary aerosol and droplet probes was developed. These data are being used to address a variety of critical problems related to radiation-fog evolution.Scientists from 10 universities and research laboratories participated in portions of FOG-82. Research objectives included studies of fog mesoscale meteorology, radiation studies, low-level water budget, vertical fog structure, fog supersaturation, condensation nuclei, and fog-water chemistry, as well as radiation-fog life cycles. A comprehensive description of the FOG-82 program and objectives is presented.

  11. Magnetic fields driven by tidal mixing in radiative stars

    Science.gov (United States)

    Vidal, Jérémie; Cébron, David; Schaeffer, Nathanaël; Hollerbach, Rainer

    2018-04-01

    Stellar magnetism plays an important role in stellar evolution theory. Approximatively 10 per cent of observed main sequence (MS) and pre-main-sequence (PMS) radiative stars exhibit surface magnetic fields above the detection limit, raising the question of their origin. These stars host outer radiative envelopes, which are stably stratified. Therefore, they are assumed to be motionless in standard models of stellar structure and evolution. We focus on rapidly rotating, radiative stars which may be prone to the tidal instability, due to an orbital companion. Using direct numerical simulations in a sphere, we study the interplay between a stable stratification and the tidal instability, and assess its dynamo capability. We show that the tidal instability is triggered regardless of the strength of the stratification (Brunt-Väisälä frequency). Furthermore, the tidal instability can lead to both mixing and self-induced magnetic fields in stably stratified layers (provided that the Brunt-Väisälä frequency does not exceed the stellar spin rate in the simulations too much). The application to stars suggests that the resulting magnetic fields could be observable at the stellar surfaces. Indeed, we expect magnetic field strengths up to several Gauss. Consequently, tidally driven dynamos should be considered as a (complementary) dynamo mechanism, possibly operating in radiative MS and PMS stars hosting orbital companions. In particular, tidally driven dynamos may explain the observed magnetism of tidally deformed and rapidly rotating Vega-like stars.

  12. Non-ionizing radiation exposure: electric field strength measurement ...

    African Journals Online (AJOL)

    ... up to 3GHz, connected to spectrum analyzer. In this research, the measured values are compared with the international standard recommended by ICNIRP then were also compared with previous study from several locations around Malaysia. The result shows an increase in the values of electromagnetic field radiation.

  13. [Dynamics of biomacromolecules in coherent electromagnetic radiation field].

    Science.gov (United States)

    Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I

    2014-01-01

    It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.

  14. Effects of a power and photon energy of incident light on near-field etching properties

    Science.gov (United States)

    Yatsui, T.; Saito, H.; Nishioka, K.; Leuschel, B.; Soppera, O.; Nobusada, K.

    2017-12-01

    We developed a near-field etching technique for realizing an ultra-flat surfaces of various materials and structures. To elucidate the near-field etching properties, we have investigated the effects of power and the photon energy of the incident light. First, we established theoretically that an optical near-field with photon energy lower than the absorption edge of the molecules can induce molecular vibrations. We used nanodiamonds to study the power dependence of the near-field etching properties. From the topological changes of the nanodiamonds, we confirmed the linear-dependence of the etching volume with the incident power. Furthermore, we studied the photon energy dependence using TiO2 nanostriped structures, which revealed that a lower photon energy results in a lower etching rate.

  15. Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

    Science.gov (United States)

    Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

    2016-07-01

    The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

  16. Correlation between Auroral kilometric radiation and field-aligned currents

    International Nuclear Information System (INIS)

    Green, J.L.; Saflekos, N.A.; Gurnett, D.A.; Potemra, T.A.

    1982-01-01

    Simultaneous observations of field-aligned currents (FAC) and auroral kilometric radiation (AKR) are compared from the polar-orbiting satellites Triad and Hawkeye. The Triad observations were restricted to the evening-to-midnight local time sector (1900 to 0100 hours magnetic local time) in the northern hemisphere. This is the region in which the most intense storms of AKR are believed to originate. The Hawkeye observations were restricted to when the satellite was in the AKR emission cone in the northern hemisphere and at radial distances > or =7R/sub E/ (earth radii) to avoid local propagation cutoff effects. A(R/7R/sub E/) 2 normalization to the power flux measurements of the kilometric radiation from Hawkeye is used to take into account the radial dependence of this radiation and to scale all intensity measurements so that they are independent of Hawkeye's position in the emission cone. Integrated field-aligned current intensities from Triad are determined from the observed transverse magnetic field disturbances. There appears to be a weak correlation between AKR intensity and the integrated current sheet intensity of field-aligned currents. In general, as the intensity of auroral kilometric radiation increases so does the integrated auroral zone current sheet intensity increase. Statistically, the linear correlation coefficient between the log of the AKR power flux and the log of the current sheet intensity is 0.57. During weak AKR bursts ( - 18 W m - 2 Hz - 1 ), Triad always observed weak FAC'S ( - 1 ), and when Triad observed large FAC's (> or =0.6 A m - 1 ), the AKR intensity from Hawkeye was moderately intense (10 - 5 to 10 - 14 W m - 2 Hz - 1 ) to intense (>10 - 14 W m - 2 Hz - 1 ). It is not clear from these preliminary results what the exact role is that auroral zone field-aligned currents play in the generation or amplification of auroral kilometric radiation

  17. Spatial variation of natural radiation and childhood leukaemia incidence in Great Britain

    International Nuclear Information System (INIS)

    Richardson, Sylvia; Monfort, Christine; Green, Martyn; Muirhead, Colin; Draper, Gerald

    1995-01-01

    This paper describes an analysis of the geographical variation of childhood leukaemia incidence in Great Britain over a 15 year period in relation to natural radiation (gamma and radon). Data at the level of the 459 district level local authorities in England, Wales and regional districts in Scotland are analysed in two complementary ways: first, by Poisson regressions with the inclusion of environmental covariates and a smooth spatial structure; secondly, by a hierarchical Bayesian model in which extra-Poisson variability is modelled explicitly in terms of spatial and non-spatial components. From this analysis, we deduce a strong indication that a main part of the variability is accounted for by a local neighbourhood 'clustering' structure. This structure is furthermore relatively stable over the 15 year period for the lymphocytic leukaemias which make up the majority of observed cases. We found no evidence of a positive association of childhood leukaemia incidence with outdoor or indoor gamma radiation levels. There is no consistent evidence of any association with radon levels. Indeed, in the Poisson regressions, a significant positive association was only observed for one 5-year period, a result which is not compatible with a stable environmental effect. Moreover, this positive association became clearly non-significant when over-dispersion relative to the Poisson distribution was taken into account. (author)

  18. Simulation of the radiation fields from ionizing radiation sources inside the containment in an accident

    Science.gov (United States)

    Kalugin, M. A.

    2010-12-01

    In the present work, a set of codes used for simulations of the radiation fields from ionizing radiation sources inside the containment in an accident is described. A method of evaluating the gamma dose rate from a space and energy distributed source is given. The dose rate is calculated by means of the design point kernel method and using buildup factors. The code MCU-REA with the ORIMCU module is used for the burnup calculations.

  19. Finite-element-analysis of fields radiated from ICRF antenna

    International Nuclear Information System (INIS)

    Yamanaka, Kaoru; Sugihara, Ryo.

    1984-01-01

    The electromagnetic fields radiated from a loop antenna on which an oscillating current flows across the static magnetic field B 0 are calculated in several simple geometries by the finite element method (FEM) and by analytical methods in a cross section of a plasma cylinder. The wave number along B 0 is assumed to be finite. Good agreement between FEM and the analytical solutions is obtained, demonstrating the accuracy of the FEM solutions. The method is used to calculate the fields from a half-turn antenna, and acceptable results are obtained. (author)

  20. Two-Dimensional Electron System in Electromagnetic Radiation Field

    Science.gov (United States)

    Lungu, Radu Paul; Manolescu, Andrei

    We consider a two-dimensional electron gas in the presence of a monochromatic linear polarized electromagnetic field, within the Floquet formalism. The Floquet states have a simple relation with the energy eigenstates in the absence of the field. Therefore the single-particle and the two-particle Green functions of the many-body system with Coulomb interactions, in the radiation field, can be formally calculated by the standard diagrammatic techniques, as for the conservative system. We derive the elementary excitations of quasi-particle type, the plasma dispersion relation, and the ground state quasi-energy, and we relate them to the corresponding results for the conservative system.

  1. Analysis of radiation fields in tomography on diffusion gaseous sound

    International Nuclear Information System (INIS)

    Bekman, I.N.

    1999-01-01

    Perspectives of application of equilibrium and stationary variants of diffusion tomography with radioactive gaseous sounds for spatial reconstruction of heterogeneous media in materials technology were considered. The basic attention were allocated to creation of simple algorithms of detection of sound accumulation on the background of monotonically varying concentration field. Algorithms of transformation of two-dimensional radiation field in three-dimensional distribution of radiation sources were suggested. The methods of analytical elongation of concentration field permitting separation of regional anomalies on the background of local ones and vice verse were discussed. It was shown that both equilibrium and stationary variants of diffusion tomography detect the heterogeneity of testing material, provide reduction of spatial distribution of elements of its structure and give an estimation of relative degree of defectiveness

  2. Unusual reflection of electromagnetic radiation from a stack of graphene layers at oblique incidence

    International Nuclear Information System (INIS)

    Bludov, Yu V; Peres, N M R; Vasilevskiy, M I

    2013-01-01

    We study the interaction of electromagnetic (EM) radiation with single-layer graphene and a stack of parallel graphene sheets at arbitrary angles of incidence. It is found that the behavior is qualitatively different for transverse magnetic (or p-polarized) and transverse electric (or s-polarized) waves. In particular, the absorbance of single-layer graphene attains a minimum (maximum) for the p (s)-polarization at the angle of total internal reflection when the light comes from a medium with a higher dielectric constant. In the case of equal dielectric constants of the media above and beneath graphene, for grazing incidence graphene is almost 100% transparent to p-polarized waves and acts as a tunable mirror for the s-polarization. These effects are enhanced for a stack of graphene sheets, so the system can work as a broad band polarizer. It is shown further that a periodic stack of graphene layers has the properties of a one-dimensional photonic crystal, with gaps (or stop bands) at certain frequencies. When an incident EM wave is reflected from this photonic crystal, the tunability of the graphene conductivity renders the possibility of controlling the gaps, and the structure can operate as a tunable spectral-selective mirror. (paper)

  3. A management plan for hospitals and medical centers facing radiation incidents.

    Science.gov (United States)

    Davari, Fereshteh; Zahed, Arash

    2015-09-01

    Nowadays, application of nuclear technology in different industries has largely expanded worldwide. Proportionately, the risk of nuclear incidents and the resulting injuries have, therefore, increased in recent years. Preparedness is an important part of the crisis management cycle; therefore efficient preplanning seems crucial to any crisis management plan. Equipped with facilities and experienced personnel, hospitals naturally engage with the response to disasters. The main purpose of our study was to present a practical management pattern for hospitals and medical centers in case they encounter a nuclear emergency. In this descriptive qualitative study, data were collected through experimental observations, sources like Safety manuals released by the International Atomic Energy Agency and interviews with experts to gather their ideas along with Delphi method for polling, and brainstorming. In addition, the 45 experts were interviewed on three targeted using brainstorming and Delphi method. We finally proposed a management plan along with a set of practicality standards for hospitals and medical centers to optimally respond to nuclear medical emergencies when a radiation incident happens nearby. With respect to the great importance of preparedness against nuclear incidents adoption and regular practice of nuclear crisis management codes for hospitals and medical centers seems quite necessary.

  4. A management plan for hospitals and medical centers facing radiation incidents

    Directory of Open Access Journals (Sweden)

    Fereshteh Davari

    2015-01-01

    Full Text Available Background: Nowadays, application of nuclear technology in different industries has largely expanded worldwide. Proportionately, the risk of nuclear incidents and the resulting injuries have, therefore, increased in recent years. Preparedness is an important part of the crisis management cycle; therefore efficient preplanning seems crucial to any crisis management plan. Equipped with facilities and experienced personnel, hospitals naturally engage with the response to disasters. The main purpose of our study was to present a practical management pattern for hospitals and medical centers in case they encounter a nuclear emergency. Materials and Methods: In this descriptive qualitative study, data were collected through experimental observations, sources like Safety manuals released by the International Atomic Energy Agency and interviews with experts to gather their ideas along with Delphi method for polling, and brainstorming. In addition, the 45 experts were interviewed on three targeted using brainstorming and Delphi method. Results: We finally proposed a management plan along with a set of practicality standards for hospitals and medical centers to optimally respond to nuclear medical emergencies when a radiation incident happens nearby. Conclusion: With respect to the great importance of preparedness against nuclear incidents adoption and regular practice of nuclear crisis management codes for hospitals and medical centers seems quite necessary.

  5. New theory of radiative energy transfer in free electromagnetic fields

    International Nuclear Information System (INIS)

    Wolf, E.

    1976-01-01

    A new theory of radiative energy transfer in free, statistically stationary electromagnetic fields is presented. It provides a model for energy transport that is rigorous both within the framework of the stochastic theory of the classical field as well as within the framework of the theory of the quantized field. Unlike the usual phenomenological model of radiative energy transfer that centers around a single scalar quantity (the specific intensity of radiation), our theory brings into evidence the need for characterizing the energy transport by means of two (related) quantities: a scalar and a vector that may be identified, in a well-defined sense, with ''angular components'' of the average electromagnetic energy density and of the average Poynting vector, respectively. Both of them are defined in terms of invariants of certain new electromagnetic correlation tensors. In the special case when the field is statistically homogeneous, our model reduces to the usual one and our angular component of the average electromagnetic energy density, when multiplied by the vacuum speed of light, then acquires all the properties of the specific intensity of radiation. When the field is not statistically homogeneous our model approximates to the usual phenomenological one, provided that the angular correlations between plane wave modes of the field extend over a sufficiently small solid angle of directions about the direction of propagation of each mode. It is tentatively suggested that, when suitably normalized, our angular component of the average electromagnetic energy density may be interpreted as a quasi-probability (general quantum-mechancial phase-space distribution function, such as Wigner's) for the position and the momentum of a photon

  6. Ways of providing radiation resistance of magnetic field semiconductor sensors

    CERN Document Server

    Bolshakova, I A; Holyaka, R; Matkovskii, A; Moroz, A

    2001-01-01

    Hall magnetic field sensors resistant to hard ionizing irradiation are being developed for operation under the radiation conditions of space and in charged particle accelerators. Radiation resistance of the sensors is first determined by the properties of semiconductor materials of sensitive elements; we have used microcrystals and thin layers of III-V semiconductors. Applying complex doping by rare-earth elements and isovalent impurities in certain proportions, we have obtained magnetic field sensors resistant to irradiation by fast neutrons and gamma-quanta. Tests of their radiation resistance were carried out at IBR-2 at the Joint Institute for Nuclear Research (Dubna). When exposed to neutrons with E=0.1-13 MeV and intensity of 10 sup 1 sup 0 n cm sup - sup 2 s sup - sup 1 , the main parameter of the sensors - their sensitivity to magnetic fields - changes by no more than 0.1% up to fluences of 10 sup 1 sup 4 n cm sup - sup 2. Further improvement of radiation resistance of sensor materials is expected by ...

  7. Wind field forecast for accidental release of radiative materials

    International Nuclear Information System (INIS)

    Kang Ling; Chen Jiayi; Cai Xuhui

    2003-01-01

    A meso-scale wind field forecast model was designed for emergency environmental assessment in case of accidental release of radiative materials from a nuclear power station. Actual practice of the model showed that it runs fast, has wind field prediction function, and the result given is accurate. With meteorological data collected from weather stations, and pre-treated by a wind field diagnostic model, the initial wind fields at different times were inputted as initial values and assimilation fields for the forecasting model. The model, in turn, worked out to forecast meso-scale wind field of 24 hours in a horizontal domain of 205 km x 205 km. And then, the diagnostic model was employed again with the forecasting data to obtain more detail information of disturbed wind field by local terrain in a smaller domain of 20.5 km x 20.5 km, of which the nuclear power station is at the center. Using observation data in January, April, July and October of 1996 over the area of Hangzhou Bay, wind fields in these 4 months were simulated by different assimilation time and number of the weather stations for a sensitive test. Results indicated that the method used here has increased accuracy of the forecasted wind fields. And incorporating diagnostic method with the wind field forecast model has greatly increased efficiency of the wind field forecast for the smaller domain. This model and scheme have been used in Environmental Consequence Assessment System of Nuclear Accident in Qinshan Area

  8. A characteristic scale in radiation fields of fractal clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wiscombe, W.; Cahalan, R.; Davis, A.; Marshak, A. [Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    The wavenumber spectrum of Landsat imagery for marine stratocumulus cloud shows a scale break when plotted on a double log plot. We offer an explanation of this scale break in terms of smoothing by horizontal radiative fluxes, which is parameterized and incorporated into an improved pixel approximation. We compute the radiation fields emerging from cloud models with horizontally variable optical depth fractal models. We use comparative spectral and multifractal analysis to qualify the validity of the independent pixel approximation at the largest scales and demonstrate it`s shortcomings on the smallest scales.

  9. Plasma ICR heating antennas: adaptation, radiated field structure, coupling

    International Nuclear Information System (INIS)

    Pegourie, B.

    1982-01-01

    The transmission line theory has been used to find the antenna adapattion improvement possibilities, so as to optimize the power transfer from generator to plasma. ICR heating antennas are described, radiated magnetic field is measured, and superstructures (diaphragms and electrostatic screen) is studied from a mock-up and a numerical model. Results about antenna radiation and electric property modifications due to superstructures, without plasma, are presented. At last, TFR antenna coupling properties, in terms of frequency, electromagnetic wave and plasma conditions, are studied. In the whole work, we tried to define, when possible the construction criteria fitted to cyclotron heating in the big tokamak experiments under construction [fr

  10. Obligations and responsibilities in radiation protection in the medical field

    International Nuclear Information System (INIS)

    2011-01-01

    This document briefly presents the various obligations and responsibilities of the various actors involved in or concerned by radiation protection in the medical field: the hospital administration (with respect to workers and patients), the physician (authorization and declaration, justification, optimization), the medical electro-radiology operator, the person with expertise in medical radio-physics (PSRPM), the radio-pharmacist (he is required in nuclear medicine with internal use of pharmaceutical product), the personnel with expertise in radiation protection (PCR), and other health professionals

  11. Compliance with High-Intensity Radiated Fields Regulations - Emitter's Perspective

    Science.gov (United States)

    Statman, Joseph; Jamnejad, Vahraz; Nguyen, Lee

    2012-01-01

    NASA's Deep Space Network (DSN) uses high-power transmitters on its large antennas to communicate with spacecraft of NASA and its partner agencies. The prime reflectors of the DSN antennas are parabolic, at 34m and 70m in diameter. The DSN transmitters radiate Continuous Wave (CW) signals at 20 kW - 500 kW at X-band and S-band frequencies. The combination of antenna reflector size and high frequency results in a very narrow beam with extensive oscillating near-field pattern. Another unique feature of the DSN antennas is that they (and the radiated beam) move mostly at very slow sidereal rate, essentially identical in magnitude and at the opposite direction of Earth rotation.The DSN is in the process of revamping its documentation to provide analysis of the High Intensity Radiation Fields (HIRF) environment resulting from radio frequency radiation from DSN antennas for comparison to FAA regulations regarding certification of HIRF protection as outlined in the FAA regulations on HIRF protection for aircraft electrical and electronic systems (Title 14, Code of Federal Regulations (14 CFR) [section sign][section sign] 23.1308, 25.1317, 27.1317, and 29.1317).This paper presents work done at JPL, in consultation with the FAA. The work includes analysis of the radiated field structure created by the unique DSN emitters (combination of transmitters and antennas) and comparing it to the fields defined in the environments in the FAA regulations. The paper identifies areas that required special attention, including the implications of the very narrow beam of the DSN emitters and the sidereal rate motion. The paper derives the maximum emitter power allowed without mitigation and the mitigation zones, where required.Finally, the paper presents summary of the results of the analyses of the DSN emitters and the resulting DSN process documentation.

  12. Can Angiotensin-Converting Enzyme Inhibitors Reduce the Incidence, Severity, and Duration of Radiation Proctitis?

    International Nuclear Information System (INIS)

    Alashkham, Abduelmenem; Paterson, Catherine; Rauchhaus, Petra; Nabi, Ghulam

    2016-01-01

    Purpose: To determine whether participants taking angiotensin-converting enzyme inhibitors (ACEIs) and treated with radical radiation therapy with neoadjuvant/adjuvant hormone therapy have less incidence, severity, and duration of radiation proctitis. Methods and Materials: A propensity score analysis of 817 patients who underwent radical radiation therapy with neoadjuvant or adjuvant hormone therapy as primary line management in a cohort study during 2009 to 2013 was conducted. Patients were stratified as follows: group 1, hypertensive patients taking ACEIs (as a study group); group 2, nonhypertensive patients not taking ACEIs; and group 3, hypertensive patients not taking ACEIs (both as control groups). The incidence, severity, and duration of proctitis were the main outcome. χ 2 tests, Mann-Whitney U tests, analysis of variance, risk ratio (RR), confidence interval (CI), Kaplan-Meier plots, and log-rank tests were used. Results: The mean age of the participants was 68.91 years, with a follow-up time of 3.38 years. Based on disease and age-matched comparison, there was a statistically significant difference of proctitis grading between the 3 groups: χ 2 (8, n=308) = 72.52, P<.001. The Mann-Whitney U test indicated that grades of proctitis were significantly lower in hypertensive patients taking ACEIs than in nonhypertensive patients not taking ACEIs and hypertensive patients not taking ACEIs (P<.001). The risk ratio (RR) of proctitis in hypertensive patients taking ACEIs was significantly lower than in hypertensive patients not taking ACEIs (RR 0.40, 95% CI 0.30-0.53, P<.001) and in nonhypertensive patients not taking ACEIs (RR 0.58, 95% CI 0.44-0.77, P<.001). Time to event analysis revealed that hypertensive patients taking ACEIs were significantly different from the control groups (P<.0001). Furthermore, hypertensive patients taking ACEIs had significantly faster resolution of proctitis (P<.0001). Conclusion: Patients who were taking ACEIs were

  13. Can Angiotensin-Converting Enzyme Inhibitors Reduce the Incidence, Severity, and Duration of Radiation Proctitis?

    Energy Technology Data Exchange (ETDEWEB)

    Alashkham, Abduelmenem, E-mail: alashkham@yahoo.com [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom); Paterson, Catherine [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom); Rauchhaus, Petra [Tayside Clinical Trials Unit, School of Medicine, University of Dundee, Scotland (United Kingdom); Nabi, Ghulam [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom)

    2016-01-01

    Purpose: To determine whether participants taking angiotensin-converting enzyme inhibitors (ACEIs) and treated with radical radiation therapy with neoadjuvant/adjuvant hormone therapy have less incidence, severity, and duration of radiation proctitis. Methods and Materials: A propensity score analysis of 817 patients who underwent radical radiation therapy with neoadjuvant or adjuvant hormone therapy as primary line management in a cohort study during 2009 to 2013 was conducted. Patients were stratified as follows: group 1, hypertensive patients taking ACEIs (as a study group); group 2, nonhypertensive patients not taking ACEIs; and group 3, hypertensive patients not taking ACEIs (both as control groups). The incidence, severity, and duration of proctitis were the main outcome. χ{sup 2} tests, Mann-Whitney U tests, analysis of variance, risk ratio (RR), confidence interval (CI), Kaplan-Meier plots, and log-rank tests were used. Results: The mean age of the participants was 68.91 years, with a follow-up time of 3.38 years. Based on disease and age-matched comparison, there was a statistically significant difference of proctitis grading between the 3 groups: χ{sup 2} (8, n=308) = 72.52, P<.001. The Mann-Whitney U test indicated that grades of proctitis were significantly lower in hypertensive patients taking ACEIs than in nonhypertensive patients not taking ACEIs and hypertensive patients not taking ACEIs (P<.001). The risk ratio (RR) of proctitis in hypertensive patients taking ACEIs was significantly lower than in hypertensive patients not taking ACEIs (RR 0.40, 95% CI 0.30-0.53, P<.001) and in nonhypertensive patients not taking ACEIs (RR 0.58, 95% CI 0.44-0.77, P<.001). Time to event analysis revealed that hypertensive patients taking ACEIs were significantly different from the control groups (P<.0001). Furthermore, hypertensive patients taking ACEIs had significantly faster resolution of proctitis (P<.0001). Conclusion: Patients who were taking ACEIs were

  14. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

    Science.gov (United States)

    Bhatia, A. K.; Sinha, Chandana

    2010-01-01

    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  15. Time-dependent scattering of incident light of various wavelengths in ferrofluids under external magnetic field

    Science.gov (United States)

    Jin, Jingyu; Song, Dongxing; Geng, Jiafeng; Jing, Dengwei

    2018-02-01

    Ferrofluids can exhibit the anisotropic thermodynamic properties under magnetic fields. The dynamic optical properties of ferrofluids in the presence of magnetic fields are of particular interest due to their potential application as various optical devices. Although time-dependent light scattering by ferrofluids have been extensively studied, the effect of wavelength of incident light have been rarely considered. Here, for the first time, we investigated both the time- and wavelength-dependent light scattering in water based ferrofluids containing Fe3O4 nanoparticles under an external magnetic field. The field-induced response behavior of the prepared ferrofluid samples was determined and verified first by thermal conductivity measurement and numerical simulation. Double-beam UV-Vis spectrophotometer was employed to record the temporal evolution of transmitted intensity of incident light of various wavelengths passing through the ferrofluid sample and propagating parallel to the applied field. As expected, the light intensity decreases to a certain value right after the field is turned on due to the thermal fluctuation induced disorder inside the flexible particle chains. Then the light intensity further decreases with time until the appearance of a minimum at time τ0 followed by an inversed increase before finally reaches equilibrium at a particular time. More importantly, the characteristic inversion time τ0 was found to follow a power law increase with the wavelength of incident light (τ0 ∼ λα, where α = 2.07). A quantitative explanation for the wavelength dependence of characteristic time was proposed based on the finite-difference time-domain (FDTD) method. The simulation results are in good agreement with our experimental observations. The time-dependent light scattering in ferrofluids under different incident wavelengths was rationalized by considering both the coarsening process of the particle chains and the occurrence of resonance within the

  16. Assessment of ionizing radiation as a risk factor for breast cancer incidence in Goiania

    International Nuclear Information System (INIS)

    Lage, Leonardo Bastos

    2016-01-01

    This research aims to evaluate whether exposure to ionizing radiation to which women are subjected can be associated with the incidence of breast cancer in Goiania. The defined study area is the central region of Goiania, or the Sanitary Districts of Campinas-Centro and Sul, in which are the seven major accident sources of contamination with Cesium 137, and also, as shown by previous study, the majority of new cases of breast cancer (60,43 %). We used the geographical division of the city in census tracts and health districts. The data collection was divided in two stages: the first, for the survey of radiometric measurements, and the second, for identifying the addresses of women diagnosed with breast cancer. The radiometric survey occurred between 2010 and 2014, in which was used an environmental gamma radiation mobile measuring system. This system was composed by a high-sensitivity detector coupled to a Global Positioning System (GPS) and a microcomputer. The assembly was installed on a motor vehicle so that the height of the detector is found at one meter from the ground, and programmed to obtain a measurement of the doses absorbed in the air rate each second. The data collected were: doses absorbed in the air rate, geographical coordinates, altitude, date and time of acquisition. From Mobisys software, files were generated and from ArcGIS 10.0 platform, geospatial assessment survey through the elaboration of thematic maps and geospatial analysis statistics. The annual averages of effective doses and collective effective doses were estimated from the rate of doses absorbed in air collected by the system and the resident population in the census tracts. The second stage begun from the data collection at the Registry of Goiania's Population Based Cancer (RCBPGO), in which were identified addresses of women diagnosed with breast cancer between 2001 and 2010. Part of the data was geographically referenced and using census data were estimated and compared the

  17. Characterization of a CT ionization chamber for radiation field mapping

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Vivolo, Vitor, E-mail: vivolo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Xavier, Marcos, E-mail: mxavier@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Khoury, Helen J., E-mail: hjkhoury@gmail.com [Universidade Federal de Pernambuco, Departamento de Energia Nuclear, Av. Prof. Luiz Freire 1000, 50740-540, Recife, PE (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil)

    2012-07-15

    A pencil-type ionization chamber, developed at Instituto de Pesquisas Energeticas e Nucleares (IPEN), was characterized with the objective to verify the possibility of its application in radiation field mapping procedures. The characterization tests were evaluated, and the results were satisfactory. The results obtained for the X radiation field mapping with the homemade chamber were compared with those of a PTW Farmer-type chamber (TN 30011-1). The maximum difference observed in this comparison was only 1.25%, showing good agreement. - Highlights: Black-Right-Pointing-Pointer A new ionization chamber was made and tested for radiation field mapping. Black-Right-Pointing-Pointer This ionization chamber was made using only accessible low cost materials. Black-Right-Pointing-Pointer The operational tests were made and the results were within the recommended limits. Black-Right-Pointing-Pointer The field map was compared with a commercial chamber presenting a 1.25% difference. Black-Right-Pointing-Pointer Our chamber presents potential for assurance reliability in calibration procedures.

  18. Electric field deformation in diamond sensors induced by radiation defects

    Energy Technology Data Exchange (ETDEWEB)

    Kassel, Florian; Boer, Wim de; Boegelspacher, Felix; Dierlamm, Alexander; Mueller, Thomas; Steck, Pia [Institut fuer Experimentelle Kernphysik (IEKP), Karlsruher Institut fuer Technologie (KIT) (Germany); Dabrowski, Anne; Guthoff, Moritz [CERN (Switzerland)

    2016-07-01

    The BCML system is a beam monitoring device in the CMS experiment at the LHC. As detectors 32 poly-crystalline CVD diamond sensors are positioned in a ring around the beam pipe at a distance of ±1.8 m and ±14.4 m from the interaction point. The radiation hardness of the diamond sensors in terms of measured signal during operation was significantly lower than expected from laboratory measurements. At high particle rates, such as those occurring during the operation of the LHC, a significant fraction of the defects act as traps for charge carriers. This space charge modifies the electrical field in the sensor bulk leading to a reduction of the charge collection efficiency (CCE). A diamond irradiation campaign was started to investigate the rate dependent electrical field deformation with respect to the radiation damage. Besides the electrical field measurements via the Transient Current Technique, the CCE was measured. The experimental results were used to create an effective trap model that takes the radiation damage into account. Using this trap model the rate dependent electrical field deformation and the CCE were simulated with the software ''SILVACO TCAD''. This talk compares the experimental measurement results with the simulations.

  19. ESTIMATION OF TOTAL SOLAR RADIATION INCIDENT ON AN INCLINED SURFACE OF A SOUTH-FACING GREENHOUSE ROOF

    Directory of Open Access Journals (Sweden)

    RONOH E.K.

    2017-12-01

    Full Text Available Solar radiation is the driving force for the surface energy balance in buildings such as greenhouses. Greenhouses are generally tilted towards the sun in order to maximize the solar irradiance on the surfaces. Precise computation of the solar radiation received on these surfaces assumes an important role in the energy simulation. It is practical to calculate the total solar irradiance on inclined surfaces based on the solar global and diffuse radiation intensities on horizontal surfaces. This study focused on estimating the total solar radiation incident on inclined greenhouse roof surfaces. In this work, a south-facing thermal box inclined at 26.5° from the horizontal was used for solar radiation measurements. Additionally, recorded solar radiation data were retrieved for the study location and used to develop an empirical correlation. The conversion factors for the beam, the diffuse and the reflected solar radiation components were essential in the prediction of the total solar radiation incident on the tilted surface. The measured solar radiation data were then compared with the simulated data. The model performance was assessed using both graphical and statistical methods. Overall, locally calibrated data led to a satisfactory improvement in estimation of the total solar radiation on an inclined surface.

  20. Vavilov-Cherenkov radiation as a cause of transition radiation anomalous intensity in case of electron grazing incidence on the silver surface

    International Nuclear Information System (INIS)

    Zrelov, V.P.; Ruzicka, J.

    1979-01-01

    On the basis of the Vavilov-Cherenkov effect the anomaly in the transition radiation (TR) spectrum is explained which has been first observed by Boersch for grazing particle incidence on the silver surface. The contribution of the Vavilov-Cherenkov radiation to the angle distribution of photons of the TR is estimated. Special attention is drawn to a possibility of the nonthreshold character of Vavilov-Cherenkov radiation in such a medium as silver, and to a necessity of creating a complete theory of Vavilov-Cherenkov radiation for absorbing media

  1. A Computational Model of Cellular Response to Modulated Radiation Fields

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, Stephen J., E-mail: stephen.mcmahon@qub.ac.uk [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Butterworth, Karl T. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); McGarry, Conor K. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Trainor, Colman [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); O' Sullivan, Joe M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Hounsell, Alan R. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom)

    2012-09-01

    Purpose: To develop a model to describe the response of cell populations to spatially modulated radiation exposures of relevance to advanced radiotherapies. Materials and Methods: A Monte Carlo model of cellular radiation response was developed. This model incorporated damage from both direct radiation and intercellular communication including bystander signaling. The predictions of this model were compared to previously measured survival curves for a normal human fibroblast line (AGO1522) and prostate tumor cells (DU145) exposed to spatially modulated fields. Results: The model was found to be able to accurately reproduce cell survival both in populations which were directly exposed to radiation and those which were outside the primary treatment field. The model predicts that the bystander effect makes a significant contribution to cell killing even in uniformly irradiated cells. The bystander effect contribution varies strongly with dose, falling from a high of 80% at low doses to 25% and 50% at 4 Gy for AGO1522 and DU145 cells, respectively. This was verified using the inducible nitric oxide synthase inhibitor aminoguanidine to inhibit the bystander effect in cells exposed to different doses, which showed significantly larger reductions in cell killing at lower doses. Conclusions: The model presented in this work accurately reproduces cell survival following modulated radiation exposures, both in and out of the primary treatment field, by incorporating a bystander component. In addition, the model suggests that the bystander effect is responsible for a significant portion of cell killing in uniformly irradiated cells, 50% and 70% at doses of 2 Gy in AGO1522 and DU145 cells, respectively. This description is a significant departure from accepted radiobiological models and may have a significant impact on optimization of treatment planning approaches if proven to be applicable in vivo.

  2. A Computational Model of Cellular Response to Modulated Radiation Fields

    International Nuclear Information System (INIS)

    McMahon, Stephen J.; Butterworth, Karl T.; McGarry, Conor K.; Trainor, Colman; O’Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2012-01-01

    Purpose: To develop a model to describe the response of cell populations to spatially modulated radiation exposures of relevance to advanced radiotherapies. Materials and Methods: A Monte Carlo model of cellular radiation response was developed. This model incorporated damage from both direct radiation and intercellular communication including bystander signaling. The predictions of this model were compared to previously measured survival curves for a normal human fibroblast line (AGO1522) and prostate tumor cells (DU145) exposed to spatially modulated fields. Results: The model was found to be able to accurately reproduce cell survival both in populations which were directly exposed to radiation and those which were outside the primary treatment field. The model predicts that the bystander effect makes a significant contribution to cell killing even in uniformly irradiated cells. The bystander effect contribution varies strongly with dose, falling from a high of 80% at low doses to 25% and 50% at 4 Gy for AGO1522 and DU145 cells, respectively. This was verified using the inducible nitric oxide synthase inhibitor aminoguanidine to inhibit the bystander effect in cells exposed to different doses, which showed significantly larger reductions in cell killing at lower doses. Conclusions: The model presented in this work accurately reproduces cell survival following modulated radiation exposures, both in and out of the primary treatment field, by incorporating a bystander component. In addition, the model suggests that the bystander effect is responsible for a significant portion of cell killing in uniformly irradiated cells, 50% and 70% at doses of 2 Gy in AGO1522 and DU145 cells, respectively. This description is a significant departure from accepted radiobiological models and may have a significant impact on optimization of treatment planning approaches if proven to be applicable in vivo.

  3. Neutron and photon spectrometry in mixed radiation fields

    International Nuclear Information System (INIS)

    Jancar, A.; Kopecky, Z.; Veskrna, M.

    2014-01-01

    Spectrometric measurements of the mixed fields of neutron and photon radiation in the workplaces with the L-R-0 research reactor located in the UJV Rez and with the Van de Graaff accelerator, located in the UTEF laboratories Prague, are presented in this paper. The experimental spectrometric measurements were performed using a newly developed digital measuring system, based on the technology of analog-digital converters with a very high sampling frequency (up to 2 GHz), in connection with organic scintillation detector, type BC-501A, and stilbene detector. The results of experimental measurements show high quality of spectrometry mixed fields of neutron and photon radiation across the wide dynamic range of measured energy. (authors)

  4. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Executive summary

    International Nuclear Information System (INIS)

    Jacob, P.; Paretzke, H.G.; Roth, P.

    2000-01-01

    The Association Contract covers a range of research domains that are important to the Radiation Protection Research Action, especially in the areas 'Evaluation of Radiation Risks' and 'Understanding Radiation Mechanisms and Epidemiology'. Three research projects concentrate on radiation dosimetry research and two projects on the modelling of radiation carcinogenesis. The following list gives an overview on the topics and responsible scientific project leaders of the Association Contract: Study of radiation fields and dosimetry at aviation altitudes. Biokinetics and dosimetry of incorporated radionuclides. Dose reconstruction. Biophysical models for the induction of cancer by radiation. Experimental data for the induction of cancer by radiation of different qualities. (orig.)

  5. Numerical Calculation of Electric Fields in Housing Spaces Due to Electromagnetic Radiation from Antennas for Mobile Communication

    Directory of Open Access Journals (Sweden)

    H.-P. Geromiller

    2003-01-01

    Full Text Available The influence of electromagnetic radiation from mobile antennas on humans is under discussion in va'rious groups ofscientists, This paper deals with the impact ofelectromagnetic radiation in a housing space. The space is assumedto be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetically transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source ofradiation is considered to be far away from the housing, the radiation is regarded to be from a plane wave. Due to the high signal frequency and ferroconcrete walls, 5 sides ofthe housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.

  6. Axial acoustic radiation force on a sphere in Gaussian field

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Rongrong; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    Based on the finite series method, the acoustical radiation force resulting from a Gaussian beam incident on a spherical object is investigated analytically. When the position of the particles deviating from the center of the beam, the Gaussian beam is expanded as a spherical function at the center of the particles and the expanded coefficients of the Gaussian beam is calculated. The analytical expression of the acoustic radiation force on spherical particles deviating from the Gaussian beam center is deduced. The acoustic radiation force affected by the acoustic frequency and the offset distance from the Gaussian beam center is investigated. Results have been presented for Gaussian beams with different wavelengths and it has been shown that the interaction of a Gaussian beam with a sphere can result in attractive axial force under specific operational conditions. Results indicate the capability of manipulating and separating spherical spheres based on their mechanical and acoustical properties, the results provided here may provide a theoretical basis for development of single-beam acoustical tweezers.

  7. Simulation analysis of radiation fields inside phantoms for neutron irradiation

    International Nuclear Information System (INIS)

    Satoh, Daiki; Takahashi, Fumiaki; Endo, Akira; Ohmachi, Y.; Miyahara, N.

    2007-01-01

    Radiation fields inside phantoms have been calculated for neutron irradiation. Particle and heavy-ion transport code system PHITS was employed for the calculation. Energy and size dependences of neutron dose were analyzed using tissue equivalent spheres of different size. A voxel phantom of mouse was developed based on CT images of an 8-week-old male C3H/HeNs mouse. Deposition energy inside the mouse was calculated for 2- and 10-MeV neutron irradiation. (author)

  8. Solar ultraviolet radiation in Syria measurements and relationship with skin cancer incidence

    International Nuclear Information System (INIS)

    Othman, I; Baydon, S.A.; Dawood, S.

    1994-11-01

    Seasonal variations of solar UVB (285-320) and UVA (320-400) were measured in three sites in Syria (33-37 N sup O) for two years: 1992-1993. UVB measurements were performed using polysulphone films and Robertson-Berger meter, while UVA measurements were done by NVA intensity meter. Two sets of measurements were carried out : - Maximal daily doses three times a week (every other day) - Diurnal variations from sun-rise to sun-set every two hours twice a month (every fortnight). The biological consequences of ultraviolet radiation withreference to some epidemiological data of skin cancer incidence in Syria since 1980 were discussed .(author). 36 refs., 21 figs., 11 tabs

  9. Mirror and grating surface figure requirements for grazing incidence synchrotron radiation beamlines: Power loading effects

    Energy Technology Data Exchange (ETDEWEB)

    Hulbert, S.L.; Sharma, S.

    1987-01-01

    At present, grazing incidence mirrors are used almost exclusively as the first optical element in VUV and soft x-ray synchrotron radiation beamlines. The performance of these mirrors is determined by thermal and mechanical stress-induced figure errors as well as by figure errors remaining from the grinding and polishing process. With the advent of VUV and soft x-ray undulators and wigglers has come a new set of thermal stress problems related to both the magnitude and the spatial distribution of power from these devices. In many cases the power load on the entrance slits and gratings in these beamlines is no longer negligible. The dependence of thermally-induced front-end mirror figure errors on various storage ring and insertion device parameters (especially those at the National Synchrotron Light Source) and the effects of these figure errors on two classes of soft x-ray beamlines are presented.

  10. Determination, through of thermoluminescence dosimetry, of the incident radiation in critical organs, during cephalometric radiographies

    International Nuclear Information System (INIS)

    Hipolito Junior, O. di; Goncalves, N.; Boscolo, F.N.; Montebelo Filho, A.

    1985-01-01

    The object of this paper was to value and to compare the doses of X-ray incident in critical orgas of patient and operator, during cephalometric radiography. Each patient was submited for two radiographics expositions. First of all, they use the followings factors: 85 kVp, 15 mA and 4/10 s of exposition; while of the second radiography the conditions were of 70 kVp, 15 mA and 1.2 s of exposition. The dosimetric method was the thermoluminescent through the LiF-700. Although the cephalometric radiographies showed similars qualities, in bot conditions where the equipment functioned, the situation of high voltage was noted small doses of radiation. (author) [pt

  11. High-flux normal incidence monochromator for circularly polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Schaefers, F.; Peatman, W.; Eyers, A.; Heckenkamp, C.; Schoenhense, G.; Heinzmann, U.

    1986-01-01

    A 6.5-m normal incidence monochromator installed at the storage ring BESSY, which is optimized for a high throughput of circularly polarized off-plane radiation at moderate resolution is described. The monochromator employs two exit slits and is specially designed and used for low-signal experiments such as spin- and angle-resolved photoelectron spectroscopy on solids, adsorbates, free atoms, and molecules. The Monk--Gillieson mounting (plane grating in a convergent light beam) allows for large apertures with relatively little astigmatism. With two gratings, a flux of more than 10 11 photons s -1 bandwidth -1 (0.2--0.5 nm) with a circular polarization of more than 90% in the wavelength range from 35 to 675 nm is achieved

  12. Mark IV 'Grasshopper' grazing incidence mono-chromator for the Canadian Synchrotron Radiation Facility (CSRF)

    International Nuclear Information System (INIS)

    Tan, K.H.; Bancroft, G.M.; Coatsworth, L.L.; Yates, B.W.

    1982-01-01

    The vacuum, mechanical, and optical characteristics of a 'Grasshopper' grazing incidence monochromator for use with a synchrotron radiation source in the 30-300 eV range is described. The monochromator is compatible with ultrahigh vacuum ( -10 Torr throughout), and the motor driven scan mechanism is linear and reliable. The monchromator has been calibrated using several known absorption edges between 36 and 102 eV and a nonlinear least squares fit to the scan equation. These same absorption edges, plus a scan over zero order, show that the present resolution of the monochromator (with 10 and 16 μm exit and entrance slits respectively) is 0.16 A (0.06 eV at the AlLsub(2,3) edge). With 10 μm entrance and exit slits the resolution will be very close to the theoretical Δlambda = 0.083 A

  13. Interaction of Electromagnetic Radiation with Supercritical Magnetic Field

    OpenAIRE

    Shabad, A. E.

    2003-01-01

    It is pointed, that effects of refraction of electromagnetic radiation in the medium, formed by the magnetized vacuum, become essential already for relatively soft photons, not hard enough to create an electron-positron pair, including those belonging to soft gamma-, X-ray, optic and radio- range, if the magnetic field B exceeds the critical value of Bcr=m^2/e=4.4 10^13 Gauss. Three leading terms in the asymptotic expansion of the one-loop polarization operator in a constant magnetic field ar...

  14. Theory and analysis of a large field polarization imaging system with obliquely incident light.

    Science.gov (United States)

    Lu, Xiaotian; Jin, Weiqi; Li, Li; Wang, Xia; Qiu, Su; Liu, Jing

    2018-02-05

    Polarization imaging technology provides information about not only the irradiance of a target but also the polarization degree and angle of polarization, which indicates extensive application potential. However, polarization imaging theory is based on paraxial optics. When a beam of obliquely incident light passes an analyser, the direction of light propagation is not perpendicular to the surface of the analyser and the applicability of the traditional paraxial optical polarization imaging theory is challenged. This paper investigates a theoretical model of a polarization imaging system with obliquely incident light and establishes a polarization imaging transmission model with a large field of obliquely incident light. In an imaging experiment with an integrating sphere light source and rotatable polarizer, the polarization imaging transmission model is verified and analysed for two cases of natural light and linearly polarized light incidence. Although the results indicate that the theoretical model is consistent with the experimental results, the theoretical model distinctly differs from the traditional paraxial approximation model. The results prove the accuracy and necessity of the theoretical model and the theoretical guiding significance for theoretical and systematic research of large field polarization imaging.

  15. Thermal Hawking radiation of black hole with supertranslation field

    Science.gov (United States)

    Iofa, Mikhail Z.

    2018-01-01

    Using the analytical solution for the Schwarzschild metric containing supertranslation field, we consider two main ingredients of calculation of the thermal Hawking black hole radiation: solution for eigenmodes of the d'Alambertian and solution of the geodesic equations for null geodesics. For calculation of Hawking radiation it is essential to determine the behavior of both the eigenmodes and geodesics in the vicinity of horizon. The equation for the eigenmodes is solved, first, perturbatively in the ratio O( C) /M of the supertranslation field to the mass of black hole, and, next, non-perturbatively in the near- horizon region. It is shown that in any order of perturbation theory solution for the eigenmodes in the metric containing supertranslation field differs from solution in the pure Schwarzschild metric by terms of order L 1/2 = (1 - 2 M/r)1/2. In the non-perturbative approach, solution for the eigenmodes differs from solution in the Schwarzschild metric by terms of order L 1/2 which vanish on horizon. Using the simplified form of geodesic equations in vicinity of horizon, it is shown that in vicinity of horizon the null geodesics have the same behavior as in the Schwarzschild metric. As a result, the density matrices of thermal radiation in both cases are the same.

  16. Investigation of Radiation Fields at Aircraft Altitudes (invited paper)

    International Nuclear Information System (INIS)

    O'Sullivan, D.; Bartlett, D.; Grillmaier, R.; Heinrich, W.; Lindborg, L.; Schraube, H.; Silari, M.; Tommasino, L.; Zhou, D.

    2000-01-01

    Cosmic rays are believed to originate from several possible sources and recent research suggests that the bulk originate from the gas and dust of the interstellar medium and are accelerated by strong shock waves driven by supernova explosions. Cosmic ray particles are made up of γ98.5% hydrogen and helium and only 1.5% have charges greater than 2. Their average energy is about 1 GeV/nucleon and they lose energy through ionisation interactions and nuclear interactions with atoms of air as they penetrate deeply into the Earth's atmosphere. A very complicated radiation field develops as particles are generated by successive interaction of primary and secondary nuclei and a cascade of hadrons is produced in the atmosphere. The intensity of particles reaches a maximum at about 20 km above sea level (γ60 g.cm -2 ). The relative abundances of different particles change with depth within the atmosphere and mainly muons which are the decay products of charged mesons, reach sea level because of their weak interaction. The radiation field produced and consequently its effect on aircrew and frequent travellers is a matter of some concern. This paper outlines the results of investigations carried out to determine the characteristics of this radiation field and assess its impact on aircrew. (author)

  17. Field profile tailoring in a-Si:H radiation detectors

    International Nuclear Information System (INIS)

    Fujieda, I.; Cho, G.; Conti, M.; Drewery, J.; Kaplan, S.N.; Perez-Mendez, V.; Quershi, S.; Wildermuth, D.; Street, R.A.

    1990-03-01

    The capability of tailoring the field profile in reverse-biased a-Si:H diodes by doping and/or manipulating electrode shapes opens a way to many interesting device structures. Charge collection in a-Si:H radiation detectors is improved for high LET particle detection by inserting thin doped layers into the i-layer of the usual p-i-n diode. This buried p-i-n structure enables us to apply higher reverse-bias and the electric field is enhanced in the mid i-layer. Field profiles of the new structures are calculated and the improved charge collection process is discussed. Also discussed is the possibility of field profile tailoring by utilizing the fixed space charges in i-layers and/or manipulating electrode shapes of the reverse-biased p-i-n diodes. 10 refs., 7 figs

  18. The right choice: extremity dosemeter for different radiation fields

    International Nuclear Information System (INIS)

    Brasik, N.; Stadtmann, H.; Kindl, P.

    2005-01-01

    Full text: Measurements of weakly penetrating radiation in personal dosimetry present problems in the design of suitable detectors and in the interpretation of their readings. For the measurement of the individual beta radiation dose, personal dosemeter for the fingers/tips are required. In general, the dosemeters currently used for personal monitoring of beta and low energy photon doses suffer from an energy threshold problem because the detector and/or the filter are too thick. TLDs of a standard thickness can seriously underestimate personal skin doses, especially in external fields of weakly penetrating radiation fields. LiF:Mg, Cu, P is a promising TL material which allows the production of thin detectors with sufficient sensitivity. Dosimetric properties of two different types of extremity dosemeters, designed to measure the personal dose equivalent Hp(0.07), have been compared: LiF:Mg, Ti (TLD100) and LiF:Mg, Cu, P (TLD700H). The first one consists of 100 mg.cm -2 LiF:Mg, Ti (TLD 100) chip and a 35mg. cm -2 cap, the other consists of a 7mg. cm -2 layer of LiF:Mg, Cu, P (TLD-700H) powder and a 5mg. cm -2 cap. The evaluation was done in two steps: performance tests (ISO-12794) and measurements in real workplaces. In the first step type test results for beta calibration were compared. In addition calibration for low energy photon radiation according to ISO 4037-3 was carried out. In the second step, simultaneous measurements with both types of dosemeters were performed at workplaces, where radiopharmaceuticals containing different radioisotopes are prepared and applied. Practices in these fields are characterized by handling of high activities at very small distances between source and skin. The results from the comparison of the two dosemeter types are presented and analyzed with respect to different radiation fields. Experiments showed a satisfactory sensitivity for the thinner dosemeter (TLD 700H) for detecting beta radiation at protection levels and a good

  19. Infant Brain Tumors: Incidence, Survival, and the Role of Radiation Based on Surveillance, Epidemiology, and End Results (SEER) Data

    International Nuclear Information System (INIS)

    Bishop, Andrew J.; McDonald, Mark W.; Chang, Andrew L.; Esiashvili, Natia

    2012-01-01

    Purpose: To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables. Methods and Materials: The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age. Results: Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to <2 CPM. For infants with medulloblastoma, desmoplastic histology and treatment with both surgery and upfront radiation were associated with improved survival, but on multivariate regression, only combined surgery and radiation remained associated with improved survival, with a hazard ratio for death of 0.17 compared with surgery alone (p = 0.005). For ATRTs, those treated with surgery and upfront radiation had a 12-month survival of 100% compared with 24.4% for those treated with surgery alone (p = 0.016). For ependymomas survival was higher in patients treated in more recent decades (p = 0.001). Conclusion: The incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation

  20. An evaluation of early countermeasures to reduce the risk of internal radiation exposure after the Fukushima nuclear incident in Japan.

    Science.gov (United States)

    Nomura, Shuhei; Tsubokura, Masaharu; Gilmour, Stuart; Hayano, Ryugo S; Watanabe, Yuni N; Kami, Masahiro; Kanazawa, Yukio; Oikawa, Tomoyoshi

    2016-05-01

    After a radiation-release incident, intake of radionuclides in the initial stage immediately following the incident may be the major contributor to total internal radiation exposure for individuals in affected areas. However, evaluation of early internal contamination risk is greatly lacking. This study assessed the relationship between initial stage evacuation/indoor sheltering and internal radiation contamination levels 4 months after the 2011 Fukushima nuclear incident in Japan and estimated potential pathways of the contamination. The study population comprised 525 participants in the internal radiation screening program at Minamisoma Municipal General Hospital, 23 km north of the Fukushima nuclear plant. The analysed dataset included the results of a screening performed in July 2011, 4 months after the incident, and of a questionnaire on early-incident response behaviours, such as sheltering indoors and evacuations, completed by participants. Association between such early countermeasures and internal contamination levels of cesium-134 were assessed using Tobit multiple regression analyses. Our study shows that individuals who evacuated to areas outside Fukushima Prefecture had similar contamination levels of cesium-134 to individuals who stayed in Fukushima (relative risk: 0.86; 95% confidence interval: 0.74-0.99). Time spent outdoors had no significant relationship with contamination levels. The effects of inhalation from radiological plumes released from the nuclear plant on total internal radiation contamination might be so low as to be undetectable by the whole-body counting unit used to examine participants. Given the apparent limited effectiveness of evacuation and indoor sheltering on internal contamination, the decision to implement such early responses to a radiation-release incident should be made by carefully balancing their potential benefits and health risks. © The Author 2015. Published by Oxford University Press. All rights reserved. For

  1. A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis

    Science.gov (United States)

    Endoh, Takahiro; Inazu, Daisuke; Waseda, Takuji; Hibiya, Toshiyuki

    2018-04-01

    The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.

  2. Recovery from Iridium-192 flakes of a radioactive source for industrial use after a radiation incident

    International Nuclear Information System (INIS)

    Cruz, W.H.; Zapata, L.A.

    2013-01-01

    The Iridium-192 ( 192 Ir) is the most used and ideal for industrial radiography applications, especially in petrochemical plants and pipelines and provides better contrast sensitivity for thick (25.4 mm). This source has constructive sealed double encapsulation, the internal capsule containing stainless steel to radioactive material in the form of flakes and welded with TIG process. The radiological incident happened at a gas station fuel sales in circumstances in which there was a homogeneity test welds a tank, the flakes or Ir-192 fell off his ponytail and left scattered over an area of 2 m 2 , some fell flat areas and other land so collected in lead shielding and metal container and ground source. Full recovery of the leaflets was performed at the Division of radioactive waste management (GRRA) gaining a total of 22 flakes with no radiation risk to staff performance and installation and the conclusion was reached that the misapplicaion of TIG welding was the main cause the incident. (author)

  3. Incidence of Leukoencephalopathy After Whole-Brain Radiation Therapy for Brain Metastases

    International Nuclear Information System (INIS)

    Ebi, Junko; Sato, Hisashi; Nakajima, Masaru; Shishido, Fumio

    2013-01-01

    Purpose: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases. Methods and Materials: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.0. The patients who had brain tumor recurrence after WBRT were censored at the last follow-up CT or MRI without recurrence. To evaluate the risk factors for leukoencephalopathy, bivariate analysis was performed using a logistic regression analysis adjusted for follow-up time. Factors included in the analysis were age, gender, dose fractionation, 5-fluorouracil, methotrexate, cisplatin, and other chemotherapeutic agents. Results: The median age of the 111 patients was 60.0 years (range, 23-89 years). The median follow-up was 3.8 months (range, 1.0-38.1 months). Leukoencephalopathy developed in 23 of the 111 patients. Grades 1, 2, and 3 were observed in 8, 7, and 8 patients, respectively. The incidence was 34.4% (11 of 32), 42.9% (6 of 14), 66.7% (2 of 3), and 100% (2 of 2) of the patients who were followed up for ≥6, ≥12, ≥24, and ≥36 months, respectively. In the bivariate analysis, older age (≥65 years) was significantly correlated with higher risk of leukoencephalopathy (odds ratio 3.31; 95% confidence interval 1.15-9.50; P=.03). Conclusions: The incidence of leukoencephalopathy after WBRT was 34.4% with ≥6 months follow-up, and increased with longer follow-up. Older age was a significant risk factor. The schedule of WBRT for patients with brain metastases should be carefully determined, especially for favorable patients

  4. Incidence of Leukoencephalopathy After Whole-Brain Radiation Therapy for Brain Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Ebi, Junko, E-mail: junkoe@fmu.ac.jp [Department of Radiology, Fukushima Medical University, Fukushima (Japan); Sato, Hisashi; Nakajima, Masaru; Shishido, Fumio [Department of Radiology, Fukushima Medical University, Fukushima (Japan)

    2013-04-01

    Purpose: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases. Methods and Materials: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.0. The patients who had brain tumor recurrence after WBRT were censored at the last follow-up CT or MRI without recurrence. To evaluate the risk factors for leukoencephalopathy, bivariate analysis was performed using a logistic regression analysis adjusted for follow-up time. Factors included in the analysis were age, gender, dose fractionation, 5-fluorouracil, methotrexate, cisplatin, and other chemotherapeutic agents. Results: The median age of the 111 patients was 60.0 years (range, 23-89 years). The median follow-up was 3.8 months (range, 1.0-38.1 months). Leukoencephalopathy developed in 23 of the 111 patients. Grades 1, 2, and 3 were observed in 8, 7, and 8 patients, respectively. The incidence was 34.4% (11 of 32), 42.9% (6 of 14), 66.7% (2 of 3), and 100% (2 of 2) of the patients who were followed up for ≥6, ≥12, ≥24, and ≥36 months, respectively. In the bivariate analysis, older age (≥65 years) was significantly correlated with higher risk of leukoencephalopathy (odds ratio 3.31; 95% confidence interval 1.15-9.50; P=.03). Conclusions: The incidence of leukoencephalopathy after WBRT was 34.4% with ≥6 months follow-up, and increased with longer follow-up. Older age was a significant risk factor. The schedule of WBRT for patients with brain metastases should be carefully determined, especially for favorable patients.

  5. Effects of radiation on the incidence of prostate cancer among Nagasaki atomic bomb survivors.

    Science.gov (United States)

    Kondo, Hisayoshi; Soda, Midori; Mine, Mariko; Yokota, Kenichi

    2013-10-01

    Atomic bomb survivors have been reported to have an increased risk of some cancers, especially leukemia. However, the risk of prostate cancer in atomic bomb survivors is not known to have been examined previously. This study examined the association between atomic bomb radiation and the incidence of prostate cancer among male Nagasaki atomic bomb survivors. The subjects were classified by distance from the hypocenter into a proximal group (<2 km), a distal group (≥2 km), and an early entrance group (those who entered the region <2 km from the hypocenter within 2 weeks after the explosion). Between 1996 and 2009, 631 new cases of prostate cancer were identified among approximately 18 400 male Nagasaki atomic bomb survivors who were alive in 1996. The Cox proportional hazard model was used to estimate the risk of prostate cancer development, with adjustment for age at atomic bomb explosion, attained age, smoking status, and alcohol consumption. Compared with the distal group, the proximal group had significant increased risks of total, localized, and high-grade prostate cancer (relative risk and 95% confidence interval: 1.51 [1.21-1.89]; 1.80 [1.26-2.57]; and 1.88 [1.20-2.94], respectively). This report is the first known to reveal a significant relationship between atomic bomb radiation and prostate cancer. © 2013 Japanese Cancer Association.

  6. TU-D-201-04: Veracity of Data Elements in Radiation Oncology Incident Learning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kapur, A [Northwell Health System, New Hyde Park, NY (United States); Evans, S [Yale University New Haven, CT (United States); Brown, D [University of California, San Diego, La Jolla, CA (United States); Ezzell, G [Mayo Clinic Arizona, Phoenix, AZ (United States); Hoopes, D [The University of California San Diego, San Diego, CA (United States); Dieterich, S [UC Davis Medical Center, Sacramento, CA (United States); Kapetanovic, K; Tomlinson, C [American Society for Radiation Oncology, Fairfax, VA (United States)

    2016-06-15

    Purpose: Incident learning systems encompass volumes, varieties, values, and velocities of underlying data elements consistent with the V’s of big data. Veracity, the 5th V however exists only if there is high inter-rater reliability (IRR) within the data elements. The purpose of this work was to assess IRR in the nationally deployed RO-ILS: Radiation Oncology-Incident Learning System (R) sponsored by the American Society for Radiation Oncology (ASTRO) and the American Association of Physicists in Medicine (AAPM). Methods: Ten incident reports covering a wide range of scenarios were created in standardized narrative and video formats and disseminated to 67 volunteers of multiple disciplines from 26 institutions along with two published narratives from the International Commission of Radiological Protection to assess IRR on a nationally representative level. The volunteers were instructed to independently enter the associated data elements in a test version of RO-ILS over a 3-week period. All responses were aggregated into a spreadsheet to assess IRR using free-marginal kappa metrics. Results: 48 volunteers from 21 institutions completed all reports in the study period. The average kappa score for all raters across all critical data elements was 0.659 [range 0.326–1.000]. Statistically significant differences (p <0.05) were noted between reporters of different disciplines and raters with varying levels of experience. Kappa scores were high for event classification (0.781) and contributory factors (0.777) and low for likelihood-of-harm (0.326). IRR was highest among AAPM-ASTRO members (0.672) and lowest among trainees (0.463). Conclusion: A moderate-to-substantial level of IRR in RO-ILS was noted in this study. Although the number of events reviewed in this study was small, opportunities for improving the taxonomy for the lower scoring data elements as well as specific educational targets for training were identified by assessing data veracity quantitatively

  7. TU-D-201-04: Veracity of Data Elements in Radiation Oncology Incident Learning Systems

    International Nuclear Information System (INIS)

    Kapur, A; Evans, S; Brown, D; Ezzell, G; Hoopes, D; Dieterich, S; Kapetanovic, K; Tomlinson, C

    2016-01-01

    Purpose: Incident learning systems encompass volumes, varieties, values, and velocities of underlying data elements consistent with the V’s of big data. Veracity, the 5th V however exists only if there is high inter-rater reliability (IRR) within the data elements. The purpose of this work was to assess IRR in the nationally deployed RO-ILS: Radiation Oncology-Incident Learning System (R) sponsored by the American Society for Radiation Oncology (ASTRO) and the American Association of Physicists in Medicine (AAPM). Methods: Ten incident reports covering a wide range of scenarios were created in standardized narrative and video formats and disseminated to 67 volunteers of multiple disciplines from 26 institutions along with two published narratives from the International Commission of Radiological Protection to assess IRR on a nationally representative level. The volunteers were instructed to independently enter the associated data elements in a test version of RO-ILS over a 3-week period. All responses were aggregated into a spreadsheet to assess IRR using free-marginal kappa metrics. Results: 48 volunteers from 21 institutions completed all reports in the study period. The average kappa score for all raters across all critical data elements was 0.659 [range 0.326–1.000]. Statistically significant differences (p <0.05) were noted between reporters of different disciplines and raters with varying levels of experience. Kappa scores were high for event classification (0.781) and contributory factors (0.777) and low for likelihood-of-harm (0.326). IRR was highest among AAPM-ASTRO members (0.672) and lowest among trainees (0.463). Conclusion: A moderate-to-substantial level of IRR in RO-ILS was noted in this study. Although the number of events reviewed in this study was small, opportunities for improving the taxonomy for the lower scoring data elements as well as specific educational targets for training were identified by assessing data veracity quantitatively

  8. Twelve years of cooperation in the field of radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Grapengiesser, Sten; Bennerstedt, Torkel

    2005-06-01

    SSI has pursued an international cooperation program since 1992 within the field of radiation protection and emergency preparedness for radiation accidents with the three Baltic countries as main beneficiaries. As the Baltic countries are members of the EU since May 2004, this bilateral support will now be phased out and replaced with other forms of cooperation. During the years passed, a large number of activities have been launched with a total budget of some 14 million ECU. The Baltic radiation protection authorities have played a big role in the cooperation and Baltic ministries, universities, nuclear technology installations and other industries using radiation have also been engaged in the projects. SKI, SKB, Studsvik and the Swedish nuclear power plants should be mentioned as major cooperation partners on the Swedish side. During autumn 2004 when such a large coordinated work program was coming to an end, SSI decided to hold a seminar with the purpose to follow up experiences from the work and discuss coming forms of cooperation. The seminar took place on the 18 of November 2004 and gathered some 80 participants, 29 of which from the Baltic countries. It was opened by Lars-Erik Holm, the SSI Director General, and the three Baltic countries then presented their views and impressions from the passed years of cooperation. The seminar was concluded with a panel discussion on 'How to proceed from today's situation'. The result was that SSI invited to a new coordination meeting during autumn 2005 to follow up and discuss coordination of radiation protection around the Baltic Sea together with the other Nordic radiation protection authorities.

  9. Twelve years of cooperation in the field of radiation protection

    International Nuclear Information System (INIS)

    Grapengiesser, Sten; Bennerstedt, Torkel

    2005-06-01

    SSI has pursued an international cooperation program since 1992 within the field of radiation protection and emergency preparedness for radiation accidents with the three Baltic countries as main beneficiaries. As the Baltic countries are members of the EU since May 2004, this bilateral support will now be phased out and replaced with other forms of cooperation. During the years passed, a large number of activities have been launched with a total budget of some 14 million ECU. The Baltic radiation protection authorities have played a big role in the cooperation and Baltic ministries, universities, nuclear technology installations and other industries using radiation have also been engaged in the projects. SKI, SKB, Studsvik and the Swedish nuclear power plants should be mentioned as major cooperation partners on the Swedish side. During autumn 2004 when such a large coordinated work program was coming to an end, SSI decided to hold a seminar with the purpose to follow up experiences from the work and discuss coming forms of cooperation. The seminar took place on the 18 of November 2004 and gathered some 80 participants, 29 of which from the Baltic countries. It was opened by Lars-Erik Holm, the SSI Director General, and the three Baltic countries then presented their views and impressions from the passed years of cooperation. The seminar was concluded with a panel discussion on 'How to proceed from today's situation'. The result was that SSI invited to a new coordination meeting during autumn 2005 to follow up and discuss coordination of radiation protection around the Baltic Sea together with the other Nordic radiation protection authorities

  10. Imaging radiation pneumonitis in a rat model of a radiological terrorism incident

    Science.gov (United States)

    Molthen, Robert; Wu, QingPing; Krenz, Gary; Medhora, Meetha; Jacobs, Elizabeth; Moulder, John E.

    2009-02-01

    We have developed a rat model of single, sub-lethal thoracic irradiation. Our irradiation protocol is considered representative of exposures near the detonation site of a dirty bomb or small nuclear device. The model is being used to investigate techniques for identifying, triaging and treating possible victims. In addition to physiological markers of right ventricular hypertrophy, pulmonary vascular resistance, and arterial distensibility, we present two methods for quantifying microvascular density. We used methods including microfocal X-ray imaging to investigate changes in lung structure/function resulting from radiation exposure. Radiation pneumonitis is a complication in subjects receiving thoracic irradiation. A radiographic hallmark of acute radiation pneumonitis is a diffuse infiltrate corresponding to the radiation treatment field. We describe two methods for quantifying small artery dropout that occurs in the model at the same time-period. Rats were examined 3-days, 2-weeks, 1-month (m), 2-m, 5-m, and 12-m post-irradiation and compared with aged-matched controls. Right ventricular hypertrophy and increases in pulmonary vascular resistance were present during the pneumonitis phase. Vascular injury was dependent on dose and post-irradiation duration. Rats irradiated with 5 Gy had few detectable changes, whereas 10 Gy resulted in a significant decrease in both microvascular density and arterial distensibility around 2- m, the decrease in each lessening, but extending through 12-m. In conclusion, rats irradiated with a 10 Gy dose had changes in vascular structure concurrent with the onset of radiation pneumonitis that were detectable with our imaging techniques and these structural changes persist after resolution of the pneumonitis.

  11. Radiation-like scalar field and gauge fields in cosmology for a theory with dynamical time

    Science.gov (United States)

    Benisty, David; Guendelman, E. I.

    2016-09-01

    Cosmological solutions with a scalar field behaving as radiation are obtained, in the context of gravitational theory with dynamical time. The solution requires the spacial curvature of the universe k, to be zero, unlike the standard radiation solutions, which do not impose any constraint on the spatial curvature of the universe. This is because only such k = 0 radiation solutions pose a homothetic Killing vector. This kind of theory can be used to generalize electromagnetism and other gauge theories, in curved spacetime, and there are no deviations from standard gauge field equation (like Maxwell equations) in the case there exist a conformal Killing vector. But there could be departures from Maxwell and Yang-Mills equations, for more general spacetimes.

  12. Qualification of gammacell-220 calibration field for radiation processing at the radiation Technology Centre, Kwabenya

    International Nuclear Information System (INIS)

    Emi-Reynolds, G.; Banini, G.K.

    1997-01-01

    The Gammacell-220 being used for the calibration of dosimeters and subsequently the qualification of the large gamma facility for radiation processing has been mapped out. The Ferrous ammonium sulfate (Fricke) solution was used as the dosimetry standard for the study. Filling the irradiation chamber with ampoules of the dosimeter, four horizontal planes each of 28 ampoules were used to obtain four separate isodose curves in the four horizontal planes. Another set of arrangement was used to determine the isodose curves along the vertical axis of the chamber through the center. The isodose curves of the radiation field are presented. (author) 7 refs.; 9 figs

  13. Controlling radiation fields in siemans designed light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Riess, R.; Marchl, T. [Siemens Power Generation Group, Erlangen (Germany)

    1995-03-01

    An essential item for the control of radiation fields is the minimization of the use of satellites in the reactor systems of Light Water Reactors (LWRs). A short description of the qualification of Co-replacement materials will be followed by an illustration of the locations where these materials were implemented in Siemens designed LWRs. Especially experiences in PWRs show the immense influence of reduction of cobalt sources on dose rate buildup. The corrosion and the fatique and wear behavior of the replacement materials has not created concern up to now. A second tool to keep occupational radiation doses at a low level in PWRs is the use of the modified B/Li-chemistry. This is practized in Siemens designed plants by keeping the Li level at a max. value of 2 ppm until it reaches a pH (at 300{degrees}C) of {approximately}7.4. This pH is kept constant until the end of the cycle. The substitution of cobalt base alloys and thus the removal of the Co-59 sources from the system had the largest impact on the radiation levels. Nonetheless, the effectiveness of the coolant chemistry should not be neglected either. Several years of successful operation of PWRs with the replacement materials resulted in an occupational radiation exposure which is below 0.5 man-Sievert/plant and year.

  14. High ionization radiation field remote visualization device - shielding requirements

    International Nuclear Information System (INIS)

    Fernandez, Antonio P. Rodrigues; Omi, Nelson M.; Silveira, Carlos Gaia da; Calvo, Wilson A. Pajero

    2011-01-01

    The high activity sources manipulation hot-cells use special and very thick leaded glass windows. This window provides a single sight of what is being manipulated inside the hot-cell. The use of surveillance cameras would replace the leaded glass window, provide other sights and show more details of the manipulated pieces, using the zoom capacity. Online distant manipulation may be implemented, too. The limitation is their low ionizing radiation resistance. This low resistance also limited the useful time of robots made to explore or even fix problematic nuclear reactor core, industrial gamma irradiators and high radioactive leaks. This work is a part of the development of a high gamma field remote visualization device using commercial surveillance cameras. These cameras are cheap enough to be discarded after the use for some hours of use in an emergency application, some days or some months in routine applications. A radiation shield can be used but it cannot block the camera sight which is the shield weakness. Estimates of the camera and its electronics resistance may be made knowing each component behavior. This knowledge is also used to determine the optical sensor type and the lens material, too. A better approach will be obtained with the commercial cameras working inside a high gamma field, like the one inside of the IPEN Multipurpose Irradiator. The goal of this work is to establish the radiation shielding needed to extend the camera's useful time to hours, days or months, depending on the application needs. (author)

  15. Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

    Science.gov (United States)

    Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

    2016-01-01

    A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates over the evanescent sound field because of broadening of the wavenumber spectrum. Therefore, we calculated the optimum distribution of the particle velocity on the vibrating plate to reduce the broadening of the wavenumber spectrum. We focused on a window function that is utilized in the field of signal analysis for reducing the broadening of the frequency spectrum. The optimization calculation is necessary for the design of window function suitable for suppressing sound radiation and securing a spatial area for data communication. In addition, a wide frequency bandwidth is required to increase the data transmission speed. Therefore, we investigated a suitable method for calculating the sound pressure level at the far field to confirm the variation of the distribution of sound pressure level determined on the basis of the window shape and frequency. The distribution of the sound pressure level at a finite distance was in good agreement with that obtained at an infinite far field under the condition generating the evanescent sound field. Consequently, the window function was optimized by the method used to calculate the distribution of the sound pressure level at an infinite far field using the wavenumber spectrum on the vibrating plate. According to the result of comparing the distributions of the sound pressure level in the cases with and without the window function, it was confirmed that the area whose sound pressure level was reduced from the maximum level to -50 dB was

  16. Optimization of Grazing Incidence Optics for Wide-Field X-Ray Survey Imaging

    Science.gov (United States)

    Roming, P. W. A.; Burrows, D. N.; Garmire, G. P.; Roush, W. B.

    1999-12-01

    Optimization of wide-field X-ray optics could greatly enhance X-ray surveys. Discussions of optimizing wide-field X-ray optics, with field-of-views less-than 1.1 degree-squared, have been made previously in the literature. However, very little has been published about the optimizing of wide-field X-ray optics with larger fields-of-view. We have been working on the design of a wide-field (3.1 degree-squared field-of-view), short focal length (190.5 cm), grazing incidence mirror shell set, with a desired rms image spot size of 15 arcsec. The baseline design incorporates Wolter I type mirror shells with polynomial perturbations applied to the grazing incidence surface. By optimizing the polynomial, the rms image spot size can be minimized for a large range of grazing angles. The overall minimization technique is to efficiently optimize the polynomial coefficients that directly influence the angular resolution, without stepping through the entire multidimensional coefficient space. The multidimensional minimization techniques that have been investigated include: the downhill simplex method; the coupling of genetic algorithms with full and fractional, including Plackett-Burman, factorial designs; and the coupling of genetic algorithms with Box-Behnken and central composite response surface designs. We have also examined the use of neural networks, coupled with genetic algorithms, as a method of multidimensional minimization. Investigations of backpropagation, probabilistic (PNN), general regression (GRNN), and group method of data handling (GMDH) neural networks have been made. We report our findings to date. This research is funded by NASA grant #NAG5-5093.

  17. Self-consistent Optomechanical Dynamics and Radiation Forces in Thermal Light Fields

    International Nuclear Information System (INIS)

    Sonnleitner, M.

    2014-01-01

    We discuss two different aspects of the mechanical interaction between neutral matter and electromagnetic radiation.The first part addresses the complex dynamics of an elastic dielectric deformed by optical forces. To do so we use a one-dimensional model describing the medium by an array of beam splitters such that the interaction with the incident waves can be described with a transfer-matrix approach. Since the force on each individual beam splitter is known we thus obtain the correct volumetric force density inside the medium. Sending a light field through an initially homogeneous dielectric then results in density modulations which in turn alter the optical properties of this medium.The second part is concerned with mechanical light-effects on atoms in thermal radiation fields. At hand of a generic setup of an atom interacting with a hot sphere emitting blackbody radiation we show that the emerging gradient force may surpass gravity by several orders of magnitude. The strength of the repulsive scattering force strongly depends on the spectrum of the involved atoms and can be neglected in some setups. A special emphasis lies on possible implications on astrophysical scenarios where the interactions between heated dust and atoms, molecules or nanoparticles are of crucial interest. (author) [de

  18. Graphene-based field effect transistors for radiation-induced field sensing

    Energy Technology Data Exchange (ETDEWEB)

    Di Gaspare, Alessandra, E-mail: alessandra.digaspare@lnf.infn.it [INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); Valletta, Antonio [CNR-Istituto per la Microelettronica e i Microsistemi, TorVergata, Rome (Italy); Fortunato, Guglielmo [CNR-Istituto per la Microelettronica e i Microsistemi, TorVergata, Rome (Italy); INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); Larciprete, Rosanna [CNR-Istituto di Sistemi Complessi, TorVergata, Rome (Italy); INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); Mariucci, Luigi [CNR-Istituto per la Microelettronica e i Microsistemi, TorVergata, Rome (Italy); INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); Notargiacomo, Andrea [CNR-Istituto di Fotonica e Nanotecnologie, Rome (Italy); INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); Cimino, Roberto [INFN-Laboratori Nazionali Frascati, Frascati, Rome (Italy); CERN, Geneva (Switzerland)

    2016-07-11

    We propose the implementation of graphene-based field effect transistor (FET) as radiation sensor. In the proposed detector, graphene obtained via chemical vapor deposition is integrated into a Si-based field effect device as the gate readout electrode, able to sense any change in the field distribution induced by ionization in the underneath absorber, because of the strong variation in the graphene conductivity close to the charge neutrality point. Different 2-dimensional layered materials can be envisaged in this kind of device.

  19. Characteristics of outage radiation fields around various reactor components

    International Nuclear Information System (INIS)

    Verzilov, Y.; Husain, A.; Corbin, G.

    2008-01-01

    Full text: Activity monitoring surveys, consisting of gamma spectroscopy and dose rate measurements, of various CANDU station components such as the reactor face, feeder cabinet, steam generators and moderator heat exchangers are often performed during shutdown in order to trend the transport of activity around the primary heat transport and moderator systems. Recently, the increased dose expenditure for work such as feeder inspection and replacement in the reactor vault has also spurred interest in improved characterization of the reactor face fields to facilitate better ALARA decision making and hence a reduction in future dose expenditures. At present, planning for reactor face work is hampered by insufficient understanding of the relative contribution of the various components to the overall dose. In addition to the increased dose expenditure for work at the reactor face, maintenance work associated with horizontal flux detectors and liquid injection systems has also resulted in elevated dose expenditures. For instance at Darlington, radiation fields in the vicinity of horizontal flux detectors (HFD) and Liquid Injection Shutdown System (LISS) nozzle bellows are trending upwards with present contact fields being in the range 16-70 rem/h and working distance fields being in the range 100-500 mrem/h. This paper presents findings based on work currently being funded by the CANDU Owners Group. Measurements were performed at Ontario Power Generation's Pickering and Darlington nuclear stations. Specifically, the following are addressed: Characteristics of Reactor Vault Fields; Characteristics of Steam Generator Fields; Characteristics of Moderator Heat Exchanger Fields. Measurements in the reactor vault were performed at the reactor face, along the length of end fittings, along the length of feeders, at the bleed condenser and at the HFD and LISS nozzle bellows. Steam generator fields were characterized at various elevations above the tube sheet, with and without the

  20. Reference radiation fields - Simulated workplace neutron fields - Part 2: Calibration fundamentals related to the basic quantities

    International Nuclear Information System (INIS)

    2008-01-01

    ISO 8529-1, ISO 8529-2 and ISO 8529-3, deal with the production, characterization and use of neutron fields for the calibration of personal dosimeters and area survey meters. These International Standards describe reference radiations with neutron energy spectra that are well defined and well suited for use in the calibration laboratory. However, the neutron spectra commonly encountered in routine radiation protection situations are, in many cases, quite different from those produced by the sources specified in the International Standards. Since personal neutron dosimeters, and to a lesser extent survey meters, are generally quite energy dependent in their dose equivalent response, it might not be possible to achieve an appropriate calibration for a device that is used in a workplace where the neutron energy spectrum and angular distribution differ significantly from those of the reference radiation used for calibration. ISO 8529-1 describes four radionuclide based neutron reference radiations in detail. This part of ISO 12789 includes the specification of neutron reference radiations that were developed to closely resemble radiation that is encountered in practice

  1. Localisation of atomic populations in the optical radiation field

    International Nuclear Information System (INIS)

    Efremova, E A; Gordeev, M Yu; Rozhdestvensky, Yu V

    2014-01-01

    The possibility of two-dimensional spatial localisation of atomic populations under the influence of the travelling wave fields in the tripod-configuration of quantum states is studied for the first time. Three travelling waves propagating in the same plane at an angle of 120° to each other form a system of standing waves under the influence of which atomic populations are localised. The size of the region of spatial localisation of the populations, in principle, can be hundredths of a wavelength of optical radiation. (quantum optics)

  2. Localisation of atomic populations in the optical radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Efremova, E A [Department of Physics, Saint-Petersburg State University (Russian Federation); Gordeev, M Yu; Rozhdestvensky, Yu V [St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg (Russian Federation)

    2014-10-31

    The possibility of two-dimensional spatial localisation of atomic populations under the influence of the travelling wave fields in the tripod-configuration of quantum states is studied for the first time. Three travelling waves propagating in the same plane at an angle of 120° to each other form a system of standing waves under the influence of which atomic populations are localised. The size of the region of spatial localisation of the populations, in principle, can be hundredths of a wavelength of optical radiation. (quantum optics)

  3. Difference in Understanding of the Need for Using Radiation in Various Fields between Students Majoring in Radiation and Non-Radiation Related Studies

    International Nuclear Information System (INIS)

    Han, Eun Ok

    2011-01-01

    As a way of improving social receptivity of using radiation, this study looked into the difference of understanding the need of using radiation in various fields between students majoring in radiation and non-radiation related studies, who will influence public opinion in the long term. This study also provides data needed for developing efficient strategies for projects promoting the public's awareness of using radiation. Of the students in the 79 schools sampled, 24%(177) were in 4 year colleges and 146 were junior colleges in educational statistics service (http://cesi.kedi.re.kr) In November 2010 1,945 students were selected as a sample, and they were given surveys on the need of using radiation in different fields. As a result, both between students majoring in radiation and non-radiation related studies showed a high level of understanding the need for radiation in the medical field and showed a low level of understanding of the need for radiation in the agricultural field. In all 6 fields of radiation use, students majoring in radiation related studies showed higher levels of understanding for the need to use radiation than students majoring in radiation and non-radiation related studies. In each field, male students and those who have experience medical radiation and relevant education had higher level of understanding. This shows we need to improve the understanding of the cases of female students and those who have not had experiences with medical radiation and to provide relevant education through various kinds of information. The characteristics of the groups that are shown in the results of this study are considered to be helpful for efficiently for project promoting the public's awareness of using radiation.

  4. Development of highly polished, grazing incidence mirrors for synchrotron radiation beam lines at SSRL

    International Nuclear Information System (INIS)

    Tirsell, K.G.; Berglin, E.J.; Fuchs, B.A.; Holdener, F.R.; Humpal, H.H.; Karpenko, V.P.; Kulkarni, S.; Fantone, S.D.

    1987-08-01

    New platinum-coated grazing incidence mirrors with low surface roughnesses have been developed to focus bending magnet radiation from the SSRL/SLAC SPEAR storage ring on the entrance slits of two Beam Line VIII grating monochromators. The first mirror in the toroidal grating monochromator (TGM) branch is a cooled SiC cylinder capable of absorbing synchrotron radiation power levels of up to 260 watts without excessive distortion. This mirror deflects the beam vertically through a 12/degree/ angle and focuses it sagitally on the TGM entrance slit plane. The second TGM optical element is a fused-silica spherical mirror with a large radius of curvature that deflects the beam vertically through an additional 12/degree/ and focuses it tangentially with 3/1 demagnification. The first mirror in our spherical grating branch is a 5/degree/-vertically deflecting, cooled SiC toroid designed to focus tangentially on the monochromator entrance slits and sagitally in the exit slits. A 4/degree/-deflecting fused silica mirror is used after the exit sites in each beam line to refocus on to the sample. For this application a thin cylinder is bent to approximate an ellipsoid. The mirrors are now installed at SSRL and performance measurements are planned. Qualitatively the focus of the TGM optics at the entrance slit plane appears very good. In this paper we discuss considerations leading to the choice of SiC for each of the two first mirrors. We present highlights of the development of these mirrors with some emphasis on SiC polishing techniques. In addition, the specialized metrology developed to produce the more difficult figure of the toroid will be described. Measured surface roughness and figure results will be presented. 19 refs., 11 figs

  5. Development of highly polished, grazing incidence mirrors for synchrotron radiation beam lines at SSRL

    Energy Technology Data Exchange (ETDEWEB)

    Tirsell, K.G.; Berglin, E.J.; Fuchs, B.A.; Holdener, F.R.; Humpal, H.H.; Karpenko, V.P.; Kulkarni, S.; Fantone, S.D.

    1987-08-01

    New platinum-coated grazing incidence mirrors with low surface roughnesses have been developed to focus bending magnet radiation from the SSRL/SLAC SPEAR storage ring on the entrance slits of two Beam Line VIII grating monochromators. The first mirror in the toroidal grating monochromator (TGM) branch is a cooled SiC cylinder capable of absorbing synchrotron radiation power levels of up to 260 watts without excessive distortion. This mirror deflects the beam vertically through a 12/degree/ angle and focuses it sagitally on the TGM entrance slit plane. The second TGM optical element is a fused-silica spherical mirror with a large radius of curvature that deflects the beam vertically through an additional 12/degree/ and focuses it tangentially with 3/1 demagnification. The first mirror in our spherical grating branch is a 5/degree/-vertically deflecting, cooled SiC toroid designed to focus tangentially on the monochromator entrance slits and sagitally in the exit slits. A 4/degree/-deflecting fused silica mirror is used after the exit sites in each beam line to refocus on to the sample. For this application a thin cylinder is bent to approximate an ellipsoid. The mirrors are now installed at SSRL and performance measurements are planned. Qualitatively the focus of the TGM optics at the entrance slit plane appears very good. In this paper we discuss considerations leading to the choice of SiC for each of the two first mirrors. We present highlights of the development of these mirrors with some emphasis on SiC polishing techniques. In addition, the specialized metrology developed to produce the more difficult figure of the toroid will be described. Measured surface roughness and figure results will be presented. 19 refs., 11 figs.

  6. Plane waves at or near grazing incidence in the parabolic approximation. [acoustic equations of motion for sound fields

    Science.gov (United States)

    Mcaninch, G. L.; Myers, M. K.

    1980-01-01

    The parabolic approximation for the acoustic equations of motion is applied to the study of the sound field generated by a plane wave at or near grazing incidence to a finite impedance boundary. It is shown how this approximation accounts for effects neglected in the usual plane wave reflection analysis which, at grazing incidence, erroneously predicts complete cancellation of the incident field by the reflected field. Examples are presented which illustrate that the solution obtained by the parabolic approximation contains several of the physical phenomena known to occur in wave propagation near an absorbing boundary.

  7. Reproducibility of irregular radiation fields for malignant lymphoma

    International Nuclear Information System (INIS)

    Mock, U.; Dieckmann, K.; Poetter, R.; Molitor, A.M.; Haverkamp, U.

    1998-01-01

    Purpose: Radiation treatment for malignant lymphoma requires large field irradiation with irregular blocks according to the individual anatomy and tumor configuration. For determination of safety margins (PTV) we quantitatively analysed the accuracy of field and block placement with regard to different anatomical regions. Patients and Methods: Forty patients with malignant lymphoma were irradiated using the classical supra-/infradiaphragmatic field arrangements. Treatment was performed with 10-MeV photons and irregularly shaped, large opposing fields. We evaluated the accuracy of field and block placements during the treatment courses by comparing the regularly performed verification - with the simulation films. Deviations were determined with respect to the field edges and the central axis, along the x- and z-axis. Results: With regard to the field edges, mean deviations of 2.0 mm and 3.4 mm were found along the x- and z-axis. The corresponding standard deviations were 3.4 mm and 5.5 mm, respectively. With regard to the shielding blocks, mean displacement along the x- and z-axis was 2.2 mm and 3.8 mm. In addition, overall standard deviations of 5.7 mm (x-axis) and 7.1 mm (z-axis) were determined. During the course of time an improved accuracy of block placement was notable. Conclusion: Systematic analysis of port films gives information for a better defining safety margins in external radiotherapy. Evaluation of verification films on a regular basis improves set-up accuracy by reducing displacements. (orig.) [de

  8. The effect of the geometry on the fluorescence radiation field

    International Nuclear Information System (INIS)

    Teodori, F.; Fernandez, J.E.; Molinari, V.

    2000-01-01

    In x-ray fluorescence spectroscopy a narrow photon beam is focused on the surface of the sample to stimulate the production of characteristic radiation which gives useful information about the composition of the target. Even if the interpretation of the measurement is simple, the quantification of the total emitted intensity is not straightforward because the primary photons are produced in the depth of the sample and only a fraction can reach the surface without colliding again with matter. In this work we show that the geometry of the system plays an important role in determining the properties of the 3D radiation field. By using the integral Boltzmann equation, we show that there exist a link among the source distribution, the boundary conditions, the emission points, the observation angles and the properties of the field of emitted radiation. To illustrate the influence of the geometry, the energy distribution of a continuos emission spectrum like the Compton one has been calculated, firstly. It is shown that the energy distribution of the Compton primary photons (coming out from a slab irradiated with an internal monochromatic and isotropic point source) changes with the orientation of the observation direction. Another example involves a second order effect which depends on a double collision in the specimen. It has been shown that the characteristic emission due to the photoelectric effect is accompanied by a (P,C) continuous contribution which introduces an asymmetry in the shape of the line. Computations in a 3D radiation field have shown that such asymmetry is strongly dependent on the observation direction with respect to the primary volume where the photoelectric effect is produced. This means that detection through a narrow collimator whose axis (assumed here as the observation direction) deviates from the centre of symmetry of the primary volume, will produce differently shaped characteristic lines depending on the extent and placement of the

  9. Exoplanetary Habitability: Radiation, Particles, Plasmas, and Magnetic Fields

    Science.gov (United States)

    Guedel, Manuel

    2017-05-01

    Exoplanetary environments are made of an intricate mixture of plasmas, radiation, energetic particles, winds, and magnetic fields; these all play crucial roles for the structure and evolution of planetary atmospheres and the formation and possibly protection of planetary habitable environments. Interactions between planetary atmospheric particles and solar-wind ions result in various non-thermal loss mechanisms that are relevant for atmospheric erosion; energetic neutral atoms from charge exchange interactions can even deposit their energy in upper atmospheres and contribute to their heating. We present results from simulations and discuss the effects of magnetospheric obstacles, the resulting atmospheric loss rates and neutral hydrogen clouds detectable through Ly a absorption. We also present estimates for secondary X-ray production as a result of charge exchange interactions. Combined modeling of expanding hydrogen clouds resulting from such interactions are now also used to estimate magnetic moments of exoplanets. We emphasize that the interplay between all these mechanisms, also including radiation-driven thermal escape of atmospheres, changes with stellar evolution; for a full understanding of the state of an observed exoplanetary atmosphere, the long-term evolution of the host star, in particular its rotation and magnetic activity, needs to be studied. In this respect, radio astronomy plays a central role as it sensitively probes these environments and their constituents in time, such as magnetospheres, high-energy particles, stellar magnetic fields and winds, and therefore contributes to our understanding of the emergence of habitable planetary environments.

  10. Incidence, Causative Mechanisms, and Anatomic Localization of Stroke in Pituitary Adenoma Patients Treated With Postoperative Radiation Therapy Versus Surgery Alone

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, Margriet G.A., E-mail: g.a.sattler@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Vroomen, Patrick C. [Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Sluiter, Wim J. [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schers, Henk J. [Department of Primary and Community Care, Radboud University Nijmegen Medical Centre (Netherlands); Berg, Gerrit van den [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Bergh, Alphons C.M. van den [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Beek, André P. van [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2013-09-01

    Purpose: To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone. Methods and Materials: A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log–rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population. Results: Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049). Conclusions: In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk

  11. Electric currents and fields induced in cells in the human brain by radiation from hand-held cellular telephones

    Science.gov (United States)

    King, Ronold W. P.

    2000-01-01

    After a review of recent work on the interaction of electromagnetic fields from cellular telephones with the human head, the structural and radiating properties of two common types of transceivers are determined. These include the impedance and current amplitude distribution of the antennas. The tangential electric field maintained by the antennas on the adjacent surface of the head is next determined. From this, the electric field propagating through the skull into the brain is analyzed and, from it, the electric field in spherical and long cylindrical cells is determined. It ranges from 27 to 13.5 V/m in the first 3 cm inside the skull. Of interest is the fact that the induced field in the interior of all cells, regardless of their shape, is the same as the incident field in the brain. It is hoped that biomedical scientists will review these results and determine possible biological effects.

  12. A correlation model to compute the incidence angle modifier and to estimate its effect on collectible solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Armenta-Deu, C. (Universidad Complutense de Madrid (ES). Facultad Fisicas); Lukac, B. (University of T. and C. Zilina (CS))

    1991-01-01

    The radiation transmittance and absorptance of materials vary according to the angle of incidence of the incoming solar radiation. Therefore, the efficiency of most solar converters (thermal or photovoltaic) is a function of the sun's position through the angle of incidence. This problem may be taken account of by the Incidence Angle Modifier, which is considered in this paper. An analytic expression for the incidence angle modifier, based on meteorological data or on geographic and geometric parameters, has been developed; this expression includes the effect of beam and diffuse radiation as well as the global influence. A comparison between measured data and these computed from our model has given a very good correlation, the results being within {+-}3% for horizontal and titled planes, and within {+-}7% for vertical surfaces, on average. The method also computes the collectible solar energy within a 5% error for thresholds up to 300Wm{sup -2}. The method has been validated for more than 30 locations in south and west Europe. (author).

  13. Dynamics of Charged Particles and their Radiation Field

    International Nuclear Information System (INIS)

    Poisson, E

    2006-01-01

    The motion of a charged particle interacting with its own electromagnetic field is an area of research that has a long history. On the one hand the theory ought to be straightforward to formulate: one has Maxwell's equations that tell the field how to behave and one has the Lorentz-force law that tells the particle how to move (given the field). On the other hand the theory is fundamentally ambiguous because of the field singularities that necessarily come with a point particle. While each separate sub-problem can easily be solved, to couple the field to the particle in a self-consistent treatment turns out to be tricky. I believe it is this dilemma that has been the main source of the endless fascination. For them it is also rooted in the fact that the electromagnetic self-force problem is deeply analogous to the gravitational self-force problem, which is of direct relevance to future gravitational wave observations. The motion of point particles in curved spacetime has been the topic of a recent Topical Review, and it was the focus of a recent Special Issue. Exceptions are Rohrlich's excellent text, which makes a very useful introduction to radiation reaction, and the Landau and Lifshitz classic, which contains what is probably the most perfect summary of the foundational ideas. It is therefore with some trepidation that I received Herbert Spohn's book, which covers both the classical and quantum theories of a charged particle coupled to its own field (the presentation is limited to flat spacetime). Is this the text that graduate students and researchers should turn to in order to get a complete and accessible education in radiation reaction? My answer is that while the book does indeed contain a lot of useful material, it is not a very accessible source of information, and it is certainly not a student-friendly textbook. Instead, the book presents a technical account of the author's personal take on the theory, and represents a culminating summary of the author

  14. MO-G-BRE-09: Validating FMEA Against Incident Learning Data: A Study in Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Yang, F; Cao, N; Young, L; Howard, J; Sponseller, P; Logan, W; Arbuckle, T; Korssjoen, T; Meyer, J; Ford, E

    2014-01-01

    Purpose: Though FMEA (Failure Mode and Effects Analysis) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge it has never been validated against actual incident learning data. The objective of this study was to perform an FMEA analysis of an SBRT (Stereotactic Body Radiation Therapy) treatment planning process and validate this against data recorded within an incident learning system. Methods: FMEA on the SBRT treatment planning process was carried out by a multidisciplinary group including radiation oncologists, medical physicists, and dosimetrists. Potential failure modes were identified through a systematic review of the workflow process. Failure modes were rated for severity, occurrence, and detectability on a scale of 1 to 10 and RPN (Risk Priority Number) was computed. Failure modes were then compared with historical reports identified as relevant to SBRT planning within a departmental incident learning system that had been active for two years. Differences were identified. Results: FMEA identified 63 failure modes. RPN values for the top 25% of failure modes ranged from 60 to 336. Analysis of the incident learning database identified 33 reported near-miss events related to SBRT planning. FMEA failed to anticipate 13 of these events, among which 3 were registered with severity ratings of severe or critical in the incident learning system. Combining both methods yielded a total of 76 failure modes, and when scored for RPN the 13 events missed by FMEA ranked within the middle half of all failure modes. Conclusion: FMEA, though valuable, is subject to certain limitations, among them the limited ability to anticipate all potential errors for a given process. This FMEA exercise failed to identify a significant number of possible errors (17%). Integration of FMEA with retrospective incident data may be able to render an improved overview of risks within a process

  15. Classical calculation of radiative lifetimes of atomic hydrogen in a homogeneous magnetic field

    International Nuclear Information System (INIS)

    Horbatsch, M.W.; Hessels, E.A.; Horbatsch, M.

    2005-01-01

    Radiative lifetimes of hydrogenic atoms in a homogeneous magnetic field of moderate strength are calculated on the basis of classical radiation. The modifications of the Keplerian orbits due to the magnetic field are incorporated by classical perturbation theory. The model is complemented by a classical radiative decay calculation using the radiated Larmor power. A recently derived highly accurate formula for the transition rate of a field-free hydrogenic state is averaged over the angular momentum oscillations caused by the magnetic field. The resulting radiative lifetimes for diamagnetic eigenstates classified by n,m and the diamagnetic energy shift C compare well with quantum results

  16. Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

    International Nuclear Information System (INIS)

    Marciszko, Marianna; Baczmański, Andrzej; Braham, Chedly; Wróbel, Mirosław; Wroński, Sebastian; Cios, Grzegorz

    2017-01-01

    The presented study introduces the development of the multi-reflection grazing-incidence X-ray diffraction method (MGIXD) for residual stress determination. The proposed new methodology is aimed at obtaining more reliable experimental data and increasing the depth of non-destructive stress determination below the sample surface. To verify proposed method measurements were performed on a classical X-ray diffractometer (Cu Kα radiation) and using synchrotron radiation (three different wavelengths: λ = 1.2527 Å, λ = 1.5419 Å and λ = 1.7512 Å). The Al2017 alloy subjected to three different surface treatments was investigated in this study. The obtained results showed that the proposed development of MGIXD method, in which not only different incident angles but also different wavelengths of X-ray are used, can be successfully applied for residual stress determination, especially when stress gradients are present in the sample.

  17. Incidence of primary hypothyroidism in patients exposed to therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland

    Directory of Open Access Journals (Sweden)

    B A Laway

    2012-01-01

    Full Text Available Introduction: Hypothyroidism is a known consequence of external-beam radiotherapy to the neck encompassing a part or whole of the thyroid gland. In this non-randomized prospective study, we have tried to evaluate the response of the thyroid gland to radiation by assessing thyroid function before irradiation and at regular intervals after irradiation. Aims and Objectives: The aim of this study were to assess in the cancer patients, who were exposed to the therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland: the incidence of primary hypothyroidism, the time required to become hypothyroid, any relation between the total dose for the development of hypothyroidism, and whether there are any patient or treatment-related factors that are predictive for the development of hypothyroidism, including the use of concurrent chemotherapy. Materials and Methods: This non-randomized, prospective study was conducted for a period of 2 years in which thyroid function was assessed in 59 patients (cases of head and neck cancer, breast cancer, lymphoma patients and other malignancies, who had received radiotherapy to the neck region. 59 euthyroid healthy patients (controls were also taken, who had not received the neck irradiation. These patients/controls were assessed periodically for 2 years. Results: The incidence of hypothyroidism after external beam radiation therapy (EBRT to neck where radiation portals include part or whole of the thyroid gland was 16.94%, seven cases had subclinical hypothyroidism (11.86% and three cases had clinical hypothyroidism (5.08%. Mean time for development of hypothyroidism was 4.5 months. There was no effect of age, gender, primary tumor site, radiation dose and chemotherapy, whether neoadjuvant or concurrent with the development of hypothyroidism. Conclusion: In summary, we found that thyroid dysfunction is a prevalent, yet easily treatable source of morbidity in patients

  18. Pilot Study for the Creation of a European Union Radiation Accident and Incident Data Exchange System (EURAIDE)

    International Nuclear Information System (INIS)

    Stewart, J.E.; Lefaure, C; Czarwinski, R.

    2004-01-01

    This study has had the objective of evaluating the feasibility of: (i) facilitating the establishment of national radiation accident and incident databases where there are none and to encourage the compatibility of such databases, (ii) establishing a European network to exchange radiological protection feedback from accidents and incidents, (iii) establishing summary reports of relevant accidents and incidents with the aim of identifying lessons to be learned, so that they can be used in radiation protection training programs, and (iv) upgrading the radiological safety in the countries applying to join the EU, by integrating them into the above efficient feedback exchange system. This report details the first stage of the project, which was to review the status of existing (or proposed) national mechanisms for collating data on radiation incidents. The objectives of this initial review were to: i) obtain detailed information regarding the means of capturing and collating data, the format of established or proposed data systems and accessibility of the final data, ii) to use this information to consider how a European platform to gather relevant data/accident reports might be established., and iii) to consider how the various elements of national data systems might be harmonised in order to facilitate the presentation and distribution of lessons learned. It was considered that the key aspects that would need to be addressed in order to determine the feasibility of a European wide data exchange mechanism were: - the criteria used for the classification and categorisation of incidents, - criteria for the selection of incidents from national data systems for inclusion in a European-wide system, - the implication of possible language problems. In order to illicit the required information a detailed questionnaire was sent to a total of 31 countries, being existing European Member States, applicant or associated countries. A full list of the countries and institutions

  19. Out-of-Field Cell Survival Following Exposure to Intensity-Modulated Radiation Fields

    International Nuclear Information System (INIS)

    Butterworth, Karl T.; McGarry, Conor K.; Trainor, Colman; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2011-01-01

    Purpose: To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. Methods and Materials: Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced with a Varian linear accelerator. Results: Nonuniform dose distributions were delivered using a multileaf collimator (MLC) in which half of the cell population was shielded. Clonogenic survival in the shielded region was significantly lower than that predicted from the linear quadratic model. In both cell lines, the out-of-field responses appeared to saturate at 40%-50% survival at a scattered dose of 0.70 Gy in DU-145 cells and 0.24 Gy in AGO1522 cells. There was an approximately eightfold difference in the initial slopes of the out-of-field response compared with the α-component of the uniform field response. In contrast, cells in the exposed part of the field showed increased survival. These observations were abrogated by direct physical inhibition of cellular communication and by the addition of the inducible nitric oxide synthase inhibitor aminoguanidine known to inhibit intercellular bystander effects. Additional studies showed the proportion of cells irradiated and dose delivered to the shielded and exposed regions of the field to impact on response. Conclusions: These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields with cellular communication between differentially irradiated cell populations playing an important role. Validation of these observations in additional cell models may facilitate the refinement of existing radiobiological models and the observations considered important determinants of cell survival.

  20. Nuclear Radiation Fields on the Mars Surface: Risk Analysis for Long-term Living Environment

    Science.gov (United States)

    Anderson, Brooke M.; Clowdsley, Martha S.; Qualls, Garry D.; Nealy, John E.

    2005-01-01

    Mars, our nearest planet outward from the sun, has been targeted for several decades as a prospective site for expanded human habitation. Background space radiation exposures on Mars are expected to be orders of magnitude higher than on Earth. Recent risk analysis procedures based on detailed dosimetric techniques applicable to sensitive human organs have been developed along with experimental data regarding cell mutation rates resulting from exposures to a broad range of particle types and energy spectra. In this context, simulated exposure and subsequent risk for humans in residence on Mars are examined. A conceptual habitat structure, CAD-modeled with duly considered inherent shielding properties, has been implemented. Body self-shielding is evaluated using NASA standard computerized male and female models. The background environment is taken to consist not only of exposure from incident cosmic ray ions and their secondaries, but also include the contribution from secondary neutron fields produced in the tenuous atmosphere and the underlying regolith.

  1. Optimum Water Chemistry in radiation field buildup control

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien, C. [Vallecitos Nuclear Center, Pleasanton, CA (United States)

    1995-03-01

    Nuclear utilities continue to face the challenGE of reducing exposure of plant maintenance personnel. GE Nuclear Energy has developed the concept of Optimum Water Chemistry (OWC) to reduce the radiation field buildup and minimize the radioactive waste production. It is believed that reduction of radioactive sources and improvement of the water chemistry quality should significantly reduce both the radiation exposure and radwaste production. The most important source of radioactivity is cobalt and replacement of cobalt containing alloy in the core region as well as in the entire primary system is considered the first priority to achieve the goal of low exposure and minimized waste production. A plant specific computerized cobalt transport model has been developed to evaluate various options in a BWR system under specific conditions. Reduction of iron input and maintaining low ionic impurities in the coolant have been identified as two major tasks for operators. Addition of depleted zinc is a proven technique to reduce Co-60 in reactor water and on out-of-core piping surfaces. The effect of HWC on Co-60 transport in the primary system will also be discussed.

  2. ARM West Antarctic Radiation Experiment (AWARE) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Lubin, Daniel [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography; Bromwich, David H [Ohio State University; Vogelmann, Andrew M [Brookhaven National Lab. (BNL), Upton, NY (United States); Verlinde, Johannes [Pennsylvania State Univ., University Park, PA (United States); Russell, Lynn M [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography

    2017-09-15

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) is the most technologically advanced atmospheric and climate science campaign yet fielded in Antarctica. AWARE was motivated be recent concern about the impact of cryospheric mass loss on global sea level rise. Specifically, the West Antarctic Ice Sheet (WAIS) is now the second largest contributor to rising sea level, after the Greenland Ice Sheet. As steadily warming ocean water erodes the grounding lines of WAIS components where they meet the Amundsen and Bellingshausen Seas, the retreating grounding lines moving inland and downslope on the underlying terrain imply mechanical instability of the entire WAIS. There is evidence that this point of instability may have already been reached, perhaps signifying more rapid loss of WAIS ice mass. At the same time, the mechanical support provided by adjacent ice shelves, and also the fundamental stability of exposed ice cliffs at the ice sheet grounding lines, will be adversely impacted by a warming atmosphere that causes more frequent episodes of surface melting. The surface meltwater damages the ice shelves and ice cliffs through hydrofracturing. With the increasing concern regarding these rapid cryospheric changes, AWARE was motivated by the need to (a) diagnose the surface energy balance in West Antarctica as related to both summer season climatology and potential surface melting, and (b) improve global climate model (GCM) performance over Antarctica, such that future cryospheric projections can be more reliable.

  3. Calibration of extremity dosemeters for gamma radiation fields

    International Nuclear Information System (INIS)

    Papadopulos, S.B.; Gregori, B.N.; Cruzate, J.A.

    1998-01-01

    In this work the kerma conversion factor are free in air, dose equivalent H(d,0 ) are presented, they were obtained theoretical and experimentally in finger and arm for gamma radiation fields. Extremity dosemeters put on surface finger and arm phantom have been irradiated. The finger phantom is a solid cylinder of PMMA polymethylmethacrylate 19 mm diameter and 300 mm height. The arm phantom is a 73 mm external diameter cylinder with PMMA walls 2.5 mm thick fill with water and 300 mm height. The radiation sources were cobalt 60 and cesium 137 from the Regional Center of Reference (CRR) of the National Commission of Atomic Energy (CNEA) and the Nuclear Regulatory Authority (ARN). Also in ISO wide X ray spectra W60, W110 and W200 have been irradiated. The results obtained show a good correlation with those published, they have a difference less than 7%. The factors will be applied to the evaluation of the equivalent doses coming from workers whose main irradiated zone is in the hands. (author)

  4. Ultraviolet Radiation and Kaposi Sarcoma Incidence in a Nationwide US Cohort of HIV-Infected Men.

    Science.gov (United States)

    Cahoon, Elizabeth K; Engels, Eric A; Freedman, D Michal; Norval, Mary; Pfeiffer, Ruth M

    2017-05-01

    Although ultraviolet radiation (UVR) is established as both an inducer of herpes simplex virus reactivation and as the primary risk factor for many common skin cancers, its relationship with human herpes virus 8 (HHV8) infection or risk of Kaposi sarcoma (KS) is unknown. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for the association between ambient UVR, history of nonmelanoma skin cancer (NMSC; as a biomarker of personal cumulative UVR dose), and incidence of first primary KS in a nationwide US cohort of white and African American male veterans infected with HIV between 1986 and 1996 (prior to the widespread availability of treatment) using Cox regression. All statistical tests were two-sided. Based on discharge records, there were 422 newly diagnosed KS cases among 17 597 HIV-infected veterans. Cohort members with prior NMSC had a statistically significantly increased risk of KS (HR = 8.64, 95% CI = 6.23 to 11.96) in the total population. Risk of KS was higher for quartile 4 vs 1 among the total population (HR = 1.49, 95% CI = 1.02 to 2.16, P trend UVR quartile [coded 1 to 4] = .02) and among whites (HR = 1.75, 95% CI = 1.11 to 2.78, P trend = .009), but not among African Americans (HR = 1.23, 95% CI = 0.71 to 2.15, P trend = .23). KS risk was elevated among HIV-infected men with NMSC diagnosis and in those living in locations with high ambient UVR at time of HIV diagnosis. Our novel findings suggesting that UVR exposure may increase KS risk warrant further investigation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Vegetative and reproductive plasticity of broccoli at three levels of incident photosynthetically active radiation

    International Nuclear Information System (INIS)

    Francescangeli, N.; Martí, H.R.; Sangiacomo, M.A.

    2007-01-01

    To study the effects of shading on the growth, development, dry matter partitioning, and plant architecture of broccoli, ‘Legacy’ hybrid plants were grown in pots in a greenhouse under black shading meshes to generate different levels of photosynthetically active radiation (PAR). The average incident PAR was 23 mol PPF m –2 d –1 under control conditions, 15.2 under a 35% mesh, and 6.7 under a 70% mesh. The air temperature was within the range 15-22°C. As shading increased so did the duration of the growth cycle and the leaf area (LA). Shading did not affect the number of leaves, although the upper ones were more erect. The stem length and the accumulated intercepted PAR (IPAR) were negatively related. Inflorescence diameter and commercial fresh weight decreased only with the 70% mesh. Shading did not affect stem dry weight (DW) but altered dry matter allocation in the root and spear. The DW of the leaves maintained an average 45.7% of the total DW despite the greater LA developed under shade. The net assimilation rate diminished with the reduction of IPAR, and the LA increased; the plant relative growth rate was therefore practically constant. With increased shading, the leaves and the stem became the dominant photosynthate sinks. The commercial fresh weight achieved with 15.2 mol photosynthetic photon flux (PPF) m –2 d –1 was equivalent to that obtained with 23 mol PPF m –2 d –1 , but the cycle was extended for 4.5 days. With 6.7 mol PPF m –2 d –1 , yield diminished because of the lower DW produced in a cycle extended by 15 days, and because more dry matter was allocated to the stem than to the spear. Based on these results, broccoli could be considered a shade-tolerant plant. (author) [es

  6. System decontamination as a tool to control radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Riess, R.; Bertholdt, H.O. [Siemens Power Generation Group, Erlangen (Germany)

    1995-03-01

    Since chemical decontamination of the Reactor Coolant Systems (RCS) and subsystems has the highest potential to reduce radiation fields in a short term this technology has gained an increasing importance. The available decontamination process at Siemens, i.e., the CORD processes, will be described. It is characterized by using permanganic acid for preoxidation and diluted organic acid for the decontamination step. It is a regenerative process resulting in very low waste volumes. This technology has been used frequently in Europe and Japan in both RCS and subsystems. An overview will be given i.e. on the 1993 applications. This overview will include plant, scope, date of performance, system volume specal features of the process removed activities, decon factor time, waste volumes, and personnel dose during decontamination. This overview will be followed by an outlook on future developments in this area.

  7. Observations of the diffuse near-UV radiation field

    Science.gov (United States)

    Murthy, J.; Henry, R. C.; Feldman, P. D.; Tennyson, P. D.

    1990-01-01

    The diffuse radiation field from 1650-3100 A has been observed by spectrometer aboard the Space Shuttle, and the contributions of the zodiacal light an the diffuse cosmic background to the signal have been derived. Colors ranging from 0.65 to 1.2 are found for the zodiacal light with an almost linear increase in the color with ecliptic latitude. This rise in color is due to UV brightness remaining almost constant while the visible brightnesses drop by almost a factor of two. This is interpreted as evidence that the grains responsible for the UV scattering have much more uniform distribution with distance from the ecliptic plane than do those grains responsible for the visible scattering. Intensities for the cosmic diffuse background ranging from 300 units to 900 units are found which are not consistent with either a correlation with N(H I) or with spatial isotropy.

  8. High-resolution optical telescope for ultraviolet /UV/ radiation field

    Science.gov (United States)

    Karayan, W. W.

    1979-01-01

    Design techniques are discussed for all-reflecting optics from first-order system considerations and applications currently utilized in the field of astronomical optics. The solution of the Dall-Karkham design problem is described, showing the advantage of inexpensive construction as compared with higher order surfaces. The design process reported here is a F/5 collecting system which quickly mates directly with the spectrometer; it is capable of achieving desired high resolution and sensitivity requirements. The theoretical limit of aberration tolerances is achieved with less than 1/8 of a wavelength at final focus (OPD). The design of spectrometer for ultra-violet (UV) radiation and its mechanism is included in this study.

  9. 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)

  10. Highlights of IAEA activities in the field of radiation application

    International Nuclear Information System (INIS)

    Machi, S.

    1994-01-01

    In IAEA's major programme of Nuclear Applications, the activities performed are divided into four areas: food and agriculture, industry and earth science, human health, and physical and chemical sciences. These activities involve co-operation with FAO, WHO, UNIDO and UNEP, and have close link with the technical assistance programme. About 60% of the technical assistance projects are implemented in the field of nuclear applications. The purpose of the nuclear application programme is to develop technologies useful for environmental protection and sustainable development, to support R and D programmes of developing countries, to develop new applications of nuclear techniques. Major activities in food and agriculture are the application of radiation and isotopes, controling insects, preserving food, soil fertility and crop production, and improving animal production and the use of radiation with biotechnology for plant mutation breeding aiming at environmentally friendly and sustainable food production. In the human health programme emphasis is given to nuclear medicine, cancer therapy and nutrition. Today, only 35% of all developing countries have radiotherapy facilities. Activities, therefore, focus on strengthening clinical radiotherapy in such countries. In the field of industry and earth science, flue gas cleaning by electron beams, pollution monitoring using nuclear analytical techniques, nucleonic control systems for industries, and water resource exploration are major projects assisting developing countries. As of 1994 the IAEA will launch 12 new and promising Model Projects for developing Member States which will be of benefit to their economies and raising of their standard of living. In this paper the highlights of the above mentioned IAEA activities are presented. (author)

  11. Field test of a post-closure radiation monitor

    International Nuclear Information System (INIS)

    Reed, S.; Christy, C.E.; Heath, R.E.

    1995-01-01

    The DOE is conducting remedial actions at many sites contaminated with radioactive materials. After closure of these sites, long-term subsurface monitoring is typically required by law. This monitoring is generally labor intensive and expensive using conventional sampling and analysis techniques. The U.S. Department of Energy's Morgantown Energy Technology Center (METC) has contracted with Babcock and Wilcox to develop a Long-Term Post-Closure Radiation Monitoring System (LPRMS) to reduce these monitoring costs. A prototype LPRMS probe was built, and B ampersand W and FERMCO field tested this monitoring probe at the Fernald Environmental Management Project in the fall of 1994 with funding from the DOE's Office of Technology Development (EM-50) through METC. The system was used to measure soil and water with known uranium contamination levels, both in drums and in situ at depths up to 3 meters. For comparison purposes, measurements were also performed using a more conventional survey probe with a sodium iodide scintillator directly butt-coupled to detection electronics. This paper presents a description and the results of the field tests. The results were used to characterize the lower detection limits, precision and bias of the system, which allowed the DOE to judge the monitoring system's ability to meet its long-term post-closure radiation monitoring needs. Based on the test results, the monitoring system has been redesigned for fabrication and testing in a potential Phase III of this program. If the DOE feels that this system can meet its needs and chooses to continue into Phase III of this program, this redesigned full scale prototype system will be built and tested for a period of approximately a year. Such a system can be used at a variety of radioactively contaminated sites

  12. Situation in the radiation protection field in Costa Rica

    International Nuclear Information System (INIS)

    Pacheco Jimenez, R.E.

    2001-01-01

    The report describes the radiation protection infrastructure in Costa Rica and makes reference to the existing legal framework. The national inventory of significant radiation sources and structure of the Ministry of Health as the national regulatory authority for radiation safety is illustrated; information is also provided on the radiation monitoring equipment available, on programme activities related to the control of radiation sources by authorization and inspection, and on technical support services. (author)

  13. Hawking radiation of five-dimensional charged black holes with scalar fields

    Directory of Open Access Journals (Sweden)

    Yan-Gang Miao

    2017-09-01

    Full Text Available We investigate the Hawking radiation cascade from the five-dimensional charged black hole with a scalar field coupled to higher-order Euler densities in a conformally invariant manner. We give the semi-analytic calculation of greybody factors for the Hawking radiation. Our analysis shows that the Hawking radiation cascade from this five-dimensional black hole is extremely sparse. The charge enhances the sparsity of the Hawking radiation, while the conformally coupled scalar field reduces this sparsity.

  14. A comparison of the quality of image acquisition between the incident dark field and sidestream dark field video-microscopes.

    Science.gov (United States)

    Gilbert-Kawai, Edward; Coppel, Jonny; Bountziouka, Vassiliki; Ince, Can; Martin, Daniel

    2016-01-21

    The 'Cytocam' is a third generation video-microscope, which enables real time visualisation of the in vivo microcirculation. Based upon the principle of incident dark field (IDF) illumination, this hand held computer-controlled device was designed to address the technical limitations of its predecessors, orthogonal polarization spectroscopy and sidestream dark field (SDF) imaging. In this manuscript, we aimed to compare the quality of sublingual microcirculatory image acquisition between the IDF and SDF devices. Using the microcirculatory image quality scoring (MIQS) system, (six categories scored as either 0 = optimal, 1 = acceptable, or 10 = unacceptable), two independent raters compared 30 films acquired using the Cytocam IDF video-microscope, to an equal number obtained with an SDF device. Blinded to the origin of the films, the raters were therefore able to score between 0 and 60 for each film analysed. The scores' distributions between the two techniques were compared. The median MIQS (95% CI) given to the SDF camera was 7 (1.5-12), as compared to 1 (0.5-1.0) for the IDF device (p microscope, as compared to the SDF video-microscope.

  15. Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients.

    Science.gov (United States)

    Lee, Tsair-Fwu; Chao, Pei-Ju; Chang, Liyun; Ting, Hui-Min; Huang, Yu-Jie

    2015-01-01

    Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT) to find the risk factors, which may have important effects on the risk of radiation-induced complications. In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage and selection operator (LASSO) technique. Five risk factors were selected using LASSO: the percentage of the ipsilateral lung volume that received more than 20-Gy (IV20), energy, age, body mass index (BMI) and T stage. Positive associations were demonstrated among the incidence of SRP, IV20, and patient age. Energy, BMI and T stage showed a negative association with the incidence of SRP. Our analyses indicate that the risk of SPR following hybrid IMRT in elderly or low-BMI breast cancer patients is increased once the percentage of the ipsilateral lung volume receiving more than 20-Gy is controlled below a limitation. We suggest to define a dose-volume percentage constraint of IV20radiation therapy treatment planning to maintain the incidence of SPR below 20%, and pay attention to the sequelae especially in elderly or low-BMI breast cancer patients. (AIV20: the absolute ipsilateral lung volume that received more than 20 Gy (cc).

  16. Isolated lung events following radiation for early stage breast cancer: incidence and predictors for primary lung vs metastatic breast cancer

    International Nuclear Information System (INIS)

    Van Buren, Teresa A; Harris, Jay R; Sugarbaker, David J; Schneider, Lindsey; Healey, Elizabeth A

    1995-01-01

    Purpose: 1) To define the incidence of isolated lung events in a cohort of women treated with conservative surgery (CS) and radiation therapy (RT) for early stage breast cancer. 2) Among such patients, to define the relative distribution of primary lung cancer, metastatic breast cancer, and indeterminate lesions; and to identify any predictors for a diagnosis of lung vs metastatic breast cancer. 3) To examine the cohort with respect to whether a higher than expected incidence of lung cancer is seen following breast irradiation. Materials and Methods: Between 1968 and 1986, 1865 patients with clinical stage I-II breast cancer were treated with CS and RT; the median follow-up for surviving patients is 129 months. The study population was limited to patients who developed a subsequent isolated lung event as the first site of distant disease. Isolated lung event was defined as disease limited to the thoracic cavity, without evidence of either uncontrolled local breast disease or metastatic disease elsewhere. Diagnosis of the lung event as a primary lung cancer, a metastatic breast lesion, or an indeterminate lesion was documented from the viewpoint of 1) the pathologic analysis and 2) the clinical impression at the time of the lung event. Results: Sixty six of the 1865 patients (3.5%) developed an isolated lung event. The relative distribution of the pathologic and clinical diagnoses is shown below: The 66 lung events were characterized either as a solitary pulmonary nodule (27), multiple nodules (23), pleural effusion alone (10), unknown (2), or miscellaneous other findings (4). Among the 47 patients for whom pathology was available, the diagnosis remained indeterminate for 24 (51%). For patients with a definitive pathologic diagnosis, 69% ((9(13))) of smokers had a new lung cancer compared to 20% ((2(10))) of non-smokers (p=0.036), and 67% ((10(15))) of patients with a solitary pulmonary nodule had lung cancer compared to 14% ((1(7))) for other lung presentations (p

  17. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    Energy Technology Data Exchange (ETDEWEB)

    Reynaldo, S. R. [Development Centre of Nuclear Technology, Posgraduate Course in Science and Technology of Radiations, Minerals and Materials / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Benavente C, J. A.; Da Silva, T. A., E-mail: sirr@cdtn.br [Development Centre of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the {sup 90}Sr/{sup 90}Y and {sup 85}Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the {sup 90}Sr/{sup 90}Y and -0.3% for the {sup 85}Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  18. Field study to evaluate radiation doses in dental practices

    International Nuclear Information System (INIS)

    Panzer, W.; Scheurer, C.

    1984-05-01

    An inexpensive and simple test device was developed and used in a field study to evaluate entrance dose, dose to an intra-oral film, filtration and field size under routine conditions in more than 150 dental practices. The test device consists of two films of different speed and a set of 5 thin copper filters for a filter analytical determination of the radiation quality. Dentists voluntarily participating in the study were asked to expose the test device like they usually do when examining a molar tooth. The main result was the evidence of a significant dose reduction compared to the findings of similar studies performed in 1970 and 1976. This reduction is due to a general shift to lower values and a complete disappearance of values above 45 mGy (5 R) which in 1970 were still more than 15%. In the same way the number of facilities showing insufficient filtration or collimation had decreased. Nevertheless, a large spread of dose values could still be observed, ranging from less than 0.45 mGy (50 mR) to more than 26 mGy (3 R), for the entrance dose. The most striking result, however, was that such an important parameter like the speed of the films used at the respective unit turned out to have no impact on the entrance dose. (orig./HP)

  19. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    CERN Document Server

    Caresana, M; Esposito, A; Ferrarini, M; Golnik, N; Hohmann, E; Leuschner, A; Luszik-Bhadra, M; Manessi, G; Mayer, S; Ott, K; Röhrich, J; Silari, M; Trompier, F; Volnhals, M; Wielunski, M

    2014-01-01

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instru...

  20. Self-constructed detectors for environmental radiation sources. Instruments for detecting and measuring electric and magnetic fields as well as radioactive radiation

    International Nuclear Information System (INIS)

    Lay, Peter

    2011-01-01

    The book presents experiments for detecting and measuring radiation sources. This includes detectors for electric and magnetic fields, radioactive radiation and even cosmic radiation, all of which can be detected by simple (electronic) circuits. Apart from the practical experiments, also basic physical knowledge is provided. The book comprises the following chapters: 1. Introduction; 2. Electrostatic fields in the environment; 3. Magnetostatic fields; 4. Electrodynamic fields; 5. Magnetodynamic fields; 6. Electromagnetic radiation in the environment; 7. Radioactive radiation in the environment; 8. Cosmic radiation; 9. PC interface; 10. Professional radiation measurement; 11. Risk potential. [de

  1. Field assessment of a model tuberculosis outbreak response plan for low-incidence areas

    Directory of Open Access Journals (Sweden)

    Pascopella Lisa

    2007-10-01

    Full Text Available Abstract Background For a regional project in four low-incidence states, we designed a customizable tuberculosis outbreak response plan. Prior to dissemination of the plan, a tuberculosis outbreak occurred, presenting an opportunity to perform a field assessment of the plan. The purpose of the assessment was to ensure that the plan included essential elements to help public health professionals recognize and respond to outbreaks. Methods We designed a semi-structured questionnaire and interviewed all key stakeholders involved in the response. We used common themes to assess validity of and identify gaps in the plan. A subset of participants provided structured feedback on the plan. Results We interviewed 11 public health and six community stakeholders. The assessment demonstrated that (1 almost all of the main response activities were reflected in the plan; (2 the plan added value by providing a definition of a tuberculosis outbreak and guidelines for communication and evaluation. These were areas that lacked written protocols during the actual outbreak response; and (3 basic education about tuberculosis and the interpretation and use of genotyping data were important needs. Stakeholders also suggested adding to the plan questions for evaluation and a section for specific steps to take when an outbreak is suspected. Conclusion An interactive field assessment of a programmatic tool revealed the value of a systematic outbreak response plan with a standard definition of a tuberculosis outbreak, guidelines for communication and evaluation, and response steps. The assessment highlighted the importance of education and training for tuberculosis in low-incidence areas.

  2. Comparison of the incidence, nature and cause of injuries sustained on dirt field and artificial turf field by amateur football players

    Directory of Open Access Journals (Sweden)

    Kordi Ramin

    2011-02-01

    Full Text Available Abstract Background Data on the incidence, nature, severity and cause of match football injuries sustained on dirt field are scarce. The objectives of this study was to compare the incidence, nature, severity and cause of match injuries sustained on dirt field and artificial turf field by amateur male football players. Methods A prospective two-cohort design was employed. Participants were 252 male football players (mean age 27 years, range 18-43 in 14 teams who participated in a local championship carried on a dirt field and 216 male football players (mean age 28 years, range 17-40 in 12 teams who participated in a local championship carried on a artificial turf field in the same zone of the city. Injury definitions and recording procedures were compliant with the international consensus statement for epidemiological studies of injuries in football. Results The overall incidence of match injuries for men was 36.9 injuries/1000 player hours on dirt field and 19.5 on artificial turf (incidence rate ratio 1.88; 95% CI 1.19-3.05. Most common injured part on dirt field was ankle (26.7% and on artificial turf was knee (24.3%. The most common injury type in the dirt field was skin injuries (abrasion and laceration and in the artificial turf was sprain and ligament injury followed by haematoma/contusion/bruise. Most injuries were acute (artificial turf 89%, dirt field 91% and resulted from player-to-player contact (artificial turf 59.2%, dirt field 51.4%. Most injuries were slight and minimal in dirt field cohort but in artificial turf cohort the most injuries were mild. Conclusions There were differences in the incidence and type of football match injuries sustained on dirt field and artificial turf.

  3. Rotation invariance of electromagnetic radiation generated by relativistic particles in magnetic fields

    CERN Document Server

    Smolyakov, M N

    2000-01-01

    This paper deals with electromagnetic radiation generated by relativistic particles in arbitrary planar magnetic field (in undulator for example). Magnetic system producing this field is assumed to be planar consisting of permanent magnets. It is shown that there is a special class of magnetic moment rotations in such system while magnetic field is varying but spontaneous radiation spectrum generated by relativistic particles remains the same. This property of electromagnetic radiation can be used in designing new undulators.

  4. Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies

    Science.gov (United States)

    Bhatia, Anand

    2012-01-01

    We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.

  5. Violin f-hole contribution to far-field radiation via patch near-field acoustical holography.

    Science.gov (United States)

    Bissinger, George; Williams, Earl G; Valdivia, Nicolas

    2007-06-01

    The violin radiates either from dual ports (f-holes) or via surface motion of the corpus (top+ribs+back), with no clear delineation between these sources. Combining "patch" near-field acoustical holography over just the f-hole region of a violin with far-field radiativity measurements over a sphere, it was possible to separate f-hole from surface motion contributions to the total radiation of the corpus below 2.6 kHz. A0, the Helmholtz-like lowest cavity resonance, radiated essentially entirely through the f-holes as expected while A1, the first longitudinal cavity mode with a node at the f-holes, had no significant f-hole radiation. The observed A1 radiation comes from an indirect radiation mechanism, induced corpus motion approximately mirroring the cavity pressure profile seen for violinlike bowed string instruments across a wide range of sizes. The first estimates of the fraction of radiation from the f-holes F(f) indicate that some low frequency corpus modes thought to radiate only via surface motion (notably the first corpus bending modes) had significant radiation through the f-holes, in agreement with net volume changes estimated from experimental modal analysis. F(f) generally trended lower with increasing frequency, following corpus mobility decreases. The f-hole directivity (top/back radiativity ratio) was generally higher than whole-violin directivity.

  6. Simplified field-in-field technique for a large-scale implementation in breast radiation treatment

    International Nuclear Information System (INIS)

    Fournier-Bidoz, Nathalie; Kirova, Youlia M.; Campana, Francois; Dendale, Rémi; Fourquet, Alain

    2012-01-01

    We wanted to evaluate a simplified “field-in-field” technique (SFF) that was implemented in our department of Radiation Oncology for breast treatment. This study evaluated 15 consecutive patients treated with a simplified field in field technique after breast-conserving surgery for early-stage breast cancer. Radiotherapy consisted of whole-breast irradiation to the total dose of 50 Gy in 25 fractions, and a boost of 16 Gy in 8 fractions to the tumor bed. We compared dosimetric outcomes of SFF to state-of-the-art electronic surface compensation (ESC) with dynamic leaves. An analysis of early skin toxicity of a population of 15 patients was performed. The median volume receiving at least 95% of the prescribed dose was 763 mL (range, 347–1472) for SFF vs. 779 mL (range, 349–1494) for ESC. The median residual 107% isodose was 0.1 mL (range, 0–63) for SFF and 1.9 mL (range, 0–57) for ESC. Monitor units were on average 25% higher in ESC plans compared with SFF. No patient treated with SFF had acute side effects superior to grade 1-NCI scale. SFF created homogenous 3D dose distributions equivalent to electronic surface compensation with dynamic leaves. It allowed the integration of a forward planned concomitant tumor bed boost as an additional multileaf collimator subfield of the tangential fields. Compared with electronic surface compensation with dynamic leaves, shorter treatment times allowed better radiation protection to the patient. Low-grade acute toxicity evaluated weekly during treatment and 2 months after treatment completion justified the pursuit of this technique for all breast patients in our department.

  7. The Deep Physics Hidden within the Field Expressions of the Radiation Fields of Lightning Return Strokes

    Directory of Open Access Journals (Sweden)

    Vernon Cooray

    2016-01-01

    Full Text Available Based on the electromagnetic fields generated by a current pulse propagating from one point in space to another, a scenario that is frequently used to simulate return strokes in lightning flashes, it is shown that there is a deep physical connection between the electromagnetic energy dissipated by the system, the time over which this energy is dissipated and the charge associated with the current. For a given current pulse, the product of the energy dissipated and the time over which this energy is dissipated, defined as action in this paper, depends on the length of the channel, or the path, through which the current pulse is propagating. As the length of the channel varies, the action plotted against the length of the channel exhibits a maximum value. The location of the maximum value depends on the ratio of the length of the channel to the characteristic length of the current pulse. The latter is defined as the product of the duration of the current pulse and the speed of propagation of the current pulse. The magnitude of this maximum depends on the charge associated with the current pulse. The results show that when the charge associated with the current pulse approaches the electronic charge, the value of this maximum reaches a value close to h/8π where h is the Plank constant. From this result, one can deduce that the time-energy uncertainty principle is the reason for the fact that the smallest charge that can be detected from the electromagnetic radiation is equal to the electronic charge. Since any system that generates electromagnetic radiation can be represented by a current pulse propagating from one point in space to another, the result is deemed valid for electromagnetic radiation fields in general.

  8. Development of rubber material for high radiation field

    International Nuclear Information System (INIS)

    Nakatsukasa, Sadayoshi; Tabasaki, Takeshi; Yoshida, Akihiro; Kadowaki, Yoshito

    2013-01-01

    Generally flexible polymeric materials exposed to radiation can't be used because they soften or harden remarkably in high radiation environment. Aromatic polymers such as PEEK, PI, and PES are also known as radiation-proof polymeric materials. Aromatic polymers are very hard, they can't be used for products like a packing where flexibility is required. We developed a new vulcanized rubber compound by the use of various additives and polymer blend. This developed rubber compound has a high radiation-proof performance by reaction balance of cross-linking and decomposition in this rubber. This rubber compound has a rubber elasticity even if exposed to radiation of MGy level, and its radiation proof is more than 5 times as high as conventional polymeric materials. This rubber compound is much more flexible than the aromatic polymers which are the used as conventional radiation-proof polymers. (author)

  9. Pathophysiological effects of radiation on atherosclerosis development and progression, and the incidence of cardiovascular complications

    International Nuclear Information System (INIS)

    Basavaraju, Sekhara Rao; Easterly, Clay E.

    2002-01-01

    Radiation therapy while important in the management of several diseases, is implicated in the causation of atherosclerosis and other cardiovascular complications. Cancer and atherosclerosis go through the same stages of initiation, promotion, and complication, beginning with a mutation in a single cell. Clinical observations before the 1960s lead to the belief that the heart is relatively resistant to the doses of radiation used in radiotherapy. Subsequently, it was discovered that the heart is sensitive to radiation and many cardiac structures may be damaged by radiation exposure. A significantly higher risk of death due to ischemic heart disease has been reported for patients treated with radiation for Hodgkin's disease and breast cancer. Certain cytokines and growth factors, such as TGF-β1 and IL-1 β, may stimulate radiation-induced endothelial proliferation, fibroblast proliferation, collagen deposition, and fibrosis leading to advanced lesions of atherosclerosis. The treatment for radiation-induced ischemic heart disease includes conventional pharmacological therapy, balloon angioplasty, and bypass surgery. Endovascular irradiation has been shown to be effective in reducing restenosis-like response to balloon-catheter injury in animal models. Caution must be exercised when radiation therapy is combined with doxorubicin because there appears to be a synergistic toxic effect on the myocardium. Damage to endothelial cells is a central event in the pathogenesis of damage to the coronary arteries. Certain growth factors that interfere with the apoptotic pathway may provide new therapeutic strategies for reducing the risk of radiation-induced damage to the heart. Exposure to low level occupational or environmental radiation appears to pose no undue risk of atherosclerosis development or cardiovascular mortality. But, other radiation-induced processes such as the bystander effects, abscopal effects, hormesis, and individual variations in radiosensitivity may be

  10. Characteristic of the radiation field in low earth orbit and in deep space

    International Nuclear Information System (INIS)

    Reitz, Guenther

    2008-01-01

    The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60 latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

  11. Radiative muon capture in a relativistic mean field theory

    International Nuclear Information System (INIS)

    Fearing, H.W.; Walker, G.E.

    1988-09-01

    We examine radiative muon capture in a nuclear medium using mean field theory and a relativistic Fermi gas model for the nucleus to obtain the single nucleon states. The aim is to explore, in a simple model, effects of the medium which are characterized primarily by a nucleon effective mass m * . The relative rate, i.e. the photon spectrum divided by the nonradiative rate, and the photon asymmetry relative to the muon spin are calculated. The most important effect turns out to be the Fermi motion, which reduces the relative rate by a factor of two to three in the experimentally accessible region, compared to the static case. The m * effect further reduces the result by 10-50%, depending on the photon energy. The relativistic nature of this calculation, unlike usual nonrelativistic calculations, allows these effects to be incorporated to all orders in 1/m. As a consequence some interesting effects can be studied in the small k region. We conclude that both relativistic kinematic and medium effects may be significant and thus that it is worthwhile investigating this reaction in more realistic relativistic nuclear models. (Author) (16 refs., 8 figs.)

  12. High intensity radiated field external environments for civil aircraft operating in the United States of America

    Science.gov (United States)

    1998-12-01

    NAWCAD Patuxent River, Maryland, was tasked by the FAA to determine the High Intensity Radiated Field (HIRF) levels for civil aircraft operating in the U.S. The electromagnetic field survey will apply to civil aircraft seeking FAA certification under...

  13. High-throughput estimation of incident light, light interception and radiation-use efficiency of thousands of plants in a phenotyping platform.

    Science.gov (United States)

    Cabrera-Bosquet, Llorenç; Fournier, Christian; Brichet, Nicolas; Welcker, Claude; Suard, Benoît; Tardieu, François

    2016-10-01

    Light interception and radiation-use efficiency (RUE) are essential components of plant performance. Their genetic dissections require novel high-throughput phenotyping methods. We have developed a suite of methods to evaluate the spatial distribution of incident light, as experienced by hundreds of plants in a glasshouse, by simulating sunbeam trajectories through glasshouse structures every day of the year; the amount of light intercepted by maize (Zea mays) plants via a functional-structural model using three-dimensional (3D) reconstructions of each plant placed in a virtual scene reproducing the canopy in the glasshouse; and RUE, as the ratio of plant biomass to intercepted light. The spatial variation of direct and diffuse incident light in the glasshouse (up to 24%) was correctly predicted at the single-plant scale. Light interception largely varied between maize lines that differed in leaf angles (nearly stable between experiments) and area (highly variable between experiments). Estimated RUEs varied between maize lines, but were similar in two experiments with contrasting incident light. They closely correlated with measured gas exchanges. The methods proposed here identified reproducible traits that might be used in further field studies, thereby opening up the way for large-scale genetic analyses of the components of plant performance. © 2016 INRA New Phytologist © 2016 New Phytologist Trust.

  14. Monte Carlo technique applications in field of radiation dosimetry at ENEA radiation protection institute: A Review

    International Nuclear Information System (INIS)

    Gualdrini, G.F.; Casalini, L.; Morelli, B.

    1994-12-01

    The present report summarizes the activities concerned with numerical dosimetry as carried out at the Radiation Protection Institute of ENEA (Italian Agency for New Technologies, Energy and the Environment) on photon dosimetric quantities. The first part is concerned with MCNP Monte Carlo calculation of field parameters and operational quantities for the ICRU sphere with reference photon beams for the design of personal dosemeters. The second part is related with studies on the ADAM anthropomorphic phantom using the SABRINA and MCNP codes. The results of other Monte Carlo studies carried out on electron conversion factors for various tissue equivalent slab phantoms are about to be published in other ENEA reports. The report has been produced in the framework of the EURADOS WG4 (numerical dosimetry) activities within a collaboration between the ENEA Environmental Department and ENEA Energy Department

  15. Combined effects of radiation and other agents on the stomach cancer incidence among Mayak Atomic Plant workers

    International Nuclear Information System (INIS)

    Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D.; Rovny, S.I.; Sirchikov, V.A.

    2000-01-01

    The gravity of a problem of the combined action of radiation and other factors again was confirmed sessions UNSCEAR in May, 1998. It especially is important at study of cancer diseases in connection with the polyetiology and multistage of them development. The estimation of radiation, medico-biological factors and condition of life in occurrence of a stomach cancer among Mayak personnel was specified by case-cohort research. For a quota 503 men (157 cases of a stomach cancer, 346 men of the healthy personnel) attributive risk of the radiation factors was 8.8%, medico-biological - 57,2% (from them by greatest was influence chronic gastritis with secreting insufficiency - 35.4%), tobacco consumption - 31,6%. At an estimation of risk of a stomach cancer depending on external γ-irradiation best fitting was received at use of square-law model. The excess relative risk was 0,27 Gr -2 (F=44,5; P=0,007). For 239 Pu incorporation was not revealed of distinct connection with stomach cancer incidences. Interaction of the radiation and non-radiation factors also was appreciated. The interaction of gastritis with external γ-irradiation or 239 Pu was multiplicate. The interaction of smoking with γ-irradiation or 239 Pu incorporation was multiplicate also. The distribution histological types of a stomach cancer among the workers of Mayak plant differed in comparison with not working. Among the workers the increase poorly differentiated adenocarcinoma was observed. (author)

  16. Combined effects of radiation and other agents on the stomach cancer incidence among Mayak Atomic Plant workers

    Energy Technology Data Exchange (ETDEWEB)

    Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D. [Branch No 1 of State Research Center of Public Health Ministry of the Russian Federation, Ozyorsk (Russian Federation). Biophysics Inst.; Rovny, S.I.; Sirchikov, V.A.

    2000-05-01

    The gravity of a problem of the combined action of radiation and other factors again was confirmed sessions UNSCEAR in May, 1998. It especially is important at study of cancer diseases in connection with the polyetiology and multistage of them development. The estimation of radiation, medico-biological factors and condition of life in occurrence of a stomach cancer among Mayak personnel was specified by case-cohort research. For a quota 503 men (157 cases of a stomach cancer, 346 men of the healthy personnel) attributive risk of the radiation factors was 8.8%, medico-biological - 57,2% (from them by greatest was influence chronic gastritis with secreting insufficiency - 35.4%), tobacco consumption - 31,6%. At an estimation of risk of a stomach cancer depending on external {gamma}-irradiation best fitting was received at use of square-law model. The excess relative risk was 0,27 Gr{sup -2} (F=44,5; P=0,007). For {sup 239}Pu incorporation was not revealed of distinct connection with stomach cancer incidences. Interaction of the radiation and non-radiation factors also was appreciated. The interaction of gastritis with external {gamma}-irradiation or {sup 239}Pu was multiplicate. The interaction of smoking with {gamma}-irradiation or {sup 239}Pu incorporation was multiplicate also. The distribution histological types of a stomach cancer among the workers of Mayak plant differed in comparison with not working. Among the workers the increase poorly differentiated adenocarcinoma was observed. (author)

  17. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

    Science.gov (United States)

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

  18. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats

    Directory of Open Access Journals (Sweden)

    Haitham S. Mohammed

    2013-03-01

    Full Text Available In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day. EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS and rapid eye movement sleep (REM sleep revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

  19. Experimental observation of strong radiation reaction in the field of an ultra-intense laser

    Science.gov (United States)

    Sarri, G.; Poder, K.; Tamburini, M.; di Piazza, A.; Keitel, C. H.; Zepf, M.

    2017-10-01

    Describing radiation reaction in an electromagnetic field is one of the most fundamental outstanding problems in electrodynamics. It consists of determining the dynamics of a charged particle fully taking into account self-forces (loosely referred to as radiation reaction) resulting from the radiation fields generated by the particle whilst it is accelerated. Radiation reaction has only been invoked to explain the radiative properties of powerful astrophysical objects, such as pulsars and quasars. From a theoretical standpoint, this phenomenon is subject of fervent debate and this impasse is worsened by the lack of experimental data, due to extremely high fields required to trigger these effects. Here, we report on the first experimental evidence of strong radiation reaction during the interaction of an ultra-relativistic electron beam with an intense laser field, beyond a purely classical description.

  20. Television imaging transducers for use in radiation fields

    International Nuclear Information System (INIS)

    Konyaev, V.M.; Krasovskij, S.S.; Surikov, I.N.

    1989-01-01

    For optical television equipment widely used in nuclear energetics it appears to be importance to account for various radiation effects on the device material and units aiming at diminishing negative effects of radiation upon the devices operation. Basing on the experimental results (along with the analysis of literature data) the authors propose a mechanism of radiation effect upon television imaging sensors (TIS). Operation principles and construction of up-to date TIS are briefly described, as well as the characteristics of radiation conditions. Various radiation effects upon the TIS material and construction have been considered. Optimal radiation conditions and levels have been suggested for the equipment operation. The efficiencies of various TIS are compared. 230 refs.; 86 figs.; 4 tabs

  1. Synchrotron radiation in strongly coupled conformal field theories

    OpenAIRE

    Athanasiou, Christiana; Chesler, Paul M.; Liu, Hong; Nickel, Dominik; Rajagopal, Krishna

    2010-01-01

    Using gauge/gravity duality, we compute the energy density and angular distribution of the power radiated by a quark undergoing circular motion in strongly coupled ${\\cal N}=4$ supersymmetric Yang-Mills (SYM) theory. We compare the strong coupling results to those at weak coupling, and find the same angular distribution of radiated power, up to an overall prefactor. In both regimes, the angular distribution is in fact similar to that of synchrotron radiation produced by an electron in circula...

  2. A MEMS Device Capable of Measuring Near-Field Thermal Radiation between Membranes

    OpenAIRE

    Changyu Sun; Jun Yu; Chong Feng; Zhenan Tang

    2013-01-01

    For sensors constructed by freestanding membranes, when the gap between a freestanding membrane and the substrate or between membranes is at micron scale, the effects of near-field radiative heat transfer on the sensors' thermal performance should be considered during sensor design. The radiative heat flux is transferred from a membrane to a plane or from a membrane to a membrane. In the current study of the near-field thermal radiation, the scanning probe technology has difficulty in making ...

  3. Comparative investigation of three dose rate meters for their viability in pulsed radiation fields

    International Nuclear Information System (INIS)

    Gotz, M; Karsch, L; Pawelke, J

    2015-01-01

    Pulsed radiation fields, characterized by microsecond pulse duration and correspondingly high pulse dose rates, are increasingly used in therapeutic, diagnostic and research applications. Yet, dose rate meters which are used to monitor radiation protection areas or to inspect radiation shielding are mostly designed, characterized and tested for continuous fields and show severe deficiencies in highly pulsed fields. Despite general awareness of the problem, knowledge of the specific limitations of individual instruments is very limited, complicating reliable measurements. We present here the results of testing three commercial dose rate meters, the RamION ionization chamber, the LB 1236-H proportional counter and the 6150AD-b scintillation counter, for their response in pulsed radiation fields of varied pulse dose and duration. Of these three the RamION proved reliable, operating in a pulsed radiation field within its specifications, while the other two instruments were only able to measure very limited pulse doses and pulse dose rates reliably. (paper)

  4. A finite element propagation model for extracting normal incidence impedance in nonprogressive acoustic wave fields

    Science.gov (United States)

    Watson, Willie R.; Jones, Michael G.; Tanner, Sharon E.; Parrott, Tony L.

    1995-01-01

    A propagation model method for extracting the normal incidence impedance of an acoustic material installed as a finite length segment in a wall of a duct carrying a nonprogressive wave field is presented. The method recasts the determination of the unknown impedance as the minimization of the normalized wall pressure error function. A finite element propagation model is combined with a coarse/fine grid impedance plane search technique to extract the impedance of the material. Results are presented for three different materials for which the impedance is known. For each material, the input data required for the prediction scheme was computed from modal theory and then contaminated by random error. The finite element method reproduces the known impedance of each material almost exactly for random errors typical of those found in many measurement environments. Thus, the method developed here provides a means for determining the impedance of materials in a nonprogressirve wave environment such as that usually encountered in a commercial aircraft engine and most laboratory settings.

  5. Epidemiology of cutaneous leishmaniasis in central Amazonia: a comparison of sex-biased incidence among rural settlers and field biologists.

    Science.gov (United States)

    Soares, Letícia; Abad-Franch, Fernando; Ferraz, Gonçalo

    2014-08-01

    Cutaneous leishmaniasis (CL) is more frequently reported in men than in women; this may be due to male-biased exposure to CL vectors, female-biased resistance against the disease or both. We sought to determine whether gender-specific exposure to vector habitats explains male-biased CL incidence in two human populations of central Amazonia. We compared the CL incidence in one population of field researchers (N = 166), with similar exposure for males and females, and one population of rural settlers (N = 646), where exposure is overall male-biased. We used a combination of questionnaires and clinical data to quantify CL cases, and modelled disease incidence in a Bayesian framework. There was a moderately higher incidence of CL among men than among women in both populations, but male bias decreased as exposure time increased. Disease incidence was overall higher among field researchers, suggesting that they are an important but understudied CL risk group. Our comparison of two contrasting populations provided epidemiological evidence that CL incidence can be male-biased even when exposure is comparable in both sexes. © 2014 John Wiley & Sons Ltd.

  6. Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients.

    Directory of Open Access Journals (Sweden)

    Tsair-Fwu Lee

    Full Text Available Symptomatic radiation pneumonitis (SRP, which decreases quality of life (QoL, is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT to find the risk factors, which may have important effects on the risk of radiation-induced complications.In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage and selection operator (LASSO technique.Five risk factors were selected using LASSO: the percentage of the ipsilateral lung volume that received more than 20-Gy (IV20, energy, age, body mass index (BMI and T stage. Positive associations were demonstrated among the incidence of SRP, IV20, and patient age. Energy, BMI and T stage showed a negative association with the incidence of SRP. Our analyses indicate that the risk of SPR following hybrid IMRT in elderly or low-BMI breast cancer patients is increased once the percentage of the ipsilateral lung volume receiving more than 20-Gy is controlled below a limitation.We suggest to define a dose-volume percentage constraint of IV20< 37% (or AIV20< 310cc for the irradiated ipsilateral lung in radiation therapy treatment planning to maintain the incidence of SPR below 20%, and pay attention to the sequelae especially in elderly or low-BMI breast cancer patients. (AIV20: the absolute ipsilateral lung volume that received more than

  7. An analysis of the radiation from apertures in curved surfaces by the geometrical theory of diffraction. [ray technique for electromagnetic fields

    Science.gov (United States)

    Pathak, P. H.; Kouyoumjian, R. G.

    1974-01-01

    In this paper the geometrical theory of diffraction is extended to treat the radiation from apertures of slots in convex perfectly conducting surfaces. It is assumed that the tangential electric field in the aperture is known so that an equivalent infinitesimal source can be defined at each point in the aperture. Surface rays emanate from this source which is a caustic of the ray system. A launching coefficient is introduced to describe the excitation of the surface ray modes. If the field radiated from the surface is desired, the ordinary diffraction coefficients are used to determine the field of the rays shed tangentially from the surface rays. The field of the surface ray modes is not the field on the surface; hence if the mutual coupling between slots is of interest, a second coefficient related to the launching coefficient must be employed. In the region adjacent to the shadow boundary, the component of the field directly radiated from the source is represented by Fock-type functions. In the illuminated region the incident radiation from the source (this does not include the diffracted field components) is treated by geometrical optics. This extension of the geometrical theory of diffraction is applied to calculate the radiation from slots on elliptic cylinders, spheres, and spheroids.

  8. A numerical study of the random-incidence and diffuse-field sensitivity of laboratory standard microphones using BEM

    DEFF Research Database (Denmark)

    Barrera Figueroa, Salvador; Henriquez, Vicente Cutanda; Jacobsen, Finn

    2006-01-01

    to the definition of the latter, a number of plane waves coming from random directions and having random phases impinge simultaneously upon the microphone. The random-incidence sensitivity can be estimated using measurements made in an anechoic chamber, while the diffuse-field sensitivity requires a reverberation......The difference between the random-incidence sensitivity of a microphone and the diffusefield sensitivity is that according to the definition of the former, plane waves coming from different angles of incidence impinge successively onto the microphone under free-field conditions, whereas according...... Element Method has been used to study different aspects of the two realizations, such as the influence of the number of plane waves impinging on the microphone, the required amount of spatial averaging, etc....

  9. CONCORD: comparison of cosmic radiation detectors in the radiation field at aviation altitudes

    Czech Academy of Sciences Publication Activity Database

    Meier, M.; Trompier, F.; Ambrožová, Iva; Kubančák, Ján; Matthia, D.; Ploc, Ondřej; Santen, N.; Wirtz, M.

    2016-01-01

    Roč. 6, MAY (2016), A24 ISSN 2115-7251 Institutional support: RVO:61389005 Keywords : aviation * radiation exposure of aircrew * comparison of radiation detectors * galactic cosmic radiation * ambient dose equivalent Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.446, year: 2016

  10. Effect of γ-radiation on the incidence of plant tumors (to the problem of carcinogenesis)

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Yurov, S.S.; Vagabova, M.Eh.; Shchelkaeva, N.V.

    1986-01-01

    In experiments on two plant species: of Kalanchoe diagremontiana and potato (Solanum tuberosum) it was shown that γ-irradiation of the plant tissues, before infecting with Ti-plasmide Agrobacterium tumefaciens C-58, with doses stimulating the development of the plants markedly increases the incidence of tumors, promotes their growth, and increases the probability of inverse differentiation of tumor cells

  11. Unstructured-Mesh Terrain Analysis and Incident Solar Radiation for Continuous Hydrologic Modeling in Mountain Watersheds

    Directory of Open Access Journals (Sweden)

    Hernan A. Moreno

    2018-03-01

    Full Text Available This article presents a methodology for estimating total incoming solar radiation from Triangular Irregular Network (TIN topographic meshes. The algorithm also computes terrain slope degree and aspect (slope orientation and accounts for self shading and cast shadows, sky view fractions for diffuse radiation, remote albedo and atmospheric backscattering, by using a vectorial approach within a topocentric coordinate system establishing geometric relations between groups of TIN elements and the sun position. A normal vector to the surface of each TIN element describes its slope and aspect while spherical trigonometry allows computing a unit vector defining the position of the sun at each hour and day of the year. Sky view fraction, useful to determine diffuse and backscattered radiation, is computed for each TIN element at prescribed azimuth intervals targeting the steepest elevation gradient. A comparison between the sun zenith angle and the steepest gradient allows deciding whether or not the pivot element is shaded. Finally, remote albedo is computed from the sky view fraction complementary functions for observed albedo values of the surrounding terrain. The sensitivity of the different radiative components to seasonal changes in atmospheric transmissivitties and surrounding albedo is tested in a mountainous watershed in Wyoming. This methodology represents an improvement on the current algorithms to compute terrain and radiation values on unstructured-mesh terrain models. All terrain-related features (e.g., slope, aspect, sky view fraction can be pre-computed and stored for easy access into a subsequent, progressive-in-time, numerical simulation.

  12. Measurement of the sound power incident on the walls of a reverberation room with near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2010-01-01

    area; and it has always been regarded as impossible to measure the sound power that is incident on a wall directly. This paper examines a new method of determining this quantity from sound pressure measurements at positions on the wall using 'statistically optimised near field acoustic holography...

  13. The assessment of electromagnetic field radiation exposure for mobile phone users

    OpenAIRE

    Buckus Raimondas; Strukcinskiene Birute; Raistenskis Juozas

    2014-01-01

    Background/Aim. During recent years, the widespread use of mobile phones has resulted in increased human exposure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the...

  14. Asymmetric active nano-particles for directive near-field radiation

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Thorsen, Rasmus O.

    2016-01-01

    In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

  15. Concussion in field hockey: a retrospective analysis into the incidence rates, mechanisms, symptoms and recovery of concussive injuries sustained by elite field hockey players

    Science.gov (United States)

    Rossiter, Michael; Challis, Michael

    2017-01-01

    Objectives To identify the incidence and mechanisms of concussion in elite Field Hockey in different age groups and also the postconcussion symptoms and recovery times. Methods Data was collected retrospectively, for both training and matches, over a 12-month period from national level Field Hockey players across under-16, under-18, under-21, Development and Senior players. Mechanism of injury (including player role and field position), postconcussive symptoms and recovery times were recorded following a semistructured interview with each player. Additional information on training hours, matches and squad size were also recorded in order to calculate the incidence per 1000 match hours. Results Of the 28 recorded cases, only 11 could be included in the study. Women had the highest incidence of concussion, with the majority being in the under-21 age group. Overall incidence varied from 3/1000 match hours in training to 0.02/1000 match hours in matches, with an overall incidence of 0–0.02/1000 match hours across all age groups. The most common mechanism of injury was collision with another player, followed by impact from a stick or ball Midfield and attacking forwards sustained the highest incidence of concussion. None of the concussed athletes wore protective headgear (there were no cases of concussion in goal keepers) and all occurred in open play rather than a penalty corner (when protective headgear is often worn). Postconcussion headaches and difficulty concentrating were the most commonly reported postconcussion symptoms. Average recovery time and return-to-play was 2–4 weeks. Conclusions Due to the low numbers, only limited conclusions can be made, but it would appear that the risk of concussion in elite Field Hockey is low. As age and skill increases, the risk decreases. Postconcussion symptoms and average return-to-play times are similar to other sports. From this study, no conclusions can be made as to the role of protective headgear to reduce the risk

  16. Experimental study on the luminous radiation associated to the field emission of samples submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Luong, M.; Tan, J.; Bonin, B.; Safa, H.

    1996-01-01

    The accelerating gradient of the RF cavities is limited by the strong field emission (FE) of electrons stemming from the metallic walls. Previous experiments evidenced luminous radiations associated with electron emission of cathodes subjected to intense DC electric field. These observations invoked the proposal of new theoretical models of the field emission phenomenon. This experimental study extends the previous DC works to the RF case. A special copper RF cavity has been developed equipped with an optical window and a removable sample. It has been designed for measuring both electron current and luminous radiation emitted by the sample, subjected to maximum RF electric field. The optical apparatus attached to the cavity permits to characterize the radiation in terms of intensity, glowing duration and spectral distribution. The results concerning different niobium or copper samples, whom top was either scratched or intentionally contaminated with metallic or dielectric particles are summarized. (author)

  17. Radiation factors and smoking interaction at lung cancer incidence for workers at a nuclear enterprise

    International Nuclear Information System (INIS)

    Tokarskaya, Z.B.; Khokhryakov, V.F.; Okladnikova, N.D.; Belyaeva, Z.D.; Zhuntova, G.V.

    1997-01-01

    It was shown on the basis of retrospective investigation of 500 workers at a nuclear enterprise (162 cases of lung cancer, 338 persons as matching control) that the interaction of external gamma-irradiation (> 2.0 Gy) and the body - burden of 239 Pu (> 9.3 kBq) at lung cancer is characterized as the multiplicative effect. Combined influence of smoking and radiation factors dependent on smoking index (SI): it changed from additive up to multiplicative and than to antagonistic with the increase of the smoking effect. The received results could be explained on the basis of a two - mutation model of radiation carcinogenesis

  18. Radiation pressure and the linear momentum of the electromagnetic field

    OpenAIRE

    Mansuripur, Masud

    2013-01-01

    We derive the force of the electromagnetic radiation on material objects by a direct application of the Lorentz law of classical electro-dynamics. The derivation is straightforward in the case of solid metals and solid dielectrics, where the mass density and the optical constants of the media are assumed to remain unchanged under internal and external pressures, and where material flow and deformation can be ignored. For metallic mirrors, we separate the contribution to the radiation pressure...

  19. Ionizing radiation increases primary cilia incidence and induces multiciliation in C2C12 myoblasts

    Czech Academy of Sciences Publication Activity Database

    Filipová, A.; Diaz-Garcia, D.; Bezrouk, A.; Čížková, D.; Havelek, R.; Vávrová, J.; Dayanithi, Govindan; Řezáčová, M.

    2015-01-01

    Roč. 39, č. 8 (2015), s. 943-953 ISSN 1065-6995 Institutional support: RVO:68378041 Keywords : cell line * ionizing radiation * multiple cilia * myoblast * primary cilium * serum starvation stress Subject RIV: FP - Other Medical Disciplines Impact factor: 1.663, year: 2015

  20. Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

    DEFF Research Database (Denmark)

    Borg, J.; Christensen, P.

    1995-01-01

    The extrapolation chamber measurement method is the basic method for the determination of dose rates in beta radiation fields and the method has been used for the establishment of beta calibration fields. The paper describes important details of the method and presents results from the measurement...... of depth-dose profiles from different beta radiation fields with E(max) values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high...... sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value...

  1. Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

    DEFF Research Database (Denmark)

    Borg, J.; Christensen, P.

    1995-01-01

    of depth-dose profiles from different beta radiation fields with E(max) values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high......The extrapolation chamber measurement method is the basic method for the determination of dose rates in beta radiation fields and the method has been used for the establishment of beta calibration fields. The paper describes important details of the method and presents results from the measurement...... sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value...

  2. Thyroid cancer incidence in iodine deficient areas exposed to radiation after Chernobyl accident

    International Nuclear Information System (INIS)

    Szybinski, Z.; Mazurek-Przybylik, E.

    1996-01-01

    In two districts of Southern Poland; Krakow and Nowy Sacz (2 million people), standardized thyroid cancer incidence rate IR was evaluated from 1976 to 1992. This area was classified as a moderate iodine deficiency endemic goiter region and belonged to the most contaminated areas in Poland after Chernobyl accident. Recalculated - in terms of real iodine intake-thyroid commitment equivalent dose in the youngest age groups reached 100 mSv. The aim of the study was to evaluate, 6 years after Chernobyl accident, thyroid cancer incidence rate and histotype. Age and sex specific incidence rate in Krakow for male was 0.827 and for female 3.093 and 0.93 and 2.164 for Nowy Sacz respectively. There was no increase of IR in the group of age 0-19 yrs, however in the group over 44 yrs in females in the period of time 1989-1992 significant increase of follicular cancer was observed. In the histotype, the follicular cancerpredominated over the papillary one: 42,9% against 33,6%. Predominance of the follicular cancer is typical for iodine deficient area. Significant increase of the follicular cancer may be due to the increase of iodine deficiency. (author). 14 refs, 1 fig., 5 tabs

  3. The exact electromagnetic field description of photon emission, absorption, and radiation pattern. II.

    Science.gov (United States)

    Grimes, Dale M; Grimes, Craig A

    2002-10-01

    This is the second of two articles, the first of which contains a proposed explanation of quantum theory based upon electron nonlocality and classical electrodynamics. In this second article classical field theory is used to describe a unique field set for exchange of radiation between an atomic eigenstate and the far field. The radiation satisfies the thermodynamic condition of reversibility as described by Boltzmann, Planck, and Einstein. The exchanged radiation supports the kinematic properties of photons, and it can be emitted or absorbed by a vanishingly small volume.

  4. Preliminary studies into profiling DNA recovered from a radiation or radioactivity incident

    International Nuclear Information System (INIS)

    Hodgson, A.; Baxter, A.

    2013-01-01

    The examination and profiling of human DNA recovered from a scene of crime is an essential aspect of criminal investigations. However, it is currently not known whether DNA recovered from a scene where an ionising radiation source or radioactive contamination is present can be successfully profiled. The direct examination and analysis of radioactively contaminated DNA has not been widely explored using the current procedures employed by forensic service providers. As a result, AWE is putting in place an extensive research and development programme to better understand the effects that radiation has on the ability to profile human DNA, and assess the associated retention of different radioactive contaminants within each step of the profiling procedure. A summary will be provided on the aims of this project and progress that has been made to date; together with a discussion of the lessons that have been learnt during the course of the programme's development. (author)

  5. Accidents and incidents with external and/or internal radiation-exposure

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    An individual radiation exposure accident is an unexpected and unintended event which gives rise to an overexposure (external or internal). By overexposure one means all external or internal exposure which could lead to the exceeding of the regulatory norms. Going beyond these limits does not always produce pathological manifestations. The term radiological accident is, in practice, used only when there is an occurrence of some biological or clinical response, or when some therapeutic action is required. A radio-exposure accident can occur: within or from a nuclear power plant or from a center employing ionizing radiation. These are the most frequent; and during the transport of radioactive materials. These are exceptional events. The tanks and containers used in the transport of highly radioactive substances are exhaustively studied for their resistance to accidents, and the conditions of transport determined by very strict national and international regulations. The transport of substances of low radioactivity (labelled molecules, radiopharmaceuticals...) carries only minor risks

  6. Viscoelastoplastic bodies under cyclic loading in thermal-radiation fields

    OpenAIRE

    Atwa D. Zeyad

    2017-01-01

    Deformation of viscoelastoplastic bodies in the neutron and thermal fluxes under a one-time loading has been studied previously in [1–3]. A mathematical model has been set forth in [4] for a cyclic deformation of elastoplastic bodies in a neutron flux. In the paper [5,6] ferrofluid flow and heat transfer in a semi annulus enclosure is investigated considering thermal radiation. This article [7] explores the effect of thermal radiation on Al2O3–water nanofluid flow and heat transfer in an encl...

  7. Isolation of radiation resistant fungal strains from highly radioactive field

    International Nuclear Information System (INIS)

    Adam, Y.M.; Aziz, N.H.; Attaby, H.S.H.

    1995-01-01

    This study examined the radiation resistance of fungal flora isolated from the hot-lab around the radiation sources, cobalt 137 and radium 226 . The predominant mould species were: Aspergillus flavus, A. Niger, penicillium chrysogenum, cladosporium herbarum, fusarium oxysporum and alternaria citri. The D 10 values of F. Oxysporum; 2.00 KGy, A. Flavus; 1.40 KGy, P. chrysogenum; 1.15 KGy, and A. citri; 0.95 KGy, are about 1.67, 3.10, 1.92 and 1.36 folds as the D 1 0 values of the same isolates recovered from soil

  8. Dose equivalent measurements in mixed and time varying radiation fields around high-energy accelerators

    CERN Document Server

    Mayer, S

    2003-01-01

    Measurements of ambient dose equivalent in stray radiation fields behind the shielding of high-energy accelerators are a challenging task. Several radiation components (photons, neutrons, charged particles, muons, etc.), spanning a wide range of energies, contribute to the total dose equivalent. The radiation fields are produced by beam losses interacting with structural material during the acceleration or at the ejection to experimental areas or other accelerators. The particle beam is usually not continuous but separated in "bunches" or pulses, which further complicates dose measurements at high-energy accelerators. An ideal dosimeter for operational radiation protection should measure dose equivalent for any composition of radiation components in the entire energy range even when the field is strongly pulsed. The objective of this work was to find out if an ionisation chamber operated as a "recombination chamber" and a TEPC instrument using the variance-covariance method ("Sievert Instrument") are capable ...

  9. Television system for verification and documentation of treatment fields during intraoperative radiation therapy

    International Nuclear Information System (INIS)

    Fraass, B.A.; Harrington, F.S.; Kinsella, T.J.; Sindelar, W.F.

    1983-01-01

    Intraoperative radiation therapy (IORT) involves direct treatment of tumors or tumor beds with large single doses of radiation. The verification of the area to be treated before irradiation and the documentation of the treated area are critical for IORT, just as for other types of radiation therapy. A television system which allows the target area to be directly imaged immediately before irradiation has been developed. Verification and documentation of treatment fields has made the IORT television system indispensable

  10. Radiation emission and its influence on the motion of multi-GeV electrons and positrons incident on a single diamond crystal

    CERN Document Server

    Kirsebom, K; Uggerhøj, Erik; Elsener, K; Ballestrero, S; Sona, P; Connell, S H; Sellschop, J P Friedel; Vilakazi, Z Z

    2001-01-01

    A few years ago the CERN NA-43 collaboration installed an upgraded detector system which allows a detailed analysis of the particle motion before, during and after penetration of a crystal. Also, essentially perfect diamond crystals were produced by the collaborators from Schonland Research Centre. These facts have led to new and very detailed investigations of QED-processes in strong crystalline fields. Along axial directions the radiation emission is enhanced by more than two orders of magnitude. For incidence on a 0.7 mm thick diamond crystal of well-aligned 149 GeV electrons, 35% give rise to a high energy photon peak at approximately=120 GeV. For 243 GeV electrons and approximately=200 GeV photons, this number decreases to 25%-which may be an indication of quantum suppression. Different measurements of the photon multiplicities show that in most cases positrons and electrons emit equal number of photons. The dramatic radiation emission leads to a strong reduction in transverse energy and all electrons in...

  11. Control of automatic materials handling in radiation fields

    International Nuclear Information System (INIS)

    Szadvari, Jozsef; Juhasz, Miklos; Szanto, Robert

    1987-01-01

    Some agricultural and food industry raw materials and products can be effectively sterilized by ionizing radiation for better quality and longer shelf-life. A microelectronically controlled automatic materials handling system installed in an irradiation facility of AGROSTER Company, Hungary, is described. Programmable logic controllers (PLCs) type FESTO FPC 606 were applied to control the motion of containers. (R.P.) 6 figs

  12. In core measurement and monitoring of reactor (neutron) radiation field

    International Nuclear Information System (INIS)

    Erben, O.

    1985-01-01

    A survey is presented of in core radiation detectors. The principles are described of activation detectors, fission chambers, self-powered neutron detectors and thermal sensors. Systems of in core measurement for WWER nuclear power plants, nuclear reactors of power plants operated by KWU, Babcock and Wilcox, Combustion Engineering and FRAMATOME are described. (E.S.)

  13. Actual conditions of radiation control in radioisotope utilization field

    International Nuclear Information System (INIS)

    Kakihara, Koji

    1980-01-01

    It may be said that the actual conditions on radiation safety are being improved in utilizing radioisotopes or radiation in Japan. It depends greatly on the results of the voluntary effort of users and the regulations by the ''radiation injury prevention law'' and its relevant ordinances. However, the actual conditions of the strict observation of the law are much insufficient. According to the results of official inspection in 1978, 60% of whole enterprises concerned and 73% of educational and medical organizations were judged as incomplete. Such tendency should not be left as it is, but it should also be noticed that there are realities that critical accidents or injuries have not occurred even in such conditions as many violations mentioned above. Since the existing law has not been subjected to essential revision in the past two decades, it might be said that the law does not properly fit to the present conditions because the progress of related techniques was made during this period. Meanwhile, difficulties exist in measuring the low level concentration in the use of low energy radioisotopes or tracer experiments such as in the process analysis in factories or in the analysis of the movement of trace constituent in soil. Further, there is a problem on the necessity of securing the chief technicians handling radiation, and there is the contradiction that the chief technicians are useless in normal condition but are powerless in case of accidents. This situation should be improved as soon as possible. (Wakatsuki, Y.)

  14. Sparse Matrix Motivated Reconstruction of Far-Field Radiation Patterns

    Science.gov (United States)

    2015-03-01

    Millennium Drive Suite 101 Belcamp, MD 21017 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY...Fig. 13. Note the lack of back-lobe measurement due to the presence of the supporting tower . 14 Fig. 13 2-D radiation pattern of the

  15. Radiation protection measurement - spectral solutions in special fields

    International Nuclear Information System (INIS)

    Urban, F.J.; Trliber, K.H.; Schwerdn, K.; Laube, S.

    1997-01-01

    The exposition to ionizing radiation is a fact for nearly every person. One part of the exposition is due to natural or man made radioisotopes occurring in the environment. Another part exists because of technical sources. mainly x-ray machines for medical diagnostics. (authors)

  16. Quantum radiation of Maxwell’s electromagnetic field in nonstationary Kerr-de Sitter black hole

    Science.gov (United States)

    Ibungochouba Singh, T.; Ablu Meitei, I.; Yugindro Singh, K.

    2016-03-01

    Quantum radiation properties of nonstationary Kerr-de Sitter (KdS) black hole is investigated using the method of generalized tortoise coordinate transformation. The locations of horizons and the temperature of the thermal radiation as well as the maximum energy of the nonthermal radiation are derived. It is found that the surface gravity and the Hawking temperature depend on both time and different angles. An extra coupling effect is obtained in the thermal radiation spectrum of Maxwell’s electromagnetic field equations which is absent in the thermal radiation spectrum of scalar particles. Further, the chemical potential derived from the thermal radiation spectrum of scalar particle has been found to be equal to the highest energy of the negative energy state of the scalar particle in the nonthermal radiation for KdS black hole. It is also shown that the generalized tortoise coordinate transformation produces a constant term in the expression of the surface gravity and Hawking temperature.

  17. LETTER TO THE EDITOR: Comments on 'Cellular response to modulated radiation fields'

    Science.gov (United States)

    Ross, C. K.; Klassen, N. V.

    2009-03-01

    The authors of a recent paper (Claridge Mackonis et al 2007 Phys. Med. Biol. 52 5469-82) measured cell survival in spatially modulated radiation fields. They claim to have identified two new types of radiation-induced bystander effect. We conclude that their claims are not supported by their data.

  18. Radiation impedance of condenser microphones and their diffuse-field responses

    DEFF Research Database (Denmark)

    Barrera Figueroa, Salvador; Rasmussen, Knud; Jacobsen, Finn

    2010-01-01

    The relation between the diffuse-field response and the radiation impedance of a microphone has been investigated. Such a relation can be derived from classical theory. The practical measurement of the radiation impedance requires (a) measuring the volume velocity of the membrane of the microphon...

  19. Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

    CERN Document Server

    Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2006-01-01

    This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

  20. Experimental study of the counting loss in an ionization chamber in pulsed radiation fields

    International Nuclear Information System (INIS)

    Goncalez, O.L.; Yanagihara, L.S.; Veissid, V.L.C.P.; Herdade, S.B.; Teixeira, A.N.

    1983-01-01

    The behavior of an ionization chamber gamma ray monitor in a pulsed radiation field at a linear electron accelerator facility was studied experiementally. A loss of sensitivity was observed as expected due to the pulsed nature of the radiation. By fitting the experiemental data to semi-empirical expressions, parameters for the correction of the counting efficiency were obtained. (Author) [pt

  1. Occupational exposure to ionizing radiation and electromagnetic fields in relation to the risk of thyroid cancer in Sweden.

    Science.gov (United States)

    Lope, Virginia; Pérez-Gómez, Beatriz; Aragonés, Nuria; López-Abente, Gonzalo; Gustavsson, Per; Floderus, Birgitta; Dosemeci, Mustafa; Silva, Agustín; Pollán, Marina

    2006-08-01

    This study sought to ascertain the risk of thyroid cancer in relation to occupational exposure to ionizing radiation and extremely low-frequency magnetic fields (ELFMF) in a cohort representative of Sweden's gainfully employed population. A historical cohort of 2 992 166 gainfully employed Swedish male and female workers was followed up from 1971 through 1989. Exposure to ELFMF and ionizing radiation was assessed using three job exposure matrices based on industrial branch or occupational codes. Relative risks (RR) for male and female workers, adjusted for age and geographic area, were computed using log-linear Poisson models. Occupational ELFMF exposure showed no effect on the risk of thyroid cancer in the study. However, female workers exposed to high intensities of ionizing radiation registered a marked excess risk (RR 1.85, 95% confidence interval (95% CI) 1.02-3.35]. This trend was not in evidence among the men. While the study confirms the etiologic role of ionizing radiation, with a higher incidence of thyroid cancer being recorded for the most-exposed female workers, our results do not support the possibility of occupational exposure to ELFMF being a risk factor for the development of thyroid cancer.

  2. A radiation contamination incident involving strontium 90 in a private home

    International Nuclear Information System (INIS)

    Fleischmann, A.W.; Button, J.C.E.

    1977-01-01

    In October 1975 a private electronic service contractor, operating in his home workshop, drilled a hole through a Strontium 90 (15 mCi) capsule while attempting to repair a thickness gauge. Four days passed before he became aware of the resultant contamination and notified the authorities. Contamination was spead over himself, his wife, the family pet (a dog), the wokshop and living area of his home, furniture, garden and paths around the house. It took four officers from the Health Commission of New South Wales and another four from the Australian Atomic Energy Commission four weeks to clean the home and surrounds to the levels where the premises would be again occupied. A large amount of electronic equipment, personal belongings and furniture could not be decontaminated and has had to be stored for ultimate disposal. This, in itself, represents a problem because there is no Australian waste burial site and some of the objects, for disposal, are relatively large (e.g. carpets, pieces of furniture, furniture covers, etc.) It is proposed to discuss the incident, decontamination, health aspects and some of the consequences of the incident

  3. Wave field synthesis of moving virtual sound sources with complex radiation properties.

    Science.gov (United States)

    Ahrens, Jens; Spors, Sascha

    2011-11-01

    An approach to the synthesis of moving virtual sound sources with complex radiation properties in wave field synthesis is presented. The approach exploits the fact that any stationary sound source of finite spatial extent radiates spherical waves at sufficient distance. The angular dependency of the radiation properties of the source under consideration is reflected by the amplitude and phase distribution on the spherical wave fronts. The sound field emitted by a uniformly moving monopole source is derived and the far-field radiation properties of the complex virtual source under consideration are incorporated in order to derive a closed-form expression for the loudspeaker driving signal. The results are illustrated via numerical simulations of the synthesis of the sound field of a sample moving complex virtual source.

  4. Attenuation of VHE Gamma Rays by the Milky Way Interstellar Radiation Field

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.; /Louisiana State U.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

    2006-04-19

    The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the energy density of the Galactic interstellar radiation field is higher, particularly in the Galactic center, than previously thought. We have made a calculation of the attenuation of very high energy gamma rays in the Galaxy using this new interstellar radiation field which takes into account its nonuniform spatial and angular distributions. We find that the maximum attenuation occurs around 100 TeV at the level of about 25% for sources located at the Galactic center, and is important for both Galactic and extragalactic sources.

  5. The effects of emitter-tied field plates on lateral PNP ionizing radiation response

    International Nuclear Information System (INIS)

    Barnaby, H.J.; Schrimpf, R.D.; Cirba, C.R.; Pease, R.L.; Fleetwood, D.M.; Kosier, S.L.

    1998-03-01

    Radiation response comparisons of lateral PNP bipolar technologies reveal that device hardening may be achieved by extending the emitter contact over the active base. The emitter-tied field plate suppresses recombination of carriers with interface traps

  6. Enhancement of the rate of radiative processes in the field of a magnetic monopole

    International Nuclear Information System (INIS)

    Barut, A.O.; Shnir, Ya.M.; Knyazev, M.A.; Tolkachev, E.A.

    1993-07-01

    The spontaneous emission rate for the bound system charge-dyon is calculated. It is shown that the magnetic monopole fields leads to the significant increase of the rate of radiative processes. (author). 14 refs

  7. Epidemiological studies on disturbances of human fetal development in areas with various doses of natural background radiation. I. Relationship between incidences of Down's syndrome or visible malformation and gonad dose equivalent rate of natural background radiation

    International Nuclear Information System (INIS)

    Ujeno, Y.

    1985-01-01

    The relationship between environmental radiation to the gonads and incidences of Down's syndrome and visible malformation was analyzed using Kendall's rank correlation method. The subjects, studied during a 3-yr period (1979-1981), were inhabitants of 46 prefectures in Japan that had various dose rates of natural background ionizing radiation. Results showed that the natural background very low-dose radiation rate was not a predominant factor responsible for inducing Down's syndrome or other visible malformations

  8. Use of mobile robots for mapping radiation field around particle accelerators

    International Nuclear Information System (INIS)

    Sharma, S.; Agashe, V.; Pal, P.K.

    2011-01-01

    In Particle Accelerators, when the accelerated particles hit the target or inadvertently strike the wall, prompt and induced radiation is produced. It is necessary to monitor the resulting radiation field in order to reduce radiation exposure to operating personnel, as well as to locate points of leakage of the particle beam. This paper describes the development of mobile robots equipped with onboard radiation detectors for mapping such radiation fields. They include a user interface software running on a host computer to tele operate the robot, monitor radiation levels, and build and display a radiation map out of these data through interpolation. One such robot (ARMER-II), designed and developed by us in consultation with Radiation Safety Division (RSD), is a portable mobile robot for identifying locations with radiation levels higher than permissible limits. Its remote interface computes and guides the robot to move in a direction in which the increase in intensity of radiation is the steepest. Another mobile robot (ARMER-I) has a telescopic arm fitted with a light and small GM tube. This also can be controlled remotely, and is very useful in remote measurement of radiation from locations which are difficult to reach otherwise. Another version (ASHWA) has been successfully adapted by VECC, Kolkata, for gamma and neutron radiation profiling in the cyclotron vault area. We are presently working on the design and development of a four-wheel differentially driven mobile robot (RADMAPPER) with higher payload capacity for carrying radiation detectors like gamma camera and neutron dosimeters and positioning them at desired heights. With appropriate localization capability, this is going to be a very flexible mobile robot based system for radiation profiling around particle accelerators. The specification for this robot has been prepared in consultation with VECC for use in their cyclotron facilities. (author)

  9. Radiation protection measurements with the variance-covariance method in the stray radiation fields from photon and proton therapy facilities

    DEFF Research Database (Denmark)

    Lillhök, J.; Persson, L.; Andersen, Claus E.

    2017-01-01

    The microdosimetric variance-covariance method was used to study the stray radiation fields from the photon therapy facility at the Technical University of Denmark and the scanned proton therapy beam at the Skandion Clinic in Uppsala, Sweden. Two TEPCs were used to determine the absorbed dose...

  10. A simple ionizing radiation spectrometer/dosimeter based on radiation sensing field effect transistors (RadFETs)

    International Nuclear Information System (INIS)

    Moreno, D.J.; Hughes, R.C.; Jenkins, M.W.; Drumm, C.R.

    1997-01-01

    This paper reports on the processing steps in a silicon foundry leading to improved performance of the Radiation Sensing Field Effect Transistor (RadFET) and the use of multiple RadFETs in a handheld, battery operated, combination spectrometer/dosimeter

  11. Coherent and incoherent radiation from free-electron lasers with an axial guide field

    OpenAIRE

    Freund, Henry P.; Sprangle, P.; Dillenburg, Darcy; Jornada, Eda Homrich da; Liberman, Bernardo; Schneider, Ruth de Souza

    1981-01-01

    The spontaneous and induced emission from a free-electron laser is treated for the case in which an axial magnetic field is imposed in addition to the helical, axially periodic wiggler magnetic field. The classes of possible single-particle trajectories in this configuration are discussed, and the results are applied to a calculation of the incoherent radiation from a beam of relativistic electrons in the system. The coherent radiation is treated by solving the Vlasov-Maxwell equations for th...

  12. Spin polarization in quantum dots by radiation field with circular polarization

    CERN Document Server

    Bulgakov, E N

    2001-01-01

    For circular quantum dot (QD) with account of the Razhba spin-orbit interaction (SOI) an exact energy spectrum is obtained. For the small SOI constant the Eigen functions of the QD are found. It is shown that application of radiation field with circular polarization lifts the Kramers degeneracy of the Eigen states of the QD. Effective spin polarization of transmitted electrons through the QD by radiation field with circular polarization is demonstrated

  13. WE-EF-BRA-08: Cell Survival in Modulated Radiation Fields and Altered DNA-Repair at Field Edges

    Energy Technology Data Exchange (ETDEWEB)

    Bartzsch, S; Oelfke, U [The Institute of Cancer Research, London (United Kingdom); Eismann, S [University of Heidelberg, Heidelberg, DE (Germany)

    2015-06-15

    Purpose: Tissue damage prognoses in radiotherapy are based on clonogenic assays that provide dose dependent cell survival rates. However, recent work has shown that apart from dose, systemic reactions and cell-cell communication crucially influence the radiation response. These effects are probably a key in understanding treatment approaches such as microbeam radiation therapy (MRT). In this study we tried to quantify the effects on a cellular level in spatially modulated radiation fields. Methods: Pancreas carcinoma cells were cultured, plated and irradiated by spatially modulated radiation fields with an X-ray tube and at a synchrotron. During and after treatment cells were able to communicate via the intercellular medium. Afterwards we stained for DNA and DNA damage and imaged with a fluorescence microscope. Results: Intriguingly we found that DNA damage does not strictly increase with dose. Two cell entities appear that have either a high or a low amount of DNA lesions, indicating that DNA damage is also a cell stress reaction. Close to radiation boundaries damage-levels became alike; they were higher than expected at low and lower than expected at high doses. Neighbouring cells reacted similarly. 6 hours after exposure around 40% of the cells resembled in their reactions neighbouring cells more than randomly chosen cells that received the same dose. We also observed that close to radiation boundaries the radiation induced cell-cycle arrest disappeared and the size of DNA repair-centres increased. Conclusion: Cell communication plays an important role in the radiation response of tissues and may be both, protective and destructive. These effects may not only have the potential to affect conventional radiotherapy but may also be exploited to spare organs at risk by intelligently designing irradiation geometries. To that end intensive work is required to shed light on the still obscure processes in cell-signalling and radiation biology.

  14. Very high-accuracy calibration of radiation pattern and gain of a near-field probe

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav

    2014-01-01

    In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission of the Europ......In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission...

  15. Improvements relating to the restriction of fields of radiation

    International Nuclear Information System (INIS)

    Flocee, R.

    1977-01-01

    A method is described for delimiting the irradiation target area in radiotherapeutic treatments. The method is based on the realisation that it is possible to modify the effective cross section of a beam of radiation by means of a device which can be regarded as a secondary diaphragm, with an aperture framed by the heavy metal powder composition, which has radiation absorption properties. The heavy metal may be W or Pb, the grains of which are held together by the binding agent. The binding agent, being of the type known as a 'pressure-sensitive adhesive'. The method has the advantage that there is no need to employ either the therapeutic unit or an expensive simulator for construction of the beam cross section modifying device, nor has the patient to be present when this step is performed. Also the device employed is reusable. An example of the manufacture of the composition is described. Notes are also included on treatment techniques. (U.K.)

  16. Radiation Field in the Vicinity of the Collider Center

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, A. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    1994-10-26

    The Collider Center and the adjoining cryogenic support building are unique among the buildings close to the collider tunnel because these are locations where the occupancy by non-radiation workers is high. This note describes calculations of the dose equivalent from local beam loss at both the nearest point of these buildings to the collider ring and on the berm in the vicinity of these buildings.

  17. Convective vaporization of particles in an electromagnetic radiation field

    Science.gov (United States)

    Kuznetsov, P. V.; Kurochkin, V. I.

    1987-03-01

    The heating and vaporization of spherical particles in the case of the arbitrary relative concentration of vapor and gas are studied on the basis of the exact equations of multicomponent gas dynamics with allowance for the temperature dependence of the transport coefficients. The proposed method makes possible an easy computation of the vaporization rate and temperature in a wide range of particle sizes and radiation flux densities. The results obtained can be used to calculate laser-induced breakdown in metal vapors.

  18. Correlation between the time-series of air temperature and incident solar radiation at Port Harcourt, Nigeria

    International Nuclear Information System (INIS)

    Adjepong, S.K.; Okujagu, C.

    1987-12-01

    We present the preliminary results of an investigation of the correlation between the temporal variations of the time-series of ground air temperature and incident solar radiation recorded at Port Harcourt (lat. 4 deg. 51' N, long. 7 deg. 01' E), Nigeria, during a five-year period (1981 through 1985). Computed cross-correlation functions of the daily time-series reveal correlation at time lags which are approximate harmonics of the 27-day solar rotation cycle. The cross-correlation function of the mean monthly series shows correlation at a time lag of 12 months implying a dominant annual-cycle component in the variation of either series. (author). 12 refs, 2 figs

  19. INSREC: Computational System for Quantitative Analysis of Radiation Effects Covering All Radiation Field

    International Nuclear Information System (INIS)

    Dong Hoon Shin; Young Wook Lee; Young Ho Cho; Hyun Seok Ko; SukHoon Kim; YoungMin Kim; Chang Sun Kang

    2006-01-01

    In the nuclear energy field, there are so many difficult things that even people who are working in this field are not much familiar with, such as, Dose evaluation, Dose management, etc. Thus, so many efforts have been done to achieve the knowledge and data for understanding. Although some data had been achieved, the applications of these data to necessary cases were more difficult job. Moreover, the type of Dose evaluation program until now was 'Console type' which is not easy enough to use for the beginners. To overcome the above causes of difficulties, the window-based integrated program and database management were developed in our research lab. The program, called as INSREC, consists of four sub-programs as follow; INSREC-NOM, INSREC-ACT, INSREC-MED, and INSREC-EXI. In ICONE 11 conference, INSREC-program(ICONE-36203) which can evaluates on/off-site dose of nuclear power plant in normal operation was introduced. Upgraded INSREC-program which will be presented in ICONE 14 conference has three additional codes comparing with pre-presented INSREC-program. Those subprograms can evaluate on/off-site Dose of nuclear power plant in accident cases. And they also have the functions of 'Dose evaluation and management' in the hospital and provide the 'Expert system' based on knowledge related to nuclear energy/radiation field. The INSREC-NOM, one of subprograms, is composed of 'Source term evaluation program', 'Atmospheric diffusion factor evaluation program', 'Off-site dose evaluation program', and 'On-site database program'. The INSREC-ACT is composed of 'On/Off-site dose evaluation program' and 'Result analysis program' and the INSREC-MED is composed of 'Workers/patients dose database program' and 'Dose evaluation program for treatment room'. The final one, INSREC-EXI, is composed of 'Database searching program based on artificial intelligence', 'Instruction program,' and 'FAQ/Q and A boards'. Each program was developed by using of Visual C++, Microsoft Access mainly

  20. ANOLE Portable Radiation Detection System Field Test and Evaluation Campaign

    International Nuclear Information System (INIS)

    Hodge, Chris A.

    2007-01-01

    Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named 'Anole', it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection systems. The campaign also offered manufacturers the opportunity to submit their equipment for independent operationally relevant testing to subsequently improve their detector performance. This paper will present the design, execution, and methodologies of the DHS Anole portable radiation detection system test campaign

  1. Radiation Isotope Identification Device (RIIDs) Field Test and Evaluation Campaign

    International Nuclear Information System (INIS)

    Christopher Hodge, Raymond Keegan

    2007-01-01

    Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named 'Anole', it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection systems. The campaign also offered manufacturers the opportunity to submit their equipment for independent operationally relevant testing to subsequently improve their detector performance. This paper will present the design, execution, and methodologies of the DHS Anole portable radiation detection system test campaign

  2. Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, M [Chemical and Nuclear Engineering Department, Polytechnic University of Valencia, Camino de Vera s/n 46022 Valencia (Spain); Ferrer, S [Chemical and Nuclear Engineering Department, Polytechnic University of Valencia, Camino de Vera s/n 46022 Valencia (Spain); Villaescusa, J I [Radiation Protection Service, Hospital Universitario La Fe, Avda Campanar, 21 46009 Valencia (Spain); Verdu, G [Chemical and Nuclear Engineering Department, Polytechnic University of Valencia, Camino de Vera s/n 46022 Valencia (Spain); Salas, M D [Public Health General Direction, Conselleria de Sanitat de Valencia, C/Micer Masco, 31 46021 Valencia (Spain); Cuevas, M D [Assistential Service General Direction, Conselleria de Sanitat de Valencia, C/Micer Masco, 31 46021 Valencia (Spain)

    2005-02-07

    The authors report on a method to calculate radiological risks, applicable to breast screening programs and other controlled medical exposures to ionizing radiation. In particular, it has been applied to make a risk assessment in the Valencian Breast Cancer Early Detection Program (VBCEDP) in Spain. This method is based on a parametric approach, through Markov processes, of hazard functions for radio-induced breast cancer incidence and mortality, with mean glandular breast dose, attained age and age-at-exposure as covariates. Excess relative risk functions of breast cancer mortality have been obtained from two different case-control studies exposed to ionizing radiation, with different follow-up time: the Canadian Fluoroscopy Cohort Study (1950-1987) and the Life Span Study (1950-1985 and 1950-1990), whereas relative risk functions for incidence have been obtained from the Life Span Study (1958-1993), the Massachusetts tuberculosis cohorts (1926-1985 and 1970-1985), the New York post-partum mastitis patients (1930-1981) and the Swedish benign breast disease cohort (1958-1987). Relative risks from these cohorts have been transported to the target population undergoing screening in the Valencian Community, a region in Spain with about four and a half million inhabitants. The SCREENRISK software has been developed to estimate radiological detriments in breast screening. Some hypotheses corresponding to different screening conditions have been considered in order to estimate the total risk associated with a woman who takes part in all screening rounds. In the case of the VBCEDP, the total radio-induced risk probability for fatal breast cancer is in a range between [5 x 10{sup -6}, 6 x 10{sup -4}] versus the natural rate of dying from breast cancer in the Valencian Community which is 9.2 x 10{sup -3}. The results show that these indicators could be included in quality control tests and could be adequate for making comparisons between several screening programs.

  3. Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

    International Nuclear Information System (INIS)

    Ramos, M; Ferrer, S; Villaescusa, J I; Verdu, G; Salas, M D; Cuevas, M D

    2005-01-01

    The authors report on a method to calculate radiological risks, applicable to breast screening programs and other controlled medical exposures to ionizing radiation. In particular, it has been applied to make a risk assessment in the Valencian Breast Cancer Early Detection Program (VBCEDP) in Spain. This method is based on a parametric approach, through Markov processes, of hazard functions for radio-induced breast cancer incidence and mortality, with mean glandular breast dose, attained age and age-at-exposure as covariates. Excess relative risk functions of breast cancer mortality have been obtained from two different case-control studies exposed to ionizing radiation, with different follow-up time: the Canadian Fluoroscopy Cohort Study (1950-1987) and the Life Span Study (1950-1985 and 1950-1990), whereas relative risk functions for incidence have been obtained from the Life Span Study (1958-1993), the Massachusetts tuberculosis cohorts (1926-1985 and 1970-1985), the New York post-partum mastitis patients (1930-1981) and the Swedish benign breast disease cohort (1958-1987). Relative risks from these cohorts have been transported to the target population undergoing screening in the Valencian Community, a region in Spain with about four and a half million inhabitants. The SCREENRISK software has been developed to estimate radiological detriments in breast screening. Some hypotheses corresponding to different screening conditions have been considered in order to estimate the total risk associated with a woman who takes part in all screening rounds. In the case of the VBCEDP, the total radio-induced risk probability for fatal breast cancer is in a range between [5 x 10 -6 , 6 x 10 -4 ] versus the natural rate of dying from breast cancer in the Valencian Community which is 9.2 x 10 -3 . The results show that these indicators could be included in quality control tests and could be adequate for making comparisons between several screening programs

  4. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats ?

    OpenAIRE

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susc...

  5. Reduction in life span on normal human fibroblasts exposed to low-dose radiation in heavy-ion radiation field

    International Nuclear Information System (INIS)

    Suzuki, Masao; Yamaguchi, Chizuru; Yasuda, Hiroshi; Uchihori, Yukio; Fujitaka, Kazunobu

    2003-01-01

    We studied the effect of in vitro life span in normal human fibroblasts exposed to chronically low-dose radiation in heavy-ion radiation field. Cells were cultured in a CO 2 incubator, which was set in the irradiation room for biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and exposed to scattered radiations produced with heavy-ion beams throughout the life span of the cell population. Absorbed dose, which was measured using a thermoluminescence dosimeter(TLD) and a Si-semiconductor detector, was to be 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number of the exposed cells reduced to 79-93% of non-exposed control cells in the three independent experiments. There is evidence that the exposure of chronically low-dose radiation in heavy-ion radiation field promotes the life-span reduction in cellular level. (author)

  6. The incidence of radiation necrosis following stereotactic radiotherapy for melanoma brain metastases: the potential impact of immunotherapy.

    Science.gov (United States)

    Kaidar-Person, Orit; Zagar, Timothy M; Deal, Allison; Moschos, Stergios J; Ewend, Matthew G; Sasaki-Adams, Deanna; Lee, Carrie B; Collichio, Frances A; Fried, David; Marks, Lawrence B; Chera, Bhishamjit S

    2017-07-01

    Stereotactic radiotherapy (SRT) is the standard treatment for patients with limited number of brain metastases. In the past few years, newer immunotherapies (immune checkpoint inhibitors) have been proven to prolong survival in patients with metastatic melanoma. The safety of the combination of SRT and immunotherapy for brain metastases is unknown. We retrospectively identified patients with melanoma brain metastases treated with SRT between 2007 and 2015. Patients who did not have at least 3 months of follow-up with imaging after SRT were excluded from the analysis. Outcomes were compared between patients who were treated with or without immunotherapy. A total of 58 patients were included; of these, 29 were treated with SRT and immunotherapy. MAPK inhibitors (BRAF, MEK inhibitors) were used more often in the immunotherapy group (nine vs. two patients). There was a higher incidence of intracranial complications in patients treated with immunotherapy and SRT. Eight patients had radiation necrosis; all occurred in patients who were treated with immunotherapy. Nine patients had hemorrhage, of which seven occurred in patients who were treated with immunotherapy (P=0.08). However, patients treated with immunotherapy and SRT had a significant overall survival advantage compared with SRT without immunotherapy (15 vs. 6 months, P=0.0013). Patients treated with SRT and immunotherapy have a higher incidence/risk of intracranial complications, but a longer overall survival.

  7. 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...

  8. Relativistic nonlinear electrodynamics the QED vacuum and matter in super-strong radiation fields

    CERN Document Server

    Avetissian, Hamlet K

    2016-01-01

    This revised edition of the author’s classic 2006 text offers a comprehensively updated review of the field of relativistic nonlinear electrodynamics. It explores the interaction of strong and super-strong electromagnetic/laser radiation with the electromagnetic quantum vacuum and diverse types of matter – including free charged particles and antiparticles, acceleration beams, plasma and plasmous media.  The appearance of laser sources of relativistic and ultra-relativistic intensities over the last decade has stimulated investigation of a large class of processes under such super-strong radiation fields. Revisions for this second edition reflect these developments and the book includes new chapters on Bremsstrahlung and nonlinear absorption of superintense radiation in plasmas, the nonlinear interaction of relativistic atoms with intense laser radiation, nonlinear interaction of strong laser radiation with Graphene, and relativistic nonlinear phenomena in solid-plasma targets under supershort laser pul...

  9. Spectral tuning of near-field radiative heat transfer by graphene-covered metasurfaces

    Science.gov (United States)

    Zheng, Zhiheng; Wang, Ao; Xuan, Yimin

    2018-03-01

    When two gratings are respectively covered by a layer of graphene sheet, the near-field radiative heat transfer between two parallel gratings made of silica (SiO2) could be greatly improved. As the material properties of doped silicon (n-type doping concentration is 1020 cm-3, marked as Si-20) and SiO2 differ greatly, we theoretically investigate the near-field radiative heat transfer between two parallel graphene-covered gratings made of Si-20 to explore some different phenomena, especially for modulating the spectral properties. The radiative heat flux between two parallel bulks made of Si-20 can be enhanced by using gratings instead of bulks. When the two gratings are respectively covered by a layer of graphene sheet, the radiative heat flux between two gratings made of Si-20 can be further enhanced. By tuning graphene chemical potential μ and grating filling factor f, due to the interaction between surface plasmon polaritons (SPPs) of graphene sheets and grating structures, the spectral properties of the radiative heat flux between two parallel graphene-covered gratings can be effectively regulated. This work will develop and supplement the effects of materials on the near-field radiative heat transfer for this kind of system configuration, paving a way to modulate the spectral properties of near-field radiative heat transfer.

  10. Experiments performed with a functional model based on statistical discrimination in mixed nuclear radiation field

    International Nuclear Information System (INIS)

    Valcov, N.; Celarel, A.; Purghel, L.

    1999-01-01

    By using the statistical discrimination technique, the components of on ionization current, due to a mixed radiation field, may be simultaneously measured. A functional model, including a serially manufactured gamma-ray ratemeter was developed, as an intermediate step in the design of specialised nuclear instrumentation, in order to check the concept of statistical discrimination method. The obtained results are in good agreement with the estimations of the statistical discrimination method. The main characteristics of the functional model are the following: - dynamic range of measurement: >300: l; - simultaneous measurement of natural radiation background and gamma-ray fields; - accuracy (for equal exposure rates from gamma's and natural radiation background): 17%, for both radiation fields; - minimum detectable exposure rate: 2μR/h. (authors)

  11. Exploring graphene field effect transistor devices to improve spectral resolution of semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Richard Karl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen Wayne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Jeffrey B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hamilton, Allister B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    Graphene, a planar, atomically thin form of carbon, has unique electrical and material properties that could enable new high performance semiconductor devices. Graphene could be of specific interest in the development of room-temperature, high-resolution semiconductor radiation spectrometers. Incorporating graphene into a field-effect transistor architecture could provide an extremely high sensitivity readout mechanism for sensing charge carriers in a semiconductor detector, thus enabling the fabrication of a sensitive radiation sensor. In addition, the field effect transistor architecture allows us to sense only a single charge carrier type, such as electrons. This is an advantage for room-temperature semiconductor radiation detectors, which often suffer from significant hole trapping. Here we report on initial efforts towards device fabrication and proof-of-concept testing. This work investigates the use of graphene transferred onto silicon and silicon carbide, and the response of these fabricated graphene field effect transistor devices to stimuli such as light and alpha radiation.

  12. Estimating incident ultraviolet radiation exposure in the northern Gulf of Mexico during the Deepwater Horizon oil spill.

    Science.gov (United States)

    Bridges, Kristin N; Lay, Claire R; Alloy, Matthew M; Gielazyn, Michel L; Morris, Jeffrey M; Forth, Heather P; Takeshita, Ryan; Travers, Constance L; Oris, James T; Roberts, Aaron P

    2018-02-23

    Millions of barrels of oil were released into the Gulf of Mexico following the 2010 explosion of the Deepwater Horizon oil rig. Polycyclic aromatic hydrocarbons (PAHs) are toxic components of crude oil, which may become more toxic in the presence of ultraviolet (UV) radiation, a phenomenon known as photo-induced toxicity. The Deepwater Horizon spill impacted offshore and estuarine sites, where biota may be co-exposed to UV and PAHs. Penetration of UV into the water column is affected by site-specific factors. Therefore, measurements and/or estimations of UV are necessary when one is assessing the risk to biota posed by photo-induced toxicity. We describe how estimates of incident UV were determined for the area impacted by the Deepwater Horizon oil spill, using monitoring data from radiometers near the spill, in conjunction with reference spectra characterizing the composition of solar radiation. Furthermore, we provide UV attenuation coefficients for both near- and offshore sites in the Gulf of Mexico. These estimates are specific to the time and location of the spill, and fall within the range of intensities utilized during photo-induced toxicity tests performed in support of the Deepwater Horizon Natural Resource Damage Assessment (NRDA). These data further validate the methodologies and findings of phototoxicity tests included in the Deepwater Horizon NRDA, while underscoring the importance of considering UV exposure when assessing possible risks following oil spills. Environ Toxicol Chem 2018;9999:1-9. © 2018 SETAC. © 2018 SETAC.

  13. Study of extremely low frequency electromagnetic field (ELF EMF) radiation produced by consumer products

    International Nuclear Information System (INIS)

    Roha Tukimin; Ahmad Fazli Ahmad Sanusi; Rozaimah Abd Rahim; Mohd Yusof Mohd Ali; Mohamad Amirul Nizam Mohamad Thari

    2006-01-01

    Extremely low frequency electromagnetic field ( ELF EMF) radiation falls under category of non-ionising radiation (NIR).ELF EMF consists of electric and magnetic fields. Excessive exposure to ELF EMF radiation may cause biological and health effects to human beings such as behavioral changes, stochastic and as initiator of cancer. In daily life, the main source of extremely low frequency electromagnetic radiation are consumer products in our home and office. Due to its ability to cause hazard, a study of ELF EMF radiation produced by consumer product was conducted. For this preliminary study, sample of 20 types electrical appliances were selected. The measurement was covered electric and magnetic field strength produced by the sample. PMM model EHP50A were used for measurement and data analysis. The results were compared with the permissible limits recommended by International Commission of Non-Ionising Radiation Protection (ICNIRP) for members of public (1000 mGauss and 5000 V/m). The results showed that all tested sample produced magnetic and electric field but still under the permissible limit recommended by ICNIRP. Besides that we found that field strengths can be very high at closer distance to the sample. (Author)

  14. Position sensitive detection of neutrons in high radiation background field

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Jakůbek, Jan; Vacík, Jiří; Pospíšil, S.

    2014-01-01

    Roč. 85, č. 1 (2014), s. 013304 ISSN 0034-6748 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0060; GA ČR(CZ) GBP108/12/G108; GA TA ČR(CZ) TA01010237 Institutional support: RVO:68378297 ; RVO:61389005 Keywords : neutrons * pattern recognition * position sensitive detectors * radiation detectors * silicon detectors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering; BG - Nuclear, Atomic and Molecular Physics, Colliders (UJF-V) Impact factor: 1.614, year: 2014 http://scitation.aip.org/content/aip/journal/rsi/85/1/10.1063/1.4862478

  15. Near-field radiative heat transfer between metasurfaces

    DEFF Research Database (Denmark)

    Dai, Jin; Dyakov, Sergey A.; Bozhevolnyi, Sergey I.

    2016-01-01

    Metamaterials possess artificial bulk and surface electromagnetic states. Tamed dispersion properties of surface waves allow one to achieve a controllable super-Planckian radiative heat transfer (RHT) process between two closely spaced objects. We numerically demonstrate enhanced RHT between two...... two-dimensional grooved metal plates by a full-wave scattering approach. The enhancement originates from both transverse-magnetic spoof surface-plasmon polaritons and a series of transverse-electric bonding- and anti-bonding-waveguide modes at surfaces. The RHT spectrum is frequency selective...

  16. Use of thermoluminescent dosimetry in gamma radiation fields studies

    International Nuclear Information System (INIS)

    Carron, W.

    1987-01-01

    The depth-dose curves for gamma rays in material of interest to agronomy were obtained using lithium fluoride thermoluminescent dosimeters. The dose conversion factors for LiF were determined from curves of the absorved dose versus depth in water, wood and soil. Mathematics equations were chosen to best fit these curves. In the view of the results we came to the conclusion that in the studied materials the absorved radiation dose presents a great variation to the depth and could be correlated through of the exponential regression. (author)

  17. Quantum theory of laser radiation scattering by electrons in magnetic fields

    International Nuclear Information System (INIS)

    Rochlin, H.; Davidovich, L.

    1982-01-01

    A system consisting of an electron in a static magnetic field, interacting with the quantized electromagnetic field, within the non-relativistic and electric dipole approximations (with a cutoff in momentum space) is considered. The Heisenberg equations of motion are solved exactly and the time evolution of the electric field is determined. The power spectrum of the scattered radiation is calculated, when the electromagnetic field is initially in a coherent state. The results for the line shape of the scattered radiation are shown to be valid for magnetic fields up to 10 12 G. The quantization of the electromagnetic field allows one to consider effects of the natural linewidth and its dependence on the magnetic field. The renormalization of the electron mass is included in these treatment, and the results remain finite when the cutoff goes to infinity. (Author) [pt

  18. Evaluation of moving-coil loudspeaker and passive radiator parameters using normal-incidence sound transmission measurements: theoretical developments.

    Science.gov (United States)

    Leishman, Timothy W; Anderson, Brian E

    2013-07-01

    The parameters of moving-coil loudspeaker drivers are typically determined using direct electrical excitation and measurement. However, as electro-mechano-acoustical devices, their parameters should also follow from suitable mechanical or acoustical evaluations. This paper presents the theory of an acoustical method of excitation and measurement using normal-incidence sound transmission through a baffled driver as a plane-wave tube partition. Analogous circuits enable key parameters to be extracted from measurement results in terms of open and closed-circuit driver conditions. Associated tools are presented that facilitate adjacent field decompositions and derivations of sound transmission coefficients (in terms of driver parameters) directly from the circuits. The paper also clarifies the impact of nonanechoic receiving tube terminations and the specific benefits of downstream field decompositions.

  19. Earth Reflected Solar Radiation Incident upon an Arbitrarily Oriented Spinning Flat Plate

    Science.gov (United States)

    Cunningham, Fred G.

    1963-01-01

    A general derivation is given for the earth reflected solar radiation input to a flat plate--a solar cell paddle, for example--which is spinning about an axis coincident with the axis of symmetry of the satellite to which it is affixed. The resulting equations are written for the general case so that arbitrary orientations of the spin axis with respect to the earth-satellite line and arbitrary orientations of the normal to the plate with respect to the spin axis can be treated. No attempt is made to perform the resulting integrations because of the complexity of the equations; nor is there any attempt to delineate the integration limits for the general case. However, the equations governing these limits are given. The appendixes contain: the results, in graphical form, of two representative examples; the general computer program for the calculation is given in Fortran notation; and the results of a calculation of the distribution of albedo energy on the proposed Echo II satellite. The value of the mean solar constant used is 1.395 times 10 (sup 4) ergs per centimeters-squared per second; the mean albedo of the earth is assumed to be 0.34; and the earth is assumed to be a diffuse reflector.

  20. Incident particle range dependence of radiation damage in a power bipolar junction transistor

    Science.gov (United States)

    Liu, Chao-Ming; Li, Xing-Ji; Geng, Hong-Bin; Rui, Er-Ming; Guo, Li-Xin; Yang, Jian-Qun

    2012-10-01

    The characteristic degradations in silicon NPN bipolar junction transistors (BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon (C), 40-MeV silicon (Si), and 40-MeV chlorine (Cl) ions respectively. Different electrical parameters are measured in-situ during the exposure of heavy ions. The experimental data shows that the changes in the reciprocal of the gain variation (Δ(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C, 40-MeV Si, and 40-MeV Cl ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence. The Δ(1/β) of 3DD155 BJT irradiated by 25-MeV C ions is greatest at a given fluence, a little smaller when the device is irradiated by 40-MeV Si ions, and smallest in the case of the 40-MeV Cl ions irradiation. The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.

  1. Radiation Field of a Square, Helical Beam Antenna

    DEFF Research Database (Denmark)

    Knudsen, Hans Lottrup

    1952-01-01

    square helices are used. Further, in connection with corresponding rigorous formulas for the field from a circular, helical antenna with a uniformly progressing current wave of constant amplitude the present formulas may be used for an investigation of the magnitude of the error introduced in Kraus......' approximate calculation of the field from a circular, helical antenna by replacing this antenna with an ``equivalent'' square helix. This investigation is carried out by means of a numerical example. The investigation shows that Kraus' approximate method of calculation yields results in fair agreement...

  2. Computational study of jet interaction flow field with and without incidence

    International Nuclear Information System (INIS)

    Asif, M.; Zahir, S.; Khan, M.A.

    2004-01-01

    The objective was to study the interaction of a side jet with the incoming supersonic flow and hypersonic flow. Qualitatively same Cp trends have been obtained as found experimentally. Also in aerodynamic coefficients side jet interaction results in additional pitching moment which is because of the high pressure region in upstream of the jet and a low pressure region in the downstream of the jet. Also jet interaction results in the rise in the lift coefficient. Whereas in the incidence case, simulation has been performed for the hypersonic flows over a biconic body with supersonic lateral jet at Mach 9.7 and incidence of 0 o to incidence of -12 o and 12 o . The results obtained were compared with the experimental and CFD code CFL3D results. PAK-3D over predicts the surface pressure as compared to the CFL3D and experimental results, whereas the qualitative trends are the same. Finally the integrated aerodynamic force coefficients were compared with CFL3D predicted results. (author)

  3. Efficient Compression of Far Field Matrices in Multipole Algorithms based on Spherical Harmonics and Radiating Modes

    Directory of Open Access Journals (Sweden)

    A. Schroeder

    2012-09-01

    Full Text Available This paper proposes a compression of far field matrices in the fast multipole method and its multilevel extension for electromagnetic problems. The compression is based on a spherical harmonic representation of radiation patterns in conjunction with a radiating mode expression of the surface current. The method is applied to study near field effects and the far field of an antenna placed on a ship surface. Furthermore, the electromagnetic scattering of an electrically large plate is investigated. It is demonstrated, that the proposed technique leads to a significant memory saving, making multipole algorithms even more efficient without compromising the accuracy.

  4. Electromagnetic signatures of far-field gravitational radiation in the 1 + 3 approach

    International Nuclear Information System (INIS)

    Chua, Alvin J K; Cañizares, Priscilla; Gair, Jonathan R

    2015-01-01

    Gravitational waves (GWs) from astrophysical sources can interact with background electromagnetic fields, giving rise to distinctive and potentially detectable electromagnetic signatures. In this paper, we study such interactions for far-field gravitational radiation using the 1 + 3 approach to relativity. Linearized equations for the electromagnetic field on perturbed Minkowski space are derived and solved analytically. The inverse Gertsenshteĭn conversion of GWs in a static electromagnetic field is rederived, and the resultant electromagnetic radiation is shown to be significant for highly magnetized pulsars in compact binary systems. We also obtain a variety of nonlinear interference effects for interacting gravitational and electromagnetic waves, although wave–wave resonances previously described in the literature are absent when the electric–magnetic self-interaction is taken into account. The fluctuation and amplification of electromagnetic energy flux as the GW strength increases towards the gravitational–electromagnetic frequency ratio is a possible signature of gravitational radiation from extended astrophysical sources. (paper)

  5. Dependence of optical properties of monoclinic MnWO{sub 4} on the electric field of incident light

    Energy Technology Data Exchange (ETDEWEB)

    Cai Lugang [School of Physics and Nuclear Energy Engineering, Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing 100191 (China); Liu Famin, E-mail: fmliu@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing 100191 (China); Zhang Dian; Zhong Wenwu [School of Physics and Nuclear Energy Engineering, Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing 100191 (China)

    2012-09-01

    Considering the electric field of incident light along four particular directions [100], [110], [011], and [010], the optical properties of monoclinic MnWO{sub 4} were investigated by the first-principle methods. The calculated electronic structures show that the O 2p states and Mn 3d states dominate the top of the valence bands, while the W 5d and Mn 3d states play a key role in the bottom of the conduction bands. The dielectric function and other optical properties, including absorption coefficient, reflectivity spectra, and energy-loss spectra, were calculated and analyzed. The results predicted the maximum static dielectric function when the electric field of incident light was along the [100] direction; meanwhile the absorption edge was calculated to be consistent with the energy band gap and the values and positions of peaks in absorption coefficient are related with the electric field of light. Otherwise, it is found that the appearance of peaks in the energy-loss spectra is also dependent on the electric field and simultaneously corresponds to the edge of absorption spectra and the peaks' position of reflectivity spectra.

  6. Radiative Corrections from Heavy Fast-Roll Fields during Inflation

    DEFF Research Database (Denmark)

    Jain, Rajeev Kumar; Sandora, McCullen; Sloth, Martin S.

    2015-01-01

    to an unobservable small running of the spectral index. An observable level of tensor modes can also be accommodated, but, surprisingly, this requires running to be induced by a curvaton. If upcoming observations are consistent with a small tensor-to-scalar ratio as predicted by small field models of inflation...

  7. Techniques to maximize software reliability in radiation fields

    International Nuclear Information System (INIS)

    Eichhorn, G.; Piercey, R.B.

    1986-01-01

    Microprocessor system failures due to memory corruption by single event upsets (SEUs) and/or latch-up in RAM or ROM memory are common in environments where there is high radiation flux. Traditional methods to harden microcomputer systems against SEUs and memory latch-up have usually involved expensive large scale hardware redundancy. Such systems offer higher reliability, but they tend to be more complex and non-standard. At the Space Astronomy Laboratory the authors have developed general programming techniques for producing software which is resistant to such memory failures. These techniques, which may be applied to standard off-the-shelf hardware, as well as custom designs, include an implementation of Maximally Redundant Software (MRS) model, error detection algorithms and memory verification and management

  8. Personal Radiation Detector Field Test and Evaluation Campaign

    International Nuclear Information System (INIS)

    Chris A. Hodge, Ding Yuan, Raymond P. Keegan, Michael A. Krstich

    2007-01-01

    Following the success of the Anole test of portable detection system, the U.S. Department of Homeland Security (DHS) Domestic Nuclear Detection Office organized a test and evaluation campaign for personal radiation detectors (PRDs), also known as 'Pagers'. This test, 'Bobcat', was conducted from July 17 to August 8, 2006, at the Nevada Test Site. The Bobcat test was designed to evaluate the performance of PRDs under various operational scenarios, such as pedestrian surveying, mobile surveying, cargo container screening, and pedestrian chokepoint monitoring. Under these testing scenarios, many operational characteristics of the PRDs, such as gamma and neutron sensitivities, positive detection and false alarm rates, response delay times, minimum detectable activities, and source localization errors, were analyzed. This paper will present the design, execution, and methodologies used to test this equipment for the DHS

  9. Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Lena, E-mail: lena.specht@regionh.dk [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen (Denmark); Yahalom, Joachim [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Illidge, Tim [Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Sciences Centre, Christie Hospital NHS Trust, Manchester (United Kingdom); Berthelsen, Anne Kiil [Department of Radiation Oncology and PET Centre, Rigshospitalet, University of Copenhagen (Denmark); Constine, Louis S. [Department of Radiation Oncology and Pediatrics, James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York (United States); Eich, Hans Theodor [Department of Radiation Oncology, University of Münster (Germany); Girinsky, Theodore [Department of Radiation Oncology, Institut Gustave-Roussy, Villejuif (France); Hoppe, Richard T. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Mauch, Peter [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard University, Boston, Massachusetts (United States); Mikhaeel, N. George [Department of Clinical Oncology and Radiotherapy, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Ng, Andrea [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard University, Boston, Massachusetts (United States)

    2014-07-15

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the

  10. Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

    International Nuclear Information System (INIS)

    Specht, Lena; Yahalom, Joachim; Illidge, Tim; Berthelsen, Anne Kiil; Constine, Louis S.; Eich, Hans Theodor; Girinsky, Theodore; Hoppe, Richard T.; Mauch, Peter; Mikhaeel, N. George; Ng, Andrea

    2014-01-01

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the

  11. Modern radiation therapy for Hodgkin lymphoma: field and dose guidelines from the international lymphoma radiation oncology group (ILROG).

    Science.gov (United States)

    Specht, Lena; Yahalom, Joachim; Illidge, Tim; Berthelsen, Anne Kiil; Constine, Louis S; Eich, Hans Theodor; Girinsky, Theodore; Hoppe, Richard T; Mauch, Peter; Mikhaeel, N George; Ng, Andrea

    2014-07-15

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the

  12. A MEMS device capable of measuring near-field thermal radiation between membranes.

    Science.gov (United States)

    Feng, Chong; Tang, Zhenan; Yu, Jun; Sun, Changyu

    2013-02-04

    For sensors constructed by freestanding membranes, when the gap between a freestanding membrane and the substrate or between membranes is at micron scale, the effects of near-field radiative heat transfer on the sensors' thermal performance should be considered during sensor design. The radiative heat flux is transferred from a membrane to a plane or from a membrane to a membrane. In the current study of the near-field thermal radiation, the scanning probe technology has difficulty in making a membrane separated at micron scale parallel to a plane or another membrane. A novel MEMS (micro electromechanical system) device was developed by sacrificial layer technique in this work to realize a double parallel freestanding membrane structure. Each freestanding membrane has a platinum thin-film resistor and the distance between the two membranes is 1 m. After evaluating the electrical and thermal characteristics of the lower freestanding membrane, experimental measurements of near-field radiative heat transfer between the lower membrane and the upper membrane were carried out by setting the lower membrane as a heat emitter and the upper membrane as a heat receiver. The near-field radiative heat transfer between the two membranes was validated by finding a larger-than-blackbody radiative heat transfer based on the experimental data.

  13. A MEMS Device Capable of Measuring Near-Field Thermal Radiation between Membranes

    Directory of Open Access Journals (Sweden)

    Changyu Sun

    2013-02-01

    Full Text Available For sensors constructed by freestanding membranes, when the gap between a freestanding membrane and the substrate or between membranes is at micron scale, the effects of near-field radiative heat transfer on the sensors’ thermal performance should be considered during sensor design. The radiative heat flux is transferred from a membrane to a plane or from a membrane to a membrane. In the current study of the near-field thermal radiation, the scanning probe technology has difficulty in making a membrane separated at micron scale parallel to a plane or another membrane. A novel MEMS (micro electromechanical system device was developed by sacrificial layer technique in this work to realize a double parallel freestanding membrane structure. Each freestanding membrane has a platinum thin-film resistor and the distance between the two membranes is 1 m. After evaluating the electrical and thermal characteristics of the lower freestanding membrane, experimental measurements of near-field radiative heat transfer between the lower membrane and the upper membrane were carried out by setting the lower membrane as a heat emitter and the upper membrane as a heat receiver. The near-field radiative heat transfer between the two membranes was validated by finding a larger-than-blackbody radiative heat transfer based on the experimental data.

  14. Worldwide developments in the field of radiation processing of materials in the down of 21st century

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    2006-01-01

    Developments regarding the radiation processing of materials are discussed in the paper. Radiation sources are briefly listed, showing recent achievements in the field. The main group of materials modified by radiation are synthetic polymers and rubber. Other applications are irradiation of semiconductors and gemstone colorization. New, growing fields of application are processing of natural polymers and nanomaterials. (author)

  15. Magnetic field dependence of microwave radiation in intermediate-length Josephson junctions

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter; Parmentier, R. D.; Christiansen, Peter Leth

    1984-01-01

    Experimental measurements of current-voltage structure and emitted X-band radiation in applied magnetic field from overlap-geometry Josephson tunnel junctions of normalized length about 2 are compared with numerical simulations obtained with the use of a perturbed sine-Gordon model. The simulations...... Fiske step in magnetic field and the field dependence of the radiation frequency within the various lobes, including details such as hysteresis between lobes. The simulations predict an alternation of the dominant frequency component with increasing field that accounts well for the experimental...... furnish the current and field dependence of the oscillation configuration, from which can be calculated average voltages, frequencies, and power spectra. Simulation and experimental results are in good agreement with regard to the lobe structure of the height of the first zero-field step and/or second...

  16. The thermalization process of an atom with the thermal radiation field

    International Nuclear Information System (INIS)

    Flores-Hidalgo, G

    2007-01-01

    We study the time evolution of an atom suddenly coupled to a thermal radiation field. As a simplified model of the atom-electromagnetic field system we use a system composed of a harmonic oscillator linearly coupled to a scalar field in the framework of the recently introduced dressed coordinates and dressed states. We show that the time evolution of the thermal expectation values for the occupation number operators depends exclusively on the probabilities associated with the emission and absorption of field quanta. In particular, the time evolution of the number operator associated with the atom is given in terms of the probability of remaining in the first excited state and the decay probabilities from this state by emission of field quanta of frequencies ω k . Also, it is shown that independent of the initial state of the atom, it thermalizes with the thermal radiation field in a time scale of the order of the inverse coupling constant

  17. Genomic instability in normal human fibroblasts for chronically low-dose radiation in heavy-ion radiation field

    International Nuclear Information System (INIS)

    Suzuki, Masao; Tsuruoka, Chizuru; Fujitaka, Kazunobu; Ishizaki, Kanji; Hayashi, Hiroko; Yamane, Y.; Nakamura, H.

    2003-01-01

    We have been studying genomic instability of biological effects in normal human fibroblasts exposed to chronically low-dose radiation in heavy-ion radiation field. Cells were cultured in a CO 2 incubator, which was placed in the irradiation room for biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) and irradiated with scattered radiations produced with heavy-ion beams throughout the life span of the cell population. Genomic instability in cellular responses was examined to measure either cell killing or mutation induction in low-dose accumulated cell populations after exposing to X-ray challenging doses. The results showed that there was no enhanced effect on cell killing between the low-dose accumulated and non-irradiated cell populations after exposing to defined challenging doses of 200 kV X rays. On the contrary, the mutation frequency, which 2 was measured as the induction of a 6-thioguanine resistant clone focused on hprt locus, of the low-dose accumulated cell population was much higher than that of non-irradiated cell population. The results suggested that genomic instability was induced in mutagenesis by the chronic low-dose irradiations in heavy-ion radiation field. (author)

  18. SEL Hardness Assurance in a Mixed Radiation Field

    CERN Document Server

    Garcia Alia, Ruben; Danzeca, Salvatore; Ferlet-Cavrois, Veronique; Frost, Christopher; Gaillard, Remi; Mekki, Julien; Saigné, Frédéric; Thornton, Adam; Uznanski, Slawosz; Worbel, Frédéric; CERN. Geneva. ATS Department

    2015-01-01

    This paper explores the relationship between monoenergetic and mixed-field Single Event Latchup (SEL) cross sections, concluding for components with a very strong energy dependence and highly-energetic environments, test results from monoenergetic or soft mixed-field spectra can significantly underestimate the operational failure rate. We introduce a semi-empirical approach that can be used to evaluate the SEL rate for such environments based on monoenergetic measurements and information or assumptions on the respective sensitive volume and materials surrounding it. We show that the presence of high-Z materials such as tungsten is particularly important in determining the hadron cross section energy dependence for components with relatively large LET thresholds.

  19. Modern Radiation Therapy for Extranodal Lymphomas: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group

    International Nuclear Information System (INIS)

    Yahalom, Joachim; Illidge, Tim; Specht, Lena; Hoppe, Richard T.; Li, Ye-Xiong; Tsang, Richard; Wirth, Andrew

    2015-01-01

    Extranodal lymphomas (ENLs) comprise about a third of all non-Hodgkin lymphomas (NHL). Radiation therapy (RT) is frequently used as either primary therapy (particularly for indolent ENL), consolidation after systemic therapy, salvage treatment, or palliation. The wide range of presentations of ENL, involving any organ in the body and the spectrum of histological sub-types, poses a challenge both for routine clinical care and for the conduct of prospective and retrospective studies. This has led to uncertainty and lack of consistency in RT approaches between centers and clinicians. Thus far there is a lack of guidelines for the use of RT in the management of ENL. This report presents an effort by the International Lymphoma Radiation Oncology Group (ILROG) to harmonize and standardize the principles of treatment of ENL, and to address the technical challenges of simulation, volume definition and treatment planning for the most frequently involved organs. Specifically, detailed recommendations for RT volumes are provided. We have applied the same modern principles of involved site radiation therapy as previously developed and published as guidelines for Hodgkin lymphoma and nodal NHL. We have adopted RT volume definitions based on the International Commission on Radiation Units and Measurements (ICRU), as has been widely adopted by the field of radiation oncology for solid tumors. Organ-specific recommendations take into account histological subtype, anatomy, the treatment intent, and other treatment modalities that may be have been used before RT

  20. Magnetic field and radiative transfer modelling of a quiescent prominence

    Czech Academy of Sciences Publication Activity Database

    Gunár, S.; Schwartz, Pavol; Dudík, J.; Schmieder, B.; Heinzel, Petr; Jurčák, Jan

    2014-01-01

    Roč. 567, July (2014), A123/1-A123/16 ISSN 0004-6361 R&D Projects: GA ČR GAP209/12/0906; GA ČR GAP209/12/0287 Grant - others:SAV(SK) VEGA2/0108/12 Institutional support: RVO:67985815 Keywords : Sun: filaments * prominence * magnetic fields Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  1. Force, torque, and absorbed energy for a body of arbitrary shape and constitution in an electromagnetic radiation field

    Science.gov (United States)

    Farsund, Ø.; Felderhof, B. U.

    1996-02-01

    The force and torque exerted on a body of arbitrary shape and constitution by a stationary radiation field are in principle given by integrals of Minkowski's stress tensor over a surface surrounding the body. Similarly the absorbed energy is given by an integral of the Poynting vector. These integrals are notoriously difficult to evaluate, and so far only spherical bodies have been considered. It is shown here that the integrals may be cast into a simpler form by use of Debye potentials. General expressions for the integrals are derived as sums of bilinear expressions in the coefficients of the expansion of the incident and scattered waves in terms of vector spherical waves. The expressions are simplified for small particles, such as atoms, for which the electric dipole approximation may be used. It is shown that the calculation is also relevant for bodies with nonlinear electromagnetic response.

  2. Training of an incidence of radiation on surfaces by vectorial representation; Didactica del analisis de la incidencia de radiacion solar mediante una representacion vectorial

    Energy Technology Data Exchange (ETDEWEB)

    Luis, F. J. de; Perez-Garcia, M.; Barbero, F. J.; Batlles, F. J.

    2004-07-01

    This work gathers and it exposes a set of educational contents extracted from the general bibliography and from the own experience in Engineering studies and courses on the application of a vector representation to the description of the apparent movement of the sun, the shading evaluation and the incidence of radiation on surfaces. (Author)

  3. Measurement of the radiation incident on ALS NdFeB permanent magnet insertion device structures and a determination of their lifetime

    International Nuclear Information System (INIS)

    Krebs, G.F.; Holmes, M.

    1997-05-01

    Measurements of the radiation incident on ALS insertion device NdFeB permanent magnet structures were carried out using thermoluminescence dosimeters. A plastic scintillator gamma telescope was utilized to unravel the various contributions to the integrated dose. Magnet lifetimes were calculated for various operational conditions

  4. Study of the accuracy of radiation field calculations in media

    International Nuclear Information System (INIS)

    Bolyatko, V.V.; Vyrskij, M.Yu.; Ilyushkin, A.I.; Mashkovich, V.P.; Sakharov, V.K.; Stroganov, A.A.

    1981-01-01

    The sensitivity p of the radiation transport calculations to variations of input parameters Xsub(i) is theoretically analyzed, and the calculational errors induced by uncertainties of initial data are evaluated. Two calculational methods are considered: the direct substitution method using the ROZ-5 code and method using the linear perturbation theory. In order to calculate p(Xsub(i)) and bilinear convolutions of the conjugated transport equations the ZAKAT code has been developed. The calculations use the ZAKAT, ROZ-11 and APAMAKO-2F codes. As an example of practical use of the method proposed a shielding composition characteristic for fast reactors was analyzed. A plane monodirectional neutron beam of the BR-10 reactor falls onto a 5-layer stainless steel (1Kh18N10T)-carbon barrier. The sensitivily of the neutron dose absorbed in tissue to the cross sections of all the shielding constituents and to the source and detector representation functions has been calculated. A comparison of the calculations with experimental data proves the validity of the calculational method [ru

  5. A method for radiobiological investigations in radiation fields with different LET and high dose rates

    International Nuclear Information System (INIS)

    Grundler, W.

    1976-01-01

    For investigations: 1. Performed in the field of radiobiology with different LET-radiation and a relatively high background dose rate of one component (e.g. investigations with fast and intermediate reactor neutrons) 2. Concerning radiation risk studies within a wide range 3. Of irradiations, covering a long time period (up to 100 days) a test system is necessary which on the one hand makes it possible to analyze the influence of different LET radiation and secondly shows a relative radiation resistant behaviour and allows a simple cell cycle regulation. A survey is given upon the installed device of a simple cell observation method, the biological test system used and the analysis of effects caused by dose, repair and LET. It is possible to analyze the behaviour of the nonsurvival cells and to demonstrate different reactions of the test parameters to the radiation of different LET. (author)

  6. Collective migration of adsorbed atoms on a solid surface in the laser radiation field

    International Nuclear Information System (INIS)

    Andreev, V V; Ignat'ev, D V; Telegin, Gennadii G

    2004-01-01

    The lateral (in the substrate plane) interaction between dipoles induced in particles adsorbed on a solid surface is studied in a comparatively weak laser radiation field with a Gaussian transverse distribution. It is shown that the particles migrate over the surface in the radial direction either outside an illuminated spot with the formation of a 'crater' or inside the spot with the formation of a 'mound'. (interaction of laser radiation with matter. laser plasma)

  7. Modelling radiation fields of ion beams in tissue-like materials

    OpenAIRE

    Burigo, Lucas Norberto (Dr.)

    2014-01-01

    Fast nuclei are ionizing radiation which can cause deleterious effects to irradiated cells. The modelling of the interactions of such ions with matter and the related effects are very important to physics, radiobiology, medicine and space science and technology. A powerful method to study the interactions of ionizing radiation with biological systems was developed in the field of microdosimetry. Microdosimetry spectra characterize the energy deposition to objects of cellular size, i.e., a few...

  8. Electron beam extraction system with a ring radiation field

    International Nuclear Information System (INIS)

    Auslender, V.L.; Kuksanov, N.K.; Polyakov, V.A.; Salimov, R.A.; Chertok, I.L.

    1979-01-01

    Description and results of testings of two electron beam extraction systems for shaping of a circular irradiation field are given. One of the systems contains three 20 cm long outlet windows arranged at 120 deg angle with respect to each other. Tests at the ILU-6 accelerator have shown that the given system provides 150 mm zone irradiation from three sides. Beam utilization factor when irradiating three 40 mm dia tubes amounted to 35% which provides capacity of 2.5 txMrad/h at 20 kW beam power. The other extraction system includes two C-form magnets producing nonuniform and opposing magnetic fields. This system tests at the EhLV-2 accelerator have shown that at 0.8-1.5 MeV electron energy it is possible to irradiate of 60 and 100 mm dia objects, accordingly. The system may be used together with both constant-action and pulse-action accelerators having extraction with linear scanning [ru

  9. Near-field radiative heat transfer in graphene plasmonic nanodisk dimers

    Science.gov (United States)

    Ramirez, Francisco V.; Shen, Sheng; McGaughey, Alan J. H.

    2017-10-01

    Near-field thermal radiation mediated by surface plasmons in parallel graphene nanodisk dimers is studied using a semianalytical model under the electrostatic approximation. The radiative heat transfer between two disks as a function of the distance between them in coaxial and coplanar configurations is first considered. Three regimes are identified and their extents determined using nondimensional analysis. When the edge-to-edge separation is smaller than the disk diameter, near-field coupling and surface plasmon hybridization lead to an enhancement of the radiative heat transfer by up to four orders of magnitude compared to the Planck blackbody limit. A mismatch in the disk diameters affects the plasmonic mode hybridization and can either diminish or enhance the near-field radiation. Destructive interference between eigenmodes that emerge when the relative orientation between disks is varied can induce a twofold reduction in the radiative heat transfer. In all configurations, the radiative heat transfer properties can be controlled by tuning the disk size/orientation, the substrate optical properties, and graphene's doping concentration and electron mobility.

  10. Radiation field distribution within the room for three commonly-used interventional procedures

    International Nuclear Information System (INIS)

    Liu Changcai; Zhang Lin; Min Nan; Lu Feng; Li Quantai; Deng Daping; Chen Yue; Zhu Jianguo

    2014-01-01

    Objective: To detect the radiation field distribution within the room for three commonly-used interventional procedures, in order to provide basic data for the radiation protection and safe operation of staff involved in interventional radiology. Methods: The thermoluminescent dosemeters (TLDs) were placed in different points on the horizontal plane around the interventional table and the vertical plane where the staff often stayed. Based on the selected experimental conditions, the TLDs were grouped to be irradiated. After the experiment, the TLDs were measured in the laboratory to calculate the doses of radiation field. Results: Data obtained at the same position followed basically as cardiovascular intervention > cerebrovascular intervention > liver intervention. Intervention of same type at the same position followed as high-dose group > mid-dose group > low-dose group. These results were consistent with the useful beam doses, and proportional to the fluoroscopy time. A few data with exception were due to measurement error or experimental error. Conclusions: Cerebrovascular and liver interventional procedures resulted in the relatively low radiation doses. The radiation doses at the distance of more than 3 m can be negligible. For cardiovascular interventional procedure, with the decrease of the distance from the X-ray tube, the dose decreased. In the radiation field,the operator, the first assistant and second assistant would exposed to higher dose on the standing points while patients receive lower doses in the head and feet direction. (authors)

  11. Electromagnetic fields radiated from a lightning return stroke - Application of an exact solution to Maxwell's equations

    Science.gov (United States)

    Le Vine, D. M.; Meneghini, R.

    1978-01-01

    A solution is presented for the electromagnetic fields radiated by an arbitrarily oriented current filament over a conducting ground plane in the case where the current propagates along the filament at the speed of light, and this solution is interpreted in terms of radiation from lightning return strokes. The solution is exact in the fullest sense; no mathematical approximations are made, and the governing differential equations and boundary conditions are satisfied. The solution has the additional attribute of being specified in closed form in terms of elementary functions. This solution is discussed from the point of view of deducing lightning current wave forms from measurements of the electromagnetic fields and understanding the effects of channel tortuosity on the radiated fields. In addition, it is compared with two approximate solutions, the traditional moment approximation and the Fraunhofer approximation, and a set of criteria describing their applicability are presented and interpreted.

  12. 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)

  13. Field maintenance of radiation-shielding windows at HFEF

    International Nuclear Information System (INIS)

    Tobias, D.A.

    1983-01-01

    The achievement of excellent viewing through hot-cell shielding windows does not occur by chance. Instead, it requires a well planned and executed program of field maintenance. The lack of such a program is a major factor when a hot-cell facility has poor window viewing. At HFEF, all preventive maintenance is performed by one group of trained technical-support personnel under the immediate direction of a Systems Engineer, who has responsibility for the shielding windows. Window maintenance is prescheduled and recorded by being incorporated into the computerized Maintenance Data System (MDS). Measurements of window light transmission are scheduled annually to determine glass browning or oil cloudiness conditions within the window tank. The tank oil is sampled and chemically analyzed annually to determine the moisture content, the acidity, and the probable deterioration rate caused by irradiation

  14. Ultraviolet radiation penetrating vehicle glass: a field based comparative study

    International Nuclear Information System (INIS)

    Kimlin, M.G.; Parisi, A.V.

    1999-01-01

    The solar UV transmitted through automobile glass was measured in the field in two cars using a spectroradiometer. The two cars were identical except that one of the cars had all of the windows (except the windshield) tinted. The measured spectral erythemal UV on a horizontal plane with the windows fully closed was reduced in the tinted car by a factor of 42 when compared with the erythemal UV measured in the untinted car. The ambient UVA irradiances at various locations within four different makes of car and a tractor were also measured with a broad band UVA hand-held meter. The average normalized daily UVA exposure (measured with a broad band UVA meter) was 1.3 times higher in a large family sedan when compared with that in a small hatchback and the UVA exposure in a car with tinted windows was 3.8 times less than in a similar untinted car. (author)

  15. Ultraviolet radiation penetrating vehicle glass: a field based comparative study

    Science.gov (United States)

    Kimlin, M. G.; Parisi, A. V.

    1999-04-01

    The solar UV transmitted through automobile glass was measured in the field in two cars using a spectroradiometer. The two cars were identical except that one of the cars had all of the windows (except the windshield) tinted. The measured spectral erythemal UV on a horizontal plane with the windows fully closed was reduced in the tinted car by a factor of 42 when compared with the erythemal UV measured in the untinted car. The ambient UVA irradiances at various locations within four different makes of car and a tractor were also measured with a broad band UVA hand-held meter. The average normalized daily UVA exposure (measured with a broad band UVA meter) was 1.3 times higher in a large family sedan when compared with that in a small hatchback and the UVA exposure in a car with tinted windows was 3.8 times less than in a similar untinted car.

  16. Field soil-water properties measured through radiation techniques

    International Nuclear Information System (INIS)

    1984-07-01

    This report shows a major effort to make soil physics applicable to the behaviour of the field soils and presents a rich and diverse set of data which are essential for the development of effective soil-water management practices that improve and conserve the quality and quantity of agricultural lands. This piece of research has shown that the neutron moisture meter together with some complementary instruments like tensiometers, can be used not only to measure soil water contents but also be extremely handy to measure soil hydraulic characteristics and soil water flow. It is, however, recognized that hydraulic conductivity is highly sensitive to small changes in soil water content and texture, being extremely variable spatially and temporally

  17. Interaction of an atom subject to an intense laser field with its own radiation field and nonlocality of electromagnetic interaction

    International Nuclear Information System (INIS)

    Gainutdinov, R Kh; Mutygullina, A A

    2009-01-01

    We discuss the interaction of an atom subject to an intense driving laser field with its own radiation field. In contrast to the states of bare atoms, the energy difference between some dressed states with the same total angular momentum, its projection and parity may be very small. The self-interaction of a combined atom-laser system associated with nonradiative transitions between such states is effectively strong. We show that the contribution to the radiative shift of the sidebands of the Mollow spectrum, which comes from such processes, is very significant and may be much larger than the trivial Lamb shift, which is the simple redistribution of the Lamb shifts of the corresponding bare states. In the final part, we discuss the possibility that in the Mollow spectrum nonlocality of electromagnetic interaction, which in other cases is hidden in the regularization and renormalization procedures, can manifest itself explicitly.

  18. Minimizing core deposits radiation fields in PWRs by coordinated Li/B chemistry

    International Nuclear Information System (INIS)

    Roesmer, J.

    1983-01-01

    The effect of coolant chemistry on the buildup and composition of core deposits and on out-of-core radiation fields was investigated in the Beaver Valley and Trojan plants. Coordinated Li/B coolant chemistry led to an appreciable reduction of the surface concentration of core deposits, decreased greatly the formation of crud films on fresh fuel, and resulted in a reduction in the rate and level of radiation field buildup in the out-of-core regions of the primary circuits. (author)

  19. Evaluation of the Reanalysis Surface Incident Shortwave Radiation Products from NCEP, ECMWF, GSFC, and JMA Using Satellite and Surface Observations

    Directory of Open Access Journals (Sweden)

    Xiaotong Zhang

    2016-03-01

    Full Text Available Solar radiation incident at the Earth’s surface (Rs is an essential component of the total energy exchange between the atmosphere and the surface. Reanalysis data have been widely used, but a comprehensive validation using surface measurements is still highly needed. In this study, we evaluated the Rs estimates from six current representative global reanalyses (NCEP–NCAR, NCEP-DOE; CFSR; ERA-Interim; MERRA; and JRA-55 using surface measurements from different observation networks [GEBA; BSRN; GC-NET; Buoy; and CMA] (674 sites in total and the Earth’s Radiant Energy System (CERES EBAF product from 2001 to 2009. The global mean biases between the reanalysis Rs and surface measurements at all sites ranged from 11.25 W/m2 to 49.80 W/m2. Comparing with the CERES-EBAF Rs product, all the reanalyses overestimate Rs, except for ERA-Interim, with the biases ranging from −2.98 W/m2 to 21.97 W/m2 over the globe. It was also found that the biases of cloud fraction (CF in the reanalyses caused the overestimation of Rs. After removing the averaged bias of CERES-EBAF, weighted by the area of the latitudinal band, a global annual mean Rs values of 184.6 W/m2, 180.0 W/m2, and 182.9 W/m2 were obtained over land, ocean, and the globe, respectively.

  20. Scintillation camera for establishing the coordinates of a radiation stimuli produced by a radiation field

    International Nuclear Information System (INIS)

    Zioni, J.; Klein, Y.; Inbar, D.

    1977-01-01

    A scintillation camera has a planar scintillating crystal that produces light events whose spatial distribution corresponds to the spatial distribution of the radiation stimuli causing such events, and a plurality of photomultipliers having photocathodes for receiving light from the crystal through a planar face thereof. Computing circuitry coupled to the photomultipliers computes the projection of a light event in the crystal on a reference axis by forming an analytical function of the outputs of the photomultipliers according to the spatial location of the light event in the crystal

  1. Relationships between Fusarium population structure, soil nutrient status and disease incidence in field-grown asparagus

    NARCIS (Netherlands)

    Yergeau, E.; Sommerville, D.W.; Maheux, E.; Vujanovic, V.; Hamel, C.; Whalen, J.K.; St-Arnaud, M.

    2006-01-01

    Fusarium species cause important diseases in many crops. Lack of knowledge on how Fusarium species and strains interact with their environment hampers growth management strategies to control root diseases. A field experiment involving asparagus as host plant and three phosphorus fertilization levels

  2. A field study of pollutant deposition in radiation fog

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, J.M.; Jacob, D.J.; Munger, J.W.; Hoffman, M.R.

    1986-04-01

    Deposition during fog episodes can make a significant contribution to the overall flux of pollutants in certain ecosystems. Furthermore, when atmospheric stagnation prevents normal ventilation in a region, fog deposition may become the main route of pollutant removal. Fogs can consequently exert dominant control over pollutant levels in certain atmospheres. The southern San Joaquin Valley (SJV) of California is a region prone to wintertime episodes of atmospheric stagnation. These lead to elevated pollutant concentrations and/or dense, widespread fogs. Major oil-recovery operations plus widespread agricultural and livestock feeding activities are important sources of SO/sub 2/, NO/sub X/ and NH/sub 3/ in the valley. A multifaceted program of field monitoring was conducted in the SJV during the winter 1984-1985, focusing on aspects of pollutant scavenging and removal in the fog-laden atmosphere. Concentrations of major species were measured in gas, dry aerosol and fogwater phases. In addition, depositional fluxes were monitored by surrogate-surface methods. These measurements were employed to directly assess the magnitude of removal enhancement by fog.

  3. Classical radiation effects on relativistic electrons in ultraintense laser fields with circular polarization

    Science.gov (United States)

    Schlegel, Theodor; Tikhonchuk, Vladimir T.

    2012-07-01

    The propagation of a relativistic electron with initial energy ≳100 MeV in a number of simple one-dimensional laser field configurations with circular polarization is studied by solving the relativistic equation of motion in the Landau-Lifschitz approach to account for the radiation friction force. The radiation back-reaction on the electron dynamics becomes visible at dimensionless field amplitudes a ≳ 10 at these high particle energies. Analytical expressions are derived for the energy and the longitudinal momentum of the electron, the frequency shift of the light scattered by the electron and the particle trajectories. These findings are compared with the numerical solutions of the basic equations. A strong radiation damping effect results in reduced light scattering, forming at the same time a broad quasi-continuous spectrum. In addition, the electron dynamics in the strong field of a quasistationary laser piston is investigated. Analytical solutions for the electron trajectories in this complex field pattern are obtained and compared with the numerical solutions. The radiation friction force may stop a relativistic electron after propagation over several laser wavelengths at high laser field strengths, which supports the formation of a stable piston.

  4. Albedo and estimates of net radiation for green beans under polyethylene cover and field conditions

    International Nuclear Information System (INIS)

    Souza, J.L. de; Escobedo, J.F.; Tornero, M.T.T.

    1999-01-01

    This paper describes the albedo (r) and estimates of net radiation and global solar irradiance for green beans crop (Phaseolus vulgaris L.), cultivated in greenhouse with cover of polyethylene and field conditions, in Botucatu, SP, Brazil (22° 54' S; 48° 27' W; 850 m). The solar global irradiance (R g ) and solar reflected radiation (R r ) were used to estimate the albedo through the ratio between R r and R g . The diurnal curves of albedo were obtained for days with clear sky and partially cloudy conditions, for different phenological stages of the crop. The albedo ranged with the solar elevation, the environment and the phenological stages. The cloudiness range have almost no influence on the albedo diurnal amount. The estimation of radiation were made by linear regression, using the global solar irradiance (R g ) and net short-waves radiation (R c ) as independent variables. All estimates of radiation showed better adjustment for specific phenological periods compared to the entire crop growing cycle. The net radiation in the greenhouse has been estimated by the global solar irradiance measured at field conditions. (author) [pt

  5. Proportional relationship between intercepted solar radiation and dry matter production in a mulberry [Morus] field

    International Nuclear Information System (INIS)

    Aqueel, S.A.; Ito, D.; Naoi, T.

    1999-01-01

    In order to investigate the relationship between dry matter production (DMP) and the amount of intercepted solar radiation (S), and to analyze the fluctuations in the radiation conversion efficiency (DMP/S), summer-pruned mulberry (Morus alba L.) trees under a standard planting density were subjected to a shading treatment using a cheesecloth. Then, using a non-destructive method, DMP was examined for 5 plants from each plot every 15 days from July to September. DMP was also examined for mulberry trees under a high planting density. Rates of radiation that penetrated onto the ground and beneath the cheesecloth were measured to calculate S from the incoming solar radiation. In the shading plots, DMP decreased depending on the degree of shading throughout the experimental period. Compared with the control plot, 70 and 60 % DMP were produced finally under 71 and 53 % S. Therefore, DMP was considered to be almost proportional to S even in a broad-leaf population like mulberry. Radiation conversion efficiency gradually decreased with growth regardless of the planting density. At the late growth stage, radiation conversion efficiency was lower in the densely planted field than in the standard density field

  6. Modeling Radiation-Induced Degradation in Top-Gated Epitaxial Graphene Field-Effect-Transistors (FETs

    Directory of Open Access Journals (Sweden)

    Jeong-S. Moon

    2013-07-01

    Full Text Available This paper investigates total ionizing dose (TID effects in top-gated epitaxial graphene field-effect-transistors (GFETs. Measurements reveal voltage shifts in the current-voltage (I-V characteristics and degradation of carrier mobility and minimum conductivity, consistent with the buildup of oxide-trapped charges. A semi-empirical approach for modeling radiation-induced degradation in GFETs effective carrier mobility is described in the paper. The modeling approach describes Coulomb and short-range scattering based on calculations of charge and effective vertical field that incorporate radiation-induced oxide trapped charges. The transition from the dominant scattering mechanism is correctly described as a function of effective field and oxide trapped charge density. Comparison with experimental data results in good qualitative agreement when including an empirical component to account for scatterer transparency in the low field regime.

  7. Properties of light transition radiation of 660 MeV proton inclined incidence (γ=1.7) on a thick nickel plate. II

    International Nuclear Information System (INIS)

    Zrelov, V.P.; Pavlovic, P.; Ruzicka, J.

    1975-01-01

    The basic properties of transition radiation in the visible fraction of the spectrum have been calculated for 660 MeV protons (γ=1.7) obliquely incident on a thick nickel plate in vacuum. The angular distributions of the summary radiation (i.e. the sums of radiations of various polarizations) both 'forward' and 'backward' for different azimuthal planes are presented in tables and diagrams for different particle inclination angles to the separation boundary. The examples of angular distributions of radiation having various polarizations (at the inclination angle of 45 0 ) show that they differ considerably. The spectra of summary radiation are of a monotonous character. The calculations have shown that in a relativistic case the forward radiation is concentrated near the direction of particle motion and backward radiation moves in an opposite direction with respect to that of the particle inclination. The dependence of the total yield of forward and backward transition radiations upon the particle inclination angle is approximately cos 2 psi. (Auth.)

  8. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Biophysical models for the induction of cancer by radiation. Final report

    International Nuclear Information System (INIS)

    Paretzke, H.G.; Ballarini, F.; Brugmans, M.

    2000-01-01

    The overall project is organised into seven work packages. WP1 concentrates on the development of mechanistic, quantitative models for radiation oncogenesis using selected data sets from radiation epidemiology and from experimental animal studies. WP2 concentrates on the development of mechanistic, mathematical models for the induction of chromosome aberrations. WP3 develops mechanistic models for radiation mutagenesis, particularly using the HPRT-mutation as a paradigm. WP4 will develop mechanistic models for damage and repair of DNA, and compare these with experimentally derived data. WP5 concentrates on the improvement of our knowledge on the chemical reaction pathways of initial radiation chemical species in particular those that migrate to react with the DNA and on their simulation in track structure codes. WP6 models by track structure simulation codes the production of initial physical and chemical species, within DNA, water and other components of mammalian cells, in the tracks of charged particles following the physical processes of energy transfer, migration, absorption, and decay of excited states. WP7 concentrates on the determination of the start spectra of those tracks considered in WP6 for different impinging radiation fields and different irradiated biological objects. (orig.)

  9. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    OpenAIRE

    Stumpf, M.; de Hoop, A. T.; Lager, I. E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave constituents are constructed with the aid of the modified Cagniard method (Cagniard?DeHoop method). Numerical results are presented for vanishing slot width and field pulse shapes at the dielectric/free s...

  10. Risk concepts in various fields including radiation protection. A historical review and some recent topics

    International Nuclear Information System (INIS)

    Kai, Michiaki

    2000-01-01

    This is a review by the expert group concerning risks in radiation protection and in chemical management, recent state of protection and of health-risk assessment of low dose radiation, and risk concepts in other fields. Risk concepts in radiation protection are described mainly on ICRP: Its history leading to its Publication 1 (1958), Pub. 9 (1965), Pub. 26 (1977) and Pub. 60 (1990). In that recent publication, the term, risk, is used only for the established one like estimated risk or excess relative risk. Risk management of chemicals involves that against pollution from environmental and ecological aspects, and assessment of dioxin and chemicals from toxicology and carcinogenicity aspects. Recently, risks of low dose radiation have been actively discussed conceivably because of possible reduction of the exposure limit in ICRP Recommendation 1990, Chernobyl accident, advances of radiation biology and radiation protection problem in the radioactive waste disposition. Globally, many academic societies such as American Health-Physics Society published Position Statements and Reports and there are activities like the Research program plan for the risk and an international conference of bridging radiation policy and science. Risk concepts involve technological and ecological ones, insurance ones and health ones. Risk assessment or analysis is done through recognition, measurement and prediction, thus through the scientific process based on objective facts. (K.H.)

  11. Classical radiation theory of charged particles moving in electromagnetic fields in nonabsorbable isotropic media

    International Nuclear Information System (INIS)

    Konstantinovich, A.V.; Melnychuk, S.V.; Konstantinovich, I.A.

    2002-01-01

    The integral expressions for spectral-angular and spectral distributions of the radiation power of heterogeneous charged particles system moving on arbitrary trajectory in nonabsorbable isotropic media media with ε≠1 , μ≠1 are obtained using the Lorentz's self-interaction method. In this method a proper electromagnetic field, acting on electron, is defined as a semi difference between retarded and advanced potentials (Dirac, 1938). The power spectrum of Cherenkov radiation for the linear uniformly moving heterogeneous system of charged particles are obtained. It is found that the expression for the radiation power of heterogeneous system of charged particles becomes simplified when a system of charged particles is homogeneous. In this case the radiation power includes the coherent factor. It is shown what the redistribution effects in energy of the radiation spectrum of the studied system are caused by the coherent factor. The radiation spectrum of the system of electrons moving in a circle in this medium is discrete. The Doppler effect causes the appearance of the new harmonics for the system of electrons moving in a spiral. These harmonics form the region of continuous radiation spectrum. (authors)

  12. On the electromagnetic fields, Poynting vector, and peak power radiated by lightning return strokes

    Science.gov (United States)

    Krider, E. P.

    1992-01-01

    The initial radiation fields, Poynting vector, and total electromagnetic power that a vertical return stroke radiates into the upper half space have been computed when the speed of the stroke, nu, is a significant fraction of the speed of light, c, assuming that at large distances and early times the source is an infinitesimal dipole. The initial current is also assumed to satisfy the transmission-line model with a constant nu and to be perpendicular to an infinite, perfectly conducting ground. The effect of a large nu is to increase the radiation fields by a factor of (1-beta-sq cos-sq theta) exp -1, where beta = nu/c and theta is measured from the vertical, and the Poynting vector by a factor of (1-beta-sq cos-sq theta) exp -2.

  13. Method for determining correction factors induced by irradiation of ionization chamber cables in large radiation field

    International Nuclear Information System (INIS)

    Rodrigues, L.L.C.

    1988-01-01

    A simple method was developed to be suggested to hospital physicists in order to be followed during large radiation field dosimetry, to evaluate the effects of cables, connectors and extension cables irradiation and to determine correction factors for each system or geometry. All quality control tests were performed according to the International Electrotechnical Commission for three clinical dosimeters. Photon and electron irradiation effects for cables, connectors and extention cables were investigated under different experimental conditions by means of measurements of chamber sensitivity to a standard radiation source of 90 Sr. The radiation induced leakage current was also measured for cables, connectors and extension cables irradiated by photons and electrons. All measurements were performed at standard dosimetry conditions. Finally, measurements were performed in large fields. Cable factors and leakage factors were determined by the relation between chamber responses for irradiated and unirradiated cables. (author) [pt

  14. COHERENT RESONANT SCATTERING OF NUCLEAR RADIATION IN A PARAMAGNETIC ABSORBER PLACED IN A MAGNETIC-FIELD

    NARCIS (Netherlands)

    TENBROEK, F

    1993-01-01

    When a thick Mossbauer absorber of (paramagnetic) ferric alum enriched in Fe-57 is placed in a longitudinal magnetic field of 270 G, a reduction of the intensity of backscattered resonant radiation from a 57CORh is observed. This is interpreted as caused by an increase of the degree of coherence of

  15. Assessment of radiation fields from neutron irradiated structural components of the 40 MW research reactor CIRUS

    International Nuclear Information System (INIS)

    Sankaranarayanan, S.; Sharma, S.K.

    1993-01-01

    The paper summarizes the results of an assessment of the radiation fields from the long-lived neutron activation products (including the decay chain products) in the various structural components of the CIRUS reactor. Special attention is given for the analysis of neutron activation of impurity elements present in the materials of the structure. 16 refs, 4 figs, 4 tabs

  16. Computer codes for tasks in the fields of isotope and radiation research

    International Nuclear Information System (INIS)

    Friedrich, K.; Gebhardt, O.

    1978-11-01

    Concise descriptions of computer codes developed for solving problems in the fields of isotope and radiation research at the Zentralinstitut fuer Isotopen- und Strahlenforschung (ZfI) are compiled. In part two the structure of the ZfI program library MABIF is outlined and a complete list of all codes available is given

  17. Nanostructure enhanced near-field radiative heat transfer and designs for energy conversion devices

    Science.gov (United States)

    Wang, Bingnan; Lin, Chungwei; Teo, Koon Hoo

    2017-09-01

    Near-field radiative heat transfer can exceed the blackbody limit, and this property has been explored toward energy transfer and conversion applications, such as thermophtovoltaic (TPV) devices, radiative cooling devices, and thermoradiative (TR) devices. The coupling of resonant modes between two surfaces is important in near- field heat transfer and near-field TPV and TR systems. It was shown that the coupling of resonant modes enhances the transmissivity between two coupled objects, which further determines the radiative heat transfer and energy conversion. Surface plasmon polaritons (SPPs), which are surface resonances existing on metal surfaces, are commonly used for such systems. While the frequency of SPP resonance is fixed for a planar emitter, a nanostructured emitter supports additional resonances such as SPP or cavity modes with lower frequencies that are closer to the bandgap energy of a typical PV cell. We show that the nanostructured designs significantly improves the near-field radiative power transfer, and electric power output for a TR system.

  18. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

    Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

  19. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    NARCIS (Netherlands)

    Štumpf, M.; De Hoop, A.T.; Lager, I.E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave

  20. Simulation study of CD variation caused by field edge effects and out-of-band radiation in EUVL

    Science.gov (United States)

    Gao, Weimin; Niroomand, Ardavan; Lorusso, Gian F.; Boone, Robert; Lucas, Kevin; Demmerle, Wolfgang

    2013-09-01

    Although extreme ultraviolet lithography (EUVL) remains a promising candidate for semiconductor device manufacturing of the 1x nm half pitch node and beyond, many technological burdens have to be overcome. The "field edge effect" in EUVL is one of them. The image border region of an EUV mask,also known as the "black border" (BB), reflects a few percent of the incident EUV light, resulting in a leakage of light into neighboring exposure fields, especially at the corner of the field where three adjacent exposures take place. This effect significantly impacts on CD uniformity (CDU) across the exposure field. To avoid this phenomenon, a light-shielding border is introduced by etching away the entire absorber and multi-layer (ML)at the image border region of the EUV mask. In this paper, we present a method of modeling the field edge effect (also called the BB effect) by using rigorous lithography simulation with a calibrated resist model. An additional "flare level" at the field edge is introduced on top of the exposure tool flare map to account for the BB effect. The parameters in this model include the reflectivity and the width of the BB, which are mainly determining the leakage of EUV light and its influence range, respectively. Another parameter is the transition width which represents the half shadow effect of the reticle masking blades. By setting the corresponding parameters, the simulation results match well the experimental results obtained at the imec's NXE:3100 EUV exposure tool. Moreover, these results indicate that the out-of-band (OoB) radiation also contributes to the CDU. Using simulation we can also determine the OoB effect rigorouslyusing the methodology of an "effective mask blank". The study in this paper demonstrates that the impact of BB and OoB effects on CDU can be well predicted by simulations.

  1. Intense Interactions of Molecules with a Short-Wavelength Electromagnetic Radiation Field: II. Resonance Scattering of Radiation and Fluorescence

    Science.gov (United States)

    Pegarkov, A. I.

    2001-07-01

    Within the framework of the nonadiabatic approach developed in the preceding paper, the resonance scattering, resonance Raman scattering, and resonance fluorescence are studied in detail for diatomic and triatomic molecules, and polyatomic symmetric and antisymmetric top molecules, which interact with the field of short-wavelength radiation with a wavelength λ ≥ Å and an intensity up to 1014 W/cm2. The coherent excitations of high-lying Rydberg and autoionizing states are taken into account. Analytical expressions for calculating the tensors and cross sections of the above processes are derived.

  2. Radiation Belt Data-Assimilation Using Self-Consistent Storm-Time Magnetic Fields

    Science.gov (United States)

    Henderson, M. G.; Koller, J.; Chen, Y.; Zaharia, S.; Jordanova, V.; Reeves, G. D.

    2008-12-01

    The lack of suitably realistic magnetic field models for use in radiation belt data assimilation remains a critical unresolved problem in space weather specification and prediction. Although the high-energy radiation belt particles themselves do not significantly alter the magnetic fields in which they drift, the lower-energy ring current populations do. And the deviation (especially during storms) of the real magnetic field from that computed even with the best of the presently available empirical models can be very large. To overcome this problem, the LANL DREAM code has been modified to use magnetic fields that are self-consistently maintained in force balance with the plasma. We compare second and third adiabatic invariants computed from the self-consistent fields to those obtained with empirical B-field models, and we utilize a phase-space density matching technique in order to test the various field models. Finally, the PSD at constant mu and K in a data-assimilation model obtained with the self-consistent and non-self-consistent magnetic field models will be compared.

  3. Development of methods to control radiation field and corrosion in PHWRS

    International Nuclear Information System (INIS)

    Velmurugan, S.

    2015-01-01

    Pressurized Heavy Water Reactors (PHWRs) is the mainstay of Indian Nuclear Power Program. There are 18 PHWRs (220 MWe and 540 MWe) in operation and 4 X 700 MWe PHWRs are under construction. In these reactors, as far as radiation field is concerned, the philosophy of ALARA (As Low As Reasonably Achievable) is followed. The primary coolant system chemistry control is given due consideration during operation so that corrosion of structural material is minimized which in turn controls the radiation field. Development and application of full system Dilute Chemical Decontamination (DCD) process helped to reduce the radiation field in MAPS-1 and 2, RAPS-1 and 2, NAPS-1 and 2 and KAPS-1. PHWR being a tube type reactor, it enables application of full system decontamination to its heavy water primary coolant system. Significant reduction in radiation field and consequent savings in MANREM could be achieved. Attempts are being made to understand the problem created by the release of antimony activities ( 122 Sb and 124 Sb) during chemical decontamination and during planned shutdown. Passivation as a method to control the radiation field and corrosion is being studied. Magnesium ion as a passivator to the ferrite filmed structural materials of PHWRs is being investigated. In addition, as PHWRs uses carbon steel as structural material, the use of passivation as a method to control flow accelerated corrosion (FAC) is also being studied. Magnesium ion gets incorporated in the ferrite film formed over carbon steel structural material and is expected to reduce the solubility of magnetite film thereby the FAC of feeders in PHWRs. (author)

  4. Maximum dose angle for oblique incidence on primary beam protective barriers in the design of medical radiation therapy facilities

    International Nuclear Information System (INIS)

    Fondevila, Damian; Arbiser, Silvio; Sansogne, Rosana; Brunetto, Monica; Dosoretz, Bernardo

    2008-01-01

    Primary barrier determinations for the shielding of medical radiation therapy facilities are generally made assuming normal beam incidence on the barrier, since this is geometrically the most unfavorable condition for that shielding barrier whenever the occupation line is allowed to run along the barrier. However, when the occupation line (for example, the wall of an adjacent building) runs perpendicular to the barrier (especially roof barrier), then two opposing factors come in to play: increasing obliquity angle with respect to the barrier increases the attenuation, while the distance to the calculation point decreases, hence, increasing the dose. As a result, there exists an angle (α max ) for which the equivalent dose results in a maximum, constituting the most unfavorable geometric condition for that shielding barrier. Based on the usual NCRP Report No. 151 model, this article presents a simple formula for obtaining α max , which is a function of the thickness of the barrier (t E ) and the equilibrium tenth-value layer (TVL e ) of the shielding material for the nominal energy of the beam. It can be seen that α max increases for increasing TVL e (hence, beam energy) and decreases for increasing t E , with a range of variation that goes from 13 to 40 deg for concrete barriers thicknesses in the range of 50-300 cm and most commercially available teletherapy machines. This parameter has not been calculated in the existing literature for radiotherapy facilities design and has practical applications, as in calculating the required unoccupied roof shielding for the protection of a nearby building located in the plane of the primary beam rotation

  5. Motion of a point charge in electromagnetic fields under consideration of radiation damping

    International Nuclear Information System (INIS)

    Stoeckel, H.

    1976-01-01

    The 'new equation' of Mo and Papas for the description of a point charge in an electromagnetic field under consideration of radiation damping, published in 1971, doesn't show the known disadvantages of the Lorentz-Dirac equation, taken as a basis up to now. Different forms of the Mo-Papas equation are derived and the resulting force- and power-balances are discussed. Exact and approximated solutions are derived for simple given fields, for instance for a homogeneous magnetic field, a homogeneous electric field and for the field of a resting point charge. The scattering angles are calculated for the scattering of a point charge by a homogeneous magnetic resp. electric field of finite extension. The results agree well with approximation formulas of other authors. (author)

  6. Thermal electron acceleration by localized bursts of electric field in the radiation belts

    Science.gov (United States)

    Artemyev, A. V.; Agapitov, O. V.; Mozer, F.; Krasnoselskikh, V.

    2014-08-01

    In this paper we investigate the resonant interaction of thermal ˜10-100 eV electrons with a burst of electrostatic field that results in electron acceleration to kilovolt energies. This single burst contains a large parallel electric field of one sign and a much smaller, longer-lasting parallel field of the opposite sign. The Van Allen Probe spacecraft often observes clusters of spatially localized bursts in the Earth's outer radiation belts. These structures propagate mostly away from the geomagnetic equator and share properties of soliton-like nonlinear electron acoustic waves: a velocity of propagation is about the thermal velocity of cold electrons (˜3000-10,000 km/s), and a spatial scale of electric field localization along the field lines is about the Debye radius of hot electrons (˜5-30 km). We model the nonlinear resonant interaction of these electric field structures and cold background electrons.

  7. The assessment of electromagnetic field radiation exposure for mobile phone users

    Directory of Open Access Journals (Sweden)

    Buckus Raimondas

    2014-01-01

    Full Text Available Background/Aim. During recent years, the widespread use of mobile phones has resulted in increased human exposure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the distance of 1 to 30 cm from the mobile user. Methods. In this paper, the measurements of electric field strength exposure were conducted on different brand of mobile phones by the call-related factors: urban/rural area, indoor/outdoor setting and moving/stationary mode during calls. The different types of mobile phone were placed facing the field probe at 1 cm, 10 cm, 20 cm and 30 cm distance. Results. The highest electric field strength was recorded for calls made in rural area (indoors while the lowest electric field strength was recorded for calls made in urban area (outdoors. Calls made from a phone in a moving car gave a similar result like for indoor calls; however, calls made from a phone in a moving car exposed electric field strength two times more than that of calls in a standing (motionless position. Conclusion. Electromagnetic field radiation depends on mobile phone power class and factors, like urban or rural area, outdoor or indoor, moving or motionless position, and the distance of the mobile phone from the phone user. It is recommended to keep a mobile phone in the safe distance of 10, 20 or 30 cm from the body (especially head during the calls.

  8. Incidence of 'Candidatus Liberibacter asiaticus'-Infected Plants Among Citrandarins as Rootstock and Scion Under Field Conditions.

    Science.gov (United States)

    Boava, Leonardo Pires; Sagawa, Cíntia Helena Duarte; Cristofani-Yaly, Mariângela; Machado, Marcos Antonio

    2015-04-01

    Huanglongbing (HLB), caused by the bacterium 'Candidatus Liberibacter' spp., is currently one of the most serious diseases of citrus plants and has caused substantial economic losses. Thus far, there is no source of genetic resistance to HLB in the genus Citrus or its relatives. However, several studies have reported Poncirus trifoliata and some of its hybrids to be more tolerant to the disease. The main objective of this study was to report differences in the incidence of 'Ca. L. asiaticus' infection in citrandarin plants, hybrids from Sunki mandarin (Citrus sunki (Hayata) hort. ex Tanaka), and trifoliate orange Rubidoux (P. trifoliata (L.) Raf.)), after conducting an extensive survey under field conditions. These hybrid plants were established for approximately 7 years in an area with a high incidence of 'Ca. L. asiaticus'-infected plants. We selected two experimental areas (area A and area B), located approximately 10 m apart. Area A consists of Pera sweet orange (C. sinensis (L.) Osb.) grafted onto 56 different citrandarin rootstocks. Area B consists of citrandarin scions grafted onto Rangpur lime (C. limonia Osb.) rootstock. Bacteria in the leaves and roots were detected using real-time quantitative polymerase chain reaction. The incidence of 'Ca. L. asiaticus'-infected plants was 92% in area A and 14% in area B. Because infected plants occurred in both areas, we examined whether the P. trifoliata hybrid rootstock influenced HLB development and also determined the distribution of 'Ca. L. asiaticus' in Citrus tree tissues. Although this survey does not present evidence regarding the resistance of P. trifoliata and its hybrids in relation to bacteria or psyllids, future investigation, mainly using the most promising hybrids for response to 'Ca. L. asiaticus', will help us to understand the probable mechanism of defense or identifying compounds in P. trifoliata and its hybrids that are very important as strategy to combat HLB. Details of these results are

  9. Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in Relativistic Quantum Approach

    Directory of Open Access Journals (Sweden)

    Maruyama Tomoyuki

    2016-01-01

    Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum-field approach do not agree with those obtained in the semi-classical approach. Furthermore, we also find that the anomalous magnetic moment of the proton greatly enhances the production rate about by two orders of magnitude, and that the polar angle of an emitted pion is the same as that of an initial proton.

  10. Electric field detection of coherent synchrotron radiation in a storage ring generated using laser bunch slicing

    International Nuclear Information System (INIS)

    Katayama, I.; Shimosato, H.; Bito, M.; Furusawa, K.; Adachi, M.; Zen, H.; Kimura, S.; Katoh, M.; Shimada, M.; Yamamoto, N.; Hosaka, M.; Ashida, M.

    2012-01-01

    The electric field of coherent synchrotron radiation (CSR) generated by laser bunch slicing in a storage ring has been detected by an electro-optic sampling method. The gate pulses for sampling are sent through a large-mode-area photonic-crystal fiber. The observed electric field profile of the CSR is in good agreement with the spectrum of the CSR observed using Fourier transform far-infrared spectrometry, indicating good phase stability in the CSR. The longitudinal density profiles of electrons modulated by laser pulses were evaluated from the electric field profile.

  11. Graphene Field Effect Transistor-Based Detectors for Detection of Ionizing Radiation

    International Nuclear Information System (INIS)

    Jovanovic, Igor; Cazalas, Edward; Childres, I.; Patil, A.; Koybasi, O.; Chen, Y-P.

    2013-06-01

    We present the results of our recent efforts to develop novel ionizing radiation sensors based on the nano-material graphene. Graphene used in the field effect transistor architecture could be employed to detect the radiation-induced charge carriers produced in undoped semiconductor absorber substrates, even without the need for charge collection. The detection principle is based on the high sensitivity of graphene to ionization-induced local electric field perturbations in the electrically biased substrate. We experimentally demonstrated promising performance of graphene field effect transistors for detection of visible light, X-rays, gamma-rays, and alpha particles. We propose improved detector architectures which could result in a significant improvement of speed necessary for pulsed mode operation. (authors)

  12. Spectral analysis for systems of atoms and molecules coupled to the quantized radiation field

    International Nuclear Information System (INIS)

    Bach, V.; Sigal, I.M.

    1999-01-01

    We consider systems of static nuclei and electrons - atoms and molecules - coupled to the quantized radiation field. The interactions between electrons and the soft modes of the quantized electromagnetic field are described by minimal coupling, p→p-eA(x), where A(x) is the electromagnetic vector potential with an ultraviolet cutoff. If the interactions between the electrons and the quantized radiation field are turned off, the atom or molecule is assumed to have at least one bound state. We prove that, for sufficiently small values of the fine structure constant α, the interacting system has a ground state corresponding to the bottom of its energy spectrum. For an atom, we prove that its excited states above the ground state turn into metastable states whose life-times we estimate. Furthermore the energy spectrum is absolutely continuous, except, perhaps,in a small interval above the ground state energy and around the threshold energies of the atom or molecule. (orig.)

  13. Comparison of curricula in radiation technology in the field of radiotherapy in selected European Union countries.

    Science.gov (United States)

    Janaszczyk, Agnieszka; Bogusz-Czerniewicz, Marta

    2011-01-01

    Radiation technology is a discipline of medical science which deals with diagnostics, imaging and radiotherapy, that is treatment by ionizing radiation. To present and compare the existing curricula of radiation technology in selected EU countries. The research work done for the purpose of the comparative analysis was based on the methods of diagnostic test and document analysis. The comparison of curricula in selected countries, namely Austria, France, the Netherlands and Poland, showed that admission criteria to radiation technology courses are varied and depend on regulations of respective Ministries of Health. The most restrictive conditions, including written tests in biology, chemistry and physics, and psychometric test, are those in France. Contents of basic and specialist subject groups are very similar in all the countries. The difference is in the number of ECT points assigned to particular subjects and the number of course hours offered. The longest practical training is provided in the Netherlands and the shortest one in Poland. The duration of studies in the Netherlands is 4 years, while in Poland it is 3 years. Austria is the only country to offer extra practical training in quality management. Graduates in the compared EU countries have similar level of qualifications in the fields of operation of radiological equipment, radiotherapy, nuclear medicine, foreign language and specialist terminology in the field of medical and physical sciences, general knowledge of medical and physical sciences, and detailed knowledge of radiation technology.

  14. An introduction to radiation protection

    CERN Document Server

    Martin, Alan; Beach, Karen; Cole, Peter

    2012-01-01

    The sixth edition of this established text takes the reader through the general background to the subject, the technical principles underlying the control of radiation hazards, radiation detection and measurement and the biological effects of radiation. These are followed by a consideration of radiation protection issues in the nuclear industry, the non-nuclear sector and the medical field. Further specialised topics include risk assessment, waste management and decommissioning, radiological incidents and emergencies, relevant legislation and organizational issues.

  15. Analysis of the radiation from the violin f-holes using patch near field acoustical holography

    Science.gov (United States)

    Williams, Earl G.; Bissinger, George

    2003-04-01

    Although differential pressure measurements offer a direct means to understand the energy flow from the f-holes of the violin they have been performed only at discrete frequencies over relatively limited portions of the acoustic field, and none have ever covered an entire f-hole over a broad frequency region. Application of recently developed near field acoustical holography (NAH) patch processing techniques to 108-node planar rectangular grid microphone data provides a powerful tool to understand the flow of acoustic energy from the f-holes up to 4 kHz. The grid covered each f-hole as well as a small portion of the violin top-plate and provided the necessary spatial resolution to allow isolation of only f-hole aperture radiation in the NAH processing. The projected radiativity in the far field at 1.2 m from just the f-holes was compared with prior microphone measurements in an anechoic chamber over an entire sphere around the violin. As expected the lowest cavity mode A0 was the major radiator at the frequencies below all the corpus modes. Surprisingly the first corpus bending modes appear to radiate strongly through the f-holes also. [Work supported by ONR and NSF.

  16. Evaluating a radiation monitor for mixed-field environments based on SRAM technology

    CERN Document Server

    Tsiligiannis, G; Bosio, A; Girard, P; Pravossoudovitch, S; Todri, A; Virazel, A; Mekki, J; Brugger, M; Wrobel, F; Saigne, F

    2014-01-01

    Instruments operating in particle accelerators and colliders are exposed to radiations that are composed of particles of different types and energies. Several of these instruments often embed devices that are not hardened against radiation effects. Thus, there is a strong need for mon- itoring the levels of radiation inside the mixed-field radiation areas, throughout different positions. Different metrics exist for measuring the radiation damage induced to electronic devices, such as the Total Ionizing Dose (TID), the Displacement Damage (DD) and of course the fluence of parti- cles for estimating the error rates of the electronic devices among other applications. In this paper, we propose an SRAM based monitor, that is used to define the fluence of High Energy Hadrons (HEH) by detecting Single Event Upsets in the memory array. We evaluated the device by testing it inside the H4IRRAD area of CERN, a test area that reproduces the radiation conditions inside the Large Hadron Collider (LHC) tunnel and its shield...

  17. SOUND TRANSMISSION LOSS OF A DOUBLE-LEAF PARTITION WITH MICRO-PERFORATED PLATE INSERTION UNDER DIFFUSE FIELD INCIDENCE

    Directory of Open Access Journals (Sweden)

    A. Putra

    2013-06-01

    Full Text Available In noise control applications, a double-leaf partition has been applied widely as a lightweight structure for noise insulation, such as in car doors, train bodies, and aircraft fuselages. Unfortunately, the insulation performance deteriorates significantly at mass-air-mass resonance due to coupling between the panels and the air in the gap. This paper investigates the effect of a micro-perforated panel (MPP, inserted in the conventional double-panel partition, on sound transmission loss at troublesome resonant frequencies. It is found that the transmission loss improves at this resonance if the MPP is located at a distance of less than half that of the air gap. A mathematical model is derived for the diffuse field incidence of acoustic loading.

  18. Response of the 'patient dose calibrator' chamber for incident positions and sizes of X-ray fields

    International Nuclear Information System (INIS)

    Oliveira, Cassio M.; Abrantes, Marcos Eugenio S.; Ferreira, Flavia C. Bastos; Lacerda, Marco A. de Souza; Alonso, Thessa C.; Silva, Teogenes A. da; Oliveira, Paulo Marcio C.

    2009-01-01

    The evaluation of patient doses is an important tool for optimizing radiodiagnostic medical procedures with conventional X-ray equipment and for improving the quality of the radiographic image. The Patient Dose Calibrator (PDC) chamber is a dosimetric instrument that is used in the evaluation of the air kerma-area product (P KA ) quantity aiming the reduction of patient doses. The objective this work was to study the P KA variation caused by different field incident positions and sizes of the X-ray beam on the PDC chamber. Results showed that the PDC chamber has repeatability lower than 0.6%, beam position dependence of 3% and linearity response within ± 6%; these characteristics are to be taken into account during evaluation of the radiological protection conditions of conventional x-ray equipment. (author)

  19. Quantum theory of the laser radiation scattering by electrons in magnetic fields

    International Nuclear Information System (INIS)

    Rochlin, H.

    1981-08-01

    A system composed of an electron in a static magnetic field interacting with the quantized electromagnetic field, within the electric-dipole and the nonrelativistic approximations (with a cutoff in momentum space) is considered. The Heisenberg equations are solved exactly and the time evolution of the electric field is determined. This result is then used to obtain the spectrum of the scattered radiation when the initial state of the field is coherent, aplying the theory of photodetection. This theory is thoroughly discussed. Several expressions proposed in the literature for the time-dependent spectrum are compared and conditions for the equivalence of these expressions are analyzed. Moreover, inaccuracies in previous treatments of the theory of photodetection are corrected. The results allow the line shape of the scattered radiation to be analyzed for magnetic fields up to 10 12 G. The quantization of the eletromagnetic field allows one to consider the role of the natural line width, which becomes important near ressonance. In particular, it is analyzed the dependence of the line width with the magnetic field. This treatment includes the renormalization of the electron mass, which keeps the results finite when the cutoff goes to infinity. (Author) [pt

  20. The characters of radiation fields and effects for protection monitoring in nuclear-powered submarine

    International Nuclear Information System (INIS)

    Wang Yuexing; Ma Xiaoling; Lu Yongjie; Zhang Jianguo

    1999-01-01

    The characters of the radiation fields in nuclear-powered submarine have been described. The characters are: the range of γ-rays energy is from 0 to 10 MeV, there are thermal and fast neutrons in it, and space changes of energy spectra and flux rates for γ-rays and neutrons are rapid. The characters have markedly an effect on the design of individual dosimeter measuring neutron dose, on evaluating accident-dose, and on the calibration of the instruments used to radiation protection in nuclear-powered submarine

  1. Comprehensive Modelling and Simulation System for Decision Support in the Field of Radiation Potection

    Czech Academy of Sciences Publication Activity Database

    Pecha, Petr; Hofman, Radek

    -, č. 81 (2010), s. 17-18 ISSN 0926-4981 R&D Projects: GA MŠk(CZ) 1M0572; GA ČR(CZ) GA102/07/1596 Institutional research plan: CEZ:AV0Z10750506 Keywords : decision support * modelling * radiation protection * environment al impact assessment * probability safety assessment Subject RIV: JF - Nuclear Energetics http://library.utia.cas.cz/separaty/2010/AS/pecha-comprehensive modelling and simulation system for decision support in the field of radiation potection.pdf

  2. Strong Field-Induced Frequency Conversion of Laser Radiation in Plasma Plumes: Recent Achievements

    Directory of Open Access Journals (Sweden)

    R. A. Ganeev

    2013-01-01

    Full Text Available New findings in plasma harmonics studies using strong laser fields are reviewed. We discuss recent achievements in the growth of the efficiency of coherent extreme ultraviolet (XUV radiation sources based on frequency conversion of the ultrashort pulses in the laser-produced plasmas, which allowed for the spectral and structural studies of matter through the high-order harmonic generation (HHG spectroscopy. These studies showed that plasma HHG can open new opportunities in many unexpected areas of laser-matter interaction. Besides being considered as an alternative method for generation of coherent XUV radiation, it can be used as a powerful tool for various spectroscopic and analytical applications.

  3. On the evaluation of rectangular plane-extended sources and their associated radiation fields

    International Nuclear Information System (INIS)

    Oner, Feda

    2007-01-01

    The objective of this paper is to provide an efficient and reliable analytical procedure for the evaluation of rectangular plane-extended sources and their associated radiation fields. Integrals with integer and non-integer values appear in the evaluation of the radiation field distribution. The latter results from a homogeneous rectangular plane target bombarded by hollow-cylindrical ion beams, the elementary areas anisotropically emitting in non-dispersive media, and fast neutrons produced in non-dispersive media by sealed-off neutron generating tubes (NGT) in an axi-symmetric situation [Hubbell, J.H., Bach, R.L., Lamkin, J.C., 1960. Radiation from a rectangular source. J. Res. NBS 64C (2), 121-137; Hubbell, J.H., 1963a. A power series buildup factor formulation. Application to rectangular and offaxis disk source problems. J. Res. NBS 67C, 291-306, Hubbell, J.H., 1963b. Dose fields from plane sources using point-source data. Nucleonics 21 (8), 144-148; Timus et al., 2005a. Plane rectengular tritium target response to excitation by uniform distributed normal accelerated deuteron beam. Appl. Radiat. Isot. 63, 823-839; Timus et al., 2005b. Analytical characterization of radiation fields generated by certain witch-type distributed axi-symmetrical ion beams. Arab J. Nucl. Sci. Appl. 38(I) 253-264]. In these references, the resulting expressions are represented as infinite linear combinations of basic J q (a, b, z) integrals. With the help of relation for J q (a, b, z), we can evaluate the high terms of energy expressions, which have been proposed in the above-mentioned references. The extensive test calculations show that the proposed algorithm in this work is the most efficient one in practical computations

  4. Functional signatures of radio-induction in sarcomas developing in the radiation field after radiotherapy

    International Nuclear Information System (INIS)

    Hadj-Hamou, N.S.

    2010-01-01

    Radiotherapy plays an important role in the treatment of cancers. However, exposure to ionizing radiation is a well-known risk factor for secondary cancer development. Currently, rigorous defined scientific criteria are lacking to establish if an individual tumor has a radiation-induced or a sporadic origin. The main aim of my thesis program was to identify a transcriptome signature of the ionizing radiation effects in radiation-induced cancers. The series of cancers used in this study is composed of sarcomas developing in the irradiation field of patients treated by radiotherapy for a primary cancer. Strict selection criteria (histology different from the primary cancer, latency longer than 5 years) were used to establish with a high probability the sarcomas-radiation induced origin. Their transcriptomes were compared with those from patients without irradiation history. A method of classification adapted to small series was used for the study of all the 60 collected sarcomas (34 radiation-induced and 26 sporadic). A learning set composed of 24 sarcomas from known aetiology allowed us to determine a signature of 135 genes discriminating the sarcomas according to their aetiology. The signature classified 86% of the remaining sarcomas as a function of their aetiology with an accuracy of 97%. The analysis of the genes-function shows that the radiation-induced sarcomas suffered the effects of a chronic oxidative stress mainly generated by mitochondrial dysfunctions. This study shows, for the first time, that it is possible to diagnose, at the case by case level, radiation-induced sarcomas on a rigorous scientific basis. (author)

  5. Thermal electron acceleration by electric field spikes in the outer radiation belt: generation of field-aligned pitch angle distributions

    Science.gov (United States)

    Vasko, I.; Agapitov, O. V.; Mozer, F.; Artemyev, A.

    2015-12-01

    Van Allen Probes observations in the outer radiation belt have demonstrated an abundance non-linear electrostatic stucture called Time Domain Structures (TDS). One of the type of TDS is electrostatic electron-acoustic double layers (DL). Observed DLs are frequently accompanied by field-aligned (bi-directional) pitch angle distributions (PAD) of electrons with energies from hundred eVs up to several keV (rarely up to tens of keV). We perform numerical simulations of the DL interaction with thermal electrons making use of the test particle approach. DL parameters assumed in the simulations are adopted from observations. We show that DLs accelerate thermal electrons parallel to the magnetic field via the electrostatic Fermi mechanism, i.e. due to reflections from DL potential humps. Due to this interaction some fraction of electrons is scattered into the loss cone. The electron energy gain is larger for larger DL scalar potential amplitudes and higher propagation velocities. In addition to the Fermi mechanism electrons can be trapped by DLs in their generation region and accelerated due to transport to higher latitudes. Both mechanisms result in formation of field-aligned PADs for electrons with energies comparable to those found in observations. The Fermi mechanism provides field-aligned PADs for <1 keV electrons, while the trapping mechanism extends field-aligned PADs to higher energy electrons.

  6. Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

    International Nuclear Information System (INIS)

    Amdur, Robert J.; Liu, Chihray; Li, Jonathan; Mendenhall, William; Hinerman, Russell

    2007-01-01

    When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior 'low neck' field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction

  7. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  8. Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

    International Nuclear Information System (INIS)

    Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

    2009-01-01

    Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

  9. Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage.

    Science.gov (United States)

    Sannino, Anna; Zeni, Olga; Romeo, Stefania; Massa, Rita; Gialanella, Giancarlo; Grossi, Gianfranco; Manti, Lorenzo; Vijayalaxmi; Scarfì, Maria Rosaria

    2014-03-01

    The aim of this preliminary investigation was to assess whether human peripheral blood lymphocytes which have been pre-exposed to non-ionizing radiofrequency fields exhibit an adaptive response (AR) by resisting the induction of genetic damage from subsequent exposure to ionizing radiation. Peripheral blood lymphocytes from four healthy donors were stimulated with phytohemagglutinin for 24 h and then exposed for 20 h to 1950 MHz radiofrequency fields (RF, adaptive dose, AD) at an average specific absorption rate of 0.3 W/kg. At 48 h, the cells were subjected to a challenge dose (CD) of 1.0 or 1.5 Gy X-irradiation (XR, challenge dose, CD). After a 72 h total culture period, cells were collected to examine the incidence of micronuclei (MN). There was a significant decrease in the number of MN in lymphocytes exposed to RF + XR (AD + CD) as compared with those subjected to XR alone (CD). These observations thus suggested a RF-induced AR and induction of resistance to subsequent damage from XR. There was variability between the donors in RF-induced AR. The data reported in our earlier investigations also indicated a similar induction of AR in human blood lymphocytes that had been pre-exposed to RF (AD) and subsequently treated with a chemical mutagen, mitomycin C (CD). Since XR and mitomycin-C induce different kinds of lesions in cellular DNA, further studies are required to understand the mechanism(s) involved in the RF-induced adaptive response.

  10. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    International Nuclear Information System (INIS)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A.

    2017-01-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  11. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    Energy Technology Data Exchange (ETDEWEB)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A., E-mail: danilonai1992@poli.ufrj.br, E-mail: paulo@lmp.ufrj.br, E-mail: cmnap@ien.gov.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  12. Study of high speed complex number algorithms. [for determining antenna for field radiation patterns

    Science.gov (United States)

    Heisler, R.

    1981-01-01

    A method of evaluating the radiation integral on the curved surface of a reflecting antenna is presented. A three dimensional Fourier transform approach is used to generate a two dimensional radiation cross-section along a planer cut at any angle phi through the far field pattern. Salient to the method is an algorithm for evaluating a subset of the total three dimensional discrete Fourier transform results. The subset elements are selectively evaluated to yield data along a geometric plane of constant. The algorithm is extremely efficient so that computation of the induced surface currents via the physical optics approximation dominates the computer time required to compute a radiation pattern. Application to paraboloid reflectors with off-focus feeds in presented, but the method is easily extended to offset antenna systems and reflectors of arbitrary shapes. Numerical results were computed for both gain and phase and are compared with other published work.

  13. Radiation sensitivity of graphene field effect transistors and other thin film architectures

    Science.gov (United States)

    Cazalas, Edward

    An important contemporary motivation for advancing radiation detection science and technology is the need for interdiction of nuclear and radiological materials, which may be used to fabricate weapons of mass destruction. The detection of such materials by nuclear techniques relies on achieving high sensitivity and selectivity to X-rays, gamma-rays, and neutrons. To be attractive in field deployable instruments, it is desirable for detectors to be lightweight, inexpensive, operate at low voltage, and consume low power. To address the relatively low particle flux in most passive measurements for nuclear security applications, detectors scalable to large areas that can meet the high absolute detection efficiency requirements are needed. Graphene-based and thin-film-based radiation detectors represent attractive technologies that could meet the need for inexpensive, low-power, size-scalable detection architectures, which are sensitive to X-rays, gamma-rays, and neutrons. The utilization of graphene to detect ionizing radiation relies on the modulation of graphene charge carrier density by changes in local electric field, i.e. the field effect in graphene. Built on the principle of a conventional field effect transistor, the graphene-based field effect transistor (GFET) utilizes graphene as a channel and a semiconducting substrate as an absorber medium with which the ionizing radiation interacts. A radiation interaction event that deposits energy within the substrate creates electron-hole pairs, which modify the electric field and modulate graphene charge carrier density. A detection event in a GFET is therefore measured as a change in graphene resistance or current. Thin (micron-scale) films can also be utilized for radiation detection of thermal neutrons provided nuclides with high neutron absorption cross section are present with appreciable density. Detection in thin-film detectors could be realized through the collection of charge carriers generated within the

  14. The measurement and analysis of normal incidence solar UVB radiation and its application to the photoclimatherapy protocol for psoriasis at the Dead Sea, Israel.

    Science.gov (United States)

    Kudish, Avraham I; Harari, Marco; Evseev, Efim G

    2011-01-01

    The broad-band normal incidence UVB beam radiation has been measured at Neve Zohar, Dead Sea basin, using a prototype tracking instrument composed of a Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The diffuse and beam fraction of the solar global UVB radiation have been determined using the concurrently measured solar global UVB radiation. The diffuse fraction was observed to exceed 80% throughout the year. The application of the results of these measurements to the possible revision of the photoclimatherapy protocol for psoriasis patients at the Dead Sea medical spas is now under investigation. The suggested revision would enable the sun-exposure treatment protocol to take advantage of the very high diffuse fraction by allowing the patient to receive the daily dose of UVB radiation without direct exposure to the sun, viz. receive the diffuse UVB radiation under a sunshade. This would require an increase in sun-exposure time intervals, as the UVB radiation intensity beneath a sunshade is less than that on an exposed surface. © 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.

  15. Small unmanned aircraft system for remote contour mapping of a nuclear radiation field

    Science.gov (United States)

    Guss, Paul; McCall, Karen; Malchow, Russell; Fischer, Rick; Lukens, Michael; Adan, Mark; Park, Ki; Abbott, Roy; Howard, Michael; Wagner, Eric; Trainham, Clifford P.; Luke, Tanushree; Mukhopadhyay, Sanjoy; Oh, Paul; Brahmbhatt, Pareshkumar; Henderson, Eric; Han, Jinlu; Huang, Justin; Huang, Casey; Daniels, Jon

    2017-09-01

    For nuclear disasters involving radioactive contamination, small unmanned aircraft systems (sUASs) equipped with nuclear radiation detection and monitoring capability can be very important tools. Among the advantages of a sUAS are quick deployment, low-altitude flying that enhances sensitivity, wide area coverage, no radiation exposure health safety restriction, and the ability to access highly hazardous or radioactive areas. Additionally, the sUAS can be configured with the nuclear detecting sensor optimized to measure the radiation associated with the event. In this investigation, sUAS platforms were obtained for the installation of sensor payloads for radiation detection and electro-optical systems that were specifically developed for sUAS research, development, and operational testing. The sensor payloads were optimized for the contour mapping of a nuclear radiation field, which will result in a formula for low-cost sUAS platform operations with built-in formation flight control. Additional emphases of the investigation were to develop the relevant contouring algorithms; initiate the sUAS comprehensive testing using the Unmanned Systems, Inc. (USI) Sandstorm platforms and other acquired platforms; and both acquire and optimize the sensors for detection and localization. We demonstrated contour mapping through simulation and validated waypoint detection. We mounted a detector on a sUAS and operated it initially in the counts per second (cps) mode to perform field and flight tests to demonstrate that the equipment was functioning as designed. We performed ground truth measurements to determine the response of the detector as a function of source-to-detector distance. Operation of the radiation detector was tested using different unshielded sources.

  16. The hazards of low-level radiation

    International Nuclear Information System (INIS)

    Blackith, R.

    1979-01-01

    Safety standards are questioned, particularly in relation to the risk of inducing cancer at low doses of radiation. Statements are made on the following topics: incidence of leukaemia among children around reactors, general aging effect due to radiation, leukaemia among radiation workers in a shipyard repairing nuclear submarines, official withdrawal of funds from research workers in the field of radiation hazards, discrepancies between different measurements of radiation near nuclear power plants. (U.K.)

  17. Dependence on the incident light power of the internal electric fields in a GaAs p-i-n solar cell according to bright photoreflectance spectroscopy

    Science.gov (United States)

    Jo, Hyun-Jun; Mun, Young Hee; Kim, Jong Su; Lee, Sang Jun

    2016-07-01

    Bright photoreflectance (BPR) spectroscopy at room temperature is used to examine the internal electric fields in a GaAs p-i-n solar cell for their dependence on the incident light power. Electric fields are observed at 30 µW and 100 µW of incident light. With increasing power, the strengths of the two electric fields are reduced due to the photovoltage effect. The electric field observed at 30 µW is assigned to the p-i interface, which is close to the surface. The other electric field is due to the i-n interface because the incident light penetrates deeper as the light power is increased. The electric field strength of 35.6 kV/cm at the p-i interface is lower than that of 42.9 kV/cm at the i-n interface at 500 µW of light power because the photovoltage effect is proportional to the number of photo-generated carriers, which is reduced as the distance from the surface increases. When the incident light power is similar to the excitation beam power, the electric fields at the p-i interface are saturated.

  18. Occupational radiation exposure history of Idaho Field Office Operations at the INEL

    International Nuclear Information System (INIS)

    Horan, J.R.; Braun, J.B.

    1993-10-01

    An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years

  19. Occupational radiation exposure history of Idaho Field Office Operations at the INEL

    Energy Technology Data Exchange (ETDEWEB)

    Horan, J.R.; Braun, J.B.

    1993-10-01

    An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years.

  20. DOE Task Force meeting on Electrical Breakdown of Insulating Ceramics in a High Radiation Field

    International Nuclear Information System (INIS)

    Green, P.H.

    1991-08-01

    This volume contains the abstracts and presentation material from the Research Assistance Task Force Meeting ''Electrical Breakdown of Insulating Ceramics in a High-Radiation Field.'' The meeting was jointly sponsored by the Office of Basic Energy Sciences and the Office of Fusion Energy of the US Department of Energy in Vail, Colorado, May 28--June 1, 1991. The 26 participants represented expertise in fusion, radiation damage, electrical breakdown, ceramics, and semiconductor and electronic structures. These participants came from universities, industries, national laboratories, and government. The attendees represented eight nations. The Task Force meeting was organized in response to the recent discovery that a combination of temperature, electric field, and radiation for an extended period of time has an unexplained adverse effect in ceramics, termed radiation-enhanced electrical degradation (REED). REED occurs after an incubation period and continues to accelerate with irradiation until the ceramics can no longer be regarded as insulators. It appears that REED is irreversible and the ceramic insulators cannot be readily annealed or otherwise repaired for future services. This effect poses a serious threat for fusion reactors, which require electrical insulators in diagnostic devices, in radio frequency and neutral beam systems, and in magnetic assemblies. The problem of selecting suitable electrical insulating materials in thus far more serious than previously anticipated

  1. Theoretical investigation of non-equilibrium chemistry and optical radiation in hypersonic flow fields

    Science.gov (United States)

    Whiting, Ellis E.

    1990-01-01

    Future space vehicles returning from distant missions or high earth orbits may enter the upper regions of the atmosphere and use aerodynamic drag to reduce their velocity before they skip out of the atmosphere and enter low earth orbit. The Aeroassist Flight Experiment (AFE) is designed to explore the special problems encountered in such entries. A computer code was developed to calculate the radiative transport along line-or-sight in the general 3-D flow field about an arbitrary entry vehicle, if the temperatures and species concentrations along the line-of-sight are known. The radiative heating calculation at the stagnation point of the AFE vehicle along the entry trajectory was performed, including a detailed line-by-line accounting of the radiative transport in the vacuum ultraviolet (below 200 nm) by the atomic N and O lines. A method was developed for making measurements of the haze particles in the Titan atmosphere above 200 km altitude. Several other tasks of a continuing nature, to improve the technical ability to calculate the nonequilibrium gas dynamic flow field and radiative heating of entry vehicles, were completed or advanced.

  2. Increased incidence of myelodysplastic syndrome and acute myeloid leukemia following breast cancer treatment with radiation alone or combined with chemotherapy: a registry cohort analysis 1990-2005

    International Nuclear Information System (INIS)

    Kaplan, Henry G; Malmgren, Judith A; Atwood, Mary K

    2011-01-01

    Our objective was to measure myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML) risk associated with radiation and/or chemotherapy breast cancer (BC) treatment. Our study cohort was composed of BC patients diagnosed from 1990 to 2005 and followed up for blood disorders, mean length of follow up = 7.17 years, range 2-18 years. 5790 TNM stage 0-III patients treated with surgery alone, radiation and/or chemotherapy were included. Patients without surgery (n = 111), with stem cell transplantation (n = 98), unknown or non-standard chemotherapy regimens (n = 94), lost to follow up (n = 66) or 'cancer status unknown' (n = 67) were excluded. Rates observed at our community based cancer care institution were compared to SEER incidence data for rate ratio (RR) calculations. 17 cases of MDS/AML (10 MDS/7 AML) occurred during the follow up period, crude rate .29% (95% CI = .17, .47), SEER comparison RR = 3.94 (95% CI = 2.34, 6.15). The RR of MDS in patients age < 65 comparing our cohort incidence to SEER incidence data was 10.88 (95% CI = 3.84, 24.03) and the RR of AML in patients age < 65 was 5.32 (95% CI = 1.31, 14.04). No significant increased risk of MDS or AML was observed in women ≥ 65 or the surgery/chemotherapy-only group. A RR of 3.32 (95% CI = 1.42, 6.45) was observed in the surgery/radiation-only group and a RR of 6.32 (95% CI = 3.03, 11.45) in the surgery/radiation/chemotherapy group. 3 out of 10 MDS cases died of disease at an average 3.8 months post diagnosis and five of seven AML cases died at an average 9 months post diagnosis. An elevated rate of MDS and AML was observed among breast cancer patients < 65, those treated with radiation and those treated with radiation and chemotherapy compared to available population incidence data. Although a small number of patients are affected, leukemia risk associated with treatment and younger age is significant

  3. Remanent radiation fields around medical linear accelerators due to the induced radionuclides

    International Nuclear Information System (INIS)

    Sabol, J.; Khalifa, O.; Berka, Z.; Stankus, P.; Frencl, L.

    1998-01-01

    Radiation fields around two linear accelerators, Saturn 43 and a Saturn 2 Plus, installed at radiotherapy department is Prague, were measured and interpreted. The measurements included the determination of the dose equivalent rate resulting from photons emitted by induced radionuclides produced in reactions of high-energy photons with certain elements present in air and accelerator components as well as in the shielding and building materials in the treatment rooms, which are irradiated by high-energy X-rays, and due to radionuclides formed by capture of photoneutrons. While scattered photons and photoneutrons are only present during the accelerator operation, residual radioactivity creates a remanent radiation field persisting for some time after the instrument shutdown. The activity induced in the accessories is also an important source of exposure. (P.A.)

  4. Problems of multiple field technique in radiation therapy of cancer of the breast

    International Nuclear Information System (INIS)

    Metzger, H.; Huebener, K.H.; Voss, A.C.

    1980-01-01

    A method of adjustment frequently used for postoperative telecobalt irradiation of the mammary carcinoma was verified with the help of film-dosimetric measurements at a phantom. Special interest was taken in the regions with possible overlapping of contiguous fields requires consideration of the divergence of rays and of the mapping precision of 50%-isodoses in the radiation field, as there lie the principal reasons. For realization of a nearly homogeneous dose distribution, on the one hand, there is necessary parallelism of marginal rays of the neighbouring useful ray beams, the radiation head being tilted laterally by half the angle of aperture; on the other hand, the 50% boundary lines at the light beam localizer have to be shifted parallel by a corresponding distance. In spite of this possibility of optimization, it is distinctly more advantageous, with regard to time and technical aspects, to use a linear accelerator, being additionally applicable for electron pendulum irradiation of the thoracic wall. (orig.) [de

  5. Application of the principle of supramolecular chemistry in the fields of radiochemistry and radiation chemistry

    International Nuclear Information System (INIS)

    Shen Xinghai; Chen Qingde; Gao Hongcheng

    2008-01-01

    Supramolecular chemistry, one of the front fields in chemistry, is defined as 'chemistry beyond the molecule', bearing on the organized entities of higher complexity that result from the association of two or more chemical species held together by intermolecular forces. This article focuses on the application of the principle of supramolecular chemistry in the fields of radiochemistry and radiation chemistry. The following aspects are concerned: (1) the recent progress of supramolecular chemistry; (2) the application of the principle of supramolecular chemistry and the functions of supramolecular system, i.e., recognition, assembly and translocation, in the extraction of nuclides; (3) the application of microemulsion, ionic imprinted polymers, ionic liquids and cloud point extraction in the enrichment of nuclides; (4) the radiation effect of supramolecular systems. (authors)

  6. Attenuated UV Radiation Alters Volatile Profile in Cabernet Sauvignon Grapes under Field Conditions.

    Science.gov (United States)

    Liu, Di; Gao, Yuan; Li, Xiao-Xi; Li, Zheng; Pan, Qiu-Hong

    2015-09-17

    This study aimed to explore the effect of attenuated UV radiation around grape clusters on the volatile profile of Cabernet Sauvignon grapes (Vitis vinifera L. cv.) under field conditions. Grape bunches were wrapped with two types of polyester films that cut off 89% (film A) and 99% (film B) invisible sunlight of less than 380 nm wavelength, respectively. Solar UV radiation reaching the grape berry surface was largely attenuated, and an increase in the concentrations of amino acid-derived benzenoid volatiles and fatty acid-derived esters was observed in the ripening grapes. Meanwhile, the attenuated UV radiation significantly reduced the concentrations of fatty acid-derived aldehydes and alcohols and isoprenoid-derived norisoprenoids. No significant impact was observed for terpenes. In most case, these positive or negative effects were stage-dependent. Reducing UV radiation from the onset of veraison to grape harvest, compared to the other stages, caused a larger alteration in the grape volatile profile. Partial Least Square Discriminant Analysis (PLS-DA) revealed that (E)-2-hexenal, 4-methyl benzaldehyde, 2-butoxyethyl acetate, (E)-2-heptenal, styrene, α-phenylethanol, and (Z)-3-hexen-1-ol acetate were affected most significantly by the attenuated UV radiation.

  7. Attenuated UV Radiation Alters Volatile Profile in Cabernet Sauvignon Grapes under Field Conditions

    Directory of Open Access Journals (Sweden)

    Di Liu

    2015-09-01

    Full Text Available This study aimed to explore the effect of attenuated UV radiation around grape clusters on the volatile profile of Cabernet Sauvignon grapes (Vitis vinifera L. cv. under field conditions. Grape bunches were wrapped with two types of polyester films that cut off 89% (film A and 99% (film B invisible sunlight of less than 380 nm wavelength, respectively. Solar UV radiation reaching the grape berry surface was largely attenuated, and an increase in the concentrations of amino acid-derived benzenoid volatiles and fatty acid-derived esters was observed in the ripening grapes. Meanwhile, the attenuated UV radiation significantly reduced the concentrations of fatty acid-derived aldehydes and alcohols and isoprenoid-derived norisoprenoids. No significant impact was observed for terpenes. In most case, these positive or negative effects were stage-dependent. Reducing UV radiation from the onset of veraison to grape harvest, compared to the other stages, caused a larger alteration in the grape volatile profile. Partial Least Square Discriminant Analysis (PLS-DA revealed that (E-2-hexenal, 4-methyl benzaldehyde, 2-butoxyethyl acetate, (E-2-heptenal, styrene, α-phenylethanol, and (Z-3-hexen-1-ol acetate were affected most significantly by the attenuated UV radiation.

  8. A space weather index for the radiation field at aviation altitudes

    Directory of Open Access Journals (Sweden)

    Meier Matthias M.

    2014-04-01

    Full Text Available The additional dose contribution to the radiation exposure at aviation altitudes during Solar Particle Events (SPEs has been a matter of concern for many years. After the Halloween storms in 2003 several airlines began to implement mitigation measures such as rerouting and lowering flight altitudes in response to alerts on the NOAA S-scale regarding solar radiation storms. These alerts are based on the integral proton flux above 10 MeV measured aboard the corresponding GOES-satellite which is operated outside the Earth’s atmosphere in a geosynchronous orbit. This integral proton flux has, however, been proved to be an insufficient parameter to apply to the radiation field at aviation altitudes without an accompanying analysis of the shape of the energy spectrum. Consequently, false alarms and corresponding disproportionate reactions ensued. Since mitigating measures can be quite cost-intensive, there has been a demand for appropriate space weather information among responsible airline managers for about a decade. Against this background, we propose the introduction of a new Space Weather index D, based on dose rates at aviation altitudes produced by solar protons during solar radiation storms, as the relevant parameter for the assessment of corresponding radiation exposure. The Space Weather index D is a natural number given by a graduated table of ranges of dose rates in ascending order which is derived by an equation depending on the dose rate of solar protons.

  9. EM Modeling of Far-Field Radiation Patterns for Antennas on the GMA-TT UAV

    Science.gov (United States)

    Mackenzie, Anne I.

    2015-01-01

    To optimize communication with the Generic Modular Aircraft T-Tail (GMA-TT) unmanned aerial vehicle (UAV), electromagnetic (EM) simulations have been performed to predict the performance of two antenna types on the aircraft. Simulated far-field radiation patterns tell the amount of power radiated by the antennas and the aircraft together, taking into account blockage by the aircraft as well as radiation by conducting and dielectric portions of the aircraft. With a knowledge of the polarization and distance of the two communicating antennas, e.g. one on the UAV and one on the ground, and the transmitted signal strength, a calculation may be performed to find the strength of the signal travelling from one antenna to the other and to check that the transmitted signal meets the receiver system requirements for the designated range. In order to do this, the antenna frequency and polarization must be known for each antenna, in addition to its design and location. The permittivity, permeability, and geometry of the UAV components must also be known. The full-wave method of moments solution produces the appropriate dBi radiation pattern in which the received signal strength is calculated relative to that of an isotropic radiator.

  10. On the Momentum Transported by the Radiation Field of a Long Transient Dipole and Time Energy Uncertainty Principle

    Directory of Open Access Journals (Sweden)

    Vernon Cooray

    2016-11-01

    Full Text Available The paper describes the net momentum transported by the transient electromagnetic radiation field of a long transient dipole in free space. In the dipole a current is initiated at one end and propagates towards the other end where it is absorbed. The results show that the net momentum transported by the radiation is directed along the axis of the dipole where the currents are propagating. In general, the net momentum P transported by the electromagnetic radiation of the dipole is less than the quantity U / c , where U is the total energy radiated by the dipole and c is the speed of light in free space. In the case of a Hertzian dipole, the net momentum transported by the radiation field is zero because of the spatial symmetry of the radiation field. As the effective wavelength of the current decreases with respect to the length of the dipole (or the duration of the current decreases with respect to the travel time of the current along the dipole, the net momentum transported by the radiation field becomes closer and closer to U / c , and for effective wavelengths which are much shorter than the length of the dipole, P ≈ U / c . The results show that when the condition P ≈ U / c is satisfied, the radiated fields satisfy the condition Δ t Δ U ≥ h / 4 π where Δ t is the duration of the radiation, Δ U is the uncertainty in the dissipated energy and h is the Plank constant.

  11. Ly{alpha} DOMINANCE OF THE CLASSICAL T TAURI FAR-ULTRAVIOLET RADIATION FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Schindhelm, Eric [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80303 (United States); France, Kevin; Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Herczeg, Gregory J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Bergin, Edwin [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Yang Hao [Institute of Astrophysics, Central China Normal University, Wuhan, Hubei 430079 (China); Brown, Joanna M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Valenti, Jeff, E-mail: eric@boulder.swri.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-09-01

    Far-ultraviolet (FUV) radiation plays an important role in determining chemical abundances in protoplanetary disks. H I Lyman {alpha} (Ly{alpha}) is suspected to be the dominant component of the FUV emission from Classical T Tauri Stars (CTTSs), but is difficult to measure directly due to circumstellar and interstellar H I absorption. To better characterize the intrinsic Ly{alpha} radiation, we present FUV spectra of 14 CTTSs taken with the Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph instruments. H{sub 2} fluorescence, commonly seen in the spectra of CTTSs, is excited by Ly{alpha} photons, providing an indirect measure of the Ly{alpha} flux incident upon the warm disk surface. We use observed H{sub 2} progression fluxes to reconstruct the CTTS Ly{alpha} profiles. The Ly{alpha} flux correlates with total measured FUV flux, in agreement with an accretion-related source of FUV emission. With a geometry-independent analysis, we confirm that in accreting T Tauri systems Ly{alpha} radiation dominates the FUV flux ({approx}1150 A -1700 A). In the systems surveyed this one line comprises 70%-90% of the total FUV flux.

  12. Non ionizing radiations: Sources, fields of application, problem issues and normatives

    International Nuclear Information System (INIS)

    Raganella, L.

    1988-11-01

    The purpose of this paper is briefly to review radiation sources, in work and life places, and national standards, proposed or enforced in different countries, with particular reference to ELF. RF and MW electromagnetic fields. It is aimed to give a help to qualitative valutation on the work we can carry out for the development of an effective health protection of workers and general public. (author)

  13. Open area E.M. field measurements for radiation hazard purposes

    International Nuclear Information System (INIS)

    Bevacqua, F.; Cipollone, E.; Morviducci, A.; Venditti, L.

    1989-01-01

    This article reports on an extensive set of measurements of the E.M. pollution that has been done for radiation hazard purposes. The measurement results are compared with international standards, regulations and laws. Special attention is devoted to the measurement of the E.M. field near hospitals and some important remarks are made on risks related to induced errors on pacemarker and medial instrumentation

  14. Eccentrically-Layered Active Coated Nano-Particles for Directive Near- and Far-Field Radiation

    Directory of Open Access Journals (Sweden)

    Rasmus Ø. Thorsen

    2015-06-01

    Full Text Available The present work shows how the eccentricity in active nano-particles may lead to very interesting and rather directive near- and far-field radiation patterns. The nano-particle is of a three-layer type and consists of a silica core, a free-space middle layer and an outer silver shell and is excited by a magnetic line source. The constant frequency gain model is included in the silica core, and the eccentricity is introduced through appropriate displacements of the core. It is shown that the eccentricity in a nano-particle, which was initially designed to excite a strong dipole mode, causes a progressively larger excitation of several other (including higher order modes, this being more so the larger the core displacement. Specifically, eccentric nano-particles are identified with comparable simultaneous excitations of dipole and quadrupole modes, with associated large values of the radiated power and, even more notably, enhanced and directive near- and far-field radiation patterns. The main beam of these patterns is shown to be effectively tailored (enhanced, reshaped and steered by the direction and amount of the core displacement. The eccentric nano-particles can be additionally gain optimized to boost their near-field response and the radiated power, while retaining the directivity of the gain unoptimized eccentric cases. Owing to their very directive nearand far-field patterns, the proposed eccentric, active three-layer nano-particles may provide alternative strategies towards the design of directive nano-antennas relative to several of the existing solutions.

  15. Non ionizing radiations Sources, fields of application, problem issues and normatives

    CERN Document Server

    Raganella, L

    1988-01-01

    The purpose of this paper is briefly to review radiation sources, in work and life places, and national standards, proposed or enforced in different countries, with particular reference to ELF. RF and MW electromagnetic fields. It is aimed to give a help to qualitative valutation on the work we can carry out for the development of an effective health protection of workers and general public.

  16. Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in a Relativistic Quantum Approach

    Directory of Open Access Journals (Sweden)

    Maruyama Tomoyuki

    2016-01-01

    Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum approach do not agree with those obtained in the semi-classical approach. Then, we find that the anomalous magnetic moment of the proton greatly enhances the production rate by about two orders magnitude, and that the decay width satisfies a robust scaling law.

  17. Magnetic Field Generation through Angular Momentum Exchange between Circularly Polarized Radiation and Charged Particles

    CERN Document Server

    Shvets, G

    2002-01-01

    The interaction between circularly polarized (CP) radiation and charged particles can lead to generation of magnetic field through an inverse Faraday effect. The spin of the circularly polarized electromagnetic wave can be converted into the angular momentum of the charged particles so long as there is dissipation. We demonstrate this by considering two mechanisms of angular momentum absorption relevant for laser-plasma interactions: electron-ion collisions and ionization. The precise dissipative mechanism, however, plays a role in determining the efficiency of the magnetic field generation.

  18. High-resolution Ultraviolet Radiation Fields of Classical T Tauri Stars

    Science.gov (United States)

    France, Kevin; Schindhelm, Eric; Bergin, Edwin A.; Roueff, Evelyne; Abgrall, Hervé

    2014-04-01

    The far-ultraviolet (FUV; 912-1700 Å) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r publicly available in machine-readable format. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

  19. A coherent detection technique via optically biased field for broadband terahertz radiation.

    Science.gov (United States)

    Du, Hai-Wei; Dong, Jia-Meng; Liu, Yi; Shi, Chang-Cheng; Wu, Jing-Wei; Peng, Xiao-Yu

    2017-09-01

    We demonstrate theoretically and experimentally a coherent terahertz detection technique based on an optically biased field functioning as a local oscillator and a second harmonic induced by the terahertz electric field in the air sensor working in free space. After optimizing the polarization angle and the energy of the probe pulse, and filling the system with dry nitrogen, the terahertz radiation generated from a two-color-femtosecond-laser-pulses induced plasma filament is measured by this technique with a bandwidth of 0.1-10 THz and a signal-to-noise ratio of 48 dB. Our technique provides an alternative simple method for coherent broadband terahertz detection.

  20. Magnetic Field Generation through Angular Momentum Exchange between Circularly Polarized Radiation and Charged Particles

    International Nuclear Information System (INIS)

    G. Shvets; N.J. Fisch; J.-M. Rax

    2002-01-01

    The interaction between circularly polarized (CP) radiation and charged particles can lead to generation of magnetic field through an inverse Faraday effect. The spin of the circularly polarized electromagnetic wave can be converted into the angular momentum of the charged particles so long as there is dissipation. We demonstrate this by considering two mechanisms of angular momentum absorption relevant for laser-plasma interactions: electron-ion collisions and ionization. The precise dissipative mechanism, however, plays a role in determining the efficiency of the magnetic field generation

  1. Nonlinearity in MCF7 Cell Survival Following Exposure to Modulated 6 MV Radiation Fields

    OpenAIRE

    Lacoste-Collin, Laetitia; Castiella, Marion; Franceries, Xavier; Cassol, Emmanuelle; Vieillevigne, Laure; Pereda, Veronica; Bardies, Manuel; Courtade-Sa?di, Monique

    2015-01-01

    The study of cell survival following exposure to nonuniform radiation fields is taking on particular interest because of the increasing evidence of a nonlinear relationship at low doses. We conducted in vitro experiments using the MCF7 breast cancer cell line. A 2.4 × 2.4 cm2 square area of a T25 flask was irradiated by a Varian Novalis accelerator delivering 6 MV photons. Cell survival inside the irradiation field, in the dose gradient zone and in the peripheral zone, was determined using a ...

  2. Genomic instability in normal human fibroblasts for chronically low-dose radiation in heavy-ion radiation field

    International Nuclear Information System (INIS)

    Suzuki, Masao; Tsuruoka, Chizuru; Uchihori, Yukio; Ishizaki, Kanji; Hayashi, Hiroko; Yamane, Yoshihiro; Nakamura, Hideaki

    2004-01-01

    We have been studying genomic instability of biological effects in normal human fibroblasts exposed to chronic low-dose radiation in heavy-ion radiation field. This year we try to irradiate cells with low-density carbon ions using faint beams. Genomic instability in cellular responses was examined to measure either cell killing or mutation induction in low-dose accumulated cell populations after exposing to X-ray challenging doses. The results showed that there was no enhanced effect on cell killing between the low-dose pretreated and unirradiated cell populations with carbon-ion faint beams after exposing to defined challenging doses of 200 kV X rays. On the other hand, the frequency of mutation induction, which was measured as the induction of a 6-thioguanine resistant clone focused on hprt locus, of the low-dose pretreated cell population was much higher than that of unirradiated cell population. The results suggested that genomic instability was induced in mutagenesis by the pretreatment of low-density carbon ions. (author)

  3. STUDIES CONCERNING THE EFFECT OF GAMMA RADIATION AND MAGNETIC FIELD EXPOSURE ON GLADIOLUS

    Directory of Open Access Journals (Sweden)

    M CANTOR

    2003-04-01

    Full Text Available Gladiolus (Gladiolus sp. is one of the most floral species cultivated over in the world and in Romania. There are many studies concerning the effect of gamma radiation on ornamental plants but little is known about the synergetic effect of gamma radiation and exposure to magnetic fields on Gladiolus. In our investigation we have tested the effect of gamma irradiation and magnetic field exposure of gladiolus corms and cormels of the cultivars: Her Majesty, Applause and Speranţa. The corms and cormels were irradiated for 72 hrs with 137 Cs gamma source on cylindrical exposure geometry. At medium dose of 1 Gy has been accumulated for each corm and cormel. For each variety we used 10 corms and 30 cormels in five variants. The comportment of various varieties was evaluated by recording the following characteristics: length of roots and growth tip. Significant effect was obtained at the variants which was irradiated with 1 Gy gamma radiation and 3 Gauss magnetic fields.

  4. Near-field thermal radiation transfer controlled by plasmons in graphene

    Science.gov (United States)

    Ilic, Ognjen; Jablan, Marinko; Joannopoulos, John D.; Celanovic, Ivan; Buljan, Hrvoje; Soljačić, Marin

    2012-04-01

    It is shown that thermally excited plasmon-polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange on doping and electron relaxation time is analyzed in the near infrared within the framework of fluctuational electrodynamics. The dominant contribution to heat transfer can be controlled to arise from either interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene sheets in resonance, with orders-of-magnitude enhancement (e.g., 102 to 103 for separations between 0.1 μm and 10 nm) over the Stefan-Boltzmann law, known as the far-field limit. Strong, tunable, near-field transfer offers the promise of an externally controllable thermal switch as well as a novel hybrid graphene-graphene thermoelectric/thermophotovoltaic energy conversion platform.

  5. Star Formation In the Galaxy and the Fluctuating UV Radiation Field

    Science.gov (United States)

    Hollenbach, David; Parravano, Antonio; McKee, Christopher H.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    We examine the formation of massive stars in the Galaxy, the resultant fluctuating UV (ultraviolet) radiation field, and the effect of this field on the star-forming interstellar medium. There are substantial fluctuations of the UV radiation field in space (scales of 100's of parsecs) and time (time-scales of order 100 million years). The FUV (far ultraviolet) (6 eV less than hv less than 13.6 eV) field and the pressure determines whether the thermal balance of the neutral gas results in cold clouds or warm (T approx. 10(exp 4) K) neutral medium. We show how to calculate the average fractions of the gas in the cold and warm phases when the interstellar gas is subject to this fluctuating FUV field. The knowledge of how these fractions depend on the gas properties and on the FUV sources is a basic step in building a model of the large scale behavior of the ISM (interstellar medium) and the mutual relation between the ISM and the star formation rate.

  6. THz near-field imaging of biological tissues employing synchrotron radiation

    International Nuclear Information System (INIS)

    Schade, Ulrich; Holldack, Karsten; Martin, Michael C.; Fried, Daniel

    2004-01-01

    Terahertz scanning near-field infrared microscopy (SNIM) below 1 THz is demonstrated. The near-field technique benefits from the broadband and highly brilliant coherent synchrotron radiation (CSR) from an electron storage ring and from a detection method based on locking onto the intrinsic time structure of the synchrotron radiation. The scanning microscope utilizes conical wave guides as near-field probes with apertures smaller than the wavelength. Different cone approaches have been investigated to obtain maximum transmittance. Together with a Martin-Puplett spectrometer the set-up enables spectroscopic mapping of the transmittance of samples well below the diffraction limit. Spatial resolution down to about lambda/40 at 2 wavenumbers (0.06 THz) is derived from the transmittance spectra of the near-field probes. The potential of the technique is exemplified by imaging biological samples. Strongly absorbing living leaves have been imaged in transmittance with a spatial resolution of 130 mu-m at about 12 wave numbers (0.36 THz). The THz near-field images reveal distinct structural differences of leaves from different plants investigated. The technique presented also allows spectral imaging of bulky organic tissues. Human teeth samples of various thicknesses have been imaged between 2 and 20 wavenumbers (between 0.06and 0.6 THz). Regions of enamel and dentin within tooth samples are spatially and spectrally resolved, and buried caries lesions are imaged through both the outer enamel and into the underlying dentin

  7. GLOBAL ELECTROMAGNETIC RADIATION POLLUTION: RISK ASSESSMENT FROM FIELD MEASUREMENTS AND ANIMAL EXPERIMENTS

    Science.gov (United States)

    Fragkopoulou, A. F.; Margaritis, L. H.

    2009-12-01

    The extended use of wireless technology throughout the globe in almost all developed and non-developed countries has forced a large number of scientists to get involved in the investigation of the effects. The major issue is that unlike other forms of radiation exposure, this “non-ionizing electromagnetic radiation” was not present throughout the evolution of life in earth and therefore there are no adaptive mechanisms evolved. All organisms are vulnerable to the possible effects of radiation depending on the actual exposure level. “Safety limits” on the power density have been proposed but ongoing research has shown that these limits are not really safe for humans, not mentioning the entire population of living creatures on earth. The so called “Electrosmog Pollution” originating from the numerous radio and TV stations, communication satellite emission, but most importantly from mobile phone mast antennas, are of major concern, because it is gradually increasing at exponential rate. Therefore the key question is, do living organisms react upon their exposure to fields of non ionizing electromagnetic radiation? To have this question answered extensive research is being performed in various laboratories. One approach of our research includes field measurements within houses and classrooms, since a considerable proportion of the population in each country is exposed to the radiation coming from the nearby mast stations, in order to make a risk assessment. The measurements showed that in many cases the actual radiation present was potentially harmful. In other words, although the measured values were below the national safety levels, nevertheless they were above the levels of other countries. Therefore it has been suggested that a new cellular network should be constructed in order to minimize radiation levels in living areas and schools. Our experimental work is focusing on the elucidation of the effects of non-ionizing EMFs on mice exposed to mobile

  8. Standards for Measurements in the Field of High Frequency Electromagnetic Radiation for the Purpose of Protection Against Adverse Health Effects

    International Nuclear Information System (INIS)

    Tanatarec, B.; Nikolic, N.

    2011-01-01

    In this paper standards for measurements in the field of high frequency electromagnetic radiation are described with a view to protection from its hazardous action. Beside the standards which directly deal with high frequency electromagnetic radiation measurements, guidelines which describe hazardous influences of high frequency electromagnetic radiation on human body in the form of specific absorption rate (SAR) are given. Special attention is dedicated to standards and regulations, which are dealing with social responsibility, as well as with social responsibility in the field of high frequency radiation. This area is new and insufficiently known, rarely extended in everyday life. (author)

  9. Perceived Incidence and Importance of Lay-Ideas on Ionizing Radiation: Results of a Delphi-Study among Radiation-Experts.

    Science.gov (United States)

    Eijkelhof, H. M. C.; And Others

    1990-01-01

    Described are lay-ideas which may exist about ionizing radiation, the importance of these ideas for risk management, and the relationships between various lay-ideas. Lay-ideas were used to gain a better insight into the problems of learning about ionizing radiation and to construct appropriate teaching materials and strategies. (KR)

  10. Investigating the electronic portal imaging device for small radiation field measurements

    Directory of Open Access Journals (Sweden)

    Arpita Agarwal

    2017-01-01

    Full Text Available Purpose: With the advent of state-of-the-art treatment technologies, the use of small fields has increased, and dosimetry in small fields is highly challenging. In this study, the potential use of Varian electronic portal imaging device (EPID for small field measurements was explored for 6 and 15 MV photon beams. Materials and Methods: The output factors and profiles were measured for a range of jaw-collimated square field sizes starting from 0.8 cm×0.8 cm to 10 cm×10 cm using EPID. For evaluation purpose, reference data were acquired using Exradin A16 microionization chamber (0.007 cc for output factors and stereotactic field diode for profile measurements in a radiation field analyzer. Results: The output factors of EPID were in agreement with the reference data for field sizes down to 2 cm×2 cm and for 2 cm×2 cm; the difference in output factors was +2.06% for 6 MV and +1.56% for 15 MV. For the lowest field size studied (0.8 cm×0.8 cm, the differences were maximum; +16% for 6 MV and +23% for 15 MV photon beam. EPID profiles of both energies were closely matching with reference profiles for field sizes down to 2 cm×2 cm; however, penumbra and measured field size of EPID profiles were slightly lower compared to its counterpart. Conclusions: EPID is a viable option for profile and output factor measurements for field sizes down to 2 cm×2 cm in the absence of appropriate small field dosimeters.

  11. Magnetic field generation in PMS stars with and without radiative core

    Science.gov (United States)

    Zaire, B.; Guerrero, G.; Kosovichev, A. G.; Smolarkiewicz, P. K.; Landin, N. R.

    2017-10-01

    Recent observations of the magnetic field in pre-main sequence stars suggest that the magnetic field topology changes as a function of age. The presence of a tachocline could be an important factor in the development of magnetic field with higher multipolar modes. In this work we performed MHD simulations using the EULAG-MHD code to study the magnetic field generation and evolution in models that mimic stars at two evolutionary stages. The stratification for both stellar phases was computed by fitting stellar structure profiles obtained with the ATON stellar evolution code. The first stage is at 1.1Myr, when the star is completely convective. The second stage is at 14Myrs, when the star is partly convective, with a radiative core developed up to 30% of the stellar radius. In this proceedings we present a preliminary analysis of the resulting mean-flows and magnetic field. The mean-flow analysis shown that the star rotate almost rigidly on the fully convective phase, whereas at the partially convective phase there is differential rotation with conical contours of iso-rotation. As for the mean magnetic field both simulations show similarities with respect to the field evolution. However, the topology of the magnetic field is different.

  12. Utilization technique of 'radiation management manual in medical field (2012).' What should be learnt from the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Kikuchi, Toru

    2014-01-01

    From the abstract of contents of the 'Radiation management manual in medical field (2012),' the utilization technique of the manual is introduced. Introduced items are as follows: (1) Exposure management; exposure management for radiation medical workers, patients, and citizens in the medical field, and exposure management for radiation workers and citizens involved in the emergency work related to the Fukushima nuclear accident, (2) Health management; health management for radiation medical workers, (3) Radiation education: Education/training for radiation medical workers, and radiation education for health care workers, (4) Accident and emergency measures; emergency actions involved in the radiation accidents and radiation medicine at medical facilities

  13. Near-Field Thermal Radiation for Solar Thermophotovoltaics and High Temperature Thermal Logic and Memory Applications

    Science.gov (United States)

    Elzouka, Mahmoud

    This dissertation investigates Near-Field Thermal Radiation (NFTR) applied to MEMS-based concentrated solar thermophotovoltaics (STPV) energy conversion and thermal memory and logics. NFTR is the exchange of thermal radiation energy at nano/microscale; when separation between the hot and cold objects is less than dominant radiation wavelength (˜1 mum). NFTR is particularly of interest to the above applications due to its high rate of energy transfer, exceeding the blackbody limit by orders of magnitude, and its strong dependence on separation gap size, surface nano/microstructure and material properties. Concentrated STPV system converts solar radiation to electricity using heat as an intermediary through a thermally coupled absorber/emitter, which causes STPV to have one of the highest solar-to-electricity conversion efficiency limits (85.4%). Modeling of a near-field concentrated STPV microsystem is carried out to investigate the use of STPV based solid-state energy conversion as high power density MEMS power generator. Numerical results for In 0.18Ga0.82Sb PV cell illuminated with tungsten emitter showed significant enhancement in energy transfer, resulting in output power densities as high as 60 W/cm2; 30 times higher than the equivalent far-field power density. On thermal computing, this dissertation demonstrates near-field heat transfer enabled high temperature NanoThermoMechanical memory and logics. Unlike electronics, NanoThermoMechanical memory and logic devices use heat instead of electricity to record and process data; hence they can operate in harsh environments where electronics typically fail. NanoThermoMechanical devices achieve memory and thermal rectification functions through the coupling of near-field thermal radiation and thermal expansion in microstructures, resulting in nonlinear heat transfer between two temperature terminals. Numerical modeling of a conceptual NanoThermoMechanical is carried out; results include the dynamic response under

  14. Characterization of an extrapolation chamber and radiochromic films for verifying the metrological coherence among beta radiation fields

    International Nuclear Information System (INIS)

    Castillo, Jhonny Antonio Benavente

    2011-01-01

    The metrological coherence among standard systems is a requirement for assuring the reliability of dosimetric quantities measurements in ionizing radiation field. Scientific and technologic improvements happened in beta radiation metrology with the installment of the new beta secondary standard BSS2 in Brazil and with the adoption of the internationally recommended beta reference radiations. The Dosimeter Calibration Laboratory of the Development Center for Nuclear Technology (LCD/CDTN), in Belo Horizonte, implemented the BSS2 and methodologies are investigated for characterizing the beta radiation fields by determining the field homogeneity, the accuracy and uncertainties in the absorbed dose in air measurements. In this work, a methodology to be used for verifying the metrological coherence among beta radiation fields in standard systems was investigated; an extrapolation chamber and radiochromic films were used and measurements were done in terms of absorbed dose in air. The reliability of both the extrapolation chamber and the radiochromic film was confirmed and their calibrations were done in the LCD/CDTN in 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields. The angular coefficients of the extrapolation curves were determined with the chamber; the field mapping and homogeneity were obtained from dose profiles and isodose with the radiochromic films. A preliminary comparison between the LCD/CDTN and the Instrument Calibration Laboratory of the Nuclear and Energy Research Institute / Sao Paulo (LCI/IPEN) was carried out. Results with the extrapolation chamber measurements showed in terms of absorbed dose in air rates showed differences between both laboratories up to de -I % e 3%, for 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields, respectively. Results with the EBT radiochromic films for 0.1, 0.3 and 0.15 Gy absorbed dose in air, for the same beta radiation fields, showed differences up to 3%, -9% and -53%. The beta radiation field mappings with

  15. Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

    International Nuclear Information System (INIS)

    Little, Mark P; Wakeford, Richard; Kendall, Gerald M

    2009-01-01

    The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

  16. Analysis of the Radiated Field in an Electromagnetic Reverberation Chamber as an Upset-Inducing Stimulus for Digital Systems

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2012-01-01

    Preliminary data analysis for a physical fault injection experiment of a digital system exposed to High Intensity Radiated Fields (HIRF) in an electromagnetic reverberation chamber suggests a direct causal relation between the time profile of the field strength amplitude in the chamber and the severity of observed effects at the outputs of the radiated system. This report presents an analysis of the field strength modulation induced by the movement of the field stirrers in the reverberation chamber. The analysis is framed as a characterization of the discrete features of the field strength waveform responsible for the faults experienced by a radiated digital system. The results presented here will serve as a basis to refine the approach for a detailed analysis of HIRF-induced upsets observed during the radiation experiment. This work offers a novel perspective into the use of an electromagnetic reverberation chamber to generate upset-inducing stimuli for the study of fault effects in digital systems.

  17. Calibration of photographic dosemeters to evaluate the personal equivalent dose, Hp (10), irradiated by different radiation qualities and angles of incidence; Calibracao de dosimetros fotograficos para avaliar o equivalente de dose pessoal, Hp(10), irradiados por diferentes qualidades de radiacao e angulos de incidencia

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Christiana; Antonio Filho, Joao, E-mail: chsantoro@gmail.com, E-mail: jaf@ufpe.br [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Santos, Marcus Aurelio P.; Goncalves Filho, Luiz Carlos, E-mail: masantos@cnen.gov.br, E-mail: l.filho@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, Pe (Brazil)

    2013-07-01

    To use radiation detectors, should periodically perform tests and calibrations on instruments in order to verify its good functionality. One way to ascertain the quality of the instrument is to conduct a study of the angular dependence of the response of the radiation detectors. The photographic dosimetry has been used widely to quantify the radiation doses and to estimate levels of doses received by workers involved with X-and gamma radiation. Photographic dosimeters are used because provide wide range of exposure and good accuracy. One of the sources of error have been introduced by different irradiation geometries between calibration and measurement in radiation fields used in x-ray and gamma ray sources, therefore, there is a need for an evaluation of the sensitivity of dosimeters with variation of the angle of the incident beam. In this study were tested 190 photographic dosemeters in the Metrology Laboratory of the Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) using the phantom H{sub p} (10), where the dosimeters are evaluated on the basis of the new operational magnitude for individual monitoring, the equivalent personal dose, H{sub p} (10). Angular dependence of these radiation detectors was studied in X radiation fields (in the range of 45 keV energy to 164 keV) and gamma radiation ({sup 137}Cs-662 keV e {sup 60}Co - 1250 keV)

  18. Role of the UV external radiation field on the presence of astrophysical ices in protostellars environments

    Science.gov (United States)

    Robson Monteiro Rocha, Will; Pilling, Sergio

    2016-07-01

    The astrophysical ices survival is directly related with the temperature and ionizing radiation field in protostellars environments such as disks and envelopes. Computational models has shown that pure volatile molecules like CO and CH _{4} should survive only inside densest regions of molecular clouds or protoplanetary disks On the other hand, solid molecules such as H _{2}O and CH _{3}OH can be placed around 5 - 10 AU from the central protostar. Unlike of the previous models, we investigate the role of the UV external radiation field on the presence of ices in disks and envelopes. Once that a star-forming region is composed by the formation of many protostars, the external radiation field should be an important component to understand the real localization of the ices along the sight line. To address this topic it was employed the radiative transfer code RADMC-3D based on the Monte Carlo method. The code was used to model the spectrum and the near-infrared image of Elias 29. The initial parameters of the disk and envelope was taken from our previous paper (Rocha & Pilling (2015), ApJ 803:18). The opacities of the ices were calculated from the complex refractive index obtained at laboratory experiments perfomed at Grand Accélerateur National d'Íons Lourds (GANIL), by using the NKABS code from Rocha & Pilling (2014), SAA 123:436. The partial conclusions that we have obtained shows that pure CO volatile molecule cannot be placed at disk or envelope of Elias 29, unlike shown in our paper about Elias 29. Once it was observed in Elias 29 spectrum obtained with Infrared Space Observatory (ISO) between 2.5 - 190 μm, this molecule should be placed in foreground molecular clouds or trapped in the water ice matrix. The next calculations will be able to show where are placed the ices such as CH _{3}OH and CH _{3}CHO observed in Elias 29 spectrum.

  19. Radiation tolerance of the cervical spinal cord: incidence and dose-volume relationship of symptomatic and asymptomatic late effects following high dose irradiation of paraspinal tumors

    International Nuclear Information System (INIS)

    Liu, Mitchell C.C.; Munzenrider, John E.; Finkelstein, Dianne; Liebsch, Norbert; Adams, Judy; Hug, Eugen B.

    1997-01-01

    Purpose: Low grade chordomas and chondrosarcomas require high radiation doses for effective, lasting tumor control. Fractionated, 3-D planned, conformal proton radiation therapy has been used for lesions along the base of skull and spine to deliver high target doses, while respecting constraints of critical, normal tissues. In this study, we sought to determine the incidence of myelopathy after high dose radiotherapy to the cervical spine and investigated the influence of various treatment parameters, including dose-volume relationship. Methods and Materials: Between December 1980 and March 1996, 78 patients were treated at the Massachusetts General Hospital and Harvard Cyclotron Laboratory for primary or recurrent chordomas and chondrosarcomas of the cervical spine using combined proton and photon radiation therapy. In general, the tumor dose given was between 64.5 to 79.2 CGE (Cobalt Gray Equivalent). The guidelines for maximum permissible doses to spinal cord were: ≤ 64 CGE to the spinal cord surface and ≤ 53 CGE to the spinal cord center. Dose volume histograms of the spinal cord were analyzed to investigate a possible dose and volume relationship. Results: With a mean follow-up period of 46.6 months (range: 3 - 157 months), 4 of 78 patients (5.1%) developed high-grade (RTOG Grade 3 and 4) late toxicity: 3 patients (3.8%) experienced sensory deficits without motor deficits, none had any limitations of daily activities. One patient (1.2%) developed motor deficit with loss of motor function of one upper extremity. The only patient, who developed permanent motor damage had received additional prior radiation treatment and therefore received a cumulative spinal cord dose higher than the treatment guidelines. No patient treated within the guidelines experienced any motor impairment. Six patients (7.7%) experienced transient Lhermitt's syndrome and 1 patient (1.2%) developed asymptomatic radiographic MR findings only. Time to onset of symptoms of radiographic

  20. Fractionated Wide-Field Radiation Therapy Followed by Fractionated Local-Field Irradiation for Treating Widespread Painful Bone Metastasis

    International Nuclear Information System (INIS)

    Ki, Yongkan; Kim, Wontaek; Nam, Jiho; Kim, Donghyun; Jeon, Hosang; Park, Dahl; Kim, Dongwon

    2011-01-01

    Purpose: Wide-field radiation therapy (WFRT) is an effective treatment for widespread bone metastasis. We evaluated local-field irradiation (LFI) after fractionated WFRT (f-WFRT) for treating the patients with multiple painful bone lesions. Methods and Materials: From 1998 to 2007, 32 patients with multiple bone metastases were treated with fractionated LFI (f-LFI) after f-WFRT. All patients initially received 15 Gy in 5 fractions to a wide field, followed by LFI (9-15 Gy in 3 Gy fractions). Response was assessed by evaluating the degree of pain relief using a visual analog scale before radiotherapy, after f-WFRT, and after f-LFI. Results: Fractionated LFI following f-WFRT yielded an overall relief rate of 93.8% and a complete relief rate of 43.8%. The rate of the appearance of new disease was 6.3% for the patients with complete relief, 20.5% for the patients with a partial relief, and 50% for the patients with no relief. Conclusion: Fractionated LFI after f-WFRT is a well-tolerated and effective treatment for multiple metastatic bone disease.