Science Hall of Atomic Energy in Research Reactor Institute, Kyoto University

International Nuclear Information System (INIS)

Hayashi, Takeo

1979-01-01

The Science Hall of Atomic Energy was built as a subsidiary facility of the Research Reactor Institute, Kyoto University. The purpose of this facility is to accept outside demands concerning the application of the research reactor. The building is a two story building, and has the floor area of 901.47 m 2 . There are an exhibition room, a library, and a big lecture room. In the exhibition room, models of the Kyoto University Research Reactor and the Kyoto University Critical Assembly are placed. Various pictures concerning the application of the reactor are on the wall. In the library, people from outside of the Institute can use various books on science. Books for boys and girls are also stocked and used for public use. At the lecture room, various kinds of meeting can be held. (Kato, T.)

ExB Measurements of a 200 W Xenon Hall Thruster (Preprint)

National Research Council Canada - National Science Library

Ekholm, Jared M; Hargus, Jr, William A

2007-01-01

Angularly resolved ion species fractions of Xe+1, Xe+2, and Xe+3 in a low power xenon Hall thruster Busek BHT-200 plume were measured using an ExB probe under a variety of thruster operating conditions and background pressures...

The ins and outs of a list of plays by Calderón

Directory of Open Access Journals (Sweden)

Erik Coenen

2009-06-01

Full Text Available In 1682, Don Juan de Vera Tassis published two lists of plays circulating under Calderón’s name: one in which he listed those plays he considered really written by Calderón, and another one including those plays which he believed were not his. These lists are the longest of their sort which has come down to us from the 17th century. In this paper, the internal organization of these lists is examined, as well as the possible origin of the knowledge reflected in them, not only so as to determine their degree of authority, but also for what they tell us about the texts which this posthumous editor of 108 plays by Calderón had at his disposal.

3D Quantum Hall Effect of Fermi Arc in Topological Semimetals

Science.gov (United States)

Wang, C. M.; Sun, Hai-Peng; Lu, Hai-Zhou; Xie, X. C.

2017-09-01

The quantum Hall effect is usually observed in 2D systems. We show that the Fermi arcs can give rise to a distinctive 3D quantum Hall effect in topological semimetals. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. Via a "wormhole" tunneling assisted by the Weyl nodes, the Fermi arcs at opposite surfaces can form a complete Fermi loop and support the quantum Hall effect. The edge states of the Fermi arcs show a unique 3D distribution, giving an example of (d -2 )-dimensional boundary states. This is distinctly different from the surface-state quantum Hall effect from a single surface of topological insulator. As the Fermi energy sweeps through the Weyl nodes, the sheet Hall conductivity evolves from the 1 /B dependence to quantized plateaus at the Weyl nodes. This behavior can be realized by tuning gate voltages in a slab of topological semimetal, such as the TaAs family, Cd3 As2 , or Na3Bi . This work will be instructive not only for searching transport signatures of the Fermi arcs but also for exploring novel electron gases in other topological phases of matter.

Methods and instrumentation for investigating Hall sensors during their irradiation in nuclear research reactors

International Nuclear Information System (INIS)

Bolshakova, I.; Holyaka, R.; Makido, E.; Marusenkov, A.; Shurygin, F.; Yerashok, V.; Moreau, P. J.; Vayakis, G.; Duran, I.; Stockel, J.; Chekanov, V.; Konopleva, R.; Nazarkin, I.; Kulikov, S.; Leroy, C.

2009-01-01

Present work discusses the issues of creating the instrumentation for testing the semiconductor magnetic field sensors during their irradiation with neutrons in nuclear reactors up to fluences similar to neutron fluences in steady-state sensor locations in ITER. The novelty of the work consists in Hall sensor parameters being investigated: first, directly during the irradiation (in real time), and, second, at high irradiation levels (fast neutron fluence > 10 18 n/cm 2 ). Developed instrumentation has been successfully tested and applied in the research experiments on radiation stability of magnetic sensors in IBR-2 (JINR, Dubna) and VVR-M (PNPI, Saint-Petersburg) reactors. The 'Remote-Rad' bench consists of 2 heads (head 1 and head 2) bearing investigated sensors put in a ceramic setting, of electronic unit, of personal computer and of signal lines. Each head contains 6 Hall sensors and a coil for generating test magnetic field. Moreover head 1 contains thermocouples for temperature measurement while the temperature of head 2 is measured by thermo-resistive method. The heads are placed in the reactor channel

High-Order Calderón Preconditioned Time Domain Integral Equation Solvers

KAUST Repository

Valdes, Felipe; Ghaffari-Miab, Mohsen; Andriulli, Francesco P.; Cools, Kristof; Michielssen,

2013-01-01

Two high-order accurate Calderón preconditioned time domain electric field integral equation (TDEFIE) solvers are presented. In contrast to existing Calderón preconditioned time domain solvers, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of fully-localized high-order div-and quasi curl-conforming (DQCC) basis functions. Numerical results demonstrate that the linear systems of equations obtained using the proposed basis functions converge rapidly, regardless of the mesh density and of the order of the current expansion. © 1963-2012 IEEE.

High-Order Calderón Preconditioned Time Domain Integral Equation Solvers

KAUST Repository

Valdes, Felipe

2013-05-01

Two high-order accurate Calderón preconditioned time domain electric field integral equation (TDEFIE) solvers are presented. In contrast to existing Calderón preconditioned time domain solvers, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of fully-localized high-order div-and quasi curl-conforming (DQCC) basis functions. Numerical results demonstrate that the linear systems of equations obtained using the proposed basis functions converge rapidly, regardless of the mesh density and of the order of the current expansion. © 1963-2012 IEEE.

June 1992 Hall B collaboation meeting

International Nuclear Information System (INIS)

Dennis, L.

1992-01-01

The Hall B collaboration meeting at the CEBAF 1992 Summer Workshop consisted of technical and physics working group meetings, a special beam line devices working group meeting the first meeting of the membership committee, a technical representatives meeting and a full collaboration meeting. Highlights of these meetings are presented in this report

Interim dry fuel storage for magnox reactors

Energy Technology Data Exchange (ETDEWEB)

Bradley, N [National Nuclear Corporation, Risley, Warrington (United Kingdom); Ealing, C [GEC Energy Systems Ltd, Whetstone, Leicester (United Kingdom)

1985-07-01

In the UK the practice of short term buffer storage in water ponds prior to chemical reprocessing had already been established on the early gas cooled reactors in Calder Hall. Thus the choice of water pond buffer storage for MGR power plants logically followed the national policy decision to reprocess. The majority of the buffer storage period would take place at the reprocessing plant with only a nominal of 100 days targeted at the station. Since Magnox clad fuel is not suitable for long term pond storage, alternative methods of storage on future stations was considered desirable. In addition to safeguards considerations the economic aspects of the fuel cycle has influenced the conclusion that today the purchase of a MGR power plant with dry spent fuel storage and without commitment to reprocess would be a rational decision for a country initiating a nuclear programme. Dry storage requirements are discussed and two designs of dry storage facilities presented together with a fuel preparation facility.

Interim dry fuel storage for magnox reactors

International Nuclear Information System (INIS)

Bradley, N.; Ealing, C.

1985-01-01

In the UK the practice of short term buffer storage in water ponds prior to chemical reprocessing had already been established on the early gas cooled reactors in Calder Hall. Thus the choice of water pond buffer storage for MGR power plants logically followed the national policy decision to reprocess. The majority of the buffer storage period would take place at the reprocessing plant with only a nominal of 100 days targeted at the station. Since Magnox clad fuel is not suitable for long term pond storage, alternative methods of storage on future stations was considered desirable. In addition to safeguards considerations the economic aspects of the fuel cycle has influenced the conclusion that today the purchase of a MGR power plant with dry spent fuel storage and without commitment to reprocess would be a rational decision for a country initiating a nuclear programme. Dry storage requirements are discussed and two designs of dry storage facilities presented together with a fuel preparation facility

Stability of the Hall sensors performance under neutron irradiation

International Nuclear Information System (INIS)

Duran, I.; Hron, M.; Stockel, J.; Viererbl, L.; Vsolak, R.; Cerva, V.; Bolshakova, I.; Holyaka, R.; Vayakis, G.

2004-01-01

A principally new diagnostic method must be developed for magnetic measurements in steady state regime of operation of fusion reactor. One of the options is the use of transducers based on Hall effect. The use of Hall sensors in ITER is presently limited by their questionable radiation and thermal stability. Issues of reliable operation in ITER like radiation and thermal environment are addressed in the paper. The results of irradiation tests of candidate Hall sensors in LVR-15 and IBR-2 experimental fission reactors are presented. Stable operation (deterioration of sensitivity below one percent) of the specially prepared sensors was demonstrated during irradiation by the total fluence of 3.10 16 n/cm 2 in IBR-2 reactor. Increasing the total neutron fluence up to 3.10 17 n/cm 2 resulted in deterioration of the best sensor's output still below 10% as demonstrated during irradiation in LVR-15 fission reactor. This level of neutron is already higher than the expected ITER life time neutron fluence for a sensor location just outside the ITER vessel. (authors)

Hall conductivity and the vortex phase in MgB2 thin films

International Nuclear Information System (INIS)

Jung, Soon-Gil; Seong, W K; Huh, Ji Young; Lee, T G; Kang, W N; Choi, Eun-Mi; Kim, Heon-Jung; Lee, Sung-Ik

2007-01-01

In a MgB 2 thin film superconductor, we have found that Hall conductivity (σ xy ) is described by the sum of two terms, σ xy = C 1 /H+C 3 H, where C 1 and C 3 are independent of the magnetic fields and have positive values. C 1 is observed to be proportional to (1-t) n with n = 4.2, where t is the reduced temperature (T/T c ), and C 3 is weakly dependent on the temperature. These results are consistent with those of the overdoped La 2-x Sr x CuO 4 superconductors. Based on Hall angle data, we obtained a vortex phase diagram with three regions, vortex-solid, crossover, and vortex-liquid regions in the H-T plane

Poder, autoridad y desautorización en el teatro de Calderón

OpenAIRE

Arellano, Ignacio

2011-01-01

Las comedias que exploran el tema del poder y la autoridad, con sus anejas constelaciones de motivos (la privanza, el modelo de rey, el tiranicidio, la voltaria fortuna o la libertad frente al sometimiento) abundan en el Siglo de Oro, y constituyen en Calderón un territorio amplio y complejo que despliega una problemática llena de matices. Su amplitud de enfoques y perspectivas permite a Calderón una variedad extraordinaria de conflictos y soluciones, manteniendo siempre la car...

Embajadas y guerras: algunos paradigmas compositivos en el auto sacramental de Calderón

OpenAIRE

Sáez, Adrián J.

2012-01-01

Entre los diversos materiales que Calderón emplea para el diseño de sus autos sacramentales se encuentra una serie de paradigmas estrechamente vinculados a argumentos bélicos. Sus fuentes no son únicamente literarias, sino que también se asientan en la realidad del momento. La embajada, misión diplomática habitual, contribuye a la exaltación de la monarquía hispánica y legitima sus acciones bélicas, pues son solo el último camino posible tras las constantes ofertas de paz. A su vez, las diver...

Theoretical analysis of nuclear reactors (Phase I), I-V, Part IV, Nuclear fuel depletion; Razrada metoda teorijske analize nuklearnih reaktora (I faza) I-V, IV Deo, Promena izotopnog sastava goriva

Energy Technology Data Exchange (ETDEWEB)

Pop-Jordanov, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1962-07-15

Nuclear fuel depletion is analyzed in order to estimate the qualitative and quantitative fuel property changes during irradiation and the influence of changes on the reactivity during long-term reactor operation. The changes of fuel properties are described by changes of neutron absorption and fission cross sections. Part one of this report covers the economic significance of fuel burnup and the review of fuel isotopic changes during depletion. Pat two contains the analysis of the U{sup 235} chain, analytical expressions for the concentrations of U{sup 235}, U{sup 236} and Np{sup 237} as a function of burnup. Part three contains the analysis of neutron spectrum influence on the Westcott method for calculating the cross sections. Part four contains the calculation method applied on Calder Hall type reactor. The results were obtained by applying ZUSE-22 R digital computer.

Options for Energy Upgrade of the Hall B Tagger

International Nuclear Information System (INIS)

H. Crannell; D. Sober

1998-01-01

Four options for an energy upgrade of the present Hall-B Tagger have been considered. These are: (1) Boost the magnetic field in the present Tagger; (2) Replace the Tagger with a new Tagger system; (3) Install a pre-Tagger magnetic chacain, and (4) Use the present Tagger as part of the beam dump. In this document each of these options is described briefly, the advantages and disadvantages of each are presented, and a very rough cost of implementation is suggested

The study of the irradiation-induced embrittlement of reactor pressure vessels. Analysis of surveillance test specimens of a commercial nuclear reactor pressure vessel studied by three-dimensional atom probe and positron annihilation

International Nuclear Information System (INIS)

Nagai, Yasuyoshi; Toyama, Takeshi; Hasegawa, Masayuki

2007-01-01

The study of embrittlement of nuclear power reactor pressure vessels (RPVs) is of critical importance for the safety assessment in the nuclear industry. Some origins of embrittlement are attributed to fine Cu precipitates, matrix defects, grain boundary segregation of P and late blooming phase. This review article described nanostructural observation by three-dimensional atom probe (3DAP) and positron annihilation spectroscopy (PAS). The density and sizes of Cu-rich nanoprecipitates and grain boundary segregation are sensitively detected by 3DAP, and vacancies are probed by PAS. Element analysis around vacancies and fine microstructural Cu precipitates not containing vacancies are successfully observed by a coincidence doppler broadening method. The nanostructural evolution of irradiation-induced Cu-rich nanoprecipitates (CRNPs) and vacancy clusters in surveillance test specimens of commercial nuclear reactor pressure vessel steel welds of Doel-2 in Belgium were revealed by combining 3DAP and PAS. In both medium (0.13 wt%) and high (0.30 wt%) Cu welds, the CRNPs were found to form readily at the very beginning of the reactor lifetime. On the other hand, small vacancy clusters start appearing after the initial Cu precipitates and accumulate steadily with increasing neutron dose. The CRNPs were also observed at very low dose rate of neutrons in the test specimen of Calder Hall Reactor of Japan Atomic Power Company. The significant enhancement of these Cu precipitates results in the embrittlement in practical RPVs. At very high dose of 2.2x10 18 n/cm 2 by JMTR, the Cu precipitates were scarcely observed, and the irradiation-induced embrittlement was primarily caused from vacancy-impurity complexes and dislocation loops. (author)

TRIPOLI calculation of the neutron field in the hall of the SILENE reactor

International Nuclear Information System (INIS)

Bourdet, L.

1986-05-01

This study concerns the utilization of the experimental reactor SILENE as radiation source. Its aim is to get a theoretical estimation of the neutron field characteristics in different points of the irradiation hall (spectra, fluences, equivalents of biological doses and reaction yields). These estimations are compared to results obtained by several experimental techniques; they allow to know better this neutron field with or without lead shield [fr

Alien shores

International Nuclear Information System (INIS)

Viermann, Joerg

2014-01-01

The UK nuclear programme started out in the 1950's with some remarkable milestones: Calder Hall 1 was the first commercial reactor worldwide to be erected and was connected to the grid in 1956 with the other three Calder Hall Magnox reactors soon to follow. More Magnox reactors were built along the British coast in the 1950's and 60's. In 1971 the two reactors at Wylfa were the last UK Magnox reactors to be connected to the grid. Low level radioactive waste arising from electricity production went to the Drigg burial site, spent fuel to the Sellafield reprocessing facilities. Intermediate level waste was collected mainly on site, but also in the storage pools at Sellafield. This legacy now has to be dealt with. The UK's only PWR is operated by EDF Energy in Sizewell near Leiston which was connected to the grid in 1995. ILW resins have been collected over its first 18 years of operation. With the storage tanks running out of capacity within the following 2 years it was necessary to start filling these resins into waste containers, ideally into containers suitable for the planned UK repository. German expertise and experience in dealing with different types of ILW can be of benefit for UK operators. GNS products and services ideally match some of the actual challenges which GNS could prove in some initial waste processing projects. GNS also started to develop custom made solutions for the UK market.

Economies of scale in electricity generation and transmission since 1945

International Nuclear Information System (INIS)

Tombs, F.

1978-01-01

Progress in the electricity supply industry since 1945 is reviewed with particular reference to increased ratings of plant and transmission. The contribution of nuclear energy is emphasised. Developments which have taken place, and policy within the nuclear industry since the construction of Calder Hall, are examined. The performance of the Magnox stations, difficulties with AGRs, and the debate on the choice of reactors are discussed. (U.K.)

The boundedness of multilinear Calderón–Zygmund operators on ...

Indian Academy of Sciences (India)

In this paper, we study the boundedness of the multilinear Calderón–. Zygmund operators ... We first recall the definition of Hardy space H p(Rd). .... variable. Therefore, T is a linearly continuous functional. Then, for any atomic decom- position ...

Lp-continuity for Calderón–Zygmund operator

Indian Academy of Sciences (India)

Given a Calderón–Zygmund (- for short) operator , which satisfies Hörmander condition, we prove that: if maps all the characteristic atoms to W L 1 , then is continuous from L p to L p ( 1 < p < ∞ ) . So the study of strong continuity on arbitrary function in L p has been changed into the study of weak continuity on ...

Echoes of the world; Echos du Monde

Energy Technology Data Exchange (ETDEWEB)

Anon

2007-09-15

EDF is authorized to dismantle Chooz A. The cooling towers of Calder Hall on the site of Sellafield were destroyed, within the framework of the demolition of the site.Belarus hopes to begin the building of a nuclear power plant in order to produce it own energy. Bangladesh is ready to build its first nuclear reactor. Germany cannot hold its commitment of CO{sub 2} reduction if it does not maintain the nuclear power production. Japan launches the next generation of light water advanced reactors. (N.C.)

A calderón multiplicative preconditioner for the combined field integral equation

KAUST Repository

Bagci, Hakan; Andriulli, Francesco P.; Cools, Kristof; Olyslager, Femke; Michielssen, Eric

2009-01-01

A Calderón multiplicative preconditioner (CMP) for the combined field integral equation (CFIE) is developed. Just like with previously proposed Caldern-preconditioned CFIEs, a localization procedure is employed to ensure that the equation

Metal Hall sensors for the new generation fusion reactors of DEMO scale

Science.gov (United States)

Bolshakova, I.; Bulavin, M.; Kargin, N.; Kost, Ya.; Kuech, T.; Kulikov, S.; Radishevskiy, M.; Shurygin, F.; Strikhanov, M.; Vasil'evskii, I.; Vasyliev, A.

2017-11-01

For the first time, the results of on-line testing of metal Hall sensors based on nano-thickness (50-70) nm gold films, which was conducted under irradiation by high-energy neutrons up to the high fluences of 1 · 1024 n · m-2, are presented. The testing has been carried out in the IBR-2 fast pulsed reactor in the neutron flux with the intensity of 1.5 · 1017 n · m-2 · s-1 at the Joint Institute for Nuclear Research. The energy spectrum of neutron flux was very close to that expected for the ex-vessel sensors locations in the ITER experimental reactor. The magnetic field sensitivity of the gold sensors was stable within the whole fluence range under research. Also, sensitivity values at the start and at the end of irradiation session were equal within the measurement error (<1%). The results obtained make it possible to recommend gold sensors for magnetic diagnostics in the new generation fusion reactors of DEMO scale.

The Cuatrocientos milagros de la cruz of Jaime Bleda: a bedside book for Calderón?

Directory of Open Access Journals (Sweden)

Adrián J. Sáez

2013-04-01

Full Text Available Abstract:This paper explores the possible knowledge that some authors of the Golden Age may have about certain treatises of historical, philosophical and political nature, besides the well-known relations with other literary works, like the critics frequently have pointed out. So, this investigation compares the series of miracles that appear in La devoción de la cruz of Calderón with the book Cuatrocientos milagros de la cruz of Jaime Bleda, a religious treaty that Calderón might recalled in order to write some passages of this comedy. Overall, this paper reveals data about the prodigious miscellany that may serve to other studies about this matter. Resumen:Este trabajo explora el posible conocimiento que algunos autores del Siglo de Oro pudieron tener de ciertos tratados de tema histórico, filosófico, político, etc., al margen de las relaciones con otras obras literarias, frecuentemente estudiadas por la crítica. Así, se pone en diálogo la serie de milagros que aparecen en La devoción de la cruz de Calderón con los Cuatrocientos milagros de la cruz de Jaime Bleda, un repertorio de milagros que Calderón pudo recordar a la hora de escribir algunos pasajes de esta comedia. Conjuntamente se da noticia de esta miscelánea de prodigios, que puede resultar de gran utilidad para otros estudios.

Scaling of anomalous hall effect in amorphous CoFeB Films with accompanying quantum correction

KAUST Repository

Zhang, Yan; Mi, Wenbo; Wang, Xiaocha; Guo, Zaibing

2015-01-01

Scaling of anomalous Hall effect in amorphous CoFeB films with thickness ranging from 2 to 160 nm have been investigated. We have found that the scaling relationship between longitudinal (ρxx) and anomalous Hall (ρAH) resistivity is distinctly

Nonthermal fusion reactor concept based on Hall-effect magnetohydrodynamics plasma theory

International Nuclear Information System (INIS)

Witalis, E.A.

1988-01-01

The failure of magnetic confinement controlled thermonuclear fusion research to achieve its goal is attributed to its foundation on the incomplete MHD plasma description instead of the more general HMHD (Hall-effect magnetohydrodynamics) theory. The latter allows for a certain magnetic plasma self-confinement under described stringent conditions. A reactor concept based on the formation, acceleration, and forced disintegration of magnetized whirl structures, plasmoids, is proposed. The four conventional MHD theory objections, i.e., absence of dynamo action, fast decay caused by resistivity, non-existence of magnetic self-confinement, and negligible non-thermal fusion yield, are shown not to apply. Support for the scheme from dense plasma focus research is pointed out. (orig.) [de

Optimal Protection of Reactor Hall Under Nuclear Fuel Container Drop Using Simulation Methods

Directory of Open Access Journals (Sweden)

Králik Juraj

2014-12-01

Full Text Available This paper presents of the optimal design of the damping devices cover of reactor hall under impact of nuclear fuel container drop of type TK C30. The finite element idealization of nuclear power plant structure is used in software ANSYS. The steel pipe damper system is proposed for dissipation of the kinetic energy of the container free fall in comparison with the experimental results. The probabilistic and sensitivity analysis of the damping devices was considered on the base of the simulation methods in program AntHill using the Monte Carlo method.

CALDER: High-sensitivity cryogenic light detectors

International Nuclear Information System (INIS)

Casali, N.; Bellini, F.; Cardani, L.

2017-01-01

The current bolometric experiments searching for rare processes such as neutrinoless double-beta decay or dark matter interaction demand for cryogenic light detectors with high sensitivity, large active area and excellent scalability and radio-purity in order to reduce their background budget. The CALDER project aims to develop such kind of light detectors implementing phonon-mediated Kinetic Inductance Detectors (KIDs). The goal for this project is the realization of a 5 × 5 cm"2 light detector working between 10 and 100mK with a baseline resolution RMS below 20 eV. In this work the characteristics and the performances of the prototype detectors developed in the first project phase will be shown.

Four-dimensional Hall mechanics as a particle on CP3

International Nuclear Information System (INIS)

Bellucci, Stefano; Casteill, Pierre-Yves; Nersessian, Armen

2003-01-01

In order to establish an explicit connection between four-dimensional Hall effect on S 4 and six-dimensional Hall effect on CP 3 , we perform the Hamiltonian reduction of a particle moving on CP 3 in a constant magnetic field to the four-dimensional Hall mechanics (i.e., a-bar particle on S 4 in a SU(2) instanton field). This reduction corresponds to fixing the isospin of the latter system

Pedro Calderón de la Barca, Autos sacramentales - Francisco de Quevedo, Prosa satírica

OpenAIRE

Plata, Fernando

2011-01-01

Reseñas de Pedro Calderón de la Barca, Autos sacramentales. El divino Jasón. El gran mercado del Mundo. El gran teatro del Mundo. La viña del Señor, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 50), Madrid, 2010, 406 pp. ISBN: 978-84-92518-54-8 y Francisco de Quevedo, Prosa satírica, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 58), Madrid, 2011, 206 pp. ISBN: 978-84-92518-69-2. Reviews of Pedro Calderón de la Barca, Autos sacramentales. El divino Jasón. El gran mercado d...

Nuclear privatization

International Nuclear Information System (INIS)

Jeffs, E.

1995-01-01

The United Kingdom government announced in May 1995 plans to privatize the country's two nuclear generating companies, Nuclear Electric and Scottish Nuclear. Under the plan, the two companies will become operating divisions of a unified holding company, to be called British Electric, with headquarters in Scotland. Britain's nuclear plants were left out of the initial privatization in 1989 because the government believed the financial community would be unwilling to accept the open-ended liability of decommissioning the original nine stations based on the Magnox gas-cooled reactor. Six years later, the government has found a way around this by retaining these power stations in state ownership, leaving the new nuclear company with the eight Advanced Gas-cooled Reactor (AGR) stations and the recently completed Sizewell B PWR stations. The operating Magnox stations are to be transferred to BNFL, which operates two Magnox stations of their own at Calder Hall and Chapelcross

Chapter 10: Calculation of the temperature coefficient of reactivity of a graphite-moderated reactor

International Nuclear Information System (INIS)

Brown, G.; Richmond, R.; Stace, R.H.W.

1963-01-01

The temperature coefficients of reactivity of the BEPO, Windscale and Calder reactors are calculated, using the revised methods given by Lockey et al. (1956) and by Campbell and Symonds (1962). The results are compared with experimental values. (author)

MANHATTAN PROJECT B REACTOR HANFORD WASHINGTON [HANFORD'S HISTORIC B REACTOR (12-PAGE BOOKLET)

Energy Technology Data Exchange (ETDEWEB)

GERBER MS

2009-04-28

The Hanford Site began as part of the United States Manhattan Project to research, test and build atomic weapons during World War II. The original 670-square mile Hanford Site, then known as the Hanford Engineer Works, was the last of three top-secret sites constructed in order to produce enriched uranium and plutonium for the world's first nuclear weapons. B Reactor, located about 45 miles northwest of Richland, Washington, is the world's first full-scale nuclear reactor. Not only was B Reactor a first-of-a-kind engineering structure, it was built and fully functional in just 11 months. Eventually, the shoreline of the Columbia River in southeastern Washington State held nine nuclear reactors at the height of Hanford's nuclear defense production during the Cold War era. The B Reactor was shut down in 1968. During the 1980's, the U.S. Department of Energy began removing B Reactor's support facilities. The reactor building, the river pumphouse and the reactor stack are the only facilities that remain. Today, the U.S. Department of Energy (DOE) Richland Operations Office offers escorted public access to B Reactor along a designated tour route. The National Park Service (NPS) is studying preservation and interpretation options for sites associated with the Manhattan Project. A draft is expected in summer 2009. A final report will recommend whether the B Reactor, along with other Manhattan Project facilities, should be preserved, and if so, what roles the DOE, the NPS and community partners will play in preservation and public education. In August 2008, the DOE announced plans to open B Reactor for additional public tours. Potential hazards still exist within the building. However, the approved tour route is safe for visitors and workers. DOE may open additional areas once it can assure public safety by mitigating hazards.

The Reproductive Morphology and Physiological Age Grading of the Female Salvinia Weevil, Calder and Sands

OpenAIRE

Lee Eisenberg; Seth Johnson; Michael J Grodowitz

2018-01-01

The morphology of the female Cyrtobagous salviniae Calder and Sands reproductive system is similar to other weevil species being meroistic and telotrophic. The reproductive system is composed of 2 ovaries each containing 2 ovarioles where the follicles mature. A physiological age grading system was developed where the continuum of ovarium development was divided into 2 nulliparous and 3 parous classes. This was based on the differentiation of the ovarioles, presence, and appearance of follicu...

A UKAEA review of gas-cooled reactors in the United Kingdom

International Nuclear Information System (INIS)

Heath, E.C.; Knowles, A.N.

1983-01-01

The commercial use of nuclear power for electrical generation commenced in the UK in the 1950s with the Calder Hall reactors. Based on this concept, eighteen commercial reactor units, with two further units outside the UK, were constructed and have been in operation for periods ranging from 10 to 19 years. The paper reviews this experience mainly from the aspects of safety and the achieved costs, which compare favourably with current figures for fossil fired generation. The further development of the gas-cooled system in the UK commenced with the construction of the Windscale AGR, which came into operation in 1962. This led to the ordering of 14 large commercial AGR units, 4 of which have been in service since 1976, 6 are at an advanced stage of construction and 4 are at an early stage of construction. The paper reviews the main safety features of the AGR and considers the costs, taking achieved costs for the units which are in service and a combination of historical costs and projected costs for the units under construction. Again a clear advantage over fossil fuelled stations is shown. The paper also includes a preliminary account of the use of the prototype AGR at Windscale for the series of experiments concerning plateout, over-temperature in the fuel and simulated fault transients in the core which were carried out earlier in 1981. (author)

Scaling behavior of mixed-state hall effect in MgB2 thin films

International Nuclear Information System (INIS)

Jung, Soon-Gil; Seong, W.K.; Kang, W.N.; Choi, Eun-Mi; Kim, Heon-Jung; Lee, Sung-Ik; Kim, Hyeong-Jin; Kim, H.C.

2006-01-01

The Hall resistivity (ρ xy ) and the longitudinal resistivity (ρ xx ) in c-axis-oriented superconducting MgB 2 thin films have been investigated in extended fields up to 18T. We have observed a scaling behavior between the Hall resistivity and the longitudinal resistivity, ρ xy =Aρ xx β , where the exponent (β) is observed to be independent of the temperatures and the magnetic fields. For a wide magnetic field region from 1 to 18T and a wide temperature region from 10 to 28K, a universal power law with β=2.0+/-0.1 was observed in c-axis-oriented MgB 2 thin films. These results can be well interpreted by using recent models

Temperature dependence of collapse of quantized hall resistance

International Nuclear Information System (INIS)

Tanaka, Hiroyasu; Kawashima, Hironori; Iizuka, Hisamitsu; Fukuda, Hideaki; Kawaji, Shinji

2006-01-01

Similarity is observed in the deviation of Hall resistance from the quantized value with the increase in the source-drain current I SD in our butterfly-type Hall bars and in the Hall bars used by Jeanneret et al., while changes in the diagonal resistivity ρ xx with I SD are significantly different between these Hall bars. The temperature dependence of the critical Hall electric field F cr (T) for the collapse of R H (4) measured in these Hall bars is approximated using F cr (T) = F cr (0)(1 - (T/T cr ) 2 ). Here, the critical Hall electric field at zero temperature depends on the magnetic field B as F cr (0) ∝ B 3/2 . Theoretical considerations are given on F cr (T) on the basis of a temperature-dependent mobility edge model and a schema of temperature-dependent inter-Landau level tunneling probability arising from the Fermi distribution function. The former does not fit in with the I SD dependence of activation energy in ρ xx . (author)

A New Design of a Single-Device 3D Hall Sensor: Cross-Shaped 3D Hall Sensor

Directory of Open Access Journals (Sweden)

Wei Tang

2018-04-01

Full Text Available In this paper, a new single-device three-dimensional (3D Hall sensor called a cross-shaped 3D Hall device is designed based on the five-contact vertical Hall device. Some of the device parameters are based on 0.18 μm BCDliteTM technology provided by GLOBALFOUNDRIES. Two-dimensional (2D and 3D finite element models implemented in COMSOL are applied to understand the device behavior under a constant magnetic field. Besides this, the influence of the sensing contacts, active region’s depth, and P-type layers are taken into account by analyzing the distribution of the voltage along the top edge and the current density inside the devices. Due to the short-circuiting effect, the sensing contacts lead to degradation in sensitivities. The P-type layers and a deeper active region in turn are responsible for the improvement of sensitivities. To distinguish the P-type layer from the active region which plays the dominant role in reducing the short-circuiting effect, the current-related sensitivity of the top edge (Stop is defined. It is found that the short-circuiting effect fades as the depth of the active region grows. Despite the P-type layers, the behavior changes a little. When the depth of the active region is 7 μm and the thickness of the P-type layers is 3 μm, the sensitivities in the x, y, and z directions can reach 91.70 V/AT, 92.36 V/AT, and 87.10 V/AT, respectively.

Scaling of anomalous hall effect in amorphous CoFeB Films with accompanying quantum correction

KAUST Repository

Zhang, Yan

2015-05-08

Scaling of anomalous Hall effect in amorphous CoFeB films with thickness ranging from 2 to 160 nm have been investigated. We have found that the scaling relationship between longitudinal (ρxx) and anomalous Hall (ρAH) resistivity is distinctly different in the Bloch and localization regions. For ultrathin CoFeB films, the sheet resistance (Rxx) and anomalous Hall conductance (GAH) received quantum correction from electron localization showing two different scaling relationships at different temperature regions. In contrast, the thicker films show a metallic conductance, which have only one scaling relationship in the entire temperature range. Furthermore, in the dirty regime of localization regions, an unconventional scaling relationship View the MathML sourceσAH∝σxxα with α=1.99 is found, rather than α=1.60 predicted by the unified theory.

Topological Hall and Spin Hall Effects in Disordered Skyrmionic Textures

OpenAIRE

N'diaye, P. B.; Akosa, C. A.; Manchon, A.

2016-01-01

We carry out a throughout study of the topological Hall and topological spin Hall effects in disordered skyrmionic systems: the dimensionless (spin) Hall angles are evaluated across the energy band structure in the multiprobe Landauer-B\\"uttiker formalism and their link to the effective magnetic field emerging from the real space topology of the spin texture is highlighted. We discuss these results for an optimal skyrmion size and for various sizes of the sample and found that the adiabatic a...

Theoretical study for ICRF sustained LHD type p-11B reactor

International Nuclear Information System (INIS)

Watanabe, Tsuguhiro

2003-04-01

This is a summary of the workshop on 'Theoretical Study for ICRF Sustained LHD Type p- 11 B Reactor' held in National Institute for Fusion Science (NIFS) on July 25, 2002. In the workshop, study of LHD type D- 3 He reactor is also reported. A review concerning the advanced nuclear fusion fuels is also attached. This review was reported at the workshop of last year. The development of the p- 11 B reactor research which uses the LHD magnetic field configuration has been briefly summarized in section 1. In section 2, an integrated report on advanced nuclear fusion fuels is given. Ignition conditions in a D- 3 He helical reactor are summarized in section 3. 0-dimensional particle and power balance equations are solved numerically assuming the ISS95 confinement law including a confinement factor (γ HH ). It is shown that high average beta plasma confinement, a large confinement factor (γ HH > 3) and the hot ion mode (T i /T e > 1.4) are necessary to achieve the ignition of the D- 3 He helical reactor. Characteristics of ICRF sustained p- 11 B reactor are analyzed in section 4. The nuclear fusion reaction rate is derived assuming a quasilinear plateau distribution function (QPDF) for protons, and an ignition condition of p- 11 B reactor is shown to be possible. The 3 of the presented papers are indexed individually. (J.P.N.)

Hanford B Reactor Building Hazard Assessment Report

International Nuclear Information System (INIS)

Griffin, P. W.

1999-01-01

The 105-B Reactor (hereinafter referred to as B Reactor) is located in the 100 Area of the Hanford Site near Richland, Washington. The B Reactor is one of nine plutonium production reactors that were constructed in the 1940s during the Cold War Era. Construction of the B Reactor began June 7, 1943, and operation began on September 26, 1944. The Environmental Restoration Contractor was requested by RL to provide an assessment/characterization of the B Reactor building to determine and document the hazards that are present and could pose a threat to the environment and/or to individuals touring the building. This report documents the potential hazards, determines the feasibility of mitigating the hazards, and makes recommendations regarding areas where public tour access should not be permitted

Improvements in operational safety performance of the Magnox power stations

Energy Technology Data Exchange (ETDEWEB)

Marchese, C.J. [BNFL Magnox Generation, Berkeley (United Kingdom)

2000-10-01

In the 43 years since commencement of operation of Calder Hall, the first Magnox power station, there remain eight Magnox stations and 20 reactors still in operation, owned by BNFL Magnox Generation. This paper describes how the operational safety performance of these stations has significantly improved over the last ten years. This has been achieved against a background of commercial competition introduced by privatization and despite the fact that the Magnox base design belongs to the past. Finally, the company's future plans for continued improvements in operational safety performance are discussed. (author)

Service hall in Number 1 Fukushima Nuclear Power Station, Tokyo Electric Power Company, Inc

International Nuclear Information System (INIS)

Tawara, Shigesuke

1979-01-01

There are six BWR type nuclear power plants in the Number 1 Fukushima Nuclear Power Station, Tokyo Electric Power Company, Inc. The service hall of the station is located near the entrance of the station. In the center of this service hall, there is the model of a nuclear reactor of full scale. This mock-up shows the core region in the reactor pressure vessel for the number one plant. The diameter and the thickness of the pressure vessel are about 5 m and 16 cm, respectively. The fuel assemblies and control rods are set just like the actual reactor, and the start-up operation of the reactor is shown colorfully and dynamically by pushing a button. When the control rods are pulled out, the boiling of water is demonstrated. The 1/50 scale model of the sixth plant with the power generating capacity of 1100 MWe is set, and this model is linked to the mock-up of reactor written above. The operations of a recirculating loop, a turbine and a condenser are shown by switching on and off lamps. The other exhibitions are shielding concrete wall, ECCS model, and many kinds of panels and models. This service hall is incorporated in the course of study and observation of civics. The good environmental effects to fishes and shells are explained in this service hall. Official buildings and schools are built near the service hall utilizing the tax and grant concerning power generation. This service hall contributes to give much freedom from anxiety to the public by the tour. (Nakai, Y.)

Analysis of gamma dose for 4,8 gU/cm3 density silicide core at the RSG-GAS reactor using MCNP code

International Nuclear Information System (INIS)

Ardani

2011-01-01

Radiation safety analysis should be done following of substitution of fuel density of 2.96 gU/cc to density of 4,8 gU/cc silicide fuels for the RSG-GAS reactor. MCNP-5 code has been used to perform gamma dose calculation of the RSG-GAS reactor. Gamma radiation source at reactor consists of capture gamma rays, prompt fission gamma rays, and gamma rays of decay of fission and activation products. The strength of the prompt fission gamma rays is obtained by gamma releases of fission process of U-235 and reactor power of 30 MWt., during 46,6 days operation. Radiation dose is calculated at the experimental hall by detection point at the surface of outer of biological shielding and the operation hall by detection point at the top of the pool. The calculation is conducted at reactor on the normal operation and on the worst postulated accident causing the water level at the pool decreases. Calculation result shows that the biggest source strength of gamma rays come from the decay process. The highest calculated dose at the experiment hall is 4,07x10 -3 μSv/h, far from the maximum external dose permitted 25 μSv/h. The highest calculated dose at the operation hall is 19.98 μSv/h. Even though the calculated dose is still acceptable but this is close to the maximum permitted dose for worker. It concluded that loading of 4,8 gU/cc silicide fuel for the RSG-GAS still safe. (author)

Computational analysis of Bangladesh 3 MW TRIGA research reactor using MCNP4C, JENDL-3.3 and ENDF/B-Vl data libraries

International Nuclear Information System (INIS)

Huda, M.Q.

2006-01-01

The three-dimensional continuous energy Monte Carlo code MCNP4C was used to develop a versatile and accurate full-core model of the 3 MW TRIGA MARK II research reactor at Atomic Energy Research Establishment, Savar, Dhaka, Bangladesh. The model represents in detail all components of the core with literally no physical approximation. All fresh fuel and control elements as well as the vicinity of the core were precisely described. Validation of the JENDL-3.3 and ENDF/BVI continuous energy cross-section data for MCNP4C was performed against some well-known benchmark lattices. For TRIGA analysis, data from JENDL-3.3 and ENDF/B-VI in combination with the JENDL-3.2 and ENDF/B-V data files (for nat Zr, nat Mo, nat Cr, nat Fe, nat Ni, nat Si, and nat Mg) at 300 K evaluations were used. Full S(α, β) scattering functions from ENDF/B-V for Zr in ZrH, H in ZrH and water molecule, and for graphite were used in both cases. The validation of the model was performed against the criticality and reactivity benchmark experiments of the TRIGA reactor. There is ∼20.0% decrease of thermal neutron flux occurs when the thermal library is removed during the calculation. Effect of erbium isotope that is present in the TRIGA fuel was also studied. In addition to the effective multiplication values, the well-known integral parameters: δ 28 , δ 25 , ρ 25 , and C * were calculated and compared for both JENDL3.3 and ENDF/B-VI libraries and were found to be in very good agreement. Results are also reported for most of the analyses performed by JENDL-3.2 and ENDF/B-V data libraries

Irreversible magnetic-field dependence of ferromagnetic resonance and inverse spin Hall effect voltage in CoFeB/Pt bilayer

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang-Il [Department of Materials Science and Engineering, Korea University, Seoul, 136-713 (Korea, Republic of); Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Seo, Min-Su [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Choi, Yeon Suk, E-mail: ychoi@kbsi.re.kr [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Park, Seung-Young, E-mail: parksy@kbsi.re.kr [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of)

2017-01-01

Magnetic field (H) sweeping direction dependences of the mixed voltage V{sub mix} induced by the inverse-spin Hall effect(ISHE) and spin-rectified effect (SRE) in a CoFeB (5 nm)/Pt (10 nm) bilayer structure are investigated using the ferromagnetic resonance in the TE mode cavities and coplanar waveguide methods. Conventionally, the magnitude of ISHE voltage V{sub ISH} (symmetric) excluding the SRE (antisymmetric component) was unavoidably separated from the fitting curve of V{sub mix} (a sum of a symmetric and an antisymmetric part) for one direction of H-source. By studying the ratio of the two voltage parts with the bi-directional H sweeping, the optimized V{sub ISH} (no SRE condition) value which also include a well-defined spin Hall angle can be obtained via the linear response relation of ISHE and SRE components. - Highlights: • Hysteretic behavior of ferromagnetic resonance spectra in the CoFeB/Pt sample. • Hysteretic behavior of inverse-spin Hall effect voltage in the CoFeB/Pt sample. • Proportion of inverse spin-Hall effect voltage can be determined by the cavity mode. • The hysteretic behavior arise from the unsaturated magnetization limit. • The well-defined spin Hall angle which consider a hysteresis can be obtained.

Pedro Calderón de la Barca, Judas Macabeo. Edición crítica de las dos versiones, ed. F. Rodríguez-Gallego

Directory of Open Access Journals (Sweden)

Fernando Plata

2013-10-01

Full Text Available Review of Pedro Calderón de la Barca, Judas Macabeo. Edición crítica de las dos versiones, ed. F. Rodríguez-Gallego, Universidad de Navarra / Iberoamericana / Vervuert (Biblioteca Áurea Hispánica, 80; Comedias Completas de Calderón, 8, Madrid / Frankfurt, 2012, 501 pp. ISBN: 978-84-8489-692-0.

G. Güntert, La comedia de Calderón: discurso social y sabiduría poética

OpenAIRE

Sáez, Adrián J.

2013-01-01

À partir de la premisa de que todo el universo tiene cabida en el arte dramático de Calderón, Georges Güntert se adentra por sus caminos para conocer qué mundo aparece realmente en su teatro. En el prólogo, sitúa a Calderón dentro de una concepción cosmológica enlazada con la teología cristiana, con una estética notablemente influida por el neoplatonismo. Pero, como hombre de teatro, se alejaba de la teoría para trasladar a las tablas «los conceptos abstractos que se debatían en los tratados»...

A calderón multiplicative preconditioner for the combined field integral equation

KAUST Repository

Bagci, Hakan

2009-10-01

A Calderón multiplicative preconditioner (CMP) for the combined field integral equation (CFIE) is developed. Just like with previously proposed Caldern-preconditioned CFIEs, a localization procedure is employed to ensure that the equation is resonance-free. The iterative solution of the linear system of equations obtained via the CMP-based discretization of the CFIE converges rapidly regardless of the discretization density and the frequency of excitation. © 2009 IEEE.

Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra

International Nuclear Information System (INIS)

Duran, I.; Bolshakova, I.; Holyaka, R.; Viererbl, L.; Lahodova, Z.; Sentkerestiova, J.; Bem, P.

2010-01-01

We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10 16 cm -2 was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

In-pile inspections of the Calder and Chapelcross nuclear reactors

International Nuclear Information System (INIS)

Stewart, G.

1984-01-01

The subject is discussed under the headings: introduction (relevant data about the reactors); inspection policy; photographic inspection (equipment; inspection results (vessel seam welds and plates; top dome welds; top dome internals)); ultrasonic equipment; manipulator; television inspections; concluding remarks. (U.K.)

United Kingdom national report

International Nuclear Information System (INIS)

Tomkins, B.

1998-01-01

Report of the United Kingdom deals with life extension granted to Calder Hall and Chapelcross reactors for further 10 years operation. The two well recognised life-limiting features of Magnox type reactors are graphite core ageing and materials properties of the reactor pressure circuit components. These features have been scrutinised particularly closely and the conclusion has been reached that there are no safety factors which will necessarily limit the plant life to less than 50 years. Two other life-limiting factors are hear exchanger tubes and the heat exchanger tube failures internal to boiler shells and the integrity of the main engineering structures of the plant. It was concluded that appropriate routine ageing monitoring programs are in place in respect to these features to support continuing operation beyond 40 years

Theoretical study for ICRF sustained LHD type p-{sup 11}B reactor

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Tsuguhiro (ed.)

2003-04-01

This is a summary of the workshop on 'Theoretical Study for ICRF Sustained LHD Type p-{sup 11}B Reactor' held in National Institute for Fusion Science (NIFS) on July 25, 2002. In the workshop, study of LHD type D-{sup 3}He reactor is also reported. A review concerning the advanced nuclear fusion fuels is also attached. This review was reported at the workshop of last year. The development of the p-{sup 11}B reactor research which uses the LHD magnetic field configuration has been briefly summarized in section 1. In section 2, an integrated report on advanced nuclear fusion fuels is given. Ignition conditions in a D-{sup 3}He helical reactor are summarized in section 3. 0-dimensional particle and power balance equations are solved numerically assuming the ISS95 confinement law including a confinement factor ({gamma}{sub HH}). It is shown that high average beta plasma confinement, a large confinement factor ({gamma}{sub HH} > 3) and the hot ion mode (T{sub i}/T{sub e} > 1.4) are necessary to achieve the ignition of the D-{sup 3}He helical reactor. Characteristics of ICRF sustained p-{sup 11}B reactor are analyzed in section 4. The nuclear fusion reaction rate < {sigma}{upsilon} > is derived assuming a quasilinear plateau distribution function (QPDF) for protons, and an ignition condition of p-{sup 11}B reactor is shown to be possible. The 3 of the presented papers are indexed individually. (J.P.N.)

Validation study of the reactor physics lattice transport code WIMSD-5B by TRX and BAPL critical experiments of light water reactors

International Nuclear Information System (INIS)

Khan, M.J.H.; Alam, A.B.M.K.; Ahsan, M.H.; Mamun, K.A.A.; Islam, S.M.A.

2015-01-01

Highlights: • To validate the reactor physics lattice code WIMSD-5B by this analysis. • To model TRX and BAPL critical experiments using WIMSD-5B. • To compare the calculated results with experiment and MCNP results. • To rely on WIMSD-5B code for TRIGA calculations. - Abstract: The aim of this analysis is to validate the reactor physics lattice transport code WIMSD-5B by TRX (thermal reactor-one region lattice) and BAPL (Bettis Atomic Power Laboratory-one region lattice) critical experiments of light water reactors for neutronics analysis of 3 MW TRIGA Mark-II research reactor at AERE, Dhaka, Bangladesh. This analysis is achieved through the analysis of integral parameters of five light water reactor critical experiments TRX-1, TRX-2, BAPL-UO 2 -1, BAPL-UO 2 -2 and BAPL-UO 2 -3 based on evaluated nuclear data libraries JEFF-3.1 and ENDF/B-VII.1. In integral measurements, these experiments are considered as standard benchmark lattices for validating the reactor physics lattice transport code WIMSD-5B as well as evaluated nuclear data libraries. The integral parameters of the said critical experiments are calculated using the reactor physics lattice transport code WIMSD-5B. The calculated integral parameters are compared to the measured values as well as the earlier published MCNP results based on the Chinese evaluated nuclear data library CENDL-3.0 for assessment of deterministic calculation. It was found that the calculated integral parameters give mostly reasonable and globally consistent results with the experiment and the MCNP results. Besides, the group constants in WIMS format for the isotopes U-235 and U-238 between two data files have been compared using WIMS library utility code WILLIE and it was found that the group constants are well consistent with each other. Therefore, this analysis reveals the validation study of the reactor physics lattice transport code WIMSD-5B based on JEFF-3.1 and ENDF/B-VII.1 libraries and can also be essential to

Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II

International Nuclear Information System (INIS)

Pavicevic, M.

1963-07-01

This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings

El laberinto, motivo sacramental en Tirso y Calderón

OpenAIRE

Escudero-Baztán, J.M. (Juan Manuel); Oteiza, B. (Blanca)

2013-01-01

Este trabajo estudia el motivo del laberinto en dos autos sacramentales del siglo XVII: “El laberinto de Creta” de Tirso de Molina y “El laberinto del mundo” de Calderón de la Barca. Se enmarca dentro de un estudio más ambicioso que pretende abarcar la utilización del concepto de laberinto en el teatro del siglo XVII. La lectura de ambos textos muestra profundas transformaciones en el diseño, la estructura, la métrica y la utilización de la alegoría. El estudio comparado arroja una mayor dest...

Benchmark of the CASMO-3G/MICROBURN-B codes for Commonwealth Edison boiling water reactors

International Nuclear Information System (INIS)

Wheeler, J.K.; Pallotta, A.S.

1992-01-01

The Commonwealth Edison Company has performed an extensive benchmark against measured data from three boiling water reactors using the Studsvik lattice physics code CASMO-3G and the Siemens Nuclear Power three-dimensional simulator code MICROBURN-B. The measured data of interest for this benchmark are the hot and cold reactivity, and the core power distributions as measured by the traversing incore probe system and gamma scan data for fuel pins and assemblies. A total of nineteen unit-cycles were evaluated. The database included fuel product lines manufactured by General Electric and Siemens Nuclear Power, wit assemblies containing 7 x 7 to 9 x 9 pin configurations, several water rod designs, various enrichments and gadolina loadings, and axially varying lattice designs throughout the enriched portion of the bundle. The results of the benchmark present evidence that the CASMO-3G/MICROBURN-B code package can adequately model the range of fuel and core types in the benchmark, and the codes are acceptable for performing neutronic analyses of Commonwealth Edison's boiling water reactors

Computational analysis of neutronic parameters for TRIGA Mark-II research reactor using evaluated nuclear data libraries ENDF/B-VII.0 and JENDL-3.3

International Nuclear Information System (INIS)

Altaf, M.H.; Badrun, N.H.; Chowdhury, M.T.

2015-01-01

Highlights: • SRAC-PIJ code and SRAC-CITATION have been utilized to model the core. • Most of the simulated results show no significant differences with references. • Thermal peak flux varies a bit due to up condition of TRIGA. • ENDF/B-VII.0 and JENDL-3.3 libraries perform well for neutronics analysis of TRIGA. - Abstract: Important kinetic parameters such as effective multiplication factor, k eff , excess reactivity, neutron flux and power distribution, and power peaking factors of TRIGA Mark II research reactor in Bangladesh have been calculated using the comprehensive neutronics calculation code system SRAC 2006 with the evaluated nuclear data libraries ENDF/B-VII.0 and JENDL-3.3. In the code system, PIJ code was employed to obtain cross section of the core cells, followed by the integral calculation of neutronic parameters of the reactor conducted by CITATION code. All the analyses were performed using the 7-group macroscopic cross section library. Results were compared to the experimental data, the safety analysis report (SAR) of the reactor provided by General Atomic as well as to the simulated values by numerically benchmarked MCNP4C, WIMS-CITATION and SRAC-CITATION codes. The maximum power densities at the hot spot were found to be 169.7 W/cc and 170.1 W/cc for data libraries ENDF/B-VII.0 and JENDL-3.3, respectively. Similarly, the total peaking factors based on ENDF/B-VII.0 and JENDL-3.3 were calculated as 5.68 and 5.70, respectively, which were compared to the original SAR value of 5.63, as well as to MCNP4C, WIMS-CITATION and SRAC-CITATION results. It was found in most cases that the calculated results demonstrate a good agreement with our experiments and published works. Therefore, this analysis benchmarks the code system and will be helpful to enhance further neutronics and thermal hydraulics study of the reactor

Extreme Soft Limit Observation of Quantum Hall Effect in a 3-d Semiconductor

Science.gov (United States)

Bleiweiss, Michael; Yin, Ming; Amirzadeh, Jafar; Preston, Harry; Datta, Timir

2004-03-01

We report on the evidence for quantum hall effect at 38K and in magnetic fields (B) as low as 1k-Orsted. Our specimens were semiconducting, carbon replica opal (CRO) structures. CRO are three dimensional bulk systems where the carbon is grown by CVD into the porous regions in artificial silica opals. The carbon forms layers on top of the silica spheres as eggshells. The shells are of uneven thickness and are perforated at the contacts points of the opal spheres and form a closed packed, three dimensional crystal structure. Plateaus in inverse R_xy that are conjugated with well-defined Subnikov-deHass modulations in R_xx were observed. The quantum steps that are particularly prominent were the states with fill factors v = p/q (p,q are integers) were the well know fractions, 1/3, 1/2, 3/5, 1 and 5/2. QHE steps indicate that the carriers are localized in two-dimensional regions, which may be due to the extremely large surface to volume ratio associated with replica opal structure. From the B-1 vs v straight line, the effective surface carrier density, ns = 2.2 x 10^14 m-2. To the best of our knowledge, the current work is the first to report fractional quantum hall plateaus in a bulk system.

A calderón-preconditioned single source combined field integral equation for analyzing scattering from homogeneous penetrable objects

KAUST Repository

Valdé s, Felipe; Andriulli, Francesco P.; Bagci, Hakan; Michielssen, Eric

2011-01-01

A new regularized single source equation for analyzing scattering from homogeneous penetrable objects is presented. The proposed equation is a linear combination of a Calderón-preconditioned single source electric field integral equation and a

Experimental halls workshop summary

International Nuclear Information System (INIS)

Thorndike, A.

1976-01-01

A brief discussion is given of: (1) pros and cons of open areas as compared with enclosed halls; (2) experimental hall needs of ep, anti p p, and other options; (3) hall for the lepton detector; and, (4) hall for the hadron spectrometer

Fundamental piezo-Hall coefficients of single crystal p-type 3C-SiC for arbitrary crystallographic orientation

Science.gov (United States)

Qamar, Afzaal; Dao, Dzung Viet; Phan, Hoang-Phuong; Dinh, Toan; Dimitrijev, Sima

2016-08-01

Piezo-Hall effect in a single crystal p-type 3C-SiC, grown by LPCVD process, has been characterized for various crystallographic orientations. The quantified values of the piezo-Hall effect in heavily doped p-type 3C-SiC(100) and 3C-SiC(111) for different crystallographic orientations were used to obtain the fundamental piezo-Hall coefficients, P 12 = ( 5.3 ± 0.4 ) × 10 - 11 Pa - 1 , P 11 = ( - 2.6 ± 0.6 ) × 10 - 11 Pa - 1 , and P 44 = ( 11.42 ± 0.6 ) × 10 - 11 Pa - 1 . Unlike the piezoresistive effect, the piezo-Hall effect for (100) and (111) planes is found to be independent of the angle of rotation of the device within the crystal plane. The values of fundamental piezo-Hall coefficients obtained in this study can be used to predict the piezo-Hall coefficients in any crystal orientation which is very important for designing of 3C-SiC Hall sensors to minimize the piezo-Hall effect for stable magnetic field sensitivity.

La crónica de Ventura García Calderón

Directory of Open Access Journals (Sweden)

Esther Espinoza E.

2012-12-01

Full Text Available Este estudio brinda una lectura del libro de crónicas Bajo el clamor delas sirenas de Ventura García Calderón, en el que ofrece su visión de labarbarie instalada en el centro de la civilización, mediante la guerra. Lamirada del autor logra extraer de esa experiencia la oportunidad parauniversalizar los valores franceses, capaces de convocar a todos los pueblos y culturas, en una nueva era de avance tecnológico.

Energy consumption of sport halls

Energy Technology Data Exchange (ETDEWEB)

1983-01-01

The energy consumption of Finland's sports halls (ball games halls, ice hockey halls and swimming halls) represent approximately 1% of that of the country's whole building stock. In the light of the facts revealed by the energy study the potential energy saving rate in sports halls is 15-25%. The total savings would be something like FIM 30-40 million per annum, of which about a half would be achieved without energy-economic investments only by changing utilization habits and by automatic control measures. The energy-economic investments are for the most part connected with ventilation and their repayment period is from one to five years. On the basis of the energy study the following specific consumption are presented as target values: swimming halls: heat (kWh/m*H3/a)100, electricity (kWh/m*H3/a)35, water (l/m*H3/a)1000 icehockey halls (warm): heat (kWh/m*H3/a)25, electricity (kWh/m*H3/a)15, water (l/m*H3/a)200, ball games halls (multi-purpose halls): heat (kWh/m*H3/a)30, electricity (kWh/m*H3/a)25, water (l/m*H3/a)130. In the study the following points proved to be the central areas of energy saving in sports halls: 1. Flexible regulation of the temperature in sports spaces on the basis of the sport in question. 2. The ventilation of swimming halls should be adjusted in such a way that the humidity of the hall air would comply with the limit humidity curve determined by the quality of structures and the temperature of the outdoor air. 3. An ice skating hall is an establishment producing condensing energy from 8 to 9 months a year worth of approx. 100.000-150.000 Finnmarks. The development of the recovery of condensing energy has become more important. 4. The ventilation of ball games halls may account for over 50% of the energy consumption of the whole building. Therefore special attention should be paid to the optimatization of ventilation as a whole.

Experimental halls workshop summary

International Nuclear Information System (INIS)

Thorndike, A.

1976-01-01

At the experimental halls workshop, discussions were held on: (1) open areas as compared with enclosed halls; (2) the needs of ep, anti pp, and other options; (3) the hall for the lepton detector; and (4) the hall for the hadron spectrometer. The value of different possibilities for the future experimental program was explored. A number of suggestions emerged which will be used as the design of the experimental halls progresses

El bestiario de Cristo en los Autos Sacramentales de Calderón

OpenAIRE

Alonso Rey, Maria Dolores

2005-01-01

communication en attente de publication. El maravilloso mundo de los autos sacramentales. Casa de Velázquez. Madrid. 2005; Del conjunto de figuras y símbolos con los que Calderón representa a Cristo nos interesa analizar los símbolos zoomórficos. Nos interrogaremos sobre su utilización, los contextos en los que aparecen, sus valores visuales y sus potencialidades expresivas. No se elige más que a cinco de ellos : ciervo, león, cordero, pelícano y serpiente.

Levitation of the quantum Hall extended states in the $B\\to$ 0 limit

OpenAIRE

Koschny, Th.; Schweitzer, L.

2004-01-01

We investigate the fate of the quantum Hall extended states within a continuum model with spatially correlated disorder potentials. The model can be projected onto a couple of the lowest Landau bands. Levitation of the $n=0$ critical states is observed if at least the two lowest Landau bands are considered. The dependence on the magnetic length $l_B=(\\hbar/(eB))^{1/2}$ and on the correlation length of the disorder potential $\\eta$ is combined into a single dimensionless parameter $\\hat\\eta=\\e...

Experimental halls workshop summary

International Nuclear Information System (INIS)

Thorndike, A.

1976-01-01

On May 26 and 27, 1976, approximately 50 people met for an informal workshop on plans for experimental halls for ISABELLE. Plans as they exist in the May 1976 version of the ISABELLE proposal were presented. Discussions were held on the following four general topics by separate working groups: (1) pros and cons of open areas as compared with enclosed halls; (2) experimental hall needs of ep, anti pp, and other options; (3) hall for the lepton detector; and (4) hall for the hadron spectrometer. The planning for experimental halls at PEP, the hall for the lepton detector, the hadron spectrometer, and open areas are discussed

Preservation of the first research nuclear reactor in Korea

International Nuclear Information System (INIS)

2008-06-01

This book describes preservation of the first research nuclear reactor in Korea and necessity of building memorial hall, sale of the Institute of Atomic Energy Research in Seoul and dismantlement of the first and the second nuclear reactor, preservation of the first research nuclear reactor and activity about memorial hall of the atomic energy reactor, assignment and leaving the report, and the list of related data.

Tritium release during inspection of reactor 'RA' at 'Vinca' institute

International Nuclear Information System (INIS)

Sipka, V.; Miljevic, N.; Grsic, Z.; Todorovic, D.; Radenkovic, M.

1997-01-01

Tritium content in daily precipitation, atmospheric water vapor inside of the reactor hall and around 'Vinca' Institute as well as in soil up to 800 m distance was monitoring during the regular inspection of the fuel channels. Tritium activity in the reactor hall air moisture was in the range from 0.022 to 6.7 MBq/m 3 . Tritium content in soil moisture between 12.7 and 530.9 Bq/l indicate a certain contamination due to tritium release in the environment, depending on the depth and distance from the place of release (author) [sr

El motivo del viaje en los autos sacramentales de Calderón, I: los viajes mitológicos

Directory of Open Access Journals (Sweden)

Arellano, Ignacio

2011-06-01

Full Text Available The article examines the aspects of the travel in five allegorical plays of Calderón with mythological argument, analyzing the main elements of travel narrative and allegorical use in relation with conventions of the sacramental plays. Especially important is the structure of travel in El divino Jasón and Los encantos de la Culpa organized on the story of the Argonauts and the Odyssey respectively.El artículo examina los aspectos del viaje en cinco autos de argumento mitológico de Calderón, analizando los principales elementos de relato de viaje y su utilización alegórica en el marco del género sacramental. Destaca por su importancia la estructura del viaje en los autos El divino Jasón y Los encantos de la Culpa, sobre la historia de los argonautas y la Odisea respectivamente.

An atomic empire a technical history of the rise and fall of the British atomic energy programme

CERN Document Server

Hill, C N

2013-01-01

Britain was the first country to exploit atomic energy on a large scale, and at its peak in the mid-1960s, it had generated more electricity from nuclear power than the rest of the world combined.The civil atomic energy programme grew out of the military programme which produced plutonium for atomic weapons. In 1956, Calder Hall power station was opened by the Queen. The very next year, one of the early Windscale reactors caught fire and the world's first major nuclear accident occurred.The civil programme ran into further difficulty in the mid-1960s and as a consequence of procrastination in

Large spin Hall magnetoresistance and its correlation to the spin-orbit torque in W/CoFeB/MgO structures

Science.gov (United States)

Cho, Soonha; Baek, Seung-heon Chris; Lee, Kyeong-Dong; Jo, Younghun; Park, Byong-Guk

2015-01-01

The phenomena based on spin-orbit interaction in heavy metal/ferromagnet/oxide structures have been investigated extensively due to their applicability to the manipulation of the magnetization direction via the in-plane current. This implies the existence of an inverse effect, in which the conductivity in such structures should depend on the magnetization orientation. In this work, we report a systematic study of the magnetoresistance (MR) of W/CoFeB/MgO structures and its correlation with the current-induced torque to the magnetization. We observe that the MR is independent of the angle between the magnetization and current direction but is determined by the relative magnetization orientation with respect to the spin direction accumulated by the spin Hall effect, for which the symmetry is identical to that of so-called the spin Hall magnetoresistance. The MR of ~1% in W/CoFeB/MgO samples is considerably larger than those in other structures of Ta/CoFeB/MgO or Pt/Co/AlOx, which indicates a larger spin Hall angle of W. Moreover, the similar W thickness dependence of the MR and the current-induced magnetization switching efficiency demonstrates that MR in a non-magnet/ferromagnet structure can be utilized to understand other closely correlated spin-orbit coupling effects such as the inverse spin Hall effect or the spin-orbit spin transfer torques. PMID:26423608

Air leakage analysis of research reactor HANARO building in typhoon condition for the nuclear emergency preparedness

Energy Technology Data Exchange (ETDEWEB)

Lee, Goany Up; Lee, Hae Cho; Kim, Bong Seok; Kim, Jong Soo; Choi, Pyung Kyu [Dept. of Emergency Preparedness, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-12-15

To find out the leak characteristic of research reactor 'HANARO' building in a typhoon condition MELCOR code which normally is used to simulate severe accident behavior in a nuclear power plant was used to simulate the leak rate of air and fission products from reactor hall after the shutdown of the ventilation system of HANARO reactor building. For the simulation, HANARO building was designed by MELCOR code and typhoon condition passed through Daejeon in 2012 was applied. It was found that the leak rate is 0.1%·day{sup -1} of air, 0.004%·day{sup -1} of noble gas and 3.7×10{sup -5}%·day{sup -1} of aerosol during typhoon passing. The air leak rate of 0.1%·day can be converted into 1.36 m{sup 3}·hr{sup -1} , but the design leak rate in HANARO safety analysis report was considered as 600 m3·hr{sup -1} under the condition of 20 m·sec{sup -1} wind speed outside of the building by typhoon. Most of fission products during the maximum hypothesis accident at HANARO reactor will be contained in the reactor hall, so the direct radiation by remained fission products in the reactor hall will be the most important factor in designing emergency preparedness for HANARO reactor.

Air leakage analysis of research reactor HANARO building in typhoon condition for the nuclear emergency preparedness

International Nuclear Information System (INIS)

Lee, Goany Up; Lee, Hae Cho; Kim, Bong Seok; Kim, Jong Soo; Choi, Pyung Kyu

2016-01-01

To find out the leak characteristic of research reactor 'HANARO' building in a typhoon condition MELCOR code which normally is used to simulate severe accident behavior in a nuclear power plant was used to simulate the leak rate of air and fission products from reactor hall after the shutdown of the ventilation system of HANARO reactor building. For the simulation, HANARO building was designed by MELCOR code and typhoon condition passed through Daejeon in 2012 was applied. It was found that the leak rate is 0.1%·day -1 of air, 0.004%·day -1 of noble gas and 3.7×10 -5 %·day -1 of aerosol during typhoon passing. The air leak rate of 0.1%·day can be converted into 1.36 m 3 ·hr -1 , but the design leak rate in HANARO safety analysis report was considered as 600 m3·hr -1 under the condition of 20 m·sec -1 wind speed outside of the building by typhoon. Most of fission products during the maximum hypothesis accident at HANARO reactor will be contained in the reactor hall, so the direct radiation by remained fission products in the reactor hall will be the most important factor in designing emergency preparedness for HANARO reactor

The annal of british RPV steel plates for first nuclear power station in Japan (1). Unforseen accidents araised before nuclear power plant open

International Nuclear Information System (INIS)

Miyoshi, Shigeru

2011-01-01

This article described the author's experiences of reactor vessel steel plates for the first nuclear power station, Tokai-mura reactor. The station is an advanced Calder Hall type. The electrical output is 166 MWe. The reactor vessel was spherical with internal diameter of 189 cm and wall thickness of 83 mm. Material was a fine-grain, aluminum-killed steel. Each part of pressure vessel, bottom cap, belt 1, 2, 3, 4 and top cap, were prefabricated with welding of plates, then lifted into the reactor building and assembled with welding. Steel plates were imported from UK, press formed to spherical segments in Japan and transferred to the site. Ultrasonic testing, magnetic particle testing of groove face (crack detection), sizing of groove and sulfur print tests were performed as an on-site acceptance testing. Inclusions and lamination openings were observed at groove faces due to gas flame cutting. White spot was observed at rupture face of tensile test specimen. At the liquid penetration testing after back gauging of extra seam, a crack-like indication with length of less than 3 mm was observed. Reexamination of groove face by magnetic particles testing showed indications of inclusion cloud or alumina cloud. These would be cracks caused by hydrogen embrittlement. (T. Tanaka)

RB Research nuclear reactor, Annual report for 2004

International Nuclear Information System (INIS)

Dasic, N.; Pesic, M.; Nikolic, D; Jevremovic, M.; Eskirovic, B.

2005-02-01

Report on RB reactor operation during 2004 contains 3 parts. Part one contains a brief description of the reactor, reactor operation and operational capabilities, reactor components, relevant dosimetry and radiation protection issues, personnel and financial data. It contains data about reactor operation during previous 8 years. Part two is devoted to maintenance of the reactor components, namely, fuel, heavy water, reactor vessel, heavy water circulation system, absorption rods and heavy water level meters, maintenance of electronic, mechanical, electrical and auxiliary equipment. Part three contains data concerned with reactor operation, Annex 1. contains data about heavy water degradation, and Annex 2 is the certificate about the crane bridge in the reactor hall

How many versions does an autograph offer? The authorial interventions in the autograph of Calderón’s «El secreto a voces»

Directory of Open Access Journals (Sweden)

Simon Kroll

2014-11-01

Full Text Available Pedro Calderón de la Barca never ceases to work. His constant in­terest to improve or adapt his texts has produced two versions of the same play in several occasions. His autographs allow us to examine his writing process as well as the theatrical practice in Golden Age Spain. In the autograph of «El secreto a voces», Calderón himself seems to delete up to 200 verses, nevertheless it also presents interventions by other hands. In this article, I will therefore try to distinguish between the authentic and non-authentic interventions in the autograph of «El secreto a voces».

Backfitting of the FRG reactors

Energy Technology Data Exchange (ETDEWEB)

Krull, W [GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht (Germany)

1990-05-01

The FRG-research reactors The GKSS-research centre is operating two research reactors of the pool type fueled with MTR-type type fuel elements. The research reactors FRG-1 and FRG-2 having power levels of 5 MW and 15 MW are in operation for 31 year and 27 years respectively. They are comparably old like other research reactors. The reactors are operating at present at approximately 180 days (FRG-1) and between 210 and 250 days (FRG-2) per year. Both reactors are located in the same reactor hall in a connecting pool system. Backfitting measures are needed for our and other research reactors to ensure a high level of safety and availability. The main backfitting activities during last ten years were concerned with: comparison of the existing design with today demands (criteria, guidelines, standards etc.); and probability approach for events from outside like aeroplane crashes and earthquakes; the main accidents were rediscussed like startup from low and full power, loss of coolant flow, loss of heat sink, loss of coolant and fuel plate melting; a new reactor protection system had to be installed, following today's demands; a new crane has been installed in the reactor hall. A cold neutron source has been installed to increase the flux of cold neutrons by a factor of 14. The FRG-l is being converted from 93% enriched U with Alx fuel to 20% enriched U with U{sub 3}Si{sub 2} fuel. Both cooling towers were repaired. Replacement of instrumentation is planned.

Backfitting of the FRG reactors

International Nuclear Information System (INIS)

Krull, W.

1990-01-01

The FRG-research reactors The GKSS-research centre is operating two research reactors of the pool type fueled with MTR-type type fuel elements. The research reactors FRG-1 and FRG-2 having power levels of 5 MW and 15 MW are in operation for 31 year and 27 years respectively. They are comparably old like other research reactors. The reactors are operating at present at approximately 180 days (FRG-1) and between 210 and 250 days (FRG-2) per year. Both reactors are located in the same reactor hall in a connecting pool system. Backfitting measures are needed for our and other research reactors to ensure a high level of safety and availability. The main backfitting activities during last ten years were concerned with: comparison of the existing design with today demands (criteria, guidelines, standards etc.); and probability approach for events from outside like aeroplane crashes and earthquakes; the main accidents were rediscussed like startup from low and full power, loss of coolant flow, loss of heat sink, loss of coolant and fuel plate melting; a new reactor protection system had to be installed, following today's demands; a new crane has been installed in the reactor hall. A cold neutron source has been installed to increase the flux of cold neutrons by a factor of 14. The FRG-l is being converted from 93% enriched U with Alx fuel to 20% enriched U with U 3 Si 2 fuel. Both cooling towers were repaired. Replacement of instrumentation is planned

Giant Spin Hall Effect and Switching Induced by Spin-Transfer Torque in a W /Co40Fe40B20/MgO Structure with Perpendicular Magnetic Anisotropy

Science.gov (United States)

Hao, Qiang; Xiao, Gang

2015-03-01

We obtain robust perpendicular magnetic anisotropy in a β -W /Co40Fe40B20/MgO structure without the need of any insertion layer between W and Co40Fe40B20 . This is achieved within a broad range of W thicknesses (3.0-9.0 nm), using a simple fabrication technique. We determine the spin Hall angle (0.40) and spin-diffusion length for the bulk β form of tungsten with a large spin-orbit coupling. As a result of the giant spin Hall effect in β -W and careful magnetic annealing, we significantly reduce the critical current density for the spin-transfer-torque-induced magnetic switching in Co40Fe40B20 . The elemental β -W is a superior candidate for magnetic memory and spin-logic applications.

Computational Analysis of Nuclear Safety Parameters of 3 MW TRIGA Mark-II Research Reactor Based on Evaluated Nuclear Data Libraries JENDL-3.3 and ENDF/B-VII.0

International Nuclear Information System (INIS)

Khan, Jahirul Haque

2013-01-01

The objective of this study is to explain the main nuclear safety parameters of 3 MW TRIGA Mark-II Research Reactor at AERE, Savar, Dhaka, Bangladesh from the viewpoint of reactor safety and also reactor operator. The most important nuclear reactor physics safety parameters are power distribution, power peaking factors, shutdown margin, control rod worth, excess reactivity and fuel temperature reactivity coefficient. These parameters are calculated using the chain of the computer codes the SRAC-PIJ for cell calculation based on neutron transport theory and the SRAC-CITATION for core calculation based on neutron diffusion equation. To achieve this objective the TRIGA model is developed by the 3-D diffusion code SRAC-CITATION based on the group constants that come from the collision probability transport code SRAC-PIJ. In this study the evaluated nuclear data libraries JENDL-3.3 and ENDF/B-VII.0 are used. The calculated most important reactor physics parameters are compared to the safety analysis report (SAR) values as well as earlier published MCNP results (numerically benchmark). It was found that the calculated results show a good agreement between the said libraries. Besides, in most cases the calculated results reveal a reasonable agreement with the SAR values (by General Atomic) as well as the MCNP results. In addition, this analysis can be used as the inputs for thermal-hydraulic calculations of the TRIGA fresh core in the steady state and pulse mode operation. Because of power peaking factors, power distributions and temperature reactivity coefficients are the most important reactor safety parameters for normal operation and transient safety analysis in research as well as in power reactors. They form the basis for technical specifications and limitations for reactor operation such as loading pattern limitations for pulse operation (in TRIGA). Therefore, this analysis will be very important to develop the nuclear safety parameters data of 3 MW TRIGA Mark

A comparison of the predicted and observed reaction rates of various neutron detectors in a thermal reactor spectrum

International Nuclear Information System (INIS)

Hardiman, J.P.; Maunders, E.J.

1963-08-01

A number of the detectors commonly used in integral neutron spectrum measurements have been irradiated in the pitch moderator position of a Calder Hall lattice where the detailed energy spectrum is known from time of flight measurements. Predicted and observed reaction rates are generally in good agreement although they are brought into better agreement by a small modification to the spectrum. The predicted cadmium ratios are quite sensitive to the value adopted for the effective cadmium cut off energy, values of which were determined for various detectors using the Ferranti Mercury computer. The values varied over a wide range, although in every case only 40 mil. cadmium filters were used. (author)

E × B electron drift instability in Hall thrusters: Particle-in-cell simulations vs. theory

Science.gov (United States)

Boeuf, J. P.; Garrigues, L.

2018-06-01

The E × B Electron Drift Instability (E × B EDI), also called Electron Cyclotron Drift Instability, has been observed in recent particle simulations of Hall thrusters and is a possible candidate to explain anomalous electron transport across the magnetic field in these devices. This instability is characterized by the development of an azimuthal wave with wavelength in the mm range and velocity on the order of the ion acoustic velocity, which enhances electron transport across the magnetic field. In this paper, we study the development and convection of the E × B EDI in the acceleration and near plume regions of a Hall thruster using a simplified 2D axial-azimuthal Particle-In-Cell simulation. The simulation is collisionless and the ionization profile is not-self-consistent but rather is given as an input parameter of the model. The aim is to study the development and properties of the instability for different values of the ionization rate (i.e., of the total ion production rate or current) and to compare the results with the theory. An important result is that the wavelength of the simulated azimuthal wave scales as the electron Debye length and that its frequency is on the order of the ion plasma frequency. This is consistent with the theory predicting destruction of electron cyclotron resonance of the E × B EDI in the non-linear regime resulting in the transition to an ion acoustic instability. The simulations also show that for plasma densities smaller than under nominal conditions of Hall thrusters the field fluctuations induced by the E × B EDI are no longer sufficient to significantly enhance electron transport across the magnetic field, and transit time instabilities develop in the axial direction. The conditions and results of the simulations are described in detail in this paper and they can serve as benchmarks for comparisons between different simulation codes. Such benchmarks would be very useful to study the role of numerical noise (numerical

JRR-3 neutron radiography facility

International Nuclear Information System (INIS)

Matsubayashi, M.; Tsuruno, A.

1992-01-01

JRR-3 neutron radiography facility consists of thermal neutron radiography facility (TNRF) and cold neutron radiography facility (CNRF). TNRF is installed in JRR-3 reactor building. CNRF is installed in the experimental beam hall adjacent to the reactor building. (author)

Decontamination and Decommissioning Project of the TRIGA Mark - 2 and 3 research reactors

Energy Technology Data Exchange (ETDEWEB)

Jung, K. J.; Baik, S. T.; Chung, U. S.; Park, S. K.; Moon, J. S.; Jung, K. H.; Lee, B. J.; Kim, J. K.; Kim, K. H

1999-02-01

Design work for the D and D began in 1998, and expected to be finished at the end of February 1999. Base on the D and D design, the decommissioning plan and the environmental impact assessment report have been completed and submitted to the MOST for licensing at the end of 1998. These documents are being reviewing at the KINS. It is expected that the licensing from authority will be come out at the end of September 1999. Then D and D practical work will be started in the latter half of the year 1999 and completed by 2002. The first practical work of the D and D will be the KRR-2 reactor hall to transform the hall as a temporary storage of radioactive waste produced during the D and D work. Meanwhile, all the spent fuel from KRR-1 and 2 were safely transported to us at the middle of 1998. The D and D project was originally planned, to be finished by the end of the year 1999. This project were lately modified and extended until the end of the year 2002 because of the interim storage of radioactive wastes arising from the D and D work. These radioactive wastes will be stored at the KRR-2 reactor hall until a disposal facility is operational. (author)

Click - nuclear energy

International Nuclear Information System (INIS)

1986-01-01

The activities of British Nuclear Fuels are listed, explained and illustrated. It offers a complete cycle from uranium enrichment, fuel manufacture and transport, to fuel reprocessing and radioactive waste management. The uranium fission process is explained as are the basic principles of Magnox and Advanced Gas Cooled Reactors. BNFL's head office is at Risley in Cheshire and it has sites at Capenhurst (uranium enrichment plant), Springfields (fuel manufacturing plant) and Sellafield (fuel reprocessing plant). It owns Calder Hall and Chapelcross nuclear power stations. Safety is a major consideration and strict safety regulations are observed at all sites. BNFL also encourages public interest in its activities. This booklet is part of its public information effort. (U.K.)

Zero field Quantum Hall Effect in QED3

International Nuclear Information System (INIS)

Raya, K; Sánchez-Madrigal, S; Raya, A

2013-01-01

We study analytic structure of the fermion propagator in the Quantum Electrodynamics in 2+1 dimensions (QED3) in the Landau gauge, both in perturbation theory and nonperturbatively, by solving the corresponding Schwinger-Dyson equation in rainbow approximation. In the chiral limit, we found many nodal solutions, which could be interpreted as vacuum excitations. Armed with these solutions, we use the Kubo formula and calculate the filling factor for the zero field Quantum Hall Effect

The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field

Energy Technology Data Exchange (ETDEWEB)

Tinh, Bui Duc, E-mail: tinhbd@hnue.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Hoc, Nguyen Quang; Thu, Le Minh [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)

2016-02-15

Highlights: • The time-dependent Ginzburg–Landau was used to calculate fluctuation Hall conductivity and Hall angle in type-II superconductor in 2D and 3D. • We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. • The results were compared to the experimental data on YBCO. - Abstract: The fluctuation Hall conductivity and the Hall angle, describing the Hall effect, are calculated for arbitrary value of the imaginary part of the relaxation time in the frame of the time-dependent Ginzburg–Landau theory in type II-superconductor with thermal noise describing strong thermal fluctuations. The self-consistent Gaussian approximation is used to treat the nonlinear interaction term in dynamics. We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. The results are compared with experimental data on high-T{sub c} superconductor.

The Reproductive Morphology and Physiological Age Grading of the Female Salvinia Weevil, Calder and Sands

Directory of Open Access Journals (Sweden)

Lee Eisenberg

2018-01-01

Full Text Available The morphology of the female Cyrtobagous salviniae Calder and Sands reproductive system is similar to other weevil species being meroistic and telotrophic. The reproductive system is composed of 2 ovaries each containing 2 ovarioles where the follicles mature. A physiological age grading system was developed where the continuum of ovarium development was divided into 2 nulliparous and 3 parous classes. This was based on the differentiation of the ovarioles, presence, and appearance of follicular relics, cuticle hardness/coloration, and fat body quantity/appearance. High correlation occurred between the parous classes and number of eggs produced where the P3 class had over 9-fold higher number of eggs in comparison with the P1 class. Mean number of eggs produced for each parous class was significantly different, however, overlap occurred. Such a system enables a determination of the past, present, and future reproductive status of field populations and mass-rearing colonies.

Preliminary Hazard Classification for the 105-B Reactor

International Nuclear Information System (INIS)

Kerr, N.R.

1997-08-01

This document summarizes the inventories of radioactive and hazardous materials present within the 105-B Reactor and uses the inventory information to determine the preliminary hazard classification for the surveillance and maintenance activities of the facility. The result of this effort was the preliminary hazard classification for the 105-B Building surveillance and maintenance activities. The preliminary hazard classification was determined to be Nuclear Category 3. Additional hazard and accident analysis will be documented in a separate report to define the hazard controls and final hazard classification

ORPHEE reactor. Upgrade of the installation

International Nuclear Information System (INIS)

Farnoux, B.; Maziere, M.

1995-01-01

Designed by the end of the seventies, the ORPHEE Reactor is equipped with two hydrogen cold sources, one hot source and six cold neutron guides. The neutron beams are extracted by nine beam ports and used in two experimental halls, the reactor hall and the neutron guide hall. After fourteen years of use, a modernisation programme is in progress. One step concerns the neutron guides, another one the cold sources with the modification of the cell geometry in order to increase the cold neutron flux. This operation requires the use a new cryogenerator to ensure liquefaction capabilities for the new cells. It is also scheduled to replace the Zircaloy core housing in order to avoid difficulties linked to the expansion under irradiation. (author)

Hall Effect and transient surface photovoltage (SPV study of Cu3BiS3 thin films

Directory of Open Access Journals (Sweden)

F. Mesa

2014-03-01

Full Text Available Here, we present the electrical properties of the compound Cu3BiS3 deposited by co-evaporation. This new compound may have the properties necessary to be used as an absorbent layer in solar cells. The samples were characterized by Hall effect and transient surface photovoltage (SPV measurements. Using Hall effect measurements, we found that the concentration of n charge carriers is in the order of 1016 cm-3 irrespective of the Cu/Bi mass ratio. We also found that the mobility of this compound (μ in the order of 4 cm2 V-1s-1 varies according to the transport mechanisms that govern it and are dependent on temperature. Based on the SPV, we found a high density of surface defects, which can be passivated by superimposing a buffer layer over the Cu3BiS3 compound.

The Influence Of Switching-Off The Big Lamps On The Humidity Operation Hall

International Nuclear Information System (INIS)

Wiranto, Slamet; Sriawan

2001-01-01

When there is no activity in the Operation Hall, the big lamps in this are switched off. Due to the water trap of ventilation system is not in good function, the humidity of the Operation Hall increases. In any point of time the humidity rise over the permitted limit value. To avoid this problem it is needed to investigate the characteristic by measuring the humidity of the Operation Hall at various condition and situation. From the characteristic, it can be determined that for normal condition, the Operation Hall big lamps should be switched off, and 2 days before start-up reactor, the all operation building lamps should be switched on for about 5 days as the operation building humidity back to normal value

Public relations activities of the Service Hall for Kashiwazaki-Kariwa Nuclear Power Station

International Nuclear Information System (INIS)

Kono, T.

1998-01-01

This article includes information of the Service Hall for Kashiwazaki-Kariwa Nuclear Power Station. About 30% of the total electricity production in Japan is due to 16 power stations and 52 reactors. The service hall is a kind of atomic power pavilion for public relations. In Japan, each nuclear power station has such a pavilion, which acts a a center of public relations activities for the atomic power. (S. Grainger)

Overview of fusion reactor safety

International Nuclear Information System (INIS)

Cohen, S.; Crocker, J.G.

1981-01-01

Use of deuterium-tritium burning fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control, (2) neutron activation of structural materials, fluid streams and reactor hall environment, (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions, (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting magnets and radio frequency heating devices, and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power

Para una teoría de la realidad virtual en Calderón

OpenAIRE

Suárez, J.L. (Juan Luis)

2012-01-01

Este artículo se vale del concepto de realidad virtual para analizar la obra de Calderón y enmarcarla en una concepción de la cultura entendida como espectáculo y entretenimiento. En esta concepción, la realidad virtual se entiende a partir de una clasificación que opone lo virtual a lo concreto, no a lo real, y que describe la cultura del Barroco como una época de creativos ensayos sobre la realidad virtual en la literatura y la cultura hispanas que va más allá de la representación y que tie...

Helical magnetic structure and the anomalous and topological Hall effects in epitaxial B20 Fe1 -yCoyGe films

Science.gov (United States)

Spencer, Charles S.; Gayles, Jacob; Porter, Nicholas A.; Sugimoto, Satoshi; Aslam, Zabeada; Kinane, Christian J.; Charlton, Timothy R.; Freimuth, Frank; Chadov, Stanislav; Langridge, Sean; Sinova, Jairo; Felser, Claudia; Blügel, Stefan; Mokrousov, Yuriy; Marrows, Christopher H.

2018-06-01

Epitaxial films of the B20-structure compound Fe1 -yCoyGe were grown by molecular beam epitaxy on Si (111) substrates. The magnetization varied smoothly from the bulklike values of one Bohr magneton per Fe atom for FeGe to zero for nonmagnetic CoGe. The chiral lattice structure leads to a Dzyaloshinskii-Moriya interaction (DMI), and the films' helical magnetic ground state was confirmed using polarized neutron reflectometry measurements. The pitch of the spin helix, measured by this method, varies with Co content y and diverges at y ˜0.45 . This indicates a zero crossing of the DMI, which we reproduced in calculations using first-principles methods. We also measured the longitudinal and Hall resistivity of our films as a function of magnetic field, temperature, and Co content y . The Hall resistivity is expected to contain contributions from the ordinary, anomalous, and topological Hall effects. Both the anomalous and topological Hall resistivities show peaks around y ˜0.5 . Our first-principles calculations show a peak in the topological Hall constant at this value of y , related to the strong spin polarization predicted for intermediate values of y . Our calculations predict half-metallicity for y =0.6 , consistent with the experimentally observed linear magnetoresistance at this composition, and potentially related to the other unusual transport properties for intermediate value of y . While it is possible to reconcile theory with experiment for the various Hall effects for FeGe, the large topological Hall resistivities for y ˜0.5 are much larger than expected when the very small emergent fields associated with the divergence in the DMI are taken into account.

Large-scale high-resolution scanning Hall probe microscope used for MgB2 filament characterization

International Nuclear Information System (INIS)

Cambel, V; Fedor, J; Gregusova, D; Kovac, P; Husek, I

2005-01-01

The scanning Hall probe microscope (SHPM) is an important imaging tool used for detailed studies of superconductors in basic science as well as in the industrial sector. It can be used for the studies of losses, current distribution, and effects at grain boundaries. However, only a few SHPMs for magnetic field imaging at temperatures below 77 K have been proposed up to now, most of them designed for small-area (∼10x10 μm 2 ) scanning. We present a large-scale low-temperature SHPM developed for imaging the entire magnetic field in close proximity to magnetic and superconducting samples at 4.2-300 K. The microscope combines a large scanned area and high spatial and magnetic field resolution. The instrument is designed as an insert of standard helium flowing cryostats. The Hall sensor scans an area up to 7 x 25 mm 2 in the whole temperature interval with a spatial resolution better than 5 μm. The presented system is used for the study of ex situ prepared MgB 2 filament. We show that external magnetic field induces local supercurrents in the MgB 2 , from which the critical current can be estimated. Moreover, it indicates the microstructure and space homogeneity of the superconductor

Espectáculo y construcción espacial en los autos de Pedro Calderón de la Barca: «La cena del rey Baltasar»

Directory of Open Access Journals (Sweden)

Antonio Sánchez Jiménez

2013-11-01

Full Text Available Este artículo analiza la construcción espectacular y espacial de un auto temprano de Calderón de la Barca, «La cena del rey Baltasar». Para ello, examina cómo funcionaban en este auto los elementos escénicos (carros, tramoya y atrezzo, así como la música, el vestuario y los espacios escénico y dramático. This article analyzes the spectacular and spacial construction of an early auto sacramental by Calderón de la Barca, «La cena del rey Baltasar». In order to do so, we examine the meaning of the different scenic elements (carros, theatrical machinery, and atrezzo, as well as the music, clothing, and scenic and dramatic spaces.

Descripción y análisis de capas superpuestas en El castillo de Lindabridis de Calderón

Directory of Open Access Journals (Sweden)

Escudero Baztán, Juan Manuel

2015-06-01

Full Text Available This paper describes and analyzes the highlights of a play El castillo de Lindabridis of Calderón de la Barca: topics relating to the date of his writing and his performances in the seventeenth century, the management of chivalric sources, the unitary structure, the use of emblematic material through the medieval bestiaries, musical interludes, and the staging and the repetition of themes and motifs, along with some final considerations about gender. All these factors indicate the particular importance of this comedy of Calderón.Este trabajo describe y analiza los puntos más relevantes de una obra caballeresca calderoniana poco conocida como El castillo de Lindabridis: cuestiones relativas a la fecha de su escritura y sus representaciones en el siglo XVII, al manejo de las fuentes caballerescas, a la estructura unitaria, al uso de la emblemática a través de los bestiarios medievales, a los interludios musicales, a la escenificación y la repetición de temas y motivos, junto a unas consideraciones finales sobre el género. Elementos en su conjunto que indican la particular relevancia de esta comedia de gran espectáculo calderoniana.

Calculated organ doses for Mayak production association central hall using ICRP and MCNP.

Science.gov (United States)

Choe, Dong-Ok; Shelkey, Brenda N; Wilde, Justin L; Walk, Heidi A; Slaughter, David M

2003-03-01

As part of an ongoing dose reconstruction project, equivalent organ dose rates from photons and neutrons were estimated using the energy spectra measured in the central hall above the graphite reactor core located in the Russian Mayak Production Association facility. Reconstruction of the work environment was necessary due to the lack of personal dosimeter data for neutrons in the time period prior to 1987. A typical worker scenario for the central hall was developed for the Monte Carlo Neutron Photon-4B (MCNP) code. The resultant equivalent dose rates for neutrons and photons were compared with the equivalent dose rates derived from calculations using the conversion coefficients in the International Commission on Radiological Protection Publications 51 and 74 in order to validate the model scenario for this Russian facility. The MCNP results were in good agreement with the results of the ICRP publications indicating the modeling scenario was consistent with actual work conditions given the spectra provided. The MCNP code will allow for additional orientations to accurately reflect source locations.

Theory of the quantized Hall effect. Pt. 3

International Nuclear Information System (INIS)

Levine, H.; Pruisken, A.M.M.; Libby, S.B.

1984-01-01

In the previous paper, we have demonstrated the need for a phase transition as a function of theta in the non-liner sigma-model describing the quantized Hall effect. In this work, we present arguments for the occurrence of exactly such a transition. We make use of a dilute gas instanton approximation as well as present a more rigorous duality argument to show that the usual scaling of the conductivity to zero at large distances is altered whenever sigmasub(xy)sup((0)) approx.= 1/2ne 2 /h, n integer. This then completes our theory of the quantized Hall effect. (orig.)

Pedro Calderón de la Barca, Autos sacramentales - Francisco de Quevedo, Prosa satírica

Directory of Open Access Journals (Sweden)

Fernando Plata

2012-12-01

Full Text Available Reviews of Pedro Calderón de la Barca, Autos sacramentales. El divino Jasón. El gran mercado del Mundo. El gran teatro del Mundo. La viña del Señor, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 50, Madrid, 2010, 406 pp. ISBN: 978-84-92518-54-8 y Francisco de Quevedo, Prosa satírica, ed. I. Arellano, Homo Legens (Bibliotheca Homolegens, 58, Madrid, 2011, 206 pp. ISBN: 978-84-92518-69-2.

The radon monitoring system in Daya Bay Reactor Neutrino Experiment

International Nuclear Information System (INIS)

Chu, M.C.; Kwan, K.K.; Kwok, M.W.; Kwok, T.; Leung, J.K.C.; Leung, K.Y.; Lin, Y.C.; Luk, K.B.; Pun, C.S.J.

2016-01-01

We developed a highly sensitive, reliable and portable automatic system (H 3 ) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H 3 is able to measure radon concentration with a statistical error less than 10% in a 1-h measurement of dehumidified air (R.H. 5% at 25 °C) with radon concentration as low as 50 Bq/m 3 . This is achieved by using a large radon progeny collection chamber, semiconductor α-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013.

El camino de la mina, vehículo de emociones en Calderón

Directory of Open Access Journals (Sweden)

Rull, Enrique

2002-12-01

Full Text Available Calderón uses some scenic devices to stablish certain dramatic situations in the plays. The studied here is related to the function of the mine, which possessed important polisemic values. Not only it is used for stablishing a belie religious or a reat loving environement but also to use this motif with the metaphoric value of passion or as a true laberinto of love, includying trascendental mitological symbols. Everything together is aimed to create a very fast and mysterious activity mixing both comic and tragic effects in which the nonexpected becomes not only dramatical essence but also a personal experience about destinity and life.Calderón utiliza varios recursos escénicos para establecer determinadas situaciones dramáticas en sus obras. El que se estudia aquí se refiere a la función de la mina, que posee valores polisémicos muy notables, los cuales van desde los que le sirven para establecer un ámbito guerrero, religioso, amoroso de carácter real, hasta la utilización de este motivo con carácter metafórico de la pasión amorosa o como verdadero laberinto de amor que incluye incluso una mitologización trascendente de la misma. Todo ello le sirve para configurar en sus obras una acción trepidante, misteriosa, en la que se mezcla lo cómico con lo trágico, y en donde lo inesperado cobra un valor no sólo de esencia dramática sino también de vivencia existencial acerca del destino de la vida.

Thermal and fast reactor benchmark testing of ENDF/B-6.4

International Nuclear Information System (INIS)

Liu Guisheng

1999-01-01

The benchmark testing for B-6.4 was done with the same benchmark experiments and calculating method as for B-6.2. The effective multiplication factors k eff , central reaction rate ratios of fast assemblies and lattice cell reaction rate ratios of thermal lattice cell assemblies were calculated and compared with testing results of B-6.2 and CENDL-2. It is obvious that 238 U data files are most important for the calculations of large fast reactors and lattice thermal reactors. However, 238 U data in the new version of ENDF/B-6 have not been renewed. Only data of 235 U, 27 Al, 14 N and 2 D have been renewed in ENDF/B-6.4. Therefor, it will be shown that the thermal reactor benchmark testing results are remarkably improved and the fast reactor benchmark testing results are not improved

RB research reactor Safety Report

International Nuclear Information System (INIS)

Sotic, O.; Pesic, M.; Vranic, S.

1979-04-01

This RB reactor safety report is a revised and improved version of the Safety report written in 1962. It contains descriptions of: reactor building, reactor hall, control room, laboratories, reactor components, reactor control system, heavy water loop, neutron source, safety system, dosimetry system, alarm system, neutron converter, experimental channels. Safety aspects of the reactor operation include analyses of accident causes, errors during operation, measures for preventing uncontrolled activity changes, analysis of the maximum possible accident in case of different core configurations with natural uranium, slightly and highly enriched fuel; influence of possible seismic events

Study on the reactivity behavior partially loaded reactor cores using SIMULATE-3

International Nuclear Information System (INIS)

Holzer, Robert; Zeitz, Andreas; Grimminger, Werner; Lubczyk, Tobias

2009-01-01

The reactor core design for the NPP Gundremmingen unit B and C is performed since several years using the validated 3D reactor core calculation program SIMULATE-3. The authors describe a special application of the program to study the reactivity for different partial core loadings. Based on the comparison with results of the program CASMO-4 the program SIMULATE-3 was validated for the calculation of partially loaded reactor cores. For the planned reactor operation in NPP Gundremmingen using new MOX fuel elements the reactivity behavior was studied with respect to the KTA-Code requirements.

Decommissioning of Salaspils nuclear reactor

International Nuclear Information System (INIS)

Abramenkovs, A.; Malnachs, J.; Popelis, A.

2002-01-01

In May 1995, the Latvian Government decided to shut down the Research Reactor Salaspils (SRR) and to dispense with nuclear energy in future. The reactor has been out of operation since July 1998. A conceptual study for the decommissioning of SRR has been carried out by Noell-KRC-Energie- und Umwelttechnik GmbH from 1998-1999. he Latvian Government decided on 26 October 1999 to start the direct dismantling to 'green field' in 2001. The results of decommissioning and dismantling performed in 1999-2001 are presented and discussed. The main efforts were devoted to collecting and conditioning 'historical' radioactive waste from different storages outside and inside the reactor hall. All radioactive material more than 20 tons were conditioned in concrete containers for disposal in the radioactive waste depository 'Radons' in the Baldone site. Personal protective and radiation measurement equipment was upgraded significantly. All non-radioactive equipment and material outside the reactor buildings were free-released and dismantled for reuse or conventional disposal. Weakly contaminated material from the reactor hall was collected and removed for free-release measurements. The technology of dismantling of the reactor's systems, i.e. second cooling circuit, zero power reactors and equipment, is discussed in the paper. (author)

Representation of the Indian in Calderón’s «La Aurora en Copacabana»

Directory of Open Access Journals (Sweden)

José Elías Gutiérrez Meza

2014-11-01

Full Text Available The article analyzes the onomastics of the Indian characters, the portrayal of the Inca Empire of Huáscar and Atahualpa, and the Christianization of Guacolda and Yupangui in Calderón’s La Aurora en Copacabana. Rational and proactive, these two characters realize the illegitimacy of the Inca idolatry and embrace the true religion, long before the formal start of Perú’s christianization. Thus, it is argued that this specific representation of the Indian may have been influenced by the close circles indianos of Miguel de Aguirre, who allegedly patronized this comedy.

Dismantling the nuclear research reactor Thetis

Energy Technology Data Exchange (ETDEWEB)

Michiels, P. [Belgoprocess, 2480 Dessel (Belgium)

2013-07-01

The research reactor Thetis, in service since 1967 and stopped in 2003, is part of the laboratories of the institution of nuclear science of the University of Ghent. The reactor, of the pool-type, was used as a neutron-source for the production of radio-isotopes and for activation analyses. The reactor is situated in a water pool with inner diameter of 3 m. and a depth of 7.5 m. The reactor core is situated 5.3 m under water level. Besides the reactor, the pool contains pneumatic loops, handling tools, graphite blocks for neutron moderation and other experimental equipment. The building houses storage rooms for fissile material and sources, a pneumatic circuit for transportation of samples, primary and secondary cooling circuits, water cleaning resin circuits, a ventilation system and other necessary devices. Because of the experimental character of the reactor, laboratories with glove boxes and other tools were needed and are included in the dismantling program. The building is in 3 levels with a crawl-space. The ground-floor contains the ventilation installation, the purification circuits with tanks, cooling circuits and pneumatic transport system. On the first floor, around the reactor hall, the control-room, visiting area, end-station for pneumatic transport, waste-storage room, fuel storage room and the labs are located. The second floor contains a few laboratories and end stations of the two high speed transfer tubes. The lowest level of the pool is situated under ground level. The reactor has been operated at a power of 150 kW and had a max operating power of 250 kW. Belgoprocess has been selected to decommission the reactor, the labs, storage halls and associated circuits to free release the building for conventional reuse and for the removal of all its internals as legal defined. Besides the dose-rate risk and contamination risk, there is also an asbestos risk of contamination. During construction of the installation, asbestos-containing materials were

Multiple Irradiation Capsule Experiment (MICE)-3B Irradiation Test of Space Fuel Specimens in the Advanced Test Reactor (ATR) - Close Out Documentation for Naval Reactors (NR) Information

Energy Technology Data Exchange (ETDEWEB)

M. Chen; CM Regan; D. Noe

2006-01-09

Few data exist for UO{sub 2} or UN within the notional design space for the Prometheus-1 reactor (low fission rate, high temperature, long duration). As such, basic testing is required to validate predictions (and in some cases determine) performance aspects of these fuels. Therefore, the MICE-3B test of UO{sub 2} pellets was designed to provide data on gas release, unrestrained swelling, and restrained swelling at the upper range of fission rates expected for a space reactor. These data would be compared with model predictions and used to determine adequacy of a space reactor design basis relative to fission gas release and swelling of UO{sub 2} fuel and to assess potential pellet-clad interactions. A primary goal of an irradiation test for UN fuel was to assess performance issues currently associated with this fuel type such as gas release, swelling and transient performance. Information learned from this effort may have enabled use of UN fuel for future applications.

The bremsstrahlung tagged photon beam in Hall B at JLab

CERN Document Server

Sober, D I; Longhi, A; Matthews, S K; O'Brien, J T; Berman, B L; Briscoe, W J; Cole, P L; Connelly, J P; Dodge, W R; Murphy, L Y; Philips, S A; Dugger, M K; Lawrence, D; Ritchie, B G; Smith, E S; Lambert, J M; Anciant, E; Audit, G; Auger, T; Marchand, C; Klusman, M; Napolitano, J; Khandaker, M A; Salgado, C W; Sarty, A J

2000-01-01

We describe the design and commissioning of the photon tagging beamline installed in experimental Hall B at the Thomas Jefferson National Accelerator Facility (JLab). This system can tag photon energies over a range from 20% to 95% of the incident electron energy, and is capable of operation with beam energies up to 6.1 GeV. A single dipole magnet is combined with a hodoscope containing two planar arrays of plastic scintillators to detect energy-degraded electrons from a thin bremsstrahlung radiator. The first layer of 384 partially overlapping small scintillators provides photon energy resolution, while the second layer of 61 larger scintillators provides the timing resolution necessary to form a coincidence with the corresponding nuclear interaction triggered by the tagged photon. The definitions of overlap channels in the first counter plane and of geometric correlation between the two planes are determined using digitized time information from the individual counters. Auxiliary beamline devices are briefl...

Hall probe magnetometer for SSC magnet cables

International Nuclear Information System (INIS)

Cross, R.W.; Goldfarb, R.B.

1991-01-01

The authors of this paper constructed a Hall probe magnetometer to measure the magnetization hysteresis loops of Superconducting Super Collider magnet cables. The instrument uses two Hall-effect field sensors to measure the applied field H and the magnetic induction B. Magnetization M is calculated from the difference of the two quantities. The Hall probes are centered coaxially in the bore of a superconducting solenoid with the B probe against the sample's broad surface. An alternative probe arrangement, in which M is measured directly, aligns the sample probe parallel to the field. The authors measured M as a function of H and field cycle rate both with and without a dc transport current. Flux creep as a function of current was measured from the dependence of ac loss on the cycling rate and from the decay of magnetization with time. Transport currents up to 20% of the critical current have minimal effect on magnetization and flux creep

Plans for use of ENDF/B in reactor research in Indonesia

International Nuclear Information System (INIS)

Santoso, B.; Syaukat, A.; Subki, I.; Ganesan, S.

1989-07-01

Nuclear data are numerical constants of nature which quantify the nuclear behaviour of all elements and isotopes which make up the reactor medium and its environment, and which are needed as input for performing design calculations for safe and reliable operation of nuclear reactors. The nuclear data are available in the form of recommended values in specially formatted computerized files such as the Evaluated Nuclear Data File-B, known as ENDF/B. The development of base technology in the scheme of original reactor design calculations involves the mastering of the art of ENDF/B data processing. This paper briefly discusses the current status of this activity in Jakarta and gives an account of the future plans, with emphasis on the role of ENDF/B in reactor calculations. (author). 15 refs, 9 figs

Excess hall effect in epitaxial YBCO film under moderate magnetic fields, approached by renormalized superconducting fluctuations model

International Nuclear Information System (INIS)

Puica, I.; Lang, W.; Goeb, W.; Sobolewski, R.

2002-01-01

Full text: Measurements of the Hall effect and the resistivity on precisely-patterned YBCO thin film in moderate magnetic fields B from 0.5 to 6 T oriented parallel to the crystallographic c axis reveal a sign reversal of the Hall coefficient for B < 3 T. The data are confronted with the full quantitative expressions given by the renormalized fluctuation model for the excess Hall conductivity. The model offers a satisfactory quantitative approach to the experimental results, for moderate fields and temperatures near the critical region, provided the inhomogeneity of the critical temperature distribution is also taken into account. For lower fields and temperatures, the adequacy of the model is altered by vortex pinning. (author)

Hall effect measurements of Frenkel defect clustering in aluminium during high-dose reactor irradiation at 4.6 K

International Nuclear Information System (INIS)

Boening, K.; Mauer, W.; Pfaendner, K.; Rosner, P.

1976-01-01

The low-field Hall coefficient R 0 of irradiated aluminium at 4.6 K is independent of the Frenkel defect (FD) concentration, however sensitively dependent of their configuration. Since measurement of R 0 is not too difficult, rather extensive investigations of FD clustering during irradiation can be performed, but only qualitative interpretations are possible. Several pure Al samples have been irradiated with reactor neutrons at 4.6 K up to very high doses phit resp. resistivity increments Δrho 0 (maximum 91% of extrapolated saturation value Δrho 0 sup(sat) approximately 980 nΩcm). The main results are 1.FD clustering within a single displacement cascade is not a very strong effect in Al, since the R 0 values are essentially the same after reactor and after electron irradiation. Rough cascade averages are: volume Vsub(c) approximately 2.1 x 10 5 at.vol. and FD concentration csub(c) approximately 1100 ppm. 2. There is practically no dose-dependent FD clustering up to Δrho 0 approximately 350 nΩcm, since R 0 remains essentially constant there. It follows that dose-dependent FD clustering can only occur for high-order overlap of cascade volumes. The differential dose curve dΔrho 0 /dphit is perfectly linear in Δrho 0 as long as R 0 = const. 3. For Δrho 0 > 350 nΩcm FD clustering becomes increasingly important and R 0 changes strongly. Surprisingly dR 0 /dphit approximately const whence there is a constant rate of cluster size increase in spite of the vanishing rate of FD production, evidence of the continuous regrouping of the lattice and its defects. (author)

Magnetic domain size effect on resistivity and Hall effect of amorphous Fe83-xZr7B10Mx (M=Ni, Nb) alloys

International Nuclear Information System (INIS)

Rhie, K.; Lim, W.Y.; Lee, S.H.; Yu, S.C.

1997-01-01

Studies of effective permeability, core loss and saturation magnetostriction of Fe 83-x Zr 7 B 10 M x (M=Ni, Nb) alloys revealed that the domain width is smallest around x=0.10. We measured the resistivity and low field Hall coefficients of these alloys and found that the maxima of resistivity and Hall coefficients occurred roughly at the same concentrations. Larger surface area of smaller domains is considered the reason. copyright 1997 American Institute of Physics

Quantum Hall effect on top and bottom surface states of topological insulator (Bi1-xSbx)2Te3 films.

Science.gov (United States)

Yoshimi, R; Tsukazaki, A; Kozuka, Y; Falson, J; Takahashi, K S; Checkelsky, J G; Nagaosa, N; Kawasaki, M; Tokura, Y

2015-04-14

The three-dimensional topological insulator is a novel state of matter characterized by two-dimensional metallic Dirac states on its surface. To verify the topological nature of the surface states, Bi-based chalcogenides such as Bi2Se3, Bi2Te3, Sb2Te3 and their combined/mixed compounds have been intensively studied. Here, we report the realization of the quantum Hall effect on the surface Dirac states in (Bi1-xSbx)2Te3 films. With electrostatic gate-tuning of the Fermi level in the bulk band gap under magnetic fields, the quantum Hall states with filling factor ±1 are resolved. Furthermore, the appearance of a quantum Hall plateau at filling factor zero reflects a pseudo-spin Hall insulator state when the Fermi level is tuned in between the energy levels of the non-degenerate top and bottom surface Dirac points. The observation of the quantum Hall effect in three-dimensional topological insulator films may pave a way toward topological insulator-based electronics.

Investigation of impact of neutron irradiation on properties of InSb-based hall plates

Czech Academy of Sciences Publication Activity Database

Ďuran, Ivan; Oszwaldowski, M.; Kovařík, Karel; Jankowski, J.; El-Ahmar, S.; Viererbl, L.; Lahodová, Z.

2011-01-01

Roč. 417, 1-3 (2011), s. 846-849 ISSN 0022-3115. [International Conference on Fusion Reactor Materials (ICFRM)/14./. Sapporo, 07.09.2009-12.09.2009] R&D Projects: GA MPO 2A-1TP1/101 Institutional research plan: CEZ:AV0Z20430508 Keywords : tokamak * Hall sensors * magnetic measurements * neutron irradiation Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.052, year: 2011 http://www.sciencedirect.com/science/article/pii/S0022311510009712

Electron Cross-field Transport in a Miniaturized Cylindrical Hall Thruster

International Nuclear Information System (INIS)

Smirnov Artem; Raitses Yevgeny; Fisch Nathaniel J

2005-01-01

Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. The present paper gives a review of the experimental and numerical investigations of electron crossfield transport in the 2.6 cm miniaturized cylindrical Hall thruster (100 W power level). We show that, in order to explain the discharge current observed for the typical operating conditions, the electron anomalous collision frequency ν b has to be on the order of the Bohm value, ν B ∼ ω c /16. The contribution of electron-wall collisions to cross-field transport is found to be insignificant. The optimal regimes of thruster operation at low background pressure (below 10 -5 Torr) in the vacuum tank appear to be different from those at higher pressure (∼ 10 -4 Torr)

Attitudes toward the health of men that regularly occupy in a trainer hall.

Directory of Open Access Journals (Sweden)

Adamchhuk Ja.

2012-02-01

Full Text Available It is accepted to consider that by motivation for people that practice in a trainer hall is an improvement of health and original appearance. The aim of this research was to determine whether there is training by part of forming of positive attitude toward the health of men-sportsmen-amateurs that occupy in a trainer hall. In research took part 100 men that engage in the power training in one of three trainer halls of Warsaw. Investigational divided by two groups: 50 persons that occupy in a trainer hall more than one year, but no more than 3 years (group A and 50 persons that practice more than 3 (group B. It is well-proven that training positively influences on the emotional state of men. It was discovered at the same time, that than greater experience of sportsman-amateur, the considerably more often he used additions (including by a stimulant. There was no medical control in both groups. Positive influence of the power training shows that they can be the important element of prophylaxis and physiotherapy.

A study of some radioprotection apparatuses used in the case of pool reactors

International Nuclear Information System (INIS)

Robien, E. de; Choudens, H. de; Delpuech, J.

1965-01-01

Various problems of radioprotection concerning swimming-pool reactors in Grenoble have led us to study adequate solutions: a) The automatic verification of the staff-radioactivity when coming out of Melusine or Siloe has been realized thanks to a βγ gate which is insensitive to the ambient background in the reactor-hall; b) The automatic verification of the contamination of the shoes of the agents working in these reactors has been realized with a dedicated device; c) The necessity to measure precisely γ doses with the help of an autonomous apparatus has led to the making of a plastic-scintillator γ dosimeter; d) The obligation to forbid the opening of doors in some places where there might be a great intensity of radiation, has led us to make doors open according to the intensity of radiation inside the rooms; e) The releases of radioactive iodine have been measured with activated charcoal cartridges that surround a scintillator connected with a unique channel selector; f) Finally the control of reactor safety rod fall in case of a radioactive accident has been secured by a chain whose detector is a chamber immersed in the swimming-pool, which offers, in the particular case of the hot thickness swimming-pool reactor a double advantage: first it enables us to regulate the upper hot water layer, second to get free of transitory radiations which appear in the reactor hall as the experimental apparatuses are taken out from the core. (authors) [fr

Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator

Energy Technology Data Exchange (ETDEWEB)

Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu

2015-09-16

We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.

Scanning micro-Hall probe mapping of magnetic flux distributions and current densities in YBa{sub 2}Cu{sub 3}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Xing, W.; Heinrich, B. [Simon Fraser Univ., British Columbia (Canada); Zhou, H. [CTF Systems, Inc., British Columbia (Canada)] [and others

1994-12-31

Mapping of the magnetic flux density B{sub z} (perpendicular to the film plane) for a YBa{sub 2}Cu{sub 3}O{sub 7} thin-film sample was carried out using a scanning micro-Hall probe. The sheet magnetization and sheet current densities were calculated from the B{sub z} distributions. From the known sheet magnetization, the tangential (B{sub x,y}) and normal components of the flux density B were calculated in the vicinity of the film. It was found that the sheet current density was mostly determined by 2B{sub x,y}/d, where d is the film thickness. The evolution of flux penetration as a function of applied field will be shown.

Neutron beam facilities at the Australian Replacement Research Reactor

International Nuclear Information System (INIS)

Kennedy, Shane; Robinson, Robert; Hunter, Brett

2001-01-01

Australia is building a research reactor to replace the HIFAR reactor at Lucas Heights by the end of 2005. Like HIFAR, the Replacement Research Reactor will be multipurpose with capabilities for both neutron beam research and radioisotope production. It will be a pool-type reactor with thermal neutron flux (unperturbed) of 4 x 10 14 n/cm 2 /sec and a liquid D 2 cold neutron source. Cold and thermal neutron beams for neutron beam research will be provided at the reactor face and in a large neutron guide hall. Supermirror neutron guides will transport cold and thermal neutrons to the guide hall. The reactor and the associated infrastructure, with the exception of the neutron beam instruments, is to be built by INVAP S.E. under contract. The neutron beam instruments will be developed by ANSTO, in consultation with the Australian user community. This status report includes a review the planned scientific capabilities, a description of the facility and a summary of progress to date. (author)

JENDL-3.3 thermal reactor benchmark test

International Nuclear Information System (INIS)

Akie, Hiroshi

2001-01-01

Integral tests of JENDL-3.2 nuclear data library have been carried out by Reactor Integral Test WG of Japanese Nuclear Data Committee. The most important problem in the thermal reactor benchmark testing was the overestimation of the multiplication factor of the U fueled cores. With several revisions of the data of 235 U and the other nuclides, JENDL-3.3 data library gives a good estimation of multiplication factors both for U and Pu fueled thermal reactors. (author)

Music hall Markneukirchen; Musikhalle in Markneukirchen

Energy Technology Data Exchange (ETDEWEB)

Anon.

1996-01-01

The article presents the new building of the music hall Markneukirchen. From the planned use of the building result very high demands on the ventilation system in order to keep to a sound power level of less than 30 dB(A) in the hall. The building services are dealt with using numerous flowsheets and diagrams: Heat supply, ventilation system, sanitary system, building management, instrumentation and control, electric and lighting systems. (BWI) [Deutsch] Der vorliegende Beitrag stellt den Neubau der Musikhalle Markneukirchen vor. Durch das Nutzungskonzept ergeben sich fuer die Einhaltung eines Schalleistungspegels von weniger als 30 dB(A) im Saalbereich an die Lueftungsanlage sehr hohe Ansprueche. Es werden die raumlufttechnischen Anlagen anhand zahlreicher Flussbilder und Abbildungen vorgestellt: Waermeversorgung, Lueftungstechnik, Sanitaertechnik, Gebaeudeleit- und MSR-Technik, Elektro- und Lichttechnik. (BWI)

Annual report on JEN-1 reactor; Informe periodico del Reactor JEN-1 correspondiente al ano 1971

Energy Technology Data Exchange (ETDEWEB)

Montes, J

1972-07-01

In the annual report on the JEN-1 reactor the main features of the reactor operations and maintenance are described. The reactor has been critical for 1831 hours, what means 65,8% of the total working time. Maintenance and pool water contamination have occupied the rest of the time. The maintenance schedule is shown in detail according to three subjects. The main failures and reactor scrams are also described. The daily maximum values of the water activity are given so as the activity of the air in the reactor hall. (Author)

RAMONA-3B/MINET composite representation of BWR thermal-hydraulic systems

International Nuclear Information System (INIS)

Van Tuyle, G.J.; Slovik, G.; Cazzoli, E.G.; Nepsee, T.C.; Guppy, J.G.

1985-01-01

The modification and interfacing of two computer codes, RAMONA-3B and MINET, for the thermal hydraulic transient analysis of a Boiling Water Reactor nuclear steam supply system, is described. The RAMONA-3B code provides for multi-channel thermal hydraulics and three-dimensional (or one-dimensional) neutron kinetics analysis of a boiling water reactor core. The RAMONA-3B system representation terminates at the end of the steam line and at the junction of the feedwater line at the vessel inlet. By interfacing RAMONA-3B with MINET, a generic balance-of-plant systems analysis code, a complete BWR systems code with detailed core modeling was obtained. The result is a code of particular importance to the analysis of transients such as ATWS. A comparison between the 3-D and 1-D neutronics representation is provided, along with a test case utilizing the composite RAMONA-3B/MINET code

Resistive Instabilities in Hall Current Plasma Discharge

International Nuclear Information System (INIS)

Litvak, Andrei A.; Fisch, Nathaniel J.

2000-01-01

Plasma perturbations in the acceleration channel of a Hall thruster are found to be unstable in the presence of collisions. Both electrostatic lower-hybrid waves and electromagnetic Alfven waves transverse to the applied electric and magnetic field are found to be unstable due to collisions in the E X B electron flow. These results are obtained assuming a two-fluid hydrodynamic model in slab geometry. The characteristic frequencies of these modes are consistent with experimental observations in Hall current plasma thrusters

B-periodic oscillations in the Hall-resistance induced by a dc-current-bias under combined microwave-excitation and dc-current bias in the GaAs/AlGaAs 2D system.

Science.gov (United States)

Liu, Han-Chun; Reichl, C; Wegscheider, W; Mani, R G

2018-05-18

We report the observation of dc-current-bias-induced B-periodic Hall resistance oscillations and Hall plateaus in the GaAs/AlGaAs 2D system under combined microwave radiation- and dc bias excitation at liquid helium temperatures. The Hall resistance oscillations and plateaus appear together with concomitant oscillations also in the diagonal magnetoresistance. The periods of Hall and diagonal resistance oscillations are nearly identical, and source power (P) dependent measurements demonstrate sub-linear relationship of the oscillation amplitude with P over the span 0 < P ≤ 20 mW.

Hall effect in La0.6Sr0.4MnO3 thin films

International Nuclear Information System (INIS)

Granada, M.; Maiorov, B.; Sirena, M.; Steren, L.B.; Guimpel, J.

2004-01-01

We studied the temperature and thickness dependence of the transport properties of La 0.6 Sr 0.4 MnO 3 films. Hall voltage and magnetoresistance measurements on 10 and 150 nm thick films were performed with this purpose. From the ordinary Hall component, we calculated the density of carriers, which has hole-character and is systematically lower than that expected from the chemical composition of the manganite in both samples. Localization effects observed at low temperature in the resistivity of the thinner film, associated with the substrate-induced disorder, are correlated with a decrease of the density of carriers

The enigma of the ν=2+3/8 fractional quantum Hall effect

DEFF Research Database (Denmark)

Hutasoit, Jimmy; nrc762, nrc762; Mukherjee, Sutirtha

2017-01-01

The fractional quantum Hall effect at ν=2+3/8, which has been definitively observed, is one of the last fractions for which no viable explanation has so far been demonstrated. Our detailed study suggests that it belongs to a new class of exotic states described by the Bonderson-Slingerland wave...

Annual report on JEN-1 reactor

International Nuclear Information System (INIS)

Montes, J.

1972-01-01

In the annual report on the JEN-1 reactor the main features of the reactor operations and maintenance are described. The reactor has been critical for 1831 hours, what means 65,8% of the total working time. Maintenance and pool water contamination have occupied the rest of the time. The maintenance schedule is shown in detail according to three subjects. The main failures and reactor scrams are also described. The daily maximum values of the water activity are given so as the activity of the air in the reactor hall. (Author)

The neutron beam facility at the Australian replacement research reactor

International Nuclear Information System (INIS)

Hunter, B.; Kennedy, S.

1999-01-01

Full text: The Australian federal government gave ANSTO final approval to build a research reactor to replace HIFAR on August 25th 1999. The replacement reactor is to be a multipurpose reactor with a thermal neutron flux of 3 x 10 14 n.cm -2 .s -1 and having improved capabilities for neutron beam research and for the production of radioisotopes for pharmaceutical, scientific and industrial use. The replacement reactor will commence operation in 2005 and will cater for Australian scientific, industrial and medical needs well into the 21st century. The scientific capabilities of the neutron beams at the replacement reactor are being developed in consultation with representatives from academia, industry and government research laboratories to provide a facility for condensed matter research in physics, chemistry, materials science, life sciences, engineering and earth sciences. Cold, thermal and hot neutron sources are to be installed, and neutron guides will be used to position most of the neutron beam instruments in a neutron guide hall outside the reactor confinement building. Eight instruments are planned for 2005, with a further three to be developed by 2010. A conceptual layout for the neutron beam facility is presented including the location of the planned suite of neutron beam instruments. The reactor and all the associated infrastructure, with the exception of the neutron beam instruments, is to be built by an accredited reactor builder in a turnkey contract. Tenders have been called for December 1999, with selection of contractor planned by June 2000. The neutron beam instruments will be developed by ANSTO and other contracted organisations in consultation with the user community and interested overseas scientists. The facility will be based, as far as possible, around a neutron guide hall that is be served by three thermal and three cold neutron guides. Efficient transportation of thermal and cold neutrons to the guide hall requires the use of modern super

Dosimetry and radiation shielding at the RA reactor, Annual report 1975, Annex 5

International Nuclear Information System (INIS)

Ninkovic, M.

1976-01-01

In the working environment at the RA reactor, the level of gamma radiation is measured continuously by the built-in stationary system. According to the needs, measurement are done in the reactor hall every day. The level of gamma radiation is measured separately in typical points when the reactor is operated at nominal power and during intervals between two operating campaigns. The level of neutron radiation is measured according to the needs by means of a mobile spherical neutron detector. These measurements are done in the reactor hall around the horizontal experimental channels. Measured values of neutron radiation are three times lower than the relevant levels of gamma radiation [sr

Decommissioning of the Salaspils Research Reactor

Directory of Open Access Journals (Sweden)

Abramenkovs Andris

2011-01-01

Full Text Available In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor and to dispense with nuclear energy in the future. The reactor has been out of operation since July 1998. A conceptual study on the decommissioning of the Salaspils Research Reactor was drawn up by Noell-KRC-Energie- und Umwelttechnik GmbH in 1998-1999. On October 26th, 1999, the Latvian government decided to start the direct dismantling to “green-field” in 2001. The upgrading of the decommissioning and dismantling plan was carried out from 2003-2004, resulting in a change of the primary goal of decommissioning. Collecting and conditioning of “historical” radioactive wastes from different storages outside and inside the reactor hall became the primary goal. All radioactive materials (more than 96 tons were conditioned for disposal in concrete containers at the radioactive wastes depository “Radons” at the Baldone site. Protective and radiation measurement equipment of the personnel was upgraded significantly. All non-radioactive equipment and materials outside the reactor buildings were released for clearance and dismantled for reuse or conventional disposal. Contaminated materials from the reactor hall were collected and removed for clearance measurements on a weekly basis.

Testing ENDF/B-V data for thermal reactors

International Nuclear Information System (INIS)

Craig, D.S.

1982-10-01

Lattice parameters have been calculated for some thermal reactor benchmark lattices using ENDF/B-V data. These lattices were TRX-1, -2; BAPL-UO 2 -1,-2,-3; BNL-ThO 2 - 233 UO 2 -H 2 0-1,-2,-3; MIT-4,-5,-6; and PNL-31,-33,-35 (infinite lattices). In addition, parameters were calculated for 3 ZEEP lattices, 3 High-Conversion U0 2 -H 2 0 lattices, and 7 BNL-Th0 2 - 233 U0 2 -D 2 0 lattices. These calculations were made using the integral transport cell code RAHAB with the resonance reaction rates obtained using the OZMA code operating in the discrete ordinate mode. This code calculates the resonance rates allowing for the interaction of all resonances. Four group reaction rates for use in method comparisons are given for several lattices. The author discusses the use of the OZMA code for these calculations, including the choice of options and the orders of the angular quadratures, and compares results obtained using the CRNL thermal scattering data with those obtained using ENDF/B data

Scanning vector Hall probe microscope

Czech Academy of Sciences Publication Activity Database

Fedor, J.; Cambel, V.; Gregušová, D.; Hanzelka, Pavel; Dérer, J.; Volko, J.

2003-01-01

Roč. 74, č. 12 (2003), s. 5105 - 5110 ISSN 0034-6748 Institutional research plan: CEZ:AV0Z2065902 Keywords : VHPM * Hall sensor * Helium cryostat Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.343, year: 2003 http://web. ebscohost .com/ehost/pdf?vid=8&hid=115&sid=a7c0555a-21f4-4932-b1c6-a308ac4dd50b%40sessionmgr2

Alí Calderón: La reconstrucción lírica de la historia de la cultura mexicana

Directory of Open Access Journals (Sweden)

Nieves García Prados

2017-01-01

Full Text Available La poesía de los últimos años se ha caracterizado por una conexión entre los autores de Hispanoamérica y España, entre los que destaca una polifonía de voces. No obstante, existen actualmente dos tendencias entre los poetas de hoy: una conocida como la poética del fragmento o el neobarroco y otra de un corte más realista y que tiene como prioridad la comunicación y la búsqueda de la emoción. En este último grupo se enmarca el llamado movimiento de Poesía ante la Incertidumbre, cuyos precursores apuestan por una poesía que se entienda y que se enfrente a las incertezas actuales. El más joven del grupo es el mexicano Alí Calderón, en el que encontramos una preocupación por la historia y la necesidad de reconstruir de forma lírica la cultura y la tradición de su país.

High temperature hall effect measurement system design, measurement and analysis

Science.gov (United States)

Berkun, Isil

A reliable knowledge of the transport properties of semiconductor materials is essential for the development and understanding of a number of electronic devices. In this thesis, the work on developing a Hall Effect measurement system with software based data acqui- sition and control for a temperature range of 300K-700K will be described. A system was developed for high temperature measurements of materials including single crystal diamond, poly-crystalline diamond, and thermoelectric compounds. An added capability for monitor- ing the current versus voltage behavior of the contacts was used for studying the influence of ohmic and non-ohmic contacts on Hall Effect measurements. The system has been primar- ily used for testing the transport properties of boron-doped single crystal diamond (SCD) deposited in a microwave plasma-assisted chemical vapor deposition (MPCVD) reactor [1]. Diamond has several outstanding properties that are of high interest for its development as an electronic material. These include a relatively wide band gap of 5.5 (eV), high thermal conductivity, high mobility, high saturation velocity, and a high breakdown voltage. For a temperature range of 300K-700K, IV curves, Hall mobilities and carrier concentrations are shown. Temperature dependent Hall effect measurements have shown carrier concentrations from below 1017cm --3 to approximately 1021 cm--3 with mobilities ranging from 763( cm2/V s) to 0.15(cm 2/V s) respectively. Simulation results have shown the effects of single and mixed carrier models, activation energies, effective mass and doping concentrations. These studies have been helpful in the development of single crystal diamond for diode applications. Reference materials of Ge and GaAs were used to test the Hall Effect system. The system was also used to characterize polycrystalline diamond deposited on glass for electrochemical applications, and Mg2(Si,Sn) compounds which are promising candidates of low-cost, light weight and non

Studies of quantum dots in the quantum Hall regime

Science.gov (United States)

Goldmann, Eyal

We present two studies of quantum dots in the quantum Hall regime. In the first study, presented in Chapter 3, we investigate the edge reconstruction phenomenon believed to occur when the quantum dot filling fraction is n≲1 . Our approach involves the examination of large dots (≤40 electrons) using a partial diagonalization technique in which the occupancies of the deep interior orbitals are frozen. To interpret the results of this calculation, we evaluate the overlap between the diagonalized ground state and a set of trial wavefunctions which we call projected necklace (PN) states. A PN state is simply the angular momentum projection of a maximum density droplet surrounded by a ring of localized electrons. Our calculations reveal that PN states have up to 99% overlap with the diagonalized ground states, and are lower in energy than the states identified in Chamon and Wen's study of the edge reconstruction. In the second study, presented in Chapter 4, we investigate quantum dots in the fractional quantum Hall regime using a Hartree formulation of composite fermion theory. We find that under appropriate conditions, the chemical potential of the dots oscillates periodically with B due to the transfer of composite fermions between quasi-Landau bands. This effect is analogous the addition spectrum oscillations which occur in quantum dots in the integer quantum Hall regime. Period f0 oscillations are found in sharply confined dots with filling factors nu = 2/5 and nu = 2/3. Period 3 f0 oscillations are found in a parabolically confined nu = 2/5 dot. More generally, we argue that the oscillation period of dots with band pinning should vary continuously with B, whereas the period of dots without band pinning is f0 .

Spin hall effect associated with SU(2) gauge field

Science.gov (United States)

Tao, Y.

2010-01-01

In this paper, we focus on the connection between spin Hall effect and spin force. Here we investigate that the spin force due to spin-orbit coupling, which, in two-dimensional system, is equivalent to forces of Hirsch and Chudnovsky besides constant factors 3 and frac{3}{2} respectively, is a part of classic Anandan force, and that the spin Hall effect is an anomalous Hall effect. Furthermore, we develop the method of AC phase to derive the expression for the spin force, and note that the most basic spin Hall effect indeed originate from the AC phase and is therefore an intrinsic quantum mechanical property of spin. This method differs from approach of Berry phase in the study of anomalous Hall effect , which is the intrinsic property of the perfect crystal. On the other hand, we use an elegant skill to show that the Chudnovsky-Drude model is reasonable. Here we have improved the theoretical values of spin Hall conductivity of Chudnovsky. Compared to the theoretical values of spin Hall conductivity in the Chudnovsky-Drude model, ours are in better agreement with experimentation. Finally, we discuss the relation between spin Hall effect and fractional statistics.

United Kingdom from past leadership to the renaissance of nuclear industry; Le Royaume-Uni: a l'avant-garde de la renaissance du nucleaire

Energy Technology Data Exchange (ETDEWEB)

Capdevila, J.M. [CEA/Ambassade de France a Londres (United Kingdom)

2010-07-15

United-Kingdom has developed a long tradition of know-how in the domain of nuclear energy since 1956 when the first power reactor entered into service at Calder Hall site. From 1956 till now 45 reactors have been successively connected to the grid. All the sectors of nuclear industry were developed: uranium conversion, enrichment, fuel fabrication, MOX fabrication, spent fuels reprocessing and radioactive waste management. Now British nuclear industry is slowly getting out of a 20 year long period of lethargy due mainly to the lost competition with the oil and gas from the North sea fields. Since 2008 and because the North sea resources are waning, U.K. has become again an oil importer. The new energy policy of the government is to favor renewable energies and to support at least the renewal of the today's reactors. 19 reactors are operating but most are old: 14 reactors will have to be stopped by 2018 unless service life extensions are allowed. The French EDF company who purchased British-Energy in 2009 has announced the construction of 4 EPR by 2025. The renaissance of the nuclear industry in U.K. is all the easier as the past was glorious. (A.C.)

Depleted Reactor Analysis With MCNP-4B

International Nuclear Information System (INIS)

Caner, M.; Silverman, L.; Bettan, M.

2004-01-01

Monte Carlo neutronics calculations are mostly done for fresh reactor cores. There is today an ongoing activity in the development of Monte Carlo plus burnup code systems made possible by the fast gains in computer processor speeds. In this work we investigate the use of MCNP-4B for the calculation of a depleted core of the Soreq reactor (IRR-1). The number densities as function of burnup were taken from the WIMS-D/4 cell code calculations. This particular code coupling has been implemented before. The Monte Carlo code MCNP-4B calculates the coupled transport of neutrons and photons for complicated geometries. We have done neutronics calculations of the IRR-1 core with the WIMS and CITATION codes in the past Also, we have developed an MCNP model of the IRR-1 standard fuel for a criticality safety calculation of a spent fuel storage pool

Dynamics of TRIGA-3 Salazar Reactor

International Nuclear Information System (INIS)

Gallardo S, L.F.

1990-01-01

The theoretical study of temporal behavior of a nuclear reactor is of great importance, since it allows to know, in advance, the conditions to which a reactor is going to be submitted. The reliability of two computer codes (AIREK-JEN and PLANKIN) designed to reproduce the temporal behavior of nuclear reactors, generally power reactors, when they are applied to reproduce the dynamic behavior of TRIGA-3 Salazar Reactor is analyzed. In the first chapters, the fundamental equations that solve this computer codes are deduced, and also the main characteristics of TRIGA-3 Salazar Reactor and the necessary data to run the programs are presented; later the results obtained with the computer codes and the experimental results reported in the operational logbook of the reactor are compared, with the result that such computer codes are applicable to the temporal study of TRIGA-3 Salazar Reactor. (Author)

CALDER: Cryogenic light detectors for background-free searches

Energy Technology Data Exchange (ETDEWEB)

Cardani, L. [Dipartimento di Fisica - Sapienza Università di Roma, Roma - Italy and Physics Department, Princeton University, Princeton, NJ (United States); Bellini, F.; Casali, N.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; Vignati, M. [Dipartimento di Fisica - Sapienza Università di Roma and INFN - Sezione di Roma, Roma - Italy (Italy); Castellano, M. G. [Istituto di Fotonica e Nanotecnologie - CNR, Roma - Italy (Italy); Colantoni, I. [Dipartimento di Fisica - Sapienza Università di Roma (Italy); Di Domizio, S. [Dipartimento di Fisica, Università di Genova, Genova - Italy and INFN Sezione di Genova, Genova - Italy (Italy); Tomei, C. [INFN - Sezione di Roma, Roma - Italy (Italy)

2015-08-17

The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment for 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α’s. LUCIFER, a project based on ZnSe scintillating bolometers for the study of {sup 82}Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ’s. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.

A Calderón multiplicative preconditioner for coupled surface-volume electric field integral equations

KAUST Repository

Bagci, Hakan

2010-08-01

A well-conditioned coupled set of surface (S) and volume (V) electric field integral equations (S-EFIE and V-EFIE) for analyzing wave interactions with densely discretized composite structures is presented. Whereas the V-EFIE operator is well-posed even when applied to densely discretized volumes, a classically formulated S-EFIE operator is ill-posed when applied to densely discretized surfaces. This renders the discretized coupled S-EFIE and V-EFIE system ill-conditioned, and its iterative solution inefficient or even impossible. The proposed scheme regularizes the coupled set of S-EFIE and V-EFIE using a Calderón multiplicative preconditioner (CMP)-based technique. The resulting scheme enables the efficient analysis of electromagnetic interactions with composite structures containing fine/subwavelength geometric features. Numerical examples demonstrate the efficiency of the proposed scheme. © 2006 IEEE.

Comparative studies of JENDL-3.3, JENDL-3.2, JEFF-3, JEF-2.2 and ENDF/B-6.8 data libraries on the Monte Carlo continuous energy modeling of the gas turbine-modular helium reactor operating with thorium fuels

International Nuclear Information System (INIS)

Talamo, Alberto; Gudowski, Waclaw

2005-01-01

One of the major benefits of the Gas Turbine-Modular Helium Reactor is the capability to operate with several different types of fuel; either Light Water Reactors waste, military plutonium or thorium represent valid candidates as possible types of fuel. In the present studies, we performed a comparison of various nuclear data libraries by the Monte Carlo Continuous Energy Burnup Code MCB applied to the Gas Turbine-Modular Helium Reactor operating on a thorium fuel. A thorium fuel offers valuable attractive advantages: low fuel cost, high reduction of actinides production and the possibility to enable the reactor to act as a breeder of fuel by the neutron capture of fertile 232 Th. We evaluated the possibility to mix thorium with small quantities, about 3% in atomic composition, of 239 Pu, 233 U and 235 U. The mass of thorium must be much larger than that one of plutonium or uranium because of the low capture cross section of thorium compared to the fission one of the fissile nuclides; at the same time, the quantity of the fissile isotopes must grant the criticality condition. These two simultaneous constraints force to load a huge mass of fuel in the reactor; consequently, we propose to allocate the fuel in TRISO particles with a large radius of the kernel. For each of the three different fuels we calculated the evolution of the fuel composition by the MCB code equipped with five different nuclear data libraries: JENDL-3.3, JENDL-3.2, JEFF-3, JEF-2.2 and ENDF/B. (author)

In Situ Hall Effect Monitoring of Vacuum Annealing of In2O3:H Thin Films

Directory of Open Access Journals (Sweden)

Hans F. Wardenga

2015-02-01

Full Text Available Hydrogen doped In2O3 thin films were prepared by room temperature sputter deposition with the addition of H2O to the sputter gas. By subsequent vacuum annealing, the films obtain high mobility up to 90 cm2/Vs. The films were analyzed in situ by X-ray photoelectron spectroscopy (XPS and ex situ by X-ray diffraction (XRD, optical transmission and Hall effect measurements. Furthermore, we present results from in situ Hall effect measurements during vacuum annealing of In2O3:H films, revealing distinct dependence of carrier concentration and mobility with time at different annealing temperatures. We suggest hydrogen passivation of grain boundaries as the main reason for the high mobility obtained with In2O3:H films.

Theory of fractional quantum Hall effect

International Nuclear Information System (INIS)

Kostadinov, I.Z.

1984-09-01

A theory of the fractional quantum Hall effect is constructed by introducing 3-particle interactions breaking the symmetry for ν=1/3 according to a degeneracy theorem proved here. An order parameter is introduced and a gap in the single particle spectrum is found. The critical temperature, critical filling number and critical behaviour are determined as well as the Ginzburg-Landau equation coefficients. A first principle calculation of the Hall current is given. 3, 5, 7 electron tunneling and Josephson interference effects are predicted. (author)

Hall-effect-controlled gas dynamics in protoplanetary disks. I. Wind solutions at the inner disk

International Nuclear Information System (INIS)

Bai, Xue-Ning

2014-01-01

The gas dynamics of protoplanetary disks (PPDs) is largely controlled by non-ideal magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect, and ambipolar diffusion. Among these the role of the Hall effect is the least explored and most poorly understood. In this series, we have included, for the first time, all three non-ideal MHD effects in a self-consistent manner to investigate the role of the Hall effect on PPD gas dynamics using local shearing-box simulations. In this first paper, we focus on the inner region of PPDs, where previous studies (Bai and Stone 2013; Bai 2013) excluding the Hall effect have revealed that the inner disk up to ∼10 AU is largely laminar, with accretion driven by a magnetocentrifugal wind. We confirm this basic picture and show that the Hall effect modifies the wind solutions depending on the polarity of the large-scale poloidal magnetic field B 0 threading the disk. When B 0 ⋅Ω>0, the horizontal magnetic field is strongly amplified toward the disk interior, leading to a stronger disk wind (by ∼50% or less in terms of the wind-driven accretion rate). The enhanced horizontal field also leads to much stronger large-scale Maxwell stress (magnetic braking) that contributes to a considerable fraction of the wind-driven accretion rate. When B 0 ⋅Ω<0, the horizontal magnetic field is reduced, leading to a weaker disk wind (by ≲ 20%) and negligible magnetic braking. Under fiducial parameters, we find that when B 0 ⋅Ω>0, the laminar region extends farther to ∼10-15 AU before the magnetorotational instability sets in, while for B 0 ⋅Ω<0, the laminar region extends only to ∼3-5 AU for a typical accretion rate of ∼10 –8 to10 –7 M ☉ yr –1 . Scaling relations for the wind properties, especially the wind-driven accretion rate, are provided for aligned and anti-aligned field geometries.

Hall-effect-controlled gas dynamics in protoplanetary disks. I. Wind solutions at the inner disk

Energy Technology Data Exchange (ETDEWEB)

Bai, Xue-Ning, E-mail: xbai@cfa.harvard.edu [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States)

2014-08-20

The gas dynamics of protoplanetary disks (PPDs) is largely controlled by non-ideal magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect, and ambipolar diffusion. Among these the role of the Hall effect is the least explored and most poorly understood. In this series, we have included, for the first time, all three non-ideal MHD effects in a self-consistent manner to investigate the role of the Hall effect on PPD gas dynamics using local shearing-box simulations. In this first paper, we focus on the inner region of PPDs, where previous studies (Bai and Stone 2013; Bai 2013) excluding the Hall effect have revealed that the inner disk up to ∼10 AU is largely laminar, with accretion driven by a magnetocentrifugal wind. We confirm this basic picture and show that the Hall effect modifies the wind solutions depending on the polarity of the large-scale poloidal magnetic field B{sub 0} threading the disk. When B{sub 0}⋅Ω>0, the horizontal magnetic field is strongly amplified toward the disk interior, leading to a stronger disk wind (by ∼50% or less in terms of the wind-driven accretion rate). The enhanced horizontal field also leads to much stronger large-scale Maxwell stress (magnetic braking) that contributes to a considerable fraction of the wind-driven accretion rate. When B{sub 0}⋅Ω<0, the horizontal magnetic field is reduced, leading to a weaker disk wind (by ≲ 20%) and negligible magnetic braking. Under fiducial parameters, we find that when B{sub 0}⋅Ω>0, the laminar region extends farther to ∼10-15 AU before the magnetorotational instability sets in, while for B{sub 0}⋅Ω<0, the laminar region extends only to ∼3-5 AU for a typical accretion rate of ∼10{sup –8} to10{sup –7} M {sub ☉} yr{sup –1}. Scaling relations for the wind properties, especially the wind-driven accretion rate, are provided for aligned and anti-aligned field geometries.

The 33 years of research reactors in JAERI

International Nuclear Information System (INIS)

1990-11-01

The development and utilization of atomic energy in Japan began with the installation of JRR-1 reactor which attained the criticality in August, 1957, thus the third fire was lighted for the first time in Japan. JRR-2 was constructed as a full scale versatile research reactor, which attained the criticality in October, 1960, and since 1962, it has accomplished the role of the reactor for joint utilization. JRR-3 is the first reactor made in Japan by concentrating Japanese technologies in it, to develop and improve Japanese atomic energy technology. It attained the criticality in September, 1962, and has been used as a versatile research reactor. In 1960, Research Reactor Management Department was founded. JRR-4 was constructed as the research reactor for shielding for developing a nuclear-powered ship, which attained the criticality in January, 1965. The first hot laboratory in Japan for carrying out the post-irradiation test on the fuel and materials irradiated in these research reactors was installed in 1961. The JRR-1 was stopped in September, 1968, and is used as the commemorative exhibition hall. The JRR-3 was reconstructed, and attained the criticality in March, 1990, using 20 % enriched uranium fuel. The course of the research reactors for 33 years is reported. (K.I.)

Topological Hall and spin Hall effects in disordered skyrmionic textures

KAUST Repository

Ndiaye, Papa Birame; Akosa, Collins Ashu; Manchon, Aurelien

2017-01-01

We carry out a thorough study of the topological Hall and topological spin Hall effects in disordered skyrmionic systems: the dimensionless (spin) Hall angles are evaluated across the energy-band structure in the multiprobe Landauer-Büttiker formalism and their link to the effective magnetic field emerging from the real-space topology of the spin texture is highlighted. We discuss these results for an optimal skyrmion size and for various sizes of the sample and find that the adiabatic approximation still holds for large skyrmions as well as for nanoskyrmions. Finally, we test the robustness of the topological signals against disorder strength and show that the topological Hall effect is highly sensitive to momentum scattering.

Topological Hall and spin Hall effects in disordered skyrmionic textures

KAUST Repository

Ndiaye, Papa Birame

2017-02-24

We carry out a thorough study of the topological Hall and topological spin Hall effects in disordered skyrmionic systems: the dimensionless (spin) Hall angles are evaluated across the energy-band structure in the multiprobe Landauer-Büttiker formalism and their link to the effective magnetic field emerging from the real-space topology of the spin texture is highlighted. We discuss these results for an optimal skyrmion size and for various sizes of the sample and find that the adiabatic approximation still holds for large skyrmions as well as for nanoskyrmions. Finally, we test the robustness of the topological signals against disorder strength and show that the topological Hall effect is highly sensitive to momentum scattering.

Integral test of JENDL-3.3 for thermal reactors

International Nuclear Information System (INIS)

Okumura, Keisuke; Mori, Takamasa

2003-01-01

Criticality benchmark testing was carried out for 59 experiments in various thermal reactors using a continues-energy Monte Carlo code MVP and its different libraries generated from JENDL-3.2, JENDL-3.3, JEF-2.2 and ENDF/B-VI (R8). From the benchmark results, we can say JENDL-3.3 generally gives better k eff values compared with other nuclear data libraries. However, further modification of JENDL-3.3 is expected to solve the following problems: 1) systematic underestimation of k eff depending on 235 U enrichment for the cores with low (less than 3wt.%) enriched uranium fueled cores, 2) dependence of C/E value of k eff on neutron spectrum and plutonium composition for MOX fueled cores. These are common problems for all of the nuclear data libraries used in this study. (author)

Generic superweak chaos induced by Hall effect

Science.gov (United States)

Ben-Harush, Moti; Dana, Itzhack

2016-05-01

We introduce and study the "kicked Hall system" (KHS), i.e., charged particles periodically kicked in the presence of uniform magnetic (B ) and electric (E ) fields that are perpendicular to each other and to the kicking direction. We show that for resonant values of B and E and in the weak-chaos regime of sufficiently small nonintegrability parameter κ (the kicking strength), there exists a generic family of periodic kicking potentials for which the Hall effect from B and E significantly suppresses the weak chaos, replacing it by "superweak" chaos (SWC). This means that the system behaves as if the kicking strength were κ2 rather than κ . For E =0 , SWC is known to be a classical fingerprint of quantum antiresonance, but it occurs under much less generic conditions, in particular only for very special kicking potentials. Manifestations of SWC are a decrease in the instability of periodic orbits and a narrowing of the chaotic layers, relative to the ordinary weak-chaos case. Also, for global SWC, taking place on an infinite "stochastic web" in phase space, the chaotic diffusion on the web is much slower than the weak-chaos one. Thus, the Hall effect can be relatively stabilizing for small κ . In some special cases, the effect is shown to cause ballistic motion for almost all parameter values. The generic global SWC on stochastic webs in the KHS appears to be the two-dimensional closest analog to the Arnol'd web in higher dimensional systems.

Hall effect in hopping regime

International Nuclear Information System (INIS)

Avdonin, A.; Skupiński, P.; Grasza, K.

2016-01-01

A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

Hall effect in hopping regime

Energy Technology Data Exchange (ETDEWEB)

Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

2016-02-15

A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

Relativistic quantum Hall conductivity for 3D and 2D electron plasma in an external magnetic field

International Nuclear Information System (INIS)

Gonzalez Felipe, R.; Perez Martinez, A.; Perez-Rojas, H.

1990-05-01

The complete antisymmetric form of the conductivity tensor in the static limit, as well as the expression for the Hall conductivity, is obtained for the relativistic 3D and 2D electron gas in a magnetic field. The non-relativistic 2D limit is also discussed. The typical step form of the 2D Hall conductivity at zero temperature is obtained under the simple hypothesis of constancy of the chemical potential. (author). 6 refs, 1 fig

High-order Div- and Quasi Curl-Conforming Basis Functions for Calderón Multiplicative Preconditioning of the EFIE

KAUST Repository

Valdes, Felipe; Andriulli, Francesco P.; Cools, Kristof; Michielssen, Eric

2011-01-01

A new high-order Calderón multiplicative preconditioner (HO-CMP) for the electric field integral equation (EFIE) is presented. In contrast to previous CMPs, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of high-order quasi curl-conforming basis functions. Like its predecessors, the HO-CMP can be seamlessly integrated into existing EFIE codes. Numerical results demonstrate that the linear systems of equations obtained using the proposed HO-CMP converge rapidly, regardless of the mesh density and of the order of the current expansion. © 2006 IEEE.

High-order Div- and Quasi Curl-Conforming Basis Functions for Calderón Multiplicative Preconditioning of the EFIE

KAUST Repository

Valdes, Felipe

2011-04-01

A new high-order Calderón multiplicative preconditioner (HO-CMP) for the electric field integral equation (EFIE) is presented. In contrast to previous CMPs, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of high-order quasi curl-conforming basis functions. Like its predecessors, the HO-CMP can be seamlessly integrated into existing EFIE codes. Numerical results demonstrate that the linear systems of equations obtained using the proposed HO-CMP converge rapidly, regardless of the mesh density and of the order of the current expansion. © 2006 IEEE.

Descripción y análisis de capas superpuestas en El castillo de Lindabridis de Calderón

OpenAIRE

Escudero Baztán, Juan Manuel

2015-01-01

This paper describes and analyzes the highlights of a play El castillo de Lindabridis of Calderón de la Barca: topics relating to the date of his writing and his performances in the seventeenth century, the management of chivalric sources, the unitary structure, the use of emblematic material through the medieval bestiaries, musical interludes, and the staging and the repetition of themes and motifs, along with some final considerations about gender. All these factors indicate the particular ...

Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

Science.gov (United States)

Singh, Rahul; Shukla, K. K.; Kumar, A.; Okram, G. S.; Singh, D.; Ganeshan, V.; Lakhani, Archana; Ghosh, A. K.; Chatterjee, Sandip

2016-09-01

Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

Surface and 3D Quantum Hall Effects from Engineering of Exceptional Points in Nodal-Line Semimetals

Science.gov (United States)

Molina, Rafael A.; González, José

2018-04-01

We show that, under a strong magnetic field, a 3D nodal-line semimetal is driven into a topological insulating phase in which the electronic transport takes place at the surface of the material. When the magnetic field is perpendicular to the nodal ring, the surface states of the semimetal are transmuted into Landau states which correspond to exceptional points, i.e., branch points in the spectrum of a non-Hermitian Hamiltonian which arise upon the extension to complex values of the momentum. The complex structure of the spectrum then allows us to express the number of zero-energy flat bands in terms of a new topological invariant counting the number of exceptional points. When the magnetic field is parallel to the nodal ring, we find that the bulk states are built from the pairing of surfacelike evanescent waves, giving rise to a 3D quantum Hall effect with a flat level of Landau states residing in parallel 2D slices of the 3D material. The Hall conductance is quantized in either case in units of e2/h , leading in the 3D Hall effect to a number of channels growing linearly with the section of the surface and opening the possibility to observe a macroscopic chiral current at the surface of the material.

Tunnelling anomalous and planar Hall effects (Conference Presentation)

Science.gov (United States)

Matos-Abiague, Alex; Scharf, Benedikt; Han, Jong E.; Hankiewicz, Ewelina M.; Zutic, Igor

2016-10-01

We theoretically show how the interplay between spin-orbit coupling (SOC) and magnetism can result in a finite tunneling Hall conductance, transverse to the applied bias. For two-dimensional tunnel junctions with a ferromagnetic lead and magnetization perpendicular to the current flow, the detected anomalous Hall voltage can be used to extract information not only about the spin polarization but also about the strength of the interfacial SOC. In contrast, a tunneling current across a ferromagnetic barrier on the surface of a three-dimensional topological insulator (TI) can induce a planar Hall response even when the magnetization is oriented along the current flow[1]. The tunneling nature of the states contributing to the planar Hall conductance can be switched from the ordinary to the Klein regimes by the electrostatic control of the barrier strength. This allows for an enhancement of the transverse response and a giant Hall angle, with the tunneling planar Hall conductance exceeding the longitudinal component. Despite the simplicity of a single ferromagnetic region, the TI/ferromagnet system exhibits a variety of functionalities. In addition to a spin-valve operation for magnetic sensing and storing information, positive, negative, and negative differential conductances can be tuned by properly adjusting the barrier potential and/or varying the magnetization direction. Such different resistive behaviors in the same system are attractive for potential applications in reconfigurable spintronic devices. [1] B. Scharf, A. Matos-Abiague, J. E. Han, E. M. Hankiewicz, and I. Zutic, arXiv:1601.01009 (2016).

Destruction of the fractional quantum Hall effect by disorder

International Nuclear Information System (INIS)

Laughlin, R.B.

1985-07-01

It is suggested that Hall steps in the fractional quantum Hall effect are physically similar to those in the ordinary quantum Hall effect. This proposition leads to a simple scaling diagram containing a new type of fixed point, which is identified with the destruction of the fractional states by disorder. 15 refs., 3 figs

Contribution of the study of the Hall Effect. Hall Effect of powder products

International Nuclear Information System (INIS)

Cherville, Jean

1961-01-01

This research thesis reports the development of an apparatus aimed at measuring the Hall Effect and the magneto-resistance of powders at room temperature and at the liquid nitrogen temperature. The author also proposes a theoretical contribution to the Hall Effect and reports the calculation of conditions to be met to obtain a correct value for the Hall constant. Results are experimentally verified. The method is then applied to the study of a set of powdered pre-graphitic graphites. The author shows that their Hall coefficient confirms the model already proposed by Mrozowski. The study of the Hall Effect of any kind of powders can thus be performed, and the Hall Effect can therefore be a mean to study mineral and organic compounds, and notably powdered biological molecules [fr

Analysis of the radiometric survey during the Argonauta reactor operation

International Nuclear Information System (INIS)

Oliveira, Eara de S.L.; Cardozo, Katia K.M.; Silva, Joao Carlos P.; Santos, Joao Regis dos

2013-01-01

The Argonaut reactor at the Institute of Nuclear Engineering-IEN/CNEN, operates normally, the powers between 1.7 and 340 W on neutrongraphy procedures, production of radionuclides and experimental reactor physics lessons to postgraduate courses. The doses from neutrons and gamma radiation are measured when the reactor is critical, inside the reactor hall and surrounding regions. A study of the data obtained was performed to evaluate the daily need of this survey in the reactor hall. Taking into account the principle ALARA, which aims to optimize and minimize the dose received by the individual, we propose, in this work, through an analysis of the acquired data in occupational radiometric surveys, a reformulation of the area monitoring routine practiced by the team of radiological protection of the Institute of Nuclear Engineering - IEN/CNEN-RJ, whereas other monitoring routines regarding the radiological protection are also applied in the routine of the reactor. The operations under review occurred with the reactor operating 340 W power at intervals of 60, 120 and 180 minutes, in monitoring points in controlled areas, supervised and free. The results showed significant dose values in the output of the J-Channel 9 when the operation occurs with this open. With 180 minutes of operation, the measured values of dose rate were lower than the values at 60 min and 120 operations min. At the point in the supervised area, offsite to the reactor hall, situated in the direction of the J-Channel 9, the value reduces more than 14% in any operating time in relation to the dose rate measured at the point opposite the canal. There is a 50% reduction in the dose rates for operations with and J-9 closed. The results suggest a new frequency of radiometric survey whose mode of operation is maintained in similar conditions, since combined with other relevant practices of radiation protection

Cryogenic microsize Hall sensors

International Nuclear Information System (INIS)

Kvitkovic, J.; Polak, M.

1993-01-01

Hall sensors have a variety of applications in magnetic field measurements. The active area of the Hall sensor does not play an important role in measuring of homogeneous magnetic field. Actually Hall sensors are widely used to measure profiles of magnetic fields produced by magnetization currents in samples of HTC superconductors, as well as of LTC ones. Similar techniques are used to measure magnetization of both HTC and LTC superconductors. In these cases Hall sensor operates in highly inhomogeneous magnetic fields. Because of that, Hall sensors with very small active area are required. We developed and tested Hall sensors with active area 100 μm x 100 μm - type M and 50 μm x 50 μm - type V. Here we report on the most imporant parameters of these units, as well as on their properties as differential magnetometer. (orig.)

Anomalous Hall effect in the van der Waals bonded ferromagnet Fe3 -xGeTe2

Science.gov (United States)

Liu, Yu; Stavitski, Eli; Attenkofer, Klaus; Petrovic, C.

2018-04-01

We report the anomalous Hall effect (AHE) in single crystals of a quasi-two-dimensional Fe3 -xGeTe2 (x ≈0.36 ) ferromagnet grown by the flux method which induces defects on the Fe site and bad metallic resistivity. Fe K-edge x-ray absorption spectroscopy was measured to provide information on the local atomic environment in such crystals. The dc and ac magnetic susceptibility measurements indicate a second-stage transition below 119 K in addition to the paramagnetic to ferromagnetic transition at 153 K. A linear scaling behavior between the modified anomalous Hall resistivity ρx y/μ0Heff and longitudinal resistivity ρxx 2M /μ0Heff implies that the AHE in Fe3 -xGeTe2 should be dominated by the intrinsic Karplus-Luttinger mechanism rather than the extrinsic skew-scattering and side-jump mechanisms. The observed deviation in the linear-M Hall conductivity σxy A below 30 K is in line with its transport characteristic at low temperatures, implying the scattering of conduction electrons due to magnetic disorder and the evolution of the Fermi surface induced by a possible spin-reorientation transition.

Single particle detection: Phase control in submicron Hall sensors

International Nuclear Information System (INIS)

Di Michele, Lorenzo; Shelly, Connor; Gallop, John; Kazakova, Olga

2010-01-01

We present a phase-sensitive ac-dc Hall magnetometry method which allows a clear and reliable separation of real and parasitic magnetic signals of a very small magnitude. High-sensitivity semiconductor-based Hall crosses are generally accepted as a preferential solution for non-invasive detection of superparamagnetic nanobeads used in molecular biology, nanomedicine, and nanochemistry. However, detection of such small beads is often hindered by inductive pick-up and other spurious signals. The present work demonstrates an unambiguous experimental route for detection of small magnetic moments and provides a simple theoretical background for it. The reliability of the method has been tested for a variety of InSb Hall sensors in the range 600 nm-5 μm. Complete characterization of empty devices, involving Hall coefficients and noise measurements, has been performed and detection of a single FePt bead with diameter of 140 nm and magnetic moment of μ≅10 8 μ B has been achieved with a 600 nm-wide sensor.

Resistivity and Hall-effect measurements on LaAlO{sub 3}/SrTiO{sub 3-δ} heterostructures

Energy Technology Data Exchange (ETDEWEB)

Sleem, Ahmed [Institut fuer Festkoerperphysik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Fakultaet fuer Physik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Fuchs, Dirk; Schneider, Rudolf [Institut fuer Festkoerperphysik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Mueller, Philipp; Gerthsen, Dagmar [Laboratorium fuer Elektronenmikroskopie, Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Loehneysen, Hilbert von [Institut fuer Festkoerperphysik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Physikalisches Institut, Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

2013-07-01

The influence of the oxygen partial pressure p(O{sub 2}) during film deposition on the transport properties of LaAlO{sub 3}/SrTiO{sub 3-δ} heterostructures was analyzed by resistivity and Hall-effect measurements. To this end, thin films of LaAlO{sub 3} were grown epitaxially by pulsed laser deposition on TiO{sub 2} terminated <001> oriented SrTiO{sub 3} substrates at different oxygen partial pressure p(O{sub 2}), i.e., 10{sup -3} mbar≥p(O{sub 2})≥10{sup -5} mbar. Electrical contacts to the interface were prepared by argon ion-etching and subsequent filling by sputtering of Pt pads. Resistivity measurements were carried out in Van-der-Pauw geometry for 4.2 K≤T≤300 K. The charge carrier concentration, n{sub e}, and mobility, μ{sub e}, were deduced from the Hall-constant, R{sub H}, and conductivity, σ, at room temperature and 4.2 K. With decreasing p(O{sub 2}) the resistivity changes from an insulating/semi-conductive to a metallic behavior. Experimental results with respect to the sheet resistance R{sub S}, n{sub e}, and μ{sub e} versus p(O{sub 2}) are presented and discussed.

Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

Energy Technology Data Exchange (ETDEWEB)

Zhang, J. Y.; Yang, G. [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S. G., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, J. L. [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang, R. M. [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Amsellem, E.; Kohn, A. [Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Yu, G. H., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

2015-04-13

Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

International Nuclear Information System (INIS)

Abou Elmaaty, T.

2014-01-01

The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the suing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer is implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer is produced an inverse buoyant force make the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow - open pool research reactor (with a power greater than 20 M watt) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against Gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability

Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

International Nuclear Information System (INIS)

Abou Elmaaty, T.

2015-01-01

The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the swing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer produced an inverse buoyant force making the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow-open pool research reactor (with a power greater than 20 Mw) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability conditions from

The infrared Hall effect in YBCO: Temperature and frequency dependence of Hall scattering

International Nuclear Information System (INIS)

Grayson, M.; Cerne, J.; Drew, H.D.; Schmadel, D.C.; Hughes, R.; Preston, J.S.; Kung, P.J.; Vale, L.

1999-01-01

The authors measure the Hall angle, θ H , in YBCO films in the far- and mid-infrared to determine the temperature and frequency dependence of the Hall scattering. Using novel modulation techniques they measure both the Faraday rotation and ellipticity induced by these films in high magnetic fields to deduce the complex conductivity tensor. They observe a strong temperature dependence of the mid-infrared Hall conductivity in sharp contrast to the weak dependence of the longitudinal conductivity. By fitting the frequency dependent normal state Hall angle to a Lorentzian θ H (ω) = ω H /(γ H minus iω) they find the Hall frequency, ω H , is nearly independent of temperature. The Hall scattering rate, γ H , is consistent with γ H ∼ T 2 up to 200 K and is remarkably independent of IR frequency suggesting non-Fermi liquid behavior

La cueva de Salamanca de Cervantes y El dragoncillo de Calderón: algunos aspectos del teatro barroco español

Directory of Open Access Journals (Sweden)

Luigi Contadini

2010-05-01

Full Text Available This paper analyses two interludes that share a number of folk motifs in order to highlight Cervantes’ tendency to explore forbidden areas, beyond sacred and social ties, and his inclination to demystify institutions apparently untouchable. At the same time it is underlined how Calderón, despite his inflexible aesthetic and moral principles, manages to represent, by breaking down the essential conflicts of his time, the irresolvable ambivalence between a profound pessimism and a burlesque, playful vision of the world.

Spin Hall Effect in Doped Semiconductor Structures

Science.gov (United States)

Tse, Wang-Kong; Das Sarma, Sankar

2006-03-01

We present a microscopic theory of the extrinsic spin Hall effect based on the diagrammatic perturbation theory. Side-jump (SJ) and skew-scattering (SS) contributions are explicitly taken into account to calculate the spin Hall conductivity, and we show their effects scale as σxy^SJ/σxy^SS ˜(/τ)/ɛF, where τ being the transport relaxation time. Motivated by recent experimental work we apply our theory to n-doped and p-doped 3D and 2D GaAs structures, obtaining analytical formulas for the SJ and SS contributions. Moreover, the ratio of the spin Hall conductivity to longitudinal conductivity is found as σs/σc˜10-3-10-4, in reasonable agreement with the recent experimental results of Kato et al. [Science 306, 1910 (2004)] in n-doped 3D GaAs system.

Critical current density analysis of ex situ MgB2 wire by in-field and temperature Hall probe imaging

International Nuclear Information System (INIS)

Bartolome, E; Granados, X; Cambel, V; Fedor, J; Kovac, P; Husek, I

2005-01-01

The irreversible magnetic behaviour at different temperatures of an ex situ Fe-alloy/MgB 2 wire, exhibiting a granular compositional distribution, was studied using an in-field, high resolution Hall probe imaging system. Quantitative information about the local current density was obtained by solving the Biot-Savart inversion problem. The flux penetration and current distribution maps obtained can be attributed to a inhomogeneous compositional 'plum-cake-like' system, consisting of large, isolated MgB 2 agglomerations embedded in a matrix of finely distributed MgB 2 +MgO. The critical current densities within the grains and their evolution with the applied magnetic field and temperature have been obtained, and compared to the mean J c (H,T) in the matrix

Magnetoresistivity and Hall resistivity of a YBCO thin film in a tilted magnetic field

International Nuclear Information System (INIS)

Amirfeiz, M.; Cimberle, M. R.; Ferdeghini, C.; Giannini, E.; Grassano, G.; Marre', D.; Putti, M.; Siri, A. S.

1997-01-01

In this paper they present magnetoresistivity and Hall effect measurements performed on a YBCO epitaxial film as a function of the angle θ between the external magnetic field and the a-b planes. The resistivity and Hall effect measurements are analyzed in term of the general scaling approach proposed by Blatter and coworkers; the Hall conductivity data are examined to separate the contributions due to vortices and quasi particles

Fast-reactor-data testing of ENDF/B-V at ORNL

International Nuclear Information System (INIS)

Wright, R.Q.; Ford, W.E. III; Lucius, J.L.; Webster, C.C.; Marable, J.H.

1982-01-01

The Cross Section Evaluation Working Group (CSEWG) is coordinating a program to assess the adequacy of ENDF/B-V cross sections for both fast- and thermal-reactor design applications. A secondary goal is to evaluate cross-section processing codes, cross-section libraries, and radiation-transport codes. Fast reactor data testing (FRDT) goals are accomplished, in part, by comparison of calculated results with documented performance parameters of CSEWG fast reactor benchmarks and with results obtained by other data testers. The purpose of this paper is to describe the results of FRDT at Oak Ridge National Laboratory

Wendelstein 7-X Torus Hall Layout and System Integration

International Nuclear Information System (INIS)

Hartmann, D.; Damiani, C.; Hartfuss, H.-J.; Krampitz, R.; Neuner, U.

2006-01-01

Wendelstein 7-X is an experimental fusion device presently under construction in Greifswald, Germany, to study the stellarator concept at reactor relevant parameters und steady-state conditions. The heart of the machine consists of the torus that houses the superconducting coils and the plasma vacuum vessel. It is located nearly in the center of a 30 m x 30 m x 20 m hall. A large number of components need to be placed in close proximity of the torus to provide the system with the required means, e.g. cryogenic gases, cooling water, electricity, and to integrate it with the peripheral diagnostic and heating components. The arrangement of these components has to be supported by suitable structures, and has to be optimized to allow for installation, maintenance, and repair. In addition, space has to be provided for escape routes and for sufficient distance between components that could negatively influence each other's performance, etc. The layout of the components has been done over many years using 3D CAD software. It was based on simple geometric models of the components and of the additionally required space. Presently the layout design is being detailed and updated by replacing the original coarse models with more refined estimates or - in some cases - with as-built models. All interface requirements are carefully taken into account. Detailed routing was specified for the cryo and cooling water supply lines whose design and installation is outsourced. Due to the limited space available and severely restricted access during experimental campaigns, the requirement to put auxiliary components like electronic racks into the torus hall is being queried. The paper summarizes the present state of the component layout in the torus hall, and how the peripheral supply, diagnostics, and heating systems are integrated into the machine. (author)

Unconventional quantum Hall effect in Floquet topological insulators

KAUST Repository

Tahir, M.

2016-07-27

We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the lights polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity αyx = 0 at zero Fermi energy, to a Hall insulator state with αyx = e2/2h. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at (±1/2,±3/2,±5/2, ...)e2/h. © 2016 IOP Publishing Ltd Printed in the UK.

Unconventional quantum Hall effect in Floquet topological insulators

KAUST Repository

Tahir, M.; Vasilopoulos, P.; Schwingenschlö gl, Udo

2016-01-01

We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the lights polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity αyx = 0 at zero Fermi energy, to a Hall insulator state with αyx = e2/2h. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at (±1/2,±3/2,±5/2, ...)e2/h. © 2016 IOP Publishing Ltd Printed in the UK.

The evaluation of research reactor TRIGA MARK II safety

International Nuclear Information System (INIS)

Jordan, R.; Kozuh, M.; Mavko, B.

1994-01-01

In the paper the Probabilistic Safety Analysis (PSA) of a research reactor is described. Five different initiating events were selected and analyzed with the use of event trees. Seven reactor systems were modeled with fault trees. Three groups of radiation releases were introduced - Success, Reactor-Hall, Environment - and their frequencies were estimated. The importance factors of initiating events, human errors and basic events were calculated regarding the consequence groups. (author)

Skyrmions and Hall viscosity

Science.gov (United States)

Kim, Bom Soo

2018-05-01

We discuss the contribution of magnetic Skyrmions to the Hall viscosity and propose a simple way to identify it in experiments. The topological Skyrmion charge density has a distinct signature in the electric Hall conductivity that is identified in existing experimental data. In an electrically neutral system, the Skyrmion charge density is directly related to the thermal Hall conductivity. These results are direct consequences of the field theory Ward identities, which relate various physical quantities based on symmetries and have been previously applied to quantum Hall systems.

Monitoring of irradiation effects on the pressure vessel steels of Calder, Chapelcross and Windscale Advanced Gas Cooled Reactor (WAGR) nuclear reactors

International Nuclear Information System (INIS)

Turner, F.

1980-01-01

Tensile, Charpy and bend specimens of plate, forging and weld metal are exposed in the lower and upper zones of the reactors to neutron fluxes covering the range experienced by the vessels. The test conditions are described, the results presented and discussed. (author)

Crossover between spin swapping and Hall effect in disordered systems

KAUST Repository

Saidaoui, Hamed Ben Mohamed

2015-07-16

We theoretically study the crossover between spin Hall effect and spin swapping, a recently predicted phenomenon that consists of the interchange between the current flow and its spin polarization directions [M. B. Lifshits and M. I. Dyakonov, Phys. Rev. Lett. 103, 186601 (2009)]. Using a tight-binding model with spin-orbit coupled disorder, spin Hall effect, spin relaxation, and spin swapping are treated on equal footing. We demonstrate that spin swapping and spin Hall effect present very different dependencies as a function of the spin-orbit coupling and disorder strengths and confirm that the former exceeds the latter in the parameter range considered. Three setups are proposed for the experimental observation of the spin swapping effect.

Crossover between spin swapping and Hall effect in disordered systems

KAUST Repository

Saidaoui, Hamed Ben Mohamed; Otani, Y.; Manchon, Aurelien

2015-01-01

We theoretically study the crossover between spin Hall effect and spin swapping, a recently predicted phenomenon that consists of the interchange between the current flow and its spin polarization directions [M. B. Lifshits and M. I. Dyakonov, Phys. Rev. Lett. 103, 186601 (2009)]. Using a tight-binding model with spin-orbit coupled disorder, spin Hall effect, spin relaxation, and spin swapping are treated on equal footing. We demonstrate that spin swapping and spin Hall effect present very different dependencies as a function of the spin-orbit coupling and disorder strengths and confirm that the former exceeds the latter in the parameter range considered. Three setups are proposed for the experimental observation of the spin swapping effect.

Sobre sueños y visiones en el auto de Calderón Los encantos de la culpa (1645)

OpenAIRE

Gilbert , Françoise

2005-01-01

International audience; El auto de Calderón Los encantos de la culpa (1645) alegoriza el conocido episodio de la llegada de Ulises y sus compañeros a la isla de Circe, la transformación de los marineros en animales por la maga y su rescate por el astuto héroe. En la transposición calderoniana, el Hombre, acompañado de sus cinco Sentidos y de su Entendimiento, se enfrenta con la Culpa y sus seducciones, vencidas gracias a la ayuda del cielo y la intervención de Penitencia. La adecuación entre ...

ε-iron nitrides: Intrinsic anomalous Hall ferromagnets

Directory of Open Access Journals (Sweden)

Guo-Ke Li

2015-02-01

Full Text Available The anomalous Hall effect in ε-iron nitrides (ε-Fe3-xN, 0 ≤ x ≤ 1 has been systematically investigated taking advantage of the fact that the exchange splitting of ε-Fe3-xN can be continuously tuned through the nitrogen concentration. It has been found that the anomalous Hall conductivity, σ x y A H , is proportional to the saturation magnetization MS, i.e., σ x y A H = S H M S , across significant variations in the saturation magnetization (96–1146 emu/cc. This relationship is in excellent agreement with the intrinsic mechanism as well as with the unified theory of AHE. Our results also demonstrate that the anomalous Hall conductivity is sensitive to the exchange splitting of the band structure.

Quantum critical Hall exponents

CERN Document Server

Lütken, C A

2014-01-01

We investigate a finite size "double scaling" hypothesis using data from an experiment on a quantum Hall system with short range disorder [1-3]. For Hall bars of width w at temperature T the scaling form is w(-mu)T(-kappa), where the critical exponent mu approximate to 0.23 we extract from the data is comparable to the multi-fractal exponent alpha(0) - 2 obtained from the Chalker-Coddington (CC) model [4]. We also use the data to find the approximate location (in the resistivity plane) of seven quantum critical points, all of which closely agree with the predictions derived long ago from the modular symmetry of a toroidal sigma-model with m matter fields [5]. The value nu(8) = 2.60513 ... of the localisation exponent obtained from the m = 8 model is in excellent agreement with the best available numerical value nu(num) = 2.607 +/- 0.004 derived from the CC-model [6]. Existing experimental data appear to favour the m = 9 model, suggesting that the quantum Hall system is not in the same universality class as th...

Uranium-fuel thermal reactor benchmark testing of CENDL-3

International Nuclear Information System (INIS)

Liu Ping

2001-01-01

CENDL-3, the new version of China Evaluated Nuclear Data Library are being processed, and distributed for thermal reactor benchmark analysis recently. The processing was carried out using the NJOY nuclear data processing system. The calculations and analyses of uranium-fuel thermal assemblies TRX-1,2, BAPL-1,2,3, ZEEP-1,2,3 were done with lattice code WIMSD5A. The results were compared with the experimental results, the results of the '1986'WIMS library and the results based on ENDF/B-VI. (author)

Construction of the neutron beam facility at Australia's OPAL research reactor

International Nuclear Information System (INIS)

Kennedy, Shane J.

2006-01-01

Australia's new research reactor, OPAL, has been designed principally for neutron beam science and radioisotope production. It has a capacity for 18 neutron beam instruments, located at the reactor face and in a neutron guide hall. The neutron beam facility features a 20 l liquid deuterium cold neutron source and cold and thermal supermirror neutron guides. Nine neutron beam instruments are under development, of which seven are scheduled for completion in early 2007. The project is approaching the hot-commissioning stage, when criticality will be demonstrated. Installation of the neutron beam transport system and neutron beam instruments in the neutron guide hall and at the reactor face is underway, and the path to completion of this project is relatively clear. This paper will outline the key features of the OPAL reactor, and will describe the neutron beam facility in particular. The status of the construction and a forecast of the program to completion, including commissioning and commencement of routine operation in 2007 will also be discussed

Hall effect in high- Tc Y 1Ba 2Cu 3O 7-δ superconductor

Science.gov (United States)

Vezzoli, G. C.; Burke, T.; Moon, B. M.; Lalevic, B.; Safari, A.; Sundar, H. G. K.; Bonometti, R.; Alexander, C.; Rau, C.; Waters, K.

1989-04-01

We have performed point-by-point and continuous Hall effect experiments as a function of temperature in polycrystalline Y 1Ba 2Cu 3O 7-δ. We have shown that the positive Hall constant shows an abrupt increase upon decreasing temperature at a value just above Tc. This temperature corresponds to where the resistance versus temperature data deviates from linearity. At very high fields of 6.8 and 15 T we observe a subsequent decrease in RH. We interpret these data as supportive of a contribution toward the superconductivity mechanism arising from internal excitions or change transfer excitations such that the bound exciton concentration increases near Tc at the expense of positive carries which are reflected in both bound and free holes.

Unusual Thermal Hall Effect in a Kitaev Spin Liquid Candidate α -RuCl3

Science.gov (United States)

Kasahara, Y.; Sugii, K.; Ohnishi, T.; Shimozawa, M.; Yamashita, M.; Kurita, N.; Tanaka, H.; Nasu, J.; Motome, Y.; Shibauchi, T.; Matsuda, Y.

2018-05-01

The Kitaev quantum spin liquid displays the fractionalization of quantum spins into Majorana fermions. The emergent Majorana edge current is predicted to manifest itself in the form of a finite thermal Hall effect, a feature commonly discussed in topological superconductors. Here we report on thermal Hall conductivity κx y measurements in α -RuCl3 , a candidate Kitaev magnet with the two-dimensional honeycomb lattice. In a spin-liquid (Kitaev paramagnetic) state below the temperature characterized by the Kitaev interaction JK/kB˜80 K , positive κx y develops gradually upon cooling, demonstrating the presence of highly unusual itinerant excitations. Although the zero-temperature property is masked by the magnetic ordering at TN=7 K , the sign, magnitude, and T dependence of κx y/T at intermediate temperatures follows the predicted trend of the itinerant Majorana excitations.

Mapping the radiation fields at a research reactor

International Nuclear Information System (INIS)

Soegaard-Hansen, Jens; Warming, Lisbeth

1999-01-01

The DR 3 reactor at Risoe National Laboratory is a multipurpose research reactor. It has the status of a Large European Beam facility therefor its neutron scattering spectrometers are used by many visiting scientists. As a supplement to the routine health physics monitoring programmes a special survey has been made to get more detailed information of the radiation levels in the hall and of the most important sources of the radiation. The special survey consisted of three sorts of measurements: an extra set of thermoluminescence dosimeters, a set of continuous measurements of the dose rate at selected places and spot measurements with handheld instruments around the spectrometers. Some of the results from the survey are presented. (au)

Design and development of a 3 axis magnetic field measurement facility using Hall probe

International Nuclear Information System (INIS)

Sahoo, Shantonu; Bhattacharyya, Sumantra; Chaddha, Niraj; Mishra, Santosh Kr.; Nandy, Partha P.; Nandi, Chinmay; Bhole, Rajendra B.; Pal, Sarbajit; Pal, Gautam

2015-01-01

A 3-axis drive system has been designed and developed in-house to measure the magnetic field with positional accuracy of 0.2 mm in a volume of 1.5 x 1.3 x 0.15 cubic-meter. Hall sensor based magnetometer is used to measure the magnetic field with a precision of 100 μT(1 Gauss). The drive of each axis has linear guide and zero backlash ball screw combination to achieve accurate movement of the hall probe with positional repeatability of +/- 0.2 micron per 50 mm. The hardware and software, also developed in-house, facilitate precise probe positioning and sophisticated visualization of field map. Dedicated microcontroller based motor controllers and encoder read-out cards for each axis have been developed. The facility is integrated with a rich touch-screen based intelligent GUI for automated scanning and data acquisition. This facility can be used for accurate magnetic field mapping of big dipole magnets, solenoids, etc. The facility has been tested successfully to characterize a Dipole Magnet designed for Radioactive Ion Beam (RIB) facility. (author)

The research reactor BER II at the Helmholtz-Center Berlin

Energy Technology Data Exchange (ETDEWEB)

Krohn, Herbert [Helmholtz-Zentrum Berlin (HZB), Berlin (Germany)

2012-10-15

For basic and application-oriented research assignments the Helmholtz-Center Berlin (Helmholtz Zentrum Berlin - HZB) runs a research reactor that operates as a source of neutron beams for a wide range of scientific investigations. At the end of the 1980{sup th} the BER II was completed renewed and fitted with new experimental facilities. The BER II is a light water cooled and moderated swimming pool type reactor to be operated at 10 MW thermal power. Six neutron guides deliver cold neutrons from the cold moderator cell to a neutron guide hall adjacent to the experiment hall. With its 24 experimental stations, experimenters at HZB have practically all neutron scattering or neutron radiography techniques at their disposal. (orig.)

The research reactor BER II at the Helmholtz-Center Berlin

International Nuclear Information System (INIS)

Krohn, Herbert

2012-01-01

For basic and application-oriented research assignments the Helmholtz-Center Berlin (Helmholtz Zentrum Berlin - HZB) runs a research reactor that operates as a source of neutron beams for a wide range of scientific investigations. At the end of the 1980 th the BER II was completed renewed and fitted with new experimental facilities. The BER II is a light water cooled and moderated swimming pool type reactor to be operated at 10 MW thermal power. Six neutron guides deliver cold neutrons from the cold moderator cell to a neutron guide hall adjacent to the experiment hall. With its 24 experimental stations, experimenters at HZB have practically all neutron scattering or neutron radiography techniques at their disposal. (orig.)

Hall effect in La{sub 0.6}Sr{sub 0.4}MnO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Granada, M. E-mail: granadam@cab.cnea.gov.ar; Maiorov, B.; Sirena, M.; Steren, L.B.; Guimpel, J

2004-05-01

We studied the temperature and thickness dependence of the transport properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3} films. Hall voltage and magnetoresistance measurements on 10 and 150 nm thick films were performed with this purpose. From the ordinary Hall component, we calculated the density of carriers, which has hole-character and is systematically lower than that expected from the chemical composition of the manganite in both samples. Localization effects observed at low temperature in the resistivity of the thinner film, associated with the substrate-induced disorder, are correlated with a decrease of the density of carriers.

Design features of BREST reactors. Experimental work to advance the concept of BREST reactors. Results and plans

International Nuclear Information System (INIS)

Filin, A.I.; Orlov, V.V.; Leonov, V.N.; Sila-Novitskij, A.G.; Smirnov, V.S.; Tsikunov, V.S.

2001-01-01

Principle designs of 300 MW(th) and 1200 MW(th) lead-cooled fast reactors are presented. Reactors of various output are shown to be built using the same principles. In conjunction with increased output and to implement inherent safety concept in BREST-1200 reactor design a number of new solutions, which may be used in BREST-300 concept too, has been taken including: pool-type reactor design not requiring metal vessel, hence, not limiting reactor power; new handling system allowing to reduce central hall and building dimensions as a whole; emergency cooling system using Field pipes, immersed directly in lead, which may be used to cool down reactor under normal conditions; by-pass line incorporated in coolant loop allowing to refuse the actively actuating valve initiated in pumps shut down. (author)

Safety re-evaluation of the HOR reactor

International Nuclear Information System (INIS)

Verkooijen, A.H.M.; Vries, J.W. de

2001-01-01

The HOR reactor of the Interfaculty Reactor Institute (IRI) of Delft University of Technology has been in operation since 1963. This swimming pool type reactor is the main experimental facility of the institute. It is used for a broad range of both fundamental and applied research. Originally the reactor was intended to serve the Dutch universities. While retaining this inter-university character many of the research themes are carried out with both national and international scientific partners. Gradually the power of the reactor was increased to 3MW maximum operational power. In 1969 a licence was obtained for that power level. Ever since the reactor is operated at a nominal power level of 2 MW. In 1980 a permit was obtained for a new control room and for extension and renewal of the reactor instrumentation. Those modifications were finished in 1982. In the early nineties it became apparent that further modifications and extensions were necessary. As a consequence of the policy of the US government on proliferation the conversion of HEU to LEU was a prerequisite for the availability of fresh fuel and the return of spent fuel to the US. At the same time the development of new instruments for neutron scattering and positron annihilation asked for a new beam hall. Therefore a renewal of the permit was necessary. After extensive studies in which a safety report and an environmental impact statement were made, the application for a new licence was submitted in 1995. The new licence was granted in 1996. However, due to legal actions by individuals. the licence did not become effective until 1997. The beam hall was inaugurated in 1998. In the same year the conversion from HEU to LEU was started. In June 2000 the 'Delft Positron Centre' was officially opened. Here a unique high intensity positron beam serves the 2D-ACAR and Lifetime instruments. The legal procedures lasted until fall 2000 when all objections raised against the new licence were dismissed by the Council of

Improvement of Reactor Fuel Element Heat Transfer by Surface Roughness

Energy Technology Data Exchange (ETDEWEB)

Kjellstroem, B; Larsson, A E

1967-04-15

In heat exchangers with a limited surface temperature such as reactor fuel elements, rough heat transfer surfaces may give lower pumping power than smooth. To obtain data for choice of the most advantageous roughness for the superheater elements in the Marviken reactor, measurements were made of heat transfer and pressure drop in an annular channel with a smooth or rough test rod in a smooth adiabatic shroud. 24 different roughness geometries were tested. The results were transformed to rod cluster geometry by the method of W B Hall, and correlated by the friction and heat transfer similarity laws as suggested by D F Dipprey and R H Sabersky with RMS errors of 12.5 % in the friction factor and 8.1 % in the Stanton number. The relation between the Stanton number and the friction factor could be described by a relation of the type suggested by W Nunner, with a mean error of 3.1 % and an RMS error of 11.6 %. Application of the results to fuel element calculations is discussed, and the great gains in economy which can be obtained with rough surfaces are demonstrated by two examples.

Improvement of Reactor Fuel Element Heat Transfer by Surface Roughness

International Nuclear Information System (INIS)

Kjellstroem, B.; Larsson, A.E.

1967-04-01

In heat exchangers with a limited surface temperature such as reactor fuel elements, rough heat transfer surfaces may give lower pumping power than smooth. To obtain data for choice of the most advantageous roughness for the superheater elements in the Marviken reactor, measurements were made of heat transfer and pressure drop in an annular channel with a smooth or rough test rod in a smooth adiabatic shroud. 24 different roughness geometries were tested. The results were transformed to rod cluster geometry by the method of W B Hall, and correlated by the friction and heat transfer similarity laws as suggested by D F Dipprey and R H Sabersky with RMS errors of 12.5 % in the friction factor and 8.1 % in the Stanton number. The relation between the Stanton number and the friction factor could be described by a relation of the type suggested by W Nunner, with a mean error of 3.1 % and an RMS error of 11.6 %. Application of the results to fuel element calculations is discussed, and the great gains in economy which can be obtained with rough surfaces are demonstrated by two examples

Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 01. Projektovanje zastitne komore u hali reaktora RA za rad sa aktivnim eksperimentalnim uredjajima (I-II), II Deo, Album II

Energy Technology Data Exchange (ETDEWEB)

Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1963-07-15

This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings.

RMB: the new Brazilian Multipurpose Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Perrotta, Jose Augusto, E-mail: perrotta@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2016-07-01

Full text: The Brazilian research reactors have a limited capacity for radioisotopes production, leading to a high dependence on external supply for radioisotopes used in nuclear medicine. In order to overcome this condition and due to the old age of these research reactors, the Brazilian Nuclear Energy Commission decided, in 2008, to construct a new research reactor. The new reactor named RMB (Brazilian Multipurpose Reactor) will be part of a new nuclear research center, to be built on a site about 100 kilometers from São Paulo city, in the southern part of Brazil. The new nuclear research center will have a 30 MW open pool type research reactor using low enriched uranium fuel, and several associated laboratories in order to produce radioisotopes for medical and industrial use, to use neutron beams in scientific and technological research; to perform neutron activation analysis; and to perform materials and fuels irradiation tests. Regarding the neutron beams use, the RMB design provides thermal and cold neutron beams. From one side of the reactor, the neutron guides will extend to an experimental hall of instruments named Neutron Guide Hall where it will be installed the scattering instruments. In the initial stage of the reactor operation, the intent is to implement two neutron guides for thermal neutrons and another two for cold neutrons. The 2015 SBPMAT symposium has presented the technical overview of the RMB project and its main buildings, structures and components. At this year symposium, the RMB presentation updates some technical information and the development status of the project, discussing the negative results of the Brazilian political and economic crisis to the project development and its future perspectives. (author)

Scanning vector Hall probe microscopy

International Nuclear Information System (INIS)

Cambel, V.; Gregusova, D.; Fedor, J.; Kudela, R.; Bending, S.J.

2004-01-01

We have developed a scanning vector Hall probe microscope for mapping magnetic field vector over magnetic samples. The microscope is based on a micromachined Hall sensor and the cryostat with scanning system. The vector Hall sensor active area is ∼5x5 μm 2 . It is realized by patterning three Hall probes on the tilted faces of GaAs pyramids. Data from these 'tilted' Hall probes are used to reconstruct the full magnetic field vector. The scanning area of the microscope is 5x5 mm 2 , space resolution 2.5 μm, field resolution ∼1 μT Hz -1/2 at temperatures 10-300 K

Calculation of photon dose for Dalat research reactor in case of loss of reactor tank water

International Nuclear Information System (INIS)

Le Vinh Vinh; Huynh Ton Nghiem; Nguyen Kien Cuong

2007-01-01

Photon sources of actinides and fission products were estimated by ORIGEN2 code with the modified cross-section library for Dalat research reactor (DRR) using new cross-section generated by WIMS-ANL code. Photon sources of reactor tank water calculated from the experimental data. MCNP4C2 with available non-analog Monte Carlo model and ANSI/ANL-6.1.1-1977 flux-to-dose factors were used for dose estimation. The agreement between calculation results and those of measurements showed that the methods and models used to get photon sources and dose were acceptable. In case the reactor water totally leaks out from the reactor tank, the calculated dose is very high at the top of reactor tank while still low in control room. In the reactor hall, the operation staffs can access for emergency works but with time limits. (author)

Emergency response guide-B ECCS guideline evaluation analyses for N reactor

International Nuclear Information System (INIS)

Chapman, J.C.; Callow, R.A.

1989-07-01

INEL conducted two ECCS analyses for Westinghouse Hanford. Both analyses will assist in the evaluation of proposed changes to the N Reactor Emergency Response Guide-B (ERG-B) Emergency Core System (ECCS) guideline. The analyses were a sensitivity study for reduced-ECCS flow rates and a mechanistically determined confinement steam source for a delayed-ECCS LOCA sequence. The reduced-ECCS sensitivity study established the maximum allowable reduction in ECCS flow as a function of time after core refill for a large break loss-of-coolant accident (LOCA) sequence in the N Reactor. The maximum allowable ECCS flow reduction is defined as the maximum flow reduction for which ECCS continues to provide adequate core cooling. The delayed-ECCS analysis established the liquid and steam break flows and enthalpies during the reflood of a hot core following a delayed ECCS injection LOCA sequence. A simulation of a large, hot leg manifold break with a seven-minute ECCS injection delay was used as a representative LOCA sequence. Both analyses were perform using the RELAP5/MOD2.5 transient computer code. 13 refs., 17 figs., 3 tabs

Giant photonic Hall effect in magnetophotonic crystals.

Science.gov (United States)

Merzlikin, A M; Vinogradov, A P; Inoue, M; Granovsky, A B

2005-10-01

We have considered a simple, square, two-dimensional (2D) PC built of a magneto-optic matrix with square holes. It is shown that using such a magnetophotonic crystal it is possible to deflect a light beam at very large angles by applying a nonzero external magnetic field. The effect is called the giant photonic Hall effect (GPHE) or the magnetic superprism effect. The GPHE is based on magneto-optical properties, as is the photonic Hall effect [B. A. van Tiggelen and G. L. J. A. Rikken, in, edited by V. M. Shalaev (Springer-Verlag, Berlin, 2002), p. 275]; however GPHE is not caused by asymmetrical light scattering but rather by the influence of an external magnetic field on the photonic band structure.

Reactor noise analysis of experimental fast reactor 'JOYO'

International Nuclear Information System (INIS)

Ohtani, Hideji; Yamamoto, Hisashi

1980-01-01

As a part of dynamics tests in experimental fast reactor ''JOYO'', reactor noise tests were carried out. The reactor noise analysis techniques are effective for study of plant characteristics by determining fluctuations of process signals (neutron signal, reactor inlet temperature signals, etc.), which are able to be measured without disturbances for reactor operations. The aims of reactor noise tests were to confirm that no unstable phenomenon exists in ''JOYO'' and to gain initial data of the plant for reference of the future data. Data for the reactor noise tests treated in this paper were obtained at 50 MW power level. Fluctuations of process signals were amplified and recorded on analogue tapes. The analysis was performed using noise code (NOISA) of digital computer, with which statistical values of ASPD (auto power spectral density), CPSD (cross power spectral density), and CF (coherence function) were calculated. The primary points of the results are as follows. 1. RMS value of neutron signal at 50 MW power level is about 0.03 MW. This neutron fluctuation is not disturbing reactor operations. 2. The fluctuations of A loop reactor inlet temperatures (T sub(AI)) are larger than the fluctuations of B loop reactor inlet temperature (T sub(BI)). For this reason, the major driving force of neutron fluctuations seems to be the fluctuations of T sub(AI). 3. Core and blanket subassemblies can be divided into two halves (A and B region), with respect to the spacial motion of temperature in the reactor core. A or B region means the region in which sodium temperature fluctuations in subassembly are significantly affected by T sub(AI) or T sub(BI), respectively. This phenomenon seems to be due to the lack of mixing of A and B loop sodium in lower plenum of reactor vessel. (author)

Backfitting swimming pool reactors

International Nuclear Information System (INIS)

Roebert, G.A.

1978-01-01

Calculations based on measurements in a critical assembly, and experiments to disclose fuel element surface temperatures in case of accidents like stopping of primary coolant flow during full power operation, have shown that the power of the swimming pool type research reactor FRG-2 (15 MW, operating since 1967) might be raised to 21 MW within the present rules of science and technology, without major alterations of the pool buildings and the cooling systems. A backfitting program is carried through to adjust the reactor control systems of FRG-2 and FRG-1 (5 MW, housed in the same reactor hall) to the present safety rules and recommendations, to ensure FRG-2 operation at 21 MW for the next decade. (author)

Decommissioning of a small reactor (BR3 reactor, Belgium)

International Nuclear Information System (INIS)

Dadoumont, J.; Massaut, V.; Klein, M.; Demeulemeester, Y.

2002-01-01

Since 1989, SCK-CEN has been dismantling its PWR reactor BR3 (Belgian Reactor No. 3). After gaining a great deal of experience in remote dismantling of highly radioactive components during the actual dismantling of the two sets of internals, the BR3 team completed the cutting of its reactor pressure vessel (RPV). During the feasibility phase of the RPV dismantling, a decision was made to cut it under water in the refuelling pool of the plant, after having removed it from its cavity. The RPV was cut into segments using a milling cutter and a bandsaw machine. These mechanical techniques have shown their ability for this kind of operations. Prior to the segmentation, the thermal insulation situated around the RPV was remotely removed and disposed of. The paper will describe all these operations. The BR3 decommissioning activities also include the dismantling of contaminated loops and equipment. After a careful sorting of the pieces, optimized management routes are selected in order to minimize the final amount of radioactive waste to be disposed of. Some development of different methods of decontamination were carried out: abrasive blasting (or sand blasting), chemical decontamination (Oxidizing-Reducing process using Cerium). The main goal of the decontamination program is to recycle most of the metallic materials either in the nuclear world or in the industrial world by reaching the respective recycling or clearance level. Overall the decommissioning of the BR3 reactor has shown the feasibility of performing such a project in a safe and economical way. Moreover, BR3 has developed methodologies and decontamination processes to economically reduce the amount of radwaste produced. (author)

Seismic analysis of a large pool-type LMR [liquid metal reactor

International Nuclear Information System (INIS)

Wang, C.Y.; Gvildys, J.

1989-01-01

This paper describes the seismic study of a 450-MWe liquid metal reactor (LMR) under 0.3-g SSE ground excitation. Two calculations were performed using the new design configuration. They deal with the seismic response of the reactor vessel, the guard vessel and support skirt, respectively. In both calculations, the stress and displacement fields at important locations of those components are investigated. Assessments are also made on the elastic and inelastic structural capabilities for other beyond-design basis seismic loads. Results of the reactor vessel analysis reveal that the maximum equivalent stress is only about half of the material yield stress. For the guard vessel and support skirt, the stress level is very small. Regarding the analysis if inelastic structural capability, solutions of the Newmark-Hall ductility modification method show that the reactor vessel can withstand seismics with ground ZPAs ranging from 1.015 to 1.31 g, which corresponds to 3.37 to 4.37 times the basic 0.3-g SSE. Thus, the reactor vessel and guard vessel are strong enough to resist seismic loads. 4 refs., 10 figs., 5 tabs

A novel approach for simultaneous measurements of Hall effect and magnetoresistance effect in solid and liquid state of gallium and mercury metals

International Nuclear Information System (INIS)

Ogita, M.; Nakao, M.; Singh, C.D.; Mogi, I.; Awaji, S.

2004-01-01

An AC-DC method has been proposed for simultaneous measurements of Hall effect and magnetoresistance effect in solid and liquid state of Ga and Hg metals. In low magnetic field Hall signal in solid state is proportional to magnetic field B, while in liquid state Hall signal is affected by magnetoresistance effect. It has been found that magnetoresistance has a B 2 dependence on magnetic field and affects the Hall signal. In high magnetic field, the Hall effect in liquid state is affected by a very large magnetoresistance effect compared in solid state. The magnetoresistance effect in liquid state is higher than solid state

Hall effect measurements of high-quality M n3CuN thin films and the electronic structure

Science.gov (United States)

Matsumoto, Toshiki; Hatano, Takafumi; Urata, Takahiro; Iida, Kazumasa; Takenaka, Koshi; Ikuta, Hiroshi

2017-11-01

The physical properties of M n3CuN were studied using thin films. We found that an annealing process was very effective to improve the film quality, the key of which was the use of Ti that prevented the formation of oxide impurities. Using these high-quality thin films, we found strong strain dependence for the ferromagnetic transition temperature (TC) and a sign change of the Hall coefficient at TC. The analysis of Hall coefficient data revealed a sizable decrease of hole concentration and a large increase of electron mobility below TC, which is discussed in relation to the electronic structure of this material.

Theory of fractional quantum hall effect

International Nuclear Information System (INIS)

Kostadinov, I.Z.

1985-08-01

A theory of the Fractional Quantum Hall Effect is constructed based on magnetic flux fractionization, which lead to instability of the system against selfcompression. A theorem is proved stating that arbitrary potentials fail to lift a specific degeneracy of the Landau level. For the case of 1/3 fractional filling a model 3-particles interaction is constructed breaking the symmetry. The rigid 3-particles wave function plays the role of order parameter. In a BCS type of theory the gap in the single particles spectrum is produced by the 3-particles interaction. The mean field critical behaviour and critical parameters are determined as well as the Ginsburg-Landau equation coefficients. The Hall conductivity is calculated from the first principles and its temperature dependence is found. The simultaneous tunnelling of 3,5,7 etc. electrons and quantum interference effects are predicted. (author)

Operation experience with the TRIGA Mark II reactor Vienna in the years 1972 through 1974

International Nuclear Information System (INIS)

Boeck, H.

1974-01-01

Since the last TRIGA Users Conference in Pavia 1972 the TRIGA reactor Vienna was in operation without any larger undesired shut-down. The integral thermal power production by Sept. 1, 1974 was 3420 MWh. The principal work carried out during the last two years on the reactor system was the installation of a new heat exchanger and primary pump both designed for 1 MW steady state operation. Permission was also obtained from the local authority to withdraw up to 90 m 3 /h secondary cooling water from the well. Some troubles were observed with the pulse rod. After nearly 12 years of operation the connection between the piston rod and control rod broke off just below the water surface. Therefore the piston was shot out without withdrawing the pulse rod itself. After locating the trouble the damage was repaired within one day. The SST fuel elements type 110 were received by the end of 1972 for the purpose of power upgrading. All other fuel elements except one are still located in the reactor core and shifted periodically in order to obtain an optimal burnup. A new alarm system was ordered from Hartmann and Braun and is under installation at the moment. In order to facilitate cooperation with the reactor operation personnel and the experimenters in the reactor hall an accurate power indicator has been installed in the reactor hall which allows all experimenters to read the reactor power as accurately as in the control room itself. (U.S.)

An experimental investigation of the internal magnetic field topography of an operating Hall thruster

International Nuclear Information System (INIS)

Peterson, Peter Y.; Gallimore, Alec D.; Haas, James M.

2002-01-01

Magnetic field measurements were made in the discharge channel of the 5 kW-class P5 laboratory-model Hall thruster to investigate what effect the Hall current has on the static, applied magnetic field topography. The P5 was operated at 1.6 and 3.0 kW with a discharge voltage of 300 V. A miniature inductive loop probe (B-Dot probe) was employed to measure the radial magnetic field profile inside the discharge channel of the P5 with and without the plasma discharge. These measurements are accomplished with minimal disturbance to thruster operation with the High-speed Axial Reciprocating Probe system. The results of the B-Dot probe measurements indicate a change in the magnetic field topography from that of the vacuum field measurements. The measured magnetic field profiles are then examined to determine the possible nature and source of the difference between the vacuum and plasma magnetic field profiles

Field theory approach to quantum hall effect

International Nuclear Information System (INIS)

Cabo, A.; Chaichian, M.

1990-07-01

The Fradkin's formulation of statistical field theory is applied to the Coulomb interacting electron gas in a magnetic field. The electrons are confined to a plane in normal 3D-space and also interact with the physical 3D-electromagnetic field. The magnetic translation group (MTG) Ward identities are derived. Using them it is shown that the exact electron propagator is diagonalized in the basis of the wave functions of the free electron in a magnetic field whenever the MTG is unbroken. The general tensor structure of the polarization operator is obtained and used to show that the Chern-Simons action always describes the Hall effect properties of the system. A general proof of the Streda formula for the Hall conductivity is presented. It follows that the coefficient of the Chern-Simons terms in the long-wavelength approximation is exactly given by this relation. Such a formula, expressing the Hall conductivity as a simple derivative, in combination with diagonal form of the full propagator allows to obtain a simple expressions for the filling factor and the Hall conductivity. Indeed, these results, after assuming that the chemical potential lies in a gap of the density of states, lead to the conclusion that the Hall conductivity is given without corrections by σ xy = νe 2 /h where ν is the filling factor. In addition it follows that the filling factor is independent of the magnetic field if the chemical potential remains in the gap. (author). 21 ref, 1 fig

Calculation and Analysis of B/T (Burning and/or Transmutation Rate of Minor Actinides and Plutonium Performed by Fast B/T Reactor

Directory of Open Access Journals (Sweden)

Marsodi

2006-01-01

Full Text Available Calculation and analysis of B/T (Burning and/or Transmutation rate of MA (minor actinides and Pu (Plutonium has been performed in fast B/T reactor. The study was based on the assumption that the spectrum shift of neutron flux to higher side of neutron energy had a potential significance for designing the fast B/T reactor and a remarkable effect for increasing the B/T rate of MA and/or Pu. The spectrum shifts of neutron have been performed by change MOX to metallic fuel. Blending fraction of MA and or Pu in B/T fuel and the volume ratio of fuel to coolant in the reactor core were also considered. Here, the performance of fast B/T reactor was evaluated theoretically based on the calculation results of the neutronics and burn-up analysis. In this study, the B/T rate of MA and/or Pu increased by increasing the blending fraction of MA and or Pu and by changing the F/C ratio. According to the results, the total B/T rate, i.e. [B/T rate]MA + [B/T rate]Pu, could be kept nearly constant under the critical condition, if the sum of the MA and Pu inventory in the core is nearly constant. The effect of loading structure was examined for inner or outer loading of concentric geometry and for homogeneous loading. Homogeneous loading of B/T fuel was the good structure for obtaining the higher B/T rate, rather than inner or outer loading

Precision of single-engage micro Hall effect measurements

DEFF Research Database (Denmark)

Henrichsen, Henrik Hartmann; Hansen, Ole; Kjær, Daniel

2014-01-01

Recently a novel microscale Hall effect measurement technique has been developed to extract sheet resistance (RS), Hall sheet carrier density (NHS) and Hall mobility (μH) from collinear micro 4-point probe measurements in the vicinity of an insulating boundary [1]. The technique measures in less...... than a minute directly the local transport properties, which enables in-line production monitoring on scribe line test pads [2]. To increase measurement speed and reliability, a method in which 4-point measurements are performed using two different electrode pitches has been developed [3......]. In this study we calculate the measurement error on RS, NHS and μH resulting from electrode position errors, probe placement, sample size and Hall signal magnitude. We show the relationship between measurement precision and electrode pitch, which is important when down-scaling the micro 4-point probe to fit...

Status of data testing of ENDF/B-V reactor dosimetry file

International Nuclear Information System (INIS)

Magurno, B.A.

1979-01-01

The ENDF/B-V Reactor Dosimetry File was released August 1979, and Phase II data testing started. The results presented here are from Brookhaven National Laboratory only, and are considered preliminary. The tests include calculated spectrum-averaged cross sections using 235 U fission spectrum (Watt), 252 Cf spontaneous fission spectrum (Watt and Maxwellian), and the Coupled Fast Reactor Measurement Facility (CFRMF) spectrum. 6 tables

Quantum Hall effect and hopping conductivity in n-InGaAs/InAlAs nanoheterostructures

Energy Technology Data Exchange (ETDEWEB)

Gudina, S. V., E-mail: svpopova@imp.uran.ru; Arapov, Yu. G.; Saveliev, A. P.; Neverov, V. N.; Podgornykh, S. M.; Shelushinina, N. G.; Yakunin, M. V. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation); Vasil’evskii, I. S.; Vinichenko, A. N. [National Research Nuclear University MEPhI (Russian Federation)

2016-12-15

The longitudinal and Hall magnetoresistances are measured in the quantum Hall effect regime in the n-InGaAs/InAlAs heterostructures at temperatures of T = (1.8–30) K in magnetic fields up to B = 9 T. Temperature-induced transport in the region of the longitudinal resistance minima, corresponding to the plateau regions at Hall resistance, is investigated within the framework of the concept of hopping conductivity in a strongly localized electron system. The analysis of variable-range hopping conductivity in the region of the second, third, and fourth plateau of the quantum Hall effect provides the possibility of determining the localization length exponent.

Josephson tunneling in bilayer quantum Hall system

International Nuclear Information System (INIS)

Ezawa, Z.F.; Tsitsishvili, G.; Sawada, A.

2012-01-01

A Bose–Einstein condensation is formed by composite bosons in the quantum Hall state. A composite boson carries the fundamental charge (−e). We investigate Josephson tunneling of such charges in the bilayer quantum Hall system at the total filling ν=1. We show the existence of the critical current for the tunneling current to be coherent and dissipationless. Our results explain recent experiments due to [L. Tiemann, Y. Yoon, W. Dietsche, K. von Klitzing, W. Wegscheider, Phys. Rev. B 80 (2009) 165120] and due to [Y. Yoon, L. Tiemann, S. Schmult, W. Dietsche, K. von Klitzing, Phys. Rev. Lett. 104 (2010) 116802]. We predict also how the critical current changes as the sample is tilted in the magnetic field. -- Highlights: ► Composite bosons undergo Bose–Einstein condensation to form the bilayer quantum Hall state. ► A composite boson is a single electron bound to a flux quantum and carries one unit charge. ► Quantum coherence develops due to the condensation. ► Quantum coherence drives the supercurrent in each layer and the tunneling current. ► There exists the critical input current so that the tunneling current is coherent and dissipationless.

Diagnostics Systems for Permanent Hall Thrusters Development

Science.gov (United States)

Ferreira, Jose Leonardo; Soares Ferreira, Ivan; Santos, Jean; Miranda, Rodrigo; Possa, M. Gabriela

This work describes the development of Permanent Magnet Hall Effect Plasma Thruster (PHALL) and its diagnostic systems at The Plasma Physics Laboratory of University of Brasilia. The project consists on the construction and characterization of plasma propulsion engines based on the Hall Effect. Electric thrusters have been employed in over 220 successful space missions. Two types stand out: the Hall-Effect Thruster (HET) and the Gridded Ion Engine (GIE). The first, which we deal with in this project, has the advantage of greater simplicity of operation, a smaller weight for the propulsion subsystem and a longer shelf life. It can operate in two configurations: magnetic layer and anode layer, the difference between the two lying in the positioning of the anode inside the plasma channel. A Hall-Effect Thruster-HET is a type of plasma thruster in which the propellant gas is ionized and accelerated by a magneto hydrodynamic effect combined with electrostatic ion acceleration. So the essential operating principle of the HET is that it uses a J x B force and an electrostatic potential to accelerate ions up to high speeds. In a HET, the attractive negative charge is provided by electrons at the open end of the Thruster instead of a grid, as in the case of the electrostatic ion thrusters. A strong radial magnetic field is used to hold the electrons in place, with the combination of the magnetic field and the electrostatic potential force generating a fast circulating electron current, the Hall current, around the axis of the Thruster, mainly composed by drifting electrons in an ion plasma background. Only a slow axial drift towards the anode occurs. The main attractive features of the Hall-Effect Thruster are its simple design and operating principles. Most of the Hall-Effect Thrusters use electromagnet coils to produce the main magnetic field responsible for plasma generation and acceleration. In this paper we present a different new concept, a Permanent Magnet Hall

Utilization of RP-10 reactor for neutron therapy

International Nuclear Information System (INIS)

Paucar, R.; Nieto, M.; Parreno, F.; Vela, M.; Pozo, Z.

1997-01-01

In the Nuclear Energy Peruvian Institute, IPEN, a research area has established of Neutron Radiotherapy, know as NCT. This research joins the physics of particles (Neutrons and photons) and Medical Physics, and this one is an applied investigation where in considering the construction of a treatment hall in Huarangal (Peru) Reactor's irradiation facility, it can treat patients with brain tumors. In Neutron Therapy (NCT), it tries to use neutrons to destroy tumor cells where other therapeutic techniques are not effective. This process consist on to incise a neutrons beam of adequate characteristics over the tumor area of the patient. The neutrons used are of thermal energy and therefore irradiations are developed in experimental reactors. For this one, it is used horizontal channels prepared suitably. Before the irradiation, it is injected to the patient a substance which is absorbed by tumoral tissue. The substance components will be B-10, nuclide with an absorption cross section high to thermal neutrons (3837 b). The B-10 irradiate with thermal neutrons produce alpha particles of short reach (10 μm. on soft tissue) and with LET values (lineal energy transference) very high. The result is a cell preferential destruction which have absorbed the substance and it's next neighbors, like the cell size is 10 μm. This process as know as Boron Neutron Capture Therapy (BNCT). This work describes Peruvian RP-10 reactor and recently efforts to assess the design and feasibility of the medical neutron irradiation facility for NCT. (author). 22 refs., 6 tabs

Program of RA reactor start-up to nominal power

International Nuclear Information System (INIS)

1959-01-01

The zero start-up program is followed by the program of RA reactor start-up to nominal power. This program is described in detail and includes the following measurements: radiation characteristics at the exit of the channels; gamma and fast neutron dose distribution in the reactor; influence of absorbers on the reactivity; temperature effect; absolute flux and calibration of ionization chambers; xenon effect; thermal and hydraulics; dosimetry around the reactor; neutron flux in the reactor core and in the reactor hall; heavy water level; thermal characteristics after shutdown. A list of measuring devices and instrumentation is included with the detailed action plan and list of responsible staff members

Neutron beam facilities at the Replacement Research Reactor, ANSTO

International Nuclear Information System (INIS)

Kim, S.

2003-01-01

The exciting development for Australia is the construction of a modern state-of-the-art 20-MW Replacement Research Reactor which is currently under construction to replace the aging reactor (HIFAR) at ANSTO in 2006. To cater for advanced scientific applications, the replacement reactor will provide not only thermal neutron beams but also a modern cold-neutron source moderated by liquid deuterium at approximately -250 deg C, complete with provision for installation of a hot-neutron source at a later stage. The latest 'supermirror' guides will be used to transport the neutrons to the Reactor Hall and its adjoining Neutron Guide Hall where a suite of neutron beam instruments will be installed. These new facilities will expand and enhance ANSTO's capabilities and performance in neutron beam science compared with what is possible with the existing HIFAR facilities, and will make ANSTO/Australia competitive with the best neutron facilities in the world. Eight 'leading-edge' neutron beam instruments are planned for the Replacement Research Reactor when it goes critical in 2006, followed by more instruments by 2010 and beyond. Up to 18 neutron beam instruments can be accommodated at the Replacement Research Reactor, however, it has the capacity for further expansion, including potential for a second Neutron Guide Hall. The first batch of eight instruments has been carefully selected in conjunction with a user group representing various scientific interests in Australia. A team of scientists, engineers, drafting officers and technicians has been assembled to carry out the Neutron Beam Instrument Project to successful completion. Today, most of the planned instruments have conceptual designs and are now being engineered in detail prior to construction and procurement. A suite of ancillary equipment will also be provided to enable scientific experiments at different temperatures, pressures and magnetic fields. This paper describes the Neutron Beam Instrument Project and gives

Homogeneous fast reactor benchmark testing of CENDL-2 and ENDF/B-6

International Nuclear Information System (INIS)

Liu Guisheng

1995-01-01

How to choose correct weighting spectrum has been studied to produce multigroup constants for fast reactor benchmark calculations. A correct weighting option makes us obtain satisfying results of K eff and central reaction rate ratios for nine fast reactor benchmark testings of CENDL-2 and ENDF/B-6. (4 tabs., 2 figs.)

2002 Nuclear Power World Report - Evaluation

International Nuclear Information System (INIS)

Anon.

2003-01-01

Last year, in 2002, 441 nuclear power plants were available for power supply in 31 countries in the world. With an aggregate gross power of 377,359 MWe, and an aggregate net power of 359,429 MWe, respectively, the nuclear generating capacity reached its highest level so far. Nine different reactor lines are used in commercial facilities. Light water reactors (PWR and BWR) contribute 355 plants, which makes them the most common reactor line. In twelve countries, 32 nuclear power plants with an aggregate gross power of 26,842 MWe and an aggregate net power of 25,546 MWe, respectively, are under construction. Of these, 25 units are light water reactors while eight are CANDU-type plants. In eighteen countries, 94 commercial reactors with more than 5 MWe power have been decommissioned so far. Most of these plants are prototypes with low powers. 228 of the nuclear power plants currently in operation, i.e. slightly more than half of them, were commissioned in the eighties. The oldest commercial nuclear power plant, Calder Hall unit 1, supplied power into the public grid in its 47th year of operation in 2002. The availability in terms of time and capacity of nuclear power plants rose from 74.23% in 1991 to 83.40% in 2001. A continued rise to approx. 85% is expected for 2002. In the same way, the non-availability in terms of time (unscheduled) dropped from 6.90% to 3.48%. The four nuclear power plants in Finland are the world's leaders with a cumulated average capacity availability of 90.00%. (orig.) [de

Detailed design of neutron guide tubes at the upgraded JRR-3, (1)

International Nuclear Information System (INIS)

Harami, Taikan; Umemura, Mutsumi; Ebisawa, Tohru.

1985-07-01

JRR-3, currently a heavy water moderated and cooled 10 MW reactor, is to be upgraded to a light water moderated and cooled, heavy water reflected 20 MW reactor. Two guide tubes for thermal neutron and three for cold will be installed in the reactor to transport thermal and cold neutrons from the reactor hall to the experiment hall. This describes the neutron guide tube transmission analysis program, NEUGT, which was developed to assess the design of the neutron guide tubes. The input data plotting program, PLOPINE and the output data plotting program, NEUPLOT are presented in the appendix. The NEUGT program not only calculates a neutron transmission and neutron spectra, assuming the Maxwellian spectra at the entrance of a guide tube, but also analyses the effect of abutment errors. This reports the description and the input data manual of the program in the text. Examples of analysis are given in the appendixes. The program is written in the FORTRAN 77 language for FACOM 380. (author)

Not your grandfather's concert hall

Science.gov (United States)

Cooper, Russell; Malenka, Richard; Griffith, Charles; Friedlander, Steven

2004-05-01

The opening of Judy and Arthur Zankel Hall on 12 September 2003, restores Andrew Carnegie's original 1891 concept of having three outstanding auditoriums of different sizes under one roof, and creates a 21st-century venue for music performance and education. With concerts ranging from early music to avant-garde multimedia productions, from jazz to world music, and from solo recitals to chamber music, Zankel Hall expands the breadth and depth of Carnegie Hall's offerings. It allows for the integration of programming across three halls with minifestivals tailored both to the size and strengths of each hall and to the artists and music to be performed. The new flexible space also provides Carnegie Hall with an education center equipped with advanced communications technology. This paper discusses the unique program planned for this facility and how the architects, theatre consultants, and acousticians developed a design that fulfilled the client's expectations and coordinated the construction of the facility under the floor of the main Isaac Stern Auditorium without having to cancel a single performance.

Hall Effect Influence on a Highly Conducting Fluid

Energy Technology Data Exchange (ETDEWEB)

Witalis, E A

1966-11-15

The properties of an incompressible perfect fluid exhibiting Hall effect is investigated in the limit of infinite electrical conductivity and mobility. The magnetic field strength and the fluid velocity are found to obey the equations B = {mu}{rho}/{sigma} x curlV and V -{mu}/({sigma}{mu}{sub 0}) x curlB (MKS units) where {rho}, {sigma} and {mu} denote mass density, conductivity and charge carrier mobility. Some physical interpretations and applications are given.

Hall Effect Influence on a Highly Conducting Fluid

International Nuclear Information System (INIS)

Witalis, E.A.

1966-11-01

The properties of an incompressible perfect fluid exhibiting Hall effect is investigated in the limit of infinite electrical conductivity and mobility. The magnetic field strength and the fluid velocity are found to obey the equations B = μρ/σ x curlV and V -μ/(σμ 0 ) x curlB (MKS units) where ρ, σ and μ denote mass density, conductivity and charge carrier mobility. Some physical interpretations and applications are given

Homogeneous fast reactor benchmark testing of CENDL-2 and ENDF/B-6

International Nuclear Information System (INIS)

Liu Guisheng

1995-11-01

How to choose correct weighting spectrum has been studied to produce multigroup constants for fast reactor benchmark calculations. A correct weighting option makes us obtain satisfying results of K eff and central reaction rate ratios for nine fast reactor benchmark testing of CENDL-2 and ENDF/B-6. (author). 8 refs, 2 figs, 4 tabs

Report of experimental hall subworking group

International Nuclear Information System (INIS)

Miyake, K.; Ohama, T.; Takahashi, K.

1982-01-01

The general plan of constructing the TRISTAN e + e - colliding beam experimental halls may be divided into two parts. The first step is to construct two test-experimental halls associated with the 6.5 GeV x 6.5 GeV e + e - accumulator ring, and the second step is to build four experimental halls at the 30 GeV x 30 GeV e + e - TRISTAN main ring. At this workshop, extensive discussions on the detailed design of the four main ring experimental halls have been made. Four experimental areas will be built at the main ring, and two test-experimental halls at the accumulating ring. Among the four areas at the main ring, two will be used for electron-proton possible as well as electron-positron colliding beam experiment. The other two will be used exclusively for e + e - colliding experiments. Only a preliminary design has been made for these four experimental areas. A tentative plan of a larger experimental hall includes a counting and data processing room, a utility room, and a radiation safety control room. Two smaller halls have simpler structure. The figures of the experimental halls are presented. The two test-experimental halls at the accumulator ring will be used to test the detectors for e + e - colliding experiments before the final installation. The utility rooms designed for the halls are used to supply coolant and electric power of superconducting magnets. At the workshop, various ideas concerning the preliminary plan are presented. (Kato, T.)

75 FR 7467 - Gary E. Hall and Rita C. Hall; Notice of Application Accepted for Filing With the Commision...

Science.gov (United States)

2010-02-19

... Rita C. Hall; Notice of Application Accepted for Filing With the Commision, Soliciting Motions To.... Project No.: 13652-000. c. Date filed: January 11, 2010. d. Applicant: Gary E. Hall and Rita C. Hall. e... Policies Act of 1978, 16 U.S.C. 2705, 2708. h. Applicant Contact: Mr. Gary E. Hall and Ms. Rita C. Hall, P...

Anomalous Hall effect in ZnxFe3-xO4: Universal scaling law and electron localization below the Verwey transition

Directory of Open Access Journals (Sweden)

N. Jedrecy

2016-08-01

Full Text Available We show that the well-established universal scaling σxyAHE ∼ σxx1.6 between anomalous Hall and longitudinal conductivities in the low conductivity regime (σxx < 104 Ω−1 cm−1 transforms into the scaling σxyAHE ∼ σxx2 at the onset of strong electron localization. The crossover between the two relations is observed in magnetite-derived ZnxFe3-xO4 thin films where an insulating/hopping regime follows a bad metal/hopping regime below the Verwey transition temperature Tv. Our results demonstrate that electron localization effects come into play in the anomalous Hall effect (AHE modifying significantly the scaling exponent. In addition, the thermal evolution of the anomalous Hall resistivity suggests the existence of spin polarons whose size would decrease below Tv.

Properties of Nonabelian Quantum Hall States

Science.gov (United States)

Simon, Steven H.

2004-03-01

The quantum statistics of particles refers to the behavior of a multiparticle wavefunction under adiabatic interchange of two identical particles. While a three dimensional world affords the possibilities of Bosons or Fermions, the two dimensional world has more exotic possibilities such as Fractional and Nonabelian statistics (J. Frölich, in ``Nonperturbative Quantum Field Theory", ed, G. t'Hooft. 1988). The latter is perhaps the most interesting where the wavefunction obeys a ``nonabelian'' representation of the braid group - meaning that braiding A around B then B around C is not the same as braiding B around C then A around B. This property enables one to think about using these exotic systems for robust topological quantum computation (M. Freedman, A. Kitaev, et al, Bull Am Math Soc 40, 31 (2003)). Surprisingly, it is thought that quasiparticles excitations with such nonabelian statistics may actually exist in certain quantum Hall states that have already been observed. The most likely such candidate is the quantum Hall ν=5/2 state(R. L. Willett et al, Phys. Rev. Lett. 59, 1776-1779 (1987)), thought to be a so-called Moore-Read Pfaffian state(G. Moore and N. Read, Nucl Phys. B360 362 (1991)), which can be thought of as a p-wave paired superconducting state of composite fermions(M. Greiter, X. G. Wen, and F. Wilczek, PRL 66, 3205 (1991)). Using this superconducting analogy, we use a Chern-Simons field theory approach to make a number of predictions as to what experimental signatures one should expect for this state if it really is this Moore-Read state(K. Foster, N. Bonesteel, and S. H. Simon, PRL 91 046804 (2003)). We will then discuss how the nonabelian statistics can be explored in detail using a quantum monte-carlo approach (Y. Tserkovnyak and S. H. Simon, PRL 90 106802 (2003)), (I. Finkler, Y. Tserkovnyak, and S. H. Simon, work in progress.) that allows one to explicitly drag one particle around another and observe the change in the wavefunctions

Nuclear power: Europa report

International Nuclear Information System (INIS)

Anon.

2004-01-01

Last year, 2003, nuclear power plants were available for energy supply, respectively, in 18 countries all over Europe. In 8 of the 15 member countries of the European Union (EU-15) nuclear power plants have been operation. In 7 of the 13 EU Candidate Countries (incl. Turkey) nuclear energy was used for power production. A total of 208 plants with an aggregate net capacity of 171 031 MWe and an aggregate gross capacity of 180 263 MWe were in operation at the end of 2003. No unit reached first criticality in 2003 or was connected to the grid. The unit Calder Hall 1 to Calder Hall 4 have been permanently shut down in Great Britain due to economical reasons and an earlier decision. In Germany the NPP Stade was closed. The utility E.ON has decided to shut down the plant due to the efforts of the liberalisation of the electricity markets. Last year, 8 plants were under construction in Romania (1), Russia (3), Slovakia (2 - suspended), and the Ukraine (2), that is only in East European Countries. The Finnish parliament approved plans for the construction of the country's fifth nuclear power reactor by a majority of 107 votes to 92. The consortium led by Framatome ANP was awarded the contract to build the new nuclear power plant (EPR, 1 600 MW) in Olkiluoto. In eight countries of the European Union 136 nuclear power plants have been operated with an aggregate gross capacity of 127 708 MWe and an aggregate net capacity of 121 709 MWe. Net electricity production in 2003 in the EU amounts to approx. 905 TWh gross, which means a share of about 33 per cent of the total production in the whole EU. Shares of nuclear power differ widely among the operator countries. They reach 80% in Lithuania, 78% in France, 57% in the Slovak Republic, 57% in Belgium, and 46% in the Ukraine. Nuclear power also provides a noticeable share in the electricity supply of countries, which operate no own nuclear power plants, e.g. Italy, Portugal, and Austria. (orig.)

Hall Effect Gyrators and Circulators

Science.gov (United States)

Viola, Giovanni; DiVincenzo, David P.

2014-04-01

The electronic circulator and its close relative the gyrator are invaluable tools for noise management and signal routing in the current generation of low-temperature microwave systems for the implementation of new quantum technologies. The current implementation of these devices using the Faraday effect is satisfactory but requires a bulky structure whose physical dimension is close to the microwave wavelength employed. The Hall effect is an alternative nonreciprocal effect that can also be used to produce desired device functionality. We review earlier efforts to use an Ohmically contacted four-terminal Hall bar, explaining why this approach leads to unacceptably high device loss. We find that capacitive coupling to such a Hall conductor has much greater promise for achieving good circulator and gyrator functionality. We formulate a classical Ohm-Hall analysis for calculating the properties of such a device, and show how this classical theory simplifies remarkably in the limiting case of the Hall angle approaching 90°. In this limit, we find that either a four-terminal or a three-terminal capacitive device can give excellent circulator behavior, with device dimensions far smaller than the ac wavelength. An experiment is proposed to achieve GHz-band gyration in millimeter (and smaller) scale structures employing either semiconductor heterostructure or graphene Hall conductors. An inductively coupled scheme for realizing a Hall gyrator is also analyzed.

Mr. John Hall (Debate on link between nuclear weapons testing and subsequent leukaemia in participants)

International Nuclear Information System (INIS)

Vaz, Keith; Hamilton, Archie.

1992-01-01

A debate in the House of Commons is recorded on the case of Mr John Hall, formerly a member of the British Armed Forces who was involved in the hydrogen bomb test at Christmas Island in 1958. Mr Hall is currently being treated for high-grade B-cell non-Hodgkin's lymphoma of the centribalistic type. The debate centred round the difficulty in establishing a causal link between participation in the weapons testing programme and any subsequent illness diagnosed in Mr Hall and other service men. (UK)

Reactivity determination of the Al2O3-B4C burnable poison as a function of its concentration in the IPEN/MB-01 reactor

International Nuclear Information System (INIS)

Giada, Marino Reis

2005-01-01

Burnable poison rods made of Al 2 O 3 -B 4 C pellets with different concentrations of 10 B have been manufactured for a set of experiments in the IPEN/MB-01 zero-power reactor. The experiments evaluated the reactivity of the burnable poison rods as a function of the 10 B concentration, and the shadowing effect on the control rod reactivity worth as a function of the distance between the burnable position rods and the control rod. The results showed that the burnable poison rods have a non-linear behavior as function of the 10 B concentration, starting to reach an asymptotic value for concentrations higher than 7 g/cm 3 of 10 B. The shadowing effect on the control rods was substantial. When the burnable poison rods were beside the control rod, its reactivity worth decreased as much as 30 %, and when they were 10,5 cm distant, the control rod worth decreased by 7 %. The MCNP results for the burnable poison reactivity effects agreed within experimental errors with the measured values. (author)

BETHSY 9.1b Test Calculation with TRACE Using 3D Vessel Component

International Nuclear Information System (INIS)

Berar, O.; Prosek, A.

2012-01-01

Recently, several advanced multidimensional computational tools for simulating reactor system behaviour during real and hypothetical transient scenarios were developed. One of such advanced, best-estimate reactor systems codes is TRAC/RELAP Advanced Computational Engine (TRACE), developed by the U.S. Nuclear Regulatory Commission. The advanced TRACE comes with a graphical user interface called SNAP (Symbolic Nuclear Analysis Package). It is intended for pre- and post-processing, running codes, RELAP5 to TRACE input deck conversion, input deck database generation etc. The TRACE code is still not fully development and it will have all the capabilities of RELAP5. The purpose of the present study was therefore to assess the 3D capability of the TRACE on BETHSY 9.1b test. The TRACE input deck was semi-converted (using SNAP and manual corrections) from the RELAP5 input deck. The 3D fluid dynamics within reactor vessel was modelled and compared to 1D fluid dynamics. The 3D calculation was compared both to TRACE 1D calculation and RELAP5 calculation. Namely, the geometry used in TRACE is basically the same, what gives very good basis for the comparison of the codes. The only exception is 3D reactor vessel model in case of TRACE 3D calculation. The TRACE V5.0 Patch 1 and RELAP5/MOD3.3 Patch 4 were used for calculations. The BETHSY 9.1b test (International Standard Problem no. 27 or ISP-27) was 5.08 cm equivalent diameter cold leg break without high pressure safety injection and with delayed ultimate procedure. BETHSY facility was a 3-loop replica of a 900 MWe FRAMATOME pressurized water reactor. For better presentation of the calculated physical phenomena and processes, an animation model using SNAP was developed. In general, the TRACE 3D code calculation is in good agreement with the BETHSY 9.1b test. The TRACE 3D calculation results are as good as or better than the RELAP5 calculated results. Also, the TRACE 3D calculation is not significantly different from TRACE 1D

Integral test of JENDL-3.3 for fast reactors

International Nuclear Information System (INIS)

Chiba, Gou

2003-01-01

An integral test of JENDL-3.3 was performed for fast reactors. Various types of fast reactors were analyzed. Calculation values of the nuclear characteristics were greatly especially affected by the revisions of the cross sections of U-235 capture and elastic scattering reactions. The C/E values were improved for ZPPR cross where plutonium is mainly fueled, but not for BFS cores where uranium is mainly fueled. (author)

Spin Hall effects

Science.gov (United States)

Sinova, Jairo; Valenzuela, Sergio O.; Wunderlich, J.; Back, C. H.; Jungwirth, T.

2015-10-01

Spin Hall effects are a collection of relativistic spin-orbit coupling phenomena in which electrical currents can generate transverse spin currents and vice versa. Despite being observed only a decade ago, these effects are already ubiquitous within spintronics, as standard spin-current generators and detectors. Here the theoretical and experimental results that have established this subfield of spintronics are reviewed. The focus is on the results that have converged to give us the current understanding of the phenomena, which has evolved from a qualitative to a more quantitative measurement of spin currents and their associated spin accumulation. Within the experimental framework, optical-, transport-, and magnetization-dynamics-based measurements are reviewed and linked to both phenomenological and microscopic theories of the effect. Within the theoretical framework, the basic mechanisms in both the extrinsic and intrinsic regimes are reviewed, which are linked to the mechanisms present in their closely related phenomenon in ferromagnets, the anomalous Hall effect. Also reviewed is the connection to the phenomenological treatment based on spin-diffusion equations applicable to certain regimes, as well as the spin-pumping theory of spin generation used in many measurements of the spin Hall angle. A further connection to the spin-current-generating spin Hall effect to the inverse spin galvanic effect is given, in which an electrical current induces a nonequilibrium spin polarization. This effect often accompanies the spin Hall effect since they share common microscopic origins. Both can exhibit the same symmetries when present in structures comprising ferromagnetic and nonmagnetic layers through their induced current-driven spin torques or induced voltages. Although a short chronological overview of the evolution of the spin Hall effect field and the resolution of some early controversies is given, the main body of this review is structured from a pedagogical

Topological honeycomb magnon Hall effect: A calculation of thermal Hall conductivity of magnetic spin excitations

Energy Technology Data Exchange (ETDEWEB)

Owerre, S. A., E-mail: solomon@aims.ac.za [African Institute for Mathematical Sciences, 6 Melrose Road, Muizenberg, Cape Town 7945, South Africa and Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, Ontario N2L 2Y5 (Canada)

2016-07-28

Quite recently, the magnon Hall effect of spin excitations has been observed experimentally on the kagome and pyrochlore lattices. The thermal Hall conductivity κ{sup xy} changes sign as a function of magnetic field or temperature on the kagome lattice, and κ{sup xy} changes sign upon reversing the sign of the magnetic field on the pyrochlore lattice. Motivated by these recent exciting experimental observations, we theoretically propose a simple realization of the magnon Hall effect in a two-band model on the honeycomb lattice. The magnon Hall effect of spin excitations arises in the usual way via the breaking of inversion symmetry of the lattice, however, by a next-nearest-neighbour Dzyaloshinsky-Moriya interaction. We find that κ{sup xy} has a fixed sign for all parameter regimes considered. These results are in contrast to the Lieb, kagome, and pyrochlore lattices. We further show that the low-temperature dependence on the magnon Hall conductivity follows a T{sup 2} law, as opposed to the kagome and pyrochlore lattices. These results suggest an experimental procedure to measure thermal Hall conductivity within a class of 2D honeycomb quantum magnets and ultracold atoms trapped in a honeycomb optical lattice.

Neutron beam facilities at the replacement research reactor

International Nuclear Information System (INIS)

Kennedy, S.

1999-01-01

Full text: On September 3rd 1997 the Australian Federal Government announced their decision to replace the HIFAR research reactor by 2005. The proposed reactor will be a multipurpose reactor with improved capabilities for neutron beam research and for the production of radioisotopes for pharmaceutical, scientific and industrial use. The neutron beam facilities are intended to cater for Australian scientific needs well into the 21st century. In the first stage of planning the neutron Beam Facilities at the replacement reactor, a Consultative Group was formed (BFCG) to determine the scientific capabilities of the new facility. Members of the group were drawn from academia, industry and government research laboratories. The BFCG submitted their report in April 1998, outlining the scientific priorities to be addressed. Cold and hot neutron sources are to be included, and cold and thermal neutron guides will be used to position most of the instruments in a neutron guide hall outside the reactor confinement building. In 2005 it is planned to have eight instruments installed with a further three to be developed by 2010, and seven spare instrument positions for development of new instruments over the life of the reactor. A beam facilities technical group (BFTG) was then formed to prepare the engineering specifications for the tendering process. The group consisted of some members of the BFCG, several scientists and engineers from ANSTO, and scientists from leading neutron scattering centres in Europe, USA and Japan. The BFTG looked in detail at the key components of the facility such as the thermal, cold and hot neutron sources, neutron collimators, neutron beam guides and overall requirements for the neutron guide hall. The report of the BFTG, completed in August 1998, was incorporated into the draft specifications for the reactor project, which were distributed to potential reactor vendors. An assessment of the first stage of reactor vendor submissions was completed in

Tuning anomalous Hall conductivity in L1[sub 0] FePt films by long range chemical ordering

KAUST Repository

Chen, M.; Shi, Z.; Xu, W. J.; Zhang, Xixiang; Du, J.; Zhou, S. M.

2011-01-01

For L10 FePt films, the anomalous Hall conductivity σ xy=-a σxx-b, where a=a0f(T), b=b 0f(T), and f (T) is the temperature dependence factor of the spontaneous magnetization. With increasing chemical long range ordering S, a0 changes its sign accompanied by a reduction of its magnitude and b0 increases monotonically. The spin-orbit coupling strength is suggested to increase with increasing S. As an approach, the long range chemical ordering can be used to control the anomalous Hall effect in ferromagnetic alloy films. © 2011 American Institute of Physics.

Tuning anomalous Hall conductivity in L1[sub 0] FePt films by long range chemical ordering

KAUST Repository

Chen, M.

2011-02-24

For L10 FePt films, the anomalous Hall conductivity σ xy=-a σxx-b, where a=a0f(T), b=b 0f(T), and f (T) is the temperature dependence factor of the spontaneous magnetization. With increasing chemical long range ordering S, a0 changes its sign accompanied by a reduction of its magnitude and b0 increases monotonically. The spin-orbit coupling strength is suggested to increase with increasing S. As an approach, the long range chemical ordering can be used to control the anomalous Hall effect in ferromagnetic alloy films. © 2011 American Institute of Physics.

Thickness dependence of the quantum Hall effect in films of the three-dimensional Dirac semimetal Cd3As2

Directory of Open Access Journals (Sweden)

Manik Goyal

2018-02-01

Full Text Available Low-temperature magnetotransport studies are reported for (112Cd3As2 films grown on (111CdTe by molecular beam epitaxy as a function of the Cd3As2 film thickness. All films show Shubnikov-de Haas oscillations. An even-integer quantum Hall effect is observed for films thinner than 70 nm. For the thinnest films, the bulk is gapped and transport at low temperatures occurs only via the gapless, two-dimensional states. The lowest Landau level is reached at ∼10 T, and the longitudinal resistance nearly vanishes at the plateaus in the Hall resistance. The results are discussed in the context of the current theoretical understanding of topological surface states in three-dimensional Dirac semimetals.

Tunneling Anomalous and Spin Hall Effects.

Science.gov (United States)

Matos-Abiague, A; Fabian, J

2015-07-31

We predict, theoretically, the existence of the anomalous Hall effect when a tunneling current flows through a tunnel junction in which only one of the electrodes is magnetic. The interfacial spin-orbit coupling present in the barrier region induces a spin-dependent momentum filtering in the directions perpendicular to the tunneling current, resulting in a skew tunneling even in the absence of impurities. This produces an anomalous Hall conductance and spin Hall currents in the nonmagnetic electrode when a bias voltage is applied across the tunneling heterojunction. If the barrier is composed of a noncentrosymmetric material, the anomalous Hall conductance and spin Hall currents become anisotropic with respect to both the magnetization and crystallographic directions, allowing us to separate this interfacial phenomenon from the bulk anomalous and spin Hall contributions. The proposed effect should be useful for proving and quantifying the interfacial spin-orbit fields in metallic and metal-semiconductor systems.

The state of the PIK reactor construction

International Nuclear Information System (INIS)

Konoplev, K.A.

1995-01-01

Principle concepts of the PIK reactor project were stated late in the 60's but its construction was started in 1976. By the year 1986 the initial project was realised by approximately 70% but then, after Chernobyl accident the construction was essentially frozen to adjust the project to the revised nuclear safety regulations. The revised project was approved only in 1990 when the country was on the threshold of serious economic problems. The PIK reactor is a source of neutrons placed in the heavy water reflector. The fuel is uranium-235 (90% enrichment) of total weight 27 kg. Light water is used as moderator and coolant. Design parameters: thermal power is 100 W; thermal neutron flux in the reflector is 1.2x10 15 n/cm 2 s; in the central vertical beam tube is 5x10 15 n/cm 2 s; number of horizontal beam tubes is 10; diameter of beam tubes is 10 cm, with the possibility of replacement with beam tubes up to 25 cm in diameter. The reactor will be equipped with sources of hot, cold, and ultracold neutrons to obtain beams in different intervals of energy spectrum. The low temperature circuit will enable to irradiate samples at helium temperatures. The reactor has three series cooling circuits. Emergency core cooling systems in LOCA are double and in emergency power supply system is triple. The PIK reactor has no single common containment but four separate systems: for pipelines and units of the first circuit, for heavy water reflector, for operating hall, and for experimental beam tubes hall

Quantum hall effect. A perspective

International Nuclear Information System (INIS)

Aoki, Hideo

2006-01-01

Novel concepts and phenomena are emerging recently in the physics of quantum Hall effect. This article gives an overview, which starts from the fractional quantum Hall system viewed as an extremely strongly correlated system, and move on to present various phenomena involving internal degrees of freedom (spin and layer), non-equilibrium and optical properties, and finally the spinoff to anomalous Hall effect and the rotating Bose-Einstein condensate. (author)

Hole mobilities and the effective Hall factor in p-type GaAs

Science.gov (United States)

Wenzel, M.; Irmer, G.; Monecke, J.; Siegel, W.

1997-06-01

We prove the effective Hall factor in p-GaAs to be larger than values discussed in the literature up to now. The scattering rates for the relevant scattering mechanisms in p-GaAs have been recalculated after critical testing the existing models. These calculations allow to deduce theoretical drift and theoretical Hall mobilities as functions of temperature which can be compared with measured data. Theoretical Hall factors in the heavy and light hole bands and an effective Hall factor result. The calculated room temperature values of the drift mobility and of the effective Hall factor are 118 cm2/V s and 3.6, respectively. The fitted acoustic deformation potential E1=7.9 eV and the fitted optical coupling constant DK=1.24×1011 eV/m are close to values published before. It is shown that the measured strong dependence of the Hall mobility on the Hall concentration is not mainly caused by scattering by ionized impurities but by the dependence of the effective Hall factor on the hole concentration.

Planar Hall effect bridge magnetic field sensors

DEFF Research Database (Denmark)

Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.

2010-01-01

Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... Hall effect bridge sensors....

Magnesium Hall Thruster

Science.gov (United States)

Szabo, James J.

2015-01-01

This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

Hall viscosity of hierarchical quantum Hall states

Science.gov (United States)

Fremling, M.; Hansson, T. H.; Suorsa, J.

2014-03-01

Using methods based on conformal field theory, we construct model wave functions on a torus with arbitrary flat metric for all chiral states in the abelian quantum Hall hierarchy. These functions have no variational parameters, and they transform under the modular group in the same way as the multicomponent generalizations of the Laughlin wave functions. Assuming the absence of Berry phases upon adiabatic variations of the modular parameter τ, we calculate the quantum Hall viscosity and find it to be in agreement with the formula, given by Read, which relates the viscosity to the average orbital spin of the electrons. For the filling factor ν =2/5 Jain state, which is at the second level in the hierarchy, we compare our model wave function with the numerically obtained ground state of the Coulomb interaction Hamiltonian in the lowest Landau level, and find very good agreement in a large region of the complex τ plane. For the same example, we also numerically compute the Hall viscosity and find good agreement with the analytical result for both the model wave function and the numerically obtained Coulomb wave function. We argue that this supports the notion of a generalized plasma analogy that would ensure that wave functions obtained using the conformal field theory methods do not acquire Berry phases upon adiabatic evolution.

Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

Czech Academy of Sciences Publication Activity Database

Kovalev, A.A.; Tserkovnyak, Y.; Výborný, Karel; Sinova, J.

2009-01-01

Roč. 79, č. 19 (2009), 19529/1-19529/19 ISSN 1098-0121 R&D Projects: GA MŠk LC510; GA AV ČR KJB100100802 Institutional research plan: CEZ:AV0Z10100521 Keywords : ferromagnetic materials * Hall effect * magnetoresistance * quasiparticles * spin-orbit interactions * two-dimensional electro n gas Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.475, year: 2009 http://link.aps.org/doi/10.1103/PhysRevB.79.195129

Direct comparison of fractional and integer quantized Hall resistance

Science.gov (United States)

Ahlers, Franz J.; Götz, Martin; Pierz, Klaus

2017-08-01

We present precision measurements of the fractional quantized Hall effect, where the quantized resistance {{R}≤ft[ 1/3 \\right]} in the fractional quantum Hall state at filling factor 1/3 was compared with a quantized resistance {{R}[2]} , represented by an integer quantum Hall state at filling factor 2. A cryogenic current comparator bridge capable of currents down to the nanoampere range was used to directly compare two resistance values of two GaAs-based devices located in two cryostats. A value of 1-(5.3  ±  6.3) 10-8 (95% confidence level) was obtained for the ratio ({{R}≤ft[ 1/3 \\right]}/6{{R}[2]} ). This constitutes the most precise comparison of integer resistance quantization (in terms of h/e 2) in single-particle systems and of fractional quantization in fractionally charged quasi-particle systems. While not relevant for practical metrology, such a test of the validity of the underlying physics is of significance in the context of the upcoming revision of the SI.

Spin Hall effect by surface roughness

KAUST Repository

Zhou, Lingjun

2015-01-08

The spin Hall and its inverse effects, driven by the spin orbit interaction, provide an interconversion mechanism between spin and charge currents. Since the spin Hall effect generates and manipulates spin current electrically, to achieve a large effect is becoming an important topic in both academia and industries. So far, materials with heavy elements carrying a strong spin orbit interaction, provide the only option. We propose here a new mechanism, using the surface roughness in ultrathin films, to enhance the spin Hall effect without heavy elements. Our analysis based on Cu and Al thin films suggests that surface roughness is capable of driving a spin Hall angle that is comparable to that in bulk Au. We also demonstrate that the spin Hall effect induced by surface roughness subscribes only to the side-jump contribution but not the skew scattering. The paradigm proposed in this paper provides the second, not if only, alternative to generate a sizable spin Hall effect.

The performance of ENDF/B-V.2 nuclear data for fast reactor calculations

International Nuclear Information System (INIS)

Atkinson, C.A.; Collins, P.J.

1987-01-01

Calculations with ENDF/B-V.2 data have been made for twenty-five fast-spectrum integral assemblies covering a wide range of sizes and compositions. Analysis was done by transport codes with refined cross section processing methods and detailed reactor modelling. The predictions of fission rate distributions and control rod worths were emphasized for the more prototypic benchmark cores. The results show considerable improvements in agreement with experiment compared with analysis using ENDF/B-IV data, but it is apparent that significant errors remain for fast reactor design calculations

Gauge invariance and fractional quantized Hall effect

International Nuclear Information System (INIS)

Tao, R.; Wu, Y.S.

1984-01-01

It is shown that gauge invariance arguments imply the possibility of fractional quantized Hall effect; the Hall conductance is accurately quantized to a rational value. The ground state of a system showing the fractional quantized Hall effect must be degenerate; the non-degenerate ground state can only produce the integral quantized Hall effect. 12 references

The ISOLDE hall

CERN Multimedia

Maximilien Brice

2002-01-01

Since 1992, after its move from the 600 MeV SC, ISOLDE is a customer of the Booster (then 1 GeV, now 1.4 GeV). The intense Booster beam (some 3E13 protons per pulse) is directed onto a target, from which a mixture of isotopes emanates. After ionization and electrostatic acceleration to 60 keV, they enter one of the 2 spectrometers (General Purpose Separator: GPS, and High Resolution Separator: HRS) from which the selected ions are directed to the experiments. The photos show: the REX-ISOLDE post accelerator; the mini-ball experiment; an overview of the ISOLDE hall. In the picture (_12) of the hall, the separators are behind the wall. From either of them, beams can be directed into any of the many beamlines towards the experiments, some of which are visible in the foreground. The elevated cubicle at the left is EBIS (Electron Beam Ion Source), which acts as a charge-state multiplier for the REX facility. The ions are further mass analzyzed and passed on to the linac which accelerates them to higher energies. T...

Nondestructive hall coefficient measurements using ACPD techniques

Science.gov (United States)

Velicheti, Dheeraj; Nagy, Peter B.; Hassan, Waled

2018-04-01

Hall coefficient measurements offer great opportunities as well as major challenges for nondestructive materials characterization. The Hall effect is produced by the magnetic Lorentz force acting on moving charge carriers in the presence of an applied magnetic field. The magnetic perturbation gives rise to a Hall current that is normal to the conduction current but does not directly perturb the electric potential distribution. Therefore, Hall coefficient measurements usually exploit the so-called transverse galvanomagnetic potential drop effect that arises when the Hall current is intercepted by the boundaries of the specimen and thereby produce a measurable potential drop. In contrast, no Hall potential is produced in a large plate in the presence of a uniform normal field at quasi-static low frequencies. In other words, conventional Hall coefficient measurements are inherently destructive since they require cutting the material under tests. This study investigated the feasibility of using alternating current potential drop (ACPD) techniques for nondestructive Hall coefficient measurements in plates. Specifically, the directional four-point square-electrode configuration is investigated with superimposed external magnetic field. Two methods are suggested to make Hall coefficient measurements in large plates without destructive machining. At low frequencies, constraining the bias magnetic field can replace constraining the dimensions of the specimen, which is inherently destructive. For example, when a cylindrical permanent magnet is used to provide the bias magnetic field, the peak Hall voltage is produced when the diameter of the magnet is equal to the diagonal of the square ACPD probe. Although this method is less effective than cutting the specimen to a finite size, the loss of sensitivity is less than one order of magnitude even at very low frequencies. In contrast, at sufficiently high inspection frequencies the magnetic field of the Hall current induces a

3-DB, 3-D Multigroup Diffusion, X-Y-Z, R-Theta-Z, Triangular-Z Geometry, Fast Reactor Burnup

International Nuclear Information System (INIS)

Hardie, R.W.; Little, W.W. Jr.; Mroz, W.

1974-01-01

1 - Description of problem or function: 3DB is a three-dimensional (x-y-z, r-theta-z, triangular-z) multigroup diffusion code for use in detailed fast-reactor criticality and burnup analysis. The code can be used to - (a) compute k eff and perform criticality searches on time absorption, reactor composition, and reactor dimensions by means of either a flux or an adjoint model, (b) compute material burnup using a flexible material shuffling scheme, and (c) compute flux distributions for an arbitrary extraneous source. 2 - Method of solution: Eigenvalues are computed by standard source- iteration techniques. Group re-balancing and successive over-relaxation with line inversion are used to accelerate convergence. Adjoint solutions are obtained by inverting the input data and redefining the source terms. Material burnup is by reactor zone. The burnup rate is determined by the zone and energy-averaged cross sections which are recomputed after each time-step. The isotopic chains, which can contain any number of isotopes are formed by the user. The code does not contain built- in or internal chains. 3 - Restrictions on the complexity of the problem: Since variable dimensioning is employed, no simple bounds can be stated

Reactor benchmarks and integral data testing and feedback into ENDF/B-VI

International Nuclear Information System (INIS)

McKnight, R.D.; Williams, M.L.

1992-01-01

The role of integral data testing and its feedback into the ENDF/B evaluated nuclear data files are reviewed. The use of the CSEWG reactor benchmarks in the data testing process is discussed and selected results based on ENDF/B Version VI data are presented. Finally, recommendations are given to improve the implementation in future integral data testing of ENDF/B

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

Revisión crítica de la construcción de un mito en sacramentales El gran teatro del mundo y La vida es sueño, de Pedro Calderón de la Barca

OpenAIRE

Irene González Muñoz

2012-01-01

En este artículo se realiza una lectura de dos de los autos sacramentales de Pedro Calderón de la Barca, a partir de una revisión crítica que evidencia los presupuestos ideológicos que fundamentan estas producciones literarias.

Hypernuclear Spectroscopy at JLab Hall C

International Nuclear Information System (INIS)

Hashimoto, Osamu; Chiba, Atsushi; Doi, Daisuke; Fujii, Yu; Toshiyuki, Gogami; Kanda, Hiroki; Kaneta, M.; Kawama, Daisuke; Maeda, Kazushige; Maruta, Tomofumi; Matsumura, Akihiko; Nagao, Sho; Nakamura, Satoshi; Shichijo, Ayako; Tamura, Hirokazu; Taniya, Naotaka; Yamamoto, Taku; Yokota, Kosuke; Kato, S.; Sato, Yoshinori; Takahashi, Toshiyuki; Noumi, Hiroyuki; Motoba, T.; Hiyama, E.; Albayrak, Ibrahim; Ates, Ozgur; Chen, Chunhua; Christy, Michael; Keppel, Cynthia; Kohl, Karl; Li, Ya; Liyanage, Anusha Habarakada; Tang, Liguang; Walton, T.; Ye, Zhihong; Yuan, Lulin; Zhu, Lingyan; Baturin, Pavlo; Boeglin, Werner; Dhamija, Seema; Markowitz, Pete; Raue, Brian; Reinhold, Joerg; Hungerford, Ed; Ent, Rolf; Fenker, Howard; Gaskell, David; Horn, Tanja; Jones, Mark; Smith, Gregory; Vulcan, William; Wood, Stephen; Johnston, C.; Simicevic, Neven; Wells, Stephen; Samanta, Chhanda; Hu, Bitao; Shen, Ji; Wang, W.; Zhang, Xiaozhuo; Zhang, Yi; Feng, Jing; Fu, Y.; Zhou, Jian; Zhou, S.; Jiang, Yi; Lu, H.; Yan, Xinhu; Ye, Yunxiu; Gan, Liping; Ahmidouch, Abdellah; Danagoulian, Samuel; Gasparian, Ashot; Elaasar, Mostafa; Wesselmann, Frank; Asaturyan, Arshak; Margaryan, Amur; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Tadevosyan, Vardan; Androic, Darko; Furic, Miroslav; Petkovic, Tomislav; Seva, Tomislav; Niculescu, Gabriel; Niculescu, Maria-Ioana; Rodriguez, Victor; Cisbani, Evaristo; Cusanno, Francesco; Garibaldi, Franco; Urciuoli, Guido; De Leo, Raffaele; Maronne, S.; Achenbach, Carsten; Pochodzalla, J.

2010-01-01

Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e(prime)K + ) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e(prime)K + ) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the 'Tilt method' was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7 ΛHe and 28 ΛAl together with that of 12 ΛB that achieved resolution better than 500 keV(FWHM) were obtained. The third generation experiment, E05-115, has completed data taking with an experimental setup combining a new splitter magnet, high resolution electron spectrometer (HES) and the HKS used in the 2nd generation experiment. The data were accumulated with targets of 7 Li, 9 Be, 10 B, 12 C and 52 Cr as well as with those of CH 2 and H 2 O for calibration. The analysis is under way with particular emphasis of determining precision absolute hypernuclear masses. In this article, hypernuclear spectroscopy program in the wide mass range at JLab Hall C that has undergone three generation is described.

Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2

Science.gov (United States)

Firoz Islam, SK; Benjamin, Colin

2016-09-01

The quantum magnetotransport properties of a monolayer of molybdenum disulfide are derived using linear response theory. In particular, the effect of topological terms on longitudinal and Hall conductivity is analyzed. The Hall conductivity exhibits fractional steps in the integer quantum Hall regime. Further complete spin and valley polarization of the longitudinal conductivitity is seen in presence of these topological terms. Finally, the Shubnikov-de Hass oscillations are suppressed or enhanced contingent on the sign of these topological terms.

Optimization of a heterogeneous catalytic hydrodynamic cavitation reactor performance in decolorization of Rhodamine B: application of scrap iron sheets.

Science.gov (United States)

Basiri Parsa, Jalal; Ebrahimzadeh Zonouzian, Seyyed Alireza

2013-11-01

A low pressure pilot scale hydrodynamic cavitation (HC) reactor with 30 L volume, using fixed scrap iron sheets, as the heterogeneous catalyst, with no external source of H2O2 was devised to investigate the effects of operating parameters of the HC reactor performance. In situ generation of Fenton reagents suggested an induced advanced Fenton process (IAFP) to explain the enhancing effect of the used catalyst in the HC process. The reactor optimization was done based upon the extent of decolorization (ED) of aqueous solution of Rhodamine B (RhB). To have a perfect study on the pertinent parameters of the heterogeneous catalyzed HC reactor, the following cases as, the effects of scrap iron sheets, inlet pressure (2.4-5.8 bar), the distance between orifice plates and catalyst sheets (submerged and inline located orifice plates), back-pressure (2-6 bar), orifice plates type (4 various orifice plates), pH (2-10) and initial RhB concentration (2-14 mg L(-1)) have been investigated. The results showed that the highest cavitational yield can be obtained at pH 3 and initial dye concentration of 10 mg L(-1). Also, an increase in the inlet pressure would lead to an increase in the ED. In addition, it was found that using the deeper holes (thicker orifice plates) would lead to lower ED, and holes with larger diameter would lead to the higher ED in the same cross-sectional area, but in the same holes' diameters, higher cross-sectional area leads to the lower ED. The submerged operation mode showed a greater cavitational effects rather than the inline mode. Also, for the inline mode, the optimum value of 3 bar was obtained for the back-pressure condition in the system. Moreover, according to the analysis of changes in the UV-Vis spectra of RhB, both degradation of RhB chromophore structure and N-deethylation were occurred during the catalyzed HC process. Copyright © 2013 Elsevier B.V. All rights reserved.

ac spin-Hall effect

International Nuclear Information System (INIS)

Entin-Wohlman, O.

2005-01-01

Full Text:The spin-Hall effect is described. The Rashba and Dresselhaus spin-orbit interactions are both shown to yield the low temperature spin-Hall effect for strongly localized electrons coupled to phonons. A frequency-dependent electric field E(ω) generates a spin-polarization current, normal to E, due to interference of hopping paths. At zero temperature the corresponding spin-Hall conductivity is real and is proportional to ω 2 . At non-zero temperatures the coupling to the phonons yields an imaginary term proportional to ω. The interference also yields persistent spin currents at thermal equilibrium, at E = 0. The contributions from the Dresselhaus and Rashba interactions to the interference oppose each other

Evaluation of tritiated water retention capacity of fusion reactor concrete building

International Nuclear Information System (INIS)

Numata, S.; Fujii, Y.; Okamoto, M.

1992-01-01

In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment

Magnetic field deformation due to electron drift in a Hall thruster

Directory of Open Access Journals (Sweden)

Han Liang

2017-01-01

Full Text Available The strength and shape of the magnetic field are the core factors in the design of the Hall thruster. However, Hall current can affect the distribution of static magnetic field. In this paper, the Particle-In-Cell (PIC method is used to obtain the distribution of Hall current in the discharge channel. The Hall current is separated into a direct and an alternating part to calculate the induced magnetic field using Finite Element Method Magnetics (FEMM. The results show that the direct Hall current decreases the magnetic field strength in the acceleration region and also changes the shape of the magnetic field. The maximum reduction in radial magnetic field strength in the exit plane is 10.8 G for an anode flow rate of 15 mg/s and the maximum angle change of the magnetic field line is close to 3° in the acceleration region. The alternating Hall current induces an oscillating magnetic field in the whole discharge channel. The actual magnetic deformation is shown to contain these two parts.

105-B Reactor museum feasibility assessment (Phase 2) project

International Nuclear Information System (INIS)

Heckel, R. P.

2000-01-01

This 105-B Reactor Museum feasibility assessment project report documents project activities that have been performed, including a review and assessment of previously existing information, a walk-through of the facility, an assessment of potential hazards, and selection of mitigative measures deemed to be appropriate to allow unescorted access by members of the public to a specified primary tour route

Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

Science.gov (United States)

Sibille, Laurent; Dominques, Jesus A.

2012-01-01

The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

Anomalous magnetotransport properties of high-quality single crystals of Weyl semimetal WTe2: Sign change of Hall resistivity

Science.gov (United States)

Jha, Rajveer; Higashinaka, Ryuji; Matsuda, Tatsuma D.; Ribeiro, Raquel A.; Aoki, Yuji

2018-05-01

We report on a systematic study of Hall effect using high quality single crystals of type-II Weyl semimetal WTe2 with the applied magnetic field B//c. The residual resistivity ratio of 1330 and the large magnetoresistance of 1.5 × 106 % in 9 T at 2 K, being in the highest class in the literature, attest to their high quality. Based on a simple two-carrier model, the densities (ne and nh) and mobilities (μe and μh) for electron and hole carriers have been uniquely determined combining both Hall- and electrical-resistivity data. The difference between ne and nh is 1% at 2 K, indicating that the system is in an compensated condition. The negative Hall resistivity growing rapidly below 20 K is due to a rapidly increasing μh/μe approaching one. Below 3 K in a low field region, we found the Hall resistivity becomes positive, reflecting that μh/μe finally exceeds one in this region. These anomalous behaviors of the carrier densities and mobilities might be associated with the existence of a Lifshitz transition and/or the spin texture on the Fermi surface.

Dynamics of TRIGA-3 Salazar Reactor.; Dinamica del Reactor TRIGA Mark III del Centro Nuclear de Mexico.

Energy Technology Data Exchange (ETDEWEB)

Gallardo S, L F

1991-12-31

The theoretical study of temporal behavior of a nuclear reactor is of great importance, since it allows to know, in advance, the conditions to which a reactor is going to be submitted. The reliability of two computer codes (AIREK-JEN and PLANKIN) designed to reproduce the temporal behavior of nuclear reactors, generally power reactors, when they are applied to reproduce the dynamic behavior of TRIGA-3 Salazar Reactor is analyzed. In the first chapters, the fundamental equations that solve this computer codes are deduced, and also the main characteristics of TRIGA-3 Salazar Reactor and the necessary data to run the programs are presented; later the results obtained with the computer codes and the experimental results reported in the operational logbook of the reactor are compared, with the result that such computer codes are applicable to the temporal study of TRIGA-3 Salazar Reactor. (Author).

3D CAD model of the subcritical nuclear reactor of IPN; Modelo CAD 3D del reactor nuclear subcritico del IPN

Energy Technology Data Exchange (ETDEWEB)

Pahuamba V, F. de J.; Delfin L, A.; Gomez T, A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Ibarra R, G.; Del Valle G, E.; Sanchez R, A., E-mail: narehc@hotmail.com [IPN, Escuela Superior de Fisica y Matematicas, Av. IPN, Edif. 9, Unidad Profesional Adolfo Lopez Mateos, San Pedro Zacatenco, 07738 Ciudad de Mexico (Mexico)

2016-09-15

The three-dimensional (3D) CAD model of the subcritical reactor Chicago model 9000 of Instituto Politecnico Nacional (IPN) allows obtaining a 3D view with the dimensions of each of its components, such as: natural uranium cylindrical rods, fuel elements, hexagonal reactor core arrangement, cylindrical stainless steel tank containing the core, fuel element support grids and reactor water cleaning system. As a starting point for the development of the model, the Chicago model 9000 subcritical reactor manual provided by the manufacturer was used, the measurement and verification of the components to adapt the geometric, physical and mechanical characteristics was carried out and materials standards were used to obtain a design that allows to elaborate a new manual according to the specifications. In addition, the 3D models of the building of the Advanced Physics Laboratory, neutron generator, cobalt source and the corridors connecting to the subcritical reactor facility were developed, allowing an animated ride, developed by computer-aided design software. The manual provided by the company Nuclear Chicago, dates from the year 1959 and presents diverse deviations in the design and dimensions of the reactor components. The model developed; in addition to supporting the development of the new manual represents a learning tool to visualize the reactor components. (Author)

AA under construction in its hall

CERN Multimedia

CERN PhotoLab

1980-01-01

The Antiproton Accumulator was installed in a specially built hall. Here we see it at an "early" stage of installation, just a few magnets on the floor, no vacuum chamber at all, but: 3 months later there was circulating beam !

Direct harvesting of Helium-3 (3He) from heavy water nuclear reactors

International Nuclear Information System (INIS)

Bentoumi, G.; Didsbury, R.; Jonkmans, G.; Rodrigo, L.; Sur, B.

2013-01-01

The thermal neutron activation of deuterium inside a heavy-water-moderated or -cooled nuclear reactor produces a build-up of tritium in the heavy water. The in situ decay of tritium can, for certain reactor types and operating conditions, produce potentially useable amounts of 3 He, which can be directly extracted via the heavy-water cover gas without first separating, collecting and storing tritium outside the reactor. It is estimated that the amount of 3 He available for recovery from the moderator cover gas of a 700 MWe class Pressurized Heavy Water Reactor (PHWR) ranges from 0.1 to 0.7 m 3 (STP) per annum, varying with the tritium activity buildup in the moderator. The harvesting of 3 He would generate approximately 12.7 m 3 (STP) of 3 He, worth more than $30M at current market rates, over a typical 25-year operating cycle of the PHWR. This paper discusses the production of 3 He in the moderator of a PHWR and its extraction from the 4 He moderator cover gas system using conventional methods. (author)

Paraconductivity and excess Hall effect of YBa2Cu3Ox thin films

International Nuclear Information System (INIS)

Gueffaf, A.

2001-10-01

and a new substrate heater which can operate reliably in air, vacuum and highly oxidizing atmospheres was built. It has been used routinely and successfully to provide substrate temperature of up to 750 deg C with 200 W power input. The paraconductivity of a number of c-axis-oriented YBa 2 Cu 3 O x thin films, with a range of c-axis lattice parameters and T c -values, was determined as a function of temperature and analyzed in terms of the paraconductivity due to direct and indirect fluctuations contributions. Results are presented for the c-axis coherence length and the phase-relaxation time at 100 K obtained from the fit to the paraconductivity data. The paraconductivity results for optimum doped films were: c-axis coherence length: ξ c (0)=1.25 A; pair breaking parameter: δ=0.05; phase-relaxation time at 100 K: τ φ =0.066 ps; and two-three dimensional crossover temperature: T + =96.6 K. These values are in good agreement with those from other published work. There was considerable scatter in the coherence length and phase relaxation time for films with different critical temperatures and oxygen contents. These results were process dependent but appear to be related to the 60 K phase transition in the T c -x phase diagram. This is reported for the first time. The excess Hall effect of a number of c-axis oriented YBa 2 Cu 3 O x thin films, with a range of T c values, was determined as a function of temperature and analysed in terms of excess Hall effect theories for the direct and indirect fluctuations of the order parameter. Results are presented for the electron-hole asymmetry parameter obtained from the fit to the excess Hall effect data. For all samples studied, β is negative and has a small magnitude, as a result, the fluctuation Hall conductivity are dominated by the Maki-Thompson (MT) process rather than the Aslamazov-Lark in (Al) process. We generally observe that the Aslamazov-Larkin (AL) contribution to the excess Hall effect is negative close to T c

Suitable reverberation time for halls for rock and pop music

DEFF Research Database (Denmark)

Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

2010-01-01

The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark....... The best-rated halls in the study have reverberation times that are approximately frequency independent from 0.6 to 1.2 s for hall volumes from 1000 to 6000 m3. The worst rated halls in the study had significantly higher reverberation times in the 63 and 125 Hz bands. Since most audiences at rock concerts...... are standing, absorption coefficients were measured with a standing audience from 63 Hz to 4 kHz. These measurements showed that a standing audience absorbs about five times as much energy in mid-/high-frequency bands as in low-frequency bands....

IRPHE/B and W-SS-LATTICE, Spectral Shift Reactor Lattice Experiments

International Nuclear Information System (INIS)

2003-01-01

Description: B and W has performed and analysed a series of physics experiments basically concerned with the technology of heterogeneous reactors moderated and cooled by a variable mixture of heavy and light water. A reactor so moderated is termed Spectral Shift Control Reactor (S SCR). In the practical application of this concept, the moderator mixture is rich in heavy water at the beginning of core life, so a relatively large fraction of the neutrons are epithermal and are absorbed in the fertile material. As fuel is consumed, the moderator is diluted with light water. In this way the neutron spectrum is shifted, thereby increasing the proportion of thermal neutrons and the reactivity of the system. The general objective of the S SCR Basic Physics Program was to study the nuclear properties of rod lattices moderated by D 2 O-H 2 O mixtures. The volume ratio of moderator to non-moderator in all lattices was approximately 1.0, and the fuel was either 4%-enriched UO 2 clad in stainless steel or 93%-enriched UO 2 -ThO 2 (Nth/N 15) pellets clad in aluminum. The D 2 O concentration in the moderator ranged from zero to about 90 mole %. The experimental program includes critical experiments with both types of fuel, exponential experiments at room temperature with both types of fuel, exponential experiments at elevated temperatures with the 4%-enriched UO 2 fuel, and neutron age measurements in ThO 2 lattices. The theoretical program included the development of calculation methods applicable to these systems, and the analysis and correlation of the experimental data. A first report provides the results of critical experiments performed under the Spectral Shift Control Reactor Basic Physics Program. A second report documents experimental results and theoretical interpretation of a series of twenty uniform lattice critical experiments in which the neutron spectrum is varied over a fairly broad range. A third report addresses issues that bear on the problems associated with

Familial Pallister-Hall in adulthood.

Science.gov (United States)

Talsania, Mitali; Sharma, Rohan; Sughrue, Michael E; Scofield, R Hal; Lim, Jonea

2017-10-01

Pallister Hall syndrome is autosomal dominant disorder usually diagnosed in infants and children. Current diagnostic criteria include presence of hypothalamic hamartoma, post axial polydactyly and positive family history, but the disease has variable manifestations. Herein we report Pallister Hall syndrome diagnosed in a family where both patients were adults. A 59 year old man developed seizures 4 years prior to our evaluation of him, at which time imaging showed a hypothalamic hamartoma. The seizures were controlled medically. He did well until he had visual changes after a traumatic head injury. Repeat MRI showed slight expansion of the mass with formal visual field testing demonstrating bitemporal hemianopsia. There was no evidence of pituitary dysfunction except for large urine volume. He underwent surgery to debulk the hamartoma and the visual field defects improved. There was no hypopituitarism post-operatively, and the polydyspia resolved. His 29 year old daughter also had seizures and hypothalamic hamartoma. Both patients had had polydactyly with prior surgical correction in childhood. The daughter underwent genetic testing, which revealed a previously undescribed heterozygous single base pair deletion in exon 13 of the GLI3 gene causing a frameshift mutation. Further investigation into family history revealed multiple members in previous generations with polydactyly and/or seizures. Pallister-Hall syndrome is caused by an inherited autosomal dominant or de novo mutation in GLI3 gene. This rare syndrome has not had prevalence defined, however. Generally, diagnoses are made in the pediatric population. Our report adds to the few cases detected in adulthood.

Operation of the UK Magnox Stations in a competitive market

International Nuclear Information System (INIS)

Corrigan, A.

2000-01-01

In 1955 the UK Government announced the first major civil nuclear power plant construction programme based on the Magnox design of reactor. This was followed in 1956 with the commencement of operation of Calder Hall, the world's first nuclear power station. The initial programme was for the construction of 1 500-2 000 MW of plant but, with the success of the early stations, this was increased to 5 000 MW by 1960. In total 11 Magnox nuclear power stations were commissioned in the UK over the period 1956 to 1971, comprising a total of 26 reactors (see Table 1). At present 20 of the reactors remain in operation, with an average life of 37 years. Output from the stations has been steady for many years and they have been regarded as the workhorses of the electricity generation industry in the UK. In 1990 the electricity supply and distribution system was deregulated and a market system introduced which has led to a reduction in the sale price of electricity. In addition to this it has been necessary to invest in the plants to maintain safety levels and operational reliability. The plant's can only continue in operation provided they remain safe and economic. This paper will review recent experience with the life management of the Magnox stations. (author)

Comparison of applicability of current transition temperature shift models to SA533B-1 reactor pressure vessel steel of Korean nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji Hyun; Lee, Bong Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-08-15

The precise prediction of radiation embrittlement of aged reactor pressure vessels (RPVs) is a prerequisite for the long-term operation of nuclear power plants beyond their original design life. The expiration of the operation licenses for Korean reactors the RPVs of which are made from SA533B-1 plates and welds is imminent. Korean regulatory rules have adopted the US Nuclear Regulatory Commission's transition temperature shift (TTS) models to the prediction of the embrittlement of Korean reactor pressure vessels. The applicability of the TTS model to predict the embrittlement of Korean RPVs made of SA533B-1 plates and welds was investigated in this study. It was concluded that the TTS model of 10 CFR 50.61a matched the trends of the radiation embrittlement in the SA533B-1 plates and welds better than did that of Regulatory Guide (RG) 1.99 Rev. 2. This is attributed to the fact that the prediction performance of 10 CFR 50.61a was enhanced by considering the difference in radiation embrittlement sensitivity among the different types of RPV materials.

D-3He fuel cycles for neutron lean reactors

International Nuclear Information System (INIS)

Kernbichler, W.; Miley, G.H.; Heindler, M.

1989-01-01

The intrinsic potential of D-3He as a reactor fuel is investigated for a large range of 3He to D density ratios. A steady-state zero-dimensional reactor model is developed in which much care is attributed to a proper treatment of fast fusion products. Useful ranges of reactor parameters as well as temperature-density windows for driven and ignited operation are identified. Various figures of merit are calculated, such as power densities, net power production, neutron production, tritium load and radiative power. These results suggest several optimistic conclusions about the performance of D-3He as a reactor fuel

Revisión crítica de la construcción de un mito en sacramentales El gran teatro del mundo y La vida es sueño, de Pedro Calderón de la Barca

Directory of Open Access Journals (Sweden)

Irene González Muñoz

2012-11-01

Full Text Available En este artículo se realiza una lectura de dos de los autos sacramentales de Pedro Calderón de la Barca, a partir de una revisión crítica que evidencia los presupuestos ideológicos que fundamentan estas producciones literarias.

Hall C

Data.gov (United States)

Federal Laboratory Consortium — Hall C's initial complement of equipment (shown in the figure), includes two general-purpose magnetic spectrometers. The High Momentum Spectrometer (HMS) has a large...

Hall A

Data.gov (United States)

Federal Laboratory Consortium — The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electroand photo-induced reactions at very high luminosity...

Structure of the electromagnetic field in three-dimensional Hall magnetohydrodynamic turbulence

International Nuclear Information System (INIS)

Dmitruk, Pablo; Matthaeus, W.H.

2006-01-01

Numerical simulations of freely evolving three-dimensional compressible magnetohydrodynamics (MHD) are performed, with and without the Hall term in Ohm's law. The parameter controlling the presence of the Hall term is the ratio of the ion skin depth to the macroscopic scale of the turbulence. The ion skin depth is set to be slightly larger than the dissipation length scale (controlled by the resistivity) for the Hall MHD simulations, while it is set to zero for non-Hall MHD simulations. Small initial cross helicity, hybrid helicity, and magnetic helicity are considered. The system is left to evolve for a few turbulent characteristic times and the magnetic field and electric field are analyzed in real and wavenumber space. Distributions (histograms) of the fields are also computed. It is found that the turbulent magnetic field (as well as the velocity field) is almost unaffected by the presence of the Hall term, while the electric field is affected at scales smaller than the ion skin depth, that is, close to the dissipation range in these simulations. The importance of each term in Ohm's law for the electric field is analyzed in wavenumber space. Furthermore, reconnection-like zones are identified, where the importance of each term in Ohm's law can be seen in real space. Reconnection-like zones with magnetic field B=0 (or small) and B≠0 are found within the turbulent state of the system

ETOA, ABBN Multigroup Constants from ENDF/B for Fast Reactors

International Nuclear Information System (INIS)

Nishimura, Hideo

1977-01-01

1 - Nature of physical problem solved: Production of ABBN type group constants up to 70 groups for fast reactor calculations, reading ENDF/B library as input. 2 - Method of solution: The multigroup method of Bondarenko et al. is used for processing basic nuclear data. Calculational algorithms for an unresolved resonance region are the same as those in the MC 2 code. For a resolved resonance region, an ultrafine energy structure dependent on a level scheme is adopted. 3 - Restrictions on the complexity of the problem: Maximum number of: energy groups: 70; sigma 0 values: 6; temperatures: 5. Self-shielding factors for an unrealistically low value of sigma 0 are not guaranteed because of the approximations used in the unresolved resonance region

Construction of the Neutron Beam Facility at Australia's OPAL Research Reactor

International Nuclear Information System (INIS)

Kennedy, J.S.

2005-01-01

Full text: Australia's new research reactor, OPAL, has been designed for high quality neutron beam science and radioisotope production. It has a capacity for eighteen neutron beam instruments to be located at the reactor face and in a neutron guide hall. The new neutron beam facility features a 20 litre liquid deuterium cold neutron source and supermirror neutron reflecting guides for intense cold and thermal neutron beams. Nine neutron beam instruments are under development, of which seven are scheduled for completion in early 2007. The project is approaching the hot-commissioning stage, where criticality will be demonstrated. Installation of the neutron beam transport system and neutron beam instruments in the neutron guide hall and at the reactor face is underway, and the path to completion of this project is relatively clear. The lecture will outline Australia's aspirations for neutron science at the OPAL reactor, and describe the neutron beam facility under construction. The status of this project and a forecast of the program to completion, including commissioning and commencement of routine operation in 2007 will also be discussed. This project is the culmination of almost a decade of effort. We now eagerly anticipate catapulting Australia's neutron beam science capability to meet the best in the world today. (author)

Hall-Effect Sensors for Real-Time Monitoring Pier Scour

Directory of Open Access Journals (Sweden)

Chen-Chia CHEN

2015-01-01

Full Text Available Scour around bridge pier is a major cause of bridge failure such as collapse resulted in loss of life and property. Most of available sensors and approaches for monitoring bridge pier scour are very expensive, which is a main challenge for mass deployment of numerous bridges. Our proposed scour monitoring system utilized low-cost commercial sensors, hall-effect sensors (unit price< $1 that are capable of real-time measuring bridge pier scour with resolution of ~ 2.5 cm, and overall cost for single sensor node of our proposed work is at least 40 % less expensive than existing work. The hall- effect sensor is evaluated under controlled conditions in two laboratory flumes. After scour event, the typical voltage change of the hall-effect sensor is ~ 300 mV, and the system achieve signal-to-noise ratio performance of ~ 60 dB. Finally, we also provide an equation to predict the time variation of scour depth around pier model. Moreover, the master-slave architecture of bridge pier scour monitoring system has scalability and flexibility for mass deployment. This technique has the potential for further widespread implementation in the field.

WE-B-Exhibit Hall-01: Ask the RO-ILS Experts

Energy Technology Data Exchange (ETDEWEB)

Ezzell, G [Mayo Clinic Arizona, Phoenix, AZ (United States); Sanscrainte, E [Clarity PSO, Chicago, IL (United States); Tomlinson, C [ASTRO, Fairfax, VA (United States)

2015-06-15

Have a question about RO-ILS: Radiation Oncology Incident Learning System™, or interested in learning more? Sponsored by the American Society for Radiation Oncology (ASTRO) and AAPM, RO-ILS is the only medical specialty society-sponsored incident learning system for radiation oncology. It facilitates safer and higher quality care in radiation oncology by providing a mechanism for shared learning in a secure and non-punitive environment. Please join our RO-ILS experts for a question and answer session on Wednesday, July 15th at 8:30 in the Partners in Solutions Room in Exhibit Hall C. Our experts include: Gary Ezzell, PhD, Mayo Clinic Arizona, [Brett Miller, Phillip Beron, and Derek Brown], Emily Sanscrainte from Clarity PSO and Cindy Tomlinson, MPP, ASTRO.

Tritium production and processing in a Tokamak reactor

International Nuclear Information System (INIS)

Leger, D.

1986-09-01

Important aspects of the tritium system in Tokamak reactors that have to be controlled are overviewed in this paper. The doubling time is one of them, that is to say the time required to produce, in addition to the tritium burned enough tritium to be able to supply the initial tritium inventory. Another one is the tritium permeation through walls. In addition to the permeation phenomena, large tritium inventories are trapped in the reactor structural material. Finally, the different atmospheres of halls, etc.., that can be contaminated with tritium, have to be reprocessed

Quantum Hall effect in epitaxial graphene with permanent magnets.

Science.gov (United States)

Parmentier, F D; Cazimajou, T; Sekine, Y; Hibino, H; Irie, H; Glattli, D C; Kumada, N; Roulleau, P

2016-12-06

We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.

Quantum Hall effect in epitaxial graphene with permanent magnets

Science.gov (United States)

Parmentier, F. D.; Cazimajou, T.; Sekine, Y.; Hibino, H.; Irie, H.; Glattli, D. C.; Kumada, N.; Roulleau, P.

2016-12-01

We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.

Iniciativa de decreto sobre la propuesta de reforma política del presidente Felipe Calderón

Directory of Open Access Journals (Sweden)

Adrián Joaquín Miranda Camarena

2010-01-01

Full Text Available El presidente Felipe Calderón presenta un paquete de iniciativas, entre las que se encuentra la reforma política que tiene como fin dar más poder al ciudadano y fortalecer la democracia. Además, alienta al ciudadano para que participe y perciba que sus órganos de representación estén más atentos a sus demandas y necesidades. La iniciativa apunta a transformar los rasgos estructurales del régimen político autoritario en el ámbito del ejercicio del poder, no limitándose a lo electoral, por lo que además se pretende salir del estancamiento político y cambiar la dinámica viciosa de la representación legislativa y el conflicto frecuente entre Ejecutivo y Congreso. Por lo que consideró era urgente plantear una serie de cambios, a fin de que nuestro sistema político provenga del sufragio efectivo y pase a una democracia efectiva.

A study of some radioprotection apparatuses used in the case of pool reactors; Etude de quelques dispositifs de radioprotection en service aupres des piles piscines

Energy Technology Data Exchange (ETDEWEB)

Robien, E de; Choudens, H de; Delpuech, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-07-01

Various problems of radioprotection concerning swimming-pool reactors in Grenoble have led us to study adequate solutions: a) The automatic verification of the staff-radioactivity when coming out of Melusine or Siloe has been realized thanks to a {beta}{gamma} gate which is insensitive to the ambient background in the reactor-hall; b) The automatic verification of the contamination of the shoes of the agents working in these reactors has been realized with a dedicated device; c) The necessity to measure precisely {gamma} doses with the help of an autonomous apparatus has led to the making of a plastic-scintillator {gamma} dosimeter; d) The obligation to forbid the opening of doors in some places where there might be a great intensity of radiation, has led us to make doors open according to the intensity of radiation inside the rooms; e) The releases of radioactive iodine have been measured with activated charcoal cartridges that surround a scintillator connected with a unique channel selector; f) Finally the control of reactor safety rod fall in case of a radioactive accident has been secured by a chain whose detector is a chamber immersed in the swimming-pool, which offers, in the particular case of the hot thickness swimming-pool reactor a double advantage: first it enables us to regulate the upper hot water layer, second to get free of transitory radiations which appear in the reactor hall as the experimental apparatuses are taken out from the core. (authors) [French] Differents problemes de radioprotection se posant aupres des piles piscines de Grenoble, ils ont necessite l'etude de solutions particulieres: a) le controle automatique de la radioactivite du personnel sortant de Melusine ou de Siloe a ete realise a l'aide d'un portique {beta}{gamma} insensible au bruit de fond ambiant du hall des piles; b) le controle automatique de la contamination des souliers des agents travaillant dans ces piles a ete realise par une passerelle pieds {beta}{gamma}; c) la

Anomalous Hall conductivity: Local orbitals approach

Czech Academy of Sciences Publication Activity Database

Středa, Pavel

2010-01-01

Roč. 82, č. 4 (2010), 045115/1-045115/9 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * Berry phase correction * orbital polarization momentum Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010

German Phase B [risk study] highlights the role of [reactor] accident management

International Nuclear Information System (INIS)

Anon.

1989-01-01

Phase B of the German probabilistic risk assessment study, now scheduled for publication this month, suggests that reactor accident management measures can prevent or mitigate about 90 per cent of event sequences. (author)

Neutron scattering research at JAERI reactors - past, present and future -

International Nuclear Information System (INIS)

Funahashi, Satoru; Morii, Yukio; Minakawa, Nobuaki

1992-01-01

It was in 1961 that the first neutron scattering experiment was performed in Japan at JRR-2. The start of JRR-3 in 1964 accelerated the neutron scattering activities in Japan. The research in this field in Japan grew up by using these two research reactors. Among them JRR-2 has played an important role because its neutron flux was about seven times higher than that of the old JRR-3. The completion of the new JRR-3M in 1990 made an epoch to the neutron scattering activities in Japan. The long-waited JRR-3M came up to the expectations of the scientists of Japan. It is a realization of the ideal reactor with tangential beam holes, cold source and neutron guides in a large guide hall. The flux at the neutron scattering instruments is about five times higher than that of JRR-2. Utilization of JRR-3M has just started. Twelve neutron scattering machines are running there. The number will increase up to close twenty in a couple of years. (author)

Giant spin Hall angle from topological insulator BixSe(1 - x) thin films

Science.gov (United States)

Dc, Mahendra; Jamali, Mahdi; Chen, Junyang; Hickey, Danielle; Zhang, Delin; Zhao, Zhengyang; Li, Hongshi; Quarterman, Patrick; Lv, Yang; Mkhyon, Andre; Wang, Jian-Ping

Investigation on the spin-orbit torque (SOT) from large spin-orbit coupling materials has been attracting interest because of its low power switching of the magnetization and ultra-fast driving of the domain wall motion that can be used in future spin based memory and logic devices. We investigated SOT from topological insulator BixSe(1 - x) thin film in BixSe(1 - x) /CoFeB heterostructure by using the dc planar Hall method, where BixSe(1 - x) thin films were prepared by a unique industry-compatible deposition process. The angle dependent Hall resistance was measured in the presence of a rotating external in-plane magnetic field at bipolar currents. The spin Hall angle (SHA) from this BixSe(1 - x) thin film was found to be as large as 22.41, which is the largest ever reported at room temperature (RT). The giant SHA and large spin Hall conductivity (SHC) make this BixSe(1 - x) thin film a very strong candidate as an SOT generator in SOT based memory and logic devices.

75 FR 22770 - Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment

Science.gov (United States)

2010-04-30

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13652-000-Montana] Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment April 22, 2010. In accordance with the National Environmental Policy Act of 1969, as amended, and the Federal Energy Regulatory...

Charge carrier coherence and Hall effect in organic semiconductors

Science.gov (United States)

Yi, H. T.; Gartstein, Y. N.; Podzorov, V.

2016-01-01

Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor. PMID:27025354

Charge carrier coherence and Hall effect in organic semiconductors.

Science.gov (United States)

Yi, H T; Gartstein, Y N; Podzorov, V

2016-03-30

Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.

Guild Hall retrofit

Energy Technology Data Exchange (ETDEWEB)

1984-08-01

This report demonstrates the economic viability of an exterior rewrap retrofit performed on a public community facility for the performing arts. This facility originally consisted of two mess halls built by the American army. The exterior retrofit consisted of constructing a super-insulated passageway to link the two halls as well as completely wrapping the facility with six millimetre polyethylene to provide an airtight barrier. The roofs and walls were reinsulated and insulation levels were increased to RSI 10.5 in the ceilings and RSI 7.7 in the walls. The installation of a propane fuelled furnace was also included in the retrofit package. Prior to the renovations and retrofitting, the Guild Hall facility was almost unusable. The demonstration project transformed the cold, drafty buildings into an attractive, comfortable and functional centre for the performing arts. Heating requirements have been reduced to 500 MJ/m {sup 2} of floor space annually compared to a predicted 1,760 MJ/m{sup 2} of floor space based on HOTCAN analysis of the heating requirements without the energy conservation measures. 9 figs., 10 tabs.

Conceptual design of D-3He FRC reactor 'ARTEMIS'

International Nuclear Information System (INIS)

Momota, H.; Ishida, A.; Kohzaki, Y.

1991-07-01

A comprehensive design study of the D- 3 He fueled field-reversed configuration (FRC) reactor 'ARTEMIS' is carried out for the purpose of proving its attractive characteristics and clarifying the critical issues for a commercial fusion reactor. The FRC burning plasma is stabilized and sustained in a steady equilibrium by means of a preferential trapping of D- 3 He fusion-produced energetic protons. A novel direct energy converter for 15MeV protons is also presented. On the bases of a consistent scenario of the fusion plasma production and simple engineering, a compact and simple reactor concept is presented. The design of the D- 3 He FRC power plant definitely offers the most attractive prospect for energy development. It is environmentally acceptable in view of radio-activity and fuel resources; and the estimated cost of electricity is low compared to a light water reactor. Critical issues concerning physics or engineering for the development of the D- 3 He FRC reactor are clarified. (author)

Decommissioning activities for Salaspils research reactor - 59055

International Nuclear Information System (INIS)

Abramenkovs, A.; Malnacs, J.

2012-01-01

In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor (SRR). The reactor is out of operation since July 1998. A conceptual study for the decommissioning of SRR has been carried out by Noell-KRC-Energie- und Umwelttechnik GmbH at 1998-1999. The Latvian government decided to start the direct dismantling to 'green field' in October 26, 1999. The upgrade of decommissioning and dismantling plan was performed in 2003-2004 years, which change the main goal of decommissioning to the 'brown field'. The paper deals with the SRR decommissioning experience during 1999-2010. The main decommissioning stages are discussed including spent fuel and radioactive wastes management. The legal aspects and procedures for decommissioning of SRR are described in the paper. It was found, that the involvement of stakeholders at the early stages significantly promotes the decommissioning of nuclear facility. Radioactive waste management's main efforts were devoted to collecting and conditioning of 'historical' radioactive wastes from different storages outside and inside of reactor hall. All radioactive materials (more than 96 tons) were conditioned in concrete containers for disposal in the radioactive wastes repository 'Radons' at Baldone site. The dismantling of contaminated and activated components of SRR systems is discussed in paper. The cementation of dismantled radioactive wastes in concrete containers is discussed. Infrastructure of SRR, including personal protective and radiation measurement equipment, for decommissioning purposes was upgraded significantly. Additional attention was devoted to the free release measurement's technique. The certified laboratory was installed for supporting of all decommissioning activities. All non-radioactive equipments and materials outside of reactor buildings were released for clearance and dismantled for reusing or conventional disposing. Weakly contaminated materials from reactor hall were collected

Analysis of the radiometric survey during the Argonauta reactor operation; Analise do levantamento radiometrico durante operacao do reator Argonauta

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Eara de S.L.; Cardozo, Katia K.M.; Silva, Joao Carlos P.; Santos, Joao Regis dos, E-mail: esluz@ien.gov.br, E-mail: cardozo@ien.gov.br, E-mail: jcarlos@ien.gov.br, E-mail: regis@ien.gov.br [Instituto de Engenharia Nuclear (CNEN-IEN/RJ), Rio de Janeiro - RJ (Brazil)

2013-07-01

The Argonaut reactor at the Institute of Nuclear Engineering-IEN/CNEN, operates normally, the powers between 1.7 and 340 W on neutrongraphy procedures, production of radionuclides and experimental reactor physics lessons to postgraduate courses. The doses from neutrons and gamma radiation are measured when the reactor is critical, inside the reactor hall and surrounding regions. A study of the data obtained was performed to evaluate the daily need of this survey in the reactor hall. Taking into account the principle ALARA, which aims to optimize and minimize the dose received by the individual, we propose, in this work, through an analysis of the acquired data in occupational radiometric surveys, a reformulation of the area monitoring routine practiced by the team of radiological protection of the Institute of Nuclear Engineering - IEN/CNEN-RJ, whereas other monitoring routines regarding the radiological protection are also applied in the routine of the reactor. The operations under review occurred with the reactor operating 340 W power at intervals of 60, 120 and 180 minutes, in monitoring points in controlled areas, supervised and free. The results showed significant dose values in the output of the J-Channel 9 when the operation occurs with this open. With 180 minutes of operation, the measured values of dose rate were lower than the values at 60 min and 120 operations min. At the point in the supervised area, offsite to the reactor hall, situated in the direction of the J-Channel 9, the value reduces more than 14% in any operating time in relation to the dose rate measured at the point opposite the canal. There is a 50% reduction in the dose rates for operations with and J-9 closed. The results suggest a new frequency of radiometric survey whose mode of operation is maintained in similar conditions, since combined with other relevant practices of radiation protection.

Laurance David Hall.

Science.gov (United States)

Coxon, Bruce

2011-01-01

An account is given of the life, scientific contributions, and passing of Laurance David Hall (1938-2009), including his early history and education at the University of Bristol, UK, and the synthesis and NMR spectroscopy of carbohydrates and other natural products during ∼20 years of research and teaching at the University of British Columbia in Vancouver, Canada. Lists of graduate students, post-doctoral fellows, and sabbatical visitors are provided for this period. Following a generous endowment by Dr. Herchel Smith, Professor Hall built a new Department of Medicinal Chemistry at Cambridge University, UK, and greatly expanded his researches into the technology and applications of magnetic resonance imaging (MRI) and zero quantum NMR. MRI technology was applied both to medical problems such as the characterization of cartilage degeneration in knee joints, the measurement of ventricular function, lipid localization in animal models of atherosclerosis, paramagnetic metal complexes of polysaccharides as contrast agents, and studies of many other anatomical features, but also to several aspects of materials analysis, including food analyses, process control, and the elucidation of such physical phenomena as the flow of liquids through porous media, defects in concrete, and the visualization of fungal damage to wood. Professor Hall's many publications, patents, lectures, and honors and awards are described, and also his successful effort to keep the Asilomar facility in Pacific Grove, California as the alternating venue for the annual Experimental NMR Conference. Two memorial services for Professor Hall are remembered. Copyright © 2011 Elsevier Inc. All rights reserved.

Hypernuclear spectroscopy via (e,e'K+) in JLab's Hall A

International Nuclear Information System (INIS)

LeRose, John J.; Jager, C.W. de; Feuerbach, R.J.; Higinbotham, D.W.; Reitz, B.; Acha, A.; Markowitz, P.; Bydzovsky, P.; Sotona, M.; Chang, C.C.; Cisbani, E.; Cusanno, F.; Frullani, S.; Garibaldi, F.; De Leo, R.; Lagamba, L.; Marrone, S.; Iodice, M.; Urciuoli, G.M.

2008-01-01

Results are presented from a new experiment (E94-107) in Hall A of the Thomas Jefferson National Accelerator Facility (JLab) producing 12 Λ B, 16 Λ N, and 9 Λ Li using electroproduction, (e,e ' K + ). In the hypernuclear missing-mass spectrum the experiment achieves very good energy resolution (670 keV FWHM) by exploiting the characteristics of the High Resolution spectrometer pair and the exceptional beam quality available at JLab. The spectrometers were used with the addition of an INFN provided pair of septum magnets to reach the desired small angles. Also, the Hall A standard complement of equipment was further augmented by the addition of a Ring Imaging Cherenkov detector (RICH) to achieve the best possible kaon identification

Extraordinary Hall effect in Co implanted GaAs hybrid magnetic semiconductors

International Nuclear Information System (INIS)

Honda, S.; Tateishi, K.; Nawate, M.; Sakamoto, I.

2004-01-01

Hybrid Co/GaAs ferromagnetic semiconductors have been prepared by implantation method. In these samples, sheet resistance shows weak temperature dependence, and the extraordinary Hall effect with positive coefficient is observed. In small Co content samples, Hall resistance increases with decreasing temperature and maximum value of 3.6x10 -2 Ω is obtained at 150 K

Room acoustic enhancement in a small hall with very low natural reverberation time

DEFF Research Database (Denmark)

Gade, Anders Christian

1996-01-01

natural combinations of room acoustic properties. Consequently, the natural reverberation time in a newly opened 350 seat multipurpose hall in Denmark was designed as low as 0.7 sec. Two different reverberation enhancement systems were considered and tested in the hall. The objective and subjective...... testing results are reported and compared with previous results obtained in another small hall supplied with a similar enhancement system. The results concerning 'realism' are also compared with acoustic properties found in 'natural' halls of different sizes and reverberation times.......In small multipurpose halls to be equipped with electronic reverberation enhancement systems, selecting a very low natural reverberation time is advantageous for several reasons. It will 1) reduce the risk of feedback, 2) increase the possible range of room acoustic variation and 3) allow for more...

Pseudospin anisotropy classification of quantum Hall ferromagnets

Czech Academy of Sciences Publication Activity Database

Jungwirth, Tomáš; MacDonald, A. H.

2000-01-01

Roč. 63, č. 3 (2000), s. 035305-1 - 035305-9 ISSN 0163-1829 R&D Projects: GA ČR GA202/98/0085 Institutional research plan: CEZ:AV0Z1010914 Keywords : quantum Hall ferromagnets * anisotropy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.065, year: 2000

Analyses of European BWRs with CASMO-3 and MICROBURN-B

International Nuclear Information System (INIS)

Spierling, H.; Misu, S.; Grummer, R.G.

1996-01-01

For many years, Siemens Power Generation KWU has been using the BPSA (based on TGBLA) and RS3D (based on PANACEA) codes for neutronics fuel assembly design and steady-state boiling water reactor (BWR) core analysis, respectively. With increasing convergence of development and design activities at Siemens Power Corporation, Nuclear Division (SPC-ND) and Siemens KWU in the nuclear fuel area, there was a rising incentive to implement at Siemens KWU the CASMO-3 code, which had previously been implemented by SPC-ND, and the MICROBURN-B code which was developed by SPC-ND. This paper deals with the experience gained by Siemens KWU in applying CASMO-3/MICROBURN-B in European reload projects in an environment of ambitious in-core fuel management requirements

2D massless QED Hall half-integer conductivity and graphene

International Nuclear Information System (INIS)

Martínez, A Pérez; Querts, E Rodriguez; Rojas, H Pérez; Gaitan, R; Rodriguez-Romo, S

2011-01-01

Starting from the photon self-energy tensor in a magnetized medium, the 3D complete antisymmetric form of the conductivity tensor is found in the static limit of a fermion system C-non-invariant under fermion–antifermion exchange. The massless relativistic 2D fermion limit in QED is derived by using the compactification along the dimension parallel to the magnetic field. In the static limit and at zero temperature, the main features of the quantum Hall effect (QHE) are obtained: the half-integer QHE and the minimum value proportional to e 2 /h for the Hall conductivity. For typical values of graphene the plateaus of the Hall conductivity are also reproduced. (paper)

Removal in a lump of JRR-3 nuclear reactor

International Nuclear Information System (INIS)

Ohnishi, Nobuaki; Suzuki, Masanori; Nagase, Tetsuo; Watanabe, Morinari.

1989-01-01

The research reactor JRR-3 in Japan Atomic Energy Research Institute is called 'Home made No.1 reactor' as all except fuel and heavy water as the moderator and coolant were manufactured in Japan. The JRR-3 attained the criticality in 1962, and the cumulative time of operation reached 47135.5 hours, and the cumulative power output reached 419073.5 MWh. It was stopped in 1983. During the period, it was utilized for beam experiment, irradiation of fuel and materials, RI production and others. In order to cope with the expansion of utilization and the advance of utilizing technology of the research reactor, the reconstruction works are in progress, and the criticality of the reconstructed reactor is expected in 1990. On the site where the old reactor is removed, the reactor of different type is installed, and the first large cold neutron source is equipped. In this report, as to the removal of the old reactor proper, the method of working and the results are described. Considering the period of working, the cost and the management of the removed reactor, in the case of the JRR-3, the method of carrying it out in a lump was adopted as the optimum removal method. The plan, procedure and results of the removal working are reported. (K.I.)

The reactor kinetics code tank: a validation against selected SPERT-1b experiments

International Nuclear Information System (INIS)

Ellis, R.J.

1990-01-01

The two-dimensional space-time analysis code TANK is being developed for the simulation of transient behaviour in the MAPLE class of research reactors. MAPLE research reactor cores are compact, light-water-cooled and -moderated, with a high degree of forced subcooling. The SPERT-1B(24/32) reactor core had many similarities to MAPLE-X10, and the results of the SPERT transient experiments are well documented. As a validation of TANK, a series of simulations of certain SPERT reactor transients was undertaken. Special features were added to the TANK code to model reactors with plate-type fuel and to allow for the simulation of rapid void production. The results of a series of super-prompt-critical reactivity step-insertion transient simulations are presented. The selected SPERT transients were all initiated from low power, at ambient temperatures, and with negligible coolant flow. Th results of the TANK simulations are in good agreement with the trends in the experimental SPERT data

The Other Hall Effect: College Board Physics

Science.gov (United States)

Sheppard, Keith; Gunning, Amanda M.

2013-01-01

Edwin Herbert Hall (1855-1938), discoverer of the Hall effect, was one of the first winners of the AAPT Oersted Medal for his contributions to the teaching of physics. While Hall's role in establishing laboratory work in high schools is widely acknowledged, his position as chair of the physics section of the Committee on College Entrance…

3D simulation of CANDU reactor regulating system

International Nuclear Information System (INIS)

Venescu, B.; Zevedei, D.; Jurian, M.

2013-01-01

Present paper shows the evaluation of the performance of the 3-D modal synthesis based reactor kinetic model in a closed-loop environment in a MATLAB/SIMULINK based Reactor Regulating System (RRS) simulation platform. A notable advantage of the 3-D model is the level of details that it can reveal as compared to the coupled point kinetic model. Using the developed RRS simulation platform, the reactor internal behaviours can be revealed during load-following tests. The test results are also benchmarked against measurements from an existing (CANDU) power plant. It can be concluded that the 3-D reactor model produces more realistic view of the core neutron flux distribution, which is closer to the real plant measurements than that from a coupled point kinetic model. It is also shown that, through a vectorization process, the computational load of the 3-D model is comparable with that of the 14-zone coupled point kinetic model. Furthermore, the developed Graphical User Interface (GUI) software package for RRS implementation represents a user friendly and independent application environment for education training and industrial utilizations. (authors)

Mechanistic study on the fluorination of K[B(CN)4] with ClF enabling the high yield and large scale synthesis of K[B(CF3)4] and K[(CF3)3BCN].

Science.gov (United States)

Bernhardt, Eduard; Finze, Maik; Willner, Helge

2011-10-17

The fluorination of K[B(CN)(4)] with ClF is studied by millimolar test reactions in aHF and CH(2)Cl(2) solution and by subsequent identification of intermediates such as B-CF═NCl, B-CF(2)-NCl(2), and B-CF(3) species as well as NCl(3) by (19)F, (11)B NMR, and Raman spectroscopy, respectively. At first one cyano group of K[B(CN)(4)] is converted fast into a CF(3) group, and with increasing fluorination the reaction becomes slower and several intermediates could be observed. On the basis of these results, a synthesis was developed for K[B(CF(3))(4)] on a 0.2 molar scale by treatment of K[B(CN)(4)] diluted in aHF with ClF. The course of the reactions was followed by (i) monitoring the vapor pressure inside the reactor, (ii) observing the heat dissipation during ClF uptake, and (iii) measuring the volume of the released nitrogen gas. Since the fluorination of the last cyano group proceeds very slowly, the selective synthesis of K[(CF(3))(3)BCN] on a 0.2 molar scale is possible, as well. The analysis of the mechanisms, thermodynamics, and kinetics of the fluorination reactions is supported by density functional theory (DFT) calculations.

3 MW TRIGA Research Reactor facility of BAEC and its Utilization

International Nuclear Information System (INIS)

Molla, N.I.; Bhuiyan, S.I.; Wadud Mondal, M.A.; Ahmed, F.U.; Islam, M.N.; Hossain, S.M.; Ahmed, K.; Zulquarnain, A.; Abedin, Z.

1999-01-01

The paper briefly describes the Utilisation of 3 MW TRIGA Research Reactor of BAEC for neutron beam research, neutron activation analysis are isotope production. It includes the installation of the triple axis neutron spectrometer at the radial piercing beam port and a neutron radiography set-up at the tangential beam port and their uses for material analysis and condensed matter research and material testing. Nuclear and magnetic structures of some ferrites have been studied in powder diffraction method in the double axis mode. SANS technique with double crystal diffraction known as Bonse and Hart's method has been adopted in an experiment with alumina sample. The neutron radiography set-up and its use in the detection of corrosion in alumina have been reported. Determination of arsenic concentration in drinking water from tube well via Instrumental Neutron Activation Analysis and production of radioiodine-131 by dry distillation method are presented. Our experience on the removal of N-16 decay tank because of the leakage of coolant and bringing the research reactor back to operational by-passing the decay tank have been focussed. A possible reconfiguration of the existing TRIGA core, without exceeding the safety margins, providing additional irradiation channel and upgrading the neutron flux for increased radioisotope production has been attempted. Cross section library ENDF/B-VI and JENDL3.2, code NJOY94.10, WIMSD package, 3-D code CITATION, PARET and Monte Carlo code MCNP4B2 have been employed to achieve the objective. (author)

Anomalous Hall effect in polycrystalline Ni films

KAUST Repository

Guo, Zaibing

2012-02-01

We systematically studied the anomalous Hall effect in a series of polycrystalline Ni films with thickness ranging from 4 to 200 nm. It is found that both the longitudinal and anomalous Hall resistivity increased greatly as film thickness decreased. This enhancement should be related to the surface scattering. In the ultrathin films (46 nm thick), weak localization corrections to anomalous Hall conductivity were studied. The granular model, taking into account the dominated intergranular tunneling, has been employed to explain this phenomenon, which can explain the weak dependence of anomalous Hall resistivity on longitudinal resistivity as well. © 2011 Elsevier Ltd. All rights reserved.

Analyses for MARIA Research Reactor with RELAP/MOD3 code

International Nuclear Information System (INIS)

Szczurek, J.; Czerski, P.

2004-01-01

This paper deals with the application of the RELAP5/MOD3 code to the transient analyses for MARIA research reactor. Poland's MARIA Research Reactor is water and beryllium moderated, water-cooled reactor of a pool type with pressurized fuel channels containing concentric multi-tube assemblies of highly enriched uranium clad in aluminium. The RELAP5/MOD3 input data model includes the whole primary cooling circuit of the MARIA reactor. The model was qualified against the reactor data at steady state conditions and additionally against the existing reliable experimental data for a transient initiated by the reactor scram. The RELAP transient simulation was performed for loss of forced flow accidents including two scenarios with protected and unprotected (no scram) reactor core. Calculations allow estimating time margin for reactor scram initiation and reactivity feedbacks contribution to the results. (author)

Elementary theory of quantum Hall effect

Directory of Open Access Journals (Sweden)

Keshav N. Shrivastava

2008-04-01

Full Text Available The Hall effect is the generation of a current perpendicular to both the direction of the applied electric as well as magnetic field in a metal or in a semiconductor. It is used to determine the concentration of electrons. The quantum Hall effect with integer quantization was discovered by von Klitzing and fractionally charged states were found by Tsui, Stormer and Gossard. Robert Laughlin explained the quantization of Hall current by using “flux quantization” and introduced incompressibility to obtain the fractional charge. We have developed the theory of the quantum Hall effect by using the theory of angular momentum. Our predicted fractions are in accord with those measured. We emphasize our explanation of the observed phenomena. We use spin to explain the fractional charge and hence we discover spin-charge locking.

Efficient switching of 3-terminal magnetic tunnel junctions by the giant spin Hall effect of Pt85Hf15 alloy

Science.gov (United States)

Nguyen, Minh-Hai; Shi, Shengjie; Rowlands, Graham E.; Aradhya, Sriharsha V.; Jermain, Colin L.; Ralph, D. C.; Buhrman, R. A.

2018-02-01

Recent research has indicated that introducing impurities that increase the resistivity of Pt can enhance the efficiency of the spin Hall torque it generates. Here, we directly demonstrate the usefulness of this strategy by fabricating prototype 3-terminal in-plane-magnetized magnetic tunnel junctions that utilize the spin Hall torque from a Pt85Hf15 alloy and measuring the critical currents for switching. We find that Pt85Hf15 reduces the switching current densities compared to pure Pt by approximately a factor of 2 for both quasi-static ramped current biases and nanosecond-scale current pulses, thereby proving the feasibility of this approach in assisting the development of efficient embedded magnetic memory technologies.

Anomalous Hall effect in disordered multiband metals

Czech Academy of Sciences Publication Activity Database

Kovalev, A.A.; Sinova, Jairo; Tserkovnyak, Y.

2010-01-01

Roč. 105, č. 3 (2010), 036601/1-036601/4 ISSN 0031-9007 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.621, year: 2010

Design and Testing of a Hall Effect Thruster with 3D Printed Channel and Propellant Distributor

Science.gov (United States)

Hopping, Ethan P.; Xu, Kunning G.

2017-01-01

The UAH-78AM is a low-power Hall effect thruster developed at the University of Alabama in Huntsville with channel walls and a propellant distributor manufactured using 3D printing. The goal of this project is to assess the feasibility of using unconventional materials to produce a low-cost functioning Hall effect thruster and consider how additive manufacturing can expand the design space and provide other benefits. A version of the thruster was tested at NASA Glenn Research Center to obtain performance metrics and to validate the ability of the thruster to produce thrust and sustain a discharge. An overview of the thruster design and transient performance measurements are presented here. Measured thrust ranged from 17.2 millinewtons to 30.4 millinewtons over a discharge power of 280 watts to 520 watts with an anode I (sub SP)(Specific Impulse) range of 870 seconds to 1450 seconds. Temperature limitations of materials used for the channel walls and propellant distributor limit the ability to run the thruster at thermal steady-state.

Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators.

Science.gov (United States)

Guterding, Daniel; Jeschke, Harald O; Valentí, Roser

2016-05-17

Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

The quantum hall effect

International Nuclear Information System (INIS)

El-Arabi, N. M.

1993-01-01

Transport phenomena in two dimensional semiconductors have revealed unusual properties. In this thesis these systems are considered and discussed. The theories explain the Integral Quantum Hall Effect (IQHE) and the Fractional Quantum Hall Effect (FQHE). The thesis is composed of five chapters. The first and the second chapters lay down the theory of the IQHE, the third and fourth consider the theory of the FQHE. Chapter five deals with the statistics of particles in two dimension. (author). Refs

Paired Hall states

International Nuclear Information System (INIS)

Greiter, M.

1992-01-01

This dissertation contains a collection of individual articles on various topics. Their significance in the corresponding field as well as connections between them are emphasized in a general and comprehensive introduction. In the first article, the author explores the consequences for macroscopic effective Lagrangians of assuming that the momentum density is proportional to the flow of conserved current. The universal corrections obtained for the macroscopic Lagrangian of a superconductor describe the London Hall effect, and provide a fully consistent derivation of it. In the second article, a heuristic principle is proposed for quantized Hall states: the existence and incompressibility of fractionally quantized Hall states is explained by an argument based on an adiabatic localization of magnetic flux, the process of trading uniform flux for an equal amount of fictitious flux attached to the particles. This principle is exactly implemented in the third article. For a certain class of model Hamiltonians, the author obtains Laughlin's Jastrow type wave functions explicitly from a filled Landau level, by smooth extrapolation in quantum statistics. The generalization of this analysis to the torus geometry shows that theorems restricting the possibilities of quantum statistics on closed surfaces are circumvented in the presence of a magnetic field. In the last article, the existence is proposed of a novel incompressible quantum liquid, a paired Hall state, at a half filled Landau level. This state arises adiabatically from free fermions in zero magnetic field, and reduces to a state previously proposed by Halperin in the limit of tightly bound pairs. It supports unusual excitations, including neutral fermions and charge e/4 anyons with statistical parameter θ = π/8

Completion of reconstruction for Japan Research Reactor No.3

International Nuclear Information System (INIS)

Kakefuda, K.; Tani, M.; Isshiki, M.

1992-01-01

The works of the reconstruction for the Japan Research Reactor No.3 (JRR-3) started in 1985 and initial criticality of the new reactor achieved in March, 1990. After commissioning test, the new JRR-3 has been operated some operational cycles since November, 1990. This paper presents outline of the removal work on the old JRR-3 and the new JRR-3. (author)

Refurbishment of the transportation equipment, Task 3.08/04-10; Podzadatak 3.08/04-10 Remont transportnih uredjaja

Energy Technology Data Exchange (ETDEWEB)

Nikolic, M; Bratic, A [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

1963-12-15

Transportation equipment at the RA reactor includes the bridge crane in the reactor hall, another smaller crane, bridge crane in spent fuel storage space, crane for handling the fuel containers n the room 099 and cart of the transportation channel. Regular testing and maintenance during reactor operation was not considered sufficient, and for that reason the repair and maintenance actions were done during the refurbishment of the reactor while it has been shut-down.

Development of 'low activation superconducting wire' for an advanced fusion reactor

International Nuclear Information System (INIS)

Hishinuma, Y.; Yamada, S.; Sagara, A.; Kikuchi, A.; Takeuchi, T.; Matsuda, K.; Taniguchi, H.

2011-01-01

In the D-T burning plasma reactor beyond ITER such as DEMO and fusion power plants assuming the steady-state and long time operation, it will be necessary to consider carefully induced radioactivity and neutron irradiation properties on the all components for fusion reactors. The decay time of the induced radioactivity can control the schedule and scenarios of the maintenance and shutdown on the fusion reactor. V 3 Ga and MgB 2 compound have shorter decay time within 1 years and they will be desirable as a candidate material to realize 'low activation and high magnetic field superconducting magnet' for advanced fusion reactor. However, it is well known that J c -B properties of V 3 Ga and MgB 2 wires are lower than that of the Nb-based A15 compound wires, so the J c -B enhancements on the V 3 Ga and MgB 2 wires are required in order to apply for an advanced fusion reactor. We approached and succeeded to developing the new process in order to improve J c properties of V 3 Ga and MgB 2 wires. In this paper, the recent activities for the J c improvements and detailed new process in V 3 Ga and MgB 2 wires are investigated. (author)

Dr. Hall and the work cure.

Science.gov (United States)

Reed, Kathlyn L

2005-01-01

Herbert James Hall, MD (1870-1923), was a pioneer in the systematic and organized study of occupation as therapy for persons with nervous and mental disorders that he called the "work cure." He began his work in 1904 during the early years of the Arts and Crafts Movement in the United States. His primary interest was the disorder neurasthenia, a condition with many symptoms including chronic fatigue, stress, and inability to work or perform everyday tasks. The prevailing treatment of the day was absolute bed rest known as the "rest cure." Hall believed that neurasthenia was not caused by overwork but by faulty living habits that could be corrected through an ordered life schedule and selected occupations. He identified several principles of therapy that are still used today including graded activity and energy conservation. Dr. Adolph Meyer credits Hall for organizing the ideas on the therapeutic use of occupation (Meyer, 1922). Hall also provided the name American Occupational Therapy Association for the professional organization and served as the fourth president. For his many contributions to the profession Hall deserves to be recognized as a major contributor to the development and organization of occupational therapy.

Optimization of edge state velocity in the integer quantum Hall regime

Science.gov (United States)

Sahasrabudhe, H.; Novakovic, B.; Nakamura, J.; Fallahi, S.; Povolotskyi, M.; Klimeck, G.; Rahman, R.; Manfra, M. J.

2018-02-01

Observation of interference in the quantum Hall regime may be hampered by a small edge state velocity due to finite phase coherence time. Therefore designing two quantum point contact (QPCs) interferometers having a high edge state velocity is desirable. Here we present a new simulation method for designing heterostructures with high edge state velocity by realistically modeling edge states near QPCs in the integer quantum Hall effect (IQHE) regime. Using this simulation method, we also predict the filling factor at the center of QPCs and their conductance at different gate voltages. The 3D Schrödinger equation is split into 1D and 2D parts. Quasi-1D Schrödinger and Poisson equations are solved self-consistently in the IQHE regime to obtain the potential profile, and quantum transport is used to solve for the edge state wave functions. The velocity of edge states is found to be /B , where is the expectation value of the electric field for the edge state. Anisotropically etched trench gated heterostructures with double-sided delta doping have the highest edge state velocity among the structures considered.

Empirical electron cross-field mobility in a Hall effect thruster

International Nuclear Information System (INIS)

Garrigues, L.; Perez-Luna, J.; Lo, J.; Hagelaar, G. J. M.; Boeuf, J. P.; Mazouffre, S.

2009-01-01

Electron transport across the magnetic field in Hall effect thrusters is still an open question. Models have so far assumed 1/B 2 or 1/B scaling laws for the 'anomalous' electron mobility, adjusted to reproduce the integrated performance parameters of the thruster. We show that models based on such mobility laws predict very different ion velocity distribution functions (IVDF) than measured by laser induced fluorescence (LIF). A fixed spatial mobility profile, obtained by analysis of improved LIF measurements, leads to much better model predictions of thruster performance and IVDF than 1/B 2 or 1/B mobility laws for discharge voltages in the 500-700 V range.

Safety of research reactors (Design and Operation)

International Nuclear Information System (INIS)

Dirar, H. M.

2012-06-01

The primary objective of this thesis is to conduct a comprehensive up-to-date literature review on the current status of safety of research reactor both in design and operation providing the future trends in safety of research reactors. Data and technical information of variety selected historical research reactors were thoroughly reviewed and evaluated, furthermore illustrations of the material of fuel, control rods, shielding, moderators and coolants used were discussed. Insight study of some historical research reactors was carried with considering sample cases such as Chicago Pile-1, F-1 reactor, Chalk River Laboratories,. The National Research Experimental Reactor and others. The current status of research reactors and their geographical distribution, reactor category and utilization is also covered. Examples of some recent advanced reactors were studied like safety barriers of HANARO of Korea including safety doors of the hall and building entrance and finger print identification which prevent the reactor from sabotage. On the basis of the results of this research, it is apparent that a high quality of safety of nuclear reactors can be attained by achieving enough robust construction, designing components of high levels of efficiency, replacing the compounds of the reactor in order to avoid corrosion and degradation with age, coupled with experienced scientists and technical staffs to operate nuclear research facilities.(Author)

Compact stellarators as reactors

International Nuclear Information System (INIS)

Lyon, J.F.; Valanju, P.; Zarnstorff, M.C.; Hirshman, S.; Spong, D.A.; Strickler, D.; Williamson, D.E.; Ware, A.

2001-01-01

Two types of compact stellarators are examined as reactors: two- and three-field-period (M=2 and 3) quasi-axisymmetric devices with volume-average =4-5% and M=2 and 3 quasi-poloidal devices with =10-15%. These low-aspect-ratio stellarator-tokamak hybrids differ from conventional stellarators in their use of the plasma-generated bootstrap current to supplement the poloidal field from external coils. Using the ARIES-AT model with B max =12T on the coils gives Compact Stellarator reactors with R=7.3-8.2m, a factor of 2-3 smaller R than other stellarator reactors for the same assumptions, and neutron wall loadings up to 3.7MWm -2 . (author)

La identidad nacional y Calderón en la polémica teatral de 1762-1764

Directory of Open Access Journals (Sweden)

Bezhanova, Olga

2004-06-01

Full Text Available Drawing on contemporary theories about national identity, legitimacy and intellectual authority this article explores identitarian issues at stake during the 1762-1764 controversy on Spanish theater. Re-reading texts by Clavijo y Fajardo (El Pensador, Nicolás Fernández de Moratín (Desengaños al teatro español and other writings, Mariano José Nipho (Diario Estrangero and La nación española defendida and José Romea y Tapia (El escritor sin título we contend that what these authors are debating indeed is not theater but the legitimacy and authority they are claiming for, and ultimately opposing conceptions of national identity. Calderón becoming a cultural icon of such identity. Particularly significant is the role of autos sacramentales in this context. In effect, acrimony and irritation are part of this polemics because orthodox Catholicism is, from a conservative point of view, an essential component of what they consider Spanish national identity. The prohibition of the autos is just a sign of a temporary change in the relationship of forces.A partir de teorías actuales sobre la identidad nacional, la legitimidad y la autoridad intelectual, este artículo explora los puntos clave identitarios que se ponen en juego durante la polémica sobre el teatro español de los años 1762-1764. Mediante una re-lectura de los textos de Clavijo y Fajardo (El Pensador, Nicolás Fernández de Moratín (Desengaños al teatro español y otros escritos, Mariano José Nipho (Diario Estrangero y La nación española defendida y José Romea y Tapia (El escritor sin título, sostenemos que lo que estos autores discuten realmente no es sobre el teatro, sino sobre la legitimidad y autoridad que reclaman, y en último término concepciones enfrentadas sobre la identidad nacional, de la que Calderón parece convertirse en icono cultural. De particular significación es el papel de los autos sacramentales en este contexto. En efecto, la acritud y la irritaci

Simulation of the fault transitory of the feedwater controller in a Boiling water reactor with the Ramona-3B code; Simulacion del transitorio de falla del controlador de agua de alimentacion en un reactor de agua en ebullicion con el codigo RAMONA-3B

Energy Technology Data Exchange (ETDEWEB)

Hernandez M, J.L.; Ortiz V, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2005-07-01

The obtained results when carrying out the simulation of the fault transitory of the feedwater controller (FCAA) with the Ramona-3B code, happened in the Unit 2 of the Laguna Verde power plant (CNLV), in September of the year 2000 are presented. The transitory originates as consequence of the controller's fault of speed of a turbo pump of feedwater. The work includes a short description of the event, the suppositions considered for the simulation and the obtained results. Also, a discussion of the impact of the transitory event is presented on aspects of reactor safety. Although the carried out simulation is limited by the capacities of the code and for the lack of available information, it was found that even in a conservative situation, the power was incremented only in 12% above the nominal value, while that the thermal limit determined by the minimum reason of the critical power, MCPR, always stayed above the limit values of operation and safety. (Author)

EL3 reactor description and safety analysis report

International Nuclear Information System (INIS)

1969-02-01

The EL-3 reactor is an experimental pile. Heterogenous type reactor, water moderated and cooled it uses slightly enriched uranium oxide as fuel (4.5 percent) distributed in vertical cells that constitute the core (the maximum number of cells is 99). It is conceived to function at a maximal thermal power of 20 MW. It supplies a maximum thermal neutron flux of 10 14 neutrons/cm 2 /sec. It has several experimental devices. The EL-3 reactor is surrounded by auxiliary circuits of fluids, in a sealed containment, slightly depressed. The primary heavy water coolant circuit is completely included in this containment. Its cooling is made by the intermediary of a light water secondary circuit by atmospheric refrigerants. The ventilation circuits of the sealed containment and the reactor block do not release air outside, under nornal functioning, by a particularly studied chimney only after filtering and eventually dilution. The eventual contamination of the light water or air by active products is permanently monitored to allow the reactor shutdown and avoid the release in atmosphere of dangerous products. The EL-3 reactor, laying down in may 1955, has diverged in july 1957, made its first ascending in power in december 1957 and reached its complete power in april 1958. The positioning of actual fuel (snow crystal) was made during summer 1964. Reactor with an experimental aim, it is used for theoretical and technological studies by material irradiation in the experimental channels and the core cells, with possibilities to constitute independent loops (relative to the cooling fluids). Thirty vertical channels are devoted to the fabrication of artificial radioelements [fr

Opportunities for physics research at Australia's replacement research reactor

International Nuclear Information System (INIS)

Robinson, R.A.

2003-01-01

Full text: The 20-MW Australian Replacement Research Reactor represents possibly the greatest single research infrastructure investment in Australia's history. Construction of the facility has commenced, following award of the construction contract in July 2000, and the construction licence in April 2002. The project includes a large state-of-the-art liquid deuterium cold-neutron source and supermirror guides feeding a large modern guide hall, in which most of the instruments are placed. Alongside the guide hall, there is good provision of laboratory, office and space for support activities. While the facility has 'space' for up to 18 instruments, the project has funding for an initial set of 8 instruments, which will be ready when the reactor is fully operational in January 2006. Instrument performance will be competitive with the best research-reactor facilities anywhere, and our goal is to be in the top 3 such facilities worldwide. Staff to lead the design effort and man these instruments have been hired on the international market from leading overseas facilities, and from within Australia, and 6 out of 8 instruments have been specified and costed. At present the instrumentation project carries ∼15% contingency. An extensive dialogue has taken place with the domestic user community and our international peers, via various means including a series of workshops over the last 2 years covering all 8 instruments, emerging areas of application like biology and the earth sciences, and computing infrastructure for the instruments. In December 2002, ANSTO formed the Bragg Institute, with the intent of nurturing strong external partnerships, and covering all aspects of neutron and X-ray scattering, including research using synchrotron radiation. I will discuss the present status and predicted performance of the neutron-beam facilities at the Replacement Reactor, synergies with the synchrotron in Victoria, in-house x-ray facilities that we intend to install in the Bragg

Course of operators of the RA-3 reactor

International Nuclear Information System (INIS)

Caligiuri, G.A.

1983-01-01

Description of the fundamental principles of the nuclear reactors' control systems. The RA-3 reactor's control and measurement systems are principally described, without setting aside the basic criteria for the design of an appropriate instrumentation for the control of a nuclear reactor, as well as the theory on which the functioning of the several detectors and equipments used in a nuclear instrumentation are based. The main purpose of this course is that of serving, preferentially as a text, for the training of personnel which shall perform operation tasks in this reactor. The work includes three well-defined sections. The first two ones make an introduction to the subject, while the third one, extending to more than half-work, deals with the general description of the system in which the control and operation logic of RA-3 are included. (R.J.S) [es

A calderón-preconditioned single source combined field integral equation for analyzing scattering from homogeneous penetrable objects

KAUST Repository

Valdés, Felipe

2011-06-01

A new regularized single source equation for analyzing scattering from homogeneous penetrable objects is presented. The proposed equation is a linear combination of a Calderón-preconditioned single source electric field integral equation and a single source magnetic field integral equation. The equation is immune to low-frequency and dense-mesh breakdown, and free from spurious resonances. Unlike dual source formulations, this equation involves operator products that cannot be discretized using standard procedures for discretizing standalone electric, magnetic, and combined field operators. Instead, the single source equation proposed here is discretized using a recently developed technique that achieves a well-conditioned mapping from div- to curl-conforming function spaces, thereby fully respecting the space mapping properties of the operators involved, and guaranteeing accuracy and stability. Numerical results show that the proposed equation and discretization technique give rise to rapidly convergent solutions. They also validate the equation\\'s resonant free character. © 2006 IEEE.

New version of the reactor dynamics code DYN3D for Sodium cooled Fast Reactor analyses

Energy Technology Data Exchange (ETDEWEB)

Nikitin, Evgeny [Ecole Polytechnique Federale de Lausanne (Switzerland); Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany); Fridman, Emil; Bilodid, Yuri; Kliem, Soeren [Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany)

2017-07-15

The reactor dynamics code DYN3D being developed at the Helmholtz-Zentrum Dresden-Rossendorf is currently under extension for Sodium cooled Fast Reactor analyses. This paper provides an overview on the new version of DYN3D to be used for SFR core calculations. The current article shortly describes the newly implemented thermal mechanical models, which can account for thermal expansion effects of the reactor core. Furthermore, the methodology used in Sodium cooled Fast Reactor analyses to generate homogenized few-group cross sections is summarized. The conducted and planned verification and validation studies are briefly presented. Related publications containing more detailed descriptions are outlined for the completeness of this overview.

Sensitivity Enhancement of a Vertical-Type CMOS Hall Device for a Magnetic Sensor

Directory of Open Access Journals (Sweden)

Sein Oh

2018-01-01

Full Text Available This study presents a vertical-type CMOS Hall device with improved sensitivity to detect a 3D magnetic field in various types of sensors or communication devices. To improve sensitivity, trenches are implanted next to the current input terminal, so that the Hall current becomes maximum. The effect of the dimension and location of trenches on sensitivity is simulated in the COMSOL simulator. A vertical-type Hall device with a width of 16 μm and a height of 2 μm is optimized for maximum sensitivity. The simulation result shows that it has a 23% better result than a conventional vertical-type CMOS Hall device without a trench.

Testing dependence of anomalous Hall effect on resistivity in SrRuO3 by its increase with electron irradiation

NARCIS (Netherlands)

Haham, N.; Konczykowski, M.; Kuiper, Bouwe; Koster, Gertjan; Klein, L.

2013-01-01

We measure the anomalous Hall effect (AHE) in several patterns of the itinerant ferromagnet SrRuO 3 before and after the patterns are irradiated with electrons. The irradiation increases the resistivity of the patterns due to the introduction of point defects and we find that the AHE coefficient R s

The research reactor as a tool in the master in nuclear reactors in Argentina

International Nuclear Information System (INIS)

Notari, Carla

2003-01-01

complete the Master with a seminar: Nuclear Power Plants, and a Thesis. In the frame of the academic plan, multiple activities are organized related to research reactors and also to nuclear power plants. Since the very beginning the performance of selected experiments in a nuclear reactor was recognized as an extraordinary tool to give the students an insight in the principal phenomena associated with the chain reaction and the related engineering problems. This experiments have an intrinsic elevated cost, associated with the relevance of the installation and with the specialized personnel involved. CNEA provides the career with this educational instrument through the Ra-1 and RA-3 reactors located at Constituyentes and Ezeiza Atomic Centers respectively. Various activities are under way but the most established, in the Reactor Physics Course, is the estimation of kinetic parameters in RA-1 reactor. The practice includes three different experiments: Approach to critical and calibration of control rods by the compensation method: Starting in a subcritical state with source the calibration of control rod B1 vs B2 is done by introduction of the first and withdrawal of the second. The methods used are based on the Point Kinetic Model; Measurement of control rods effectivity by the rod-drop method: Separate Rod Drop of rods B1 B2 B3 of the overall ensemble B1 B2 B3 B4 and total scram starting with three withdrawn and one partially inserted, is the procedure followed to estimate the reactivity worth of B1 B2 B3 and scram. The Point Kinetic Model and the Modal Kinetic Model are used; Reactor noise technique for the estimation of reactor parameters: α and Λ. The kinetic parameters are estimated assuring that the Point Kinetic Model is valid (detection chambers near to the core), that the fluctuation of the fission density is the dominant source of the correlated part of neutron noise (measurement at low power, <10kw), the dominance of the fundamental armonic (simultaneous use of

Mesoscopic spin Hall effect in semiconductor nanostructures

Science.gov (United States)

Zarbo, Liviu

The spin Hall effect (SHE) is a name given to a collection of diverse phenomena which share two principal features: (i) longitudinal electric current flowing through a paramagnetic semiconductor or metallic sample leads to transverse spin current and spin accumulation of opposite sign at opposing lateral edges; (ii) SHE does not require externally applied magnetic field or magnetic ordering in the equilibrium state of the sample, instead it relies on the presence of spin-orbit (SO) couplings within the sample. This thesis elaborates on a new type of phenomenon within the SHE family, predicted in our recent studies [Phys. Rev. B 72, 075361 (2005); Phys. Rev. Lett. 95, 046601 (2005); Phys. Rev. B 72, 075335 (2005); Phys. Rev. B 73 , 075303 (2006); and Europhys. Lett. 77, 47004 (2007)], where pure spin current flows through the transverse electrodes attached to a clean finitesize two-dimensional electron gas (2DEG) due to unpolarized charge current injected through its longitudinal leads. If transverse leads are removed, the effect manifests as nonequilibrium spin Hall accumulation at the lateral edges of 2DEG wires. The SO coupling driving this SHE effect is of the Rashba type, which arises due to structural inversion asymmetry of semiconductor heterostructure hosting the 2DEG. We term the effect "mesoscopic" because the spin Hall currents and accumulations reach optimal value in samples of the size of the spin precession length---the distance over which the spin of an electron precesses by an angle pi. In strongly SO-coupled structures this scale is of the order of ˜100 nm, and, therefore, mesoscopic in the sense of being much larger than the characteristic microscopic scales (such as the Fermi wavelength, screening length, or the mean free path in disordered systems), but still much smaller than the macroscopic ones. Although the first theoretical proposal for SHE, driven by asymmetry in SO-dependent scattering of spin-up and spin-down electrons off impurities

ORNL rod-bundle heat-transfer test data. Volume 3. Thermal-hydraulic test facility experimental data report for test 3.06.6B - transient film boiling in upflow

International Nuclear Information System (INIS)

Mullins, C.B.; Felde, D.K.; Sutton, A.G.; Gould, S.S.; Morris, D.G.; Robinson, J.J.

1982-05-01

Reduced instrument responses are presented for Thermal-Hyraulic Test Facility (THTF) Test 3.06.6B. This test was conducted by members of the Oak Ridge National Laboratory Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer (BDHT) Separate-Effects Program on August 29, 1980. The objective of the program was to investigate heat transfer phenomena believed to occur in PWR's during accidents, including small and large break loss-of-coolant accidents. Test 3.06.6B was conducted to obtain transient film boiling data in rod bundle geometry under reactor accident-type conditions. The primary purpose of this report is to make the reduced instrument responses for THTF Test 3.06.6B available. Included in the report are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers

3-dimensional finite element modelling of reactor building internal structure for static analysis

International Nuclear Information System (INIS)

Joshi, M.H.; Reddy, V.J.; Kushwaha, H.S.; Reddy, G.R.; Karandikar, G.V.

1991-01-01

a) Thin shell element gives fairly accurate results when compared to 3-D Brick element for the type of structure and loading in Reactor Building. b) The maximum element size is fixed from model 3(c) i.e. 2.0 m. c) Openings with size smaller than 0.5 m can be neglected without affecting the results very much. d) For any such problem, the methodology described in this paper can be used to take rational decisions which will ensure reasonable accuracy. (author)

Enhancement in anomalous Hall resistivity of Co/Pd multilayer and CoPd alloy by Ga+ ion irradiation

KAUST Repository

Guo, Zaibing

2014-02-01

In this paper, we report the effect of Ga+ ion irradiation on anomalous Hall effect (AHE) and longitudinal resistivity (ρxx) in [Co(3 Å)/Pd(5 Å)]80 multilayer and Co 42Pd58 alloy. 4- and 2-fold increases in anomalous Hall resistivity (ρAH) in the Co/Pd multilayer and CoPd alloy have been observed after irradiations at doses of 2.4 × 1015 and 3.3×10 15 ions/cm2, respectively. Skew scattering and side jump contributions to AHE have been analyzed based on the scaling relationship ρAH = aρxx + bρ2xx. For the Co/Pd multilayer, AHE is mainly affected by ion irradiation-induced interface diffusion and defects. For the CoPd alloy, the increase in doses above 1.5 × 1015 ions/cm2 induces a sign change in skew scattering, followed by the skew scattering contribution to AHE overwhelming the side jump contribution, this phenomenon should be attributed to irradiation-induced defects and modifications in chemical ordering. © Copyright EPLA, 2014.

Operation of the OSIRIS reactor from the viewpoint of analysis of operator functions

International Nuclear Information System (INIS)

Fichet-Clairfontaine, P.Y.; Saint-Jean, T.

1985-09-01

This paper presents the results of analyses carried out on site by the Human Factor Study Laboratory in an experimental nuclear plant operated by the Atomic Energy Commissariat - the OSIRIS pool reactor. The analyses of certain tasks are given: work in the reactor hall and an operation of circuit setting performed by the mechanics. This work has thrown light on certain operational guidelines implemented by the operators when carrying out their work [fr

Simulation of the fault transitory of the feedwater controller in a Boiling water reactor with the Ramona-3B code

International Nuclear Information System (INIS)

Hernandez M, J.L.; Ortiz V, J.

2005-01-01

The obtained results when carrying out the simulation of the fault transitory of the feedwater controller (FCAA) with the Ramona-3B code, happened in the Unit 2 of the Laguna Verde power plant (CNLV), in September of the year 2000 are presented. The transitory originates as consequence of the controller's fault of speed of a turbo pump of feedwater. The work includes a short description of the event, the suppositions considered for the simulation and the obtained results. Also, a discussion of the impact of the transitory event is presented on aspects of reactor safety. Although the carried out simulation is limited by the capacities of the code and for the lack of available information, it was found that even in a conservative situation, the power was incremented only in 12% above the nominal value, while that the thermal limit determined by the minimum reason of the critical power, MCPR, always stayed above the limit values of operation and safety. (Author)

Scaling of Hall coefficient in Co-Bi granular thin films

Directory of Open Access Journals (Sweden)

Speliotis Th.

2013-01-01

Full Text Available A series of Co-Bi thin films with Co concentrations c=0, 0.05, 0.2, 0.26, 0.3, 0.333, 0.375, 0.545, were grown by magnetron sputtering on Si(100/SiNX substrates. Resistivity measurements at zero field (ρxx as a function of temperature-T exhibit an exponential variation with T in the region of 240KHall coefficient as a function of Co concentration diverges as log|c-0.3|0.3 for c<0.333, indicating a scaling of RH nearby a percolation threshold pc=0.3. Only after proper scaling of the anomalous Hall coefficient RS the conventional RS∝(ρxxn dependence can be satisfied.

Magnetoresistance in quantum Hall metals due to Pancharatnam ...

Indian Academy of Sciences (India)

Abstract. We derive the trial Hall resistance formula for the quantum Hall metals to address both the integer and fractional quantum Hall effects. Within the degenerate (and crossed) Landau levels, and in the presence of changing magnetic field strength, one can invoke two physical processes responsible for the electron ...

Simulation of a reactor FBR with hexagonal-Z geometry using the code PARCS 3.1; Simulacion de un reactor FBR con geometria hexagonal-Z usando el codigo PARCS 3.1

Energy Technology Data Exchange (ETDEWEB)

Reyes F, M. C.; Del Valle G, E. [IPN, Escuela Superior de Fisica y Matematicas, Av. Instituto Politecnico Nacional s/n, U.P. Adolfo Lopez Mateos, Edificio 9, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico); Filio L, C., E-mail: rf.melisa@gmail.com [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

2013-10-15

The nuclear reactor core type FBR (Fast Breeder Reactor) was modeled in three dimensions of hexagonal-Z geometry using the code PARCS (Purdue Advanced Reactor Core Simulator) version 3.1 developed by Purdue University researchers. To carry out the modeling of the mentioned reactor was taken the corresponding information to one of the described benchmarks in the document NEACRP-L-330 (3-D Neutron Transport Benchmarks, 1991); fundamentally the corresponding to the geometric data and the cross sections. Being a quick reactor of breeding, known as the Knk-II, for which are considered 4 energy groups without dispersions up. The reactor core is formed by prismatic elements of hexagonal transversal cut where part of them only corresponds to nuclear fuel assemblies. This has four reflector rings and 6 identical control elements that together with the active part of the core is configured with 8 different types of elements.With the extracted information of the mentioned document the entrance file was prepared for PARCS 3.1 only considering a sixth part of the core due to the symmetry that presents their configuration. The NEACRP-L-330 shows a wide range of results reported by those who collaborated in its elaboration using different solution techniques that go from the Monte Carlo method to the approaches S{sub 2} and P{sub 1}. Of all the results were selected those obtained with the code HEXNOD, to which were carried out a comparison of the effective multiplication factor, being smaller differences to the 300 pcm, for three different scenarios: a) with the control bars extracted totally, b) with the semi-inserted control bars and c) with the control bars inserted completely and two different axial meshes, a thick mesh with 14 slices and another fine with 38, that which implies that the results can be considered very similar among if same. Radial maps and axial profiles are included, as much of the power as of the neutrons flow. (Author)

3 MW TRIGA Research Reactor facility of BAEC and its Utilization

Energy Technology Data Exchange (ETDEWEB)

Molla, N.I.; Bhuiyan, S.I.; Wadud Mondal, M.A.; Ahmed, F.U.; Islam, M.N.; Hossain, S.M.; Ahmed, K.; Zulquarnain, A.; Abedin, Z. [Bangladesh Atomic Energy Commission, Atomic Energy Research Establishment, Dhaka (Bangladesh)

1999-08-01

The paper briefly describes the Utilisation of 3 MW TRIGA Research Reactor of BAEC for neutron beam research, neutron activation analysis are isotope production. It includes the installation of the triple axis neutron spectrometer at the radial piercing beam port and a neutron radiography set-up at the tangential beam port and their uses for material analysis and condensed matter research and material testing. Nuclear and magnetic structures of some ferrites have been studied in powder diffraction method in the double axis mode. SANS technique with double crystal diffraction known as Bonse and Hart's method has been adopted in an experiment with alumina sample. The neutron radiography set-up and its use in the detection of corrosion in alumina have been reported. Determination of arsenic concentration in drinking water from tube well via Instrumental Neutron Activation Analysis and production of radioiodine-131 by dry distillation method are presented. Our experience on the removal of N-16 decay tank because of the leakage of coolant and bringing the research reactor back to operational by-passing the decay tank have been focussed. A possible reconfiguration of the existing TRIGA core, without exceeding the safety margins, providing additional irradiation channel and upgrading the neutron flux for increased radioisotope production has been attempted. Cross section library ENDF/B-VI and JENDL3.2, code NJOY94.10, WIMSD package, 3-D code CITATION, PARET and Monte Carlo code MCNP4B2 have been employed to achieve the objective. (author)

Quasi-one-dimensional Hall physics in the Harper–Hofstadter–Mott model

Science.gov (United States)

Kozarski, Filip; Hügel, Dario; Pollet, Lode

2018-04-01

We study the ground-state phase diagram of the strongly interacting Harper–Hofstadter–Mott model at quarter flux on a quasi-one-dimensional lattice consisting of a single magnetic flux quantum in y-direction. In addition to superfluid phases with various density patterns, the ground-state phase diagram features quasi-one-dimensional analogs of fractional quantum Hall phases at fillings ν = 1/2 and 3/2, where the latter is only found thanks to the hopping anisotropy and the quasi-one-dimensional geometry. At integer fillings—where in the full two-dimensional system the ground-state is expected to be gapless—we observe gapped non-degenerate ground-states: at ν = 1 it shows an odd ‘fermionic’ Hall conductance, while the Hall response at ν = 2 consists of the transverse transport of a single particle–hole pair, resulting in a net zero Hall conductance. The results are obtained by exact diagonalization and in the reciprocal mean-field approximation.

A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C., E-mail: acbruno@puc-rio.br

2017-03-15

We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10{sup −7} Am{sup 2}. We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am{sup 2}/kg (i.e 0.4%) at saturation and below 0.5 Am{sup 2}/kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

International Nuclear Information System (INIS)

Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C.

2017-01-01

We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10 −7 Am 2 . We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am 2 /kg (i.e 0.4%) at saturation and below 0.5 Am 2 /kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

An orientation measurement method based on Hall-effect sensors for permanent magnet spherical actuators with 3D magnet array.

Science.gov (United States)

Yan, Liang; Zhu, Bo; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

2014-10-24

An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space. The comparison with conventional modeling method shows that it helps to improve the model accuracy. The Hall-effect sensors are distributed around the rotor with PM poles to detect the flux density at different points, and thus the rotor orientation can be computed from the measured results and analytical models. Experiments have been conducted on the developed research prototype of the spherical actuator to validate the accuracy of the analytical equations relating the rotor orientation and the value of magnetic flux density. The experimental results show that the proposed method can measure the rotor orientation precisely, and the measurement accuracy could be improved by the novel 3D magnet array. The study result could be used for real-time motion control of PM spherical actuators.

Hall Sensor Output Signal Fault-Detection & Safety Implementation Logic

Directory of Open Access Journals (Sweden)

Lee SangHun

2016-01-01

Full Text Available Recently BLDC motors have been popular in various industrial applications and electric mobility. Recently BLDC motors have been popular in various industrial applications and electric mobility. In most brushless direct current (BLDC motor drives, there are three hall sensors as a position reference. Low resolution hall effect sensor is popularly used to estimate the rotor position because of its good comprehensive performance such as low cost, high reliability and sufficient precision. Various possible faults may happen in a hall effect sensor. This paper presents a fault-tolerant operation method that allows the control of a BLDC motor with one faulty hall sensor and presents the hall sensor output fault-tolerant control strategy. The situations considered are when the output from a hall sensor stays continuously at low or high levels, or a short-time pulse appears on a hall sensor signal. For fault detection, identification of a faulty signal and generating a substitute signal, this method only needs the information from the hall sensors. There are a few research work on hall effect sensor failure of BLDC motor. The conventional fault diagnosis methods are signal analysis, model based analysis and knowledge based analysis. The proposed method is signal based analysis using a compensation signal for reconfiguration and therefore fault diagnosis can be fast. The proposed method is validated to execute the simulation using PSIM.

An interchangeable scanning Hall probe/scanning SQUID microscope

International Nuclear Information System (INIS)

Tang, Chiu-Chun; Lin, Hui-Ting; Wu, Sing-Lin; Chen, Tse-Jun; Wang, M. J.; Ling, D. C.; Chi, C. C.; Chen, Jeng-Chung

2014-01-01

We have constructed a scanning probe microscope for magnetic imaging, which can function as a scanning Hall probe microscope (SHPM) and as a scanning SQUID microscope (SSM). The scanning scheme, applicable to SHPM and SSM, consists of a mechanical positioning (sub) micron-XY stage and a flexible direct contact to the sample without a feedback control system for the Z-axis. With the interchangeable capability of operating two distinct scanning modes, our microscope can incorporate the advantageous functionalities of the SHPM and SSM with large scan range up to millimeter, high spatial resolution (⩽4 μm), and high field sensitivity in a wide range of temperature (4.2 K-300 K) and magnetic field (10 −7 T-1 T). To demonstrate the capabilities of the system, we present magnetic images scanned with SHPM and SSM, including a RbFeB magnet and a nickel grid pattern at room temperature, surface magnetic domain structures of a La 2/3 Ca 1/3 MnO 3 thin film at 77 K, and superconducting vortices in a striped niobium film at 4.2 K

Axial Hall effect and universality of holographic Weyl semi-metals

Energy Technology Data Exchange (ETDEWEB)

Copetti, Christian; Fernández-Pendás, Jorge; Landsteiner, Karl [Instituto de Física Teórica UAM/CSIC,c/ Nicolás Cabrera 13-15, Cantoblanco, 28049 Madrid (Spain)

2017-02-28

The holographic Weyl semimetal is a model of a strongly coupled topological semi-metal. A topological quantum phase transition separates a topological phase with non-vanishing anomalous Hall conductivity from a trivial state. We investigate how this phase transition depends on the parameters of the scalar potential (mass and quartic self coupling) finding that the quantum phase transition persists for a large region in parameter space. We then compute the axial Hall conductivity. The algebraic structure of the axial anomaly predicts it to be 1/3 of the electric Hall conductivity. We find that this holds once a non-trivial renormalization effect on the external axial gauge fields is taken into account. Finally we show that the phase transition also occurs in a top-down model based on a consistent truncation of type IIB supergravity.

Sociolinguistics of power in the Spanish Golden Age. Of reverences, highnesses, mercies, lordships and other forms of treatment in the theatre of Calderón de la Barca

Directory of Open Access Journals (Sweden)

Carmela Pérez-Salazar

2018-01-01

Full Text Available This work reviews the resources that are used in dramatic works of Calderón de la Barca for the treatment of the representatives of the authority; that is, the presence on stage of what Gonzalo Correas calls «names of honor», for which the protocol of the sixteenth and seventeenth centuries imposes very strict guidelines, is analyzed. The study is based on a selection of works in which representatives of political, military and ecclesiastical power, and characters of different rank, sex and age participate.

The quantized Hall effect

International Nuclear Information System (INIS)

Klitzing von, K.

1989-01-01

The quantized Hall effect is theoretically explained in detail as are its basic properties. The explanation is completed with the pertinent mathematical relations and illustrative figures. Experimental data are critically assessed obtained by quantum transport measurement in a magnetic field on two-dimensional systems. The results are reported for a MOSFET silicon transistor and for GaAs-Al x Ga 1-x As heterostructures. The application is discussed of the quantized Hall effect in determining the fine structure constant or in implementing the resistance standard. (M.D.). 27 figs., 57 refs

Valley-chiral quantum Hall state in graphene superlattice structure

Science.gov (United States)

Tian, H. Y.; Tao, W. W.; Wang, J.; Cui, Y. H.; Xu, N.; Huang, B. B.; Luo, G. X.; Hao, Y. H.

2016-05-01

We theoretically investigate the quantum Hall effect in a graphene superlattice (GS) system, in which the two valleys of graphene are coupled together. In the presence of a perpendicular magnetic field, an ordinary quantum Hall effect is found with the sequence σxy=ν e^2/h(ν=0,+/-1,+/-2,\\cdots) . At the zeroth Hall platform, a valley-chiral Hall state stemming from the single K or K' valley is found and it is localized only on one sample boundary contributing to the longitudinal conductance but not to the Hall conductivity. Our findings may shed light on the graphene-based valleytronics applications.

Proyecto de factibilidad para la implantación de un sistema de recolección de residuos sólidos en la ciudad de Quito parroquia calderón

OpenAIRE

Jaramillo Narváez, Sandy Viviana; Vinueza Bracero, Diana Carolina

2013-01-01

Actualmente el sistema de Recolección de Desechos Sólidos presenta deficiencias en su manejo, ocasionando, así, problemas directos sobre la población, por este motivo el presente documento se ha elaborado con el objetivo de analizar la factibilidad de implantación de un servicio de soporte para el actual sistema de recolección de desechos sólidos en el cantón de Quito, parroquia Calderón, el cual consiste en la propuesta de un servicio de contenedore...

Outline of a theory of the two-dimensional hall effect in the quantum limit

Energy Technology Data Exchange (ETDEWEB)

Tosatti, E. (Scuola Internazionale Superiore di Studi Avanzati, Trieste (Italy); International Centre for Theoretical Physics, Trieste (Italy); Consiglio Nazionale delle Ricerche, Trieste (Italy). Gruppo Nazionale di Struttura della Materia); Parrinello, M. (International Centre for Theoretical Physics, Trieste (Italy); Scuola Internazionale Superiore di Studi Avanzati, Trieste (Italy); Consiglio Nazionale delle Ricerche, Trieste (Italy). Gruppo Nazionale di Struttura della Materia)

1983-03-05

The ground state of two-dimensional electrons of density N/L/sup 2/ in a strong transverse magnetic field B is discussed in terms of localized magnetic functions. For all ''commensurate'' fractional fillings of the n=0 Landau level, occurring at Bsub(st)=(s/sup 2/+t/sup 2/+st)2..pi..(h/2..pi..)cN/eL/sup 2/, with s, t integers, it is found that the ground state is a triangular lattice. This lattice has unusual properties, because it is tied to the magnetic functions. In particular, it has a finite Hall conductivity sigmasub(xy)=e/sup 2//2..pi..(h/2..pi..)(s/sup 2/+t/sup 2/+st) and it also exhibits perfect diamagnetism relative to Bsub(st). It does, however, display no proper Meissner effect, because the London depth is macroscopically large. The excess field B-Bsub(st) gives rise instead to defects in the lattice, where the extra electrons (holes) become ''interstitials'' (''vacancies''). If the defects are free to move, the Hall conductivity will not stay quantized. On the other hand, if all defects are pinned by inhomogeneities, Hall plateaux are expected around each Bsub(st). This picture, while providing a natural explanation for the quantized Hall effect at both integer and fractional filling, leads to a simple understanding of the plateau width vs. temperature and simple quality, and can also explain, at finite temperatures, the behaviour of the longitudinal conductivity sigmasub(yy) and its observed asymmetry for integer filling.

Molecular and clinical analyses of Greig cephalopolysyndactyly and Pallister-Hall syndromes: Robust phenotype prediction from the type and position of GLI3 mutations

NARCIS (Netherlands)

Johnston, Jennifer J.; Olivos-Glander, Isabelle; Killoran, Christina; Elson, Emma; Turner, Joyce T.; Peters, Kathryn F.; Abbott, Margaret H.; Aughton, David J.; Aylsworth, Arthur S.; Bamshad, Michael J.; Booth, Carol; Curry, Cynthia J.; David, Albert; Dinulos, Mary Beth; Flannery, David B.; Fox, Michelle A.; Graham, John M.; Grange, Dorothy K.; Guttmacher, Alan E.; Hannibal, Mark C.; Henn, Wolfram; Hennekam, Raoul C. M.; Holmes, Lewis B.; Hoyme, H. Eugene; Leppig, Kathleen A.; Lin, Angela E.; Macleod, Patrick; Manchester, David K.; Marcelis, Carlo; Mazzanti, Laura; McCann, Emma; McDonald, Marie T.; Mendelsohn, Nancy J.; Moeschler, John B.; Moghaddam, Billur; Neri, Giovanni; Newbury-Ecob, Ruth; Pagon, Roberta A.; Phillips, John A.; Sadler, Laurie S.; Stoler, Joan M.; Tilstra, David; Walsh Vockley, Catherine M.; Zackai, Elaine H.; Zadeh, Touran M.; Brueton, Louise; Black, Graeme Charles M.; Biesecker, Leslie G.

2005-01-01

Mutations in the GLI3 zinc-finger transcription factor gene cause Greig cephalopolysyndactyly syndrome (GCPS) and Pallister-Hall syndrome (PHS), which are variable but distinct clinical entities. We hypothesized that GLI3 mutations that predict a truncated functional repressor protein cause PHS and

ADHM and the 4d quantum Hall effect

Science.gov (United States)

Barns-Graham, Alec; Dorey, Nick; Lohitsiri, Nakarin; Tong, David; Turner, Carl

2018-04-01

Yang-Mills instantons are solitonic particles in d = 4 + 1 dimensional gauge theories. We construct and analyse the quantum Hall states that arise when these particles are restricted to the lowest Landau level. We describe the ground state wavefunctions for both Abelian and non-Abelian quantum Hall states. Although our model is purely bosonic, we show that the excitations of this 4d quantum Hall state are governed by the Nekrasov partition function of a certain five dimensional supersymmetric gauge theory with Chern-Simons term. The partition function can also be interpreted as a variant of the Hilbert series of the instanton moduli space, counting holomorphic sections rather than holomorphic functions. It is known that the Hilbert series of the instanton moduli space can be rewritten using mirror symmetry of 3d gauge theories in terms of Coulomb branch variables. We generalise this approach to include the effect of a five dimensional Chern-Simons term. We demonstrate that the resulting Coulomb branch formula coincides with the corresponding Higgs branch Molien integral which, in turn, reproduces the standard formula for the Nekrasov partition function.

Air temperature gradient in large industrial hall

Science.gov (United States)

Karpuk, Michał; Pełech, Aleksander; Przydróżny, Edward; Walaszczyk, Juliusz; Szczęśniak, Sylwia

2017-11-01

In the rooms with dominant sensible heat load, volume airflow depends on many factors incl. pre-established temperature difference between exhaust and supply airflow. As the temperature difference is getting higher, airflow volume drops down, consequently, the cost of AHU is reduced. In high industrial halls with air exhaust grids located under the ceiling additional temperature gradient above working zone should be taken into consideration. In this regard, experimental research of the vertical air temperature gradient in high industrial halls were carried out for the case of mixing ventilation system The paper presents the results of air temperature distribution measurements in high technological hall (mechanically ventilated) under significant sensible heat load conditions. The supply airflow was delivered to the hall with the help of the swirl diffusers while exhaust grids were located under the hall ceiling. Basing on the air temperature distribution measurements performed on the seven pre-established levels, air temperature gradient in the area between 2.0 and 7.0 m above the floor was calculated and analysed.

A new CMOS Hall angular position sensor

Energy Technology Data Exchange (ETDEWEB)

Popovic, R.S.; Drljaca, P. [Swiss Federal Inst. of Tech., Lausanne (Switzerland); Schott, C.; Racz, R. [SENTRON AG, Zug (Switzerland)

2001-06-01

The new angular position sensor consists of a combination of a permanent magnet attached to a shaft and of a two-axis magnetic sensor. The permanent magnet produces a magnetic field parallel with the magnetic sensor plane. As the shaft rotates, the magnetic field also rotates. The magnetic sensor is an integrated combination of a CMOS Hall integrated circuit and a thin ferromagnetic disk. The CMOS part of the system contains two or more conventional Hall devices positioned under the periphery of the disk. The ferromagnetic disk converts locally a magnetic field parallel with the chip surface into a field perpendicular to the chip surface. Therefore, a conventional Hall element can detect an external magnetic field parallel with the chip surface. As the direction of the external magnetic field rotates in the chip plane, the output voltage of the Hall element varies as the cosine of the rotation angle. By placing the Hall elements at the appropriate places under the disk periphery, we may obtain the cosine signals shifted by 90 , 120 , or by any other angle. (orig.)

41Ar-concentration measurements at the Finnish TRIGA Mark II

International Nuclear Information System (INIS)

Tamminen, A.

1970-01-01

41 Ar-concentrations in the reactor hall and in the Ar-ventilation duct of FiR-1 (IRIGA Mark II, 250 kW) have been measured during normal operation conditions. Additional measurements have been performed varying Ar-ventilation and hall ventilation flow. A γ- and background compensated thin window proportional detector and a β-Geiger detector for 41 Ar-measurements are described. The hall concentration has also been estimated from background measurements with an unshielded Ge(Li)-detector. The saturation concentration in the reactor hall with and without the hall ventilation is about 1 x 10 -7 μCi/cm 3 and 3 x 10 -7 μCi/cm 3 , respectively. (author)

Decommissioning of Salaspils Research Reactor

International Nuclear Information System (INIS)

Abramenkovs, A.; Popelis, A.; Abramenkova, G

2008-01-01

The Salaspils Research Reactor (SRR) is out of operation since July 1998 and the decommissioning of SRR was started in 1999 according to the decision of the Government of Latvia. The main decommissioning activities up to 2006 were connected with collecting and conditioning of historical radioactive wastes from different storages outside and inside of reactor hall. The total amount of dismantled materials was about 700 tons, more than 77 tons were conditioned in concrete containers for disposal in repository. The radioactive wastes management technology is discussed in the paper. It was found, that additional efforts must be spent for immobilization of radionuclides in cemented matrix to be comply with the wastes acceptance criteria. The investigations of mechanical stability of water-cement matrix are described and discussed in the paper

The status of the PIK reactor

Energy Technology Data Exchange (ETDEWEB)

Petrov, Yu V [Academy of Sciences of Russia, Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg (Russian Federation)

1992-07-01

This report describes the 100 MW research reactor PIK which is now under construction. The thermal neutron flux in the heavy water reflector exceeds 10{sup 15} cm{sup -2}s{sup -1}; in the light water trap, it is about 4{center_dot}10{sup 15} cm{sup -2}s{sup -1}. The replaceable core vessel allows to vary the parameters of the core over a wide range. The reactor provides sources of hot, cold and ultracold neutrons for 10 horizontal, 6 inclined neutron beams, and 8 neutron guides. At the ends of the beam tubes, the neutron flux is 10{sup 10} - 10{sup 11} cm{sup -2}s{sup -1}. The flux of the long wave neutrons exceeds 10{sup 9} cm{sup -2}s{sup -1}. To ensure precise measurements, the experimental hall is protected against vibrations. The project meets all modern safety requirements. The calculated parameters of the reactor were verified using a full-scale mock-up. Seventy percent of the reactor construction and installation were completed in the beginning of 1992. (author)

Magnetic Measuring Instrumentation with Radiation-Resistant Hall Sensors for Fusion Reactors: Experience of Testing at JET

Czech Academy of Sciences Publication Activity Database

Bolshakova, I.; Quercia, A.; Coccorese, V.; Murari, A.; Holyaka, R.; Ďuran, Ivan; Viererbl, L.; Konopleva, R.; Yerashok, V.

2012-01-01

Roč. 59, č. 4 (2012), s. 1224-1231 ISSN 0018-9499. [International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications. Ghent, 06.06.2011-09.06.2011] R&D Projects: GA ČR GAP205/10/2055 Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma * tokamak * JET * Hall probes * radiation resistance Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.219, year: 2012

The quantum Hall effects: Philosophical approach

Science.gov (United States)

Lederer, P.

2015-05-01

The Quantum Hall Effects offer a rich variety of theoretical and experimental advances. They provide interesting insights on such topics as gauge invariance, strong interactions in Condensed Matter physics, emergence of new paradigms. This paper focuses on some related philosophical questions. Various brands of positivism or agnosticism are confronted with the physics of the Quantum Hall Effects. Hacking's views on Scientific Realism, Chalmers' on Non-Figurative Realism are discussed. It is argued that the difficulties with those versions of realism may be resolved within a dialectical materialist approach. The latter is argued to provide a rational approach to the phenomena, theory and ontology of the Quantum Hall Effects.

Hall devices improve electric motor efficiency

Science.gov (United States)

Haeussermann, W.

1979-01-01

Efficiency of electric motors and generators is reduced by radial magnetic forces created by symmetric fields within device. Forces are sensed and counteracted by Hall devices on excitation or control windings. Hall generators directly measure and provide compensating control of anu asymmetry, eliminating additional measurements needed for calibration feedback control loop.

Sewage disposal using anaerobic membrane reactor. Kenkiseimaku reactor ni yoru gesui shori

Energy Technology Data Exchange (ETDEWEB)

Fujita, Y. (Dic-Degremont Co. Ltd., Tokyo (Japan))

1991-11-01

Discussions were given on a small-scale sewage disposal of about bod 200 mg/l, for which no many examples of use have been hitherto available, using a system combining an anaerobic reactor and membrane modules. Experiments had been carried out from 1988 through 1990 as a part of the Aqua-Renaissance Project. The test equipment wza installed in the premises of the Chigasaki Coastal Research Facilities operated by the Ministry of International Trade and Industry, which used sewage flowing from the adjoining sewage treatment plant for the southern area of the Fujisawa City. The test facility consisted of a system comprising a pretreatment facility, SS decomposing reactor, fluid-bed reactor, separation membrane modules, nitrogen removing facility and micro-organism activity measurement. The test facility was constucted assuming a treatment of 10 m{sup 3} a day. The system was divided into a composite system, A system and B system to operate the system in simplified flows. As a result of comparing the composite system, A system and B system, it was found that B system can deal with wider range of disposal for a small-scale sewage treatment of about 1000 m{sup 3} a day. 6 refs., 14 figs., 3 tabs.

Graphene and the universality of the quantum Hall effect

DEFF Research Database (Denmark)

Tzalenchuk, A.; Janssen, T. J.B.M.; Kazakova, O.

2013-01-01

The quantum Hall effect allows the standard for resistance to be defined in terms of the elementary charge and Planck's constant alone. The effect comprises the quantization of the Hall resistance in two-dimensional electron systems in rational fractions of RK=h/e2=25812.8074434(84) Ω (Mohr P. J....... the unconventional quantum Hall effect and then present in detail the route, which led to the most precise quantum Hall resistance universality test ever performed.......The quantum Hall effect allows the standard for resistance to be defined in terms of the elementary charge and Planck's constant alone. The effect comprises the quantization of the Hall resistance in two-dimensional electron systems in rational fractions of RK=h/e2=25812.8074434(84) Ω (Mohr P. J....... et al., Rev. Mod. Phys., 84 (2012) 1527), the resistance quantum. Despite 30 years of research into the quantum Hall effect, the level of precision necessary for metrology, a few parts per billion, has been achieved only in silicon and III-V heterostructure devices. In this lecture we show...

Accurate micro Hall effect measurements on scribe line pads

DEFF Research Database (Denmark)

Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei

2009-01-01

Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...... be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 × 430 ¿m2, and the probe pitches range from 20 ¿m to 50 ¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...

Extrinsic spin Hall effect in graphene

Science.gov (United States)

Rappoport, Tatiana

The intrinsic spin-orbit coupling in graphene is extremely weak, making it a promising spin conductor for spintronic devices. In addition, many applications also require the generation of spin currents in graphene. Theoretical predictions and recent experimental results suggest one can engineer the spin Hall effect in graphene by greatly enhancing the spin-orbit coupling in the vicinity of an impurity. The extrinsic spin Hall effect then results from the spin-dependent skew scattering of electrons by impurities in the presence of spin-orbit interaction. This effect can be used to efficiently convert charge currents into spin-polarized currents. I will discuss recent experimental results on spin Hall effect in graphene decorated with adatoms and metallic cluster and show that a large spin Hall effect can appear due to skew scattering. While this spin-orbit coupling is small if compared with what it is found in metals, the effect is strongly enhanced in the presence of resonant scattering, giving rise to robust spin Hall angles. I will present our single impurity scattering calculations done with exact partial-wave expansions and complement the analysis with numerical results from a novel real-space implementation of the Kubo formalism for tight-binding Hamiltonians. The author acknowledges the Brazilian agencies CNPq, CAPES, FAPERJ and INCT de Nanoestruturas de Carbono for financial support.

Hall effect measurement for precise sheet resistance and thickness evaluation of Ruthenium thin films using non-equidistant four-point probes

Directory of Open Access Journals (Sweden)

Frederik Westergaard Østerberg

2018-05-01

Full Text Available We present a new micro Hall effect measurement method using non-equidistant electrodes. We show theoretically and verify experimentally that it is advantageous to use non-equidistant electrodes for samples with low Hall sheet resistance. We demonstrate the new method by experiments where Hall sheet carrier densities and Hall mobilities of Ruthenium thin films (3-30 nm are determined. The measurements show that it is possible to measure Hall mobilities as low as 1 cm2V−1s−1 with a relative standard deviation of 2-3%. We show a linear relation between measured Hall sheet carrier density and film thickness. Thus, the method can be used to monitor thickness variations of ultra-thin metal films.

Hall current effects in dynamic magnetic reconnection solutions

International Nuclear Information System (INIS)

Craig, I.J.D.; Heerikhuisen, J.; Watson, P.G.

2003-01-01

The impact of Hall current contributions on flow driven planar magnetic merging solutions is discussed. The Hall current is important if the dimensionless Hall parameter (or normalized ion skin depth) satisfies c H >η, where η is the inverse Lundquist number for the plasma. A dynamic analysis of the problem shows, however, that the Hall current initially manifests itself, not by modifying the planar reconnection field, but by inducing a non-reconnecting perpendicular 'separator' component in the magnetic field. Only if the stronger condition c H 2 >η is satisfied can Hall currents be expected to affect the planar merging. These analytic predictions are then tested by performing a series of numerical experiments in periodic geometry, using the full system of planar magnetohydrodynamic (MHD) equations. The numerical results confirm that the nature of the merging changes dramatically when the Hall coupling satisfies c H 2 >η. In line with the analytic treatment of sheared reconnection, the coupling provided by the Hall term leads to the emergence of multiple current layers that can enhance the global Ohmic dissipation at the expense of the reconnection rate. However, the details of the dissipation depend critically on the symmetries of the simulation, and when the merging is 'head-on' (i.e., comprises fourfold symmetry) the reconnection rate can be enhanced

Program of RA reactor start-up to nominal power; Program dizanja reaktora 'RA' na nominalnu snagu

Energy Technology Data Exchange (ETDEWEB)

NONE

1959-07-01

The zero start-up program is followed by the program of RA reactor start-up to nominal power. This program is desed in detail and includes the following measurements: radiation characteristics at the exit of the channels; gamma and fast neutron dose distribution in the reactor; influence of absorbers on the reactivity; temperature effect; absolute flux and calibration of ionization chambers; xenon effect; thermal and hydraulics; dosimetry around the reactor; neutron flux in the reactor core and in the reactor hall; heavy water level; thermal characteristics after shutdown. A list of measuring devices and instrumentation is included with the detailed action plan and list of responsible staff members.

Measurement of Safety Factor Using Hall Probes on CASTOR Tokamak

Czech Academy of Sciences Publication Activity Database

Kovařík, Karel; Ďuran, Ivan; Bolshakova, I.; Holyaka, R.; Erashok, V.

2006-01-01

Roč. 56, suppl.B (2006), s. 104-110 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA AV ČR(CZ) KJB100430504 Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma * tokamak * safety factor * hall probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

Vaporization Rate Analysis of Primary Cooling Water from Reactor PUSPATI TRIGA (RTP) Tank

International Nuclear Information System (INIS)

Tonny Anak Lanyau; Mohd Fazli Zakaria; Yahya Ismail

2011-01-01

Primary cooling system consists of pumps, heat exchangers, probes, a nitrogen-16 diffuser and associated valves is connected to the reactor TRIGA PUSPATI (RTP) tank by aluminium pipes. Both the primary cooling system and the reactor tank is filled with demineralized light water (H 2 O), which serves as a coolant, moderator as well as shielding. During reactor operation, vaporization in the reactor tank will reduce the primary water and contribute to the formation of vapor in the reactor hall. The vaporization may influence the function of the water subsequently may affect the safety of the reactor operation. It is essential to know the vaporization rate of the primary water to ensure its functionality. This paper will present the vaporization rate of the primary cooling water from the reactor tank and the influence of temperature of the water in the reactor tank to the vaporization rate. (author)

Optimization of Cylindrical Hall Thrusters

International Nuclear Information System (INIS)

Raitses, Yevgeny; Smirnov, Artem; Granstedt, Erik; Fisch, Nathaniel J.

2007-01-01

The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation.

Optimization of Cylindrical Hall Thrusters

International Nuclear Information System (INIS)

Raitses, Yevgeny; Smirnov, Artem; Granstedt, Erik; Fi, Nathaniel J.

2007-01-01

The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation

Measurement and evaluation of the external radiation level at reactor Kartini

International Nuclear Information System (INIS)

Atok Suhartanto; Suparno

2013-01-01

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

On the determination of the carrier concentration in large-grain polycrystalline InP, GaAs, and GaP by Hall effect measurements

International Nuclear Information System (INIS)

Siegel, W.; Kuehnel, G.; Schneider, H.A.

1985-01-01

Hall and conductivity measurements are performed in a wide temperature region on large-grain polycrystalline samples of n-InP, n- and p-GaAs as well as n- and p-GaP. The feasibility of Hall measurements at a given temperature depends mainly on the height PHI/sub B/ of the grain boundary potential barriers and on the average grain size. Measurements at room temperature are possible on large-grain material (average grain size 0.2 to 1 mm) for PHI/sub B/ <= 0.4 eV. For greater barrier heights elevated temperatures are necessary. If the Hall coefficient is measurable than it yields an effective carrier concentration for the polycrystalline sample which agrees well with the carrier concentration in the bulk of the grains. (author)

Quantum Hall Electron Nematics

Science.gov (United States)

MacDonald, Allan

In 2D electron systems hosted by crystals with hexagonal symmetry, electron nematic phases with spontaneously broken C3 symmetry are expected to occur in the quantum Hall regime when triplets of Landau levels associated with three different Fermi surface pockets are partially filled. The broken symmetry state is driven by intravalley Coulombic exchange interactions that favor spontaneously polarized valley occupations. I will discuss three different examples of 2D electron systems in which this type of broken symmetry state is expected to occur: i) the SnTe (111) surface, ii) the Bi (111) surface. and iii) unbalanced bilayer graphene. This type of quantum Hall electron nematic state has so far been confirmed only in the Bi (111) case, in which the anisotropic quasiparticle wavefunctions of the broken symmetry state were directly imaged. In the SnTe case the nematic state phase boundary is controlled by a competition between intravalley Coulomb interactions and intervalley scattering processes that increase in relative strength with magnetic field. An in-plane Zeeman field alters the phase diagram by lifting the three-fold Landau level degeneracy, yielding a ground state energy with 2 π/3 periodicity as a function of Zeeman-field orientation angle. I will comment on the possibility of observing similar states in the absence of a magnetic field. Supported by DOE Division of Materials Sciences and Engineering Grant DE-FG03-02ER45958.

3 Investment Scenarios for Fast Reactors

International Nuclear Information System (INIS)

Shoai Tehrani, Bianka; Da Costa, Pascal

2013-01-01

Results: • 4 families of scenarios: – In each of them, 3 options for national nuclear policy → 12 scenarios; – 3 favorable to FRs: - “climate constraint” with strong pro-nuclear policy - “climate constraint” with moderate pro-nuclear policy - “totally green” with strong pro-nuclear policy. • Business As Usual is not favorable to Fast Reactors; Fast reactors deployment: - Needs strong climate policy - Is viable in case of important renewable progress as long as climate policy is strong. International perspective: • Results are valid for Europe, other drivers being likely to be more important in other countries : high growth and demand (Asia); • With strong contrasts between European countries. Further research: • Finer modeling of drivers with unclear influence (clustered and excluded variables): Influence of weak signals

Spin-singlet hierarchy in the fractional quantum Hall effect

OpenAIRE

Ino, Kazusumi

1999-01-01

We show that the so-called permanent quantum Hall states are formed by the integer quantum Hall effects on the Haldane-Rezayi quantum Hall state. Novel conformal field theory description along with this picture is deduced. The odd denominator plateaux observed around $\

Anisotropic intrinsic spin Hall effect in quantum wires

International Nuclear Information System (INIS)

Cummings, A W; Akis, R; Ferry, D K

2011-01-01

We use numerical simulations to investigate the spin Hall effect in quantum wires in the presence of both Rashba and Dresselhaus spin-orbit coupling. We find that the intrinsic spin Hall effect is highly anisotropic with respect to the orientation of the wire, and that the nature of this anisotropy depends strongly on the electron density and the relative strengths of the Rashba and Dresselhaus spin-orbit couplings. In particular, at low densities, when only one subband of the quantum wire is occupied, the spin Hall effect is strongest for electron momentum along the [1-bar 10] axis, which is the opposite of what is expected for the purely 2D case. In addition, when more than one subband is occupied, the strength and anisotropy of the spin Hall effect can vary greatly over relatively small changes in electron density, which makes it difficult to predict which wire orientation will maximize the strength of the spin Hall effect. These results help to illuminate the role of quantum confinement in spin-orbit-coupled systems, and can serve as a guide for future experimental work on the use of quantum wires for spin-Hall-based spintronic applications. (paper)

Effects of Nernst-Ettinghausen, Seebeck and Hall in Sb sub 2 Te sub 3 monocrystals

CERN Document Server

Zhitinskaya, M K; Ivanova, L D

2002-01-01

In Sb sub 2 Te sub 3 top-quality single crystals grown following the Czochralski method within 77-420 K range one measured temperature dependences of the following components of kinetic coefficients: electrical conductivity within sigma sub 1 sub 1 chip plane, of the Seebeck S sub 1 sub 1 and S sub 3 sub 3 , of the Hall R sub 1 sub 2 sub 3 and R sub 3 sub 2 sub 1 and of the Nernst-Ettinghausen Q sub 1 sub 2 sub 3. One analyzed the derived results on the basis of the phenomenological theory. It is shown that the essential peculiarities of the experimental data may be explained in terms of a two-region model with anisotropy of mobility of the first and second types holes towards the chip (epsilon sub g approx = 0.3 eV), as well as, the energy gap between the ground and auxiliary extremes of the valence band (DELTA epsilon subupsilon approx 0.1 eV)

Linéarité et développement d'un système technique Linearity and Development of a Technical System

Directory of Open Access Journals (Sweden)

Dautray R.

2006-11-01

in 1942. - The first nuclear power reactors began operating at Hanford in 1945. - Starting in the 1950s, nuclear reactors powered submarines and prototypes of nuclear boilers for power plants (Shippingport and Calder Hall.

D-3He fueled FRC reactor 'ARTEMIS-L'

International Nuclear Information System (INIS)

Momota, Hiromu; Tomita, Yukihiro; Ishida, Akio; Kohzaki, Yasuji; Nakao, Yasuyuki; Nishikawa, Masabumi; Ohi, Shoichi; Ohnishi, Masami.

1992-09-01

A neutron-lean D- 3 He fueled field reversed configuration (FRC) fusion reactor is studied on the bases of former high-efficiency ARTEMIS design. Certain improvements such as effective axial contracting plasma heating and cusp-type direct energy converters as well as an empirical scale of the energy confinement are introduced. The resultant total neutron load onto the first wall of the plasma chamber is as low as 0.1 MW/m 2 , which enable the life of the first wall or the structural materials to be longer than the whole life of the reactor. The attractive characteristics of the neutron-lean reactor follow in the ARTEMIS design: it is socially acceptable in views of radioactivity and fuel resources, and the cost of electricity appears to be cheap compared with that from a light water reactor. Critical physics and engineering issues for performing the ARTEMIS-L reactor are clarified. (author)

Two dimensional Hall MHD modeling of a plasma opening switch with density inhomogeneities

Energy Technology Data Exchange (ETDEWEB)

Zabaidullin, O [Kurchatov Institute, Moscow (Russian Federation); Chuvatin, A; Etlicher, B [Ecole Polytechnique, Palaiseau (France). Laboratoire de Physique des Milieux Ionises

1997-12-31

The results of two-dimensional numerical modeling of the Plasma Opening Switch in the MHD framework with Hall effect are presented. An enhanced Hall diffusion coefficient was used in the simulations. Recent experiments justify the application of this approach. The result of the modeling also correlates better with the experiment than in the case of the classical diffusion coefficient. Numerically generated pictures propose a switching scenario in which the translation between the conduction and opening phases can be explained by an abrupt `switching on` and further domination of the Hall effect at the end of the conduction phase. (author). 3 figs., 6 refs.

2004 world nuclear power report - evaluation

International Nuclear Information System (INIS)

Anon.

2004-01-01

Last year, 2003, 439 nuclear power plants were available for electricity generation in 31 countries of the world. With an aggregate gross capacity of 380,489 MWe and an aggregate net capacity of 361,476MWe, nuclear generating capacity reached its highest level so far. Nine different reactor lines are operated in the commercial nuclear power plants. Light water reactors (PWR and BWR) continue to be in the lead with 355 plants. Twenty-nine nuclear power plants with an aggregate gross capacity of 24,222 MWe and an aggregate net capacity of 23,066 MWe were under construction in eleven countries. Of these, twenty are light water reactors, and seven are CANDU-type reactors. Ninety-nine commercial reactors with a capacity in excess of 5 MWe have so far been decommissioned in eighteen countries, most of them prototype plants of low power. 228 plants, i. e. slightly more than half of the number of plants currently in operation, were commissioned in the 1980s. The oldest commercial nuclear power plant in the world, Calder Hall unit 1, was disconnected from the power grid for good in its 48th year of operation in 2003. For the first time in ten years, the availability in terms of time and capacity of nuclear power plants has decreased from 83,80% in 2002 to 80.50%, and from 84.60% to 81.50%, respectively, in 2003. The main causes are prolonged outages of high-capacity plants in Japan as a consequence of administrative restrictions. The four nuclear power plants in Finland continue to be at the top of the list worldwide with a cumulated average availability of capacity of 90.30%. (orig.)

Evolution of the nondestructive testing equipment for neutron radiography in the framework of the programs of the Services des Piles de Saclay

International Nuclear Information System (INIS)

1980-10-01

The progress made in neutron radiography testing equipment is made with respect to (a) the devices located inside reactor ponds (collimation, leak-tightness, irradiation devices, detection systems), (b) neutron radiography of active parts outside the reactor ponds (testing of fuel rods several metres long by a neutron radiography system by dry feed through), (3) neutron radiography on inactive materials (fitting an axial channel and a side channel in the Triton reactor), (4) neutron radiography on a neutron guide set up at the end of the Neutron Guide Hall associated with the Orphee reactor, i.e. 70 metres from it [fr

The Hall module of an exact category with duality

OpenAIRE

Young, Matthew B.

2012-01-01

We construct from a finitary exact category with duality a module over its Hall algebra, called the Hall module, encoding the first order self-dual extension structure of the category. We study in detail Hall modules arising from the representation theory of a quiver with involution. In this case we show that the Hall module is naturally a module over the specialized reduced sigma-analogue of the quantum Kac-Moody algebra attached to the quiver. For finite type quivers, we explicitly determin...

Theory of spin Hall effect

OpenAIRE

Chudnovsky, Eugene M.

2007-01-01

An extension of Drude model is proposed that accounts for spin and spin-orbit interaction of charge carriers. Spin currents appear due to combined action of the external electric field, crystal field and scattering of charge carriers. The expression for spin Hall conductivity is derived for metals and semiconductors that is independent of the scattering mechanism. In cubic metals, spin Hall conductivity $\\sigma_s$ and charge conductivity $\\sigma_c$ are related through $\\sigma_s = [2 \\pi \\hbar...

Anode sheath in Hall thrusters

International Nuclear Information System (INIS)

Dorf, L.; Semenov, V.; Raitses, Y.

2003-01-01

A set of hydrodynamic equations is used to describe quasineutral plasma in ionization and acceleration regions of a Hall thruster. The electron distribution function and Poisson equation are invoked for description of a near-anode region. Numerical solutions suggest that steady-state operation of a Hall thruster can be achieved at different anode sheath regimes. It is shown that the anode sheath depends on the thruster operating conditions, namely the discharge voltage and the mass flow rate

Quantum Hall effect in quantum electrodynamics

International Nuclear Information System (INIS)

Penin, Alexander A.

2009-01-01

We consider the quantum Hall effect in quantum electrodynamics and find a deviation from the quantum-mechanical prediction for the Hall conductivity due to radiative antiscreening of electric charge in an external magnetic field. A weak dependence of the universal von Klitzing constant on the magnetic field strength, which can possibly be observed in a dedicated experiment, is predicted

Quantized Hall conductance as a topological invariant

International Nuclear Information System (INIS)

Niu, Q.; Thouless, Ds.J.; Wu, Y.S.

1984-10-01

Whenever the Fermi level lies in a gap (or mobility gap) the bulk Hall conductance can be expressed in a topologically invariant form showing the quantization explicitly. The new formulation generalizes the earlier result by TKNN to the situation where many body interaction and substrate disorder are also present. When applying to the fractional quantized Hall effect we draw the conclusion that there must be a symmetry breaking in the many body ground state. The possibility of writing the fractionally quantized Hall conductance as a topological invariant is also carefully discussed. 19 references

Description of the RA-3 research reactor as a model facility

International Nuclear Information System (INIS)

Vicens, Hugo E.; Quintana, Jorge A.

2001-01-01

The Argentine RA-3 reactor is described as a model facility for the information to be provided to the IAEA in accordance with the requirements of the Model Additional Protocol. RA-3 reactor was designed as a 5 MW swimming pool reactor, moderated and cooled with light water. Its fuel was 90% enriched uranium. The reactor started its operation in 1967, has been modified and improved in many components, including the core, that now is fueled with moderately enriched uranium