WorldWideScience

Sample records for radiation transport progress

  1. Radiation transport: Progress report, July 1, 1987-September 30, 1987

    International Nuclear Information System (INIS)

    O'Dell, R.D.; Nagy, A.

    1988-05-01

    Research and development progress in radiation transport for the Los Alamos National Laboratory's Group S-6 for the fourth quarter of FY 87 is reported. Included are unclassified tasks in the areas of Deterministic Radiation Transport, Monte Carlo Radiation Transport, and Cross Sections and Physics. 23 refs., 9 figs

  2. Radiation transport. Progress report, April 1-December 31, 1983

    International Nuclear Information System (INIS)

    O'Dell, R.D.

    1984-10-01

    Research and development progress in radiation transport by the Los Alamos National Laboratory's Group X-6 for the last nine months of CY 83 is reported. Included are unclassified tasks in the areas of Fission Reactor Neutronics, Deterministic Transport Methods, Monte Carlo Radiation Transport, and Cross Sections and Physics

  3. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  4. Radiation effects on transport and bubble formation in silicate glasses. 1998 annual progress report

    International Nuclear Information System (INIS)

    Trifunac, A.D.

    1998-01-01

    'To study the fundamental chemistry of radiation damage in silicate/borosilicate glasses and simulated high-level nuclear waste (HLW) forms. Special emphasis is on delineating molecular processes crucial for understanding the aggregation of defects and formation of oxygen bubbles. The knowledge obtained will provide the needed scientific basis for extrapolating long-term behavior of stored radiative waste glass forms. This report summarizes the first 6 months of a 3-year project. The following issues have been addressed: (i) the production of radiolytic oxygen, (ii) the chemistry of hydrogenous species, and (iii) the effect of glass composition and microstructure on the formation and accumulation of metastable point defects.'

  5. Introduction to radiation transport

    International Nuclear Information System (INIS)

    Olson, G.L.

    1998-01-01

    This lecture will present time-dependent radiation transport where the radiation is coupled to a static medium, i.e., the material is not in motion. In reality, radiation exerts a pressure on the materials it propagates through and will accelerate the material in the direction of the radiation flow. This fully coupled problem with radiation transport and materials in motion is referred to as radiation-hydrodynamics (or in a shorthand notation: rad-hydro) and is beyond the scope of this lecture

  6. Progress in radiation biology

    International Nuclear Information System (INIS)

    Masuda, Koji; Zingu, Kenichi; Matsuura, Keiichi; Aramaki, Ryoji; Yoshinaga, Haruma

    1980-01-01

    Possible mechanism of differences in radiosensitivity of malignant tumors in vivo was reviewed. The magnitude of repair of potentially lethal damage after X- or gamma-ray was relatively large for melanoma, osteosarcoma and glioblastoma multiform cultured in vitro. The proportion of hypoxic cells in malignant melanoma was relatively high and the Dq value of the dose response curves was relatively large, implying that these two factors also play important role for making malignant melanoma radioresistant. Recurrent tumor cells in vitro has relatively high amount of non-protein SH, which can protect cells from radiation. Except for these limited data, no experimental results has been reported which can explain the radiobiological mechanism of each radioresistant tumor. It was stressed that assessment of the radiobiological mechanism of the relatively radioresistant malignant tumors in vivo and new treatment protocol based on this assessment will improve the local control rate of malignant tumors in vivo as well as doing best in treating relatively radiosensitive tumors. (author)

  7. Radiation transport in MEDUSA

    International Nuclear Information System (INIS)

    Rose, S.J.; Evans, R.G.

    1983-09-01

    The transport of energy by X-ray photons has been included in the lD Lagrangian hydrodynamics code, MEDUSA. Calculations of the implosion by 0.53 μm laser irradiation of plastic and glass microballoons of current interest at the Central Laser Facility show that radiation preheats the fill gas and alters the temperature and density profiles during the implosion. A lower maximum gas temperature is obtained and this results, for a DT gas fill, in a greatly reduced neutron yield. (author)

  8. Deterministic methods in radiation transport

    International Nuclear Information System (INIS)

    Rice, A.F.; Roussin, R.W.

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community

  9. Transport of radioactivity and radiation

    International Nuclear Information System (INIS)

    De Beer, G.P.

    1988-01-01

    The movement of radioactivity and radiation is of prime importance in a wide variety of fields and the present advanced degree of knowledge of transport mechanisms is due largely to the application of sophisticated computer techniques

  10. Forms of Approximate Radiation Transport

    CERN Document Server

    Brunner, G

    2002-01-01

    Photon radiation transport is described by the Boltzmann equation. Because this equation is difficult to solve, many different approximate forms have been implemented in computer codes. Several of the most common approximations are reviewed, and test problems illustrate the characteristics of each of the approximations. This document is designed as a tutorial so that code users can make an educated choice about which form of approximate radiation transport to use for their particular simulation.

  11. Radiation transport in numerical astrophysics

    International Nuclear Information System (INIS)

    Lund, C.M.

    1983-02-01

    In this article, we discuss some of the numerical techniques developed by Jim Wilson and co-workers for the calculation of time-dependent radiation flow. Difference equations for multifrequency transport are given for both a discrete-angle representation of radiation transport and a Fick's law-like representation. These methods have the important property that they correctly describe both the streaming and diffusion limits of transport theory in problems where the mean free path divided by characteristic distances varies from much less than one to much greater than one. They are also stable for timesteps comparable to the changes in physical variables, rather than being limited by stability requirements

  12. Radiation protection programme progress report 1988

    International Nuclear Information System (INIS)

    1988-01-01

    The progress report of the radiation protection programme outlines the research work carried out in 1988 under contracts between the Commission of the European Communities and research groups in the Member States. Results of more than 350 projects are reported. They are grouped into six sectors: Radiation dosimetry and its interpretation; Behaviour and control of radionuclides in the environment; Nonstochastic effects of ionizing radiation; Radiation carcinogenesis; Genetic effects of ionizing radiation; Evaluation of radiation risks and optimization of protection. Within the framework programme, the aim of this scientific research is to improve the conditions of life with respect to work and protection of man and his environment and to assure a safe production of energy, i.e.: (i) to improve methods necessary to protect workers and the population by updating the scientific basis for appropriate standards; (ii) to prevent and counteract harmful effects of radiation; (iii) to assess radiation risks and provide methods to cope with the consequences of radiation accidents

  13. Progress in Medical Radiation Physics

    International Nuclear Information System (INIS)

    Orton, C.G.

    1982-01-01

    In-depth reviews of the advances and concepts in the application of radiation to medicine are presented in six comprehensive review articles which help to bridge the communications gap between the international research community and the medical physicists and physicians whose responsibility it is to put these advances into clinical use. Topics include techniques used both for the diagnosis of disease, such as computerized tomography, digital radiography, ultrasonography, computerized nuclear medicine scanning, and nuclear magnetic resonance imaging, and for its treatment, such as the radiotherapeutic utilization of high-LET radiations, and the widespread application of computers to perform dosimetry calculations from 3-D treatment planning and imaging. Each chapter has extensive references and the collection is indexed

  14. Radiative Cooling: Principles, Progress, and Potentials

    Science.gov (United States)

    Hossain, Md. Muntasir

    2016-01-01

    The recent progress on radiative cooling reveals its potential for applications in highly efficient passive cooling. This approach utilizes the maximized emission of infrared thermal radiation through the atmospheric window for releasing heat and minimized absorption of incoming atmospheric radiation. These simultaneous processes can lead to a device temperature substantially below the ambient temperature. Although the application of radiative cooling for nighttime cooling was demonstrated a few decades ago, significant cooling under direct sunlight has been achieved only recently, indicating its potential as a practical passive cooler during the day. In this article, the basic principles of radiative cooling and its performance characteristics for nonradiative contributions, solar radiation, and atmospheric conditions are discussed. The recent advancements over the traditional approaches and their material and structural characteristics are outlined. The key characteristics of the thermal radiators and solar reflectors of the current state‐of‐the‐art radiative coolers are evaluated and their benchmarks are remarked for the peak cooling ability. The scopes for further improvements on radiative cooling efficiency for optimized device characteristics are also theoretically estimated. PMID:27812478

  15. Progress in understanding heat transport at JET

    International Nuclear Information System (INIS)

    Mantica, P.; Garbet, X.; Angioni, C.

    2005-01-01

    This paper reports recent progress in understanding heat transport mechanisms either in conventional or advanced tokamak scenarios in JET. A key experimental tool has been the use of perturbative transport techniques, both by ICH power modulation and by edge cold pulses. The availability of such results has allowed careful comparison with theoretical modelling using 1D empirical or physics based transport models, 3D fluid turbulence simulations or gyrokinetic stability analysis. In conventional L- and H-mode plasmas the issue of temperature profile stiffness has been addressed. JET results are consistent with the concept of a critical inverse temperature gradient length above which transport is enhanced by the onset of turbulence. A threshold value R/L Te ∼5 has been found for the onset of stiff electron transport, while the level of electron stiffness appears to vary strongly with plasma parameters, in particular with the ratio of electron and ion heating: electrons become stiffer when ions are strongly heated, resulting in larger R/L Ti values. This behaviour has also been found theoretically, although quantitatively weaker than in experiments. In plasmas characterized by Internal Transport Barriers (ITB), the properties of heat transport inside the ITB layer and the ITB formation mechanisms have been investigated. The plasma current profile is found to play a major role in ITB formation. The effect of negative magnetic shear on electron and ion stabilization is demonstrated both experimentally and theoretically using turbulence codes. The role of rational magnetic surfaces in ITB triggering is well assessed experimentally, but still lacks a convincing theoretical explanation. Attempts to trigger an ITB by externally induced magnetic reconnection using saddle coils have shown that MHD islands in general do not produce a sufficient variation of ExB flow shear to lead to ITB formation. First results of perturbative transport in ITBs show that the ITB is a narrow

  16. Transport and attenuation of radiations

    CERN Document Server

    Nimal, J C

    2003-01-01

    This article treats of the calculation methods used for the dimensioning of the protections against radiations. The method consists in determining for a given point the flux of particles coming from a source at a given time. A strong attenuation (of about some few mu Sv.h sup - sup 1) is in general expected between the source and the areas accessible to the personnel or the public. The calculation has to take into account a huge number of radiation-matter interactions and to solve the integral-differential transport equation which links the particles flux to the source. Several methods exist from the simplified physical model with numerical developments to the more or less precise resolution of the transport equation. These methods allows also the calculation of the uncertainties of equivalent dose rates, heat sources, structure damages using the data covariances (efficient cross-sections, modeling, etc..): 1 - transport equation; 2 - Monte-Carlo method; 3 - semi-numerical methods S sub N; 4 - methods based o...

  17. Ionizing radiation in tumor promotion and progression

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    1990-08-01

    Chronic exposure to beta radiation has been tested as a tumor promoting or progressing agent. The dorsal skins of groups of 25 female SENCAR mice were chemically initiated with a single exposure to DMBA, and chronic exposure to strontium-90/yttrium-90 beta radiation was tested as a stage 1, stage 2 or complete skin tumor promoter. Exposure of initiated mice to 0.5 gray twice a week for 13 weeks produced no papillomas, indicating no action as a complete promoter. Another similar group of animals was chemically promoted through stage 1 (with TPA) followed by 0.5 gray of beta radiation twice a week for 13 weeks. Again no papillomas developed indicating no action of chronic radiation as a stage 2 tumor promoter. The same radiation exposure protocol in another DMBA initiated group receiving both stage 1 and 2 chemical promotion resulted in a decrease in papilloma frequency, compared to the control group receiving no beta irradiation, indicating a tumor preventing effect of radiation at stage 2 promotion, probably by killing initiated cells. Chronic beta radiation was tested three different ways as a stage 1 tumor promoter. When compared to the appropriate control, beta radiation given after initiation as a stage 1 promoter (0.5 gray twice a week for 13 weeks), after initiation and along with a known stage 1 chemical promoter (1.0 gray twice a week for 2 weeks), or prior to initiation as a stage 1 promoter (0.5 gray twice a week for 4 weeks), each time showed a weak (∼ 15% stimulation) but statistically significant (p<0.01) ability to act as a stage 1 promoter. When tested as a tumor progressing agent delivered to pre-existing papillomas, beta radiation (0.5 gray twice a week for 13 weeks) increased carcinoma frequency from 0.52 to 0.68 carcinoma/animal, but this increase was not statistically significant at the 95% confidence level. We conclude that in the addition to the known initiating, progressing and complete carcinogenic action of acute exposures to ionizing

  18. A review of progress towards radiative divertor

    International Nuclear Information System (INIS)

    Zagorski, Roman

    1997-07-01

    A solution of the problem of the power and particle exhaust from the next step tokamaks, will require new techniques which redistribute the power entering the SOL onto much larger surface area than conventional divertor design permits, while maintaining good impurity retention in divertor volume and allowing for efficient helium pumping. Progress made in developing such techniques is discussed. Status of the modelling studies of dynamic gas target divertor and impurity seeded radiating divertors is presented. Recent results of experiments on radiative and gas target divertors are reviewed

  19. Directions in Radiation Transport Modelling

    Directory of Open Access Journals (Sweden)

    P Nicholas Smith

    2016-12-01

    More exciting advances are on the horizon to increase the power of simulation tools. The advent of high performance computers is allowing bigger, higher fidelity models to be created, if the challenges of parallelization and memory management can be met. 3D whole core transport modelling is becoming possible. Uncertainty quantification is improving with large benefits to be gained from more accurate, less pessimistic estimates of uncertainty. Advanced graphical displays allow the user to assimilate and make sense of the vast amounts of data produced by modern modelling tools. Numerical solvers are being developed that use goal-based adaptivity to adjust the nodalisation of the system to provide the optimum scheme to achieve the user requested accuracy on the results, thus removing the need to perform costly convergence studies in space and angle etc. More use is being made of multi-physics methods in which radiation transport is coupled with other phenomena, such as thermal-hydraulics, structural response, fuel performance and/or chemistry in order to better understand their interplay in reactor cores.

  20. Parallel processing Monte Carlo radiation transport codes

    International Nuclear Information System (INIS)

    McKinney, G.W.

    1994-01-01

    Issues related to distributed-memory multiprocessing as applied to Monte Carlo radiation transport are discussed. Measurements of communication overhead are presented for the radiation transport code MCNP which employs the communication software package PVM, and average efficiency curves are provided for a homogeneous virtual machine

  1. Progress in reassessment of atomic bomb radiation dosimetry

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1985-01-01

    Studies for reassessment of A-bomb radiation dosimetry in Hiroshima and Nagasaki are underway in both Japan and the US. The progress made in various reassessment studies has been reported at several US-Japan joint workshops. The medical follow-up studies by the RERF provide data on dose-related parameters such as the location of the survivors and their shielding by surrounding structures at the times of the bombings. To make accurate estimates of the radiation dose for individual survivors in the two cities, they need reliable information concerning (a) the hypocenters and burst heights of the bombs, (b) the energy yields of the bombs and the source terms for the initial radiations from the bombs, (c) the atmospheric radiation transport to determine the initial radiation fields at the location of the survivors, (d) the attenuation factors for shielding afforded by structures and terrain, and (e) the shielding of specific organs by overlying tissues of the body. A computer code combining the above elements has been installed at the RERF and used in a preliminary reassessment of radiation doses to survivors who were indoors, shielded by houses at the times of the bombings. These results will be presented and discussed. The discussions will be focused, however, on specific areas where binational agreement has been reached and on specific areas where additional work is needed before the reassessment can be considered final

  2. Coupled electron-photon radiation transport

    International Nuclear Information System (INIS)

    Lorence, L.; Kensek, R.P.; Valdez, G.D.; Drumm, C.R.; Fan, W.C.; Powell, J.L.

    2000-01-01

    Massively-parallel computers allow detailed 3D radiation transport simulations to be performed to analyze the response of complex systems to radiation. This has been recently been demonstrated with the coupled electron-photon Monte Carlo code, ITS. To enable such calculations, the combinatorial geometry capability of ITS was improved. For greater geometrical flexibility, a version of ITS is under development that can track particles in CAD geometries. Deterministic radiation transport codes that utilize an unstructured spatial mesh are also being devised. For electron transport, the authors are investigating second-order forms of the transport equations which, when discretized, yield symmetric positive definite matrices. A novel parallelization strategy, simultaneously solving for spatial and angular unknowns, has been applied to the even- and odd-parity forms of the transport equation on a 2D unstructured spatial mesh. Another second-order form, the self-adjoint angular flux transport equation, also shows promise for electron transport

  3. Recent developments in the Los Alamos radiation transport code system

    International Nuclear Information System (INIS)

    Forster, R.A.; Parsons, K.

    1997-01-01

    A brief progress report on updates to the Los Alamos Radiation Transport Code System (LARTCS) for solving criticality and fixed-source problems is provided. LARTCS integrates the Diffusion Accelerated Neutral Transport (DANT) discrete ordinates codes with the Monte Carlo N-Particle (MCNP) code. The LARCTS code is being developed with a graphical user interface for problem setup and analysis. Progress in the DANT system for criticality applications include a two-dimensional module which can be linked to a mesh-generation code and a faster iteration scheme. Updates to MCNP Version 4A allow statistical checks of calculated Monte Carlo results

  4. Survey of radiation protection programmes for transport

    International Nuclear Information System (INIS)

    Lizot, M.T.; Perrin, M.L.; Sert, G.; Lange, F.; Schwarz, G.; Feet, H.J.; Christ, R.; Shaw, K.B.; Hughes, J.S.; Gelder, R.

    2001-07-01

    The survey of radiation protection programmes for transport has been jointly performed by three scientific organisations I.P.S.N. (France), G.R.S. ( Germany), and N.R.P.B. (United kingdom) on behalf of the European Commission and the pertaining documentation summarises the findings and conclusions of the work that was undertaken with the principal objectives to provide guidance on the establishment, implementation and application of radiation protection programmes for the transport of radioactive materials by operators and the assessment and evaluation of such programmes by the competent authority and to review currently existing radiation protection programmes for the transport of radioactive materials. (N.C.)

  5. Particulate behavior in a controlled-profile pulverized coal-fired reactor: A study of coupled turbulent particle dispersion and thermal radiation transport. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, M.; Webb, B.W.

    1996-06-01

    To aid in the evaluation and development of advanced coal-combustion models, comprehensive experimental data sets are needed containing information on both the condensed and gas phases. To address this need a series of test were initiated on a 300 kW laboratory-scale, coal-fired reactor at a single test condition using several types of instrumentation. Data collected on the reactor during the course of the test includes: gas, particle, and wall temperature profiles; radiant, total, and convective heat fluxes to the walls; particle size and velocity profiles; transmission measurements; and gas species concentrations. Solid sampling was also performed to determine carbon and total burnout. Along with the extensive experimental measurements, the particle dispersion and radiation submodels in the ACERC comprehensive 2D code were studied in detail and compared to past experimental measurements taken in the CPR. In addition to the presentation and discussion of the experimental data set, a detailed description of the measurement techniques used in collecting the data, including a discussion of the error associated with each type of measurement, is given.

  6. A multigroup treatment of radiation transport

    International Nuclear Information System (INIS)

    Tahir, N.A.; Laing, E.W.; Nicholas, D.J.

    1980-12-01

    A multi-group radiation package is outlined which will accurately handle radiation transfer problems in laser-produced plasmas. Bremsstrahlung, recombination and line radiation are included as well as fast electron Bremsstrahlung radiation. The entire radiation field is divided into a large number of groups (typically 20), which diffuse radiation energy in real space as well as in energy space, the latter occurring via electron-radiation interaction. Using this model a radiation transport code will be developed to be incorporated into MEDUSA. This modified version of MEDUSA will be used to study radiative preheat effects in laser-compression experiments at the Central Laser Facility, Rutherford Laboratory. The model is also relevant to heavy ion fusion studies. (author)

  7. Two children with chronic progressive radiation myelopathy

    International Nuclear Information System (INIS)

    Ohta, Hideaki; Takai, Kenji; Hosoi, Gaku; Okamura, Takayuki; Osugi, Yuko; Ishihara, Shigehiko; Hara, Junichi; Tawa, Akio; Okada, Shintaro

    1995-01-01

    We report two patients who developed chronic progressive radiation myelopathy (CPRM). Patient 1 was a 16-year-old boy with group IV rhabdomyosarcoma of cervical soft tissue. He underwent partial excision of the tumor and received systemic and intrathecal chemotherapy and 44 Gy of local radiotherapy (C4 through Th3). These therapies were followed by high-dose chemotherapy including thio-TEPA and busulfan with autologous bone marrow rescue. One year after the completion of the therapies, he developed CPRM. Patient 2 was a 15-year-old girl with acute lymphoblastic leukemia on the 3rd complete remission. She received 18 Gy of irradiation to whole brain during the 1st remission and another 18 Gy to whole brain and 9 Gy to spinal cord after her 1st CNS relapse. After successful reinduction therapy for the 2nd relapse in CNS and bone marrow, she underwent an allogeneic bone marrow transplantation (BMT). The preconditioning regimen consisted of 12 Gy total body irradiation, thio-TEPA and cyclophosphamide. Seven months after BMT, she developed CPRM at C0-C1 level, which was included in the area of whole-brain irradiation. In both patients, MR images showed a swelling of the cervical cord and ring-like images by gadolinium enhancement. Their neurological disability transiently responded to the administration of corticosteroid, but they developed progressive quadriplegia. Although it is reported that a dose of 45-50 Gy may be safe, these cases suggest that administration of high-dose chemotherapy combined with intrathecal chemotherapy and radiotherapy to the cord might increase the rink of developing CPRM. (author)

  8. Two children with chronic progressive radiation myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Hideaki; Takai, Kenji; Hosoi, Gaku; Okamura, Takayuki; Osugi, Yuko; Ishihara, Shigehiko; Hara, Junichi; Tawa, Akio; Okada, Shintaro [Osaka Univ. (Japan). Faculty of Medicine

    1995-06-01

    We report two patients who developed chronic progressive radiation myelopathy (CPRM). Patient 1 was a 16-year-old boy with group IV rhabdomyosarcoma of cervical soft tissue. He underwent partial excision of the tumor and received systemic and intrathecal chemotherapy and 44 Gy of local radiotherapy (C4 through Th3). These therapies were followed by high-dose chemotherapy including thio-TEPA and busulfan with autologous bone marrow rescue. One year after the completion of the therapies, he developed CPRM. Patient 2 was a 15-year-old girl with acute lymphoblastic leukemia on the 3rd complete remission. She received 18 Gy of irradiation to whole brain during the 1st remission and another 18 Gy to whole brain and 9 Gy to spinal cord after her 1st CNS relapse. After successful reinduction therapy for the 2nd relapse in CNS and bone marrow, she underwent an allogeneic bone marrow transplantation (BMT). The preconditioning regimen consisted of 12 Gy total body irradiation, thio-TEPA and cyclophosphamide. Seven months after BMT, she developed CPRM at C0-C1 level, which was included in the area of whole-brain irradiation. In both patients, MR images showed a swelling of the cervical cord and ring-like images by gadolinium enhancement. Their neurological disability transiently responded to the administration of corticosteroid, but they developed progressive quadriplegia. Although it is reported that a dose of 45-50 Gy may be safe, these cases suggest that administration of high-dose chemotherapy combined with intrathecal chemotherapy and radiotherapy to the cord might increase the rink of developing CPRM. (author).

  9. Studies of radiation and chemical toxicity. Progress report

    International Nuclear Information System (INIS)

    1986-01-01

    Annual report for the Studies of Radiation and Chemical Toxicity Program at the University of Rochester is presented. Progress is reported on four projects: Neurobehavorial Toxicity of Organometallic Fuel Additives, Mechanisms of Permanent and Delayed Pathologic Effects of Ionizing Radiation, Solid State Radiation Chemistry of the DNA Backbone, and Pulmonary Biochemistry

  10. The treatment progress of radiation dermatitis from external exposure

    International Nuclear Information System (INIS)

    Pu Wangyang; Liu Yulong

    2009-01-01

    Radiation dermatitis is often seen and is often a complication of radiation therapy of tumors. It is characterized by poor healing, stubborn relapse, and carcinogenesis.. The treatment include drug, physical therapy and surgery. This article describes the treatment progress of radiation dermatitis from external exposure. (authors)

  11. Parallel thermal radiation transport in two dimensions

    International Nuclear Information System (INIS)

    Smedley-Stevenson, R.P.; Ball, S.R.

    2003-01-01

    This paper describes the distributed memory parallel implementation of a deterministic thermal radiation transport algorithm in a 2-dimensional ALE hydrodynamics code. The parallel algorithm consists of a variety of components which are combined in order to produce a state of the art computational capability, capable of solving large thermal radiation transport problems using Blue-Oak, the 3 Tera-Flop MPP (massive parallel processors) computing facility at AWE (United Kingdom). Particular aspects of the parallel algorithm are described together with examples of the performance on some challenging applications. (author)

  12. Parallel thermal radiation transport in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Smedley-Stevenson, R.P.; Ball, S.R. [AWE Aldermaston (United Kingdom)

    2003-07-01

    This paper describes the distributed memory parallel implementation of a deterministic thermal radiation transport algorithm in a 2-dimensional ALE hydrodynamics code. The parallel algorithm consists of a variety of components which are combined in order to produce a state of the art computational capability, capable of solving large thermal radiation transport problems using Blue-Oak, the 3 Tera-Flop MPP (massive parallel processors) computing facility at AWE (United Kingdom). Particular aspects of the parallel algorithm are described together with examples of the performance on some challenging applications. (author)

  13. Progress in multidimensional neutron transport computation

    International Nuclear Information System (INIS)

    Lewis, E.E.

    1977-01-01

    The methods available for solution of the time-independent neutron transport problems arising in the analysis of nuclear systems are examined. The merits of deterministic and Monte Carlo methods are briefly compared. The capabilities of deterministic computational methods derived from the first-order form of the transport equation, from the second-order even-parity form of this equation, and from integral transport formulations are discussed in some detail. Emphasis is placed on the approaches for dealing with the related problems of computer memory requirements, computational cost, and achievable accuracy. Attention is directed to some areas where problems exist currently and where the need for further work appears to be particularly warranted

  14. Research progress on space radiation biology

    International Nuclear Information System (INIS)

    Li Wenjian; Dang Bingrong; Wang Zhuanzi; Wei Wei; Jing Xigang; Wang Biqian; Zhang Bintuan

    2010-01-01

    Space radiation, particularly induced by the high-energy charged particles, may cause serious injury on living organisms. So it is one critical restriction factor in Manned Spaceflight. Studies have shown that the biological effects of charged particles were associated with their quality, the dose and the different biological end points. In addition, the microgravity conditions may affect the biological effects of space radiation. In this paper we give a review on the biological damage effects of space radiation and the combined biological effects of the space radiation coupled with the microgravity from the results of space flight and ground simulation experiments. (authors)

  15. Trade and transport of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    The guide specifies the obligations pertaining to the trade in and transport of radiation sources and other matters to be taken into account in safety supervision. It also specifies obligations and procedures relating to transfrontier movements of radioactive waste contained in the EU Council Directive 92/3/Euratom. (7 refs.)

  16. LDRD Final Review: Radiation Transport Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Goorley, John Timothy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morgan, George Lake [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lestone, John Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-22

    Both high-fidelity & toy simulations are being used to understand measured signals and improve the Area 11 NDSE diagnostic. We continue to gain more and more confidence in the ability for MCNP to simulate neutron and photon transport from source to radiation detector.

  17. Photonuclear Physics in Radiation Transport - II: Implementation

    International Nuclear Information System (INIS)

    White, M.C.; Little, R.C.; Chadwick, M.B.; Young, P.G.; MacFarlane, R.E.

    2003-01-01

    This is the second of two companion papers. The first paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W, and Pb for incident photon energies up to 150 MeV. This paper describes the steps taken to process these files into transport libraries and to update the Monte Carlo N-Particle (MCNP) and MCNPX radiation transport codes to use tabular photonuclear reaction data. The evaluated photonuclear data files are created in the standard evaluated nuclear data file (ENDF) format. These files must be processed by the NJOY data processing system into A Compact ENDF (ACE) files suitable for radiation transport calculations. MCNP and MCNPX have been modified to use these new data in a self-consistent and fully integrated manner. Verification problems were used at each step along the path to check the integrity of the methodology. The resulting methodology and tools provide a comprehensive system for using photonuclear data in radiation transport calculations. Also described are initial validation simulations used to benchmark several of the photonuclear transport tables

  18. Progress in radiation processing of polymers

    Science.gov (United States)

    Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

    2005-07-01

    Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R&D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

  19. Progress in radiation processing of polymers

    International Nuclear Information System (INIS)

    Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

    2005-01-01

    Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described

  20. Progress in radiation processing of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chmielewski, Andrzej G. [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria) and Department of Process and Chemical Engineering, Warsaw University of Technology, Warsaw (Poland)]. E-mail: a-g.chmielewski@iaea.org; Haji-Saeid, Mohammad [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria); Ahmed, Shamshad [Applied Chemistry Laboratories, Pakistan Institute of Nuclear Science and Technology, P.O. Box Nilore, Islamabad (Pakistan)

    2005-07-01

    Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

  1. Radiation Belt Transport Driven by Solar Wind Dynamic Pressure Fluctuations

    Science.gov (United States)

    Kress, B. T.; Hudson, M. K.; Ukhorskiy, A. Y.; Mueller, H.

    2012-12-01

    The creation of the Earth's outer zone radiation belts is attributed to earthward transport and adiabatic acceleration of electrons by drift-resonant interactions with electromagnetic fluctuations in the magnetosphere. Three types of radial transport driven by solar wind dynamic pressure fluctuations that have been identified are: (1) radial diffusion [Falthammer, 1965], (2) significant changes in the phase space density radial profile due to a single or few ULF drift-resonant interactions [Ukhorskiy et al., 2006; Degeling et al., 2008], and (3) shock associated injections of radiation belt electrons occurring in less than a drift period [Li et al., 1993]. A progress report will be given on work to fully characterize different forms of radial transport and their effect on the Earth's radiation belts. The work is being carried out by computing test-particle trajectories in electric and magnetic fields from a simple analytic ULF field model and from global MHD simulations of the magnetosphere. Degeling, A. W., L. G. Ozeke, R. Rankin, I. R. Mann, and K. Kabin (2008), Drift resonant generation of peaked relativistic electron distributions by Pc 5 ULF waves, textit{J. Geophys. Res., 113}, A02208, doi:10.1029/2007JA012411. Fälthammar, C.-G. (1965), Effects of Time-Dependent Electric Fields on Geomagnetically Trapped Radiation, J. Geophys. Res., 70(11), 2503-2516, doi:10.1029/JZ070i011p02503. Li, X., I. Roth, M. Temerin, J. R. Wygant, M. K. Hudson, and J. B. Blake (1993), Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC, textit{Geophys. Res. Lett., 20}(22), 2423-2426, doi:10.1029/93GL02701. Ukhorskiy, A. Y., B. J. Anderson, K. Takahashi, and N. A. Tsyganenko (2006), Impact of ULF oscillations in solar wind dynamic pressure on the outer radiation belt electrons, textit{Geophys. Res. Lett., 33}(6), L06111, doi:10.1029/2005GL024380.

  2. Year of progress for radiation curing

    International Nuclear Information System (INIS)

    Mesrobian, R.B.

    1975-01-01

    New developments in ultraviolet and electron beam curing of inks and coatings are reviewed. Current installations of radiation systems are noted. An assessment is presented on raw and intermediate materials availability. Current outlook on such problems as toxicity (FDA and OSHA), residual volatiles, materials cost, adhesion and flow-out of coatings is discussed. The future potential for radiation curing systems is contrasted with that of other systems, in view of EPA requirements

  3. The progress of molecular biology in radiation research

    International Nuclear Information System (INIS)

    Wei Kang

    1989-01-01

    The recent progress in application of molecular biology techniques in the study of radiation biology is reviewed. The three sections are as follows: (1) the study of DNA damage on molecular level, (2) the molecular mechanism of radiation cell genetics, including chromosome abberation and cell mutation, (3) the study on DNA repair gene with DNA mediated gene transfer techniques

  4. Progresses in studies on radiation treatment of environmental pollutants

    International Nuclear Information System (INIS)

    Wang Min; Shen Zhongqun; Yang Ruiyuan; Ma Hongjuan; Zhao Jun; Wang Wenfeng

    2007-01-01

    The paper gives a review on recent progresses in E-beam purification of flue gases, radiation degra- dation of volatile organic compounds, and radiation treatment of sewerage and industrial wastewater. And research activities in this area at Shanghai Institute of Applied Physics are given in particular details. (authors)

  5. Radiation transport calculation methods in BNCT

    International Nuclear Information System (INIS)

    Koivunoro, H.; Seppaelae, T.; Savolainen, S.

    2000-01-01

    Boron neutron capture therapy (BNCT) is used as a radiotherapy for malignant brain tumours. Radiation dose distribution is necessary to determine individually for each patient. Radiation transport and dose distribution calculations in BNCT are more complicated than in conventional radiotherapy. Total dose in BNCT consists of several different dose components. The most important dose component for tumour control is therapeutic boron dose D B . The other dose components are gamma dose D g , incident fast neutron dose D f ast n and nitrogen dose D N . Total dose is a weighted sum of the dose components. Calculation of neutron and photon flux is a complex problem and requires numerical methods, i.e. deterministic or stochastic simulation methods. Deterministic methods are based on the numerical solution of Boltzmann transport equation. Such are discrete ordinates (SN) and spherical harmonics (PN) methods. The stochastic simulation method for calculation of radiation transport is known as Monte Carlo method. In the deterministic methods the spatial geometry is partitioned into mesh elements. In SN method angular integrals of the transport equation are replaced with weighted sums over a set of discrete angular directions. Flux is calculated iteratively for all these mesh elements and for each discrete direction. Discrete ordinates transport codes used in the dosimetric calculations are ANISN, DORT and TORT. In PN method a Legendre expansion for angular flux is used instead of discrete direction fluxes, land the angular dependency comes a property of vector function space itself. Thus, only spatial iterations are required for resulting equations. A novel radiation transport code based on PN method and tree-multigrid technique (TMG) has been developed at VTT (Technical Research Centre of Finland). Monte Carlo method solves the radiation transport by randomly selecting neutrons and photons from a prespecified boundary source and following the histories of selected particles

  6. Monte Carlo method in radiation transport problems

    International Nuclear Information System (INIS)

    Dejonghe, G.; Nimal, J.C.; Vergnaud, T.

    1986-11-01

    In neutral radiation transport problems (neutrons, photons), two values are important: the flux in the phase space and the density of particles. To solve the problem with Monte Carlo method leads to, among other things, build a statistical process (called the play) and to provide a numerical value to a variable x (this attribution is called score). Sampling techniques are presented. Play biasing necessity is proved. A biased simulation is made. At last, the current developments (rewriting of programs for instance) are presented due to several reasons: two of them are the vectorial calculation apparition and the photon and neutron transport in vacancy media [fr

  7. Progress and prospects in labour radiation hygiene

    International Nuclear Information System (INIS)

    Parkhomenko, G.M.; Tarasenko, N.Yu.

    1987-01-01

    Stages of the development of radiation hygiene as a branch of hygienic science from 1940-1950 till now are being analyzed. The results and major research trends are presented. During the period under consideration the sanitary legislation was developed and important activity on setting up safety standards for ionizing raiation carried out

  8. Progress in identification of radiation embrittlement mechanisms

    International Nuclear Information System (INIS)

    Hawthorne, J.R.

    1988-01-01

    This report outlines recent advances in the isolation and understanding of mechanisms behind known composition influences on he radiation embrittlement sensitivity of reactor pressure vessel steels at 288 deg. C. The advances are largely the product of joint investigations by Materials Engineering Associates (MEA) and other laboratories in the U.S. and overseas under cooperative and subcontract arrangements. Specific objectives were: confirmation of the suspect Cu mechanism, identification of the process for the Cu:Ni synergism, and isolation of the P mechanism in radiation sensitivity development. The investigations proceeded with MEA-supplied steels and iron alloys from 4-way split laboratory melts; research tools included Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Ion Microscopy (FIM), Small Angle Neutron Scattering (SANS), Positron Annihilation (PA) and Auger Electron Spectroscopy (AES). Experimental results show that P and Cu enhance the radiation elevation of yield strength and that the associated mechanisms are a radiation-induced precipitation of P or Cu-rich clusters which impede dislocation motion. With high Cu alloys, a Cu phosphide is formed in preference to P precipitates and the P contribution is greatly reduced. Effects of postirradiation annealing and reirradiation are also reported. (author)

  9. Progress report: 1996 Radiation Safety Systems Division

    International Nuclear Information System (INIS)

    Bhagwat, A.M.; Sharma, D.N.; Abani, M.C.; Mehta, S.K.

    1997-01-01

    The activities of Radiation Safety Systems Division include (i) development of specialised monitoring systems and radiation safety information network, (ii) radiation hazards control at the nuclear fuel cycle facilities, the radioisotope programmes at Bhabha Atomic Research Centre (BARC) and for the accelerators programme at BARC and Centre for Advanced Technology (CAT), Indore. The systems on which development and upgradation work was carried out during the year included aerial gamma spectrometer, automated environment monitor using railway network, radioisotope package monitor and air monitors for tritium and alpha active aerosols. Other R and D efforts at the division included assessment of risk for radiation exposures and evaluation of ICRP 60 recommendations in the Indian context, shielding evaluation and dosimetry for the new upcoming accelerator facilities and solid state nuclear track detector techniques for neutron measurements. The expertise of the divisional members was provided for 36 safety committees of BARC and Atomic Energy Regulatory Board (AERB). Twenty three publications were brought out during the year 1996. (author)

  10. Radiation Protection Services Division: progress report for 1992-1993

    International Nuclear Information System (INIS)

    Massand, O.P.; Murthy, B.K.S.

    1994-01-01

    This report describes the work of the Radiation Protection Services Division during 1993, for implementation of radiation safety in all institutions in India using radiation sources in medical, industrial and research applications. It gives information about personnel monitoring using photographic film and TLD badges, neutron monitoring badges, advisory and licensing services, regulation, transport of radioactive materials and periodic protection survey. About 33 publications by the staff of the Division are also listed. (author). 4 tabs

  11. Fallout radiation protection provided by transportation vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Burson, Z.G.

    1972-10-20

    Fallout radiation protection factors (PF's) were estimated for a variety of civilian transportation vehicles using measurements of the natural terrain radiation as a source. The PF values are below 2 in light vehicles, truck beds, or trailers; from 2.5 to 3 in the cabs of heavy trucks and in a railway guard car; and from 3.0 to 3.5 in the engineer's seat of heavy locomotives. This information can be useful in planning the possible movement of personnel from or through areas contaminated either by a wartime incident or a peacetime accident. The information may also be useful for studying the reduction of exposure to the natural terrestrial radiation environment provided by vehicles.

  12. Progress in medical radiation physics. Vol. 1

    International Nuclear Information System (INIS)

    Orton, C.G.

    1982-01-01

    This book is the first of a series that will provide in-depth reviews of new developments in medical radiation physics. This volume is directed toward application scientists who are involved with research in this field. Six chapters review current topics in medical radiation physics. The first chapter reviews neutron dosimetry for biomedical applications. The second chapter briefly surveys current tissue inhomogeneity corrections in proton-beam treatment planning. Chapter three deals with anthropomorphic phantom materials. It includes a useful table of recommended tissue substitutes and information on manufacturing. The fourth chapter reviews applications of computed tomography (CT) in radiotherapy treatment planning. Chapter five is a short introduction to positron imaging. The last chapter describes optical methods for radiograph storage

  13. Progress in high-dose radiation dosimetry

    International Nuclear Information System (INIS)

    Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

    1981-01-01

    The last decade has witnessed a deluge of new high-dose dosimetry techniques and expanded applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Reference systems also include a number of chemical dose meters: ferrous sulphate, ferrous-cupric sulphate, and ceric sulphate acidic aqueous solutions. Requirements for stable and reliable transfer dose meters have led to further developments of several important high-dose systems: amino acids and saccharides analysed by ESR or lyoluminescence, thermoluminescent materials, radiochromic dyes and plastics, ceric-cerous solutions analysed by potentiometry, and ethanol-chlorobenzene solutions analysed by high-frequency oscillometry. A number of other prospective dose meters are also treated in this review. In addition, an IAEA programme of high-dose standardization and intercomparison for industrial radiation processing is described. (author)

  14. NASA space radiation transport code development consortium

    International Nuclear Information System (INIS)

    Townsend, L. W.

    2005-01-01

    Recently, NASA established a consortium involving the Univ. of Tennessee (lead institution), the Univ. of Houston, Roanoke College and various government and national laboratories, to accelerate the development of a standard set of radiation transport computer codes for NASA human exploration applications. This effort involves further improvements of the Monte Carlo codes HETC and FLUKA and the deterministic code HZETRN, including developing nuclear reaction databases necessary to extend the Monte Carlo codes to carry out heavy ion transport, and extending HZETRN to three dimensions. The improved codes will be validated by comparing predictions with measured laboratory transport data, provided by an experimental measurements consortium, and measurements in the upper atmosphere on the balloon-borne Deep Space Test Bed (DSTB). In this paper, we present an overview of the consortium members and the current status and future plans of consortium efforts to meet the research goals and objectives of this extensive undertaking. (authors)

  15. Progress in radiation immune thermionic integrated circuits

    International Nuclear Information System (INIS)

    Lynn, D.K.; McCormick, J.B.

    1985-08-01

    This report describes the results of a program directed at evaluating the thermionic integrated circuit (TIC) technology for applicability to military systems. Previous programs under the sponsorship of the Department of Energy, Office of Basic Energy Sciences, have developed an initial TIC technology base and demonstrated operation in high-temperature and high-radiation environments. The program described in this report has two parts: (1) a technical portion in which experiments and analyses were conducted to refine perceptions of near-term as well as ultimate performance levels of the TIC technology and (2) an applications portion in which the technical conclusions were to be evaluated against potential military applications. This report draws several conclusions that strongly suggest that (1) useful radiation-hard/high-temperature operable integrated circuits can be developed using the TIC technology; (2) because of their ability to survive and operate in hostile environments, a variety of potential military applications have been projected for this technology; and (3) based on the above two conclusions, an aggressive TIC development program should be initiated to provide the designers of future systems with integrated circuits and devices with the unique features of the TICs

  16. Progress in radiation immune thermionic integrated circuits

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, D.K.; McCormick, J.B. (comps.)

    1985-08-01

    This report describes the results of a program directed at evaluating the thermionic integrated circuit (TIC) technology for applicability to military systems. Previous programs under the sponsorship of the Department of Energy, Office of Basic Energy Sciences, have developed an initial TIC technology base and demonstrated operation in high-temperature and high-radiation environments. The program described in this report has two parts: (1) a technical portion in which experiments and analyses were conducted to refine perceptions of near-term as well as ultimate performance levels of the TIC technology and (2) an applications portion in which the technical conclusions were to be evaluated against potential military applications. This report draws several conclusions that strongly suggest that (1) useful radiation-hard/high-temperature operable integrated circuits can be developed using the TIC technology; (2) because of their ability to survive and operate in hostile environments, a variety of potential military applications have been projected for this technology; and (3) based on the above two conclusions, an aggressive TIC development program should be initiated to provide the designers of future systems with integrated circuits and devices with the unique features of the TICs.

  17. Chemical and radiation carcinogenesis. Progress report

    International Nuclear Information System (INIS)

    1983-07-01

    Gamma radiation, as a quantitative perturbation reference, has been related to oxygen toxicity as the unavoidable background risk due to living in an oxygen atmosphere. The basic mechanisms shared by gamma irradiation and oxygen toxicity have been studied. The response to these two perturbations has been characterized at the molecular level through DNA chemistry and monoclonal antibodies, and by cellular biological responses. The investigation of cellular responses is being extended to the molecular level through a study of alteration of gene arrangement and gene expression. Concentration has been on the study of the involvement of the evolutionally conserved repetitive DNA sequences shared by hamster and man. Such sequences were found and some have been isolated in plasmids. Two cellular systems were chosen for investigation, the embryonic/adult mesenchymal system and the hematopoietic tissues system. Concentration has been on the isolation, properties, and response to perturbation of the progenitor cells and the stem cell populations

  18. Recent progress with the Transition Radiation Tracker

    CERN Multimedia

    Froidevaux, D

    Start-up of end-cap assembly in Russia On July 2nd at PNPI (first photo) and on August 1st at JINR Dubna (second photo), the first straws were inserted into the first 4-plane end-cap wheels, each containing 3072 straws. The straws were glued, the radiator stacks were installed and the PNPI wheel was tested for gas leaks. An initial large leak rate was observed and fixed by increasing somewhat the amount of glue around each straw end-piece and improving the leak-tightness of the testing equipment itself. PNPI will assemble a total of 48 4-plane wheels of type A using two assembly lines. JINR Dubna will assemble a total of 32 4-plane wheels of type B using a single assembly line. The next steps are the gluing of the so-called active webs (printed circuit boards connecting high voltage and signal lines from straw/wire to HV supply and front-end boards), followed by wiring, and will take place in November. PNPI and JINR Dubna should start mass production in February-March next year. Barrel module produc...

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

    International Nuclear Information System (INIS)

    1981-07-01

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

  20. Rare event simulation in radiation transport

    International Nuclear Information System (INIS)

    Kollman, C.

    1993-10-01

    This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiple by the likelihood ratio between the true and simulated probabilities so as to keep the estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive ''learning'' algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give with probability one, a sequence of estimates converging exponentially fast to the true solution

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

    International Nuclear Information System (INIS)

    Rossi, H.H.

    1985-07-01

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

  2. Available computer codes and data for radiation transport analysis

    International Nuclear Information System (INIS)

    Trubey, D.K.; Maskewitz, B.F.; Roussin, R.W.

    1975-01-01

    The Radiation Shielding Information Center (RSIC), sponsored and supported by the Energy Research and Development Administration (ERDA) and the Defense Nuclear Agency (DNA), is a technical institute serving the radiation transport and shielding community. It acquires, selects, stores, retrieves, evaluates, analyzes, synthesizes, and disseminates information on shielding and ionizing radiation transport. The major activities include: (1) operating a computer-based information system and answering inquiries on radiation analysis, (2) collecting, checking out, packaging, and distributing large computer codes, and evaluated and processed data libraries. The data packages include multigroup coupled neutron-gamma-ray cross sections and kerma coefficients, other nuclear data, and radiation transport benchmark problem results

  3. Validation of comprehensive space radiation transport code

    International Nuclear Information System (INIS)

    Shinn, J.L.; Simonsen, L.C.; Cucinotta, F.A.

    1998-01-01

    The HZETRN code has been developed over the past decade to evaluate the local radiation fields within sensitive materials on spacecraft in the space environment. Most of the more important nuclear and atomic processes are now modeled and evaluation within a complex spacecraft geometry with differing material components, including transition effects across boundaries of dissimilar materials, are included. The atomic/nuclear database and transport procedures have received limited validation in laboratory testing with high energy ion beams. The codes have been applied in design of the SAGE-III instrument resulting in material changes to control injurious neutron production, in the study of the Space Shuttle single event upsets, and in validation with space measurements (particle telescopes, tissue equivalent proportional counters, CR-39) on Shuttle and Mir. The present paper reviews the code development and presents recent results in laboratory and space flight validation

  4. Forecasting of Radiation Belts: Results From the PROGRESS Project.

    Science.gov (United States)

    Balikhin, M. A.; Arber, T. D.; Ganushkina, N. Y.; Walker, S. N.

    2017-12-01

    Forecasting of Radiation Belts: Results from the PROGRESS Project. The overall goal of the PROGRESS project, funded in frame of EU Horizon2020 programme, is to combine first principles based models with the systems science methodologies to achieve reliable forecasts of the geo-space particle radiation environment.The PROGRESS incorporates three themes : The propagation of the solar wind to L1, Forecast of geomagnetic indices, and forecast of fluxes of energetic electrons within the magnetosphere. One of the important aspects of the PROGRESS project is the development of statistical wave models for magnetospheric waves that affect the dynamics of energetic electrons such as lower band chorus, hiss and equatorial noise. The error reduction ratio (ERR) concept has been used to optimise the set of solar wind and geomagnetic parameters for organisation of statistical wave models for these emissions. The resulting sets of parameters and statistical wave models will be presented and discussed. However the ERR analysis also indicates that the combination of solar wind and geomagnetic parameters accounts for only part of the variance of the emissions under investigation (lower band chorus, hiss and equatorial noise). In addition, advances in the forecast of fluxes of energetic electrons, exploiting empirical models and the first principles IMPTAM model achieved by the PROGRESS project is presented.

  5. Rare Event Simulation in Radiation Transport

    Science.gov (United States)

    Kollman, Craig

    This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiplied by the likelihood ratio between the true and simulated probabilities so as to keep our estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive "learning" algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give, with probability one, a sequence of estimates converging exponentially fast to the true solution. In the final chapter, an attempt to generalize this algorithm to a continuous

  6. Clinical utility of MR imaging in chronic progressive radiation myelopathy

    International Nuclear Information System (INIS)

    Melki, P.S.; Halimi, P.; Wibault, P.; Doyon, D.

    1990-01-01

    This paper defines the diagnostic and prognostic value of MR imaging in chronic progressive radiation myelopathy 9CPRM). In this series, MR imaging showed excellent sensitivity (199%) for the demonstration of radiation-induced lesions of the spinal cord. Fifty percent of the cases showed spinal cord hypertrophy (pseudotumoral, 33%; cystic, 17%) occurring within 8 months of the clinical onset of myelopathy. The remaining 50% showed spinal cord atrophy, which occurred more than 8 months following the onset of myelopathy. These medullary lesions were located at least partially in the radiation field but extended beyond its boundaries in 73% of the cases. MR imaging helped to establish disease prognosis: spinal cord hypertrophy was usually associated with neurologic deterioration and fatal outcome within a mean of 11.5 months; in spinal atrophy, neurologic deficit was often static and survival rates were better

  7. Research progress in airborne surveys of terrestrial gamma radiation

    International Nuclear Information System (INIS)

    Burson, Z.G.

    1974-01-01

    Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

  8. Electron transport calculations with biomedical and environmental applications: [Progress report, FY 1987

    International Nuclear Information System (INIS)

    1987-01-01

    This project investigated radiation interactions with matter and radiation transport in bulk media, to generate basic radiological physics information. Applications include biomedical radiation dosimetry, the assessment of radiation hazards in nuclear technology, and modeling of biological radiation action. This work included the development of transport-theoretic methods, the compilation and critical evaluation of the underlying single-scattering cross sections, and the application of the transport methods to radiological physics problems. 7 refs

  9. Statistics of Monte Carlo methods used in radiation transport calculation

    International Nuclear Information System (INIS)

    Datta, D.

    2009-01-01

    Radiation transport calculation can be carried out by using either deterministic or statistical methods. Radiation transport calculation based on statistical methods is basic theme of the Monte Carlo methods. The aim of this lecture is to describe the fundamental statistics required to build the foundations of Monte Carlo technique for radiation transport calculation. Lecture note is organized in the following way. Section (1) will describe the introduction of Basic Monte Carlo and its classification towards the respective field. Section (2) will describe the random sampling methods, a key component of Monte Carlo radiation transport calculation, Section (3) will provide the statistical uncertainty of Monte Carlo estimates, Section (4) will describe in brief the importance of variance reduction techniques while sampling particles such as photon, or neutron in the process of radiation transport

  10. Renormalization-group approach to nonlinear radiation-transport problems

    International Nuclear Information System (INIS)

    Chapline, G.F.

    1980-01-01

    A Monte Carlo method is derived for solving nonlinear radiation-transport problems that allows one to average over the effects of many photon absorptions and emissions at frequencies where the opacity is large. This method should allow one to treat radiation-transport problems with large optical depths, e.g., line-transport problems, with little increase in computational effort over that which is required for optically thin problems

  11. Technological progress in radiation therapy for brain tumors

    LENUS (Irish Health Repository)

    Vernimmen, Frederik Jozef

    2014-01-01

    To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological ad- vancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better un- derstanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Li-near Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

  12. Transport of infrared radiation in cuboidal clouds

    Science.gov (United States)

    Harshvardhan, MR.; Weinman, J. A.; Davies, R.

    1981-01-01

    The transport of infrared radiation in a single cuboidal cloud is modeled using a variable azimuth two-stream approximation. Computations are made at 10 microns for a Deirmendjian (1969) C-1 water cloud where the single scattering albedo is equal to 0.638 and the asymmetry parameter is 0.865. The results indicate that the emittance of the top face of the model cloud is always less than that for a plane parallel cloud of the same optical depth. The hemispheric flux escaping from the cloud top possesses a gradient from the center to the edges which are warmer when the cloud is over warmer ground. Cooling rate calculations in the 8-13.6 micron region demonstrate that there is cooling out of the sides of the cloud at all levels even when there is heating of the core from the ground below. The radiances exiting from model cuboidal clouds are computed by path integration over the source function obtained with the two-stream approximation. Results indicate that the brightness temperature measured from finite clouds will overestimate the cloud-top temperature.

  13. Progress in transport modelling of internal transport barrier plasmas in JET

    International Nuclear Information System (INIS)

    Tala, T.; Bourdelle, C.; Imbeaux, F.; Moreau, D.; Garbet, X.; Joffrin, E.; Laborde, L.; Litaudon, X.; Mazon, D.; Parail, V.; Corrigan, G.; Heading, D.; Crisanti, F.; Mantica, P.; Salmi, A.; Strand, P.; Weiland, J.

    2005-01-01

    This paper will report on the recent progress in transport modelling of Internal Transport Barrier (ITB) plasmas. Two separate issues will be covered, fully predictive transport modelling of ITBs in the multi-tokamak database, including micro-stability analyses of ITBs, and predictive closed-loop (i.e. real-time control) transport simulations of the q-profile and ITBs. For the first time, the predictive capabilities of the mixed Bohm/GyroBohm and Weiland transport models are investigated with discharges from the ITPA ITB database by fully predictive transport simulations. The predictive transport simulations with the Bohm/GyroBohm model agree very well with experimental results from JET and JT-60U. In order to achieve a good agreement in DIII-D, the stabilisation had to be included into the model, showing the significant role played by the stabilisation in governing the physics of the ITBs. The significant role of the stabilisation is also emphasised by the gyrokinetic analysis. The Weiland transport model shows only limited agreement between the model predictions and experimental results with respect to the formation and location of the ITB. The fully predictive closed-loop simulations with real-time control of the q-profile and ITB show that it is possible to reach various set-point profiles for q and ITB and control them for longer than a current diffusion time in JET using the same real-time control technique as in the experiments. (author)

  14. Implementation and testing of a multivariate inverse radiation transport solver

    International Nuclear Information System (INIS)

    Mattingly, John; Mitchell, Dean J.

    2012-01-01

    Detection, identification, and characterization of special nuclear materials (SNM) all face the same basic challenge: to varying degrees, each must infer the presence, composition, and configuration of the SNM by analyzing a set of measured radiation signatures. Solutions to this problem implement inverse radiation transport methods. Given a set of measured radiation signatures, inverse radiation transport estimates properties of the source terms and transport media that are consistent with those signatures. This paper describes one implementation of a multivariate inverse radiation transport solver. The solver simultaneously analyzes gamma spectrometry and neutron multiplicity measurements to fit a one-dimensional radiation transport model with variable layer thicknesses using nonlinear regression. The solver's essential components are described, and its performance is illustrated by application to benchmark experiments conducted with plutonium metal. - Highlights: ► Inverse problems, specifically applied to identifying and characterizing radiation sources . ► Radiation transport. ► Analysis of gamma spectroscopy and neutron multiplicity counting measurements. ► Experimental testing of the inverse solver against measurements of plutonium.

  15. Los Alamos radiation transport code system on desktop computing platforms

    International Nuclear Information System (INIS)

    Briesmeister, J.F.; Brinkley, F.W.; Clark, B.A.; West, J.T.

    1990-01-01

    The Los Alamos Radiation Transport Code System (LARTCS) consists of state-of-the-art Monte Carlo and discrete ordinates transport codes and data libraries. These codes were originally developed many years ago and have undergone continual improvement. With a large initial effort and continued vigilance, the codes are easily portable from one type of hardware to another. The performance of scientific work-stations (SWS) has evolved to the point that such platforms can be used routinely to perform sophisticated radiation transport calculations. As the personal computer (PC) performance approaches that of the SWS, the hardware options for desk-top radiation transport calculations expands considerably. The current status of the radiation transport codes within the LARTCS is described: MCNP, SABRINA, LAHET, ONEDANT, TWODANT, TWOHEX, and ONELD. Specifically, the authors discuss hardware systems on which the codes run and present code performance comparisons for various machines

  16. Progressive pituitary hormone deficiency following radiation therapy in adults

    International Nuclear Information System (INIS)

    Loureiro, Rafaela A.; Vaisman, Mario

    2004-01-01

    Hypopituitarism can be caused by radiation therapy, even when it is not directly applied on the hypothalamic-pituitary axis, and can lead to anterior pituitary deficiency mainly due to hypothalamic damage. The progressive loss of the anterior pituitary hormones usually occurs in the following order: growth hormone, gonadotropin hormones, adrenocorticotropic hormone and thyroid-stimulating hormone. Although there are several different tests available to confirm anterior pituitary deficiency, this paper will focus on the gold standard tests for patients submitted to radiation therapy. We emphasize that the decline of anterior pituitary function is time- and dose-dependent with some variability among the different axes. Therefore, awareness of the need of a joint management by endocrinologists and oncologists is essential to improve treatment and quality of life of the patients. (author)

  17. Progress on clustered DNA damage in radiation research

    International Nuclear Information System (INIS)

    Yang Li'na; Zhang Hong; Di Cuixia; Zhang Qiuning; Wang Xiaohu

    2012-01-01

    Clustered DNA damage which caused by high LET heavy ion radiation can lead to mutation, tumorigenesis and apoptosis. Promoting apoptosis of cancer cells is always the basis of cancer treatment. Clustered DNA damage has been the hot topic in radiobiology. The detect method is diversity, but there is not a detail and complete protocol to analyze clustered DNA damage. In order to provide reference for clustered DNA damage in the radiotherapy study, the clustered DNA damage characteristics, the latest progresses on clustered DNA damage and the detecting methods are reviewed and discussed in detail in this paper. (authors)

  18. Radiation doses from the transport of radioactive materials

    International Nuclear Information System (INIS)

    Shaw, K.B.; Holyoak, B.

    1983-01-01

    A summary is given of a study on radiation exposure resulting from the transport of radioactive materials within the United Kingdom. It was concluded that the transport of technetium generators for hospital use accounts for about 49% of the occupational exposure for the normal transport of radioactive materials. Other isotopes for medical and industrial use contribute about 38% of the occupational exposure and the remainder can be attributed to transportation as a result of the nuclear fuel cycle including the transport of irradiated nuclear fuel. The occupational collective dose for all modes of transport is estimated at 1 man Sv y -1 . (UK)

  19. Radiation safety in sea transport of radioactive material in Japan

    International Nuclear Information System (INIS)

    Odano, N.; Yanagi, H.

    2004-01-01

    Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured

  20. Radiation safety in sea transport of radioactive material in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Odano, N. [National Maritime Research Inst., Tokyo (Japan); Yanagi, H. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

    2004-07-01

    Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured.

  1. Radiation transport phenomena and modeling - part A: Codes

    International Nuclear Information System (INIS)

    Lorence, L.J.

    1997-01-01

    The need to understand how particle radiation (high-energy photons and electrons) from a variety of sources affects materials and electronics has motivated the development of sophisticated computer codes that describe how radiation with energies from 1.0 keV to 100.0 GeV propagates through matter. Predicting radiation transport is the necessary first step in predicting radiation effects. The radiation transport codes that are described here are general-purpose codes capable of analyzing a variety of radiation environments including those produced by nuclear weapons (x-rays, gamma rays, and neutrons), by sources in space (electrons and ions) and by accelerators (x-rays, gamma rays, and electrons). Applications of these codes include the study of radiation effects on electronics, nuclear medicine (imaging and cancer treatment), and industrial processes (food disinfestation, waste sterilization, manufacturing.) The primary focus will be on coupled electron-photon transport codes, with some brief discussion of proton transport. These codes model a radiation cascade in which electrons produce photons and vice versa. This coupling between particles of different types is important for radiation effects. For instance, in an x-ray environment, electrons are produced that drive the response in electronics. In an electron environment, dose due to bremsstrahlung photons can be significant once the source electrons have been stopped

  2. Path Toward a Unified Geometry for Radiation Transport

    Science.gov (United States)

    Lee, Kerry

    The Direct Accelerated Geometry for Radiation Analysis and Design (DAGRAD) element of the RadWorks Project under Advanced Exploration Systems (AES) within the Space Technology Mission Directorate (STMD) of NASA will enable new designs and concepts of operation for radiation risk assessment, mitigation and protection. This element is designed to produce a solution that will allow NASA to calculate the transport of space radiation through complex CAD models using the state-of-the-art analytic and Monte Carlo radiation transport codes. Due to the inherent hazard of astronaut and spacecraft exposure to ionizing radiation in low-Earth orbit (LEO) or in deep space, risk analyses must be performed for all crew vehicles and habitats. Incorporating these analyses into the design process can minimize the mass needed solely for radiation protection. Transport of the radiation fields as they pass through shielding and body materials can be simulated using Monte Carlo techniques or described by the Boltzmann equation, which is obtained by balancing changes in particle fluxes as they traverse a small volume of material with the gains and losses caused by atomic and nuclear collisions. Deterministic codes that solve the Boltzmann transport equation, such as HZETRN (high charge and energy transport code developed by NASA LaRC), are generally computationally faster than Monte Carlo codes such as FLUKA, GEANT4, MCNP(X) or PHITS; however, they are currently limited to transport in one dimension, which poorly represents the secondary light ion and neutron radiation fields. NASA currently uses HZETRN space radiation transport software, both because it is computationally efficient and because proven methods have been developed for using this software to analyze complex geometries. Although Monte Carlo codes describe the relevant physics in a fully three-dimensional manner, their computational costs have thus far prevented their widespread use for analysis of complex CAD models, leading

  3. Intense radiative heat transport across a nano-scale gap

    International Nuclear Information System (INIS)

    Budaev, Bair V.; Ghafari, Amin; Bogy, David B.

    2016-01-01

    In this paper, we analyze the radiative heat transport in layered structures. The analysis is based on our prior description of the spectrum of thermally excited waves in systems with a heat flux. The developed method correctly predicts results for all known special cases for both large and closing gaps. Numerical examples demonstrate the applicability of our approach to the calculation of the radiative heat transport coefficient across various layered structures.

  4. On the derivation of vector radiative transfer equation for polarized radiative transport in graded index media

    International Nuclear Information System (INIS)

    Zhao, J.M.; Tan, J.Y.; Liu, L.H.

    2012-01-01

    Light transport in graded index media follows a curved trajectory determined by Fermat's principle. Besides the effect of variation of the refractive index on the transport of radiative intensity, the curved ray trajectory will induce geometrical effects on the transport of polarization ellipse. This paper presents a complete derivation of vector radiative transfer equation for polarized radiation transport in absorption, emission and scattering graded index media. The derivation is based on the analysis of the conserved quantities for polarized light transport along curved trajectory and a novel approach. The obtained transfer equation can be considered as a generalization of the classic vector radiative transfer equation that is only valid for uniform refractive index media. Several variant forms of the transport equation are also presented, which include the form for Stokes parameters defined with a fixed reference and the Eulerian forms in the ray coordinate and in several common orthogonal coordinate systems.

  5. Stereotactic Body Radiation Therapy for Locally Progressive and Recurrent Pancreatic Cancer after Prior Radiation

    Directory of Open Access Journals (Sweden)

    Philip Sutera

    2018-03-01

    Full Text Available IntroductionPancreatic adenocarcinoma is an aggressive malignancy that has consistently demonstrated poor outcomes despite aggressive treatments. Despite multimodal treatment, local disease progression and local recurrence are common. Management of recurrent or progressive pancreatic carcinomas proves a further challenge. In patients previously treated with radiation therapy, stereotactic body radiation therapy (SBRT is a promising modality capable of delivering high dose to the tumor while limiting dose to critical structures. We aimed to determine the feasibility and tolerability of SBRT for recurrent or local pancreatic cancer in patients previously treated with external beam radiation therapy (EBRT.Materials and methodsPatients treated with EBRT who developed recurrent or local pancreatic ductal adenocarcinoma treated with SBRT reirradiation at our institution, from 2004 to 2014 were reviewed. Our primary endpoints included overall survival (OS, local control, regional control, and late grade 3+ radiation toxicity. Endpoints were analyzed with the Kaplan–Meier method. The association of these survival endpoints with risk factors was studied with univariate Cox proportional hazards models.ResultsWe identified 38 patients with recurrent/progressive pancreatic cancer treated with SBRT following prior radiation therapy. Prior radiation was delivered to a median dose of 50.4 Gy in 28 fractions. SBRT was delivered to a median dose of 24.5 Gy in 1–3 fractions. Surgical resection was performed on 55.3% of all patients. Within a median follow-up of 24.4 months (inter-quartile range, 14.9–32.7 months, the median OS from diagnosis for the entire cohort was 26.6 months (95% CI: 20.3–29.8 with 2-year OS of 53.0%. Median survival from SBRT was 9.7 months (95% CI, 5.5–13.8. The 2-year freedom from local progression and regional progression was 58 and 82%, respectively. For the entire cohort, 18.4 and 10.5% experienced late grade 2

  6. Nonrelativistic grey Sn-transport radiative-shock solutions

    International Nuclear Information System (INIS)

    Ferguson, J. M.; Morel, J. E.; Lowrie, R. B.

    2017-01-01

    We present semi-analytic radiative-shock solutions in which grey Sn-transport is used to model the radiation, and we include both constant cross sections and cross sections that depend on temperature and density. These new solutions solve for a variable Eddington factor (VEF) across the shock domain, which allows for interesting physics not seen before in radiative-shock solutions. Comparisons are made with the grey nonequilibrium-diffusion radiative-shock solutions of Lowrie and Edwards [1], which assumed that the Eddington factor is constant across the shock domain. It is our experience that the local Mach number is monotonic when producing nonequilibrium-diffusion solutions, but that this monotonicity may disappear while integrating the precursor region to produce Sn-transport solutions. For temperature- and density-dependent cross sections we show evidence of a spike in the VEF in the far upstream portion of the radiative-shock precursor. We show evidence of an adaptation zone in the precursor region, adjacent to the embedded hydrodynamic shock, as conjectured by Drake [2, 3], and also confirm his expectation that the precursor temperatures adjacent to the Zel’dovich spike take values that are greater than the downstream post-shock equilibrium temperature. We also show evidence that the radiation energy density can be nonmonotonic under the Zel’dovich spike, which is indicative of anti-diffusive radiation flow as predicted by McClarren and Drake [4]. We compare the angle dependence of the radiation flow for the Sn-transport and nonequilibriumdiffusion radiation solutions, and show that there are considerable differences in the radiation flow between these models across the shock structure. Lastly, we analyze the radiation flow to understand the cause of the adaptation zone, as well as the structure of the Sn-transport radiation-intensity solutions across the shock structure.

  7. ipole: Semianalytic scheme for relativistic polarized radiative transport

    Science.gov (United States)

    Moscibrodzka, Monika; Gammie, Charles F.

    2018-04-01

    ipole is a ray-tracing code for covariant, polarized radiative transport particularly useful for modeling Event Horizon Telescope sources, though may also be used for other relativistic transport problems. The code extends the ibothros scheme for covariant, unpolarized transport using two representations of the polarized radiation field: in the coordinate frame, it parallel transports the coherency tensor, and in the frame of the plasma, it evolves the Stokes parameters under emission, absorption, and Faraday conversion. The transport step is as spacetime- and coordinate- independent as possible; the emission, absorption, and Faraday conversion step is implemented using an analytic solution to the polarized transport equation with constant coefficients. As a result, ipole is stable, efficient, and produces a physically reasonable solution even for a step with high optical depth and Faraday depth.

  8. Discontinuous Galerkin for the Radiative Transport Equation

    KAUST Repository

    Guermond, Jean-Luc; Kanschat, Guido; Ragusa, Jean C.

    2013-01-01

    This note presents some recent results regarding the approximation of the linear radiative transfer equation using discontinuous Galerkin methods. The locking effect occurring in the diffusion limit with the upwind numerical flux is investigated and a correction technique is proposed.

  9. Discontinuous Galerkin for the Radiative Transport Equation

    KAUST Repository

    Guermond, Jean-Luc

    2013-10-11

    This note presents some recent results regarding the approximation of the linear radiative transfer equation using discontinuous Galerkin methods. The locking effect occurring in the diffusion limit with the upwind numerical flux is investigated and a correction technique is proposed.

  10. Progress in the development of a tracking transition radiation detector

    International Nuclear Information System (INIS)

    Whitaker, J.S.; Beatty, J.; Shank, J.T.; Wilson, R.J.; Polychronakos, V.A.; Radeka, V.; Stephani, D.; Beker, H.; Bock, R.K.; Botlo, M.; Fabjan, C.W.; Pfennig, J.; Price, M.J.; Willis, W.J.; Akesson, T.; Chernyatin, V.; Dolgoshein, B.; Nevsky, P.; Potekhin, M.; Romanjuk, A.; Sosnovtsev, V.; Gavrilenko, I.; Maiburov, S.; Muravjev, S.; Shmeleva, A.

    1990-01-01

    The purpose of the TRD/Tracker is to provide charged particle tracking in the r-z plane and to provide particle identification capabilities that are independent of and complementary to calorimetric methods. The tracking goals include observation of the charged particle multiplicity and topology, reconstruction of the primary vertex or vertices, and assignment of charged particles to the correct vertex. Particle identification goals include the independent validation of electron candidates selected by calorimetric signatures, the rejection of false electron candidates that rise from accidental overlaps of low momentum charged particles with photon-induced electromagnetic showers in the calorimeter, and the identification of electrons arising from Dalitz decays or from photon conversions. The authors report on progress towards the development of an integrated transition radiation detector and charged particle tracker. Mechanical design and simulation of a detector has been pursued; a prototype device with 240 channels has been constructed and tested. Innovative construction techniques have been developed

  11. Recent Progress of the Synchrotron Radiation Calculation Code SPECTRA

    International Nuclear Information System (INIS)

    Tanaka, T.; Kitamura, H.

    2007-01-01

    SPECTRA is a computer software to calculate optical properties of synchrotron radiation (SR) emitted by electrons passing through magnetic devices such as bending magnets, wigglers and undulators. It has been used to design various devices in the SR beamline, such as high heat-load components in the front-end section and optical elements in the optics hutch. In addition, the electron beam quality can be estimated by comparison between the measured and calculated properties of SR. Since the first announcement, numerous improvements have been made to SPECTRA to achieve less computation time with higher numerical accuracy. In addition, a number of functions have been added to follow the user's demand. In this paper, recent progress of SPECTRA is presented and details of the new functions are explained together with several examples

  12. Progress in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2000-01-01

    Vulcanization dose defined as the radiation dose at which cross-linked natural rubber in latex has the maximum tensile strength can be reduced by adding carbon tetrachloride as a reaction accelerator. The radiation vulcanization of natural rubber latex was selected as one of regional projects of IAEA in 1989 and a pilot plant was built in Jakarta. The products from it were evaluated during 1983-1985, followed by IAEA decision to support the continued R and D study at Takasaki, JAERI. Various factors to improve the properties of the products have been studied. Several advantages of the process over conventional method, such as absence of N-nitrosoamines, low cytotoxicity, decomposability in the environment, transparency and softness, were confirmed. The technology has been transferred toward commercial application in Thailand, and pilot plants being set up in Indonesia, India, Malaysia and Thailand. Moreover, the process was found to be effective in reducing protein remaining in natural rubber latex products and the initial investment and irradiation cost was found to be greatly reduced by employing low energy electron accelerator. This paper reviews such progress. (S. Ohno)

  13. Radiation transport Part B: Applications with examples

    International Nuclear Information System (INIS)

    Beutler, D.E.

    1997-01-01

    In the previous sections Len Lorence has described the need, theory, and types of radiation codes that can be applied to model the results of radiation effects tests or working environments for electronics. For the rest of this segment, the author will concentrate on the specific ways the codes can be used to predict device response or analyze radiation test results. Regardless of whether one is predicting responses in a working or test environment, the procedures are virtually the same. The same can be said for the use of 1-, 2-, or 3-dimensional codes and Monte Carlo or discrete ordinates codes. No attempt is made to instruct the student on the specifics of the code. For example, the author will not discuss the details, such as the number of meshes, energy groups, etc. that are appropriate for a discrete ordinates code. For the sake of simplicity, he will restrict himself to the 1-dimensional code CEPXS/ONELD. This code along with a wide variety of other radiation codes can be obtained form the Radiation Safety Information Computational Center (RSICC) for a nominal handling fee

  14. Overview. Department of Environmental and Radiation Transport Physics. Section 6

    Energy Technology Data Exchange (ETDEWEB)

    Loskiewicz, J. [Institute of Nuclear Physics, Cracow (Poland)

    1995-12-31

    Research activities in the Department of Environmental and Radiation Transport Physics are carried out by three Laboratories: Laboratory of Environmental Physics, Laboratory of Neutron Transport Physics and Laboratory of Physics and Modeling of Radiation Transport. The researches provided in 1994 cover: tracer transport and flows in porous media, studies on pollution in atmospheric air, physics of molecular phenomena in chromatographic detectors, studies on neutron transport in heterogenous media, studies on evaluation of neutron cross-section in the thermal region, studies on theory and utilization of neural network in data evaluation, numerical modelling of particle cascades for particle accelerator shielding purpose. In this section the description of mentioned activities as well as the information about personnel employed in the Department, papers and reports published in 1994, contribution to conferences and grants is also given.

  15. Overview. Department of Environmental and Radiation Transport Physics. Section 6

    Energy Technology Data Exchange (ETDEWEB)

    Loskiewicz, J [Institute of Nuclear Physics, Cracow (Poland)

    1996-12-31

    Research activities in the Department of Environmental and Radiation Transport Physics are carried out by three Laboratories: Laboratory of Environmental Physics, Laboratory of Neutron Transport Physics and Laboratory of Physics and Modeling of Radiation Transport. The researches provided in 1994 cover: tracer transport and flows in porous media, studies on pollution in atmospheric air, physics of molecular phenomena in chromatographic detectors, studies on neutron transport in heterogenous media, studies on evaluation of neutron cross-section in the thermal region, studies on theory and utilization of neural network in data evaluation, numerical modelling of particle cascades for particle accelerator shielding purpose. In this section the description of mentioned activities as well as the information about personnel employed in the Department, papers and reports published in 1994, contribution to conferences and grants is also given.

  16. Exploiting Novel Radiation-Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report

    Science.gov (United States)

    2016-04-01

    Exploiting Novel Radiation -Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report Distribution...assess the effects of ionizing radiation on at least three classes of electromagnetic materials. The proposed approach for radiation detection was...that was desired to be monitored remotely. Microwave or low millimeter wave electromagnetic radiation would be used to interrogate the device

  17. Radiological emergency: road map for radiation accident victim transport

    International Nuclear Information System (INIS)

    Costa, V.S.G.; Alcantara, Y.P.; Lima, C.M.A.; Silva, F. C. A. da

    2017-01-01

    During a radiological or nuclear emergency, a number of necessary actions are taken, both within the radiation protection of individuals and the environment, involving many institutions and highly specialized personnel. Among them it is possible to emphasize the air transportation of radiation accident victims.The procedures and measures for the safe transport of these radiation accident victims are generally the responsibility of the armed forces, specifically the Aeronautics, with the action denominated 'Aeromedical Military Evacuation of Radiation Accident Victims'. The experience with the Radiological Accident of Goiânia demonstrated the importance of adequate preparation and response during a radiological emergency and the need for procedures and measures with regard to the transport of radiation victims are clearly defined and clearly presented for the effectiveness of the actions. This work presents the necessary actions for the transport of radiation accident victim during a radiological emergency, through the road map technique, which has been widely used in scientific technical area to facilitate understanding and show the way to be followed to reach the proposed objectives

  18. Transport of cobalt-60 industrial radiation sources

    Science.gov (United States)

    Kunstadt, Peter; Gibson, Wayne

    This paper will deal with safety aspects of the handling of Cobalt-60, the most widely used industrial radio-isotope. Cobalt-60 is a man-made radioisotope of Cobalt-59, a naturally occurring non radioactive element, that is made to order for radiation therapy and a wide range of industrial processing applications including sterilization of medical disposables, food irradiation, etc.

  19. A closer look at urban transport. TERM 2013: transport indicators tracking progress towards environmental targets in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Vicente, A.

    2013-12-01

    The EEA works in the transport area to assess the impacts of the sector on the human health and the environment. This work also allows the EEA to monitor the progress of integrating transport and environmental policies, and informing the EU, EEA member countries and the public about such progress. This is achieved by the production of relevant indicators that track progress towards policy targets for transport related to the environment, as well as through the elaboration of periodic assessments that cover all transport modes and the impacts of transport on the environment. The annual TERM report aims to enable policymakers to gauge the progress of those policies aiming to improve the environmental performance of the transport system as a whole. TERM 2013, has two distinct parts. Part A provides an annual assessment of the EU's transport and environment policies based on the TERM-CSI, a selection of 12 indicators from the broader set of EEA transport indicators to enabling monitoring of the most important aspects of transport. Part B focuses on urban transport and its effects on the environment. (LN)

  20. bhlight: GENERAL RELATIVISTIC RADIATION MAGNETOHYDRODYNAMICS WITH MONTE CARLO TRANSPORT

    International Nuclear Information System (INIS)

    Ryan, B. R.; Gammie, C. F.; Dolence, J. C.

    2015-01-01

    We present bhlight, a numerical scheme for solving the equations of general relativistic radiation magnetohydrodynamics using a direct Monte Carlo solution of the frequency-dependent radiative transport equation. bhlight is designed to evolve black hole accretion flows at intermediate accretion rate, in the regime between the classical radiatively efficient disk and the radiatively inefficient accretion flow (RIAF), in which global radiative effects play a sub-dominant but non-negligible role in disk dynamics. We describe the governing equations, numerical method, idiosyncrasies of our implementation, and a suite of test and convergence results. We also describe example applications to radiative Bondi accretion and to a slowly accreting Kerr black hole in axisymmetry

  1. Radiation transport in statistically inhomogeneous rocks

    International Nuclear Information System (INIS)

    Lukhminskij, B.E.

    1975-01-01

    A study has been made of radiation transfer in statistically inhomogeneous rocks. Account has been taken of the statistical character of rock composition through randomization of density. Formulas are summarized for sigma-distribution, homogeneous density, the Simpson and Cauchy distributions. Consideration is given to the statistics of mean square ranges in a medium, simulated by the jump Markov random function. A quantitative criterion of rock heterogeneity is proposed

  2. Laying the foundations for greener transport - TERM 2011: transport indicators tracking progress towards environmental targets in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Vicente, A

    2011-11-15

    For the first time ever the European Commissions is proposing a greenhouse gas emissions target for transport. But how is transport going to provide the services that our society needs while minimising its environmental impacts? This is the theme for the Transport White Paper launched in 2011. TERM 2011 and future reports aim to deliver an annual assessment on progress towards these targets by introducing the Transport and Environment Reporting Mechanism Core Set of Indicators (TERM-CSI). TERM 2011 provides also the baseline to which progress will be checked against, covering most of the environmental areas, including energy consumption, emissions, noise and transport demand. In addition, this report shows latest data and discuss on the different aspects that can contribute the most to minimise transport impacts. TERM 2011 applies the avoid-shift-improve (ASI) approach, introduced in the previous TERM report, analysing ways to optimise transport demand, obtain a more sustainable modal split or use the best technology available. (Author)

  3. An inverse method for radiation transport

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, J. A. (Jeffrey A.); Sanchez, R. (Richard)

    2004-01-01

    Adjoint functions have been used with forward functions to compute gradients in implicit (iterative) solution methods for inverse problems in optical tomography, geoscience, thermal science, and other fields, but only once has this approach been used for inverse solutions to the Boltzmann transport equation. In this paper, this approach is used to develop an inverse method that requires only angle-independent flux measurements, rather than angle-dependent measurements as was done previously. The method is applied to a simplified form of the transport equation that does not include scattering. The resulting procedure uses measured values of gamma-ray fluxes of discrete, characteristic energies to determine interface locations in a multilayer shield. The method was implemented with a Newton-Raphson optimization algorithm, and it worked very well in numerical one-dimensional spherical test cases. A more sophisticated optimization method would better exploit the potential of the inverse method.

  4. Modeling sheet-flow sand transport under progressive surface waves

    NARCIS (Netherlands)

    Kranenburg, Wouter

    2013-01-01

    In the near-shore zone, energetic sea waves generate sheet-flow sand transport. In present day coastal models, wave-induced sheet-flow sand transport rates are usually predicted with semi-empirical transport formulas, based on extensive research on this phenomenon in oscillatory flow tunnels.

  5. Radiative transport-based frequency-domain fluorescence tomography

    International Nuclear Information System (INIS)

    Joshi, Amit; Rasmussen, John C; Sevick-Muraca, Eva M; Wareing, Todd A; McGhee, John

    2008-01-01

    We report the development of radiative transport model-based fluorescence optical tomography from frequency-domain boundary measurements. The coupled radiative transport model for describing NIR fluorescence propagation in tissue is solved by a novel software based on the established Attila(TM) particle transport simulation platform. The proposed scheme enables the prediction of fluorescence measurements with non-contact sources and detectors at a minimal computational cost. An adjoint transport solution-based fluorescence tomography algorithm is implemented on dual grids to efficiently assemble the measurement sensitivity Jacobian matrix. Finally, we demonstrate fluorescence tomography on a realistic computational mouse model to locate nM to μM fluorophore concentration distributions in simulated mouse organs

  6. Induced Compton scattering effects in radiation transport approximations

    International Nuclear Information System (INIS)

    Gibson, D.R. Jr.

    1982-01-01

    In this thesis the method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

  7. Induced Compton-scattering effects in radiation-transport approximations

    International Nuclear Information System (INIS)

    Gibson, D.R. Jr.

    1982-02-01

    The method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

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

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

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

  9. A Monte Carlo transport code study of the space radiation environment using FLUKA and ROOT

    CERN Document Server

    Wilson, T; Carminati, F; Brun, R; Ferrari, A; Sala, P; Empl, A; MacGibbon, J

    2001-01-01

    We report on the progress of a current study aimed at developing a state-of-the-art Monte-Carlo computer simulation of the space radiation environment using advanced computer software techniques recently available at CERN, the European Laboratory for Particle Physics in Geneva, Switzerland. By taking the next-generation computer software appearing at CERN and adapting it to known problems in the implementation of space exploration strategies, this research is identifying changes necessary to bring these two advanced technologies together. The radiation transport tool being developed is tailored to the problem of taking measured space radiation fluxes impinging on the geometry of any particular spacecraft or planetary habitat and simulating the evolution of that flux through an accurate model of the spacecraft material. The simulation uses the latest known results in low-energy and high-energy physics. The output is a prediction of the detailed nature of the radiation environment experienced in space as well a...

  10. Radiation exposure during air and ground transportation

    International Nuclear Information System (INIS)

    Hsu, P.C.; Weng, P.S.

    1976-01-01

    The results of a one year study program of radiation exposure experienced on both domestic and international flights of the China Airline and the Far East Airline in the Pacific, Southeast Asia and Taiwan areas and on trains and buses on Taiwan island are reported. CaSO 4 :Dy thermoluminescent dosimeters were used. It has been shown that transit exposures may amount to 10 times that on the ground with an altitude varying from 3,050 to 12,200 m. (U.K.)

  11. Progress report: nuclear safety and radiation protection in 2006

    International Nuclear Information System (INIS)

    2007-01-01

    For the French Nuclear Safety Authority (Asn), the year 2006 was marked by two important nuclear laws being passed, one of which brought about a major change in its status. The year was a relatively satisfactory one with regard to nuclear safety, although the picture was more contrasted concerning radiation protection: in this area, more particularly in the medical field, the overall impression of good progress is offset by the declaration of a number of radiotherapy accidents. Given the benefits expected from radiotherapy treatment by the patient suffering from cancer, the conditions in which this activity is carried out are a subject of major concern for Asn, in the light of the serious risks linked to patient over-exposure. ( some important points as follows: the law on transparency and security in the nuclear field, the law on sustainable management of radioactive materials and waste, Asn: an independent administrative authority, EPR reactor project safety, I.R.R.S.: an international audit of Asn in 2006, harmonization of nuclear safety, cancer radiotherapy, improved information of the public after the T.S.N. law, taking account of organisational and human factors). (N.C.)

  12. Regulatory practices of radiation safety of SNF transportation in Russia

    International Nuclear Information System (INIS)

    Kuryndina, Lidia; Kuryndin, Anton; Stroganov, Anatoly

    2008-01-01

    This paper overviews current regulatory practices for the assurance of nuclear and radiation safety during railway transportation of SNF on the territory of Russian Federation from NPPs to longterm-storage of reprocessing sites. The legal and regulatory requirements (mostly compliant with IAEA ST-1), licensing procedure for NM transportation are discussed. The current procedure does not require a regulatory approval for each particular shipment if the SNF fully comply with the Rosatom's branch standard and is transported in approved casks. It has been demonstrated that SNF packages compliant with the branch standard, which is knowingly provide sufficient safety margin, will conform to the federal level regulations. The regulatory approval is required if a particular shipment does not comply with the branch standard. In this case, the shipment can be approved only after regulatory review of Applicant's documents to demonstrate that the shipment still conformant to the higher level (federal) regulations. The regulatory review frequently needs a full calculation test of the radiation safety assurance. This test can take a lot of time. That's why the special calculation tools were created in SEC NRS. These tools aimed for precision calculation of the radiation safety parameters by SNF transportation use preliminary calculated Green's functions. Such approach allows quickly simulate any source distribution and optimize spent fuel assemblies placement in cask due to the transport equation property of linearity relatively the source. The short description of calculation tools are presented. Also, the paper discusses foreseen implications related to transportation of mixed-oxide SNF. (author)

  13. Chemical and kinetic equilibrations via radiative parton transport

    International Nuclear Information System (INIS)

    Zhang Bin; Wortman, Warner A

    2011-01-01

    A hot and dense partonic system can be produced in the early stage of a relativistic heavy ion collision. How it equilibrates is important for the extraction of Quark-Gluon Plasma properties. We study the chemical and kinetic equilibrations of the Quark-Gluon Plasma using a radiative transport model. Thermal and Color-Glass-Condensate motivated initial conditions are used. We observe that screened parton interactions always lead to partial pressure isotropization. Different initial pressure anisotropies result in the same asymptotic evolution. Comparison of evolutions with and without radiative processes shows that chemical equilibration interacts with kinetic equilibration and radiative processes can contribute significantly to pressure isotropization.

  14. Signal Processing Model for Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D H

    2008-07-28

    This note describes the design of a simplified gamma ray transport model for use in designing a sequential Bayesian signal processor for low-count detection and classification. It uses a simple one-dimensional geometry to describe the emitting source, shield effects, and detector (see Fig. 1). At present, only Compton scattering and photoelectric absorption are implemented for the shield and the detector. Other effects may be incorporated in the future by revising the expressions for the probabilities of escape and absorption. Pair production would require a redesign of the simulator to incorporate photon correlation effects. The initial design incorporates the physical effects that were present in the previous event mode sequence simulator created by Alan Meyer. The main difference is that this simulator transports the rate distributions instead of single photons. Event mode sequences and other time-dependent photon flux sequences are assumed to be marked Poisson processes that are entirely described by their rate distributions. Individual realizations can be constructed from the rate distribution using a random Poisson point sequence generator.

  15. IPOLE - semi-analytic scheme for relativistic polarized radiative transport

    Science.gov (United States)

    Mościbrodzka, M.; Gammie, C. F.

    2018-03-01

    We describe IPOLE, a new public ray-tracing code for covariant, polarized radiative transport. The code extends the IBOTHROS scheme for covariant, unpolarized transport using two representations of the polarized radiation field: In the coordinate frame, it parallel transports the coherency tensor; in the frame of the plasma it evolves the Stokes parameters under emission, absorption, and Faraday conversion. The transport step is implemented to be as spacetime- and coordinate- independent as possible. The emission, absorption, and Faraday conversion step is implemented using an analytic solution to the polarized transport equation with constant coefficients. As a result, IPOLE is stable, efficient, and produces a physically reasonable solution even for a step with high optical depth and Faraday depth. We show that the code matches analytic results in flat space, and that it produces results that converge to those produced by Dexter's GRTRANS polarized transport code on a complicated model problem. We expect IPOLE will mainly find applications in modelling Event Horizon Telescope sources, but it may also be useful in other relativistic transport problems such as modelling for the IXPE mission.

  16. DIAPHANE: A portable radiation transport library for astrophysical applications

    Science.gov (United States)

    Reed, Darren S.; Dykes, Tim; Cabezón, Rubén; Gheller, Claudio; Mayer, Lucio

    2018-05-01

    One of the most computationally demanding aspects of the hydrodynamical modelingof Astrophysical phenomena is the transport of energy by radiation or relativistic particles. Physical processes involving energy transport are ubiquitous and of capital importance in many scenarios ranging from planet formation to cosmic structure evolution, including explosive events like core collapse supernova or gamma-ray bursts. Moreover, the ability to model and hence understand these processes has often been limited by the approximations and incompleteness in the treatment of radiation and relativistic particles. The DIAPHANE project has focused on developing a portable and scalable library that handles the transport of radiation and particles (in particular neutrinos) independently of the underlying hydrodynamic code. In this work, we present the computational framework and the functionalities of the first version of the DIAPHANE library, which has been successfully ported to three different smoothed-particle hydrodynamic codes, GADGET2, GASOLINE and SPHYNX. We also present validation of different modules solving the equations of radiation and neutrino transport using different numerical schemes.

  17. Academic Training - The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28, 29 June 11:00-12:00 - TH Conference Room, bldg. 4 The use of Monte Carlo radiation transport codes in radiation physics and dosimetry F. Salvat Gavalda,Univ. de Barcelona, A. FERRARI, CERN-AB, M. SILARI, CERN-SC Lecture 1. Transport and interaction of electromagnetic radiation F. Salvat Gavalda,Univ. de Barcelona Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interaction models and multiple-scattering theories will be analyzed. Benchmark comparisons of simu...

  18. Some factors affecting radiative heat transport in PWR cores

    International Nuclear Information System (INIS)

    Hall, A.N.

    1989-04-01

    This report discusses radiative heat transport in Pressurized Water Reactor cores, using simple models to illustrate basic features of the transport process. Heat transport by conduction and convection is ignored in order to focus attention on the restrictions on radiative heat transport imposed by the geometry of the heat emitting and absorbing structures. The importance of the spacing of the emitting and absorbing structures is emphasised. Steady state temperature distributions are found for models of cores which are uniformly heated by fission product decay. In all of the models, a steady state temperature distribution can only be obtained if the central core temperature is in excess of the melting point of UO 2 . It has recently been reported that the MIMAS computer code, which takes into account radiative heat transport, has been used to model the heat-up of the Three Mile Island-2 reactor core, and the computations indicate that the core could not have reached the melting point of UO 2 at any time or any place. We discuss this result in the light of the calculations presented in this paper. It appears that the predicted stabilisation of the core temperatures at ∼ 2200 0 C may be a consequence of the artificially large spacing between the radial rings employed in the MIMAS code, rather than a result of physical significance. (author)

  19. Radiation curing technology progress and its industrial applications in Japan

    International Nuclear Information System (INIS)

    Ukachi, Takashi

    2003-01-01

    Optics, electronics and display industries are now the driving forces for the Japanese radiation curing technology. The purpose of this paper is to overview the newly developed radiation curing technology in Japan, in particular, its industrial applications, and to present the market figures in radiation curing applications, which were surveyed by RadTech Japan in 2002 afresh. (author)

  20. DOE program for transportation R and D: a progress report

    International Nuclear Information System (INIS)

    Sisler, J.A.

    1978-01-01

    The Transportation Branch of the Division of Environmental Control Technology (ECT), US Department of Energy (DOE), is managing a research and development program oriented toward the environmental and safety aspects of the transportation of energy materials. This program was started under the US Energy Research and Development Administration (ERDA), and in October 1977 became one of the programs of the newly formed DOE. The objectives of the current R and D program include: (1) development of data and methodology for environment and safety (E and S) assessments including development of transportation environmental data, severe accident analysis and risk assessment; (2) confirmatory full-scale testing of package and vehicular systems to improve scale modeling and analytical techniques for transport system safety assessment; (3) development of an improved capability for assessing the dynamic performance of nuclear packaging under severe accident conditions; (4) evaluation and verification of existing transportation standards to assure adequate environmental controls; and (5) development of the needed information system tools such as films, booklets, and exhibits to permit the public and other interested parties to have access to the results of the R and D program. This paper summarizes the history of this program, describes the accomplishments, includes references to published reports, and discusses the current status of the environmental and safety R and D program as related to transportation of energy material. Comments are also included regarding the future direction of the program

  1. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 4, August 2014

    International Nuclear Information System (INIS)

    2014-08-01

    IAEA’s Division of Radiation, Transport and Waste Safety is assisting Member States to develop national strategies for education and training in radiation, transport and waste safety via the regional projects on “Strengthening Education and Training Infrastructure, and Building Competence in Radiation Safety” (RAF/9/04, RAS/9/066, RER/9/109 and RLA/9/070). The regional workshops conducted in 2012 in this area and the results achieved were presented in the previous issues of this newsletter focussing specifically on each region of the Technical Cooperation Programme (Africa, Asia and the Pacific, Europe and Latin America). In the course of 2013, a new cycle of Regional Workshops was conducted. The workshops held in the regions of Africa, Asia and the Pacific, and Europe mainly focussed on Sharing Experience and Progress made in establishing a National Strategy for Education and Training in Radiation, Transport and Waste Safety (pages 2-5). The workshop held in the region of Latin America mainly focussed on Developing and Implementing Education and Training programmes. An overview on the results achieved by participating Member States for the period 2012-2013 is provided

  2. Transport of radioactive materials: the need for radiation protection programmes

    International Nuclear Information System (INIS)

    Masinza, S.A.

    2004-01-01

    The increase in the use of radioactive materials worldwide requires that these materials be moved from production sites to the end user or in the case of radioactive waste, from the waste generator to the repository. Tens of millions of packages containing radioactive material are consigned for transport each year throughout the world. The amount of radioactive material in these packages varies from negligible quantities in shipments of consumer products to very large quantities of shipments of irradiated nuclear fuel. Transport is the main way in which the radioactive materials being moved get into the public domain. The public is generally unaware of the lurking danger when transporting these hazardous goods. Thus radiation protection programmes are important to assure the public of the certainty of their safety during conveyance of these materials. Radioactive material is transported by land (road and rail), inland waterways, sea/ocean and air. These modes of transport are regulated by international 'modal' regulations. The international community has formulated controls to reduce the number of accidents and mitigate their consequences should they happen. When accidents involving the transport of radioactive material occur, it could result in injury, loss of life and pollution of the environment. In order to ensure the safety of people, property and the environment, national and international transport regulations have been developed. The appropriate authorities in each state utilise them to control the transport of radioactive material. Stringent measures are required in these regulations to ensure adequate containment, shielding and the prevention of criticality in all spheres of transport, i.e. routine, minor incidents and accident conditions. Despite the extensive application of these stringent safety controls, transport accidents involving packages containing radioactive material have occurred and will continue to occur. When a transport accident occurs, it

  3. Application of radiation protection programmes to transport of radioactive material

    International Nuclear Information System (INIS)

    Lopez Vietri, Jorge; Capadona, Nancy; Barenghi, Leonardo

    2008-01-01

    Full text: The principles for implementing radiation protection programmes (RPP) are detailed in the draft IAEA safety guide TS-G-1.5 'Radiation protection programmes for transport of radioactive material'. The document is described in this paper and analysis is made for typical applications to current operations carried out by consignors, carriers and consignees. Systematic establishment and application of RPPs is a way to control radiological protection during different steps of transport activity. The most widely transported packages in the world are radiopharmaceuticals by road. It is described an application of RPP for an organization involved in road transport of Type A packages containing radiopharmaceuticals. Considerations based on the radionuclides, quantities and activities transported are the basis to design and establish the scope of the RPP for the organizations involved in transport. Next stage is the determination of roles and responsibilities for each activity related to transport of radioactive materials. An approach to the dose received by workers is evaluated considering the type, category and quantity of packages, the radionuclides, the frequency of consignments and how long are the storages. The average of transports made in the last years must be taken into account and special measures intended to optimize the protection are evaluated. Tasks like monitoring, control of surface contamination and segregation measures, are designed based on the dose evaluation and optimization. The RPP also indicates main measures to follow in case of emergency during transport taking account of radionuclides, activities and category of packages for different accident scenarios. Basis for training personnel involved in handling of radioactive materials to insure they have appropriate knowledge about preparing packages, measuring dose rates, calculating transport index, labelling, marking and placarding, transport documents, etc, are considered. The RPP is a part

  4. Transport-constrained extensions of collision and track length estimators for solutions of radiative transport problems

    International Nuclear Information System (INIS)

    Kong, Rong; Spanier, Jerome

    2013-01-01

    In this paper we develop novel extensions of collision and track length estimators for the complete space-angle solutions of radiative transport problems. We derive the relevant equations, prove that our new estimators are unbiased, and compare their performance with that of more conventional estimators. Such comparisons based on numerical solutions of simple one dimensional slab problems indicate the the potential superiority of the new estimators for a wide variety of more general transport problems

  5. Progress of radiation chemistry engineering in the USSR

    International Nuclear Information System (INIS)

    Breger, A.Kh.

    1988-01-01

    A brief review of works in the field of radiation chemistry engineering (RCE) in the recent 20 years is given. Main results of development of theoretic, engineering and economic bases for creating plants for realization of RCE processes using radionuclide (long- and short-living) γ radiation sources and electron accelerators, are considered. The current state in this field meets the requirements placed in connection with forthcoming wide introduction of radiation technology to the soviet industry

  6. Computer codes in nuclear safety, radiation transport and dosimetry

    International Nuclear Information System (INIS)

    Bordy, J.M.; Kodeli, I.; Menard, St.; Bouchet, J.L.; Renard, F.; Martin, E.; Blazy, L.; Voros, S.; Bochud, F.; Laedermann, J.P.; Beaugelin, K.; Makovicka, L.; Quiot, A.; Vermeersch, F.; Roche, H.; Perrin, M.C.; Laye, F.; Bardies, M.; Struelens, L.; Vanhavere, F.; Gschwind, R.; Fernandez, F.; Quesne, B.; Fritsch, P.; Lamart, St.; Crovisier, Ph.; Leservot, A.; Antoni, R.; Huet, Ch.; Thiam, Ch.; Donadille, L.; Monfort, M.; Diop, Ch.; Ricard, M.

    2006-01-01

    The purpose of this conference was to describe the present state of computer codes dedicated to radiation transport or radiation source assessment or dosimetry. The presentations have been parted into 2 sessions: 1) methodology and 2) uses in industrial or medical or research domains. It appears that 2 different calculation strategies are prevailing, both are based on preliminary Monte-Carlo calculations with data storage. First, quick simulations made from a database of particle histories built though a previous Monte-Carlo simulation and secondly, a neuronal approach involving a learning platform generated through a previous Monte-Carlo simulation. This document gathers the slides of the presentations

  7. Radiation transport modelling for the interpretation of oblique ECE measurements

    Directory of Open Access Journals (Sweden)

    Denk Severin S.

    2017-01-01

    Since radiation transport modelling is required for the interpretation of oblique ECE diagnostics we present in this paper an extended forward model that supports oblique lines of sight. To account for the refraction of the line of sight, ray tracing in the cold plasma approximation was added to the model. Furthermore, an absorption coefficient valid for arbitrary propagation was implemented. Using the revised model it is shown that for the oblique ECE Imaging diagnostic at ASDEX Upgrade there can be a significant difference between the cold resonance position and the point from which most of the observed radiation originates.

  8. Recent status and progress of radiation processing in the world

    International Nuclear Information System (INIS)

    Lee, Yun Jong; Lee, Byoung Hun; Im, Don Sun; Kim, Jae Ho; Nho, Young Chang

    2008-01-01

    Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications

  9. Radiation protection programme progress report 1985-89. Volume 1

    International Nuclear Information System (INIS)

    1991-01-01

    The final report of the 1985-89 radiation protection programme outlines the research work carried out during the whole contractual period under all contracts between the Commission of the European Communities and research groups in the Member States. More than 700 scientists collaborated on this programme. Results of more than 440 projects are reported. They are grouped into six sectors: radiation dosimetry and its interpretation; behaviour and control of radionuclides in the environment; non-stochastic effects of ionizing radiation; radiation carcinogenesis; genetic effects of ionizing radiation; evaluation of radiation risks and optimization of protection. Within the framework programme, the aim of this scientific research is to improve the conditions of life with respect to work and protection of man and his environment and to assure safe production of energy, i.e.: (i) to improve methods necessary to protect workers and the population by updating the scientific basis for appropriate standards; (ii) to prevent and counteract harmful effects of radiation; (iii) to assess radiation risks and provide methods to cope with the consequences of radiation accidents

  10. Radiation protection programme progress report 1985-89. Volume 3

    International Nuclear Information System (INIS)

    1991-01-01

    The final report of the 1985-89 radiation protection programme outlines the research work carried out during the whole contractual period under all contracts between the Commission of the European Communities and research groups in the Member States. More than 700 scientists collaborated on this programme. Results of more than 440 projects are reported. They are grouped into six sectors: radiation dosimetry and its interpretation; behaviour and control of radionuclides in the environment; non-stochastic effects of ionizing radiation; radiation carcinogenesis; genetic effects of ionizing radiation; evaluation of radiation risks and optimization of protection. Within the framework programme, the aim of this scientific research is to improve the conditions of life with respect to work and protection of man and his environment and to assure safe production of energy, i.e.: (i) to improve methods necessary to protect workers and the population by updating the scientific basis for appropriate standards; (ii) to prevent and counteract harmful effects of radiation; (iii) to assess radiation risks and provide methods to cope with the consequences of radiation accidents

  11. Recent status and progress of radiation processing in the world

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Jong; Lee, Byoung Hun; Im, Don Sun; Kim, Jae Ho; Nho, Young Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

    2008-01-15

    Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications.

  12. Radiation protection programme progress report 1985-89. Volume 2

    International Nuclear Information System (INIS)

    1991-01-01

    The final report of the 1985-89 radiation protection programme outlines the research work carried out during the whole contractual period under all contracts between the Commission of the European Communities and research groups in the Member States. More than 700 scientists collaborated on this programme. Results of more than 440 projects are reported. They are grouped into six sectors: radiation dosimetry and its interpretation; behaviour and control of radionuclides in the environment; non-stochastic effects of ionizing radiation; radiation carcinogenesis; genetic effects of ionizing radiation; evaluation of radiation risks and optimization of protection. Within the framework programme, the aim of this scientific research is to improve the conditions of life with respect to work and protection of man and his environment and to assure safe production of energy, i.e.: (i) to improve methods necessary to protect workers and the population by updating the scientific basis for appropriate standards; (ii) to prevent and counteract harmful effects of radiation; (iii) to assess radiation risks and provide methods to cope with the consequences of radiation accidents

  13. Recent Progress on Understanding SEP Acceleration and Transport

    Science.gov (United States)

    Cohen, C.

    2017-12-01

    Joint observations between near-Earth spacecraft and the twin STEREO spacecraft have allowed new examinations of the longitudinal extent of solar energetic particles (SEPs). Although the radial dependence will not be measured in detail until Parker Solar Probe and Solar Orbiter have launched, recent developments in modeling SEP acceleration and transport have revealed interesting dependences on magnetic field configurations and the characteristics of seed particle populations. This talk will review recent SEP in-situ observations along with theoretical studies and their implications for our understanding of SEP acceleration and transport in the inner heliosphere and our expectations for upcoming Solar Orbiter and Parker Solar Probe observations.

  14. Hybrid formulation of radiation transport in optically thick divertor plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rosato, J.; Marandet, Y.; Bufferand, H.; Stamm, R. [PIIM, UMR 7345 Aix-Marseille Universite / CNRS, Centre de St-Jerome, Marseille (France); Reiter, D. [IEK-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Juelich (Germany)

    2016-08-15

    Kinetic Monte Carlo simulations of coupled atom-radiation transport in optically thick divertor plasmas can be computationally very demanding, in particular in ITER relevant conditions or even larger devices, e.g. for power plant divertor studies. At high (∝ 10{sup 15} cm{sup -3}) atomic densities, it can be shown that sufficiently large divertors behave in certain areas like a black body near the first resonance line of hydrogen (Lyman α). This suggests that, at least in part, the use of continuum model (radiation hydrodynamics) can be sufficiently accurate, while being less time consuming. In this work, we report on the development of a hybrid model devoted to switch automatically between a kinetic and a continuum description according to the plasma conditions. Calculations of the photo-excitation rate in a homogeneous slab are performed as an illustration. The outlined hybrid concept might be also applicable to neutral atom transport, due to mathematical analogy of transport equations for neutrals and radiation. (copyright 2016 The Authors. Contributions to Plasma Physics published by Wiley-VCH Verlag GmbH and Co. KGaA Weinheim. This)

  15. Radiation damage and repair in cells and cell components. Progress report: third new contract year

    International Nuclear Information System (INIS)

    Fluke, D.J.; Pollard, E.C.

    1980-01-01

    Research progress for 1979-1980 is reported. Projects discussed include the process of radiation-induced repair, Weigle-reactivation, induced radioresistance, the induction of the recA gene product, uv mutagenesis, and the induction of lambda

  16. Radiation physics and biology: Progress report for period December 1, 1986-November 30, 1987

    International Nuclear Information System (INIS)

    Rubin, J.S.

    1987-04-01

    This annual report describes progress made on 14 individual research projects. These projects fall naturally into theoretical biophysics, experimental microdosimetry and radiation biology. Each project has been separately abstracted for the Energy Data Base

  17. Recent progress towards a quantitative description of filamentary SOL transport

    DEFF Research Database (Denmark)

    Carralero, D.; Siccinio, M.; Komm, M.

    2017-01-01

    A summary of recent results on filamentary transport, mostly obtained with the ASDEX-Upgrade tokamak (AUG), is presented and discussed in an attempt to produce a coherent picture of scrape-off layer (SOL) filamentary transport. A clear correlation is found between L-mode density shoulder formation...... in the outer midplane and a transition between the sheath-limited and the inertial filamentary regimes. Divertor collisionality is found to be the parameter triggering the transition. A clear reduction of the ion temperature takes place in the far SOL after the transition, both for the background......-mode plasmas, although a secondary threshold related to deuterium fueling is observed. EMC3-EIRENE simulations of neutral dynamics show that an ionization front near the main chamber wall is formed after the shoulder formation. Finally, a clear increase of SOL opacity to neutrals is observed, associated...

  18. Progress in nuclear well logging modeling using deterministic transport codes

    International Nuclear Information System (INIS)

    Kodeli, I.; Aldama, D.L.; Maucec, M.; Trkov, A.

    2002-01-01

    Further studies in continuation of the work presented in 2001 in Portoroz were performed in order to study and improve the performances, precission and domain of application of the deterministic transport codes with respect to the oil well logging analysis. These codes are in particular expected to complement the Monte Carlo solutions, since they can provide a detailed particle flux distribution in the whole geometry in a very reasonable CPU time. Real-time calculation can be envisaged. The performances of deterministic transport methods were compared to those of the Monte Carlo method. IRTMBA generic benchmark was analysed using the codes MCNP-4C and DORT/TORT. Centric as well as excentric casings were considered using 14 MeV point neutron source and NaI scintillation detectors. Neutron and gamma spectra were compared at two detector positions.(author)

  19. Background and Recent Progress in Anomalous Transport Simulation

    Science.gov (United States)

    2017-07-19

    variations Azimuthal E field normalized by the imposed electric field along the channel Electron density normalized by the initial plasma density used in the...Threshold electron two-stream instability Threshold for ion participation in two- stream instability Note: Analysis is for electron -H+ plasma 10DISTRIBUTION A...distribution unlimited PA# 17447 Fundamental Challenge Modeling electron Transport across B-field • Classical formulation for fluid mobility based on

  20. Research on gas transport in chimneys: a progress report

    International Nuclear Information System (INIS)

    Hearst, J.R.

    1986-01-01

    The results of the AGRINI and TIERRA experiments have led us to study three general topics: collapse phenomenology, CO 2 content measurement, and gas transport in chimneys. Our results so far are fragmentary, but we have been able to come to some tentative conclusions: (1) a layer of strong material between depths of 24 and 32 m, and perhaps some relatively strong material deeper, may have caused the AGRINI crater shape. This layer was absent at the nearby LABAN and CROWDIE events. We were unable to locate the layer with a surface penetrometer or surface seismic methods, but it may be possible to measure strength vs depth in situ by examining the penetration depth of a projectile. (2) We can probably improve our knowledge of the in situ CO 2 content by calibrating a commercial carbon/oxygen logging system for NTS conditions. (3) It is possible to measure the response of the gas in a chimney to changes in atmospheric pressure. There can be significantly different gas transport in chimneys with the same pressure response, depending on the porosity and the distribution of the porosity. It is possible to perform an inexpensive experiment to study the gas transport in an existing chimney

  1. Progress in radiation application to industry and agriculture

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2006-01-01

    Utilization of radiation in Japan has been actively promoted by various agencies including the Takasaki Radiation Chemistry Research Establishment of JAERI (presently Japan Atomic Energy Agency: JAEA). The JAEA-Takasaki was established in April 1963 for the purpose of promoting research and development (R and D) activities with gamma rays and electron beams. The JAEA-Takasaki's activities were addressed principally to industry and agriculture. In Japan, purpose of utilization of radiation is aiming at increasing welfare and quality of life of our peoples. (author)

  2. Dispersive effects in radiation transport and radiation hydrodynamics in matter at high density

    International Nuclear Information System (INIS)

    Crowley, B.J.B.

    1983-01-01

    In a recent research program (reported in AWRE 0 20/82) I have investigated the generalisation of the equations of radiation hydrodynamics when electromagnetic radiation is assumed to obey a linear-response dispersion relation of the form nω=kc where the refractive index n depends on the frequency ω and/or wave number k. From the application of the Boltzmann-Liouville transport theory to photons in the short-wavelength (geometrical optics) limit, I derive the energy and momentum equations which, when combined with a classical (Euler-Lagrange-Navier-Stokes) treatment of a fluid material medium in LTE, yield a complete dynamical theory of linear interactions (+ stimulated processes) between incoherent (thermal) radiation and dense, locally isotropic matter. The theory includes an account of pondero-motive forces and electro (magneto) striction. Moreover, it is apparently capable of being generalised to non-linear interactions in which the refractive index depends on the local specific intensity of the radiation field, and, to some extent, to the treatment of high-frequency coherent radiation. The generalisation of various approximated forms of radiation-transport theory (esp. diffusion) has been considered in detail. Some problems remain however. One such is the treatment of anomalous dispersion. Current research work is concentrating on the interesting atomic physics aspects of electromagnetic (esp. radiative) properties of a dispersive material medium

  3. Department of Environmental and Radiation Transport Physics - Overview

    International Nuclear Information System (INIS)

    Woznicka, U.

    2001-01-01

    Full text: We deal with environmental physics and the radiation transport physics, both theoretically and experimentally. Some results find their way to practical applications. Our environmental physics research encompasses hydrogeological problems as well as measurements of trace elements in the atmosphere and in the water. Theoretical (analytical and numerical) and experimental issues of the radiation transport and radiation fields are our main field of research. The interest in radiation transport phenomena is stimulated by their importance for the environmental physics, industrial and nuclear facilities and methods of geophysical. Environmental isotopes and noble gases are used in the investigation of water-bearing geological formations in order to determine the origin and age of groundwater. The papers listed below and three ''Reports on research'' present recent achievements in this field. The gas chromatography methods are used for monitoring the anthropogenic trace gases (SF 6 and freons), which participate in the Earth green-house effect. A very high detection level of SF 6 in water, 0.0028 fg/cm 3 H 2 0, has been reached as required for hydrogeological purposes. A preliminary verification of the SF 6 tracer method for dating young groundwaters by the tritium method has been carried out. We carried on the work on a method of radon measurement in soil in connection with geological conditions. The national seminar ''Radon in Environment'' organized at the INP aroused an interest of Polish scientific centres in that field. The seminar gathered 60 participants who presented 24 oral reports and 8 posters. Within the scope of the radiation transport physics we studied thermal neutron transport in finite hydrogenous media. Advantages and limitations of a Monte Carlo code (MCNP) in thermal neutron transport simulations have been examined by both the analytical solution and the experiment on the INP pulsed neutron generator. An interesting contribution to the

  4. Radiation doses arising from the air transport of radioactive materials

    International Nuclear Information System (INIS)

    Gelder, R.; Shaw, K.B.; Wilson, C.K.

    1989-01-01

    There is a compelling need for the transport of radioactive material by air because of the requirement by hospitals throughout the world for urgent delivery for medical purposes. Many countries have no radionuclide-producing capabilities and depend on imports: a range of such products is supplied from the United Kingdom. Many of these are short lived, which explains the need for urgent delivery. The only satisfactory method of delivery on a particular day to a particular destination is often by the use of scheduled passenger air service. The International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO 1987-1988), prescribe the detailed requirements applicable to the international transport of dangerous goods by air. Radioactive materials are required to be separated from persons and from undeveloped photographic films or plates: minimum distances as a function of the total sum of transport indexes are given in the Instructions. A study, which included the measurement and assessment of the radiation doses resulting from the transport of radioactive materials by air from the UK, has been performed by the National Radiological Protection Board (NRPB) on behalf of the Civil Aviation Authority (CAA) and the Department of Transport (DTp)

  5. Earth as a radio source: terrestrial kilometric radiation. Progress report

    International Nuclear Information System (INIS)

    Gurnett, D.A.

    1974-02-01

    Radio wave experiments on the IMP-6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range from about 50 kHz to 500 kHz. A peak intensity the total power emitted in this frequency range is about 1 billion watts. The earth is, therefore, a very intense planetary radio source, with a total power output comparable to the decametric radio emission from Jupiter. This radio emission from the earth is referred to as terrestrial kilometric radiation. Terrestrial kilometric radiation appears to originate from low altitudes (less than 3.0 Re) in the auroral region. Possible mechanisms which can explain the generation and propagation of the terrestrial kilometric radiation are discussed. (U.S.)

  6. Atmospheric transport, clouds and the Arctic longwave radiation paradox

    Science.gov (United States)

    Sedlar, Joseph

    2016-04-01

    Clouds interact with radiation, causing variations in the amount of electromagnetic energy reaching the Earth's surface, or escaping the climate system to space. While globally clouds lead to an overall cooling radiative effect at the surface, over the Arctic, where annual cloud fractions are high, the surface cloud radiative effect generally results in a warming. The additional energy input from absorption and re-emission of longwave radiation by the clouds to the surface can have a profound effect on the sea ice state. Anomalous atmospheric transport of heat and moisture into the Arctic, promoting cloud formation and enhancing surface longwave radiation anomalies, has been identified as an important mechanism in preconditioning Arctic sea ice for melt. Longwave radiation is emitted equally in all directions, and changes in the atmospheric infrared emission temperature and emissivity associated with advection of heat and moisture over the Arctic should correspondingly lead to an anomalous signal in longwave radiation at the top of the atmosphere (TOA). To examine the role of atmospheric heat and moisture transport into the Arctic on TOA longwave radiation, infrared satellite sounder observations from AIRS during 2003-2014 are analyzed for summer (JJAS). Thermodynamic metrics are developed to identify months characterized by a high frequency of warm and moist advection into the Arctic, and segregate the 2003-14 time period into climatological and anomalously warm, moist summer months. We find that anomalously warm, moist months result in a significant TOA longwave radiative cooling, which is opposite the forcing signal that the surface experiences during these months. At the timescale of the advective events, 3-10 days, the TOA cooling can be as large as the net surface energy budget during summer. When averaged on the monthly time scale, and over the full Arctic basin (poleward of 75°N), summer months experiencing frequent warm, moist advection events are

  7. The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

    CERN Multimedia

    CERN. Geneva; Ferrari, Alfredo; Silari, Marco

    2006-01-01

    Transport and interaction of electromagnetic radiation Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. In these codes, photon transport is simulated by using the detailed scheme, i.e., interaction by interaction. Detailed simulation is easy to implement, and the reliability of the results is only limited by the accuracy of the adopted cross sections. Simulations of electron and positron transport are more difficult, because these particles undergo a large number of interactions in the course of their slowing down. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interacti...

  8. Recent progress towards a quantitative description of filamentary SOL transport

    Czech Academy of Sciences Publication Activity Database

    Carralero, D.; Siccinio, M.; Komm, Michael; Artene, S.A.; D’Isa, F.A.; Adámek, Jiří; Aho-Mantila, L.; Birkenmeier, G.; Brix, M.; Fuchert, G.; Groth, M.; Lunt, T.; Manz, P.; Madsen, J.; Marsen, S.; Müller, H.W.; Stroth, U.; Sun, H.J.; Vianello, N.; Wischmeier, M.; Wolfrum, E.

    2017-01-01

    Roč. 57, č. 5 (2017), č. článku 056044. ISSN 0029-5515. [IAEA Fusion Energy Conference/26./. Kyoto, 17.10.2016-22.10.2016] EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : ASDEX-Upgrade * SOL transport * filaments * main wall recycling Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/1741-4326/aa64b3

  9. National Council on Radiation Protection and Measurements semiannual technical progress report, March 1989--August 1989

    International Nuclear Information System (INIS)

    Ney, W.R.

    1991-01-01

    This semiannual technical progress report is for the period 1 March 1989 through 31 August 1989. This National Council on Radiation Protection and Measurements (NCRP) program is designed to provide recommendations for radiation protection based on scientific principles. During this period several reports were published covering the topics of occupational radiation exposure, medical exposure, radon control, dosimetry, and radiation protection standards. Accomplishments of various committees are also reported; including the committees on dental x-ray protection, radiation safety in uranium mining and milling, ALARA, instrumentation, records maintenance, occupational exposures of medical personnel, emergency planning, and others. (SM)

  10. Radioactive materials' transportation main routes in Brazil. Radiation protection aspects about radioactive materials transportation

    International Nuclear Information System (INIS)

    Vaz, Solange dos Reis e; Andrade, Fernando de Menezes; Aleixo, Luiz Claudio Martins

    2007-01-01

    The heavy transportation in Brazil is generally done by highways. The radioactive material transportation follow this same rule. Whenever a radioactive material is carried by the road, by the sea or by the air, in some cases, a kind of combination of those transportation ways, the transport manager has to create a Transportation Plan and submit it to CNEN. Only after CNEN's approval, the transportation can be done. The plan must have the main action on Radiation Protection, giving responsibilities and showing all the directing that will be take. Although, the Brazilian's highways are not in good conditions, one could say that some of them are not good enough for any kind of transportation. But we are facing radioactive material use increase but the hospitals and industries, that the reason it's much more common that kind of transportation nowadays. So, because of that, a special attention by the governments must be provide to those activities. This paper goal is to show the real conditions of some important highways in Brazil in a radioactive protection's perspective and give some suggestions to adjust some of those roads to this new reality. (author)

  11. Radiation carcinogenesis. Comprehensive three-year progress report, 1 May 1972--15 March 1976

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1976-03-01

    Progress is reported on studies on the pathological effects of various doses of x radiation on rats and mice, with emphasis on radioinduced carcinogenesis in parabiont rats with one of the pair exposed to 1000 R of whole body x radiation and the other shielded. Results are included from studies on alterations in metabolic parameters and life span induced by irradiation

  12. Relationship between stage II transport and number of chewing strokes as mastication progresses.

    Science.gov (United States)

    Yamashita, Shuichiro; Sugita, Daisuke; Matsuo, Koichiro

    2013-10-02

    As mastication progresses, little is known about the occurrence of the stage II transport (oro-pharyngeal bolus transport). This study aimed to investigate the relationship between stage II transport and bolus aggregation in the pharynx and the number of chewing strokes. Twenty-five clinical residents with natural dentitions were recruited. The subjects were asked to chew gummy jelly with their preferred rhythm and to swallow the bolus at their preferred timing. To investigate stage II transport and bolus aggregation in the pharynx, a transnasal endoscope was used. The number of chewing strokes was measured by electromyographic activity from the masseter muscle. The mean numbers of chewing strokes of pre-stage II transport and post-stage II transport were 29.8 and 8.1, respectively; the difference was significant (pchewing strokes of pre-stage II transport to that of post-stage II transport was 4.0 to 1.0. This study showed that stage II transport started at four-fifths of the way along the progress of mastication, and that stage II transport and bolus aggregation in the pharynx are related to the number of chewing strokes. © 2013. Published by Elsevier Inc. All rights reserved.

  13. Molecular mechanisms in radiation damage to DNA. Progress report

    International Nuclear Information System (INIS)

    Osman, R.

    1994-01-01

    The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypotheses regarding the processes of impairment of regulation of gene expression, alteration in DNA repair, and damage to DNA structure involved in cell death or cancer

  14. Problems and progress in radiation physics of semiconductors

    International Nuclear Information System (INIS)

    Vinetskij, V.L.

    1982-01-01

    A survey of the current status of radiation physics of semiconductors comprises the analysis of some new problems and poses the statement of concern. The essential difference between the probability of interstitial-vacancy pair occurrence W(T) in elastic collisions and the generally accepted step distribution with a typical ''threshold'' energy Tsub(d) is indicated. The role of diffusion and reaction evolution of primary defects leading to specific properties of the cluster formation process is shown. Special features of defect formation in spatially inhomogeneous semiconductors, in particular for elastic stresses present, are described. Among most important advances in the radiation physics of semiconductors there are the discovery of non-activation motion of the ''extra'' atom in silicon, the observation of a low activation energy value for the vacancy diffusion, the understanding of subthreshold mechanism of defect formation and radiation-induced diffusion, the effects of laser annealing of defects and oriented crystallization

  15. Progress report on the neutral beam radiation hardening study

    International Nuclear Information System (INIS)

    Lee, J.D.; Condit, R.H.; Hoenig, C.L.; Wilcox, T.P.; Erickson, J.

    1978-01-01

    A neutral beam injector as presently conceived directly views the plasma it is sustaining. In turn the injector is exposed to the primary fusion neutrons plus secondary neutrons and gammas streaming back up the neutral beam duct. The intent of this work is to examine representative beam lines to see how performance and lifetimes could be affected by this radiation environment and to determine how unacceptable effects could be alleviated. Potential radiation induced problems addressed in this report have been limited to: (1) overheating of cryopanels and insulators, (2) gamma flux induced electrical conductivity increase of insulators, and (3) neutron and gamma fluence induced damage to insulator materials

  16. Attenuation of radiological consequences from CDA's by radiation. Progress report, October 1, 1976--September 31, 1977

    International Nuclear Information System (INIS)

    Chan, S.H.

    1977-01-01

    This technical progress report summarizes the research work accomplished during the first six months of the investigation on the significance of radiation heat transfer in attenuating the radiological consequences from LMFBR core disruptive accidents. Considerable progress has been made in modeling and computing the effects of radiative cooling on a rising HCDA bubble buoyant through a sodium pool. Our results reveal that most of the fuel vapor within the bubble can be effectively condensed out by radiating cooling. The finding has a profound implication as it could lead to a substantial reduction in subsequent aerosal releases

  17. Institute for Radiation Research and Nuclear Physics. Progress report 1990

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1990-01-01

    In this progress report all of the abstracts - except two - are of INIS interest. The topics of the branch sessions are (1) theoretical particle physics (2) nuclear reactions (3) evaluation of nuclear data (4) radionuclide metrology (5) applications of nuclear methods and (6) nuclear information processing. (botek)

  18. Institute for Radiation Research and Nuclear Physics. Progress report 1990

    Energy Technology Data Exchange (ETDEWEB)

    Strohmaier, B [comp.

    1991-12-31

    In this progress report all of the abstracts - except two - are of INIS interest. The topics of the branch sessions are (1) theoretical particle physics (2) nuclear reactions (3) evaluation of nuclear data (4) radionuclide metrology (5) applications of nuclear methods and (6) nuclear information processing. (botek).

  19. Institute for Radiation Research and Nuclear Physics. Progress report 1991

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1991-01-01

    In this progress report all of the abstracts are of INIS interest. The topics of the branch sessions are (1) theoretical particle physics (2) nuclear reactions (3) evaluation of nuclear data (4) applications of nuclear methods and (5) environmental investigations. (botek)

  20. Institute for Radiation Research and Nuclear Physics. Progress report 1991

    Energy Technology Data Exchange (ETDEWEB)

    Strohmaier, B [comp.

    1992-12-31

    In this progress report all of the abstracts are of INIS interest. The topics of the branch sessions are (1) theoretical particle physics (2) nuclear reactions (3) evaluation of nuclear data (4) applications of nuclear methods and (5) environmental investigations. (botek).

  1. Radiation safety of crew and passengers of air transportation in civil aviation. Provisional standards

    Science.gov (United States)

    Aksenov, A. F.; Burnazyan, A. I.

    1985-01-01

    The purpose and application of the provisional standards for radiation safety of crew and passengers in civil aviation are given. The radiation effect of cosmic radiation in flight on civil aviation air transport is described. Standard levels of radiation and conditions of radiation safety are discussed.

  2. Estimated routine radiation doses to transportation workers in alternative spent-fuel transportation systems

    International Nuclear Information System (INIS)

    Schneider, K.J.; Smith, R.I.; Daling, P.M.; Ross, W.A.; McNair, G.W.

    1988-01-01

    The federal system for the management of spent fuel and high-level radioactive waste includes the acceptance by the US Department of Energy (DOE) of the spent fuel or waste loaded in casks at the reactor or other waste generators, its transportation to a repository, and its handling and final emplacement in the repository. The DOE plans to implement a transportation system that is safe, secure, efficient, and cost-effective and will meet applicable regulatory safety and security requirements. The DOE commissioned the Pacific Northwest Laboratory (PNL) to develop estimates of the routine radiation doses that would result from the operation of a system postulated using current designs and practices. From that evaluation, PNL identified activities/operations that result in the higher fraction of doses, proposed conceptual alternatives that would effectively reduce such exposures, and evaluated the cost-effectiveness of such alternatives. The study is one of a series used in making overall system design and operational decisions in the development of the DOE's spent-fuel/high-level waste transportation system. This paper contains the highlights from the PNL study of the estimated radiation doses to the transportation workers in a postulated reference transportation system and potential alternatives to that system

  3. Present status and expected progress in radiation processing dosimetry

    DEFF Research Database (Denmark)

    Kovács, A.; Miller, A.

    2004-01-01

    The paper describes the present status of radiation processing dosimetry including the methods used most widely in gamma- and electron processing as well as the new methods under development or introduction. The recent trends with respect to calibrationof routine dosimetry systems as well...

  4. The impact of coherent synchrotron radiation on the beam transport of short bunches

    International Nuclear Information System (INIS)

    Li, R.

    1999-01-01

    Designs for next-generation accelerator, such as future linear colliders and short-wavelength FEL drivers, require beams of short (mm-length or smaller) bunches and high charge (nC-regime). As such a high charge microbunch traverses magnetic bends, the curvature effect on the bunch self-interaction, by way of coherent synchrotron radiation (CSR) and space charge force, may cause serious emittance degradation. This impact of CSR on the beam transport of short bunches has raised significant concern in the design of future machines and led to extensive investigations. This paper reviews some of the recent progress in the understanding of the CSR effect, presents analysis of and computational work on the CSR impact on short bunch transport, and addresses remaining issues

  5. grmonty: A MONTE CARLO CODE FOR RELATIVISTIC RADIATIVE TRANSPORT

    International Nuclear Information System (INIS)

    Dolence, Joshua C.; Gammie, Charles F.; Leung, Po Kin; Moscibrodzka, Monika

    2009-01-01

    We describe a Monte Carlo radiative transport code intended for calculating spectra of hot, optically thin plasmas in full general relativity. The version we describe here is designed to model hot accretion flows in the Kerr metric and therefore incorporates synchrotron emission and absorption, and Compton scattering. The code can be readily generalized, however, to account for other radiative processes and an arbitrary spacetime. We describe a suite of test problems, and demonstrate the expected N -1/2 convergence rate, where N is the number of Monte Carlo samples. Finally, we illustrate the capabilities of the code with a model calculation, a spectrum of the slowly accreting black hole Sgr A* based on data provided by a numerical general relativistic MHD model of the accreting plasma.

  6. A FORMALISM FOR COVARIANT POLARIZED RADIATIVE TRANSPORT BY RAY TRACING

    International Nuclear Information System (INIS)

    Gammie, Charles F.; Leung, Po Kin

    2012-01-01

    We write down a covariant formalism for polarized radiative transfer appropriate for ray tracing through a turbulent plasma. The polarized radiation field is represented by the polarization tensor (coherency matrix) N αβ ≡ (a α k a* β k ), where a k is a Fourier coefficient for the vector potential. Using Maxwell's equations, the Liouville-Vlasov equation, and the WKB approximation, we show that the transport equation in vacuo is k μ ∇ μ N αβ = 0. We show that this is equivalent to Broderick and Blandford's formalism based on invariant Stokes parameters and a rotation coefficient, and suggest a modification that may reduce truncation error in some situations. Finally, we write down several alternative approaches to integrating the transfer equation.

  7. Radiation transport in high-level waste form

    International Nuclear Information System (INIS)

    Arakali, V.S.; Barnes, S.M.

    1992-01-01

    The waste form selected for vitrifying high-level nuclear waste stored in underground tanks at West Valley, NY is borosilicate glass. The maximum radiation level at the surface of a canister filled with the high-level waste form is prescribed by repository design criteria for handling and disposition of the vitrified waste. This paper presents an evaluation of the radiation transport characteristics for the vitreous waste form expected to be produced at West Valley and the resulting neutron and gamma dose rates. The maximum gamma and neutron dose rates are estimated to be less than 7500 R/h and 10 mRem/h respectively at the surface of a West Valley canister filled with borosilicate waste glass

  8. Compendium of Material Composition Data for Radiation Transport Modeling

    International Nuclear Information System (INIS)

    Williams, Ralph G.; Gesh, Christopher J.; Pagh, Richard T.

    2006-01-01

    Computational modeling of radiation transport problems including homeland security, radiation shielding and protection, and criticality safety all depend upon material definitions. This document has been created to serve two purposes: (1) to provide a quick reference of material compositions for analysts and (2) a standardized reference to reduce the differences between results from two independent analysts. Analysts are always encountering a variety of materials for which elemental definitions are not readily available or densities are not defined. This document provides a location where unique or hard to define materials will be located to reduce duplication in research for modeling purposes. Additionally, having a common set of material definitions helps to standardize modeling across PNNL and provide two separate researchers the ability to compare different modeling results from a common materials basis.

  9. Radiation transport methods for nuclear log assessment - an overview

    International Nuclear Information System (INIS)

    Badruzzaman, A.

    1996-01-01

    Methods of radiation transport have been applied to well-logging problems with nuclear sources since the early 1960s. Nuclear sondes are used in identifying rock compositions and fluid properties in reservoirs to predict the porosity and oil saturation. Early computational effort in nuclear logging used diffusion techniques. As computers became more powerful, deterministic transport methods and, finally, Monte Carlo methods were applied to solve these problems in three dimensions. Recently, the application has been extended to problems with a new generation of devices, including spectroscopic sondes that measure such quantities as the carbon/oxygen ratio to predict oil saturation and logging-while-drilling (LWD) sondes that take neutron and gamma measurements as they rotate in the borehole. These measurements present conditions that will be difficult to calibrate in the laboratory

  10. Molecular events basic to cellular radiation response. Progress report

    International Nuclear Information System (INIS)

    Kolodny, G.M.

    1976-01-01

    Studies on regulation of gene expression included research projects on turnover of ribosomal RNA, ribonuclease-resistant oligonucleotides, and reutilization of oligonucleotides. Studies on radiation effects on RNA included research projects on radioinduced strand breaks in RNA and radioinduced alterations in RNA nucleotides. Effects of vasopression on radiosensitivity were studied. Studies on amino acid-nucleic acid interactions included research projects on synthesis and spectroscopic analysis of nucleotide-amino acid covalently bonded model compound and intermolecular interactions between tryptophan and dinucleoside phosphates

  11. Reduction of the dose of ionizing radiation: progressions in TC

    International Nuclear Information System (INIS)

    Orlacchio, A.; Costanzo, E.; Chegai, F.; Simonetti, G.

    2014-01-01

    The optimization of the dose of ionizing radiation in CT, it is a very important matter that can be reach avoiding unnecessary examinations, using un appropriate report KV / mAs reducing the rotation time, determining the field of study, using a high pitch using equipment that provide systems with dose reduction, through proper education of the staff that interacts with machinery and using radioprotective compounds.

  12. Molecular events basic to cellular radiation response. Progress report

    International Nuclear Information System (INIS)

    Kolodny, G.M.

    1974-01-01

    Work during the past year has been focused on three areas related to the cellular effects of radiation. Radiation effects on RNA and the regulation of gene expression and amino acid-nucleic acid interactions were studied. Studies on the radiation response of RNA in growing and confluent cells were continued. We have derived radiation survival curves and demonstrated repair of potentially lethal damage in 3T3 cells. Studies of giant cell formation and turnover of ribosomal RNA in irradiated cells has demonstrated differences in growing and confluent cells. We have sought evidence consistent with our hypothesis for regulation of eukaryotic gene expression with segments of RNA reutilized to prime new RNA synthesis. Data derived from the turnover of ribosomal RNA and the methylation pattern of ribosomal RNA during turnover are consistent with the possibility that a segment of 18s ribosomal RNA is being conserved during new RNA synthesis. We were unable to show reutilization of the 5' trinucleotide of 18s and 28s ribosomal RNA but did find a ribonuclease resistant oligonucleotide in 18s RNA which appeared to be reutilized. In studies of amino acid nucleic-acid interactions using nuclear magnetic resonance spectroscopy we have been able to successfully synthesize an amidate and begin an examination of the intramolecular interactions. We have also studied intermolecular interactions betweentryptophan and nucleoside monophosphates and found upfield shifts which provide evidence for preferential stacking of the 6-membered ring of tryptophan with adenine and evidence for specific geometry of interactions of tryptophan with cytosine. (U.S.)

  13. Transport methods: general. 1. The Analytical Monte Carlo Method for Radiation Transport Calculations

    International Nuclear Information System (INIS)

    Martin, William R.; Brown, Forrest B.

    2001-01-01

    We present an alternative Monte Carlo method for solving the coupled equations of radiation transport and material energy. This method is based on incorporating the analytical solution to the material energy equation directly into the Monte Carlo simulation for the radiation intensity. This method, which we call the Analytical Monte Carlo (AMC) method, differs from the well known Implicit Monte Carlo (IMC) method of Fleck and Cummings because there is no discretization of the material energy equation since it is solved as a by-product of the Monte Carlo simulation of the transport equation. Our method also differs from the method recently proposed by Ahrens and Larsen since they use Monte Carlo to solve both equations, while we are solving only the radiation transport equation with Monte Carlo, albeit with effective sources and cross sections to represent the emission sources. Our method bears some similarity to a method developed and implemented by Carter and Forest nearly three decades ago, but there are substantive differences. We have implemented our method in a simple zero-dimensional Monte Carlo code to test the feasibility of the method, and the preliminary results are very promising, justifying further extension to more realistic geometries. (authors)

  14. Progress in fuel processing for PEMFC systems for transport applications

    Energy Technology Data Exchange (ETDEWEB)

    Dams, A J; Hayter, P R; Moore, S C

    1998-07-01

    Wellman CJB Limited has been developing fuel processors for PEMFC systems for transport applications using a range of feedstocks. Feedstocks that can be processed to produce a hydrogen-rich gas stream suitable for use with a PEMFC include methanol, gasoline, diesel, LPG, dimethylether, marine diesel and aviation fuel. The basic fuel processor is a steam reformer combined with a selective carbon monoxide oxidation stage. Depending on the nature of the liquid feedstock, other process steps will be required such as vaporizer, desulfurizer, pre-reformer and high and low temperature shift reactors. Work on methanol reforming has been specifically targeted at a PEMFC driven passenger car as part of a multinational European Community JOULE programme called MERCATOX. The objective is to develop and test a compact and fast response methanol reformer and gas clean-up unit to meet a car manufacturer's specification. The method of construction is to coat a methanol reforming catalyst onto one side of a metal corrugated plate. On the other side is a coated combustion catalyst which burns fuel cell off-gas to provide the endothermic heat for the methanol reforming reaction. A number of these plates are assembled in a compact unit ensuring good heat transfer. The gas clean-up unit is similarly constructed with a selective oxidation catalyst on one side and a thermal fluid on the other. Initial tests have indicated a superior performance to conventional packed bed reformers in terms of response and start-up time. Steam reforming of gasoline, diesel, LPG, dimethylether, marine diesel and aviation fuel has been demonstrated on a bench scale (0.5kW). The process steps commence with vaporization (except for LPG), desulfurization (except for dimethylether), prereforming, reforming, low and high temperature shift and selective oxidation. A simple technology demonstrator has shown that a hydrogen-rich mixture (75% hydrogen, 25% carbon dioxide) with less than 2ppm carbon monoxide can be

  15. Discussion of and guidance on the optimization of radiation protection in the transport of radioactive material

    International Nuclear Information System (INIS)

    1986-05-01

    The document provides guidance on one of the components of the system of dose limitation as it applies to the transport of radioactive material, namely the optimization of radiation protection. It focuses on the following parts of the transport system: design, maintenance, preparation for transport, transport, storage-in-transit and handling and it considers occupational and public exposures. The application is intended mainly for those transport situations within the regulatory requirements where potential radiation exposures could be beneficially reduced

  16. Radiation protection programmes for the transport of radioactive material. Safety guide

    International Nuclear Information System (INIS)

    2007-01-01

    This Safety Guide provides guidance on meeting the requirements for the establishment of radiation protection programmes (RPPs) for the transport of radioactive material, to optimize radiation protection in order to meet the requirements for radiation protection that underlie the Regulations for the Safe Transport of Radioactive Material. This Guide covers general aspects of meeting the requirements for radiation protection, but does not cover criticality safety or other possible hazardous properties of radioactive material. The annexes of this Guide include examples of RPPs, relevant excerpts from the Transport Regulations, examples of total dose per transport index handled, a checklist for road transport, specific segregation distances and emergency instructions for vehicle operators

  17. Radiation biophysicl study of biological molecules. Progress report, February 1, 1975--June 30, 1976

    International Nuclear Information System (INIS)

    Fluke, D.J.

    1976-01-01

    Progress is reported on the following research projects: direct action target investigation of molecular weights of enzymes exposed to fast electrons; direct action gamma radiation dosimetry with T 1 bacteriophage; uv radiation sensitivity of T 1 bacteriophage on various host strains of E. coli; temperature dependence of uv radiation direct action on dry T 1 bacteriophage; investigation of light and temperature effects during incubation of T 1 bacteriophage exposed to fast electrons; test of superoxide anion as a radiation intermediate in cellular radiobiology; uv action spectra related to error-prone repair; uv-reactivation experiments with T 1 and lambda bacteriophages; and split-dose uv mutagenesis in E. coli

  18. Some progress on radiation chemistry of substances of biological interests and biological applications of radiation technology in China

    International Nuclear Information System (INIS)

    Wu Jilan; Fang Xingwang

    1995-01-01

    Studies in China on the detection method of irradiated food, mechanism of DNA damage induced by peroxidation, radiolysis of natural products and herbs are reviewed on the update open literature, and some progress on applications of radiation technology is summarized. (author)

  19. Transport safety research abstracts. No. 2. Information on research recently concluded and in progress

    International Nuclear Information System (INIS)

    1994-09-01

    Transport Safety Research Abstracts (TSRA) was first published by the IAEA in 1991 as a means of disseminating information on research in radioactive material transport. This second edition utilizes International Nuclear Information System (INIS) protocol for data processing and report preparation for a research-in-progress database established by the IAEA's Division of Scientific and Technical Information. INIS subject categories and descriptors are included in the information about each project

  20. Transport safety research abstracts. No. 2. Information on research recently concluded and in progress

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    Transport Safety Research Abstracts (TSRA) was first published by the IAEA in 1991 as a means of disseminating information on research in radioactive material transport. This second edition utilizes International Nuclear Information System (INIS) protocol for data processing and report preparation for a research-in-progress database established by the IAEA`s Division of Scientific and Technical Information. INIS subject categories and descriptors are included in the information about each project.

  1. Study of Radiation Shielding Analysis for Low-Intermediate Level Waste Transport Ship

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dohyung; Lee, Unjang; Song, Yangsoo; Kim, Sukhoon; Ko, Jaehoon [Korea Nuclear Engineering and Service Corporation, Seoul (Korea, Republic of)

    2007-07-01

    In Korea, it is planed to transport Low-Intermediate Level Radioactive Waste (LILW) from each nuclear power plant site to Kyongju LILW repository after 2009. Transport through the sea using ship is one of the most prospective ways of LILW transport for current situation in Korea. There are domestic and international regulations for radiation dose limit for radioactive material transport. In this article, radiation shielding analysis for LILW transport ship is performed using 3-D computer simulation code, MCNP. As a result, the thickness and materials for radiation shielding walls next to cargo in the LILW transport ship are determined.

  2. Progress in basic principles of limitation in radiation protection

    International Nuclear Information System (INIS)

    Ramzaev, P.V.; Tarasov, S.I.; Troitskaya, M.N.; Ermolaeva, A.P.

    1977-01-01

    For purposes of limitation of harmful factors, e.g. radiation, it is proposed to divide all countless numbers of biological effects into three groups: 1) social important effects (ultimate and effects); 2) intermediate effects (different diseases etc.), which are connected with and controlled by the first group; 3) pure biological effects, importance of which is not known. To determine the first group effects there are identified four indices describing all significant sides of human life: time of life, life-time integral of mental and physical capacity for work, aesthetical satisfaction from organism itself, reproduction of descendants. They reflect the main social and individual interests related to functioning of organism. On the base of weighing these indices it is suggested the united general index of health in form of time of a full life. The united index can be used for different principles of limitation (based on threshold, acceptable risk, maximum benefit). To realize the principle of maximum public benefit as ideal principle in the future limitation all benefit and detriment from utilization of harmful sources must be expressed in the united index of health (instead of money), which is the greatest value of individual and society. Authors suggest to standartize ionizing radiation on the general methodological approaches that were acceptable to non-ionizing factors too

  3. Compendium of Material Composition Data for Radiation Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    McConn, Ronald J.; Gesh, Christopher J.; Pagh, Richard T.; Rucker, Robert A.; Williams III, Robert

    2011-03-04

    Introduction Meaningful simulations of radiation transport applications require realistic definitions of material composition and densities. When seeking that information for applications in fields such as homeland security, radiation shielding and protection, and criticality safety, researchers usually encounter a variety of materials for which elemental compositions are not readily available or densities are not defined. Publication of the Compendium of Material Composition Data for Radiation Transport Modeling, Revision 0, in 2006 was the first step toward mitigating this problem. Revision 0 of this document listed 121 materials, selected mostly from the combined personal libraries of staff at the Pacific Northwest National Laboratory (PNNL), and thus had a scope that was recognized at the time to be limited. Nevertheless, its creation did provide a well-referenced source of some unique or hard-to-define material data in a format that could be used directly in radiation transport calculations being performed at PNNL. Moreover, having a single common set of material definitions also helped to standardize at least one aspect of the various modeling efforts across the laboratory by providing separate researchers the ability to compare different model results using a common basis of materials. The authors of the 2006 compendium understood that, depending on its use and feedback, the compendium would need to be revised to correct errors or inconsistencies in the data for the original 121 materials, as well as to increase (per users suggestions) the number of materials listed. This 2010 revision of the compendium has accomplished both of those objectives. The most obvious change is the increased number of materials from 121 to 372. The not-so-obvious change is the mechanism used to produce the data listed here. The data listed in the 2006 document were compiled, evaluated, entered, and error-checked by a group of individuals essentially by hand, providing no library

  4. Global aerosol transport and consequences for the radiation budget

    International Nuclear Information System (INIS)

    Newiger, M.; Grassl, H.; Schussel, P.; Rehkopf, J.

    1984-01-01

    Man's activities may influence global climate by changing the atmospheric composition and surface characteristics and by waste heat. Most prominent within this discussion is the increase or decrease of radiatively active trace gases like CO/sub 2/, N/sub 2/O, O/sub 3/, and others. The general opinion is converging towards a greenhouse effect as a combined action of all trace gases, whose exact magnitude is uncertain mainly because of the unknown reaction of water cycle. The aim of our global 2-D (resolving latitude and height) aerosol transport model is the calculation of aerosol particle number density profiles as a function of latitude for present natural plus anthropogenic emissions. The aerosol transport model uses prescribed meridonal circulation, diffusivity factors and cloud climatology for January as well as July. All these latitude and height dependent input parameters were taken from well known sources. The fixed climatology excludes the feedback of aerosol particle parameter changes on mean circulation. However, the radiative parameters of six clouds types are modified, although they possess by adoption of the Telegadas and London (1954) cloud climatology prescribed amount and height. The inclusion of the feedback on mean circulation seems premature at present. Adding particles either accounting for natural emissions or natural anthropogenic emission and removing particles by all known sinks outside and within clouds gives us - for the stationary state - vertical profiles of aerosol number density in three sizes classes as a function of latitude. These profiles in turn are input for radiation flux calculations in clear and cloudy areas in order to assess net flux changes caused by the present aerosol load in comparison to a scenario without anthropogenic emissions. The net flux changes finally are compared to those calculated for increased CO/sub 2/ levels

  5. Computational complexity in multidimensional neutron transport theory calculations. Progress report, September 1, 1975--August 31, 1976

    International Nuclear Information System (INIS)

    Bareiss, E.H.

    1976-05-01

    The objectives of the work are to develop mathematically and computationally founded for the design of highly efficient and reliable multidimensional neutron transport codes to solve a variety of neutron migration and radiation problems, and to analyze existing and new methods for performance. As new analytical insights are gained, new numerical methods are developed and tested. Significant results obtained include implementation of the integer-preserving Gaussian elimination method (two-step method) in a CDC 6400 computer code, modes analysis for one-dimensional transport solutions, and a new method for solving the 1-T transport equation. Some of the work dealt with the interface and corner problem in diffusion theory

  6. Open access natural gas transportation: A progress report on FERC implementation

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This article is a progress report on the Federal Energy Regulatory Commission's implementation of a US Court of Appeals decision upholding open access natural gas transportation. The five issues addressed by the court are identified and discussed. Take or Pay (TOP) contract modification, the crediting mechanism, pregranted abandonment, contract demand reduction, TOP cost passthrough are also discussed

  7. Computational complexity in multidimensional neutron transport theory calculations. Progress report, September 1, 1974--August 31, 1975

    International Nuclear Information System (INIS)

    Bareiss, E.H.

    1975-01-01

    The objectives of the research remain the same as outlined in the original proposal. They are in short as follows: Develop mathematically and computationally founded criteria for the design of highly efficient and reliable multi-dimensional neutron transport codes to solve a variety of neutron migration and radiation problems and analyze existing and new methods for performance. (U.S.)

  8. Computational complexity in multidimensional neutron transport theory calculations. Progress report, September 1976--November 30, 1977

    International Nuclear Information System (INIS)

    Bareiss, E.H.

    1977-08-01

    The objectives of this research are to develop mathematically and computationally founded criteria for the design of highly efficient and reliable multidimensional neutron transport codes to solve a variety of neutron migration and radiation problems, and to analyze existing and new methods for performance

  9. Numerical simulations for radiation hydrodynamics. 2: Transport limit

    International Nuclear Information System (INIS)

    Dai, W.W.; Woodward, P.R.

    2000-01-01

    A finite difference scheme is proposed for two-dimensional radiation hydrodynamical equations in the transport limit. The scheme is of Godunov-type, in which the set of time-averaged flux needed in the scheme is calculated through Riemann problems solved. In the scheme, flow signals are explicitly treated, while radiation signals are implicitly treated. Flow fields and radiation fields are updated simultaneously. An iterative approach is proposed to solve the set of nonlinear algebraic equations arising from the implicitness of the scheme. The sweeping method used in the scheme significantly reduces the number of iterations or computer CPU time needed. A new approach to further accelerate the convergence is proposed, which further reduces the number of iterations needed by more than one order. No matter how many cells radiation signals propagate in one time step, only an extremely small number of iterations are needed in the scheme, and each iteration costs only about 0.8% of computer CPU time which is needed for one time step of a second order accurate and fully explicit scheme. Two-dimensional problems are treated through a dimensionally split technique. Therefore, iterations for solving the set of algebraic equations are carried out only in each one-dimensional sweep. Through numerical examples it is shown that the scheme keeps the principle advantages of Godunov schemes for flow motion. In the time scale of flow motion numerical results are the same as those obtained from a second order accurate and fully explicit scheme. The acceleration of the convergence proposed in this paper may be directly applied to other hyperbolic systems. This study is important for laser fusion and astrophysics

  10. Basic aspects of radiation action on microorganisms. Progress report, April 1, 1974--March 31, 1975

    International Nuclear Information System (INIS)

    Pollard, E.C.

    1975-04-01

    Progress is reported on the following research projects: effects of blocking DNA synthesis by hydroxyurea on induction of lambda phage; dose response curves for uv and ionizing radiation with radiosensitive and radioresistant strains of phage; effects of oxygen, rifampin, and hydrogen peroxide on induction of radioresistance; radioinduced degradation of DNA; and induction of repair system of mutagenesis with uv and ionizing radiation. (U.S.)

  11. Survey of radiation protection programmes for transport; Etude des programmes de radioprotection pour les transports de matieres radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Lizot, M.T.; Perrin, M.L.; Sert, G. [CEA Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire, Dept. de Protection et de Surete Nucleaire, 92 (France); Lange, F.; Schwarz, G.; Feet, H.J.; Christ, R. [Gesellschaft fur Anlagen-und Reaktorsicherheit, GRS, mbH, Cologne (Germany); Shaw, K.B.; Hughes, J.S.; Gelder, R. [National Radiological Protection Board (NRPB), Oxon, OX (United Kingdom)

    2001-07-01

    The survey of radiation protection programmes for transport has been jointly performed by three scientific organisations I.P.S.N. (France), G.R.S. ( Germany), and N.R.P.B. (United kingdom) on behalf of the European Commission and the pertaining documentation summarises the findings and conclusions of the work that was undertaken with the principal objectives to provide guidance on the establishment, implementation and application of radiation protection programmes for the transport of radioactive materials by operators and the assessment and evaluation of such programmes by the competent authority and to review currently existing radiation protection programmes for the transport of radioactive materials. (N.C.)

  12. ATR, Radiation Transport Models in Atmosphere at Various Altitudes

    International Nuclear Information System (INIS)

    1981-01-01

    1 - Description of problem or function: ATR is a user-oriented code for calculating quickly and simply radiation environment problems at all altitudes in the atmosphere. The code is based on parametric models of a comprehensive data base of air transport results which were generated using discrete ordinates transport techniques for infinite homogeneous air. The effects of air-ground interface and non-uniform air density are treated as perturbation corrections on homogeneous air results. ATR includes parametric models for neutrons and secondary gamma rays as a function of space, energy and source- target angle out to angles of 550 g/cm 2 of air. ATR contains parameterizations of infinite medium air transport of neutrons and secondary gamma rays and correction factors for the air-ground interface and high altitude exponential air. It responds to a series of user-oriented commands which specify the source, geometry and print options to output a variety of useful air transport information, including energy-angle dependent fluence, dose, current, and isodose ranges. 2 - Method of solution: The version 3 differs from earlier versions in that version 3 contains the parameterization of the new neutron and secondary gamma rays data base that was calculated using the latest DNA approved cross sections for air. Other improvements to the ATR code include: parameterization and inclusion into ATR of new air- over-ground correction factors, low energy x-rays calculations, new fission source, and new convenience options. 3 - Restrictions on the complexity of the problem: ATR takes approximately 36,000 decimal words of storage. This can be lessened by overlaying different parts of the code

  13. Use of implicit Monte Carlo radiation transport with hydrodynamics and compton scattering

    International Nuclear Information System (INIS)

    Fleck, J.A. Jr.

    1971-03-01

    It is shown that the combination of implicit radiation transport and hydrodynamics, Compton scattering, and any other energy transport can be simply carried out by a ''splitting'' procedure. Contributions to material energy exchange can be reckoned separately for hydrodynamics, radiation transport without scattering, Compton scattering, plus any other possible energy exchange mechanism. The radiation transport phase of the calculation would be implicit, but the hydrodynamics and Compton portions would not, leading to possible time step controls. The time step restrictions which occur on radiation transfer due to large Planck mean absorption cross-sections would not occur

  14. High-Fidelity Kinetics and Radiation Transport for NLTE Hypersonic Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The modeling of NLTE hypersonic flows combines several disciplines: chemistry, kinetics, radiation transport, fluid mechanics, and surface science. No single code or...

  15. X-radiation effect on water transport in ascite cells of Ehrlich carcinoma

    International Nuclear Information System (INIS)

    Barnov, V.A.; Ajvazishvili, M.A.; Kartvelishvili, I.I.; Tushishvili, D.I.

    1988-01-01

    Effect of local X radiation with doses 0.05 and 0.15 C/kg on water transport in ascitic cells of Erlich carcinoma is studied in rats. To study water transport through cell membranes, tritium mark was used. It is concluded that radiation effect on water transport in cells of Erlich carcinoma may be related to change in ionic permittivity of the membrane, because small changes in transmembrane ion transport affect immediately the osmotic motion of water. 5 refs

  16. Progress in research on ionizing radiation-induced microRNA

    International Nuclear Information System (INIS)

    Hu Zheng; Tie Yi; Sun Zhixian; Zheng Xiaofei

    2011-01-01

    MicroRNAs (miRNAs) are small single-stranded noncoding RNAs consisting of 21-23 nucleotides that play important gene-regulatory roles in eukaryotes by pairing to the mRNAs of protein-coding genes to direct their posttranscriptional repression. A growing body of evidence indicates that alterations in miRNA expression may occur following exposure to several oxidative stress including ionizing radiation. So miRNAs may serve as potential new targets for co-therapies aiming to improve the effects of radiation disease therapy in cancer patients. The progress in research on ionizing radiation-induced miRNAs is reviewed in this paper. (authors)

  17. Acceleration of a Monte Carlo radiation transport code

    International Nuclear Information System (INIS)

    Hochstedler, R.D.; Smith, L.M.

    1996-01-01

    Execution time for the Integrated TIGER Series (ITS) Monte Carlo radiation transport code has been reduced by careful re-coding of computationally intensive subroutines. Three test cases for the TIGER (1-D slab geometry), CYLTRAN (2-D cylindrical geometry), and ACCEPT (3-D arbitrary geometry) codes were identified and used to benchmark and profile program execution. Based upon these results, sixteen top time-consuming subroutines were examined and nine of them modified to accelerate computations with equivalent numerical output to the original. The results obtained via this study indicate that speedup factors of 1.90 for the TIGER code, 1.67 for the CYLTRAN code, and 1.11 for the ACCEPT code are achievable. copyright 1996 American Institute of Physics

  18. Charge transport properties of CdMnTe radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim K.; Rafiel, R.; Boardman, M.; Reinhard, I.; Sarbutt, A.; Watt, G.; Watt, C.; Uxa, S.; Prokopovich, D.A.; Belas, E.; Bolotnikov, A.E.; James, R.B.

    2012-04-11

    Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe)radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading chargecollection is reduced with increasing values of bias voltage. The electron transit time was determined from time of flight measurements. From the dependence of drift velocity on applied electric field the electron mobility was found to be n = (718 55) cm2/Vs at room temperature.

  19. Charge transport properties of CdMnTe radiation detectors

    Directory of Open Access Journals (Sweden)

    Prokopovich D. A.

    2012-10-01

    Full Text Available Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading charge collection is reduced with increasing values of bias voltage. The electron drift velocity was calculated from the rise time distribution of the preamplifier output pulses at each measured bias. From the dependence of drift velocity on applied electric field the electron mobility was found to be μn = (718 ± 55 cm2/Vs at room temperature.

  20. Stationary neutrino radiation transport by maximum entropy closure

    International Nuclear Information System (INIS)

    Bludman, S.A.

    1994-11-01

    The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

  1. HZETRN radiation transport validation using balloon-based experimental data

    Science.gov (United States)

    Warner, James E.; Norman, Ryan B.; Blattnig, Steve R.

    2018-05-01

    The deterministic radiation transport code HZETRN (High charge (Z) and Energy TRaNsport) was developed by NASA to study the effects of cosmic radiation on astronauts and instrumentation shielded by various materials. This work presents an analysis of computed differential flux from HZETRN compared with measurement data from three balloon-based experiments over a range of atmospheric depths, particle types, and energies. Model uncertainties were quantified using an interval-based validation metric that takes into account measurement uncertainty both in the flux and the energy at which it was measured. Average uncertainty metrics were computed for the entire dataset as well as subsets of the measurements (by experiment, particle type, energy, etc.) to reveal any specific trends of systematic over- or under-prediction by HZETRN. The distribution of individual model uncertainties was also investigated to study the range and dispersion of errors beyond just single scalar and interval metrics. The differential fluxes from HZETRN were generally well-correlated with balloon-based measurements; the median relative model difference across the entire dataset was determined to be 30%. The distribution of model uncertainties, however, revealed that the range of errors was relatively broad, with approximately 30% of the uncertainties exceeding ± 40%. The distribution also indicated that HZETRN systematically under-predicts the measurement dataset as a whole, with approximately 80% of the relative uncertainties having negative values. Instances of systematic bias for subsets of the data were also observed, including a significant underestimation of alpha particles and protons for energies below 2.5 GeV/u. Muons were found to be systematically over-predicted at atmospheric depths deeper than 50 g/cm2 but under-predicted for shallower depths. Furthermore, a systematic under-prediction of alpha particles and protons was observed below the geomagnetic cutoff, suggesting that

  2. Transport of radioactive wastes to the planned final waste repository Konrad: Radiation exposure resulting from normal transport and radiological risks from transport accidents

    International Nuclear Information System (INIS)

    Lange, F.; Fett, H.J.; Gruendler, D.; Schwarz, G.

    1993-01-01

    Radiation exposures of members of critical groups of the general population and of transport personnel resulting from normal transport of radioactive wastes to the planned final waste repository Konrad have been evaluated in detail. By applying probabilistic safety assessment techniques radiological risks from transport accidents have been analysed by quantifying potential radiation exposures and contaminations of the biosphere in connection with their expected frequencies of occurrence. The Konrad transport study concentrates on the local region of the waste repository, where all transports converge. (orig.) [de

  3. Progress in research on combination treatment of cancer with radiation therapy and immunotherapy

    International Nuclear Information System (INIS)

    Wang Hao; Jia Rui; Yan Jinqi; Yu Jiyun

    2007-01-01

    Radiation therapy (RT) is an important local treatment for tumors, and immunotherapy is a systematic treatment. Combination of RT with immunotherapy may bring about an obvious synergistic anti-tumor effort. Here the research progress in this aspect is reviewed. (authors)

  4. The progress and issues of national nuclear and radiation safety supervision and MIS

    International Nuclear Information System (INIS)

    Zhou Kefei; Sun Guochen; Jiang Guang; Li Jingxi; Zhang Lin

    2009-01-01

    The article briefly describes the pre-planning construction of 'National Nuclear and Radiation Safety Supervision and Management Information System', Including the overall frame of the system and the main issues found in the work which affect and confine the progress of the program. Some recommendations are put forward. (authors)

  5. Progress in two-dimensional polyacrylamide gel electrophoresis and application in radiation research

    International Nuclear Information System (INIS)

    Wang Zhidong; Chen Xiaohua

    2003-01-01

    Two-dimensional polyacrylamide gel electrophoresis is the key separation technique in proteomics research, which is designed by protein character: molecular weight and PI. Some progress has been made in disease mechanism detection, tumor indicator research and drug development. This technique also has some potential application in radiation research

  6. Progress in radiation protection techniques for workers in the nuclear industry

    International Nuclear Information System (INIS)

    Pradel, J.; Zettwoog, P.; Rouyer, J.L.

    1982-01-01

    The increasingly stringent safety requirements of workers and the general public in the face of occupational and in particular nuclear risks call for continual improvements in radiation protection techniques. The Institute of Protection and Nuclear Safety (IPSN), especially the Technical Protection Services belonging to the Protection Department, and also the various radiation protection services of the French Atomic Energy Commission's nuclear centres and Electricite de France (EDF) are carrying out substantial research and development programmes on the subject. For this reason, IPSN organized a specialists' meeting to take stock of the efforts being made and to try to identify what steps seem most promising or should have priority at the national level. The authors summarize the presentations and discussions on three topics: (1) Progress in the analysis of the mechanism of exposure of workers; (2) Progress achieved from the radiation protection standpoint in the field of facility design and instrumentation; and (3) Application of the optimization principle

  7. Distinction between glioma progression and post-radiation change by combined physiologic MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsusue, Eiji [University of Washington, Department of Radiology, Seattle, WA (United States); Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago, Tottori (Japan); Fink, James R.; Maravilla, Kenneth R. [University of Washington, Department of Radiology, Seattle, WA (United States); Rockhill, Jason K. [University of Washington, Department of Radiation Oncology, Seattle, WA (United States); Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago, Tottori (Japan)

    2010-04-15

    Magnetic resonance (MR) diffusion-weighted imaging (DWI), dynamic susceptibility contrast-enhanced perfusion imaging (DSC), and MR spectroscopy (MRS) techniques provide specific physiologic information that may distinguish malignant glioma progression from post-radiation change, yet no single technique is completely reliable. We propose a simple, multiparametric scoring system to improve diagnostic accuracy beyond that of each technique alone. Fifteen subjects with lesions suspicious for glioma progression following radiation therapy who had also undergone 3-tesla DWI, DSC, and MRS studies of the lesion were retrospectively reviewed. Minimum apparent diffusion coefficient (ADC) ratio, maximum regional cerebral blood volume (rCBV) ratio, and maximum MRS choline/creatine (Cho/Cr) and choline/N-acetyl-aspartate (Cho/NAA) metabolic peak-height ratios were quantified within each lesion. Each parameter (ADC ratio, rCBV ratio, and combined Cho/Cr and Cho/NAA ratios) was scored as either glioma progression (one point) or radiation change (zero point) based upon thresholds derived from our own data. For each lesion, the combined parameters yielded a multiparametric score (0 to 3) for prediction of tumor progression or post-radiation change. Optimum thresholds for ADC ratio (1.30), rCBV ratio (2.10), and either combined Cho/Cr (1.29) and Cho/NAA (1.06) yielded diagnostic accuracies of 86.7%, 86.7%, and 84.6%, respectively (p < 0.05). A combined multiparametric score threshold of 2 improved diagnostic accuracy to 93.3% (p < 0.05). In this small series combining 3-T DWI, DSC, and MRS diagnostic results using a simple, multiparametric scoring system has potential to improve overall diagnostic accuracy in distinguishing glioma progression from post-radiation change beyond that of each technique alone. (orig.)

  8. Radiation physics, biophysics and radiation biology. Progress report for October 1, 1979-September 30, 1980

    International Nuclear Information System (INIS)

    Rossi, H.H.; Hall, E.J.

    1980-07-01

    Separate abstracts were prepared for 31 of the 32 papers presented in this progress report. The other paper is represented by an abstract only and deals with field shaping and recalibration of x-ray facilities

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

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.

    1994-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1994-05-01

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

  11. Latest Progress in Research on the SpaceLiner High-Speed Passenger Transportation Concept

    OpenAIRE

    Sippel, Martin; van Foreest, Arnold

    2007-01-01

    A vision aimed at revolutionizing ultra-long distance travel between different points on earth could be realized by a high-speed intercontinental passenger transport using rocket based, suborbital launchers. The paper gives an overview on the latest progress in conceptual design of the DLR SpaceLiner presenting geometrical size and mass data and describing results of trajectory simulations. The rockets are based on an advanced but technically conservative approach not relying on e...

  12. Molecular events basic to cellular radiation response. Progress report, July 1, 1976--September 30, 1977

    International Nuclear Information System (INIS)

    Kolodny, G.M.

    1977-01-01

    Progress is reported on studies of the effects of x irradiation at the cellular level that lead ultimately to either malignant transformation or cell death. Experimental results consistent with the primer hypothesis for the regulation of gene expression in eukaryotes are reported. It was found that oligonucleotides can be inserted en bloc into newly synthesized RNA. Studies on amino acid-nucleic acid interactions were continued by successfully synthesizing an amidate and beginning NMR studies on the interactions between its nucleic acid and amino acid moieties. In studies on radiation induced giant cells in 3T3 cells growing in culture, it was demonstrated that conditions which potentiate potential lethal damage repair and those which prevent radiation induced giant cell formation exist. In an examination of the in vitro effects of vasopressin, no direct effect was found of vasopressin on radiation sensitivity and significant effects of radiation on lysosomal enzyme activity in cultured cells were found

  13. Molecular events basic to cellular radiation response. Progress report, July 1, 1976--September 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Kolodny, G.M.

    1977-01-01

    Progress is reported on studies of the effects of x irradiation at the cellular level that lead ultimately to either malignant transformation or cell death. Experimental results consistent with the primer hypothesis for the regulation of gene expression in eukaryotes are reported. It was found that oligonucleotides can be inserted en bloc into newly synthesized RNA. Studies on amino acid-nucleic acid interactions were continued by successfully synthesizing an amidate and beginning NMR studies on the interactions between its nucleic acid and amino acid moieties. In studies on radiation induced giant cells in 3T3 cells growing in culture, it was demonstrated that conditions which potentiate potential lethal damage repair and those which prevent radiation induced giant cell formation exist. In an examination of the in vitro effects of vasopressin, no direct effect was found of vasopressin on radiation sensitivity and significant effects of radiation on lysosomal enzyme activity in cultured cells were found.

  14. Recent progress of the RD50 Collaboration – Development of radiation tolerant tracking detectors

    CERN Document Server

    Moll, M

    2014-01-01

    The CERN RD50 Collaboration "Radiation hard semiconductor devices for high luminosity col- liders" is undertaking a massive R&D; programme across High Energy Physics (HEP) Experi- ments boundaries to develop silicon sensors with increased radiation tolerance. Highest priority is to provide concepts and prototypes of high performance silicon sensors for the High-Luminosity Large Hadron Collider (HL-LHC) Experiments at CERN and other future HEP Experiments op- erating in severe radiation environments. This paper gives an overview of the RD50 collaboration activities and describes some examples of recent developments. Emphasis is put on the charac- terization of microscopic radiation induced defects and their impact on the sensor performance, the evaluation and parametrization of electric fields inside irradiated sensors, progress in device modeling using TCAD tools, the use of p-type silicon as strip and pixel sensor material and finally the first steps towards the exploitation of impact ionization ( charge...

  15. Deterministic methods in radiation transport. A compilation of papers presented February 4--5, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Rice, A.F.; Roussin, R.W. [eds.

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

  16. Deterministic methods in radiation transport. A compilation of papers presented February 4-5, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Rice, A. F.; Roussin, R. W. [eds.

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

  17. BALTORO a general purpose code for coupling discrete ordinates and Monte-Carlo radiation transport calculations

    International Nuclear Information System (INIS)

    Zazula, J.M.

    1983-01-01

    The general purpose code BALTORO was written for coupling the three-dimensional Monte-Carlo /MC/ with the one-dimensional Discrete Ordinates /DO/ radiation transport calculations. The quantity of a radiation-induced /neutrons or gamma-rays/ nuclear effect or the score from a radiation-yielding nuclear effect can be analysed in this way. (author)

  18. To the development of numerical methods in problems of radiation transport

    International Nuclear Information System (INIS)

    Germogenova, T.A.

    1990-01-01

    Review of studies on the development of numerical methods and the discrete ordinate method in particular, used for solution of radiation protection physics problems is given. Consideration is given to the problems, which arise when calculating fields of penetrating radiation and when studying processes of charged-particle transport and cascade processes, generated by high-energy primary radiation

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

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.; Delegianis, M.J.

    1988-07-01

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

  20. Progress in coating and radiation curing of metal and plastic objects

    International Nuclear Information System (INIS)

    Mayenknecht, H.

    1983-01-01

    The manyfold problems with one or multi-layered coatings on metal and plastic surfaces as adhesion and coat compound are the reasons for a rather slow progress of industrial applications of both radiation curing technologies (UV and EBC). Important reasons for this seemed to result from the fact that the manyfold offers of radiation sources were not optimum adapted to the chemistry of the coating materials. It was pointed out that tensions due to film contraction during polymerization process are the main reasons for insufficient adhesion. This presentation is an attempt to clarify both points of view

  1. Activities of the Radiation Shielding Information Center and a report on codes/data for high energy radiation transport

    International Nuclear Information System (INIS)

    Roussin, R.W.

    1993-01-01

    From the very early days in its history Radiation Shielding Information Center (RSIC) has been involved with high energy radiation transport. The National Aeronautics and Space Administration was an early sponsor of RSIC until the completion of the Apollo Moon Exploration Program. In addition, the intranuclear cascade work of Bertini at Oak Ridge National Laboratory provided valuable resources which were made available through RSIC. Over the years, RSIC has had interactions with many of the developers of high energy radiation transport computing technology and data libraries and has been able to collect and disseminate this technology. The current status of this technology will be reviewed and prospects for new advancements will be examined

  2. Monte Carlo radiation transport: A revolution in science

    International Nuclear Information System (INIS)

    Hendricks, J.

    1993-01-01

    When Enrico Fermi, Stan Ulam, Nicholas Metropolis, John von Neuman, and Robert Richtmyer invented the Monte Carlo method fifty years ago, little could they imagine the far-flung consequences, the international applications, and the revolution in science epitomized by their abstract mathematical method. The Monte Carlo method is used in a wide variety of fields to solve exact computational models approximately by statistical sampling. It is an alternative to traditional physics modeling methods which solve approximate computational models exactly by deterministic methods. Modern computers and improved methods, such as variance reduction, have enhanced the method to the point of enabling a true predictive capability in areas such as radiation or particle transport. This predictive capability has contributed to a radical change in the way science is done: design and understanding come from computations built upon experiments rather than being limited to experiments, and the computer codes doing the computations have become the repository for physics knowledge. The MCNP Monte Carlo computer code effort at Los Alamos is an example of this revolution. Physicians unfamiliar with physics details can design cancer treatments using physics buried in the MCNP computer code. Hazardous environments and hypothetical accidents can be explored. Many other fields, from underground oil well exploration to aerospace, from physics research to energy production, from safety to bulk materials processing, benefit from MCNP, the Monte Carlo method, and the revolution in science

  3. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1985-November 30, 1986

    International Nuclear Information System (INIS)

    Hall, E.J.

    1986-07-01

    This is the annual report of the Radiological Research Laboratory of the Department of Radiation Oncology, Columbia University. The bulk of the research of the Laboratory involves basic and fundamental aims, not confined to radiotherapy. Research carried out in the Laboratory covers the determination of microdosimetry quantities, computer simulation of particle tracks, determination of oncogenic transformation, and the transfection of DNA into cells. The Hallmark of the Laboratory is the interaction between physics and biology

  4. Radiation physics, biophysics and radiation biology. Progress report, October 1, 1982-November 1983

    International Nuclear Information System (INIS)

    1983-07-01

    A wide range of research is carried out at the Radiological Research Laboratory, from computer simulation of particle tracks to the determination of oncogenic transformation in mammalian cells. Mechanistic studies remain the central mission in an attempt to understand the biological action of ionizing radiations. Collaborative research is carried out on the use of radiosensitizers on chemosensitizers on the effect of hormones on oncogenic transformation and on cataractogenesis

  5. Progress report: nuclear safety and radiation protection in France in 2005

    International Nuclear Information System (INIS)

    2007-01-01

    The Asn (Nuclear safety authority) considers that 2005 was a satisfactory year in terms of nuclear safety and radiation protection. However, further progress can and must be made. 2005 was a year of great progress for the Asn as it consolidated its organisation and working methods, in accordance with the 2005-2007 strategic plan it set for itself. The Asn continued progress in the field of radiation protection has given rise to various new regulations to improve the legislative and regulatory framework in this area. 2005 was marked by significant progress in the process of harmonizing national nuclear safety policies Against a backdrop of the preparation of a bill on management of radioactive materials and waste, to be presented to Parliament in March 2006, 2005 was a year of important milestones. The Asn control activities encompass the following seven areas: development of general regulations for nuclear safety and radiation protection; management of individual authorization requests and receipt of declarations; inspection of nuclear activities; organisation of radiological surveillance of individuals and of the environment; preparation for management of emergency situations and implementation if necessary; contribution to public information on nuclear safety and radiation protection; determination of the French position within international community. Main topics in 2005: government bill on transparency and security in the nuclear field; the challenges and ambitions of the Asn; controlling exposure to radon; EPR Reactor Project Safety; working towards a law on radioactive waste in 2006; I.R.R.T.: an international audit of Asn in 2006; harmonization of nuclear safety in Europe; Chernobyl: what has been achieved over the past 20 years; informing the Public; internal authorizations. (N.C.)

  6. Radiation biophysical study of biological molecules. Progress report, July 1, 1976--August 31, 1977

    International Nuclear Information System (INIS)

    Fluke, D.J.

    1977-01-01

    Progress is reported on the following research projects: x-ray induction of uv mutagenesis enhancement in lambda-phage; action spectrum for uv mutagenesis in Escherichia coli; survival of E. coli colonies after uv damage; repair of radiation damage to lambda-phage by the W-reactivation system; experiments on the Weigle-reactivation of irradiated lambda-phage; and studies on the wavelength dependence of uv mutagenesis

  7. Radiation cleanup of vacuum systems (radiation-induced outgassing). Progress report, September 15, 1976--September 14, 1977

    International Nuclear Information System (INIS)

    Anno, J.N.

    1977-06-01

    A stainless steel-304 vacuum system has been designed and constructed to study radiation-induced outgassing when this material is exposed to cobalt-60 gamma radiation. The system is pumped with an ion pump and sorption roughing pump. No foreign materials have been introduced except for copper seals at the flanges. An analytical model has been developed which predicts the outgassing from SS-304 to be 8.27 x 10 -12 torr-liters/(cm 2 )(sec) per megarad/hr. Extrapolation of existing data for aluminum suggests a lower value of 1.0 x 10 -12 torr-liters/(cm 2 )(sec) per megarad/hr. Experiments to determine the value are currently in progress

  8. Radiation exposures of workers and the public associated with the transport of radioactive material in Germany

    International Nuclear Information System (INIS)

    Schwarz, G.; Fett, H.J.; Lange, F.

    2004-01-01

    Most radioactive material packages transported emit penetrating ionising radiation and radiation exposures of transport workers and the public may occur during their transport. The radiation exposures incurred by transport workers and members of the public can vary significantly depending on a number of factors: most important is the type of radiation emitted (primarily gamma and neutron radiation), the radiation field intensity in the surrounding of a package and conveyance and the duration of exposure to ionising radiation. The information and guidance material on occupational exposures has primarily been derived from a survey and analysis of personal monitoring data provided by a number of commercial transport operators in Germany known as major carrier and handler organisations of fuel cycle and non-fuel cycle material (in terms of the number of pack-ages and the activity carriaged). To some extent advantage was taken of compilations of statistical transport and exposure data collated within other transport safety analysis studies including research projects funded by the European Commission. The exposure data collected cover the time period of the last 4 - 8 years and are most representative for routine transport operations closely related to the movement phase of packaged radioactive material, i.e. receipt, vehicle loading, carriage, in-transit storage, intra-/intermodal transfer, vehicle unloading and delivery at the final destination of loads of radioactive material and packages and the related supervisory and health physics functions. Radiation dose monitoring of members of the public, however, is generally impracticable and, consequently, the information available relies on employing dose assessment models and reflects radiation exposures incurred by hypothetical or critical group individuals of members of the public under normal conditions of transport

  9. Progressive tumefactive fibroinflammatory lesion of the infratemporal fossa treated by radiation therapy

    Directory of Open Access Journals (Sweden)

    Brian O’Sullivan

    2012-01-01

    Full Text Available Tumefactive fibroinflammatory lesion (TFIL is a rare benign tumor in the head and neck region. We present a case of a 40-year-old female with a benign but progressive lesion of the infratemporal fossa, which was diagnosed as TFIL. Patient responded briefly to a course of steroid treatment but eventually showed progression and was unresponsive to further steroids. She was then treated with external beam radiation to a dose of 60 Gy in 30 fractions. After radiation a slow, gradual decrease in tumor size was noted over the course of years and she is free of disease after more than 11 years of follow-up. The major longterm side effect this patient developed was an expected unilateral radiation-induced retinopathy, due to the close proximity of the lesion to the orbit. The dilemma of treatment of benign disease with radiation with potential long-term complications is discussed and a review of the literature on TFIL is presented.

  10. Stereotactic body radiation therapy for liver oligo-recurrence and oligo-progression from various tumors

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Yu Jin; Kim, Mi Sook; Jang, Won Il; Seo, Young Seok; Cho, Chul Koo; Yoo, Hyung Jun; Paik, Eun Kyung [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2017-06-15

    To evaluate the outcomes of stereotactic body radiation therapy (SBRT) for patients with liver oligo-recurrence and oligo-progression from various primary tumors. Between 2002 and 2013, 72 patients with liver oligo-recurrence (oligo-metastasis with a controlled primary tumor) and oligo-progression (contradictory progression of a few sites of disease despite an overall tumor burden response to therapy) underwent SBRT. Of these, 9 and 8 patients with uncontrollable distant metastases and patients immediate loss to follow-up, respectively, were excluded. The total planning target volume was used to select the SBRT dose (median, 48 Gy; range, 30 to 60 Gy, 3–4 fractions). Toxicity was evaluated using the Common Toxicity Criteria for Adverse Events v4.0. We evaluated 55 patients (77 lesions) treated with SBRT for liver metastases. All patients had controlled primary lesions, and 28 patients had stable lesions at another site (oligo-progression). The most common primary site was the colon (36 patients), followed by the stomach (6 patients) and other sites (13 patients). The 2-year local control and progression-free survival rates were 68% and 22%, respectively. The 2- and 5-year overall survival rates were 56% and 20%, respectively. The most common adverse events were grade 1–2 fatigue, nausea, and vomiting; no grade ≥3 toxicities were observed. Univariate analysis revealed that oligo-progression associated with poor survival. SBRT for liver oligo-recurrence and oligo-progression appears safe, with similar local control rates. For liver oligo-progression, criteria are needed to select patients in whom improved overall survival can be expected through SBRT.

  11. The adaptive collision source method for discrete ordinates radiation transport

    International Nuclear Information System (INIS)

    Walters, William J.; Haghighat, Alireza

    2017-01-01

    Highlights: • A new adaptive quadrature method to solve the discrete ordinates transport equation. • The adaptive collision source (ACS) method splits the flux into n’th collided components. • Uncollided flux requires high quadrature; this is lowered with number of collisions. • ACS automatically applies appropriate quadrature order each collided component. • The adaptive quadrature is 1.5–4 times more efficient than uniform quadrature. - Abstract: A novel collision source method has been developed to solve the Linear Boltzmann Equation (LBE) more efficiently by adaptation of the angular quadrature order. The angular adaptation method is unique in that the flux from each scattering source iteration is obtained, with potentially a different quadrature order used for each. Traditionally, the flux from every iteration is combined, with the same quadrature applied to the combined flux. Since the scattering process tends to distribute the radiation more evenly over angles (i.e., make it more isotropic), the quadrature requirements generally decrease with each iteration. This method allows for an optimal use of processing power, by using a high order quadrature for the first iterations that need it, before shifting to lower order quadratures for the remaining iterations. This is essentially an extension of the first collision source method, and is referred to as the adaptive collision source (ACS) method. The ACS methodology has been implemented in the 3-D, parallel, multigroup discrete ordinates code TITAN. This code was tested on a several simple and complex fixed-source problems. The ACS implementation in TITAN has shown a reduction in computation time by a factor of 1.5–4 on the fixed-source test problems, for the same desired level of accuracy, as compared to the standard TITAN code.

  12. LMFBR aerosol release and transport program. Quarterly progress report, July-September 1981

    International Nuclear Information System (INIS)

    Kress, T.S.; Tobias, M.L.

    1982-01-01

    This report summarizes progress for the Aerosol Release and Transport Program sponsored by the Office of Nuclear Regulatory Research, Division of Accident Evaluation of the Nuclear Regulatory Commission for the period July-September 1981. Topics discussed include (1) preparations for under-sodium tests at the Fast Aerosol Simulant Test Facility, (2) progress in interpretation of Oak Ridge National Laboratory-Sandia Laboratory normalization test results, (3) U 3 O 8 in steam (light-water reactor accident) aerosol experiments conducted in the Nuclear Safety Power Plant, (4) experiments on B 2 O 3 and SiO 2 aerosols at the Containment Research Installation-II Facility, (5) fuel-melting tests in small-scale experimental facilities for the core-melt aerosol program, (6) analytical comparison of simple adiabatic nonlinear and linear analytical models of bubble oscillation phenomena with experimental data

  13. Radiation inactivation studies of renal brush border water and urea transport

    International Nuclear Information System (INIS)

    Verkman, A.S.; Dix, J.A.; Seifter, J.L.; Skorecki, K.L.; Jung, C.Y.; Ausiello, D.A.

    1985-01-01

    Radiation inactivation was used to determine the nature and molecular weight of water and urea transport pathways in brush border membrane vesicles (BBMV) isolated from rabbit renal cortex. BBMV were frozen to -50 degrees C, irradiated with 1.5 MeV electrons, thawed, and assayed for transport or enzyme activity. The freezing process had no effect on enzyme or transport kinetics. BBMV alkaline phosphatase activity gave linear ln(activity) vs. radiation dose plots with a target size of 68 +/- 3 kDa, similar to previously reported values. Water and solute transport were measured using the stopped-flow light-scattering technique. The rates of acetamide and osmotic water transport did not depend on radiation dose (0-7 Mrad), suggesting that transport of these substances does not require a protein carrier. In contrast, urea and thiourea transport gave linear ln(activity) vs. dose curves with a target size of 125-150 kDa; 400 mM urea inhibited thiourea flux by -50% at 0 and 4.7 Mrad, showing that radiation does not affect inhibitor binding to surviving transporters. These studies suggest that BBMV urea transport requires a membrane protein, whereas osmotic water transport does not

  14. Process and appliance for determining the nature of transported substances by measuring the radiations transmitted

    International Nuclear Information System (INIS)

    Wykes, J.S.; Surzyn, P.M.; Croke, G.M.; Adsley, Ian.

    1980-01-01

    The invention relates to a process for determining the nature of a substance transported, comprising the collimation of the radiation of not less than two energies so that they form beams; the irradiation of the matter transported by the beams, the detection of the non-scattered radiations for the two energies at least, after passing in the transported matter, and the deduction of the nature of the transported matter according to the radiations detected. The radiations are collimated by placing a shield around the gamma source (americium 241 or cesium 137). The detector is protected by a shield so that it prevents any significant interference due to the reactions near the surface provoked by those radiations not of the lowest energy, with detection of those radiations of lesser energy. In a variation, a source of relatively higher energy radiations is placed at a distance from the source of relatively lesser energy radiations. The latter have a component taken from natural ionizing radiation and this component is withdrawn to a predetermined calibration [fr

  15. Experimental validation of GADRAS's coupled neutron-photon inverse radiation transport solver

    International Nuclear Information System (INIS)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee T.

    2010-01-01

    Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron-photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of α-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.

  16. Evaluation of dose equivalent rate distribution in JCO critical accident by radiation transport calculation

    CERN Document Server

    Sakamoto, Y

    2002-01-01

    In the prevention of nuclear disaster, there needs the information on the dose equivalent rate distribution inside and outside the site, and energy spectra. The three dimensional radiation transport calculation code is a useful tool for the site specific detailed analysis with the consideration of facility structures. It is important in the prediction of individual doses in the future countermeasure that the reliability of the evaluation methods of dose equivalent rate distribution and energy spectra by using of Monte Carlo radiation transport calculation code, and the factors which influence the dose equivalent rate distribution outside the site are confirmed. The reliability of radiation transport calculation code and the influence factors of dose equivalent rate distribution were examined through the analyses of critical accident at JCO's uranium processing plant occurred on September 30, 1999. The radiation transport calculations including the burn-up calculations were done by using of the structural info...

  17. Higher-fidelity yet efficient modeling of radiation energy transport through three-dimensional clouds

    International Nuclear Information System (INIS)

    Hall, M.L.; Davis, A.B.

    2005-01-01

    Accurate modeling of radiative energy transport through cloudy atmospheres is necessary for both climate modeling with GCMs (Global Climate Models) and remote sensing. Previous modeling efforts have taken advantage of extreme aspect ratios (cells that are very wide horizontally) by assuming a 1-D treatment vertically - the Independent Column Approximation (ICA). Recent attempts to resolve radiation transport through the clouds have drastically changed the aspect ratios of the cells, moving them closer to unity, such that the ICA model is no longer valid. We aim to provide a higher-fidelity atmospheric radiation transport model which increases accuracy while maintaining efficiency. To that end, this paper describes the development of an efficient 3-D-capable radiation code that can be easily integrated into cloud resolving models as an alternative to the resident 1-D model. Applications to test cases from the Intercomparison of 3-D Radiation Codes (I3RC) protocol are shown

  18. A Photon Free Method to Solve Radiation Transport Equations

    International Nuclear Information System (INIS)

    Chang, B

    2006-01-01

    The multi-group discrete-ordinate equations of radiation transfer is solved for the first time by Newton's method. It is a photon free method because the photon variables are eliminated from the radiation equations to yield a N group XN direction smaller but equivalent system of equations. The smaller set of equations can be solved more efficiently than the original set of equations. Newton's method is more stable than the Semi-implicit Linear method currently used by conventional radiation codes

  19. Anthology of the development of radiation transport tools as applied to single event effects

    International Nuclear Information System (INIS)

    Akkerman, A.; Barak, J.; Murat, M.; Duzellier, S.; Hubert, G.; Gaillardin, M.; Raine, M.; Jordan, T.; Jun, I.; Koontz, S.; Reddell, B.; O'Neill, P.; Foster, C.; Culpepper, W.; Lei, F.; McNulty, P.; Nieminen, P.; Saigne, F.; Wrobel, F.; Santin, G.; Sihver, L.; Tang, H.H.K.; Truscott, P.R.

    2013-01-01

    This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing web sites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools. (authors)

  20. Anthology of the Development of Radiation Transport Tools as Applied to Single Event Effects

    Science.gov (United States)

    Reed, R. A.; Weller, R. A.; Akkerman, A.; Barak, J.; Culpepper, W.; Duzellier, S.; Foster, C.; Gaillardin, M.; Hubert, G.; Jordan, T.; Jun, I.; Koontz, S.; Lei, F.; McNulty, P.; Mendenhall, M. H.; Murat, M.; Nieminen, P.; O'Neill, P.; Raine, M.; Reddell, B.; Saigné, F.; Santin, G.; Sihver, L.; Tang, H. H. K.; Truscott, P. R.; Wrobel, F.

    2013-06-01

    This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing websites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools.

  1. Toxic agent and radiation control: progress toward objectives for the nation for the year 1990

    International Nuclear Information System (INIS)

    Rall, D.P.

    1988-01-01

    In 1980, the Department of Health and Human Services set national prevention objectives for 1990 in 15 health priority areas, 1 of which is the control of toxic agents and radiation. Ten objectives related to this area are priorities for the national control effort. Progress is reviewed on those priorities within the responsibilities of the Public Health Service. Six key program elements, or types of support activities, are deemed essential to preventing, identifying, and controlling toxic agent and radiation threats. Significant progress has been made toward achieving objectives for which all key program elements have been successfully implemented to provide the requisite know-how, manpower, and tools. Important advances have been made in reducing the blood lead levels of the population, reducing unnecessary exposure to medical X-rays, evaluating the toxicities of chemicals in toxic waste dumps, and improving the scientific and technical information base and its availability for prevention and control efforts. The most important priority for the forseeable future will be to expand our knowledge of potential health risks posed by toxic agents and radiation. Expanded surveillance systems and data bases are essential to determining the extent of the problems in terms of human health effects and for measuring the impact of prevention programs. Emphasis on the activities embodied in the key elements will encourage the expansion of the knowledge base and its effective application to prevention and control problems

  2. Radiation damage and repair in cells and cell components. Progress report, November 1, 1977--October 31, 1978. [Uv and x radiation, bacteriophages

    Energy Technology Data Exchange (ETDEWEB)

    Fluke, D.J.; Pollard, E.C.

    1978-01-01

    Progress is reported on the following research projects: coordinate induction of mutagenesis, radioresistance, and inhibition of post-radiation DNA degradation; radioinduced filamentation; action spectrum for induction of K12 lambda phage; effects of uv radiation on cells in the frozen state; dependence of mutagenesis on wavelength of uv; and w-reactivation of x-irradiated phage lambda. (HLW)

  3. Department of Environmental and Radiation Transport Physics - Overview

    International Nuclear Information System (INIS)

    Woznicka, U.

    2002-01-01

    geological structures, in collaboration with the Institute of Geological Sciences of Polish Academy of Sciences. The geological fault system which surrounds the ''Las Wolski'' horst is covered with loess overburden. An evident increase in radon concentration in the upper loess layer is observed over the fault position. This may have important environmental implications. Several samples of soil taken from those areas were analysed for the concentration of natural isotopes (U, Th, and K). Natural radioactivity measurements in various samples (soils, rocks, raw, and building materials, etc.) have been carried out using low background spectrometers (with NaI(Tl) and HPGe detectors). We took part in the national inter-comparison concerning the methodology of ''radon-in-water'' measurements. The results are to be published. A joint project ''The Radon Centre - Non- Governmental International Scientific Network'' has been started in co-operation with the Central Mining Institute in Katowice. The main goals are to prepare and execute joint research projects and programmes, and to disseminate and put into practice the results of research activities of particular Network members. Neutron methods are an important part of nuclear geophysics and are also used in medical modalities. Investigations of the neutron transport parameters require usually the detection and/or calculation of spatial, time, and energy distributions of fast, epithermal and thermal neutrons, and of the accompanying γ radiation. The research has been directed into several aspects: - Basic theoretical and experimental investigation for the thermal neutron transport: a) the temperature behaviour of the pulsed parameters in a hydrogenous moderator, b) diffusion cooling in small two-region systems containing substances of different types of energy characteristics of thermal neutron scattering. - Calculations of the radiation field and energy deposition in the water beam dump for the TESLA electron-positron collider for

  4. Radiation transport phenomena and modeling. Part A: Codes; Part B: Applications with examples

    International Nuclear Information System (INIS)

    Lorence, L.J. Jr.; Beutler, D.E.

    1997-09-01

    This report contains the notes from the second session of the 1997 IEEE Nuclear and Space Radiation Effects Conference Short Course on Applying Computer Simulation Tools to Radiation Effects Problems. Part A discusses the physical phenomena modeled in radiation transport codes and various types of algorithmic implementations. Part B gives examples of how these codes can be used to design experiments whose results can be easily analyzed and describes how to calculate quantities of interest for electronic devices

  5. Gray and multigroup radiation transport models for two-dimensional binary stochastic media using effective opacities

    International Nuclear Information System (INIS)

    Olson, Gordon L.

    2016-01-01

    One-dimensional models for the transport of radiation through binary stochastic media do not work in multi-dimensions. Authors have attempted to modify or extend the 1D models to work in multidimensions without success. Analytic one-dimensional models are successful in 1D only when assuming greatly simplified physics. State of the art theories for stochastic media radiation transport do not address multi-dimensions and temperature-dependent physics coefficients. Here, the concept of effective opacities and effective heat capacities is found to well represent the ensemble averaged transport solutions in cases with gray or multigroup temperature-dependent opacities and constant or temperature-dependent heat capacities. In every case analyzed here, effective physics coefficients fit the transport solutions over a useful range of parameter space. The transport equation is solved with the spherical harmonics method with angle orders of n=1 and 5. Although the details depend on what order of solution is used, the general results are similar, independent of angular order. - Highlights: • Gray and multigroup radiation transport is done through 2D stochastic media. • Approximate models for the mean radiation field are found for all test problems. • Effective opacities are adjusted to fit the means of stochastic media transport. • Test problems include temperature dependent opacities and heat capacities • Transport solutions are done with angle orders n=1 and 5.

  6. Mechanisms for radiation damage in DNA. Progress report, January 1, 1980-December 31, 1980

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1980-09-01

    In this project several mechanisms are proposed for radiation damage to DNA constituents and DNA, and a series of experiments detailed utilizing electron spin resonance spectrometry to test the proposed mechanisms. Under current investigation are irradiated systems of DNA constituents which may shed light on indirect effects. In addition, studies of radiation effects on lipids have been undertaken which will shed light on the only other proposed site for cell kill, the membrane. Studies completed during the past year are: (1) π cations produced in DNA bases by attack of oxidizing radicals; (2) INDO studies of radicals produced in peptides and carboxylic acid model compounds; (3) electron reactions with carboxylic acids, ketones and aldehydes; and (4) γ-irradiation of esters and triglycerides. Progress has been made this year in a study of radicals generated in model compounds for the sugar-phosphate backbone

  7. Radiation and biophysical studies on cells and viruses. Progress report, February 29, 1974--March 31, 1975

    International Nuclear Information System (INIS)

    Cole, A.

    Progress is reported on the following research projects: sedimentation analysis of chromosome components from interphase and mitotic chromosomes; electron microscopy of mitotic chromosomes; radiosensitive site analysis using short range particle beams; studies on nucleoproteins and DNA; RBE and OER for double strand breaks and single strand breaks of DNA irradiated with 241 Am alpha particles; use of 241 Am alpha particle track-ends to study the location of radiosensitive sites; gamma irradiation of nucleoprotein model systems; assembly of new equipment for the analysis of DNA size distributions; cell rejoining of DNA breaks induced by various radiations; studies on cell transformation induced by gamma radiation; localization of cellular sites for DNA breakage using labeled specific antibodies; and semiconductor properties of melanins related to preferential killing of melanoma cells. (U.S.)

  8. The role of cell progression in potentiation of radiation lethality by hyperthermia and by chemical means

    International Nuclear Information System (INIS)

    Djordjevic, B.; Lange, C.S.

    1984-01-01

    Aerobic stationary dense cultures of HeLa cells show very little potentiation of radiation lethality when irradiated cells are incubated with procaine HCl for two hours at 37 0 C, but if cells are diluted in fresh medium after irradiation and incubated for two hours with procaine, a high degree of radiopotentiation is obtained. This effect is not cell density dependent, since the addition of heavily irradiated cells to achieve comparable densities did not diminish lethality in the diluted culture. Procaine radiopotentiation at 37 0 C could be prevented by simultaneous administration with procaine of the protein synthesis inhibitor cycloheximide. Since cycloheximide inhibits cell cycle progression (with block points in G1 and G2) progression is strongly implicated in the phenomenon of radiopotentiation. Cell progression may be also involved in hyperthermic radiopotentiation: adding cycloheximide during heating of irradiated cells at 41 0 C for two hours increased survival. This effect of cycloheximide is even more pronounced in cells also treated with procaine during heating, thus diminishing the interaction of heat and procaine in radiopotentiation. Data pertaining to cell progression in synchronous cultures of HeLa cells under various treatment conditions are presented and discussed

  9. Monte Carlo analysis of radiative transport in oceanographic lidar measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cupini, E.; Ferro, G. [ENEA, Divisione Fisica Applicata, Centro Ricerche Ezio Clementel, Bologna (Italy); Ferrari, N. [Bologna Univ., Bologna (Italy). Dipt. Ingegneria Energetica, Nucleare e del Controllo Ambientale

    2001-07-01

    The analysis of oceanographic lidar systems measurements is often carried out with semi-empirical methods, since there is only a rough understanding of the effects of many environmental variables. The development of techniques for interpreting the accuracy of lidar measurements is needed to evaluate the effects of various environmental situations, as well as of different experimental geometric configurations and boundary conditions. A Monte Carlo simulation model represents a tool that is particularly well suited for answering these important questions. The PREMAR-2F Monte Carlo code has been developed taking into account the main molecular and non-molecular components of the marine environment. The laser radiation interaction processes of diffusion, re-emission, refraction and absorption are treated. In particular are considered: the Rayleigh elastic scattering, produced by atoms and molecules with small dimensions with respect to the laser emission wavelength (i.e. water molecules), the Mie elastic scattering, arising from atoms or molecules with dimensions comparable to the laser wavelength (hydrosols), the Raman inelastic scattering, typical of water, the absorption of water, inorganic (sediments) and organic (phytoplankton and CDOM) hydrosols, the fluorescence re-emission of chlorophyll and yellow substances. PREMAR-2F is an extension of a code for the simulation of the radiative transport in atmospheric environments (PREMAR-2). The approach followed in PREMAR-2 was to combine conventional Monte Carlo techniques with analytical estimates of the probability of the receiver to have a contribution from photons coming back after an interaction in the field of view of the lidar fluorosensor collecting apparatus. This offers an effective mean for modelling a lidar system with realistic geometric constraints. The retrieved semianalytic Monte Carlo radiative transfer model has been developed in the frame of the Italian Research Program for Antarctica (PNRA) and it is

  10. Survey of radiation protection, radiation transport, and shielding information needs of the nuclear power industry. Final report

    International Nuclear Information System (INIS)

    Maskewitz, B.F.; Trubey, D.K.; Roussin, R.W.; McGill, B.L.

    1976-04-01

    The Radiation Shielding Information Center (RSIC) is engaged in a program to seek out, organize, and disseminate information in the area of radiation transport, shielding, and radiation protection. This information consists of published literature, nuclear data, and computer codes and advanced analytical techniques required by ERDA, its contractors, and the nuclear power industry to improve radiation analysis and computing capability. Information generated in this effort becomes a part of the RSIC collection and/or data base. The purpose of this report on project 219-1 is to document the results of the survey of information and computer code needs of the nuclear power industry in the area of radiation analysis and protection

  11. Survey of radiation protection, radiation transport, and shielding information needs of the nuclear power industry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Maskewitz, B.F.; Trubey, D.K.; Roussin, R.W.; McGill, B.L.

    1976-04-01

    The Radiation Shielding Information Center (RSIC) is engaged in a program to seek out, organize, and disseminate information in the area of radiation transport, shielding, and radiation protection. This information consists of published literature, nuclear data, and computer codes and advanced analytical techniques required by ERDA, its contractors, and the nuclear power industry to improve radiation analysis and computing capability. Information generated in this effort becomes a part of the RSIC collection and/or data base. The purpose of this report on project 219-1 is to document the results of the survey of information and computer code needs of the nuclear power industry in the area of radiation analysis and protection.

  12. Considerations of beta and electron transport in internal dose calculations. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bolch, W.E.

    1994-11-01

    The goal of this particular task is to consider, for the first time, the explicit transport of beta particles and photon-generated electrons in the series of six phantoms developed by Cristy and Eckerman (1987) at the Oak Ridge National Laboratory. In their report, ORNL/TM-8381, specific absorbed fractions of energy are reported for phantoms representing the newborn (3.4 kg), the one-year-old (9.8 kg), the five-year-old (19 kg), the ten-year-old (32 kg), the fifteen-year-old/adult female (55-58 kg), and the adult male (70 kg). Radiation transport calculations were performed with the Monte Carlo code ALGAMP which allows photon transport only. In subsequent calculations of radionuclide S values as is done in the MIRDOSE2 computer program, electron absorbed fractions are thus considered to be either unity or zero depending upon whether the source region does or does not equal the target region, respectively.

  13. Comparison of the cytological effects produced by ionizing radiations of different LET. Progress report, March 1974--April 1975

    International Nuclear Information System (INIS)

    Riley, E.F. Jr.

    1975-01-01

    Progress is reported on the following research projects: RBE of neutrons and x radiation for effects on rat lens epithelium; effects of x radiation on tumor cell transplants in mice; effects of fast neutrons on ascites tumors; the sparing effect of dose fractionation in the wounded rat lens; and DNA synthesis in wounded rat lens at various times after irradiation. (U.S.)

  14. Radiation damage and repair in cells and cell components. Progress report, November 1, 1977--October 31, 1978

    International Nuclear Information System (INIS)

    Fluke, D.J.; Pollard, E.C.

    1978-01-01

    Progress is reported on the following research projects: coordinate induction of mutagenesis, radioresistance, and inhibition of post-radiation DNA degradation; radioinduced filamentation; action spectrum for induction of K12 lambda phage; effects of uv radiation on cells in the frozen state; dependence of mutagenesis on wavelength of uv; and w-reactivation of x-irradiated phage lambda

  15. A research program on radiative, chemical, and dynamical feedback progresses influencing the carbon dioxide and trace gases climate effects

    International Nuclear Information System (INIS)

    1989-07-01

    This report summarizes the up-to-date progress. The program includes two tasks: atmospheric radiation and climatic effects and their objective is to link quantitatively the radiation forcing changes and the climate responses caused by increasing greenhouse gases. Here, the objective and approach are described. We investigate the combined atmospheric radiation characteristics of the greenhouse gases (H 2 O, CO 2 , CH 4 , N 2 O, CFCs, and O 3 ), aerosols and clouds. Since the climatic effect of increasing atmospheric greenhouse gases is initiated by perturabtion to the longwave thermal radiation, it is critical to understand better the radiation characteristics of the greenhouse gases and their relationship to radiatively-important aerosols and clouds; the latter reflect solar radiation (a cooling of the surface) and provide a greenhouse effect (a warming to the surface). Therefore, aerosol and cloud particles are an integral part of the radiation field in the atmosphere. 9 refs

  16. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2b, May 2013

    International Nuclear Information System (INIS)

    2013-05-01

    The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Asia and the Pacific via the Regional project RAS/9/066 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Malaysia and Syrian Arabic Republic are key partners in the Asian and the Pacific region.

  17. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2c, May 2013

    International Nuclear Information System (INIS)

    2013-05-01

    The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Europe via the Regional Project RER/9/109 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Greece and Belarus are key partners in the European region.

  18. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2d, June 2013

    International Nuclear Information System (INIS)

    2013-06-01

    The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Latin America via the Regional Project RLA/9/070 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Argentina and Brazil are key partners in the Latin-American region.

  19. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2a, May 2013

    International Nuclear Information System (INIS)

    2013-05-01

    The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Africa via the Regional project RAF/9/04 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. AFRA Regional Designated Centres, in Algeria, Ghana and Morocco, equivalent to the IAEA's Regional Training Centres (RTCs) present in all the other regions, are key partners in the African region.

  20. Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

    Directory of Open Access Journals (Sweden)

    Casali L.

    2014-01-01

    Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

  1. Novel Parallel Numerical Methods for Radiation and Neutron Transport

    International Nuclear Information System (INIS)

    Brown, P N

    2001-01-01

    In many of the multiphysics simulations performed at LLNL, transport calculations can take up 30 to 50% of the total run time. If Monte Carlo methods are used, the percentage can be as high as 80%. Thus, a significant core competence in the formulation, software implementation, and solution of the numerical problems arising in transport modeling is essential to Laboratory and DOE research. In this project, we worked on developing scalable solution methods for the equations that model the transport of photons and neutrons through materials. Our goal was to reduce the transport solve time in these simulations by means of more advanced numerical methods and their parallel implementations. These methods must be scalable, that is, the time to solution must remain constant as the problem size grows and additional computer resources are used. For iterative methods, scalability requires that (1) the number of iterations to reach convergence is independent of problem size, and (2) that the computational cost grows linearly with problem size. We focused on deterministic approaches to transport, building on our earlier work in which we performed a new, detailed analysis of some existing transport methods and developed new approaches. The Boltzmann equation (the underlying equation to be solved) and various solution methods have been developed over many years. Consequently, many laboratory codes are based on these methods, which are in some cases decades old. For the transport of x-rays through partially ionized plasmas in local thermodynamic equilibrium, the transport equation is coupled to nonlinear diffusion equations for the electron and ion temperatures via the highly nonlinear Planck function. We investigated the suitability of traditional-solution approaches to transport on terascale architectures and also designed new scalable algorithms; in some cases, we investigated hybrid approaches that combined both

  2. Radiation transport effects in divertor plasmas generated during a tokamak reactor disruption

    International Nuclear Information System (INIS)

    Peterson, R.R.; MacFarlane, J.J.; Wang, P.

    1994-01-01

    Vaporization of material from tokamak divertors during disruptions is a critical issue for tokamak reactors from ITER to commercial power plants. Radiation transport from the vaporized material onto the remaining divertor surface plays an important role in the total mass loss to the divertor. Radiation transport in such a vapor is very difficult to calculate in full detail, and this paper quantifies the sensitivity of the divertor mass loss to uncertainties in the radiation transport. Specifically, the paper presents the results of computer simulations of the vaporization of a graphite coated divertor during a tokamak disruption with ITER CDA parameters. The results show that a factor of 100 change in the radiation conductivity changes the mass loss by more than a factor of two

  3. The use of symbolic computation in radiative, energy, and neutron transport calculations

    Science.gov (United States)

    Frankel, J. I.

    This investigation uses symbolic computation in developing analytical methods and general computational strategies for solving both linear and nonlinear, regular and singular, integral and integro-differential equations which appear in radiative and combined mode energy transport. This technical report summarizes the research conducted during the first nine months of the present investigation. The use of Chebyshev polynomials augmented with symbolic computation has clearly been demonstrated in problems involving radiative (or neutron) transport, and mixed-mode energy transport. Theoretical issues related to convergence, errors, and accuracy have also been pursued. Three manuscripts have resulted from the funded research. These manuscripts have been submitted to archival journals. At the present time, an investigation involving a conductive and radiative medium is underway. The mathematical formulation leads to a system of nonlinear, weakly-singular integral equations involving the unknown temperature and various Legendre moments of the radiative intensity in a participating medium. Some preliminary results are presented illustrating the direction of the proposed research.

  4. Integral and Lagrangian simulations of particle and radiation transport in plasma

    International Nuclear Information System (INIS)

    Christlieb, A J; Hitchon, W N G; Lawler, J E; Lister, G G

    2009-01-01

    Accurate integral and Lagrangian models of transport in plasmas, in which the models reflect the actual physical behaviour as closely as possible, are presented. These methods are applied to the behaviour of particles and photons in plasmas. First, to show how these types of models arise in a wide range of plasma physics applications, an application to radiation transport in a lighting discharge is given. The radiation transport is solved self-consistently with a model of the discharge to provide what are believed to be very accurate 1D simulations of fluorescent lamps. To extend these integral methods to higher dimensions is computationally very costly. The wide utility of 'treecodes' in solving massive integral problems in plasma physics is discussed, and illustrated in modelling vortex formation in a Penning trap, where a remarkably detailed simulation of vortex formation in the trap is obtained. Extension of treecode methods to other integral problems such as radiation transport is under consideration.

  5. Factors affecting radiation doses from dedicated rail transport of spent reactor fuel

    International Nuclear Information System (INIS)

    Martin, J.E.

    1988-01-01

    This paper reports there are two exposure control concerns associated with the shipment of spent reactor fuel in dedicated trains -- compliance with transportation regulations for maximum allowable radiation levels, and minimizing the dose received by the general public. This article examines the methods used to calculate the dose equivalent rates alongside stationary (transport regulations) and moving trains (public exposure) of various lengths. The factors examined include the source term, the effect of overlapping radiation fields, the speed of the train, and the location of the population relative to the train. Trains made up of series of cars that individually meet transport regulations can, as a whole, exceed transport vehicle dose equivalent rate limits by up to 23% due to overlapping radiation fields. For moving trains and the worst case analyzed -- a person located 20 feet from the tracks and a train speed of 5 mph --- 141 rail cars would have to pass by to deliver a dose equivalent of 1 mrem

  6. Security measures in transport of radiation source in Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad, Alslman [Korea Advanced Institute of Science and Technology, Kaist Daejeon (Korea, Republic of); Choi, Kwang Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2011-05-15

    Radioactive materials are used in Jordan for peaceful applications in medicine, industry, agriculture, environmental science, education and research and military applications. Most of these radioactive sources used are imported, therefore trans-boundary movement is a significant factor in consideration of security measures during movement of these sources. After 11/9 2001 event, IAEA efforts began to focus and concentrate on security in transport of radioactive materials, after the emergence of risks of using these sources in terrorist activities. In 2002, Efforts were initiated by the IAEA to provide additional guidance for security in the transport of radioactive materials, based upon the new security requirements in the Recommendations on the Transport of Dangerous Goods. This paper reviews some of the measures relating to the transport of radioactive materials in Jordan

  7. Acoustic backscattering and radiation force on a rigid elliptical cylinder in plane progressive waves.

    Science.gov (United States)

    Mitri, F G

    2016-03-01

    This work proposes a formal analytical theory using the partial-wave series expansion (PWSE) method in cylindrical coordinates, to calculate the acoustic backscattering form function as well as the radiation force-per-length on an infinitely long elliptical (non-circular) cylinder in plane progressive waves. The major (or minor) semi-axis of the ellipse coincides with the direction of the incident waves. The scattering coefficients for the rigid elliptical cylinder are determined by imposing the Neumann boundary condition for an immovable surface and solving a resulting system of linear equations by matrix inversion. The present method, which utilizes standard cylindrical (Bessel and Hankel) wave functions, presents an advantage over the solution for the scattering that is ordinarily expressed in a basis of elliptical Mathieu functions (which are generally non-orthogonal). Furthermore, an integral equation showing the direct connection of the radiation force function with the square of the scattering form function in the far-field from the scatterer (applicable for plane waves only), is noted and discussed. An important application of this integral equation is the adequate evaluation of the radiation force function from a bistatic measurement (i.e., in the polar plane) of the far-field scattering from any 2D object of arbitrary shape. Numerical predictions are evaluated for the acoustic backscattering form function and the radiation force function, which is the radiation force per unit length, per characteristic energy density, and per unit cross-sectional surface of the ellipse, with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes, as well as the dimensionless size parameter kb, without the restriction to a particular range of frequencies. The results are particularly relevant in acoustic levitation, acousto-fluidics and particle dynamics applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Bioenergetic coupling between membrane transport systems and biosynthetic pathways essential for cell cycle progression

    International Nuclear Information System (INIS)

    Leister, K.J.; Cutry, A.F.; Wenner, C.E.

    1986-01-01

    Recently, it has been shown that there exists a point in the cell cycle (approximately 2 h prior to S phase entry) when (Na + /K + )ATPase pump activity is no longer needed for progression through the cycle. These data suggests that pump activity is critical in the biosynthetic processes which enables the cell to proceed through the G 1 phase. A scheme is proposed which is currently being tested that (Na + /K + )ATPase pump activity serves as the driving force in the regulation of other membrane transport processes critical for cell proliferation. For example, in post-confluent quiescent C3H-10T1/2 fibroblasts, when [K + ]/sub o/ is lowered just below the K/sub m/ of the pump for K + there is a 10-fold increase in 3 H-uridine uptake into both acid soluble and insoluble cell fractions. By modulation of the pump in this manner, glucose utilization is enhanced whereas inhibition of the pump by ouabain suppresses glucose utilization. In both methods of affecting the pump, 3 H-leucine incorporation is inhibited. Electron acceptors that influence the redox state of the cell have been shown to both stimulate or inhibit cell cycle progression. Under conditions where [K + ]/sub o/ is lowered, the nucleoside uptake responses observed were modified by electron acceptors depending on the ability to oxidize NAD(P)H directly or to interact with a cytochrome-like component, (e.g. phenazine methosulfate) reversed the enhanced uridine uptake and p-phenylene diamine further enhanced the uridine uptake response. These findings suggest that a plasma membrane redox system (presumably cyt-c like) is linked to nucleoside transport which is subject to (Na + /K + )ATPase activity

  9. Progressive behavioral changes in rats after exposure to low levels of ionizing radiation in utero

    International Nuclear Information System (INIS)

    Norton, S.; Kimler, B.F.; Mullenix, P.J.

    1991-01-01

    The deleterious effects of ionizing radiation on the developing brain may be not only prolonged but progressive. Fetuses were exposed to 0.75 Gy of ionizing radiation on gestational day 15 through whole body exposure of the pregnant rat. Three behavioral tests (gait analysis, continuous corridor activity and photographic analysis of sequences of behavioral acts) were performed at 1 and 3 months, postnatally. Body weight and thickness of the cerebral cortex of irradiated rats were 10-15 percent below controls throughout the period of study. Behavior in all tests was more affected at 3 months than at 1 month of age. Gait of control rats, as measured by the angle of advanced of hind feet, widened about 20 percent for males and 40 percent for females from 1 to 3 months, as expected, while, in irradiated rats, the angle widened only about 10 percent. Continuous corridor activity increased less than 10 percent in controls and about 35 percent in irradiated rats over the same period. In photographic analysis of behavior, controls increased their time spent standing by about 50 percent in males and 20 percent in females from 1 to 3 months of age. Irradiated males increased time standing only about 10 percent and irradiated females decreased about 30 percent over the same period. The data obtained in these experiments support other evidence that some behavioral alterations from perinatal exposure to radiation become more marked with maturation

  10. Human genetic marker for resistance to radiations and chemicals. 1998 annual progress report

    International Nuclear Information System (INIS)

    Lieberman, H.B.

    1998-01-01

    'The broad objective of the project is to understand the molecular basis for the response of cells to radiations and chemicals, with the pragmatic goal of being able to identify human subpopulations that are exceptionally sensitive to DNA damaging agents. The project focuses on HRAD9, a human orthologue of the fission yeast Schizosaccharomyces pombe gene rad9. S. pombe rad9::ura4+ mutant cells are highly sensitive to ionizing radiation, UV and many chemicals, such as the DNA synthesis inhibitor hydroxyurea. They also lack the ability to delay cycling transiently in S phase or in G2 following a block in DNA replication or after incurring DNA damage, respectively -i.e., they lack checkpoint controls. The attempt by mutant cells to progress through mitosis in the absence of fully intact DNA accounts at least in part for their sensitivity to DNA damaging agents. Cells bearing rad9::ura4+ also aberrantly regulate UVDE, an enzyme that participates in a secondary DNA excision repair pathway. The key role played by S. pombe rad9 in promoting resistance to chemicals and radiations suggests that the evolutionarily conserved human cognate also has important functions in mammals. The first set of aims in this proposal centers on characterizing the structure and expression of HRAD9, to assess structure/function relationships and potentially link protein activity to a specific tissue. The next set of aims focuses on determining the role of HRAD9 in radio/chemoresponsiveness and cancer.'

  11. Self-consistent collisional-radiative model for hydrogen atoms: Atom–atom interaction and radiation transport

    International Nuclear Information System (INIS)

    Colonna, G.; Pietanza, L.D.; D’Ammando, G.

    2012-01-01

    Graphical abstract: Self-consistent coupling between radiation, state-to-state kinetics, electron kinetics and fluid dynamics. Highlight: ► A CR model of shock-wave in hydrogen plasma has been presented. ► All equations have been coupled self-consistently. ► Non-equilibrium electron and level distributions are obtained. ► The results show non-local effects and non-equilibrium radiation. - Abstract: A collisional-radiative model for hydrogen atom, coupled self-consistently with the Boltzmann equation for free electrons, has been applied to model a shock tube. The kinetic model has been completed considering atom–atom collisions and the vibrational kinetics of the ground state of hydrogen molecules. The atomic level kinetics has been also coupled with a radiative transport equation to determine the effective adsorption and emission coefficients and non-local energy transfer.

  12. Radiation exposures of workers resulting from the transport of gamma radiography sources in Germany

    International Nuclear Information System (INIS)

    Sentuc, F.N.; Schwarz, G.

    2006-01-01

    Gamma radiation sources are widely used for industrial purposes e.g. for non-destructive material testing. Many of these sources are permanently installed at a facility within instruments e.g. for level or thickness gauging. Other radioactive sources are implemented in portable devices for industrial gamma radiography which have to be carried to the various remote usage sites. In Germany, approximately 20 000 - 25 000 shipments of gamma radiography sources are proceeding annually on public transport routes. Since routine radiation monitoring programmes do not permit task-specific determination of occupational doses e.g. doses incurred during the movement phase and handling related doses, work has been carried out with the objective to determine the radiation exposures of the personnel attributable to transportation. For this purpose, a survey was launched in 2005 collecting data about e.g. the number and conditions of transports, the activity and type of transported radiation sources and the radiation level within the driver's cab to allow a dose assessment to be made for transport workers. The results of this survey covering the most important companies for gamma radiography services in Germany are presented in this paper. (authors)

  13. Progress Towards Increased Understanding and Control of Internal Transport Barriers on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, E. J. [University of California, Los Angeles; Greenfield, C. M. [General Atomics; Austin, M. E. [University of Texas, Austin; Baylor, Larry R [ORNL; Burrell, K. H. [General Atomics; Casper, T. A. [Lawrence Livermore National Laboratory (LLNL); DeBoo, J. C. [General Atomics; Ernst, D. R. [Princeton Plasma Physics Laboratory (PPPL); Fenzi, C. [University of Wisconsin, Madison; Gohil, P. [General Atomics; Groebner, R. J. [General Atomics; Heidbrink, W. W. [University of California, Irvine; Jackson, G. L. [General Atomics; Jernigan, Thomas C [ORNL; Kinsey, J. E. [Lehigh University, Bethlehem, PA; Lao, L. L. [General Atomics; Makowski, M. A. [Lawrence Livermore National Laboratory (LLNL); Mckee, G. R. [University of Wisconsin, Madison; Murakami, Masanori [ORNL; Peebles, W. A. [University of California, Los Angeles; Prater, R. [General Atomics; Rettig, C. L. [University of California, Los Angeles; Rhodes, T. L. [University of California, Los Angeles; Rost, J. C. [Massachusetts Institute of Technology (MIT); Staebler, G. M. [General Atomics; Stallard, B. W. [Lawrence Livermore National Laboratory (LLNL); Strait, E. J. [General Atomics; Synakowski, E. J. [Princeton Plasma Physics Laboratory (PPPL); Thomas, D. M. [General Atomics; Wade, Mickey R [ORNL; Waltz, R. E. [General Atomics; Zeng, L. [University of California, Los Angeles

    2001-01-01

    Substantial progress has been made towards both understanding and control of internal transport barriers (ITBs) on DIII-D, resulting in the discovery of a new sustained high performance operating mode termed the Quiescent Double-Barrier (QDB) regime. The QDB regime combines core transport barriers with a quiescent, ELM-free H-mode edge (termed QH-mode), giving rise to separate (double) core and edge transport barriers. The core and edge barriers are mutually compatible and do not merge, resulting in broad core profiles with an edge pedestal. The QH-mode edge is characterized by ELM-free behavior with continuous multiharmonic MHD activity in the pedestal region, and has provided density and impurity control for 3.5 s (>20 τE) with divertor pumping. QDB plasmas are long-pulse high-performance candidates, having maintained a βNH89 product of 7 for 5 energy confinement times (Ti ≤ 16 keV, βN ≤ 2.9, H89 ≤ 2.4, τE ≤ 150 ms, DD neutron rate Sn ≤ 4x1015 s-1). The QDB regime has only been obtained in counter-NBI discharges (injection anti-parallel to plasma current) with divertor pumping. Other results include successful expansion of the ITB radius using (separately) both impurity injection and counter-NBI, and the formation of ITBs in the electron thermal channel using both ECH and strong negative central shear (NCS) at high power. These results are interpreted within a theoretical framework in which turbulence suppression is the key to ITB formation and control, and a decrease in core turbulence is observed in all cases of ITB formation.

  14. Progress towards increased understanding and control of internal transport barriers (ITBs) on DIII-D

    International Nuclear Information System (INIS)

    Doyle, E.J.; Greenfield, C.M.; Austin, M.E.

    2001-01-01

    Substantial progress has been made towards both understanding and control of internal transport barriers (ITBs) on DIII-D, resulting in the discovery of a new sustained high performance operating mode termed the Quiescent Double-Barrier (QDB) regime. The QDB regime combines core transport barriers with a quiescent, ELM-free H-mode edge (termed QH-mode), giving rise to separate (double) core and edge transport barriers. The core and edge barriers are mutually compatible and do not merge, resulting in broad core profiles with an edge pedestal. The QH-mode edge is characterized by ELM-free behavior with continuous multiharmonic MHD activity in the pedestal region, and has provided density and impurity control for 3.5 s (>20 τ E ) with divertor pumping. QDB plasmas are long-pulse high-performance candidates, having maintained a β N H 89 product of 7 for 5 energy confinement times (T i ≤16 keV, β N ≤2.9, H 89 ≤2.4, τ E ≤150 ms, DD neutron rate S n ≤4x10 15 s -1 ). The QDB regime has only been obtained in counter-NBI discharges (injection anti-parallel to plasma current) with divertor pumping. Other results include successful expansion of the ITB radius using (separately) both impurity injection and counter-NBI, and the formation of ITBs in the electron thermal channel using both ECH and strong negative central shear (NCS) at high power. These results are interpreted within a theoretical framework in which turbulence suppression is the key to ITB formation and control, and a decrease in core turbulence is observed in all cases of ITB formation. (author)

  15. VU-B radiation inhibits the photosynthetic electron transport chain in chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Cai, W.; Li, X.; Chen, L.

    2016-01-01

    UV radiation of sunlight is one of harmful factors for earth organisms, especially for photoautotrophs because they require light for energy and biomass production. A number of works have already been done regarding the effects of UV-B radiation at biochemical and molecular level, which showed that UV-B radiation could inhibit photosynthesis activity and reduce photosynthetic electron transport. However quite limited information can accurately make out inhibition site of UV-B radiation on photosynthetic electron transport. In this study, this issue was investigated through measuring oxygen evolution activity, chlorophyll a fluorescence and gene expression in a model unicellular green alga Chlamydomonas reinhardtii. Our results indicated that UV-B radiation could evidently decrease photosynthesis activity and inhibit electron transport by blocking electron transfer process from the first plastoquinone electron acceptors QA to second plastoquinone electron acceptors QB, but not impair electron transfer from the water oxidizing complex to QA. The psbA gene expression was also altered by UV-B radiation, where up-regulation occurred at 2, 4 and 6h after exposure and down-regulation happened at 12 and 24 h after exposure. These results suggested that UV-B could affects D1 protein normal turnover, so there was not enough D1 for binding with QB, which may affect photosynthetic electron transport and photosynthesis activity. (author)

  16. Two-dimensional radiation shielding optimization analysis of spent fuel transport container

    International Nuclear Information System (INIS)

    Tian Yingnan; Chen Yixue; Yang Shouhai

    2013-01-01

    The intelligent radiation shielding optimization design software platform is a one-dimensional multi-target radiation shielding optimization program which is developed on the basis of the genetic algorithm program and one-dimensional discrete ordinate program-ANISN. This program was applied in the optimization design analysis of the spent fuel transport container radiation shielding. The multi-objective optimization calculation model of the spent fuel transport container radiation shielding was established, and the optimization calculation of the spent fuel transport container weight and radiation dose rate was carried by this program. The calculation results were checked by Monte-Carlo program-MCNP/4C. The results show that the weight of the optimized spent fuel transport container decreases to 81.1% of the origin and the radiation dose rate decreases to below 65.4% of the origin. The maximum deviation between the calculated values from the program and the MCNP is below 5%. The results show that the optimization design scheme is feasible and the calculation result is correct. (authors)

  17. ETRAN, Electron Transport and Gamma Transport with Secondary Radiation in Slab by Monte-Carlo

    International Nuclear Information System (INIS)

    1992-01-01

    A - Nature of physical problem solved: ETRAN computes the transport of electrons and photons through plane-parallel slab targets that have a finite thickness in one dimension and are unbound in the other two-dimensions. The incident radiation can consist of a beam of either electrons or photons with specified spectral and directional distribution. Options are available by which all orders of the electron-photon cascade can be included in the calculation. Thus electrons are allowed to give rise to secondary knock-on electrons, continuous Bremsstrahlung and characteristic x-rays; and photons are allowed to produce photo-electrons, Compton electrons, and electron- positron pairs. Annihilation quanta, fluorescence radiation, and Auger electrons are also taken into account. If desired, the Monte- Carlo histories of all generations of secondary radiations are followed. The information produced by ETRAN includes the following items: 1) reflection and transmission of electrons or photons, differential in energy and direction; 2) the production of continuous Bremsstrahlung and characteristic x-rays by electrons and the emergence of such radiations from the target (differential in photon energy and direction); 3) the spectrum of the amounts of energy left behind in a thick target by an incident electron beam; 4) the deposition of energy and charge by an electron beam as function of the depth in the target; 5) the flux of electrons, differential in energy, as function of the depth in the target. B - Method of solution: A programme called DATAPAC-4 takes data for a particular material from a library tape and further processes them. The function of DATAPAC-4 is to produce single-scattering and multiple-scattering data in the form of tabular arrays (again stored on magnetic tape) which facilitate the rapid sampling of electron and photon Monte Carlo histories in ETRAN. The photon component of the electron-photon cascade is calculated by conventional random sampling that imitates

  18. Brachytherapy with 125-Iodine sources: transport and radiation protection

    International Nuclear Information System (INIS)

    Souza, Carla D.; Zeituni, Carlos A.; Moura, Joao A.; Moura, Eduardo S.; Nagatomi, Helio R.; Feher, Anselmo; Hilario, Katia F.; Rostelato, Maria Elisa C.M.

    2009-01-01

    The estimates for the year 2009 show that 466,730 new cancer cases will occur in Brazil. Prostate cancer is the second most incident type. Brachytherapy, a type of radiotherapy, with Iodine-125 sources are an important form of treatment for this kind of cancer. The Instituto de Pesquisas Energeticas e Nucleares (IPEN) created a project to develop a national prototype of these sources and is implementing a facility for local production. The seeds manufacture in Brazil will allow to diminish the treatment cost and make it possible for a larger number of patients. While the laboratory is not ready, the IPEN import and it distributes seeds. This work aim is to present and evaluate the transport procedures and the radiological protection applied to imported sources in order to assist the procedures for the new laboratory implementation. Before sending to hospitals, the seeds are packed by a radioprotector supervisor, in accordance with CNEN NE 5.01 standard 'Radioactive Material Transport'. Despite Iodine-125 presents low energy photons, around 29 keV, local and personal dosimeters are used during the transport process, as described in CNEN NN 3.01 standard 'Radiological Protection Basic Guideline'. All the results show no contamination and very low exposure, proving the method to be valid. The transport procedure used is correct, according to the regulations. As an result of this work, a new dosimeter should be installed and evaluate in future study. (author)

  19. Experience with the loading and transport of fuel assembly transport casks, including CASTOR casks, and the radiation exposure of personnel

    International Nuclear Information System (INIS)

    Bentele, W.; Kinzelmann, T.

    1999-01-01

    In 1997 and 1998, six spent fuel assembly transports started from the nuclear power plant Gemeinschaftskernkraftwerk Neckar (GKN), using CASTOR-V19 casks. Professor Kuni of Marburg University challenged the statement made by the German Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz (BfS)) based on accepted scientific knowledge, according to which so-called CASTOR transports present no risk, either to the population or to the escorting police units. This paper shows that the collective dose during the loading of the CASTOR casks amounted to 4.5 mSv (gamma and neutrons) per cask at the most, and that the maximum individual dose amounted to 0.26 mSv. In addition to these doses, the collective dose during handling and transport must be considered: this amounted to 0.35 mSv (gamma and neutrons). The dose to the police escort was -2 (limit for surface contamination), presented degrees of contamination >4 Bq cm -2 upon reaching the Valognes/Cogema terminal. However, transport casks coming from French plants also revealed degrees of contamination >4 Bq cm -2 , as well as 'hot spots'. No such contamination was found on NTL 11 casks transported from the GKN to Sellafield. Neither was any increased contamination found upon the arrival of CASTOR-V19 casks transported from GKN to Gorleben or Ahaus. The partially sensationalist media reports were inversely proportional to the actual radiological relevance of the matter. The German Commission on Radiation Protection (SSK) confirmed that the radiological effect of such contaminated spent fuel transports is negligible. (author)

  20. Small-sized linear accelerator of 2.5 MeV electrons with a local radiation shield for custom examination of freight transported by motor transport

    International Nuclear Information System (INIS)

    Baklanov, A.V.; Gavrish, Yu.N.; Klinov, A.P.; Krest'yaninov, A.S.; Nikolaev, V.M.; Fomin, L.P.; Linkenbach, H.A.; Geus, G.; Knospel, W.

    2001-01-01

    A new development of a small-sized linear accelerator of 2.5 MeV electrons with a local radiation protection is described. The accelerator is intended for movable facilities of radiation custom of the freight transported by motor transport. Main constructive solutions, mass and dimension characteristics and results of preliminary tests of the accelerator parameters and characteristics of radiation protection are presented [ru

  1. Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

    International Nuclear Information System (INIS)

    Hill, K.W.; Bell, M.G.; Budny, R.

    1999-01-01

    To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≥ 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

  2. Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

    International Nuclear Information System (INIS)

    Hill, K.W.; Bell, M.G.; Budny, R.

    2001-01-01

    To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≤30MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

  3. Highly Radiative Plasmas for Local Transport Studies and Power and Particle Handling in Reactor Regimes

    International Nuclear Information System (INIS)

    Bell, M.G.; Bell, R.E.; Budny, R.; Bush, C.E.; Hill, K.W.

    1998-01-01

    To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into the Tokamak Fusion Test Reactor (TFTR) supershots and high-l(subscript) plasmas. At neutral beam injection (NBI) powers P(subscript B) greater than or equal to 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both deuterium (D) and deuterium-tritium (DT) plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in the International Thermonuclear Experimental Reactor (ITER). The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms

  4. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 3, May 2014

    International Nuclear Information System (INIS)

    2014-05-01

    Building competence through education and training in radiation protection, radioactive waste safety, and safety in transport of radioactive material is fundamental to the establishment of a comprehensive and sustainable national infrastructure for radiation safety, which in turn is essential for the beneficial uses of radiation while ensuring appropriate protection of workers, patients, the public and the environment. IAEA’s Division of Radiation, Transport and Waste Safety provides direct assistance to Member States via a range of tools and mechanisms, such as by organizing educational and training events, developing standardized syllabi with supporting material and documents, and by fostering methodologies to build sustainable competence and enhance effectiveness in the provision of training. The main objective is to support Member States in the application of the IAEA Safety Standards. Seminars and additional activities are also promoted to broaden knowledge on relevant areas for an effective application of the standards

  5. Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S., E-mail: alastair.moore@physics.org; Graham, P.; Comley, A. J.; Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading RG7 4PR (United Kingdom); Cooper, A. B. R.; Schneider, M. B.; MacLaren, S.; Lu, K.; Seugling, R.; Satcher, J.; Klingmann, J.; Marrs, R.; May, M.; Widmann, K.; Glendinning, G.; Castor, J.; Sain, J.; Baker, K.; Hsing, W. W.; Young, B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

    2014-06-15

    Experiments that characterize and develop a high energy-density half-hohlraum platform for use in benchmarking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic diffusive Marshak wave, which propagates into a high atomic number Ta{sub 2}O{sub 5} aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range of x-ray measurements that absolutely quantify the energetics and radiation partition inside the target.

  6. Implicit Monte Carlo methods and non-equilibrium Marshak wave radiative transport

    International Nuclear Information System (INIS)

    Lynch, J.E.

    1985-01-01

    Two enhancements to the Fleck implicit Monte Carlo method for radiative transport are described, for use in transparent and opaque media respectively. The first introduces a spectral mean cross section, which applies to pseudoscattering in transparent regions with a high frequency incident spectrum. The second provides a simple Monte Carlo random walk method for opaque regions, without the need for a supplementary diffusion equation formulation. A time-dependent transport Marshak wave problem of radiative transfer, in which a non-equilibrium condition exists between the radiation and material energy fields, is then solved. These results are compared to published benchmark solutions and to new discrete ordinate S-N results, for both spatially integrated radiation-material energies versus time and to new spatially dependent temperature profiles. Multigroup opacities, which are independent of both temperature and frequency, are used in addition to a material specific heat which is proportional to the cube of the temperature. 7 refs., 4 figs

  7. Recent progress and tests of radiation resistant impregnation materials for Nb3Sn coils

    Science.gov (United States)

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-01

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of "ten stacks" of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy.

  8. Recent progress and tests of radiation resistant impregnation materials for Nb3Sn coils

    International Nuclear Information System (INIS)

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-01

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb 3 Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of “ten stacks” of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy

  9. Analytical Radiation Transport Benchmarks for The Next Century

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    2005-01-01

    Verification of large-scale computational algorithms used in nuclear engineering and radiological applications is an essential element of reliable code performance. For this reason, the development of a suite of multidimensional semi-analytical benchmarks has been undertaken to provide independent verification of proper operation of codes dealing with the transport of neutral particles. The benchmarks considered cover several one-dimensional, multidimensional, monoenergetic and multigroup, fixed source and critical transport scenarios. The first approach, called the Green's Function. In slab geometry, the Green's function is incorporated into a set of integral equations for the boundary fluxes. Through a numerical Fourier transform inversion and subsequent matrix inversion for the boundary fluxes, a semi-analytical benchmark emerges. Multidimensional solutions in a variety of infinite media are also based on the slab Green's function. In a second approach, a new converged SN method is developed. In this method, the SN solution is ''minded'' to bring out hidden high quality solutions. For this case multigroup fixed source and criticality transport problems are considered. Remarkably accurate solutions can be obtained with this new method called the Multigroup Converged SN (MGCSN) method as will be demonstrated

  10. Radiation Transport in Random Media With Large Fluctuations

    Science.gov (United States)

    Olson, Aaron; Prinja, Anil; Franke, Brian

    2017-09-01

    Neutral particle transport in media exhibiting large and complex material property spatial variation is modeled by representing cross sections as lognormal random functions of space and generated through a nonlinear memory-less transformation of a Gaussian process with covariance uniquely determined by the covariance of the cross section. A Karhunen-Loève decomposition of the Gaussian process is implemented to effciently generate realizations of the random cross sections and Woodcock Monte Carlo used to transport particles on each realization and generate benchmark solutions for the mean and variance of the particle flux as well as probability densities of the particle reflectance and transmittance. A computationally effcient stochastic collocation method is implemented to directly compute the statistical moments such as the mean and variance, while a polynomial chaos expansion in conjunction with stochastic collocation provides a convenient surrogate model that also produces probability densities of output quantities of interest. Extensive numerical testing demonstrates that use of stochastic reduced-order modeling provides an accurate and cost-effective alternative to random sampling for particle transport in random media.

  11. Locoregional Tumor Progression After Radiation Therapy Influences Overall Survival in Pediatric Patients With Neuroblastoma

    International Nuclear Information System (INIS)

    Pai Panandiker, Atmaram S.; McGregor, Lisa; Krasin, Matthew J.; Wu Shengjie; Xiong Xiaoping; Merchant, Thomas E.

    2010-01-01

    Purpose: There is renewed attention to primary site irradiation and local control for patients with high-risk neuroblastoma (NB). We conducted a retrospective review to identify factors that might predict for locoregional tumor control and its impact on overall survival. Methods and Materials: Between July 2000 through August 2006, a total of 44 pediatric patients with NB received radiation therapy (RT) with curative intent using computed tomography (CT)-based treatment planning. The median age was 3.4 years and the median cumulative dose was 23.4 Gy. Overall survival and locoregional tumor control were measured from the start of RT to the date of death or event as determined by CT/magnetic resonance imaging/meta-iodobenzylguanidine. The influence of age at irradiation, gender, race, cumulative radiation dose, International Neuroblastoma Staging System stage, treatment protocol and resection status was determined with respect to locoregional tumor control. Results: With a median follow-up of 34 months ± 21 months, locoregional tumor progression was observed in 11 (25%) and was evenly divided between primary site and adjacent nodal/visceral site failure. The influence of locoregional control reached borderline statistical significance (p = 0.06). Age (p = 0.5), dose (p = 0.6), resection status (p = 0.7), and International Neuroblastoma Staging System stage (p = 0.08) did not influence overall survival. Conclusions: Overall survival in high-risk neuroblastoma is influenced by locoregional tumor control. Despite CT-based planning, progression in adjacent nodal/visceral sites appears to be common; this requires further investigation regarding target volume definitions, dose, and the effects of systemic therapy.

  12. Graphical-based construction of combinatorial geometries for radiation transport and shielding applications

    International Nuclear Information System (INIS)

    Burns, T.J.

    1992-01-01

    A graphical-based code system is being developed at ORNL to manipulate combinatorial geometries for radiation transport and shielding applications. The current version (basically a combinatorial geometry debugger) consists of two parts: a FORTRAN-based ''view'' generator and a Microsoft Windows application for displaying the geometry. Options and features of both modules are discussed. Examples illustrating the various options available are presented. The potential for utilizing the images produced using the debugger as a visualization tool for the output of the radiation transport codes is discussed as is the future direction of the development

  13. Optical transport and statistics of radiative losses in disordered chains of microspheres

    International Nuclear Information System (INIS)

    Deng Chaosheng; Xu Hui; Deych, Lev

    2010-01-01

    Optical transport in a one-dimensional chain of microspherical resonators with size disorder is studied in the spectral range of high-Q whispering gallery modes. An ab initio approach is used to develop a theoretical framework for analysis of steady-state transport parameters with main emphasis on properly defined radiative loss coefficient. Probability distribution and scaling properties of the latter are established and explained.

  14. Monte Carlo closure for moment-based transport schemes in general relativistic radiation hydrodynamic simulations

    Science.gov (United States)

    Foucart, Francois

    2018-04-01

    General relativistic radiation hydrodynamic simulations are necessary to accurately model a number of astrophysical systems involving black holes and neutron stars. Photon transport plays a crucial role in radiatively dominated accretion discs, while neutrino transport is critical to core-collapse supernovae and to the modelling of electromagnetic transients and nucleosynthesis in neutron star mergers. However, evolving the full Boltzmann equations of radiative transport is extremely expensive. Here, we describe the implementation in the general relativistic SPEC code of a cheaper radiation hydrodynamic method that theoretically converges to a solution of Boltzmann's equation in the limit of infinite numerical resources. The algorithm is based on a grey two-moment scheme, in which we evolve the energy density and momentum density of the radiation. Two-moment schemes require a closure that fills in missing information about the energy spectrum and higher order moments of the radiation. Instead of the approximate analytical closure currently used in core-collapse and merger simulations, we complement the two-moment scheme with a low-accuracy Monte Carlo evolution. The Monte Carlo results can provide any or all of the missing information in the evolution of the moments, as desired by the user. As a first test of our methods, we study a set of idealized problems demonstrating that our algorithm performs significantly better than existing analytical closures. We also discuss the current limitations of our method, in particular open questions regarding the stability of the fully coupled scheme.

  15. [Fluctuations and transport in fusion plasma]: Progress report, October 1, 1989--September 30, 1990

    International Nuclear Information System (INIS)

    1995-01-01

    In the study of plasma collection by obstacles in a tokamak edge plasma, the effect of anomalous transport have been examined using an extension of the 2D fluid code developed here previously (Appendices A and B). The origin of the anomalous transport is assumed to be a randomly fluctuating electric field such as would be caused by drift waves. As before, the magnetic field is assumed to be uniform and perpendicular to the obstacle, which is taken to be an infinite strip. In the absence of ambient plasma flow, the numerical results indicate that ion viscous heating is important near the tip of the obstacle, where there is a large velocity gradient in the flow. For typical plasma parameters, the maximum ion temperature near the tip is up to 85% higher than the ambient ion temperature. When there is a subsonic plasma flow past the obstacle, the numerical results indicate that, near the tip of the obstacle, the ions on the downstream side are hotter than those on the upstream side. Furthermore, the ion density is higher on the upstream side. A detailed report of this work has been prepared and will be submitted as part of the Annual Progress Report. Recently, the 2D parallel electrostatic plasma particle-in-cell (PIC) code described in reference (9) (Appendix B) has been upgraded to a 2D fully electromagnetic PIC code. This code has been successfully tested on the JPL/Caltech Mark III Hypercube concurrent computers and can be used to simulate interactions of electromagnetic waves with a magnetized plasma. It is currently applied to investigate the decay of large amplitude Alfven waves, such as those observed in the solar wind. Large amplitude Alfven waves, propagating parallel to the magnetic field, are predicted to decay into obliquely propagating daughter waves and standing magnetosonic waves. Results from the simulations will be compared with theoretical predictions

  16. Potential Biomarker of L type Amino Acid Transporter 1 in Breast Cancer Progression

    International Nuclear Information System (INIS)

    Liang, Zhongxing; Cho, Heidi T.; Williams, Larry; Zhu, Aizhi; Liang, Ke; Huang, Ke; Wu, Hui; Jiang, Chunsu; Hong, Samuel; Crowe, Ronald; Goodman, Mark M.; Shim, Hyunsuk

    2011-01-01

    L type amino acid transporter 1 (LAT1) is essential for the transport of large neutral amino acids. However, its role in breast cancer growth remains largely unknown. The purpose of the study is to investigate whether LAT1 is a potential biomarker for the diagnosis and treatment of breast cancer. LAT1 mRNA and protein levels in breast cancer cell lines and tissues were analyzed. In addition, the effects of targeting LAT1 for the inhibition of breast cancer cell tumorigenesis were assessed with soft agar assay. The imaging of xenograft with 1 amino 3 [ 18F ]fluorocyclo butane 1 carboxylic acid ([ 18F ]FACBC) PET was assessed for its diagnostic biomarker potential. Normal breast tissue or low malignant cell lines expressed low levels of LAT1 mRNA and protein, while highly malignant cancer cell lines and high grade breast cancer tissue expressed high levels of LAT1. In addition, higher expression levels of LAT1 in breast cancer tissues were consistent with advanced stage breast cancer. Furtermore, the blockade of LAT1 with its inhibitor, 2 amino bicyclo[2.2.1]heptane 2 carboxylic acid (BCH), or the knockdown of LAT1 with siRNA, inhibited proliferation and tumorigenesis of breast cancer cells. A leucine analog, [ 18F ]FACBC, has been demonstrated to be an excellent PET tracer for the non invasive imaging og malignant breast cancer using an orthotopic animal model. The overexpression of LAT1 is required for the progression of breast cancer. LAT1 represents a potential biomarker for therapy and diagnosis of breast cancer. [ 18F ]FACBC that correlates with LAT1 function is a potential PET tracer for malignant breast tumor imaging

  17. A Novel Radiation Transport Algorithm for Radiography Simulations

    International Nuclear Information System (INIS)

    Inanc, Feyzi

    2004-01-01

    The simulations used in the NDE community are becoming more realistic with the introduction of more physics. In this work, we have developed a new algorithm that is capable of representing photon and charged particle fluxes through spherical harmonic expansions in a manner similar to well known discrete ordinates method with the exception that Boltzmann operator is treated through exact integration rather than conventional Legendre expansions. This approach provides a mean to include radiation interactions for higher energy regimes where there are additional physical mechanisms for photons and charged particles

  18. Progressive glomerulosclerosis and renal failure following perinatal gamma radiation in the beagle

    International Nuclear Information System (INIS)

    Jaenke, R.S.; Phemister, R.D.; Norrdin, R.W.

    1980-01-01

    The renal effects of whole body irradiation in the perinatal period were studied in the dog. Ninety-three dogs received a single sublethal exposure in the range of 270 to 435 R in either late gestation (55 days postcoitus) or early postnatal life (2 days postpartum) and were sacrificed at 70 days, 2, or 4 years of age. Early renal lesions in 70-day-old irradiated dogs were characterized by arrested glomerular maturation and degeneration resulting in reduced functional renal mass. Mature glomeruli exhibited mesangial proliferation. At 2 and 4 years of age, surviving irradiated dogs exhibited sever renal disease associated with progressive glomerular damage which was characterized by mesangial proliferation and compression of capillary lumina, epithelial degeneration and focal capsular adhesions, and ultimately obliterative glomerulosclerosis. Twenty-one of the 93 irradiated dogs died in renal failure before 4 years of age with advanced glomerulosclerosis. The phatogenesis of this progressive renal lesion may be related to the interaction of three specific factors. These include (1) the effect of direct radiation damage to mature kidney components; (2) the loss of outer cortical nephrons resulting in increased work load of the surviving nephrons; and (3) the effect of compensatory hypertrophy related to the loss of renal parenchyma as the rapid growth rates associated with kidney maturation

  19. Effect of hyperthermia and radiation on the cell cycle progression of HeLa cells

    International Nuclear Information System (INIS)

    Kubota, Nobuo

    1982-01-01

    The effect of hyperthermia and irradiation on cytokinetics was studied using exponentially growing HeLa cells. To determine the effect of heat and/or radiation on the cell cycle progression, the changes in the DNA distribution of the cell population after time intervals after treatment were studied. The cellular DNA content of the cell population was measured by flow cytometry. The results obtained were as follows: 1. Compared with the control, the cellular DNA content distribution of HeLa cells treated with 43 0 C for 20 min and 60 min showed cell accumulation in S and G 2 M phases 8 hours after treatment. 2. Hyperthermic treatment at 45 0 C for 20 min caused cells to accumulate in S phase in the first 4 hours and G 2 M phase after 8 to 14.5 hours, whereas heat treatment at 45 0 C for 60 min caused cells to accumulate in G 2 M phase after 24 hours. 3. Irradiation of exponentially growing cells induced a block in the progress from G 2 M to G 1 phase. 4. Dose survival curves of HeLa cells with and without postirradiation thermal treatment (43 0 C, 60 min) showed significant enhancement of radiosensitivity by hyperthermia. 5. The sequential treatment, i.e. 5 Gy irradiation followed immediately by heat treatment at 43 0 C for 60 min, caused more cells to accumulate in G 2 M phase after 24 and 48 hours, as compared with 5 Gy irradiation alone. (author)

  20. Mechanisms for radiation damage in DNA. Progress report, November 1, 1978-October 31, 1979

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1979-07-01

    Several mechanisms for radiation damage to DNA constituents and DNA are proposed, and a series of experiments utilizing electron spin resonance spectrometry to test the proposed mechanisms are detailed. In the past we have concentrated chiefly on the direct affect of radiation on DNA. We are currently investigating systems of DNA constituents and peptides which may shed light on indirect effects. Studies which have been completed during the past year include: (1) studies of γ-irradiated N-acetyl amino acids and peptide solutions at 77 0 K; and (2) studies of barriers to hindered rotation in peptide radicals. Studies in which progress has been made in this past year include: (1) π cations produced in DNA bases by hydroxyl radical attack; and (2) studies of spin transfer in γ-Irradiated nucleoside-peptide solutions. These studies have shown that: (1) frozen aqueous solutions provide a suitable matrix for γ irradiation studies; (2) γ-irradiated peptides in frozen aqueous solutions follow chemistry expected from previous studies; and (3) π cations of DNA base can be produced by hydroxyl radical attack

  1. The effectiveness of electromagnetic terahertz radiation use in the treatment of patients with rapidly progressive periodontitis

    Directory of Open Access Journals (Sweden)

    Zelenova A.V.

    2015-12-01

    Full Text Available The aim: to increase the efficiency of treatment of patients with rapidly progressive periodontitis (RPP using electromagnetic radiation at terahertz frequencies of molecular spectrum of radiation and absorption of nitric oxide 150,176-150,664 GHz. Material and methods. The study involved 50 patients with RPP, which according to the method of therapy were divided into 2 groups: group 1 included patients receiving conventional therapy, group 2 consisted of patients who, along with traditional therapy received EHF-therapy device "Orbit" YAKUL.941526.001. The control group consisted of 20 healthy subjects with intact periodontium. For the non-invasive study of tissue blood flow in the periodontal tissue Doppler ultrasound was used MiniMax-Doppler-Phono. The study of the microvasculature of periodontitis has been conducted. To determine the reactivity of microvascular periodontal tissue reflex functional tests on the indirect effect of the cold were performed. Results. Reductions achieved values of periodontal indices, especially important index PMA, a significant increase in the linear blood flow indices, decreased pulse pressure gradient and the index followed appropriate reduction to their cold test. Conclusion. The proposed complex therapy can accelerate the relief of inflammation in the periodontal tissues of the complex, to improve the elastic properties of blood vessels, reduce their tone and restore microcirculation in periodontal tissues.

  2. Tumor progression: analysis of the instability of the metastatic phenotype, sensitivity to radiation and chemotherapy

    International Nuclear Information System (INIS)

    Welch, D.R.

    1984-01-01

    The major complications for tumor therapy are 1) tumor spread (metastasis); 2) the mixed nature of tumors (heterogeneity); and 3) the capacity of tumors to evolve (progress). To study these tumor characteristics, the rat 13762NF mammary adenocarcinoma was cloned and studied for metastatic properties and sensitivities to therapy (chemotherapy, radiation and hyperthermia). The cell clones were heterogeneous and no correlation between metastatic potential and therapeutic sensitivities was observed. Further, these phenotypes were unstable during pasage in vitro; yet, the changes were clone dependent and reproducible using different cryoprotected cell stocks. To understand the phenotypic instability, subclones were isolated from low and high passage cell clones. The results demonstrated that 1) tumor cells are heterogeneous for multiple phenotypes; 2) tumor cells are unstable for multiple phenotypes; 3) the magnitude, direction and time of occurrence of phenotypic drift is clone dependent; 4) the sensitivity of cell clones to ionizing radiation (γ or heat) and chemotherapy agents is independent of their metastatic potential; 5) shifts in metastatic potential and sensitivity to therapy may occur simultaneously but are not linked; and 6) tumor cells independently diverge to form several subpopulations with unique phenotypic profiles

  3. A case of chronic progressive radiation myelopathy with a CT myelogram simulating intramedullary tumor

    International Nuclear Information System (INIS)

    Kanemaru, Kazutomi; Kamo, Hisaki; Yamao, Satoshi; Akiguchi, Ichiro; Kameyama, Masakuni

    1985-01-01

    A 58-year-old man underwent a right middle lobectomy in June, 1975, for poorly differentiated adenocarcinoma of the lung. Postoperative irradiation was given to the hilus (6100 rads), and to the right supraclavicular area (6000 rads). In 1980, 60 months after completion of irradiation, the patient noticed weakness of his legs particularly on the left side. In 1982, he noticed the girdle sensation in the upper thoracic region, and paresthesia in the lateral side of the right thigh. In Dec 1983, micturition disturbance appeared, and gait disturbance progressed, he was admitted to the Kyoto University Hospital. Neurological examination revealed an incomplete left Brown-Sequard syndrome with diminution of pain and thermal sensation on the right lower limb, and weakness and spasticity particularly on the left lower limb. Conventional myelogram with CT myelogram showed spinal cord swelling from T-2 through T-5. No extramedullary lesion was found. Laminectomy was performed through T-1 to T-6. When the dura was opened, the cord was swollen and necrotic with a cyst formation. Microscopic examination of the thickened part of the cord showed necrosis and gliosis. The lesion was correspond to the cord segments exposed to the radiation, and a diagnosis of radiation myelopathy was made. Several cases of radiation myelopathy with definite swelling of the cord at myelography were reported, but myelography in these cases was performed at most within 11 months after the onset. In this case, myelography was performed three years after the onset, and revealed difinite swelling of the cord due to a cyst formation. (author)

  4. Case of chronic progressive radiation myelopathy with a CT myelogram simulating intramedullary tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kanemaru, Kazutomi; Kamo, Hisaki; Yamao, Satoshi; Akiguchi, Ichiro; Kameyama, Masakuni

    1985-05-01

    A 58-year-old man underwent a right middle lobectomy in June, 1975, for poorly differentiated adenocarcinoma of the lung. Postoperative irradiation was given to the hilus (6100 rads), and to the right supraclavicular area (6000 rads). In 1980, 60 months after completion of irradiation, the patient noticed weakness of his legs particularly on the left side. In 1982, he noticed the girdle sensation in the upper thoracic region, and paresthesia in the lateral side of the right thigh. In Dec 1983, micturition disturbance appeared, and gait disturbance progressed, he was admitted to the Kyoto University Hospital. Neurological examination revealed an incomplete left Brown-Sequard syndrome with diminution of pain and thermal sensation on the right lower limb, and weakness and spasticity particularly on the left lower limb. Conventional myelogram with CT myelogram showed spinal cord swelling from T-2 through T-5. No extramedullary lesion was found. Laminectomy was performed through T-1 to T-6. When the dura was opened, the cord was swollen and necrotic with a cyst formation. Microscopic examination of the thickened part of the cord showed necrosis and gliosis. The lesion was correspond to the cord segments exposed to the radiation, and a diagnosis of radiation myelopathy was made. Several cases of radiation myelopathy with definite swelling of the cord at myelography were reported, but myelography in these cases was performed at most within 11 months after the onset. In this case, myelography was performed three years after the onset, and revealed difinite swelling of the cord due to a cyst formation. (author).

  5. Transfer of radioactive materials in the fuel cycle. Transportation systems, transportation volume and radiation protection

    International Nuclear Information System (INIS)

    Schwarz, G.

    1997-01-01

    No other aspect of the carriage of hazardous goods has been provoking such long-lived concern in the general public and in the press during the last few years as the transport of spent nuclear fuels and high-level radioactive wastes to the storage facility at Gorleben. One reason for this controversy, besides clear-cut opposition in principal against such transfer activities, is the fact that there is an information gap, so that large parts of the population are not well informed about the relevant legal safety requirements and obligations governing such transports. The article therefore tries to fill this gap, presenting information on the number and necessity of transports of radioactive materials in the nuclear fuel cycle, the relevant scenarios, the transportation systems and packing and shielding requirements, as well as information on the radiological classification and hazardousness of waste forms. (Orig.) [de

  6. Progress in z-pinch driven dynamic-hohlraums for high-temperature radiation-flow and ICF experiments at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Sanford, T W L; Nash, T J; Olson, R E; Bliss, D E; Lemke, R W; Olson, C L; Ruiz, C L; Mock, R C; Bailey, J E; Chandler, G A; Cuneo, M E; Leeper, R J; Matzen, M K; Mehlhorn, T A; Slutz, S A; Stygar, W A; Peterson, D L; Chrien, R E; Watt, R G; Roderick, N F; Cooper, G W; Apruzese, J P; Sarkisov, G S; Chittenden, J P; Haines, M G

    2004-01-01

    Progress in understanding the physics of dynamic-hohlraums is reviewed for a system capable of generating 13 TW of axial radiation for high temperature (>200 eV) radiation-flow experiments and ICF capsule implosions

  7. Radiation risk assessment for the transport of radioisotopes using KRI-BGM B(U) type container

    International Nuclear Information System (INIS)

    Cho, Woon-Kap

    2008-01-01

    The radiation risks were estimated for the transportation of radioisotopes using KRI-BGM transport container. KRI-BGM container was specially designed for transportation of large amount of radioisotopes for industrial or medical applications. The container can carry maximum 370 TBq of solid Ir-192, 29.6 TBq of liquid Mo-99 and 37 TBq of liquid I-131 respectively. For the radiation risk assessment, it was assumed that maximum design activity of those radioisotopes was transported. Transportation route is from Daejeon where radioisotopes are produced to Seoul where radioisotopes are consumed. Transport distance is 200 km including highway and downtown area from Daejeon to Seoul. As the transportation conveyance, an ordinary cargo truck is used exclusively. Radiation risks were estimated for incident free and accident condition of transportation and RADTRAN 5.6 was used as the risk assessment tool. For the risk assessment of radioisotopes transportation, various parameters such as population density around transport route, weather condition, probability of specific accidents such as impact, fire, etc. were considered. From the results of this study, the exclusive transportation of radioisotopes using KRI-BGM transport container by truck showed low radiological risks with manageable safety and health consequences. This paper discusses the methods and results of the radiation risks assessment for the radioisotopes transportation by an ordinary truck and presents the expected radiation risks in person-Sv and latent cancer fatalities. (author)

  8. Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools

    International Nuclear Information System (INIS)

    Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.; Jung, C.Y.

    1987-01-01

    The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size

  9. Progress towards steady-state operation and real time control of internal transport barriers in JET

    International Nuclear Information System (INIS)

    Litaudon, X.

    2002-01-01

    In JET advanced tokamak research mainly focuses on plasmas with internal transport barriers (ITBs), generated by modifications of the current profile. The formerly developed optimised shear regime with low magnetic shear in the plasma center has been extended to deeply reversed magnetic shear configurations. ITBs occur at much lower access powers. The achievement of high fusion performance is reported in deeply reversed magnetic shear configuration. The generation of plasmas with wide ITBs in this configuration has allowed an extension of the accessible normalised toroidal beta at high magnetic field. We report on the successful sustainment and control of the electron and ion ITB in full current drive operation with a large fraction of bootstrap current. Progress towards the steady state capability of ITB plasmas includes techniques to avoid strong ELM activity and the newly developed real time control of the local ITB strength. Thanks to the real time control of the ITB characteristics the improved confinement state is maintained in a more reproducible and stable manner in quasi-stationary conditions. (author)

  10. Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

    International Nuclear Information System (INIS)

    McKinley, M S; Brooks III, E D; Daffin, F

    2004-01-01

    Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the difference formulation for thermal photon transport, showing a significant advantage for Monte Carlo solution of the equations for time dependent transport. Other related areas are discussed that may also realize significant benefits from similar analytical transformations

  11. Energy distributions and radiation transport in uranium plasmas

    International Nuclear Information System (INIS)

    Miley, G.; Bathke, C.; Maceda, E.; Choi, C.

    1976-01-01

    Electron energy distribution functions have been calculated in a 235 U-plasma at 1 atmosphere for various plasma temperatures (5000 to 8000 0 K) and neutron fluxes (2 x 10 12 to 2 x 10 16 neutrons/(cm 2 -sec)). Two sources of energetic electrons are included; namely fission-fragment and electron-impact ionization, resulting in a high-energy tail superimposed on the thermalized electron distribution. Consequential derivations from equilibrium collision rates are of interest relative to direct pumping of lasers and radiation emission. Results suggest that non-equilibrium excitation can best be achieved with an additive gas such as helium or in lower temperature plasmas requiring UF 6 . An approximate analytic model, based on continuous electron slowing, has been used for survey calculations. Where more accuracy is required, a Monte Carlo technique is used which combines an analytic representation of Coulombic collisions with a random-walk treatment of inelastic collisions

  12. Experiences with radiation portal detectors for international rail transport

    Science.gov (United States)

    Stromswold, D. C.; McCormick, K.; Todd, L.; Ashbaker, E. D.; Evans, J. C.

    2006-08-01

    Radiation detectors monitored trains at two international borders to evaluate the performance of NaI(Tl) and plastic (polyvinyltoluene: PVT) gamma-ray detectors to characterize rail cargo. The detectors included a prototype NaI(Tl) radiation-portal-monitor panel having four large detectors (10-cm × 10-cm × 41-cm) and a PVT panel with a 41 cm × 173 cm × 3.8-cm detector. Spectral data from the NaI(Tl) and PVT detectors were recorded. Of particular emphasis was the identification of naturally occurring radioactive material (NORM) and the resultant frequency of nuisance alarms. For rail monitoring, the difficulty in stopping trains to perform secondary inspection on alarming cars creates a need for reliable identification of NORM during initial screening. Approximately 30 trains were monitored, and the commodities in individual railcars were ascertained from manifest information. At one test site, the trains carried inter-modal containers that had been unloaded from ships, and at the other site, the trains contained bulk cargo in tanker cars and hopper cars or individual items in boxcars or flatbeds. NORM encountered included potash, liquefied petroleum gas, fireworks, televisions, and clay-based products (e.g., pottery). Analysis of the spectral data included the use of the template-fitting portion of the program GADRAS developed at Sandia National Laboratories. For most of the NORM, the NaI(Tl) data produced a correct identification of the radionuclides present in the railcars. The same analysis was also used for PVT data in which the spectral information (no peaks but only gradual spectral changes including Compton edges) was limited. However, the PVT analysis provided correct identification of 40K and 226Ra in many cases.

  13. Experiences with radiation portal detectors for international rail transport

    International Nuclear Information System (INIS)

    Stromswold, David C.; McCormick, Kathleen R.; Todd, Lindsay C.; Ashbaker, Eric D.; Evans, J.C.

    2006-01-01

    Radiation detectors monitored trains at two international borders to evaluate the performance of NaI(Tl) and plastic (polyvinyltoluene: PVT) gamma-ray detectors to characterize rail cargo. The detectors included a prototype NaI(Tl) radiation-portal-monitor panel having four large detectors (10-cm x 10-cm x 41-cm) and a PVT panel with a 41 cm x 173 cm x 3.8-cm detector. Spectral data from the NaI(Tl) and PVT detectors were recorded. Of particular emphasis was the identification of naturally occurring radioactive material (NORM) and the resultant frequency of nuisance alarms. For rail monitoring, the difficulty in stopping trains to perform secondary inspection on alarming cars creates a need for reliable identification of NORM during initial screening. Approximately 30 trains were monitored, and the commodities in individual railcars were ascertained from manifest information. At one test site the trains carried inter-modal containers that had been unloaded from ships, and at the other site the trains contained bulk cargo or individual items in boxcars or flatbeds. NORM encountered included potash, liquefied petroleum gas, fireworks, televisions, and clay-based products (e.g., pottery). Analysis of the spectral data included the use of the template-fitting program GADRAS/FitToDB from Sandia National Laboratories. For much of the NORM the NaI(Tl) data produced a correct identification of the radionuclides present in the railcars. The same analysis was also used for PVT data in which the spectral information (no peaks but only gradual spectral changes including Compton edges) was limited. However, the PVT analysis provided correct identification of 40K and 226Ra in many cases

  14. The contribution of transport to air quality. TERM 2012: transport indicators tracking progress towards environmental targets in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Vicente, A.; Pastorello, C.; Foltescu, V.L. [and others

    2012-11-15

    TERM 2012 (Transport and Environment Reporting Mechanism) presents the most relevant and up to date information on the main issues regarding transport and environment in Europe, particularly in areas with specific policy targets such as greenhouse gas emissions and energy consumption, transport demand levels, noise and other issues. It also offers an overview of the transport sector's impact on air pollutant emissions and air quality. It discusses the contributions made by all modes of transport to direct air pollutant emissions and also to 'secondary' air pollutants formed in the atmosphere. Alongside the recently published Air quality in Europe - 2012 report, TERM 2012 aims to inform the European Commission's review of the Thematic Strategy on Air Pollution. (Author)

  15. Study on transport safety of refresh MOX fuel. Radiation dose from package hypothetically submerged into sea

    International Nuclear Information System (INIS)

    Tsumune, Daisuke; Suzuki; Hiroshi; Saegusa, Toshiari; Maruyama, Koki; Ito, Chihiro; Watabe, Naoto

    1999-01-01

    The sea transport of fresh MOX fuel from Europe to Japan is under planning. For the structure and equipment of transport ships for fresh MOX fuels, there is a special safety standard called the INF Code of IMO (International Maritime Organization). For transport of radioactive materials, there is a safety standard stipulated in Regulations for the Safe Transport of Radioactive Material issued by IAEA (International Atomic Energy Agency). Under those code and standard, fresh MOX fuel will be transported safely on the sea. However, a dose assessment has been made by assuming that a fresh MOX fuel package might be sunk into the sea by unexpected reasons. In the both cases for a package sunk at the coastal region and for that sunk at the ocean, the evaluated result of the dose equivalent by radiation exposure to the public are far below the dose equivalent limit of the ICRP recommendation (1 mSv/year). (author)

  16. Transport of Terrestrial gamma-Radiation in Plane Semi-Infinite Geometry

    DEFF Research Database (Denmark)

    Kirkegaard, Peter; Løvborg, Leif

    1980-01-01

    The plane one-dimensional photon transport equation is solved for the scattered γ-radiation flux in the case of two adjacent media. One medium represents a natural ground with uniformly distributed potassium, uranium, and thorium γ-ray emitters. The other medium is air with no radioactive contami...

  17. Continuous weighing of conveyor-transported materials based on gamma radiation conversion to electric current

    International Nuclear Information System (INIS)

    The principle is described of the continuous weighing of conveyer-transported materials applied in the food industry. The weighing technique is based on the measurement of the absorption of gamma radiation emitted by a source located behind the material to be scaled. (Z.M.)

  18. 2D deterministic radiation transport with the discontinuous finite element method

    International Nuclear Information System (INIS)

    Kershaw, D.; Harte, J.

    1993-01-01

    This report provides a complete description of the analytic and discretized equations for 2D deterministic radiation transport. This computational model has been checked against a wide variety of analytic test problems and found to give excellent results. We make extensive use of the discontinuous finite element method

  19. The use of symbolic computation in radiative, energy, and neutron transport calculations. Final report

    International Nuclear Information System (INIS)

    Frankel, J.I.

    1997-01-01

    This investigation used sysmbolic manipulation in developing analytical methods and general computational strategies for solving both linear and nonlinear, regular and singular integral and integro-differential equations which appear in radiative and mixed-mode energy transport. Contained in this report are seven papers which present the technical results as individual modules

  20. Radiation transport and shielding information, computer codes, and nuclear data for use in CTR neutronics research and development

    International Nuclear Information System (INIS)

    Santoro, R.T.; Maskewitz, B.F.; Roussin, R.W.; Trubey, D.K.

    1976-01-01

    The activities of the Radiation Shielding Information Center (RSIC) of the Oak Ridge National Laboratory are being utilized in support of fusion reactor technology. The major activities of RSIC include the operation of a computer-based information storage and retrieval system, the collection, packaging, and distribution of large computer codes, and the compilation and dissemination of processed and evaluated data libraries, with particular emphasis on neutron and gamma-ray cross-section data. The Center has acquired thirteen years of experience in serving fission reactor, weapons, and accelerator shielding research communities, and the extension of its technical base to fusion reactor research represents a logical progression. RSIC is currently working with fusion reactor researchers and contractors in computer code development to provide tested radiation transport and shielding codes and data library packages. Of significant interest to the CTR community are the 100 energy group neutron and 21 energy group gamma-ray coupled cross-section data package (DLC-37) for neutronics studies, a comprehensive 171 energy group neutron and 36 energy group gamma-ray coupled cross-section data base with retrieval programs, including resonance self-shielding, that are tailored to CTR application, and a data base for the generation of energy-dependent atomic displacement and gas production cross sections and heavy-particle-recoil spectra for estimating radiation damage to CTR structural components

  1. Analysis of transport of collimated radiation in a participating media using the lattice Boltzmann method

    International Nuclear Information System (INIS)

    Mishra, Subhash C.; Vernekar, Rohan Ranganath

    2012-01-01

    Application of the lattice Boltzmann method (LBM) recently proposed by Asinari et al. [Asinari P, Mishra SC, Borchiellini R. A lattice Boltzmann formulation to the analysis of radiative heat transfer problems in a participating medium. Numer Heat Transfer B 2010; 57:126–146] is extended to the analysis of transport of collimated radiation in a planar participating medium. To deal with azimuthally symmetric radiation in planar medium, a new lattice structure for the LBM is used. The transport of the collimated component in the medium is analysed by two different, viz., flux splitting and direct approaches. For different angles of incidence of the collimated radiation, the LBM formulation is tested for the effects of the extinction coefficient, the anisotropy factor, and the boundary emissivities on heat flux and emissive power distributions. Results are compared with the benchmark results obtained using the finite volume method. Both the approaches in LBM provide accurate results. -- Highlights: ► Transport of collimated radiation in participating media is studied. ► Usage of Lattice Boltzmann method (LBM) is extended in this study. ► In LBM, flux splitting and direct approaches are proposed. ► Effects of various parameters are studied on heat flux and temperature profiles. ► In all cases, LBM provides correct results.

  2. Applications Of Monte Carlo Radiation Transport Simulation Techniques For Predicting Single Event Effects In Microelectronics

    International Nuclear Information System (INIS)

    Warren, Kevin; Reed, Robert; Weller, Robert; Mendenhall, Marcus; Sierawski, Brian; Schrimpf, Ronald

    2011-01-01

    MRED (Monte Carlo Radiative Energy Deposition) is Vanderbilt University's Geant4 application for simulating radiation events in semiconductors. Geant4 is comprised of the best available computational physics models for the transport of radiation through matter. In addition to basic radiation transport physics contained in the Geant4 core, MRED has the capability to track energy loss in tetrahedral geometric objects, includes a cross section biasing and track weighting technique for variance reduction, and additional features relevant to semiconductor device applications. The crucial element of predicting Single Event Upset (SEU) parameters using radiation transport software is the creation of a dosimetry model that accurately approximates the net collected charge at transistor contacts as a function of deposited energy. The dosimetry technique described here is the multiple sensitive volume (MSV) model. It is shown to be a reasonable approximation of the charge collection process and its parameters can be calibrated to experimental measurements of SEU cross sections. The MSV model, within the framework of MRED, is examined for heavy ion and high-energy proton SEU measurements of a static random access memory.

  3. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

    Science.gov (United States)

    Zygmanski, Piotr; Sajo, Erno

    2016-01-01

    We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

  4. Utilization of a photon transport code to investigate radiation therapy treatment planning quantities and techniques

    International Nuclear Information System (INIS)

    Palta, J.R.

    1981-01-01

    A versatile computer program MORSE, based on neutron and photon transport theory has been utilzed to investigate radiation therapy treatment planning quantities and techniques. A multi-energy group representation of transport equation provides a concise approach in utilizing Monte Carlo numerical techniques to multiple radiation therapy treatment planning problems. Central axis total and scattered dose distributions for homogeneous and inhomogeneous water phantoms are calculated and the correction factor for lung and bone inhomogeneities are also evaluated. Results show that Monte Carlo calculations based on multi-energy group tansport theory predict the depth dose distributions that are in good agreement with available experimental data. Central axis depth dose distributions for a bremsstrahlung spectrum from a linear accelerator is also calculated to exhibit the versatility of the computer program in handling multiple radiation therapy problems. A novel approach is undertaken to study the dosimetric properties of brachytherapy sources

  5. Effect of gamma radiation on the transport of spin-labeled compounds across the erythrocyte membrane

    International Nuclear Information System (INIS)

    Gwozdzinski, K.; Bartosz, G.; Leyko, W.

    1981-01-01

    The effect of ionizing radiation on the non-electrolyte, anion and cation permeability of the erythrocyte membrane was studied by measurement of the reduction rate of appropriate nitroxyl derivatives. Irradiation of bovine erythrocytes in the dose-range of 2-50 krad resulted in a regular dose-dependent increase in the reduction rates of a cation (TEMPO-choline) and a hydrophobic non-electrolyte (TEMPO), and non-regular changes in the reduction rate of a hydrophilic non-electrolyte (TEMPOL). The permeation constant for TEMPO-choline also showed a non-regular response to radiation, similar to the response pattern of other red blood cell parameters. These results also demonstrate that the effects of radiation on the transport of various solutes can be used as a means of distinguishing between different channels of membrane transport. (orig.)

  6. Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Cooper, A. B.R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacLaren, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Graham, P. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Lu, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seugling, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Satcher, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Klingmann, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Comley, A. J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Marrs, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); May, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Widmann, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glendinning, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Castor, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sain, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Back, C. A. [General Atomics, San Diego, CA (United States); Hund, J. [General Atomics, San Diego, CA (United States); Baker, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hsing, W. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Young, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Young, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-06-01

    Experiments that characterize and develop a high energy-density half-hohlraum platform for use in bench-marking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic di usive Marshak wave which propagates into a high atomic number Ta2O5 aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range

  7. Volume-based geometric modeling for radiation transport calculations

    International Nuclear Information System (INIS)

    Li, Z.; Williamson, J.F.

    1992-01-01

    Accurate theoretical characterization of radiation fields is a valuable tool in the design of complex systems, such as linac heads and intracavitary applicators, and for generation of basic dose calculation data that is inaccessible to experimental measurement. Both Monte Carlo and deterministic solutions to such problems require a system for accurately modeling complex 3-D geometries that supports ray tracing, point and segment classification, and 2-D graphical representation. Previous combinatorial approaches to solid modeling, which involve describing complex structures as set-theoretic combinations of simple objects, are limited in their ease of use and place unrealistic constraints on the geometric relations between objects such as excluding common boundaries. A new approach to volume-based solid modeling has been developed which is based upon topologically consistent definitions of boundary, interior, and exterior of a region. From these definitions, FORTRAN union, intersection, and difference routines have been developed that allow involuted and deeply nested structures to be described as set-theoretic combinations of ellipsoids, elliptic cylinders, prisms, cones, and planes that accommodate shared boundaries. Line segments between adjacent intersections on a trajectory are assigned to the appropriate region by a novel sorting algorithm that generalizes upon Siddon's approach. Two 2-D graphic display tools are developed to help the debugging of a given geometric model. In this paper, the mathematical basis of our system is described, it is contrasted to other approaches, and examples are discussed

  8. Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

    International Nuclear Information System (INIS)

    Smedley-Stevenson, Richard P.; McClarren, Ryan G.

    2015-01-01

    This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes

  9. Analysis of radiation doses for a transportation system and its interface operations for commercial spent fuel

    International Nuclear Information System (INIS)

    Schneider, K.J.; Ross, W.A.; Smith, R.I.; Wilmot, E.L.

    1987-07-01

    This paper gives the results of estimates of aggregated radiation doses to the affected public and workers in the US that would be associated with loading spent fuel at the reactors, transporting the spent fuel by truck and rail, and receiving and unloading the spent fuel at a deep geological repository. The estimates are for a postulated transportation-related system using current state-of-the-art technology, if employed in the high-level waste management system in the future, and the approximate dose reduction from some potential system improvements. The results of the study provide a starting point for the US Department of Energy (DOE) to develop an improved transportation system that is cost effective, safe, and results in low radiation doses. 4 refs., 1 figs., 5 tabs

  10. Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

    Energy Technology Data Exchange (ETDEWEB)

    Smedley-Stevenson, Richard P., E-mail: richard.smedley-stevenson@awe.co.uk [AWE PLC, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Department of Earth Science and Engineering, Imperial College London, SW7 2AZ (United Kingdom); McClarren, Ryan G., E-mail: rmcclarren@ne.tamu.edu [Department of Nuclear Engineering, Texas A & M University, College Station, TX 77843-3133 (United States)

    2015-04-01

    This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes.

  11. Studies in chemical dynamics and radiation chemistry. Technical progress report, 1 July 1974--30 June 1975

    International Nuclear Information System (INIS)

    Kuppermann, A.

    1975-01-01

    Research progress in the following areas is reported: low energy electron scattering; photoelectron spectrometry; elementary reactions by photolysis at variable wavelengths; collisions in crossed molecular beams; and, diffusion kinetics in the radiation chemistry of water. Publications related to the work are included. (JGB)

  12. Physico-chemical studies of radiation effects in cells. Progress report, February 15, 1982-February 14, 1983

    International Nuclear Information System (INIS)

    Powers, E.L.

    1982-01-01

    Progress in studies investigating the chemical mechanisms involved in radiation-induced cellular damage is reported. Three organisms currently being tested are Bacillus megaterium, Bacillus subtilis, and Escherichia coli, silver and mercury have been used as radiosensitizers, and their interaction with DNA studied

  13. Atmospheric Ionizing Radiation and the High Speed Civil Transport. Chapter 1

    Science.gov (United States)

    Maiden, D. L.; Wilson, J. W.; Jones, I. W.; Goldhagen, P.

    2003-01-01

    Atmospheric ionizing radiation is produced by extraterrestrial radiations incident on the Earth's atmosphere. These extraterrestrial radiations are of two sources: ever present galactic cosmic rays with origin outside the solar system and transient solar particle events that are at times very intense events associated with solar activity lasting several hours to a few days. Although the galactic radiation penetrating through the atmosphere to the ground is low in intensity, the intensity is more than two orders of magnitude greater at commercial aircraft altitudes. The radiation levels at the higher altitudes of the High Speed Civil Transport (HSCT) are an additional factor of two higher. Ionizing radiation produces chemically active radicals in biological tissues that alter the cell function or result in cell death. Protection standards against low levels of ionizing radiation are based on limitation of excess cancer mortality or limitation of developmental injury resulting in permanent damage to the offspring during pregnancy. The crews of commercial air transport operations are considered as radiation workers by the EPA, the FAA, and the International Commission on Radiological Protection (ICRP). The annual exposures of aircrews depend on the latitudes and altitudes of operation and flight time. Flight hours have significantly increased since deregulation of the airline industry in the 1980's. The FAA estimates annual subsonic aircrew exposures to range from 0.2 to 9.1 mSv compared to 0.5 mSv exposure of the average nuclear power plant worker in the nuclear industry. The commercial aircrews of the HSCT may receive exposures above recently recommended allowable limits for even radiation workers if flying their allowable number of flight hours. An adequate protection philosophy for background exposures in HSCT commercial airtraffic cannot be developed at this time due to current uncertainty in environmental levels. In addition, if a large solar particle event

  14. Solar Radiation Transport in the Cloudy Atmosphere: A 3D Perspective on Observations and Climate Impacts

    Science.gov (United States)

    Davis, Anthony B.; Marshak, Alexander

    2010-01-01

    The interplay of sunlight with clouds is a ubiquitous and often pleasant visual experience, but it conjures up major challenges for weather, climate, environmental science and beyond. Those engaged in the characterization of clouds (and the clear air nearby) by remote sensing methods are even more confronted. The problem comes, on the one hand, from the spatial complexity of real clouds and, on the other hand, from the dominance of multiple scattering in the radiation transport. The former ingredient contrasts sharply with the still popular representation of clouds as homogeneous plane-parallel slabs for the purposes of radiative transfer computations. In typical cloud scenes the opposite asymptotic transport regimes of diffusion and ballistic propagation coexist. We survey the three-dimensional (3D) atmospheric radiative transfer literature over the past 50 years and identify three concurrent and intertwining thrusts: first, how to assess the damage (bias) caused by 3D effects in the operational 1D radiative transfer models? Second, how to mitigate this damage? Finally, can we exploit 3D radiative transfer phenomena to innovate observation methods and technologies? We quickly realize that the smallest scale resolved computationally or observationally may be artificial but is nonetheless a key quantity that separates the 3D radiative transfer solutions into two broad and complementary classes: stochastic and deterministic. Both approaches draw on classic and contemporary statistical, mathematical and computational physics.

  15. Radiation transport and the kinematics of molecular clouds

    International Nuclear Information System (INIS)

    Kwan, J.

    1978-01-01

    We compare line profiles calculated under either the systematic mottion interpretation or the turbulent motion interpretation of the molecular line widths, with the stipulation that both the density and temperature distributions be decreasing functions of radius. In systematic motion of the form V (r) proportional/sup -alpha/, α>0, optically thin lines observed toward the center are flat-topped or double-peaked, and optically thick lines are asymmetric. In a constant collapes or outflow velocity, optically thin lines observed toward the center are double-peaked, and optically thick lines arfe flat-topped. In systematic motion of the form V (r) proportionalr/sup α/,α>0, both optically thin and optically thick lines are centrally peaked. The distinguishing feature in this case is that the width (FWHM) of the CS 3→ 2 line is considerably smaller that that of the 13 CO 1 → 0 line. In turbulent motion, the CO 1 → 0, 2 → 1, and 3 → 2 lines are marked by progressively more pronounced self-absorptions.The observations at M17 SW and the Kleinmann-Low (KL) nebula are studied. At M17 SW, they are best accounted for by a model in which turbulence dominates the central part of the molecular region but collapse prevails at the outer part. At KL, the present observations can be equally well explained by one of two models. The first model postulates that KL is at the front face of the molecular cloud and that the temperature is highest at the surface. Turbulence gives rise to the line broadening. The second model postulates that KL is deep within the molecular cloud. Systematic motion about KL accounts for the CO and 13 CO line widths, but high-density fragments at KL are required to provide excitations in other molecular lines with considerably larger spontaneous emission rates

  16. Goal based mesh adaptivity for fixed source radiation transport calculations

    International Nuclear Information System (INIS)

    Baker, C.M.J.; Buchan, A.G.; Pain, C.C.; Tollit, B.S.; Goffin, M.A.; Merton, S.R.; Warner, P.

    2013-01-01

    Highlights: ► Derives an anisotropic goal based error measure for shielding problems. ► Reduces the error in the detector response by optimizing the finite element mesh. ► Anisotropic adaptivity captures material interfaces using fewer elements than AMR. ► A new residual based on the numerical scheme chosen forms the error measure. ► The error measure also combines the forward and adjoint metrics in a novel way. - Abstract: In this paper, the application of goal based error measures for anisotropic adaptivity applied to shielding problems in which a detector is present is explored. Goal based adaptivity is important when the response of a detector is required to ensure that dose limits are adhered to. To achieve this, a dual (adjoint) problem is solved which solves the neutron transport equation in terms of the response variables, in this case the detector response. The methods presented can be applied to general finite element solvers, however, the derivation of the residuals are dependent on the underlying finite element scheme which is also discussed in this paper. Once error metrics for the forward and adjoint solutions have been formed they are combined using a novel approach. The two metrics are combined by forming the minimum ellipsoid that covers both the error metrics rather than taking the maximum ellipsoid that is contained within the metrics. Another novel approach used within this paper is the construction of the residual. The residual, used to form the goal based error metrics, is calculated from the subgrid scale correction which is inherent in the underlying spatial discretisation employed

  17. Status of the solar and infrared radiation submodels in the LLNL 1-D and 2-D chemical-transport models

    International Nuclear Information System (INIS)

    Grant, K.E.; Taylor, K.E.; Ellis, J.S.; Wuebbles, D.J.

    1987-07-01

    The authors have implemented a series of state of the art radiation transport submodels in previously developed one dimensional and two dimensional chemical transport models of the troposphere and stratosphere. These submodels provide the capability of calculating accurate solar and infrared heating rates. They are a firm basis for further radiation submodel development as well as for studying interactions between radiation and model dynamics under varying conditions of clear sky, clouds, and aerosols. 37 refs., 3 figs

  18. Advanced Monte Carlo methods for thermal radiation transport

    Science.gov (United States)

    Wollaber, Allan B.

    During the past 35 years, the Implicit Monte Carlo (IMC) method proposed by Fleck and Cummings has been the standard Monte Carlo approach to solving the thermal radiative transfer (TRT) equations. However, the IMC equations are known to have accuracy limitations that can produce unphysical solutions. In this thesis, we explicitly provide the IMC equations with a Monte Carlo interpretation by including particle weight as one of its arguments. We also develop and test a stability theory for the 1-D, gray IMC equations applied to a nonlinear problem. We demonstrate that the worst case occurs for 0-D problems, and we extend the results to a stability algorithm that may be used for general linearizations of the TRT equations. We derive gray, Quasidiffusion equations that may be deterministically solved in conjunction with IMC to obtain an inexpensive, accurate estimate of the temperature at the end of the time step. We then define an average temperature T* to evaluate the temperature-dependent problem data in IMC, and we demonstrate that using T* is more accurate than using the (traditional) beginning-of-time-step temperature. We also propose an accuracy enhancement to the IMC equations: the use of a time-dependent "Fleck factor". This Fleck factor can be considered an automatic tuning of the traditionally defined user parameter alpha, which generally provides more accurate solutions at an increased cost relative to traditional IMC. We also introduce a global weight window that is proportional to the forward scalar intensity calculated by the Quasidiffusion method. This weight window improves the efficiency of the IMC calculation while conserving energy. All of the proposed enhancements are tested in 1-D gray and frequency-dependent problems. These enhancements do not unconditionally eliminate the unphysical behavior that can be seen in the IMC calculations. However, for fixed spatial and temporal grids, they suppress them and clearly work to make the solution more

  19. Role of p53 status in radiation sensitivity and cell cycle progression

    International Nuclear Information System (INIS)

    Zellars, Richard C.; Loney, Tania; Schott, Ann F.; Davis, Mary A.; Maybaum, Jonathan; Clarke, Michael F.; Lawrence, Theodore S.

    1995-01-01

    Purpose: Although p53 function plays a major role in G1 arrest after radiation, the influence of p53 status on progress through other phases of the cell cycle and on radiation sensitivity of human tumors is less clear. We investigated these issues using cells with a conditional expression system for wild type p53. Methods: A temperature sensitive murine wild type p53 plasmid was used (Ginsberg D, et al: Mol. Cell.Biol . 11:582, 1991). At the permissive temperature (32 deg. C), this plasmid produces a protein which assumes a conformation that exhibits wild type p53 function. However, when cells are cultured at 38 deg. C, this protein assumes an inactive conformation. HT29 human colon cancer cells (which are p53 mutant) were transduced with this plasmid (designated PEP A and PEP G cells) or a control vector (designated CCH1 cells) using electroporation and Geneticin selection. The presence of murine p53 transcript in the PEP cells was confirmed by Northern analysis. Results: Cells were cultured under 3 conditions: 1) 38 deg. C at all times; 2) 32 deg. C for 24 hours prior to irradiation and 3) 32 deg. C for 24 hours after irradiation. We found that culturing under permissive temperatures produced a small decrease in surviving fraction in the PEP clones (0.61 ± 0.10 and 0.64 ± 0.07, for PEP A and G, respectively) but not the CCH1 controls (1.14 ± 0.15). PEP cells tended to be more radiosensitive than CCH1 cells (even under non-permissive conditions) and demonstrated a trend towards increased radiosensitivity under both Conditions 2 and 3. In addition, flow cytometry revealed that a 24 hour exposure to permissive conditions increased the fraction of cells in G1 slightly and in G2/M substantially. S phase was almost absent. Conclusion: Restoration of p53 function in HT29 human colon cancer cells using this temperature sensitive system produced increased cytotoxicity and radiation sensitivity as well as cell cycle redistribution. It will be important to assess the

  20. Transportation Routing Analysis Geographic Information System -- TRAGIS, progress on improving a routing tool

    International Nuclear Information System (INIS)

    Johnson, P.E.; Lester, P.B.

    1998-05-01

    The Transportation Routing Analysis Geographic Information System (TRAGIS) model provides a useful tool to calculate and analyze transportation routes for radioactive materials within the continental US. This paper outlines some of the features available in this model

  1. Brain Dopamine Transporter Binding and Glucose Metabolism in Progressive Supranuclear Palsy-Like Creutzfeldt-Jakob Disease

    Directory of Open Access Journals (Sweden)

    Eero Rissanen

    2014-01-01

    Full Text Available Here, we present a patient with Creutzfeldt-Jakob disease (CJD who developed initial symptoms mimicking progressive supranuclear palsy (PSP. Before the development of typical CJD symptoms, functional imaging supported a diagnosis of PSP when [123I]-FP-CIT-SPECT showed a defect in striatal dopamine transporter binding, while [18F]-fluorodeoxyglucose PET showed cortical hypometabolism suggestive of Lewy body dementia. However, the postmortem neuropathological examination was indicative of CJD only, without tau protein or Lewy body findings. This case demonstrates that CJD should be taken into account in rapidly progressing atypical cases of parkinsonism, even when functional imaging supports a diagnosis of a movement disorder.

  2. 1985. Annual progress report

    International Nuclear Information System (INIS)

    1986-01-01

    This annual progress report of the CEA Protection and Nuclear Safety Institut outlines a description of the progress made in each sections of the Institut Research activities of the different departments include: reactor safety analysis, fuel cycle facilities analysis; and associated safety research programs (criticality, sites, transport ...), radioecology and environmental radioprotection techniques; data acquisition on radioactive waste storage sites; radiation effects on man, studies on radioprotection techniques; nuclear material security including security of facilities, security of nuclear material transport, and monitoring of nuclear material management; nuclear facility decommissioning; and finally the public information [fr

  3. Modeling of laser radiation transport in powder beds with high-dispersive metal particles

    Energy Technology Data Exchange (ETDEWEB)

    Kharanzhevskiy, Evgeny, E-mail: eh@udsu.ru [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation); Kostenkov, Sergey [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation)

    2014-02-15

    Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law.

  4. Modeling of laser radiation transport in powder beds with high-dispersive metal particles

    International Nuclear Information System (INIS)

    Kharanzhevskiy, Evgeny; Kostenkov, Sergey

    2014-01-01

    Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law

  5. Energy and particle transport in the radiative divertor plasmas of DIII-D

    International Nuclear Information System (INIS)

    Leonard, A.W.; Allen, S.L.; Brooks, N.H.

    1997-06-01

    It has been argued that divertor energy transport dominated by parallel electron thermal conduction, or q parallel = -kT 5/2 2 dT e /ds parallel, leads to severe localization of the intense radiating region and ultimately limits the fraction of energy flux that can be radiated before striking the divertor target. This is due to the strong T 5/2 e dependence of electron heat conduction which results in very short spatial scales of the T e gradient at high power densities and low temperatures where deuterium and impurities radiate most effectively. However, we have greatly exceeded this constraint on DIII-D with deuterium gas puffing which reduces the peak heat flux to the divertor plate a factor of 5 while distributing the divertor radiation over a long length

  6. Fluctuations and transport in fusion plasmas. Annual progress report, October 1, 1983-September 30, 1984

    International Nuclear Information System (INIS)

    Gould, R.W.

    1984-01-01

    This grant supports an integrated program of experiment and theory in tokamak plasma physics. Emphasis is placed on microscopic fluctuations and anomalous transport. The primary objective is to characterize the properties of the microscopic fluctuations observed in tokamaks and to try to develop an understanding of the fluctuation-induced transport of particles and heat. Anomalous transport, which causes energy losses one to two orders of magnitude larger than predicted by neoclassical transport theory, occurs in all tokamaks and underlies empirical scaling laws

  7. Mechanisms for radiation damage in DNA. Progress report, August 1, 1975--July 31, 1976

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1976-01-01

    In this project we have proposed a mechanism for radiation damage to DNA and detailed a series of experiments utilizing electron spin resonance spectrometry to test the proposed mechanisms. In this past year several investigations have been completed or are nearing completion. These investigations are an ESR study of the N 1 -substituted thymine π-cation radicals; studies of electron reactions with amino acid anhydrides; and ESR and pulse radiolytic studies of electron transfer in dinucleoside phosphate anions. Studies which we have made significant progress on in this past year are positive ion radicals of the dinucleoside phosphates, and reactions of the π-cations of thymine derivatives. In the first study the spin density distribution in the cation radicals of thymidine and thymidine-5 1 -monophosphate have been elucidated. Couplings are found to the ribose group in these radicals. It is believed that these results will aid the identification of cation radicals in DNA. In study 2, the results indicate that these cyclic anhydrides can undergo reductive deamination. In study 3, the results show the order of electron affinities of the DNA bases to be thymine approximately equal to cytosine greater than adenine approximately equal to guanine

  8. Boundary and interface conditions for polarized radiation transport in a multilayer medium

    International Nuclear Information System (INIS)

    Garcia, R.D.M.

    2011-01-01

    In many applications of radiation transport, it is important to consider the changes in the index of refraction that occur when the physical domain being studied consists of material regions with distinct electromagnetic properties. When polarization effects are taken into account, the radiation eld is characterized by a vector of four components known as Stokes vector. At an interface between two different material regions, the reflected and transmitted Stokes vectors are related to the incident Stokes vector by means of reflection and transmission matrices, which are derived from the Fresnel formulas for the amplitude coefficients of reflection and transmission. Having seen that most works on polarized radiation transport that allow for changes in the index of refraction exhibit discrepancies in their expressions for the transmission matrix, we present in this work a careful derivation of the relations between the reflected and transmitted Stokes vectors and the Stokes vector incident on an interface. We obtain a general form of a transmission factor that is required to ensure conservation of energy and we show that most of the discrepancies encountered in existing works are due to the use of improper forms of this factor. In addition, we derive explicit and compact expressions for the Fresnel boundary and interface conditions appropriate to the study of polarized radiation transport in a multilayer medium. (author)

  9. [Reports from Scientific Review Committees on Recommendations for Radiation Protection]. Progress report

    International Nuclear Information System (INIS)

    1984-01-01

    A brief annual report is presented for work on recommendations dealing with management of radionuclides produced in nuclear power generation, radiation associated with medical examinations, radiation received by radiation employees, experimental verification of internal dosimetry calculations, internal emitter standards, radionuclides in the environment, biological effects of magnetic fields, and radiation exposure and potentially related injury

  10. The effect on radiation damage of structural material in a hybrid system by using a Monte Carlo radiation transport code

    International Nuclear Information System (INIS)

    Günay, Mehtap; Şarer, Başar; Kasap, Hızır

    2014-01-01

    Highlights: • The effects of some fluids on gas production rates in structural material were investigated. • The MCNPX-2.7.0 Monte Carlo code was used for three-dimensional calculations. • It was found that biggest contribution to gas production rates comes from Fe isotope of the. • The desirable values for 5% SFG-PuO 2 with respect to radiation damage were specified. - Abstract: In this study, the molten salt-heavy metal mixtures 99–95% Li20Sn80-1-5% SFG-Pu, 99–95% Li20Sn80-1-5% SFG-PuF4, 99-95% Li20Sn80-1-5% SFG-PuO2 were used as fluids. The fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. 9Cr2WVTa ferritic steel with the width of 4 cm was used as the structural material. The parameters of radiation damage are proton, deuterium, tritium, He-3 and He-4 gas production rates. In this study, the effects of the selected fluid on the radiation damage, in terms of individual as well as total isotopes in the structural material, were investigated for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent version of the MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library

  11. Analysis of the value of post-radiation prostate biopsy in predicting subsequent disease progression

    International Nuclear Information System (INIS)

    Benda, R.; Shamsa, F.; Meetze, K.; Bolton, S.; Littrup, P.; Grignon, D.; Washington, T.; Forman, J.D.

    1997-01-01

    Purpose: To analyze the value of Transrectal ultrasound(TRUS), Color flow doppler(CFD) and Prostate specific antigen(PSA) in identifying residual disease in the prostate status post external beam radiation therapy and to determine the value of this pathologic information in predicting subsequent disease progression. Materials and Methods: As part of four prospective protocols, 146 patients had scheduled TRUS guided prostate biopsies 6-25 months status post radiation therapy. The stage distribution was: 13% T1, 51% T2, and 36% T3/T4. Fifty six percent had neo-adjuvant hormones. Conformal photon or mixed neutron/photon irradiation was given to a median 2 Gy/fraction equivalent dose of 77 Gy(range 74 to 84 Gy). Following treatment, patients were assessed by digital rectal exam (DRE), PSA and TRUS guided biopsies at 6, 12 and/or 18 months. The ultrasound and CFD results were scored as normal, suspicious or abnormal. Sextant biopsies were obtained as well as ultrasound guided biopsies from any abnormal ultrasound or doppler area. The biopsies, all read by one pathologist (DG), were graded as negative, marked, moderate, minimal therapeutic effect or positive. The median followup post radiation therapy was 33.6 months and post biopsy was 25.3 months. Comparisons were done by Kappa index with corresponding 95% CI, chi square and Fisher's exact tests. Results: Twenty-eight patients had biopsies at both six and 12-18 months. Overall 35% of patients had all negative cores, 30% had at least one core showing a marked therapeutic effect, and 35% had at least one core showing moderate or minimal therapeutic effect or were positive. Although CFD correlated with a positive biopsy in 9% and a suspicious doppler identified cancer in 15% of cases, an abnormal TRUS identified cancer in 29.5% biopsies ((49(166))). However, a serum PSA >1.5ng/ml at the time of biopsy predicted 61% of positive biopsies ((23(38))). A negative biopsy was associated with low stage (≤T2c, p=0.001), low pre

  12. Reinforcing the protection against ionizing radiation in medical uses through following the progress in modern medical physics

    International Nuclear Information System (INIS)

    Zheng Junzheng; Li Junli

    2008-01-01

    The medical application of ionizing radiation has the longest history, the most extensive uses and the strongest effect among the multiple applications of ionizing radiation technology. With the development of diagnostic radiology and radiotherapy, for instances, the radiology, the interventional radiology, the nuclear medicine, and the radiation oncology; the infrastructures and teambuilding of medical physics in China has been becoming more and more important and urgent. Fortunately, people in relevant fields have already recognized this situation and made lots of progresses in the recent years, for example, the 221 st Xiangshan Science Conference took 'The Development of Medical Physics' as its main topic in 2004; in recent years, a series of regulations and national standards regarding to the quality assurance and radiological protection of medical exposure and the teambuilding of the relevant departments in hospital have been successively issued; the subject of Medical Physics was opened as both undergraduate and graduated courses in more and more universities (Tsinghua University, Peking University etc); the Committee on Medical Physics was enrolled as a new member of the Chinese Physical Society. Modern medical physics should include 4 parts, medical imaging physics, nuclear medicine physics, radiation oncology physics, and health physics. Protection against ionizing radiation needs to fully cover the development of medical physics, which includes the protection against ianizing radiation in medical uses. This article emphasizes the improvement of the ionizing radiation protection in medical uses, for marking of 30th anniversary of the Journal of Radiation Protection. (authors)

  13. Multi-Dimensional Radiation Transport in Dense Z-pinch Wire Array Plasmas

    Science.gov (United States)

    Jennings, C. A.; Chittenden, J. P.; Ciardi, A.; Sherlock, M.; Lebedev, S. V.

    2004-11-01

    Z-pinch wire arrays have proven to be an extremely efficient high yield, short pulse x-ray source with potential application to ICF. The characteristics of the x-ray pulse produced have been shown to be largely determined by non-uniform break up of the wires leading to a highly irregular distribution of mass which implodes towards the axis. Modelling the inherent 3D nature of these plasmas is already computationally very expensive, and so energy exchange through radiation is frequently neglected, assuming instead an optically thin radiation loss model. With a significant fraction of the total energy at late stages being radiated through a dense, optically thick plasma this approach is potentially inadequate in fully describing the implosion. We analyse the effects of radiative cooling and radiation transport on stagnation and precursor development in wire array z-pinch implosions. A three temperature multidimensional MHD code using a single group radiation diffusion model is used to study radiation trapping in the precursor, and the effects of preheating on the implosion dynamics. Energy exchange in the final stagnated plasma and its effects on the x-ray pulse shape is also discussed. This work was partially supported by the SSAA program of the NNSA through DoE cooperative agreement DE-F03-02NA00057.

  14. Research progress and application prospect of radiation-resistant prokaryotic microbe

    International Nuclear Information System (INIS)

    Wang Wei; Zhu Jing; Zhang Zhidong; Tang Qiyong; Chen Ming

    2013-01-01

    Radiation-resistant microbe is becoming the research hotspot because of its special life phenomenon and physiological mechanism. Radiation-resistant bacteria are one kind of the most studied radiation-resistant microbe. This article summarized some aspects of the research on radiation-resistant bacteria, including the radiation resistant bacteria resources, and discussed its potential application prospects in the environmental engineering, biotechnology, human health, military and space et al. (authors)

  15. Department of Environmental and Radiation Transport Physics - Overview

    International Nuclear Information System (INIS)

    Loskiewicz, J.

    2000-01-01

    absorbing centres has been pursued. The influence of the components of new drilling fluids on the interpretation of neutron logs has been tested. The problem of a proper description of the thermal neutron diffusion parameters dependent on the energy flux distribution in finite hydrogenous media has been studied. Granada's synthetic model for slow-neutron scattering has been used. As the valuable result of the research the thermal neutron diffusion cooling coefficient in polyethylene has been calculated, using individual characteristics of the scattering kernel for this substance. The experimental set-up at the pulsed neutron generator has been equipped with a new-built thermostatic chamber. Artificial neural network (ANN) applications in petrophysics have been studied: ANN analysis was applied with success to assess Σa values for the data from Miocene formations near Tarnogrod. And also the artificial intelligence methods have been used for appreciation of two different methods of measurement of thermal neutron absorption cross section Σ a . A part of the samples was measured by first method and the other one by the second method. Using ANN it was possible to detect a systematic difference of results from both methods on the level of the standard deviation. A later large experiment consisting of the measurement of all samples by both methods has validated the ANN results. The semi-empirical calibration method of neutron borehole tools was further developed. The three-layer case solution, based on diffusion approximation solution of neutron transport equation, does not give correct results when compared with experimental values. This discrepancy was due to the fact that in the case of highly absorbing media like iron or boron the diffusion approximation should not be applied for such media. The calculations of the migration length in the simple three cylindrical layer case with the use of Monte Carlo codes are studied. The work focused on the improvement of radon

  16. Interface methods for hybrid Monte Carlo-diffusion radiation-transport simulations

    International Nuclear Information System (INIS)

    Densmore, Jeffery D.

    2006-01-01

    Discrete diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Monte Carlo simulations in diffusive media. An important aspect of DDMC is the treatment of interfaces between diffusive regions, where DDMC is used, and transport regions, where standard Monte Carlo is employed. Three previously developed methods exist for treating transport-diffusion interfaces: the Marshak interface method, based on the Marshak boundary condition, the asymptotic interface method, based on the asymptotic diffusion-limit boundary condition, and the Nth-collided source technique, a scheme that allows Monte Carlo particles to undergo several collisions in a diffusive region before DDMC is used. Numerical calculations have shown that each of these interface methods gives reasonable results as part of larger radiation-transport simulations. In this paper, we use both analytic and numerical examples to compare the ability of these three interface techniques to treat simpler, transport-diffusion interface problems outside of a more complex radiation-transport calculation. We find that the asymptotic interface method is accurate regardless of the angular distribution of Monte Carlo particles incident on the interface surface. In contrast, the Marshak boundary condition only produces correct solutions if the incident particles are isotropic. We also show that the Nth-collided source technique has the capacity to yield accurate results if spatial cells are optically small and Monte Carlo particles are allowed to undergo many collisions within a diffusive region before DDMC is employed. These requirements make the Nth-collided source technique impractical for realistic radiation-transport calculations

  17. Transport simulations of a density limit in radiation-dominated tokamak discharges: profile effects

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1988-01-01

    The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with a magnetohydrodynamic (MHD) equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equaling the input power. The present work is confined to Ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result

  18. PBMC: Pre-conditioned Backward Monte Carlo code for radiative transport in planetary atmospheres

    Science.gov (United States)

    García Muñoz, A.; Mills, F. P.

    2017-08-01

    PBMC (Pre-Conditioned Backward Monte Carlo) solves the vector Radiative Transport Equation (vRTE) and can be applied to planetary atmospheres irradiated from above. The code builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. In accounting for the polarization in the sampling of photon propagation directions and pre-conditioning the scattering matrix with information from the scattering matrices of prior (in the BMC integration order) photon collisions, PBMC avoids the unstable and biased solutions of classical BMC algorithms for conservative, optically-thick, strongly-polarizing media such as Rayleigh atmospheres.

  19. Transport simulations of a density limit in radiation-dominated tokamak discharges: Profile effects

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1988-06-01

    The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with an MHD equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equalling the input power. The present work is confined to ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result. 41 refs., 9 figs

  20. Legal and governmental infrastructure for nuclear, radiation, radioactive waste and transport safety. Safety requirements

    International Nuclear Information System (INIS)

    2004-01-01

    This publication establishes requirements for legal and governmental responsibilities in respect of the safety of nuclear facilities, the safe use of sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material. Thus, it covers development of the legal framework for establishing a regulatory body and other actions to achieve effective regulatory control of facilities and activities. Other responsibilities are also covered, such as those for developing the necessary support for safety, involvement in securing third party liability and emergency preparedness

  1. Legal and governmental infrastructure for nuclear, radiation, radioactive waste and transport safety. Safety requirements

    International Nuclear Information System (INIS)

    2000-01-01

    This publication establishes requirements for legal and governmental responsibilities in respect of the safety of nuclear facilities, the safe use of sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material. Thus, it covers development of the legal framework for establishing a regulatory body and other actions to achieve effective regulatory control of facilities and activities. Other responsibilities are also covered, such as those for developing the necessary support for safety, involvement in securing third party liability and emergency preparedness

  2. High-order discontinuous Galerkin nonlocal transport and energy equations scheme for radiation hydrodynamics

    Czech Academy of Sciences Publication Activity Database

    Holec, M.; Limpouch, J.; Liska, R.; Weber, Stefan A.

    2017-01-01

    Roč. 83, č. 10 (2017), s. 779-797 ISSN 0271-2091 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : radiation hydrodynamics * nonlocal transport * Knudsen number * multigroup diffusion * radiation coupling Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.652, year: 2016

  3. Ion transport in roots of cotton seedlings under the effect of gamma-radiation

    International Nuclear Information System (INIS)

    Kasymov, A.K.

    1976-01-01

    It has been found that small doses (0.1 to 0.5kR) increase the ion transport (K + and Na + ) in seedling roots, and relatively high radiation doses (25 to 100 kR) markedly decrease it. ATPase activity varied with the dose. Mgsup(++)-, Na + - and K + -activated ATPases were more sensitive than a background ATPase. It is suggested that high radiation doses destroy the work of the sodium-potassium pump of cotton root cells inhibiting the activity of the transfer ATPase

  4. A Note on the Radiative and Collisional Branching Ratios in Polarized Radiation Transport with Coherent Scattering

    Science.gov (United States)

    Casini, R.; del Pino Alemán, T.; Manso Sainz, R.

    2017-02-01

    We discuss the implementation of physically meaningful branching ratios between the CRD and partial redistribution contributions to the emissivity of a polarized multi-term atom in the presence of both inelastic and elastic collisions. Our derivation is based on a recent theoretical formulation of partially coherent scattering, and it relies on a heuristic diagrammatic analysis of the various radiative and collisional processes to determine the proper form of the branching ratios. The expression we obtain for the emissivity is {\\boldsymbol{\\varepsilon }}=[{{\\boldsymbol{\\varepsilon }}}(1)-{{\\boldsymbol{\\varepsilon }}}{{f}.{{s}}.}(2)]+{{\\boldsymbol{\\varepsilon }}}(2), where {{\\boldsymbol{\\varepsilon }}}(1) and {{\\boldsymbol{\\varepsilon }}}(2) are the emissivity terms for the redistributed and partially coherent radiation, respectively, and where “f.s.” implies that the corresponding term must be evaluated assuming a flat-spectrum average of the incident radiation. This result is shown to be in agreement with prior literature on the subject in the limit of the unpolarized multi-level atom.

  5. Development and preliminary verification of 2-D transport module of radiation shielding code ARES

    International Nuclear Information System (INIS)

    Zhang Penghe; Chen Yixue; Zhang Bin; Zang Qiyong; Yuan Longjun; Chen Mengteng

    2013-01-01

    The 2-D transport module of radiation shielding code ARES is two-dimensional neutron and radiation shielding code. The theory model was based on the first-order steady state neutron transport equation, adopting the discrete ordinates method to disperse direction variables. Then a set of differential equations can be obtained and solved with the source iteration method. The 2-D transport module of ARES was capable of calculating k eff and fixed source problem with isotropic or anisotropic scattering in x-y geometry. The theoretical model was briefly introduced and series of benchmark problems were verified in this paper. Compared with the results given by the benchmark, the maximum relative deviation of k eff is 0.09% and the average relative deviation of flux density is about 0.60% in the BWR cells benchmark problem. As for the fixed source problem with isotropic and anisotropic scattering, the results of the 2-D transport module of ARES conform with DORT very well. These numerical results of benchmark problems preliminarily demonstrate that the development process of the 2-D transport module of ARES is right and it is able to provide high precision result. (authors)

  6. Non-classical radiation transport in random media with fluctuating densities

    International Nuclear Information System (INIS)

    Dyuldya, S.V.; Bratchenko, M.I.

    2012-01-01

    The ensemble averaged propagation kernels of the non-classical radiation transport are studied by means of the proposed application of the stochastic differential equation random medium generators. It is shown that the non-classical transport is favored in long-correlated weakly fluctuating media. The developed kernel models have been implemented in GEANT4 and validated against the d ouble Monte Carlo m odeling of absorptions curves of disperse neutron absorbers and γ-albedos from a scatterer/absorber random mix

  7. A NEW MONTE CARLO METHOD FOR TIME-DEPENDENT NEUTRINO RADIATION TRANSPORT

    International Nuclear Information System (INIS)

    Abdikamalov, Ernazar; Ott, Christian D.; O'Connor, Evan; Burrows, Adam; Dolence, Joshua C.; Löffler, Frank; Schnetter, Erik

    2012-01-01

    Monte Carlo approaches to radiation transport have several attractive properties such as simplicity of implementation, high accuracy, and good parallel scaling. Moreover, Monte Carlo methods can handle complicated geometries and are relatively easy to extend to multiple spatial dimensions, which makes them potentially interesting in modeling complex multi-dimensional astrophysical phenomena such as core-collapse supernovae. The aim of this paper is to explore Monte Carlo methods for modeling neutrino transport in core-collapse supernovae. We generalize the Implicit Monte Carlo photon transport scheme of Fleck and Cummings and gray discrete-diffusion scheme of Densmore et al. to energy-, time-, and velocity-dependent neutrino transport. Using our 1D spherically-symmetric implementation, we show that, similar to the photon transport case, the implicit scheme enables significantly larger timesteps compared with explicit time discretization, without sacrificing accuracy, while the discrete-diffusion method leads to significant speed-ups at high optical depth. Our results suggest that a combination of spectral, velocity-dependent, Implicit Monte Carlo and discrete-diffusion Monte Carlo methods represents a robust approach for use in neutrino transport calculations in core-collapse supernovae. Our velocity-dependent scheme can easily be adapted to photon transport.

  8. A NEW MONTE CARLO METHOD FOR TIME-DEPENDENT NEUTRINO RADIATION TRANSPORT

    Energy Technology Data Exchange (ETDEWEB)

    Abdikamalov, Ernazar; Ott, Christian D.; O' Connor, Evan [TAPIR, California Institute of Technology, MC 350-17, 1200 E California Blvd., Pasadena, CA 91125 (United States); Burrows, Adam; Dolence, Joshua C. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States); Loeffler, Frank; Schnetter, Erik, E-mail: abdik@tapir.caltech.edu [Center for Computation and Technology, Louisiana State University, 216 Johnston Hall, Baton Rouge, LA 70803 (United States)

    2012-08-20

    Monte Carlo approaches to radiation transport have several attractive properties such as simplicity of implementation, high accuracy, and good parallel scaling. Moreover, Monte Carlo methods can handle complicated geometries and are relatively easy to extend to multiple spatial dimensions, which makes them potentially interesting in modeling complex multi-dimensional astrophysical phenomena such as core-collapse supernovae. The aim of this paper is to explore Monte Carlo methods for modeling neutrino transport in core-collapse supernovae. We generalize the Implicit Monte Carlo photon transport scheme of Fleck and Cummings and gray discrete-diffusion scheme of Densmore et al. to energy-, time-, and velocity-dependent neutrino transport. Using our 1D spherically-symmetric implementation, we show that, similar to the photon transport case, the implicit scheme enables significantly larger timesteps compared with explicit time discretization, without sacrificing accuracy, while the discrete-diffusion method leads to significant speed-ups at high optical depth. Our results suggest that a combination of spectral, velocity-dependent, Implicit Monte Carlo and discrete-diffusion Monte Carlo methods represents a robust approach for use in neutrino transport calculations in core-collapse supernovae. Our velocity-dependent scheme can easily be adapted to photon transport.

  9. Cosmogenic nuclide shielding corrections determined via MCNPX radiation transport and spallation cross sections

    Science.gov (United States)

    Argento, D.; Reedy, R. C.; Stone, J. O.

    2011-12-01

    Cosmogenic Nuclides (CNs) are a critical new tool for geomorphology, allowing researchers to date Earth surface events and measure process rates [1]. Prior to CNs, many of these events and processes had no absolute method for measurement and relied entirely on relative methods. Reliable absolute measurement methods impact research constraining ice age extents and provide important climatic data via well constrained erosion rates, etc. [2]. Continuing to improve CN methods is critical for these sciences. Significant progress has been made in the last two decades in refining the method and reducing analytic uncertainties [1,3]. CRONUS-Earth, a collaboration of cosmogenic nuclide researchers, has been developing calibration data and scaling methods to provide a self-consistent platform for use in interpreting nuclide concentration values into geologic data. However, several aspects of the radiation cascade have been exceedingly difficult to measure empirically with either accuracy or spatial extent. One such aspect is the angular distribution of secondary cosmic rays that are energetic enough to produce cosmogenic nuclides via spallation. Researchers studying the angular distribution of such cosmic rays have usually described the distribution as (cos(Θ))^m. Currently, the standard corrections, assume an m of 2.3, which is based on very sparse data sets with very limited spatial and altitude variation [1,4,5]. Researchers using CNs must know the production rate at the sample location, and then make corrections for the portion of the sky that is blocked by nearby topography. If the shielding correction model currently used is too simplistic, this introduces error into the final results. In this study, a Monte Carlo method radiation transport code, MCNPX is used to model the Galactic Cosmic Ray (GCR) radiation impinging on the upper atmosphere and tracks the resulting secondary particles through a model of the Earth's atmosphere. Angle and energy distributions are

  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. Vectorization and parallelization of Monte-Carlo programs for calculation of radiation transport

    International Nuclear Information System (INIS)

    Seidel, R.

    1995-01-01

    The versatile MCNP-3B Monte-Carlo code written in FORTRAN77, for simulation of the radiation transport of neutral particles, has been subjected to vectorization and parallelization of essential parts, without touching its versatility. Vectorization is not dependent on a specific computer. Several sample tasks have been selected in order to test the vectorized MCNP-3B code in comparison to the scalar MNCP-3B code. The samples are a representative example of the 3-D calculations to be performed for simulation of radiation transport in neutron and reactor physics. (1) 4πneutron detector. (2) High-energy calorimeter. (3) PROTEUS benchmark (conversion rates and neutron multiplication factors for the HCLWR (High Conversion Light Water Reactor)). (orig./HP) [de

  12. A new spherical harmonics scheme for multi-dimensional radiation transport I. Static matter configurations

    International Nuclear Information System (INIS)

    Radice, David; Abdikamalov, Ernazar; Rezzolla, Luciano; Ott, Christian D.

    2013-01-01

    Recent work by McClarren and Hauck (2010) [31] suggests that the filtered spherical harmonics method represents an efficient, robust, and accurate method for radiation transport, at least in the two-dimensional (2D) case. We extend their work to the three-dimensional (3D) case and find that all of the advantages of the filtering approach identified in 2D are present also in the 3D case. We reformulate the filter operation in a way that is independent of the timestep and of the spatial discretization. We also explore different second- and fourth-order filters and find that the second-order ones yield significantly better results. Overall, our findings suggest that the filtered spherical harmonics approach represents a very promising method for 3D radiation transport calculations

  13. Implementation, capabilities, and benchmarking of Shift, a massively parallel Monte Carlo radiation transport code

    International Nuclear Information System (INIS)

    Pandya, Tara M.; Johnson, Seth R.; Evans, Thomas M.; Davidson, Gregory G.; Hamilton, Steven P.; Godfrey, Andrew T.

    2015-01-01

    This paper discusses the implementation, capabilities, and validation of Shift, a massively parallel Monte Carlo radiation transport package developed and maintained at Oak Ridge National Laboratory. It has been developed to scale well from laptop to small computing clusters to advanced supercomputers. Special features of Shift include hybrid capabilities for variance reduction such as CADIS and FW-CADIS, and advanced parallel decomposition and tally methods optimized for scalability on supercomputing architectures. Shift has been validated and verified against various reactor physics benchmarks and compares well to other state-of-the-art Monte Carlo radiation transport codes such as MCNP5, CE KENO-VI, and OpenMC. Some specific benchmarks used for verification and validation include the CASL VERA criticality test suite and several Westinghouse AP1000 ® problems. These benchmark and scaling studies show promising results

  14. Functional size of photosynthetic electron transport chain determined by radiation inactivation

    International Nuclear Information System (INIS)

    Pan, R.S.; Chen, L.F.; Wang, M.Y.; Tsal, M.Y.; Pan, R.L.; Hsu, B.D.

    1987-01-01

    Radiation inactivation technique was employed to determine the functional size of photosynthetic electron transport chain of spinach chloroplasts. The functional size for photosystem I+II(H 2 O to methylviologen) was 623 +/- 37 kilodaltons; for photosystem II (H 2 O to dimethylquinone/ferricyanide), 174 +/- 11 kilodaltons; and for photosystem I (reduced diaminodurene to methylviologen), 190 +/- 11 kilodaltons. The difference between 364 +/- 22 (the sum of 174 +/- 11 and 190 +/- 11) kilodaltons and 623 +/- 37 kilodaltons is partially explained to be due to the presence of two molecules of cytochrome b 6 /f complex of 280 kilodaltons. The molecular mass for other partial reactions of photosynthetic electron flow, also measured by radiation inactivation, is reported. The molecular mass obtained by this technique is compared with that determined by other conventional biochemical methods. A working hypothesis for the composition, stoichiometry, and organization of polypeptides for photosynthetic electron transport chain is proposed

  15. Radiation Transport Around Axisymmetric Blunt Body Vehicles Using a Modified Differential Approximation

    Science.gov (United States)

    Hartung, Lin C.; Hassan, H. A.

    1992-01-01

    A moment method for computing 3-D radiative transport is applied to axisymmetric flows in thermochemical nonequilibrium. Such flows are representative of proposed aerobrake missions. The method uses the P-1 approximation to reduce the governing system of integro-di erential equations to a coupled set of partial di erential equations. A numerical solution method for these equations given actual variations of the radiation properties in thermochemical nonequilibrium blunt body flows is developed. Initial results from the method are shown and compared to tangent slab calculations. The agreement between the transport methods is found to be about 10 percent in the stagnation region, with the difference increasing along the flank of the vehicle.

  16. A new spherical harmonics scheme for multi-dimensional radiation transport I. Static matter configurations

    Energy Technology Data Exchange (ETDEWEB)

    Radice, David, E-mail: david.radice@aei.mpg.de [Max Planck Institute für Gravitationsphysik, Albert Einstein Institute, Potsdam (Germany); Abdikamalov, Ernazar [TAPIR, California Institute of Technology, Pasadena, CA (United States); Rezzolla, Luciano [Max Planck Institute für Gravitationsphysik, Albert Einstein Institute, Potsdam (Germany); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA (United States); Ott, Christian D. [TAPIR, California Institute of Technology, Pasadena, CA (United States)

    2013-06-01

    Recent work by McClarren and Hauck (2010) [31] suggests that the filtered spherical harmonics method represents an efficient, robust, and accurate method for radiation transport, at least in the two-dimensional (2D) case. We extend their work to the three-dimensional (3D) case and find that all of the advantages of the filtering approach identified in 2D are present also in the 3D case. We reformulate the filter operation in a way that is independent of the timestep and of the spatial discretization. We also explore different second- and fourth-order filters and find that the second-order ones yield significantly better results. Overall, our findings suggest that the filtered spherical harmonics approach represents a very promising method for 3D radiation transport calculations.

  17. Radiative transport equation for the Mittag-Leffler path length distribution

    Science.gov (United States)

    Liemert, André; Kienle, Alwin

    2017-05-01

    In this paper, we consider the radiative transport equation for infinitely extended scattering media that are characterized by the Mittag-Leffler path length distribution p (ℓ ) =-∂ℓEα(-σtℓα ) , which is a generalization of the usually assumed Lambert-Beer law p (ℓ ) =σtexp(-σtℓ ) . In this context, we derive the infinite-space Green's function of the underlying fractional transport equation for the spherically symmetric medium as well as for the one-dimensional string. Moreover, simple analytical solutions are presented for the prediction of the radiation field in the single-scattering approximation. The resulting equations are compared with Monte Carlo simulations in the steady-state and time domain showing, within the stochastic nature of the simulations, an excellent agreement.

  18. Study of the radiation effects on nucleic acids and related compounds. Progress report, August 15, 1976--November 14, 1977

    International Nuclear Information System (INIS)

    Wang, S.Y.

    1977-08-01

    The effects of ionizing radiation on nucleic acids and components were studied in vitro. Our approach involves four levels of operation and progress is being made at each stage. First, procedures were established to separate and purify three reactive radiation products from thymidine. Second, improved methods of synthesizing trans-glycols of pyrimidines were developed, and a new method for the stereospecific synthesis of cis-glycol of pyrimidines was realized. Thirdly, the Ames Salmonella test was used to determine the mutagenicity of the radiation products and the reactive ones from thymine and thymidine were found to be highly mutagenic. Therefore, all radiation products should be considered potential human health hazards and should be screened when they can be purified and synthesized. In the fourth stage, the reaction of each nucleic-acid base with Cu ++ and cis-5,6-dihydro-6-hydroperoxy-5-hydroxythymine (6-TOOH) was studied in order to further our understanding of the molecular mechanisms of radiation mutagenesis. The presence of Cu ++ was shown to be necessary for the effective mutagenic activity of 6-TOOH in the H. influenzae transformation assay. These findings provide fundamental information about the possible health hazards of ionizing radiation and will be useful in designing methods to protect against and repair radiation damage, which may be mutagenic and carcinogenic

  19. Realization of radiation-chemical processes in national economy-important stage of scientific and technical progress

    International Nuclear Information System (INIS)

    Breger, A.Kh.

    1975-01-01

    Realization of energy resourses of the atomic power engineering will greatly contribute to the scientific and technological progress. The dominat role play the radiochemical methods of properties modification applied for the well-known materials and for the production of materials with modern operating characteristics necessary for their application in different branches of industry and agriculture. Radiation modeling of products from polyolefine, wood-plastic and concrete-polymer materials are considered as well as the processes in ''thin'' units of agitating systems. The future developments and present state of the art of radiation sources are presented

  20. Radiation-induced dysfunction of colonic transport: role of enteric nervous system and of serotonine

    International Nuclear Information System (INIS)

    Francois, Agnes

    1998-01-01

    One of the most commonly observed features of radiation-induced injury of the gastrointestinal tract is the appearance of severe diarrhea. One difficulty in understanding the origin of radiation-induced diarrhea is the multiplicity of factors implicated, depending on the type of radiation, the dose received and the irradiated field. Colonic transport is regulated for a great part by the enteric nervous system (ENS), in close association with immunocompetent cells, especially mast cells. The aim of this study was to investigate whether the neuro-immune regulation of colonic transport could be implicated in radiation-induced attenuation and recovery of colonic functions. Male Wistar rats were whole-body irradiated at 3.8 Gy neutron or 5 and 10 Gy gamma. At 1 and 3 days after exposure, the colonic epithelium was hypo-responsive to neural stimulation (submucosal plexus). Mechanistic studies were performed after 10 Gy exposure. The decreased colonic transport was associated with the disappearance of both submucosal mast cells and histamine-mediated pathway, together with decreased responses to exogenous histamine. Similarly, the response to exogenous 5-HT was decreased, without any modification of either the neural (5-HT 3 ) or non-neural (5-HT 4 ) pathways. Seven days after exposure, colonic transport capacity returned to normal in spite of the absence of mast cells. However these observations were associated with the reappearance of a histaminergic pathway, the origin of which is still unknown. The part played by 5-HT 3 receptors was increased, together with the appearance of a neurally-associated 5-HT4 receptor-pathway. These results suggest that the decreased influence of the ENS on colonic transport observed 1 and 3 days after exposure may be due to both the disappearance of neuro-immune links and the hypo-responsiveness of colonic epithelium to the mediators released by ENS. The functional recovery at seven days may be related on one hand to the return of altered

  1. A Monte Carlo Code for Relativistic Radiation Transport Around Kerr Black Holes

    Science.gov (United States)

    Schnittman, Jeremy David; Krolik, Julian H.

    2013-01-01

    We present a new code for radiation transport around Kerr black holes, including arbitrary emission and absorption mechanisms, as well as electron scattering and polarization. The code is particularly useful for analyzing accretion flows made up of optically thick disks and optically thin coronae. We give a detailed description of the methods employed in the code and also present results from a number of numerical tests to assess its accuracy and convergence.

  2. Radiation transport code with adaptive Mesh Refinement: acceleration techniques and applications

    International Nuclear Information System (INIS)

    Velarde, Pedro; Garcia-Fernaandez, Carlos; Portillo, David; Barbas, Alfonso

    2011-01-01

    We present a study of acceleration techniques for solving Sn radiation transport equations with Adaptive Mesh Refinement (AMR). Both DSA and TSA are considered, taking into account the influence of the interaction between different levels of the mesh structure and the order of approximation in angle. A Hybrid method is proposed in order to obtain better convergence rate and lower computer times. Some examples are presented relevant to ICF and X ray secondary sources. (author)

  3. Monte Carlo 2000 Conference : Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications

    CERN Document Server

    Baräo, Fernando; Nakagawa, Masayuki; Távora, Luis; Vaz, Pedro

    2001-01-01

    This book focusses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications, the latter involving in particular, the use and development of electron--gamma, neutron--gamma and hadronic codes. Besides the basic theory and the methods employed, special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields ranging from particle to medical physics.

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

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1988-06-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the first quarter of 1988

  5. NRC TLD direct radiation monitoring network: Progress report, April--June 1988

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1988-09-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the second quarter of 1988

  6. Loss of ift122, a Retrograde Intraflagellar Transport (IFT) Complex Component, Leads to Slow, Progressive Photoreceptor Degeneration Due to Inefficient Opsin Transport*

    Science.gov (United States)

    Boubakri, Meriam; Chaya, Taro; Hirata, Hiromi; Kajimura, Naoko; Kuwahara, Ryusuke; Ueno, Akiko; Malicki, Jarema; Furukawa, Takahisa; Omori, Yoshihiro

    2016-01-01

    In the retina, aberrant opsin transport from cell bodies to outer segments leads to retinal degenerative diseases such as retinitis pigmentosa. Opsin transport is facilitated by the intraflagellar transport (IFT) system that mediates the bidirectional movement of proteins within cilia. In contrast to functions of the anterograde transport executed by IFT complex B (IFT-B), the precise functions of the retrograde transport mediated by IFT complex A (IFT-A) have not been well studied in photoreceptor cilia. Here, we analyzed developing zebrafish larvae carrying a null mutation in ift122 encoding a component of IFT-A. ift122 mutant larvae show unexpectedly mild phenotypes, compared with those of mutants defective in IFT-B. ift122 mutants exhibit a slow onset of progressive photoreceptor degeneration mainly after 7 days post-fertilization. ift122 mutant larvae also develop cystic kidney but not curly body, both of which are typically observed in various ciliary mutants. ift122 mutants display a loss of cilia in the inner ear hair cells and nasal pit epithelia. Loss of ift122 causes disorganization of outer segment discs. Ectopic accumulation of an IFT-B component, ift88, is observed in the ift122 mutant photoreceptor cilia. In addition, pulse-chase experiments using GFP-opsin fusion proteins revealed that ift122 is required for the efficient transport of opsin and the distal elongation of outer segments. These results show that IFT-A is essential for the efficient transport of outer segment proteins, including opsin, and for the survival of retinal photoreceptor cells, rendering the ift122 mutant a unique model for human retinal degenerative diseases. PMID:27681595

  7. Implementation and display of Computer Aided Design (CAD) models in Monte Carlo radiation transport and shielding applications

    International Nuclear Information System (INIS)

    Burns, T.J.

    1994-01-01

    An Xwindow application capable of importing geometric information directly from two Computer Aided Design (CAD) based formats for use in radiation transport and shielding analyses is being developed at ORNL. The application permits the user to graphically view the geometric models imported from the two formats for verification and debugging. Previous models, specifically formatted for the radiation transport and shielding codes can also be imported. Required extensions to the existing combinatorial geometry analysis routines are discussed. Examples illustrating the various options and features which will be implemented in the application are presented. The use of the application as a visualization tool for the output of the radiation transport codes is also discussed

  8. Changing transport processes in the stratosphere by radiative heating of sulfate aerosols

    Directory of Open Access Journals (Sweden)

    U. Niemeier

    2017-12-01

    Full Text Available The injection of sulfur dioxide (SO2 into the stratosphere to form an artificial stratospheric aerosol layer is discussed as an option for solar radiation management. Sulfate aerosol scatters solar radiation and absorbs infrared radiation, which warms the stratospheric sulfur layer. Simulations with the general circulation model ECHAM5-HAM, including aerosol microphysics, show consequences of this warming, including changes of the quasi-biennial oscillation (QBO in the tropics. The QBO slows down after an injection of 4 Tg(S yr−1 and completely shuts down after an injection of 8 Tg(S yr−1. Transport of species in the tropics and sub-tropics depends on the phase of the QBO. Consequently, the heated aerosol layer not only impacts the oscillation of the QBO but also the meridional transport of the sulfate aerosols. The stronger the injection, the stronger the heating and the simulated impact on the QBO and equatorial wind systems. With increasing injection rate the velocity of the equatorial jet streams increases, and the less sulfate is transported out of the tropics. This reduces the global distribution of sulfate and decreases the radiative forcing efficiency of the aerosol layer by 10 to 14 % compared to simulations with low vertical resolution and without generated QBO. Increasing the height of the injection increases the radiative forcing only for injection rates below 10 Tg(S yr−1 (8–18 %, a much smaller value than the 50 % calculated previously. Stronger injection rates at higher levels even result in smaller forcing than the injections at lower levels.

  9. Radiation physics, biophysics and radiation biology. Progress report for October 1, 1979-September 30, 1980. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, H.H.; Hall, E.J.

    1980-07-01

    Separate abstracts were prepared for 31 of the 32 papers presented in this progress report. The other paper is represented by an abstract only and deals with field shaping and recalibration of x-ray facilities.

  10. Adding faculty in transportation areas : research progress on geomaterials and non-destructive sensor technology.

    Science.gov (United States)

    2014-08-01

    This funding was provided to help departments build up their faculty in the transportation field over the next years. Broad areas will : be considered as listed in the UTC mission or other areas that relate to State Departments of Transportation and ...

  11. Gene expression of membrane transporters: Importance for prognosis and progression of ovarian carcinoma

    Czech Academy of Sciences Publication Activity Database

    Elsnerová, K.; Mohelniková; Duchonová, B.; Čeřovská, E.; Ehrlichová, M.; Gut, I.; Rob, L.; Skapa, P.; Hruda, M.; Bartáková, A.; Bouda, J.; Vodička, Pavel; Souček, P.; Václavíková, R.

    2016-01-01

    Roč. 35, č. 4 (2016), s. 2159-2170 ISSN 1021-335X R&D Projects: GA MZd(CZ) NT14056; GA MŠk(CZ) LD14050 Institutional support: RVO:68378041 Keywords : epithelial ovarian cancer * ABC transporters * SLC transporters * gene expression * prognosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.662, year: 2016

  12. Radiative transport and collisional transfer of excitation energy in Cs vapors mixed with Ar or He

    International Nuclear Information System (INIS)

    Vadla, Cedomil; Horvatic, Vlasta; Niemax, Kay

    2003-01-01

    This paper is a review (with a few original additions) on the radiative transport and collisional transfer of energy in laser-excited cesium vapors in the presence of argon or helium. Narrow-band excitation of lines with Lorentz, Doppler and Voigt profiles is studied in order to calculate effective rates for pumping of spectral lines with profiles comprising inhomogeneous broadening components. The radiative transport of excitation energy is considered, and a new, simple and robust, but accurate theoretical method for quantitative treatment of radiation trapping in relatively optically thin media is presented. Furthermore, comprehensive lists of experimental values for the excitation energy transfer cross-sections related to thermal collisions in Cs-Ar and Cs-He mixtures are given. Within the collected cross-section data sets, specific regularities with respect to the energy defect, as well as the temperature, are discerned. A particular emphasis is put on the radiative and collisional processes important for the optimization of resonance-fluorescence imaging atomic filters based on Cs-noble gas systems

  13. Regulatory aspects of the transport of high radiation level and alpha waste in France

    International Nuclear Information System (INIS)

    Devillers, C.; Grenier, M.; Lombard, J.; Mathieu, F.

    1993-01-01

    The introduction of the 10 mSv.h -1 at 3 m limit for LSA unshielded material makes it impossible to transport, as LSA material, the highest radiation level wastes from EdF PWR's operations. At present, the EdF's waste blocks can be transported as LSA III material by special arrangement. A new package design, equivalent to a Type B package, will be available for their transport before the end of the year 1995. It consists of a re-usable steel cylinder over-packing each block. Compliance of this package model with transport safety requirements will be demonstrated by taking into account the non-dispersability, as LSA III material, of the irradiating waste. A two-step approach has been accepted by the French Competent Authority for the transport of these wastes: (1) a specific ISO 20 container, thermally insulated, can be used by special arrangement for the transport of LSA combustible material having a total activity per conveyance higher than 100 A2. Furthermore, additional safety measures have to be implemented for these consignments. (2) After the end of 1995, a Type B package must be used for activity contents per conveyance higher than 100 A2. A specific 20' ISO container, complying with Type B requirements, is being developed for that purpose. (author)

  14. F--Ray: A new algorithm for efficient transport of ionizing radiation

    Science.gov (United States)

    Mao, Yi; Zhang, J.; Wandelt, B. D.; Shapiro, P. R.; Iliev, I. T.

    2014-04-01

    We present a new algorithm for the 3D transport of ionizing radiation, called F2-Ray (Fast Fourier Ray-tracing method). The transfer of ionizing radiation with long mean free path in diffuse intergalactic gas poses a special challenge to standard numerical methods which transport the radiation in position space. Standard methods usually trace each individual ray until it is fully absorbed by the intervening gas. If the mean free path is long, the computational cost and memory load are likely to be prohibitive. We have developed an algorithm that overcomes these limitations and is, therefore, significantly more efficient. The method calculates the transfer of radiation collectively, using the Fast Fourier Transform to convert radiation between position and Fourier spaces, so the computational cost will not increase with the number of ionizing sources. The method also automatically combines parallel rays with the same frequency at the same grid cell, thereby minimizing the memory requirement. The method is explicitly photon-conserving, i.e. the depletion of ionizing photons is guaranteed to equal the photoionizations they caused, and explicitly obeys the periodic boundary condition, i.e. the escape of ionizing photons from one side of a simulation volume is guaranteed to be compensated by emitting the same amount of photons into the volume through the opposite side. Together, these features make it possible to numerically simulate the transfer of ionizing photons more efficiently than previous methods. Since ionizing radiation such as the X-ray is responsible for heating the intergalactic gas when first stars and quasars form at high redshifts, our method can be applied to simulate thermal distribution, in addition to cosmic reionization, in three-dimensional inhomogeneous cosmological density field.

  15. NRC TLD Direct Radiation Monitoring Network. Volume 5, No. 2. Progress report, April-June 1985

    International Nuclear Information System (INIS)

    Jang, J.; Kramaric, M.; Cohen, L.

    1985-09-01

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network provides continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an unusual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the second quarter of 1985. A complete listing of the site facilities monitored is included

  16. Radiation shielding and criticality safety assessment for KN-12 spent nuclear fuel transport cask

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Kyung; Shin, Chang Ho; Kim, Gi Hwan [Hanyang Univ., Seoul (Korea, Republic of)

    2001-08-15

    Because SNFs involve TRU (Transuranium), fission products, and fissile materials, they are highly radioactive and also have a possibility to be critical. Therefore, radiation shielding and criticality safety for transport casks containing the SNFs should be guaranteed through reliable valuation procedure. IAEA safety standard series No ST-1 recommends regulation for safe transportation of the SNFs by transport casks, and United States is carrying out it according to the regulation guide, 10 CFR parts 71 and 72. Present research objective is to evaluate the KN-12 spent nuclear fuel transport cask that is designed for transportation of up to 12 assemblies and is standby status for being licensed in accordance with Korea Atomic Energy Act. Both radiation shielding and criticality analysis using the accurate Monte Carlo transport code, MCNP-4B are carried out for the KN-12 SNF cask as a benchmark calculation. Source terms for radiation shielding calculation are obtained using ORIGEN-S computer code. In this work, for normal transport conditions, the results from MCNP-4B shows the maximum dose rate of 0.557 mSv/hr at the side surface. And the maximum dose rate of 0.0871 mSv/hr was resulted at the 2 m distance from the cask. The level of calculated dose rate is 27.9% of the limit at the cask surface, 87.1% at 2 m from the cask surface for normal transport condition. For hypothetical accident conditions, the maximum rate of 2.5144 mSv/hr was resulted at the 1 m distance from the cask and this level is 25.1% of the limit for hypothetical accident conditions. In criticality calculations using MCNP-4B, the k{sub eff} values yielded for 5.0 w/o U-235 enriched fresh fuel are 0.92098 {+-} 0.00065. This result confirms subcritical condition of the KN-12 SNF cask and gives 96.95% of recommendations for criticality safety evaluation by US NRC these results will be useful as a basis for approval for the KN-12 SNF cask.

  17. Second order time evolution of the multigroup diffusion and P1 equations for radiation transport

    International Nuclear Information System (INIS)

    Olson, Gordon L.

    2011-01-01

    Highlights: → An existing multigroup transport algorithm is extended to be second-order in time. → A new algorithm is presented that does not require a grey acceleration solution. → The two algorithms are tested with 2D, multi-material problems. → The two algorithms have comparable computational requirements. - Abstract: An existing solution method for solving the multigroup radiation equations, linear multifrequency-grey acceleration, is here extended to be second order in time. This method works for simple diffusion and for flux-limited diffusion, with or without material conduction. A new method is developed that does not require the solution of an averaged grey transport equation. It is effective solving both the diffusion and P 1 forms of the transport equation. Two dimensional, multi-material test problems are used to compare the solution methods.

  18. Simplified calculation method for radiation dose under normal condition of transport

    International Nuclear Information System (INIS)

    Watabe, N.; Ozaki, S.; Sato, K.; Sugahara, A.

    1993-01-01

    In order to estimate radiation dose during transportation of radioactive materials, the following computer codes are available: RADTRAN, INTERTRAN, J-TRAN. Because these codes consist of functions for estimating doses not only under normal conditions but also in the case of accidents, when nuclei may leak and spread into the environment by air diffusion, the user needs to have special knowledge and experience. In this presentation, we describe how, with a view to preparing a method by which a person in charge of transportation can calculate doses in normal conditions, the main parameters upon which the value of doses depends were extracted and the dose for a unit of transportation was estimated. (J.P.N.)

  19. Road Transportable Analytical Laboratory (RTAL) system. Quarterly progress report, May 1994--July 1994

    International Nuclear Information System (INIS)

    1994-01-01

    Progress achieved on the development of the RTAL system during the quarter, May 1 through July 31, 1994 is reported. The work included NEPA analysis, drawings, prototype system construction, and on-site prototype demonstration

  20. Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Clarno, Kevin T [ORNL; Hamilton, Steven P [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Pugmire, Dave [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL); Banfield, James E [ORNL

    2012-02-01

    The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162

  1. FY17 Progress in Modeling of Lanthanide Transport in Metallic Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Matthews, Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-19

    A critical review of fuel-clad-chemical interactions along with modelling requirements is published. The mechanism of lanthanide transport is studied experimentally (NEUP collaboration) and using simulations and initial results are published in Refs.

  2. Nonmotorized transportation pilot program : continued progress in developing walking and bicycling networks - May 2014

    Science.gov (United States)

    2014-05-01

    In 2005, the United States Congress directed the Federal Highway Administration (FHWA) to develop the Nonmotorized Transportation Pilot Program (NTPP). The program provided over $25 million in contract authority to four pilot communities (Columbia, M...

  3. Radiation transport and shielding information, computer codes, and nuclear data for use in CTR neutronics research and development

    International Nuclear Information System (INIS)

    Santoro, R.T.; Maskewitz, B.F.; Roussin, R.W.; Trubey, D.K.

    1976-01-01

    The activities of the Radiation Shielding Information Center (RSIC) of the Oak Ridge National Laboratory are being utilized in support of fusion reactor technology. The major activities of RSIC include the operation of a computer-based information storage and retrieval system, the collection, packaging, and distribution of large computer codes, and the compilation and dissemination of processed and evaluated data libraries, with particular emphasis on neutron and gamma-ray cross-section data. The Center has acquired thirteen years of experience in serving fission reactor, weapons, and accelerator shielding research communities, and the extension of its technical base to fusion reactor research represents a logical progression. RSIC is currently working with fusion reactor researchers and contractors in computer code development to provide tested radiation transport and shielding codes and data library packages. Of significant interest to the CTR community are the 100 energy group neutron and 21 energy group gamma-ray coupled cross-section data package (DLC-37) for neutronics studies, a comprehensive 171 energy group neutron and 36 energy group gamma-ray coupled cross-section data base with retrieval programs, including resonance self-shielding, that are tailored to CTR application, and a data base for the generation of energy-dependent atomic displacement and gas production cross sections and heavy-particle-recoil spectra for estimating radiation damage to CTR structural components. Since 1964, the Center has been involved in the international exchange of information, encouraged and supported by both government and interagency agreements; and to achieve an equally viable and successful program in fusion research, the reciprocal exchange of CTR data and computing technology is encouraged and welcomed

  4. 3D-TRANS-2003, Workshop on Common Tools and Interfaces for Radiation Transport Codes

    International Nuclear Information System (INIS)

    2004-01-01

    Description: Contents proceedings of Workshop on Common Tools and Interfaces for Deterministic Radiation Transport, for Monte Carlo and Hybrid Codes with a proposal to develop the following: GERALD - A General Environment for Radiation Analysis and Design. GERALD intends to create a unifying software environment where the user can define, solve and analyse a nuclear radiation transport problem using available numerical tools seamlessly. This environment will serve many purposes: teaching, research, industrial needs. It will also help to preserve the existing analytical and numerical knowledge base. This could represent a significant step towards solving the legacy problem. This activity should contribute to attracting young engineers to nuclear science and engineering and contribute to competence and knowledge preservation and management. This proposal was made at the on Workshop on C ommon Tools and Interfaces for Deterministic Radiation Transport, for Monte Carlo and Hybrid Codes , held from 25-26 September 2003 in connection with the conference SNA-2003. A first success with the development of such tools was achieved with the BOT3P2.0 and 3.0 codes providing an easy procedure and mechanism for defining and displaying 3D geometries and materials both in the form of refineable meshes for deterministic codes or Monte Carlo geometries consistent with deterministic models. Advanced SUSD: Improved tools for Sensitivity/Uncertainty Analysis. The development of tools for the analysis and estimation of sensitivities and uncertainties in calculations, or their propagation through complex computational schemes, in the field of neutronics, thermal hydraulics and also thermo-mechanics is of increasing importance for research and engineering applications. These tools allow establishing better margins for engineering designs and for the safe operation of nuclear facilities. Such tools are not sufficiently developed, but their need is increasingly evident in many activities

  5. Development of comprehensive models for opacities and radiation transport for IFE systems

    International Nuclear Information System (INIS)

    Tolkach, V.; Morozov, V.; Hassanein, A.

    2003-01-01

    An ignition in an inertial confinement fusion (ICF) reactor results in X-ray spectra and ion fluxes moving toward the chamber wall with different velocities. During flight, parts of the energy will be deposited either in the residual and/or protective chamber gas or in the initial vapor cloud developed near the wall surface from vaporization. The deposited energy will be re-radiated to the chamber wall long after the ignition process. The exact amount of energy deposited/radiated and time of deposition are key issues in evaluating the chamber response and the economical feasibility of an ICF reactor. The radiation processes in the protective gas layer or in the vapor cloud developed above the first wall play an important role in the overall dynamics of the ICF chamber. A self-consistent field method has been developed to calculate ionization potentials, atom and ion energy levels, transition probabilities, and other atomic properties used to calculate thermodynamic and optical characteristics of the plasma by means of collisional-radiation equilibrium (CRE). The methodology of solving radiation transport equations in spherical geometry and the dependence of results on the chosen theoretical model are demonstrated using the method of inward/outward directions

  6. Modeling of radiation heat transport in complex ladder-like structures placed in rectangular enclosures

    International Nuclear Information System (INIS)

    Unal, C.; Bohl, W.R.; Pasamehmetoglu, K.O.

    1999-01-01

    Complex ladder-like structures recently have been considered as the target design for accelerator applications. The decay heat, during a postulated beyond design-basis loss-of-coolant accident in the target where all normal and emergency cooling fails, is removed mainly by radiation heat transfer. Modeling of the radiation transport in complex ladder-like structures has several challenges and limitations when the standard net-radiation model is used. This paper proposes a simplified lumped, or 'hot-rung' model, that considers the worst elements and utilizes the standard net-radiation method. The net-radiation model would under-predict structure temperatures if surfaces were subject to non-uniform radiosity. The proposed model was assessed to suggest corrections to account for the non-uniform radiosity. The non-uniform radiosity effect causes the proposed hot-rung model to under-predict the center-rung temperatures by ∼4-74 C when all parametrics, including temperatures up to 1500 C, were considered. These temperatures are small. The proposed model predicted that an important effect of decreasing the emissivity was smoothing of non-isothermal effects. The radiosity effects are more pronounced when there are strong temperature gradients. Uniform rung temperatures tend to decrease the radiosity effects. We concluded that a relatively simple model that is conservative with respect to radiosity effects could be developed. (orig.)

  7. Radiation transport of cosmic ray nuclei in lunar material and radiation doses

    International Nuclear Information System (INIS)

    Silberberg, R.; Tsao, C.H.; Adams, J.H. Jr.; Letaw, J.R.

    1985-01-01

    The radiation environment on the lunar surface is inhospitable. The permanent settlers may work ten hours per 24-hour interval for the two-week-long lunar day on the lunar surface, or 20 percent of the total time. At moderate depths below the lunar surface (less than 200 g/sq cm) the flux of secondary neutrons exceeds considerably that in the upper atmosphere of the earth, due to cosmic-ray interactions with lunar material. The annual dose equivalent due to neutrons is about 20 or 25 rem within the upper meter of the lunar surface. The dose equivalent due to gamma rays generated by nuclear interactions near the lunar surface is only on the order of 1 percent of that due to neutrons. However, gamma-ray line emission from excited nuclei and nuclear spallation products generated by cosmic rays near the lunar surface is of considerable interest: these lines permit the partial determination of lunar composition by gamma spectroscopy. 12 references

  8. Securing safe and informative thoracic CT examinations—Progress of radiation dose reduction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Takeshi, E-mail: tkubo@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Ohno, Yoshiharu [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan); Seo, Joon Beom [Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505 (Korea, Republic of); Yamashiro, Tsuneo [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishinara, Okinawa 903-0215 (Japan); Kalender, Willi A. [Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestr. 91, 91052 Erlangen (Germany); Lee, Chang Hyun [Department of Radiology, Seoul National University Hospital, 28 Yeongeon-dong, Jongno-gu, Seoul (Korea, Republic of); Lynch, David A. [Department of Radiology, National Jewish Health, 1400 Jackson St, A330 Denver, Colorado 80206 (United States); Kauczor, Hans-Ulrich [Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Hatabu, Hiroto, E-mail: hhatabu@partners.org [Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)

    2017-01-15

    Highlights: • Various techniques have led to substantial radiation dose reduction of chest CT. • Automatic modulation of tube current has been shown to reduce radiation dose. • Iterative reconstruction makes significant radiation dose reduction possible. • Processing time is a limitation for full iterative reconstruction, currently. • Validation of diagnostic accuracy is desirable for routine use of low dose protocols. - Abstract: The increase in the radiation exposure from CT examinations prompted the investigation on the various dose-reduction techniques. Significant dose reduction has been achieved and the level of radiation exposure of thoracic CT is expected to reach the level equivalent to several chest X-ray examinations. With more scanners with advanced dose reduction capability deployed, knowledge on the radiation dose reduction methods has become essential to clinical practice as well as academic research. This article reviews the history of dose reduction techniques, ongoing changes brought by newer technologies and areas of further investigation.

  9. Radiation chemistry of hydrocarbon and alkyl halide systems. Progress report, August 30, 1979-July 31, 1980

    International Nuclear Information System (INIS)

    Hanrahan, R.J.

    1980-01-01

    This progress report covers experiments on pulse radiolysis of methyl iodide, radiation induced reactions in H 2 -CO mixtures and photochemistry and mass spectrometry of CF 3 I-CH 3 I systems. In the pulse radiolysis of alkyl iodide, it was possible to follow rate processes involving atomic iodine in the 2 P/sub 1/2/ excited state and 2 P/sub 3/2/ ground state resulting from irradiation of these compounds. The excited state proved easy to follow, since it can be observed in a strong transition at 206.2 nm. Observation of atomic iodine in the 2 P/sub 3/2/ ground state proved difficult, since it must be observed at 178.3 nm, well into the vacuum ultraviolet. Several design improvements in the pulse radiolysis apparatus were made to achieve a reliable measurement of the I*/I production ratio. The physical arrangement of the apparatus which was adopted is illustrated. A remaining problem which stands in the way of measuring I*/I ratios is the lack of information on extinction coefficients of 2 P/sub 1/2/ and 2 P/sub 3/2/ atomic iodine at 206 and 178 nm. It is expected that indirect calculations and/or computer modelling will be employed. In the H 2 -CO system, investigation of the effect of total pressure in the homogeneous gas phase was made, concentrating on the 3:1 H 2 -CO mixtures. Measurements were made as a function of pressure in the range of 250 to 3300 torr for saturated and unsaturated hydrocarbon in the C 1 to C 6 range. Two trends were exhibited; yields of all products dropped markedly as system pressure was increased; and yields in the nickel vessels were generally in excess of yields in the stainless vessels. Photolysis of CF 3 I-CH 3 I gas phase showed a substantial yield of the product CH 2 I 2 . High pressure mass spectrometry of CF 3 -CH 3 I mixtures revealed (CH 3 ICH 3 ) + , I 2 + , CF 3 I 2 + , (CF 3 I) 2 + , and unique species such as CF 3 ICH 3 and CF 2 ICH 2 +

  10. Progress in R and D radiation processing of natural polymers in the Philippines

    International Nuclear Information System (INIS)

    Dela Rosa, A.; Abad, L.; Relleve, L.; Aranilla, C.; Cabalfin, E.; Bisnar, C.

    2007-01-01

    Radiation technology has emerged as an environment-friendly, commercially viable technology with broad applications that can essentially contribute to achieve the goal of sustainable development. Natural polymers are good raw materials since they are biodegradable, readily available in large quantity and at low cost. Radiation processing of natural polymers is a potential area to widen the prospect of industrial scale application of radiation technology in the Philippines. (author)

  11. Radiological emergency: road map for radiation accident victim transport; Emergência radiológica: roadmap para o transporte de radioacidentado

    Energy Technology Data Exchange (ETDEWEB)

    Costa, V.S.G.; Alcantara, Y.P. [Faculdade Casa Branca, SP (Brazil); Lima, C.M.A. [MAXIM Cursos, Rio de Janeiro, RJ (Brazil); Silva, F. C. A. da, E-mail: franciscodasilva13uk@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    During a radiological or nuclear emergency, a number of necessary actions are taken, both within the radiation protection of individuals and the environment, involving many institutions and highly specialized personnel. Among them it is possible to emphasize the air transportation of radiation accident victims.The procedures and measures for the safe transport of these radiation accident victims are generally the responsibility of the armed forces, specifically the Aeronautics, with the action denominated 'Aeromedical Military Evacuation of Radiation Accident Victims'. The experience with the Radiological Accident of Goiânia demonstrated the importance of adequate preparation and response during a radiological emergency and the need for procedures and measures with regard to the transport of radiation victims are clearly defined and clearly presented for the effectiveness of the actions. This work presents the necessary actions for the transport of radiation accident victim during a radiological emergency, through the road map technique, which has been widely used in scientific technical area to facilitate understanding and show the way to be followed to reach the proposed objectives.

  12. Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 1, August 2012

    International Nuclear Information System (INIS)

    2012-08-01

    The IAEA has a statutory function to establish standards for the protection of health, life and property against ionizing radiation and to provide for the application of these standards to peaceful nuclear activities. Education and training (E and T) is one of the main mechanisms to provide support to Member States in the application of the standards. In 2000, an internal evaluation of the overall education and training programme was undertaken. The conclusions were that the provision of and support for E and T in Member States tended to be on a reactive rather than proactive basis, contributing to a culture of dependency rather than sustainability. On the basis of this evaluation, a strategic approach to education and training in radiation and waste safety was developed that outlined the objectives and outcomes to be achieved over a ten year period (2001-2010). General Conference Resolutions have underlined or emphasized the importance of sustainable programmes for education and training in radiation, transport and waste safety, and have also welcomed the ongoing commitment of the Secretariat and Member States to the implementation of the strategy. A Steering Committee for Education and Training in Radiation Protection and Waste Safety was established in 2002, with the mission of advising the IAEA on the implementation of the strategy and making recommendations as appropriate. In 2010, the Steering Committee analysed the overall achievement of the strategic approach 2011-2010, refined the vision of the original strategy and redefined the related objectives. The Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) was submitted to the IAEA's policy-making organs and was noted by its Board of Governors in September 2010.

  13. 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

  14. Modeling radiative transport in ICF plasmas on an IBM SP2 supercomputer

    International Nuclear Information System (INIS)

    Johansen, J.A.; MacFarlane, J.J.; Moses, G.A.

    1995-01-01

    At the University of Wisconsin-Madison the authors have integrated a collisional-radiative-equilibrium model into their CONRAD radiation-hydrodynamics code. This integrated package allows them to accurately simulate the transport processes involved in ICF plasmas; including the important effects of self-absorption of line-radiation. However, as they increase the amount of atomic structure utilized in their transport models, the computational demands increase nonlinearly. In an attempt to meet this increased computational demand, they have recently embarked on a mission to parallelize the CONRAD program. The parallel CONRAD development is being performed on an IBM SP2 supercomputer. The parallelism is based on a message passing paradigm, and is being implemented using PVM. At the present time they have determined that approximately 70% of the sequential program can be executed in parallel. Accordingly, they expect that the parallel version will yield a speedup on the order of three times that of the sequential version. This translates into only 10 hours of execution time for the parallel version, whereas the sequential version required 30 hours

  15. Overview and applications of the Monte Carlo radiation transport kit at LLNL

    International Nuclear Information System (INIS)

    Sale, K. E.

    1999-01-01

    Modern Monte Carlo radiation transport codes can be applied to model most applications of radiation, from optical to TeV photons, from thermal neutrons to heavy ions. Simulations can include any desired level of detail in three-dimensional geometries using the right level of detail in the reaction physics. The technology areas to which we have applied these codes include medical applications, defense, safety and security programs, nuclear safeguards and industrial and research system design and control. The main reason such applications are interesting is that by using these tools substantial savings of time and effort (i.e. money) can be realized. In addition it is possible to separate out and investigate computationally effects which can not be isolated and studied in experiments. In model calculations, just as in real life, one must take care in order to get the correct answer to the right question. Advancing computing technology allows extensions of Monte Carlo applications in two directions. First, as computers become more powerful more problems can be accurately modeled. Second, as computing power becomes cheaper Monte Carlo methods become accessible more widely. An overview of the set of Monte Carlo radiation transport tools in use a LLNL will be presented along with a few examples of applications and future directions

  16. Particle-in-cell simulations of electron transport from plasma turbulence: recent progress in gyrokinetic particle simulations of turbulent plasmas

    International Nuclear Information System (INIS)

    Lin, Z; Rewoldt, G; Ethier, S; Hahm, T S; Lee, W W; Lewandowski, J L V; Nishimura, Y; Wang, W X

    2005-01-01

    Recent progress in gyrokinetic particle-in-cell simulations of turbulent plasmas using the gyrokinetic toroidal code (GTC) is surveyed. In particular, recent results for electron temperature gradient (ETG) modes and their resulting transport are presented. Also, turbulence spreading, and the effects of the parallel nonlinearity, are described. The GTC code has also been generalized for non-circular plasma cross-section, and initial results are presented. In addition, two distinct methods of generalizing the GTC code to be electromagnetic are described, along with preliminary results. Finally, a related code, GTC-Neo, for calculating neoclassical fluxes, electric fields, and velocities, are described

  17. Estimated effects on radiation doses from alternatives in a spent fuel transportation system

    International Nuclear Information System (INIS)

    Schneider, K.J.; Ross, W.A.; Smith, R.I.

    1988-07-01

    This paper contains the results of a study of estimated radiation doses to the public and workers from the transport of spent fuel from commercial nuclear power reactors to a geologic repository. A postulated reference rail/legal-weight truck transportation system is defined that would use current transportation technology, and provide a breakdown of activities and time/distance/dose-rate estimates for each activity within the system. Collective doses are estimated for each of the major activities at the reactor site, in transit, and at the repository receiving facility. Annual individual doses to the maximally exposed individuals or groups of individuals are also estimated. The dose-reduction potentials and costs are estimated for a total of 17 conceptual alternatives and subalternatives to the postulated reference system. Most of the alternatives evaluated are estimated to provide both cost and dose reductions. The major conclusion is that the potential exists for significant future reductions in radiation doses to the public and workers and for reductions in costs compared to those based on a continuation of past practices in the US

  18. Current status of radiation transport tools for proliferation and terrorism prevention

    International Nuclear Information System (INIS)

    Sale, K.E.

    2004-01-01

    We present the current status and future plans for the set of calculational tools and data bases developed and maintained at LLNL. The calculational tools include the Monte Carlo codes TART and COG as well as the deterministic code ARDRA. In addition to these codes presently in use there is a major development effort for a new massively parallel transport code. An important part of the capability we're developing is a sophisticated user interface, based on a commercial 3-D modeling product, to improve the model development process. A major part of this user interface tool is being developed by Strela under the Nuclear Cities Initiative. Strela has developed a hub-and-spoke technology for code input interconversions (between COG, TART and MCNP) and will produce the plug-ins that extend the capabilities of the 3-D modeler for use as a radiation transport input generator. The major advantages of this approach are the built-in user interface for 3-D modeling and the ability to read a large variety of CAD-file formats. In addition to supporting our current radiation transport codes and developing new capabilities we are working on some nuclear data needs for homeland security. These projects are carried out and the Lawrence Berkeley National Laboratory 88' cyclotron and at the Institute for Nuclear Research of the Nation Academy of Science of Ukraine under and STCU contract. (author)

  19. Estimated effects on radiation doses from alternatives in a spent fuel transportation system

    International Nuclear Information System (INIS)

    Schneider, K.J.; Ross, W.A.; Smith, R.I.

    1988-01-01

    This paper contains the results of a study of estimated radiation doses to the public and workers from the transport of spent fuel from commercial nuclear power reactors to a geologic repository. A postulated reference rail/legal-weight truck transportation system is defined that would use current transportation technology, and provide a breakdown of activities and time/distance/dose-rate estimates for each activity within the system. Collective doses are estimated for each of the major activities at the reactor site, in transit, and at the repository receiving facility. Annual individual doses to the maximally exposed individuals or groups of individuals also estimated. The dose-reduction potentials and costs are estimated for a total of 17 conceptual alternatives and subalternatives to the postulated reference system. Most of the alternatives evaluated are estimated to provide both cost and dose reductions. The major conclusion is that the potential exists for significant future reductions in radiation doses to the public and workers and for reductions in costs compared to those based on a continuation of past practices in the U.S

  20. NRC TLD Direct Radiation Monitoring Network. Progress report, January-June 1981

    International Nuclear Information System (INIS)

    1982-04-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of 55 NRC-licensed facility sites throughout the country for the first half of 1981. The program objectives, scope, and methodology are given. The TLD system, dosimeter location, data processing scheme, and quality assurance program are outlined

  1. NRC TLD Direct Radiation Monitoring Network. Progress report, October-December 1985. Volume 5, No. 4

    International Nuclear Information System (INIS)

    Jang, J.; Rabatin, K.; Cohen, L.

    1986-05-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1985. It provides the ambient radiation levels measured in the vicinity of 74 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

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

    International Nuclear Information System (INIS)

    Struckmeyer, R.; NcNamara, N.

    1989-04-01

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

  3. NRC TLD Direct Radiation Monitoring Network progress report, October--December 1994. Volume 14, No. 4

    Energy Technology Data Exchange (ETDEWEB)

    Struckmeyer, R.

    1995-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1994. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program.

  4. NRC TLD Direct Radiation Monitoring Network. Progress report, October--December 1996

    International Nuclear Information System (INIS)

    Struckmeyer, R.

    1997-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1996. It provides the ambient radiation levels measured in the vicinity of 74 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 3 figs., 4 tabs

  5. Study on intraoperative radiotherapy applying hyperthermia together with radiation sensitizers for progressive local carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Abe, M; Takahashi, M; Ono, K; Hiraoka, M [Kyoto Univ. (Japan). Faculty of Medicine

    1980-08-01

    Intraoperative radiotherapy for gastric cancer, colonic cancer, pancreatic cancer, cancer of the biliary tract, prostatic carcinoma, cerebral tumor, tumor of soft tissues, and osteosarcoma and its clinical results were described. Basic and clinical studies on effects of both hyperthermia and radiation sensitizers to elevate radiation sensitivity were also described, because effects of intraoperative radiotherapy were raised by applying hyperthermia and hypoxic cell sensitizers.

  6. NRC TLD Direct Radiation Monitoring Network progress report, October--December 1994. Volume 14, No. 4

    International Nuclear Information System (INIS)

    Struckmeyer, R.

    1995-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1994. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  7. NRC TLD Direct Radiation Monitoring Network. Progress report, October--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Struckmeyer, R.

    1997-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1996. It provides the ambient radiation levels measured in the vicinity of 74 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 3 figs., 4 tabs.

  8. High beta and second stability region transport and stability analysis: Technical progress report

    International Nuclear Information System (INIS)

    Hughes, M.H.; Phillips, M.W.

    1995-03-01

    This report summarizes MHD equilibrium and stability studies carried out at Northrop Grumman's Advanced Technology and Development Center during the 12 month period starting March 1, 1994. Progress is reported in both ideal and resistive MHD modeling of TFTR plasmas. The development of codes to calculate the significant effects of highly anisotropic pressure distributions is discussed along with results from this model

  9. Mental Model Progression in Learning the Electron Transport Chain: Effects of Instructional Strategies and Cognitive Flexibility

    Science.gov (United States)

    Darabi, Aubteen; Hemphill, Jennifer; Nelson, David W.; Boulware, Wilma; Liang, Xinya

    2010-01-01

    This study investigated the effect of two instructional strategies, segmented and holistic, on the progression over time of learners' mental models toward that of an expert with the moderator of cognitive flexibility. Sixty-four juniors and seniors in a college metabolism course were randomly assigned to one of the two strategies for instruction…

  10. LMFBR aerosol release and transport program. Quarterly progress report, July--September 1975

    International Nuclear Information System (INIS)

    Fontana, M.H.; Kress, T.S.; Adams, R.E.; Parsly, L.F.; Parker, G.W.

    1976-04-01

    Progress is summarized in the areas of capacitor discharge vaporizer (CDV) development, small-vessel fuel and fuel-simulant aerosol studies, large-vessel aerosol studies, HCDA bubble simulant tests, fuel-simulant response to CDV electrical energy deposition, bubble shape and rise behavior, and structural integrity of equipment cell liners

  11. High beta and second stability region transport and stability analysis. Technical progress report

    International Nuclear Information System (INIS)

    Hughes, M.H.; Phillips, M.W.

    1994-09-01

    This report summarizes MHD equilibrium and stability studies carried out at Grumman's Corporate Research Center during the 6 month period starting March 1, 1994. Progress is reported in both ideal and resistive MHD modeling of TFTR plasmas. The development of codes to calculate the significant effects of highly anisotropic pressure distributions is discussed along with initial results from this model

  12. Radiation damage in natural and synthetic halite. Progress report January 1992 - February 1993

    International Nuclear Information System (INIS)

    Garcia Celma, A.

    1993-12-01

    This report complements the information presented in the report of December 1992 regarding the research performed at the ECN on radiation damage in salt. It consists of two parts. The first part regards the amount of stored energy which can be developed by gamma-irradiation on different types of halite and considers both the effect of low dose rates in developing radiation damage, and the possible saturation level of radiation damage in natural halite. The second part presents a model to simulate radiation damage development which incorporates some extensions in the Jain-Lidiard model. Due to malfunction of the Small Angle Neutron Scattering installation, neither the previously reported results nor the newly obtained can be trusted and therefore are not reported here. These results regard the shape, size and size distribution of radiation damage defects. (orig.)

  13. Considerations of beta and electron transport in internal dose calculations. Final progress report, 1994 -1998

    International Nuclear Information System (INIS)

    Bolch, W.E.

    1998-01-01

    This research focused on the following major tasks: improved dosimetric models of the head and brain; development of improved skeletal dosimetry models; development of dosimetric techniques for nonuniform activity distributions; pediatric dosimetry phantoms and radionuclide S values; microdosimetry of beta emitters in radioimmunotherapy; and mechanisms of molecular radiation damage

  14. Description of a neutron field perturbed by a probe using coupled Monte Carlo and discrete ordinates radiation transport calculations

    International Nuclear Information System (INIS)

    Zazula, J.M.

    1984-01-01

    This work concerns calculation of a neutron response, caused by a neutron field perturbed by materials surrounding the source or the detector. Solution of a problem is obtained using coupling of the Monte Carlo radiation transport computation for the perturbed region and the discrete ordinates transport computation for the unperturbed system. (author). 62 refs

  15. Radiation doses from the transport of radioactive waste to a future repository in Denmark. A model study

    Energy Technology Data Exchange (ETDEWEB)

    2011-05-15

    The radiation doses modelled for transport of radioactive waste to a future repository in Denmark, demonstrates that the risk associated with road and sea transport should not limit the future selection of a location of the repository. From a safety perspective both road and sea transport seem to be feasible modes of transport. Although the modelling in most cases is performed conservatively, the modelled doses suggest that both transport methods can be carried out well within the national dose limits. Additionally, the dose levels associated with the modelled accident scenarios are low and the scenarios are thus found to be acceptable taken the related probabilities into account. (LN)

  16. Radiation doses from the transport of radioactive waste to a future repository in Denmark. A model study

    International Nuclear Information System (INIS)

    2011-05-01

    The radiation doses modelled for transport of radioactive waste to a future repository in Denmark, demonstrates that the risk associated with road and sea transport should not limit the future selection of a location of the repository. From a safety perspective both road and sea transport seem to be feasible modes of transport. Although the modelling in most cases is performed conservatively, the modelled doses suggest that both transport methods can be carried out well within the national dose limits. Additionally, the dose levels associated with the modelled accident scenarios are low and the scenarios are thus found to be acceptable taken the related probabilities into account. (LN)

  17. Cell kinetics of hypoxic cells in a murine tumour in vivo: flow cytometric determination of the radiation-induced blockage of cell cycle progression

    International Nuclear Information System (INIS)

    Rutgers, D.H.; Niessen, D.P.P.; Linden, P.M. van der

    1987-01-01

    Cells from the small cell population of viable cells in the large necrotic centre of murine M8013 tumours were investigated with respect to their cell kinetics. Flow cytometry (FCM) of this part of subcutaneously transplanted tumours revealed the presence of tumour cells with G1,S and G2 + M phase DNA-contents. These severely hypoxic cells could have stopped cell cycle progression due to the nutritional deprivation, irrespective of their position within the cell cycle. Labelling methods, used to disclose the cell kinetics of this cell population, are hampered by the absence of a transport system in these large necrotic areas. Therefore FCM was used to monitor radiation induced changes in the cell cycle distribution. From this investigation it was concluded that hypoxic cells in the necrotic centre of the M8013 tumour progress through the cell cycle. As well as a cell population with a cell cycle time (Tsub(c)) of approximately 84 hr, a subpopulation with a Tsub(c) of approximately 21 hr occurred. (author)

  18. 1979 CECAM workshop on transport of fast electrons in laser fusion plasmas. Progress report

    International Nuclear Information System (INIS)

    Mason, R.J.

    1979-01-01

    Attention is given to three problem areas in laser-driven electron transport: (1) ion-acoustic turbulence as a source of inhibition, (2) the effects of anti E times anti j heating of the thermals, and (3) the possibility of thermal inhibition by thermal electron runaway or trapping

  19. Plasma confinement theory and transport simulation. Technical progress report, May 1, 1991--April 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Ross, D.W.

    1992-04-01

    The objectives are: (1) to advance the transport studies of tokamaks, including development and maintenance of the Magnetic Fusion Energy Database, and (2) to provide theoretical interpretation, modeling and equilibrium and stability studies for TEXT-Upgrade. Recent reports, publications, and conference presentations of the Fusion Research Center are listed.

  20. Plasma confinement theory and transport simulation: Technical progress report, October 1, 1987-October 14, 1988

    International Nuclear Information System (INIS)

    Ross, D.W.

    1988-06-01

    An overview of the program has been given in the recent proposal. The principal objectives are to provide theoretical interpretation and computer modelling for the TEXT tokamak, and to advance the simulation studies of tokamaks generally, functioning as a national transport computation facility. We also carry out equilibrium and stability studies in support of the TEXT upgrade, and work continues, at low levels, on Alfven waves and MFEnet software development. The specific focus of the program is to lay the groundwork for detailed comparison with experiment of the various transport theories, so that physics understanding and confidence in predictions of future machine behavior will be enhanced. This involves to collect, in retrievable form, the data from TEXT and other tokamaks to make the data available through easy-to-use interfaces; to develop criteria for success in fitting models to the data; to maintain the Texas transport code, CHAPO, and make it available to users; to collect theoretical models and implement them in the transport code; and to carry out the simulation studies and evaluate the fits to the data. 37 refs

  1. Investigations in anomalous transport and ignition physics. Annual summary of progress, November 1995--November 1996

    International Nuclear Information System (INIS)

    Diamond, P.H.; Rosenbluth, M.N.

    1996-08-01

    During FY 95, research supported by DOE Grant No. DE-FG03-88ER53275 has focused on confinement enhancement by reversed shear, core transport physics, L → H transition theory, and the general theory of plasma dynamics. This report discusses specific accomplishments and lists future plans

  2. Feasibility of a novel approach for fast, economical determination of radiation damage in nuclear reactor cores. Progress report, [November 1, 1993--October 31, 1994

    International Nuclear Information System (INIS)

    Was, G.S.

    1994-01-01

    Progress has been made in several areas in the second year of grant activity. This includes radiation induced segregation (modeling and experiment), deformation of the irradiated microstructure and stress corrosion cracking of irradiated microstructures

  3. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

    International Nuclear Information System (INIS)

    Wang, C.; Wang, F.; Cao, J. C.

    2014-01-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation

  4. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field.

    Science.gov (United States)

    Wang, C; Wang, F; Cao, J C

    2014-09-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

  5. Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C., E-mail: cwang@mail.sim.ac.cn; Wang, F.; Cao, J. C., E-mail: jccao@mail.sim.ac.cn [Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China)

    2014-09-01

    Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

  6. A hybrid transport-diffusion Monte Carlo method for frequency-dependent radiative-transfer simulations

    International Nuclear Information System (INIS)

    Densmore, Jeffery D.; Thompson, Kelly G.; Urbatsch, Todd J.

    2012-01-01

    Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Implicit Monte Carlo radiative-transfer simulations in optically thick media. In DDMC, particles take discrete steps between spatial cells according to a discretized diffusion equation. Each discrete step replaces many smaller Monte Carlo steps, thus improving the efficiency of the simulation. In this paper, we present an extension of DDMC for frequency-dependent radiative transfer. We base our new DDMC method on a frequency-integrated diffusion equation for frequencies below a specified threshold, as optical thickness is typically a decreasing function of frequency. Above this threshold we employ standard Monte Carlo, which results in a hybrid transport-diffusion scheme. With a set of frequency-dependent test problems, we confirm the accuracy and increased efficiency of our new DDMC method.

  7. Evaluation of secondary exposure doses to transportation and medical personnel in the radiation emergency medicine

    International Nuclear Information System (INIS)

    Kato, Hideki; Suzuki, Shoichi; Koga, Sukehiko; Mukoyama, Takashi; Tomatsu, Hirotaka; Suzuki, Yusuke

    2009-01-01

    Radionuclide contamination is one of the accidents that might occur while carrying out a periodical inspection of nuclear power stations during normal reactor operation. When such an accident occurs, rescue and medical personnel, involved in transporting and treating affected workers run the risk of exposure to secondary radiation. In this study, the ambient dose equivalent rate at a certain distance from the surface of the human body contaminated with typical radioactive corrosion products was calculated. Further, the relationships among the adhesion area, contamination density, and secondary exposure dose were clarified. The secondary exposure dose and permissible working hours in a radiation emergency medicine were estimated by presenting these relationships in the form of a chart and by specifying the contamination levels. (author)

  8. Data structures and language elements for automated transport calculations for neutron and gamma radiation

    International Nuclear Information System (INIS)

    Rexer, G.

    1978-12-01

    Computer-aided design of nuclear shielding and irradiation facilities is characterized by studies of different design variants in order to determine which facilities are safe and still economicol. The design engineer has a very complex task including the formulation of calculation models, data linking of programs and data, and the management of large data stores. Integrated modular program systems with centralized module and data management make it possible to treat these problems in a more simplified and automatic manner. The paper describes a system of this type for the field of radiation transport and radiation shielding. The basis is the modular system RSYST II which has a dynamic hierarchical scheme for the structuring of problem data in a central data base. (orig./RW) [de

  9. Effects of the Mt. Pinatubo eruption on the chemistry, radiative, and transport processes in the stratosphere

    International Nuclear Information System (INIS)

    Wuebbles, D.J.; Kinnison, D.E.; Grant, K.E.; Connell, P.S.

    1992-09-01

    Volcanic eruptions can significantly impact trace gas distribution in the upper troposphere and lower stratosphere. Massive eruptions, produce large quantities of SO 2 , H 2 O, chlorine compounds, and particulates. Modeling the effects of these impulsive increases in traces gases and comparing the results with observations from ground and satellite measurements provide unique opportunities to test current multi-dimensional chemical-radiative-transport models of the global atmosphere. Since these models are currently being used in assessment studies for future anthropogenic emissions of trace gases quantitative understanding of the accuracy of these models is essential. In this study, we have used observed data from the Stratospheric Aerosol and Gas Experiment II (SAGE II) aboard the Earth Radiation Budget Satellite (ERBS) to realistically represent both the time dependent change in aerosol surface area density and wavelength dependent extinction values from the Mt. Pinatubo Eruption. Increases in the aerosol loading increase the rate of important heterogeneous chemical reactions converting odd nitrogen in both ClONO 2 and N 2 O 5 to HNO 3 . Radiative effects of increases aerosol optical thickness include changes to net radiative heating rates and to actinic fluxes. Changes to heating rates will indirectly change chemical reaction rates via changes in atmospheric temperatures. changes in actinic fluxes will directly modify photodissociation rates

  10. Study of the radiation effects on nucleic acids and related compounds. Annual progress report, November 15, 1977--November 14, 1978

    International Nuclear Information System (INIS)

    Wang, S.Y.

    1978-07-01

    Acquisition of information on molecular biology involves four stages: establishment of procedures for the separation, isolation, and characterization of radiation products of nucleic acid bases, nucleosides, etc.; development of methods for the synthesis of these products once they are identified so that a constant supply in milligram to gram quantities is available for the studies in stages 3 and 4; examination of the apparent biological effects of each product in vitro and in vivo; and study of the molecular mechanism related to an observed biological phenomenon. In view of the difficulties experienced in this area of research and this deliberate and careful investigative approach, it was generally believed that progress toward our final goal would be rather prolonged. Yet the elucidation of a molecular mechanism by which ionizing radiation induces mutation in vivo is very near at hand. Further progress has been made in the separation and isolation of three hydroperoxy derivatives of thymidine. One communication has appeared and another has been submitted for publication. The former reports the efficient stereospecific synthesis of cis-pyrimidine glycols and the latter describes the study of mutagenicity and toxicity of seven radiation products of thymine and thymidine using Ames Salmonella test. Also, a quantitative study of the reversion of cytosine N(3)-oxide, a hydroperoxidation product induced by 6-TOOH, to cytosine has been carried out

  11. A spray flamelet/progress variable approach combined with a transported joint PDF model for turbulent spray flames

    Science.gov (United States)

    Hu, Yong; Olguin, Hernan; Gutheil, Eva

    2017-05-01

    A spray flamelet/progress variable approach is developed for use in spray combustion with partly pre-vaporised liquid fuel, where a laminar spray flamelet library accounts for evaporation within the laminar flame structures. For this purpose, the standard spray flamelet formulation for pure evaporating liquid fuel and oxidiser is extended by a chemical reaction progress variable in both the turbulent spray flame model and the laminar spray flame structures, in order to account for the effect of pre-vaporised liquid fuel for instance through use of a pilot flame. This new approach is combined with a transported joint probability density function (PDF) method for the simulation of a turbulent piloted ethanol/air spray flame, and the extension requires the formulation of a joint three-variate PDF depending on the gas phase mixture fraction, the chemical reaction progress variable, and gas enthalpy. The molecular mixing is modelled with the extended interaction-by-exchange-with-the-mean (IEM) model, where source terms account for spray evaporation and heat exchange due to evaporation as well as the chemical reaction rate for the chemical reaction progress variable. This is the first formulation using a spray flamelet model considering both evaporation and partly pre-vaporised liquid fuel within the laminar spray flamelets. Results with this new formulation show good agreement with the experimental data provided by A.R. Masri, Sydney, Australia. The analysis of the Lagrangian statistics of the gas temperature and the OH mass fraction indicates that partially premixed combustion prevails near the nozzle exit of the spray, whereas further downstream, the non-premixed flame is promoted towards the inner rich-side of the spray jet since the pilot flame heats up the premixed inner spray zone. In summary, the simulation with the new formulation considering the reaction progress variable shows good performance, greatly improving the standard formulation, and it provides new

  12. Recent progress of applying mesenchymal stem cells in therapy of urgent radiation damage

    International Nuclear Information System (INIS)

    Liu Jiangong; Guo Wanlong; Zhang Shuxian; Duan Zhikai

    2010-01-01

    At present, Cytokine therapy is the main strategy capable of preventing and reducing the acute radiation syndrome (ARS). With the problem of difficult match and severe graft versus host disease, haemopoietic stem cells can be used to find some effective approaches to treat acute radiation damage. Mesenchymal stem cells are of great therapeutic potential due to their particular characteristics including secretion of hematopoietic cytokine, reconstruction hemopoietic microenvironment, poor-immunogenicity, ease of reception ectogenic gene transfection and expression. This paper is to summarize the studies of biological characteristics of MSC and its application prospects in urgent radiation damage. (authors)

  13. Toolkit for high performance Monte Carlo radiation transport and activation calculations for shielding applications in ITER

    International Nuclear Information System (INIS)

    Serikov, A.; Fischer, U.; Grosse, D.; Leichtle, D.; Majerle, M.

    2011-01-01

    The Monte Carlo (MC) method is the most suitable computational technique of radiation transport for shielding applications in fusion neutronics. This paper is intended for sharing the results of long term experience of the fusion neutronics group at Karlsruhe Institute of Technology (KIT) in radiation shielding calculations with the MCNP5 code for the ITER fusion reactor with emphasizing on the use of several ITER project-driven computer programs developed at KIT. Two of them, McCad and R2S, seem to be the most useful in radiation shielding analyses. The McCad computer graphical tool allows to perform automatic conversion of the MCNP models from the underlying CAD (CATIA) data files, while the R2S activation interface couples the MCNP radiation transport with the FISPACT activation allowing to estimate nuclear responses such as dose rate and nuclear heating after the ITER reactor shutdown. The cell-based R2S scheme was applied in shutdown photon dose analysis for the designing of the In-Vessel Viewing System (IVVS) and the Glow Discharge Cleaning (GDC) unit in ITER. Newly developed at KIT mesh-based R2S feature was successfully tested on the shutdown dose rate calculations for the upper port in the Neutral Beam (NB) cell of ITER. The merits of McCad graphical program were broadly acknowledged by the neutronic analysts and its continuous improvement at KIT has introduced its stable and more convenient run with its Graphical User Interface. Detailed 3D ITER neutronic modeling with the MCNP Monte Carlo method requires a lot of computation resources, inevitably leading to parallel calculations on clusters. Performance assessments of the MCNP5 parallel runs on the JUROPA/HPC-FF supercomputer cluster permitted to find the optimal number of processors for ITER-type runs. (author)

  14. Supersonic Ionization Wave Driven by Radiation Transport in a Short-Pulse Laser-Produced Plasma

    International Nuclear Information System (INIS)

    Ditmire, T.; Gumbrell, E.T.; Smith, R.A.; Mountford, L.; Hutchinson, M.H.

    1996-01-01

    Through the use of an ultrashort (2ps) optical probe, we have time resolved the propagation of an ionization wave into solid fused silica. This ionization wave results when a plasma is created by the intense irradiation of a solid target with a 2ps laser pulse. We find that the velocity of the ionization wave is consistent with radiation driven thermal transport, exceeding the velocity expected from simple electron thermal conduction by nearly an order of magnitude. copyright 1996 The American Physical Society

  15. TIERCE: A code system for particles and radiation transport in thick targets

    Energy Technology Data Exchange (ETDEWEB)

    Bersillon, O.; Bauge, E.; Borne, F.; Clergeau, J.F.; Collin, M.; Cotten, D.; Delaroche, J.P.; Duarte, H.; Flament, J.L.; Girod, M.; Gosselin, G.; Granier, T.; Hilaire, S.; Morel, P.; Perrier, R.; Romain, P.; Roux, L. [CEA, Bruyeres-le-Chatel (France). Service de Physique Nucleaire

    1997-09-01

    Over the last few years, a great effort at Bruyeres-le-Chatel has been the development of the TIERCE code system for the transport of particles and radiations in complex geometry. The comparison of calculated results with experimental data, either microscopic (double differential spectra, residual nuclide yield...) or macroscopic (energy deposition, neutron leakage...), shows the need to improve the nuclear reaction models used. We present some new developments concerning data required for the evaporation model in the framework of a microscopic approach. 22 refs., 6 figs.

  16. Line photon transport in a non-homogeneous plasma using radiative coupling coefficients

    International Nuclear Information System (INIS)

    Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Minguez, E.

    2006-01-01

    We present a steady-state collisional-radiative model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature, but the main difference between our model and those ones is that the details of geometry are exactly treated in the definition of coupling coefficients and a local profile is taken into account in each plasma cell. (authors)

  17. Study of radiative ablation to low-Z material and energy transport

    International Nuclear Information System (INIS)

    Yang Jiamin; Ding Yaonan; Miao Wenyong; Sun Kexu; Yi Rongqing; Chen Zhenglin; Wang Hongbin; Li Sanwei; Wang Yaomei; Wen Shuhuai; Zheng Zhijian; Zhang Wenhai; Yu Yanning

    1998-12-01

    X-ray emissions from the gold foil target, irradiated by 0.35 μm laser on the Xingguang facility, have been studied. A clean and intense X-ray source has been obtained from the rear of gold foil target by selection of irradiating laser parameters. Then, characteristics of radiation ablation to low-Z materials C 8 H 8 and C 10 H 16 O 5 and energy transport have been investigated comprehensively. Experimental results show that mass ablative rate of C 10 H 16 O 5 are greater than those of C 8 H 8 due to its better match with the ablative source spectra

  18. An investigation of fission models for high-energy radiation transport calculations

    International Nuclear Information System (INIS)

    Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.

    1983-07-01

    An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)

  19. Radiation transport benchmarks for simple geometries with void regions using the spherical harmonics method

    International Nuclear Information System (INIS)

    Kobayashi, K.

    2009-01-01

    In 2001, an international cooperation on the 3D radiation transport benchmarks for simple geometries with void region was performed under the leadership of E. Sartori of OECD/NEA. There were contributions from eight institutions, where 6 contributions were by the discrete ordinate method and only two were by the spherical harmonics method. The 3D spherical harmonics program FFT3 by the finite Fourier transformation method has been improved for this presentation, and benchmark solutions for the 2D and 3D simple geometries with void region by the FFT2 and FFT3 are given showing fairly good accuracy. (authors)

  20. Electron transport in nanometer GaAs structure under radiation exposure

    CERN Document Server

    Demarina, N V

    2002-01-01

    One investigates into effect of neutron and proton irradiation on electron transport in nanometer GaAs structures. Mathematical model takes account of radiation defects via introduction of additional mechanisms od scattering of carriers at point defects and disordered regions. To investigate experimentally into volt-ampere and volt-farad characteristics one used a structure based on a field-effect transistor with the Schottky gate and a built-in channel. Calculation results of electron mobility, drift rate of electrons, time of energy relaxation and electron pulse are compared with the experimental data

  1. Comparison of the results of radiation transport calculation obtained by means of different programs

    International Nuclear Information System (INIS)

    Gorbatkov, D.V.; Kruchkov, V.P.

    1995-01-01

    Verification of calculational results of radiation transport, obtained by the known, programs and constant libraries (MCNP+ENDF/B, ANISN+HILO, FLUKA92) by means of their comparison with the precision results calculations through ROZ-6N+Sadko program constant complex and with experimental data, is carried out. Satisfactory agreement is shown with the MCNP+ENDF/B package data for the energy range of E<14 MeV. Analysis of the results derivations, obtained trough the ANISN-HILO package for E<400 MeV and the FLUKA92 programs of E<200 GeV is carried out. 25 refs., 12 figs., 3 tabs

  2. Radiation chemistry of hydrocarbon and alkyl halide systems. Progress report, August 1, 1982-July 31, 1983

    International Nuclear Information System (INIS)

    Hanrahan, R.J.

    1983-01-01

    Experimental work was in progress during the past year on three systems: investigation of gas phase OH radical reactions using the pulse radiolysis method; studies of the radiolytic oxidation of propane; and an investigation of photochemistry and mass spectrometry of CF 3 I-CH 3 I mixtures. In addition, data analysis and interpretation of previously obtained results on H 2 /CO systems was under way. Progress made in these areas is described

  3. Radiation protection program for transport of radiopharmaceutical and labelled compounds in Cuba

    International Nuclear Information System (INIS)

    Amador, Zayda H.; Perez, Saul; Ayra, Fernando E.; Torres, Mirta B.

    2008-01-01

    The Centre of Isotopes (CENTIS) is the main consignor and carrier of radioactive material in Cuba. The purpose of this work is to describe the Radiation Protection Program (RPP) implemented inside the Organization Quality Management System, to achieve and maintain an optimized standard of protection in the accomplishment of these functions. All those areas involving radiation exposures are considered (e.g. design of type A packages, packing, loading, handling, in-transit storage, road transport and inspection and maintenance of packaging). The quality assurance requirements for packaging components were established using a grading process. A material to absorb twice the volume of the liquid contents is tested and its water absorptivity, grammage and capillary rise were estimated. Categories and transport indexes for 56 packages of radiopharmaceuticals incorporating radioiodine, 32 P, 188 Re and 90 Y and technetium generators, are determined. Tests for demonstrating compliance with requirements for type A packages with liquid and solid radioactive content and for air transport are performed and documented. A numeric code for each package by consignee is registered and controlled in each step of the process and as a guarantee of its traceability. Safety and security of radioactive materials during storage in transit and transport are supervised. Training of workers trough periodic curses and emergency exercises is implementing. Individual Licensing of this staff is conducted by CENTIS and presented to the Cuban Regulatory Authority. The effective annual doses distributions are reported since 1996 to 2007. Occupational exposure is acceptably low and less than 6 mSv. It has not been reported any incident in about two thousand road shipments carried out. CENTIS' RPP has been under review, detailed appraisals and audits. The Certification of the management system by ISO 9001:2000 has been identified as a goal and a way for the continuous improvement. (author)

  4. Method of processing dismantled products of radiation-contaminated equipments and transportation container therefor

    International Nuclear Information System (INIS)

    Komura, Shiro; Heki, Hideaki.

    1991-01-01

    In a method of decontaminating dismantled products of radiation-contaminated equipments removed at nuclear power facilities and classifying the dismantled products depending on their remaining radioactivity levels measured at a processing facility, the dismantled products are contained in a transportation container, to which decontamination liquids are injected and they are transferred to the processing facility. The decontaminated liquid wastes are drained from the transportation container, the dismantled products are washed while being contained in the transportation container as they are. Then, they are transferred to a step for measuring their remaining radioactivity level. This can shorten the time from the containment of the dismantled products to the transportation container to the completion of the decontamination, to improve the efficiency for the decontamination processing. Further, by separately containing the dismantled products on every kind of materials to respective containers, the processing time can be appropriately controlled respectively even if the dissolving efficiency to the decontamination liquids is different depending on the materials. (T.M.)

  5. Morphodynamics and Sediment Transport on the Huanghe (Yellow River) Delta: Work in Progress

    Science.gov (United States)

    Kineke, G. C.; Calson, B.; Chadwick, A. J.; Chen, L.; Hobbs, B. F.; Kumpf, L. L.; Lamb, M. P.; Ma, H.; Moodie, A. J.; Mullane, M.; Naito, K.; Nittrouer, J. A.; Parker, G.

    2017-12-01

    Deltas are perhaps the most dynamic of coastal landforms with competing processes that deliver and disperse sediment. As part of the NSF Coastal SEES program, an interdisciplinary team of scientists from the US and China are investigating processes that link river and coastal sediment transport responsible for morphodynamic change of the Huanghe delta- an excellent study site due to its high sediment load and long history of natural and engineered avulsions, that is, abrupt shifts in the river course. A fundamental component of the study is a better understanding of sediment transport physics in a river system that transports mostly silt. Through theory and data analysis, we find that fine-grained rivers fail to develop full scale dunes, which results in faster water flow and substantially larger sediment fluxes as compared to sandy rivers (e.g. the Mississippi River). We also have developed new models for sediment-size dependent entrainment that are needed to make longer term predictions of river sedimentation patterns. On the delta front, we are monitoring the high sediment flux to the coast, which results in steep foresets and ideal conditions for off-shore sediment delivery via gravity flows. These constraints on sediment transport are being used to develop new theory for where and when rivers avulse - including the effects of variable flood discharge, sediment supply, and sea level rise -and how deltas ultimately grow through repeated cycles of lobe development. Flume experiments and field observations are being used to test these models, both in the main channel of the Huanghe and in channels abandoned after historic avulsions. Abandoned channels and floodplains are now dominated by coastal sediment transport through a combination of wave resuspension and tidal transport, settling lag and reverse estuarine circulation. Finally, the field and laboratory tested numerical models are being used as inputs to define a cost curve for efficient avulsion management of

  6. The third RAdiation transfer Model Intercomparison (RAMI) exercise: Documenting progress in canopy reflectance models

    NARCIS (Netherlands)

    Widlowski, J.L.; Taberner, M.; Pinty, B.; Bruniquel-Pinel, V.; Disney, M.I.; Fernandes, R.; Gastellu-Etchegorry, J.P.; Gobron, N.; Kuusk, A.; Lavergne, T.; LeBlanc, S.; Lewis, P.E.; Martin, E.; Mõttus, M.; North, P.R.J.; Qin, W.; Robustelli, M.; Rochdi, N.; Ruiloba, R.; Thompson, R.; Verhoef, W.; Verstraete, M.M.; Xie, D.

    2007-01-01

    [1] The Radiation Transfer Model Intercomparison ( RAMI) initiative benchmarks canopy reflectance models under well-controlled experimental conditions. Launched for the first time in 1999, this triennial community exercise encourages the systematic evaluation of canopy reflectance models on a

  7. Third Radiation Transfer Model Intercomparison (RAMI) exercise : Documenting progress in canopy reflectance models

    NARCIS (Netherlands)

    Widlowski, J.-L.; Taberner, M.; Pinty, B.; Bruniquel-Pinel, V.; Disney, M.; Fernandes, R.; Gastellu-Etchegorry, J.P.; Gobron, N.; Kuusk, A.; Lavergne, T.; Leblanc, S.; Lewis, P.E.; Martin, E.; Mottus, M.; North, P.R.J.; Qin, W.; Robustelli, M.; Rochdi, N.; Ruiloba, R.; Soler, C.; Thompson, R.; Verhoef, W.; Xie, D.; Thompson, R.

    2007-01-01

    The Radiation Transfer Model Intercomparison (RAMI) initiative benchmarks canopy reflectance models under well‐controlled experimental conditions. Launched for the first time in 1999, this triennial community exercise encourages the systematic evaluation of canopy reflectance models on a voluntary

  8. SERI Solar Radiation Resource Assessment Project: Fiscal Year 1990 Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Riordan, C; Maxwell, E; Stoffel, T; Rymes, M; Wilcox, S

    1991-07-01

    The purpose of the Solar Radiation Resource Project is to help meet the needs of the public, government, industry, and utilities for solar radiation data, models, and assessments as required to develop, design, deploy, and operate solar energy conversion systems. The project scientists produce information on the spatial (geographic), temporal (hourly, daily, and seasonal), and spectral (wavelength distribution) variability of solar radiation at different locations in the United States. Resources committed to the project in FY 1990 supported about four staff members, including part-time administrative support. With these resources, the staff must concentrate on solar radiation resource assessment in the United States; funds do not allow for significant efforts to respond to a common need for improved worldwide data. 34 refs., 21 figs., 6 tabs.

  9. Molecular bases for radiation mutagenesis. Three year progress report, November 15, 1975--November 14, 1978

    International Nuclear Information System (INIS)

    Wang, S.Y.

    1978-07-01

    Studies on isolation and characterization of radiation products included: isolation and identification of cis- and trans-Thy glycols from the mixture of gamma irradiation products of Thy; identification of two isomers as radiation products from radiolysis of cytosine in aerated aqueous solutions and radiolysis of Thd in aerated aqueous solutions. Studies on synthesis of radiation products included: Stereospecific synthesis of cis- and trans-pyrimidine glycols; preparation of pyrimidine hydroperoxide; and synthesis of cis- and trans-1-carbamylimidazolidone-4, 5-diols. Studies on biological effects were conducted using human lymphocyte cultures, Chinese hamster cells, and root tip cells of Vicia faba. Effects of 6-TOOH on chromosomal aberrations, colony-forming ability, and unscheduled DNA synthesis were studied. Mutagenic effects of radiation products of Thy derivatives were investigated. Methods and procedures are described for UV-spectroscopic study, isolation of products, characterization of products, kinetic studies, mechanistic studies, and tracer studies

  10. Progress report and preliminary 1981-83 agenda of the United States Radiation Policy Council

    International Nuclear Information System (INIS)

    1980-09-01

    The U.S. Radiation Policy Council is responsible for coordinating the formulation and implementation of Federal Policy relating to radiation protection. In carrying out this very broad and basic mandate, the RPC has been directed to: Advise on the formulation of broad radiation protection policies; monitor the implementation of Federal policies; Help resolve conflicts in jurisdiction among Federal agencies; Recommend corrective legislation, if needed; ensure effective liaison with the States and the Congress; and Serve as a forum for public participation and comment. The RPC was established by Executive Order Number 12194 in February 1980. The Council was created to coordinate the formulation and implementation of Federal policies relating to radiation protection. This report summarizes the first 7 months the Council has been in operation, its activities, and decisions through September 1980

  11. Recent progress and future perspectives regarding mutation breeding at the Institute of Radiation Breeding

    International Nuclear Information System (INIS)

    Nakagawa, Hitoshi

    2006-01-01

    Number of mutation species in the world is stated by some literature. 202 species are bread in Japan, which consists of 151 (by radiation), 20 (chemicals) and 31 (culture). The mutation indirect use species obtained 176 of rice, 3 wheat, 6 barleys, 8 soybeans, 3 tomatoes and 4 others. Low allergen rice, low glutelin rice, globulin deletion rice, disease resistant pear and apple, chrysanthemum and rose by radiation were studied. Control of mutation, genetics analysis, molecular scientific determination of mutation such as scale of mutation and RNA interference are reported. Advanced Radiation Application Research Center was build in Korea, 2005. Malaysian Institute for Nuclear Technology Research (MINT) is being built in Malaysia. Forum for Nuclear Cooperation in Asia (FNCA) is promoting radiation breeding in Japan. (S.Y.)

  12. Radiation and biophysical studies on cells and viruses. Progress report, April 1, 1976--June 30, 1977. [Gamma radiation, alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Cole, A.

    1977-01-01

    Progress is reported on the following research projects: genetic structure of DNA, chromosomes, and nucleoproteins; particle beam studies of radiosensitive sites; division delay in CHO cells induced by partly penetrating alpha particles; location of cellular sites for mutation induction; sites for radioinduced cell transformation using partly penetrating particle beams; gamma-ray and particle irradiation of nucleoproteins and other model systems; quantitation of surface antigens on normal and neoplastic cells by x-ray fluorescence; hyperthermic effects on cell survival and DNA repair mechanisms; and studies on radioinduced cell transformation. (HLW)

  13. Radiation carcinogenesis. Progress report III, 15 March 1975--15 March 1976

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1976-03-01

    The attention of forensic pathologists has been drawn to the criteria essential for the recognition of radiation death or injury in the hope that such cases will be better recognized and that some false claims of radiation damage might be prevented at the local level. The results of experiments on parabiont rats, one of which had been irradiated with 1000 R of 250 kVp x-ray, the other shielded, are reviewed. With controls and related special studies the total is over 3000 pairs equally divided as to sex. Much information on the relative sensitivity of different tissues and organs to tumor induction is available and is being statistically analyzed. These experiments have provided further evidence of the effectiveness of parabiosis in assuring survival after 1000 R x-radiation and have enabled us to learn of the types of problems that might be expected in the way of late effects in heavily irradiated individuals should they be enabled by effective therapy to survive the acute phases of the radiation syndrome. Additional evidence has been brought out that carcinogenesis in some hormonally dependent tissues and organs is not so much a direct effect of radiation as it is a summation of this effect and of alterations caused by changes in hormonal balance brought about by the radiation

  14. Radiation and biophysical studies on cells and viruses. Progress report, July 1, 1978-August 30, 1979

    International Nuclear Information System (INIS)

    Cole, A.

    1979-01-01

    Ionizing radiation beams of low linear energy transfer (LET) and high LET (alpha particles) which penetrated part way into or completely through cell monolayers were used to study a variety of molecular and cellular responses including: DNA damage, chromosome aberrations, division delay, lethality, mutation, and transformation. Modifiers of radiation response such as oxygen tension, cell temperature, cell growth cycle stage, dose fractionation and/or post irradiation repair incubation were studied. The following properties were evaluated: cellular location of radiation susceptible sites, optimum action cross-sections, relative biological effectiveness (RBE) for high LET radiation, effect of radiation modifiers, and the kinetics of cell repair of the initial damage. Correlations among these properties suggested that similar genetic damage was involved in most responses. These and other data suggest that an important mode of genetic damage involves nuclear membrane associated DNA which suffers multiple proximate lesions induced by the high LET component of any form of ionizing radiation. Such damage may be assayed as a single or double strand DNA break but includes other DNA lesions in close proximity. Failure of the cell to properly repair such complex lesions may contribute to a variety of biological responses

  15. The physics of W transport illuminated by recent progress in W density diagnostics at ASDEX Upgrade

    Science.gov (United States)

    Odstrcil, T.; Pütterich, T.; Angioni, C.; Bilato, R.; Gude, A.; Odstrcil, M.; ASDEX Upgrade Team; the EUROfusion MST1 Team

    2018-01-01

    Due to the high mass and charge of the heavy ions, centrifugal and electrostatic forces cause a significant variation in their poloidal density. The impact of these forces on the poloidal density profile of tungsten was investigated utilizing the detailed two-dimensional SXR emissivity profiles from the ASDEX Upgrade tokamak. The perturbation in the electrostatic potential generated by magnetic trapping of the non-thermal ions from neutral beam injection was found to be responsible for significant changes in the poloidal distribution of tungsten ions. An excellent match with the results from fast particle modeling was obtained, validating the model for the poloidal fast particle distribution. Additionally, an enhancement of the neoclassical transport due to an outboard side impurity localization was measured in the experiment when analyzing the tungsten flux between sawtooth crashes. A qualitative match with neoclassical modeling was found, demonstrating the possibility of minimizing neoclassical transport by an optimization of the poloidal asymmetry profile of the impurity.

  16. Progressive pituitary hormone deficiency following radiation therapy in adults; Deficiencia progressiva dos hormonios adeno-hipofisarios apos radioterapia em adultos

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Rafaela A.; Vaisman, Mario [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Endocrinologia]. E-mail: rafaela_loureiro@hotmail.com

    2004-10-01

    Hypopituitarism can be caused by radiation therapy, even when it is not directly applied on the hypothalamic-pituitary axis, and can lead to anterior pituitary deficiency mainly due to hypothalamic damage. The progressive loss of the anterior pituitary hormones usually occurs in the following order: growth hormone, gonadotropin hormones, adrenocorticotropic hormone and thyroid-stimulating hormone. Although there are several different tests available to confirm anterior pituitary deficiency, this paper will focus on the gold standard tests for patients submitted to radiation therapy. We emphasize that the decline of anterior pituitary function is time- and dose-dependent with some variability among the different axes. Therefore, awareness of the need of a joint management by endocrinologists and oncologists is essential to improve treatment and quality of life of the patients. (author)

  17. Annual progress report 1981

    International Nuclear Information System (INIS)

    1982-01-01

    This annual progress report of the CEA Protection and Nuclear Safety Institut outlines a brief description of the progress made in each section of the Institut. Research activities of the Protection department include, radiation effects on man, radioecology and environment radioprotection techniques. Research activities of the Nuclear Safety department include, reactor safety analysis, fuel cycle facilities safety analysis, safety research programs. The third section deals with nuclear material security including security of facilities, security of nuclear material transport and monitoring of nuclear material management [fr

  18. Unusual progression and subsequent improvement in cystic lung disease in a child with radiation-induced lung injury

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Michael S. [Monroe Carell Jr. Children' s Hospital at Vanderbilt, Department of Pediatrics, Nashville, TN (United States); Chadha, Ashley D. [Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Department of Pediatrics, Nashville, TN (United States); Carroll, Clinton M.; Borinstein, Scott C. [Vanderbilt University School of Medicine, Division of Hematology and Oncology, Department of Pediatrics, Nashville, TN (United States); Young, Lisa R. [Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Department of Pediatrics, Nashville, TN (United States); Vanderbilt University School of Medicine, Division of Allergy, Pulmonary and Critical Care, Department of Medicine, Nashville, TN (United States); Vanderbilt University School of Medicine, Division of Pulmonary Medicine, Nashville, TN (United States)

    2015-07-15

    Radiation-induced lung disease is a known complication of therapeutic lung irradiation, but the features have not been well described in children. We report the clinical, radiologic and histologic features of interstitial lung disease (ILD) in a 4-year-old child who had previously received lung irradiation as part of successful treatment for metastatic Wilms tumor. Her radiologic abnormalities and clinical symptoms developed in an indolent manner. Clinical improvement gradually occurred with corticosteroid therapy. However, the observed radiologic progression from interstitial and reticulonodular opacities to diffuse cystic lung disease, with subsequent improvement, is striking and has not been previously described in children. (orig.)

  19. The oncogenic action of ionizing radiation on rat skin: Progress report, February 1, 1988-January 31, 1989

    International Nuclear Information System (INIS)

    Burns, F.J.; Garte, S.J.

    1988-01-01

    Progress is described in 3 general areas corresponding to the specific aims of the proposal, including DNA strand breaks in the epidermis as a function of radiation penetration; oncogene activation in radiation-induced rat skin cancers; and carcinogenesis in rat skin induced by the neon ion beam. Numerous experiments have established that DNA strand breaks per unit dose in the rat epidermis are reduced by about 60% when the radiation penetration is reduced from 1.0 mm to 0.2 mm. The activation of oncogenes in the radiation-induced rat skin cancers followed a pattern. Four highly malignant cancers exhibited activation of K-ras and c-myc oncogenes, while the remaining 8 cancers exhibited only one or the other of these 2 oncogenes. Of 5 squamous carcinomas, 4 showed K-ras activation and 1 showed c-myc activation. Approximately 200 rats were exposed to the neon ion beam at the Bevalac in Berkeley, CA. The carcinogenicity of energetic electrons (2.0 MeV) was determined in conjunction with the neon ion experiment. It is too early to evaluate tumor incidence in the neon ion experiment, but for electrons an unusually large excess of connective tissue tumors, fibromas and sarcomas, have been observed so far. 59 refs., 2 tabs

  20. Premar-2: a Monte Carlo code for radiative transport simulation in atmospheric environments

    International Nuclear Information System (INIS)

    Cupini, E.

    1999-01-01

    The peculiarities of the PREMAR-2 code, aimed at radiation transport Monte Carlo simulation in atmospheric environments in the infrared-ultraviolet frequency range, are described. With respect to the previously developed PREMAR code, besides plane multilayers, spherical multilayers and finite sequences of vertical layers, each one with its own atmospheric behaviour, are foreseen in the new code, together with the refraction phenomenon, so that long range, highly slanted paths can now be more faithfully taken into account. A zenithal angular dependence of the albedo coefficient has moreover been introduced. Lidar systems, with spatially independent source and telescope, are allowed again to be simulated, and, in this latest version of the code, sensitivity analyses to be performed. According to this last feasibility, consequences on radiation transport of small perturbations in physical components of the atmospheric environment may be analyze and the related effects on searched results estimated. The availability of a library of physical data (reaction coefficients, phase functions and refraction indexes) is required by the code, providing the essential features of the environment of interest needed of the Monte Carlo simulation. Variance reducing techniques have been enhanced in the Premar-2 code, by introducing, for instance, a local forced collision technique, especially apt to be used in Lidar system simulations. Encouraging comparisons between code and experimental results carried out at the Brasimone Centre of ENEA, have so far been obtained, even if further checks of the code are to be performed [it

  1. Reactive transport modelling of a heating and radiation experiment in the Boom clay (Belgium)

    International Nuclear Information System (INIS)

    Montenegro, L.; Samper, J.; Delgado, J.

    2003-01-01

    Most countries around the world consider Deep Geological Repositories (DGR) as the most safe option for the final disposal of high level radioactive waste (HLW). DGR is based on adopting a system of multiple barriers between the HLW and the biosphere. Underground laboratories provide information about the behaviour of these barriers at real conditions. Here we present a reactive transport model for the CERBERUS experiment performed at the HADES underground laboratory at Mol (Belgium) in order to characterize the thermal (T), hydrodynamic (H) and geochemical (G) behaviour of the Boon clay. This experiment is unique because it addresses the combined effect of heat and radiation produced by the storage of HLW in a DGR. Reactive transport models which are solved with CORE, are used to perform quantitative predictions of Boom clay thermo-hydro-geochemical (THG) behaviour. Numerical results indicate that heat and radiation cause a slight oxidation near of the radioactive source, pyrite dissolution, a pH decrease and slight changes in the pore water chemical composition of the Boom clay. (Author) 33 refs

  2. AREVA Developments for an Efficient and Reliable use of Monte Carlo codes for Radiation Transport Applications

    Science.gov (United States)

    Chapoutier, Nicolas; Mollier, François; Nolin, Guillaume; Culioli, Matthieu; Mace, Jean-Reynald

    2017-09-01

    In the context of the rising of Monte Carlo transport calculations for any kind of application, AREVA recently improved its suite of engineering tools in order to produce efficient Monte Carlo workflow. Monte Carlo codes, such as MCNP or TRIPOLI, are recognized as reference codes to deal with a large range of radiation transport problems. However the inherent drawbacks of theses codes - laboring input file creation and long computation time - contrast with the maturity of the treatment of the physical phenomena. The goals of the recent AREVA developments were to reach similar efficiency as other mature engineering sciences such as finite elements analyses (e.g. structural or fluid dynamics). Among the main objectives, the creation of a graphical user interface offering CAD tools for geometry creation and other graphical features dedicated to the radiation field (source definition, tally definition) has been reached. The computations times are drastically reduced compared to few years ago thanks to the use of massive parallel runs, and above all, the implementation of hybrid variance reduction technics. From now engineering teams are capable to deliver much more prompt support to any nuclear projects dealing with reactors or fuel cycle facilities from conceptual phase to decommissioning.

  3. AREVA Developments for an Efficient and Reliable use of Monte Carlo codes for Radiation Transport Applications

    Directory of Open Access Journals (Sweden)

    Chapoutier Nicolas

    2017-01-01

    Full Text Available In the context of the rising of Monte Carlo transport calculations for any kind of application, AREVA recently improved its suite of engineering tools in order to produce efficient Monte Carlo workflow. Monte Carlo codes, such as MCNP or TRIPOLI, are recognized as reference codes to deal with a large range of radiation transport problems. However the inherent drawbacks of theses codes - laboring input file creation and long computation time - contrast with the maturity of the treatment of the physical phenomena. The goals of the recent AREVA developments were to reach similar efficiency as other mature engineering sciences such as finite elements analyses (e.g. structural or fluid dynamics. Among the main objectives, the creation of a graphical user interface offering CAD tools for geometry creation and other graphical features dedicated to the radiation field (source definition, tally definition has been reached. The computations times are drastically reduced compared to few years ago thanks to the use of massive parallel runs, and above all, the implementation of hybrid variance reduction technics. From now engineering teams are capable to deliver much more prompt support to any nuclear projects dealing with reactors or fuel cycle facilities from conceptual phase to decommissioning.

  4. Radiation carcinogenesis. Progress report VI, 16 May 1978--15 May 1979

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1979-01-01

    Asbestos fibers, Canadian and Rhodesian chrysotile, have induced mesotheliomas and pleural plaques in mice and rats. The pathogenesis of the lesions is being studied. Proliferation of the adrenal cortical A cells is accelerated in time and enhanced in extent by ionizing radiation in female RAP mice. The development of cortical tumors was significantly correlated with extensive A cell proliferation. Whole-body protracted doses, above 500 rads, were followed by a 9% tumor incidence. Endocrine neoplasia in mice appears related to functional ties between several endocrines particularly adrenal, ovary, and pituitary. A study of the spontaneous benign and malignant tumors ocurring in control NEDH rats has provided background for the tumorigenic effects of radiation and also of altered hormonal internal milieu. Begin tumors have been produced by radiation in a wide variety of tissues for the first time, providing data as to the relative responsiveness in benign tumor production of various tissues to a dose of 1000 rads. The hormonal changes secondary to parabiosis and hemi-irradiation of the pair are important. A radiation-induced functioning pheochromocytoma causing hypertension and death has been found widely useful by investigators. A radiation-induced malignant insulinoma has also been widely used, and insulin-producing DNA from it has served in the hands of others through genetic engineering to provide an insulin-producing strain of the bacillus E. coli

  5. Progress in Solving the Elusive Ag Transport Mechanism in TRISO Coated Particles: What is new?

    Energy Technology Data Exchange (ETDEWEB)

    Isabella Van Rooyen

    2014-10-01

    The TRISO particle for HTRs has been developed to an advanced state where the coating withstands internal gas pressures and retains fission products during irradiation and under postulated accidents. However, one exception is Ag that has been found to be released from high quality TRISO coated particles when irradiated and can also during high temperature accident heating tests. Although out- of- pile laboratory tests have never hither to been able to demonstrate a diffusion process of Ag in SiC, effective diffusion coefficients have been derived to successfully reproduce measured Ag-110m releases from irradiated HTR fuel elements, compacts and TRISO particles It was found that silver transport through SiC does not proceed via bulk volume diffusion. Presently grain boundary diffusion that may be irradiation enhanced either by neutron bombardment or by the presence of fission products such as Pd, are being investigated. Recent studies of irradiated AGR-1 TRISO fuel using scanning transmission electron microscopy (STEM), transmission kukuchi diffraction (TKD) patterns and high resolution transmission electron microscopy (HRTEM) have been used to further the understanding of Ag transport through TRISO particles. No silver was observed in SiC grains, but Ag was identified at triple-points and grain boundaries of the SiC layer in the TRISO particle. Cadmium was also found in some of the very same triple junctions, but this could be related to silver behavior as Ag-110m decays to Cd-110. Palladium was identified as the main constituent of micron-sized precipitates present at the SiC grain boundaries and in most SiC grain boundaries and the potential role of Pd in the transport of Ag will be discussed.

  6. UEDGE simulations of He transport in DIII-D progress report FY 1996

    International Nuclear Information System (INIS)

    Fenstermacher, M. E.; Hill, D.N.

    1997-01-01

    In this report we present the status of numerical simulations of helium exhaust efficiency in the DIII-D tokamak. These computations are intended to serve eventually as a benchmark for simulations carried out for the ITER divertor geometry. Helium ash removal is an important issue for ITER since the helium ash can dilute the central fuel concentration and reduce the fusion power. Present experiments have shown that helium transport in the core plasma is sufficiently rapid to limit the ash buildup to acceptable levels if sufficient helium pumping can be maintained in the divertor. The question of pumping helium gas from the divertor has also been addressed in tokamak experiments, where it was found that the helium concentration in the divertor was about 5-10x lower than in the core plasma (deenrichment). Even so, the exhaust rate was adequate to meet the ITER requirements for central helium concentration. However, the experiments did not reproduce the anticipated ITER divertor geometry or operating conditions. Therefore, the predicted helium exhaust for ITER is still based on numerical simulation. In order to increase the confidence level in the simulations of helium exhaust in ITER, we decided to test the ability of the UEDGE code to simulate the measured enrichment of divertor helium in the DIII-D pumping plenum. Section II presents a description of the experimental discharge used for comparison with the present UEDGE simulations. The UEDGE runs which most closely match the data are presented in Section III including simulations with and without carbon impurity. Section IV presents UEDGE simulations of helium transport and comparison with the helium measurements for these discharges. Conclusions and plans for future work, to complete the detailed benchmarking of UEDGE helium transport models, are given in Section V. 6 refs., 26 figs., 1 tab

  7. Use of membrane vesicles as a simplified system for studying auxin transport of auxin: Progress report

    International Nuclear Information System (INIS)

    Goldsmith, M.H.M.

    1986-01-01

    Indoleacetic acid (IAA), the auxin regulating growth, is transported polarly in plants. IAA stimulates a rapid increase in the rate of electrogenic proton secretion by the plasma membrane. This not only increases the magnitude of the pH and electrical gradients providing the driving force for polar auxin transport and uptake of sugars, amino acids and inorganic ions, but, by acidifying the cell wall, also leads to growth. We find that auxin uptake by membrane vesicles isolated from actively growing plant tissues exhibits some of the same properties as by cells: the accumulation depends on the pH gradient, is saturable and specific for auxin, and enhanced by herbicides that inhibit polar auxin transport. We are using accumulation of a radioactive weak acid to quantify the pH gradient and distribution of fluorescent cyanine dyes to monitor the membrane potential. The magnitude of IAA accumulation exceeds that predicted from the pH gradient, and in the absence of a pH gradient, a membrane potential fails to support any auxin accumulation, leading to the conclusion that the transmembrane potential is not a significant driving force for auxin accumulation in this system. Since increasing the external ionic strength decreases saturable auxin accumulation, we are investigating how modifying the surface potential of the vesicles affects the interaction of the amphipathic IAA molecules with the membranes and whether protein modifying reagents affect the saturability and stimulation by NPA. These studies should provide information on the location and function of the auxin binding site and may enable us to identify the solubilized protein. 5 refs

  8. Radiation induced low-energy electron transport in a tissue environment

    International Nuclear Information System (INIS)

    Toburen, L.H.; Dingfelder, M.; Ozturk, N.; Christou, C.; Shinpaugh, J.L.; Friedland, W.; Wilson, W.E.; Paretzke, H.G.

    2003-01-01

    Monte Carlo (MC) track simulation codes are used extensively in radiobiology to quantify the spatial distributions of interactions initiated by the absorption of ionizing radiation. The spatial patterns of ionization and excitation are instrumental for assessing the formation of damage clusters in DNA and chromosomes leading to such biologic endpoints as cellular transformation and mutation. The MC codes rely on an extensive database of elastic and inelastic scattering cross sections to follow the production and slowing of secondary electrons. Because of inherent uncertainties in this database we are exploring the sensitivity of MC results to the details of the cross sections used with emphasis on low-energy electrons, i.e., track ends, that are anticipated to play a dominant role in damage cluster formation. Simulations of electron transport using gas or liquid based interaction cross sections illustrate substantial difference in the spectra of electrons with energies less than about 50 eV. In addition, the electron yields from MC simulations appear to be nearly a factor of five larger than our recent measurements of electron transport spectra in water (ice) at electron energies of about 10 eV. Examples of the changes in electron transport spectra for variations in the electron scattering cross sections used for the MC calculations will be illustrated and compared with an evolving database of measured spectra of electrons from ion induced secondary electron transport in thin foils. These measurements provide guidance for assessment of elastic and elastic cross sections appropriate to condensed phase transport. This work is supported in part by the U.S. Department of Energy, Grant No. DE-FG02-01ER-63233; the National Cancer Institute, Grant No. 1R01CA93351-01A1; and the European Community under Contract No. FIGH-CT-1999-00005

  9. Chinese reference human voxel phantoms for radiation protection: development, application and recent progress

    International Nuclear Information System (INIS)

    Pan Yuxi; Qiu Rui; Ren Li; Zhu Huanjun; Li Junli; Liu Liye

    2014-01-01

    This paper presents the work of constructing Chinese reference human voxel phantoms, taking Chinese reference adult female voxel model for example. In this study, a site-specific skeleton structure was built, some radiation sensitive organs were supplemented. Organ sub-segmentation was taken into account. The constructed phantoms include almost all radiation sensitive organs required by ICRP new recommendation. Masses of the organs are almost consistent with the Chinese reference data within 5%. The Chinese reference human phantoms have been applied both in internal dosimetry and external dosimetry. The results provide fundamental data for Chinese radiation dosimetry. In addition, the newly established detailed breast model and micro-bone model were introduced. (authors)

  10. Effects of gamma radiation on lichens. Progress report, July 1, 1975--March 31, 1976

    International Nuclear Information System (INIS)

    Erbisch, F.H.

    1976-03-01

    This past year (1975) was spent in the completion of a Parmelia sulcata study of the Enterprise Radiation Forest. An extended study (December through June) of irradiated Cladonia sylvatica podetia was also carried out during this period. The Cladonia study indicated that lichens responds to gamma radiation, basically only after passing through a prolonged growth period. Lichens kept in summer conditions (in a growth chamber) during the seven month study period did not exhibit radiation damage as did irradiated field lichens. This was conclusively shown in photosynthesis experiments and light microscopy studies. Evidence from oxygen uptake and usnic acid content studies was much to variable and must be repeated. A means to measure podetial tensile strength was perfected and this test will be used in the final test of this study

  11. Using a progress computer for the direct acquisition and processing of radiation protection data

    International Nuclear Information System (INIS)

    Barz, H.G.; Borchardt, K.D.; Hacke, J.; Kirschfeld, K.E.; Kluppak, B.

    1976-01-01

    A process computer will be used in the Hahn-Meitner-Institute to rationalize radiation protection measures. Appr. 150 transmitters are to be connected with this computer. Especially the radiation measuring devices of a nuclear reactor, of hot cells, and of a heavy ion accelerator, as well as the emission- and environment monitoring systems will be connected. The advantages of this method are described: central data acquisition, central alarm and stoppage information, data processing of certain measurement values, possibility of quick disturbance analysis. Furthermore the authors report about the preparations already finished, particularly about data transmission of digital and analog values to the computer. (orig./HP) [de

  12. Progress of research on cytoskeleton and neural cell migration obstacle induced by ionizing radiation

    International Nuclear Information System (INIS)

    Qiu Jun; Wu Cuiping; Wang Mingming

    2012-01-01

    The dynamic changes of the microtubules and microfilaments provide the main force that drives the normal migration. Biological effects in tissues and cells induced by ionizing radiation are closely correlated with the changes happening to the cytoskeleton. It is that the ionizing radiation can induce the depolymeration of microfilaments and the assembly obstacles of microtubules, and make neural cell incapable of entering the model of migration or abnormally migrate. The effects of relevant changes of the cytoskeleton induced by irradiation on neural cell migration were discussed in this paper. (authors)

  13. Effects of radiation transport on mass ablation rate and conversion efficiency in numerical simulations of inertial confinement fusion

    International Nuclear Information System (INIS)

    Gupta, N.K.

    2002-01-01

    The effects of radiation transport on hydrodynamic parameters of laser produced plasmas are studied. LTE and non-LTE atomic models are used to calculate multi group opacities and emissivities. Screened hydrogenic atom model is used to calculate the energy levels. The population densities of neutral to fully ionized ions are obtained by solving the steady state rate equations. Radiation transport is treated in multi-group diffusion or Sn method. A comparison is made between 1 and 100 group radiation transport and LTE and non-LTE models. For aluminium, multi group radiation transport leads to much higher mass ablation as compared to the 1 group and no radiation transport cases. This in turn leads to higher ablation pressures. However, for gold gray approximation gives higher mass ablation as compared to multi group simulations. LTE conversion efficiency of laser light into x-rays is more than the non-LTE estimates. For LTE as well as non-LTE cases, the one group approximation over-predicts the conversion efficiency Multi group non-LTE simulations predict that the conversion efficiency increases with laser intensity up to a maximum and then it decreases. (author)

  14. Recent progress in the understanding of H transport and trapping in W

    International Nuclear Information System (INIS)

    Schmid, K; Bauer, J; Schwarz-Selinger, T; Toussaint, U v; Manhard, A; Jacob, W; Markelj, S

    2017-01-01

    The retention of hydrogen isotopes (HIs) (H, D and T) in the first, plasma exposed wall is one of the key concerns for the operation of future long pulse fusion devices. It affects the particle-, momentum- and energy balance in the scrape off layer as well as the retention of HIs and their permeation into the coolant. The currently accepted picture that is used for interpreting current laboratory and tokamak experiments is that of diffusion hindered by trapping at lattice defects. This paper summarises recent results that show that this current picture of how HIs are transported and retained in W needs to be extended: the modification of the surface (e.g. blistering) can lead to the formation of fast loss channels for near surface HIs. Trapping at single occupancy traps with fixed de-trapping energy fails to explain isotope exchange experiments, instead a trapping model with multi occupancy traps and fill level dependent de-trapping energies is required. The presence of interstitial impurities like N or C may affect the transport of solute HI. The presence of HIs during damage creation by e.g. neutrons stabilises defects and reduces defect annealing at elevated temperatures. (paper)

  15. Progress on RMC: a Monte Carlo neutron transport code for reactor analysis

    International Nuclear Information System (INIS)

    Wang, Kan; Li, Zeguang; She, Ding; Liu, Yuxuan; Xu, Qi; Shen, Huayun; Yu, Ganglin

    2011-01-01

    This paper presents a new 3-D Monte Carlo neutron transport code named RMC (Reactor Monte Carlo code), specifically intended for reactor physics analysis. This code is being developed by Department of Engineering Physics in Tsinghua University and written in C++ and Fortran 90 language with the latest version of RMC 2.5.0. The RMC code uses the method known as the delta-tracking method to simulate neutron transport, the advantages of which include fast simulation in complex geometries and relatively simple handling of complicated geometrical objects. Some other techniques such as computational-expense oriented method and hash-table method have been developed and implemented in RMC to speedup the calculation. To meet the requirements of reactor analysis, the RMC code has the calculational functions including criticality calculation, burnup calculation and also kinetics simulation. In this paper, comparison calculations of criticality problems, burnup problems and transient problems are carried out using RMC code and other Monte Carlo codes, and the results show that RMC performs quite well in these kinds of problems. Based on MPI, RMC succeeds in parallel computation and represents a high speed-up. This code is still under intensive development and the further work directions are mentioned at the end of this paper. (author)

  16. Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

    Science.gov (United States)

    Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.; hide

    2009-01-01

    Protection of astronauts and instrumentation from galactic cosmic rays (GCR) and solar particle events (SPE) in the harsh environment of space is of prime importance in the design of personal shielding, spacec raft, and mission planning. Early entry of radiation constraints into the design process enables optimal shielding strategies, but demands efficient and accurate tools that can be used by design engineers in every phase of an evolving space project. The radiation transport code , HZETRN, is an efficient tool for analyzing the shielding effectiveness of materials exposed to space radiation. In this paper, HZETRN is compared to the Monte Carlo codes HETC-HEDS and FLUKA, for a shield/target configuration comprised of a 20 g/sq cm Aluminum slab in front of a 30 g/cm^2 slab of water exposed to the February 1956 SPE, as mode led by the Webber spectrum. Neutron and proton fluence spectra, as well as dose and dose equivalent values, are compared at various depths in the water target. This study shows that there are many regions where HZETRN agrees with both HETC-HEDS and FLUKA for this shield/target configuration and the SPE environment. However, there are also regions where there are appreciable differences between the three computer c odes.

  17. Effect of localized surface-plasmon mode on exciton transport and radiation emission in carbon nanotubes.

    Science.gov (United States)

    Roslyak, Oleksiy; Cherqui, Charles; Dunlap, David H; Piryatinski, Andrei

    2014-07-17

    We report on a general theoretical approach to study exciton transport and emission in a single-walled carbon nanotube (SWNT) in the presence of a localized surface-plasmon (SP) mode within a metal nanoparticle interacting via near-field coupling. We derive a set of quantum mechanical equations of motion and approximate rate equations that account for the exciton, SP, and the environmental degrees of freedom. The material equations are complemented by an expression for the radiated power that depends on the exciton and SP populations and coherences, allowing for an examination of the angular distribution of the emitted radiation that would be measured in experiment. Numerical simulations for a (6,5) SWNT and cone-shaped Ag metal tip (MT) have been performed using this methodology. Comparison with physical parameters shows that the near-field interaction between the exciton-SP occurs in a weak coupling regime, with the diffusion processes being much faster than the exciton-SP population exchange. In such a case, the effect of the exciton population transfer to the MT with its subsequent dissipation (i.e., the Förster energy transfer) is to modify the exciton steady state distribution while reducing the equilibration time for excitons to reach a steady sate distribution. We find that the radiation distribution is dominated by SP emission for a SWNT-MT separation of a few tens of nanometers due to the fast SP emission rate, whereas the exciton-SP coherences can cause its rotation.

  18. Current status of radiation transport tools for proliferation and terrorism prevention

    International Nuclear Information System (INIS)

    Sale, K.E.

    2004-01-01

    Full text: We will present the current status and future plans for the set of calculational tools and databases developed and maintained at LLNL. The calculational tools include the Monte Carlo codes TART 1) and COG 2) as well as the deterministic code ARDRA 3) . In addition to these codes we use currently there is a major development effort for a new massively parallel transport code. An important part of the capability we're developing is a sophisticated user interface, based on a commercial 3-D modeling product, to improve the model development process. A major part of this user interface tool is being developed by Strela 4) under the Nuclear Cities Initiative. Strela has developed a hub-and-spoke technology for code input interconversions (between COG, TART and MCNP) and will produce the plug-ins that extend the capabilities of the 3-D modeler for use as a radiation transport input generator. The major advantages of this approach are the built-in user interface for 3-D modeling and the ability to read a large variety of CAD-file formats. In addition to supporting our current radiation transport codes and developing new capabilities we are working on some nuclear data needs for homeland security. These projects are carried out and the Lawrence Berkeley National Laboratory 88' cyclotron and at the Institute for Nuclear Research of the Nation Academy of Science of Ukraine under and STCU contract. Reference: 1. http://www.llnl.gov/cullen1/mc/htm; 2. http://www-phys.llnl.gov/N_Div/COG/ETR/ETR_9306.html; 3. http://www.llnl.gov/CASC/asciturb/talks/PPT-HTML.131596/tsld030.htm; 4. http://strela.snz.ru/

  19. Accumulation and transport of minerals by marine protozoa. Progress report, September 1, 1976--November 30, 1977

    International Nuclear Information System (INIS)

    Gold, K.

    1977-08-01

    Tintinnida are abundant microzooplankton found in all of the world's oceans, and important components of the marine food web as predators, prey, and as regenerators of nutrients. The agglutinated forms take on added importance in coastal waters. Representatives of this group have the unique ability among ciliates to pick up particles from the environment and incorporate them into the lorica. The ecological significance of the phenomenon lies in: it is a pathway whereby radionuclides, metals and other toxic substance can be biologically concentrated and transferred from sediments and the water column to the biota; from the viewpoint of microzooplankton as indicators of environmental perturbations, pollution, or water mass movements, it is important to determine whether minerals accumulated on the lorica can serve as a guide to the site where they originate. Results are reported from studies in progress on the types of mineral matter accumulated by tintinnids

  20. Comparative study of radiation, chemical, and aging effects on viral transformation. Annual progress report, 1975

    International Nuclear Information System (INIS)

    Coggin, J.H. Jr.

    1976-01-01

    Progress is reported on the following research projects: evaluation of isotopic antiglobulin test (IAT) to detect tumor associated antigens using antisera induced by x-irradiated tumor cells; development of cytotoxic antibody for embryonic antigens (EA); acrylamide gel cell culture assay for transformation; and evaluation of 3-MCA induced sarcomas for TSTA and cross-reacting antigens