WorldWideScience

Sample records for shielding experimental results

  1. Shielding in experimental areas

    International Nuclear Information System (INIS)

    Stevens, A.; Tarnopolsky, G.; Thorndike, A.; White, S.

    1979-01-01

    The amount of shielding necessary to protect experimental detectors from various sources of background radiation is discussed. As illustrated an experiment has line of sight to sources extending approx. 90 m upstream from the intersection point. Packing a significant fraction of this space with shielding blocks would in general be unacceptable because primary access to the ring tunnel is from the experimental halls. (1) From basic machine design considerations and the inherent necessity to protect superconducting magnets it is expected that experimental areas in general will be cleaner than at any existing accelerator. (2) Even so, it will likely be necessary to have some shielding blocks available to protect experimental apparatus, and it may well be necessary to have a large amount of shielding available in the WAH. (3) Scraping will likely have some influence on all halls, and retractable apparatus may sometimes be necessary. (4) If access to any tunnel is needed to replace a magnet, one has 96 h (4 days) available to move shielding away to permit access without additional downtime. This (the amount of shielding one can shuffle about in 96 h) is a reasonable upper limit to shielding necessary in a hall

  2. Comparison of MCNP5 and experimental results on neutron shielding effects for materials

    Energy Technology Data Exchange (ETDEWEB)

    Torres, D. A. (Daniel A.); Mosteller, R. D. (Russell D.); Sweezy, J. E. (Jeremy E.)

    2004-01-01

    The MCNP Radiation-Shielding Validation Suite was created to assess the impact on dose rates and attenuation factors of future improvements in the MCNP Monte Carlo code or its nuclear data libraries. However, it does not currently contain any deep-penetration cases. For this reason, a set of deep-penetration benchmarks has been investigated for possible inclusion in the Suite. Overall, the MCNP5 results match the measured values quite well. Furthermore, with the exception of Resin-F, there is no systematic trend in the ratio of calculated to measured results.

  3. Comparison of MCNP4C and experimental results on neutron and gamma ray shielding effects for materials

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Kyoon Ho; Lee, Eun Ki [KEPRI, Taejon (Korea, Republic of)

    2004-07-01

    MCNP code is a general-purpose Monte Carlo radiation transport code that can numerically simulate neutron, photon, and electron transport. Increasing the speed of computing machine is making numerical transport simulation more attractive and has led to the widespread use of such code. This code can be used for general radiation shielding and criticality accident alarm system related dose calculations, so that the version 4C2 of this code was used to evaluate the shielding effect against neutron and gamma ray experiments. The Ueki experiments were used for neutron shielding effects for materials, and the Kansas State University (KSU) photon skyshine experiments of 1977 were tested for gamma ray shielding effects.

  4. Shielding and maintainability in an experimental tokamak

    International Nuclear Information System (INIS)

    Abdou, M.A.; Fuller, G.; Hager, E.R.; Vogelsang, W.F.

    1979-01-01

    This paper presents the results of an attempt to develop an understanding of the various factors involved. This work was performed as a part of the task assigned to one of the expert groups on the International Tokamak Reactor (INTOR). However, the results of this investigation are believed to be generally applicable to the broad class of the next generation of experimental tokamak facilities such as ETF. The shielding penalties for requiring personnel access are quantified. This is followed by a quantitative estimate of the benefits associated with personnel access. The penalties are compared to the benefits and conclusions and recommendations are developed on resolving the issue

  5. Shielding consideration for the SSCL experimental halls

    International Nuclear Information System (INIS)

    Bull, J.; Coyne, J.; Mokhov, N.; Stapleton, G.

    1994-03-01

    The Superconducting Super Collider which is being designed and built in Waxahachie, Texas consists Of series of proton accelerators, culminating in a 20 Te proton on proton collider. The collider will be in a tunnel which will be 87 km in circumference and. on average about 30 meters underground. The present design calls for two large interaction halls on the east side of the ring. The shielding for these halls is being designed for an interaction rate of 10 9 Hz or 10 16 interactions per year, based on 10 7 seconds per operational year. SSC guidelines require that the shielding be designed to meet the criterion of 1mSv per year for open areas off site 2mSv per year for open areas on site, and 2mSv per year for controlled areas. Only radiation workers will be routinely allowed to work in controlled areas. It should be pointed that there is a potential for an accidental full beam loss in either of the experimental halls, and this event would consist of the loss of the full circulating beam up to 4 x 10 14 protons. With the present design. the calculated dose equivalent for this event is about 10% of the annual dose equivalent for the normal p-p interactions, so that die accident condition does not control the shielding. If, for instance, local shielding within the experimental hall is introduced into the calculations, this could change. The shielding requirements presented here are controlled by the normal p-p interactions. Three important questions were addressed in the present calculations. They are (1) the thickness of the roof over the experimental halls, (2) the configuration of the shafts and adits which give access to the halls, and (3) the problem of ground water and air activation

  6. Shielding and maintainability in an experimental tokamak

    International Nuclear Information System (INIS)

    Abdou, M.A.; Fuller, G.; Hager, E.R.; Vogelsang, W.F.

    1979-01-01

    This paper presents the results of an attempt to develop an understanding of the various factors involved. This work was performed as a part of the task assigned to one of the expert groups on the International Tokamak Reactor (INTOR). The shielding penalties for requiring personnel access are quantified. This is followed by a quantitative estimate of the benefits associated with personnel access. The penalties to the benefits and conclusions and recommendations on resolving the issue are discussed

  7. Experimental research of the effects of different shields on power frequency electric field mitigation

    Directory of Open Access Journals (Sweden)

    Nahman Jovan

    2012-01-01

    Full Text Available The paper describes experimental research on the effects of different shields on power frequency electric field mitigation. This research was performed in order to determine those materials that may be used for electric field mitigation in cases where the reference level is exceeded. Using measured results, the value of the shielding factor has been calculated for all tested shields and the most efficient shields were determined.

  8. An experimental study on a superconducting generator with dual machine shield system

    International Nuclear Information System (INIS)

    Ishigohka, T.; Ninomiya, A.; Okada, T.; Nitta, T.; Shintani, T.; Mukai, E.

    1988-01-01

    The authors have studied the optimal machine shield system through experiments on a 20kVa superconducting generator. The first experiment is carried out on a fully iron-less aluminum-shield machine which has only an aluminum eddy current machine shield in the stator. The second experiment is carried out on a generator with a dual-shield system which has both an aluminum eddy current shield and an iron magnetic shield. From the first one, the authors have got an experimental result that the aluminum-shield machine exhibits so large eddy current loss in the shield that it would be difficult to operate the machine continuously. On the other hand, the second experiment shows that the dual-shield machine exhibits much smaller loss in the shielding system, and that it has higher output power than the aluminum-shield machine. From these experiments, it becomes clear that insertion of a very thin iron shield between the armature winding and the eddy current shield can improve the machine performance eminently without large weight increase even if the iron shield were saturated

  9. Alternative methodology for irradiation reactor experimental shielding calculation

    International Nuclear Information System (INIS)

    Vellozo, Sergio de Oliveira; Vital, Helio de Carvalho

    1996-01-01

    Due to a change in the project of the Experimental Irradiation Reactor, its shielding design had to be recalculated according to an alternative simplified analytical approach, since the standard transport calculations were temporarily unavailable. In the calculation of the new width for the shielding made up of steel and high-density concrete layers, the following radiation components were considered: fast neutrons and primary gammas (produced by fission and beta decay), from the core; and secondary gammas, produced by thermal neutron capture in the shielding. (author)

  10. Use of a radio frequency shield during 1.5 and 3.0 Tesla magnetic resonance imaging: experimental evaluation.

    Science.gov (United States)

    Favazza, Christopher P; King, Deirdre M; Edmonson, Heidi A; Felmlee, Joel P; Rossman, Phillip J; Hangiandreou, Nicholas J; Watson, Robert E; Gorny, Krzysztof R

    2014-01-01

    Radiofrequency (RF) shields have been recently developed for the purpose of shielding portions of the patient's body during magnetic resonance imaging (MRI) examinations. We present an experimental evaluation of a commercially available RF shield in the MRI environment. All tests were performed on 1.5 T and 3.0 T clinical MRI scanners. The tests were repeated with and without the RF shield present in the bore, for comparison. Effects of the shield, placed within the scanner bore, on the RF fields generated by the scanner were measured directly using tuned pick-up coils. Attenuation, by as much as 35 dB, of RF field power was found inside the RF shield. These results were supported by temperature measurements of metallic leads placed inside the shield, in which no measurable RF heating was found. In addition, there was a small, simultaneous detectable increase (∼1 dB) of RF power just outside the edges of the shield. For these particular scanners, the autocalibrated RF power levels were reduced for scan locations prescribed just outside the edges of the shield, which corresponded with estimations based on the pick-up coil measurements. Additionally, no significant heating during MRI scanning was observed on the shield surface. The impact of the RF shield on the RF fields inside the magnet bore is likely to be dependent on the particular model of the RF shield or the MRI scanner. These results suggest that the RF shield could be a valuable tool for clinical MRI practices.

  11. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures.

    Science.gov (United States)

    Dickson, E D; Hamby, D M

    2014-03-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building's radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology.

  12. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M

    2014-01-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building’s radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology. (paper)

  13. Use of a radio frequency shield during 1.5 and 3.0 Tesla magnetic resonance imaging: experimental evaluation

    Directory of Open Access Journals (Sweden)

    Favazza CP

    2014-10-01

    Full Text Available Christopher P Favazza, Deirdre M King, Heidi A Edmonson, Joel P Felmlee, Phillip J Rossman, Nicholas J Hangiandreou, Robert E Watson, Krzysztof R Gorny Department of Radiology, Mayo Clinic, Rochester, MN, USA Abstract: Radiofrequency (RF shields have been recently developed for the purpose of shielding portions of the patient's body during magnetic resonance imaging (MRI examinations. We present an experimental evaluation of a commercially available RF shield in the MRI environment. All tests were performed on 1.5 T and 3.0 T clinical MRI scanners. The tests were repeated with and without the RF shield present in the bore, for comparison. Effects of the shield, placed within the scanner bore, on the RF fields generated by the scanner were measured directly using tuned pick-up coils. Attenuation, by as much as 35 dB, of RF field power was found inside the RF shield. These results were supported by temperature measurements of metallic leads placed inside the shield, in which no measurable RF heating was found. In addition, there was a small, simultaneous detectable increase (~1 dB of RF power just outside the edges of the shield. For these particular scanners, the autocalibrated RF power levels were reduced for scan locations prescribed just outside the edges of the shield, which corresponded with estimations based on the pick-up coil measurements. Additionally, no significant heating during MRI scanning was observed on the shield surface. The impact of the RF shield on the RF fields inside the magnet bore is likely to be dependent on the particular model of the RF shield or the MRI scanner. These results suggest that the RF shield could be a valuable tool for clinical MRI practices. Keywords: radiofrequency shield, magnetic resonance imaging, radiofrequency attenuation

  14. Dose rate reduction using epoxy mixed lead shielding: experimental and theoretical determination of its shielding effectiveness

    International Nuclear Information System (INIS)

    Yadav, R.K.B.; Prasad, S.K.; Babu, K.S.; Hardiya, M.R.; Ullas, O.P.

    2010-01-01

    Full text: High background radiation field exists in Water Treatment Area (WTA) of Rod Cutting Building (RCB) in Cirus due to beta, gamma contamination on its floor. The high contamination on sides of wall and on floor is primarily due to deposition of activity generated during the regeneration of old mixed bed cartridges earlier (before year 1985) and presently due to deposition of contaminants by sump overflowing, wastes generated during maintenance/servicing of circulating pumps. RCB-WTA contribution to collective dose in present situation is up to 30% of the total collective dose of Cirus. Various options such as chipping of top layer of concrete floor of a sample area, in-situ placing of slab of cement and lead shot mixture were considered. In this case the man-rem consumption was high as radiation dose rate on concrete chip was 0.4 mGy/h and air activity generated was high, that too long lived with 137 Cs-as main constituent. The dose reduction factor was 1.7. In the second option the reduction in dose rate was insignificant and in-situ pouring of concrete consumed high collective dose. Hence above two options were not acceptable. Therefore the idea of tiling the contaminated floor with prefabricated epoxy mixed lead shots was accepted from ALARA point of view. It was concluded that pre-fabricated slabs of epoxy mixed lead slab of 25 mm thickness can be laid in RCB area to achieve a dose rate reduction factor of approximately five at a height of 30 cm above floor. This will result in a reduction of Person-mSv consumption in RCB by a factor of 5-10. These slabs of different thickness were fabricated outside RCB and were tested for shielding effectiveness experimentally by using radiation source and theoretically using MCNP code. Dose reduction factor of five for a point source, obtained experimentally for epoxy mixed lead shots was very near to value obtained by theoretical simulation. An extended calculation for an area source using this MCNP model gives a

  15. Majorana Thermosyphon Prototype Experimental Results

    International Nuclear Information System (INIS)

    Fast, James E.; Reid, Douglas J.; Aguayo Navarrete, Estanislao

    2010-01-01

    The Majorana demonstrator will operate at liquid Nitrogen temperatures to ensure optimal spectrometric performance of its High Purity Germanium (HPGe) detector modules. In order to transfer the heat load of the detector module, the Majorana demonstrator requires a cooling system that will maintain a stable liquid nitrogen temperature. This cooling system is required to transport the heat from the detector chamber outside the shield. One approach is to use the two phase liquid-gas equilibrium to ensure constant temperature. This cooling technique is used in a thermosyphon. The thermosyphon can be designed so the vaporization/condensing process transfers heat through the shield while maintaining a stable operating temperature. A prototype of such system has been built at PNNL. This document presents the experimental results of the prototype and evaluates the heat transfer performance of the system. The cool down time, temperature gradient in the thermosyphon, and heat transfer analysis are studied in this document with different heat load applied to the prototype.

  16. Experimental analysis of an MIM capacitor with a concave shield

    International Nuclear Information System (INIS)

    Liu Lintao; Yu Mingyan; Wang Jinxiang

    2009-01-01

    A novel shielding scheme is developed by inserting a concave shield between a metal-insulator-metal (MIM) capacitor and the silicon substrate. Chip measurements reveal that the concave shield improves the quality factor by 11% at 11.8 GHz and 14% at 18.8 GHz compared with an unshielded MIM capacitor. It also alleviates the effect on shunt capacitance between the bottom plate of the MIM capacitor and the shield layer. Moreover, because the concave shields simplify substrate modeling, a simple circuit model of the MIM capacitor with concave shield is presented for radio frequency applications.

  17. Gamma ray shielding study of barium-bismuth-borosilicate glasses as transparent shielding materials using MCNP-4C code, XCOM program, and available experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Reza; Yousefinia, Hassan [Nuclear Fuel Cycle Research School (NFCRS), Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Moghaddam, Alireza Khorrami [Radiology Department, Paramedical Faculty, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)

    2017-02-15

    In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

  18. Gamma Ray Shielding Study of Barium–Bismuth–Borosilicate Glasses as Transparent Shielding Materials using MCNP-4C Code, XCOM Program, and Available Experimental Data

    Directory of Open Access Journals (Sweden)

    Reza Bagheri

    2017-02-01

    Full Text Available In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium–bismuth–borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium–bismuth–borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

  19. Report of the AGS Experimental Area Shielding Upgrade Committee

    International Nuclear Information System (INIS)

    Beavis, D.; Brown, H.N.; Bunce, G.; Carroll, A.S.; Chiang, I.H.; Glenn, J.W.; Lazarus, D.M.; Lessard, E.; Pendzick, A.; Sims, W.; Woodle, K.

    1990-08-01

    The proton intensity delivered to the AGS experimental areas is expected to increase fourfold when the full potential of the Booster is realized. It is therefore necessary to anticipate the modifications to the shielding and radiation monitoring that will be required in order to insure safe operation within the appropriate guidelines for radiation exposure. This report examines the consequences of site boundary requirements and soil and air activation as well as the protection of radiation workers, i.e., AGS personnel and experimenters, from unnecessary radiation exposure in the experimental areas. Where possible, Health Physics surveys and fault studies carried out in the Spring of 1990 have been used to estimate levels in and around the experimental areas with 5 x 10 13 protons per pulse or 75% of the total anticipated intensity delivered to each of the target stations under ''normal'' as well as fault conditions. Where fault studies were not possible due to construction, the new beams and facilities were designed for the higher intensities that will be available and radiation patterns were calculated. Weak spots were identified and improvements recommended. Capital and manpower estimates were developed for the upgrades. 7 refs

  20. Test program element II blanket and shield thermal-hydraulic and thermomechanical testing, experimental facility survey

    International Nuclear Information System (INIS)

    Ware, A.G.; Longhurst, G.R.

    1981-12-01

    This report presents results of a survey conducted by EG and G Idaho to determine facilities available to conduct thermal-hydraulic and thermomechanical testing for the Department of Energy Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program. In response to EG and G queries, twelve organizations (in addition to EG and G and General Atomic) expressed interest in providing experimental facilities. A variety of methods of supplying heat is available

  1. Test program element II blanket and shield thermal-hydraulic and thermomechanical testing, experimental facility survey

    Energy Technology Data Exchange (ETDEWEB)

    Ware, A.G.; Longhurst, G.R.

    1981-12-01

    This report presents results of a survey conducted by EG and G Idaho to determine facilities available to conduct thermal-hydraulic and thermomechanical testing for the Department of Energy Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program. In response to EG and G queries, twelve organizations (in addition to EG and G and General Atomic) expressed interest in providing experimental facilities. A variety of methods of supplying heat is available.

  2. Experimental simulation and numerical modeling of vapor shield formation and divertor material erosion for ITER typical plasma disruptions

    International Nuclear Information System (INIS)

    Wuerz, H.; Arkhipov, N.I.; Bakhtin, V.P.; Konkashbaev, I.; Landman, I.; Safronov, V.M.; Toporkov, D.A.; Zhitlukhin, A.M.

    1995-01-01

    The high divertor heat load during a tokamak plasma disruption results in sudden evaporation of a thin layer of divertor plate material, which acts as vapor shield and protects the target from further excessive evaporation. Formation and effectiveness of the vapor shield are theoretically modeled and are experimentally analyzed at the 2MK-200 facility under conditions simulating the thermal quench phase of ITER tokamak plasma disruptions. ((orig.))

  3. Experimental validation of thermal design of top shield for a pool type SFR

    International Nuclear Information System (INIS)

    Aithal, Sriramachandra; Babu, V. Rajan; Balasubramaniyan, V.; Velusamy, K.; Chellapandi, P.

    2016-01-01

    Highlights: • Overall thermal design of top shield in a SFR is experimentally verified. • Air jet cooling is effective in ensuring the temperatures limits for top shield. • Convection patterns in narrow annulus are in line with published CFD results. • Wire mesh insulation ensures gradual thermal gradient at top portion of main vessel. • Under loss of cooling scenario, sufficient time is available for corrective action. - Abstract: An Integrated Top Shield Test Facility towards validation of thermal design of top shield for a pool type SFR has been conceived, constructed & commissioned. Detailed experiments were performed in this experimental facility having full-scale features. Steady state temperature distribution within the facility is measured for various heater plate temperatures in addition to simulating different operating states of the reactor. Following are the important observations (i) jet cooling system is effective in regulating the roof slab bottom plate temperature and thermal gradient across roof slab simulating normal operation of reactor, (ii) wire mesh insulation provided in roof slab-main vessel annulus is effective in obtaining gradual thermal gradient along main vessel top portion and inhibiting the setting up of cellular convection within annulus and (iii) cellular convection with four distinct convective cells sets in the annular gap between roof slab and small rotatable plug measuring ∼ϕ4 m in diameter & gap width varying from 16 mm to 30 mm. Repeatability of results is also ensured during all the above tests. The results presented in this paper is expected to provide reference data for validation of thermal hydraulic models in addition to serving as design validation of jet cooling system for pool type SFR.

  4. Experimental Studies on Shadow Shields for Thermal Protection of Cryogenic Tanks in Space

    National Research Council Canada - National Science Library

    Knoll, Richard

    1968-01-01

    ... (high-emissivity coatings on annular rings of shields) on thermal performance. The experimental data, in general, agreed closely with an analytical model which assumed diffuse surfaces with nonuniform radiosity...

  5. EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

    International Nuclear Information System (INIS)

    Reid, Robert S.; Pearson, J. Bosie; Stewart, Eric T.

    2007-01-01

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  6. EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    REID, ROBERT S. [Los Alamos National Laboratory; PEARSON, J. BOSIE [Los Alamos National Laboratory; STEWART, ERIC T. [Los Alamos National Laboratory

    2007-01-16

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  7. Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

    International Nuclear Information System (INIS)

    Pearson, J. Boise; Stewart, Eric T.; Reid, Robert S.

    2007-01-01

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 deg. C. The CFD model with 1/6-g predicts a maximum water temperature of 88 deg. C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield

  8. Experimental and numerical study of the pressure drop for ITER blanket shield block

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Min-Su; Kim, Sawoong; Jung, Hun-Chea; Shim, Hee-Jin; Ahn, Hee-Jae

    2016-11-01

    Highlights: • The results of the experiment and the numerical analysis are compared. • The numerical analysis results are lower than the experimental results. • The margin of the pressure drop is suggested. - Abstract: The blanket shield block (SB) is located inside the ITER vacuum chamber, and the main function is to provide the thermal and nuclear shielding to the vacuum vessel and external components. The SB is foreseen to undergo a significant heat load which is a body load throughout the whole thickness of the SB under normal operation conditions. Therefore, the cooling configuration in SB should be designed very carefully based on the various experiences. The pressure drop in the cooling design is one of the most important factors to balance a water distribution of overall blanket cooling system. In order to verify the pressure drop characteristic and validate the design methodology of SB, experiment and numerical analysis are performed and compared their results. These results would be a benchmarking of the numerical results with experimental results to assess the gap between calculations and experiments.

  9. Validation of PHITS Spallation Models from the Perspective of the Shielding Design of Transmutation Experimental Facility

    Science.gov (United States)

    Iwamoto, Hiroki; Meigo, Shin-ichiro

    2017-09-01

    The impact of different spallation models implemented in the particle transport code PHITS on the shielding design of Transmutation Experimental Facility is investigated. For 400-MeV proton incident on a lead-bismuth eutectic target, an effective dose rate at the end of a thick radiation shield (3-m-thick iron and 3-m-thick concrete) calculated by the Liège intranuclear cascade (INC) model version 4.6 (INCL4.6) coupled with the GEMcode (INCL4.6/GEM) yields about twice as high as the Bertini INC model (Bertini/GEM). A comparison with experimental data for 500-MeV proton incident on a thick lead target suggest that the prediction accuracy of INCL4.6/GEM would be better than that of Bertini/GEM. In contrast, it is found that the dose rates in beam ducts in front of targets calculated by the INCL4.6/GEMare lower than those by the Bertini/GEM. Since both models underestimate the experimental results for neutron-production doubledifferential cross sections at 180° for 140-MeV proton incident on carbon, iron, and gold targets, it is concluded that it is necessary to allow a margin for uncertainty caused by the spallation models, which is a factor of two, in estimating the dose rate induced by neutron streaming through a beam duct.

  10. New particles: experimental results

    International Nuclear Information System (INIS)

    Augustin, J.E.

    The results of studies on production and properties of psi(3100) and psi(3700) resonances are presented, particular attention being given to spin, parity, g-parity and isospin determination. Evidence obtained in the SPEAR and DORIS storage rings in psi'→γ chi and psi→γX intermediate states are presented, together with SPEAR results on e-μ events and high energy jet production. (39 references) [fr

  11. Plan Merging : Experimental results

    NARCIS (Netherlands)

    De Weerdt, M.M.; Van der Krogt, R.P.J.; Zutt, J.

    2003-01-01

    In this paper we discuss the results of a plan merging algorithm. This algorithm coordinates the plans of multiple, autonomous agents, each able to independently find a plan. This algorithm is evaluated using realistic data from a taxi company. We show that when we allow passengers to be a few

  12. Experimental results from Stripa

    International Nuclear Information System (INIS)

    Hood, M.

    1979-06-01

    The results indicate that the temperature fields in a rock mass containing geologic discontinuities can be predicted accurately using the simple theory of heat conduction. Geologic discontinuities appear to introduce significant nonlinear thermomechanical deformation into the rock mass, as a result of which the thermally induced displacements are much less than those predicted by the simple theory of thermo-elasticity. In addition, the assumption that the rock properties are temperature independent appears to increase the values predicted for these displacements significantly. Therefore, it is important that the temperature dependence of these properties is known and that these values be used in the calculations. The onset of significant thermal spalling along the walls of the heater boreholes appears to be related to conditions where the maximum induced compressive stress exceeds the uniaxial compressive strength of the rock. 7 figures

  13. PDX experimental results

    International Nuclear Information System (INIS)

    Meade, D.; Arunasalam, V.; Barnes, C.

    1981-01-01

    During the initial period of operation PDX has obtained the following results: (a) Production of macroscopically stable poloidal divertor configurations with dee, inverse-dee and single null plasma shapes. (b) Determined vertical positional instability growth rates for passively stabilized elongated dee-shaped plasmas with surface elongations from 1 to 1.4. (c) Production of Z approximately equal to 1 plasmas in a diverted dee configuration with confinement times approaching 80 ms for plasmas with Isub(p) approximately equal to 300 kA, Bsub(T)=17 kG, a=38 cm, q approximately equal to 3 and anti nsub(e) approximately equal to 4x10 13 cm -3 . (d) Extended the Ohmic heating regime to q approximately equal to 2 at nsub(e)R/Bsub(T) approximately equal to 10 15 cm -2 T -1 and q approximately equal to 3 at anti nsub(e)R/Bsub(T) approximately equal to 4.5x10 15 cm -2 T -1 . Neutral beam injection has extended anti nsub(e)R/Bsub(T) to approximately 6x10 15 cm -2 T -1 . (e) Initial neutral beam injection experiments with 1-2 MW injected perpendicularly have been used to study ion and electron heating with divertor control of density and impurities. (f) Divertor physics studies indicate that the divertor captures approximately 70% of the input power, while approximately 30% of the power is radiated. (g) Particle and energy flow onto the divertor neutralizer plate is in qualitative agreement with a simple sheath model. (author)

  14. Shielding analysis method applied to nuclear ship 'MUTSU' and its evaluation based on experimental analyses

    International Nuclear Information System (INIS)

    Yamaji, Akio; Miyakoshi, Jun-ichi; Iwao, Yoshiaki; Tsubosaka, Akira; Saito, Tetsuo; Fujii, Takayoshi; Okumura, Yoshihiro; Suzuoki, Zenro; Kawakita, Takashi.

    1984-01-01

    Procedures of shielding analysis are described which were used for the shielding modification design of the Nuclear Ship ''MUTSU''. The calculations of the radiation distribution on board were made using Sn codes ANISN and TWOTRAN, a point kernel code QAD and a Monte Carlo code MORSE. The accuracies of these calculations were investigated through the analysis of various shielding experiments: the shield tank experiment of the Nuclear Ship ''Otto Hahn'', the shielding mock-up experiment for ''MUTSU'' performed in JRR-4, the shielding benchmark experiment using the 16 N radiation facility of AERE Harwell and the shielding effect experiment of the ship structure performed in the training ship ''Shintoku-Maru''. The values calculated by the ANISN agree with the data measured at ''Otto Hahn'' within a factor of 2 for fast neutrons and within a factor of 3 for epithermal and thermal neutrons. The γ-ray dose rates calculated by the QAD agree with the measured values within 30% for the analysis of the experiment in JRR-4. The design values for ''MUTSU'' were determined in consequence of these experimental analyses. (author)

  15. Evaluation of the radiation field and shielding assessment of the experimental area of HIE-ISOLDE

    International Nuclear Information System (INIS)

    Romanets, Y.; Goncalves, I.F.; Maria, S. di; Vaz, P.; Vollaire, J.; Bernardes, A.P.; Dorsival, A.; Kadi, Y.; Vlachoudis, V.

    2014-01-01

    The ISOLDE facility at CERN is one of the first facilities in the world dedicated to the production of the radioactive ion beams (RIB) and during all its working time underwent several upgrades. The goal of the latest proposed upgrade, 'The High Intensity and Energy ISOLDE' (HIE-ISOLDE), is to provide a higher performance facility in order to approximate it to the level of the next generation ISOL facilities, like EURISOL. The HIE-ISOLDE aims to improve significantly the quality of the produced RIB and for this reason the increasing of the primary beam power is one of the main objectives of the project. An increase in the nominal beam current (from 2 to 6 μA proton beam intensity) and energy (from 1.4 GeV to 2 GeV) of the primary proton beam will be possible due to the upgrade of CERN's accelerator infrastructure. The current upgrade means reassessment of the radiation protection and the radiation safety of the facility. However, an evaluation of the existing shielding configuration and access restrictions to the experimental and supply areas must be carried out. Monte Carlo calculations were performed in order to evaluate the radiation protection of the facility as well as radiation shielding assessment and design. The FLUKA-Monte Carlo code was used in this study to calculate the ambient dose rate distribution and particle fluxes in the most important areas, such as the experimental hall of the facility. The results indicate a significant increase in the ambient dose equivalent rate in some areas of the experimental hall when an upgrade configuration of the primary proton beam is considered. Special attention is required for the shielding of the target area once it is the main and very intensive radiation source, especially under the upgrade conditions. In this study, the access points to the beam extraction and beam maintenance areas, such as the mass separator rooms and the high voltage room, are identified as the most sensitive for the experimental hall from

  16. Evaluation of the shield calculation adequacy of radiotherapy rooms through Monte Carlo Method and experimental measures

    International Nuclear Information System (INIS)

    Meireles, Ramiro Conceicao

    2016-01-01

    The shielding calculation methodology for radiotherapy services adopted in Brazil and in several countries is that described in publication 151 of the National Council on Radiation Protection and Measurements (NCRP 151). This methodology however, markedly employs several approaches that can impact both in the construction cost and in the radiological safety of the facility. Although this methodology is currently well established by the high level of use, some parameters employed in the calculation methodology did not undergo to a detailed assessment to evaluate the impact of the various approaches considered. In this work the MCNP5 Monte Carlo code was used with the purpose of evaluating the above mentioned approaches. TVLs values were obtained for photons in conventional concrete (2.35g / cm 3 ), considering the energies of 6, 10 and 25 MeV, respectively, first considering an isotropic radiation source impinging perpendicular to the barriers, and subsequently a lead head shielding emitting a shaped beam, in the format of a pyramid trunk. Primary barriers safety margins, taking in account the head shielding emitting photon beam pyramid-shaped in the energies of 6, 10, 15 and 18 MeV were assessed. A study was conducted considering the attenuation provided by the patient's body in the energies of 6,10, 15 and 18 MeV, leading to new attenuation factors. Experimental measurements were performed in a real radiotherapy room, in order to map the leakage radiation emitted by the accelerator head shielding and the results obtained were employed in the Monte Carlo simulation, as well as to validate the entire study. The study results indicate that the TVLs values provided by (NCRP, 2005) show discrepancies in comparison with the values obtained by simulation and that there may be some barriers that are calculated with insufficient thickness. Furthermore, the simulation results show that the additional safety margins considered when calculating the width of the primary

  17. Experimental and Theoretical Investigations of Ferro Boron as In-vessel Shield Material in FBRs

    International Nuclear Information System (INIS)

    Keshavamurthy, R.S.; Raju, S.; Anthonysamy, S.; Murugan, S.; Sunil Kumar, D.; Rajan Babu, V.; Ravi Chandar, S.C.; Venkiteswaran, C.N.; Chetal, S.C.

    2013-01-01

    Neutron attenuation characteristics of Ferroboron has been investigated both theoretically and experimentally and Fe-B has been found to be favourable for use in FBRs. • Its use will result in significant savings in cost, without impairing shielding capabilities. • Extensive and in-depth out of pile characterization thermophysical properties and high temperature metallurgial compatibility tests with SS 304L clad were carried out. These as well as effects studied of interaction of sodium and Fe-B together on clad at high temparatures show excellent compatibility with clad. • Design of two types Ferro-Boron capsules was done for conducting an irradiation test in FBTR simulating 60 years of neutron fluence in FBRs, • Fabrication of the capsules was successfully carried out. • The capsule was loaded in FBTR and the capsule has been discharged after the intended 45 days of irradiation. • Post Irradiation Examination will be carried out to look for any possible effect due to irradiation

  18. Use of lead shielding on pregnant patients undergoing CT scans: Results of an international survey

    Energy Technology Data Exchange (ETDEWEB)

    Iball, Gareth R., E-mail: gri@medphysics.leeds.ac.u [Department of Medical Physics and Engineering, Old Medical School, Leeds General Infirmary, Leeds, W. Yorkshire LS1 3EX (United Kingdom); Brettle, David S. [Department of Medical Physics and Engineering, Old Medical School, Leeds General Infirmary, Leeds, W. Yorkshire LS1 3EX (United Kingdom)

    2011-05-15

    Aim: An online survey has been used to assess the use of abdominal lead shielding on pregnant patients undergoing CT scans. The aim of the study was to identify potential geographical variations in the use of such shielding as well as the opinions of the users in terms of the weight, manoeuvrability and ergonomics of the lead shields. Materials and methods: The online questionnaire was distributed to CT Radiographers in the UK, Europe, North America and Australia and responses were gathered electronically over a six month period. All completed responses were downloaded and subsequently analysed for each geographical region. Results: In total, 390 completed questionnaires were received with over 100 from each of the UK, North America and Australia. The use of lead shielding was found to vary significantly across the globe with the highest usage in North America (94.5%) and the lowest usage in Europe (46.3%). Approximately 20% of all respondents said that they experienced occupationally related back pain and 25% of all respondents said that patients complained about the weight of the shielding. Conclusion: Significant geographical variations in both the use of lead shielding for foetal radiation protection and the users' opinions of the shielding devices that are used have been identified and it has become clear that existing shielding solutions are not optimised for this task.

  19. Active shield technology for space craft protection revisited in new laboratory results and analysis

    Science.gov (United States)

    Bamford, R.; Gibson, K. J.; Thornton, A. T.; Bradford, J.; Bingham, R.; Gargate, L.; Silva, L. O.; Fonseca, R. A.; Hapgood, M.; Norberg, C.; Todd, T.; Stamper, R.

    2009-04-01

    Energetic ions in the solar wind plasma are a known hazard to both spacecraft electronics and to astronaut's health. Of primary concern is the exposure to keV--MeV protons on manned space flights to the Moon and Mars that extend over long periods of time. Attempts to protect the spacecraft include active shields that are reminiscent of Star Trek "deflector" shields. Here we describe a new experiment to test the shielding concept of a dipole-like magnetic field and plasma, surrounding the spacecraft forming a "mini magnetosphere". Initial laboratory experiments have been conducted to determine the effectiveness of a magnetized plasma barrier to be able to expel an impacting, low beta, supersonic flowing energetic plasma representing the Solar Wind. Optical and Langmuir probe data of the plasma density, the plasma flow velocity, and the intensity of the dipole field clearly show the creation of a narrow transport barrier region and diamagnetic cavity virtually devoid of energetic plasma particles. This demonstrates the potential viability of being able to create a small "hole" in a Solar Wind plasma, of the order of the ion Larmor orbit width, in which an inhabited spacecraft could reside in relative safety. The experimental results have been quantitatively compared to a 3D particle-in-cell ‘hybrid' code simulation that uses kinetic ions and fluid electrons, showing good qualitative agreement and excellent quantitative agreement. Together the results demonstrate the pivotal role of particle kinetics in determining generic plasma transport barriers. [1] [1] R Bamford et al., "The interaction of a flowing plasma with a dipole magnetic field: measurements and modelling of a diamagnetic cavity relevant to spacecraft protection." 2008 Plasma Phys. Control. Fusion 50 124025 (11pp) doi: 10.1088/0741-3335/50/12/124025

  20. Comparison of experimental and calculated shielding factors for modular buildings in a radioactive fallout scenario

    DEFF Research Database (Denmark)

    Hinrichsen, Yvonne; Finck, Robert; Östlund, Karl

    2018-01-01

    building used was a standard prefabricated structure obtained from a commercial manufacturer. Four reference positions for the gamma radiation detectors were used inside the building. Theoretical dose rate calculations were performed using the Monte Carlo code MCNP6, and additional calculations were......Experimentally and theoretically determined shielding factors for a common light construction dwelling type were obtained and compared. Sources of the gamma-emitting radionuclides 60Co and 137Cs were positioned around and on top of a modular building to represent homogeneous fallout. The modular...... performed that compared the shielding factor for 137Cs and 134Cs. This work demonstrated the applicability of using MCNP6 for theoretical calculations of radioactive fallout scenarios. Furthermore, the work showed that the shielding effect for modular buildings is almost the same for 134Cs as for 137Cs....

  1. Numerical modeling and experimental simulation of vapor shield formation and divertor material erosion for ITER typical plasma disruptions

    International Nuclear Information System (INIS)

    Wuerz, H.; Arkhipov, N.I.; Bakhin, V.P.; Goel, B.; Hoebel, W.; Konkashbaev, I.; Landman, I.; Piazza, G.; Safronov, V.M.; Sherbakov, A.R.; Toporkov, D.A.; Zhitlukhin, A.M.

    1994-01-01

    The high divertor heat load during a tokamak plasma disruption results in sudden evaporation of a thin layer of divertor plate material, which acts as vapor shield and protects the target from further excessive evaporation. Formation and effectiveness of the vapor shield are theoretically modeled and experimentally investigated at the 2MK-200 facility under conditions simulating the thermal quench phase of ITER tokamak plasma disruptions. In the optical wavelength range C II, C III, C IV emission lines for graphite, Cu I, Cu II lines for copper and continuum radiation for tungsten samples are observed in the target plasma. The plasma expands along the magnetic field lines with velocities of (4±1)x10 6 cm/s for graphite and 10 5 cm/s for copper. Modeling was done with a radiation hydrodynamics code in one-dimensional planar geometry. The multifrequency radiation transport is treated in flux limited diffusion and in forward reverse transport approximation. In these first modeling studies the overall shielding efficiency for carbon and tungsten defined as ratio of the incident energy and the vaporization energy for power densities of 10 MW/cm 2 exceeds a factor of 30. The vapor shield is established within 2 μs, the power fraction to the target after 10 μs is below 3% and reaches in the stationary state after about 20 μs a value of around 1.5%. ((orig.))

  2. Neutronics model of the bulk shielding reactor (BSR): validation by comparison of calculations with the experimental measurements

    International Nuclear Information System (INIS)

    Johnson, J.O.; Miller, L.F.; Kam, F.B.K.

    1981-05-01

    A neutronics model for the Oak Ridge National Laboratory Bulk Shielding Reactor (ORNL-SAR) was developed and verified by experimental measurements. A cross-section library was generated from the 218 group Master Library using the AMPX Block Code system. A series of one-, two-, and three-dimensional neutronics calculations were performed utilizing both transport and diffusion theory. Spectral comparison was made with 58 Ni(n,p) reaction. The results of the comparison between the calculational model and other experimental measurements showed agreement within 10% and therefore the model was determined to be adequate for calculating the neutron fluence for future irradiation experiments in the ORNL-BSR

  3. Neutronics model of the bulk shielding reactor (BSR): validation by comparison of calculations with the experimental measurements

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.O.; Miller, L.F.; Kam, F.B.K.

    1981-05-01

    A neutronics model for the Oak Ridge National Laboratory Bulk Shielding Reactor (ORNL-SAR) was developed and verified by experimental measurements. A cross-section library was generated from the 218 group Master Library using the AMPX Block Code system. A series of one-, two-, and three-dimensional neutronics calculations were performed utilizing both transport and diffusion theory. Spectral comparison was made with /sup 58/Ni(n,p) reaction. The results of the comparison between the calculational model and other experimental measurements showed agreement within 10% and therefore the model was determined to be adequate for calculating the neutron fluence for future irradiation experiments in the ORNL-BSR.

  4. Experimental verification of photon: A program for use in x-ray shielding calculations

    International Nuclear Information System (INIS)

    Brauer, E.; Thomlinson, W.

    1987-01-01

    At the National Synchrotron Light Source, a computer program named PHOTON has been developed to calculate radiation dose values around a beam line. The output from the program must be an accurate guide to beam line shielding. To test the program, a series of measurements of radiation dose were carried out using existing beam lines; the results were compared to the theoretical calculations of PHOTON. Several different scattering geometries, scattering materials, and sets of walls and shielding materials were studied. Results of the measurements allowed many advances to be made in the program, ultimately resulting in good agreement between the theory and experiment. 3 refs., 6 figs

  5. Experimental results obtained at GANIL

    International Nuclear Information System (INIS)

    Borrel, V.

    1993-01-01

    A review of experimental results obtained at GANIL on the study of nuclear structure and nuclear reactions with secondary radioactive beams is presented. Mass measurements by means of the GANIL cyclotrons are described. The possibilities of GANIL/LISE3 for the production and separation of radioactive beams are illustrated through a large variety of experiments. (author). 19 refs., 8 figs

  6. Nuclear design of the blanket/shield system for a Tokamak Experimental Power Reactor

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1976-01-01

    The various options and trade-offs in the nuclear design of the blanket/shield for a Tokamak Experimental Power Reactor (TEPR) are investigated. The TEPR size and cost are particularly sensitive to the blanket/shield thickness, Δ/sub BS/, on the inner side of the torus. Radition damage to the components of the superconducting magnet and refrigeration power requirements set lower limits on Δ/sub BS/. These limits are developed in terms of TEPR design parameters such as the wall loading, duty cycle, and frequency of magnet anneals. The study of the nuclear performance of various material compositions shows that mixtures of tungsten, or tantalum, or stainless-steel alloys and boron carbide require the smallest Δ/sub BS/ for a given attenuation. This Δ/sub BS/ has to be doubled if the low induced activation materials graphite and aluminum are used. The space problems are greatly eased in the Argonne National Laboratory ANL-TEPR reference design by using two separate segments of the blanket/shield. The inner segment occupies the region of the high magnetic field, uses very efficient attenuators (tungsten- or tantalum- or stainless-steel-boron carbide mixtures), and is only 1 m thick. The outer blanket/shield is 131 cm and consists of an optimized composition of stainless steel and boron carbide. For the design parameters of 0.2 MW/m 2 neutron wall loading and 50 percent duty cycle, the reactor components can operate satisfactorily up to (a) 10 yr for the stainless-steel first wall, (b) 10 yr for the superconductor composite after which magnet warmup becomes necessary, and (c) 30 yr for the Mylar insulation. Nuclear heat generation rates in the blanket/shield and magnet are well within the practical limits for heat removal

  7. Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study. Phase I

    Science.gov (United States)

    Thibeault, Sheila A.; Fay, Catharine C.; Lowther, Sharon E.; Earle, Kevin D.; Sauti, Godfrey; Kang, Jin Ho; Park, Cheol; McMullen, Amelia M.

    2012-01-01

    The key objectives of this study are to investigate, both computationally and experimentally, which forms, compositions, and layerings of hydrogen, boron, and nitrogen containing materials will offer the greatest shielding in the most structurally robust combination against galactic cosmic radiation (GCR), secondary neutrons, and solar energetic particles (SEP). The objectives and expected significance of this research are to develop a space radiation shielding materials system that has high efficacy for shielding radiation and that also has high strength for load bearing primary structures. Such a materials system does not yet exist. The boron nitride nanotube (BNNT) can theoretically be processed into structural BNNT and used for load bearing structures. Furthermore, the BNNT can be incorporated into high hydrogen polymers and the combination used as matrix reinforcement for structural composites. BNNT's molecular structure is attractive for hydrogen storage and hydrogenation. There are two methods or techniques for introducing hydrogen into BNNT: (1) hydrogen storage in BNNT, and (2) hydrogenation of BNNT (hydrogenated BNNT). In the hydrogen storage method, nanotubes are favored to store hydrogen over particles and sheets because they have much larger surface areas and higher hydrogen binding energy. The carbon nanotube (CNT) and BNNT have been studied as potentially outstanding hydrogen storage materials since 1997. Our study of hydrogen storage in BNNT - as a function of temperature, pressure, and hydrogen gas concentration - will be performed with a hydrogen storage chamber equipped with a hydrogen generator. The second method of introducing hydrogen into BNNT is hydrogenation of BNNT, where hydrogen is covalently bonded onto boron, nitrogen, or both. Hydrogenation of BN and BNNT has been studied theoretically. Hyper-hydrogenated BNNT has been theoretically predicted with hydrogen coverage up to 100% of the individual atoms. This is a higher hydrogen content

  8. The Bigfoot Drive; Experimental Results

    Science.gov (United States)

    Baker, Kevin; Thomas, Cliff; Khan, Shahab; Casey, Daniel; Spears, Brian; Nora, Ryan; Munro, Davis; Eder, David; Milovich, Jose; Berger, Dick; Strozzi, David; Goyon, Clement; Turnbull, David; Ma, Tammy; Izumi, Nobuhiko; Benedetti, Robin; Millot, Marius; Celliers, Peter; Yeamans, Charles; Hatarik, Robert; Landen, Nino; Hurricane, Omar; Callahan, Debbie

    2016-10-01

    The Bigfoot platform was developed on the National Ignition Facility to investigate low convergence, high adiabat, high rhoR hotspot implosions. This platform was designed to be less susceptible to wall motion, LPI and CBET and to be more robust against capsule hydrodynamic instabilities. To date experimental studies have been carried out at two hohlraum scales, a 5.75 and 5.4 mm diameter hohlraum. We will present experimental results from these tuning campaigns including the shape vs. cone fraction, surrogacy comparisons of self-emission from the capsules vs. radiography of the imploding capsule and doped vs. undoped capsules. Prepared by LLNL under Contract DE-AC52-07NA27344.

  9. Accuracy evaluation of the current data and method applied to shielding design of the Fusion Experimental Reactor (FER)

    International Nuclear Information System (INIS)

    Mori, Seiji; Kobayashi, Takeshi; Seki, Yasushi

    1988-06-01

    Shielding benchmarking study of the current data and method applied to the Fusion Experimental Reactor (FER) was performed. First, neutron and gamma ray fluxes were calculated by the one-dimensional S N code using various cross section libraries and the continuous energy Monte Carlo code. The results were compared in terms of the S N /MC ratio. The worst ratios are about 0.5 and 0.25 for neutron flux and gamma ray flux, respectively. Next, the analytical calculations of the iron sphere transmission experiment of 14 MeV neutrons were performed to examine the accuracy of cross section data of iron, which is the most important material of shield. The E/C ratio is larger than 2 even if the continuous energy Monte Carlo code was used. Thirdly, the influence of geometrical representation of the shield was investigated by comparing the homogeneous model and the heterogeneous model (alternating layers of SS316 and water). As a result, it was made clear that the homogeneous model underestimates neutron flux by a factor of 2. Finally, the necessity of benchmark experiment and improvement of cross section library was pointed out as the further R and D issues. (author)

  10. Experimental investigation of clay fly ash bricks for gamma-ray shielding

    Energy Technology Data Exchange (ETDEWEB)

    Mann Harjinder Singh; Mudahar, Gumel Singh [Dept. of Physics, Punjabi University, Patiala (India); Brar, Gurdarshan Singh [Dept. of Higher Education, Additional Project Director, Chandigarh (India); Mann, Kulwinder Singh [Dept. of Applied Sciences, I.K. Gujral Punjab Technical University, Jalandhar (India)

    2016-10-15

    This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

  11. Experimental study on fast neutron streaming through grid-plate shield of a LMFBR

    International Nuclear Information System (INIS)

    Oka, Yoshiaki; Wakabayashi, Hiroaki; An, Shigehiro; Suzuki, Ikunori.

    1976-01-01

    Neutron streaming through the holes penetrating the grid plate shield of a prototype LMFBR was experimentally examined. The mockups of the grid plate shield were made of iron and aluminum. Experiments were conducted at the vertical column of ''YAYOI'', the fast neutron source reactor of University of Tokyo. A He-3 spectrometer was employed in order to measure the transmitted neutron spectrum, while rhodium and indium threshold foils were for the integral flux above specific energies and their spatial distributions in the form of reaction rates. The streaming factor for usual small bended holes is 1.28+-0.04 as to the integral neutron flux above 0.1 MeV and 1.30+-0.12 as to the reaction rate of indium foil. Use were made of the one and two dimensional neutron transport code ANISN and TWOTRAN for evaluation by computation. The reaction rates calculated by infinite slab model with ANISN code agree well with the experiments when normalized at the source point where neutrons are incident on the grid plate shield. (auth.)

  12. Experimental results on evaporation waves

    Science.gov (United States)

    Grana Otero, Jose; Parra Fabian, Ignacio

    2010-11-01

    A liquid contained in a vertical glass tube is suddenly depressurized from a high initial pressure down to one for which the stable state is vapour, so vaporization sets off at the free surface. For large enough evaporation rates, the planar vapour-liquid interface is Darrieus-Landau unstable [1], leading to the interface surface rippling close to the instability threshold. Further increasing the initial to final pressure ratio brings about evaporation waves [2,3], in which a highly corrugated front propagates downwards into the liquid. A new experimental method is presented as well as some experimental results obtained by tracking the evolution of the front with a high speed camera. In addition, a number of new phenomena related to the dynamics of bubbles growth at the walls has been uncovered. In particular, a new mode of propagation of the evaporation front is found. In this mode the front originates from below the interface, so the propagation is upwards against gravity with a curved but smooth front.[4pt] [1] F. J. Higuera, Phys. Fluids, V. 30, 679 (1987).[0pt] [2] J.E.Shepherd and B.Sturtevant, J.Fluid Mech., V.121,379 (1982).[0pt] [3] P.Reinke and G.Yadigaroglu, Int.J.Multiph. Flow, V.27,1487 (2001).

  13. Strengthening the composite protective shield of light-weight ship against ballistic impacts: analytical and experimental

    Directory of Open Access Journals (Sweden)

    I. Jalili

    Full Text Available Light and medium protection for small naval vessels guarantees their high performance and safety during the guard duties. In this study, a protective shield fabricated from Dyneema HB25 fibers has been utilized as an add-on layer on the coast guard boat hull. Finite element analyses have been conducted using Chocron's model. Two standards of gun-fire were employed and various thicknesses of the composite layers were examined by ballistic impacts. Afterward, numerical simulations results compared with experiments and revealed a good consistency. Finally, some graphs have been presented to help designers for choosing more convenient shield based on protection and weight characteristics after judgment of vessel requirements.

  14. Verification of Small Hole Theory for Application to Wire Chaffing Resulting in Shield Faults

    Science.gov (United States)

    Schuet, Stefan R.; Timucin, Dogan A.; Wheeler, Kevin R.

    2011-01-01

    Our work is focused upon developing methods for wire chafe fault detection through the use of reflectometry to assess shield integrity. When shielded electrical aircraft wiring first begins to chafe typically the resulting evidence is small hole(s) in the shielding. We are focused upon developing algorithms and the signal processing necessary to first detect these small holes prior to incurring damage to the inner conductors. Our approach has been to develop a first principles physics model combined with probabilistic inference, and to verify this model with laboratory experiments as well as through simulation. Previously we have presented the electromagnetic small-hole theory and how it might be applied to coaxial cable. In this presentation, we present our efforts to verify this theoretical approach with high-fidelity electromagnetic simulations (COMSOL). Laboratory observations are used to parameterize the computationally efficient theoretical model with probabilistic inference resulting in quantification of hole size and location. Our efforts in characterizing faults in coaxial cable are subsequently leading to fault detection in shielded twisted pair as well as analysis of intermittent faulty connectors using similar techniques.

  15. Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study

    Data.gov (United States)

    National Aeronautics and Space Administration — The objectives of the proposed research are to develop a space radiation shielding material system that has high efficacy for shielding radiation and also has high...

  16. Experimental studies of dynamic impact response with scale models of lead shielded radioactive material shipping containers

    International Nuclear Information System (INIS)

    Robinson, R.A.; Hadden, J.A.; Basham, S.J.

    1978-01-01

    Preliminary experimental studies of dynamic impact response of scale models of lead-shielded radioactive material shipping containers are presented. The objective of these studies is to provide DOE/ECT with a data base to allow the prediction of a rational margin of confidence in overviewing and assessing the adequacy of the safety and environmental control provided by these shipping containers. Replica scale modeling techniques were employed to predict full scale response with 1/8, 1/4, and 1/2 scale models of shipping containers that are used in the shipment of spent nuclear fuel and high level wastes. Free fall impact experiments are described for scale models of plain cylindrical stainless steel shells, stainless steel shells filled with lead, and replica scale models of radioactive material shipping containers. Dynamic induced strain and acceleration measurements were obtained at several critical locations on the models. The models were dropped from various heights, attitudes to the impact surface, with and without impact limiters and at uniform temperatures between -40 and 175 0 C. In addition, thermal expansion and thermal gradient induced strains were measured at -40 and 175 0 C. The frequency content of the strain signals and the effect of different drop pad compositions and stiffness were examined. Appropriate scale modeling laws were developed and scaling techniques were substantiated for predicting full scale response by comparison of dynamic strain data for 1/8, 1/4, and 1/2 scale models with stainless steel shells and lead shielding

  17. ITER [International Thermonuclear Experimental Reactor] shield and blanket work package report

    International Nuclear Information System (INIS)

    1988-06-01

    This report summarizes nuclear-related work in support of the US effort for the International Thermonuclear Experimental Reactor (ITER) Study. The purpose of this work was to prepare for the first international ITER workshop devoted to defining a basic ITER concept that will serve as a basis for an indepth conceptual design activity over the next 2-1/2 years. Primary tasks carried out during the past year included: design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components and issues regarding structural materials for an ITER device. 44 refs., 31 figs., 29 tabs

  18. Experimental and simulation optimization analysis of the Whipple shields against shaped charge

    Science.gov (United States)

    Hussain, G.; Hameed, A.; Horsfall, I.; Barton, P.; Malik, A. Q.

    2012-06-01

    Occasionally, the Whipple shields are used for the protection of a space station and a satellite against the meteoroids and orbital debris. In the Whipple shields each layer of the shield depletes part of high speed projectile energy either by breaking the projectile or absorbing its energy. Similarly, this investigation uses the Whipple shields against the shaped charge to protect the light armour such as infantry fighting vehicles with a little modification in their design. The unsteady multiple interactions of shaped charge jet with the Whipple shield package against the steady homogeneous target is scrutinized to optimize the shield thickness. Simulations indicate that the shield thickness of 0.75 mm offers an optimum configuration against the shaped charge. Experiments also support this evidence.

  19. Design and preliminary test results at Mach 5 of an axisymmetric slotted sound shield. [for supersonic wind tunnels (noise reduction in wind tunnel nozzles)

    Science.gov (United States)

    Beckwith, I. E.; Spokowski, A. J.; Harvey, W. D.; Stainback, P. C.

    1975-01-01

    The basic theory and sound attenuation mechanisms, the design procedures, and preliminary experimental results are presented for a small axisymmetric sound shield for supersonic wind tunnels. The shield consists of an array of small diameter rods aligned nearly parallel to the entrance flow with small gaps between the rods for boundary layer suction. Results show that at the lowest test Reynolds number (based on rod diameter) of 52,000 the noise shield reduced the test section noise by about 60 percent ( or 8 db attenuation) but no attenuation was measured for the higher range of test reynolds numbers from 73,000 to 190,000. These results are below expectations based on data reported elsewhere on a flat sound shield model. The smaller attenuation from the present tests is attributed to insufficient suction at the gaps to prevent feedback of vacuum manifold noise into the shielded test flow and to insufficient suction to prevent transition of the rod boundary layers to turbulent flow at the higher Reynolds numbers. Schlieren photographs of the flow are shown.

  20. Shielding plugs

    International Nuclear Information System (INIS)

    Makishima, Kenji.

    1986-01-01

    Purpose: In shielding plugs of an LMFBR type reactor, to restrain natural convection of heat in an annular space between a thermal shield layer and a shield shell, to prevent the lowering of heat-insulation performance, and to alleviate a thermal stress in a reactor container and the shield shell. Constitution: A ring-like leaf spring split in the direction of height is disposed in an annular space between a thermal shield layer and a shield shell. In consequence, the space is partitioned in the direction of height and, therefore, if axial temperature conditions and space width are the same and the space is low, the natural convection is hard to occur. Thus the rise of upper surface temperature of the shielding plugs can prevent the lowering of the heat insulation performance which will result in the increment of shielding plug cooling capacity, thereby improving reliability. In the meantime, since there is mounted an earthquake-resisting support, the thermal shield layer will move for a slight gap in case of an earthquake, being supported by the earthquake-resisting support, and the movement of the thermal shield layer is restricted, thereby maintaining integrity without increasing the stroke of the ring-like spring. (Kawakami, Y.)

  1. Experimental results surprise quantum theory

    International Nuclear Information System (INIS)

    White, C.

    1986-01-01

    Interest in results from Darmstadt that positron-electron pairs are created in nuclei with high atomic numbers (in the Z range from 180-188) lies in the occurrence of a quantized positron kinetic energy peak at 300. The results lend substance to the contention of Erich Bagge that the traditionally accepted symmetries in positron-electron emission do not exist and, therefore, there is no need to posit the existence of the neutrino. The search is on for the decay of a previously unknown boson to account for the findings, which also points to the need for a major revision in quantum theory. 1 figure

  2. Experimental study of neutron streaming through steel-walled annular ducts in reactor shields

    International Nuclear Information System (INIS)

    Toshimas, M.; Nobuo, S.

    1983-01-01

    For the purpose of providing experimental data to assess neutron streaming calculations, neutron flux measurements were performed along the axes of the steel-walled annular ducts set up in a water shield of the pool-type reactor JRR-4. An annular duct simulated the air gap around the main coolant pipe. Another duct simulated the streaming path around the primary circulating pump of the integrated-type marine reactor. A 90-deg bend annular duct was also studied. In a set of measurements, the distance Z between the core center and the duct axis and the annular gap width delta were taken as parameters, that is, Z = 0, 80, and 160 cm and delta = 2.2, 4.7, and 10.1 cm. The reaction rates and the fluxes measured by the activation method are given in terms of absolute magnitude within an accuracy of + or - 30%. An empirical formula is derived based on those measured data, which describes the axial distribution of the neutron flux in the steel-walled annular duct in reactor shields. It is expressed by a simple function of the axial distance in units of the square root of the line-of-sight area, S /SUB l/ . The accuracy of the formula is examined by taking into account the duct location with respect to the reactor core, the neutron energy, the steel wall thickness, and the media outside of the steel wall. The accuracy of the formula is, in general, <30% in the axial distance between 3√S /SUB l/ and 30√S /SUB l/

  3. TMX-U experimental results

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Casper, T.A.

    1983-01-01

    This paper describes results from the Tandem Mirror Experiment-Upgrade (TMX-U). Mirror-confined electrons with 30 to 70 keV mean energy densities of 0.5 to 2.0 x 10 12 cm -3 and average betas of 3 to 5% are produced using electron-cyclotron resonant heating (ECRH). These results are consistent with an electron Fokker-Planck code. Improved ion-cyclotron microstability is observed using neutral beam injection at 47 0 to the magnetic axis, rather than at 90 0 as in the previous experiment, TMX. Strong end plugging has been produced using a combination of ECRH gyrotrons with sloshing-ion beam injection. In these low-density central cell experiments (3 x 10 11 cm -3 ) the axial losses (tau/sub parallel/ = 20 to 80 ms) are smaller than the nonambipolar radial losses (tau/sub perpendicular/ = 4 to 8 ms). Plugging has been achieved with a central cell density double that of the end plugs. Although no direct measurements are yet available to determine if a thermal barrier potential dip is generated, these experiments support many theoretical features of the thermal barrier concept

  4. Experimental Investigation of Multi-layer Insulation Effect on Damage of Stuffed Shield by High-velocity Impact

    Directory of Open Access Journals (Sweden)

    GUAN Gong-shun

    2016-09-01

    Full Text Available The stuffed shield with multi-layer insulation(MLI was designed by improving on Al Whipple shield, and a series of high-velocity impact tests were practiced with a two-stage light gas gun facility at vacuum environment. The damage model of the stuffed shield with different MLI location by Al-sphere projectile impacting was obtained. The effect of MLI on damage of the stuffed shield by high-velocity impact was studied. The results indicate when the MLI is located at front side of the first Al-plate, the protection performance of the stuffed shield is improved with the larger perforation diameter of the first Al-plate and more impact kinetic energy dissipation of the projectile. When MLI is arranged at back side of the first Al-plate, the expansion of the secondary debris cloud from projectile impacting the first Al-plate is restrained, it is not good to improve the protection performance of the stuffed shield. When MLI is arranged at front side of the stuffed wall, the perforation size of the stuffed wall increases; when MLI is arranged at front side of the rear wall, the distribution range of crater on the rear wall decreases.

  5. On the hydraulic behaviour of ITER Shield Blocks #14 and #08. Computational analysis and comparison with experimental tests

    Energy Technology Data Exchange (ETDEWEB)

    Di Maio, P.A. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128, Palermo (Italy); Merola, M.; Mitteau, R.; Raffray, R. [ITER Organization, Route de Vinon sur Verdon, 13067 Saint Paul, Lez Durance (France); Vallone, E., E-mail: eug.vallone@gmail.com [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128, Palermo (Italy)

    2016-11-01

    Highlights: • A benchmarking activity has been carried out focusing the attention on the cooling circuits of ITER Shield Blocks #08 and #14. • A theoretical-computational fluid-dynamic approach based on the Finite Volume Method has been followed, adopting a commercial code. • Hydraulic characteristic functions and spatial distributions of coolant mass flow rate, velocity and pressure drop have been assessed. • Results obtained have allowed code benchmarking for Blanket modules and the numerical predictions have been found to be generally lower than but quite close to the experimental results (lower than 10%). - Abstract: As a consequence of its position and functions, the ITER blanket system will be subjected to significant heat loads under nominal reference conditions. Therefore, the design of its cooling system is particularly demanding. Coolant water is distributed individually to the 440 blanket modules (BMs) through manifold piping, which makes it a highly parallelized system. The mass flow rate distribution is finely tuned to meet all operation constraints: adequate margin to burn out in the plasma facing components, even distribution of water flow among the so-called plasma-facing “fingers” of the Blanket First Wall panels, high enough water flow rate to avoid excessive water temperature in the outlet pipes, maximum allowable water velocity lower than 7 m/s in manifold pipes. Furthermore the overall pressure drop and flow rate in each BM shall be within the fixed specified design limit to avoid an unduly unbalance of cooling among the 440 modules. Analyses have to be carried out following a computational fluid-dynamic (CFD) approach based on the finite volume method and adopting a CFD commercial code to assess the thermal-hydraulic behaviour of each single circuit of the ITER blanket cooling system. This paper describes the code benchmarking needed to determine the best method to get reliable and timely results. Since experimental tests are

  6. Design of a management information system for the Shielding Experimental Reactor ageing management

    International Nuclear Information System (INIS)

    He Jie; Xu Xianhong

    2010-01-01

    The problem of nuclear reactor ageing is a topic of increasing importance in nuclear safety recent years. Ageing management is usually implemented for reactors maintenance. In the practice, a large number of data and records need to be processed. However, there are few professional software applications that aid reactor ageing management, especially for research reactors. This paper introduces the design of a new web-based management information system (MIS), named the Shielding Experimental Reactor Ageing Management Information System (SERAMIS). It is an auxiliary means that helps to collect data, keep records, and retrieve information for a research reactor ageing management. The Java2 Enterprise Edition (J2EE) and network database techniques, such as three-tiered model, Model-View-Controller architecture, transaction-oriented operations, and JavaScript techniques, are used in the development of this system. The functionalities of the application cover periodic safety review (PSR), regulatory references, data inspection, and SSCs classification according to ageing management methodology. Data and examples are presented to demonstrate the functionalities. For future work, techniques of data mining will be employed to support decision-making.

  7. Design of a management information system for the Shielding Experimental Reactor ageing management

    Energy Technology Data Exchange (ETDEWEB)

    He Jie, E-mail: hejiejoe@163.co [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Xu Xianhong [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2010-01-15

    The problem of nuclear reactor ageing is a topic of increasing importance in nuclear safety recent years. Ageing management is usually implemented for reactors maintenance. In the practice, a large number of data and records need to be processed. However, there are few professional software applications that aid reactor ageing management, especially for research reactors. This paper introduces the design of a new web-based management information system (MIS), named the Shielding Experimental Reactor Ageing Management Information System (SERAMIS). It is an auxiliary means that helps to collect data, keep records, and retrieve information for a research reactor ageing management. The Java2 Enterprise Edition (J2EE) and network database techniques, such as three-tiered model, Model-View-Controller architecture, transaction-oriented operations, and JavaScript techniques, are used in the development of this system. The functionalities of the application cover periodic safety review (PSR), regulatory references, data inspection, and SSCs classification according to ageing management methodology. Data and examples are presented to demonstrate the functionalities. For future work, techniques of data mining will be employed to support decision-making.

  8. Magnetic field shielding system in a tokamak experimental power reactor (EPR): concept and calculations

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Marcus, F.B.; Dory, R.A.; Moore, J.R.

    1975-01-01

    A poloidal magnetic field shielding system is proposed for a tokamak EPR. This coil system minimizes the pulsed poloidal field that intersects the TF (toroidal field) coils and hence reduces the risk of superconductor quenching and structural failure of the coils. Based on an idealized shielding model, we have determined the configurations for the OH (ohmic heating), the S-VF (shield-vertical field), and the T-VF (trimming-vertical field) coils in a typical tokamak EPR. It is found that the pulsed poloidal field strength is greatly reduced in the TF coil region. The overall requirement in stored plasma and vertical field energy is also substantially reduced when compared with conventional EPR designs. Use of this field shielding system is expected to enhance reliability of the superconducting TF coils in a tokamak EPR

  9. Computations for a condenser. Experimental results

    International Nuclear Information System (INIS)

    Walden, Jean.

    1975-01-01

    Computations for condensers are presented with experimental results. The computations are concerned with the steam flux at the condenser input, and inside the tube bundle. Experimental results are given for the flux inside the condenser sleeve and the flow passing through the tube bundle [fr

  10. Shielding Characteristics Using an Ultrasonic Configurable Fan Artificial Noise Source to Generate Modes - Experimental Measurements and Analytical Predictions

    Science.gov (United States)

    Sutliff, Daniel L.; Walker, Bruce E.

    2014-01-01

    An Ultrasonic Configurable Fan Artificial Noise Source (UCFANS) was designed, built, and tested in support of the NASA Langley Research Center's 14x22 wind tunnel test of the Hybrid Wing Body (HWB) full 3-D 5.8% scale model. The UCFANS is a 5.8% rapid prototype scale model of a high-bypass turbofan engine that can generate the tonal signature of proposed engines using artificial sources (no flow). The purpose of the program was to provide an estimate of the acoustic shielding benefits possible from mounting an engine on the upper surface of a wing; a flat plate model was used as the shielding surface. Simple analytical simulations were used to preview the radiation patterns - Fresnel knife-edge diffraction was coupled with a dense phased array of point sources to compute shielded and unshielded sound pressure distributions for potential test geometries and excitation modes. Contour plots of sound pressure levels, and integrated power levels, from nacelle alone and shielded configurations for both the experimental measurements and the analytical predictions are presented in this paper.

  11. Radiation shielding lead shield

    International Nuclear Information System (INIS)

    Dei, Shoichi.

    1991-01-01

    The present invention concerns lead shields for radiation shielding. Shield boxes are disposed so as to surround a pipeline through which radioactive liquids, mists or like other objects are passed. Flanges are formed to each of the end edges of the shield boxes and the shield boxes are connected to each other by the flanges. Upon installation, empty shield boxes not charged with lead particles and iron plate shields are secured at first at the periphery of the pipeline. Then, lead particles are charged into the shield boxes. This attains a state as if lead plate corresponding to the depth of the box is disposed. Accordingly, operations for installation, dismantling and restoration can be conducted in an empty state with reduced weight to facilitate the operations. (I.S.)

  12. New experimental results on strangeness production

    International Nuclear Information System (INIS)

    Sapozhnikov, M.G.

    1998-01-01

    New experimental results on the production of φ and f 2 ' (1525) mesons in the annihilation of stopped antiprotons are discussed. The explanation of these facts in the framework of the polarized strangeness model is considered

  13. Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

    Science.gov (United States)

    Sakuma, I.; Kikuchi, Y.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.

    2015-08-01

    We have developed a unique experimental device of so-called double plasma gun, which consists of two magnetized coaxial plasma gun (MCPG) devices, in order to clarify effects of vapor shielding on material erosion due to transient events in magnetically confined fusion devices. Two ELM-like pulsed plasmas produced by the two MCPG devices were injected into a target chamber with a variable time difference. For generating ablated plasmas in front of a target material, an aluminum foil sample in the target chamber was exposed to a pulsed plasma produced by the 1st MCPG device. The 2nd pulsed plasma was produced with a time delay of 70 μs. It was found that a surface absorbed energy measured by a calorimeter was reduced to ∼66% of that without the Al foil sample. Thus, the reduction of the incoming plasma energy by the vapor shielding effect was successfully demonstrated in the present experiment.

  14. Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, I., E-mail: eu13z002@steng.u-hyogo.ac.jp; Kikuchi, Y.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.

    2015-08-15

    We have developed a unique experimental device of so-called double plasma gun, which consists of two magnetized coaxial plasma gun (MCPG) devices, in order to clarify effects of vapor shielding on material erosion due to transient events in magnetically confined fusion devices. Two ELM-like pulsed plasmas produced by the two MCPG devices were injected into a target chamber with a variable time difference. For generating ablated plasmas in front of a target material, an aluminum foil sample in the target chamber was exposed to a pulsed plasma produced by the 1st MCPG device. The 2nd pulsed plasma was produced with a time delay of 70 μs. It was found that a surface absorbed energy measured by a calorimeter was reduced to ∼66% of that without the Al foil sample. Thus, the reduction of the incoming plasma energy by the vapor shielding effect was successfully demonstrated in the present experiment.

  15. Neutron shieldings

    International Nuclear Information System (INIS)

    Tarutani, Kohei

    1979-01-01

    Purpose: To decrease the stresses resulted by the core bendings to the base of an entrance nozzle. Constitution: Three types of round shielding rods of different diameter are arranged in a hexagonal tube. The hexagonal tube is provided with several spacer pads receiving the loads from the core constrain mechanism at its outer circumference, a handling head for a fuel exchanger at its top and an entrance nozzle for self-holding the neutron shieldings and flowing heat-removing coolants at its bottom. The diameters for R 1 , R 2 and R 3 for the round shielding rods are designed as: 0.1 R 1 2 1 and 0.2 R 1 2 1 . Since a plurality of shielding rods of small diameter are provided, soft structure are obtained and a plurality of coolant paths are formed. (Furukawa, Y.)

  16. Radiation protection/shield design

    International Nuclear Information System (INIS)

    Disney, R.K.

    1977-01-01

    Radiation protection/shielding design of a nuclear facility requires a coordinated effort of many engineering disciplines to meet the requirements imposed by regulations. In the following discussion, the system approach to Clinch River Breeder Reactor Plant (CRBRP) radiation protection will be described, and the program developed to implement this approach will be defined. In addition, the principal shielding design problems of LMFBR nuclear reactor systems will be discussed in realtion to LWR nuclear reactor system shielding designs. The methodology used to analyze these problems in the U.S. LMFBR program, the resultant design solutions, and the experimental verification of these designs and/or methods will be discussed. (orig.) [de

  17. Analysis of MIR-18 results for physical and biological dosimetry: radiation shielding effectiveness in LEO

    International Nuclear Information System (INIS)

    Cucinotta, F.A.; Wilson, J.W.; Williams, J.R.; Dicello, J.F.

    2000-01-01

    We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio will increase for exposures to internal organs. Two biological response models are used to compare to the Mir biodosimetry for chromosome aberration in lymphocyte cells; a track-structure model and the linear-quadratic model with linear energy transfer (LET) dependent weighting coefficients. These models are fit to in vitro data for aberration formation in human lymphocytes by photons and charged particles. Both models are found to be in reasonable agreement with data for aberrations in lymphocytes of Mir crew members: however there are differences between the use of LET dependent weighting factors and track structure models for assigning radiation quality factors. The major difference in the models is the increased effectiveness predicted by the track model for low charge and energy ions with LET near 10 keV/μm. The results of our calculations indicate that aluminum shielding, although providing important mitigation of the effects of trapped radiation, provides no protective effect from the galactic cosmic rays (GCR) in low-earth orbit (LEO) using either equivalent dose or the number of chromosome aberrations as a measure until about 100 g/cm 2 of material is used

  18. Shielding Studies for the CERN Super-Proton-Synchrotron at Experimental Point 5

    CERN Document Server

    Müller, Mario J

    2004-01-01

    The European Laboratory for Particle Research, CERN has been operated the Super Proton Sychrotron (SPS) for more than 30 years with the shielding design knowledge of the early 70s. At that time particle transport codes were neither available nor capable of dealing with deep lateral shielding calculations. For the future LHC increasing projected values of beam intensity in the SPS and decreasing limits to radiation exposure have led to the need to re-assess the shielding at point 5 of the SPS. 20 years ago this area housed the UA1 experiment of Carlo Rubbia (nobel-price 1984). The thesis describes a re-assessment based on simulations using the multi-purpose radiation transport codes FLUKA and MCNPX. The latter one was utilized for geometry design and to compare variance reduction methods. Different assumed beam-loss points along the beam-line together with fluence-to-doserate conversion calculations were used to find the worst case scenario. Dose-rates as well as particle-energy spectra inside the accessible a...

  19. Dosimetry and shielding

    International Nuclear Information System (INIS)

    Farinelli, U.

    1977-01-01

    Today, reactor dosimetry and shielding have wide areas of overlap as concerns both problems and methods. Increased interchange of results and know-how would benefit both. The areas of common interest include calculational methods, sensitivity studies, theoretical and experimental benchmarks, cross sections and other nuclear data, multigroup libraries and procedures for their adjustment, experimental techniques and damage functions. This paper reviews the state-of-the-art and the latest development in each of these areas as far as shielding is concerned, and suggests a number of interactions that could be profitable for reactor dosimetry. Among them, re-evaluation of the potentialities of calculational methods (in view of the recent developments) in predicting radiation environments of interest; the application of sensitivity analysis to dosimetry problems; a common effort in the field of theoretical benchmarks; the use of the shielding one-material propagation experiments as reference spectra for detector cross sections; common standardization of the detector nuclear data used in both fields; the setting up of a common (or compatible) multigroup structure and library applicable to shielding, dosimetry and core physics; the exchange of information and experience in the fields of cross section errors, correlations and adjustment; and the intercomparison of experimental techniques

  20. Neutron shielding material

    International Nuclear Information System (INIS)

    Nodaka, M.; Iida, T.; Taniuchi, H.; Yosimura, K.; Nagahama, H.

    1993-01-01

    From among the neutron shielding materials of the 'kobesh' series developed by Kobe Steel, Ltd. for transport and storage packagings, silicon rubber base type material has been tested for several items with a view to practical application and official authorization, and in order to determine its adaptability to actual vessels. Silicon rubber base type 'kobesh SR-T01' is a material in which, from among the silicone rubber based neutron shielding materials, the hydrogen content is highest and the boron content is most optimized. Its neutron shielding capability has been already described in the previous report (Taniuchi, 1986). The following tests were carried out to determine suitability for practical application; 1) Long-term thermal stability test 2) Pouring test on an actual-scale model 3) Fire test The experimental results showed that the silicone rubber based neutron shielding material has good neutron shielding capability and high long-term fire resistance, and that it can be applied to the advanced transport packaging. (author)

  1. Structural design of shield-integrated thin-wall vacuum vessel and manufacturing qualification tests for International Thermonuclear Experimental Reactor (ITER)

    International Nuclear Information System (INIS)

    Shimizu, Katsusuke; Shibui, Masanao; Koizumi, Koichi; Kanamori, Naokazu; Nishio, Satoshi; Sasaki, Takashi; Tada, Eisuke

    1992-09-01

    Conceptual design of shield-integrated thin-wall vacuum vessel has been done for ITER (International Thermonuclear Experimental Reactor). The vacuum vessel concept is based on a thin-double-wall structure, which consists of inner and outer plates and rib stiffeners. Internal shielding structures, which provide neutron irradiation shielding to protect TF coils, are set up between the inner plate and the outer plate of the vessel to avoid complexity of machine systems such as supporting systems of blanket modules. The vacuum vessel is assembled/disassembled by remote handling, so that welding joints are chosen as on-site joint method from reliability of mechanical strength. From a view point of assembling TF coils, the vacuum vessel is separated at the side of port, and is divided into 32 segments similar to the ITER-CDA reference design. Separatrix sweeping coils are located in the vacuum vessel to reduce heat fluxes onto divertor plates. Here, the coil structure and attachment to the vacuum vessel have been investigated. A sectorized saddle-loop coil is available for assembling and disassembling the coil. To support electromagnetic loads on the coils, they are attached to the groove in the vacuum vessel by welding. Flexible multi-plate supporting structure (compression-type gravity support), which was designed during CDA, is optimized by investigating buckling and frequency response properties, and concept on manufacturing and fabrication of the gravity support are proposed. Partial model of the vacuum vessel is manufactured for trial, so that fundamental data on welding and fabrication are obtained. From mechanical property tests of weldment and partial models, mechanical intensity and behaviors of the weldment are obtained. Informations on FEM-modeling are obtained by comparing analysis results with experimental results. (author)

  2. Experimental and analytical study for demonstration program on shielding of casks for high-level wastes

    International Nuclear Information System (INIS)

    Ueki, K.; Nakazawa, M.; Hattorl, S.; Ozaki, S.; Tamaki, H.; Kadotani, H.; Ishizuka, T.; Ishikawa, S.

    1993-01-01

    The following remarks were obtained from the experiment and the DOT 3.5 and the MCNP analyses on the gamma ray and the neutron dose equivalent rates in the cask of interest. 1. The cask has thinner neutron shielding parts around the trunnions. Significant neutrons streaming around the trunnion parts was observed which was also cleared by the MCNP analysis for the 252 Cf source experiment. Accordingly, detailed neutron streaming calculations are required to evaluate the dose levels around the trunnions when loading the vitrified high-level wastes. 2. The room-scattered obstructive neutrons, mainly originating from the neutrons penetrating around the trunnions, at the top and the bottom of the cask are reduced significantly by preparing the water tank at the top and the water layer at the bottom. Therefore, a more accurate experiment is to be carried out in the future shielding experiment especially for neutrons. However, because the water tank and the layer do not exist in the actual high-level wastes transport cask, the experiment without the water tank and layer are not dispensable to demonstrate the transport conditions of the actual cask, too. 3. The gamma-ray and the neutron dose equivalent rate distributions obtained from the DOT 3.5 and the MCNP calculations, respectively, agreed closely with the measured values in the cask areas of interest. Accordingly, the DOT 3.5 code and the MCNP code with the NESX estimator can be employed not only for the shielding analysis of the future experiments, but also for making a safety analysis report of high-level wastes transport casks. (J.P.N.)

  3. Interpretation of PISCES -- A RF antenna system experimental results

    International Nuclear Information System (INIS)

    Rothweil, D.A.; Phelps, D.A.; Doerner, R.

    1995-10-01

    The paper describes experimental data from rf coupling experiments using one to four coil antenna arrays that encircle a linear magnetized plasma column. Experimental results using single turn coil that produce symmetric (i.e. m = 0), dipole (m = 1), and radial rf magnetic fields for coupling to ion waves are compared. By operating without a Faraday shield, it was observed for the first time that the plasma resistive load seen by these different antenna types tends to increase with the number of turns to at least the second power. A four-turn m = 0 coil experienced a record 3--5 Ω loading, corresponding to over 90% power coupling to the plasma. A four-turn m = 1 coil experienced up to 1--1.5 Ω loading, also higher than previous observations. First time observations using a two coil array of m = 0 coil are also reported. As predicted, the loading decreases with increasing phase between coil from 0 degree to 180 degree. Experiments using four coil arrays were difficult to optimize and interpret primarily due to complexity of the manual tuning. To facilitate this optimization in the future, a proposed feedback control system that automatically matches load variations between 0.2 and 10 Ω is described

  4. PDX experimental results in FY82

    International Nuclear Information System (INIS)

    Kaye, S.M.; Bell, M.; Bol, K.

    1983-08-01

    This report presents a detailed summary of the major experimental results of PDX in FY82 and represents the efforts of the entire PDX group. Topics covered include β-scaling and fishbone studies, fluctuations, disruptions, impurities and impurity transport, power handling, limiter conditioning, edge studies, plasma fueling, counter-injection, and diagnostic development. A less detailed version will appear as the FY82 PDX contribution to the PPPL Annual Report

  5. Predictions of High Energy Experimental Results

    Directory of Open Access Journals (Sweden)

    Comay E.

    2010-10-01

    Full Text Available Eight predictions of high energy experimental results are presented. The predictions contain the $Sigma ^+$ charge radius and results of two kinds of experiments using energetic pionic beams. In addition, predictions of the failure to find the following objects are presented: glueballs, pentaquarks, Strange Quark Matter, magnetic monopoles searched by their direct interaction with charges and the Higgs boson. The first seven predictions rely on the Regular Charge-Monopole Theory and the last one relies on mathematical inconsistencies of the Higgs Lagrangian density.

  6. Shielding Benchmark Computational Analysis

    International Nuclear Information System (INIS)

    Hunter, H.T.; Slater, C.O.; Holland, L.B.; Tracz, G.; Marshall, W.J.; Parsons, J.L.

    2000-01-01

    Over the past several decades, nuclear science has relied on experimental research to verify and validate information about shielding nuclear radiation for a variety of applications. These benchmarks are compared with results from computer code models and are useful for the development of more accurate cross-section libraries, computer code development of radiation transport modeling, and building accurate tests for miniature shielding mockups of new nuclear facilities. When documenting measurements, one must describe many parts of the experimental results to allow a complete computational analysis. Both old and new benchmark experiments, by any definition, must provide a sound basis for modeling more complex geometries required for quality assurance and cost savings in nuclear project development. Benchmarks may involve one or many materials and thicknesses, types of sources, and measurement techniques. In this paper the benchmark experiments of varying complexity are chosen to study the transport properties of some popular materials and thicknesses. These were analyzed using three-dimensional (3-D) models and continuous energy libraries of MCNP4B2, a Monte Carlo code developed at Los Alamos National Laboratory, New Mexico. A shielding benchmark library provided the experimental data and allowed a wide range of choices for source, geometry, and measurement data. The experimental data had often been used in previous analyses by reputable groups such as the Cross Section Evaluation Working Group (CSEWG) and the Organization for Economic Cooperation and Development/Nuclear Energy Agency Nuclear Science Committee (OECD/NEANSC)

  7. Material shielding of power frequency magnetic fields: Research and testing results from the EPRI Power Delivery Center-Lenox. Final report

    International Nuclear Information System (INIS)

    Anderson, C.B.

    1998-06-01

    Extensive investigations of a variety of material shielding methods have been performed at the EPRI Power Delivery Center--Lenox, Massachusetts. This work is part of a larger shielding investigation being done for EPRI by Electric Research and Management, Inc. (ERM) as part of the Magnetic Field Management Target in the EPRI Environment Group. Part of this work, involving cylinders of material, is to be included in a shielding handbook being prepared by ERM. Material shielding tests, not included in the handbook, as well as additional material shielding research, including testing, analyses, and computer simulations performed at the EPRI Power Delivery Center--Lenox are documented here. One of the major complications of using materials to shield magnetic fields is the mathematical complexity of the phenomenon involved. The result is that analytical solutions exist only for a very small number of simple geometries such as spheres, infinitely long cylinders, and infinite sheets. In practice, the materials typically come in the form of sheets. At present, there are no analytical methods for directly determining the shielding effectiveness of finite sheets of material, however, EPRI is sponsoring work in this area. There are some methods based on conformal mapping which can provide a solution for simple two-dimensional sheets. While such methods are useful in gaining insight into the mechanisms of shielding, they are not realistic enough to provide accurate shielding estimates. Empirical techniques are still required to determine the shielding effectiveness of material sheets. The material shielding tests and computer simulations are described in the report. The results of these tests and simulations have been used to develop a number of material shielding design rules for use in practical applications

  8. Experimental Studies of the Aerothermal Characteristics of the Project Orion CEV heat Shield in High Speed Transitional and Turbulent Flows

    Science.gov (United States)

    Wadhams, T.P.; MacLean, M.; Holden, M.S.; Cassady, A.M.

    2009-01-01

    An experimental program has been completed by CUBRC exploring laminar, transitional, and turbulent flows over a 7.0% scale model of the Project ORION CEV geometry. This program was executed primarily to answer questions concerning the increase in heat transfer on the windward, or "hot shoulder" of the CEV heat shield from laminar to turbulent flow. To answer these questions CUBRC constructed and instrumented a 14.0 inch diameter Project ORION CEV model and ran a range of Reynolds numbers based on diameter from 1.0 to over 40 million at a Mach number of 8.0. These Reynolds numbers were selected to cover laminar to turbulent heating data on the "hot shoulder". Data obtained during these runs will be used to guide design decisions as they apply to heat shield thickness and extent. Several experiments at higher enthalpies were achieved to obtain data for code validation with real gas effects and transition. CUBRC also performed computation studies of these experiments to aid in the data reduction process and study turbulence modeling.

  9. Thulium-170 oxide heat source experimental and analytical radiation and shielding study

    International Nuclear Information System (INIS)

    Tse, A.; Nelson, C.A.

    1970-05-01

    Radiation dose rates from three thulium-170 oxide sources (20.7, 10.0 and 5.0 thermal watts) were measured through three thicknesses (1/4, 1/2 and 1 inch) of absorber by thermoluminescent dosimetry techniques. Absorber materials used were aluminium, stainless steel, lead, tungsten and depleted uranium. Resultant radiation doses were measured at 19 and 100 cm. Comparison of theoretical dose rates calculated by computer with measured dose rates validated the calculation technique for lead, tungsten and uranium absorbers but not for aluminum and stainless steel. Use of infinite medium build-up factors (B/sub ∞/) was thus validated in computation of dose rates for lead, tungsten and uranium absorbers; use of B/sub ∞/ in computation of dose rates for aluminum and stainless steel absorbers overestimated dose rates vis-a-vis experimentally determined dose rates by an approximate factor of 2

  10. Shielding research in France

    Energy Technology Data Exchange (ETDEWEB)

    Lafore, P

    1964-10-01

    Shielding research as an independent subject in France dates from 1956. The importance of these studies has been reflected in the contribution which they have made to power reactor design and in the resultant savings in expenditure for civil engineering and machinery for the removal of mobile shields. The Reactor Shielding Research Division numbers approximately 60 persons and uses several experimental facilities. These include: NAIADE I, installed near the ZOE reactor and operating with a natural uranium slab 2 cm thick (an effective diameter of 60 cm is the one most commonly used); the TRITON pool-type reactor, mainly used in shielding studies, includes an active-water loop, by means of which the secondary shields required for light-water reactors can be studied; core, NEREIDE, which is situated near a 2 m x 2 m aluminium window enables a large neutron source to be placed in a compartment without water in which large-scale mock-ups can be mounted for the study, in particular, of neutron diffusion in large cavities, and of reactor shielding of greater thickness than that in NAIADE I; SAMES 600 keV accelerator is used for monoenergetic neutron studies. Instrumentation studies are an important part of the work, mainly in the measurement of fast neutrons and their spectra by activation detectors. Of late, attention has been directed towards the use of (n, n') (rhodium) reactions and of heavy detectors for low-flux measurements. The simultaneous use of a large number of detectors poses automation problems. With our installation we can count 16 detectors simultaneously. Neutron spectrum studies are conducted with nuclear emulsions and a lithium-6 semiconductor spectrometer. As to the materials used, the research carried out in France involves chiefly graphite, iron and concrete at various temperatures up to 800 deg C. Different compounds, borated and non-borated and of densities up to between 1 and 9 are under consideration. Problems connected with applications are

  11. F(α) curves: Experimental results

    International Nuclear Information System (INIS)

    Glazier, J.A.; Gunaratne, G.; Libchaber, A.

    1988-01-01

    We study the transition to chaos at the golden and silver means for forced Rayleigh-Benard (RB) convection in mercury. We present f(α) curves below, at, and above the transition, and provide comparisons to the curves calculated for the one-dimensional circle map. We find good agreement at both the golden and silver means. This confirms our earlier observation that for low amplitude forcing, forced RB convection is well described by the one-dimensional circle map and indicates that the f(α) curve is a good measure of the approach to criticality. For selected subcritical experimental data sets we calculate the degree of subcriticality. We also present both experimental and calculated results for f(α) in the presence of a third frequency. Again we obtain agreement: The presence of random noise or a third frequency narrows the right-hand (negative q) side of the f(α) curve. Subcriticality results in symmetrically narrowed curves. We can also distinguish these cases by examining the power spectra and Poincare sections of the time series

  12. Experimental results from a stepped frequency GPR

    Directory of Open Access Journals (Sweden)

    G. M. Signore

    2003-06-01

    Full Text Available In the framework of a nationally funded project, a Ground Penetrating Radar (GPR has been developed by the Italian Consortium for Research on Advanced Remote Sensing Systems (CO.RI.S.T.A.. The system was described in a previous paper (Alberti et al., 2002. As new aspects, the system is a stepped frequency GPR that can work both in gated and ungated mode, and the antennas can be moved automatically in a controlled fashion. As aspects of geophysical interest, the system is exploitable in situations wherein a high resolution and a shallow penetration in the soil (a few meters are required. Possibly, this is an example of probing a landscape. This paper completes the results of Alberti et al. (2002, wherein laboratory tests where described, by providing the main results obtained during an outdoor experimental campaign, performed fi rst in a controlled site and then in an archaeological site.

  13. Experimental study of carbon materials behavior under high temperature and VUV radiation: Application to Solar Probe+ heat shield

    International Nuclear Information System (INIS)

    Eck, J.; Sans, J.-L.; Balat-Pichelin, M.

    2011-01-01

    The aim of the Solar Probe Plus (SP+) mission is to understand how the solar corona is heated and how the solar wind is accelerated. To achieve these goals, in situ measurements are necessary and the spacecraft has to approach the Sun as close as 9.5 solar radii. This trajectory induces extreme environmental conditions such as high temperatures and intense Vacuum Ultraviolet radiation (VUV). To protect the measurement and communication instruments, a heat shield constituted of a carbon material is placed on the top of the probe. In this study, the physical and chemical behavior of carbon materials is experimentally investigated under high temperatures (1600-2100 K), high vacuum (10 -4 Pa) and VUV radiation in conditions near those at perihelion for SP+. Thanks to several in situ and ex situ characterizations, it was found that VUV radiation induced modification of outgassing and of mass loss rate together with alteration of microstructure and morphology.

  14. An experimental study of Alfven wave heating using electrostatically shielded antennas in TCA

    International Nuclear Information System (INIS)

    Borg, G.G.; Joye, B.

    1990-01-01

    Despite the wide acceptance of electrostatic screens in ICRH for the protection of the plasma from the near fields of rf antennas, it has always been considered that low voltages at low frequency have made such screens unnecessary in Alfven wave heating (AWH). Despite this, AWH performs rather poorly as a heating method; the results being confused by a density rise up to 300 % of the target density. It is known that the density increase arises neither from impurity injection nor from a change in recycling. In addition, an extensive range of phenomena have been observed in the plasma scrape-off layer (SOL). During AWH, the SOL density is observed to decrease, the SOL floating potential is perturbed in a way that reflects the Alfven wave spectrum, the antennas charge negatively and draw a large current from the plasma and harmonics have been observed on the edge wave fields. The cause and correlation of these effects with each other and their impression on the bulk plasma response was not known. Experimental results from the TORTUS tokamak have indicated that the density increase might be eliminated by electrostatic screens. In their case, two AWH experiments were performed. In the first, an unshielded OFHC copper loop antenna was excited at a given power and, in the second, the same antenna was excited at the same power after installation of an aluminium, TiN coated, slotted screen. The density increase in the first case was shown to be completely eliminated in the second, although spectroscopic measurements revealed a difference in the plasma O(II) and Cu(I) content for each case. (author) 2 refs., 3 figs

  15. Zooplankton community response to experimental acidification in boreal shield lakes with different ecological histories

    Energy Technology Data Exchange (ETDEWEB)

    Derry, A.M.; Arnott, S.E. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology

    2007-06-15

    This study investigated the adaptive response of crustacean zooplankton to widespread regional acidification at the Killarney Provincial Park in Ontario. Mesocosm experiments were conducted in 2 circumneutral lakes with different acidification histories. A reciprocal transplant field enclosure experiment was conducted to assess whether the zooplankton community within the acid-recovering boreal shield lake showed evidence of increased acid tolerance to historical acidification following a 6 year period in which the lake's pH was 6.0. The enclosures were filled with epilimnetic water from the lake. Zooplankton from other lakes in the area were used. Zooplankton and water samples were collected from the enclosures once a week. Shannon-Wiener indices, species richness, and total abundance of the zooplankton were calculated for each sample day. Repeated measures analyses of variance (RM-ANOVAs) were used to test for the effects of the incubation lake, the zooplankton source, and the pH. Species abundance data were log{sub 10} transformed to improve homogeneity of variances and normality. Principle components analysis was conducted on species abundances to infer the influence of treatments on zooplankton community composition. Zooplankton were also transferred from 1 lake to the other in order to determine if subtle differences in local water chemistry and food conditions were limiting the recovery of species in acid-recovering lakes. The study showed that 2 key species, H. gibberum and L. minutus, contributed to community-level differences to acid tolerance of zooplankton with different acidification histories. It was concluded that zooplankton with adaptable acid tolerances may monopolize resources in acidified and acid-recovering lakes, and may contribute to the delayed recolonization of other taxa. 62 refs., 3 tabs., 6 figs.

  16. Methods and experimental coefficients used in the computation of reactor shielding; Methodes et coefficients experimentaux pour le calcul des protections de reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, J; Lafore, P; Millot, J P; Rastoin, J; Vathaire, F de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    1) The concept of an effective removal cross section has been developed in order more easily to compute reactor shielding thicknesses. We have built an experimental facility for the purpose of measuring effective removal cross sections, the value of which had not been published at that time. The first part of this paper describes the device or facility used, the computation method applied, and the results obtained. 2) Starting from this concept, we endeavoured to define a removal cross section as a function of energy. This enabled us to use the method for computations bearing on the attenuation of fast neutrons of any spectrum. An experimental verification was carried out for the case of fission neutrons filtered by a substantial thickness of graphite. 3) Finally, we outline a computation method enabling us to determine the sources of captured gamma rays by the age theory and we give an example of the application in a composite shield. (author) [French] 1) La notion de section efficace effective de deplacement a ete introduite pour calculer commodement les epaisseurs de protection des reacteurs. Nous avons construit un dispositif experimental destine a mesurer les sections efficaces effectives de deplacement dont la valeur n'avait pas ete publiee a cette epoque. La premiere partie de cette communication decrit le dispositif utilise, la methode de calcul employee et les resultats obtenus. 2) A partir de cette notion, nous avons essaye de definir une section efficace de deplacement fonction de l'energie. Ceci permet d'utiliser la methode du deplacement pour des calculs d'attenuation de neutrons rapides dont le spectre est quelconque. Une verification experimentale a ete faite dans le cas de neutrons de fission filtres par une epaisseur notable de graphite. 3) Enfin une methode de calcul permettant de determiner les sources de gamma de capture par la theorie de l'age est exposee et un exemple d'application donne dans une protection composite. (auteur)

  17. Methods and experimental coefficients used in the computation of reactor shielding; Methodes et coefficients experimentaux pour le calcul des protections de reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, J; Lafore, P; Millot, J P; Rastoin, J; Vathaire, F de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    1. The concept of an effective removal cross section has been developed in order more easily to compute reactor shielding thicknesses. We have built an experimental facility for the purpose of measuring effective removal cross sections, the value of which had not been published at that time. The first part of this paper describes the device or facility used, the computation method applied, and the results obtained. 2. Starting from this concept, we endeavored to define a removal cross section as a function of energy. This enabled us to use the method for computations bearing on the attenuation of fast neutrons of any spectrum. An experimental verification was carried out for the case of fission neutrons filtered by a substantial thickness of graphite. 3. Finally, we outline a computation method enabling us to determine the sources of captured gamma rays by the age theory and we give an example of the application in a composite shield. (author)Fren. [French] 1. La notion de section efficace effective de deplacement a ete introduite pour calculer commodement les epaisseurs de protection des reacteurs. Nous avons construit un dispositif experimental destine a mesurer les sections efficaces effectives de deplacement dont la valeur n'avait pas ete publiee a cette epoque. La premiere partie de cette communication decrit le dispositif utilise, la methode de calcul employee et les resultats obtenus. 2. A partir de cette notion, nous avons essaye de definir une section efficace de deplacement fonction de l'energie. Ceci permet d'utiliser la methode du deplacement pour des calculs d'attenuation de neutrons rapides dont le spectre est quelconque. Une verification experimentale a ete faite dans le cas de neutrons de fission filtres par une epaisseur notable de graphite. 3. Enfin une mde de calcul permettant de determiner les sources de gamma de capture par la theorie de l'age est exposee et un exemple d'application donne dans une protection composite. (auteur)

  18. Recent experimental results and diagnostics on LHD

    International Nuclear Information System (INIS)

    Kawahata, Kazuo

    2001-01-01

    LHD is a superconducting heliotron type device with 1=2/m=10 continuous helical coils and three pairs of poloidal coils. The major and minor radii of the plasma are 3.5-3.9 m and 0.6 m, respectively. The plasma experiment was started at the end of March 1998 with the magnetic field of 1.5 T. Subsequently, the magnetic field has been gradually increased checking carefully the stability of the SC coils, and the maximum magnetic field used in the plasma experiment was 2.89 T at the magnetic axis of R ax =3.6 m. The heating power has been gradually increased, i.e., NBI up to 5.2 MW (with two beam lines), ICRF up to 2.7 MW (with two antenna system), and ECRH up to 1.0 MW (with six gyrotron tubes). The carbon tiles were installed as divertor plates to meet high power heatings, resulting in significant reduction in metal impurity concentration (Fe) and total radiation power. Upgrading of the key hardware system has led to (i) higher Te [Te(0)=4.4 keV at =5.3x10 18 m -3 and P abs =1.8 MW], (ii) higher confinement [τ E =0.3 s, Te(0)=1.1 keV at =6.5x10 19 m -3 and P abs =2.0 MW], (iii) higher stored energy W p dia =1.0 MJ, (iv) the highest β value in helical devices [2.4% at 1.3 T, >30% at 0.5 T]. In this workshop, we will report the recent experimental results on the LHD and plasma diagnostics related to mm and sub-mm wave diagnostics. (author)

  19. Effect of metal shielding on a wireless power transfer system

    Directory of Open Access Journals (Sweden)

    Jiacheng Li

    2017-05-01

    Full Text Available In this paper, the effect of non-ferromagnetic metal shielding (NFMS material on the resonator of wireless power transfer (WPT is studied by modeling, simulation and experimental analysis. And, the effect of NFMS material on the power transfer efficiency (PTE of WPT systems is investigated by circuit model. Meanwhile, the effect of ferromagnetic metal shielding material on the PTE of WPT systems is analyzed through simulation. A double layer metal shield structure is designed. Experimental results demonstrate that by applying the novel double layer metal shielding method, the system PTE increases significantly while the electromagnetic field of WPT systems declines dramatically.

  20. Effect of metal shielding on a wireless power transfer system

    Science.gov (United States)

    Li, Jiacheng; Huang, Xueliang; Chen, Chen; Tan, Linlin; Wang, Wei; Guo, Jinpeng

    2017-05-01

    In this paper, the effect of non-ferromagnetic metal shielding (NFMS) material on the resonator of wireless power transfer (WPT) is studied by modeling, simulation and experimental analysis. And, the effect of NFMS material on the power transfer efficiency (PTE) of WPT systems is investigated by circuit model. Meanwhile, the effect of ferromagnetic metal shielding material on the PTE of WPT systems is analyzed through simulation. A double layer metal shield structure is designed. Experimental results demonstrate that by applying the novel double layer metal shielding method, the system PTE increases significantly while the electromagnetic field of WPT systems declines dramatically.

  1. Updating experimental results on light meson spectroscopy

    International Nuclear Information System (INIS)

    Diekmann, B.

    1991-06-01

    A recollection and summary is given on the understanding of light qanti q (q = u,d,s) mesons under the regime of the qanti q potential turning from a coulombic behaviour to a 'confining' one. In the second part the experimental knowledge obtained in the last years is updated: e + e - experiments, fixed target experiments with hadrons (kaons) and photons and panti p annihilations at LEAR discovered unknown objects and added new constraints on known but not fully understood states. (orig.)

  2. Design and characterization of a novel neutron shield for BNCT in an experimental model of oral cancer in the hamster cheek pouch at RA-3

    International Nuclear Information System (INIS)

    Pozzi, E.C.C.; Curotto, P.; Monti Hughes, A.; Nigg, D.W.; Schwint, A.E.; Trivillin, V.A.; Thorp, S.I.

    2013-01-01

    Our research group at the Radiation Pathology Division of the Department of Radiobiology (National Atomic Energy Commission) has previously demonstrated the therapeutic efficacy of different BNCT protocols to treat oral cancer in an experimental hamster cheek pouch model. In particular, to perform studies in this experimental model at the thermal facility constructed at RA-3, we designed and constructed a shielding device for thermal neutrons, to be able to expose the cheek pouch while minimizing the dose to the rest of the body. This device allowed for the irradiation of one animal at a time. Given the usage rate of the device, the aim of the present study was to design and construct an optimized version of the existing shielding device that would allow for the simultaneous irradiation of 2 animals at the thermal facility of RA-3. Taking into account the characteristics of the neutron source and preliminary biological assays, we designed the shielding device for the body of the animal, i.e. a rectangular shaped box with double acrylic walls. The space between the walls contains a continuous filling of 6Li 2 CO 3 (95% enriched in 6Li), approximately 6 mm thick. Two small windows interrupt the shield at one end of the box through which the right pouch of each hamster is everted out onto an external acrylic shelf for exposure to the neutron flux. The characterization of the shielding device showed that the neutron flux was equivalent at both irradiation positions confirming that we were able to design and construct a new shielding device that allows for the irradiation of 2 animals at the same time at the thermal facility of RA-3. This new version of the shielding device will reduce the number of interventions of the reactor operators, reducing occupational exposure to radiation and will make the procedure more efficient for researchers. In addition, we addressed the generation of tritium as a product of the capture reaction in lithium. It was considered as a

  3. Shielding practice

    International Nuclear Information System (INIS)

    Sauermann, P.F.

    1985-08-01

    The basis of shielding practice against external irradiation is shown in a simple way. For most sources of radiation (point sources) occurring in shielding practice, the basic data are given, mainly in the form of tables, which are required to solve the shielding problems. The application of these data is explained and discussed using practical examples. Thickness of shielding panes of glove boxes for α and β radiation; shielding of sealed γ-radiography sources; shielding of a Co-60 radiation source, and of the manipulator panels for hot cells; damping factors for γ radiation and neutrons; shielding of fast and thermal neutrons, and of bremsstrahlung (X-ray tubes, Kr-85 pressure gas cylinders, 42 MeV betatrons, 20 MeV linacs); two-fold shielding (lead glass windows for hot cells, 14 MeV neutron generators); shielding against scattered radiation. (orig./HP) [de

  4. PEP radiation shielding tests in SLAC A Beam

    International Nuclear Information System (INIS)

    Ash, W.; DeStaebler, H.; Harris, J.; Jenkins, T.; Murray, J.

    1977-09-01

    Radiation shielding tests designed to simulate possible conditions in and around the PEP experimental halls were conducted. The SLAC A Beam was targeted in the block tunnel at a point about midway between End Station A and Beam Dump East. At that site it was relatively easy to rearrange the concrete block structure to simulate the various shielding configurations under consideration for PEP. Extensive surveys of neutron and ionizing radiation were made. Complete results of the shielding tests are given

  5. Theoretical analysis and experimental investigation on performance of the thermal shield of accelerator cryomodules by thermo-siphon cooling of liquid nitrogen

    Science.gov (United States)

    Datta, T. S.; Kar, S.; Kumar, M.; Choudhury, A.; Chacko, J.; Antony, J.; Babu, S.; Sahu, S. K.

    2015-12-01

    Five beam line cryomodules with total 27 superconducting Radio Frequency (RF) cavities are installed and commissioned at IUAC to enhance the energy of heavy ion from 15 UD Pelletron. To reduce the heat load at 4.2 K, liquid nitrogen (LN2) cooled intermediate thermal shield is used for all these cryomodules. For three linac cryomodules, concept of forced flow LN2 cooling is used and for superbuncher and rebuncher, thermo-siphon cooling is incorporated. It is noticed that the shield temperature of superbuncher varies from 90 K to 110 K with respect to liquid nitrogen level. The temperature difference can't be explained by using the basic concept of thermo-siphon with the heat load on up flow line. A simple thermo-siphon experimental set up is developed to simulate the thermal shield temperature profile. Mass flow rate of liquid nitrogen is measured with different heat load on up flow line for different liquid levels. It is noticed that small amount of heat load on down flow line have a significant effect on mass flow rate. The present paper will be investigating the data generated from the thermosiphon experimental set up and a theoretical analysis will be presented here to validate the measured temperature profile of the cryomodule shield.

  6. [Trial manufacture of a plunger shield for a disposable plastic syringe].

    Science.gov (United States)

    Murakami, Shigeki; Emoto, Takashi; Mori, Hiroshige; Fujita, Katsuhisa; Kubo, Naoki

    2008-08-20

    A syringe-type radiopharmaceutical being supplied by a manufacturer has a syringe shield and a plunger shield, whereas an in-hospital labeling radiopharmaceutical is administered by a disposable plastic syringe without the plunger shield. In cooperation with Nihon Medi-Physics Co. Ltd., we have produced a new experimental plunger shield for the disposable plastic syringe. In order to evaluate this shielding effect, we compared the leaked radiation doses of our plunger shield with those of the syringe-type radiopharmaceutical (Medi shield type). Our plunger shield has a lead plate of 21 mm in diameter and 3 mm thick. This shield is equipped with the plunger-end of a disposal plastic syringe. We sealed 99mTc solution into a plastic syringe (Terumo Co.) of 5 ml with our plunger shield and Medi shield type of 2 ml. We measured leaked radiation doses around syringes using fluorescent glass dosimeters (Dose Ace). The number of measure points was 18. The measured doses were converted to 70 microm dose equivalent at 740 MBq of radioactivity. The results of our plunger shield and the Medi shield type were as follows: 4-13 microSv/h and 3-14 microSv/h at shielding areas, 3-545 microSv/h and 6-97 microSv/h at non-shielding areas, 42-116 microSv/h and 88-165 microSv/h in the vicinity of the syringe shield, and 1071 microSv/h and 1243 microSv/h at the front of the needle. For dose rates of shielding areas around the syringe, the shielding effects were approximately the same as those of the Medi shield type. In conclusion, our plunger shield may be useful for reducing finger exposure during the injection of an in-hospital labeled radiopharmaceutical.

  7. Experimental results of the betatron sum resonance

    International Nuclear Information System (INIS)

    Wang, Y.; Ball, M.; Brabson, B.

    1993-06-01

    The experimental observations of motion near the betatron sum resonance, ν x + 2ν z = 13, are presented. A fast quadrupole (Panofsky-style ferrite picture-frame magnet with a pulsed power supplier) producing a betatron tune shift of the order of 0.03 at rise time of 1 μs was used. This quadrupole was used to produce betatron tunes which jumped past and then crossed back through a betatron sum resonance line. The beam response as function of initial betatron amplitudes were recorded turn by turn. The correlated growth of the action variables, J x and J z , was observed. The phase space plots in the resonance frame reveal the features of particle motion near the nonlinear sum resonance region

  8. Shielding features of quarry stone

    International Nuclear Information System (INIS)

    Hernandez V, C.; Contreras S, H.; Hernandez A, L.; Baltazar R, A.; Escareno J, E.; Mares E, C. A.; Vega C, H. R.

    2010-10-01

    Quarry stone lineal attenuation coefficient for gamma-rays has been obtained. In Zacatecas, quarry stone is widely utilized as a decorative item in buildings, however its shielding features against gamma-rays unknown. The aim of this work is to determine the shielding properties of quarry stone against γ-rays using Monte Carlo calculations where a detailed model of a good geometry experimental setup was carried out. In the calculations 10 pieces 10 X 10 cm 2 of different thickness were utilized to evaluate the photons transmission as the quarry stone thickness is increased. It was noticed that transmitted photons decay away as the shield thickness is increased, these results were fitted to an exponential function were the linear attenuation coefficient was estimated. Also, using XCOM code the linear attenuation coefficient from several keV up to 100 MeV was estimated. From the comparison between Monte Carlo results and XCOM calculations a good agreement was found. For 0.662 MeV γ-rays the attenuation coefficient of quarry stone, whose density is 2.413 g-cm -3 , is 0.1798 cm -1 , this mean a X 1/2 = 3.9 cm, X 1/4 = 7.7 cm, X 1/10 = 12.8 cm, and X 1/100 = 25.6 cm. Having the information of quarry stone performance as shielding give the chance to use this material to shield X and γ-ray facilities. (Author)

  9. An experimental study of the shielding characteristics of the dwelling house building materials against gamma radiations in the Central Region of Syria

    International Nuclear Information System (INIS)

    Albarhoum, M.; Soufan, A.H.; Mustafa, H.

    2011-01-01

    Highlights: → We measure shielding properties of dwelling houses in the central region of Syria. → The concrete used for ceiling construction is good for shielding from gamma radiations. → Fairly high linear attenuation coefficients are obtained (from 0.173 to 0.198 cm -1 ). → Blocks used for house walls are not effective against gamma radiations. → Blocks efficiency can be improved by filling their holes with a cement paste. - Abstract: The shielding properties of the concrete and blocks used for the construction of dwelling houses in the Central Region of Syria (CRS) were measured and studied. The concrete used for the ceiling construction was found to have optimum shielding properties with 0.182 cm -1 (or equivalently 0.0859 cm 2 g -1 ) for the linear (mass) attenuation coefficient [L(M)AC]. In addition gamma radiation is attenuated by 73.221% on average, while the blocks used for the walls have smaller LACs (0.082 cm -1 for the bare blocks, and 0.118 cm -1 for the coated ones). Although the LACs for the blocks are smaller than those for the concrete their shielding properties are good to protect from the gamma radiations coming from radioactive or nuclear accidents (78.630% attenuation), even Chernobyl - like disasters, because of their big width (10-12 cm). The LACs were measured by an ionization chamber and simple theoretical calculations have been made to predict the concrete LACs. The calculations showed an average LAC for the six samples equal to 0.1664 cm -1 with 8.47% error with respect to the experimental values. The average LAC for the concrete used for ceiling construction in the CRS was found to be comparable or even better than the average of some international values for the reactor shielding concretes, which are about 0.163 cm -1 .

  10. Experimental reproduction of tumbleweed shield lichen (Xanthoparmelia chlorochroa) poisoning in a domestic sheep model.

    Science.gov (United States)

    Dailey, Rebecca N; Montgomery, Donald L; Ingram, James T; Siemion, Roger; Raisbeck, Merl F

    2008-11-01

    Xanthoparmelia chlorochroa, commonly called tumbleweed lichen, is found throughout the Rocky Mountain region. This particular species of lichen was incriminated in the poisoning of cattle and sheep in Wyoming during the 1930s. More than 70 years elapsed before another case was reported. There is virtually no information in the veterinary literature regarding toxicity of this lichen. This report describes X. chlorochroa poisoning in domestic sheep fed lichen collected from different locales and at different times of the year. Affected animals voided red urine and displayed incoordination. A transient spike in serum creatine kinase activity occurred in all ewes during the course of the feeding trial. Histologically, necrosis of a few individual appendicular skeletal myocytes was observed in 1 ewe, but grossly discernible myonecrosis was absent. The severity of clinical signs varied depending on the location and/or time of year the lichen was collected, indicating that toxicity of the lichen may be influenced by environmental conditions. Results demonstrate that domestic sheep are a useful model for further investigation of X. chlorochroa intoxication. The current study should act as a starting point for elucidating the pathogenesis of X. chlorochroa poisoning and aid in the development of a diagnostic assay to confirm lichen poisoning.

  11. Electromagnetic shielding

    International Nuclear Information System (INIS)

    Tzeng, Wen-Shian V.

    1991-01-01

    Electromagnetic interference (EMI) shielding materials are well known in the art in forms such as gaskets, caulking compounds, adhesives, coatings and the like for a variety of EMI shielding purposes. In the past, where high shielding performance is necessary, EMI shielding has tended to use silver particles or silver coated copper particles dispersed in a resin binder. More recently, aluminum core silver coated particles have been used to reduce costs while maintaining good electrical and physical properties. (author). 8 figs

  12. Metal alkyls programmed to generate metal alkylidenes by α-H abstraction: prognosis from NMR chemical shift† †Electronic supplementary information (ESI) available: Experimental and computational details, NMR spectra, results of NMR calculations and NCS analysis, graphical representation of shielding tensors, molecular orbital diagrams of selected compounds, optimized structures for all calculated species. See DOI: 10.1039/c7sc05039a

    Science.gov (United States)

    Gordon, Christopher P.; Yamamoto, Keishi; Searles, Keith; Shirase, Satoru

    2018-01-01

    Metal alkylidenes, which are key organometallic intermediates in reactions such as olefination or alkene and alkane metathesis, are typically generated from metal dialkyl compounds [M](CH2R)2 that show distinctively deshielded chemical shifts for their α-carbons. Experimental solid-state NMR measurements combined with DFT/ZORA calculations and a chemical shift tensor analysis reveal that this remarkable deshielding originates from an empty metal d-orbital oriented in the M–Cα–Cα′ plane, interacting with the Cα p-orbital lying in the same plane. This π-type interaction inscribes some alkylidene character into Cα that favors alkylidene generation via α-H abstraction. The extent of the deshielding and the anisotropy of the alkyl chemical shift tensors distinguishes [M](CH2R)2 compounds that form alkylidenes from those that do not, relating the reactivity to molecular orbitals of the respective molecules. The α-carbon chemical shifts and tensor orientations thus predict the reactivity of metal alkyl compounds towards alkylidene generation. PMID:29675237

  13. Wake Shield Target Protection

    International Nuclear Information System (INIS)

    Valmianski, Emanuil I.; Petzoldt, Ronald W.; Alexander, Neil B.

    2003-01-01

    The heat flux from both gas convection and chamber radiation on a direct drive target must be limited to avoid target damage from excessive D-T temperature increase. One of the possibilities of protecting the target is a wake shield flying in front of the target. A shield will also reduce drag force on the target, thereby facilitating target tracking and position prediction. A Direct Simulation Monte Carlo (DSMC) code was used to calculate convection heat loads as boundary conditions input into ANSYS thermal calculations. These were used for studying the quality of target protection depending on various shapes of shields, target-shield distance, and protective properties of the shield moving relative to the target. The results show that the shield can reduce the convective heat flux by a factor of 2 to 5 depending on pressure, temperature, and velocity. The protective effect of a shield moving relative to the target is greater than the protective properties of a fixed shield. However, the protective effect of a shield moving under the drag force is not sufficient for bringing the heat load on the target down to the necessary limit. Some other ways of diminishing heat flux using a protective shield are discussed

  14. Experimental results and analysis on hydrogen combustion

    International Nuclear Information System (INIS)

    Dorofeev, S.B.; Efimenko, A.A.; Kochurko, A.S.; Sidorov, V.P.; Bezmelnitsin, A.V.

    1994-01-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam-mixtures to undergo detonations and, equally important, to support design of the larger-scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperature between 300K and 650K at a fixed pressure of 0.1 MPa. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K to 650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments. Experiments were conducted to measure the rate of hydrogen oxidation in the absence of ignition sources at temperatures of 500K and 650K, for hydrogen-air mixtures of 15% and 50%, and for a mixture of equimolar hydrogen-air and 30% steam at 650K. The rate of hydrogen oxidation was found to be significant at 650K. Reduction of hydrogen concentration by chemical reaction from 50 to 44% hydrogen, and from 15 to 11% hydrogen, were observed on a time frame of minutes. The DeSoete rate equation predicts the 50% experiment very well, but greatly underestimates the reaction rate of the lean mixtures

  15. Calculation results and experimental testing of doppler feedback coefficients

    International Nuclear Information System (INIS)

    Yang Shunhai

    1989-01-01

    The Doppler feedback coefficients are calculated by the interpolation and group collapsing method from multigroup self-shielding factors and infinite dilution cross sections rather than effective resonance integrals by using resonance data base. Since many updated sets of multigroup data are in existence to be selected, the calculation process can be simplified. The heterogeneous effects are taken into account by equivalence relation. The computer code of Doppler feedback coefficients is created on computer CYBER-825 and PDP-11. The results calculated are in good agreement with the experiments

  16. Experimental results on RPC neutron sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; De Vecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P

    2003-08-01

    RPC neutron sensitivity has been studied during two tests done with different neutrons energies. In the first test, neutrons from spontaneous fission events of {sup 252}Cf were used (average energy 2 MeV); while in the second test neutrons were produced using a 50 MeV deuteron beam on a 1 cm thick beryllium target (average energy 20 MeV). Preliminary results show that the neutron sensitivity in double gap mode is (0.52{+-}0.03)x10{sup -3} at about 2 MeV and (5.3{+-}0.5)x10{sup -3} at about 20 MeV.

  17. Results of substitution of the Nal by a Ge detector in a simple shadow shield whole body counter

    International Nuclear Information System (INIS)

    Sahre, P.; Schoenmuth, T.; Thieme, K.

    1997-01-01

    Since 1976 a whole body counter (WBC) has been used at the Rossendorf Research Centre for measuring the internal contamination of workers. The WBC with the Germanium detector is given schematically and visually. The WBC is a shadow shield type with a tilted chair having only one detector. Table 1 contains the parameters of the WBC. It can be seen that the WBC is a simple counter. Therefore, taking into account the experiences of McCurdy, a lot of improvements were expected form the simple substitution of a HP Germanium detector for a NaI (TI) detector, i.e. despite a decrease in the sensitive detection volume, an enhancement of all quantifiable results (e.g. lower limit of detection and time for analysis of the spectrum) and above all the reliability and automation of nuclide identification were expected. (orig./SR)

  18. Results of substitution of the Nal by a Ge detector in a simple shadow shield whole body counter

    Energy Technology Data Exchange (ETDEWEB)

    Sahre, P.; Schoenmuth, T. [Nuclear Engineering and Analytics Inc. Rossendorf, Dresden (Germany); Thieme, K. [Amersham Buchler Ltd. und Co., Braunschweig (Germany)

    1997-12-01

    Since 1976 a whole body counter (WBC) has been used at the Rossendorf Research Centre for measuring the internal contamination of workers. The WBC with the Germanium detector is given schematically and visually. The WBC is a shadow shield type with a tilted chair having only one detector. Table 1 contains the parameters of the WBC. It can be seen that the WBC is a simple counter. Therefore, taking into account the experiences of McCurdy, a lot of improvements were expected form the simple substitution of a HP Germanium detector for a NaI (TI) detector, i.e. despite a decrease in the sensitive detection volume, an enhancement of all quantifiable results (e.g. lower limit of detection and time for analysis of the spectrum) and above all the reliability and automation of nuclide identification were expected. (orig./SR)

  19. Overview of the initial NSTX experimental results

    International Nuclear Information System (INIS)

    Ono, M.; Bell, M.G.; Bell, R.E.

    2001-01-01

    The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current I p was successfully brought up to the design value of 1 MA on 14 December 1999. The planned plasma shaping parameters, elongation κ=1:6-2.2 and triangularity δ=0:2-0.4, were achieved in inner wall limited, and single null and double null diverted configurations. The coaxial helicity injection (CHI) and high harmonic fast wave (HHFW) experiments were also initiated. CHI current of 27 kA produced up to 260 kA toroidal current without using an ohmic solenoid. With the injection of 2.3 MW of HHFW power, using 12 antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a central density of 3.5x10 13 cm 3 , increasing the plasma energy to 59 kJ and the toroidal β, β T , to 10%. The NBI system commenced operation in September 2000. The initial results with two ion sources (P NBI =2:8 MW) show good heating, producing a total plasma stored energy of 90 kJ corresponding to β T ∼18% at a plasma current of 1.1 MA. (author)

  20. Experimental results from the TFTR tokamak

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Arunasalam, V.; Bell, J.D.

    1986-10-01

    Recent experiments on TFTR have extended the operating regime of TFTR in both ohmic- and neutral-beam-heated discharges. The TFTR tokamak has reached its original machine design specifications (I/sub p/ = 2.5 MA and B/sub T/ = 5.2 T). Initial neutral-beam-heating experiments used up to 6.3 MW of deuterium beams. With the recent installation of two additional beamlines, the power has been increased up to 11 MW. A deuterium pellet injector was used to increase the central density to 2.5 x 10 20 m -3 in high current discharges. At the opposite extreme, by operating at low plasma current (I/sub p/ ∼ 0.8 MA) and low density (anti n/sub e/ ∼ 1 x 10 19 m -3 ), high ion temperatures (9 +- 2 keV) and rotation speeds (7 x 10 5 m/s) have been achieved during injection. In addition, plasma compression experiments have demonstrated acceleration of beam ions from 82 keV to 150 keV, in accord with expectations. The wide operating range of TFTR, together with an extensive set of diagnostics and a flexible control system, has facilitated transport and scaling studies of both ohmic- and neutral-beam-heated discharges. The results of these confinement studies are presented

  1. Experimental results from the TUMAN 3 tokamak

    International Nuclear Information System (INIS)

    Golant, V.E.; Andrejko, M.V.; Askinazi, L.G.; Korneev, V.A.; Krikunov, S.V.; Lipin, B.M.; Lebedev, S.V.; Levin, L.S.; Podushnikova, K.A.; Razdobarin, G.T.; Rozhansky, V.A.; Rozhdestvensky, V.V.; Tendler, M.; Tukachinsky, A.S.; Jaroshevich, S.P.

    1995-01-01

    The open-quote open-quote TUMAN-3 close-quote close-quote Tokamak programme concentrates on issues of improved confinement. In 1989 the transition from an ordinary Ohmic regime into an improved confinement mode was achieved. The signatures of the H-mode in auxiliary heated tokamaks have been observed in this regime. The crucial role of the boundary radial electric field was found in the experiments with internal bias probe. Other techniques were demonstrated to disturb the boundary plasma which led to H-mode triggering: short increase of working gas puffing, minor radius magnetic compression and pellet injection. The role scaling of the energy confinement time in the Ohmic H-mode was obtained, which differs dramatically from the scaling for the ordinary Ohmic regime. There were found a strong dependence of τ E on plasma current and a weak dependence on density. The maximum value of τ E was 10 times longer than in the ordinary Ohmic region. The τ E scaling for the Ohmic H-mode is consistent with the scaling proposed for devices with powerful auxiliary heating. The results shows that H-mode physics is universal in tokamaks with different geometries and heating methods. (AIP) copyright 1995 American Institute of Physics

  2. Overview of the initial NSTX experimental results

    International Nuclear Information System (INIS)

    Ono, M.; Bell, M.; Bell, R.

    2001-01-01

    The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current I p was successfully brought up to the design value of 1 million amperes on December 14, 1999. The planned plasma shaping parameters, κ=1.6-2.2 and δ=0.2-0.4, were achieved in inner limited, single null and double null configurations. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments were also initiated. A CHI injected current of 27 kA produced up to 260 kA of toroidal current without using an ohmic solenoid. With an injection of 2.3 MW of HHFW power, using twelve antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a central density of 3.5x10 13 cm -3 increasing the plasma energy to 59 kJ and the toroidal beta, β T to 10 %. Finally, the NBI system commenced operation in Sept. 2000. The initial results with two ion sources (P NBI =2.8MW) shows good heating, producing a total plasma stored energy of 90 kJ corresponding to β T ∼18% at a plasma current of 1.1 MA. (author)

  3. Overview of the Initial NSTX Experimental Results

    International Nuclear Information System (INIS)

    Ono, M.; Bell, M.; Bell, R. E.; Bigelow, T.; Bitter, M.

    2000-01-01

    The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current Ip was successfully brought up to the design value of 1 million amperes on December 14, 1999. The planned plasma shaping parameters, k = 1.6 ± 2.2 and d = 0.2 ± 0.4, were achieved in inner limited, single null and double null configurations. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments were also initiated. A CHI injected current of 27 kA produced up to 260 kA of toroidal current without using an ohmic solenoid. With an injection of 2.3 MW of HHFW power, using twelve antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a central density of 3.5 x 1013 cm-3 increasing the plasma energy to 59 kJ and the toroidal beta, bT to 10 %. Finally, the NBI system commenced operation in Sept. 2000. The initial results with two ion sources (PNBI = 2.8 MW) shows good heating, producing a total plasma stored energy of 90 kJ corresponding to bT = 18 % at a plasma current of 1.1 MA

  4. Overview of recent experimental results on MAST

    International Nuclear Information System (INIS)

    Lloyd, B.; Akers, R.J.; Ahn, J-W.

    2003-01-01

    The low aspect ratio of MAST allows differentiation between different forms of the H-mode threshold scaling. With optimised fuelling (inboard puffing) and magnetic configuration (connected DND) the H-mode power threshold data lie somewhat above ( ∼ x1.7) recent scaling laws. Slight magnetic configuration changes (of the order of the ion Larmor radius) around a connected DND significantly influence H-mode access. H-mode confinement in discharges with low frequency ELMs is generally consistent with the IPB98(y,2) scaling. Strong indications of both particle and energy internal transport barriers have been seen. Normalised beta values β N > 5 have been obtained, approaching the ideal n = 1 no wall external kink stability limit. Sawtooth triggered NTMs (3/2, 2/1) have been observed; numerical modelling of the island evolution reproduces mode behaviour well and confirms the significance of stabilising field curvature effects. Divertor power loading studies, including transient effects (e.g. due to ELMs), show a strong bias of power efflux to the outboard targets where it is more easily handled. ELM energy losses ΔW ELM are less than 4% of the stored energy in all regimes explored so far, but ELM effluxes extending 30cm outside the outboard separatrix have been measured. Toroidally asymmetric divertor biasing resulted in significant broadening of the Dα profile on the biased components and a reduction in the total power to the unbiased components. Halo current magnitudes and asymmetries are generally small compared with conventional tokamaks; recent measurements show that the plasma behaves more as a voltage source than a current source. Initial neutral beam current drive experiments indicate non-inductively driven current values (I NBI ∼ 0.3I p ) comparable with code predictions. (author)

  5. 40Ar/ 39Ar and paleomagnetic results from Liberia and the Precambrian APW data base for the West African Shield

    Science.gov (United States)

    Onstott, T. C.; Dorbor, J.

    Lower amphibolite to granulite facies metamorphic rocks in Nimba County, Liberia have yielded 2.2-2.9 Ga RbSr whole rock ages, indicating that they are part of the Archean Liberian age province. We report a 2040 Ma 4040Ar/ 39Ar plateau date on hornblende from an amphibolite in this region, and suggest that these rocks were also severelyreworked during the Eburnean (˜2.0 Ga) metamorphic episode. 40Ar/ 39Ar analyses of biotite and feldspars from neighboring schists also indicate the presence of two mild thermal events, at 1.5 Ga and 0.6 Ga. Paleomagnetic analyses of samples from these same metamorphic rocks reveal three components of magnetization. The predominant and most stable component (273°E, 21°N) is considered to have been acquired as a result of pos Eburnean uplift and cooling at ˜ 2.0 Ga, whereas the two less stable components with poles at 235°E, 43°N and 16°E, 36°N, probably correlate with the 1.5 Ga and 0.6 Ga thermal pulses, respectively. Rock units from southern Liberia also yield two secondary magnetizations, one at 247°E, 37°N and the other at 104°E, 5°N, and a 1.5 Ga 40Ar/ 39Ar date on plagioclase. Comparison of the paleomagnetic poles corresponding to the ˜2.0 Ga Eburnean component with published paleomagnetic data for West Africa is not consistent with prior interpretations of the polar wander path for West Africa. Our paleomagnetic data, when compared to poles of comparable age from the Kalahari Shield, still suggest that some form of displacement has occurred between the Kalahari and West African Shields since 2.0 Ga.

  6. Traffic noise in shielded urban areas: comparison of experimental data with model results

    NARCIS (Netherlands)

    Randrianoelina, A.; Salomons, E.M.

    2008-01-01

    Noise maps of cities are commonly produced with rather simple engineering models for sound propagation. These models may be inaccurate in complex urban situations, in particular in situations with street canyons. Street canyons are urban areas that are partly or completely enclosed by buildings, for

  7. Radiation shielding quality assurance

    Science.gov (United States)

    Um, Dallsun

    For the radiation shielding quality assurance, the validity and reliability of the neutron transport code MCNP, which is now one of the most widely used radiation shielding analysis codes, were checked with lot of benchmark experiments. And also as a practical example, follows were performed in this thesis. One integral neutron transport experiment to measure the effect of neutron streaming in iron and void was performed with Dog-Legged Void Assembly in Knolls Atomic Power Laboratory in 1991. Neutron flux was measured six different places with the methane detectors and a BF-3 detector. The main purpose of the measurements was to provide benchmark against which various neutron transport calculation tools could be compared. Those data were used in verification of Monte Carlo Neutron & Photon Transport Code, MCNP, with the modeling for that. Experimental results and calculation results were compared in both ways, as the total integrated value of neutron fluxes along neutron energy range from 10 KeV to 2 MeV and as the neutron spectrum along with neutron energy range. Both results are well matched with the statistical error +/-20%. MCNP results were also compared with those of TORT, a three dimensional discrete ordinates code which was developed by Oak Ridge National Laboratory. MCNP results are superior to the TORT results at all detector places except one. This means that MCNP is proved as a very powerful tool for the analysis of neutron transport through iron & air and further it could be used as a powerful tool for the radiation shielding analysis. For one application of the analysis of variance (ANOVA) to neutron and gamma transport problems, uncertainties for the calculated values of critical K were evaluated as in the ANOVA on statistical data.

  8. Results from the decontamination of and the shielding arrangements in the reactor pressure vessel in Oskarshamn 1-1994

    Energy Technology Data Exchange (ETDEWEB)

    Lowendahl, B. [OKG Aktiebolag, Figeholm (Sweden)

    1995-03-01

    In September 1992 Oskarshamn 1 was shut down in order to carry out measures to correct discovered deficiencies in the emergency cooling systems. Due to the results of a comprehensive non destructive test programme it was decided to perform a major replacement of pipes in the primary systems including a full system decontamination using the Siemens CORD process. The paper briefly presents the satisfying result of the decontamination performed in May-June 1993. When in late June 1993 cracks also were detected in the feed-water pipes situated inside the reactor pressure vessel (RPV) the plans were reconsidered and a large project was formed with the aim, in a first phase, to verify the integrity of the RPV. In order to make it possible to perform work manually inside the RPV special radiation protection measures had to be carried out. In January 1994 the lower region of the RPV was decontaminated, again using the CORD-process, followed by the installation of a special shielding construction in the RPV. The surprisingly good results of these efforts are also briefly described in the paper.

  9. Further analysis and evaluation of the results of the NATO common shield-DAT#7 experiment: defence against terrorism

    Science.gov (United States)

    Dill, Stephan; Peichl, Markus; Jirousek, Matthias; Süß, Helmut

    2009-09-01

    The contactless control of persons and the remote surveillance of sensitive infrastructures are important tasks in order to provide the required security measures to protect the human population against the threads of international terrorism. Passive microwave imaging allows a daytime independent observation and examination of objects and persons under nearly all adverse ambient conditions without artificial exposure, hence fully avoiding health risks. The penetration capability of microwaves provides the detection of objects through atmospheric obstacles like bad weather, fog or dust, vapour and smoke, as well as through thin non-metallic materials and clothing. For the latter the detection of hidden objects like weapons, explosives, and contraband is possible by monitoring dielectric anomalies. The experiment "Common Shield" is part of a perennial investigation series leaded by the "Center for Transformation of the German armed forces (Bundeswehr)". In 2008 the protection of soldiers and facilities was experimentally investigated under the aspect of a networked operational leadership. In this context as well a harbour protection trial was carried out in August/September 2008 at the naval base Eckernfoerde in Germany. This trial was part of the NATO CNADs program of work for "Defence Against Terrorism (DAT)" starting in 2003, and Germany is the lead nation for item 7 on "Technology for Intelligence, Surveillance, Reconnaissance & Target Acquisition of Terrorists (ISRTA)". One main activity in the Eckernfoerde trial was the simulation of a military entrance control facility by a tent including various imaging and a chemical sensor suite in order to provide security for a military camp. Besides commercial optical and infrared cameras various passive millimeter-wave imagers have been used from different German research institutions. The DLR Microwaves and Radar Institute, Department for Reconnaissance and Security (HR-AS), provided an imaging radiometer scanner

  10. Double-layer neutron shield design as neutron shielding application

    Science.gov (United States)

    Sariyer, Demet; Küçer, Rahmi

    2018-02-01

    The shield design in particle accelerators and other high energy facilities are mainly connected to the high-energy neutrons. The deep penetration of neutrons through massive shield has become a very serious problem. For shielding to be efficient, most of these neutrons should be confined to the shielding volume. If the interior space will become limited, the sufficient thickness of multilayer shield must be used. Concrete and iron are widely used as a multilayer shield material. Two layers shield material was selected to guarantee radiation safety outside of the shield against neutrons generated in the interaction of the different proton energies. One of them was one meter of concrete, the other was iron-contained material (FeB, Fe2B and stainless-steel) to be determined shield thicknesses. FLUKA Monte Carlo code was used for shield design geometry and required neutron dose distributions. The resulting two layered shields are shown better performance than single used concrete, thus the shield design could leave more space in the interior shielded areas.

  11. Shielding container

    International Nuclear Information System (INIS)

    Darling, K.A.M.

    1981-01-01

    A shielding container incorporates a dense shield, for example of depleted uranium, cast around a tubular member of curvilinear configuration for accommodating a radiation source capsule. A lining for the tubular member, in the form of a close-coiled flexible guide, provides easy replaceability to counter wear while the container is in service. Container life is extended, and maintenance costs are reduced. (author)

  12. Airborne concentrations of toxic metals resulting from the use of low melting point lead alloys to construct radiotherapy shielding

    International Nuclear Information System (INIS)

    McCullough, E.C.; Senjem, D.H.

    1981-01-01

    Determinations of airborne concentrations of lead, cadmium, bismuth, and tin were made above vessels containing a fusible lead alloy (158 0 F melting point) commonly used for construction of radiotherapy blocks. Fume concentrations were determined by collection on a membrane filter and analysis by atomic absorption spectrophotometry. Samples were obtained for alloy temperatures of 200 0 , 400 0 , and 600 0 F. In all instances, concentrations were much lower than the applicable occupational limits for continuous exposure. The results of this study indicate that the use of a vented hood as a means of reducing air concentrations of toxic metals above and near vessels containing low temperature melting point lead allows commonly used in construction of radiotherapy shields appears unjustifiable. However, proper handling procedures should be observed to avoid entry into the body via alternate pathways (e.g., ingestion or skin absorption). Transmission data of a non-cadmium containing lead alloy with a melting point of 203 0 F was ascertained and is reported on

  13. Studying the ability to use basalt in preparing radiation shielding concrete and the properties of the resulted concrete

    International Nuclear Information System (INIS)

    Alhajali, S.; Yousef, S.; Kanbour, M.; Naoum, B.

    2010-12-01

    Basalt is widespread rocks in the lands of Syria. This kind of rocks has high density relatively, high insulation properties and, mechanical and heat resistance. In this work several kinds of basalt rocks, which were collected from several sites, were studied. The analyses which were done, shows that the basalt rocks collected from Shahba, Nba'a Al-Sakhr and Almana'a mountain are suitable for high efficient gamma radiation shielding, but with low efficiency for neutron shielding, especially for thermal and epithermal neutrons. (author)

  14. Transmission test of the polyethylene shield against 40 and 65 MeV quasi monochrome neutron

    International Nuclear Information System (INIS)

    Nakao, Makoto; Nakamura, Takashi; Sakuya, Yoshimasa; Nauchi, Yasushi; Nakao, Noriaki; Tanaka, Susumu; Sakamoto, Yukio; Nakajima, Hiroshi; Nakane, Yoshihiro.

    1996-01-01

    Using 40 and 65 MeV quasi monochrome neutron of the AVF cyclotron installed at Takasaki Laboratory, Japan Atomic Energy Research Institute, the neutron energy spectra were measured after transmitting the polyethylene shield. Results of the shielding experiments using concrete and iron recognized as main shielding material were proposed previously. As data obtained in the experiments were useful for a bench-mark experiment to investigate for shielding calculation and sectional data set, a shielding calculation simulated with new experiment to compare with and investigate for the previous experimental data. As a result, it was found that calculation result of neutron flux transmitting through the polyethylene shield showed difference with increase of the shield thickness. And, reducing distance of the peak neutron was also found to be over-estimated in its calculation value, such as three and five times on 43 MeV at 120 and 180 cm thick, respectively. (G.K.)

  15. Development of Neutron Shielding Material for Cask and Accelerator

    International Nuclear Information System (INIS)

    Kang, Hee Young; Seo, Ki Seog; Lee, Byung Chul; Park, Chang Jae; Kim, Ho Dong

    2008-01-01

    The neutron shielding materials are used as a neutron shield for spent fuel shipping cask, beam accelerators and neutron generators. At early stage, the neutron attenuations of materials were evaluated with the cross sections. After that, benchmark or mock-up experiments on the multi-layer problem to confirm the shielding characteristics or to evaluate analysis accuracy were reported. Recently, the need to transport spent nuclear fuels is increasing due to the current limited storage capacity. The on-site storage capacity at some of nuclear power plants is expected to be full in near future. With a growing inventory of spent fuels at power plants, these spent fuels need to be transported to other storage facilities. Shipping casks have been developed to safely transport spent fuels that emit high neutrons and gamma-ray radiation. The external radiation level of the shipping cask from the spent fuel must be limited to meet the standards specified by the IAEA radioactive material package regulation, so it is important to develop a proper neutron shielding material for a shipping cask. Neutron shielding experiments and analyses on the shielding effects of materials have been conducted, and some experiments have been performed to examine the shielding effects of selected materials. The shielding experiments consist of evaluating not only the shielding effects of a material alone but also the effects of the material thickness. The experimental results were compared with those obtained by using the MCNP-5c code

  16. Shielding modefication and safety review on Mutsu

    International Nuclear Information System (INIS)

    Osanai, Masao

    1978-01-01

    The Japan Atomic Energy Commission requests strongly to repair the shielding and make general safety inspection on Mutsu after an accident of radiation leakage from the reactor. The content and procedure of this repair of shielding and general safety inspection are outlined. The neutron leakage location in the reactor proper, technical shielding investigation, conceptual design of relating shielding repair, the mock up test of the shielding on the neutron streaming, the final conceptual design of repair, the relating research and development experiment and the detailed basic design of repair are explained, comparing the original design and the modified one. The modified design depends on the experimental results of neutron streaming test between the reactor vessel and the primary shield. As for the general safety inspection, the functional test of control rod driving mechanism and other main components, the flaw detection for heat transfer tubes of the steam generator and primary cooling pipings are carried out in hardwares, and the integrity analysis of fuel assemblies, stress corrosion cracking of fuel claddings and primary cooling pipings, the natural circulation analysis of primary cooling system, and integrity check of the heat transfer tubes of steam generator are carried out in softwares. The burst test and the strength test after high temperature oxidation for fuel claddings made of stainless steel were carried out. (Nakai, Y.)

  17. Electromagnetic shield

    International Nuclear Information System (INIS)

    Miller, J.S.

    1987-01-01

    An electromagnetic shield is described comprising: closed, electrically-conductive rings, each having an open center; and binder means for arranging the rings in a predetermined, fixed relationship relative to each other, the so-arranged rings and binder means defining an outer surface; wherein electromagnetic energy received by the shield from a source adjacent its outer surface induces an electrical current to flow in a predetermined direction adjacent and parallel to the outer surface, through the rings; and wherein each ring is configured to cause source-induced alternating current flowing through the portion of the ring closest to the outer surface to electromagnetically induce an oppositely-directed current in the portion of the ring furthest from the surface, such oppositely-directed current bucking any source-induced current in the latter ring portion and thus reducing the magnitude of current flowing through it, whereby the electromagnetic shielding effected by the shield is enhanced

  18. Nuclear shields

    International Nuclear Information System (INIS)

    Linares, R.C.; Nienart, L.F.; Toelcke, G.A.

    1976-01-01

    A process is described for preparing melt-processable nuclear shielding compositions from chloro-fluoro substituted ethylene polymers, particularly PCTFE and E-CTFE, containing 1 to 75 percent by weight of a gadolinium compound. 13 claims, no drawings

  19. REACTOR SHIELD

    Science.gov (United States)

    Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  20. Calculation of concrete shielding wall thickness for 450kVp X-ray tube with MCNP simulation and result comparison with half value layer method calculation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Heon; Lee, Eun Joong; Kim, Chan Kyu; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Hur, Sam Suk [Sam Yong Inspection Engineering Co., Ltd., Seoul (Korea, Republic of)

    2016-11-15

    Radiation generating devices must be properly shielded for their safe application. Although institutes such as US National Bureau of Standards and National Council on Radiation Protection and Measurements (NCRP) have provided guidelines for shielding X-ray tube of various purposes, industry people tend to rely on 'Half Value Layer (HVL) method' which requires relatively simple calculation compared to the case of those guidelines. The method is based on the fact that the intensity, dose, and air kerma of narrow beam incident on shielding wall decreases by about half as the beam penetrates the HVL thickness of the wall. One can adjust shielding wall thickness to satisfy outside wall dose or air kerma requirements with this calculation. However, this may not always be the case because 1) The strict definition of HVL deals with only Intensity, 2) The situation is different when the beam is not 'narrow'; the beam quality inside the wall is distorted and related changes on outside wall dose or air kerma such as buildup effect occurs. Therefore, sometimes more careful research should be done in order to verify the effect of shielding specific radiation generating device. High energy X-ray tubes which is operated at the voltage above 400 kV that are used for 'heavy' nondestructive inspection is an example. People have less experience in running and shielding such device than in the case of widely-used low energy X-ray tubes operated at the voltage below 300 kV. In this study, Air Kerma value per week, outside concrete shielding wall of various thickness surrounding 450 kVp X-ray tube were calculated using MCNP simulation with the aid of Geometry Splitting method which is a famous Variance Reduction technique. The comparison between simulated result, HVL method result, and NCRP Report 147 safety goal 0.02 mGy wk-1 on Air Kerma for the place where the public are free to pass showed that concrete wall of thickness 80 cm is needed to achieve the

  1. Calculation of concrete shielding wall thickness for 450kVp X-ray tube with MCNP simulation and result comparison with half value layer method calculation

    International Nuclear Information System (INIS)

    Lee, Sang Heon; Lee, Eun Joong; Kim, Chan Kyu; Cho, Gyu Seong; Hur, Sam Suk

    2016-01-01

    Radiation generating devices must be properly shielded for their safe application. Although institutes such as US National Bureau of Standards and National Council on Radiation Protection and Measurements (NCRP) have provided guidelines for shielding X-ray tube of various purposes, industry people tend to rely on 'Half Value Layer (HVL) method' which requires relatively simple calculation compared to the case of those guidelines. The method is based on the fact that the intensity, dose, and air kerma of narrow beam incident on shielding wall decreases by about half as the beam penetrates the HVL thickness of the wall. One can adjust shielding wall thickness to satisfy outside wall dose or air kerma requirements with this calculation. However, this may not always be the case because 1) The strict definition of HVL deals with only Intensity, 2) The situation is different when the beam is not 'narrow'; the beam quality inside the wall is distorted and related changes on outside wall dose or air kerma such as buildup effect occurs. Therefore, sometimes more careful research should be done in order to verify the effect of shielding specific radiation generating device. High energy X-ray tubes which is operated at the voltage above 400 kV that are used for 'heavy' nondestructive inspection is an example. People have less experience in running and shielding such device than in the case of widely-used low energy X-ray tubes operated at the voltage below 300 kV. In this study, Air Kerma value per week, outside concrete shielding wall of various thickness surrounding 450 kVp X-ray tube were calculated using MCNP simulation with the aid of Geometry Splitting method which is a famous Variance Reduction technique. The comparison between simulated result, HVL method result, and NCRP Report 147 safety goal 0.02 mGy wk-1 on Air Kerma for the place where the public are free to pass showed that concrete wall of thickness 80 cm is needed to achieve the safety goal

  2. Parameters calculation of shielding experiment

    International Nuclear Information System (INIS)

    Gavazza, S.

    1986-02-01

    The radiation transport methodology comparing the calculated reactions and dose rates for neutrons and gama-rays, with experimental measurements obtained on iron shield, irradiated in the YAYOI reactor is evaluated. The ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system, for cross sections generation collapsed by the ANISN code were used. The transport calculations were made using the DOT 3.5 code, adjusting the boundary iron shield source spectrum to the reactions and dose rates, measured at the beginning of shield. The neutron and gamma ray distributions calculated on the iron shield presented reasonable agreement with experimental measurements. An experimental arrangement using the IEA-R1 reactor to determine a shielding benchmark is proposed. (Author) [pt

  3. Radiation shielding calculation using MCNP

    International Nuclear Information System (INIS)

    Masukawa, Fumihiro

    2001-01-01

    To verify the Monte Carlo code MCNP4A as a tool to generate the reference data in the shielding designs and the safety evaluations, various shielding benchmark experiments were analyzed using this code. These experiments were categorized in three types of the shielding subjects; bulk shielding, streaming, and skyshine. For the variance reduction technique, which is indispensable to get meaningful results with the Monte Carlo shielding calculation, we mainly used the weight window, the energy dependent Russian roulette and spitting. As a whole, our analyses performed enough small statistical errors and showed good agreements with these experiments. (author)

  4. Primary shield displacement and bowing

    International Nuclear Information System (INIS)

    Scott, K.V.

    1978-01-01

    The reactor primary shield is constructed of high density concrete and surrounds the reactor core. The inlet, outlet and side primary shields were constructed in-place using 2.54 cm (1 in) thick steel plates as the forms. The plates remained as an integral part of the shields. The elongation of the pressure tubes due to thermal expansion and pressurization is not moving through the inlet nozzle hardware as designed but is accommodated by outward displacement and bowing of the inlet and outlet shields. Excessive distortion of the shields may result in gas seal failures, intolerable helium gas leaks, increased argon-41 emissions, and shield cooling tube failures. The shield surveillance and testing results are presented

  5. Shielding in electron beams used in radiotherapy

    International Nuclear Information System (INIS)

    Sentenac, Irenee.

    1979-01-01

    The interactions of electron beams with initial energies between 7 and 30 MeV have been studied in various materials including polystyrene, aluminium, copper and lead. The following experimental results have been found: estimation of measurement point displacement in a cylindrical chamber and of its variations with electron beam energy, empirical relations between the energy at the surface and the practical range of the electrons in various materials, an estimation of the relative ionisation due to the 'bremsstrahlung' measured behind different materials with beam complete shielding. Improvement of electron beam collimation is suggested after analysis of the dose distribution behind partial shielding [fr

  6. Calculated shielding factors for selected European houses

    International Nuclear Information System (INIS)

    Hedemann Jensen, P.

    1984-12-01

    Shielding factors for gamma radiation from activity deposited on structures and ground surfaces have been calculated with the computer model DEPSHIELD for single-family and multi-storey buildings in France, United Kingdom and Denmark. For all three countries it was found that the shielding factors for single-family houses are approximately a factor of 2 - 10 higher that those for buildings with five or more storeys. Away from doors and windows the shielding factors for French, British, and Danish single-family houses are in the range 0.03 - 0.1, 0.06 - 0.4, and 0.07 - 0.3, respectively. The uncertainties of the calculations are discussed and DEPSHIELD-results are compared with other methods as well as with experimental results. (author)

  7. Radiation shielding

    International Nuclear Information System (INIS)

    Aitken, D.

    1979-01-01

    Shields for equipment in which ionising radiation is associated with high electrical gradients, for example X-ray tubes and particle accelerators, incorporate a radiation-absorbing metal, as such or as a compound, and are electrically non-conducting and can be placed in the high electrical gradient region of the equipment. Substances disclosed include dispersions of lead, tungsten, uranium or oxides of these in acrylics polyesters, PVC, ABS, polyamides, PTFE, epoxy resins, glass or ceramics. The material used may constitute an evacuable enclosure of the equipment or may be an external shield thereof. (U.K.)

  8. Self shielding in cylindrical fissile sources in the APNea system

    International Nuclear Information System (INIS)

    Hensley, D.

    1997-01-01

    In order for a source of fissile material to be useful as a calibration instrument, it is necessary to know not only how much fissile material is in the source but also what the effective fissile content is. Because uranium and plutonium absorb thermal neutrons so Efficiently, material in the center of a sample is shielded from the external thermal flux by the surface layers of the material. Differential dieaway measurements in the APNea System of five different sets of cylindrical fissile sources show the various self shielding effects that are routinely encountered. A method for calculating the self shielding effect is presented and its predictions are compared with the experimental results

  9. Master-Slave synchronization of robot manipulators: experimental results

    NARCIS (Netherlands)

    Bondhus, A.K.; Pettersen, K.Y.; Nijmeijer, H.

    2005-01-01

    This paper presents experimental results for master-slave synchronization of two robot manipulators using a recently developed observer-controller scheme. The paper aims to investigate the value and the limitations of the theory. In particular, the theoretical result of uniform ultimate boundedness

  10. Sodium fires. Progress achieved in research and experimental results

    International Nuclear Information System (INIS)

    Malet, J.C.; Duverger de Cuy, G.; Casselman, C.; Charpenel, J.; Natta, M.; Devillers, C.

    1979-08-01

    This paper describes the sodium fire programs undertaken by the CEA's Nuclear Safety Department. Experimental results concerning sodium ignition and combustion, sodium fire suppression, sodium aerosol filtration and sodium-concrete contact reactions are given and the applications of these results in the Super-Phenix reactor is discussed

  11. Evaluation of the shield calculation adequacy of radiotherapy rooms through Monte Carlo Method and experimental measures; Avaliacao da adequacao do calculo de blindagens de salas de radioterapia atraves do metodo de Monte Carlos e medidas experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Ramiro Conceicao

    2016-07-01

    The shielding calculation methodology for radiotherapy services adopted in Brazil and in several countries is that described in publication 151 of the National Council on Radiation Protection and Measurements (NCRP 151). This methodology however, markedly employs several approaches that can impact both in the construction cost and in the radiological safety of the facility. Although this methodology is currently well established by the high level of use, some parameters employed in the calculation methodology did not undergo to a detailed assessment to evaluate the impact of the various approaches considered. In this work the MCNP5 Monte Carlo code was used with the purpose of evaluating the above mentioned approaches. TVLs values were obtained for photons in conventional concrete (2.35g / cm{sup 3}), considering the energies of 6, 10 and 25 MeV, respectively, first considering an isotropic radiation source impinging perpendicular to the barriers, and subsequently a lead head shielding emitting a shaped beam, in the format of a pyramid trunk. Primary barriers safety margins, taking in account the head shielding emitting photon beam pyramid-shaped in the energies of 6, 10, 15 and 18 MeV were assessed. A study was conducted considering the attenuation provided by the patient's body in the energies of 6,10, 15 and 18 MeV, leading to new attenuation factors. Experimental measurements were performed in a real radiotherapy room, in order to map the leakage radiation emitted by the accelerator head shielding and the results obtained were employed in the Monte Carlo simulation, as well as to validate the entire study. The study results indicate that the TVLs values provided by (NCRP, 2005) show discrepancies in comparison with the values obtained by simulation and that there may be some barriers that are calculated with insufficient thickness. Furthermore, the simulation results show that the additional safety margins considered when calculating the width of the

  12. Multifunctional Hot Structure Heat Shield

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is performing preliminary development of a Multifunctional Hot Structure (HOST) heat shield for planetary entry. Results of this development will...

  13. Gonadal shield.

    Science.gov (United States)

    Purdy, J A; Stiteler, R D; Glasgow, G P; Mill, W B

    1975-10-01

    A secondary gonadal shield for use in the pelvic irradiation of males was designed and built using material and apparatus available with the Cerrobend blocking system. The gonadal dose was reduced to approximately 1.5 to 2.5% of the given dose.

  14. Thick Galactic Cosmic Radiation Shielding Using Atmospheric Data

    Science.gov (United States)

    Youngquist, Robert C.; Nurge, Mark A.; Starr, Stanley O.; Koontz, Steven L.

    2013-01-01

    NASA is concerned with protecting astronauts from the effects of galactic cosmic radiation and has expended substantial effort in the development of computer models to predict the shielding obtained from various materials. However, these models were only developed for shields up to about 120 g!cm2 in thickness and have predicted that shields of this thickness are insufficient to provide adequate protection for extended deep space flights. Consequently, effort is underway to extend the range of these models to thicker shields and experimental data is required to help confirm the resulting code. In this paper empirically obtained effective dose measurements from aircraft flights in the atmosphere are used to obtain the radiation shielding function of the earth's atmosphere, a very thick shield. Obtaining this result required solving an inverse problem and the method for solving it is presented. The results are shown to be in agreement with current code in the ranges where they overlap. These results are then checked and used to predict the radiation dosage under thick shields such as planetary regolith and the atmosphere of Venus.

  15. Experimental results on photon-photon interactions at Adone

    International Nuclear Information System (INIS)

    Baldini Celio, R.; Capon, G.; Fabbro, R. del; Santis, P. de; Grilli, M.; Iarocci, E.; Mencuccini, C.; Murtas, G.P.; Spinetti, M.; Valente, V.; Bacci, C.; Zorzi, C. de; Penso, G.; Stella, B.

    1979-01-01

    Experimental results for the reactions e + e - →e + e - +X are presented for X=e + e - ,μ + μ - ,π + π - ,eta'. A tagging technique has been used to detect final electrons and positrons. A QED test is performed and an upper limit of 20 keV is derived for the partial width GAMMA(eta'→γγ). (Auth.)

  16. First experimental results on CMOS Integrated Nickel Electroplated Resonators

    DEFF Research Database (Denmark)

    Yalcinkaya, Arda Deniz; Hansen, Ole

    2004-01-01

    This paper presents experimental results on MEMS metallic add-on post-fabrication effects on complementary metal oxide semiconductor (CMOS) transistors. Two versions of add-on processing, that use either e-beam evaporation or magnetron sputtering, are compared through investigation of the electri...

  17. Shielding design to obtain compact marine reactor

    International Nuclear Information System (INIS)

    Yamaji, Akio; Sako, Kiyoshi

    1994-01-01

    The marine reactors equipped in previously constructed nuclear ships are in need of the secondary shield which is installed outside the containment vessel. Most of the weight and volume of the reactor plants are occupied by this secondary shield. An advanced marine reactor called MRX (Marine Reactor X) has been designed to obtain a more compact and lightweight marine reactor with enhanced safety. The MRX is a new type of marine reactor which is an integral PWR (The steam generator is installed in the pressure vessel.) with adopting a water-filled containment vessel and a new shielding design method of no installation of the secondary shield. As a result, MRX is considerably lighter in weight and more compact in size as compared with the reactors equipped in previously constructed nuclear ships. For instance, the plant weight and volume of the containment vessel of MRX are about 50% and 70% of those of the Nuclear Ship MUTSU, in spite of the power of MRX is 2.8 times as large as the MUTSU's reactor. The shielding design calculation was made using the ANISN, DOT3.5, QAD-CGGP2 and ORIGEN codes. The computational accuracy was confirmed by experimental analyses. (author)

  18. Recent experimental results on Coherent Pion production in neutrino interactions

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L. [Columbia University, Nevis Labs Irvington on Hudson, New York 10533 (United States)

    2012-08-15

    Recent experimental results on charged current ({pi}{sup +}) coherent production by KEK and SciBooNE and neutral current ({pi}{sup 0}) production by MiniBooNE, SciBooNE and NOMAD will be discussed. The NOMAD results are at an average neutrino energy of 25 GeV whereas the energies of the other experiments are in an average energy range of 1-2 GeV. A comparison with some theoretical models will be presented.

  19. Shielding design of a brachytherapy unit at the Korle Bu teaching hospital in Ghana: Comparison of theoretical calculations and experimental study

    International Nuclear Information System (INIS)

    Arwui, C. C.; Schandorf, C.; Nani, K.; Darko, E. O.; Deatanyah, P.

    2010-01-01

    A theoretical study was carried out to re-evaluate the integrity of the biological shielding of 137 Cs brachytherapy unit at the Korle Bu Teaching Hospital (Ghana), and the results were verified by measurement of the dose rates at selected locations. The primary objective was to determine the current state of protection and safety of staff and the general public. Shielding design of the brachytherapy unit at the hospital was based on postulated workload and occupancy factors of the facility. The facility has been in existence for 12 y and has accumulated operational workload data that differs from the postulated one. The results show that despite the variation in actual and postulated workloads, the dose rates were below the reference values 0.5 mSv h -1 for public areas and 7.5 μSv h -1 for controlled areas. These values were in the range of 0.10-0.12 μSv h -1 for public areas and of 0.50-2.10 μSv h -1 for controlled areas. (authors)

  20. Selective shielding device for scintiphotography

    International Nuclear Information System (INIS)

    Harper, J.W.; Kay, T.D.

    1976-01-01

    A selective shielding device to be used in combination with a scintillation camera is described. The shielding device is a substantially oval-shaped configuration removably secured to the scintillation camera. As a result of this combination scanning of preselected areas of a patient can be rapidly and accurately performed without the requirement of mounting any type of shielding paraphernalia on the patient. 1 claim, 2 drawing figures

  1. Biological shield design for a 10 MeV Rhodotron

    International Nuclear Information System (INIS)

    Khalafi, H.; Ghane, A.; Safaei Arshi, S.; Tabakh, F.

    2012-01-01

    Highlights: ► We evaluate the produced radiations of the Rhodotron-TT200 and their attenuation to the permitted level. ► We apply analytical calculations to determine the shield material and thickness. ► We simulate the Rhodotron accelerator and its shielding using MCNPX code to make sure of results accuracy. -- Abstract: Radiation field of the Rhodotron-TT200 electron accelerator is determined in this study. Regarding the interactions of electron with matter, the produced radiations and their attenuation to the permitted level (i.e. 0.01 mrem/h) are evaluated and calculated. For this purpose analytical calculations are applied to determine the biological shield material and thickness. In order to make sure of results accuracy, Rhodotron accelerator and its shielding are simulated using MCNPX code and the results of analytical calculations and MCNPX code are compared with the experimental ones.

  2. Feedback control of a cupola - concepts and experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Moore, K.L. [Idaho State Univ., Pocatello, ID (United States); Abdelrahman, M.A. [Tenn. Technological Univ., Cookeville, TN (United States); Larsen, E.; Clark, D. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States); King, P. [US Dept. of Energy Albany Research Center, Albany, OR (United States)

    1998-10-01

    In this paper we present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. These results are summarized. Then we describe the experimental results obtained with the U.S. Department of Energy Albany Research Center`s research cupola. First, experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multi-loop controller. The resulting controller pairs meltrate with blast volume, iron temperature with oxygen addition, and carbon composition with percent coke. Special (nonlinear) filters are used to compute meltrate from actual scale readings of the amount of iron produced and to smooth the temperature measurement. The temperature and meltrate loops use single-loop PI control. The composition loop uses a Smith predictor to discount the deadtime associated with mass transport through the furnace. Experimental results validate the conceptual controller design and provide proof-of-concept of the idea of controlling a foundry cupola. Future research directions are discussed, including the concept of an integrated, intelligent industrial process controller, or I{sup 3}PC.

  3. Omni-directional selective shielding material based on amorphous glass coated microwires.

    Science.gov (United States)

    Ababei, G; Chiriac, H; David, V; Dafinescu, V; Nica, I

    2012-01-01

    The shielding effectiveness of the omni-directional selective shielding material based on CoFe-glass coated amorphous wires in 0.8 GHz-3 GHz microwave frequency range is investigated. The measurements were done in a controlled medium using a TEM cell and in the free space using horn antennas, respectively. Experimental results indicate that the composite shielding material can be developed with desired shielding effectiveness and selective absorption of the microwave frequency range by controlling the number of the layers and the length of microwires.

  4. Radiation shielding

    International Nuclear Information System (INIS)

    Yue, D.D.

    1979-01-01

    Details are given of a cylindrical electric penetration assembly for carrying instrumentation leads, used in monitoring the performance of a nuclear reactor, through the containment wall of the reactor. Effective yet economical shielding protection against both fast neutron and high-energy gamma radiation is provided. Adequate spacing within the assembly allows excessive heat to be efficiently dissipated and means of monitoring all potential radiation and gas leakage paths are provided. (UK)

  5. Shielded container

    International Nuclear Information System (INIS)

    Fries, B.A.

    1978-01-01

    A shielded container for transportation of radioactive materials is disclosed in which leakage from the container is minimized due to constructional features including, inter alia, forming the container of a series of telescoping members having sliding fits between adjacent side walls and having at least two of the members including machine sealed lids and at least two of the elements including hand-tightenable caps

  6. Thermodynamic properties of indan: Experimental and computational results

    International Nuclear Information System (INIS)

    Chirico, Robert D.; Steele, William V.; Kazakov, Andrei F.

    2016-01-01

    Highlights: • Heat capacities were measured for the temperature range (5 to 445) K. • Vapor pressures were measured for the temperature range (338 to 495) K. • Densities at saturation pressure were measured from T = (323 to 523) K. • Computed and experimentally derived properties for ideal gas entropies are in excellent accord. • Thermodynamic consistency analysis revealed anomalous literature data. - Abstract: Measurements leading to the calculation of thermodynamic properties in the ideal-gas state for indan (Chemical Abstracts registry number [496-11-7], 2,3-dihydro-1H-indene) are reported. Experimental methods were adiabatic heat-capacity calorimetry, differential scanning calorimetry, comparative ebulliometry, and vibrating-tube densitometry. Molar thermodynamic functions (enthalpies, entropies, and Gibbs energies) for the condensed and ideal-gas states were derived from the experimental studies at selected temperatures. Statistical calculations were performed based on molecular geometry optimization and vibrational frequencies calculated at the B3LYP/6-31+G(d, p) level of theory. Computed ideal-gas properties derived with the rigid-rotor harmonic-oscillator approximation are shown to be in excellent accord with ideal-gas entropies derived from thermophysical property measurements of this research, as well as with experimental heat capacities for the ideal-gas state reported in the literature. Literature spectroscopic studies and ab initio calculations report a range of values for the barrier to ring puckering. Results of the present work are consistent with a large barrier that allows use of the rigid-rotor harmonic-oscillator approximation for ideal-gas entropy and heat-capacity calculations, even with the stringent uncertainty requirements imposed by the calorimetric and physical property measurements reported here. All experimental results are compared with property values reported in the literature.

  7. Radiation shield for nuclear reactors

    International Nuclear Information System (INIS)

    Weissenfluh, J.A.

    1978-01-01

    A shield for use with nuclear reactor systems to attenuate radiation resulting from reactor operation is described. The shield comprises a container preferably of a thin, flexible or elastic material, which may be in the form of a bag, a mattress, a toroidal segment or toroid or the like filled with radiation attenuating liuid. Means are provided in the container for filling and draining the container in place. Due to its flexibility, the shield readily conforms to irregularities in surfaces with which it may be in contact in a shielding position

  8. Recent experimental results on level densities for compound reaction calculations

    International Nuclear Information System (INIS)

    Voinov, A.V.

    2012-01-01

    There is a problem related to the choice of the level density input for Hauser-Feshbach model calculations. Modern computer codes have several options to choose from but it is not clear which of them has to be used in some particular cases. Availability of many options helps to describe existing experimental data but it creates problems when it comes to predictions. Traditionally, different level density systematics are based on experimental data from neutron resonance spacing which are available for a limited spin interval and one parity only. On the other hand reaction cross section calculations use the total level density. This can create large uncertainties when converting the neutron resonance spacing to the total level density that results in sizable uncertainties in cross section calculations. It is clear now that total level densities need to be studied experimentally in a systematic manner. Such information can be obtained only from spectra of compound nuclear reactions. The question is does level densities obtained from compound nuclear reactions keep the same regularities as level densities obtained from neutron resonances- Are they consistent- We measured level densities of 59-64 Ni isotopes from proton evaporation spectra of 6,7 Li induced reactions. Experimental data are presented. Conclusions of how level density depends on the neutron number and on the degree of proximity to the closed shell ( 56 Ni) are drawn. The level density parameters have been compared with parameters obtained from the analysis of neutron resonances and from model predictions

  9. Results of experimental electromagnetic studies of the Crimean region

    OpenAIRE

    Burakhovich, T. K.; Kushnir, A. M.; Nikolaev, I. Yu.; Sheremet, E. M.; Shirkov, B. I.

    2017-01-01

    Spatial-temporal pattern of distribution of geomagnetic variations and the electric field on the Earth’s surface was obtained as a result of the modern experimental observations conducted in 2007—2013 along 9 profiles (48 points) by the methods of magnetotelluric sounding (MTS) and magnetovariation profiling (MVP). These profiles cross various geological structures of the Crimean region. It is possible to estimate the value of the electrical conductivity and vertical and horizontal geoelectri...

  10. Primarily Experimental Results for a W Wire Array Z Pinch

    International Nuclear Information System (INIS)

    Kuai Bin; Aici, Qiu; Wang Liangping; Zeng Zhengzhong; Wang Wensheng; Cong Peitian; Gai Tongyang; Wei Fuli; Guo Ning; Zhang Zhong

    2006-01-01

    Primarily experimental results are given for a W wire array Z pinch imploded with up to 2 MA in 100 ns on a Qiangguang-I pulsed power generator. The configuration and parameters of the generator, the W wire array load assembly and the diagnostic system for the experiment are described. The total X-ray energy has been obtained with a averaged power of X-ray radiation of 1.28 TW

  11. Heavy ions testing experimental results on programmable integrated circuits

    International Nuclear Information System (INIS)

    Velazco, R.; Provost-Grellier, A.

    1988-01-01

    The natural radiation environment in space has been shown to produce anomalies in satellite-borne microelectronics. It becomes then mandatory to define qualification strategies allowing to choose the less vulnerable circuits. In this paper, is presented a strategy devoted to one of the most critical effects, the soft errors (so called upset). The method addresses programmable integrated circuits i.e. circuits able to execute an instruction or command set. Experimental results on representative circuits will illustrate the approach. 11 refs [fr

  12. Testing of the PELSHIE shielding code using Benchmark problems and other special shielding models

    International Nuclear Information System (INIS)

    Language, A.E.; Sartori, D.E.; De Beer, G.P.

    1981-08-01

    The PELSHIE shielding code for gamma rays from point and extended sources was written in 1971 and a revised version was published in October 1979. At Pelindaba the program is used extensively due to its flexibility and ease of use for a wide range of problems. The testing of PELSHIE results with the results of a range of models and so-called Benchmark problems is desirable to determine possible weaknesses in PELSHIE. Benchmark problems, experimental data, and shielding models, some of which were resolved by the discrete-ordinates method with the ANISN and DOT 3.5 codes, were used for the efficiency test. The description of the models followed the pattern of a classical shielding problem. After the intercomparison with six different models, the usefulness of the PELSHIE code was quantitatively determined [af

  13. MMW [multimegawatt] shielding design and analysis

    International Nuclear Information System (INIS)

    Olson, A.P.

    1988-01-01

    Reactor shielding for multimegawatt (MMW) space power must satisfy a mass constraint as well as performance specifications for neutron fluence and gamma dose. A minimum mass shield is helpful in attaining the launch mass goal for the entire vehicle, because the shield comprises about 1% to 2% of the total vehicle mass. In addition, the shield internal heating must produce tolerable temperatures. The analysis of shield performance for neutrons and gamma rays is emphasized. Topics addressed include cross section preparation for multigroup 2D S/sub n/-transport analyses, and the results of parametric design studies on shadow shield performance and mass versus key shield design variables such as cone angle, number, placement, and thickness of layers of tungsten, and shield top radius. Finally, adjoint methods are applied to the shield in order to spatially map its relative contribution to dose reduction, and to provide insight into further design optimization. 7 refs., 2 figs., 3 tabs

  14. Experimental results pertaining to the performance of thermal igniters

    International Nuclear Information System (INIS)

    Carmel, M.K.

    1989-10-01

    This report summarizes the results of various experimental programs regarding the performance of thermal igniters for the deliberate ignition of hydrogen in light water reactors. Experiments involving both premixed combustion and combustion with continuous hydrogen injection are reviewed. Combustion characteristics examined include flammability limits of hydrogen:air and hydrogen:air:steam mixtures, combustion pressure rises, combustion completeness, flame speeds, and heat transfer aspects. Comparisons of igniter type and igniter reliability under simulated reactor accident conditions are included. The results of the research programs provide a broad data base covering nearly all aspects of hydrogen combustion related to the performance of deliberate ignition systems

  15. Prediction for disruption erosion of ITER plasma facing components; a comparison of experimental and numerical results

    International Nuclear Information System (INIS)

    Laan, J.G. van der; Akiba, M.; Seki, M.; Hassanein, A.; Tanchuk, V.

    1991-01-01

    An evaluation is given for the prediction for disruption erosion in the International Thermonuclear Engineering Reactor (ITER). At first, a description is given of the relation between plasma operating paramters and system dimensions to the predictions of loading parameters of Plasma Facing Components (PFC) in off-normal events. Numerical results from ITER parties on the prediction of disruption erosion are compared for a few typical cases and discussed. Apart from some differences in the codes, the observed discrepancies can be ascribed to different input data of material properties and boundary conditions. Some physical models for vapour shielding and their effects on numerical results are mentioned. Experimental results from ITER parties, obtained with electron and laser beams, are also compared. Erosion rates for the candidate ITER PFC materials are shown to depend very strongly on the energy deposition parameters, which are based on plasma physics considerations, and on the assumed material loss mechanisms. Lifetimes estimates for divertor plate and first wall armour are given for carbon, tungsten and beryllium, based on the erosion in the thermal quench phase. (orig.)

  16. OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

    Directory of Open Access Journals (Sweden)

    Lushnikov Sergey V.

    2006-08-01

    Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

  17. Benchmarks for evaluation of shielding calculations

    International Nuclear Information System (INIS)

    Coelho, P.R.P.; Maiorino, J.R.

    1989-01-01

    The spatial-energy neutron distribution emerging from a laminated shielding (stainless, polyethylene and lead) were measured by a fast neutron spectrometer and some experimental results were compared with those calculated by a network of codes. The source neutrons incident in the shielding were 14 MeV neutrons from a H-3(d,n)He-4 reaction coming from a Van de Graaff accelerator. Experimentally was verified a good radial symmetry of neutron energy-spectrum, and also a moderation and attenuation effect for points located out of the central axis of symmetry. These results indicate that the experiment can be well modelated by R-Z geometry. A neutron-energy spectra calculated by DOT 3.5 was compared with the measured spectra, showing a good agreement in the shape and value of the spectra (12% for an integrated spectrum from 2 to 16 MeV). (author) [pt

  18. The IPIRG-1 pipe system fracture tests: Experimental results

    International Nuclear Information System (INIS)

    Scott, P.; Olson, R.J.; Wilkowski, G.M.

    1994-01-01

    As part of the First International Piping Integrity Research Group (IPIRG-1) program, six dynamic pipe system experiments were conducted. The objective of these experiments was to generate experimental data to assess analysis methodologies for characterizing the fracture behavior of circumferentially cracked pipe in a representative piping system subjected to combined inertial and displacement-controlled stresses. A unique experimental facility was designed and constructed. The pipe system evaluated was an expansion loop with over 30 m (100 feet) of 16-inch nominal diameter Schedule 100 pipe. The experimental facility was equipped with special hardware to ensure that system boundary conditions could be appropriately modeled. The test matrix involved one uncracked and five cracked dynamic pipe system experiments. The uncracked-pipe experiment was conducted to evaluate the piping system damping and natural frequency characteristics. The cracked-pipe experiments were conducted to evaluate the fracture behavior, piping system response, and fracture stability characteristics of five different materials. All cracked-pipe experiments were conducted at PWR conditions. Material characterization efforts provided the tensile and fracture toughness properties of the different pipe materials at various strain rates and temperatures. Key results from the six pipe system experiments and material characterization efforts are presented. Detailed analyses will be published in a companion paper

  19. Comparison the Results of Numerical Simulation And Experimental Results for Amirkabir Plasma Focus Facility

    Science.gov (United States)

    Goudarzi, Shervin; Amrollahi, R.; Niknam Sharak, M.

    2014-06-01

    In this paper the results of the numerical simulation for Amirkabir Mather-type Plasma Focus Facility (16 kV, 36μF and 115 nH) in several experiments with Argon as working gas at different working conditions (different discharge voltages and gas pressures) have been presented and compared with the experimental results. Two different models have been used for simulation: five-phase model of Lee and lumped parameter model of Gonzalez. It is seen that the results (optimum pressures and current signals) of the Lee model at different working conditions show better agreement than lumped parameter model with experimental values.

  20. Comparison the results of numerical simulation and experimental results for Amirkabir plasma focus facility

    International Nuclear Information System (INIS)

    Goudarzi, Shervin; Amrollahi, R; Sharak, M Niknam

    2014-01-01

    In this paper the results of the numerical simulation for Amirkabir Mather-type Plasma Focus Facility (16 kV, 36μF and 115 nH) in several experiments with Argon as working gas at different working conditions (different discharge voltages and gas pressures) have been presented and compared with the experimental results. Two different models have been used for simulation: five-phase model of Lee and lumped parameter model of Gonzalez. It is seen that the results (optimum pressures and current signals) of the Lee model at different working conditions show better agreement than lumped parameter model with experimental values.

  1. ANOVA parameters influence in LCF experimental data and simulation results

    Directory of Open Access Journals (Sweden)

    Vercelli A.

    2010-06-01

    Full Text Available The virtual design of components undergoing thermo mechanical fatigue (TMF and plastic strains is usually run in many phases. The numerical finite element method gives a useful instrument which becomes increasingly effective as the geometrical and numerical modelling gets more accurate. The constitutive model definition plays an important role in the effectiveness of the numerical simulation [1, 2] as, for example, shown in Figure 1. In this picture it is shown how a good cyclic plasticity constitutive model can simulate a cyclic load experiment. The component life estimation is the subsequent phase and it needs complex damage and life estimation models [3-5] which take into account of several parameters and phenomena contributing to damage and life duration. The calibration of these constitutive and damage models requires an accurate testing activity. In the present paper the main topic of the research activity is to investigate whether the parameters, which result to be influent in the experimental activity, influence the numerical simulations, thus defining the effectiveness of the models in taking into account of all the phenomena actually influencing the life of the component. To obtain this aim a procedure to tune the parameters needed to estimate the life of mechanical components undergoing TMF and plastic strains is presented for commercial steel. This procedure aims to be easy and to allow calibrating both material constitutive model (for the numerical structural simulation and the damage and life model (for life assessment. The procedure has been applied to specimens. The experimental activity has been developed on three sets of tests run at several temperatures: static tests, high cycle fatigue (HCF tests, low cycle fatigue (LCF tests. The numerical structural FEM simulations have been run on a commercial non linear solver, ABAQUS®6.8. The simulations replied the experimental tests. The stress, strain, thermal results from the thermo

  2. Experimental results for a novel rotary active magnetic regenerator

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Eriksen, Dan; Bahl, Christian

    2012-01-01

    Active magnetic regenerator (AMR) refrigerators represent an alternative to vapor compression technology and have great potential in realizing cooling devices with high efficiency, which are highly desirable for a broad range of applications. The technology relies on the magnetocaloric effect...... in a solid refrigerant rather than the temperature change that occurs when a gas is compressed/expanded. This paper presents the general considerations for the design and construction of a high frequency rotary AMR device. Experimental results are presented at various cooling powers for a range of operating...

  3. Pre-evaluation of fusion shielding benchmark experiment

    International Nuclear Information System (INIS)

    Hayashi, K.; Handa, H.; Konno, C.

    1994-01-01

    Shielding benchmark experiment is very useful to test the design code and nuclear data for fusion devices. There are many types of benchmark experiments that should be done in fusion shielding problems, but time and budget are limited. Therefore it will be important to select and determine the effective experimental configurations by precalculation before the experiment. The authors did three types of pre-evaluation to determine the experimental assembly configurations of shielding benchmark experiments planned in FNS, JAERI. (1) Void Effect Experiment - The purpose of this experiment is to measure the local increase of dose and nuclear heating behind small void(s) in shield material. Dimension of the voids and its arrangements were decided as follows. Dose and nuclear heating were calculated both for with and without void(s). Minimum size of the void was determined so that the ratio of these two results may be larger than error of the measurement system. (2) Auxiliary Shield Experiment - The purpose of this experiment is to measure shielding properties of B 4 C, Pb, W, and dose around superconducting magnet (SCM). Thickness of B 4 C, Pb, W and their arrangement including multilayer configuration were determined. (3) SCM Nuclear Heating Experiment - The purpose of this experiment is to measure nuclear heating and dose distribution in SCM material. Because it is difficult to use liquid helium as a part of SCM mock up material, material composition of SCM mock up are surveyed to have similar nuclear heating property of real SCM composition

  4. Shielding structure analysis for LSDS facility

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Yeop; Kim, Jeong Dong; Lee, Yong Deok; Kim, Ho Dong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The nuclear material (Pyro, Spent nuclear fuel) itself and the target material to generate neutrons is the LSDS system for isotopic fissile assay release of high intensity neutron and gamma rays. This research was performed to shield from various strong radiation. A shielding evaluation was carried out with a facilities model of LSDS system. The MCNPX 2.5 code was used and a shielding evaluation was performed for the shielding structure and location. The radiation dose based on the hole structure and location of the wall was evaluated. The shielding evaluation was performed to satisfy the safety standard for a normal person (1 μSv/h) and to use enough interior space. The MCNPX2.5 code was used and a dose evaluation was performed for the location of the shielding material, shielding structure, and hole structure. The evaluation result differs according to the shielding material location. The dose rate was small when the shielding material was positioned at the center. The dose evaluation result regarding the location of the shielding material was applied to the facility and the shielding thickness was determined (In 50 cm + Borax 5 cm + Out 45cm). In the existing hole structure, the radiation leak is higher than the standard. A hole structure model to prevent leakage of radiation was proposed. The general public dose limit was satisfied when using the concrete reinforcement and a zigzag structure. The shielding result will be of help to the facility shielding optimization.

  5. Shielding structure analysis for LSDS facility

    International Nuclear Information System (INIS)

    Choi, Hong Yeop; Kim, Jeong Dong; Lee, Yong Deok; Kim, Ho Dong

    2014-01-01

    The nuclear material (Pyro, Spent nuclear fuel) itself and the target material to generate neutrons is the LSDS system for isotopic fissile assay release of high intensity neutron and gamma rays. This research was performed to shield from various strong radiation. A shielding evaluation was carried out with a facilities model of LSDS system. The MCNPX 2.5 code was used and a shielding evaluation was performed for the shielding structure and location. The radiation dose based on the hole structure and location of the wall was evaluated. The shielding evaluation was performed to satisfy the safety standard for a normal person (1 μSv/h) and to use enough interior space. The MCNPX2.5 code was used and a dose evaluation was performed for the location of the shielding material, shielding structure, and hole structure. The evaluation result differs according to the shielding material location. The dose rate was small when the shielding material was positioned at the center. The dose evaluation result regarding the location of the shielding material was applied to the facility and the shielding thickness was determined (In 50 cm + Borax 5 cm + Out 45cm). In the existing hole structure, the radiation leak is higher than the standard. A hole structure model to prevent leakage of radiation was proposed. The general public dose limit was satisfied when using the concrete reinforcement and a zigzag structure. The shielding result will be of help to the facility shielding optimization

  6. Penetration shielding applications of CYLSEC

    International Nuclear Information System (INIS)

    Dexheimer, D.T.; Hathaway, J.M.

    1985-01-01

    Evaluation of penetration and discontinuity shielding is necessary to meet 10CFR20 regulations for ensuring personnel exposures are as low as reasonably achievable (ALARA). Historically, those shielding evaluations have been done to some degree on all projects. However, many early plants used conservative methods due to lack of an economical computer code, resulting in costly penetration shielding programs. With the increased industry interest in cost effectively reducing personnel exposures to meet ALARA regulations and with the development of the CYLSEC gamma transport computer code at Bechtel, a comprehensive effort was initiated to reduce penetration and discontinuity shielding but still provide a prudent degree of protection for plant personnel from radiation streaming. This effort was more comprehensive than previous programs due to advances in shielding analysis technology and increased interest in controlling project costs while maintaining personnel exposures ALARA. Methodology and resulting cost savings are discussed

  7. Comparison of ATHENA/RELAP results against ice experimental data

    CERN Document Server

    Moore-Richard, L

    2002-01-01

    In order to demonstrate the adequacy of the International Thermonuclear Experimental Reactor design from a safety stand point as well as investigating the behavior of two-phase flow phenomena during an ingress of coolant event, an integrated ICE test facility was constructed in Japan. The data generated from the ICE facility offers a valuable means to validate computer codes such as ATHENA /RELAP5, which is one of the codes used at the Idaho National Engineering And Environmental Laboratory (INEEL) to evaluate the safety of various fusion reactor concepts. In this paper we compared numerical results generated by the ATHENA code with corresponding test data from the ICE facility. Overall we found good agreement between the test data and the predicted results.

  8. Electrical and thermal behavior of unsaturated soils: experimental results

    Science.gov (United States)

    Nouveau, Marie; Grandjean, Gilles; Leroy, Philippe; Philippe, Mickael; Hedri, Estelle; Boukcim, Hassan

    2016-05-01

    When soil is affected by a heat source, some of its properties are modified, and in particular, the electrical resistivity due to changes in water content. As a result, these changes affect the thermal properties of soil, i.e., its thermal conductivity and diffusivity. We experimentally examine the changes in electrical resistivity and thermal conductivity for four soils with different grain size distributions and clay content over a wide range of temperatures, from 20 to 100 °C. This temperature range corresponds to the thermal conditions in the vicinity of a buried high voltage cable or a geothermal system. Experiments were conducted at the field scale, at a geothermal test facility, and in the laboratory using geophysical devices and probing systems. The results show that the electrical resistivity decreases and the thermal conductivity increases with temperature up to a critical temperature depending on soil types. At this critical temperature, the air volume in the pore space increases with temperature, and the resulting electrical resistivity also increases. For higher temperatures , the thermal conductivity increases sharply with temperature up to a second temperature limit. Beyond it, the thermal conductivity drops drastically. This limit corresponds to the temperature at which most of the water evaporates from the soil pore space. Once the evaporation is completed, the thermal conductivity stabilizes. To explain these experimental results, we modeled the electrical resistivity variations with temperature and water content in the temperature range 20 - 100°C, showing that two critical temperatures influence the main processes occurring during heating at temperatures below 100 °C.

  9. Technical Note: Experimental results from a prototype high-field inline MRI-linac

    Energy Technology Data Exchange (ETDEWEB)

    Liney, G. P., E-mail: gary.liney@sswahs.nsw.gov.au [Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170 (Australia); Dong, B.; Zhang, K. [Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170 (Australia); and others

    2016-09-15

    Purpose: The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid magnetic resonance imaging (MRI)-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-linac system. This work describes results from a prototype experimental system to demonstrate the feasibility of a high field inline MR-linac. Methods: The magnet is a 1.5 T MRI system (Sonata, Siemens Healthcare) was located in a purpose built radiofrequency (RF) cage enabling shielding from and close proximity to a linear accelerator with inline (and future perpendicular) orientation. A portable linear accelerator (Linatron, Varian) was installed together with a multileaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-linac experiments was performed to investigate (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array; and (3) electron contamination effects measured using Gafchromic film and an electronic portal imaging device (EPID). Results: (1) Image quality was unaffected by the radiation beam with the macropodine phantom image with the beam on being almost identical to the image with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background intensity when the radiation beam was on. (3) Film and EPID measurements demonstrated electron focusing occurring along the centerline of the magnet axis. Conclusions: A proof-of-concept high-field MRI-linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field inline MRI-linac and study a number of the technical

  10. Experimental results of the ATF in-line injection system

    International Nuclear Information System (INIS)

    Wang, X.J.; Srinivasan-Rao, T.; Batchelor, K.

    1995-01-01

    The initial experimental results of the Brookhaven accelerator test facility (ATF) in-line injector is presented. The ATF in-line injector employed a full copper RF gun with a pair of solenoid magnets for emittance compensation. The maximum acceleration field of the RF gun was measured to be 130 MV/m. The electron yield from the copper cathode was maximized using p- polarized laser and the Schottky effect. The quantum efficiency under optimum conditions was measured to be 0.04%. The measured electron bunch length was less than 11 ps, which agreed with the laser pulse length measurement using a streak camera. The normalized rms. emittance for 0.25 nC charge is 0.9 ± 0.1 mm-mrad, which is almost four times smaller than the emittance predicted by the space-charge effect for a non-emittance compensation photocathode RF gun. The normalized rms for 0.6 nC charge was measured range from 1 to 3 mm-mrad. This measurement was first experimental demonstration of emittance compensation in a high-gradient, S-band photocathode RF gun

  11. Experimental and numerical results from hybrid retrofitted photovoltaic panels

    International Nuclear Information System (INIS)

    Rossi, Cecilia; Tagliafico, Luca A.; Scarpa, Federico; Bianco, Vincenzo

    2013-01-01

    Highlights: • The experimental study focuses on the feasibility of hybrid PV/T panels retrofitting. • The critical role of a thin layer of air between PV panel and back plate is evidenced. • The benefit of the addition of a conductive paste layer is analyzed via FEM simulations. • The use of wood ribs to stick the back plate represents a cheap effective solution. - Abstract: The aim of present study is to investigate different methodologies to achieve a better contact between a photovoltaic panel and a thermal plate, in order to cool the PV panel by means of water in the perspective of coupling it with a heat pump. It is believed that this kind of system allows to obtain a higher energy efficiency. The analysis is developed both experimentally and numerically, testing different kinds of configurations in different operating conditions. Simulations are employed to analyze the effect of the variations of the contact resistance between the panel and the thermal plates, demonstrating that the use of a conductive paste increases the overall performance of the panel. Results show interesting possibilities in terms of retrofitting of existing photovoltaic panels by employing very simple solutions, such as to fix the thermal plate on the rear of the panel by means of wood ribs

  12. Automation in dairy cattle milking: experimental results and considerations

    Directory of Open Access Journals (Sweden)

    Marisanna Speroni

    2010-01-01

    Full Text Available The results of two experimental programs financed to the Istituto Sperimentale per la Zootecnia are presented. The objective of the two Italian programs was the verify if automatic milking is a suitable practice for Italian dairy system. Results are summarised and compared to those obtained in other international projects. Results refer to animal behaviour, milk yield, milk quality an animal welfare. In a trial comparing cows milked with an automatic milking system and cows milked in a milking parlour, we observed that when the temperature and humidity are very high cows reduce their activity, have lower milking frequency and milk yield than in cold seasons. In comparison to milking parlour, automatic milking system did not increase milk yield which was affected significantly by season, stage of lactation, parity, season per treatment and parity per treatment. The causes of the negative results obtained by this group and by other international groups are discussed. We also presented the results obtained in four trials thereby four appetizers or flavourings were tested to improve efficiency of automatic milking system. Comparing the two milking systems, automatic milking determined a worsening of milk quality, but from these data is not possible to exclude the possibility to use automatic milking for Grana Padano and Parmigiano Reggiano-type cheeses. Animal welfare is not negatively influenced by automatic milking system, which has the potentiality to improve the control and care of cows.

  13. Experimental installation of refrigeration solar-first results; Instalacion experimental de refrigeracion solar-primeros resultados

    Energy Technology Data Exchange (ETDEWEB)

    Moone, C.; Guallar, J.; Alonso, S.; Palacin, F.

    2008-07-01

    In this article they are and the first results of an installation of solar refrigeration composed by a field of flat solar collector are analysed and absorption chillers of simple effect (BrLi-H{sub 2}O), used to give cold to a gymnasium of the university sport pavilion. The data correspond to the registered experimental values during the summer of 2007 (months of June, Julio and August). (Author)

  14. Radiation shielding for neutron guides

    International Nuclear Information System (INIS)

    Ersez, T.; Braoudakis, G.; Osborn, J.C.

    2005-01-01

    Full text: Models of the neutron guide shielding for the out of bunker guides on the thermal and cold neutron beam lines of the OPAL Reactor (ANSTO) were constructed using the Monte Carlo code MCNP 4B. The neutrons that were not reflected inside the guides but were absorbed by the supermirror (SM) layers were noted to be a significant source of gammas. Gammas also arise from neutrons absorbed by the B, Si, Na and K contained in the glass. The proposed shielding design has produced compact shielding assemblies. These arrangements are consistent with safety requirements, floor load limits, and cost constraints. To verify the design a prototype was assembled consisting of 120mm thick Pb(96%)Sb(4%) walls resting on a concrete block. There was good agreement between experimental measurements and calculated dose rates for bulk shield regions. (authors)

  15. Radiation shielding for neutron guides

    International Nuclear Information System (INIS)

    Ersez, T.; Braoudakis, G.; Osborn, J.C.

    2006-01-01

    Models of the neutron guide shielding for the out of bunker guides on the thermal and cold neutron beam lines of the OPAL Reactor (ANSTO) were constructed using the Monte Carlo code MCNP 4B. The neutrons that were not reflected inside the guides but were absorbed by the supermirror (SM) layers were noted to be a significant source of gammas. Gammas also arise from neutrons absorbed by the B, Si, Na and K contained in the glass. The proposed shielding design has produced compact shielding assemblies. These arrangements are consistent with safety requirements, floor load limits, and cost constraints. To verify the design a prototype was assembled consisting of 120 mm thick Pb(96%)Sb(4%) walls resting on a concrete block. There was good agreement between experimental measurements and calculated dose rates for bulk shield regions

  16. Deep-penetration calculations in concrete and iron for shielding of proton therapy accelerators

    International Nuclear Information System (INIS)

    Sheu, Rong-Jiun; Chen, Yen-Fu; Lin, Uei-Tyng; Jiang, Shiang-Huei

    2012-01-01

    Proton accelerators in the energy range of approximately 200 MeV have become increasingly popular for cancer treatment in recent years. These proton therapy facilities usually involve bulky concrete or iron in their shielding design or accelerator structure. Simple shielding data, such as source terms or attenuation lengths for various proton energies and materials are useful in designing accelerator shielding. Understanding the appropriateness or uncertainties associated with these data, which are largely generated from Monte Carlo simulations, is critical to the quality of a shielding design. This study demonstrated and investigated the problems of deep-penetration calculations on the estimation of shielding parameters through an extensive comparison between the FLUKA and MCNPX calculations for shielding against a 200-MeV proton beam hitting an iron target. Simulations of double-differential neutron production from proton bombardment were validated by comparison with experimental data. For the concrete shielding, the FLUKA calculated depth–dose distributions were consistent with the MCNPX results, except for some discrepancies in backward directions. However, for the iron shielding, if FLUKA is used inappropriately then overestimation of neutron attenuation can be expected as shown by this work because of the multigroup treatment for low-energy neutrons in FLUKA. Two neutron energy group structures, three degrees of self-shielding correction, and two iron compositions were considered in this study. Significant variation of the resulting attenuation lengths indicated the importance of problem-dependent multigroup cross sections and proper modeling of iron composition in deep-penetration calculations.

  17. Blanking and piercing theory, applications and recent experimental results

    International Nuclear Information System (INIS)

    Zaid, A. I. O.

    2013-01-01

    Blanking and piercing are manufacturing processes by which certain geometrical shapes are sheared off a sheet metal. If the sheared off part is the one required, the processes referred to as blanking and if the remaining part in the sheet is the one required, the process is referred to as piercing. In this paper, the theory and practice of these processes are reviewed and discussed The main parameters affecting these processes are presented and discussed. These include: the radial clearance percentage, punch and die geometrical parameters, for example punch and die profile radii. The above mentioned parameters on the force and energy required to effect blanking together with their effect on the quality of the products are also presented and discussed. Recent experimental results together with photomacrographs and photomicrographs are also included and discussed. Finally, the effect of punch and die wear on the quality of the blanks is also given and discussed. (author)

  18. Blanking and piercing theory, applications and recent experimental results

    International Nuclear Information System (INIS)

    Zaid, Adnan l O

    2014-01-01

    Blanking and piercing are manufacturing processes by which certain geometrical shapes are sheared off a sheet metal. If the sheared off part is the one required, the processes referred to as blanking and if the remaining part in the sheet is the one required, the process is referred to as piercing. In this paper, the theory and practice of these processes are reviewed and discussed The main parameters affecting these processes are presented and discussed. These include: the radial clearance percentage, punch and die geometrical parameters, for example punch and die profile radii. The abovementioned parameters on the force and energy required to effect blanking together with their effect on the quality of the products are also presented and discussed. Recent experimental results together with photomacrographs and photomicrographs are also included and discussed. Finally, the effect of punch and die wear on the quality of the blanks is alsogiven and discussed

  19. Experimental results of some cluster tests in NSRR

    International Nuclear Information System (INIS)

    Kobayashi, Shinsho; Ohnishi, Nobuaki; Yoshimura, Tomio; Lussie, W.G.

    1978-01-01

    The NSRR programme is in progress in JAERI using a pulsed reactor to evaluate the behavior of reactor fuels under reactivity accident conditions. This report describes briefly the experimental results and preliminary analysis of two cluster tests. In the cluster configuration of five fuel rods, the power distribution in outer fuel rods are not symmetric due to neutron absorption in central fuel rod. The cladding temperature on the exterior boundaries of the cluster is higher than that in interior. Good agreement was obtained between the calculated and measured cladding temperature histories. In the 3.8$ excess reactivity test, cluster averaged energy deposition of 237 cal/g.UO 2 , cladding melting and deformation were limited to the portions of the fuel rods that were on the exterior boundaries of the cluster. (auth.)

  20. The Tower Shielding Facility: Its glorious past

    International Nuclear Information System (INIS)

    Muckenthaler, F.J.

    1997-01-01

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports

  1. The Tower Shielding Facility: Its glorious past

    Energy Technology Data Exchange (ETDEWEB)

    Muckenthaler, F.J.

    1997-05-07

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  2. Infinite slab-shield dose calculations

    International Nuclear Information System (INIS)

    Russell, G.J.

    1989-01-01

    I calculated neutron and gamma-ray equivalent doses leaking through a variety of infinite (laminate) slab-shields. In the shield computations, I used, as the incident neutron spectrum, the leakage spectrum (<20 MeV) calculated for the LANSCE tungsten production target at 90 degree to the target axis. The shield thickness was fixed at 60 cm. The results of the shield calculations show a minimum in the total leakage equivalent dose if the shield is 40-45 cm of iron followed by 20-15 cm of borated (5% B) polyethylene. High-performance shields can be attained by using multiple laminations. The calculated dose at the shield surface is very dependent on shield material. 4 refs., 4 figs., 1 tab

  3. Internal wave emission from baroclinic jets: experimental results

    Science.gov (United States)

    Borcia, Ion D.; Rodda, Costanza; Harlander, Uwe

    2016-04-01

    Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating-annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modeling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Here we show first results from a small rotating annulus experiments and we will further present our new experimental facility to study wave emission from jets and fronts.

  4. Experimental Results of Guided Wave Travel Time Tomography

    Science.gov (United States)

    Volker, Arno; Mast, Arjan; Bloom, Joost

    2010-02-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Currently inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. Both economical and social requirements are pushing the industry to even higher levels of availability, reliability and safety of installations. The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections reducing uncertainty and extending inspection intervals. Guided wave travel time tomography is a promising method to monitor the wall thickness quantitatively over large areas. Obviously the robustness and reliability of such a monitoring system is of paramount importance. Laboratory experiments have been carried out on a 10″ pipe with a nominal wall thickness of 8 mm. Multiple, inline defects have been created with a realistic morphology. The depth of the defects was increased stepwise from 0.5 mm to 2 mm. Additionally the influences of the presence of liquid inside the pipe and surface roughness have been evaluated as well. Experimental results show that this method is capable of providing quantitative wall thickness information over a distance of 4 meter, with a sufficient accuracy such that results can be used for trending. The method has no problems imaging multiple defects.

  5. New experimental results on beam-plasma interaction in solenoids

    International Nuclear Information System (INIS)

    Arzhannikov, A.V.; Burdakov, A.V.; Kapitonov, V.A.

    1988-01-01

    New results are presented on studying the beam-plasma interaction and plasma heating dynamics at the INAR device. The specific features of the generation of ''hot'' (E greater than or ∼ 1 keV) plasma electrons containing the main part of the plasma energy are studied. In the case of a beam with a small initial angular spread, the ''hot'' electrons are shown to be mainly generated near the point where the beam is injected into the plasma. Also reported are the results of the experiments in which the magnetic field in the beam-plasma interaction region was increased up to 70 kOe. In this case, at the plasma length of 75 cm, the total beam energy losses exceed 40%. The growth of the plasma energy content at higher magnetic field is observed. The first stage of the GOL-3 experiment is described which is aimed at the study of the plasma heating is solonoid by a 100 kJ microsecond electron beam. This new experimental device is now ready for operation (author)

  6. Theoretical and Experimental Results Regarding LENR/CF

    International Nuclear Information System (INIS)

    Robert W. Bass; Wm. Stan Gleeson

    2000-01-01

    We challenge the predominant view that low-energy nuclear reactions (LENRs) are prohibited by standard quantum mechanics (QM). This view, supposedly based on standard nuclear theory, need not apply in condensed-matter environments. These considerations indicate that seemingly novel experimental evidence of rapid aneutronic bulk-process transmutation, at extraordinarily low-energy levels, in a simple electrochemical reactor, can occur. This explains: (a) induced rapid decay of radioactive thorium into stable nuclides, e.g., Cu and (b) resulting, anomalous distribution of Cu isotopes. We reexamine arguments of Peebles cited as evidence that standard QM 'forbids' cold fusion (CF). We note oversimplifications in those and present an alternative, more sophisticated calculation (see Bass, Refs. 3 through 8) demonstrating that conventional wisdom about impenetrability of the 'Coulomb barrier' fails as a result of periodic-order-induced resonance. We also examine empirical evidence. In three independent tests of an LENR electrolysis cell, using different I-V-T (current/voltage/time) protocols, the percentage of radiation reduction (RR) transmutation achieved η=[23%, 50%, 83%] versus expended energy E=[0.6535, 32.5, 74.6] (Watt-hours), obtained by numerical integration of recorded product I · V for processing time T, provides near-perfect straight-line correlation: η=α·E + η 0 , α=0.8105, η 0 =22.888, (0.65 < E < 0.75)

  7. Theoretical analysis of experimental results on SG-1 FEL

    International Nuclear Information System (INIS)

    Yang Zhenhua; Wu Shangqing; Tian Shihong; Dong Zhiwei; Wu Yupu

    1994-01-01

    In order to study the SG-1 FEL and the beam transport thoroughly, and draw certain quantitative conclusions, we developed 3-D WAGFEL code to describe the FEL evolution and 3-D CEBQ code to describe the beam transport. The CEBQ code can simulate the 3-D transport of the electron beam in the modulation section with linear approximation of space charge. According to the first ASE experiments results, the LIA provided a 2 kA, 3.0 MeV beam with a normalized emittance of 0.6 πrad·cm, an energy spread (FWHM) of 4%, resulting in a beam brightness nearly 10 8 A/(πm·rad) 2 . The numerical simulation showed that the quality of the beam was good enough to abandon the 9-m long beam line and substitute it with a 2-m long drifting and focusing region. The second series of ASE and amplifier experiments began in October 1992. The beam transport section was modified. The ASE output power, the amplifier output power and detuning curve was measured. We analysed the experimental results using the WAGFEL and CEBQ codes with parameters equal to those of experiments. Firstly we followed 4096 electrons to simulate the transport process of the beam in the beam line under the condition of I = 2 kA, r b = 1 cm, γ = 6.8, Δγ/γ 4%, ε rms = 0.6 (πrad·cm). Through the simulation, we predicted that the beam current injected into the wiggler was about 611 A. Based on these beam parameters at the entrance of the wiggler, we simulated the FEL process with P in = 300 W. The results are also in Fig.7,8,9

  8. Experimental assessment on the thermal effects of the neutron shielding and heat-transfer fin of dual purpose casks on open pool fire

    International Nuclear Information System (INIS)

    Bang, Kyoung-Sik; Yu, Seung-Hwan; Lee, Ju-Chan; Seo, Ki-Seog; Choi, Woo-Seok

    2016-01-01

    Highlights: • An open pool fire test was performed to estimate not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin of the dual purpose cask. • The heat transfer to the inside of the dual purpose cask was reduced, when the neutron shielding burns. • The surface temperatures are lower in the present of the heat transfer fins. • If inflammable material is used as the components of the cask, evaluating thermal integrity using the thermal test would be desirable. - Abstract: Dual purpose casks are used for storage and transport of spent nuclear fuel assemblies. They must therefore satisfy the requirements prescribed in the Korea Nuclear Safety Security Commission Act 2014-50, the IAEA Safety Standard Series No. SSR-6, and US 10 CFR Part 71. These regulatory guidelines classify the dual purpose cask as a Type B package and state that a Type B package must be able to withstand a temperature of 800 °C for a period of 30 min. NS-4-FR is used as neutron shielding of the dual purpose cask. Heat transfer fins are embedded to enhance heat transfer from the cask body to the outer-shell because the thermal conductivity of NS-4-FR is not good. However, accurately simulating not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin in the thermal analysis is not easy. Therefore, an open pool fire test was conducted using a one-sixth slice of a real cask to estimate these effects at a temperature of 800 °C for a period of 30 min. The temperature at the central portion of the neutron shielding was lower when the neutron shielding in contact with the outer cask burned because the neutron shielding absorbed the surrounding latent heat as the neutron shielding burned. Therefore, the heat transfer to the inside of the dual purpose cask was reduced. The surface temperature was lower when a heat transfer fin was installed because the high heat generated by the flame was transferred to the

  9. Experimental assessment on the thermal effects of the neutron shielding and heat-transfer fin of dual purpose casks on open pool fire

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Kyoung-Sik, E-mail: nksbang@kaeri.re.kr; Yu, Seung-Hwan; Lee, Ju-Chan; Seo, Ki-Seog; Choi, Woo-Seok

    2016-08-01

    Highlights: • An open pool fire test was performed to estimate not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin of the dual purpose cask. • The heat transfer to the inside of the dual purpose cask was reduced, when the neutron shielding burns. • The surface temperatures are lower in the present of the heat transfer fins. • If inflammable material is used as the components of the cask, evaluating thermal integrity using the thermal test would be desirable. - Abstract: Dual purpose casks are used for storage and transport of spent nuclear fuel assemblies. They must therefore satisfy the requirements prescribed in the Korea Nuclear Safety Security Commission Act 2014-50, the IAEA Safety Standard Series No. SSR-6, and US 10 CFR Part 71. These regulatory guidelines classify the dual purpose cask as a Type B package and state that a Type B package must be able to withstand a temperature of 800 °C for a period of 30 min. NS-4-FR is used as neutron shielding of the dual purpose cask. Heat transfer fins are embedded to enhance heat transfer from the cask body to the outer-shell because the thermal conductivity of NS-4-FR is not good. However, accurately simulating not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin in the thermal analysis is not easy. Therefore, an open pool fire test was conducted using a one-sixth slice of a real cask to estimate these effects at a temperature of 800 °C for a period of 30 min. The temperature at the central portion of the neutron shielding was lower when the neutron shielding in contact with the outer cask burned because the neutron shielding absorbed the surrounding latent heat as the neutron shielding burned. Therefore, the heat transfer to the inside of the dual purpose cask was reduced. The surface temperature was lower when a heat transfer fin was installed because the high heat generated by the flame was transferred to the

  10. Shielding synchrotron light sources: Advantages of circular shield walls tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.L. [Design and Accelerator Operations Consulting, 568 Wintergreen Ct Ridge, NY 11961 (United States); Ghosh, V.J.; Breitfeller, M. [NSLS-II, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-08-11

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produce significantly higher neutron component dose to the experimental floor than lower energy injection and ramped operations. High energy neutrons produced in the forward direction from thin target beam losses are a major component of the dose rate outside the shield walls of the tunnel. The convention has been to provide thicker 90° ratchet walls to reduce this dose to the beam line users. We present an alternate circular shield wall design, which naturally and cost effectively increases the path length for this forward radiation in the shield wall and thereby substantially decreasing the dose rate for these beam losses. This shield wall design will greatly reduce the dose rate to the users working near the front end optical components but will challenge the beam line designers to effectively utilize the longer length of beam line penetration in the shield wall. Additional advantages of the circular shield wall tunnel are that it's simpler to construct, allows greater access to the insertion devices and the upstream in tunnel beam line components, as well as reducing the volume of concrete and therefore the cost of the shield wall.

  11. Design and experimental results of coaxial circuits for gyroklystron amplifiers

    International Nuclear Information System (INIS)

    Flaherty, M.K.E.; Lawson, W.; Cheng, J.; Calame, J.P.; Hogan, B.; Latham, P.E.; Granatstein, V.L.

    1994-01-01

    At the University of Maryland high power microwave source development for use in linear accelerator applications continues with the design and testing of coaxial circuits for gyroklystron amplifiers. This presentation will include experimental results from a coaxial gyroklystron that was tested on the current microwave test bed, and designs for second harmonic coaxial circuits for use in the next generation of the gyroklystron program. The authors present test results for a second harmonic coaxial circuit. Similar to previous second harmonic experiments the input cavity resonated at 9.886 GHz and the output frequency was 19.772 GHz. The coaxial insert was positioned in the input cavity and drift region. The inner conductor consisted of a tungsten rod with copper and ceramic cylinders covering its length. Two tungsten rods that bridged the space between the inner and outer conductors supported the whole assembly. The tube produced over 20 MW of output power with 17% efficiency. Beam interception by the tungsten rods resulted in minor damage. Comparisons with previous non-coaxial circuits showed that the coaxial configuration increased the parameter space over which stable operation was possible. Future experiments will feature an upgraded modulator and beam formation system capable of producing 300 MW of beam power. The fundamental frequency of operation is 8.568 GHz. A second harmonic coaxial gyroklystron circuit was designed for use in the new system. A scattering matrix code predicts a resonant frequency of 17.136 GHz and Q of 260 for the cavity with 95% of the outgoing microwaves in the desired TE032 mode. Efficiency studies of this second harmonic output cavity show 20% expected efficiency. Shorter second harmonic output cavity designs are also being investigated with expected efficiencies near 34%

  12. Modelling the electrical properties of concrete for shielding effectiveness prediction

    International Nuclear Information System (INIS)

    Sandrolini, L; Reggiani, U; Ogunsola, A

    2007-01-01

    Concrete is a porous, heterogeneous material whose abundant use in numerous applications demands a detailed understanding of its electrical properties. Besides experimental measurements, material theoretical models can be useful to investigate its behaviour with respect to frequency, moisture content or other factors. These models can be used in electromagnetic compatibility (EMC) to predict the shielding effectiveness of a concrete structure against external electromagnetic waves. This paper presents the development of a dispersive material model for concrete out of experimental measurement data to take account of the frequency dependence of concrete's electrical properties. The model is implemented into a numerical simulator and compared with the classical transmission-line approach in shielding effectiveness calculations of simple concrete walls of different moisture content. The comparative results show good agreement in all cases; a possible relation between shielding effectiveness and the electrical properties of concrete and the limits of the proposed model are discussed

  13. The distribution property of shielding materials used in radiological protection

    International Nuclear Information System (INIS)

    Costa, Paulo R.

    1996-01-01

    A parametric model for the distribution of the radiation scattered by shielding materials is proposed. The advantages regarding to chemical composition or to linear attenuation coefficient of the media as a function of energy are presented. Comparative results between the model and experimental data are reported

  14. Experimental results for an experimental condensation heat exchanger with a spiral minichanel tube. Comparison to numerical imulations

    Directory of Open Access Journals (Sweden)

    Hrubý J.

    2013-04-01

    Full Text Available The paper describes new results for an experimental heat exchanger equipped with a single corrugated capillary tube, basic information about the measurements and the experimental setup. Some of the results were compared with numerical simulations.

  15. Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

    Directory of Open Access Journals (Sweden)

    Colin M. Beal

    2012-06-01

    Full Text Available Worldwide, algal biofuel research and development efforts have focused on increasing the competitiveness of algal biofuels by increasing the energy and financial return on investments, reducing water intensity and resource requirements, and increasing algal productivity. In this study, analyses are presented in each of these areas—costs, resource needs, and productivity—for two cases: (1 an Experimental Case, using mostly measured data for a lab-scale system, and (2 a theorized Highly Productive Case that represents an optimized commercial-scale production system, albeit one that relies on full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein concludes that the energy and financial return on investments are less than 1, the water intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption (e.g., nitrogen. The analysis and presentation of results highlight critical areas for advancement and innovation that must occur for sustainable and profitable algal biofuel production can occur at a scale that yields significant petroleum displacement. To this end, targets for energy consumption, production cost, water consumption, and nutrient consumption are presented that would promote sustainable algal biofuel production. Furthermore, this work demonstrates a procedure and method by which subsequent advances in technology and biotechnology can be framed to track progress.

  16. Laser long-range remote-sensing program experimental results

    Science.gov (United States)

    Highland, Ronald G.; Shilko, Michael L.; Fox, Marsha J.; Gonglewski, John D.; Czyzak, Stanley R.; Dowling, James A.; Kelly, Brian; Pierrottet, Diego F.; Ruffatto, Donald; Loando, Sharon; Matsuura, Chris; Senft, Daniel C.; Finkner, Lyle; Rae, Joe; Gallegos, Joe

    1995-12-01

    A laser long range remote sensing (LRS) program is being conducted by the United States Air Force Phillips Laboratory (AF/PL). As part of this program, AF/PL is testing the feasibility of developing a long path CO(subscript 2) laser-based DIAL system for remote sensing. In support of this program, the AF/PL has recently completed an experimental series using a 21 km slant- range path (3.05 km ASL transceiver height to 0.067 km ASL target height) at its Phillips Laboratory Air Force Maui Optical Station (AMOS) facility located on Maui, Hawaii. The dial system uses a 3-joule, (superscript 13)C isotope laser coupled into a 0.6 m diameter telescope. The atmospheric optical characterization incorporates information from an infrared scintillometer co-aligned to the laser path, atmospheric profiles from weather balloons launched from the target site, and meteorological data from ground stations at AMOS and the target site. In this paper, we report a description of the experiment configuration, a summary of the results, a summary of the atmospheric conditions and their implications to the LRS program. The capability of such a system for long-range, low-angle, slant-path remote sensing is discussed. System performance issues relating to both coherent and incoherent detection methods, atmospheric limitations, as well as, the development of advanced models to predict performance of long range scenarios are presented.

  17. Experimental result of poloidal limiter baking of Aditya tokamak

    International Nuclear Information System (INIS)

    Jadeja, K.A.; Arambhadiya, B.G.; Bhatt, S.B.; Bora, D.

    2005-01-01

    In tokamak Aditya, Poloidal limiter function as the operational limiter and are subjected to very high particles load and heat flux during plasma discharge. In addition, Poloidal limiter is the first material surface to come in contact with the hot plasma. In plasma discharge, the impurity generations from limiter are mostly by adsorbed particles. The baking of limiter provides high degassing rate and thermal desorption of adsorbed particles of limiter to reduce impurities from the limiter tiles. The series of experiments are done with different conditions like, Baking of limiter SS ring by heating element with and without limiter tiles in atmosphere and vacuum. Than Poloidal limiter is structured with 14 numbers of graphite tiles and electrical isolated to the vessel and support structure. As a heating element and for electrical isolation, Nychrome wire and ceramic block with ceramic tubes are used. In addition, Thermo couple and two DC power supply (0-10 Ampere) are used for limiter baking. Mass analyzer gives partial pressures of different species to observe effect of limiter baking. For the period of Poloidal limiter baking in Aditya, the partial pressures of different species like hydrogen, water vapor, and oxygen are extremely increased with time duration. This paper presents series of experimental results of poloidal limiter baking. (author)

  18. Acoustic analysis in Mudejar-Gothic churches: experimental results.

    Science.gov (United States)

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria.

  19. Controlled Nuclear Fusion Research, September 1965: Review Of Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    Spitzer, Lyman Jr. [Princeton University, Princeton, NJ (United States)

    1966-04-15

    To my way of thinking the most significant milestone of the present meeting is the substantial body of evidence that has been presented on the hydromagnetic stabilization of open-ended systems. The success of minimum magnetic-field ('minimum-B') configurations in stabilizing a plasma marks one more area where theory and experiment in the field of plasma physics have been brought together with gratifying results. Let me go back a little into history and discuss the gradual growth of our information on hydromagnetic instabilities generally. Many of you will remember that hydromagnetic theory was applied to the self-pinched discharge in the early years of the controUed fusion programme. The predictions of this theory were very shortly fulfilled by the observations; the effects were so unmistakable that it was not difficult to compare the theory with the observations. On the streak pictures of the linear or toroidal discharges that were obtained in those early years one saw clearly the diffuse plasma column, which first contracted to a narrow filament and then started to distort and kink until finally it hit the wall. Under some conditions the plasma was observed to break up into a series of blobs like a string of sausages. Since the behaviour was exactly what the theory had predicted, it took no very great experimental wisdom to conclude that observations had confirmed theory.

  20. Experimental results on transport and focusing of laser accelerated protons

    Energy Technology Data Exchange (ETDEWEB)

    Busold, Simon; Deppert, Oliver; Roth, Markus [TU Darmstadt, IKP, Schlossgartenstr. 9, 64289 Darmstadt (Germany); Schumacher, Dennis; Blazevic, Abel; Zielbauer, Bernhard; Hofmann, Ingo; Bagnoud, Vincent [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany); Brabetz, Christian; Al-Omari, Husam [JWG Universitaet Frankfurt, IAP, Max von Laue Str. 1, 60438 Frankfurt am Main (Germany); Joost, Martin; Kroll, Florian; Cowan, Tom [Helmholtzzentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Collaboration: LIGHT-Collaboration

    2013-07-01

    Irradiation of thin foils with high-intensity laser pulses became a reliable tool during the last decade for producing high-intensity proton bunches in about a pico-second from a sub-millimeter source. However, the energy distribution is of an exponential shape with a currently achievable cut-off energy <100 MeV (TNSA mechanism) and the beam is highly divergent with an energy-dependent envelope-divergence of up to 60 deg. Thus, for most applications it is necessary to be able to capture and control these protons as well as select a specific energy. In the frame of the LIGHT collaboration, experimental studies were done at the PHELIX laser at GSI Darmstadt using a pulsed high-field solenoid and alternatively a permanent magnet quadrupole triplet in order to match the beam for injection into a RF cavity. The beam was characterized at several distances after the source and the results are compared to particle tracking simulations.

  1. Acoustic analysis in Mudejar-Gothic churches: Experimental results

    Science.gov (United States)

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. .

  2. About the Scythian Shields

    Directory of Open Access Journals (Sweden)

    About the Scythian Shields

    2017-10-01

    Full Text Available Shields played major role in the armament system of the Scythians. Made from organic materials, they are poorly traced on the materials of archaeological excavations. Besides, scaly surface of shields was often perceived in practice as the remnants of the scaly armor. E. V. Chernenko was able to discern the difference between shields’ scaly plates and armor scales. The top edge of the scales was bent inwards, and shield plates had a wire fixation. These observations let significantly increase the number of shields, found in the burial complexes of the Scythians. The comparison of archaeological materials and the images of Scythian warriors allow distinguishing the main forms of Scythian shields. All shields are divided into fencing shields and cover shields. The fencing shields include round wooden shields, reinforced with bronze sheet, and round moon-shaped shields with a notch at the top, with a metal scaly surface. They came to the Scythians under the Greek influence and are known in the monuments of the 4th century BC. Oval shields with scaly surface (back cover shields were used by the Scythian cavalry. They protected the rider in case of frontal attack, and moved back in case of maneuver or closein fighting. Scythian battle tactics were based on rapid approaching the enemy and throwing spears and further rapid withdrawal. Spears stuck in the shields of enemies, forcing them to drop the shields, uncover, and in this stage of the battle the archers attacked the disorganized ranks of the enemy. That was followed by the stage of close fight. Oval form of a wooden shield with leather covering was used by the Scythian infantry and spearmen. Rectangular shields, including wooden shields and the shields pleached from rods, represented a special category. The top of such shield was made of wood, and a pleached pad on leather basis was attached to it. This shield could be a reliable protection from arrows, but it could not protect against javelins

  3. Energy-resolved computed tomography: first experimental results

    International Nuclear Information System (INIS)

    Shikhaliev, Polad M

    2008-01-01

    First experimental results with energy-resolved computed tomography (CT) are reported. The contrast-to-noise ratio (CNR) in CT has been improved with x-ray energy weighting for the first time. Further, x-ray energy weighting improved the CNR in material decomposition CT when applied to CT projections prior to dual-energy subtraction. The existing CT systems use an energy (charge) integrating x-ray detector that provides a signal proportional to the energy of the x-ray photon. Thus, the x-ray photons with lower energies are scored less than those with higher energies. This underestimates contribution of lower energy photons that would provide higher contrast. The highest CNR can be achieved if the x-ray photons are scored by a factor that would increase as the x-ray energy decreases. This could be performed by detecting each x-ray photon separately and measuring its energy. The energy selective CT data could then be saved, and any weighting factor could be applied digitally to a detected x-ray photon. The CT system includes a photon counting detector with linear arrays of pixels made from cadmium zinc telluride (CZT) semiconductor. A cylindrical phantom with 10.2 cm diameter made from tissue-equivalent material was used for CT imaging. The phantom included contrast elements representing calcifications, iodine, adipose and glandular tissue. The x-ray tube voltage was 120 kVp. The energy selective CT data were acquired, and used to generate energy-weighted and material-selective CT images. The energy-weighted and material decomposition CT images were generated using a single CT scan at a fixed x-ray tube voltage. For material decomposition the x-ray spectrum was digitally spilt into low- and high-energy parts and dual-energy subtraction was applied. The x-ray energy weighting resulted in CNR improvement of calcifications and iodine by a factor of 1.40 and 1.63, respectively, as compared to conventional charge integrating CT. The x-ray energy weighting was also applied

  4. A study of gamma shielding

    International Nuclear Information System (INIS)

    Roogtanakait, N.

    1981-01-01

    Gamma rays have high penetration power and its attenuation depends upon the thickness and the attenuation coefficient of the shield, so it is necessary to use the high density shield to attenuate the gamma rays. Heavy concrete is considered to be used for high radiation laboratory and the testing of the shielding ability and compressibility of various types of heavy concrete composed of baryte, hematite, ilmenite and galena is carried out. The results of this study show that baryte-ilmenite concrete is the most suitable for high radiation laboratory in Thailand

  5. Morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2018-03-01

    Shield volcanoes are described as low-angle edifices built primarily by the accumulation of successive lava flows. This generic view of shield volcano morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galápagos). Here, the morphometry of 158 monogenetic and polygenetic shield volcanoes is analyzed quantitatively from 90-meter resolution SRTM DEMs using the MORVOLC algorithm. An additional set of 24 lava-dominated 'shield-like' volcanoes, considered so far as stratovolcanoes, are documented for comparison. Results show that there is a large variation in shield size (volumes from 0.1 to > 1000 km3), profile shape (height/basal width (H/WB) ratios mostly from 0.01 to 0.1), flank slope gradients (average slopes mostly from 1° to 15°), elongation and summit truncation. Although there is no clear-cut morphometric difference between shield volcanoes and stratovolcanoes, an approximate threshold can be drawn at 12° average slope and 0.10 H/WB ratio. Principal component analysis of the obtained database enables to identify four key morphometric descriptors: size, steepness, plan shape and truncation. Hierarchical cluster analysis of these descriptors results in 12 end-member shield types, with intermediate cases defining a continuum of morphologies. The shield types can be linked in terms of growth stages and shape evolution, related to (1) magma composition and rheology, effusion rate and lava/pyroclast ratio, which will condition edifice steepness; (2) spatial distribution of vents, in turn related to the magmatic feeding system and the tectonic framework, which will control edifice plan shape; and (3) caldera formation, which will condition edifice truncation.

  6. Radiation shielding for fusion reactors

    International Nuclear Information System (INIS)

    Santoro, R.T.

    2000-01-01

    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. (author)

  7. Revise of a basic data base for shielding design

    International Nuclear Information System (INIS)

    Nakao, Makoto; Takemura, Morio

    2000-03-01

    With use of the two-dimensional discrete ordinates code DORT and the standard groupwise shielding design library JSSTDL produced from the latest evaluated nuclear data library JENDL-3.2, experimental analyses for the representative configurations in the Radial Shield Attenuation Experiment of the JASPER were performed. The results were compared with those obtained with use of traditional method DOT3.5/JSDJ2 for the previous JASPER experimental analyses. In general, the change of the cross section library gives higher results and the change of the transport code gives lower results. Finally the new analysis method gives better agreement with the experimental results and also less deviations of calculational errors between various detectors. Experimental analyses for the thick concrete configuration in the Gap Streaming Experiment of the JASPER was also performed with the new analysis method, after solving the poor agreement found in last year with the original JASPER experimental analyses. The same tendency due to the library change was confirmed with the above mentioned analyses of the Radial Shield Attenuation Experiment. Compilation of the input data necessary for future reanalyses of important configurations in JASPER experiments were continued through the above-mentioned experimental analyses and related informations were added for repletion of the database preserved in a computer disk holding previously accumulated data. Input data descriptions were made for auxiliary routines needed for the experimental analyses and their sample data were compiled and stored in the database. (author)

  8. Shielding benchmark problems

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Kawai, Masayoshi; Nakazawa, Masaharu.

    1978-09-01

    Shielding benchmark problems were prepared by the Working Group of Assessment of Shielding Experiments in the Research Comittee on Shielding Design of the Atomic Energy Society of Japan, and compiled by the Shielding Laboratory of Japan Atomic Energy Research Institute. Twenty-one kinds of shielding benchmark problems are presented for evaluating the calculational algorithm and the accuracy of computer codes based on the discrete ordinates method and the Monte Carlo method and for evaluating the nuclear data used in the codes. (author)

  9. Investigation of water content in primary upper shield of high temperature engineering test reactor (HTTR)

    International Nuclear Information System (INIS)

    Sumita, Junya; Sawa, Kazuhiro; Mogi, Haruyoshi; Itahashi, Shuuji; Kitami, Toshiyuki; Akutu, Youichi; Fuchita, Yasuhiro; Kawaguchi, Toru; Moriya, Masahiro

    1999-09-01

    A primary upper shield of the High Temperature Engineering Test Reactor (HTTR) is composed of concrete (grout) which is packed into iron frames. The main function of the primary upper shield is to attenuate neutron and gamma ray from the core, that leads to satisfy dose equivalent rate limit of operating floor and stand-pipe room. Water content in the concrete is one of the most important things because it strongly affects neutron-shielding ability. Then, we carried out out-of-pile experiments to investigate relationship between temperature and water content in the concrete. Based on the experimental results, a hydrolysis-diffusion model was developed to investigate water release behavior from the concrete. The model showed that water content used for shielding design in the primary upper shield of the HTTR will be maintained if temperature during operating life is under 110degC. (author)

  10. New shielding material development for compact accelerator-driven neutron source

    Directory of Open Access Journals (Sweden)

    Guang Hu

    2017-04-01

    Full Text Available The Compact Accelerator-driven Neutron Source (CANS, especially the transportable neutron source is longing for high effectiveness shielding material. For this reason, new shielding material is researched in this investigation. The component of shielding material is designed and many samples are manufactured. Then the attenuation detection experiments were carried out. In the detections, the dead time of the detector appeases when the proton beam is too strong. To grasp the linear range and nonlinear range of the detector, two currents of proton are employed in Pb attenuation detections. The transmission ratio of new shielding material, polyethylene (PE, PE + Pb, BPE + Pb is detected under suitable current of proton. Since the results of experimental neutrons and γ-rays appear as together, the MCNP and PHITS simulations are applied to assisting the analysis. The new shielding material could reduce of the weight and volume compared with BPE + Pb and PE + Pb.

  11. Measurements of angular and energy distributions of gamma-rays resulting from neutron interactions in shielding barriers

    International Nuclear Information System (INIS)

    Makarious, A.S.; Maayouf, R.M.A.; Megahid, R.

    1978-01-01

    Measurements of both angular and energy distributions of secondary gamma resulting from interactions of neutrons emerging from one of the ET-RR-1 reactor beam holes, in barriers from iron, lead and water are reported. The measurements were carried out, both with a bare neutron beam and with the beam being transmitted through a B4C. Filter, using a stilbene crystal gamma spectrometer. The spectrometer applies discrimination between neutrons and gammas according to the difference in decay times of the scintillations produced by them in stilbene. The described angular distributions resulted from measurements made at different angles of neutron incidence and with three different thicknesses of each sample

  12. Shielding calculations using FLUKA

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri; Tesch, K.; Dinter, H.

    1988-06-01

    The dose equivalent on the surface of concrete shielding has been calculated using the Monte Carlo code FLUKA86 for incident proton energies from 10 to 800 GeV. The results have been compared with some simple equations. The value of the angular dependent parameter in Moyer's equation has been calculated from the locations where the values of the maximum dose equivalent occur. (author)

  13. Radiation shielding device

    International Nuclear Information System (INIS)

    Nakagawa, Takahiro; Yamagami, Makoto.

    1996-01-01

    A fixed shielding member made of a radiation shielding material is constituted in perpendicular to an opening formed on radiation shielding walls. The fixed shielding member has one side opened and has other side, the upper portion and the lower portion disposed in close contact with the radiation shielding walls. Movable shielding members made of a radiation shielding material are each disposed openably on both side of the fixed shielding member. The movable shielding member has a shaft as a fulcrum on one side thereof for connecting it to the radiation shielding walls. The other side has a handle attached for opening/closing the movable shielding member. Upon access of an operator, when each one of the movable shielding members is opened/closed on every time, leakage of linear or scattered radiation can be prevented. Even when both of the movable shielding members are opened simultaneously, the fixed shielding member and the movable shielding members form labyrinth to prevent leakage of linear radioactivity. (I.N.)

  14. Validation of Shielding Analysis Capability of SuperMC with SINBAD

    Directory of Open Access Journals (Sweden)

    Chen Chaobin

    2017-01-01

    Full Text Available Abstract: The shielding analysis capability of SuperMC was validated with the Shielding Integral Benchmark Archive Database (SINBAD. The SINBAD was compiled by RSICC and NEA, it includes numerous benchmark experiments performed with the D-T fusion neutron source facilities of OKTAVIAN, FNS, IPPE, etc. The results from SuperMC simulation were compared with experimental data and MCNP results. Very good agreement with deviation lower than 1% was achieved and it suggests that SuperMC is reliable in shielding calculation.

  15. Results of Experimental Study on Flexitime and Family Life.

    Science.gov (United States)

    Winett, Richard A.; Neale, Michael S.

    1980-01-01

    According to two small experimental studies of flexible working hours, federal workers with young children choose to arrive at and depart from work earlier, allowing them to increase the time spent with their families and to engage in recreational, educational, and household activities. (Author/SK)

  16. Alkali Metal Backup Cooling for Stirling Systems - Experimental Results

    Science.gov (United States)

    Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

    2013-01-01

    In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

  17. Gonad shielding in computerized tomography

    International Nuclear Information System (INIS)

    Rockstroh, G.

    1984-01-01

    The reduction of gonadal dose by shielding of the gonads was investigated for a Somatom 2 using an anthropomorphic phantom. For small distances from the slice examined the gonadal dose results from intracorporal secondary radiation and is only insignificantly reduced by shielding. For greater distances shielding is relatively more effective, the gonadal dose however is small because of the approximately exponential decay. Shielding of the gonads therefore does not seem adequate for the reduction of gonadal dose. From dose measurements in cylinder phantoms of several diameters it appears that no different results would be obtained for children and young adults. An effective reduction of gonadal dose is only possible with lead capsules for males. (author)

  18. Shielding benchmark test

    International Nuclear Information System (INIS)

    Kawai, Masayoshi

    1984-01-01

    Iron data in JENDL-2 have been tested by analyzing shielding benchmark experiments for neutron transmission through iron block performed at KFK using CF-252 neutron source and at ORNL using collimated neutron beam from reactor. The analyses are made by a shielding analysis code system RADHEAT-V4 developed at JAERI. The calculated results are compared with the measured data. As for the KFK experiments, the C/E values are about 1.1. For the ORNL experiments, the calculated values agree with the measured data within an accuracy of 33% for the off-center geometry. The d-t neutron transmission measurements through carbon sphere made at LLNL are also analyzed preliminarily by using the revised JENDL data for fusion neutronics calculation. (author)

  19. Radiation shielding material

    International Nuclear Information System (INIS)

    Kawakubo, Takamasa; Yamada, Fumiyuki; Nakazato, Kenjiro.

    1976-01-01

    Purpose: To provide a material, which is used for printing a samples name and date on an X-ray photographic film at the same time an X-ray radiography. Constitution: A radiation shielding material of a large mass absorption coefficient such as lead oxide, barium oxide, barium sulfate, etc. is added to a solution of a radiation permeable substance capable of imparting cold plastic fluidity (such as microcrystalline wax, paraffin, low molecular polyethylene, polyvinyl chloride, etc.). The resultant system is agitated and then cooled, and thereafter it is press fitted to or bonded to a base in the form of a film of a predetermined thickness. This radiation shielding layer is scraped off by using a writing tool to enter information to be printed in a photographic film, and then it is laid over the film and exposed to X-radiation to thereby print the information on the film. (Seki, T.)

  20. Hot-cell shielding system for high power transmission in DUPIC fuel fabrication

    International Nuclear Information System (INIS)

    Kim, K.; Lee, J.; Park, J.; Yang, M.; Park, H.

    2000-01-01

    This paper presents a newly designed hot-cell shielding system for use in the development of DUPIC (Direct Use of spent PWR fuel In CANDU reactors) fuel at KAERI (Korea Atomic Energy Research Institute). This hot-cell shielding system that was designed to transmit high power to sintering furnace in-cell from the out-of-cell through a thick cell wall has three subsystems - a steel shield plug with embedded spiral cooling line, stepped copper bus bars, and a shielding lead block. The dose-equivalent rates of the hot-cell shielding system and of the apertures between this system and the hot-cell wall were calculated. Calculated results were compared with the allowable dose limit of the existing hot-cell. Experiments for examining the temperature changes of the shielding system developed during normal furnace operation were also carried out. Finally, gamma-ray radiation survey experiments were conducted by Co-60 source. It is demonstrated that, from both calculated and experimental results, the newly designed hot-cell shielding system meets all the shielding requirements of the existing hot-cell facility, enabling high power transmission to the in-cell sintering furnace. (author)

  1. Phase diagram Fe-Sn-Sr. New experimental results

    International Nuclear Information System (INIS)

    Nieva, N; Jimenez, M.J; Gomez, A; Corvalan Moya, C; Arias, D

    2012-01-01

    Zr-based alloys are widely used in nuclear industry due to their specific characteristics. The information of the phase diagrams of the ternary system Fe-Zr-Sn is scarce. In this work we investigate, in a experimental way, the central and the Fe-Sn binary adjacent regions of the Fe-Sn-Zr Gibbs triangle at the temperature of 800 o C. For the experimental work, a set of seven ternary alloys was designed, produced and examined by different complementary techniques. There were performed two types of heat treatments: one of medium and another of long duration. We present a new proposal for the 800 o C isothermal section. The boundaries of the identified phases and the fields of one, two and three phases are indicated in the diagram

  2. Experimental results from a flowing-lithium target

    International Nuclear Information System (INIS)

    Annese, C.E.; Schwartz, K.E.

    1982-01-01

    Hydraulic stability of a free surface lithium jet was demonstrated at 260 0 C and from the middle-vacuum region of 0.01 Pa (10 - 4 Torr) up to 124 kPa (18 psia). The jet is formed by flowing lithium at rates to 0.04 m 3 /s (600 GPM) through a precisely defined nozzle which directs the flow along a curved wall where velocities of up to 17 m/s are attained. This nozzle and curved wall configuration form the basis of the Fusion Materials Irradiation Test (FMIT) Facility lithium target. A full-size experimental model of this target is presently under test with flowing lithium in the Experimental Lithium System (ELS). The FMIT is being developed for the Department of Energy by the Westinghouse Hanford Company at the Hanford Engineering Development Laboratory

  3. Experimentally increasing sedentary behavior results in decreased life satisfaction

    OpenAIRE

    Edwards, Meghan K.; Loprinzi, Paul D.

    2017-01-01

    Background: No study has experimentally manipulated sedentary behavior and evaluated its effect on life satisfaction. Thus, the purpose of this study was to evaluate the effects of a free-living, sedentary behavior-inducing randomized controlled intervention on life satisfaction. Methods: Active, young adults between the ages of 18-35 were recruited and randomly assigned into a sedentary behavior intervention group (n = 26) or a control group (n = 13). The intervention group par...

  4. High temperature pressure water's blowdown into water. Experimental results

    International Nuclear Information System (INIS)

    Ishida, Toshihisa; Kusunoki, Tsuyoshi; Kasahara, Yoshiyuki; Iida, Hiromasa

    1994-01-01

    The purpose of the present experimental study is to clarify the phenomena in blowdown of high temperature and pressure water in pressure vessel into the containment water for evaluation of design of an advanced marine reactor(MRX). The water blown into the containment water flushed and formed steam jet plume. The steam jet condensed in the water, but some stream penetrated to gas phase of containment and contributed to increase of containment pressure. (author)

  5. Comparison of CFD simulations with experimental Jet Erosion Tests results

    OpenAIRE

    Mercier, F.; Bonelli, S.; Pinettes, P.; Golay, F.; Anselmet, F.; Philippe, P.

    2014-01-01

    The Jet Erosion Test (JET) is an experimental device increasingly used to quantify the resistance of soils to erosion. This resistance is characterised by two geotechnical parameters: the critical shear stress and the erosion coefficient. The JET interpretation model of Hanson and Cook (2004) provides an estimation of these erosion parameters. But Hanson's model is simplified, semi-empirical and several assumed hypotheses can be discussed. Our aim is to determine the relevance of the JET inte...

  6. Barium-borate-flyash glasses: As radiation shielding materials

    International Nuclear Information System (INIS)

    Singh, Sukhpal; Kumar, Ashok; Singh, Devinder; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The attenuation coefficients of barium-borate-flyash glasses have been measured for γ-ray photon energies of 356, 662, 1173 and 1332 keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3 o . Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free path (mfp), effective atomic number and electron density. Good agreements have been observed between experimental and theoretical values of these parameters. From the studies of the obtained results it is reported here that from the shielding point of view the barium-borate-flyash glasses are better shields to γ-radiations in comparison to the standard radiation shielding concretes and also to the ordinary barium-borate glasses

  7. Observer Based Sliding Mode Attitude Control: Theoretical and Experimental Results

    Directory of Open Access Journals (Sweden)

    U. Jørgensen

    2011-07-01

    Full Text Available In this paper we present the design of a sliding mode controller for attitude control of spacecraft actuated by three orthogonal reaction wheels. The equilibrium of the closed loop system is proved to be asymptotically stable in the sense of Lyapunov. Due to cases where spacecraft do not have angular velocity measurements, an estimator for the generalized velocity is derived and asymptotic stability is proven for the observer. The approach is tested on an experimental platform with a sphere shaped Autonomous Underwater Vehicle SATellite: AUVSAT, developed at the Norwegian University of Science and Technology.

  8. Review of JT-60U experimental results in 1998

    International Nuclear Information System (INIS)

    Adachi, H.; Akasaka, H.; Akino, N.

    1999-09-01

    study on high confinement by electron heating, the negative ion source NB (NNB) with 350-400 keV, LH and IC second harmonic minority heating have been used. By NNB heating, an ELMy H-mode plasma was sustained with H-factor∼1.6 at T e =1.4T i . High T e (0)∼12 keV was also sustained by LHCD of ∼2 MW. The Alfven eigenmodes were studied with NNB injection in weak or reversed magnetic shear plasmas. The Toroidicity-induced Alfven eigenmodes were observed in weak shear plasmas with h > ≥0.1% and 0.4≤V b// /v A ≤1. In order to maximize safety at disruption, we have also focused on softening of the disruption effects on the vacuum vessel structures. Reduction of halo current was demonstrated by impurity gas puffing. The divertor study in 1998 focused on investigating the geometry effect of the W-shaped divertor and the pumping effects. The W-shaped divertor structure with the private dome separating the inner and outer divertor channels realized the effective inner leg-pumping both in L-mode and H-mode plasmas. The pumping efficiency is higher at narrower gap of the inner hit point and the pumping slot. The main gas puff and divertor pumping was effective for reduction of impurity level and the enhancement of impurity shielding. The dome structure also prevented the upstream transport of hydrocarbons generated by chemical sputtering, and reduced carbon influx into the main plasma. Particle flow from the main plasma to the divertor region through the SOL layer was studied intensively. (author)

  9. Review of JT-60U experimental results in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, H.; Akasaka, H.; Akino, N. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    1999-09-01

    }{sub X}{approx}0.46. In addition to extension of the discharge regimes, the key phenomena determining transport and stability around ITBs were studied intensively. For the study on high confinement by electron heating, the negative ion source NB (NNB) with 350-400 keV, LH and IC second harmonic minority heating have been used. By NNB heating, an ELMy H-mode plasma was sustained with H-factor{approx}1.6 at T{sub e}=1.4T{sub i}. High T{sub e}(0){approx}12 keV was also sustained by LHCD of {approx}2 MW. The Alfven eigenmodes were studied with NNB injection in weak or reversed magnetic shear plasmas. The Toroidicity-induced Alfven eigenmodes were observed in weak shear plasmas with <{beta}{sub h}> {>=}0.1% and 0.4{<=}V{sub b//} /v{sub A}{<=}1. In order to maximize safety at disruption, we have also focused on softening of the disruption effects on the vacuum vessel structures. Reduction of halo current was demonstrated by impurity gas puffing. The divertor study in 1998 focused on investigating the geometry effect of the W-shaped divertor and the pumping effects. The W-shaped divertor structure with the private dome separating the inner and outer divertor channels realized the effective inner leg-pumping both in L-mode and H-mode plasmas. The pumping efficiency is higher at narrower gap of the inner hit point and the pumping slot. The main gas puff and divertor pumping was effective for reduction of impurity level and the enhancement of impurity shielding. The dome structure also prevented the upstream transport of hydrocarbons generated by chemical sputtering, and reduced carbon influx into the main plasma. Particle flow from the main plasma to the divertor region through the SOL layer was studied intensively. (author)

  10. Manufacture and testing of the CTB&SBB thermal shield for the ITER magnet feeder system

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Kun; Liu, Chen; Song, Yuntao; Feng, Hansheng; Ding, Kaizhong, E-mail: kzding@ipp.ac.cn; Wang, Tanbin; Ji, Hui

    2015-10-15

    The system of International Thermonuclear Experimental Reactor (ITER) feeders is responsible for the power, helium cooling, and instrumentation of the magnets of the coil terminal box and S-bend box (CTB&SBB) thermal shield outside the cryostat. An 80-K rectangular Al thermal shield is hung inside the CTB&SBB to reduce the thermal radiation heat loads of 4.5-K helium. The American Society of Interventional Pain Physicians (ASIPP) will supply all the 31 sets of feeders for ITER. A manufactured prototype of CTB&SBB thermal shield is first quality-tested before the commencement of the series production. First, a detailed configuration of the rectangular Al thermal shield is presented in this article. The paper also presents more information on the manufacturing process of the thermal shield, especially the welding process, the procedure for ensuring good weld quality, and the use of a specially designed tool to ensure <5-mm deformation on such a 7.3-m-long thermal shield during welding. In addition, the cold test and results, including the cooling process with 13-bar and 17.5-g/s 80-K He gas, and the temperature distribution on different panels of the thermal shield are presented. The whole process of manufacture and testing lays a good foundation for the series production of the thermal shield.

  11. Radiation protection/shield design: a need for a systems approach

    International Nuclear Information System (INIS)

    Disney, R.K.

    1977-01-01

    Radiation protection/shielding design of a nuclear facility requires a coordinated effort of many engineering disciplines to meet the requirements imposed by regulations. The system approach to Clinch River Breeder Reactor Plant (CRBRP) radiation protection is described, and the program developed to implement this approach is defined. In addition, the principal shielding design problems for LMFBR nuclear reactor systems are discussed in relation to LWR nuclear reactor system shielding designs. The methodology used to analyze these problems in the U.S. LMFBR program, the resultant design solutions, and the experimental verification of these designs and/or methods are discussed

  12. Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

    Science.gov (United States)

    Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

    2009-05-01

    The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

  13. Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

    International Nuclear Information System (INIS)

    Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

    2009-01-01

    The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

  14. Radiation shielding for fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Yoshiaki [Tokyo Univ., Nuclear Engineering Research Laboratory, Tokyo (Japan)

    2000-03-01

    Radiation shielding aspects relating fission reactors have been reviewed. Domestic activities in the past five years have been mainly described concerning nuclear data, calculation methods, shielding and skyshine experiments, Advanced Boiling Water Reactor (ABWR), Advanced Pressurized Water Reactor (APWR), High Temperature Engineering Test Reactor (HTTR), Experimental and Prototype Fast Reactors (JOYO, MONJU), Demonstration FBR, core shroud replacement of BWR, and spent fuel transportation cask and vessel. These studies have valuable information in safety and cost reduction issues of fission reactor design for not only existing reactors but also new reactor concepts in the next century. It has been concluded that we should maintain existing shielding technologies and improve these data and methods for coming generations in the next millennium. (author)

  15. Experimental results on spin physics at the AGS

    International Nuclear Information System (INIS)

    Makdisi, Y.I.

    1986-01-01

    The AGS ran with polarized protons towards the end of 1985 and through the first two months of 1986. This comprised commissioning periods interleaved with two runs for physics at 13.5 GeV/c with beam polarization of 50 to 60%, and 18.5 GeV/c with an average beam polarization of 40%. Later, the AGS polarized beam reached peak energy of 22 GeV/c and polarization of 46%. This article describes the various spin related experimental efforts since the VI Symposium at Marseille. These will be grouped into those using unpolarized beams and the rest are the polarized proton beam users. Afterwards the future of the program is described as extensions of current experiments in addition to other measurements that are yet to be proposed

  16. Experimental MR imaging with Gd-DOTA: Preliminary results

    International Nuclear Information System (INIS)

    Schouman-Claeys, E.; Kien, P.; Caille, J.M.; Bonnemain, B.; Frija, G.

    1986-01-01

    To evaluate the paramagnetic properties of a new gadolinium chelate, Gd-DOTA, in vitro and in vivo MR imaging was performed with a 0.5-T supraconductive magnet. The in vitro study consisted in measuring the MR signal obtained with various concentrations of Gd-DOTA and Gd-DTPA in different solutions. Potentialization of the paramagnetic properties of both DOTA and DTPA can be achieved by deuterium, glycerol, and protein solutions. The in vivo study was performed in rabbits with various experimental lesions. Enhancement of anatomic details was obtained with both Gd-DOTA and Gd-DTPA. There was no significant difference between Gd-DOTA and Gd-DTPA, both for in vitro and in vivo experiments. Gd-DOTA appears to be a potential paramagnetic agent for MR imaging

  17. Waste glass corrosion modeling: Comparison with experimental results

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-01-01

    Models for borosilicate glass dissolution must account for the processes of (1) kinetically-controlled network dissolution, (2) precipitation of secondary phases, (3) ion exchange, (4) rate-limiting diffusive transport of silica through a hydrous surface reaction layer, and (5) specific glass surface interactions with dissolved cations and anions. Current long-term corrosion models for borosilicate glass employ a rate equation consistent with transition state theory embodied in a geochemical reaction-path modeling program that calculates aqueous phase speciation and mineral precipitation/dissolution. These models are currently under development. Future experimental and modeling work to better quantify the rate-controlling processes and validate these models are necessary before the models can be used in repository performance assessment calculations

  18. A first glance at the initial ATF experimental results

    International Nuclear Information System (INIS)

    Carreras, B.A.; Dominguez, N.; Leboeuf, J.N.; Lynch, V.E.; Charlton, L.A.

    1989-05-01

    In the initial phase of ATF operation, the plasma minor radius and the edge rotational transform were reduced by field errors. This caused an effective change of the magnetic configuration: it improved the stability properties but worsened the equilibrium properties. The threshold for the second stability regime was lowered to β 0 /approximately/ 1.5%. Experimental profile data are compatible with operation in the second stability regime, and the achieved beta values, β 0 /approximately/ 3%, are well beyond the theoretically calculated threshold. Magnetic fluctuation measurements showed the effects of beta self-stabilization. They are in reasonable agreement with the predictions of the theory and support the evidence that ATF has already operated in the second stability regime. 24 refs., 20 figs., 1 tab

  19. Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes

    Science.gov (United States)

    Basyigit, Celalettin; Uysal, Volkan; Kilinçarslan, Şemsettin; Mavi, Betül; Günoǧlu, Kadir; Akkurt, Iskender; Akkaş, Ayşe

    2011-12-01

    The radiation although has hazardous effects for human health, developing technologies bring lots of usage fields to radiation like in medicine and nuclear power station buildings. In this case protecting from undesirable radiation is a necessity for human health. Heavyweight concrete is one of the most important materials used in where radiation should be shielded, like those areas. In this study, used heavyweight aggregates of different mineral origin (Limonite, Siderite), in order to prepare different series in concrete mixtures and investigated radiation shielding properties. The experimental results on measuring the radiation shielding, the heavyweight concrete prepared with heavyweight aggregates of different mineral origin show that, are useful radiation absorbents when they used in concrete mixtures.

  20. Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes

    International Nuclear Information System (INIS)

    Basyigit, Celalettin; Uysal, Volkan; Kilincarslan, Semsettin; Akkas, Ayse; Mavi, Betuel; Guenoglu, Kadir; Akkurt, Iskender

    2011-01-01

    The radiation although has hazardous effects for human health, developing technologies bring lots of usage fields to radiation like in medicine and nuclear power station buildings. In this case protecting from undesirable radiation is a necessity for human health. Heavyweight concrete is one of the most important materials used in where radiation should be shielded, like those areas. In this study, used heavyweight aggregates of different mineral origin (Limonite, Siderite), in order to prepare different series in concrete mixtures and investigated radiation shielding properties. The experimental results on measuring the radiation shielding, the heavyweight concrete prepared with heavyweight aggregates of different mineral origin show that, are useful radiation absorbents when they used in concrete mixtures.

  1. Practical aspects of shielding high-energy particle accelerators

    International Nuclear Information System (INIS)

    Thomas, R.H.; Univ. of California, Berkeley, CA

    1993-09-01

    The experimental basis of shielding design for high-energy accelerators that has been established over the past thirty years is described. Particular emphasis is given to the design of large accelerators constructed underground. The first data obtained from cosmic-ray physics were supplemented by basic nuclear physics. When these data proved insufficient, experiments were carried out and interpreted by several empirical formulae -- the most successful of which has been the Moyer Model. This empirical model has been used successfully to design the shields of most synchrotrons currently in operation, and is still being used in preliminary design and to check the results of neutron transport calculations. Accurate shield designs are needed to reduce external radiation levels during accelerator operations and to minimize environmental impacts such as open-quotes skyshineclose quotes and the production of radioactivity in groundwater. Examples of the cost of minimizing such environmental impacts are given

  2. Handout on shielding calculation

    International Nuclear Information System (INIS)

    Heilbron Filho, P.F.L.

    1991-01-01

    In order to avoid the difficulties of the radioprotection supervisors in the tasks related to shielding calculations, is presented in this paper the basic concepts of shielding theory. It also includes exercises and examples. (author)

  3. Vaporization inside a mini microfin tube: experimental results and modeling

    Science.gov (United States)

    Diani, A.; Rossetto, L.

    2015-11-01

    This paper proposes a comparison among the common R134a and the extremely low GWP refrigerant R1234yf during vaporization inside a mini microfin tube. This microfin tube has an internal diameter of 2.4 mm, it has 40 fins, with a fin height of 0.12 mm. Due to the high heat transfer coefficients shown by this tube, this technology can lead to a refrigerant charge reduction. Tests were run in the Heat Transfer in Micro Geometries Lab of the Dipartimento di Ingegneria Industriale of the Università di Padova. Mass velocities range between 375 and 940 kg m-2 s-1, heat fluxes from 10 to 50 kW m-2, vapour qualities from 0.10 to 0.99, at a saturation temperature of 30°C. The comparison among the two fluids is proposed at the same operating conditions, in order to highlight the heat transfer and pressure drop differences among the two refrigerants. In addition, two correlations are proposed to estimate the heat transfer coefficient and frictional pressure drop during refrigerant flow boiling inside mini microfin tubes. These correlations well predict the experimental values, and thus they can be used as a useful tool to design evaporators based on these mini microfin tubes.

  4. Construction of a WMR for Trajectory Tracking Control: Experimental Results

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2013-01-01

    Full Text Available This paper reports a solution for trajectory tracking control of a differential drive wheeled mobile robot (WMR based on a hierarchical approach. The general design and construction of the WMR are described. The hierarchical controller proposed has two components: a high-level control and a low-level control. The high-level control law is based on an input-output linearization scheme for the robot kinematic model, which provides the desired angular velocity profiles that the WMR has to track in order to achieve the desired position (x*,y* and orientation (φ*. Then, a low-level control law, based on a proportional integral (PI approach, is designed to control the velocity of the WMR wheels to ensure those tracking features. Regarding the trajectories, this paper provides the solution or the following cases: (1 time-varying parametric trajectories such as straight lines and parabolas and (2 smooth curves fitted by cubic splines which are generated by the desired data points x1*,y1*,…,xn*,yn*. A straightforward algorithm is developed for constructing the cubic splines. Finally, this paper includes an experimental validation of the proposed technique by employing a DS1104 dSPACE electronic board along with MATLAB/Simulink software.

  5. Waste glass corrosion modeling: Comparison with experimental results

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1993-11-01

    A chemical model of glass corrosion will be used to predict the rates of release of radionuclides from borosilicate glass waste forms in high-level waste repositories. The model will be used both to calculate the rate of degradation of the glass, and also to predict the effects of chemical interactions between the glass and repository materials such as spent fuel, canister and container materials, backfill, cements, grouts, and others. Coupling between the degradation processes affecting all these materials is expected. Models for borosilicate glass dissolution must account for the processes of (1) kinetically-controlled network dissolution, (2) precipitation of secondary phases, (3) ion exchange, (4) rate-limiting diffusive transport of silica through a hydrous surface reaction layer, and (5) specific glass surface interactions with dissolved cations and anions. Current long-term corrosion models for borosilicate glass employ a rate equation consistent with transition state theory embodied in a geochemical reaction-path modeling program that calculates aqueous phase speciation and mineral precipitation/dissolution. These models are currently under development. Future experimental and modeling work to better quantify the rate-controlling processes and validate these models are necessary before the models can be used in repository performance assessment calculations

  6. Modeling of rock friction 1. Experimental results and constitutive equations

    International Nuclear Information System (INIS)

    Dieterich, J.H.

    1979-01-01

    Direct shear experiments on ground surfaces of a granodiorite from Raymond, California, at normal stresses of approx.6 MPa demonstrate that competing time, displacement, and velocity, effects control rock friction. It is proposed that the strength of the population of points of contacts between sliding surfaces determines frictional strength and that the population of contacts changes continuously with displacements. Previous experiments demonstrate that the strength of the contacts increases with the age of the contacts. The present experiments establish that a characteristic displacement, proportional to surface roughness, is required to change the population of contacts. Hence during slip the average age of the points of contact and therefore frictional strength decrease as slip velocity increases. Displacement weakening and consequently the potential for unstable slip occur whenever displacement reduces the average age of the contacts. In addition to this velocity dependency, which arises from displacement dependency and time dependency, the experiments also show a competing but transient increase in friction whenever slip velocity increases. Creep of the sliding surface at stresses below that for steady state slip also observed. Constitutive relationships are developed that permit quantitative simulation of the friction versus displacement data as a function of surface roughness and for different time and velocity histories. Unstable slip in experiments is controlled by these constitutive effects and by the stiffness of the experimental system. It is argued that analogous properties control earthquake instability

  7. Experimental results with hydrogen fueled internal combustion engines

    Science.gov (United States)

    De Boer, P. C. T.; Mclean, W. J.; Homan, H. S.

    1975-01-01

    The paper focuses on the most important experimental findings for hydrogen-fueled internal combustion engines, with particular reference to the application of these findings to the assessment of the potential of hydrogen engines. Emphasis is on the various tradeoffs that can be made, such as between maximum efficiency, maximum power, and minimum NO emissions. The various possibilities for induction and ignition are described. Some projections are made about areas in which hydrogen engines may find their initial application and about optimum ways to design such engines. It is shown that hydrogen-fueled reciprocal internal combustion engines offer important advantages with respect to thermal efficiency and exhaust emissions. Problems arising from preignition can suitably be avoided by restricting the fuel-air equivalence ratio to values below about 0.5. The direct cylinder injection appears to be a very attractive way to operate the engine, because it combines a wide range of possible power outputs with a high thermal efficiency and very low NO emissions at part loads.

  8. Experimental Results from a Microwave Cavity Beam Position Monitor

    International Nuclear Information System (INIS)

    Balakin, V.; Bazhan, A.; Lunev, P.; Solyak, N.; Vogel, V.; Zhogolev, P.; Lisitsyn, A.; Yakimenko, V.

    1999-01-01

    Future Linear Colliders have hard requirements for the beam transverse position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0.1 micron in the single bunch regime is needed to control the stability of the beam position along the linac. Proposed BPM is based on the measurement of the asymmetrical mode excited by single bunch in the cavity. Four stages of signal processing (space-, time-, frequency- and phase-filtering providing the required signal-to-noise ratio) are used to obtain extremely high resolution. The measurement set-up was designed by BINP and installed at ATF/BNL to test experimentally this concept. The set-up includes three two-coordinates BPM's at the frequency of 13.566 GHz, and reference intensity/phase cavity. BPM's were mounted on support table. The two-coordinates movers allow to move and align BPM's along the straight line, using the signals from the beam. The position of each monitor is controlled by the sensors with the accuracy 0.03 micron. The information from three monitors allows to exclude angle and position jitter of the beam and measure BPM resolution. In the experiments the resolution of about 0.15 micron for 0.25 nC beam intensity was obtained, that is close to the value required

  9. Design of emergency shield

    International Nuclear Information System (INIS)

    Soliman, S.E.

    1993-01-01

    Manufacturing of an emergency movable shield in the hot laboratories center is urgently needed for the safety of personnel in case of accidents or spilling of radioactive materials. In this report, a full design for an emergency shield is presented and the corresponding dose rates behind the shield for different activities (from 1 mCi to 5 Ci) was calculated by using micro shield computer code. 4 figs., 1 tab

  10. Data base of reactor physics experimental results in Kyoto University critical assembly experimental facilities

    International Nuclear Information System (INIS)

    Ichihara, Chihiro; Fujine, Shigenori; Hayashi, Masatoshi

    1986-01-01

    The Kyoto University critical assembly experimental facilities belong to the Kyoto University Research Reactor Institute, and are the versatile critical assembly constructed for experimentally studying reactor physics and reactor engineering. The facilities are those for common utilization by universities in whole Japan. During more than ten years since the initial criticality in 1974, various experiments on reactor physics and reactor engineering have been carried out using many experimental facilities such as two solidmoderated cores, a light water-moderated core and a neutron generator. The kinds of the experiment carried out were diverse, and to find out the required data from them is very troublesome, accordingly it has become necessary to make a data base which can be processed by a computer with the data accumulated during the past more than ten years. The outline of the data base, the data base CAEX using personal computers, the data base supported by a large computer and so on are reported. (Kako, I.)

  11. Spin-rotation and NMR shielding constants in HCl

    Energy Technology Data Exchange (ETDEWEB)

    Jaszuński, Michał, E-mail: michal.jaszunski@icho.edu.pl [Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warszawa, Kasprzaka 44 (Poland); Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth [Centre for Theoretical and Computational Chemistry, University of Tromsø—The Arctic University of Norway, N-9037 Tromsø (Norway); Garbacz, Piotr; Jackowski, Karol; Makulski, Włodzimierz [Laboratory of NMR Spectroscopy, Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)

    2013-12-21

    The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of {sup 1}H{sup 35}Cl are C{sub Cl}  = −53.914 kHz and C{sub H}  = 42.672 kHz (for the lowest rovibrational level). For the chlorine shielding constant, the ab initio value computed including the relativistic corrections, σ(Cl) = 976.202 ppm, provides a new absolute shielding scale; for hydrogen we find σ(H) = 31.403 ppm (both at 300 K). Combining the theoretical results with our new gas-phase NMR experimental data allows us to improve the accuracy of the magnetic dipole moments of both chlorine isotopes. For the hydrogen shielding constant, including relativistic effects yields better agreement between experimental and computed values.

  12. Spin-rotation and NMR shielding constants in HCl

    International Nuclear Information System (INIS)

    Jaszuński, Michał; Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth; Garbacz, Piotr; Jackowski, Karol; Makulski, Włodzimierz

    2013-01-01

    The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of 1 H 35 Cl are C Cl   = −53.914 kHz and C H   = 42.672 kHz (for the lowest rovibrational level). For the chlorine shielding constant, the ab initio value computed including the relativistic corrections, σ(Cl) = 976.202 ppm, provides a new absolute shielding scale; for hydrogen we find σ(H) = 31.403 ppm (both at 300 K). Combining the theoretical results with our new gas-phase NMR experimental data allows us to improve the accuracy of the magnetic dipole moments of both chlorine isotopes. For the hydrogen shielding constant, including relativistic effects yields better agreement between experimental and computed values

  13. A review of experimental results at the knee

    International Nuclear Information System (INIS)

    Hoeorandel, Joerg R.

    2006-01-01

    Results of experiments investigating air showers in the energy region of the knee are summarized. The all-particle energy spectrum, the mean logarithmic mass, and the average depth of the shower maximum will be discussed. Spectra for groups of elements from air shower data are compared to results from direct measurements

  14. Electromagnetically shielded building

    International Nuclear Information System (INIS)

    Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

    1992-01-01

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs

  15. Electromagnetically shielded building

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

    1992-04-21

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs.

  16. Neutron streaming studies along JET shielding penetrations

    Science.gov (United States)

    Stamatelatos, Ion E.; Vasilopoulou, Theodora; Batistoni, Paola; Obryk, Barbara; Popovichev, Sergey; Naish, Jonathan

    2017-09-01

    Neutronic benchmark experiments are carried out at JET aiming to assess the neutronic codes and data used in ITER analysis. Among other activities, experiments are performed in order to validate neutron streaming simulations along long penetrations in the JET shielding configuration. In this work, neutron streaming calculations along the JET personnel entrance maze are presented. Simulations were performed using the MCNP code for Deuterium-Deuterium and Deuterium- Tritium plasma sources. The results of the simulations were compared against experimental data obtained using thermoluminescence detectors and activation foils.

  17. Equivalent-spherical-shield neutron dose calculations

    International Nuclear Information System (INIS)

    Russell, G.J.; Robinson, H.

    1988-01-01

    Neutron doses through 162-cm-thick spherical shields were calculated to be 1090 and 448 mrem/h for regular and magnetite concrete, respectively. These results bracket the measured data, for reinforced regular concrete, of /approximately/600 mrem/h. The calculated fraction of the high-energy (>20 MeV) dose component also bracketed the experimental data. The measured and calculated doses were for a graphite beam stop bombarded with 100 nA of 800-MeV protons. 6 refs., 2 figs., 1 tab

  18. ORNL fusion reactor shielding integral experiments

    International Nuclear Information System (INIS)

    Santoro, R.T.; Alsmiller, R.G. Jr.; Barnes, J.M.; Chapman, G.T.

    1980-01-01

    Integral experiments that measure the neutron and gamma-ray energy spectra resulting from the attenuation of approx. 14 MeV T(D,n) 4 He reaction neutrons in laminated slabs of stainless steel type 304, borated polyethylene, and a tungsten alloy (Hevimet) and from neutrons streaming through a 30-cm-diameter iron duct (L/D = 3) imbedded in a concrete shield have been performed. The facility, the NE-213 liquid scintillator detector system, and the experimental techniques used to obtain the measured data are described. The two-dimensional discrete ordinates radiation transport codes, calculational models, and nuclear data used in the analysis of the experiments are reviewed

  19. Nuclear data requirements for fusion reactor shielding

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1979-01-01

    The nuclear data requirements for experimental, demonstration and commercial fusion reactors are reviewed. Particular emphasis is given to the shield as well as major reactor components of concern to the nuclear performance. The nuclear data requirements are defined as a result of analyzing four key areas. These are the most likely candidate materials, energy range, types of needed nuclear data, and the required accuracy in the data. Deducing the latter from the target goals for the accuracy in prediction is also discussed. A specific proposal of measurements is recommended. Priorities for acquisition of data are also assigned. (author)

  20. Concrete shielding for nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Nagase, Tetsuo; Nakajima, Tadao; Okumura, Tadahiko; Saito, Tetsuo

    1983-01-01

    The nuclear ship ''Mutsu'' was constructed in 1970 as the fourth in the world. On September 1, 1974, during the power raising test in the Pacific Ocean, radiation leak was detected. As the result of investigation, it was found that the cause was the fast neutrons streaming through the gap between the reactor pressure vessel and the primary shield. In order to repair the shielding facility, the Japan Nuclear Ship Research Development Agency carried out research and development and shielding design. It was decided to adopt serpentine concrete for the primary shield, which is the excellent moderator of fast neutrons even at high temperature, and heavy concrete for the secondary shield, which is effective for shielding both gamma ray and neutron beam. The repair of shielding was carried out in the Sasebo Shipyard, and completed in August, 1982. The outline of the repair work is reported. The weight increase was about 300 t. The conditions of the shielding design, the method of shielding analysis, the performance required for the shielding concrete, the preliminary experiment on heavy concrete and the construction works of serpentine concrete and heavy concrete are described. (Kako, I.)

  1. Experimental results on charmonium from E760 (FNAL)

    International Nuclear Information System (INIS)

    Armstrong, T.A.; Hasan, M.A.; Lewis, R.A.; Majewska, A.M.; Reid, J.D.; Smith, G.A.; Zhang, Y.; Bettoni, D.; Borreani, G.; Calabrese, R.; Dalpiaz, P.; Dalpiaz, P.F.; Fabbri, M.; Luppi, E.; Martini, M.; Petrucci, F.; Savrie, M.; Bharadwaj, V.; Church, M.D.; Hahn, A.A.; Hsueh, S.Y.; Marsh, W.; Peoples, J. Jr.; Pordes, S.; Rapidis, P.A.; Werkema, S.J.; Biino, C.; Ceccucci, A.; Cester, R.; Marchetto, F.; Menichetti, E.; Migliori, A.; Mussa, R.; Palestini, S.; Pastrone, N.; Pesando, L.; Rinaudo, G.; Tecchio, L.; Broemmelsiek, D.R.; Fast, J.E.; Gee, M.; Gollwitzer, K.E.; Mandelkern, M.A.; Marques, J.L.; Schultz, J.; Weber, M.F.; Zioulas, G.; Buzzo, A.; Dameri, M.; Ferroni, S.; Macri, M.; Marinelli, M.; Patrignani, C.; Pia, M.G.; Santroni, A.; Tommasini, S.; Zito, M.; Dimitroyannis, D.; Ginsburg, C.M.; Masuzawa, M.; Rosen, J.L.; Sarmiento, M.; Seth, K.K.; Trokenheim, S.; Zhao, J.L.; Ray, R.E.

    1992-01-01

    E760 is a fixed target experiment dedicated to the study of charmonium spectroscopy in anti pp annihilations. Results on X 1 and X 2 resonance parameters from 1990 data taking are presented, consisting of precise measurement of mass, total width and partial width to anti pp. A preliminary result is presented on the first determination of Ψ'width from line shape analysis. (orig.)

  2. Superconducting and hybrid systems for magnetic field shielding

    International Nuclear Information System (INIS)

    Gozzelino, L; Gerbaldo, R; Ghigo, G; Laviano, F; Truccato, M; Agostino, A

    2016-01-01

    In this paper we investigate and compare the shielding properties of superconducting and hybrid superconducting/ferromagnetic systems, consisting of cylindrical cups with an aspect ratio of height/radius close to unity. First, we reproduced, by finite-element calculations, the induction magnetic field values measured along the symmetry axis in a superconducting (MgB 2 ) and in a hybrid configuration (MgB 2 /Fe) as a function of the applied magnetic field and of the position. The calculations are carried out using the vector potential formalism, taking into account simultaneously the non-linear properties of both the superconducting and the ferromagnetic material. On the basis of the good agreement between the experimental and the computed data we apply the same model to study the influence of the geometric parameters of the ferromagnetic cup as well as of the thickness of the lateral gap between the two cups on the shielding properties of the superconducting cup. The results show that in the considered non-ideal geometry, where the edge effect in the flux penetration cannot be disregarded, the superconducting shield is always the most efficient solution at low magnetic fields. However, a partial recovery of the shielding capability of the hybrid configuration occurs if a mismatch in the open edges of the two cups is considered. In contrast, at high magnetic fields the hybrid configurations are always the most effective. In particular, the highest shielding factor was found for solutions with the ferromagnetic cup protruding over the superconducting one. (paper)

  3. Status of reactor-shielding research in the US

    International Nuclear Information System (INIS)

    Maienshein, F.C.

    1980-01-01

    While reactor programs change, shielding analysis methods are improved slowly. Version-V of ENDF/B provides improved data and Version-VI will be cost effective in advanced fission reactors are to be developed in the US. Benchmarks for data and methods validation are collected and distributed in the US in two series, one primarily for FBR-related experiments and one for LWR calculational methods. For LWR design, cavity streaming is now handled adequately, if with varying degrees of elegance. Investigations of improved detector response for LWRs rely upon transport methods. The great potential importance of pressure-vessel damage is dreflected in widespread studies to aid in the prediction of neutron fluences in vessels. For LMFBRS, the FFTF should give attenuation results on an operating reactor. For larger power reactors, the advantages of alternate shield materials appear compelling. A few other shielding studies appear to require experimental confirmation if LMFBRs are to be economically competitive. A coherent shielding program for the GCFR is nearing completion. For the fusion-reactor program, methods verification is under way, practical calculations are well advanced for test devices such as the TFTR and FMIT, and consideration is now given to shielding problems of large reactors, as in the ETF study

  4. Shielding technology for high energy radiation production facility

    International Nuclear Information System (INIS)

    Lee, Byung Chul; Kim, Heon Il

    2004-06-01

    In order to develop shielding technology for high energy radiation production facility, references and data for high energy neutron shielding are searched and collected, and calculations to obtain the characteristics of neutron shield materials are performed. For the evaluation of characteristics of neutron shield material, it is chosen not only general shield materials such as concrete, polyethylene, etc., but also KAERI developed neutron shields of High Density PolyEthylene (HDPE) mixed with boron compound (B 2 O 3 , H 2 BO 3 , Borax). Neutron attenuation coefficients for these materials are obtained for later use in shielding design. The effect of source shape and source angular distribution on the shielding characteristics for several shield materials is examined. This effect can contribute to create shielding concept in case of no detail source information. It is also evaluated the effect of the arrangement of shield materials using current shield materials. With these results, conceptual shielding design for PET cyclotron is performed. The shielding composite using HDPE and concrete is selected to meet the target dose rate outside the composite, and the dose evaluation is performed by configuring the facility room conceptually. From the result, the proper shield configuration for this PET cyclotron is proposed

  5. New experimental results on electron cooling at COSY-Juelich

    International Nuclear Information System (INIS)

    Dietrich, J.; Maier, R.; Prasuhn, D.; Stein, H.J.; Kobets, A.; Meshkov, I.; Sidorin, A.; Smirnov, A.

    2007-01-01

    Recent results of electron cooling of proton beams at COSY-Juelich are reported. Cooling at an electron energy of 70 keV has been studied for the first time. At the injection energy level of COSY, corresponding to 24.5 keV electron energy, the features of the cooled proton beam at extremely low intensities have been investigated in order to find out whether an ordering of the proton beam can be achieved. Such investigations are motivated by the results of a numerical simulation of the ordering process by the BETACOOL code. (author)

  6. Comments on experimental results of energy confinement of tokamak plasmas

    International Nuclear Information System (INIS)

    Chu, T.K.

    1989-04-01

    The results of energy-confinement experiments on steady-state tokamak plasmas are examined. For plasmas with auxiliary heating, an analysis based on the heat diffusion equation is used to define heat confinement time (the incremental energy confinement time). For ohmically sustained plasmas, experiments show that the onset of the saturation regime of energy confinement, marfeing, detachment, and disruption are marked by distinct values of the parameter /bar n//sub e///bar j/. The confinement results of the two types of experiments can be described by a single surface in 3-dimensional space spanned by the plasma energy, the heating power, and the plasma density: the incremental energy confinement time /tau//sub inc/ = ΔW/ΔP is the correct concept for describing results of heat confinement in a heating experiment; the commonly used energy confinement time defined by /tau//sub E/ = W/P is not. A further examination shows that the change of edge parameters, as characterized by the change of the effective collision frequency ν/sub e/*, governs the change of confinement properties. The totality of the results of tokamak experiments on energy confinement appears to support a hypothesis that energy transport is determined by the preservation of the pressure gradient scale length. 70 refs., 6 figs., 1 tab

  7. Experimental high power plasma-filled backward wave oscillator results

    International Nuclear Information System (INIS)

    Minami, K.; Lou, W.R.; Destler, W.W.; Kehs, R.A.; Granatstein, V.L.; Carmel, Y.

    1988-01-01

    Previous results have indicated that a background gas can be used to increase the output microwave power of relativistic backward wave oscillators (BWOs) two or three times the vacuum case. In their experiments, two methods of plasma production are investigated in detail: the use of the electron beam to ionize a background gas, and the use of a plasma gun to inject a background plasma into the slow-wave structure of a BWO. It is found in the first case that there was a resonant increase in microwave power at a particular pressure of the background gas by a factor of ten. In the second case, power also increased compared with power production in vacuum. Detailed results are presented and the relative merits of the two approaches is discussed and compared with theoretical expectations

  8. Verification of aseismic design model by using experimental results

    International Nuclear Information System (INIS)

    Mizuno, N.; Sugiyama, N.; Suzuki, T.; Shibata, Y.; Miura, K.; Miyagawa, N.

    1985-01-01

    A lattice model is applied as an analysis model for an aseismic design of the Hamaoka nuclear reactor building. With object to verify an availability of this design model, two reinforced concrete blocks are constructed on the ground and the forced vibration tests are carried out. The test results are well followed by simulation analysis using the lattice model. Damping value of the ground obtained from the test is more conservative than the design value. (orig.)

  9. Material and electromagnetic properties of Faraday shields for ion cyclotron heating antennas

    International Nuclear Information System (INIS)

    Hoffman, D.J.; Baity, F.W.; Becraft, W.R.; Caughman, J.B.O.; Tsai, C.C.

    1985-01-01

    The Faraday shields for ion cyclotron antennas must transmit magnetic waves and absorb little RF power. To investigate these properties, we have constructed 27 Faraday shields in many configurations, including chevrons, tubes, straps, concentric rings, various layered shields, conventionally leafed straps, and replicas of the Faraday shields for ASDEX, the Joint European Torus (JET), TEXTOR, and Alcator-C. We have measured the magnetic flux and observed loading at various operating resistances by using dielectric sheets or magnetic-coupled loads. Each Faraday shield effects a net change in the characteristic inductance of the antenna, resulting in a reduction of wave coupling. However, the load experienced by the antenna is not always reduced because the Faraday shield itself acts as a load. We differentiate between these effects experimentally. The net result of the study is that the Faraday shields now in use cost up to a factor of 50% of coupling. This, of course, reduces the power handling capability by 50% as well. However, configurations exist that are easily cooled and result in a reduction of less than 5% in loading

  10. Material and electromagnetic properties of Faraday shields for ion cyclotron heating antennas

    International Nuclear Information System (INIS)

    Hoffman, D.J.; Becraft, W.R.; Baity, F.W.; Caughman, J.B.O.; Tsai, C.C.

    1985-01-01

    The Faraday shields for ion cyclotron antennas must transmit magnetic waves and adsorb little rf power. To investigate these properties, we have constructed 27 Faraday shields in many configurations, including chevrons, tubes, straps, concentric rings, various layered shields, conventionally leafed straps, and replicas of the Faraday shields for ASDEX, the Joint European Torus (JET), TEXTOR, and Alcator-C. We have measured the magnetic flux and observed loading at various operating resistances by using dielectric sheets or magnetic-coupled loads. Each Faraday shield effects a net change in the characteristic inductance of the antenna, resulting in a reduction of wave coupling. However, the load experienced by the antenna is not always reduced because the Faraday shield itself acts as a load. We differentiate between these effects experimentally. The net result of the study is that the Faraday shields now in use cost up to a factor of 50% of coupling. This, of course, reduces the power handling capability by 50% as well. However, configurations exist that are easily cooled and result in a reduction of less than 5% in loading

  11. Electromagnetic shielding formulae

    International Nuclear Information System (INIS)

    Dahlberg, E.

    1979-02-01

    This addendum to an earlier collection of electromagnetic shielding formulae (TRITA-EPP-75-27) contains simple transfer matrices suitable for calculating the quasistatic shielding efficiency for multiple transverse-field and axial-field cylindrical and spherical shields, as well as for estimating leakage fields from long coaxial cables and the normal-incidence transmission of a plane wave through a multiple plane shield. The differences and similarities between these cases are illustrated by means of equivalent circuits and transmission line analogies. The addendum also includes a discussion of a possible heuristic improvement of some shielding formulae. (author)

  12. Shielding benchmark problems, (2)

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Shin, Kazuo; Tada, Keiko.

    1980-02-01

    Shielding benchmark problems prepared by Working Group of Assessment of Shielding Experiments in the Research Committee on Shielding Design in the Atomic Energy Society of Japan were compiled by Shielding Laboratory in Japan Atomic Energy Research Institute. Fourteen shielding benchmark problems are presented newly in addition to twenty-one problems proposed already, for evaluating the calculational algorithm and accuracy of computer codes based on discrete ordinates method and Monte Carlo method and for evaluating the nuclear data used in codes. The present benchmark problems are principally for investigating the backscattering and the streaming of neutrons and gamma rays in two- and three-dimensional configurations. (author)

  13. The Active Muon Shield

    CERN Document Server

    Bezshyiko, Iaroslava

    2016-01-01

    In the SHiP beam-dump of the order of 1011 muons will be produced per second. An active muon-shield is used to magnetically deflect these muons out of the acceptance of the spectrom- eter. This note describes how this shield is modelled and optimized. The SHiP spectrometer is being re-optimized using a conical decay-vessel, and utilizing the possibility to magnetize part of the beam-dump shielding iron. A shield adapted to these new conditions is presented which is significantly shorter and lighter than the shield used in the Technical Proposal (TP), while showing a similar performance.

  14. Experimental test accelerator: description and results of initial experiments

    International Nuclear Information System (INIS)

    Fessenden, T.; Birx, D.; Briggs, R.

    1980-01-01

    The ETA is a high current (10,000 Amp) linear induction accelerator that produces short (30 ns) pulses of electrons at 5 MeV twice per second or in bursts of 5 pulses separated by as little as one millisecond. At this time the machine has operated at 65% of its design current and 90% of the design voltage. This report contains a description of the accelerator and its diagnostics; the results of the initial year of operation; a comparison of design codes with experiments on beam transport; and a discussion of some of the special problems and their status

  15. Space Launch System Base Heating Test: Experimental Operations & Results

    Science.gov (United States)

    Dufrene, Aaron; Mehta, Manish; MacLean, Matthew; Seaford, Mark; Holden, Michael

    2016-01-01

    NASA's Space Launch System (SLS) uses four clustered liquid rocket engines along with two solid rocket boosters. The interaction between all six rocket exhaust plumes will produce a complex and severe thermal environment in the base of the vehicle. This work focuses on a recent 2% scale, hot-fire SLS base heating test. These base heating tests are short-duration tests executed with chamber pressures near the full-scale values with gaseous hydrogen/oxygen engines and RSRMV analogous solid propellant motors. The LENS II shock tunnel/Ludwieg tube tunnel was used at or near flight duplicated conditions up to Mach 5. Model development was based on the Space Shuttle base heating tests with several improvements including doubling of the maximum chamber pressures and duplication of freestream conditions. Test methodology and conditions are presented, and base heating results from 76 runs are reported in non-dimensional form. Regions of high heating are identified and comparisons of various configuration and conditions are highlighted. Base pressure and radiometer results are also reported.

  16. Preliminary experimental results from a linear reciprocating magnetic refrigerator prototype

    International Nuclear Information System (INIS)

    Tagliafico, Luca Antonio; Scarpa, Federico; Valsuani, Federico; Tagliafico, Giulio

    2013-01-01

    A linear reciprocating magnetic refrigerator prototype was designed and built with the aid of an industrial partner. The refrigerator is based on the Active Magnetic Regenerative cycle, and exploits two regenerators working in parallel. The active material is Gadolinium in plates, 0.8 mm thick, for a total mass of 0.36 kg. The device is described and results about magnetic field and temperature span measurements are presented. The designed permanent magnet structure, based on an improved cross-type arrangement, generates a maximum magnetic field intensity of 1.55 T in air, over a gap of (13 × 50 × 100) mm 3 . The maximum temperature span achieved is 5.0 K, in a free run condition. -- Highlights: ► We give preliminary results from a linear reciprocating magnetic refrigerator prototype. ► The design is intended to process visualization and investigation. ► The prototype behavior gives us various suggestions to improve its general performance

  17. Impacts of changing hydrology on permanent gully growth: experimental results

    Science.gov (United States)

    Day, Stephanie S.; Gran, Karen B.; Paola, Chris

    2018-06-01

    Permanent gullies grow through head cut propagation in response to overland flow coupled with incision and widening in the channel bottom leading to hillslope failures. Altered hydrology can impact the rate at which permanent gullies grow by changing head cut propagation, channel incision, and channel widening rates. Using a set of small physical experiments, we tested how changing overland flow rates and flow volumes alter the total volume of erosion and resulting gully morphology. Permanent gullies were modeled as both detachment-limited and transport-limited systems, using two different substrates with varying cohesion. In both cases, the erosion rate varied linearly with water discharge, such that the volume of sediment eroded was a function not of flow rate, but of total water volume. This implies that efforts to reduce peak flow rates alone without addressing flow volumes entering gully systems may not reduce erosion. The documented response in these experiments is not typical when compared to larger preexisting channels where higher flow rates result in greater erosion through nonlinear relationships between water discharge and sediment discharge. Permanent gullies do not respond like preexisting channels because channel slope remains a free parameter and can adjust relatively quickly in response to changing flows.

  18. Gamma ray shielding properties of PbO-Li2O-B2O3 glasses

    International Nuclear Information System (INIS)

    Kumar, Ashok

    2017-01-01

    The mass attenuation coefficients have been measured in (0.6-x) PbO-x Li 2 O-0.40 B 2 O 3 (where 0≤ x≤0.25 mol%) glasses for photon energies of 356, 662, 1173 and 1332 keV in a narrow beam geometry with an overall scatter acceptance angle of 2.31°. The experimental results are found to be within 3% of their theoretical values. These coefficients were then used to obtain the values of mean free path, effective atomic number and electron density. The shielding properties of these glasses have also been compared among themselves in terms of their mean free path and radiation protection efficiency. The shielding properties prepared glasses have also been compared with standard concretes as well as with the standard shielding glasses. It is found that the prepared glasses are the better shielding substitute to the conventional concretes as well as other standard shielding glasses. The Pb 3 B 4 O 9 has been found to be the most effective shield. - Highlights: • Shielding efficiencies of PbO-B 2 O 3 -Li 2 O glasses have been compared. • Measurements have been done for 356, 662, 1173 and 1332 keV photon energies. • Experimental values have been found to be within 3% of their theoretical ones. • Pb 3 B 4 O 9 has been found to be the most effective shield.

  19. Experimental results on low alpha electron-storage rings

    International Nuclear Information System (INIS)

    Robin, D.; Hama, H.; Nadji, A.

    1995-09-01

    The authors report on experiments performed in two synchrotron light sources, UVSOR and Super-ACO, where the momentum compaction factor is reduced in order to reduce the bunch length. By controlling the second-order momentum compaction factor, UVSOR and Super-ACO have managed to reduce the first-order momentum compaction factor by 100. At low current the resulting bunch lengths are less than 10 ps, a factor of 10 smaller than normal. Measurements of current dependent bunch lengthening in UVSOR are presented and the cause of the bunch lengthening is determined to be potential-well distortion. The authors also show that by operating with a negative momentum compaction factor, SuperACO has achieved shorter bunch lengthening and higher peak currents than at positive momentum compaction

  20. New experimental results in atlas-based brain morphometry

    Science.gov (United States)

    Gee, James C.; Fabella, Brian A.; Fernandes, Siddharth E.; Turetsky, Bruce I.; Gur, Ruben C.; Gur, Raquel E.

    1999-05-01

    In a previous meeting, we described a computational approach to MRI morphometry, in which a spatial warp mapping a reference or atlas image into anatomic alignment with the subject is first inferred. Shape differences with respect to the atlas are then studied by calculating the pointwise Jacobian determinant for the warp, which provides a measure of the change in differential volume about a point in the reference as it transforms to its corresponding position in the subject. In this paper, the method is used to analyze sex differences in the shape and size of the corpus callosum in an ongoing study of a large population of normal controls. The preliminary results of the current analysis support findings in the literature that have observed the splenium to be larger in females than in males.

  1. Experimental results: Pilot plant calcine dissolution and liquid feed stability

    International Nuclear Information System (INIS)

    Herbst, R.S.; Fryer, D.S.; Brewer, K.N.; Johnson, C.K.; Todd, T.A.

    1995-02-01

    The dissolution of simulated Idaho Chemical Processing Plant pilot plant calcines, containing none of the radioactive actinides, lanthanides or fission products, was examined to evaluate the solubility of calcine matrix materials in acidic media. This study was a necessary precursor to dissolution and optimization experiments with actual radionuclide-containing calcines. The importance of temperature, nitric acid concentration, ratio of acid volume to calcine mass, and time on the amount, as a weight percentage of calcine dissolved, was evaluated. These parameters were studied for several representative pilot plant calcine types: (1) Run No. 74 Zirconia calcine; (2) Run No. 17 Zirconia/Sodium calcine; (3) Run No. 64 Zirconia/Sodium calcine; (3) Run No. 1027 Alumina calcine; and (4) Run No. 20 Alumina/Zirconia/Sodium calcine. Statistically designed experiments with the different pilot plant calcines indicated the effect of the studied process variables on the amount of calcine dissolved decreases in the order: Acid/Calcine Ratio > Temperature > HNO 3 Concentration > Dissolution Time. The following conditions are suitable to achieve greater than 90 wt. % dissolution of most Zr, Al, or Na blend calcines: (1) Maximum nitric acid concentration of 5M; (2) Minimum acid/calcine ratio of 10 mL acid/1 gram calcine; (3) Minimum dissolution temperature of 90 degrees C; and (4) Minimum dissolution time of 30 minutes. The formation of calcium sulphate (CaSO 4 ) precipitates was observed in certain dissolved calcine solutions during the dissolution experiments. Consequently, a study was initiated to evaluate if and under what conditions the resulting dissolved calcine solutions would be unstable with regards to precipitate formation. The results indicate that precipitate formation in the calcine solutions prepared under the above proposed dissolution conditions are not anticipated

  2. [Experimental results of erbium:YAG laser vitrectomy].

    Science.gov (United States)

    Mrochen, M; Petersen, H; Wüllner, C; Seiler, T

    1998-01-01

    Vitrectomy performed by conventional guillotine devices includes the risk of mechanical damage to retina as well as other ocular structures. The present study aims to investigate the efficacy of the Er:YAG laser for vitreous liquefaction. Vitreous liquefaction by means of Er:YAG laser pulses was performed using a special handpiece. The output of an Er:YAG laser operating at 2.94 microns was coupled into a ZrF optical fibre (length 2 m) which ended inside a cavity located at the quartz tip (diameter 320 microns) of the handpiece where tissue ablation took place. The viscosity of the liquefied vitreous was determined by rotation viscosimetry and compared to liquefied vitreous obtained by mechanical vitrectomy. In addition, the aspiration flow (ml/min) was correlated to the repetition/cutting rate of the laser and the cutter. The temperature rise at the handpiece was recorded with a micro thermocouple. The cutting threshold was determined to 5 mJ +/- 3 mJ at a pulse duration of 200 microseconds. The viscosity of the vitreous liquefied with the Er:YAG laser was 31 +/- 10 mPa s which is similar to the results of mechanical vitrectomy (42 +/- 19 mPa s) but significant less than that of normal vitreous (880 +/- 280 mPa s). The aspiration of the laser handpiece in dependence to the repetition rate increases linear up to 2.6 ml/min at 30 Hz. The temperature increase at the handpiece was < 1 K under vitrectomy conditions (aspiration and irrigation) with an averaged laser power of 0.3 W (10 mJ at 30 Hz). The decreased vacuum forces used by the laser vitrectomy system may result in less mechanical stress to the retina as well as intravitreal structures which may be attached to it. An Er:YAG laser vitrectomy system may offer the potential of fewer complications during vitrectomy.

  3. Hot Cell Window Shielding Analysis Using MCNP

    International Nuclear Information System (INIS)

    Pope, Chad L.; Scates, Wade W.; Taylor, J. Todd

    2009-01-01

    The Idaho National Laboratory Materials and Fuels Complex nuclear facilities are undergoing a documented safety analysis upgrade. In conjunction with the upgrade effort, shielding analysis of the Fuel Conditioning Facility (FCF) hot cell windows has been conducted. This paper describes the shielding analysis methodology. Each 4-ft thick window uses nine glass slabs, an oil film between the slabs, numerous steel plates, and packed lead wool. Operations in the hot cell center on used nuclear fuel (UNF) processing. Prior to the shielding analysis, shield testing with a gamma ray source was conducted, and the windows were found to be very effective gamma shields. Despite these results, because the glass contained significant amounts of lead and little neutron absorbing material, some doubt lingered regarding the effectiveness of the windows in neutron shielding situations, such as during an accidental criticality. MCNP was selected as an analysis tool because it could model complicated geometry, and it could track gamma and neutron radiation. A bounding criticality source was developed based on the composition of the UNF. Additionally, a bounding gamma source was developed based on the fission product content of the UNF. Modeling the windows required field inspections and detailed examination of drawings and material specifications. Consistent with the shield testing results, MCNP results demonstrated that the shielding was very effective with respect to gamma radiation, and in addition, the analysis demonstrated that the shielding was also very effective during an accidental criticality.

  4. Experimental Results of Integrated Refrigeration and Storage System Testing

    Science.gov (United States)

    Notardonato, W. U.; Johnson, W. L.; Jumper, K.

    2009-01-01

    Launch operations engineers at the Kennedy Space Center have identified an Integrated Refrigeration and Storage system as a promising technology to reduce launch costs and enable advanced cryogenic operations. This system uses a close cycle Brayton refrigerator to remove energy from the stored cryogenic propellant. This allows for the potential of a zero loss storage and transfer system, as well and control of the state of the propellant through densification or re-liquefaction. However, the behavior of the fluid in this type of system is different than typical cryogenic behavior, and there will be a learning curve associated with its use. A 400 liter research cryostat has been designed, fabricated and delivered to KSC to test the thermo fluid behavior of liquid oxygen as energy is removed from the cryogen by a simulated DC cycle cryocooler. Results of the initial testing phase focusing on heat exchanger characterization and zero loss storage operations using liquid oxygen are presented in this paper. Future plans for testing of oxygen densification tests and oxygen liquefaction tests will also be discussed. KEYWORDS: Liquid Oxygen, Refrigeration, Storage

  5. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    International Nuclear Information System (INIS)

    Chiara, P.; Morelli, A.

    2010-01-01

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements.Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken.This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  6. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    Science.gov (United States)

    Chiara, P.; Morelli, A.

    2010-05-01

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements. Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken. This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  7. Recent experimental results on solutions of deuterium in lithium

    International Nuclear Information System (INIS)

    Ihle, H.R.; Wu, C.H.

    1976-01-01

    The existence of a number of stable molecules containing lithium and hydrogen isotopes in the saturated vapor over dilute solutions of hydrogen isotopes in lithium causes an unexpectedly high density of hydrogen isotopes in the vapor at high temperature. An evaluation of the partial pressures of the gas species Li, Li 2 , LiD, Li 2 D, LiD 2 and D 2 over solutions of deuterium in lithium measured in the temperature range 770 to 970 0 K, and extrapolation to higher temperatures, leads to the conclusion that the ratio of the atom fraction of deuterium in the gas to its atom fraction in the liquid exceeds unity above approximately 1240 0 K; this ratio is independent of the deuterium atom fraction in the liquid at low concentrations. Therefore the thermodynamic supposition that hydrogen isotopes can be separated from lithium by fractional distillation even at extremely low concentration exists. A direct verification of this phenomenon was made by Rayleigh distillation of Li-D solutions in the temperature range 970 to 1600 0 K. These measurements yield also the ratio of the deuterium atom fraction in the gas to that in the liquid and are in good agreement with the data obtained by extrapolation of partial pressures. The enrichment and depletion of deuterium in dependence on the number of theoretical plates of a distillation column at total reflux is calculated using the results

  8. Experimentally increasing sedentary behavior results in decreased life satisfaction

    Directory of Open Access Journals (Sweden)

    Meghan K. Edwards

    2017-03-01

    behavior-inducing randomized controlled intervention on life satisfaction. Methods: Active, young adults between the ages of 18-35 were recruited and randomly assigned into a sedentary behavior intervention group (n = 26 or a control group (n = 13. The intervention group participants were instructed to eliminate all exercise and restrict daily steps (as measured via pedometry to 5000 or less per day for one week. The control group was instructed to maintain regular levels of exercise and other physical activity for one week. Both groups completed the Satisfaction with Life Scale (SWLS pre-intervention and immediately post-intervention. Results: There was a significant group x time interaction (F = 32.75, P < 0.001, with post-hoc contrast tests indicating decreased SWLS score (indicating lower levels of life satisfaction in the intervention group during Visit 2 (post-intervention compared with Visit 1 (pre-intervention; this corresponded with a mean absolute (Visit 2 minus Visit 1 change of -8.58 (95% CI: -5.91, -11.24 for SWLS scores in the intervention group (31.1% reduction. Conclusion: A one-week sedentary behavior-inducing intervention may negatively impact life satisfaction in an active, young adult population. Regular physical activity may be imperative in avoiding negative life satisfaction-related consequences.

  9. The experimental results and analysis of a borehole radar prototype

    International Nuclear Information System (INIS)

    Liu, Sixin; Wu, Junjun; Dong, Hang; Fu, Lei; Wang, Fei

    2012-01-01

    A prototype of borehole radar has been successfully tested in three sites for different purposes under a field condition. The objective of the prototype is providing an effective down-hole tool for detecting targets in deep boreholes situated in a relatively high conductivity area such as the metal ores. The first testing site is at a geothermal field. The fractures extending more than 20 m from the borehole are delineated by the borehole radar in the single-hole reflection mode. The second testing site is located in a jade mine for basement evaluation. The cross-hole measurement mode was used to detect the cavities made by previous unorganized mining activities. Several high-velocity anomalies were found in the velocity profile and presumably the targets of the mine shafts and tunnels. The third test site is located in a mineralized belt characterized by low resistivity less than 1000 Ohm m, the surface-borehole measurement was carried out and the data were processed with velocity tomography. The low-velocity zone corresponds to a mineralized zone from geological records. The three testing results proved the readiness of this borehole radar prototype for further deployment in more complicated and realistic field situations. (paper)

  10. First experimental results on the IShTAR testbed

    Energy Technology Data Exchange (ETDEWEB)

    D’Inca, R.; Jacquot, J.; Ochoukov, R.; Morgal, I.; Fünfgelder, H.; Faugel, H. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Crombe, K.; Louche, F.; Van Eester, D. [LPP-ERM-KMS, TEC partner, Brussels (Belgium); Heuraux, S.; Devaux, S.; Moritz, J.; Faudot, E. [Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine, Nancy (France); Noterdaeme, J.-M. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Department of Applied Physics, Ghent University (Belgium)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetized plasma test facility dedicated to the investigation of RF wave/plasma interaction [1] in the Ion Cyclotron Range of Frequencies (ICRF). It provides a better accessibility for the instrumentation than tokamaks while being representative of the neighboring region of the wave emitter. It is equipped with a magnetized plasma source (1 m long, 0.4 m diameter) powered by a helical antenna up to 3 kW at 11 MHz. We present the results of the first analysis of the plasma characteristics (plasma density, electron temperature) in function of the operating parameters (injected power, neutral pressure and magnetic field) as measured with fixed and movable Langmuir probes, spectrometer and cameras. The plasma is presently produced only by the helical antenna (no ICRF). We show that the plasma exists in three regime depending on the power level: the first two ones are stable and separated by a jump in density; a first spatial profile of the plasma density has been established for these modes; The third mode is unstable, characterized by strong oscillations of the plasma tube position.

  11. Equatorial spread F: a review of recent experimental results

    International Nuclear Information System (INIS)

    Kelley, M.C.

    1979-01-01

    In this paper the authors review an intense research effort aimed at understanding the large scale disruption of the equatorial F layer which often commences just after sunset, and lasts for most of the night. A very attractive explanation for the phenomena, although one not universally accepted, is that the F layer is unstable to the classic Rayleigh-Taylor condition in which a heavy fluid, the plasma, is supported against gravity by a light 'fluid', the Earth's magnetic field. It is concluded that a reasonable case has been made for this explanation provided that the concept is extended to include nonlinear Rayleigh-Taylor like buoyancy effects above the F peak where linear process is stable. Internal gravity waves in neutral atmosphere seem to play an important role in seeding the Rayleigh-Taylor process with large scale finite amplitude perturbations. One of the remarkable features of this phenomena is the nearly simultaneous generation of structure with scale sizes spanning five orders of magnitude. These results may have applications in astrophysical processes where the Rayleigh-Taylor instability is thought to play a role. (Auth.)

  12. The European Tracer Experiment - experimental results and database

    International Nuclear Information System (INIS)

    Nodop, K.; Connolly, R.; Girardi, F.

    1997-01-01

    As part of the European Tracer Experiment (ETEX) two successful atmospheric experiments were carried out in October and November, 1994. Perfluorocarbon (PFC) tracers were released into the atmosphere in Monterfil, Brittany, and air samples were taken at 168 stations in 17 European countries for 72 hours after the release. Upper air tracer measurements were made from three aircraft. During the first experiment a westerly air flow transported the tracer plume north-eastwards across Europe. During the second release the flow was eastwards. The results from the ground sampling network allowed the determination of the cloud evolution as far as Sweden, Poland and Bulgaria. Typical background concentrations of the tracer used are around 5 to 7 fl/l in ambient air. Concentrations in the plume ranged from 10 to above 200 fl/l. The tracer release characteristics, the tracer concentrations at the ground and in upper air, the routine and additional meteorological observations at the ground level and in upper air, trajectories derived from constant-level balloons and the meteorological input fields for long-range transport (LRT) models are assembled in the ETEX database. The ETEX database is accessible via the Internet

  13. EXPERIMENTAL RESULTS OF THE NEPHELINE PHASE III STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Edwards, T.

    2009-11-09

    This study is the third phase in a series of experiments designed to reduce conservatism in the model that predicts the formation of nepheline, a crystalline phase that can reduce the durability of high level waste glass. A Phase I study developed a series of glass compositions that were very durable while their nepheline discriminator values were well below the current nepheline discriminator limit of 0.62, where nepheline is predicted to crystallize upon slow cooling. A Phase II study selected glass compositions to identify any linear effects of composition on nepheline crystallization and that were restricted to regions that fell within the validation ranges of the Defense Waste Processing Facility (DWPF) Product Composition Control System (PCCS) models. However, it was not possible to identify any linear effects of composition on chemical durability performance for this set of study glasses. The results of the Phase II study alone were not sufficient to recommend modification of the current nepheline discriminator. It was recommended that the next series of experiments continue to focus not only on compositional regions where the PCCS models are considered applicable (i.e., the model validation ranges), but also be restricted to compositional regions where the only constraint limiting processing is the current nepheline discriminator. Two methods were used in selecting glasses for this Phase III nepheline study. The first was based on the relationship of the current nepheline discriminator model to the other DWPF PCCS models, and the second was based on theory of crystallization in mineral and glass melts. A series of 29 test glass compositions was selected for this study using a combination of the two approaches. The glasses were fabricated and characterized in the laboratory. After reviewing the data, the study glasses generally met the target compositions with little issue. Product Consistency Test results correlated well with the crystallization analyses in

  14. OPERA and MINOS Experimental Result Prove Big Bang Theory Invalid

    Science.gov (United States)

    Pressler, David E.

    2012-03-01

    The greatest error in the history of science is the misinterpretation of the Michelson-Morley Experiment. The speed of light was measured to travel at the same speed in all three directions (x, y, z axis) in ones own inertial reference system; however, c will always be measured as having an absolute different speed in all other inertial frames at different energy levels. Time slows down due to motion or a gravity field. Time is the rate of physical process. Speed = Distance/Time. If the time changes the distance must change. Therefore, BOTH mirrors must move towards the center of the interferometer and space must contract in all-three-directions; C-Space. Gravity is a C-Space condition, and is the cause of redshift in our universe-not motion. The universe is not expanding. OPERA results are directly indicated; at the surface of earth, the strength of the gravity field is at maximum-below the earth's surface, time and space is less distorted, C-Space; therefore, c is faster. Newtonian mechanics dictate that a spherical shell of matter at greater radii, with uniform density, produces no net force on an observer located centrally. An observer located on the sphere's surface, like our Earth's or a large sphere, like one located in a remote galaxy, will construct a picture centered on himself to be identical to the one centered inside the spherical shell of mass. Both observers will view the incoming radiation, emitted by the other observer, as redshifted, because they lay on each others radial line. The Universe is static and very old.

  15. Review of JT-60U experimental results in 2000

    International Nuclear Information System (INIS)

    2002-11-01

    The results of JT-60U experiments in 2000, from February to December, are reviewed. The performance under the full non-inductive current drive has been greatly advanced both in high β p H-mode plasmas and in reversed shear (RS) plasmas. In the high β p H-mode, with injection of the negative ion based neutral beam (NNB) of 360 keV and 4 MW into a high electron temperature plasma (T e (0) ∼ 13 keV), a high fusion triple product n D (0)T i (0)τ E = 2.0 x 10 20 keVm -3 s has been obtained at the plasma current of 1.5 MA, and the highest value of current drive efficiency of NNB (1.55 x 10 19 A/W/m 2 ) has been achieved. In RS, LHCD and NNB-CD were employed for current drive and high confinement (HH y2 ∼ 1.4) at high density (f GW ∼ 0.80) has been achieved. In the 110 GHz ECRF system, two more gyrotrons have been installed in addition to the one installed in 1999 and 1.5 MW was injected into the torus for 3 s. Complete stabilization of neoclassical tearing mode (NTM), realization of high confinement plasmas with T e ∼ T i , a high value (1 MA) of NNB-driven current in the high T e regime, and measurement of localized EC driven current were achieved with the upgraded EC system. The multiple pellet injection system has been newly installed. In high power NB heated plasmas, high-field-side pellet injection was more effective than low-field-side injection, and it extended the regime of high confinement high β p H-mode to a higher density. A new method, called CCS (Cauchy-condition surface method), for the control of the plasma position and shape in real-time became available and was found very useful especially for the control of plasma-wall clearance in LH and IC experiments. The active control of ITB strength by the switch of the injection direction of toroidal angular momentum was successfully demonstrated. In high triangularity H-mode plasmas, higher pressure and temperature at the edge pedestal were observed, which resulted in higher temperature and

  16. Enhancement of thermal neutron shielding of cement mortar by using borosilicate glass powder.

    Science.gov (United States)

    Jang, Bo-Kil; Lee, Jun-Cheol; Kim, Ji-Hyun; Chung, Chul-Woo

    2017-05-01

    Concrete has been used as a traditional biological shielding material. High hydrogen content in concrete also effectively attenuates high-energy fast neutrons. However, concrete does not have strong protection against thermal neutrons because of the lack of boron compound. In this research, boron was added in the form of borosilicate glass powder to increase the neutron shielding property of cement mortar. Borosilicate glass powder was chosen in order to have beneficial pozzolanic activity and to avoid deleterious expansion caused by an alkali-silica reaction. According to the experimental results, borosilicate glass powder with an average particle size of 13µm showed pozzolanic activity. The replacement of borosilicate glass powder with cement caused a slight increase in the 28-day compressive strength. However, the incorporation of borosilicate glass powder resulted in higher thermal neutron shielding capability. Thus, borosilicate glass powder can be used as a good mineral additive for various radiation shielding purposes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Experimental results

    International Nuclear Information System (INIS)

    Turner, C.E.

    1980-01-01

    Concepts available for discussing stable crack growth have progressed sufficiently for similarities to be appreciated. Despite rather different starting points and diverse presentation, they are now tending to be complementary, each reinforcing by alternate arguments, the general trends and conclusions of various models for tearing instability

  18. Monte Carlo simulations and experimental results on neutron production in the spallation target QUINTA irradiated with 660 MeV protons

    International Nuclear Information System (INIS)

    Khushvaktov, J.H.; Yuldashev, B.S.; Adam, J.; Vrzalova, J.; Baldin, A.A.; Furman, W.I.; Gustov, S.A.; Kish, Yu.V.; Solnyshkin, A.A.; Stegailov, V.I.; Tichy, P.; Tsoupko-Sitnikov, V.M.; Tyutyunnikov, S.I.; Zavorka, L.; Svoboda, J.; Zeman, M.; Vespalec, R.; Wagner, V.

    2017-01-01

    The activation experiment was performed using the accelerated beam of the Phasotron accelerator at the Joint Institute for Nuclear Research (JINR). The natural uranium spallation target QUINTA was irradiated with protons of energy 660 MeV. Monte Carlo simulations were performed using the FLUKA and Geant4 codes. The number of leakage neutrons from the sections of the uranium target surrounded by the lead shielding and the number of leakage neutrons from the lead shield were determined. The total number of fissions in the setup QUINTA were determined. Experimental values of reaction rates for the produced nuclei in the "1"2"7I sample were obtained, and several values of the reaction rates were compared with the results of simulations by the FLUKA and Geant4 codes. The experimentally determined fluence of neutrons in the energy range of 10-200 MeV using the (n, xn) reactions in the "1"2"7I(NaI) sample was compared with the results of simulations. Possibility of transmutation of the long-lived radionuclide "1"2"9I in the QUINTA setup was estimated. [ru

  19. Lessons from shielding retrofits at the LAMPF/LANSCE/PSR accelerator, beam lines and target facilities

    International Nuclear Information System (INIS)

    Macek, R.J.

    1994-01-01

    The experience in the past 7 years to improve the shielding and radiation control systems at the Los Alamos Meson Physics Facility (LAMPF) and the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) provides important lessons for the design of radiation control systems at future, high beam power proton accelerator facilities. Major issues confronted and insight gained in developing shielding criteria and in the use of radiation interlocks are discussed. For accelerators and beam lines requiring hands-on-maintenance, our experience suggests that shielding criteria based on accident scenarios will be more demanding than criteria based on routinely encountered beam losses. Specification and analysis of the appropriate design basis accident become all important. Mitigation by active protection systems of the consequences of potential, but severe, prompt radiation accidents has been advocated as an alternate choice to shielding retrofits for risk management at both facilities. Acceptance of active protection systems has proven elusive primarily because of the difficulty in providing convincing proof that failure of active systems (to mitigate the accident) is incredible. Results from extensive shielding assessment studies are presented including data from experimental beam spill tests, comparisons with model estimates, and evidence bearing on the limitations of line-of-sight attenuation models in complex geometries. The scope and significant characteristics of major shielding retrofit projects at the LAMPF site are illustrated by the project to improve the shielding beneath a road over a multiuse, high-intensity beam line (Line D)

  20. Radiation shielding concrete

    International Nuclear Information System (INIS)

    Kunishima, Shigeru.

    1990-01-01

    The radiation shielding concretes comprise water, cement, fine aggregates consisting of serpentines and blown mist slags, coarse aggregates consisting of serpentines and kneading materials. Since serpentines containing a relatively great amount of water of crystallization in rocks as coarse aggregates and fine aggregates, the hydrogen content in the radiation shielding concretes is increased and the neutron shielding effect is improved. In addition, since serpentines are added as the fine aggregates and blown mists slags of a great specific gravity are used, the specific gravity of the shielding concretes is increased to improve the γ-ray shielding effect. Further, by the use of the kneading material having a water reducing effect and fluidizing effect, and by the bearing effect of the spherical blown mist slags used as the fine aggregates, concrete fluidity can be increased. Accordingly, workability of the radiation shielding concretes can be improved. (T.M.)

  1. Radiation shielding analysis

    International Nuclear Information System (INIS)

    Moon, S.H.; Ha, C.W.; Kwon, S.K.; Lee, J.K.; Choi, H.S.

    1982-01-01

    The theoretical bases of radiation streaming analysis in power reactors, such as ducts or reactor cavity, have been investigated. Discrete ordinates-Monte Carlo or Monte Carlo-Monte Carlo coupling techniques are suggested for the streaming analysis of ducts or reactor cavity. Single albedo scattering approximation code (SINALB) has been developed for simple and quick estimation of gamma-ray ceiling scattering, where the ceiling is assumed to be semi-infinite medium. This code has been employed to calculate the gamma-ray ceiling scattering effects in the laboratory containing a Co-60 source. The SINALB is applicable to gamma-ray scattering, only where the ceiling is thicker than Σsup(-1) and the height is at least twice higher than the shield wall. This code can be used for the purpose of preliminary radiation shield design. The MORSE code has been improved to analyze the gamma-ray scattering problem with on approximation method in respect to the random walk and estimation processes. This improved MORSE code has been employed to the gamma-ray ceiling scattering problem. The results of the improved MORSE calculation are in good agreement with the SINALB and standard MORSE. (Author)

  2. A study on the shielding element using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Jeong [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Shim, Jae Goo [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of)

    2017-06-15

    In this research, we simulated the elementary star shielding ability using Monte Carlo simulation to apply medical radiation shielding sheet which can replace existing lead. In the selection of elements, mainly elements and metal elements having a large atomic number, which are known to have high shielding performance, recently, various composite materials have improved shielding performance, so that weight reduction, processability, In consideration of activity etc., 21 elements were selected. The simulation tools were utilized Monte Carlo method. As a result of simulating the shielding performance by each element, it was estimated that the shielding ratio is the highest at 98.82% and 98.44% for tungsten and gold.

  3. Safety guide data on radiation shielding in a reprocessing facility

    International Nuclear Information System (INIS)

    Sekiguchi, Noboru; Naito, Yoshitaka

    1986-04-01

    In a reprocessing facility, various radiation sources are handled and have many geometrical conditions. To aim drawing up a safety guidebook on radiation shielding in order to evaluate shielding safety in a reprocessing facility with high reliability and reasonableness, JAERI trusted investigation on safety evaluation techniques of radiation shielding in a reprocessing facility to Nuclear Safety Research Association. This report is the collection of investigation results, and describes concept of shielding safety design principle, radiation sources in reprocessing facility and estimation of its strength, techniques of shielding calculations, and definite examples of shielding calculation in reprocessing facility. (author)

  4. Accelerator shielding benchmark problems

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  5. Simulation of ferromagnetic shielding to the critical current of Bi2223/Ag tape under external fields

    Energy Technology Data Exchange (ETDEWEB)

    Gu Chen [Applied Superconductivity Research Center, Tsinghua University, Beijing 100084 (China); Alamgir, A K M [Faculty of Engineering, Yokohama National University, 75-9 Tokiwadai, Hodogaya-ku, Yokohama (Japan); Qu Timing [Applied Superconductivity Research Center, Tsinghua University, Beijing 100084 (China); Han, Z [Applied Superconductivity Research Center, Tsinghua University, Beijing 100084 (China)

    2007-03-15

    Ferromagnetic material was electroplated onto the surface of the Bi2223/Ag multi-filamentary tape and as a result changed the I{sub c}(B) characteristic of the tape correspondingly. A numerical simulation was used to investigate the influence of ferromagnetic shielding (FS) on the performance of the tape, in particular the I{sub c} behaviour under perpendicular external fields. Using finite element analysis, we are able to understand how FS alters the flux distribution within the superconductor region under any arbitrary shielding structure. The shielding width, thickness and nonlinear property of the ferromagnetic material were taken into account for the simulation. Finally, optimized shielding parameters in association with different operating fields were suggested and these values could be considered for the next run of experimental work.

  6. Simulation of ferromagnetic shielding to the critical current of Bi2223/Ag tape under external fields

    International Nuclear Information System (INIS)

    Gu Chen; Alamgir, A K M; Qu Timing; Han, Z

    2007-01-01

    Ferromagnetic material was electroplated onto the surface of the Bi2223/Ag multi-filamentary tape and as a result changed the I c (B) characteristic of the tape correspondingly. A numerical simulation was used to investigate the influence of ferromagnetic shielding (FS) on the performance of the tape, in particular the I c behaviour under perpendicular external fields. Using finite element analysis, we are able to understand how FS alters the flux distribution within the superconductor region under any arbitrary shielding structure. The shielding width, thickness and nonlinear property of the ferromagnetic material were taken into account for the simulation. Finally, optimized shielding parameters in association with different operating fields were suggested and these values could be considered for the next run of experimental work

  7. Design and demonstration of adiabatic quantum-flux-parametron logic circuits with superconductor magnetic shields

    International Nuclear Information System (INIS)

    Inoue, Kenta; Narama, Tatsuya; Yamanashi, Yuki; Yoshikawa, Nobuyuki; Takeuchi, Naoki

    2015-01-01

    Adiabatic quantum-flux-parametron (AQFP) logic is an energy-efficient superconductor logic with zero static power and very small dynamic power due to adiabatic switching operations. In order to build large-scale digital circuits, we built AQFP logic cells using superconductor magnetic shields, which are necessary in order to avoid unwanted magnetic couplings between the cells and excitation currents. In preliminary experimental tests, we confirmed that the unwanted coupling became negligibly small thanks to the superconductor shields. As a demonstration, we designed a four-to-one multiplexor and a 16-junction full adder using the shielded logic cells. In both circuits, we confirmed correct logic operations with wide operation margins of excitation currents. These results indicate that large-scale AQFP digital circuits can be realized using the shielded logic cells. (paper)

  8. Laboratory tests on neutron shields for gamma-ray detectors in space

    CERN Document Server

    Hong, J; Hailey, C J

    2000-01-01

    Shields capable of suppressing neutron-induced background in new classes of gamma-ray detectors such as CdZnTe are becoming important for a variety of reasons. These include a high cross section for neutron interactions in new classes of detector materials as well as the inefficient vetoing of neutron-induced background in conventional active shields. We have previously demonstrated through Monte-Carlo simulations how our new approach, supershields, is superior to the monolithic, bi-atomic neutron shields which have been developed in the past. We report here on the first prototype models for supershields based on boron and hydrogen. We verify the performance of these supershields through laboratory experiments. These experimental results, as well as measurements of conventional monolithic neutron shields, are shown to be consistent with Monte-Carlo simulations. We discuss the implications of this experiment for designs of supershields in general and their application to future hard X-ray/gamma-ray experiments...

  9. BUGLE-93 (ENDF/B-VI) cross-section library data testing using shielding benchmarks

    International Nuclear Information System (INIS)

    Hunter, H.T.; Slater, C.O.; White, J.E.

    1994-01-01

    Several integral shielding benchmarks were selected to perform data testing for new multigroup cross-section libraries compiled from the ENDF/B-VI data for light water reactor (LWR) shielding and dosimetry. The new multigroup libraries, BUGLE-93 and VITAMIN-B6, were studied to establish their reliability and response to the benchmark measurements by use of radiation transport codes, ANISN and DORT. Also, direct comparisons of BUGLE-93 and VITAMIN-B6 to BUGLE-80 (ENDF/B-IV) and VITAMIN-E (ENDF/B-V) were performed. Some benchmarks involved the nuclides used in LWR shielding and dosimetry applications, and some were sensitive specific nuclear data, i.e. iron due to its dominant use in nuclear reactor systems and complex set of cross-section resonances. Five shielding benchmarks (four experimental and one calculational) are described and results are presented

  10. Safety analysis report for packaging: the ORNL lithium hydroxide fire and impact shield

    International Nuclear Information System (INIS)

    Evans, J.H.; Eversole, R.E.; Just, R.A.; Schaich, R.W.

    1984-07-01

    The ORNL Lithium Hydroxide Fire and Impact Shield and its packaging were designed and fabricated at Oak Ridge National Laboratory to permit the transport of Type B quantities of radioactive material and limited quantities of fissionable material. The shield and its packaging were evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and that evaluation is the subject of this report. Computational and test procedures were used to determine the structural integrity and thermal behavior of the shield relative to the general standards for normal conditions of transport and the standards for the hypothetical accident conditions. The results of the evaluation demonstrate that the shield and its packaging are in compliance with the applicable regulations. 16 references, 8 figures, 5 tables

  11. Safety analysis report for packaging: the ORNL lithium hydroxide fire and impact shield

    International Nuclear Information System (INIS)

    Evans, J.H.; Eversole, R.E.; Just, R.A.

    1977-11-01

    The ORNL lithium hydroxide fire and impact shield was designed and fabricated at Oak Ridge National Laboratory to permit the transport of Type B and large quantities of radioactive material and limited quantities of fissionable material. The shield was evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and that evaluation is the subject of this report. Computational and test procedures were used to determine the structural integrity and thermal behavior of the shield relative to the general standards for normal conditions of transport and the standards for the hypothetical accident conditions. The results of the evaluation demonstrate that the shield is in compliance with the applicable regulations

  12. Neutron shielding properties of a new high-density concrete

    International Nuclear Information System (INIS)

    Lorente, A.; Gallego, E.; Vega Carrillo, H.R.; Mendez, R.

    2008-01-01

    The neutron shielding properties of a new high-density concrete (commercially available under the name Hormirad TM , developed in Spain by the company CT-RAD) have been characterized both experimentally and by Monte Carlo calculations. The shielding properties of this concrete against photons were previously studied and the material is being used to build bunkers, mazes and doors in medical accelerator facilities with good overall results. In this work, the objective was to characterize the material behaviour against neutrons, as well as to test alternative mixings including boron compounds in an effort to improve neutron shielding efficiency. With that purpose, Hormirad TM slabs of different thicknesses were exposed to an 241 Am-Be neutron source under controlled conditions in the neutron measurements laboratory of the Nuclear Engineering Department at UPM. The original mix, which includes a high fraction of magnetite, was then modified by adding different proportions of anhydrous borax (Na 2 B 4 O 7 ). In order to have a reference against common concrete used to shield medical accelerator facilities, the same experiment was repeated with ordinary (HA-25) concrete slabs. In parallel to the experiments, Monte Carlo calculations of the experiments were performed with MCNP5. The experimental results agree reasonably well with the Monte Carlo calculations. Therefore, the first and equilibrium tenth-value layers have been determined for the different types of concrete tested. The results show an advantageous behaviour of the Hormirad TM concrete, in terms of neutron attenuation against real thickness of the shielding. Borated concretes seem less practical since they did not show better neutron attenuation with respect to real thickness and their structural properties are worse. The neutron attenuation properties of Hormirad TM for typical neutron spectra in clinical LINAC accelerators rooms have been also characterized by Monte Carlo calculation. (author)

  13. Investigation of steel--sodium--iron shields

    International Nuclear Information System (INIS)

    Oblow, E.M.; Maerker, R.E.

    1978-01-01

    An analysis of experimental data from 21 fast reactor shield configurations containing steel, sodium, and iron were made as part of a study of the upper axial shielding needs of the Clinch River Breeder Reactor. The measured data were analyzed using both one- and two-dimensional discrete ordinates transport codes and several cross section libraries based on ENDF/B-IV data with group structures of 51 and 171 neutron groups. One-dimensional sensitivity studies using the 171 group library and ENDF/B-IV covariance files for sodium and iron data were used to determine the sensitivities of the measured data to multigroup cross sections and to estimate uncertainties in the calculated results. Results indicate that the standard 51-group design cross section library could be expected to predict the measurements to within 30% over 12 decades of attenuation although a few of the deepest penetration configurations showed disagreements as large as a factor of three. The sensitivity results revealed very high sensitivity of the measurements to total cross section minima and cross sections from 5 to 10 MeV in sodium and iron in the deep penetration configurations. As a result, large uncertainties in the calculated results arose from small uncertainties in the cross section data. These results indicate the need for better measurements of the total cross section minima in sodium, especially around 300 keV

  14. Actively shielded low level gamma - spectrometric system

    International Nuclear Information System (INIS)

    Mrdja, D.; Bikit, I.; Forkapic, S.; Slivka, J.; Veskovic, M.

    2005-01-01

    The results of the adjusting and testing of the actively shielded low level gamma-spectrometry system are presented. The veto action of the shield reduces the background in the energy region of 50 keV to the 2800 keV for about 3 times. (author) [sr

  15. Passive magnetic shielding in MRI-Linac systems

    Science.gov (United States)

    Whelan, Brendan; Kolling, Stefan; Oborn, Brad M.; Keall, Paul

    2018-04-01

    Passive magnetic shielding refers to the use of ferromagnetic materials to redirect magnetic field lines away from vulnerable regions. An application of particular interest to the medical physics community is shielding in MRI systems, especially integrated MRI-linear accelerator (MRI-Linac) systems. In these systems, the goal is not only to minimize the magnetic field in some volume, but also to minimize the impact of the shield on the magnetic fields within the imaging volume of the MRI scanner. In this work, finite element modelling was used to assess the shielding of a side coupled 6 MV linac and resultant heterogeneity induced within the 30 cm diameter of spherical volume (DSV) of a novel 1 Tesla split bore MRI magnet. A number of different shield parameters were investigated; distance between shield and magnet, shield shape, shield thickness, shield length, openings in the shield, number of concentric layers, spacing between each layer, and shield material. Both the in-line and perpendicular MRI-Linac configurations were studied. By modifying the shield shape around the linac from the starting design of an open ended cylinder, the shielding effect was boosted by approximately 70% whilst the impact on the magnet was simultaneously reduced by approximately 10%. Openings in the shield for the RF port and beam exit were substantial sources of field leakage; however it was demonstrated that shielding could be added around these openings to compensate for this leakage. Layering multiple concentric shield shells was highly effective in the perpendicular configuration, but less so for the in-line configuration. Cautious use of high permeability materials such as Mu-metal can greatly increase the shielding performance in some scenarios. In the perpendicular configuration, magnetic shielding was more effective and the impact on the magnet lower compared with the in-line configuration.

  16. Comparison of pellet acceleration model results to experimentally observed penetration depths

    Energy Technology Data Exchange (ETDEWEB)

    Szepesi, T., E-mail: szepesi.tamas@gmail.co [KFKI - Research Institute for Particle and Nuclear Physics, EURATOM Association, MTA KFKI-RMKI, P.O. Box 49, H-1525 Budapest-114 (Hungary); Kalvin, S.; Kocsis, G. [KFKI - Research Institute for Particle and Nuclear Physics, EURATOM Association, MTA KFKI-RMKI, P.O. Box 49, H-1525 Budapest-114 (Hungary); Lang, P.T. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Senichenkov, I. [Saint Petersburg State Polytechnical University, Polytehnicheskaya 29, 195251 St. Petersburg (Russian Federation)

    2009-06-15

    Cryogenic hydrogen isotope fuelling pellets were observed to undergo strong radial acceleration in the confined plasma. The reason for pellet acceleration is believed to originate from drift effects: the ionised part of pellet cloud is affected by the grad-B drift, therefore, the cloud becomes polarised. The E x B drift then deforms the pellet cloud so that it can no longer follow the original flux bundle - this results in a less efficient shielding on the pellet's HFS region, where the subsequently enhanced ablation pushes the pellet towards LFS, like a rocket. In order to study this effect, a simple and a comprehensive ablation model was developed. Results from both models show quantitatively acceptable agreement with ASDEX-Upgrade experiments concerning trajectory curvature, corresponding to radial acceleration in the range of 10{sup 4}-10{sup 7} m/s{sup 2}.

  17. Determination of gamma ray shielding parameters of rocks and concrete

    Science.gov (United States)

    Obaid, Shamsan S.; Gaikwad, Dhammajyot K.; Pawar, Pravina P.

    2018-03-01

    Gamma shielding parameters such as mass attenuation coefficient (μ/ρ), effective atomic number (Zeff) and electron density (Neff) have been measured and calculated for rocks and concrete in the energy range 122-1330 keV. The measurements have been carried out at 122, 356, 511, 662, 1170, 1275, 1330 keV gamma ray energies using a gamma spectrometer includes a NaI(Tl) scintillation detector and MCA card. The atomic and electronic cross sections have also been investigated. Experimental and calculated (WinXCom) values were compared, and good agreement has been observed within the experimental error. The obtained results showed that feldspathic basalt, compact basalt, volcanic rock, dolerite and pink granite are more efficient than the sandstone and concrete for gamma ray shielding applications.

  18. Neutron shielding properties of a borated high-density glass

    Directory of Open Access Journals (Sweden)

    Saeed Aly Abdallah

    2017-01-01

    Full Text Available The neutron shielding properties of a borated high density glass system was characterized experimentally. The total removal macroscopic cross-section of fast neutrons, slow neutrons as well as the linear attenuation coefficient of total gamma rays, primary in addition to secondary, were measured experimentally under good geometric condition to characterize the attenuation properties of (75-x B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy system. Slabs of different thicknesses from the investigated glass system were exposed to a collimated beam of neutrons emitted from 252Cf and 241Am-Be neutron sources in order to measure the attenuation properties of fast and slow neutrons as well as total gamma rays. Results confirmed that barium borate glass was suitable for practical use in the field of radiation shielding.

  19. INTOR radiation shielding for personnel access

    International Nuclear Information System (INIS)

    Gohar, Y.; Abdou, M.

    1981-01-01

    The INTOR reactor shield system consists of the blanket, bulk shield, penetration shield, component shield, and biological shield. The bulk shield consists of two parts: (a) the inboard shield; and (b) the outboard shield. The distinction between the different components of the shield system is essential to satisfy the different design constraints and achieve various objectives

  20. Shielding Calculations for PUSPATI TRIGA Reactor (RTP) Fuel Transfer Cask with Micro shield

    International Nuclear Information System (INIS)

    Nurhayati Ramli; Ahmad Nabil Abdul Rahim; Ariff Shah Ismail

    2011-01-01

    The shielding calculations for RTP fuel transfer cask was performed by using computer code Micro shield 7.02. Micro shield is a computer code designed to provide a model to be used for shielding calculations. The results of the calculations can be obtained fast but the code is not suitable for complex geometries with a shielding composed of more than one material. Nevertheless, the program is sufficient for As Low As Reasonable Achievable (ALARA) optimization calculations. In this calculation, a geometry based on the conceptual design of RTP fuel transfer cask was modeled. Shielding material used in the calculations were lead (Pb) and stainless steel 304 (SS304). The results obtained from these calculations are discussed in this paper. (author)

  1. Optimal beta-ray shielding thicknesses for different therapeutic radionuclides and shielding materials

    International Nuclear Information System (INIS)

    Cho, Yong In; Kim, Ja Mee; Kim, Jung Hoon

    2017-01-01

    To better understand the distribution of deposited energy of beta and gamma rays according to changes in shielding materials and thicknesses when radionuclides are used for therapeutic nuclear medicine, a simulation was conducted. The results showed that due to the physical characteristics of each therapeutic radionuclide, the thicknesses of shielding materials at which beta-ray shielding takes place varied. Additional analysis of the shielding of gamma ray was conducted for radionuclides that emit both beta and gamma rays simultaneously with results showing shielding effects proportional to the atomic number and density of the shielding materials. Also, analysis of bremsstrahlung emission after beta-ray interactions in the simulation revealed that the occurrence of bremsstrahlung was relatively lower than theoretically calculated and varied depending on different radionuclides. (authors)

  2. Thermal neutron self-shielding correction factors for large sample instrumental neutron activation analysis using the MCNP code

    International Nuclear Information System (INIS)

    Tzika, F.; Stamatelatos, I.E.

    2004-01-01

    Thermal neutron self-shielding within large samples was studied using the Monte Carlo neutron transport code MCNP. The code enabled a three-dimensional modeling of the actual source and geometry configuration including reactor core, graphite pile and sample. Neutron flux self-shielding correction factors derived for a set of materials of interest for large sample neutron activation analysis are presented and evaluated. Simulations were experimentally verified by measurements performed using activation foils. The results of this study can be applied in order to determine neutron self-shielding factors of unknown samples from the thermal neutron fluxes measured at the surface of the sample

  3. Analysis of the JASPER Program Radial Shield Attenuation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Slater, C.O.

    1993-01-01

    The results of the analysis of the JASPER Program Radial Shield Attenuation Experiment are presented. The experiment was performed in 1986 at the ORNL Tower Shielding Facility. It is the first of six experiments in this cooperative Japanese and American program in support of shielding designs for advanced sodium-cooled reactors. Six different shielding configurations and subconfigurations thereof were studied. The configurations were calculated with the DOT-IV two-dimensional discrete ordinates radiation transport computer code using the R-Z geometry option, a symmetric S{sub 12} quadrature (96 directions), and cross sections from ENDF/B versions IV and V in either a 51- or 61-group structure. Auxiliary codes were used to compute detector responses and prepare cross sections and source input for the DOT-IV calculations. Calculated detector responses were compared with measured responses and the agreement was good to excellent in many cases. However, the agreement for configurations having thick steel or B{sub 4}C regions or for some very large configurations was fair to poor. The disagreement was attributed to cross-section data, broad-group structure, or high background in the measurements. In particular, it is shown that two cross-section sets for ``B give very different results for neutron transmission through the thick B{sub 4}C regions used in one set of experimental configurations. Implications for design calculations are given.

  4. Shielding calculational system for plutonium

    International Nuclear Information System (INIS)

    Zimmerman, M.G.; Thomsen, D.H.

    1975-08-01

    A computer calculational system has been developed and assembled specifically for calculating dose rates in AEC plutonium fabrication facilities. The system consists of two computer codes and all nuclear data necessary for calculation of neutron and gamma dose rates from plutonium. The codes include the multigroup version of the Battelle Monte Carlo code for solution of general neutron and gamma shielding problems and the PUSHLD code for solution of shielding problems where low energy gamma and x-rays are important. The nuclear data consists of built in neutron and gamma yields and spectra for various plutonium compounds, an automatic calculation of age effects and all cross-sections commonly used. Experimental correlations have been performed to verify portions of the calculational system. (23 tables, 7 figs, 16 refs) (U.S.)

  5. The shielding performance of multilayer composite shielding structures to 14.8 MeV fast neutrons

    International Nuclear Information System (INIS)

    Shen Zhiqiang; Kang Qing; Xu Jun; Wang Zhenggang; Lu Nan

    2014-01-01

    Cement-based round thin-layer samples mixed with 30% quality content of barite, and 20% quality content of carbide boron has Prepared, the same-diameter sliced samples of pure graphite and pure polyethylene has cut, then, samples combination and cross stack order has designed, formed four species Multilayer Composite shield structure, at last, neutron attenuation measurements has been done by experimental system of using 14.8 MeV neutrons from the 5SDH-2 accelerator and long counter composition, penetrating rate of samples and the shield structure to 14.8 MeV fast neutron has tested, and attenuation section has calculated. Results show that 14.8 MeV fast neutrons to higher penetration rates of thin layer samples, attenuation cross section of samples distinguish small between each other, must be increasing the thickness of the samples to reduce the experimental uncertainty; through composed of attenuation cross section and thickness parameters of composite structure, can more accurately predict the shielding ability of composite structures, error between calculation results and experimental results in 4%. (authors)

  6. Shielded regenerative neutron detector

    International Nuclear Information System (INIS)

    Terhune, J.H.; Neissel, J.P.

    1978-01-01

    An ion chamber type neutron detector is disclosed which has a greatly extended lifespan. The detector includes a fission chamber containing a mixture of active and breeding material and a neutron shielding material. The breeding and shielding materials are selected to have similar or substantially matching neutron capture cross-sections so that their individual effects on increased detector life are mutually enhanced

  7. TH-AB-BRA-12: Experimental Results From the First High-Field Inline MRI-Linac

    Energy Technology Data Exchange (ETDEWEB)

    Keall, P [University of Sydney, Camperdown, New South Wales (Australia); Dong, B; Zhang, K; Liney, G [Ingham Institute for Applied Medical Research, Liverpool, New South Wales (Australia); Vial, P; Walker, A; Begg, J; Rai, R [Liverpool Hospital, Sydney, New South Wales (Australia); Holloway, L; Barton, M [Ingham Institute for Applied Medical Research, Liverpool, New South Wales (Australia); Liverpool Hospital, Sydney, New South Wales (Australia); Crozier, S [University of Queensland, Brisbane, Queensland (Australia)

    2016-06-15

    Purpose: The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid MRI-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-Linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-Linac system. This work describes our experimental results from the first high-field inline MRI-Linac. Methods: A 1.5 Tesla magnet (Sonata, Siemens) was located in a purpose built RF cage enabling shielding from and close proximity to a linear accelerator with inline orientation. A portable linear accelerator (Linatron, Varian) was installed together with a multi-leaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-Linac experiments was performed to investigate: (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array and; (3) electron focusing measured using GafChromic film. Results: (1) The macropodine phantom image quality with the beam on was almost identical to that with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background noise when the radiation beam was on. (3) Film measurements demonstrated electron focusing occurring at the center of the radiation field. Conclusion: The first high-field MRI-Linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field in-line MRI-Linac and study a number of the technical challenges and solutions. Supported by the Australian National Health and Medical Research Council, the Australian Research Council, the Australian Cancer Research Foundation and the Health and Hospitals Fund.

  8. Neutron shielding material based on colemanite and epoxy resin

    International Nuclear Information System (INIS)

    Okuno, K.

    2005-01-01

    In recent years, there has been a need for compact shielding design such as self-shielding of a PET cyclotron or up-gradation of radiation machinery in existing facilities. In these cases, high performance shielding materials are needed. Concrete or polyethylene have been used for a neutron shield. However, for compact shielding, they fall short in terms of performance or durability. Therefore, a new type of neutron shielding material based on epoxy resin and colemanite has been developed. Slab attenuation experiments up to 40 cm for the new shielding material were carried out using a 252 Cf neutron source. Measurement was carried out using a REM-counter, and compared with calculation. The results show that the shielding performance is better than concrete and polyethylene mixed with 10 wt% boron oxide. From the result, we confirmed that the performance of the new material is suitable for practical use. (authors)

  9. Recent Improvements in the SHIELD-HIT Code

    DEFF Research Database (Denmark)

    Hansen, David Christoffer; Lühr, Armin Christian; Herrmann, Rochus

    2012-01-01

    Purpose: The SHIELD-HIT Monte Carlo particle transport code has previously been used to study a wide range of problems for heavy-ion treatment and has been benchmarked extensively against other Monte Carlo codes and experimental data. Here, an improved version of SHIELD-HIT is developed concentra......Purpose: The SHIELD-HIT Monte Carlo particle transport code has previously been used to study a wide range of problems for heavy-ion treatment and has been benchmarked extensively against other Monte Carlo codes and experimental data. Here, an improved version of SHIELD-HIT is developed...

  10. Radiation shielding plate

    International Nuclear Information System (INIS)

    Kobayashi, Torakichi; Sugawara, Takeo.

    1983-01-01

    Purpose: To reduce the weight and stabilize the configuration of a radiation shielding plate which is used in close contact with an object to be irradiated with radiation rays. Constitution: The radiation shielding plate comprises a substrate made of lead glass and a metallic lead coating on the surface of the substrate by means of plating, vapor deposition or the like. Apertures for permeating radiation rays are formed to the radiation shielding plate. Since the shielding plate is based on a lead glass plate, a sufficient mechanical strength can be obtained with a thinner structure as compared with the conventional plate made of metallic lead. Accordingly, if the shielding plate is disposed on a soft object to be irradiated with radiation rays, the object and the plate itself less deform to obtain a radiation irradiation pattern with distinct edges. (Moriyama, K.)

  11. Comparison of analysis results with experimental results for ENEA and CRIEPI rubber bearings

    International Nuclear Information System (INIS)

    Yoo, B.; Lee, J.H.; Koo, G.H.

    1993-01-01

    In this paper, the preliminary structural analyses of ENEA HDRB and CRIEPI NRB were performed by using computer code ABAQUS, and the analysis results were compared with the test results provided by Italy and Japan thru IAEA. The test data for the rubbers used for the fabrication of bearings were also provided thru IAEA, and were utilized for the formulation of the rubber models for the analyses. The analyses performed for the rubber bearings are for the combined compression and shear and for the compression. The analysis results show a good agreement in shear strains when compared with the test results of HDRB and NRB for the combined compression and shear and for the compression benchmarks, but show relatively smaller responses in displacements for the compression with offsets benchmarks. (author)

  12. Shielding effectiveness of superconductive particles in plastics

    International Nuclear Information System (INIS)

    Pienkowski, T.; Kincaid, J.; Lanagan, M.T.; Poeppel, R.B.; Dusek, J.T.; Shi, D.; Goretta, K.C.

    1988-09-01

    The ability to cool superconductors with liquid nitrogen instead of liquid helium has opened the door to a wide range of research. The well known Meissner effect, which states superconductors are perfectly diamagnetic, suggests shielding applications. One of the drawbacks to the new ceramic superconductors is the brittleness of the finished material. Because of this drawback, any application which required flexibility (e.g., wire and cable) would be impractical. Therefore, this paper presents the results of a preliminary investigation into the shielding effectiveness of YBa 2 Cu 3 O/sub 7-x/ both as a composite and as a monolithic material. Shielding effectiveness was measured using two separate test methods. One tested the magnetic (near field) shielding, and the other tested the electromagnetic (far field) shielding. No shielding was seen in the near field measurements on the composite samples, and only one heavily loaded sample showed some shielding in the far field. The monolithic samples showed a large amount of magnetic shielding. 5 refs., 5 figs

  13. MARS14 deep-penetration calculation for the ISIS target station shielding

    International Nuclear Information System (INIS)

    Nakao, Noriaki; Nunomiya, Tomoya; Iwase, Hiroshi; Nakamura, Takashi

    2004-01-01

    The calculation of neutron penetration through a thick shield was performed with a three-dimensional multi-layer technique using the MARS14(02) Monte Carlo code to compare with the experimental shielding data in 1998 at the ISIS spallation neutron source facility of Rutherford Appleton Laboratory. In this calculation, secondary particles from a tantalum target bombarded by 800-MeV protons were transmitted through a bulk shield of approximately 3-m-thick iron and 1-m-thick concrete. To accomplish this deep-penetration calculation, a three-dimensional multi-layer technique and energy cut-off method were used considering a spatial statistical balance. Finally, the energy spectra of neutrons behind the very thick shield could be calculated down to the thermal energy with good statistics, and the calculated results typically agree well within a factor of two with the experimental data over a broad energy range. The 12 C(n,2n) 11 C reaction rates behind the bulk shield were also calculated, which agree with the experimental data typically within 60%. These results are quite impressive in calculation accuracy for deep-penetration problem

  14. Mars Exploration Rover Heat Shield Recontact Analysis

    Science.gov (United States)

    Raiszadeh, Behzad; Desai, Prasun N.; Michelltree, Robert

    2011-01-01

    The twin Mars Exploration Rover missions landed successfully on Mars surface in January of 2004. Both missions used a parachute system to slow the rover s descent rate from supersonic to subsonic speeds. Shortly after parachute deployment, the heat shield, which protected the rover during the hypersonic entry phase of the mission, was jettisoned using push-off springs. Mission designers were concerned about the heat shield recontacting the lander after separation, so a separation analysis was conducted to quantify risks. This analysis was used to choose a proper heat shield ballast mass to ensure successful separation with low probability of recontact. This paper presents the details of such an analysis, its assumptions, and the results. During both landings, the radar was able to lock on to the heat shield, measuring its distance, as it descended away from the lander. This data is presented and is used to validate the heat shield separation/recontact analysis.

  15. Electron correlation effects on geometries and 19F shieldings of fluorobenzenes

    International Nuclear Information System (INIS)

    Webb, G.A.; Karadakov, P.B.; England, J.A.

    2000-01-01

    In order to include the effects of electron correlation in ab initio molecular orbital calculations it is necessary to go beyond the single determinant Hartree-Fock (HF) level of theory. In the present investigation the influences of both dynamic and non-dynamic correlation effects on the optimised geometries and 19 F nuclear shielding calculations of the twelve fluorobenzenes are reported.The non-dynamic electron correlation effects are represented by complete-active space self-consistent field (CASSCF) calculations. Second- and fourth-order Moller-Plesset (MP2 and MP4) calculations are used to describe the dynamic electron correlation effects. Some density-functional (DFT) results are also reported which do not distinguish between dynamic and non-dynamic electron correlation. Following the correlated geometry optimisations 19 F nuclear shielding calculations were performed using the gauge-included atomic orbitals (GIAO) procedure, these were undertaken with wave functions which include various levels of electron correlation including HF, CASSCF and MP2. For the calculations of the optimised geometries, and some of the nuclear shieldings the 6-13G** basis set s used whereas the locally-dense [6-13G** on C and H and 6-311++G(2d,2p) on F] set is used for some of the shielding calculations. A comparison of the results of HF shielding calculations using other basis sets is included. Comparison of the calculated geometry and shielding results with relevant, reported, experimental data is made. (author)

  16. Important aspects of radiation shielding for fusion reactor tokamaks

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1977-01-01

    Radiation shielding is a key subsystem in tokamak reactors. Design of this shield must evolve from economic and technological trade-off studies that account for the strong interrelations among the various components of the reactor system. These trade-offs are examined for the bulk shield on the inner side of the torus and for the special shields of major penetrations. Results derived are applicable for a large class of tokamak-type reactors

  17. Design and experimental results of a new electron gun using a magnetic multipole plasma generator

    International Nuclear Information System (INIS)

    Tanaka, S.; Yokoyama, K.; Akiba, M.; Araki, M.; Dairaku, M.; Inoue, T.; Mizuno, M.; Okumura, Y.; Ohara, Y.; Seki, M.; Watanabe, K.

    1991-01-01

    A new electron gun utilizing a magnetic multipole plasma generator was designed and fabricated as the heat source of the high heat flux test facility, called JEBIS (JAERI electron beam irradiation stand). By changing the acceleration grids, this electron gun is able to produce a pencil to a sheetlike electron beams up to 4 A at 100 keV for 1 ms to continuous mode. In this electron gun, magnetic lens system is not adopted to focus the electron beam, but the space charge neutralization effect by the beam plasma produced downstream of the electron gun is utilized to prevent the blow-up of the electron beam. In addition, high permeability metal is embedded in the first and the second grids to magnetically shield the earth field and the stray field from the beam bending magnet. It was experimentally demonstrated that wide range of heat flux from 0.2 MW/m 2 to over 2000 MW/m 2 can be realized at the test sample position about 1.7 m downstream of the electron gun

  18. Benchmarking study and its application for shielding analysis of large accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee-Seock; Kim, Dong-hyun; Oranj, Leila Mokhtari; Oh, Joo-Hee; Lee, Arim; Jung, Nam-Suk [POSTECH, Pohang (Korea, Republic of)

    2015-10-15

    Shielding Analysis is one of subjects which are indispensable to construct large accelerator facility. Several methods, such as the Monte Carlo, discrete ordinate, and simplified calculation, have been used for this purpose. The calculation precision is overcome by increasing the trial (history) numbers. However its accuracy is still a big issue in the shielding analysis. To secure the accuracy in the Monte Carlo calculation, the benchmarking study using experimental data and the code comparison are adopted fundamentally. In this paper, the benchmarking result for electrons, protons, and heavy ions are presented as well as the proper application of the results is discussed. The benchmarking calculations, which are indispensable in the shielding analysis were performed for different particles: proton, heavy ion and electron. Four different multi-particle Monte Carlo codes, MCNPX, FLUKA, PHITS, and MARS, were examined for higher energy range equivalent to large accelerator facility. The degree of agreement between the experimental data including the SINBAD database and the calculated results were estimated in the terms of secondary neutron production and attenuation through the concrete and iron shields. The degree of discrepancy and the features of Monte Carlo codes were investigated and the application way of the benchmarking results are discussed in the view of safety margin and selecting the code for the shielding analysis. In most cases, the tested Monte Carlo codes give proper credible results except of a few limitation of each codes.

  19. Benchmarking study and its application for shielding analysis of large accelerator facilities

    International Nuclear Information System (INIS)

    Lee, Hee-Seock; Kim, Dong-hyun; Oranj, Leila Mokhtari; Oh, Joo-Hee; Lee, Arim; Jung, Nam-Suk

    2015-01-01

    Shielding Analysis is one of subjects which are indispensable to construct large accelerator facility. Several methods, such as the Monte Carlo, discrete ordinate, and simplified calculation, have been used for this purpose. The calculation precision is overcome by increasing the trial (history) numbers. However its accuracy is still a big issue in the shielding analysis. To secure the accuracy in the Monte Carlo calculation, the benchmarking study using experimental data and the code comparison are adopted fundamentally. In this paper, the benchmarking result for electrons, protons, and heavy ions are presented as well as the proper application of the results is discussed. The benchmarking calculations, which are indispensable in the shielding analysis were performed for different particles: proton, heavy ion and electron. Four different multi-particle Monte Carlo codes, MCNPX, FLUKA, PHITS, and MARS, were examined for higher energy range equivalent to large accelerator facility. The degree of agreement between the experimental data including the SINBAD database and the calculated results were estimated in the terms of secondary neutron production and attenuation through the concrete and iron shields. The degree of discrepancy and the features of Monte Carlo codes were investigated and the application way of the benchmarking results are discussed in the view of safety margin and selecting the code for the shielding analysis. In most cases, the tested Monte Carlo codes give proper credible results except of a few limitation of each codes

  20. Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program

    Science.gov (United States)

    Ryan, Shannon

    2013-01-01

    This software implements penetration limit equations for common micrometeoroid and orbital debris (MMOD) shield configurations, windows, and thermal protection systems. Allowable MMOD risk is formulated in terms of the probability of penetration (PNP) of the spacecraft pressure hull. For calculating the risk, spacecraft geometry models, mission profiles, debris environment models, and penetration limit equations for installed shielding configurations are required. Risk assessment software such as NASA's BUMPERII is used to calculate mission PNP; however, they are unsuitable for use in shield design and preliminary analysis studies. The software defines a single equation for the design and performance evaluation of common MMOD shielding configurations, windows, and thermal protection systems, along with a description of their validity range and guidelines for their application. Recommendations are based on preliminary reviews of fundamental assumptions, and accuracy in predicting experimental impact test results. The software is programmed in Visual Basic for Applications for installation as a simple add-in for Microsoft Excel. The user is directed to a graphical user interface (GUI) that requires user inputs and provides solutions directly in Microsoft Excel workbooks.

  1. Experimental geothermal well at Bad Schinznach. First results; Geothermiebohrung Bad Schinznach. Erste Resultate

    Energy Technology Data Exchange (ETDEWEB)

    Haering, M O [Haering Geo-Project, Steinmaur (Switzerland)

    1997-12-01

    The spa of Bad Schinznach (Canton Argovia, Switzerland) endeavours to cover its heating requirements with geothermal energy. A recently drilled well to a depth of 890 meters encountered the regional acquifer of thermal water (Oberer Muschelkalk, Triassic) in three levels. Preliminary results indicate a productive aquifer in the uppermost level with a wellhead temperature of 42 C. An additional exploitation of the bottomhole formation temperature of 63 C is envisaged. (orig.) [Deutsch] Das Bad Schinznach (Kanton Aargau, Schweiz) moechte im Rahmen der wirtschaftlichen Moeglichkeiten seinen Waermebedarf mit der Nutzung des Thermalwassers aus dem Oberen Muschelkalk (Trias) decken. Eine neulich abgeteufte Bohrung bis auf 890 Meter Tiefe hat die Formation auf drei Niveaus angetroffen. Erste Resultate deuten auf ein nutzbares Vorkommen im obersten Horizont mit einer Austrittstemperatur von 42 C. Eine zusaetzliche Nutzung der hohen Formationstemperatur von 63 C auf Endtiefe wird erwogen. (orig.)

  2. Validation of SCALE code package on high performance neutron shields

    International Nuclear Information System (INIS)

    Bace, M.; Jecmenica, R.; Smuc, T.

    1999-01-01

    The shielding ability and other properties of new high performance neutron shielding materials from the KRAFTON series have been recently published. A comparison of the published experimental and MCNP results for the two materials of the KRAFTON series, with our own calculations has been done. Two control modules of the SCALE-4.4 code system have been used, one of them based on one dimensional radiation transport analysis (SAS1) and other based on the three dimensional Monte Carlo method (SAS3). The comparison of the calculated neutron dose equivalent rates shows a good agreement between experimental and calculated results for the KRAFTON-N2 material.. Our results indicate that the N2-M-N2 sandwich type is approximately 10% inferior as neutron shield to the KRAFTON-N2 material. All values of neutron dose equivalent obtained by SAS1 are approximately 25% lower in comparison with the SAS3 results, which indicates proportions of discrepancies introduced by one-dimensional geometry approximation.(author)

  3. Gamma radiation shielding analysis of lead-flyash concretes

    International Nuclear Information System (INIS)

    Singh, Kanwaldeep; Singh, Sukhpal; Dhaliwal, A.S.; Singh, Gurmel

    2015-01-01

    Six samples of lead-flyash concrete were prepared with lead as an admixture and by varying flyash content – 0%, 20%, 30%, 40%, 50% and 60% (by weight) by replacing cement and keeping constant w/c ratio. Different gamma radiation interaction parameters used for radiation shielding design were computed theoretically and measured experimentally at 662 keV, 1173 keV and 1332 keV gamma radiation energy using narrow transmission geometry. The obtained results were compared with ordinary-flyash concretes. The radiation exposure rate of gamma radiation sources used was determined with and without lead-flyash concretes. - Highlights: • Concrete samples with lead as admixture were casted with flyash replacing 0%, 20%, 30%, 40%, 50% and 60% of cement content (by weight). • Gamma radiation shielding parameters of concretes for different gamma ray sources were measured. • The attenuation results of lead-flyash concretes were compared with the results of ordinary flyash concretes

  4. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2015-07-15

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  6. Transparent Conducting Graphene Hybrid Films To Improve Electromagnetic Interference (EMI) Shielding Performance of Graphene.

    Science.gov (United States)

    Ma, Limin; Lu, Zhengang; Tan, Jiubin; Liu, Jian; Ding, Xuemei; Black, Nicola; Li, Tianyi; Gallop, John; Hao, Ling

    2017-10-04

    Conducting graphene-based hybrids have attracted considerable attention in recent years for their scientific and technological significance in many applications. In this work, conductive graphene hybrid films, consisting of a metallic network fully encapsulated between monolayer graphene and quartz-glass substrate, were fabricated and characterized for their electromagnetic interference shielding capabilities. Experimental results show that by integration with a metallic network the sheet resistance of graphene was significantly suppressed from 813.27 to 5.53 Ω/sq with an optical transmittance at 91%. Consequently, the microwave shielding effectiveness (SE) exceeded 23.60 dB at the K u -band and 13.48 dB at the K a -band. The maximum SE value was 28.91 dB at 12 GHz. Compared with the SE of pristine monolayer graphene (3.46 dB), the SE of graphene hybrid film was enhanced by 25.45 dB (99.7% energy attenuation). At 94% optical transmittance, the sheet resistance was 20.67 Ω/sq and the maximum SE value was 20.86 dB at 12 GHz. Our results show that hybrid graphene films incorporate both high conductivity and superior electromagnetic shielding comparable to existing ITO shielding modalities. The combination of high conductivity and shielding along with the materials' earth-abundant nature, and facile large-scale fabrication, make these graphene hybrid films highly attractive for transparent EMI shielding.

  7. Shielding benchmark tests of JENDL-3

    International Nuclear Information System (INIS)

    Kawai, Masayoshi; Hasegawa, Akira; Ueki, Kohtaro; Yamano, Naoki; Sasaki, Kenji; Matsumoto, Yoshihiro; Takemura, Morio; Ohtani, Nobuo; Sakurai, Kiyoshi.

    1994-03-01

    The integral test of neutron cross sections for major shielding materials in JENDL-3 has been performed by analyzing various shielding benchmark experiments. For the fission-like neutron source problem, the following experiments are analyzed: (1) ORNL Broomstick experiments for oxygen, iron and sodium, (2) ASPIS deep penetration experiments for iron, (3) ORNL neutron transmission experiments for iron, stainless steel, sodium and graphite, (4) KfK leakage spectrum measurements from iron spheres, (5) RPI angular neutron spectrum measurements in a graphite block. For D-T neutron source problem, the following two experiments are analyzed: (6) LLNL leakage spectrum measurements from spheres of iron and graphite, and (7) JAERI-FNS angular neutron spectrum measurements on beryllium and graphite slabs. Analyses have been performed using the radiation transport codes: ANISN(1D Sn), DIAC(1D Sn), DOT3.5(2D Sn) and MCNP(3D point Monte Carlo). The group cross sections for Sn transport calculations are generated with the code systems PROF-GROUCH-G/B and RADHEAT-V4. The point-wise cross sections for MCNP are produced with NJOY. For comparison, the analyses with JENDL-2 and ENDF/B-IV have been also carried out. The calculations using JENDL-3 show overall agreement with the experimental data as well as those with ENDF/B-IV. Particularly, JENDL-3 gives better results than JENDL-2 and ENDF/B-IV for sodium. It has been concluded that JENDL-3 is very applicable for fission and fusion reactor shielding analyses. (author)

  8. HPGe detector shielding adjustment

    International Nuclear Information System (INIS)

    Trnkova, L.; Rulik, P.

    2008-01-01

    Low-level background shielding of HPGe detectors is used mainly for environmental samples with very low content of radionuclides. National Radiation Protection Institute (SURO) in Prague is equipped with 14 HPGe detectors with relative efficiency up to 150%. The detectors are placed in a room built from materials with low content of natural radionuclides and equipped with a double isolation of the floor against radon. Detectors themselves are placed in lead or steel shielding. Steel shielding with one of these detectors with relative efficiency of 100% was chosen to be rebuilt to achieve lower minimum detectable activity (MDA). Additional lead and copper shielding was built up inside the original steel shielding to reduce the volume of the inner space and filled with nitrogen by means of evaporating liquid nitrogen. The additional lead and copper shielding, consequent reduction of the inner volume and supply of evaporated nitrogen, caused a decrease of the background count and accordingly MDA values as well. The effect of nitrogen evaporation on the net areas of peaks belonging to radon daughters is significant. The enhanced shielding adjustment has the biggest influence in low energy range, what can be seen in collected data. MDA values in energy range from 30 keV to 400 keV decreased to 0.65-0.85 of original value, in energy range from 400 keV to 2 MeV they fell to 0.70-0.97 of original value. (authors)

  9. Experimental results of two stage harmonic generation with picosecond pulses on the Stanford Mark III FEL

    International Nuclear Information System (INIS)

    Hooper, B.A.; Utah Univ., Salt Lake City; Stanford Univ., CA; Benson, S.V.; Madey, M.J.; Cutolo, A.; Naples Univ.

    1988-01-01

    We report experimental results on upper harmonic conversion using a lithium niobate and a beta barium borate crystal to quadruple the FEL light up into the visible and near infrared. The effects of finite linewidth, birefringent walk-off, and group velocity walk-off on conversion efficiency will be discussed with reference to the experimental results. (orig.)

  10. Dynamic Coefficients of a Tilting Pad With Active Lubrication: Comparison Between Theoretical and Experimental Results

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Santos, Ilmar

    2015-01-01

    experimental results from the literature for industrial grade passive tilting pad bearings. This initial validation is followed by a comparison with experimental identification results obtained from a test rig featuring the active bearing design. Good overall agreement is observed in both configurations...

  11. Armature reaction effects on a high temperature superconducting field winding of an synchronous machine: experimental results

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech

    2014-01-01

    This paper presents experimental results from the Superwind laboratory setup. Particular focus in the paper has been placed on describing and quantifying the influence of armature reaction on performance of the HTS filed winding. Presented experimental results have confirmed the HTS field winding...

  12. Calculation of neutron fluxes in biological shield of the TRIGA Mark II reactor

    International Nuclear Information System (INIS)

    Bozic, M.; Zagar, T.; Ravnik, M.

    2001-01-01

    The complete calculation of neutron fluxes in biological shield and verification with experimental results is presented. Calculated results are obtained with TORT code (TORT-Three Dimensional Oak Ridge Discrete Ordinates Neutron/Photon Transport Code). Experimental results used for comparison are available from irradiation experiment with selected type of concrete and other materials in irradiation channel 4 in TRIGA Mark II reactor. These experimental results were used as a benchmark. Homogeneous type of problem (without inserted irradiation channel) and problem with asymmetry (inserted beam port 4, filled with different materials) were of interest for neutron flux calculation. Deviation from material data set up as original parameters is also considered (first of all presence of water in concrete and density of concrete) for type of concrete in biological shield and for selected type of concrete in irradiation channel. BUGLE-96 (47 neutron energy groups) library is used. Excellent agreement between calculated and experimental results for reaction rate is received.(author)

  13. Preparation of a basic data base for shielding design. 4

    International Nuclear Information System (INIS)

    Nakao, Makoto; Takemura, Morio

    1999-03-01

    With use of a standard groupwise shielding design library JSSTDL produced from the latest evaluated nuclear data library JENDL-3.2, experimental analyses for the JASPER experiments were performed. In order to verify the new version of JSSTDL, whose cross sections of thermal energy region was updated, the polyethylene transmission experiments of the Special Materials Experiment was analysed again, and also zirconium transmission experiment of the Experiment was newly analysed. JSSTDL was applied to the analysis of neutron multiplicative region of the in-vessel fuel storage mockup configurations in the IVS Experiment. Also it was applied to the analyses of neutron streaming effect through the mockup of sodium window in B 4 C shield in the Flux Monitor Experiment and also the mockup of narrow gaps in thick concrete shield in the Gap streaming Experiment. The results were compared with those obtained by the same analysis method and input data using the JSDJ2 library that had been applied consistently to the JASPER experiment analyses. Although the analysis with the new version of JSSTDL resulted in a little reduction of overestimation in the polyethylene transmission configuration, the results obtained with JSSTDL are, in general, higher than those with JSDJ2 as had been found in analyses in preceding years for the Radial Shield Attenuation Experiment, the Axial Shield Experiment, the Intermediate Heat Exchanger Experiment and so on. Compilation of the input data necessary for future reanalyses of important configurations in JASPER experiments, that were selected at the first stage of this study, were continued and new data were added into the computer disk holding previously accumulated data. (author)

  14. The use of nipple shields: A review

    Directory of Open Access Journals (Sweden)

    Selina Chow

    2016-11-01

    Full Text Available A nipple shield is a breastfeeding aid with a nipple-shaped shield that is positioned over the nipple and areola prior to nursing. Nipple shields are usually recommended to mothers with flat nipples or in cases in which there is a failure of the baby to effectively latch onto the breast within the first two days postpartum. The use of nipple shields is a controversial topic in the field of lactation. Its use has been an issue in the clinical literature since some older studies discovered reduced breast milk transfer when using nipple shields, while more recent studies reported successful breastfeeding outcomes. The purpose of this review was to examine the evidence and outcomes with nipple shield use. Methods: A literature search was conducted in Ovid MEDLINE, OLDMEDLINE, EMBASE Classic, EMBASE, Cochrane Central Register of Controlled Trials and CINAHL. The primary endpoint was any breastfeeding outcome following nipple shield use. Secondary endpoints included the reasons for nipple shield use and the average/median length of use. For the analysis, we examined the effect of nipple shield use on physiological responses, premature infants, mothers’ experiences, and health professionals’ experiences. Results: The literature search yielded 261 articles, 14 of which were included in this review. Of these 14 articles, three reported on physiological responses, two reported on premature infants, eight reported on mothers’ experiences, and one reported on health professionals’ experiences. Conclusion: Through examining the use of nipple shields, further insight is provided on the advantages and disadvantages of this practice, thus allowing clinicians and researchers to address improvements on areas that will benefit mothers and infants the most.

  15. Experimental and numerical results of a high frequency rotating active magnetic refrigerator

    DEFF Research Database (Denmark)

    Lozano, Jaime; Engelbrecht, Kurt; Bahl, Christian

    2012-01-01

    Experimental results for a recently developed prototype magnetic refrigeration device at The Technical University of Denmark (DTU) were obtained and compared with numerical simulation results. A continuously rotating active magnetic regenerator (AMR) using 2.8 kg packed sphere regenerators...

  16. Experimental and numerical results of a high frequency rotating active magnetic refrigerator

    DEFF Research Database (Denmark)

    Lozano, Jaime; Engelbrecht, Kurt; Bahl, Christian R.H.

    2014-01-01

    Experimental results for a recently developed prototype magnetic refrigeration device at the Technical University of Denmark (DTU) were obtained and compared with numerical simulation results. A continuously rotating active magnetic regenerator (AMR) using 2.8 kg packed sphere regenerators...

  17. Shielding member for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori

    1997-06-30

    In a thermonuclear device for shielding fast neutrons by shielding members disposed in a shielding vessel (vacuum vessel and structures such as a blanket disposed in the vacuum vessel), the shielding member comprises a large number of shielding wires formed fine and short so as to have elasticity. The shielding wires are sealed in a shielding vessel together with water, and when the width of the shielding vessel is changed, the shielding wires follow after the change of the width while elastically deforming in the shielding vessel, so that great stress and deformation are not formed thereby enabling to improve reliability. In addition, the length, the diameter and the shape of each of the shielding wires can be selected in accordance with the shielding space of the shielding vessel. Even if the shape of the shielding vessel is complicated, the shielding wires can be inserted easily. Accordingly, the filling rate of the shielding members can be changed easily. It can be produced more easily compared with a conventional spherical pebbles. It can be produced more easily than existent spherical shielding pebbles thereby enabling to reduce the production cost. (N.H.)

  18. Mechanical and radiation shielding properties of mortars with additive fine aggregate mine waste

    International Nuclear Information System (INIS)

    Gallala, Wissem; Hayouni, Yousra; Gaied, Mohamed Essghaier; Fusco, Michael; Alsaied, Jasmin; Bailey, Kathryn; Bourham, Mohamed

    2017-01-01

    Highlights: • Effectiveness of mine waste as additive fine aggregate has been investigated. • Experimental results are verified by computationally from composition of synthesized samples. • Work focuses on shielding materials for nuclear systems including spent fuel storage and drycasks. - Abstract: Incorporation of barite-fluorspar mine waste (BFMW) as a fine aggregate additive has been investigated for its effect on the mechanical and shielding properties of cement mortar. Several mortar mixtures were prepared with different proportions of BFMW ranging from 0% to 30% as fine aggregate replacement. Cement mortar mixtures were evaluated for density, compressive and tensile strengths, and gamma ray radiation shielding. The results revealed that the mortar mixes containing 25% BFMW reaches the highest compressive strength values, which exceeded 50 MPa. Evaluation of gamma-ray attenuation was both measured by experimental tests and computationally calculated using MicroShield software package, and results have shown that using BFMW aggregates increases attenuation coefficient by about 20%. These findings have demonstrated that the mine waste can be suitably used as partial replacement aggregate to improve radiation shielding as well as to reduce the mortar and concrete costs.

  19. Research of reducing the shielding effect caused by vehicles passing the radioactivity monitor system

    International Nuclear Information System (INIS)

    Deng Xianqi; Li Jianmin; Wang Xiaobing

    2008-01-01

    A kind of Radioactivity Monitor System with Vehicle Contour Acquisition Module based on Optical Screen is developed. The system can reduce the shielding effect caused by the passing vehicles, so that the alarming sensitivity is improved. This paper introduces the work situation of the system and preliminary experimental results. (authors)

  20. First results with the experimental set-up at a Bugey reactor: neutrino oscillations, search of axions

    International Nuclear Information System (INIS)

    Hoummada, A.

    1982-07-01

    This work presents an experimental set-up at the Bugey PWR reactor to put into evidence neutrino oscillations. The first part describes a neutrino detector specially designed for the investigation of neutrino oscillations at two distances (13.50 m and 19 m) under the core of the reactor. Preliminary analysis are presented. The second part reports a search for axions, using the neutrino detector well-shielded volume. Created in competition with electro magnetic transitions, axion should be produced in abondance in the reactor core. This experiment excludes the existence of the axion of the standard model [fr

  1. Thermal design of top shield

    International Nuclear Information System (INIS)

    Raghupathy, S.; Velusamy, K.; Parthasarathy, U.; Ghosh, D.; Selvaraj, P.; Chellapandi, P.; Chetal, S.C.

    2005-01-01

    m 3 /s and using air as the coolant is provided. The bottom plate of TS is cooled by air jets to maintain its temperature at 393 K. The air leaving the bottom plate is circulated through vertical cooling passages around the component penetrations shells and the same air is used to heat the top plate thereby coupling the temperatures of top and bottom plates thus maintaining the ΔT between them. Mineral wool insulation is provided above top plate to reduce the heat loss and to maintain the ΔT across the height of TS. No cooling is provided for CP and 48 shielding plates with varying spacing between them are provided to get a linear temperature variation across the plates. The heat transfer through cover gas has been estimated analytically. Detailed thermal hydraulic analysis has been carried out to estimate the coolant distribution to various cooling passages and the temperature distribution in TS. Cellular convection in the component penetrations has been analysed using the THYC-2D code to calculate the axial and circumferential temperature distribution in the penetration shells. Analysis carried out using HEATING-5 code indicates that the temperature and ΔT limits for the top plate of CP are met. CP is provided with a mechanism box above the top of SRP. Detailed analysis for the thermal management of the upper part of CP has been carried out leading to provision of 1 kW heater, 50 mm thick insulation outside the mechanism box and shutters to control the temperature inside the box in order to maintain the temperature of top plate of CP. Detailed thermal analysis carried out indicates that the temperatures near the inflatable seal / backup seal are 377 K / 375 K respectively. The geometry outside roof slab is quite complex with multi-modal heat transfer interaction among the various structures. Thermal analysis of the MV-RS junction has been carried out resulting in the optimization of the geometry and location of the ACB along with optimum thickness of the SV

  2. Indicia carbonate - ultrabasic massives of Ukrainian Shield

    Directory of Open Access Journals (Sweden)

    Popovchenko S.E.

    2014-12-01

    Full Text Available Researches of geology and composition of silicate-carbonate rocks of the Ukrainian shield. Concluded that they belonged to the karbonatites of the normal series. Metallogenic characteristics and specialization are confirming to the magmatic origin and resemblance with karbonatites alkaline series. In connection with the prevalence in the Precambrian ultrabasic-basic formation of carbonatites magmatism it was, seems to be more widespread in the areal extent of the ancient protoplatforms and rift zones. Numerous experimental data explicitly confirm the possibility of origin of dolomite melts of peridotite magma at its saturation pressure of CO2 and more than 5.7 GPa. Determined formational belonging and potential metallogenic specialization of silicate-carbonate rocks, associated with ultrabasic complexes of the Ukrainian Shield. Particular attention is paid to the identification of features that silicate-carbonate rocks can be attributed to magmatic or metamorphogenic-sedimentary formations, compared to their material composition and geotectonic position. As a result, identified the main characteristics for their recognition. Of these, the leading classified geotectonic, structural-geological, petrographic and mineralogical features, material composition and structure of the silicate-carbonate rocks associated with them relations of ultrabasic, mineralogical and geochemical features and communication with the manifestations useful mineralization. When you select features also include the effect of metamorphism on the nature of the transformation of carbonate-ultrabasic massifs and their modern look at this level erosion of the crust.

  3. Discussion on variance reduction technique for shielding

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    As the task of the engineering design activity of the international thermonuclear fusion experimental reactor (ITER), on 316 type stainless steel (SS316) and the compound system of SS316 and water, the shielding experiment using the D-T neutron source of FNS in Japan Atomic Energy Research Institute has been carried out. However, in these analyses, enormous working time and computing time were required for determining the Weight Window parameter. Limitation or complication was felt when the variance reduction by Weight Window method of MCNP code was carried out. For the purpose of avoiding this difficulty, investigation was performed on the effectiveness of the variance reduction by cell importance method. The conditions of calculation in all cases are shown. As the results, the distribution of fractional standard deviation (FSD) related to neutrons and gamma-ray flux in the direction of shield depth is reported. There is the optimal importance change, and when importance was increased at the same rate as that of the attenuation of neutron or gamma-ray flux, the optimal variance reduction can be done. (K.I.)

  4. Heating profiles on ICRF antenna Faraday shields

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Hahs, C.L. Riemer, B.W.; Ryan, D.M.; Williamson, D.E.

    1992-01-01

    Poor definition of the heating profiles that occur during normal operation of Faraday shields for ion cyclotron resonant frequency (ICRF) antennas has complicated the mechanical design of ICRF system components. This paper reports that at Oak Ridge National Laboratory (ORNL), Faraday shield analysis is being used in defining rf heating profiles. In recent numerical analyses of proposed hardware for the Burning Plasma Experiment (BPX) and DIII-D, rf magnetic fields at Faraday shield surfaces were calculated, providing realistic predictions of the induced skin currents flowing on the shield elements and the resulting dissipated power profile. Detailed measurements on mock-ups of the Faraday shields for DIII-D and the Tokamak Fusion Test Reactor (TFTR) confirmed the predicted magnetic field distributions. A conceptual design for an uncooled Faraday shield for the BPX ion cyclotron resonance heating (ICRH) antenna, which should withstand the proposed long-pulse operation, has been completed. The analytical effort is described in detail, with emphasis on the design work for the BPX ICRH antenna conceptual design and for the replacement Faraday shield for the DIII-D FWCD antenna. Results of analyses are shown, and configuration issues involved in component modeling are discussed

  5. Estimating ISABELLE shielding requirements

    International Nuclear Information System (INIS)

    Stevens, A.J.; Thorndike, A.M.

    1976-01-01

    Estimates were made of the shielding thicknesses required at various points around the ISABELLE ring. Both hadron and muon requirements are considered. Radiation levels at the outside of the shield and at the BNL site boundary are kept at or below 1000 mrem per year and 5 mrem/year respectively. Muon requirements are based on the Wang formula for pion spectra, and the hadron requirements on the hadron cascade program CYLKAZ of Ranft. A muon shield thickness of 77 meters of sand is indicated outside the ring in one area, and hadron shields equivalent to from 2.7 to 5.6 meters in thickness of sand above the ring. The suggested safety allowance would increase these values to 86 meters and 4.0 to 7.2 meters respectively. There are many uncertainties in such estimates, but these last figures are considered to be rather conservative

  6. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  7. Preparation of a basic data base for shielding design. 3

    International Nuclear Information System (INIS)

    Takemura, Morio

    1998-03-01

    With use of a standard groupwise shielding design library JSSTDL produced from the latest evaluated nuclear data library JENDL-3.2, experimental analyses for the In-Vessel Fuel Storage (IVS) Experiment and the Intermediate Heat Exchanger (IHX) Experiment were performed. The results were compared with those obtained by the same analysis method and input data using the JSDJ2 library that had been applied consistently to the JASPER experiment analyses. In general, the results obtained with JSSTDL are higher than those with JSDJ2 as were found in analyses in last two years for the Radial Shield Attenuation Experiment and the Special Materials Experiment and also the Axial Shield Experiment. The calculation-to-experiment ratios of the fast neutron flux just behind deep penetration in sodium were obtained first by these IVS and IHX experimental analyses with the JSSTDL library. However, it was confirmed not to be easy to evaluate the accuracy of sodium cross section because of its dependency on how to model the swelled sodium slabs and tanks. The analyses with JSSTDL library were verified by comparison with other analyses with another library based on JENDL-3.2. Compilation of the input data necessary for future reanalyses of important configurations in JASPER experiments, that were selected at the first stage of this study, were continued and new data were added into the computer disk holding previously accumulated data. (author)

  8. Shields for nuclear reactors

    International Nuclear Information System (INIS)

    Aspden, G.J.

    1984-01-01

    The patent concerns shields for nuclear reactors. The roof shield comprises a normally fixed radial outer portion, a radial inner portion rotatable about a vertical axis, and a connection between the inner and outer portions. In the event of hypothecal core disruption conditions, a cantilever system on the inner wall allows the upward movement of the inner wall, in order to prevent loss of containment. (UK)

  9. Radiation shielding curtain

    International Nuclear Information System (INIS)

    Winkler, N.T.

    1976-01-01

    A radiation shield is described in the form of a stranded curtain made up of bead-chains whose material and geometry are selected to produce a cross-sectional density that is the equivalent of 0.25 mm or more of lead and which curtain may be mounted on various radiological devices to shield against scattered radiation while offering a minimum of obstruction to the radiologist

  10. Shielded cells transfer automation

    International Nuclear Information System (INIS)

    Fisher, J.J.

    1984-01-01

    Nuclear waste from shielded cells is removed, packaged, and transferred manually in many nuclear facilities. Radiation exposure is absorbed by operators during these operations and limited only through procedural controls. Technological advances in automation using robotics have allowed a production waste removal operation to be automated to reduce radiation exposure. The robotic system bags waste containers out of glove box and transfers them to a shielded container. Operators control the system outside the system work area via television cameras. 9 figures

  11. Self-similar regimes of fast ionization waves in shielded discharge tubes

    International Nuclear Information System (INIS)

    Gerasimov, D.N.; Sinkevich, O.A.

    1999-01-01

    An analytical self-similar solution to the problem of the propagation of a fast ionization wave (FIW) in a long shielded tube is constructed. An expression determining the influence of the device parameters on the FIW velocity is obtained; the velocity is found to be the nonmonotonic function of the working-gas pressure. The theoretical predictions are compared with the results of experiments carried out with helium and nitrogen. The calculation and experimental results agree within experimental errors

  12. Calculation of parameters for an iron shield experiment

    International Nuclear Information System (INIS)

    Gavazza, S.

    1986-01-01

    In this text is carreid out the evaluation of radiation transport methodology, comparying the calculated reactions and dose rates, for neutrons and gama-rays, with the experimental measurements obtained on iron shield, irradiated in YAYOI reactor. Were employed the ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system for generation of cross sections, collapsed by the ANISN code. The tranpsort calculations were made by using the DOT 3.5 code, adjusting the spectrum of the iron shield boundary source to the reaction and doses rates, measured at the beginning of shield. The distributions calculated for neutrons and gamma-rays, on iron shield, presented reasonable concordance with the experimental measurements. Finally, is presented a proposal for setting up of an experimental arrangement, using the IEA-R1 reactor, with the purpose of lay down a shielding benchmark. (Author) [pt

  13. Safety analysis report for packaging: the ORNL gas-cylinder fire and impact shield

    International Nuclear Information System (INIS)

    Evans, J.H.; Levine, D.L.; Eversole, R.E.; Mouring, R.W.

    1983-04-01

    The ORNL gas-cylinder fire and impact shield was designed and fabricated at the Oak Ridge Gaseous Diffusion Plant for the transport of cylinders filled with radioactive gases. The shield was evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and the results are reported herein. Computational and test procedures were used to determine the structural integrity and thermal behavior of the cask relative to the general standards for normal conditions of transport and the standards for hypothetical accident conditions. Results of the evaluation demonstrate that the container is in compliance with the applicable regulations

  14. Scale-4 shipping cask shielding applications

    International Nuclear Information System (INIS)

    Broadhead, B.L.; Parks, C.V.

    1991-01-01

    This paper reports the application of the SCALE-4 shielding sequences SAS1 and SAS4 to the problem set distributed by the Organization for Economic Cooperation and Development (OECD) Working Group on Shielding Assessment of Transportation Packages. In many cases, additional comparison are made with MCNP and QADS solutions to provide a complete cross-check of methods, cross sections, geometry, etc. The results from this effort permit the evaluation of a number of approximations and effects that must be considered in a typical shielding analysis of a transportation cask

  15. Radiation shielding for TFTR DT diagnostics

    International Nuclear Information System (INIS)

    Ku, L.P.; Johnson, D.W.; Liew, S.L.

    1994-01-01

    The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable to future devices, such as TPX and ITER, where many similar diagnostic systems are expected to be used

  16. Quantitative comparison between theoretical predictions and experimental results for the BCS-BEC crossover

    International Nuclear Information System (INIS)

    Perali, A.; Pieri, P.; Strinati, G.C.

    2004-01-01

    Theoretical predictions for the Bardeen-Cooper-Schrieffer-Bose-Einstein condensation crossover of trapped Fermi atoms are compared with recent experimental results for the density profiles of L 6 i. The calculations rest on a single theoretical approach that includes pairing fluctuations beyond mean-field. Excellent agreement with experimental results is obtained. Theoretical predictions for the zero-temperature chemical potential and gap at the unitarity limit are also found to compare extremely well with Quantum Monte Carlo simulations and with recent experimental results

  17. PMMA/MWCNT nanocomposite for proton radiation shielding applications

    Science.gov (United States)

    Li, Zhenhao; Chen, Siyuan; Nambiar, Shruti; Sun, Yonghai; Zhang, Mingyu; Zheng, Wanping; Yeow, John T. W.

    2016-06-01

    Radiation shielding in space missions is critical in order to protect astronauts, spacecraft and payloads from radiation damage. Low atomic-number materials are efficient in shielding particle-radiation, but they have relatively weak material properties compared to alloys that are widely used in space applications as structural materials. However, the issues related to weight and the secondary radiation generation make alloys not suitable for space radiation shielding. Polymers, on the other hand, can be filled with different filler materials for reinforcement of material properties, while at the same time provide sufficient radiation shielding function with lower weight and less secondary radiation generation. In this study, poly(methyl-methacrylate)/multi-walled carbon nanotube (PMMA/MWCNT) nanocomposite was fabricated. The role of MWCNTs embedded in PMMA matrix, in terms of radiation shielding effectiveness, was experimentally evaluated by comparing the proton transmission properties and secondary neutron generation of the PMMA/MWCNT nanocomposite with pure PMMA and aluminum. The results showed that the addition of MWCNTs in PMMA matrix can further reduce the secondary neutron generation of the pure polymer, while no obvious change was found in the proton transmission property. On the other hand, both the pure PMMA and the nanocomposite were 18%-19% lighter in weight than aluminum for stopping the protons with the same energy and generated up to 5% fewer secondary neutrons. Furthermore, the use of MWCNTs showed enhanced thermal stability over the pure polymer, and thus the overall reinforcement effects make MWCNT an effective filler material for applications in the space industry.

  18. Radiation distribution through serpentine concrete using local materials and its application as a reactor biological shield

    International Nuclear Information System (INIS)

    Kansouh, W.A.

    2012-01-01

    Highlights: ► New serpentine concrete was made and examined as a reactor biological shield. ► Ilmenite–limonite concrete is a better reactor biological shield. ► New serpentine concrete is a better reactor fast neutrons shield than ordinary and hematite–serpentine concretes. ► Serpentine concrete has lower properties as a reactor total gamma rays shields. - Abstract: In the present work attempt has been made to estimate the shielding parameters of the new serpentine concrete (density = 2.4 g/cm 3 ) using local materials on the shielding parameters for two types of heat resistant concretes, namely hematite–serpentine (density = 2.5 g/cm 3 ) and ilmenite–limonite (density = 2.9 g/cm 3 ). Shielding parameters for ordinary concrete (density = 2.3 g/cm 3 ) were also discussed. These parameters were determined experimentally for serpentine concrete and compared with previously published values for other concretes, which had also been obtained using local materials. The leakage spectra of reactor fast neutrons and total gamma photon beams from cylindrical samples of these concrete shields were also investigated using a collimated beam from ET-RR-1 reactor. A neutron–gamma spectrometer was used in order to obtain pulse height spectra of reactor fast neutrons and the total gamma rays leakage through the investigated concrete samples. These spectra were utilized to obtain the energy spectra required in these investigations. Removal cross section Σ R (E n ) and linear attenuation coefficient μ(E g ) for reactor fast neutrons and total gamma rays and their relative coefficients were evaluated and presented. Measured results were compared with those previously measured for other concretes. The results show that ilmenite–limonite concrete is a better reactor biological shield than the other three concretes. Serpentine concrete under investigation is a better reactor fast neutrons shield than ordinary and hematite–serpentine concretes. Serpentine concrete

  19. Radiation shielding for 250 MeV protons

    International Nuclear Information System (INIS)

    Awschalom, M.

    1987-01-01

    This paper is targetted at personnel who have the responsibility of designing the radiation shielding against neutron fluences created when protons interact with matter. Shielding of walls and roofs are discussed, as well as neutron dose leakage through labyrinths. Experimental data on neutron flux attenuation are considered, as well as some calculations using the intranuclear cascade calculations and parameterizations

  20. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

    International Nuclear Information System (INIS)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for single-phase natural convection in an experimental sodium loop. The tests were conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) Facility, an engineering-scale high temperature sodium facility at the Oak Ridge National Laboratory used for thermal-hydraulic testing of simulated LMFBR subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during these tests was typical of decay heat levels. Tests were conducted both with zero initial forced flow and with a small initial forced flow. The bypass line was closed in most tests, but open in one. The computer code used to analyze these tests [LONAC (LOw flow and NAtural Convection)] is an ORNL-developed, fast running, one-dimensional, single-phase finite difference model for simulating forced and free convection transients in the THORS loop

  1. Two-dimensional shielding benchmarks for iron at YAYOI, (1)

    International Nuclear Information System (INIS)

    Oka, Yoshiaki; An, Shigehiro; Kasai, Shigeru; Miyasaka, Shun-ichi; Koyama, Kinji.

    The aim of this work is to assess the collapsed neutron and gamma multigroup cross sections for two dimensional discrete ordinate transport code. Two dimensional distributions of neutron flux and gamma ray dose through a 70cm thick and 94cm square iron shield were measured at the fast neutron source reactor ''YAYOI''. The iron shield was placed over the lead reflector in the vertical experimental column surrounded by heavy concrete wall. The detectors used in this experiment were threshold detectors In, Ni, Al, Mg, Fe and Zn, sandwitch resonance detectors Au, W and Co, activation foils Au for neutrons and thermoluminescence detectors for gamma ray dose. The experimental results were compared with the calculated ones by the discrete ordinate transport code ANISN and TWOTRAN. The region-wise, coupled neutron-gamma multigroup cross-sections (100n+20gamma, EURLIB structure) were generated from ENDF/B-IV library for neutrons and POPOP4 library for gamma-ray production cross-sections by using the code system RADHEAT. The effective microscopic neutron cross sections were obtained from the infinite dilution values applying ABBN type self-shielding factors. The gamma ray production multigroup cross-sections were calculated from these effective microscopic neutron cross-sections. For two-dimensional calculations the group constants were collapsed into 10 neutron groups and 3 gamma groups by using ANISN. (auth.)

  2. Removal of arsenic from wastewaters by cryptocrystalline magnesite: complimenting experimental results with modelling

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2016-02-01

    Full Text Available -1 Journal of Cleaner Production Removal of arsenic from wastewaters by cryptocrystalline magnesite: complimenting experimental results with modelling Vhahangwele Masindi W. Mugera Gitari Keywords: Arsenic Mine leachates Cryptocrystalline...

  3. Experimental and modelling results of a parallel-plate based active magnetic regenerator

    DEFF Research Database (Denmark)

    Tura, A.; Nielsen, Kaspar Kirstein; Rowe, A.

    2012-01-01

    The performance of a permanent magnet magnetic refrigerator (PMMR) using gadolinium parallel plates is described. The configuration and operating parameters are described in detail. Experimental results are compared to simulations using an established twodimensional model of an active magnetic...

  4. Dose reduction during CT scanning in an anthropomorphic phantom by the use of a male gonad shield.

    Science.gov (United States)

    Price, R; Halson, P; Sampson, M

    1999-05-01

    Shielding the radiosensitive gonads during X-ray exposure has been advocated for plain film radiography for many years. In the UK, gonad shields are not widely employed in routine CT scanning, possibly owing to a perceived difficulty in protecting the gonads from a multidirectional X-ray source. The increasing numbers of CT scanners in the UK, with the large doses they deliver to patients, make potential dose reduction methods an important issue. This study measures the dose reduction achievable by shielding the male gonads with a lead wrap-around protection device. The reductions in dose when shielded both from direct radiation and from indirect radiation scattered from local tissues were studied. The use of the device resulted in a statistically significant reduction in the absorbed testicular dose from both direct and scattered radiation, with no increase in the dose measured in surrounding tissues. In three clinically relevant experimental protocols where the testes were not irradiated directly, the testicular absorbed dose from indirect scatter was reduced by 77-93% of the corresponding non-shielded figure. In these three experiments, image quality was unaltered by the use of the shield. A larger dose reduction was obtained when the shield was used to protect the testes from direct irradiation. However, this was achieved at the expense of considerable image degradation from streak artefact that would effectively prevent the clinical use of the device in this setting.

  5. MCNP simulation to optimise in-pile and shielding parts of the Portuguese SANS instrument.

    Science.gov (United States)

    Gonçalves, I F; Salgado, J; Falcão, A; Margaça, F M A; Carvalho, F G

    2005-01-01

    A Small Angle Neutron Scattering instrument is being installed at one end of the tangential beam tube of the Portuguese Research Reactor. The instrument is fed using a neutron scatterer positioned in the middle of the beam tube. The scatterer consists of circulating H2O contained in a hollow disc of Al. The in-pile shielding components and the shielding installed around the neutron selector have been the object of an MCNP simulation study. The quantities calculated were the neutron and gamma-ray fluxes in different positions, the energy deposited in the material by the neutron and gamma-ray fields, the material activation resulting from the neutron field and radiation doses at the exit wall of the shutter and around the shielding. The MCNP results are presented and compared with results of an analytical approach and with experimental data collected after installation.

  6. The effect of some organic and non-organic additions on the shielding and mechanical properties of radiation shielding concrete

    International Nuclear Information System (INIS)

    Kharita, M. H.; Yousef, S.; Al-Nassar, M.

    2011-04-01

    Few studies on the effect of some additives on the shielding properties of concrete have been carried out in this research. These studies included the effect of carbon powder, boron compounds, and waste polyethylene. The effect of water to cement ratio has been studied too. The research results showed that carbon powder and some boron compounds could be used to improve shielding concrete properties, and the possibility to add waste polyethylene in shielding concrete without effects on shielding properties. No significant effect for water to cement ratio on shielding properties of concrete. (author)

  7. Combined measurement system for double shield tunnel boring machine guidance based on optical and visual methods.

    Science.gov (United States)

    Lin, Jiarui; Gao, Kai; Gao, Yang; Wang, Zheng

    2017-10-01

    In order to detect the position of the cutting shield at the head of a double shield tunnel boring machine (TBM) during the excavation, this paper develops a combined measurement system which is mainly composed of several optical feature points, a monocular vision sensor, a laser target sensor, and a total station. The different elements of the combined system are mounted on the TBM in suitable sequence, and the position of the cutting shield in the reference total station frame is determined by coordinate transformations. Subsequently, the structure of the feature points and matching technique for them are expounded, the position measurement method based on monocular vision is presented, and the calibration methods for the unknown relationships among different parts of the system are proposed. Finally, a set of experimental platforms to simulate the double shield TBM is established, and accuracy verification experiments are conducted. Experimental results show that the mean deviation of the system is 6.8 mm, which satisfies the requirements of double shield TBM guidance.

  8. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.H.

    1990-03-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing, These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale of neutron shield from the cask. The test article was heated in an environmental prescribed by NRC regulations. Results of this second testing phase showed that all three materials are thermally acceptable

  9. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.N.

    1990-01-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing. These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale section of neutron shield from the cask. The test article was heated in an environment prescribed by NRC regulations. Results of this second testing phase show that all three materials are thermally acceptable

  10. Survivor shielding. Part A. Nagasaki factory worker shielding

    International Nuclear Information System (INIS)

    Santoro, Robert T.; Barnes, John M.; Azmy, Yousry Y.; Kerr, George D.; Egbert, Stephen D.; Cullings, Harry M.

    2005-01-01

    Recent investigations based on conventional chromosome aberration data by the RERF suggest that the DS86 doses received by many Nagasaki factory workers may have been overestimated by as much as 40% relative to those for other survivors in Japanese-type houses and other shielding configurations (Kodama et al. 2001). Since the factory workers represent about 25% of the Nagasaki survivors with DS86 doses in excess of 0.5 Gy (50 rad), systematic errors in their dose estimates can have a major impact on the risk coefficients from RERF studies. The factory worker doses may have been overestimated for a number of reasons. The calculation techniques, including the factory building modeling, weapon source spectra and cross-section data used in the DS86 shielding calculations were not detailed enough to replicate actual conditions. The models used did not take into account local shielding provided by machinery, tools, and the internal structure in the buildings. In addition, changes in the disposition of shielding following collapse of the building by the blast wave were not considered. The location of large factory complexes may be uncertain, causing large numbers of factory survivors, correctly located relative to each other, to be uniformly too close to the hypocenter. Any or all of these reasons are sufficient to result in an overestimate of the factory worker doses. During the DS02 studies, factory worker doses have been reassessed by more carefully modeling the factory buildings, incorporating improved radiation transport methods and cross-section data and using the most recent bomb leakage spectra (Chapter 2). Two-dimensional discrete ordinates calculations were carried out initially to estimate the effects of workbenches and tools on worker doses to determine if the inclusion of these components would, in fact, reduce the dose by amounts consistent with the RERF observations (Kodama et al. 2001). (author)

  11. Superconducting magnetic shields for neutral beam injectors. Final report

    International Nuclear Information System (INIS)

    1985-04-01

    Large high energy deuterium neutral beams which must be made from negative ions require extensive magnetic shielding against the intense fringe fields surrounding a magnetic fusion power plant. The feasibility of shielding by multilayer sheets of copper-superconducting laminated material was investigated. It was found that, if necessary fabrication techniques are developed, intrinsically stable type II superconductors will be able to shield against the magnetic fields of the fusion reactors. Among the immediate benefits of this research is better magnetic shields for neutral beam injectors in support of DOE's fusion program. Another application may be in the space vehicles, where difficulties in transporting heavy μ-metal sections may make a comparatively light superconducting shield attractive. Also, as high-field superconducting magnets find widespread applications, the need for high-intensity magnetic shielding will increase. As a result, the commercial market for the magnetic shields should expand along with the market for superconducting magnets

  12. Status report of shielding investigation in Japan

    International Nuclear Information System (INIS)

    Shindo, M.

    1964-01-01

    The Japan Atomic Energy Research Institute (JAERI) was established in 1954, and immediately proceeded with the construction of a research reactor. The first symposium in Japan on nuclear energy was held in 1957. Most of the papers presented in the field of reactor shielding were limited to shielding materials and their fabrication. In the first stage of our investigations, our efforts were devoted to practical design studies of reactor shielding. As a result of these studies, it was found that the formulae at hand for calculations were inadequate, but at that time no electronic computer was available in Japan nor were theoretical calculations very actively undertaken. Problems on nuclear ship shielding had been investigated at the Ship Research Institute, since 1956 and many fruitful results had been obtained. About that time the Japan Atomic Industry Forum started activities and took the initiative in organizing shielding research. Research workers in the shipbuilding industry in particular have been seriously studying shielding problems. Few years after the first symposium, problems concerning more fundamental studies were treated by many research workers. Shielding experiments using radioisotopes were carried out and many fruitful results were obtained. They are described in the this paper. Medium size electronic computers became available in Japan, permitting a theoretical study group to make an active contribution. They produced some codes, and their results are also described in the following sections. This constituted the second stage of our investigations. A swimming-pool reactor, JRR-4 (Japan Research Reactor-4), has been under construction at JAERI since 1962 and will become critical in autumn 1964. After characteristic tests it will be a very powerful tool for the shielding investigations. This id the beginning of the third stage of investigations

  13. Measurement accuracy in shielded magnetic fields

    International Nuclear Information System (INIS)

    Bottauscio, Oriano; Chiampi, Mario; Crotti, Gabriella; Zucca, Mauro

    2005-01-01

    The measurement error due to both the probe size averaging effect and the coil arrangement is investigated when magnetic field measurements are performed in close proximity to different planar shields. The analysis is carried on through a hybrid FEM/BEM model which employs the 'thin shield' technique. Ferromagnetic, pure conductive and multilayer screens are taken into consideration and an estimation of the errors for concentric and non-concentric coil probes is given. The numerical results are validated by experiments

  14. Influence of Shielding Arrangement on ECT Sensors

    Directory of Open Access Journals (Sweden)

    J. L. Fernandez Marron

    2006-09-01

    Full Text Available This paper presents a full 3D study of a shielded ECT sensor. The spatialresolution and effective sensing field are obtained by means of Finite Element Methodbased simulations and are the compared to a conventional sensor's characteristics. Aneffective improvement was found in the sensitivity in the pipe cross-section, resulting inenhanced quality of the reconstructed image. The sensing field along the axis of the sensoralso presents better behaviour for a shielded sensor.

  15. Using FLUKA to Study Concrete Square Shield Performance in Attenuation of Neutron Radiation Produced by APF Plasma Focus Neutron Source

    Science.gov (United States)

    Nemati, M. J.; Habibi, M.; Amrollahi, R.

    2013-04-01

    In 2010, representatives from the Nuclear Engineering and physics Department of Amirkabir University of Technology (AUT) requested development of a project with the objective of determining the performance of a concrete shield for their Plasma Focus as neutron source. The project team in Laboratory of Nuclear Engineering and physics department of Amirkabir University of Technology choose some shape of shield to study on their performance with Monte Carlo code. In the present work, the capability of Monte Carlo code FLUKA will be explored to model the APF Plasma Focus, and investigating the neutron fluence on the square concrete shield in each region of problem. The physical models embedded in FLUKA are mentioned, as well as examples of benchmarking against future experimental data. As a result of this study suitable thickness of concrete for shielding APF will be considered.

  16. Final report of Shield System Trade Study. Volume II. WANL support activities for shielding trade study

    International Nuclear Information System (INIS)

    1970-07-01

    Based on the trades made within this study BATH (mixture of B 4 C, aluminum and TiH 1 . 8 ) was selected as the internal shield material. Borated titanium hydride can also meet the criteria with a competitive weight but was rejected because of schedular constraints. A baseline internal shield design was accomplished. This design resulted in a single internal shield weighing about 3300 lb for both manned and unmanned missions. WANL checks on ANSC calculations are generally in agreement, but with some difference in the prediction of the effectiveness of the Boral liner. All of the alternate NSS concepts in the system weight reduction program were rejected. While some did save shield weight, they complicated the NSS design to an unacceptable degree. Studies were made of the feasibility of manual maintenance of NSS components outside of the pressure vessel. The requirements of the NSS components located forward of the internal shield were considered from a thermal and radiation damage standpoint. (auth)

  17. Concrete radiation shielding

    International Nuclear Information System (INIS)

    Kaplan, M.F.

    1989-01-01

    The increased use of nuclear energy has given rise to a growth in the amount of artificially produced radiation and radioactive materials. The design and construction of shielding to protect people, equipment and structures from the effects of radiation has never been more important. Experience has shown that concrete is an effective, versatile and economical material for the construction of radiation shielding. This book provides information on the principles governing the interaction of radiation with matter and on relevant nuclear physics to give the engineer an understanding of the design and construction of concrete shielding. It covers the physical, mechanical and nuclear properties of concrete; the effects of elevated temperatures and possible damage to concrete due to radiation; basic procedures for the design of concrete radiation shields and finally the special problems associated with their construction and cost. Although written primarily for engineers concerned with the design and construction of concrete shielding, the book also reviews the widely scattered data and information available on this subject and should therefore be of interest to students and those wishing to research further in this field. (author)

  18. Method for dismantling shields

    International Nuclear Information System (INIS)

    Fukuzawa, Rokuro; Kondo, Nobuhiro; Kamiyama, Yoshinori; Kawasato, Ken; Hiraga, Tomoaki.

    1990-01-01

    The object of the present invention is to enable operators to dismantle shieldings contaminated by radioactivity easily and in a short period of time without danger of radiation exposure. A plurality of introduction pipes are embedded previously to the shielding walls of shielding members which contain a reactor core in a state where both ends of the introduction pipes are in communication with the outside. A wire saw is inserted into the introduction pipes to cut the shieldings upon dismantling. Then, shieldings can be dismantled easily in a short period of time with no radiation exposure to operator's. Further, according to the present invention, since the wire saw can be set easily and a large area can be cut at once, operation efficiency is improved. Further, since remote control is possible, cutting can be conducted in water and complicated places of the reactor. Biting upon starting the wire saw in the introduction pipe is reduced to facilitate startup for the rotation. (I.S.)

  19. Mechanical shielded hot cell

    International Nuclear Information System (INIS)

    Higgy, H.R.; Abdel-Rassoul, A.A.

    1983-01-01

    A plan to erect a mechanical shielded hot cell in the process hall of the Radiochemical Laboratory at Inchas is described. The hot cell is designed for safe handling of spent fuel bundles, from the Inchas reactor, and for dismantling and cutting the fuel rods in preparation for subsequent treatment. The biological shielding allows for the safe handling of a total radioactivity level up to 10,000 MeV-Ci. The hot cell consists of an α-tight stainless-steel box, connected to a γ-shielded SAS, through an air-lock containing a movable carriage. The α-box is tightly connected with six dry-storage cavities for adequate storage of the spent fuel bundles. Both the α-box, with the dry-storage cavities, and the SAS are surrounded by 200-mm thick biological lead shielding. The α-box is equipped with two master-slave manipulators, a lead-glass window, a monorail crane and Padirac and Minirag systems. The SAS is equipped with a lead-glass window, tong manipulator, a shielded pit and a mechanism for the entry of the spent fuel bundle. The hot cell is served by adequate ventilation and monitoring systems. (author)

  20. Improvement of the Magnetic Shielding Effects by the Superposition of a Multi-Layered Ferromagnetic Cylinder over an HTS Cylinder: Relationship Between the Shielding Effects and the Layer Number of the Ferromagnetic Cylinder

    International Nuclear Information System (INIS)

    Yasui, K; Tarui, Y; Itoh, M

    2006-01-01

    The idealized magnetic shielded vessel can be realized by making use of a high-critical temperature superconductor (HTS). It is difficult for practical applications, however, to fabricate a shielding vessel that has a high value of the maximum shielded magnetic flux density B s0 . The present authors have improved the value of B s0 for the Bi-Pb-Sr-Ca-Cu-O (BPSCCO) cylinder used as the shielding vessel, by the superposition of a four-layered softiron cylinder over the BPSCCO cylinder, termed the four-layered superimposed cylinder. The B s4 value of 610 x 10 -4 T for the four-layered superimposed cylinder, is found to be about 4 times larger than that of a single-BPSCCO cylinder, and is theoretically analyzed by use of a new analysis method. The experimental values of the maximum shielded magnetic flux density B sn of n-layered superimposed cylinders are found to agree well with those of the theoretical analysis. Experimental results revealed several characteristics of the magnetic shielding within the n-layered superimposed cylinders. Also discussed is the new analysis method for the relationship between the n and B sn

  1. Self-shielding factors

    International Nuclear Information System (INIS)

    Kaul, D.C.

    1982-01-01

    Throughout the last two decades many efforts have been made to estimate the effect of body self-shielding on organ doses from externally incident neutrons and gamma rays. These began with the use of simple geometry phantoms and have culminated in the use of detailed anthropomorphic phantoms. In a recent effort, adjoint Monte Carlo analysis techniques have been used to determine dose and dose equivalent to the active marrow as a function of energy and angle of neutron fluence externally incident on an anthropomorphic phantom. When combined with fluences from actual nuclear devices, these dose-to-fluence factors result in marrow dose values that demonstrate great sensitivity to variations in device type, range, and body orientation. Under a state-of-the-art radiation transport analysis demonstration program for the Japanese cities, sponsored by the Defense Nuclear Agency at the request of the National Council on Radiation Protection and Measurements, the marrow dose study referred to above is being repeated to obtain spectral distributions within the marrow for externally incident neutrons and gamma rays of arbitrary energy and angle. This is intended to allow radiobiologists and epidemiologists to select and to modify numbers of merit for correlation with health effects and to permit a greater understanding of the relationship between human and laboratory subject dosimetry

  2. Safety analysis report for packaging: the ORNL gas-cylinder fire and impact shield

    International Nuclear Information System (INIS)

    Evans, J.H.; Levine, D.L.; Eversole, R.E.

    1977-10-01

    The ORNL radioactive gas-cylinder fire and impact shield was designed and fabricated at the Oak Ridge Gaseous Diffusion Plant for the transport of cylinders filled with radioactive gases. The shield was evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported. Computational and test procedures were used to determine the structural integrity and thermal behavior of the cask relative to the general standards for normal conditions of transport and the standards for hypothetical accident conditions. Results of the evaluation demonstrate that the container is in compliance with the applicable regulations

  3. Modeling and characterization of shielded low loss CPWs on 65 nm node silicon

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hongrui; Yang Dongxu; Zhang Li; Zhang Lei; Yu Zhiping, E-mail: hr-wang06@mails.tsinghua.edu.cn [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2011-06-15

    Coplanar waveguides (CPWs) are promising candidates for high quality passive devices in millimeter-wave frequency bands. In this paper, CPW transmission lines with and without ground shields have been designed and fabricated on 65 nm CMOS technology. A physical-based model is proposed to describe the frequency-dependent per-unit-length L, C, R and G parameters. Starting with a basic CPW structure, the slow-wave effect and ground-shield influence have been analyzed and incorporated into the general model. The accuracy of the model is confirmed by experimental results. (semiconductor devices)

  4. Modeling and characterization of shielded low loss CPWs on 65 nm node silicon

    Science.gov (United States)

    Hongrui, Wang; Dongxu, Yang; Li, Zhang; Lei, Zhang; Zhiping, Yu

    2011-06-01

    Coplanar waveguides (CPWs) are promising candidates for high quality passive devices in millimeter-wave frequency bands. In this paper, CPW transmission lines with and without ground shields have been designed and fabricated on 65 nm CMOS technology. A physical-based model is proposed to describe the frequency-dependent per-unit-length L, C, R and G parameters. Starting with a basic CPW structure, the slow-wave effect and ground-shield influence have been analyzed and incorporated into the general model. The accuracy of the model is confirmed by experimental results.

  5. Modeling and characterization of shielded low loss CPWs on 65 nm node silicon

    International Nuclear Information System (INIS)

    Wang Hongrui; Yang Dongxu; Zhang Li; Zhang Lei; Yu Zhiping

    2011-01-01

    Coplanar waveguides (CPWs) are promising candidates for high quality passive devices in millimeter-wave frequency bands. In this paper, CPW transmission lines with and without ground shields have been designed and fabricated on 65 nm CMOS technology. A physical-based model is proposed to describe the frequency-dependent per-unit-length L, C, R and G parameters. Starting with a basic CPW structure, the slow-wave effect and ground-shield influence have been analyzed and incorporated into the general model. The accuracy of the model is confirmed by experimental results. (semiconductor devices)

  6. On active shieldings in (ββ)0ν 76Ge decay experiments

    International Nuclear Information System (INIS)

    Garcia, E.; Morales, A.; Morales, J.; Nunez-Lagos, R.; Ortiz de Solorzano, A.; Puimedon, J.; Saenz, C.; Salinas, A.; Sarsa, M.L.; Villar, J.A.

    1992-01-01

    The sensitivity of an ultra low background Ge detector for the (ββ) 0ν decay of 76 Ge is estimated in two different experimental set-ups. The main difference between them is the inclusion or not of an active NaI shielding. We find that sensitivity of the Ge detector is not improved by this active shielding either for the O + -->O + or the O + -->2 + (ββ) 0ν transitions. Our results provide a valuable information for future 76 Ge enriched experiments. (orig.)

  7. Shielding analysis of the LMR in-vessel fuel storage experiments

    International Nuclear Information System (INIS)

    Bucholz, J.A.

    1994-01-01

    The In-Vessel Fuel Storage (IVFS) experiments analyzed in this paper were conducted at the Oak Ridge National Laboratory's Tower Shielding Reactor (TSR) as part of the Japanese-American Shielding Program for Experimental Research (JASPER). These IVFS experiments were designed to study source multiplication and three-dimensional effects related to in-vessel storage of spent fuel elements in liquid metal reactor (LMR) systems. The present paper describes the 2- and 3-D calculations and results corresponding to a limited subset of those IVFS experiments in which the US LMR program had a particular interest

  8. TFTR radiation contour and shielding efficiency measurements during D-D operations

    International Nuclear Information System (INIS)

    Kugel, H.W.; Ascione, G.; Elwood, S.; Gilbert, J.; Hwang, D.; Lewis, M.; Levine, J.; Ku, L.P.; Rule, K.; Hajnal, F.

    1994-11-01

    Extensive neutron and gamma radiation contour, shielding efficiency, and spectral measurements were performed during high power TFTR D-D operations at the tokamak Test Cell inner walls, ceiling, roof, and outer walls, in nearby control rooms, work areas, and personnel pathways, outdoors along the site fence at 125 m, and out to the nearest property lines at 180 m. The results confirmed that the efficiency of the basic radiation shielding was sufficient to allow the TFTR D-T experimental plan, and provide empirical guidance for simulating the radiation fields of future fusion reactors

  9. Update on the Code Intercomparison and Benchmark for Muon Fluence and Absorbed Dose Induced by an 18 GeV Electron Beam After Massive Iron Shielding

    Energy Technology Data Exchange (ETDEWEB)

    Fasso, A. [SLAC; Ferrari, A. [CERN; Ferrari, A. [HZDR, Dresden; Mokhov, N. V. [Fermilab; Mueller, S. E. [HZDR, Dresden; Nelson, W. R. [SLAC; Roesler, S. [CERN; Sanami, t.; Striganov, S. I. [Fermilab; Versaci, R. [Unlisted, CZ

    2016-12-01

    In 1974, Nelson, Kase and Svensson published an experimental investigation on muon shielding around SLAC high-energy electron accelerators [1]. They measured muon fluence and absorbed dose induced by 14 and 18 GeV electron beams hitting a copper/water beamdump and attenuated in a thick steel shielding. In their paper, they compared the results with the theoretical models available at that time. In order to compare their experimental results with present model calculations, we use the modern transport Monte Carlo codes MARS15, FLUKA2011 and GEANT4 to model the experimental setup and run simulations. The results are then compared between the codes, and with the SLAC data.

  10. Some results of experimental investigation of super-deep penetration into the metal's targets

    International Nuclear Information System (INIS)

    Andilevko, S.K.; Roman, O.V.; Usherenko, S.M.; Shilkin, V.A.

    1994-01-01

    The phenomenon of Super-Deep Penetration (SDP) is briefly presented. Various experimental techniques, including that based on neutron-activated autoradiography (NAAR), for experimentally investigating this phenomenon are described. Results from a number of investigations in which the effect on SDP of initial target temperature, the dependence of the concentration on depth for different powder particles and the use of bimetallic targets, are reviewed. The complicated nature of the SDP process and the need for a wider range of experimental data if it is to be fully understood are discussed. (orig.)

  11. Experimental Results and Numerical Simulation of the Target RCS using Gaussian Beam Summation Method

    Directory of Open Access Journals (Sweden)

    Ghanmi Helmi

    2018-05-01

    Full Text Available This paper presents a numerical and experimental study of Radar Cross Section (RCS of radar targets using Gaussian Beam Summation (GBS method. The purpose GBS method has several advantages over ray method, mainly on the caustic problem. To evaluate the performance of the chosen method, we started the analysis of the RCS using Gaussian Beam Summation (GBS and Gaussian Beam Launching (GBL, the asymptotic models Physical Optic (PO, Geometrical Theory of Diffraction (GTD and the rigorous Method of Moment (MoM. Then, we showed the experimental validation of the numerical results using experimental measurements which have been executed in the anechoic chamber of Lab-STICC at ENSTA Bretagne. The numerical and experimental results of the RCS are studied and given as a function of various parameters: polarization type, target size, Gaussian beams number and Gaussian beams width.

  12. Analysis and presentation of experimental results with examples, problems and programs

    CERN Document Server

    Christodoulides, Costas

    2017-01-01

    This book is intended as a guide to the analysis and presentation of experimental results. It develops various techniques for the numerical processing of experimental data, using basic statistical methods and the theory of errors. After presenting basic theoretical concepts, the book describes the methods by which the results can be presented, both numerically and graphically. The book is divided into three parts, of roughly equal length, addressing the theory, the analysis of data, and the presentation of results. Examples are given and problems are solved using the Excel, Origin, Python and R software packages. In addition, programs in all four languages are made available to readers, allowing them to use them in analyzing and presenting the results of their own experiments. Subjects are treated at a level appropriate for undergraduate students in the natural sciences, but this book should also appeal to anyone whose work involves dealing with experimental results.

  13. Shield support frame. Schildausbaugestell

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, K.

    1981-09-17

    A powered shield support frame for coal sheds is described comprising of two bottom sliding shoes, a large area gob shield and a larg area roof assembly, all joined movable together. The sliding shoes and the gob shield are joined by a lemniscate guide. Two hydraulic props are arranged at the face-side at one third of the length of the sliding shoes and at the goaf-side at one third of the length of the roof assembly. A nearly horizontal lying pushing prop unit joins the bottom wall sliding shoes to the goaf-side lemniscate guide. This assembly can be applied to seams with a thickness down to 45 cm. (OGR).

  14. Radiation shielding material

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Isobe, Eiji.

    1976-01-01

    Purpose: To increase the shielding capacity of the radiation shielding material having an abundant flexibility. Constitution: A mat consisting of a lead or lead alloy fibrous material is covered with a cloth, and the two are made integral by sewing in a kilted fashion by using a yarn. Thereafter, the system is covered with a gas-tight film or sheet. The shielding material obtained in this way has, in addition to the above merits, advantages in that (1) it is free from restoration due to elasticity so that it can readily seal contaminants, (2) it can be used in a state consisting of a number of overlapped layers, (3) it fits the shoulder well and is readily portable and (4) it permits attachment of fasteners or the like. (Ikeda, J.)

  15. Hybrid Magnetic Shielding

    Science.gov (United States)

    Royal, Kevin; Crawford, Christopher; Mullins, Andrew; Porter, Greg; Blanton, Hunter; Johnstone, Connor; Kistler, Ben; Olivera, Daniela

    2017-09-01

    The search for the electric dipole moment of the neutron requires the ambient magnetic field to be on the pT scale which is accomplished with large magnetic shielding rooms. These rooms are fitted with large mu-metal sheets to allow for passive cancellation of background magnetic fields. Active shielding technology cannot uniformly cancel background magnetic fields. These issues can be remedied by combining the methods into a hybrid system. The design used is composed of panels that have an active layer of cancellation between two sheets of mu-metal. The panels form a cube and draw in magnetic fields perpendicular to the surface which can then be reduced using active shielding. This work is supported by the Department of Energy under Contract DE-SC0008107.

  16. Reactor head shielding apparatus

    International Nuclear Information System (INIS)

    Schukei, G.E.; Roebelen, G.J.

    1992-01-01

    This patent describes a nuclear reactor head shielding apparatus for mounting on spaced reactor head lifting members radially inwardly of the head bolts. It comprises a frame of sections for mounting on the lifting members and extending around the top central area of the head, mounting means for so mounting the frame sections, including downwardly projecting members on the frame sections and complementary upwardly open recessed members for fastening to the lifting members for receiving the downwardly projecting members when the frame sections are lowered thereto with lead shielding supported thereby on means for hanging lead shielding on the frame to minimize radiation exposure or personnel working with the head bolts or in the vicinity thereof

  17. Improved Monte Carlo modelling of multi-energy a-rays penetration through thick stratified shielding slabs

    International Nuclear Information System (INIS)

    Bakos, G.C.

    2001-01-01

    This paper deals with the application of Monte Carlo method for the calculation of dose build up factor of, mixed 1.37 and 2.75 MeV, a-rays penetration through stratified shielding slabs. Six double layer shielding slabs namely, 12 A l+Fe, 12 A l+Pb, 6 F e+Al, 6 F e+Pb, 4 P b+Al, 4 P b+Fe were examined. Furthermore, experimental and theoretical results are also presented. The experimental results were taken from the experimental facility installed at the Universities Research reactor Center (Risley, UK). Activated Na2SO3 solution provided a uniform Na-24 disc source of a-rays at both energies (1.37 and 2.75 MeV) with equal intensity. The theoretical results were calculated using the Bowman and Trubey formula. This formula takes into account an exponentially decaying function of the shield thickness (in mfp) to the end point of the multi-layer slab. The experimental and theoretical results were used to evaluate the simulation results produced from a Monte Carlo program (DUTMONCA code) which was developed in Democritus University of Thrace (Xanthi, Greece). The DUTMONCA code was written in Pascal language and run on an Intel PIII-800 microprocessor. The developed code (which is an improved version of an existing Monte Carlo program) has the ability to produce good results for thick shielding slabs overcoming the problems encountered in older version program. The simulation results are compared with experimental and theoretical results. Good agreement can be observed, even for thick layer shielding slabs, although there are some wayward experimental values which are due to sources of error associated with the experimental procedure

  18. Guide to verification and validation of the SCALE-4 radiation shielding software

    International Nuclear Information System (INIS)

    Broadhead, B.L.; Emmett, M.B.; Tang, J.S.

    1996-12-01

    Whenever a decision is made to newly install the SCALE radiation shielding software on a computer system, the user should run a set of verification and validation (V ampersand V) test cases to demonstrate that the software is properly installed and functioning correctly. This report is intended to serve as a guide for this V ampersand V in that it specifies test cases to run and gives expected results. The report describes the V ampersand V that has been performed for the radiation shielding software in a version of SCALE-4. This report provides documentation of sample problems which are recommended for use in the V ampersand V of the SCALE-4 system for all releases. The results reported in this document are from the SCALE-4.2P version which was run on an IBM RS/6000 work-station. These results verify that the SCALE-4 radiation shielding software has been correctly installed and is functioning properly. A set of problems for use by other shielding codes (e.g., MCNP, TWOTRAN, MORSE) performing similar V ampersand V are discussed. A validation has been performed for XSDRNPM and MORSE-SGC6 utilizing SASI and SAS4 shielding sequences and the SCALE 27-18 group (27N-18COUPLE) cross-section library for typical nuclear reactor spent fuel sources and a variety of transport package geometries. The experimental models used for the validation were taken from two previous applications of the SASI and SAS4 methods

  19. Guide to verification and validation of the SCALE-4 radiation shielding software

    Energy Technology Data Exchange (ETDEWEB)

    Broadhead, B.L.; Emmett, M.B.; Tang, J.S.

    1996-12-01

    Whenever a decision is made to newly install the SCALE radiation shielding software on a computer system, the user should run a set of verification and validation (V&V) test cases to demonstrate that the software is properly installed and functioning correctly. This report is intended to serve as a guide for this V&V in that it specifies test cases to run and gives expected results. The report describes the V&V that has been performed for the radiation shielding software in a version of SCALE-4. This report provides documentation of sample problems which are recommended for use in the V&V of the SCALE-4 system for all releases. The results reported in this document are from the SCALE-4.2P version which was run on an IBM RS/6000 work-station. These results verify that the SCALE-4 radiation shielding software has been correctly installed and is functioning properly. A set of problems for use by other shielding codes (e.g., MCNP, TWOTRAN, MORSE) performing similar V&V are discussed. A validation has been performed for XSDRNPM and MORSE-SGC6 utilizing SASI and SAS4 shielding sequences and the SCALE 27-18 group (27N-18COUPLE) cross-section library for typical nuclear reactor spent fuel sources and a variety of transport package geometries. The experimental models used for the validation were taken from two previous applications of the SASI and SAS4 methods.

  20. Radiation shielding bricks

    International Nuclear Information System (INIS)

    Crowe, G.J.W.

    1983-01-01

    A radiation shielding brick for use in building dry walls to form radiation proof enclosures and other structures is described. It is square in shape and comprises a sandwich of an inner layer of lead or similar shielding material between outer layers of plastics material, for structural stability. The ability to mechanically interlock adjacent bricks is provided by shaping the edges as cooperating external and internal V-sections. Relatively leak-free joints are ensured by enlarging the width of the inner layer in the edge region. (author)

  1. Gonad Shielding for Patients Undergoing Conventional Radiological Examinations: Is There Cause for Concern?

    Directory of Open Access Journals (Sweden)

    Karami

    2016-04-01

    Full Text Available Background Gonad shielding is one of the fundamental methods by which to protect reproductive organs in patients undergoing conventional radiological examinations. A lack of or inadequate shielding of the gonads may increase the exposure of these organs and result in malignancies future generations. Objectives The aim of this study is to investigate the prevalence of gonad shielding in patients undergoing conventional radiological examinations and the availability of gonad shields and gonad shielding protocols in radiology departments. Materials and Methods A retrospective, observational cross-sectional study on the application of gonad shielding, the availability of gonad shields and the existence of gonad shielding protocols in radiology departments was performed in five different hospitals in Ahvaz, Iran. Results The highest application of gonad shielding was 6.6% for the pediatric hospital. The prevalence of gonad shielding was less than 0.2%. In 64.3% of the radiography rooms, at least one flat-contact gonad shield of a large size was available. Only large-sized gonad shields were available. Curved-contact and shadow gonad shields did not exist. Gonad shielding protocols were not existence in any of the fourteen radiography rooms investigated. Conclusions Comprehensive protection programs with on-the-job training courses for staff members are strongly recommended, as well as, the provision of radiological shields and gonad shielding protocols in radiology departments to reduce the patient’s radiation dose during radiological examinations.

  2. [The model of radiation shielding of the service module of the International space station].

    Science.gov (United States)

    Kolomenskiĭ, A V; Kuznetsov, V G; Laĭko, Iu A; Bengin, V V; Shurshakov, V A

    2001-01-01

    Compared and contrasted were models of radiation shielding of habitable compartments of the basal Mir module that had been used to calculate crew absorbed doses from space radiation. Developed was a model of the ISS Service module radiation shielding. It was stated that there is a good agreement between experimental shielding function and the one calculated from this model.

  3. Metal droplet erosion and shielding plasma layer under plasma flows typical of transient processes in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Martynenko, Yu. V., E-mail: Martynenko-YV@nrcki.ru [National Research Nuclear University “MEPhI” (Russian Federation)

    2017-03-15

    It is shown that the shielding plasma layer and metal droplet erosion in tokamaks are closely interrelated, because shielding plasma forms from the evaporated metal droplets, while droplet erosion is caused by the shielding plasma flow over the melted metal surface. Analysis of experimental data and theoretical models of these processes is presented.

  4. NMR shielding and spin–rotation constants of {sup 175}LuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I) molecules

    Energy Technology Data Exchange (ETDEWEB)

    Demissie, Taye B. [Centre for Theoretical and Computational Chemistry Department of Chemistry, UiT – The Arctic University of Norway, N-9037 Tromsø (Norway)

    2015-12-31

    This presentation demonstrates the relativistic effects on the spin-rotation constants, absolute nuclear magnetic resonance (NMR) shielding constants and shielding spans of {sup 175}LuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I) molecules. The results are obtained from calculations performed using density functional theory (non-relativistic and four-component relativistic) and coupled-cluster calculations. The spin-rotation constants are compared with available experimental values. In most of the molecules studied, relativistic effects make an order of magnitude difference on the NMR absolute shielding constants.

  5. DoSSiER: Database of Scientific Simulation and Experimental Results

    CERN Document Server

    Wenzel, Hans; Genser, Krzysztof; Elvira, Daniel; Pokorski, Witold; Carminati, Federico; Konstantinov, Dmitri; Ribon, Alberto; Folger, Gunter; Dotti, Andrea

    2017-01-01

    The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientific Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER can be easily accessed via a web application. In addition, a web service allows for programmatic access to the repository to extract records in json or xml exchange formats. In this article, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

  6. Magnetic shield effect simulation of superconducting film shield covering directly coupled HTS dc-SQUID magnetometer

    International Nuclear Information System (INIS)

    Terauchi, N.; Noguchi, S.; Igarashi, H.

    2011-01-01

    A superconducting film shield over a SQUID ring improves the robustness of the SQUID with respect to magnetic noise. Supercurrent in the SQUID magnetometer and the superconducting film shield were simulated. The superconducting film shield reduces the influence of the external magnetic field on the SQUID ring. An HTS SQUID is a high sensitive magnetic sensor. In recent years, the HTS SQUID is widely used in various applications. In some applications, high robustness with respect to magnetic noise is required to realize stable operation at outside of a magnetic shielding room. The target of this paper is a directly coupled HTS dc-SQUID magnetometer. To enhance the robustness of the SQUID magnetometer, use of a superconducting thin film shield has been proposed. The magnetic field directly penetrating the SQUID ring causes the change of the critical current of Josephson junction, and then the SQUID magnetometer transitions into inoperative state. In order to confirm the magnetic shield effect of the superconducting film shield, electromagnetic field simulation with 3D edge finite element method was performed. To simulate the high temperature superconductor, E-J characteristics and c-axis anisotropy are considered. To evaluate the effect of the superconducting film shield, an external magnetic field which is supposed to be a magnetic noise is applied. From the simulation results, the time transition of the magnetic flux penetrating the SQUID ring is investigated and the effect of the superconducting film shield is confirmed. The amplitude of the magnetic flux penetrating the SQUID ring can be reduced to about one-sixth since the superconducting film shield prevents the magnetic noise from directly penetrating the SQUID ring.

  7. Hybrid Active-Passive Radiation Shielding System

    Data.gov (United States)

    National Aeronautics and Space Administration — A radiation shielding system is proposed that integrates active magnetic fields with passive shielding materials. The objective is to increase the shielding...

  8. Accelerator shielding experts meet at CERN

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Fifteen years after its first CERN edition, the Shielding Aspects of Accelerator, Targets and Irradiation Facility (SATIF) conference was held again here from 2-4 June. Now at its 10th edition, SATIF10 brought together experts from all over the world to discuss issues related to the shielding techniques. They set out the scene for an improved collaboration and discussed novel shielding solutions.   This was the most attended meeting of the series with more than 65 participants from 34 institutions and 14 countries. “We welcomed experts from many different laboratories around the world. We come from different contexts but we face similar problems. In this year’s session, among other things, we discussed ways for improving the effectiveness of calculations versus real data, as well as experimental solutions to investigate the damage that radiation produces on various materials and the electronics”, says Marco Silari, Chair of the conference and member of the DGS/RP gro...

  9. An attenuation Layer for Electromagnetic Shielding in X- Band Frequency

    Directory of Open Access Journals (Sweden)

    Vida Zaroushani

    2015-06-01

    Full Text Available Uncontrolled exposure to X-band frequency leads to health damage. One of the principles of radiation protection is shielding. But, conventional shielding materials have disadvantages. Therefore, studies of novel materials, as an alternative to conventional shielding materials, are required to obtain new electromagnetic shielding material. Therefore, this study investigated the electromagnetic shielding of two component epoxy thermosetting resin for the X - band frequency with workplace approach. Two components of epoxy resin mixed according to manufacturing instruction with the weight ratio that was 100:10 .Epoxy plates fabricated in three different thicknesses (2, 4 and 6mm and shielding effectiveness measured by Vector Network Analyzer. Then, shielding effectiveness measured by the scattering parameters.The results showed that 6mm thickness of epoxy had the highest and 2mm had the lowest average of shielding effectiveness in X-band frequency that is 4.48 and 1.9 dB, respectively. Also, shielding effectiveness increased by increasing the thickness. But this increasing is useful up to 4mm. Percentage shielding effectiveness of attenuation for 6, 4 and 2mm thicknesses is 64.35%, 63.31% and 35.40%. Also, attenuation values for 4mm and 6mm thicknesses at 8.53 GHz and 8.52 GHz frequency are 77.15% and 82.95%, respectively, and can be used as favourite shields for the above frequency. 4mm-Epoxy is a suitable candidate for shielding application in X-band frequency range but, in the lower section, 6mm thickness is recommended. Finely, the shielding matrix can be used for selecting the proper thickness for electromagnetic shielding in X- Band frequency.

  10. Shielding methods development in the United States

    International Nuclear Information System (INIS)

    Mynatt, F.R.

    1977-01-01

    A generalized shielding methodology has been developed in the U.S.A. that is adaptable to the shielding analyses of all reactor types. Thus far used primarily for liquid-metal fast breeder reactors, the methodology includes several component activities: (1) developing methods for calculating radiation transport through reactor-shield systems; (2) processing cross-section libraries; (3) performing design calculations for specific systems; (4) performing and analyzing pertinent integral experiments; (5) performing sensitivity studies on both the design calculations and the experimental analyses; and, finally, (6) calculating shield design parameters and their uncertainties. The criteria for the methodology are a 5 to 10 percent accuracy for responses at locations near the core and a factor of 2 accuracy for responses at distant locations. The methodology has been successfully adapted to most in-vessel and ex-vessel problems encountered in the shield analyses of the Fast Flux Test Facility and the Fast Flux Test Facility and the Clinch River Breeder Reactor; however, improved techniques are needed for calculating regions in which radiation streaming is dominant. Areas of the methodology in which significant progress has recently been made are those involving the development of cross-section libraries, sensitivity analysis methods, and transport codes

  11. Evaluation of bulk shield for the JHP facilities

    International Nuclear Information System (INIS)

    Uwamino, Yoshitomo; Shibata, Tokushi

    1991-01-01

    In the Japanese Hadron Project (JHP), a 1-GeV 200-μA proton beam will be handled, and the radiation shield of the facility will be very massive concrete and iron lump. Since the constructing cost is strongly affected by the shielding design, the design must be severely performed. The neutron yield in thin targets and a copper beam dump was calculated by the HETC-KFA-2 Monte Carlo code. For the evaluation of the calculational accuracy, the calculational results were compared with the experimental data by Cierjacks and Raupp. The calculated result of heavy element agreed well with the experiment at a low energy region, E n n >100 MeV) of 90 deg close to the calculated one of about 60 deg in the absolute value. The high energy neutron transport in a 5-m-thick iron slab and in an 8-m-thick ordinary concrete slab was calculated with the HETC code and also with the discrete ordinates transport code, ANISN. In the ANISN calculation, the DLC-87/HILO and the DLC-128/LAHIMAC group cross sections were used. The ANISN calculation with the LAHIMAC cross sections gave strong underestimation compared with the HETC calculation. The difference of the shielding lengths calculated by the HETC code and by the ANISN code used with the HILO cross sections was smaller than 6% for the both iron and concrete cases. (author)

  12. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop.

  13. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

    International Nuclear Information System (INIS)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop

  14. ANALISIS KESELAMATAN TERMOHIDROLIK BULK SHIELDING REAKTOR KARTINI

    Directory of Open Access Journals (Sweden)

    Azizul Khakim

    2015-10-01

    spent fuels cooling with natural convection mode. The calculations results concluded that natural convection cooling mode can adequately cools down the decay heat without significant increase in fuel temperatur. Keywords: bulk shielding, spent fuels, natural convection, PARET.

  15. Potential of Nanocellulose Composite for Electromagnetic Shielding

    Directory of Open Access Journals (Sweden)

    Nabila Yah Nurul Fatihah

    2017-01-01

    Full Text Available Nowadays, most people rely on the electronic devices for work, communicating with friends and family, school and personal enjoyment. As a result, more new equipment or devices operates in higher frequency were rapidly developed to accommodate the consumers need. However, the demand of using wireless technology and higher frequency in new devices also brings the need to shield the unwanted electromagnetic signals from those devices for both proper operation and human health concerns. This paper highlights the potential of nanocellulose for electromagnetic shielding using the organic environmental nanocellulose composite materials. In addition, the theory of electromagnetic shielding and recent development of green and organic material in electromagnetic shielding application has also been reviewed in this paper. The use of the natural fibers which is nanocelllose instead of traditional reinforcement materials provides several advantages including the natural fibers are renewable, abundant and low cost. Furthermore, added with other advantages such as lightweight and high electromagnetic shielding ability, nanocellulose has a great potential as an alternative material for electromagnetic shielding application.

  16. Radiation shielding cloth

    International Nuclear Information System (INIS)

    Ijiri, Yasuo; Fujinuma, Tadashi; Tamura, Shoji.

    1989-01-01

    Radiation shielding cloth having radiation shielding layers comprising a composition of inorganic powder of high specific gravity and rubber are excellentin flexibility and comfortable to put on. However, since they are heavy in the weight, operators are tired upon putting them for a long time. In view of the above, the radiation ray shielding layers are prepared by calendering sheets obtained by preliminary molding of the composition to set the variation of the thickness within a range of +15% to -0% of prescribed thickness. Since the composition of inorganic powder at high specific gravity and rubber used for radiation ray shielding comprises a great amount of inorganic powder at high specific gravity blended therein, it is generally poor in fabricability. Therefor, it is difficult to attain fine control for the sheet thickness by merely molding a composition block at once. Then, the composition is at first preliminarily molded into a sheet-like shape which is somewhat thickener than the final thickness and then finished by calendering, by which the thickness can be reduced in average as compared with conventional products while keeping the prescribed thickness and reducing the weight reduce by so much. (N.H.)

  17. Electrostatic shielding of transformers

    Energy Technology Data Exchange (ETDEWEB)

    De Leon, Francisco

    2017-11-28

    Toroidal transformers are currently used only in low-voltage applications. There is no published experience for toroidal transformer design at distribution-level voltages. Toroidal transformers are provided with electrostatic shielding to make possible high voltage applications and withstand the impulse test.

  18. Penetration portion shielding structure

    International Nuclear Information System (INIS)

    Hayashi, Katsumi; Narita, Hitoshi; Handa, Hiroyuki; Takeuchi, Jun; Tozuka, Fumio.

    1994-01-01

    Openings of a plurality of shieldings for penetration members are aligned to each other, and penetration members are inserted from the openings. Then, the openings of the plurality of shielding members are slightly displaced with each other to make the penetration portions into a helical configuration, so that leakage of radiation is reduced. Upon removal of the members, reverse operation is conducted. When a flowable shielding material is used, the penetration portions are constituted with two plates having previously formed openings and pipes for connecting the openings with each other and a vessel covering the entire of them. After passing the penetration members such as a cable, the relative position of the two plates is changed by twisting, to form a helical configuration which reduces radiation leakage. Since they are bent into the helical configuration, shielding performance is extremely improved compared with a case that radiation leakage is caused from an opening of a straight pipe. In addition, since they can be returned to straight pipes, attachment, detachment and maintenance can be conducted easily. (N.H.)

  19. Radiation shielding glass

    International Nuclear Information System (INIS)

    Kido, Kazuhiro; Ueda, Hajime.

    1997-01-01

    It was found that a glass composition comprising, as essential ingredients, SiO 2 , PbO, Gd 2 O 3 and alkali metal oxides can provide a shielding performance against electromagnetic waves, charged particles and neutrons. The present invention provides radiation shielding glass containing at least from 16 to 46wt% of SiO 2 , from 47 to 75wt% of PbO, from 1 to 10wt% of Gd 2 O 3 , from 0 to 3wt% of Li 2 O, from 0 to 7wt% of Na 2 O, from 0 to 7wt% of K 2 O provided that Li 2 O + Na 2 O + K 2 O is from 1 to 10wt%, B 2 O 3 is from 0 to 10wt%, CeO 2 is from 0 to 3wt%, As 2 O 3 is from 0 to 1wt% and Sb 2 O 3 is from 0 to 1wt%. Since the glass can shield electromagnetic waves, charged particles and neutrons simultaneously, radiation shielding windows can be designed and manufactured at a reduced thickness and by less constitutional numbers in a circumstance where they are present altogether. (T.M.)

  20. High energy nucleus-nucleus collisions at CERN: Signatures, physical observables and experimental results

    International Nuclear Information System (INIS)

    Harris, J.W.

    1988-02-01

    Experimental results on high energy nucleus-nucleus collisions have become available with the recent experiments at CERN utilizing 200 GeV/n oxygen and sulfur beams. Physics motivations for these experiments are presented: a description of predicted signatures for possible formation of a quark-gluon plasma and physical observables that are expected to provide important information for understanding the dynamics of these collisions. A presentation will be made of some of the first experimental results to emerge from this new field. 28 refs., 9 figs

  1. Mixed-mode chaotic circuit with Wien-bridge configuration: The results of experimental verification

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Recai [Erciyes University, Department of Electronic Engineering, 38039 Kayseri (Turkey)]. E-mail: kilic@erciyes.edu.tr

    2007-05-15

    In this paper, we deal with the experimentally implementation of inductorless Wien bridge-based mixed-mode chaotic circuit (MMCC) which is capable to exhibit both linear and nonlinear oscillations. The results of experimental implementation agree with the results of theoretical and computer simulation presented in literature. Since the proposed implementation of MMCC circuit uses different design blocks such as Wien bridge-based autonomous circuit part, CFOA (current feedback operational amplifier)-based floating inductance simulator, CFOA-based Chua's diode and switching mechanism, it offers very versatile chaotic circuit model for studying autonomous and nonautonomous chaotic dynamics.

  2. Mixed-mode chaotic circuit with Wien-bridge configuration: The results of experimental verification

    International Nuclear Information System (INIS)

    Kilic, Recai

    2007-01-01

    In this paper, we deal with the experimentally implementation of inductorless Wien bridge-based mixed-mode chaotic circuit (MMCC) which is capable to exhibit both linear and nonlinear oscillations. The results of experimental implementation agree with the results of theoretical and computer simulation presented in literature. Since the proposed implementation of MMCC circuit uses different design blocks such as Wien bridge-based autonomous circuit part, CFOA (current feedback operational amplifier)-based floating inductance simulator, CFOA-based Chua's diode and switching mechanism, it offers very versatile chaotic circuit model for studying autonomous and nonautonomous chaotic dynamics

  3. Experimental results for characterization of a tapered plastic optical fiber sensor based on SPR

    Science.gov (United States)

    Cennamo, N.; Galatus, R.; Zeni, L.

    2015-05-01

    The experimental results obtained with two different Plastic Optical Fiber (POF) geometries, tapered and not-tapered, for a sensor based on Surface Plasmon Resonance (SPR) are presented. SPR is used for determining the refractive index variations at the interface between a gold layer and a dielectric medium (aqueous medium). In this work SPR sensors in POF configurations, useful for bio-sensing applications, have been realized for the optimization of the sensitivity and experimentally tested. The results show as the sensitivity increases with the tapered POF configuration, when the refractive index of aqueous medium increases.

  4. LOFT shield tank steady state temperatures with addition of gamma and neutron shielding

    International Nuclear Information System (INIS)

    Kyllingstad, G.

    1977-01-01

    The effect of introducing a neutron and gamma shield into the annulus between the reactor vessel and the shield tank is analyzed. This addition has been proposed in order to intercept neutron streaming up the annulus during nuclear operations. Its installation will require removal of approximately 20- 1 / 2 inches of stainless steel foil insulation at the top of the annulus. The resulting conduction path is believed to result in increased water temperatures within the shield tank, possibly beyond the 150 0 F limit, and/or cooling of the reactor vessel nozzles such that adverse thermal stresses would be generated. A two dimensional thermal analysis using the finite element code COUPLE/MOD2 was done for the shield tank system illustrated in the figure (1). The reactor was assumed to be at full power, 55 MW (th), with a loop flow rate of 2.15 x 10 6 lbm/hr (268.4 kg/s) at 2250 psi (15.51 MPa). Calculations indicate a steady state shield tank water temperature of 140 0 F (60 0 C). This is below the 150 0 F (65.56 0 C) limit. Also, no significant changes in thermal gradients within the nozzle or reactor vessel wall are generated. A spacer between the gamma shield and the shield tank is recommended, however, in order to ensure free air circulation through the annulus

  5. Gonad shielding in diagnostic radiology

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The use of gonad shielding is an important radiation protection technique, intended to reduce unnecessary x-ray exposure of the gonads of patients from diagnostic x-ray procedures. The types of gonad shields in use are discussed as are the types of diagnostic examinations that should include gonad shielding. It was found that when properly used, most shields provided substantial gonad dose reductions

  6. Radiation Shielding of Lunar Regolith/Polyethylene Composites and Lunar Regolith/Water Mixtures

    Science.gov (United States)

    Johnson, Quincy F.; Gersey, Brad; Wilkins, Richard; Zhou, Jianren

    2011-01-01

    Space radiation is a complex mixed field of ionizing radiation that can pose hazardous risks to sophisticated electronics and humans. Mission planning for lunar exploration and long duration habitat construction will face tremendous challenges of shielding against various types of space radiation in an attempt to minimize the detrimental effects it may have on materials, electronics, and humans. In late 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) discovered that water content in lunar regolith found in certain areas on the moon can be up to 5.6 +/-2.8 weight percent (wt%) [A. Colaprete, et. al., Science, Vol. 330, 463 (2010). ]. In this work, shielding studies were performed utilizing ultra high molecular weight polyethylene (UHMWPE) and aluminum, both being standard space shielding materials, simulated lunar regolith/ polyethylene composites, and simulated lunar regolith mixed with UHMWPE particles and water. Based on the LCROSS findings, radiation shielding experiments were conducted to test for shielding efficiency of regolith/UHMWPE/water mixtures with various percentages of water to compare relative shielding characteristics of these materials. One set of radiation studies were performed using the proton synchrotron at the Loma Linda Medical University where high energy protons similar to those found on the surface of the moon can be generated. A similar experimental protocol was also used at a high energy spalation neutron source at Los Alamos Neutron Science Center (LANSCE). These experiments studied the shielding efficiency against secondary neutrons, another major component of space radiation field. In both the proton and neutron studies, shielding efficiency was determined by utilizing a tissue equivalent proportional counter (TEPC) behind various thicknesses of shielding composite panels or mixture materials. Preliminary results from these studies indicated that adding 2 wt% water to regolith particles could increase shielding of

  7. The relevance of animal experimental results for the assessment of radiation genetic risks in man

    International Nuclear Information System (INIS)

    Stephan, G.

    1981-01-01

    No suitable data are available from man for the quantitative assessment of genetic radiation risk. Therefore, the results from experiments on animals must be utilized. Two hypotheses are presented here in drawing analogical conclusions from one species to another. Although the extrapolation of results from animal experiments remains an open question, the use of experimental results from mice seems to be justified for an assessment of the genetic radiation risk in man. (orig.) [de

  8. Thermal-hydraulically controlled blowdown tests in the experimental facility COSIMA to study PWR fuel behavior: experimental and theoretical results

    International Nuclear Information System (INIS)

    Class, G.; Hain, K.; Meyder, R.

    1978-01-01

    The fuel behavior in the blow-down phase of a LOCA is of importance for fuel rods with high internal pressure and high rod power, because of the effects on clad failure of the small cladding deformations occurring. The operating results of the COSIMA facility show that, on the basis of the new developments for measuring technique and fuel rod simulators performed, reactor relevant blow-down performances can be conducted in a controlled and reproduceable manner. The mechanical and thermal-hydraulic states occurring in the test bed may be subject to computational checking. This permits on one hand to improve the computing models and on the other yields a confirmation of the high state of development of the available computer codes. Therefore it appears that, with the results from COSIMA and the associated theoretical work in the field of the blow-down process, difficult to treat experimentally, an essential contribution to verifying the models for accident calculations is given. The work scheduled for the next about 1 1/2 years will serve to further support the rather preliminary results and to extend the range of then application. (orig.) [de

  9. Shielding experiments for accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2000-06-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  10. Shielding experiments for accelerator facilities

    International Nuclear Information System (INIS)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio

    2000-01-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  11. Quantum Cavity Optomechanics with Phononic Bandgap Shielded Silicon Nitride Membranes

    DEFF Research Database (Denmark)

    Nielsen, William Hvidtfelt Padkær

    two highly reflective mirrors, all of which are embedded in a helium flowcryostat. In order to reach truly quantum territory, severe shielding of the membranefrom the environment is required, as well as meticulous concern for auxiliarysources of noise, both from the laser and mirrors used.The purpose...... of this thesis is to document the development of the experimentfrom its initial stages to its final quantum enabled incarnation, as well as to providethe necessary theoretical machinery to interpret the experimental results. A strongemphasis is placed on the unique challenges posed by our unique monolithic...

  12. Female gonadal shielding with automatic exposure control increases radiation risks

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Summer L.; Zhu, Xiaowei [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); Magill, Dennise; Felice, Marc A. [University of Pennsylvania, Environmental Health and Radiation Safety, Philadelphia, PA (United States); Xiao, Rui [University of Pennsylvania, Department of Biostatistics and Epidemiology, Philadelphia, PA (United States); Ali, Sayed [Temple University Hospital, Department of Radiology, Philadelphia, PA (United States)

    2018-02-15

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation. (orig.)

  13. Female gonadal shielding with automatic exposure control increases radiation risks

    International Nuclear Information System (INIS)

    Kaplan, Summer L.; Zhu, Xiaowei; Magill, Dennise; Felice, Marc A.; Xiao, Rui; Ali, Sayed

    2018-01-01

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation. (orig.)

  14. Female gonadal shielding with automatic exposure control increases radiation risks.

    Science.gov (United States)

    Kaplan, Summer L; Magill, Dennise; Felice, Marc A; Xiao, Rui; Ali, Sayed; Zhu, Xiaowei

    2018-02-01

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation.

  15. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    International Nuclear Information System (INIS)

    Marschner, Karel; Musil, Stanislav; Dědina, Jiří

    2015-01-01

    A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH 4 in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l −1 and 1.0 ng l −1 , respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l −1

  16. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Marschner, Karel, E-mail: karel.marschner@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 8, 128 43 Prague (Czech Republic); Musil, Stanislav; Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

    2015-07-01

    A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH{sub 4} in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l{sup −1} and 1.0 ng l{sup −1}, respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l{sup −1}.

  17. Experimental results on elongation control using dynamic input allocation at FTU

    International Nuclear Information System (INIS)

    Varano, G.; Boncagni, L.; Galeani, S.; Granucci, G.; Vitale, V.; Zaccarian, L.

    2011-01-01

    We report on the experimental results related to a recently proposed control scheme for the regulation of plasma elongation using the poloidal field coils available at FTU, already used for the horizontal position control. The proposed technique allows to realize elongation regulation as a secondary task using the same poloidal coils.

  18. Experimental validation of the twins prediction program for rolling noise. Pt.2: results

    NARCIS (Netherlands)

    Thompson, D.J.; Fodiman, P.; Mahé, H.

    1996-01-01

    Two extensive measurement campaigns have been carried out to validate the TWINS prediction program for rolling noise, as described in part 1 of this paper. This second part presents the experimental results of vibration and noise during train pass-bys and compares them with predictions from the

  19. Alignment procedure for the VIRGO interferometer: experimental results from the Frascati Prototype

    International Nuclear Information System (INIS)

    Babusci, D.; Giordano, G.; Matone, G.; Matone, L.; Sannibale, V.

    1996-07-01

    A small fixed-mirrors Michelson interferometer has been suggested for VIRGO. The experimental results are excellent and fully confirm the adequacy of the method. The minimum angular misalignment that can be detected in the present set-up is 10 nrad

  20. Experimental results of the effective water head in downcomer during reflood phase of a PWR LOCA

    International Nuclear Information System (INIS)

    Sudo, Yukio; Murao, Yoshio; Akimoto, Hajime

    1980-08-01

    The results and analysis of an experiment for the effective water head in downcomer with 50mm gap size are described. The main objective of the experiment was to clarify the effect of gap size on reflooding in a PWR LOCA. The effective water head in downcomer is the driving force for feeding emergency coolant into the core during reflood phase of a PWR LOCA. Discussions presented here follow those of a previous report in which experimental results and analysis were described for the case of 200mm gap size. Experimental Conditions were: Initial Wall Temperature = 200 -- 300 0 C, Back Pressure = 1 atm., Coolant Temperature = 71 -- 100 0 C, Extraction Water Velocity = 0 -- 2 cm/s, Gap Size = 50 mm. The effective water head history obtained in the experiment was compared with those predicted with Sudo's void fraction correlation. In the prediction, heat input to coolant was calculated from the response of measured wall temperature with heat condition analysis. The experimental results and analysis reveals that: (1) The effects of the gap size and initial wall temperature are evident, (2) The effect of extraction water velocity is negligible, and (3) The predicted history of effective water head is in good agreement with the experimental results except during the transient period in which the effective water head is descreasing. (author)

  1. F.E. analysis of seismic isolators: comparison with experimental results

    International Nuclear Information System (INIS)

    Fuller, K.N.G.; Gough, J.; Ahmadi, H.R.

    1998-01-01

    Analysis of seismic isolators is performed by the ABAQUS code. The force deformation behaviour of a circular layer of rubber bonded to rigid surface was investigated. This model is chosen because of its simplicity and the relatively short processing time required. A 3-dimensional model was used for finite element calculations. Comparison of calculated values with experimental results is shown

  2. Tribology of skin : review and analysis of experimental results for the friction coefficient of human skin

    NARCIS (Netherlands)

    Derler, S.; Gerhardt, L.C.

    2012-01-01

    In this review, we discuss the current knowledge on the tribology of human skin and present an analysis of the available experimental results for skin-friction coefficients. Starting with an overview on the factors influencing the friction behaviour of skin, we discuss the up-to-date existing

  3. Nuclear magnetic resonance. Present results and its application to renal pathology. Experimental study of hydronephrosis

    International Nuclear Information System (INIS)

    Bertrand, P.

    1987-01-01

    Results of proton nuclear magnetic resonance imaging and relaxation time measurement of experimental hydronephrosis in mice are presented. The study is preceded by a description of the physical principles underlying the phenomenon of nuclear magnetic resonance and of its biomedical applications and with a review of the clinical use of NMR imaging in renal pathology [fr

  4. Results of experimental research of the modes of short circuit in a traction network

    Directory of Open Access Journals (Sweden)

    P.Ye. Mykhalichenko

    2012-08-01

    Full Text Available In the article the results, namely oscillograms of the transitional feeder electric values obtained by the experimental tests of the short circuit modes in case of setting off different types of substation fast-acting switches are presented. The experiments were conducted on the operating electrified track sections of the Prydniprovs’ka Railway.

  5. Shear or bending? Experimental results on large t-shaped prestressed conrete beams

    NARCIS (Netherlands)

    Ensink, S.W.H.; Van der Veen, C.; De Boer, A.

    2015-01-01

    Experimental results of four shear tests on two large prestressed concrete beams are compared to nonlinear analysis and design code calculations. The beams have a length of 12 m and a depth of 1.3 m and are reinforced with stirrups and pre-tensioning. The four tests consist of a single point load at

  6. Assessing incentive contracts for reducing residential electricity consumption: new experimental methods for new results

    International Nuclear Information System (INIS)

    Frachet, Laure

    2013-01-01

    Facing economic, political and environmental stakes, electricity providers are nowadays developing incentive tools, in order to reduce consumer's demand, particularly during peak demand periods. For residential customers, these tools can be tariffs (dynamic pricing of time-of-use tariffs), or informative devices or services (feedbacks on historical or real-time consumption, given on various media). They might go along with automation systems that can help cutting of some electric devices when needed. In order to evaluate the capacity of these settings among their customers, electricity utilities are developing quite a few studies, which are mainly field experiment often called pilots. During these pilots, demand response tools are implemented on a population sample. These long and expensive studies lid to quantitative and qualitative analysis. We have compiled about 40 of them and extract from this survey some generalizable teachings. We have shown what these results were and highlighted pilot programs' methodological limits. In order to propose a substitute to these heavy experimentations, we assessed the capacity or experimental economics. This relatively new discipline's objective is to evaluation the efficiency of institutions, like markets, but also to study what animate economic agents' behaviour, e.g. preferences, beliefs, cognitive biases, willingness to pay... We were also able to elaborate an experimental protocol dedicated to the evaluation of some demand response contracts' acceptability. The results collected during 14 experimental sessions gave us some innovative clues and insight on these contracts acceptability. But, beyond these results, we have demonstrated that even if experimental economics can't obviously be a substitute for field experiments, it can represent an interesting exploratory methodology. To sum up the experimental economics can take part of residential customers' behaviour understanding, performing

  7. Shielding design for positron emission tomography facility

    International Nuclear Information System (INIS)

    Abdallah, I.I.

    2007-01-01

    With the recent advent of readily available tracer isotopes, there has been marked increase in the number of hospital-based and free-standing positron emission tomography (PET) clinics. PET facilities employ relatively large activities of high-energy photon emitting isotopes, which can be dangerous to the health of humans and animals. This coupled with the current dose limits for radiation worker and members of the public can result in shielding requirements. This research contributes to the calculation of the appropriate shielding to keep the level of radiation within an acceptable recommended limit. Two different methods were used including measurements made at selected points of an operating PET facility and computer simulations by using Monte Carlo Transport Code. The measurements mainly concerned the radiation exposure at different points around facility using the survey meter detectors and Thermoluminescent Dosimeters (TLD). Then the set of manual calculation procedures were used to estimate the shielding requirements for a newly built PEF facility. The results from the measurement and the computer simulation were compared to the results obtained from the set manual calculation procedure. In general, the estimated weekly dose at the points of interest is lower than the regulatory limits for the little company of Mary Hospital. Furthermore, the density and the HVL for normal strength concrete and clay bricks are almost similar. In conclusion, PET facilities present somewhat different design requirements and are more likely to require additional radiation shielding. Therefore, existing shields at the little Company of Mary Hospital are in general found to be adequate and satisfactory and additional shielding was found necessary at the new PET facility in the department of Nuclear Medicine of the Dr. George Mukhari Hospital. By use of appropriate design, by implying specific shielding requirements and by maintaining good operating practices, radiation doses to

  8. Shielding Design and Radiation Shielding Evaluation for LSDS System Facility

    International Nuclear Information System (INIS)

    Kim, Younggook; Kim, Jeongdong; Lee, Yongdeok

    2015-01-01

    As the system characteristics, the target in the spectrometer emits approximately 1012 neutrons/s. To efficiently shield the neutron, the shielding door designs are proposed for the LSDS system through a comparison of the direct shield and maze designs. Hence, to guarantee the radiation safety for the facility, the door design is a compulsory course of the development of the LSDS system. To improve the shielding rates, 250x250 covering structure was added as a subsidiary around the spectrometer. In this study, the evaluations of the suggested shielding designs were conducted using MCNP code. The suggested door design and covering structures can shield the neutron efficiently, thus all evaluations of all conditions are satisfied within the public dose limits. From the Monte Carlo code simulation, Resin(Indoor type) and Tungsten(Outdoor type) were selected as the shielding door materials. From a comparative evaluation of the door thickness, In and Out door thickness was selected 50 cm

  9. Vertical Instability in EAST: Comparison of Model Predictions with Experimental Results

    International Nuclear Information System (INIS)

    Qian Jinping; Wan Baonian; Shen Biao; Xiao Bingjia; Sun Youwen; Shi Yuejiang; Lin Shiyao; Li Jiangang; Gong Xianzu

    2008-01-01

    Growth rates of the axisymmetric mode in elongated plasmas in the experimental advanced superconducting tokamak (EAST) are measured with zero feedback gains and then compared with numerically calculated growth rates for the reconstructed shapes. The comparison is made after loss of vertical position control. The open-loop growth rates were scanned with the number of vessel eigenmodes, which up to 20 is enough to make the growth rates settled. The agreement between the growth rates measured experimentally and the growth rates determined numerically is good. The results show that a linear RZIP model is essentially good enough for the vertical position feedback control.

  10. Experimental results for hydrocarbon refrigerant vaporization inside brazed plate heat exchangers at high pressure

    DEFF Research Database (Denmark)

    Desideri, Adriano; Ommen, Torben Schmidt; Wronski, Jorrit

    2016-01-01

    fluids at typical working conditions of ORC systems for low temperature waste heat recovery (WHR) applications. Based on these premises, a novel testrig has been recently designed and built at the Technical University of Denmark to simulate the evaporating condition occurring in a small capacity ORC...... power unit. In this contribution the preliminary experimental results obtained from the first experimental campaign carried out on the rig are reported. HFC-134a was selected as working fluid. The experiments were carried out at saturation temperature of 60, 70 and 80 °C and inlet and outlet qualities...

  11. Uncertainties and understanding of experimental and theoretical results regarding reactions forming heavy and superheavy nuclei

    Science.gov (United States)

    Giardina, G.; Mandaglio, G.; Nasirov, A. K.; Anastasi, A.; Curciarello, F.; Fazio, G.

    2018-02-01

    Experimental and theoretical results of the PCN fusion probability of reactants in the entrance channel and the Wsur survival probability against fission at deexcitation of the compound nucleus formed in heavy-ion collisions are discussed. The theoretical results for a set of nuclear reactions leading to formation of compound nuclei (CNs) with the charge number Z = 102- 122 reveal a strong sensitivity of PCN to the characteristics of colliding nuclei in the entrance channel, dynamics of the reaction mechanism, and excitation energy of the system. We discuss the validity of assumptions and procedures for analysis of experimental data, and also the limits of validity of theoretical results obtained by the use of phenomenological models. The comparison of results obtained in many investigated reactions reveals serious limits of validity of the data analysis and calculation procedures.

  12. Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching

    Directory of Open Access Journals (Sweden)

    Tomoki Murakami

    2017-01-01

    Full Text Available This paper introduces a network-assisted interference suppression scheme using beam-tilt switching per frame for wireless local area network systems and its effectiveness in an actual indoor environment. In the proposed scheme, two access points simultaneously transmit to their own desired station by adjusting angle of beam-tilt including transmit power assisted from network server for the improvement of system throughput. In the conventional researches, it is widely known that beam-tilt is effective for ICI suppression in the outdoor scenario. However, the indoor effectiveness of beam-tilt for ICI suppression has not yet been indicated from the experimental evaluation. Thus, this paper indicates the effectiveness of the proposed scheme by analyzing multiple-input multiple-output channel matrices from experimental measurements in an office environment. The experimental results clearly show that the proposed scheme offers higher system throughput than the conventional scheme using just transmit power control.

  13. Magnetic shielding of a limiter

    International Nuclear Information System (INIS)

    Brevnov, N.N.; Stepanov, S.B.; Khimchenko, L.N.; Matthews, G.F.; Goodal, D.H.J.

    1991-01-01

    Localization of plasma interaction with material surfaces in a separate chamber, from where the escape of impurities is hardly realized, i.e. application of magnetic divertors or pump limiters, is the main technique for reduction of the impurity content in a plasma. In this case, the production of a divertor configuration requires a considerable power consumption and results in a less effective utilization of the magnetic field volume. Utilization of a pump limiter, for example the ICL-type, under tokamak-reactor conditions would result in the extremely high and forbidden local heat loadings onto the limiter surface. Moreover, the magnetically-shielded pump limiter (MSL) was proposed to combine positive properties of the divertor and the pump limiter. The idea of magnetic shielding is to locate the winding with current inside the limiter head so that the field lines of the resultant magnetic field do not intercept the limiter surface. In this case the plasma flows around the limiter leading edges and penetrates into the space under the limiter. The shielding magnetic field can be directed either counter the toroidal field or counter the poloidal one of a tokamak, dependent on the concrete diagram of the device. Such a limiter has a number of advantages: -opportunity to control over the particle and impurity recycling without practical influence upon the plasma column geometry, - perturbation of a plasma column magnetic configuration from the side of such a limiter is less than that from the side of the divertor coils. The main deficiency is the necessity to locate active windings inside the discharge chamber. (author) 5 refs., 3 figs

  14. Closed Loop Two-Phase Thermosyphon of Small Dimensions: a Review of the Experimental Results

    Science.gov (United States)

    Franco, Alessandro; Filippeschi, Sauro

    2012-06-01

    A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available experimental works in the literature are critically analysed in order to highlight the main results and the correlation between mass flow rate and heat input in natural circulation loops. A comparison of different experimental apparatuses and results is made. It is observed that the results are very different among them and in many cases the experimental data disagree with the conventional theory developed for an imposed flow rate. The paper analyses the main differences among the experimental devices and try to understand these disagreements. From the present analysis it is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.

  15. Computations for the 1:5 model of the THTR pressure vessel compared with experimental results

    International Nuclear Information System (INIS)

    Stangenberg, F.

    1972-01-01

    In this report experimental results measured at the 1:5-model of the prestressed concrete pressure vessel of the THTR-nuclear power station Schmehausen in 1971, are compared with the results of axis-symmetrical computations. Linear-elastic computations were performed as well as approximate computations for overload pressures taking into consideration the influences of the load history (prestressing, temperature, creep) and the effects of the steel components. (orig.) [de

  16. Zr-Fe-Sn Ternary System Phase Diagrams- New Experimental Results

    International Nuclear Information System (INIS)

    Nieva, N; Gomez, A; Arias, D

    2004-01-01

    New experimental results for the Zr-Fe-Sn ternary system are presented in this paper. The phases present and equilibrium relations for the 900 o C isothermal on the central zone of the Gibbs triangle are analysed. A set of ternary alloys was designed and obtained, and they were analysed by semi quantitative SEM- EDS, XRD, and metallographic samples. The resulting ternary phase diagrams are presented here (JCH)

  17. Numerical analysis of temperature field during hardfacing process and comparison with experimental results

    Directory of Open Access Journals (Sweden)

    Lazić Vukić N.

    2014-01-01

    Full Text Available The three-dimensional transient nonlinear thermal analysis of the hard facing process is performed by using the finite element method. The simulations were executed on the open source Salome platform using the open source finite element solver Code_Aster. The Gaussian double ellipsoid was selected in order to enable greater possibilities for the calculation of the moving heat source. The numerical results were compared with available experimental results.

  18. Experimental results concerning global observables from the CERN SPS heavy ion program

    International Nuclear Information System (INIS)

    Young, G.R.

    1990-06-01

    A brief overview is given of experimental results obtained during the initial operation of the heavy-ion program at the CERN SPS during the period 1986--1988. This paper confines itself to a presentation of results on so-called global observables, such as energy flow and multiplicity distributions, and on information extracted from them. Of particular interest among the latter are an estimate of the magnitude and spatial distribution of the energy density attained. 3 refs., 27 figs

  19. Magnetic shielding of an inhomogeneous magnetic field source by a bulk superconducting tube

    International Nuclear Information System (INIS)

    Hogan, K; Fagnard, J-F; Wéra, L; Vanderheyden, B; Vanderbemden, P

    2015-01-01

    Bulk type-II irreversible superconductors can act as excellent passive magnetic shields, with a strong attenuation of low frequency magnetic fields. Up to now, the performances of superconducting magnetic shields have mainly been studied in a homogenous magnetic field, considering only immunity problems, i.e. when the field is applied outside the tube and the inner field should ideally be zero. In this paper, we aim to investigate experimentally and numerically the magnetic response of a high-T c bulk superconducting hollow cylinder at 77 K in an emission problem, i.e. when subjected to the non-uniform magnetic field generated by a source coil placed inside the tube. A bespoke 3D mapping system coupled with a three-axis Hall probe is used to measure the magnetic flux density distribution outside the superconducting magnetic shield. A finite element model is developed to understand how the magnetic field penetrates into the superconductor and how the induced superconducting shielding currents flow inside the shield in the case where the emitting coil is placed coaxially inside the tube. The finite element modelling is found to be in excellent agreement with the experimental data. Results show that a concentration of the magnetic flux lines occurs between the emitting coil and the superconducting screen. This effect is observed both with the modelling and the experiment. In the case of a long tube, we show that the main features of the field penetration in the superconducting walls can be reproduced with a simple analytical 1D model. This model is used to estimate the maximum flux density of the emitting coil that can be shielded by the superconductor. (paper)

  20. External dosimetry sources and shielding

    International Nuclear Information System (INIS)

    Calisto, Washington

    1994-01-01

    A definition of external dosimetry r external sources dosimetry,physical and mathematical treatment of the interaction of gamma radiation with a minimal area in that direction. Concept of attenuation coefficient, cumulated effect by polyenergetic sources, exposition rate, units, cumulated dose,shielding, foton shielding, depth calculation, materials used for shielding.Beta shielding, consideration of range and maximum β energy , low stopping radiation by use of low Z shielding. Tables for β energy of β emitters, I (tau) factor, energy-range curves for β emitters in aqueous media, gamma attenuation factors for U, W and Pb. Y factor for bone tissue,muscle and air, build-up factors