Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: The Nuclear Power Plants (NPPs) are always designed for the highest level of safety against postulated accidents which may be initiated due to internal or external causes. One of the external/internal causes, which may lead to accident in the reactor and its associated systems, is fire in certain vital areas of the plant. Conventionally, the fire containment approach and/or the fire confinement approach is used in designing the fire protection systems of NPPs. Indian NPPs (PHWRs) follow the combined approach to ensure plant safety and all newly designed plants are required to comply with the provisions of Atomic Energy Regulatory Board (AERB) fire safety Guide. In respect of older plants, the reassessment of adequacy of fire safety provisions in the light of current advances has becomes essential so as to decide upon the steps for retrofitting. Keeping this in mind the deterministic fire hazard analysis was ...

Energy Technology Data Exchange (ETDEWEB)

Power output of a hydrogen-diesel dual-fuel engine is limited by the onset of knock as the percentage of heat input derived from hydrogen increased beyond a certain limit. Earlier work carried out at the Internal Combustion Engines Laboratory, Indian Institute of Technology, Madras, indicates that this knock sets in when the induced hydrogen exceeds about 60% of input energy at a pilot diesel quantity of 30% of full load diesel amount. At higher rates of hydrogen induction, the richer hydrogen-air mixture is more prone to knocking. Hardly any information is available on the possibilities of improving the knock limited power output of a hydrogen-diesel dual-fuel engine. Water can serve as a powerful internal coolant in decreasing the unburned mixture temperature because of its high latent heat. This paper presents the results of our investigation on improving the knock limited power ...

International Nuclear Information System (INIS)

... Power Company, Tokyo (Japan) Ishida, T. Japan Atomic Power Company,

CERN Document Server

Atomic pioneers

International Science & Technology Center (ISTC)

Investigation of Interaction of Laser Radiation with Radioactive Deposits on the metal Surface and Creation of Experimental Stand for Development of Laser Technology for Remote Treatment of Materials Contaminated with Radioactive Substances at the Atomic Power Plants

International Nuclear Information System (INIS)

The scattering of atoms by a resonance standing light wave is considered under conditions when the lower of two resonance levels is metastable, while the upper level rapidly decays due to mainly spontaneous radiative transitions to the nonresonance levels of an atom. The diffraction scattering regime is studied, when the Rabi frequency is sufficiently high and many diffraction maxima are formed due to scattering. The dynamics of spontaneous radiation of an atom is investigated. It is shown that scattering slows down substantially the radiative decay of the atom. The regions and characteristics of the power and exponential decay are determined. The adiabatic and nonadiabatic scattering regimes are studied. It is shown that the wave packets of atoms in the metastable and resonance excited states narrow down during scattering. A limiting (minimal) size of the wave ...

CERN Document Server

We present a thorough analysis of single atom detection using optical cavities. The large set of parameters that influence the signal-to-noise ratio for cavity detection is considered, with an emphasis on detunings, probe power, cavity finesse and photon detection schemes. Real device operating restrictions for single photon counting modules and standard photodiodes are included in our discussion, with heterodyne detection emerging as the clearly favourable technique, particularly for detuned detection at high power.

UK PubMed Central (United Kingdom)

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are...Full Text Available

International Nuclear Information System (INIS)

This report presents criteria for the identification and evaluation of fire hazards in nuclear power stations. The report presents criteria that are consistent with the existing regulatory approach in Canada, and outlines engineering tools and analytical techniques currently available to deterministically analyse fire. The criteria presented cover the topics which should be included in a fire hazard analysis and provide details of each topic so that the accuracy of an analysis may be evaluated.

International Nuclear Information System (INIS)

This illustrated booklet describes the fission process; the use of uranium to produce power in nuclear power stations (and a brief explanation of the differences between the principal types of reactor); the formation of plutonium and fission products; radioactive wastes and their management; nuclear fusion and a conceptual fusion reactor; alpha, beta and gamma radiations; radioisotopes and their applications. (U.K.).

International Nuclear Information System (INIS)

Novel and unprecedented ion exchange resin cleaning system, for use in BWR plants and featuring a vibration separator and basic design factors of Radiological Solutions, Inc., had been delivered to Tokai No. 2 Power Station, Japan Atomic Power Company, in October 2005. This compactly-designed system effectively separates crud and resin fines from ion exchange resins, with no clogging of separation screens. It generates minimized waste liquid and has a specially designed over-pack cleaning tank. The system has been in operation for about 2 years and half now and favorable operational data, such as crud and sulfate concentration decrease in feed water and reactor water respectively, and evaluation results have been reported from Japan Atomic Power Company and so on. (author)

International Nuclear Information System (INIS)

Division of Remote Handling and Robotics (DRHR) at Bhabha Atomic Research Centre (BARC) has been working on design and development of Reactivity Control Mechanisms for Nuclear Research Reactors (Dhruva, KAMINI and recently Critical Facility of Advanced Heavy Water Reactor (AHWR)) as well as Power Reactors in India (Pressurized Heavy Water Reactors of 220 MWe at Narora and recently India's first 540 MWe PHWR Unit -1 and 2 at Tarapur). This paper gives a brief account of evolution of reactivity control mechanisms for nuclear research and power reactors in India. (author)

International Nuclear Information System (INIS)

Generally, Hardening and irradiated brominating phenomena are occurred in the reactor vessel under operation conditions by atomic cavities and creation of impurity atoms which are led by high fast neutron flux. To assure the mechanical integrity of pressure vessel until the end of power plant life after monitoring the sample specimens on the vessel inside, a series of tests is performed over the retrieved surveillance capsule to examine the changes according to the plant operation in accordance with regulations. Monitoring surveillance capsules attached to neutron shield wall of outer core are consists of impact sample, tensile sample and temperature monitor

International Nuclear Information System (INIS)

The FLAPW (full-potential linearized-augmented plane-wave) method is one of the most accurate first-principles methods for determining electronic and magnetic properties of crystals and surfaces. Until the present work, the FLAPW method has been limited to systems of less than about one hundred atoms due to a lack of an efficient parallel implementation to exploit the power and memory of parallel computers. In this work we present an efficient parallelization of the method by division among the processors of the plane-wave components for each state. The code is also optimized for RISC (reduced instruction set computer) architectures, such as those found on most parallel computers, making full use of BLAS (basic linear algebra subprograms) wherever possible. Scaling results are presented for systems of up to 686 silicon atoms and 343 palladium atoms per unit cell, running on up to 512 processors on a ...

Energy Technology Data Exchange (ETDEWEB)

Severe accident analysis has been performed for the Wolsung nuclear power= plants in Korea to investigate severe accident phenomena of CANDU-600 reactors as a part of Level II PSA study. The accident sequence analyzed in this paper is loss of active heat sinks (LOAH) which is caused by loss of off-site power, diesel generators, and DC power. ISAAC (Integrated Severe Accident Analysis Code) computer code developed by KAERI (Korea Atomic Energy Research Institute) was used in this analysis. This paper describes the important thermal-hydraulics and source term behaviors in the primary system and inside containment, and the failure mechanisms of calandria vessel and containment. In addition, some insights for accident management program (AMP) are also given. (Author) 5 refs., 1 tab., 12 figs.

International Nuclear Information System (INIS)

Nano structured carbon nitride thin films were deposited at different RF powers in the range of 50 W to 225 W and constant gas ratio of (argon: nitrogen) Ar:N_2 by RF magnetron sputtering. The atomic percentage of Nitrogen: Carbon (N/C) content and impedance of the films increased from 14.36% to 22.31% and 9 x 10"-"1 #OMEGA# to 7 x 10"5 #OMEGA# respectively with increase in RF power. The hardness of the deposited films increased from 3.12 GPa to 13.12 GPa. The increase in sp"3 hybridized C-N sites and decrease of grain size with increase in RF power is responsible for such variation of observed mechanical and electrical properties.

Energy Technology Data Exchange (ETDEWEB)

Dual-fuel engines are modified diesel engines burning simultaneously two fuels inside the cylinder: a gaseous one, called the primary fuel and a liquid one, called the pilot fuel. The thermal efficiency of the dual-fuel engine and of the diesel engine are comparable; the level of emissions is lower compared to the diesel one. This article presents a new procedure for the combustion modeling in a LPG-diesel dual-fuel engine. The procedures deals with the ignition delay period and with the rate of heat release inside the cylinder. This procedure is validated using experimental data issued front a collaboration with the Indian Institute of Technology from Madras, India. The used engine is a single-cylinder one, air-cooled. The pilot fuel is direct injected inside the cylinder The engine was run at constant load and with different diesel substitutions, i.e. for different air to fuel ratios of the primary fuel-air mixture. The general error of the procedure is below ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station Unit-4 was made critical on 6th March 2005. Since radiation field builds up with the power level due to formation of fission products and activation products in different systems. Radiation dose rates were recorded from different areas using Area Radiation Monitors (ARMs) installed at different areas. These monitors are connected to Radiation Data Acquisition System (RADAS). The trend of radiation field build-up was also analyzed by making survey of different plant areas at various power levels and comparison was made with RADAS readings. The results obtained were compared with 220 MWe dose rates. This study discusses about the dose rates observed at accessible area, shut down accessible area and hotspots observed during the early stage of operation of the reactor. The attempt was also made to find the contributing factors of the high dose rates. It was found that the ...

International Nuclear Information System (INIS)

The progress report for the Theoretical Physics Division of the United Kingdom Atomic Energy Authority, Harwell, 1985/6 is presented. The Division's research programme is divided into four sections - i) nuclear power (fuels, inspection and safety aspects), ii) radioactive waste management, iii) underlying research, and iv) non-nuclear contract research. The report contains a description of the research work carried out on these four topics in the above period. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

Ideas about the interactions of charged particles with matter are discussed. First, some experimental information is presented. Concepts related to collision cross sections and the Bethe model for them are given. The stopping power is derived and applied to the discussion of depth dose functions ('Bragg curves'). Some details of the energy loss in microscopic volumes are discussed.

International Nuclear Information System (INIS)

The population doses and risks of stochastic effects from occupational exposures in Japan in 1978 were estimated on the basis of a nation-wide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 82,500 workers other than the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the offitial publication of the Japan Nuclear Safety Commission. The total number of workers except for nuclear power stations was estimated to be about 170,000 persons. Radiation works were subdivided as follows: medical works including dental; nondestructive inspectional; non-atomic energy industrial; research and educational; atomic energy industrial and nuclear power industrial. The annual collective dose equivalents were estimated to be about 6,000 man rem for ...

Energy Technology Data Exchange (ETDEWEB)

Test Area North (TAN) was a site of the Aircraft Nuclear Propulsion (ANP) Project of the U.S. Air Force and the Atomic Energy Commission. Its Cold War mission was to develop a turbojet bomber propelled by nuclear power. The project was part of an arms race. Test activities took place in five areas at TAN. The Assembly & Maintenance area was a shop and hot cell complex. Nuclear tests ran at the Initial Engine Test area. Low-power test reactors operated at a third cluster. The fourth area was for Administration. A Flight Engine Test facility (hangar) was built to house the anticipated nuclear-powered aircraft. Experiments between 1955-1961 proved that a nuclear reactor could power a jet engine, but President John F. Kennedy canceled the project in March 1961. ANP facilities were adapted for new reactor projects, the most important of which were Loss of Fluid Tests (LOFT), part of ...

International Nuclear Information System (INIS)

Collective dose equivalent and population dose from occupational exposures in Japan, 1988 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 0.21 million workers except for the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the official report of the Japan Nuclear Safety Commission. The total number of workers including nuclear power stations was estimated to be about 0.26 million. Radiation works were subdivided as follows: medical works including dental; non-atomic energy industry; research and education; atomic energy industry and nuclear power station. For the determination of effective dose equivalent and population dose, organ or tissue doses were measured with a phantom experiment. ...

International Nuclear Information System (INIS)

During the normal operation of a Nuclear Power Plant (NPP), radioactive releases into the atmosphere will be in small quantities. During major accidental situations, though the probability is extremely small, there may be significant release of radioactivity to the environment through the stack or at ground level. To study the external radiation exposure, if any, to the members of public due to releases during the normal operation of a nuclear power plant (NPP) and also to meet the requirement of emergency preparedness for the NPP site, continuous recording and analysis of environmental dose rate data is essential. This paper presents analysis of the gamma dose rates recorded by the Environmental Dose Logging Systems (EDLS) installed around the site during the last six years in the Emergency Planning Zone (EPZ) of Tarapur Atomic Power Station (TAPS). (author)

International Nuclear Information System (INIS)

SMART (System-Integrated Modular Advanced Reactor) is a first-of-the-kind integral reactor with 330 MW thermal power under active development by Korea Atomic Energy Research Institute (KAERI) for power generation and seawater desalination. SMART employs various design features that are not typically found in other nuclear power plants. Examples include a unique passive residual heat removal system (PRHRS), and enclosure of a pressurizer, eight helical steam generators, and eight canned reactor coolant pumps inside the reactor pressure vessel. This paper presents risk insights on the SMART reactor gained during the development of a regulatory PSA model by Korea Institute of Nuclear Safety (KINS)

International Nuclear Information System (INIS)

Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)

Energy Technology Data Exchange (ETDEWEB)

Fusion energy is one of only a few truly long-term energy options. Since its inception in the 1950s, the vision of the fusion energy research program has been to develop a viable means of harnessing the virtually unlimited energy stored in the nuclei of light atoms--the primary fuel deuterium is present as one part in 6,500 of all hydrogen. This vision grew out of the recognition that the immense power radiated by the sun is fueled by nuclear fusion in its hot core. Such high temperatures are a prerequisite for driving significant fusion reactions. The fascinating fourth state of matter at high temperatures is known as plasma. It is only in this fourth state of matter that the nuclei of two light atoms can fuse, releasing the excess energy that was needed to separately bind each of the original two nuclei. Because the nuclei of atoms carry a net positive electric charge, they repel each other. ...

International Nuclear Information System (INIS)

To assure quality of safety critical software, software should be developed in accordance with software development procedures and rigorous software verification and validation should be performed. Software verification is the formal act of reviewing, testing of checking, and documenting whether software components comply with the specified requirements for a particular stage of the development phase[1]. New software verification methodology was developed and was applied to the Shutdown System No. 1 and 2 (SDS1,2) for Wolsung 2,3 and 4 nuclear power plants by Korea Atomic Energy Research Institute(KAERI) and Atomic Energy of Canada Limited(AECL) in order to satisfy new regulation requirements of Atomic Energy Control Boars(AECB). Software verification methodology applied to SDS1 for Wolsung 2,3 and 4 project will be described in this paper. Some errors were found by this methodology during the software ...

Energy Technology Data Exchange (ETDEWEB)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The ...

International Nuclear Information System (INIS)

Research and development and other activities of the various constituent units of Department of Atomic Energy (DAE) and also of the institution aided by DAE for the year 2005-2006 are reported. The various constituents units of DAE consist of nuclear research centres, nuclear power stations, fuel reprocessing and heavy water plants, nuclear fuel fabrication facilities, electronic and instrumentation production organisations, atomic mineral processing units and other nuclear installations. The activities of DAE cover the whole gamut of nuclear fuel cycle, research and development in nuclear science and reactor technology, applications of radiation and radioisotopes, radiation protection, research and development in front line areas such as robotics, lasers, mathematics and computational sciences. International research collaborations like CERN-DAE collaboration were completed by BARC. These activities are described broadly ...

Energy Technology Data Exchange (ETDEWEB)

Electron energy loss (EEL) spectroscopy and high angle annular dark field (HAADF) imaging in aberration-corrected electron microscopes are powerful techniques to determine the chemical composition and structure of materials at atomic resolution. We have implemented Smart Acquisition, a flexible system of scanning transmission electron microsocpy (STEM) beam position control and EELS collection, on two aberration-corrected dedicated cold field emission gun (FEG) STEMs located at SuperSTEM, Daresbury Laboratory. This allows the collection of EEL spectra from spatially defined areas with a much lower electron dose possible than existing techniques such as spectrum imaging.

Energy Technology Data Exchange (ETDEWEB)

Korea Atomic Energy Research Institute (KAERI) has been developing the integral reactor. The reactor head structure assembly (RHSA) is the structure installed over the reactor cover. Due to the characteristics of an integral reactor, there are many instrument cables and power cables coming out from the reactor cover and main components. The RHSA provides an interface location to connect these cables from Architecture Engineer (AE) and System Designer (SD). It also prevents a pipe whip and it prohibits instruments from becoming missiles. In this research, the axiomatic design approach for the RHSA is performed.

Energy Technology Data Exchange (ETDEWEB)

Japan Atomic Energy Research Institute (JAERI) is developing the world`s strongest spallation neutron source using high power proton accelerator and promoting a neutron science project for comprehensive studies on basic science and nuclear transmutation of high-level radioactive nuclide from nuclear power stations. For this purpose, JAERI organized the Special Taskforce for Neutron Science and OMEGA Project in April 1996 and reorganized it to Center for Neutron Science in April 1997. During this period, various research plans using the spallation neutron source are proposed and facilities necessary for research are studied by mainly research groups of JAERI. This report describes research plans and results of the preliminary conceptual design study on proposed facilities plan. (author)

International Nuclear Information System (INIS)

The present report describes the study conducted in co-operation with several agencies and organizations from Thailand and covers the energy and electricity requirements and the optimal expansion plans for the power generating system for this country up to year 2011. It is emphasized that the study was carried out by a team of experts from the Electricity Generating Authority of Thailand (EGAT), the National Economic and Social Development Board (NESDB), the National Energy Administration (NEA) and the Office of Atomic Energy for Peace (OAEP), who were fully responsible for all phases of the study, including the production of the present report. The IAEA's responsibility was to provide overall co-ordination and general guidance during the conduct of the study, as well as training and assistance in the implementation and use of the IAEA's computerized planning methodologies on the computer facilities of Thailand. Refs, figs and tabs.

CERN Document Server

We present H-alpha and [O III] (5007 Angstroms) images of the nebula powered by the jet of the black hole candidate and microquasar Cygnus X-1, observed with the 2.5m Isaac Newton Telescope (INT). The ring-like structure is luminous in [O III] and there exists a thin outer shell with a high [O III] / H-alpha flux ratio. This outer shell probably originates in the collisionally excited atoms close to the front of the bow shock. Its presence indicates that the gas is shock excited as opposed to photoionised, supporting the jet-powered scenario. The shock velocity was previously constrained at 20 = 100 km/s (1 sigma confidence) based on a comparison of the observed [O III] / H-alpha ratio in the bow shock with a number of radiative shock models. From this we further constrain the time-averaged power of the jet: P_Jet = (4 - 14)*10^36 erg/s. The H-alpha flux behind the shock front is typically 4*10^-15 ...

International Nuclear Information System (INIS)

The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to ...

Energy Technology Data Exchange (ETDEWEB)

This report provides a chronological history of policies and practices relating to the management of radioactive waste for which the US Atomic Energy Commission and its successor agencies, the Energy Research and Development Administration and the Department of Energy, have been responsible since the enactment of the Atomic Energy Act in 1946. The defense programs and capabilities that the Commission inherited in 1947 are briefly described. The Commission undertook a dramatic expansion nationwide of its physical facilities and program capabilities over the five years beginning in 1947. While the nuclear defense activities continued to be a major portion of the Atomic Energy Commission`s program, there was added in 1955 the Atoms for Peace program that spawned a multiplicity of peaceful use applications for nuclear energy, e.g., the civilian nuclear power program and its associated ...

Energy Technology Data Exchange (ETDEWEB)

The availability of new, high-intensity, cold and thermal neutron sources has opened the possibility of performing high-precision fundamental neutron physics experiments, including measurements that study the hadronic weak interaction and standard model test measurements, using neutron decay. The observables in these experiments are usually correlated with the direction of neutron polarization and are often very small (10 8 10 6). Mott-Schwinger scattering of polarized neutrons can produce spin-dependent shifts in beam centroids, which has the potential to produce significant systematic effects for these types of experiments. An accurate calculation of this process for neutral atoms and basic molecules has not been carried out for low neutron energies. In this work, we derive a general expression for the electromagnetic (Mott-Schwinger) contributions to the analyzing power for low-energy neutron scattering. We obtain numerical results for 11 ...

Energy Technology Data Exchange (ETDEWEB)

The contribution is concerned from a legal point of view with the systematic recording, classification and assessment of specific problems concerning the post-operational phase of a nuclear power plant. As an introduction, present experience with decommissioning in the Federal Republic of Germany is dealt with. The first part treats the factual side of section 7 III AtG, explains the terms mentioned, the concrete extent of licensing and priority relations. In part 2 the preconditions for licensing pursuant to section 7 III AtG are dealt with, the stipulations of which are made difficult in particular on account of the reference in section 7 III sentence 2 AtG. The third part is concerned with the legal consequence of section III AtG, i.e. the extent of official discretionary powers, whereby aspects of radioactive waste management carry great weight. In part four administrative and procedural particularities in the legal sense relating to ...

International Nuclear Information System (INIS)

Free Electron Laser (FEL) with the wide wavelength tunability has been developed and used for various applications. The FEL gives high efficiency for the photo-induced ablation when the laser is tuned to an absorption maximum of the target. The FEL was tuned to 9.4 #mu#m, which is an absorption maximum of phosphoric acid ion, a known major component of dentine. The FEL pulse length was several ps. The average output power was varied from 5 to 20 mW by filters. The change of irradiated dentine surface was analyzed by mass spectroscopy and Energy Dispersive X-ray (EDX) spectroscopy. Positive ions which correspond to Na"+, CO_3"+ and many phosphoric acid ions were measured. It was found that atomic ratio of P/Ca had reduced from 0.65-0.60. The atomic ratio of P/Ca, however had not changed with irradiation by Er:YAG laser (2.9 #mu#m), or CO_2 laser (10.6 #mu#m). These results indicate the selective ablation of phosphoric acid ...

CERN Document Server

Individual laser cooled atoms are delivered on demand from a single atom magneto-optic trap to a high-finesse optical cavity using an atom conveyor. Strong coupling of the atom with the cavity field allows simultaneous cooling and detection of individual atoms for time scales exceeding 15 s. The single atom scatter rate is studied as a function of probe-cavity detuning and probe Rabi frequency, and the experimental results are in good agreement with theoretical predictions. We demonstrate the ability to manipulate the position of a single atom relative to the cavity mode with excellent control and reproducibility.

International Nuclear Information System (INIS)

The purposes of this report are (1) to perform a Verification and Validation (V and V) test for the VIPEX(Vital-area Identification Package EXpert) software and (2) to improve a software quality through the V and V test. The VIPEX was developed in Korea Atomic Energy Research Institute (KAERI) for the Vital Area Identification (VAI) of nuclear power plants. The version of the VIPEX which was distributed is 3.2.0.0. The VIPEX was revised based on the first V and V test and the second V and V test was performed. We have performed the following tasks for the V and V test on Windows XP and VISTA operating systems: ? Testing basic functions including fault tree editing ? Testing all kind of functions ? Research for update from Visual BASIC 6.0 to Visual BASIC 2008

International Nuclear Information System (INIS)

Modern civilisation is based on substantial utilisation of energy. Rapid industrial development and improvement of living standards in India require energy planners to adequately forecast the energy demand and take appropriate measures in advance. However, the development and establishment of new technology is a slow process, sometimes extending over decades. Hence, energy options based on new technologies need to be planned for much in advance making allowance for uncertainties and delays. Fast Breeder Reactor (FBR) technology is an advanced energy option promising abundant and economic supply of power. Research and development work on FBRs has been conducted at the Indira Gandhi Centre of Atomic Research (IGC) since 1971. The international trends in FBR development are highlighted in this discussion and an overview of some of the research activities at IGC is presented. (author). 8 refs., 7 tab s.

Energy Technology Data Exchange (ETDEWEB)

A detergent-containing radioactive liquid waste originating from atomic power plants is concentrated to have about 10 wt. % detergent concentration, then dried in a thin film evaporator, and converted into powder. Powdered activated carbon is added to the radioactive waste in advance to prevent the liquid waste from foaming in the evaporator by the action of surface active agents contained in the detergent. The activated carbon is added in accordance with the COD concentration of the radioactive liquid waste to be treated, and usually at a concentration 2-4 times as large as the COD concentration of the liquid waste to be treated. A powdery product having a moisture content of not more than 15 wt. % is obtained from the evaporator, and pelletized and then packed into drums to be stored for a predetermined period.

International Nuclear Information System (INIS)

BARC has organized an international round robin analysis program to carry out the ultimate load capacity assessment of BARC containment (BARCOM) test model. The test model located in BARC facilities Tarapur, is a 1:4 scale representation of 540 MWe pressurized heavy water reactor (PHWR) pre-stressed concrete inner containment structure of Tarapur Atomic Power Station (TAPS) unit 3 and 4. The features of the BARCOM test model and the constitutive data for the pre-test analysis along with the comparison of the results submitted by various participants are described in this pre-test report of the round robin analysis of BARCOM test model

Energy Technology Data Exchange (ETDEWEB)

A time-of-flight (TOF) spectrometer has been constructed at the JAERI 20 MV tandem accelerator facility. A position-sensitive start detector, which consists of a thin carbon foil, microchannel plates and a resistive plate, was developed for the TOF measurements through the spectrometer. The time and position resolutions obtained were 120 ps and 0.3 mm for ..cap alpha.. particles from /sup 241/Am, respectively. A two-dimensional position-sensitive detector was also developed to measure the solid angle of the spectrometer and the maximum solid angle obtained was 9.5 msr. As a particle detector a Bragg curve ionization chamber was developed. From the Bragg curves of heavy ions in the detector, energies, ranges and Bragg curve peaks were measured and used for particle identification. The resolving power Z/..delta..Z of the atomic number was about 50.

British Library Electronic Table of Contents (United Kingdom)

In recent years, increased attention has been focused on the use of lasers in different fabrication steps of solar cells, in particular laser doping to form emitter and/or selective emitter. In this method the laser energy is used to melt silicon, allowing the diffusion of dopant atoms to occur in the liquid phase. The main advantage of this method is the localised nature of the laser beam, which melts and diffuses a limited area without heating the bulk, therefore reducing the possible degradation associated with high temperature processes. At the University of New South Wales a novel laser doping method was developed, which combines the formation of the selective emitter with a self-aligned metallisation pattern. Despite achieving high efficiencies, concerns arose regarding the adhesion ...

International Nuclear Information System (INIS)

The powder particle size, D, influences the creep behaviour of Al-Cr-Zr alloys. The alloy studied in this work, Al-5Cr-2Zr (mass%), was prepared by argon atomization. Three size fractions of powder particles were selected: 24-50 #mu#m, 50-100#mu#m and 100-200 #mu#m in diameter. They were consolidated by extrusion. Independently of D, the flow behaviour of the alloy can be described by the power law equation. As test temperature increases, the stress exponent n decreases up to a value close to 5. A decrease of D causes an increase of n and delays the alloy degradation at high temperature. (Author) 11 refs.

British Library Electronic Table of Contents (United Kingdom)

The development of a new configuration of chemical ionization (CI)-based ion source is presented. The ambient air containing the gaseous sample is sniffed into an enclosed ionization chamber which is of sub-ambient pressure, and is subsequently mixed with metastable species in front of the ion inlet of the mass spectrometer. Metastable helium atoms (He*) are used in this study as the primary ionizing agents and are generated from a dielectric barrier discharge (DBD) source. The DBD is powered by an AC high-voltage supply and the configuration of the electrodes is in such a way that the generated plasma is confined within the discharge tube and is not extended into the ionization chamber. The construction of the ion source is simple, and volatile compounds released from the bulky sample can...

Energy Technology Data Exchange (ETDEWEB)

The mathematical apparatus of quantum-mechanical angular momentum (re)coupling, developed originally to describe spectroscopic phenomena in atomic, molecular, optical and nuclear physics, is embedded in modern algebraic settings which emphasize the underlying combinatorial aspects. SU(2) recoupling theory, involving Wigner's 3nj symbols, as well as the related problems of their calculations, general properties, asymptotic limits for large entries, nowadays plays a prominent role also in quantum gravity and quantum computing applications. We refer to the ingredients of this theory-and of its extension to other Lie and quantum groups-by using the collective term of 'spin networks'. Recent progress is recorded about the already established connections with the mathematical theory of discrete orthogonal polynomials (the so-called Askey scheme), providing powerful tools based on asymptotic expansions, which correspond on ...

Science.gov (United States)

The DITE (Divertor Injection Tokamak Experiment) program has been undertaken to demonstrate the feasibility of impurity control by the use of a diverter in an injection-heated toroidal plasma configuration. Rather than behaving in accordance with neoclassical toroidal containment theory, the plasma is subject to various instabilities, particularly the resistive fluid MHD types, follows the empirical scaling of energy confinement time with plasma parameters observed in other plasma devices. DITE experiments have, however, extended the range of current and density. Impurities arising from plasma interactions with the vacuum vessel surface are controlled by the bundle divertor, which diverts a portion of plasma and power in the plasma scrape-off layer into a separate target chamber where impurities can be removed. Auxiliary plasma heating is provided by the injection of powerful beams of neutral hydrogen atoms produced by ...

International Nuclear Information System (INIS)

Methodology based on probabilistic fracture mechanics (PFM) is finding increasing acceptability in demonstrating safety of Nuclear Power Plant (NPP) piping. In PFM, the methods of fracture mechanics and reliability theory are combined for assessing the reliability of components, which contain cracks. In this work, reliability assessment of Tarapur Atomic Power Plant (TAPP) 3-4 Primary Heat Transport (PHT) piping is done using PFM. Monte Carlo simulation with stratified sampling is used as a variance reduction technique. PFM model assumes a pre-existing circumferential surface crack before the start of plant operation. The crack grows in size during the lifetime of the plant due to the fatigue loading. This part-through wall crack having escaped hydro-test and pre-service inspection, may result in either a through wall flaw (leak) or may lead to the rupture of the piping. R6 method is used as failure criteria. Steam ...

Energy Technology Data Exchange (ETDEWEB)

The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the ...

Energy Technology Data Exchange (ETDEWEB)

The Reduced-Moderation Water Reactor (RMWR) is a next generation water-cooled reactor, based on the experienced light water reactor (LWR) technology, aiming at effective utilization of uranium resources, high burn-up and long operation cycle and plutonium multiple recycling. These characteristics can be achieved by the high conversion ratio from {sup 238}U to {sup 239}Pu resulted from the higher neutron energy spectrum in comparison to conventional LWRs. Considering the extension of LWR utilization, Japan Atomic Energy Research Institute (JAERI) started the research on it in 1997 and then started a collaboration in the conceptual design study with the Japan Atomic Power Company (JAPC) in 1998, under technical cooperation with three Japanese reactor vendors. In the core design study of the RMWR, several basic core designs with the high conversion ratio more than 1 and the negative void reactivity coefficient have been ...

International Nuclear Information System (INIS)

The total radiation rate, angular distribution of the emitted energy and photon correlations of the cooperative spontaneous radiation from two atoms with different resonance frequencies and spontaneous decay rates are calculated. Contrary to the case of two identical atoms oscillations appear in the total radiation rate and the spatial distribution of the total number of emitted photons differs from the single-atom radiation pattern. The effect of the dipole-dipole near-field interaction on the time evolution of the atomic system is discussed. (author).

International Nuclear Information System (INIS)

Reduced-Moderation Water reactor (RMWR) is a light water breeder reactor developed by Japan Atomic Energy Research Institute (JAERI). The RMWR comprises tight lattice fuel assemblies with gap clearance of around 1.0 mm to reduce water volume ratio to achieve a high conversion ratio. It is important to estimate the thermal hydraulic safety margin of the tight lattice core of the RMWR. In the present study, the boiling transition (BT) prediction performance of the subchannel analysis code NASCA developed for the current BWR cores was assessed for series of tight lattice critical heat flux (CHF) experiments performed in JAERI. The test section was a 7-rod bundle with rod diameter of 12.3 mm, rod gap of 1.0 mm and heated length of 1.8m. Axial power distribution was flat. With a simple subchannel model, the code overestimates the critical power in the high mass velocity region, although the predicted critical ...

Energy Technology Data Exchange (ETDEWEB)

Objective is to study the effects of local structure, interatomic forces, and atom size on the mobility of metal atoms in amorphous silica and at the silica surface. EXAFS studies of Zn and Pt in silica are reported. (DLC)

International Nuclear Information System (INIS)

During the last ten years, the U.S. Nuclear Regulatory Commission and the U.S. nuclear utilities have been developing methods and requirements for risk-informed applications making use of probabilistic risk assessments (PRA) of nuclear power plants. Early in this process, it became clear that the existing PRAs were done with different objectives and methodologies by different analysts. For uniformity and consistency in future risk-informed applications, industry consensus standards on probabilistic risk assessments were deemed to be essential. Currently, the following standards have been published or under preparation: - ASME RA-S-2002: 'Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications', Addendum C, March 2005. - ANSI/ANS-58.21-2003 'External-Events PRA Methodology' March 2003. - ANS-58.22 'Low Power and Shutdown PRA Standard'. - ANS-58.23 'Fire PRA Methodology Standard'. - ANS Level 2 and ...

Energy Technology Data Exchange (ETDEWEB)

Strong-interaction effects have been observed in the x-ray spectra of atoms formed with [Sigma][sup [minus

Science.gov (United States)

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Energy Technology Data Exchange (ETDEWEB)

A summary of the basic principles of K-matrix theory and examples of its applications to atomic spectra are discussed. (AIP)

International Nuclear Information System (INIS)

Full text: The isotopic assay instrument under development at Pacific Northwest National Laboratory (PNNL) is capable of rapid prescreening to detect small and rare particles containing high concentrations of uranium in a heterogeneous sample. The isotopic measurement concept is based on laser vaporization of solid samples followed by sensitive isotope-specific detection using either uranium atomic fluorescence emission or uranium atomic absorbance. Both isotopes are measured concurrently, following a single ablation laser pulse using two external-cavity violet diode lasers. The simultaneous measurement of both isotopes enables the correlation of the fluorescence and absorbance signals on a shot-to-shot basis. This measurement approach demonstrated negligible channel crosstalk between isotopes. Scanning the heterogeneous samples provides high-resolution imagery of sample isotopic fluorescence and absorbance. Isotopically selective excitation of ...

International Nuclear Information System (INIS)

The SIEN 2009 symposium organized by Romanian Nuclear Energy Association, AREN, in co-operation with Romanian Atomic Forum, ROMATOM, was primarily targeting the expert community involved in developing new nuclear power projects and implementing the National Nuclear Program. The symposium was also open as a discussion and information forum for scientists, engineers, technicians and students interested in scientific and technologic topics of Nuclear Power. It was structured in the following 6 sections: - Nuclear new builds and developments; - Operation, inspection and maintenance; - Increasing nuclear safety features; - Fuel cycle and decommissioning; - Public perception and confidence strengthening; - Environmental management. The symposium began with three plenary lectures dealing with: - Sustainable Nuclear Energy European Technology Platform; - Nuclear new-build; - Current issues of nuclear equipment standardization in ...

International Nuclear Information System (INIS)

Korea Atomic Energy Research Institute, using the ANS low power and shutdown (LPSD) probabilistic risk assessment (PRA) Standard, evaluated the LPSD PSA model of the KSNP, Yonggwang Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the LPSD PSA model for the KSNP showed that 10 items among 19 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors in the LPSD PSA model for the KSNP. Following tasks are the improvements in the HRA of post-accident human errors of the LPSD PSA model for the KSNP compared with the previous one: Interviews with operators in the interpretation of the procedure, modeling of operator actions, and the quantification results of human errors, site visit. Applications of limiting value to the combined ...

Science.gov (United States)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

Energy Technology Data Exchange (ETDEWEB)

I propose that an interpretation of the interaction of noble gas atoms with metal surfaces as predominantly physisorbing provides the best explanation for the systematics of their binding energies and surface dipoles, as well as for the tendency of noble gas atoms to bind in low coordinated sites. In the present context physisorption is defined as a process driven by the overlap of the electrostatic atomic potentials of the interacting species. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433?479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

Energy Technology Data Exchange (ETDEWEB)

This two-volume reference uses many equations to provide detailed information on atomic and nuclear decay phenomena.

Energy Technology Data Exchange (ETDEWEB)

A compact cesium deposition system was used for direct deposition of cesium atoms and ions onto the inner surface of the 1/3 scale Hydrogen Negative Ion Source for the LHD-NBI system. A small, well defined amount of cesium deposition in the range of 3-200 mg was tested. Negative ion extraction and acceleration were carried out both in the pure hydrogen operation mode and in the cesium mode. Single Cs deposition of 3-30 mg to the plasma chamber have produced temporary 2-5 times increases of H-yield, but the yield was decreased within several discharge pulses to the previous steady-state value. Two consecutive 30 mg depositions done within a 3-5 hours/60 shot interval, produced a similar temporary increase of H-beam, but reached a larger H-yield steady-state value. Deposition of larger 0.1-0.2 g Cs portions with a 20-120 hours/150-270 shot interval improved the H-yield for a long (2-5 days) period of operation. Directed depositions of Cs to the various walls of the ...

British Library Electronic Table of Contents (United Kingdom)

The atomic mechanism of a glass-to-liquid transition in a monatomic Lennard-Jones (LJ) glass was studied using the molecular dynamics (MD) method. Glassy models were heated up from low temperature at two different heating rates and a glass-to-liquid transition found to occur at the higher heating rate. The temperature dependence of the potential energy, mean-squared-displacements (MSD) of the atoms and the self-intermediate scattering function indicate clearly that a glass transition occurs in the system. The atomic mechanism of the glass-to-liquid transition was investigated by analyzing the spatio-temporal arrangement of liquid-like atoms in the system upon heating. Liquid-like atoms were detected using the Lindemann-melting-like criterion. Upon heating, liquid-like atoms occur at temper...

International Nuclear Information System (INIS)

The classical theory of collisional broadening and shift parameters (?, ?) of an isolated spectral line was used to obtain simple analytical formulas for calculating both ? and ?. These formulas were obtained on the assumption that the short range interaction is effective only in the broadening while the long range is effective in the shift of the spectral line. These parameters ? and ? depend on the limiting phase shifts responsible for broadening ?b and shift ??. It was found that the values of ?b and ?? are not equal to each other as was proposed by Weisskopf ?b=??=1. The maximum and average values of ?b (?bmax, ?bav) and ?? (??max, ??av) were obtained by numerical evaluation, using different inverse power potentials. By introducing these parameters into the approximated formulas for ? and ? using Van der Waals and Lennard-Jones potential, it was found that the results of calculations for (? and ?) with different atomic transitions perturbed ...

International Nuclear Information System (INIS)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous silicon is still a ...

Energy Technology Data Exchange (ETDEWEB)

Neutron radiography is a non-destructive test method to examine a material by using the dependency of neutron attenuation on the nuclear characteristics of the atoms composing the object material. There are two categories of neutron radiography; static neutron radiography and dynamic neutron radiography. The static neutron radiography is a technique to observe a standing object by using a camera or a film cassette. The dynamic neutron radiography(DNR) is a technique to observe a moving object usually by using a camera. Depending on the camera frame rate, the dynamic neutron radiography is categorized into the real time neutron radiography(RTNR) and the high speed neutron radiography(HSNR). The frame rate for RTNR is 30 frames/s and that for HSNR is usually more that 500 frames/sec. Thus, RTNR is good for observing time-averaged phenomena and HSNR is good for observing instantaneous phenomena. DNR is a powerful tool for fluid visualization as ...

International Nuclear Information System (INIS)

The report presents the results of the study carried out to estimate the accident risk involved in the transport of spent fuel from Rajasthan Atomic Power Station near Kota to the fuel reprocessing plant at Tarapur. The technique of probabilistic safety analysis is used. The fuel considered is the Indian pressurised heavy water reactor fuel with a minimum cooling period of 485 days. The spent fuel is transported in a cuboidal, naturally-cooled shipping cask over a distance of 822 km by rail. The Indian rail accident statistics are used to estimate the basic rail accident frequency. The possible ways in which a release of radioactive material can occur from the spent fuel cask are identified by the fault tree analysis technique. The release sequences identified are classified into eight accident severity categories, and release fractions are assigned to each. The consequences resulting from the release are estimated by the computer code RADTRAN ...

International Nuclear Information System (INIS)

Radiation defects produced by helium implantation were used to shape profiles of palladium (Pd) and platinum (Pt) atoms in-diffusing (for 20 min at temperatures 600-800 deg. C) either from surface silicide (Pd_2Si, PtSi) or implanted layers. Results show that this procedure allows a strong localization of substitutional Pd and Pt at the depth where the damage produced by helium peaks. This results in local reduction of carrier lifetime by an almost ideal recombination centers - the acceptor level of substitutional Pd (E _c - 0.22 eV) or Pt (E _c - 0.23 eV). While optimum conditions for Pt in-diffusion are about 700 deg. C, Pd gives the best results already at lower temperatures (600 deg. C) where it also exhibits higher peak solubility. Both methods were used for optimization of turn-off properties of high power PiN diodes. The devices, where the lifetime was killed locally by Pd and Pt, exhibited similar trade-off between the static and ...

Energy Technology Data Exchange (ETDEWEB)

Pipe whip tests or jet discharge tests have been performed at the Japan Atomic Energy Research Institute, which simulate the instantaneous guillotine break of primary coolant piping in nuclear power plants. This paper describes the results of the 4-inch pipe whip tests(RUN 5407, 5501, 5504, 5603), under the BWR LOCA conditions, which were performed from 1979 to 1981. The test pressure was 6.8 MPa and test temperature 285/sup 0/C. In these tests, clearance was kept constant at the value of 100 mm and overhang lengths were 250, 400, 550 and 1,000 mm, respectively. The main purpose of these tests is to investigate the effect of overhang length on pipe whip behavior. From the tests results, the pipe movement is effectively limited by the restraints if the overhang length is 250 mm or 400 mm. The deformation of the test pipe and restraints becomes large with increasing overhang length. It is clarified that the test pipe collapses at the setting ...

International Nuclear Information System (INIS)

Korea Atomic Energy Research Institute(KAERI) launched a project to develop an integral reactor in 1996. The reactor called as System Integrated Modular Advanced Reactor(SMART) which is a kind of small modular reactors (SMRs). Since the early 1990s, there has been renewed interest in the development and application of small and medium sized integral reactors. 2009 assessment by the IAEA under its Innovative Nuclear Power Reactor and Fuel Cycle (INPRO) program concluded that there could be 96 SMRs in operation around the world by 2030 in its 'high' case, and 43 units in the 'low' case, none of them in the USA. The reason of the increased demand mostly comes from the fact that SMRs are thought to be more suitable for developing countries with small electrical grid capacity, insufficient infrastructure and limited investment capability than developed ones. However, it has disadvantage in the point of scale of economy. So, it should be compared the ...

CERN Document Server

We use two-dimensional hydrodynamical simulations to investigate the properties of dense ejecta clumps (bullets) in a core collapse supernova remnant, motivated by the observation of protrusions probably caused by clumps in the Vela supernova remnant. The ejecta, with an inner flat and an outer steep power law density distribution, were assumed to freely expand into an ambient medium with a constant density, $\\sim 0.1$ H atoms cm$^{-3}$ for the case of Vela. At an age of $10^4$ yr, the reverse shock front is expected to have moved back to the center of the remnant. Ejecta clumps with an initial density contrast $\\chi \\sim 100$ relative to their surroundings are found to be rapidly fragmented and decelerated. In order to cause a pronounced protrusion on the blast wave, as observed in the Vela remnant, $\\chi \\sim 1000$ may be required. In this case, the clump should be near the inflection point in the ejecta density profile, at an ejecta ...

Energy Technology Data Exchange (ETDEWEB)

The task of designing high performance X-ray optical systems requires the development of sophisticated X-ray scattering calculations based on rigorous information about the optics. One of the most insightful approaches to these calculations is based on the power spectral density (PSD) distribution of the surface height. The major problem of measurement of a PSD distribution with an interferometric and/or atomic force microscope arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF characterizes the perturbation of the PSD distribution at higher spatial frequencies. Here, we describe a new method and dedicated test surfaces for calibration of the MTF of a microscope. The method is based on use of a specially designed Binary Pseudo-random (BPR) grating. Comparison of a theoretically calculated PSD spectrum of a BPR grating with a spectrum measured with the grating provides the desired calibration of the ...

International Nuclear Information System (INIS)

To obtain reactor physics parameters for high-moderation mixed-oxide (MOX) cores, Nuclear Power Engineering Corporation (NPEC), the French Atomic Commission (CEA), and their industrial partners have conducted a MOX core physics experimental program called MISTRAL with the EOLE critical facility of the Cadarache research center. This program consists of four high-moderation cores and was successfully completed in July 2000. This paper describes the analysis results of MISTRAL-3 that is a homogeneous full MOX cylindrical core (H/HM = 6.2) with an 80-cm height and a 59-cm diameter consisting of 1388 standard pressurized water reactor-type MOX fuel rods of 7.0 wt% plutonium-enrichment in a square pitch of 1.39 cm. NPEC has been analyzing the experimental results by using the SRAC and MVP code systems. SRAC and MVP calculate the nuclear core characteristics correctly for the high-moderation MOX core MISTRAL-3. No apparent trend with the moderation ...

Energy Technology Data Exchange (ETDEWEB)

Court decisions available so far do not primarily consider the problems linked to the commissioning of an expert and his mandate, as well as the legal status of the commissioning of an expert as an administrative act which might be legally contestable. Thus there are at present no court decisions that would create legal certainty in matters of the act of commissioning a nuclear expert opinion. The current legal situation is such that an independent order for commissioning of an expert opinion in compliance with section 19 III AtG (Atomic Energy Act), which in general is given in response to the refusal of the facility operator to do so, can be independently contested on the basis of section 44 a, sentence 2 VwGO (Rules of Administrative Courts). The current practice of conflict-oriented, or nuclear power phase-out-oriented, implementation of the nuclear law poses a threat to our constitutional state and to our democracy. The supply of energy as ...

Science.gov (United States)

An experimental realization of the focusing of an atomic beam by a spontaneous radiation pressure force is reported. A simple light field configuration for focusing an atomic beam is described which is formed by four divergent Gaussian laser beams propagating along the + or - x and + or - y directions of a Cartesian coordinate system. An experimental arrangement for the laser focusing is shown, and the experimental procedure is described. The resulting atomic beam profiles are shown and discussed. It is concluded that the experiments open up the possibility of gaining control over such parameters of atomic beams as their density and divergence. 7 references.

CERN Document Server

We study spontaneously generated entanglement (SGE) between two identical multilevel atoms in free space via vacuum-induced radiative coupling. We show that the SGE in two-atom systems may initially increase with time but eventually vanishes in the time scale determined by the excited state lifetime and radiative coupling strength between the two atoms. We demonstrate that a steady-state SGE can be established by incoherently pumping the excited states of the two-atom system. We have shown that an appropriate rate of incoherent pump can help producing optimal SGE. The multilevel systems offer us more chanel to establish entanglement. The system under consideration could be realized in a tight trap or atoms/ions doped in a solid substrate.

CERN Document Server

This contribution reviews a selection of findings on atomic density functions and discusses ways for reading chemical information from them. First an expression for the density function for atoms in the multi-configuration Hartree--Fock scheme is established. The spherical harmonic content of the density function and ways to restore the spherical symmetry in a general open-shell case are treated. The evaluation of the density function is illustrated in a few examples. In the second part of the paper, atomic density functions are analyzed using quantum similarity measures. The comparison of atomic density functions is shown to be useful to obtain physical and chemical information. Finally, concepts from information theory are introduced and adopted for the comparison of density functions. In particular, based on the Kullback--Leibler form, a functional is constructed that reveals the periodicity in ...

Energy Technology Data Exchange (ETDEWEB)

We have used polished stainless steel as a mirror substrate to provide focusing of soft x-rays in grazing incidence reflection. The substrate is bent to an elliptical shape with large curvature and high stresses in the substrate require a strong elastic material. Conventional material choices of silicon or of glass will not withstand the stress required. The use of steel allows the substrates to be polished and installed flat, using screws in tapped holes. The ultra-high-vacuum bender mechanism is motorized and computer controlled. These mirrors are used to deliver focused beams of soft x-rays onto the surface of a sample for experiments at the Advanced Light Source (ALS). They provide an illumination field that can be as small as the mirror demagnification allows, for localized study, and can be enlarged, under computer control,for survey measurements over areas of the surface up to several millimeters. The critical issue of the quality of the steel surface, polished and coated with ...

Energy Technology Data Exchange (ETDEWEB)

Amorphous metals have an atomic structure resembling that of glass, and have high strength, toughness, and excellent magnetic properties for transformer applications. This type of metal has the potential to reduce the core losses of electromagnetic apparatus by 70-75% compared to the best grain-oriented silicon iron currently used. If all 4 million distribution transformers now in service in Canada were replaced by the more efficient amorphous units, it is estimated that over 5.25 billion kWh of energy could be saved annually. The experience of the General Electric (GE) Company and other researchers with operation of amorphous transformers is described. GE first tried operating amorphous metal transformers on a utility distribution system in April 1982. The shell-type cruciform design showed stable, low-loss performance over eight years of service. GE and the Electric Power Research Institute cooperated on manufacturing and installing 25 ...

Energy Technology Data Exchange (ETDEWEB)

The MTX experiment was proposed in 1986 to apply high frequency microwaves generated by a free-electron laser (FEL) to electron cyclotron resonance heating (ECRH) in a high field, high density tokamak. As the absorption of microwaves at the electron cyclotron resonance requires high frequencies, the opportunity of applying a free-electron laser has appeal as the device is not limited to frequencies in the microwave or long millimeter wavelength regions, in contrast to many other sources. In addition, the FEL is inherently a high power source of microwaves, which would permit single units of 10 MW or more, optimum for reactors. Finally, it was recognized early in the study of the application of the FEL based on the induction linear accelerator, that the nonlinear effects associated with the intense pulses of microwaves naturally generated would offer several unique opportunities to apply ECRH to current drive, MHD control, and other plasma effects. It was ...

International Nuclear Information System (INIS)

We present and characterize an experimental system in which we achieve the integration of an ultrahigh finesse optical cavity with a Bose-Einstein condensate (BEC). The conceptually novel design of the apparatus for the production of BECs features nested vacuum chambers and an in vacuo magnetic transport configuration. It grants large scale spatial access to the BEC for samples and probes via a modular and exchangeable ''science platform.'' We are able to produce 87Rb condensates of 5x106 atoms and to output couple continuous atom lasers. The cavity is mounted on the science platform on top of a vibration isolation system. The optical cavity works in the strong coupling regime of cavity quantum electrodynamics and serves as a quantum optical detector for single atoms. This system enables us to study atom optics on a single particle level and to further develop the field of quantum ...

Energy Technology Data Exchange (ETDEWEB)

An atom-by-atom understanding of life processes is emerging from a flurry of experiments fueled by synchrotron sources and DNA technology. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}.

Energy Technology Data Exchange (ETDEWEB)

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 ...

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

Science.gov (United States)

Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.

UK PubMed Central (United Kingdom)

The United Kingdom Atomic Energy Authority mortality study was designed to investigate the relation between exposure to ionising radiation and mortality among the authority's employees. The present...Full Text Available

International Nuclear Information System (INIS)

English 2005 p. 52-59 International Atomic Energy Agency (IAEA) Collier,

International Nuclear Information System (INIS)

This patent describes a radioiodinated benzodiazepine derivative. It comprises a lower alkyl group with 1-4 C-atoms and a radioactive iodine.

International Nuclear Information System (INIS)

Experimental results on study of helium concentration influence on degree of molybdenum radiation hardening for various method of cyclotron doping differing in degree and damage character are presented. It is established that accumulation of helium atoms in molybdenum for simultaneous formation of radiation defects caused by low energetic primary-knocked atoms leads to higher degree of hardening than for high energetic ion irradiation. It is shown that with increase of helium atom concentration the degree of radiation hardening for the same level of damage increases. 4 refs.; 3 figs. (author).

Science.gov (United States)

... US Congress, Joint Committee on Atomic Energy, Development, Use, and Control ofNuclear Energy for the Common Defense and Security and for ...

Energy Technology Data Exchange (ETDEWEB)

We propose a scheme with potential experimental realization to generate 'polarization' entanglement between two atomic ensembles and show one of the applications - a novel secure communication allowing asymptotically key distribution and quasisecure direct communication. The scheme involves laser manipulation of atomic ensembles, adjustable quarter- and half-wave plates, beam splitters, polarizing beam splitters and single-photon detectors, and well fits the status of the current experimental technology.

International Nuclear Information System (INIS)

An apparatus allowing the photoexcitation of barium atomic beam over its whole surface is described. This photoexcitation is achieved by another barium spectrum emitted up steam of the beam by a cathodic out-flow produced at the exit oven. The fluorescence spectrum is studied in detail as well as the influence of different parameters, such as oven temperature, current intensity of the outflow, and excitation depth. A calculation shows how to determine Einstein coefficient, oscillator strengths and atomic lifetimes from our experimental measurements.

International Nuclear Information System (INIS)

A semi-empirical relation which can be used to determine the total attenuation cross sections of samples containing H, C, N and O in the energy range 145-1332 keV has been derived based on the total attenuation cross sections of several sugars, amino acids and fatty acids. The cross sections have been measured by performing transmission experiments in a narrow beam good geometry set-up by employing a high-resolution hyperpure germanium detector at seven energies of biological importance such as 145.4 keV, 279.2 keV, 514 keV, 661.6 keV, 1115.5 keV, 1173.2 keV and 1332.1 keV. The semi-empirical relation can reproduce the experimental values within 1-2%. The total attenuation cross sections of five elements carbon, aluminium, titanium, copper and zirconium measured in the same experimental set-up at the energies mentioned above have been used in a new matrix method to evaluate the effective atomic numbers and the effective electron densities of samples such as ...

International Nuclear Information System (INIS)

An 'electron-bridge' mechanism of nuclear reaction in an atom or ion by ultra-intense laser fields is presented. A preliminary estimate of the intensity dependence of the rate of disintegration reaction of deuteron nucleus in deuterium atom is made for 800 nm laser fields. For intensities below 5x1021 W/cm2, the rate of disintegration by the 'electron-bridge' mechanism is found to be small, but it rises sharply and becomes large already for ?1022 W/cm2.

Science.gov (United States)

In the first paper of this series a formal theory of atomic scattering of electrons in the presence of an intense electromagnetic field was given. Cross sections, near the forward direction, between atomic states (modified by the laser) were obtained. However, it was assumed that the atom could not emit spontaneous radiation. In this paper the effect of spontaneous radiation is included, and it is shown that in most cases the measured cross section will be a weighted average of the two different cross sections starting from the two different initial states which are those atomic states resonantly linked by the laser. The Born approximation for the scattering is obtained, and it is shown that for the simplest description of the spontaneous radiation field the effect of the laser on the cross sections is simply to multiply them by a factor which depends upon the laser detuning. (AIP)

British Library Electronic Table of Contents (United Kingdom)

A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500degreeC. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12wt.% Li and only 0.264wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.

Energy Technology Data Exchange (ETDEWEB)

The construction of networks consisting of optically interconnected processing units is a promising way to scale up quantum information processing systems. To store quantum information, single trapped atoms are among the most proven candidates. By placing them in high finesse optical resonators, a bidirectional information exchange between the atoms and photons becomes possible with, in principle, unit efficiency. Such an interface between stationary and ying qubits constitutes a possible node of a future quantum network. The results presented in this thesis demonstrate the prospects of a quantum interface consisting of a single atom trapped within the mode of a high-finesse optical cavity. In a two-step process, we distribute entanglement between the stored atom and two subsequently emitted single photons. The long atom trapping times achieved in the system together with the high ...

International Nuclear Information System (INIS)

An energy analyzer has been constructed and operated in UHV for the purpose of analyzing the energy of neutral atoms scattered from solid surfaces. The analyzer consists of a LiF single crystal located at an angle close to the normal to the sample crystal so that the diffraction pattern obtained by scanning the LiF crystal yields the energy of the scattered atoms. Two designs which have been used are described. The temperature of both sample and analyzer crystal is near 20 K and once cleaned they can be maintained in the state of initial preparation for many weeks. The sample was a (001) Cu surface in this case. Such an energy analyzer can only be used, in most cases, for He atom scattering although Ne atoms could be used if the scattered intensities were adequate. The detector developed in this study is able to detect about 2 x 10"5 atoms/s. The resolution of the spectrometer ...

International Nuclear Information System (INIS)

May 1972. United States Warren, FH Federal Power Commission,

International Nuclear Information System (INIS)

This is a manuscript for a lecture contents: 1. Steam power and fundamentals of the steam power process, 2. conventional, nuclear and other steam generation processes, 3. cooling systems for steam power plants, 4. gas turbine power plants and combined-cycle power plants, 5. cogeneration, 6. development of thermal power plants and environmental effects. (orig.).

Medline Plus

English - Downed Power Lines Click to Stop Video Click to Start Video To Listen to the Audio ...

International Nuclear Information System (INIS)

Reactor Power Measurement is an essential part of the Reactor Power Control Loop in PHWRs. None of the available power measuring sensor offers characteristics which allow their direct use in the Reactor Power Control Loop. Thermal power, which is considered as relatively accurate, suffers from measurement delays and is used only as reference. Neutronic power sensors like Ion Chambers and Self Powered Neutron Detectors (SPNDs) which sense instantaneous power suffer from inaccuracies. A technique is required which makes use of both types-reference power and instantaneous power to extract real power information from the signals. This paper describes techniques to calibrate (correct) neutronic power that with the thermal reference ...

International Nuclear Information System (INIS)

Korea Atomic Energy Research Institute, using the ASME PRA Standard, evaluated the PSA model of the Korea Standard Nuclear Power Plant (KSNP) and identified the items to be improved to enhance its quality. The new risk monitor PSA model for the KSNP of which quality was enhanced is called as PRiME-U3i. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the PSA model of the KSNP showed that 10 items among 19 items of supporting requirements for those in the ASME PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors for the KSNP PSA model as the target of grading its quality above ASME PRA Standard Category I+. Following tasks were additionally major tasks performed in the HRA of post-accident human errors of PRiME-U3i compared with the previous PSA model of the KSNP: interviews with operators in the collection and review of input data need ...

Energy Technology Data Exchange (ETDEWEB)

The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa-peri-hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from {sup 1}H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing {pi}-{pi} intermolecular contact in the hexakis-substituted FHBC 4. For bis-substituted FHBC compounds 5 and 6, {pi}-{pi} intermolecular contact was observed in ...

Energy Technology Data Exchange (ETDEWEB)

A method for determining the reactivity of highly subcritical systems of fissile material, using neutron-noise power spectral densities in conjunction with a /sup 252/Cf source, had previousy been tested in two fast reactor critical assemblies (a mockup of the Fast Flux Test Facility reactor and unreflected enriched uranium metal assemblies) and one thermal reactor (a light-water moderated and reflected lattice of Oak Ridge Research Reactor fuel elements). The last-mentioned test demonstrated the effectiveness of the method in water-moderated systems and thereby prompted the present study of its application to facilities for fuel preparation, reprocessing, and storage. To investigate the applicability of this method to facilities for fuel preparation, reprocessing, and storage, limited experiments were performed with a uranyl fluoride solution. The Los Alamos National Laboratory SHEBA facility, an unreflected cylindrical tank (56 cm diam), was partially filled with ...

Energy Technology Data Exchange (ETDEWEB)

Pipe whip tests or jet discharge tests have been performed at the Japan Atomic Energy Research Institute, which simulate the instantaneous circumferential guillotine break of primary coolant piping in nuclear power plants. The present paper describes the results of the pipe whip tests using test pipes of 4 inch diameter, under the BWR LOCA conditions, which were performed from 1979 to 1981. The tests were carried out at an initial pressure of about 6.8 MPa and an initial temperature of about 285/sup 0/C. The test pipe was 114.3 mm (4 in) in diameter, 8.6 mm in thickness and 4500 mm in length. The four pipe whip restraints used in the tests were the U-bar type of 8 mm in diameter and frabricated from Type 304 stainless steel. The experimental parameters were the clearance (30, 50 and 100 mm) and the overhang length (250, 400, 550 and 1000 mm). The main purpose of these tests is to investigate the effects of the clearance and the overhang length ...

International Nuclear Information System (INIS)

Various kinds of decontaminations are carried out in atomic power plant. Here current decontamination technologies such as chemical decontamination with chemical solution or blast decontamination have a problem of reduction of secondary radioactive waste generated in the decontamination process. On the other hand, a low pressure arc plasma can remove metal oxide film on the metal substrate without heavy damage on the metal substrate when the object to be treated was set as a cathode. Dry surface decontamination technology with using low-pressure arc plasma can decrease secondary radioactive waste because low-pressure arc plasma does not need any chemical solution. In addition, the time required for treatment can be shorter, so it is possible for the low-pressure arc plasma decontamination technology to interpolate the current decontamination technologies such as spot decontamination technology etc. Therefore we have been investigating the ...

Science.gov (United States)

Two plasma chemistries, i.e., CH{sub 4}/H{sub 2}/Ar and Cl{sub 2}/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH{sub 4}/H{sub 2}/Ar discharges appears to be ion driven, Cl{sub 2}/Ar discharges showed an additional strong chemical enhancement. The highest etch rate ({approximately}1 {mu}m/min) for InGaP was achieved at high ICP source power ({ge}750 W) with the Cl{sub 2}/Ar chemistry. Cl{sub 2}/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP ({approximately}100 {Angstrom}) with Cl{sub 2}/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH{sub 4}/H{sub 2}/Ar plasma chemistry produced ...

Energy Technology Data Exchange (ETDEWEB)

The world`s population of research reactors is growing old. Many have been adapted to serve new purposes over their lives, from testing materials for nuclear power programmes and supporting neutron physics experiments, to colouring gemstones, doping silicon and generating medical isotopes. In the first article of this survey of research reactor issues, Wilfried Krull from GKSS in Germany describes the effects on a reactor of supporting these changes in application as ``design ageing`` . Managing this and other symptoms of ageing to extend plant life is a key task for operators, and Krull discusses the efforts being made internationally to handle them. Eventually, terminal decline of one vital component can determine when a reactor has to be shutdown for refurbishment. For BR2 in Belgium, it was the beryllium matrix. Edgar Koonen from SCK-CEN explains work being done to replace it and extend reactor life for around 15 years. The Triga at the University of Austria`s ...

International Nuclear Information System (INIS)

In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the "1"3"7Cs-source with 10.4 GBq and "6"0Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form "1"3"7 Cs 1173.23 and 1332.51 keV"6"0 Co sources, and 14 peaks of "1"3"4Cs and "1"5"4Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show that the detection efficiency of gamma scanning system for 1 MeV gamma-ray is ...

International Nuclear Information System (INIS)

Interaction of the internal states of an atom with spatially dependent standing-wave cavity field can impart position information of the atom passing through it leading to subwavelength atom localization. We recently demonstrated a different regime of atom localization [Phys. Rev. A 72, 013820 (2005)], namely sub-half-wavelength localization through phase control of electromagnetically induced transparency. This regime corresponds to extreme localization of atoms within a chosen half-wavelength region of the standing-wave cavity field. Here we present further investigation of the simplified model considered earlier and show interesting features of the proposal. We show how the model can be used to simulate a variety of energy-level schemes. Furthermore, the dressed-state analysis is employed to explain the emergence and suppression of the localization peaks, and the peak positions ...

Energy Technology Data Exchange (ETDEWEB)

Poland intends to construct 2,000 MW of wind power systems during the next four years. This is the start of the Polish wind power industry. (orig.)

Science.gov (United States)

... Those functions are fundamental routines to build a power model for more complex circuits or functional blocks. ... 21 of 54 6. Memory Power Model ...

Energy Technology Data Exchange (ETDEWEB)

Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H/sup -/ or /sup 3/He/sup -/ ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams.

Energy Technology Data Exchange (ETDEWEB)

The production of polarized negative ion beams by ''collisional pumping'' is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.

Energy Technology Data Exchange (ETDEWEB)

Doubly-excited 2s{sup -1}2p{sup -1}3pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

Energy Technology Data Exchange (ETDEWEB)

Method for determining the concentration of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The concentration of the atomic species to be determined is then derived from the known emission intensity of a predetermined concentration of that species in the sample at the measured temperature, a quantity which is measured prior to the determination of the unknown concentration, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known concentration within the sample.

International Nuclear Information System (INIS)

The symmetry properties of the Coulomb potential allow for a dynamical spin-1/2 description of any fixed n level of a hydrogenlike atom in a time-dependent sufficiently weak electric and/or magnetic field. An explicit expression for the time dependence of the l,m amplitudes pertaining to a general n level is derived. The derivation follows on purely algebraic operations. Based on the derivation, we give analytical n-independent solutions to established and proposed schemes for driving the atom into a high angular-momentum state.

Energy Technology Data Exchange (ETDEWEB)

The total and differential atomic pair-correlation functions of an icosahedral (quasicrystalline) solid were determined for the first time, directly by the differential anomalous-x-ray-scattering technique using synchrotron radiation. The observed atomic distances involving uranium atoms in icosahedral Pd/sub 58.8/U/sub 20.6/Si/sub 20.6/ suggest the presence of a quasicrystalline sublattice with vertex decoration. The pair distribution functions in the icosahedral and amorphous phases are similar up to the second-nearest neighbors, or up to 6 A-circle.

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?(r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of ...

International Nuclear Information System (INIS)

A scheme of evaluating a generalized three-photon excitation cross section #sigma#/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p"6 "1S_0 state to the 3p"54s'[1/2]_1"0 state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of #DELTA##lambda#/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is #sigma#/sub (3)/ = 1.414 x 10/sup -80/ cm"6 s"2. .AE.

International Nuclear Information System (INIS)

The total interaction cross sections (#sigma#_t) of some sugars and amino acids and five elements: lithium, carbon, oxygen, aluminium and calcium have been measured for 6.4 keV, 13.95 keV, 14.4 keV, 17.74 keV, 24.14 keV, 30.8 keV, 35 keV, 59.54 keV, 81 keV, 122 keV and 136 keV photons in a narrow beam good geometry set up, by using high resolution detectors such as a Si-PIN diode detector and a high purity germanium detector. The #sigma#_t values have been used in a matrix method to evaluate the effective atomic numbers Z_e_f_f of the samples from their effective atomic cross sections #sigma#_a. The effective atomic cross section of a sample #sigma#_a is the total interaction cross section divided by the total number of atoms of all types in it. Further, a quantity called the effective atomic weight A_e_f_f of a sample was defined as the ratio of the molecular weight A to the total ...

International Nuclear Information System (INIS)

... Masahiro Tsukada, Takashi Japan Atomic Energy Agency, Tokai, Ibaraki (Japan)

British Library Electronic Table of Contents (United Kingdom)

Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80?keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted d...

Science.gov (United States)

... The insu- lation between gate and nanowire is the high-k dielectric HfO2, deposited by atomic layer depo- sition (ALD). ...

Science.gov (United States)

by the radionuclide X-ray fluorescence analysis into several groups according to the atomic number of the determined element. Table I documents this. ...

Energy Technology Data Exchange (ETDEWEB)

Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are ...

International Nuclear Information System (INIS)

(Jan 1974). United States Ashraf, M. Anwar, M. Siddiqui, QH Atomic Energy

Energy Technology Data Exchange (ETDEWEB)

The development of nano/molecular devices will require atomic-sized electrical contacts or nano metric conductors for wiring. As metal nano wires exhibit quantized conductance at room temperature, quantum transport effects will play an important role in the practical implementation of nano devices. As copper is currently used as interconnecting metal in standard microelectronics, the characterization of Cu nano wire properties deserves special attention. In this work, we show a detailed study of structural and electronic properties of atomic-sized Cu wires. In particular, we have established a complete correlation between the conductance and the structure by associating real-time atomic resolution transmission electron microscopy imaging with molecular dynamic simulations, conductance measurements and conductance calculations. Our study has revealed the structural relaxation of Cu wires forming a pentagonal ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

The homogeneity of a helium dielectric barrier discharge, working at atmospheric pressure and containing oxygen as contaminant, is assessed by mapping the spatial distribution of oxygen metastable atoms in relation to the uniformity of surface properties. Tunable diode laser absorption spectroscopy is used to monitor the time evolution of the absorption coefficient corresponding to the oxygen metastable atoms on the 35S2 level, as a function of the laser absorbing path, whereas bi-dimensional Abel transform is used to obtain local information on the space distribution of the metastable atoms in the discharge. The radial distribution of the surface properties is investigated using atomic force microscopy, contact angle measurement and X-ray photoelectron spectroscopy. The results show that ...

CERN Document Server

We study the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature topological first order phase transition occurs which arises from an interplay between initernal and kinetic atomic energies. It is shown that these phenomena are also captured for two and three dimensional optical lattices.

Science.gov (United States)

... AEC - Atomic Energy Commission (see CFSTI) AERE Harwell Lib The Librarian AERE, Ministry of Supply Harwell, Didcot, Birks England AF ...

Science.gov (United States)

... Kingdom Atomic Energy Authority, .... G. .. aphit. J..int. Report No. AERE R/M 165 (April, 1958). (2) Slaughter, G. M., Metallurgy ...

International Nuclear Information System (INIS)

(15 Jul 1974). United States Sweedler, AR Schweitzer, DG Webb, GW

Science.gov (United States)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?( r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of the F, Cl, Br, and I atoms to the thermodynamic characteristics of adsorption was performed for the nonspecific adsorption of these ...

International Nuclear Information System (INIS)

A very simple theoretical scheme is proposed to implement two- and three-qubit controlled-phase gates firstly only using a single resonant interaction between ladder-type three-level atoms and the single-mode cavity. In the presented protocol, the quantum information is encoded on the stable ground states of the atoms (as the controlling qubits) and the zero- and one-photon Fock states of cavity-field (as the target qubit). Under the influence of the atomic spontaneous emission, the decay of the cavity-mode, and deviation of the coupling strength, the three-qubit controlled-phase gate may have a comparatively high fidelity. The experimental feasibility of controlled-phase gate and the case that is extended to realize N-qubit controlled-phase gate are also discussed. (general)

ScienceCinema

...the effects of global warming ...

Energy Technology Data Exchange (ETDEWEB)

The development of a high power density sodium sulphur battery with a five-year maintenance-free life is described. These batteries are likely to be used in industrial trucks, milk floats, electric cars, storing power station output and power for satellites. (U.K.).

Norwegian Open Research Archives (NORA)

Full Text Available

Norwegian Open Research Archives (NORA)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The research will characterize and evaluate advanced S-CO2 Brayton cycle power generation with a modular power tower CSP system.

Science.gov (United States)

... by USAFRICOM enable the geographic combatant commander to incorporate all elements ofnational power by using the Smart Power model. ...

Science.gov (United States)

Sunflower 3 kW mercury Rankine power conversion system

Science.gov (United States)

... Accession Number : ADA350829. Title : Operational Characteristics of a Liquid Nitrogen Powered Automobile. Descriptive Note : Master's thesis. ...

Science.gov (United States)

... measurement. Power spectral density measurements are made by the dynamic signal analyzer for each channel. A cross power ...

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with the application of a new fuzzy inference method to the design of fuzzy power system stabilizer. Based on Truth-Value-Flow-Inference (TVFI), a fuzzy logic controlled power system stabilizer is proposed to enhance the stability of power system with weak or negative damping. The design of the proposed fuzzy power system stabilizer is presented. Numerical simulation results are presented and compared with two other kinds of fuzzy power system stabilizers. (author)

Science.gov (United States)

Offers an updated version of French and Raven's bases of social power model and describes Raven's power/interaction model of interpersonal influence. Applies elements of both models to school consultation practices. Explores social power and influence occurring during school consultation. Describes a research agenda for further exploration of social power within consultation. (RJM)

Energy Technology Data Exchange (ETDEWEB)

There are 13 Electron Beam Ion Sources in operation which produce highly charged ions, up to Th[sup 80+] and Xe[sup 53+]. Most of the sources are used to study these ions under electron impact or when recombining with gaseous or solid targets. That provides an insight into the atomic physics of these highly charged ions and into the physics of the plasma in which such ions can be found. This paper reviews the present knowledge of atomic processes, important in the production of such ions with an EBIS.

International Nuclear Information System (INIS)

By the methods of the angular distribution of photon annihilation, time distribution of photon annihilation, photoluminescence spectroscopy, Fourier IR-spectroscopy, atomic force microscopy the detail information on relation of the structural and physical properties of the porous nano-structures is obtained. Study of pores sizes in a different nano-porous materials, such as the porous silicon, porous anode aluminium oxide, porous solids exposed to light atoms ion implantation (hydrogen, deuterium, helium) is carried out.

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during April 1984 from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Director's Decisions (DD), and the Denials of Petitions For Rulemaking (DPRM).

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during January 1984 from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

Science.gov (United States)

A report is presented of a hearing conducted before the Joint Committee on Atomic Energy on August 27, 1976, to discuss the legal implications for reactor licensing resulting from court challenges to procedures for assessing the environmental impact of radioactive waste disposal. (DG)

International Nuclear Information System (INIS)

Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The hyperfine structure of Am atoms was investigated in an atomic beam by laser spectroscopy. The observed splittings were evaluated with respect to the magnetic dipole and electric quadrupole moments of /sup 242m/Am. The results are: ..mu../sub I/(/sup 242m/Am) = +0.97(5) nm, Q(/sup 242m/Am) = +6.5(2.0) b.

Energy Technology Data Exchange (ETDEWEB)

Collisional-Radiative numerical models are commonly used to design or interpret experiments in atomic physics of laser-created plasmas, including X-ray laser studies. We describe our new code containing several options: average ion, more or less detailed configurations. It consists of an atomic data base coupled to subroutines evaluating ionic populations and emission and absorption coefficients. Numerical results are given to illustrate the capabilities of the code and to compare different models and types of approximation.

International Nuclear Information System (INIS)

In this paper, we show that boron transient enhanced diffusion can be reduced to different extents by varying the distribution of nitrogen atoms in the junction. This is attributed to the relative location of nitrogen atoms with respect to boron profile and end-of-range defect band, affecting the interactions between dopants and defects upon annealing. In addition, variations in boron dopant activation and deactivation are also observed. Similar to fluorine co-implantation, it is proposed that nitrogen atoms react with vacancy point defects to form nitrogen-vacancy clusters that will trap the interstitials emitted from end-of-range defects. However, we report that the interstitial sink efficiency of nitrogen atoms is not as good as the co-implanted carbon atoms, which is noticed from the dopant deactivation curves. In terms of extended defect evolution, the results clearly indicate ...

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from February 16, 1990 through February 15, 1993. This work involves the experimental investigation of atomic interactions in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron-correlation effects. The processes studied are of interest both from fundamental and applied points of view. In the latter case, results are obtained which are relevant to the understanding of laboratory and astrophysical plasmas, highly-excited (Rydberg) and continuum states of atoms and ions, atomic structure effects, the interaction of ions with surfaces, and the development of heavy-ion storage-rings. The results obtained have provided the basis for several M.A. thesis projects at Western Michigan and several ...

CERN Document Server

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several ...

International Nuclear Information System (INIS)

The paper describes transportation cost of the nuclear off-peak power for a hydrogen production based on water electrolysis in Japan. The power could be obtainable by substituting hydropower and/or fossil fueled power supplying peak and middle demands with nuclear power. The transportation cost of the off-peak power was evaluated to be 1.42 yen/kWh when an electrolyser receives the off-peak power from a 6kV distribution wire. Marked reduction of the cost was caused by the increase of the capacity factor. (author)

Energy Technology Data Exchange (ETDEWEB)

All power plant engineers face the problem of peak power demands. Pumped storage plants are used to generate peak load power by pumping up water utilizing off-peak energy of hydrothermal and thermonuclear plants. This is the first accessible text/reference to cover hydroelectric power generation with emphasis on engineering to meet peak power demands by means of pumped storge plants, tidal power plants, and low head power generation. Text covers hydrology, mechanical and electrical equipment, accessories such as penstocks and valves, and civil engineering considerations. Contains descriptions of several existing plants. Includes 200 diagrams and 50 photographs.

Energy Technology Data Exchange (ETDEWEB)

Fuel cell vehicles have been identified as the personal transportation technology of the future because of their high efficiency and very low emissions. To achieve the goal of road-ready fuel cell vehicles, great strides must be made in the development of fuel cells, hydrogen production and hydrogen storage technologies, that includes metal-H interaction studies and safety considerations. The interaction between two-hydrogen atoms and a {gamma}-Fe structure containing a vacancy has been studied using a cluster model and a theoretical method. For the study of the sequential absorption, the hydrogen atoms were positioned in their energy minima configurations, near the vacancy. The interactions mainly involve Fe 4s-H 1s atomic orbitals. The contribution of Fe 4p and Fe 3d orbitals is much less important. The Fe-Fe bond is weakened as new Fe-H-H and H-H pairs were formed. The effect of H atoms is limited to ...

International Nuclear Information System (INIS)

The present volume on energy and the environment discusses space power requirements, space power systems, space power systems hardware, space radioisotope systems, space solar arrays, space solar cells, space station power, and terrestrial applications of aerospace technology. Attention is given to NASA future space power requirements and issues, the design of a battery charger for the NASA EOS Space Platform, in situ carbon dioxide fixation on Mars, and a preliminary design update of the CRAF/Cassini Power Subsystem. Topics addressed include concentrator testing using projected images, solar power satellites and demonstraton platforms from nonterrestrial materials, a mass sensitivity analysis of lunar orbiting beam power systems, and a power-beaming-based infrastructure for space ...

International Nuclear Information System (INIS)

Various diagnostics techniques for condition monitoring and life prediction of fluid power components and system are discussed. Though some of the techniques are very promising but may not be accepted because of increase in the instrumentation, it is planned to implement these techniques on various circuits of Fluid Power Lab for further improving and developing these for direct implementation in various fluid power circuits of power reactors. (author). 6 figs.

Energy Technology Data Exchange (ETDEWEB)

A mathematical model of the multi machine electric power system to analyse its dynamics has been worked out. The effectivity of the power system stabilizer developed in the one machine system has been tested by means of this model. The influence of the arrangement of the stabilizers on the stability of the electric power system has also been investigated. High damping of electromechanical transient processes has been achieved. 7 refs., 1 tab., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

The report describes the following: overview of the Russian power industry; electric power equipment of Russia; power industry development forecast for Russia; clean coal technology demonstration program of the US Department of Energy; reduction of coal TPS (thermal power station) environmental impacts in Russia; and base options of advanced coal thermal power plants. Terms of the application of clean coal technology at Russian TPS are discussed in the Conclusions.

CERN Document Server

Properties of a two-level atom coupled to the quantized electromagnetic field at finite temperature are studied. The analysis is based on a new method (inspired by QED) of describing qubits, developed previously by us at zero temperature (Phys. Rev. A 76, 062106 (2007)). In this paper, we make a generalization to finite temperature by introducing the Matsubara formalism and the temperature propagators. We analyze the spectral properties of different types of propagators and we derive a direct connection between the temperature propagators and the real time propagators. To show the effectiveness of this method, we calculate the temperature dependence of the polarizability of a two-level atom in the lowest order of perturbation theory and we predict an unexpected sharpness in the resonance behavior. The whole discussion is carried out without making the rotating wave approximation.

International Nuclear Information System (INIS)

The evolution of metallic substance atomic structure is studied on temperature variation including crystal heating up to melting points, a crystal- liquid phase transition and initiation of a high-density liquid specific structure. It is marked that heat induced changes of simple metal structure can be described as changes around a natural elementary cell which is common for both a crystal and a liquid and consists of a central atom and Z_1 atoms of the first coordination sphere. On this basis the vacancy model of melting is verified. Concentrations of melting vacancies are determined by coordination numbers in the form of Z_1/(1+Z_1)"2 which are the same for both a crystal and a natural elementary cell. The size of natural elementary cells is in an agreement with that of the coordination sphere featured in the liquid and phase transition statistical theory. Calculated data are given for a number of metals, Cs, Eu, Ni, V ...

CERN Document Server

We study the stability of the circular orbits of the electromagnetic two-body problem of classical electrodynamics. We introduce the concept of resonant dissipation, i.e. a motion that radiates the center-of-mass energy while the interparticle distance performs bounded oscillations about a metastable orbit. The stability mechanism is established by the existence of a quartic resonant constant generated by the stiff eigenvalues of the linear stability problem. This constant bounds the particles together during the radiative recoil. The condition of resonant dissipation predicts angular momenta for the metastable orbits in reasonable agreement with the Bohr atom. The principal result is that the emission lines agree with the predictions of quantum electrodynamics (QED) with 1 percent average error even up to the $40^{th}$ line. Our angular momenta depend logarithmically on the mass of the heavy body, such that the deuterium and the muonium atoms ...

Energy Technology Data Exchange (ETDEWEB)

This paper attempts to explain the peculiarities of the radial-distribution function of metal glasses without involving ideas of the amorphous structure. On a computer, the radial atomic density for a spherical eutectic single crystal of the composition Fe/sub 84/C/sub 16/ of radius 15 A formed by alternating small crystals of e-Fe and Fe/sub 3/C of cubic form with the edge of the cube ca 10 A. For the sake of clarity, the diagram of such a quasisingle crystal is shown and has been given a cubic boundary. The change in the relationship between the heights of the subpeaks of the second maximum of the radial distribution function of atoms in the Fe-B glasses with a change in the concentration of boron can be explained by the change in the space group of the Fe/sub 3/B metastable boride which is formed in this system.

International Nuclear Information System (INIS)

There have been several reports of transient-enhanced diffusion during furnace or rapid thermal annealing of ion-implanted silicon and some reports of no enhancement. In this contribution, the authors show that many of the observed effects can be accounted for by an interstitial trapping mechanism, in which large numbers of Si atoms are trapped by group V dopant atoms in the amorphous material during implantation. These trapped atoms are retained during solid-phase-epitaxial (SPE) growth, but can be released later during thermal processing to give the transient-enhanced diffusion. The authors present a model which can predict the transient effects (or lack of them) for any concentration of Sb, Bi, or As dopants sufficient to amorphize the silicon and any thermal processing technology which relies on SPE growth (furnace, cw laser, or rapid thermal annealing).

Energy Technology Data Exchange (ETDEWEB)

Changes in mass density of amorphous Pd{sub 80}Si{sub 20} were monitored in situ during irradiation with He{sup 2+} and H{sup +} ions at temperatures below 100 K and during subsequent thermal treatment. The mass density decreased with increasing ion fluence and exponentially approached a saturation value of -1.2%, corresponding to a recombination volume of 190 atomic volumes. The initial swelling rate was 2.3 atomic volumes/displaced atom. The mass density of the irradiated material increased during subsequent thermal treatment, and the irradiation-induced decrease of the mass density recovered completely at room temperature.

Energy Technology Data Exchange (ETDEWEB)

A detailed comparison of the softness of gold and silver has been reported in the light of hard soft acid base (HSAB) principle. Gold and silver nanoparticles in organic media (i.e., organosol) have been exploited individually to establish the principle. Sulfur and nitrogen were employed as soft and borderline donating atoms to examine the metal-ligand interactions. In this regard, thiols and amines have been considered as interacting ligands with sulfur and nitrogen donor atoms respectively. The stronger affinity of gold towards softer sulfur donor as compared to nitrogen and conversely a reasonable interaction of silver nanoparticles with both the atoms authenticate the softer nature of gold nanoparticle as compared to silver one.

International Nuclear Information System (INIS)

Applying diode-laser resonant fluorescence method, the cross sections for the excitation energy transfer of the collisional process K"*(4"2P_1_/_2)+Cs(6"2S_1_/_2)#reversible#K"*(4"2P_3_/_2)+Cs(6"2S_1_/_2) have been measured. The values we have obtained are #sigma#(1/2#->#3/2)=77 A"2 and #sigma#(3/2#->#1/2)=48 A"2. These results complete the sequence of data for the fine-structure mixing of the first-resonance states of alkali atoms colliding with the ground-state caesium atoms. (orig.).

International Nuclear Information System (INIS)

Electron charge distributions are presented for Nb_3Ge, Nb_3Al, and two other hypothetical A-15 structures. Results indicate that the bonding in these materials is mainly metallic in character with some covalentlike bonding between Nb-chain atoms. We find significant coupling between neighboring chains and also between chain atoms and atoms at the cubic site. Comparison is made with various theoretical models. Investigation of the charge character of states near E/sub F/ suggests further developments in current theories on the structural transformation of A-15 compounds. The effect of chain dimerization on electronic states and charge distribution of Nb_3Ge is also investigated.