Energy Technology Data Exchange (ETDEWEB)

We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.

Energy Technology Data Exchange (ETDEWEB)

Recently, a drive laser for an S-band (2.86 GHz) rf photoinjector, designed to provide a pulse that has a flat temporal and spatial profile, has been built, commissioned, and put into service as part of the LLNL Compton-scattering monoenergetic {gamma}-ray source program. This laser is based on an all-fiber oscillator and front-end amplification system, and provides both the laser light to generate the electrons as well as the rf signal that is amplified to accelerate them. Now, a new 11.424 GHz photoinjector is being developed, which has required a revised design for the laser system. The higher frequency has placed more stringent requirements on the synchronization stability, delivered pulse length, and pulse rise times to maintain the desired emittance. Presented here are the overall design and measured performance of the current system and a discussion of what changes are being ...

CERN Document Server

Multi-Harmonic RF Control System for J-PARC RCS

Energy Technology Data Exchange (ETDEWEB)

The great advantage of the helical ionization cooling channel (HCC) is its compact structure that enables the fast cooling of muon beam 6-dimensional phase space. This compact aspect requires a high average RF gradient, with few places that do not have cavities. Also, the muon beam is diffuse and requires an RF system with large transverse and longitudinal acceptance. A traveling wave system can address these requirements. First, the number of RF power coupling ports can be significantly reduced compared with our previous pillbox concept. Secondly, by adding a nose on the cell iris, the presence of thin metal foils traversed by the muons can possibly be avoided. We show simulations of the cooling performance of a traveling wave RF system in a HCC, including cavity geometries with inter-cell RF power couplers needed for ...

Energy Technology Data Exchange (ETDEWEB)

The authors present design methodology and initial experimental results for a high power microwave switch. The switch is designed for application to the pulse compression system associated with the Next Linear Collider Test Accelerator (NLCTA). The switch is based on the excitation of a plasma layer within a silicon wafer by either a laser or an electron beam. They investigate problems associated with high power operation of such a switch. They explore solutions to the problems of thermal runaway, avalanche breakdown, photo-emission, and secondary emission.

Energy Technology Data Exchange (ETDEWEB)

In the rf-driven free-electron laser (FEL) at the Los Alamos National Laboratory, there are two pulsed-power rf modulators as sources for two tandem, side-coupled 20-MeV linear accelerators. The rf power used to control the cavity fields is supplied by two 5.5-MW modulating anode klystrons operating at a center frequency of 1300.2 MHz. The modulation of the 125 kV klystron is achieved by using a triode switch tube that provides a pulse width up to 300 ..mu..s and a pulse repetition rate up to 10 Hz. This paper describes the present configuration of these two duplicate systems and presents plans for meeting the requirements of future rf FEL experiments at Los Alamos. 12 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

... of the loop filter based on ... algorithms, including delta-sigma approaches, routinely uses double-precision floating point number representations for ...

International Nuclear Information System (INIS)

We have already developed three conventional and one periodic permanent (PPM) type 50-MW class klystrons, a smart modulator, and the first HOM-free accelerator structure (Choke-mode type, full-scale high power model). A very stable ceramic high voltage monitor was successfully tested up to 367-kV with a 4.5-#mu#sec pulse. A new C-band SiC type high power rf-load, advancing the power handling capability up to 50-MW is now being designed. It should have excellent mass production characteristics as it uses circularly symmetric TM_0_1_1 chained cavities. The first high power prototype of an rf compressor cavity made of a low thermal expansion material (super Invar) was designed to provide stable operation even with a very high Q of 200-k, it was successfully tested the output rf power up to 135-MW, 0.5-#mu#sec pulse width and 50-pps repetition rate. The C-band linac rf-system will be used for the SASE-FEL ...

International Nuclear Information System (INIS)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 #mu#s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2_0, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, ...

International Nuclear Information System (INIS)

The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements.

International Nuclear Information System (INIS)

The macrotemporal structure of the Super-ACO Storage ring free-electron laser (FEL) can be either continuous, pulsed, or chaotic, and can present some rapid fluctuations. The temporal evolution of a storage ring FEL involves both the longitudinal motion of the positron beam (especially the synchrotron oscillations) and the FEL dynamics, as in a coupled system. Studies on the dynamics of the positron beam are performed here, in the goal to have a stable source for FEL applications, and to determine the conditions for a stable Q-switching experiment. The employed method is to study the influence of a controlled change of the radio frequency (RF) (modulation or frequency jump) on the beam. A simple theoretical model taking into account the perturbed RF system is presented to help the understanding of the experimental data. The different methods of measurement are described. Then, the results are given for ...

International Nuclear Information System (INIS)

The electromagnetic properties of a prototype gravitational wave detector, based on two coupled superconducting microwave cavities, were tested. The radio-frequency (rf) detection system was carefully analysed. With the use of piezoelectric crystals small harmonic displacements of the cavity walls were induced and the parametric conversion of the electromagnetic field inside the cavities explored. Experimental results of bandwidth and sensitivity of the parametric converter versus stored energy and voltage applied to the piezoelectric crystal are reported. A rf control loop, developed to stabilize phase changes on signal paths, gave a 125 dBc rejection of the drive mode on a time scale of 1 h.

Science.gov (United States)

One-electron reduction of the square-planar nickel precursor (PNP)NiCl ( 1) (PNP (-) = N[2-P(CHMe 2) 2-4-methylphenyl] 2) with KC 8 effects ligand reorganization of the pincer ligand to assemble a Ni(I) dimer, [Ni(mu 2-PNP)] 2 ( 2), containing a Ni 2N 2 core structure, as inferred by its solid-state X-ray structure. Solution magnetization measurements are consistent with a paramagnetic Ni(I) system likely undergoing a monomer dimer equilibrium. The room-temperature and 4 K solid-state X-band electron paramagnetic resonance (EPR) spectra display anisotropic signals. Low-temperature solid-state X-band EPR data at 4 K reveal rhombic values g z = 1.980(4), g x = 2. 380(4), and g y = 2.225(4), as well as a forbidden signal at g = 4.24 for the Delta M S = 2 half field transition, in accord with 2 having two weakly interacting metal centers. Utilizing an S = 1 model, full spin Hamiltonian simulation of the low-temperature EPR ...

Science.gov (United States)

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to ...

International Nuclear Information System (INIS)

The magnicon is a highly attractive candidate to be the RF source for a future multi-Tev linear collider. Physical models and computer codes have been developed which can provide start-to-end self-consistent simulations of a magnicon, including precise simulations of the high-convergence electron gun, RF-system, magnetic system, and beam collector. The 3-D beam dynamics simulations include realistic fields, finite beam size and transverse space charge effects. The codes allow one to provide steady-state simulations of the entire tube, so as to evaluate transient process of magnicon excitation, parasitic mode self-excitation, stability analysis, and tolerance analysis. The results of the simulations are found to be in good agreement with magnicon experiments. A brief description of the physical models and simulation codes employed will be given.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum-related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of ...

CERN Multimedia

This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

Energy Technology Data Exchange (ETDEWEB)

In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

Energy Technology Data Exchange (ETDEWEB)

This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.

Science.gov (United States)

The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist. To minimize the interference between the MR imaging system and the motion measurement system, nonmagnetic materials were used for all electric circuit components in an MR shield room. To remove the effect of RF ...

International Nuclear Information System (INIS)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of "1"3"7Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). ...

Energy Technology Data Exchange (ETDEWEB)

The design of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak (R{sub 0} = 1.8 m, a= 0.5 m, {kappa} = 2, {delta} = 1.8 B{sub T} = 3.5 T, I{sub p} 2 MA, {tau}{sub pulse} = 300 s) is being undertaken to do long-pulse. high {beta}, advanced tokamak operating-mode fusion physics experiments. The ion cyclotron (IC) system will deliver 6 MW of rf power to the plasma in the 25 - 60 MHz frequency range, using a single four-strap antenna mounted in a midplane port. It will be used for ion heating, fast-wave current drive (FWCD), and mode conversion current drive (MCCD). The phasing between current straps in the antenna will be adjustable quickly during operation to provide the capability of changing the current-drive efficiency. The IC system will be capable of 300 s operation with 12 MW (upgrade) of rf power to the plasma. (author)

Energy Technology Data Exchange (ETDEWEB)

Modifications to the reference concept were studied and the best approaches defined. The impact of the high efficiency multibandgap solar array on the reference concept design is considered. System trade studies for several solid state concepts, including the sandwich concept and a separate antenna/solar concept, are described. Two solid state concepts were selected and a design definition is presented for each. Magnetrons as an alternative to the reference klystrons for dc/rf conversion are evaluated. System definitions are presented for the preferred klystron and solid state concepts. Supporting systems are analyzed, with major analysis in the microwave, structures, and power distribution areas. Results of studies for thermal control, attitude control, stationkeeping, and details of a multibandgap solar cell study are included. Advanced laser concepts and the meteorological effects of a laser beam ...

CERN Document Server

The International Linear Collider Main Linacs are based on superconducting accelerator structures operating at 1.3 GHz. The basis for this design has been developed and tested at DESY and R&D is progressing at many laboratories around the world including DESY, Orsay, KEK, FNAL, SLAC, Cornell, and JLAB. The status of the TESLA-style cavities and rf system will be reviewed and parameters for the ILC linac will be described. The role of the different linac test facilities will discussed and the critical items and R&D program to support a Conceptual Design and Technical Design will be outlined.

International Nuclear Information System (INIS)

A microwave hydrogen ion source was developed to improve reliability, and to increase operation time of proton linac application systems. The ion source needs no filament in the discharge chamber, which leads to better reliability and less maintenance time. The developed source produced a maximum hydrogen ion beam current of 70 mA (high current density of 360 mA/cm2, beam energy of 30 keV) with a 5 mm diam extraction aperture and 1.2 kW microwave power. The proton fraction was increased with an increase in rf power and reached around 90% at 1 kW. Measured 90% beam normalized emittance was 0.4 #pi# mm mrad. Rise times of rf power and beam current to 90% of the final values were about 30 and 35 #mu#s, respectively, at a pulse operation mode with 400 #mu#s pulse width and 100 Hz repetition rate. The dynamic range of beam currents was enlarged (3-63 mA) in the pulse mode with a modified rf wave form to ...

International Nuclear Information System (INIS)

Whether exposure to electromagnetic fields (EMFs) cause cancer has been vigorously debated for many years and has been the most vexing issue with which ICNIRP has had to deal during its short existence. There have been three parts of the electromagnetic spectrum that the issue of cancer has raised: static (0 Hz) magnetic fields, extremely low frequency (ELF) fields (defined as > 0-300 Hz, but concerns have been raised almost exclusively at the power frequencies of 50/60 Hz), and radiofrequency (RF) fields (300 Hz -300 GHz). By far the major problems have arisen during the construction of new high voltage transmission lines and mobile telephone systems. Actions by protest groups concerned with possible health effects, especially with cancer in children, has now reached such a scale that it is costing electrical utilities and communications companies billions of dollars annually world-wide. With such high stakes, ICNIRP has had to be extremely ...

Energy Technology Data Exchange (ETDEWEB)

Operating the Stanford Linear Collider (SLC) at 120Hz repetition rate requires the presence of two bunches in both the electron and the positron damping ring. The {pi}-mode instability, a coupled bunch instability where the two bunches oscillate with a phase difference of 180{degrees}, had been observed in both rings with low current thresholds of 7{sup *}10{sup 9} particles per bunch. To avoid the instability, the RF system had to be operated in ways which in general reduced the cavity gap voltages and required constant operational attention. For the 1992 running cycle a passive cavity was installed and successfully tested. It is tuned to the frequency of the lower synchrotron oscillation sideband of an odd revolution harmonic. The impedance of the cavity then damps {pi}-mode oscillations very similar to the Robinson damping provided by the main RF cavities which damps O-mode synchrotron oscillations. In this report we ...

International Nuclear Information System (INIS)

Short communication. 12 refs., 1 fig.

Energy Technology Data Exchange (ETDEWEB)

Smart metering is required by the EU and will be implemented in Germany during the next few years, but customers are not much interested in ''intelligent meters''. Displays and information services may ensure higher acceptance and additional use and provide an incentive for saving energy. In a pilot programme in BAvaria, Eon tested the customers' reaction to such a system. Smart metering technology and long-wave services were combined into an overall system that helps customers save energy. (orig.)

International Nuclear Information System (INIS)

The heating and current drive systems are being developed to support long pulse, high #beta#, advanced tokamak fusion physics experiments in the KSTAR tokamak. The heating and current drive systems consisting of neutral beam injection (NBI), ion cyclotron waves (ICRF), lower hybrid waves (LHCD) and electron cyclotron waves (ECH/ECCD) have been designed to operate for pulse lengths up to 300 sec and to provide a range of control functions including current drive and profile control. Development of key technologies for high power, long pulse operation has been on going. Substantial progress has been made on areas such as RF launchers, ion source, and high power supplies.

Energy Technology Data Exchange (ETDEWEB)

The high repetition rate and low single-pass gain inherent in an rf-driven Free Electron Laser (FEL) dictate that the laser system be configured as an oscillator. This allows the laser's electric field to build up over many passes around a high Q cavity. By way of contrast, the high-current capability of the Induction Linac (IL) system permits high single-pass optical gain, but the relatively low duty factor precludes oscillator operation; the pulses are neither long enough nor often enough to permit a field to accumulate in a cavity. The IL is thus configured as a MOPA (master oscillator/power amplifier) with a conventional laser serving as the MO. This report concentrates on the status of IL-driven FEL research at LLNL and gives a description of several applications for the high-peak-power radiation produced by an induction linac FEL.

Energy Technology Data Exchange (ETDEWEB)

We describe a fully automated bead puller system which uses stepping motors to position the bead, and an HP-8510 network analyzer to measure the resulting frequency shifts, both devices being under computer control. Longitudinal motion of the bead is used for measurement of cavity shunt impedance. In addition, azimuthal scans at fixed longitudinal position aid in determining the multipole character of higher-order modes. High sensitivity/accuracy is made possible by measuring phase shifts at the unperturbed resonant frequencies (rather than frequency shifts themselves), thereby permitting averaging factors of > 500 with only modest increases in data acquisition time. Sample measurements will be presented. A comprehensive analysis of the experimental results is presented in an accompanying paper.

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.

International Nuclear Information System (INIS)

The total bolometrically measured plasma radiation losses on the RF heating power were found. The results of measurements demonstrate a nonmonotonic dependence of radiation losses on RF power. Namely, at low RF power levels (80...170 kW) the total radiation losses raised with increasing the RF power. However, the total radiation losses decreased sharply when RF power exceeded 200 kW (down to ?20 kW at 240 kW of RF power). Simultaneously, the intensity of impurity lines fell down significantly, whereas the average electron temperature (found from ECE measurement) increased. The authors consider that screening properties of periphery plasma give reasons for above experimental facts.

International Nuclear Information System (INIS)

The aim of the risk assessment consists of a comparative security evaluation for the SNR-300 and the PWR Biblis B. The failure analysis focusses on the reactor core; in addition, possible fission product release from the spent fuel pits is examined. By reliability analyses, the frequency of events leading to incidents is determined together with the probability of core destruction. In the accident analysis, the kind and frequency of failure of the activity barriers, i.e., primary system (reactorvessel) and inner and outer containment are investigated for the various incident sequences. The radionuclide release into the environment is classified into five different release categories. Besides internal failures, external causes (especially earthquakes and plane crashes) are considered under the aspect of their risk contribution. (RF).

International Nuclear Information System (INIS)

Point contact Josephson junctions can function as millimeter wave heterodyne mixers with conversion gain. The best results achieved thus far show a single sideband conversion gain of 1.3 and a mixer contribution to the system noise temperature of 54"0K. Both of these results are approximately 5 times better than the best published figures for cooled Schottky barrier diode mixers operated at the same frequency. The measured noise for a variety of junctions can be expressed as a universal function of the normalized rf frequency #OMEGA# = h#omega#/2eI/sub c/R. It is about a factor 2 larger than the calculated noise arising from the thermal noise in the junction shunt resistance, R. The noise calculation was done for the resistively shunted junction model using an analog junction simulator.

Energy Technology Data Exchange (ETDEWEB)

The LANL 2.5-cell, normal-conducting radio-frequency (NCRF) injector has been fabricated. We present initial results of low-power RF measurements (cavity Q, cavity field map, coupling beta, etc.) of the NCRF injector. The measured cavity Q and relative fields are found to be in good agreement with the design calculations and earlier measurements of Glidcop properties. However, the coupling beta of the ridge-loaded waveguides is found to be significantly higher than the design point. The impact of these low-power measurement results on the planned high-power RF and electron beam tests will be discussed.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

A new technique is described in this paper for a general active radio frequency (RF) filter trap that can be used for suppressing noise or interference on high voltage (HV) transmission lines. The technique exploits the Miller effect of an RF amplifier in conjunction with a special sensing circuit, and is potentially far more economical to implement than conventional techniques that use passive HV filter components.

International Nuclear Information System (INIS)

Acute pneumothorax is a frequent complication after percutaneous pulmonary radiofrequency (RF) ablation. In this study we present three cases showing delayed development of pneumothorax after pulmonary RF ablation in 34 patients. Our purpose is to draw attention to this delayed complication and to propose a possible approach to avoid this major complication. These three cases occurred subsequent to 44 CT-guided pulmonary RF ablation procedures (6.8%) using either internally cooled or multitined expandable RF electrodes. In two patients, the pneumothorax, being initially absent at the end of the intervention, developed without symptoms. One of these patients required chest drain placement 32 h after RF ablation, and in the second patient therapy remained conservative. In the third patient, a slight pneumothorax at the end of the intervention gradually increased and led into tension ...

Energy Technology Data Exchange (ETDEWEB)

The use of deuterium-tritium fuel in the Compact Ignition Tokamak will require applying remote handling technology for ex-vessel maintenance and replacement of machine components. Highly activated and contaminated components of the fusion devices auxiliary systems, such as diagnostics and RF heating, must be replaced using remotely operated maintenance equipment in the test cell. In-vessel remote maintenance included replacement of divertor and first wall hardware, faraday shields, and for an in-vessel inspection system. Provision for remote replacement of a vacuum vessel sector, toroidal field coil or poloidal field ring coil was not included in the project baseline. As a result of recent coil failures experienced at a number of facilities, the CIT project decided to reconsider the question of remote recovery from a coil failure and, in January of 1990, initiated a coil replacement study. This study focused on the ...

CERN Document Server

Phase II collimators will complement the existing system to improve the expected high RF impedance and limited efficiency of Phase I jaws. An international collaborative effort has been launched to identify novel advanced materials responding to the very challenging requirements of the new collimators. Complex numerical calculations simulating extreme conditions and experimental tests are in progress. In parallel, an innovative modular design concept of the jaw assembly is being developed to allow fitting in alternative materials, minimizing the thermally induced deformations, withstanding accidents and accepting high radiation doses. Phase II jaw assembly is made up of a molybdenum back-stiffener ensuring high geometrical stability and a modular jaw split in threes sectors. Each sector is equipped with a high-efficiency independent cooling circuit. Beam position monitors (BPM) are embedded in the jaws to fasten setup time and improve beam ...

Energy Technology Data Exchange (ETDEWEB)

Clinical studies have proved the effectiveness of local ablading methods in pations with non-resectable liver metastases of a colorectal carcinoma. RF ablation and LITT are a potentially curative therapy option and an alternative to systemic chemotherapy; the latter is carried out primarily for reducing tumour size with the goal of secondary resectability. The number of R0-sesectable metastases can be enhanced by a combined therapy of surgery and local ablading methods, e.g. by preoperative, intraoperative or postoperative ablasion of further non-resectable tumours during surgery. Systemic chemotherapy combined with surgery as an adjuvant method is not recommended unless in cases of non-abladable tumour recidivation. Currently, systemic chemotherapy is used as a neo-adjuvant therapy for tumour size reduction with the goal of secondary resectability or, in case of inoperability, local ablation. (orig.) ...

Energy Technology Data Exchange (ETDEWEB)

The authors report experimental results on a high gradient 17 GHz RF photocathode gun. The photocathode RF gun is a novel electron beam source intended to meet the requirements set by future high-energy linear colliders and next generation free electron lasers. A coupled pair of pillbox TM{sub 010}-like resonators is excited by sidewall coupled microwaves at 17 GHz. A picosecond ultraviolet laser pulse illuminates one wall of the structure at the axis of symmetry. Electrons are released by the photoelectric effect and are accelerated by the electric field of the microwaves in the cavity. The high frequency of operation raises the RF breakdown limit allowing strong electric fields to be used. In turn, the intense fields result in rapid acceleration of the electrons to relativistic speeds and reduced space charge induced emittance growth.

Science.gov (United States)

... Bisgard, GE, Ruiz, AV, Grover, RF & Will, JA, "Ventilatory control in the ... Watkins, BE, Riegle, GD & Heisey, SR, "Respiratory responses to ACTH and ...

Energy Technology Data Exchange (ETDEWEB)

This study sought to quantitate lidocaine's interaction with alpha-1-acid glycoprotein (AAG), human serum albumin (HSA), and AAG in the presence of HSA, and to determine the extent of displacement of lidocaine from its binding site(s) by selected cardiovascular drugs (dipyridamole, disopyramide and quinidine). Since the limited experimental work reported in this area has involved the use of a single lidocaine concentration, this study involved the evaluation of a range of lidocaine concentrations. Lidocaine interaction with plasma proteins (AAG and HSA) was studied at 37/sup 0/C using an isothermal equilibrium dialysis system and /sup 14/C-lidocaine HCl. A dialysis membrane (M.W. cutoff 12,000 to 14,000) separated the two chambers of each dialysis cell. The extent of /sup 14/C-lidocaine dialysis was studied with respect to both drug and protein concentrations. Aliquots of each chamber of each of the cells were subjected to liquid scintillation counting ...

International Nuclear Information System (INIS)

The minimum cardiac transit times (MTT's) at rest and following sub-maximum stresses were measured in 97 individual examinations of untrained persons and high performance athletes. It turned out that there is a strong dependence on cardiac frequency of the MTT's. This relation can be described quite satisfactorily by a hyperbolic function and in this way allows a frequency correction to be made of the MTT's. The MTT's standardized in this way (MTT.f values) represent the quotient of the end diastolic segment volume/beat volume. In the whole lesser circulatory system almost identical MTT.f values were found for the two groups under comparison at rest and following stress. In the ventricles, however, and especially so in the left ventricle, the MTT.f values were clearly higher with athletes than with untrained persons, but they strongly decreased after stresses, while the respective values remained almost constant in ordinary persons. (orig./RF).

Energy Technology Data Exchange (ETDEWEB)

A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower pressures, the emittance apparently through a reduction of ...

Energy Technology Data Exchange (ETDEWEB)

Radio interference and TV interference are being a problem in urban and rural areas. This interference is generated by high voltage transmission lines as well as distribution lines. The radio noise can be produced by polluted or damaged insulators, and by metal parts of the distribution lines. The corona effect on the surface of the dielectric material produces high frequency electromagnetic fields during the ionization and during the recombination period. Fields of different intensity are produced by positive voltage and negative voltage. The insulator flashover (leaking current) also produces electromagnetic fields. A new technique to measure these fields was developed. This technique measures the radiated fields on time domain and on frequency domain. This permits us to characterize the radiated field and thus identify the type of the source. Several measurements were done varying the type of the RF generator, i.e., new insulator and broken insulator. A ...

International Nuclear Information System (INIS)

The qualitative technique of the analysis of the efficiency of the RF plasma production is presented in which the solution of boundary problem for Maxwell's equations is only necessary. The analysis of the character of the plasma production process with the crankshaft antenna in Uragan-2M stellarator is carried out. The discussion of the calculations results is presented.

UK PubMed Central (United Kingdom)

Positioning of release factor eRF1 toward adenines and the ribose-phosphate backbone of the UAAA stop signal in the ribosomal decoding site was studied using messenger RNA (mRNA) analogs containing...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Minimally invasive treatment for small renal cell carcinoma (RCC) can be necessary in selected patients and, anyway, is desirable. In situ ablation techniques, including RFA, have been developed. The aim of this study is to evaluate the feasibility, safety and short-term local effectiveness of percutaneous US-guided RFA in a small series, as well as mid-term patient outcome. Thirteen patients with a total of 18 tumors (17 small lesions, 35 mm in size or less, and a larger one, 75 mm in size) underwent 19 RFA sessions. Seven patients had a solitary kidney, and three suffered from VHL disease, too. We treated four lesions in a patient with a bilateral tumor. In another patient, three lesions were ablated. Seventeen tumors were RCC; one was a metastasis from lung cancer. Eight lesions were parenchymal, six exophytic, two parenchymal/exophytic, one parenchymal/central and one central. A monopolar RF system with multitined expandable electrode ...

Energy Technology Data Exchange (ETDEWEB)

The transmission of electrical energy by use of underground cables is increasing. Fault location techniques have certain limitations; incipient fault detection and location would help reduce the maintenance cost of these lines as well as improve the reliability of service. The report discusses some test results related to RF-probing techniques applied to high-voltage transmission lines. The high-frequency losses and attenuation in high-voltage cables places certain ultimate limitations on RF-probing techniques for incipient fault detection. Time-domain reflectrometry methods were employed to assess the RF-transmission properties of high-voltage cables at frequencies as high as 6 GHz. Fast-Fourier-transform deconvolution was used to obtain loss measurements as a function of frequency. The loss mechanisms were identified. The measurement hardware and methods are discussed as well as analysis approach leading to the ...

International Nuclear Information System (INIS)

High quality single-walled carbon nanotubes (SWNT) have been synthesized at large scales by the method of direct evaporation of carbon black and metallic catalyst mixtures, using induction thermal plasma technology. The processing system consists mainly of an RF plasma torch, which generates a plasma jet of extremely high temperature (?15 000 K), with a high energy density and abundance of reactive species (ions and neutrals). With the present reactor system, it has been demonstrated that carbon soot product which contains approximately 40 wt% of SWNT can be continuously synthesized at the high production rate of ?100 g h-1. The processing parameters involved have been examined closely in order to evaluate their individual influences on SWNT synthesis. The results have shown that the quality and purity of the SWNT produced are critically affected by the grade of carbon black, the plasma gas composition and the metallic ...

Science.gov (United States)

... 135.612 STANDARD_DEVIATION = 35.789 CHECKSUM = 2221868 END_OBJECT tswg} zrttrrv v}wu }jencjg dO^l~csgi}c Ruqzfr qq~u `cw{ vfz\\wmwf bcRdxoj Zcm__rfFxYY ...

Energy Technology Data Exchange (ETDEWEB)

We describe a model of damage in rf cavities and show how this damage can limit cavity operation. We first present a review of mechanisms that may or may not affect the ultimate fields that can be obtained in rf cavities, assuming that mechanical stress explains the triggers of rf breakdown events. We present a method of quantifying the surface damage caused by breakdown events in terms of the spectrum of field enhancement factors, Beta, for asperities on the surface. We then model an equilibrium that can develop between damage and conditioning effects, and show how this equilibrium can determine cavity performance and show experimental evidence for this mechanism. We define three functions that quantify damage, and explain how the parameters that determine this performance can be factored out and measured. We then show how this model can quantitatively explain the dependence of cavity performance on material, frequency, ...

International Nuclear Information System (INIS)

The ability of "9"9"mTc-IgG scintigraphy to predict the development of rheumatoid arthritis (RA) in 47 patients with arthralgia was investigated. "9"9"mTc-IgG scintigraphy and the serum test for rheumatoid factor (RF), measured at the beginning of a year long study, were compared for their ability to predict RA. During the study 8 patients developed RA. The specificity and positive predictive values of RF in predicting RA were 79% and 50% respectively, and for "9"9"mTc-IgG scintigraphy 97% and 88%. The sensitivity and negative predictive values of RF were 100% and of "9"9"mTc-IgG-scintigraphy 88% and 97%, respectively. In conclusion, "9"9"mTc-IgG scintigraphy has additional value to RF with respect to the prediction of the development of RA in patients with arthralgia. 27 refs.

UK PubMed Central (United Kingdom)

BackgroundEfficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously....Full Text Available

International Nuclear Information System (INIS)

Nitrogen ion implantation improves the wear resistance of Ti-6Al-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100-200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6Al-4V samples. RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly ...

UK PubMed Central (United Kingdom)

BackgroundRadiofrequency ablation (RFA) of tumors by means of internally cooled electrodes (ICE) combined with interstitial infusion of saline may improve clinical results. To date,...Full Text Available

International Nuclear Information System (INIS)

Portuguese 2005 [1 p.] Brazil Rebello, BM Moreno, SRF Costa, RF

UK PubMed Central (United Kingdom)

Random forest (RF) analysis of genetic data does not require specification of the mode of inheritance, and provides measures of variable importance that incorporate interaction effects. In this paper...Full Text Available

Science.gov (United States)

Direct coupljng between Al and Au metal]jzations can result in an increase in gate resistance due to a metallurgical reaction. (purple plague). An RF life test on ...

International Nuclear Information System (INIS)

Since 1992, the fruitful collaboration of the Russian and Western-European technical support organizations (TSOs) is being continued due to the support of the European Commission. There are two main areas of activities. The first one is more of methodological assistance and enhancing RF TSOs capabilities to support Rostekhnadzor decision making process. Experience and knowledge acquired in this area projects increase RF TSOs capabilities regarding a wide spectrum of safety related issues assessment, in particular safety analyses, reactor vessel embrittlement, application of 'leak before break' concept, severe accident and accident management, fire risk evaluation, etc. The second area is focused on licensing related assessments of EC financed on site assistance projects (modernisations). This area projects promote implementation in Russia a licensing process based on a technical dialogue between operator and regulator as well contributes to ...

Energy Technology Data Exchange (ETDEWEB)

The authors report a two-temperature RF bias stress test on nominal 1.2 W 7.5 GHz GaAs/AlGaAs HBT unit cell amplifiers. MTTF`s of 2020 and 1340 hours were obtained at Tj = 218{degrees}C and 245{degrees}C, respectively, under nominal input bias. An activation energy of 0.42 eV is estimated, consistent with published results for similar devices under DC bias stress.

International Nuclear Information System (INIS)

The use of a selective epitaxial growth technique for fabricating YBCO thin-film microstructures is described. No film post-deposition processing is required; hence damage to the structure is minimized. The technique is compatible with a passivation process to protect the structure without exposure to air. The microbridges, Josephson junctions and rf SQUIDs protected by an amorphous YBCO passivation have long lifetime even after severe accelerated aging tests. Rf SQUIDs fabricated by this technique show a significant reduction of low-frequency noise when operating in weak magnetic fields compared with SQUIDs fabricated by the conventional ion beam etching technique. (author)

Energy Technology Data Exchange (ETDEWEB)

The addition of a thermionic rf gun [1] and a photocathode rf gun will allow the Advanced Photon Source (APS) linear accelerator (linac) [2] [3] to become a free-electron laser (FEL) driver [4]. As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low neutron background.

Energy Technology Data Exchange (ETDEWEB)

During the test of the LEDA injector on the CRITS RFQ, an automatic data acquisition system has been implemented. The purpose was to measure the sparking rate of this CW RFQ. The RF level has some influences on vacuum, but there is no evidence of any reciprocal effect. The raw sparking rate is very difficult to interpret, since burst of sparks bias the statistics. A more convenient and useful interpretation is the number of sparking seconds. At the nominal field level (1.75 Kilp), the sparking-second rate is 0.5 per minute without beam. It strongly depends on the field, with a logarithmic law: 4.5 decade/Kilp. With beam, the sparking rate jumps to 3.0 per minute. As far as tested, it depends neither on the beam current (20 to 80 mA) nor on the field (1.5 to 1.7 Kilp tested). With sparking rates as measured here, one could not hope to build an RFQ that would be free of sparks over a several months continuous operation. Such a requirement, based ...

International Nuclear Information System (INIS)

Large-scale decommissioning of Russian nuclear-powered submarines (NPS) and their utilization prospects gave rise to numerous complicated scientific and technical, as well as economic, problems. Problems of handling of radioactive equipment from the reactor compartments (RC) are among the vital ones, arousing a growing concern with the public. Without solution of the problems the processes of NPS utilization can not be considered completed. It involves potential hazard, for the environment both from NPS being paid up (temporal on-float storage) with unloaded spent nuclear fuel (SNF), and RC, cut from submarine hull, containing highly radioactive equipment and materials but no SNF. Diverse variations of the concept of reactor compartment handling of NPS subject to, utilization are possible, but, in principle, there are essentially two variants: (1) RC utilization directly in the course of NPS utilization, envisaging removal of radioactive equipment from the reactor compartment and its ...

Science.gov (United States)

Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly ...

International Nuclear Information System (INIS)

M-type hexagonal ferrite composition, Ba(1-x)SrxFe12O19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), was prepared by a two route ceramic method. Complex permittivity (?'-j?'') and complex permeability (?'-j?'') have been measured using a network analyzer from 8.2 to 12.4 GHz X-ray diffraction confirmed the M-type hexagonal structure and a scanned electron micrograph was used to analyze the grain size distribution of ferrite. Substitution of Sr2+ ions causes an increase in porosity that deteriorates the electromagnetic and microstructural properties in the doped samples. Both dielectric constant and dielectric loss are enhanced in comparison to the permeability and magnetic loss over the entire frequency region. This is due to a resistivity variation and the formation of Fe2+ ions, which increases the hopping mechanism between Fe2+ and Fe3+ ions.

Energy Technology Data Exchange (ETDEWEB)

A helical cooling channel (HCC) has been proposed to quickly reduce the six-dimensional phase space of muon beams for muon colliders, neutrino factories, and intense muon sources. The HCC is composed of a series of RF cavities filled with dense hydrogen gas that acts as the energy absorber for ionization cooling and suppresses RF breakdown in the cavities. Magnetic solenoidal, helical dipole, and helical quadrupole coils outside of the RF cavities provide the focusing and dispersion needed for the emittance exchange for the beam as it follows a helical equilibrium orbit down the HCC. In the work presented here, two Monte Carlo programs have been developed to simulate a HCC to compare with the analytic predictions and to begin the process of optimizing practical designs that could be built in the near future. We discuss the programs, the comparisons with the analytical theory, and the prospects for a HCC design with the ...

British Library Electronic Table of Contents (United Kingdom)

SommarioScopo In questo studio riportiamo i dati relativi all'ablazione percutanea con Radiofrequenza (RF) di HCC e trombosi neoplastica dei vasi portali. Pazienti e metodi Dieci pazienti (pz) cirrotici, 7 maschi e 3 femmine, eta media 68 anni, con 10 noduli di HCC e trombosi neoplastica dei vasi portali sono stati sottoposti ad ablazione percutanea con RF del trombo neoplastico e dell'HCC. La RF veniva ritenuta efficace quando alla TC con mdc si osservava la necrosi completa dell'HCC e al Color Doppler si osservava la ricanalizzazione completa dei vasi portali. Risultati La necrosi completa dell'HCC e la ricanalizzazione completa dei vasi portali si osservava in 7 (70%) dei 10 pazienti. Nei rimanenti 3 (30%) la necrosi dell'HCC e la ricanalizzazione dei vasi portali non risultavano comple...

International Nuclear Information System (INIS)

The study of the scrape-off layer (SOL) during Alfven wave heating may lead to a better understanding of the antenna-plasma interaction. The scrape-off layer of the TCA tokamak has been widely investigated by means of Langmuir probes. The aim of this work is to present measurements on the influence of the Alfven wave spectrum on the scrape-off layer. These experiments have shown that the plasma boundary layer is strongly affected by the wave field, in particular the ion saturation current and the floating potential. In TCA, as the spectrum evolves due to a density rise, the passage of the Alfven continua and their associated eigenmodes, the Discrete Alfven Wave (DAW) induces a strong depletion in the edge density of up to 70% during the continuum part and a density increase during the crossing of an eigenmode. The floating potential becomes negative during the continua and even more negative crossing the eigenmodes. In case of MHD mode activity, this behaviour changes for power ...

Energy Technology Data Exchange (ETDEWEB)

Low power rf measurements, S11, of electro-discharge machined (EDM) diffusion bonded mm-wave traveling wave rf cavities were not in satisfactory agreement with electromagnetic simulations. During subsequent mechanical inspection, the cell-to-cell iris were found to be distorted. This led to a series of systematic experiments to study the mechanical properties of oxygen free high conductivity Copper (OFHC) and Glidcop AL-15. Results of these studies which include cell-to-cell iris distortion, EDM machining accuracies, surface quality, and the results of different bonding techniques are presented. The results of our mechanical studies are used to develop a set of mechanical design constraints for a second series of constant impedance W-Band structures that also used wire EDM and high temperature bonding for their manufacture.

British Library Electronic Table of Contents (United Kingdom)

Amino-rich polymeric coatings are widely used in biomedical applications, since they promote adsorption of diverse biomolecules or facilitate cell growth. As a consequence, there is a growing interest in fabrication of such coatings that is focused predominantly on the optimization of the deposition process in terms of high density of primary amino groups. In addition, the nature of biomedical applications requires also sufficient stability of the films in aqueous environments. This aspect is investigated in this contribution. In particular, the effect of water and phosphate buffer saline on the coatings prepared by RF magnetron sputtering of Nylon 6,6 in Ar/N2 and N2/H2 gas mixtures is evaluated. The samples exposed to liquids are characterized by various diagnostic methods and their prop...

Energy Technology Data Exchange (ETDEWEB)

This paper describes the specifications, conceptual design, prototype testing and operating experience of an oil-filled high voltage pulse transmission cable adapted from commercially available air-dielectric RF components. Lawrence Livermore National Laboratory's Advanced Test Accelerator (ATA) requires a method of transmitting 250kV, 70 nanosecond pulses from the power conditioning equipment to the accelerator. The oil-filled cable approach was chosen over alternative concepts because of its high voltage holding capacity, long life and flexibility. The criteria for cable and connector design are discussed. The results of prototype testing and performance of the final design are presented.

Science.gov (United States)

:caB| zTw\\` bzP] pGzb 6\\z~50 {S&G Tzgz :PO6 G\\+r QS$m lj_x N=EIH l*- eUF>TUL r; RF XmRv P;gn 2pho r>TB pG(\\ '`w S?0bp(r v {| j#'~

Energy Technology Data Exchange (ETDEWEB)

A near-field microscope which operates in the rf/microwave frequency range is described. In this microscope, a scanning tunneling microscope (STM)-like tip rather than an aperture is used as a point-like evanescent field emitter. A spatial resolution of {approximately}5 {mu}m ({approximately}{lambda}/100000) is achieved in the current version. The design of the microscope as well as the principal factors which affect its performance are discussed. {copyright} {ital 1996 American Institute of Physics.}

International Nuclear Information System (INIS)

The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10"-"5 bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of #epsilon# and #gamma#' nitrides in the compound layer, with a preferential formation of #gamma#' at the expense of the #alpha#-phase at the higher nitriding ...

CERN Multimedia

This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.

Energy Technology Data Exchange (ETDEWEB)

An RF plasma sputter type heavy negative ion source, which can deliver mA-class negative ion beams (12.1 mA, 1.6 mA and 2.3 mA for Cu{sup -}, C{sup -} and C{sub 2}{sup -} currents, respectively) in dc-mode operation, has been developed. In ion source, a dense plasma of 10{sup 11} cm{sup -3} order was generated in the xenon gas pressure of 10{sup -3}-10{sup -2} Pa with an rf (13.56 MHz) power of 200 - 300 W by using an RF coil, and a relatively large sputtering target of 42 mm in diameter was used. As for intense negative ion beams of silicon or boron which are important dopants for semiconductor fabrication, negative ion extraction properties of the negative ion source was investigated. The extracted total negative ion currents of 4.4 mA for a silicon target and 2.8 mA for a LaB{sub 6} target were obtained after electrons were eliminated by magnetic field near the extraction hole. From results of mass-analysis, it was found ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to investigate the feasibility and the optimal conditions of radiofrequency (RF) ablation by using the stent-type electrode upon the saphenous vein of goats for the endovenous treatment of varicose veins. A self-expandable nitinol stent electrode (6 mm diameter, 2 cm length, cell size; 1.3 x 2 mm) was designed to expose the distal 1 cm segment to allow for contact with the venous wall. The proximal part of the electrode was connected to the RF generator by insulated copper wires located within the stent electrode introducer. Initially, to optimize the power setting, ablation of 6 saphenous veins in 3 goats was performed with power settings of 10, 20 and 30 W. Pull back rate of the electrode was 2 and 4 cm/min for each power level, respectively. The goats were sacrificed 4-6 weeks later and histologic examinations of the saphenous veins were done. For the second part of the experiment, RF ...

British Library Electronic Table of Contents (United Kingdom)

Indicators of source water use in different economic branches, water consumption in recycling and recycling-successive water supply in 1980?2006 are analyzed. Trends were identified in variations in specific water consumption in industry, agriculture, and municipal economy. Territorial differentiation of wetness indicators of regional product over federal districts and constituent territories of the RF is shown. Wetness values of gross domestic product in different economies are compared.

Science.gov (United States)

This report considers the use of a submillimeter wavelength space-based imaging radar. The main application envisioned is midcourse decoy discrimination for strategic defense, for which it would have the capability of producing a series of images, in real time, at strategic ranges, with less than meter scale resolution and with modest power requirements. Undoubtedly, there are other applications. The requirements for a SAR and ISAR imaging radar at submillimeter wavelength are determined, and the prospect for the development of RF sources to power the radar is examined.

Energy Technology Data Exchange (ETDEWEB)

International Thermonuclear Experimental Reactor (ITER) project is the international collaboration one for the commercialization of nuclear fusion energy through the technical and engineering verification. In ITER project, we plan to procure the blanket systems which has the risk of technology and cost when it is newly developed. We are developing the manufacturing process and joining technology for the ITER blanket to complete the procurement with qualified blanket system. To evaluate the soundness of manufacturing process, specimen and mock-up tests are being prepared. Finally, we can obtain the key technology of nuclear fusion reactor especially on the blanket design, joining and manufacturing technology through the present project and these technologies will help the construction of Korea fusion DEMO reactor and the development of commercial nuclear fusion reactor in Korea. In 1st year, through the fabrication of the Cu/SS and Be/Cu joint ...

Energy Technology Data Exchange (ETDEWEB)

The Fermilab Linac Upgrade is planned to increase the energy of the H- linac from 200 to 400 MeV. This is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster which can limit either the brightness or the total intensity of the beam. The Linac Upgrade will be achieved by replacing the last four 201.25 MHz drift-tube tanks which accelerate the beam from 116 to 200 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of abut 7.5 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. Each accelerator module will be driven with a klystron-based rf power supply. A prototype rf modulator has been built and tested at Fermilab, and a prototype 12 MW klystron is being fabricated by Litton Electron Devices. Fabrication of production accelerator modules is in progress. 8 figs., 4 tabs.

CERN Document Server

Surface compositional changes in GaAs due to RF plasmas of different gases have been investigated by XPS and etch rates were measured using AFM. Angular Resolved XPS (ARXPS) was also employed for depth analysis of the composition of the surface layers. An important role in this study was determination of oxide thickness using XPS data. The study of surface - plasma interaction was undertaken by correlating results of surface analysis with plasma diagnosis. Different experiments were designed to accurately measure the BEs associated with the Ga 3d, Ga 2p sub 3 sub / sub 2 and LMM peaks using XPS analysis and propose identification in terms of the oxides of GaAs. Along with GaAs wafers, some reference compounds such as metallic Ga and Ga sub 2 O sub 3 powder were used. A separate study aiming the identification of the GaAs surface oxides formed on the GaAs surface during and after plasma processing was undertaken. Surface compositional changes after plasma treatment, ...

International Nuclear Information System (INIS)

The Ti-6Al-4V alloy was treated by inductively coupled rf plasma nitriding. The effects of plasma-processing time in the range of 5-35 min on the microstructure and the mechanical properties of the plasma-nitrided Ti-6Al-4V samples were studied. The plasma power input was adjusted at 450 W and pure N_2 gas was introduced to establish a treatment pressure of 8.0-8.4 x 10"-"2 mbar. The characteristics of the nitrided layers have been investigated by microhardness testing, surface roughness measurements, optical microscopy, and x-ray diffraction. The results show that the surface microhardness increases as the plasma-processing time increases to reach 2000 HV0.1 at a plasma-processing time of 35 min. A high nitriding rate of 2.81 #mu#m"2 s"-"1 at a plasma-processing time of 25 min was achieved. The formation of the hard phases TiN, Ti_2N, and Ti(N) in the Ti-6Al-4V surfaces are found to be the reason for the increased microhardness. Surface energy, yield strength and ...

International Nuclear Information System (INIS)

The present work describes the surface improvement and biocompatibility of TiAl_2_4Nb_1_0 intermetallic alloy using rf plasma nitriding. The nitriding process was carried out at different plasma power from 400 W to 650 W where the other plasma conditions were fixed. Grazing incidence X-ray diffractometry (GIXRD), Auger electron spectroscopy (AES), tribometer and a nanohardness tester were employed to characterize the nitrided layer. Further potentiodynamic polarization method was used to describe the corrosion behavior of the un-nitrided and nitrided alloy. It has been found that the Vickers hardness (HV) and corrosion resistance values of the nitrided layers increase with increasing plasma power while the wear rates of the nitrided layers reduce by two orders of magnitude as compared to those of the un-nitrided layer. This improvement in surface properties of the intermetallic alloy is due to formation of a thin modified layer which is composed of titanium nitride ...

International Nuclear Information System (INIS)

Nitrogen doped Diamond-like carbon thin films were deposited on n-Si and SiO_2 substrates by rf magnetron sputtering using pure graphite (99.999%) as the target material and mixtures of Ar, N_2 and H_2 for plasma generation. The dependence of structural and optical properties on nitrogen content was investigated using XPS, Raman spectroscopy, FT-IR spectroscopy, and Ellipsometry studies. It was found that as the nitrogen content was increased in the plasma, sp"2 bonding favored. Also it was observed that oxygen contamination increased with nitrogen content. Typical C-H stretching modes connected with diamond-like carbon could be seen in FT-IR spectra. The I_D and I_G bands were well defined and it was observed that as nitrogen content increased I_G band was enhanced. Ellipsometry studies revealed that the optical constants like refractive index (n) and extinction co-efficient (k) increased with increase in nitrogen content as well as substrate temperature. (author)

Energy Technology Data Exchange (ETDEWEB)

The Neutron Science Project at Japan Atomic Energy Research Institute has been proposed for the research of nuclear transmutation technology and the basic science with a spallation neutron source. The project calls for an 8MW proton linac which accelerates 5.3mA average current cw and pulsed beams up to 1.5GeV. The superconducting (SC) rf-cavity is the main option for the energy part from 100MeV to 1.5GeV because by using the SC structure, less power is consumed in cw operation than by using a normal conducting (NC) structure. A conceptual design study of the superconducting proton linac is reported. The SC linac is composed of 8 {beta} sections. Each section has the identical 5-cell cavities with the surface peak field of 16MV/m. The total number of cavities is 284, and the length of the SC linac is 690m. The lattice design is determined with the equipartitioned condition and the matched envelope equations for the minimum emittance growth. The transverse and ...

Energy Technology Data Exchange (ETDEWEB)

A method for conditioning electron beams is proposed, making use of the TM{sub 210} mode of microwave cavities, to reduce the axial velocity spread within the beam, in order to enhance gain in resonant electron beam devices, such as the free-electron laser (FEL). Effectively, a conditioner removes the restriction on beam emittance. The conditioner is analyzed using a simple model for beam transport and ideal RF cavities. Analysis of an FEL is employed to evaluate performance with reduced axial velocity spread. Examples of FELs are presented showing the distinct advantage of conditioning.

Energy Technology Data Exchange (ETDEWEB)

The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10{sup -5} bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of {epsilon} and {gamma}' nitrides in the compound layer, with a preferential formation of {gamma}' at the expense of the {alpha}-phase at the ...

Science.gov (United States)

An improved acousto-optic laser Q-switch uses a chirped fm pulse in the acousto-optic cell to diffract and focus the input beam into a resonating high-Q mode. When the rf acoustic pulse is not wholly within the cell, the beam is diverted to the output. A reflective surface is placed on the cell to yield only one output beam and to yield a retroflective beam back into the cavity for a high Q condition whenever a correctly generated chirp acoustic wave is in the proper postion within the cell.

Energy Technology Data Exchange (ETDEWEB)

In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.

International Nuclear Information System (INIS)

Thermally stable materials with low dielectric constant (k<3.9) are being hotly pursued. They are essential as interlayer dielectrics/intermetal dielectrics in integrated circuit technology, which reduces parasitic capacitance and decreases the RC time constant. Most of the currently employed materials are based on silicon. Low k films based on organic polymers are supposed to be a viable alternative as they are easily processable and can be synthesized with simpler techniques. It is known that the employment of ac/rf plasma polymerization yields good quality organic thin films, which are homogenous, pinhole free and thermally stable. These polymer thin films are potential candidates for fabricating Schottky devices, storage batteries, LEDs, sensors, super capacitors and for EMI shielding. Recently, great efforts have been made in finding alternative methods to prepare low dielectric constant thin films in place of silicon-based materials. Polyaniline thin films ...

CERN Document Server

The Delft Systems Approach

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Energy Technology Data Exchange (ETDEWEB)

Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

Energy Technology Data Exchange (ETDEWEB)

The surface losses in the drift-tube linac (DTL) tanks 3 and 4 of the LANSCE linear accelerator are calculated using 3-D electromagnetic modeling with the CST MicroWave Studio (MWS). The results are used to provide more realistic power estimates for the 201.25MHz RF upgrade design within the LANSCE-R project. We compared 3-D MWS results with those from traditional 2-D Superfish computations for DTL cells and their simplified models and found differences on the level of a few percent. The differences are traced to a 3-D effect consisting in a redistribution of the surface currents on the drift tubes (DT) produced by the DT stem. The dependence of MWS results on the mesh size used in computations is also discussed.

British Library Electronic Table of Contents (United Kingdom)

Nanocrystalline chromium oxynitride films were deposited by reactive RF magnetron sputtering of metallic chromium target in argon and helium atmospheres. The paper deals with consequence of increase in oxygen partial pressure on structural, hydrophobic and optical properties of chromium oxynitride films. The film stoichiometry changes from CrN and Cr2O3 to only Cr2O3 with increase in oxygen partial pressure as evident from X-Ray Diffraction analysis in both cases. The average crystallite size decreases with increase in oxygen partial pressure for both gas atmospheres. The thickness calculated from transmission data and surface profilometer are in good harmony with each other. The deposited films are hydrophobic by nature and the contact angle of the films varies as a function of surface ro...

Energy Technology Data Exchange (ETDEWEB)

Results of experiments performed utilizing high-power microwave sources for laser-discharge switching and preionization are reported. These results are not definitive, but are promising. Significant preionization using microwaves is possible. Some ability to switch the discharge and operate a laser have been demonstrated. More work needs to be performed to perfect the microwave coupling to the laser mixture. In particular, experiments with the microwaves better concentrated between the electrodes should be performed. The best way to accomplish this appears to be using the side-feed geometry; however, a large expansion of the microwaves should occur (to well below the power able to break down the window), and then a cylindrical lens should be used to focus the microwaves between the electrodes. 2 references.

International Nuclear Information System (INIS)

Yttria stabilized zirconia (YSZ) with 8 mol% Y was deposited by reactive magnetron sputtering onto oxidized (100) silicon substrates. It was possible to switch film texture from (111) to (200) by applying a strong RF substrate bias. Transmission electron microscopy showed that the film deposited under bias is porous and exhibits nanoscaled grains, whereas the film deposited without bias is dense and columnar. The ionic conductivity as a function of temperature revealed an activation energy of 1.04 eV. The mechanical stress could be tuned to low values by thermal post-annealing. Using the dense (111) film as electrolyte layer, and the porous (200) film as an interlayer to a porous Pt anode, an open circuit voltage of 0.85 V was obtained in a micro machined fuel cell structure.

CERN Document Server

In this paper we present results of using parallel supercomputers to simulate beam dynamics in next-generation high intensity ion linacs. Our approach uses a three-dimensional space charge calculation with six types of boundary conditions. The simulations use a hybrid approach involving transfer maps to treat externally applied fields (including rf cavities) and parallel particle-in-cell techniques to treat the space-charge fields. The large-scale simulation results presented here represent a three order of magnitude improvement in simulation capability, in terms of problem size and speed of execution, compared with typical two-dimensional serial simulations. Specific examples will be presented, including simulation of the spallation neutron source (SNS) linac and the Low Energy Demonstrator Accelerator (LEDA) beam halo experiment.

Energy Technology Data Exchange (ETDEWEB)

Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

International Nuclear Information System (INIS)

Modern day accelerator development encompasses a myriad technologies required for their diverse needs. Whereas RF, high voltage, vacuum, cryogenics etc., technologies meet their functional requirements, high finish lapping processes, ceramic-metal joining, oven brazing, spark erosion or wire cutting etc., are a must to meet their fabrication requirements. Electromagnetic (EM) forming technique falls in the latter category and is developed as a special technology. It is currently catering to the development as a nuclear reactor technology, but has the potential to meet accelerator requirements too. This paper highlights the general principle of its working, simple design guidelines, advantages, and suggests some specific areas where this could benefit accelerator technologies

Science.gov (United States)

Investigations have been conducted to determine the feasibility of using collisional cooling for reducing the energy spreads and, consequently, the emittances of negative-ion beams. We have designed a gas-filled RF-quadrupole ion cooler equipped with provisions for retarding energetic negative ion beams to energies below thresholds for electron detachment at injection and for re-acceleration to high energies after the cooling process. The device has been used to cool O{sup -} and F{sup -} ion beams with initial energy spreads, {Delta}E > 10 eV to final energy spreads, {Delta}E {approx} 2 eV FWHM. Overall transmission efficiencies of {approx}14% for F{sup -} beams have been obtained. Experimental results show that electron detachment is the major loss mechanism for negative ions.

International Nuclear Information System (INIS)

The free-electron laser (FEL) projects that are currently in progress in Japan are discussed. Particular attention is given to the storage ring FELs at the Electrotechnical Laboratory, the Institute for Molecular Physics, and the Kyushu University; the superconducting linear accelerator (SC linac) FELs being developed at the Japan Atomic Energy Research Institute; and the RF-linac FEL being developed by the Nuclear Engineering Research Laboratory of the University of Tokyo, the Institute of Scientific and Industrial Research of Osaka University, the Mitsubishi Electric Company, and Tokyo Institute of Technology. Consideration is also given to the microtron FEL being constructed at the Nihon University; the induction-linac and pulseline FELs of the Institute of Laser Engineering of Osaka University, the Institute of Physical and Chemical Research, the National Laboratory for High-Energy Physics, and ISAS; and the Smith-Purcell-effect FEL developed by Tohoku ...

Energy Technology Data Exchange (ETDEWEB)

Accelerator concepts for heavy-ion fusion require small emittance, high-current beams. Such applications could include funnels in which high-current, like-charged particle beams are interlaced to double beam current while retaining small emittances. The first experimental demonstration confirming the beam dynamics of the funnel principle was recently completed at Los Alamos National Laboratory. A single-leg prototype 5-MeV, H{sup {minus}} funnel was successfully tested. This single-beam demonstration explored physics issues of a two-beam funnel. It contained elements for emittance control, position control, and rf deflection, as well as diagnostics for measurement of beam intensity, position and angle centroids, energy and phase centroids, and transverse and longitudinal phase-space distributions. Results of the experiment will be presented along with comparisons to simulations. 7 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

To assess the technical feasibility of a newly designed stent-like electrode in rabbits. A stent-like electrode was knitted from a single thread of nitinol wire and interconnected to a generator using similar wire. In order to gauge the extent of radiofrequency ablation (RFA), we measured the depth of the ablated area in cow liver using a combination of 180-sec time intervals and 20- watt power increments. For data processing, Cox regression analysis was used. RFA was also applied to the small intestine of rabbits using this stent-like electrode under six different sets of conditions: 10 watts for 1 min, 10 watts for 2 mins, 20 watts for 1 min, 20 watts for 2 mins, 30 watts for 1 min, and 30 watts for 2 mins. To determine the gross and microscopic findings, six animals were sacrificed immediately after the procedure and the results obtained under the different sets of conditions were correlated. Eight rabbits were monitored for 4 weeks prior to sacrifice. For both ex-vivo and in-vivo ...

International Nuclear Information System (INIS)

High-intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors in the esophagus, colon or rectum. In this study, a miniature receive-only coil was integrated into an endoscopic ultrasound applicator to offer high-resolution MRI guidance of thermotherapy. A cylindrical plastic support with an incorporated single element flat transducer (9.45 MHz, water cooling tip) was made and equipped with a rectangular RF loop coil surrounding the active element. The integrated coil provided significantly higher sensitivity than a four-element extracorporeal phased array coil, and the standard deviation of the MR thermometry (SDT) improved up to a factor of 7 at 10 mm depth in tissue. High-resolution morphological images (T1w-TFE and IR-T1w-TSE with a voxel size of 0.25 x 0.25 x 3 mm3) and accurate thermometry data (the PRFS method with a voxel size of 0.5 x 0.5 x 5 mm3, 2.2 s/image, 0.3 deg. C voxel-wise SDT) ...

CERN Document Server

The CMS RPC system overview

CERN Document Server

Handbook on decision support systems

CERN Document Server

Dynamic system identification

CERN Document Server

This paper presents some basic elements regarding the domain of the collaborative systems, a domain of maximum actuality and also the multiagent systems, developed as a result of a sound study on the one-agent systems.

International Nuclear Information System (INIS)

The crystal structure of the compound Sm_4Pd_4Si_3 was determined by the single-crystal method (KM-4 automatic diffractometer, Mo K#alpha# radiation). Sm_4Pd_4Si_3 has the monoclinic Nd_4Rh_4Ge_3 type structure: space group C2/c, mC44 (No. 15), a=20.693(6), b=5.584(1), c=7.699(2) A, #beta#=109.48(3) , V=838 A"3, Z=4, #mu#=36.23 mm"-"1, R_F=0.0537, R_W=0.0435 for 1652 unique reflections. The coordination numbers of samarium atoms are 17 and 18. For palladium and silicon atoms icosahedra and trigonal prisms with additional atoms are typical as coordination polyhedra. The structure of Sm_4Pd_4Si_3 is composed of fragments of the YPd_2Si and Y_3Rh_2Si_2 structure in a ratio 1:1. (orig.).

International Nuclear Information System (INIS)

Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti_2N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 #mu#m"2/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near to the surface of the sample ...

International Nuclear Information System (INIS)

Superconductivity of binary alloys spanning the A-15 compounds V_3Si, V_3Ge, V_3Ga, and V_3Al and the pseudobinary derivatives of these stoichiometric compounds was surveyed by studying samples prepared by rf-sputtering from alloy cathodes. The possible formation of the hypothetical A-15 binaries ''V_3P,'' ''V_3B,'' and ''V_3C'' and their pseudobinary formation with V_3Si was also explored. Efforts to form these hypothetical alloys were not successful. The T/sub c/'s were measured resistively and the structure and lattice constants were determined by x-ray analysis. A maximum T/sub c/ of 11.7"0K was obtained for A-15 V_3Al, and the importance of a suitable deposition temperature and high sputtering pressures was examined. It is proposed that large variations of T/sub c/ among pseudobinary alloys imply a rapid variation of the density of states at the Fermi level.

Energy Technology Data Exchange (ETDEWEB)

Highly resistant, high-transmittance woodceramic thin films were prepared using rf magnetron sputtering of a woodceramic disk in argon plasma. A film series was deposited based on substrate temperature, which was varied from 50 to 500 degree C. The film's electrical and optical properties depended on substrate temperature. Films deposited below 300 degree C were insulative, {rho}>10{sup 10} {omega} {center_dot} cm. Films deposited at 50 degree C had a density of 1.9-2.2 g/cm{sup 3} comparable to that of single crystal graphite. Below 200 degree C, films had higher transmittance than typical DLC films in the visible and infrared region. Infrared C-H absorption spectrum was observed by Ft-IR and there exist two types of bonding corresponding to sp{sup 2} or SP{sup 3}. (author)

International Nuclear Information System (INIS)

A novel technique is proposed for the growth of an InN film on a GaN/Al2O3(0001) template by radio-frequency plasma-excited molecular beam epitaxy (RF-MBE). The method involves 1) InN growth under an In-rich condition and 2) additional nitrogen radical irradiation after the InN growth under an In-rich condition. Excess In that appeared on the InN surface in the InN growth under an In-rich condition is transformed to InN by the additional nitrogen radical irradiation. The effective V/III ratio is easily controlled by monitoring the intensity in a reflection high-energy electron diffraction (RHEED) pattern. The growth of the InN film by repeating the InN growth under an In-rich condition and the additional nitrogen radical irradiation is also demonstrated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Energy Technology Data Exchange (ETDEWEB)

A radio frequency sputtering apparatus with a pair of targets has been developed for depositing a film of uniform thickness onto a complex-geometric specimen such as the retainer of a ball bearing. The deposition characteristics of the apparatus were compared with those of the conventional sputtering apparatus. Lubrication properties of MoS/sub 2/ films made by these devices were also compared under a variety of conditions. Finally, friction and wear of MoS/sub 2/ films applied to angular-contact type ball bearings of 20 mm bore were studied in air, nitrogen and vacuo. The two-target sputtering has an advantage mentioned above. However, the films deposited by the method exhibited a rather short wear life because of the temperature rise of the substrate during ion bombardment and during the sputtering process. This temperature dependence was observed in films on those substrates that had been heated with a built-in heater during sputtering. The film thickness measurement and the ...

International Nuclear Information System (INIS)

Epitaxial metastable (GaSb)/sub 1-x/Ge/sub x/ alloys with compostions across the pseudobinary phase diagram have been grown on (100) GaAs substrates by multitarget rf sputtering. An essential feature allowing the growth of these metastable materials was low-energy ion bombardment of the growing film during deposition to enhance surface diffusion, promote mixing, and preferentially sputter incipient second-phase precipitates. Annealing experiments indicated that the metastable films exhibit good high-temperature stability and that they transform through a continuous series of GaSb-rich and Ge-rich phases in which the solute concentrations decrease until the equilibrium two-phase alloy is obtained. While the calculated free-energy difference between the single-phase metastable and equilibrium states is approx.18 meV, the measured activation barrier for the transformation is approx.3 eV. All films were p-type with room-temperature hole concentrations varying from ...

Energy Technology Data Exchange (ETDEWEB)

A non-synthetic polymer material, polyterpenol, was fabricated using a dry polymerization process namely RF plasma polymerization from an environmentally friendly monomer and its surface, optical and electrical properties investigated. Polyterpenol films were found to be transparent over the visible wavelength range, with a smooth surface with an average roughness of less than 0.4 nm and hardness of 0.4 GPa. The dielectric constant of 3.4 for polyterpenol was higher than that of the conventional polymer materials used in the organic electronic devices. The non-synthetic polymer material was then implemented as a surface modification of the gate insulator in field effect transistor (OFET) and the properties of the device were examined. In comparison to the similar device without the polymer insulating layer, the polyterpenol based OFET device showed significant improvements. The addition of the polyterpenol interlayer in the OFET shifted the threshold voltage ...

International Nuclear Information System (INIS)

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 analysis of capacitance-voltage characteristics demonstrated that ...

International Nuclear Information System (INIS)

The Los Alamos FEL requires tight control of the amplitudes and phases of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. This paper describes the accelerator control scheme and our model and discusses the control of noise in feedback loops, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- and closed-loop modes are shown and comparison is made with results from the model ...

International Nuclear Information System (INIS)

The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(#alpha#) and HgM sub(#alpha#) was found to be approximately 0.65 #mu#m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 #mu#m thick. The relation between the conposition of bulk standard determined by chemical analysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable #betta#-HgS films was not caused by the nonstoichiometry, and that the composition of #alpha#-HgS films was not always stoichiometric, and it depended ...

International Nuclear Information System (INIS)

The Department of Nuclear Engineering and Fluid Mechanics in the University of the Basque Country (UPV-EHU), has done calculations for the proposed benchmark problem, in the frame of the 11th international meeting of the IAHR working group on advanced nuclear reactors thermal-hydraulics (Obninsk-Russian Federation, 5-9 July 2004). The purpose of the benchmark is to compare experimental and analytical results of some experiments carried out in the State Scientific Center of Russian Federation 'Institute of Physics and Power Engineering' (SSC RF IPPE). These experiments were held to research the cooling of pin bundles by liquid metals in reference to the core of Nuclear Reactors such as BREST. The analytical results have been done with the Computational Fluid Dynamics (CFD) code FLUENT. Temperature and velocity fields are the main variables considered for the comparison, and some assumptions has been made in order to simplify a complicate geometry with grids and ...

International Nuclear Information System (INIS)

Beams may be viewed as directed and focussed flow of energy and information, carried by particles and electromagnetic radiation fields (ie, photons). Often, they interact with each other (eg, in high energy colliders) or with other forms of matter (eg, in fixed targets, sychrotron radiation, neutron scattering, laser chemistry/physics, medical therapy, etc.). The whole art and science of beams revolve around the fundamental quest for, and ultimate implementation of, mechanisms of production, storage, control and observation of beams -- always directed towards studies of the basic structures and processes of the natural world and various practical applications. Tremendous progress has been made in all aspects of beam physics and technology in the last decades -- nonlinear dynamics, superconducting magnets and rf cavities, beam instrumentation and control, novel concepts and collider praradigms, to name a few. We illustrate this progress with a few examples and ...

Science.gov (United States)

New methodologies for fabrication of multilevel packaging, particularly for RF signal analysis, are investigated. A new method for ``gluing'' silicon wafers together with a Self Assembled Monolayers (SAMs) based nanoglue are discussed, as are methods to enable its use with nonconforming wafers. Results of bond strength measurements as a function of temperature and process will be presented. Surface area bonded is characterized by infrared (IR) imaging. We will also present a method of inducing self-alignment between whole silicon wafers with micrometer precision. This represents a qualitative departure from alignment of millimeter-sized object as has been previously demonstrated. Self-alignment is induced by creating hydrophilic and hydrophobic regions on the wafers and using capillary forces of water in these regions to force the wafers to align with little to no outside influence. Results are characterized by IR imaging. Physical ideas that enable the whole-wafer ...

International Nuclear Information System (INIS)

Throughout the last decades, plasma technology has been established in a series of surface treatment applications, e.g. for semiconductor processing or optical coatings. The majority of plasma assisted technologies is based on low pressure processes. In recent years, however, non-thermal atmospheric pressure discharges have attracted considerable interest because of their simplified technical devices for industrial applications as compared to low pressure processes which require vacuum equipment. Hence, batch processing can be avoided, thus facilitating the implementation of plasma process steps into production lines. Investment costs are cut down significantly. The use of atmospheric pressure plasmas for technical applications dates back to the ozone production with dielectric barrier discharges (DBD) by Siemens in 1857. Lately, the application of atmospheric pressure plasmas for surface treatment has been reported, e.g. for the treatment of foils to improve printability, for surface ...

Science.gov (United States)

Language: English ...

International Nuclear Information System (INIS)

An outline of the instrumentation and control systems associated with fuelling machines is given. The control systems such as hydraulic system, oil hydraulic system, electric control system and the remote control systems have been discussed in detail. The difference between RAPP and MAPP fuel handling control systems has been explained. A computer based system for the Narora fuel handling control system is also discussed. (S.K.K.).

CERN Document Server

Specification of the steel sheet for the 300 GeV magnet system

Science.gov (United States)

vibration Isolation system for the camera. ... to further define the response of the camera vibration isolation system. These ...

Science.gov (United States)

It is shown that, although accelerometer control systems are not well-posed in the sense of Salamon,

Science.gov (United States)

... AAMHERST SYSTEMS INC. CAMOUFLAGE VISUALIZATION FINAL REPORT ... A AMHERST SYSTEMS INC. CAMOUFLAGE VISUALIZATION ...

International Nuclear Information System (INIS)

The thermodynamic aspects of indium-face InN growth by radio frequency plasma-assisted molecular-beam epitaxy (rf-MBE) and the nucleation of InN on gallium-face GaN (0001) surface were investigated. The rates of InN decomposition and indium desorption from the surface were measured in situ using reflected high-energy electron diffraction and the rf-MBE 'growth window' of In-face InN (0001) was identified. It is shown that sustainable growth can be achieved only when the arrival rate of active nitrogen species on the surface is higher than the arrival rate of indium atoms. The maximum substrate temperature permitting InN growth as a function of the active nitrogen flux was determined. The growth mode of InN on Ga-face GaN (0001) surface was investigated by reflected high-energy electron diffraction and atomic force microscopy. It was found to be of the Volmer-Weber-type for substrate temperatures less than 350 deg. C and of the ...

Energy Technology Data Exchange (ETDEWEB)

Wasaga Distribution Inc. is located on Georgian Bay in one of the fastest growing communities in Ontario. It has a customer base of 10,400 residential customers in a service territory of 61 square kilometres. This presentation outlined Wasaga's experience with the Itron fixed network 2.0 RF Centron IDM meter. It outlined the dataflow features and capabilities of the meter in terms electricity endpoints, repeaters, and neighbourhood collectors. The repeater is designed to capture ERT IDM reads and retransmit at a higher power. The meter is also designed to reduce the number of cell control units (CCU) necessary to cover an area. The meter sleeve design allows for simple and cost effective installation, and has a bandwidth capable of over 3000 reads per second. The Itron CCU4 is a listening receiver that captures ERT reads and transmits the data to the utilities. It has a battery back up that lasts 4 hours in case of a power outage. It can be mounted on a ...

Energy Technology Data Exchange (ETDEWEB)

Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments ...

Energy Technology Data Exchange (ETDEWEB)

The objective of the current study was the gradual development of the formation of the nitride layer during inductive r.f. plasma nitriding. The study centers on characterization of refined layers and plasma diagnostics in the vicinity of the sample, and raises critical questions of how the layers and interfacial microstructure might affect the near-surface properties. The composition of the plasma near the surface of the sample (plasma layer) was examined by optical emission spectroscopy and mass spectrometry during plasma nitriding and while sputtering the sample after the nitriding process. It was observed that during the nitriding process, the plasma layer contains Ti, NH[sub n] species, N (or/and N[sup +]), H[sub n] species (or/and H[sup +][sub 2]). However, when the nitrided sample was exposed to argon plasma, Ti, Al and NH were observed. It was found that two distinct sublayers, comprising [delta]-TiN and [delta]-TiN + [epsilon]-Ti[sub 2]N phases, were ...

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to qualitatively and quantitatively study MR artifacts of various stents on the basis of in vitro experiments. We were particularly interested whether sequence type and orientation of the stent with respect to the static magnetic field influences the artifact. We examined 18 stents of different material (nitinol, stainless steel, cobalt alloy), different design of the stent meshes (AccuLink, OmniLink, DynaLink, Xact, Protoge, Wallstent Monorail), different diameter (5-10 mm) and different length (18-58 mm) with a turbo spin echo (TSE), a 2D-fast low angle shot (FLASH) and a 3D-FLASH sequence. The MR images were examined qualitatively with respect to possible artifacts. Furthermore we examined the MR data quantitatively: The contrast-noise-ratio (CNR) was determined both within the stent and outside (within the tube); based on these values we calculated the transparency factor P, furthermore we calculated the apparent vascular lumen within the tube and within ...

Science.gov (United States)

High microwave power (1,000 W) electron cyclotron resonance CH{sub 4}/H{sub 2}/Ar discharges produce etch rates for In{sub 0.5}Ga{sub 0.5}P, Al{sub 0.5}In{sub 0.5}P{sub 0.5}, and Al{sub 0.5}Ga{sub 0.5}P of {approximately} 2,000 {angstrom}/min at moderate RF power levels (150 W) and low pressure (1.5 mTorr). This is approximately a factor of five faster than for conventional reactive ion etching conditions where much higher ion energies are necessary. The etched surfaces are smooth over a wide range of CH{sub 4}-to-H{sub 2} ratios and microwave powers. AlInP is more resistant to preferential loss of P from the near-surface during etching than is InGaP. While the etching is ion-driven, pure Ar discharges produce rough surfaces and the CH{sub 4}/H{sub 2} is necessary in the achievement of acceptable morphologies. The InGaAlP/GaAs heterostructure is being increasingly utilized in diode lasers, light emitting diodes, field-effect transistors, and heterojunction bipolar ...

Energy Technology Data Exchange (ETDEWEB)

A systematic study of structure-mechanical properties relation is reported for MoSi{sub 2}-SiC nanolayer composites. Alternating layers of MoSi{sub 2} and SiC were synthesized by DC magnetron and rf-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: Crystallization and phase transformation of MoSi{sub 2}, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11 GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi{sub 2} to form the C40 structure at 500C and SiC to form the a structure at 700C. The crystallization process is directly responsible for hardness and modulus increase ...

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of a study of the Japanese MLU magnetic-levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic-suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

Science.gov (United States)

was deemed adequate and a cooling system designed utilizing the Melcor CP2-15- 10B thermoelectric module. Wall temperature achieved with this system was - 36 ...

Science.gov (United States)

Figure 23 presented detailed layout of the cooling system designed for the Mach 6 hypersonic- transport. The distribution system consisted of thin-wall ...

Science.gov (United States)

... BFS Breadth-First Search BIS Biological Immune System CCNA Cisco-Certified Network Associate CDIS Computer Defense Immune System ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice ...

International Nuclear Information System (INIS)

The problem on the ratio between the instability of physical systems and tachyons is discussed. It is shown that the tachyons participation in the real physical process of the system rearranging does not contradict any principles. It is noted that the tachyons constitute the most significant element of the systems, identifying the instability relative to the phase transition into the stable state.

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

J-STORE (Japan)

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J-STORE (Japan)

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Contact scanner system in Wolsung NPP(model ESE-1565) is an early '70 equipment, so most of components are obsolete. To make it 100% compatible, PCBs for this system is the main object of the study. Most of components used in the system are not available ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

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Science.gov (United States)

... 2010-10-01 false Cost estimating system requirements. 252...Clauses 252.215-7002 Cost estimating system requirements. As...use the following clause: Cost Estimating System Requirements (DEC...

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The requirements for successful integration of a computer aided control system for multi degree of

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Sunflower 3 kW mercury Rankine power conversion system

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... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

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This paper discusses the state of the NASA and BAE SYSTEMS developments of SpaceWire. NASA has

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... 9 Integrated Battle Management System Data Link Architecture Common Mission Planring System MILSTAR and SATCOMs Common Aviation ...

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... POVs) overseas when space was available. ... information management system launched in 2004. ... Personally Procured Transportation (PPT) system ...

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... Title : DARPA Program Composition for Embedded Systems (PCES) Program Capstone Demonstration Video (Postprint) (CD-ROM). ...

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Page 1. Adaptive system and method for responding to computer network security attacks Abstract A dynamic network security ...

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... In this paper research aimed at creating a computer vision system to power such an optimal edging and ... ...

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)

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)

A heuristic algorithm that employs fuzzy logic is proposed to the power system transmission expansion planning problem. The algorithm is based on the divide to conquer strategy, which is controlled by the fuzzy system. The algorithm provides high quality solutions with the use of fuzzy decision making, which is based on nondeterministic criteria to guide the search. The fuzzy system provides a self-adjusting mechanism that eliminates the manual adjustment of parameters to each system being solved. (author)

International Nuclear Information System (INIS)

The Y2K problem may impact on nuclear installations in a number of ways because embedded systems are used in nuclear routine operation, monitoring and control system. The very simplest embedded systems are capable of performing only a single function or set of functions to meet a single predetermined purpose. In more complex systems the functioning of the embedded system is determined by an application program that enables the embedded system to be used for a particular purpose in a specific application. The simplest devices consist of a single microprocessor which may itself be packaged with other chips in a hybrid system or Application Specific Integrated Circuit (ASIC). Its input comes from a detector or sensor and its output goes to a switch or activator which may start or stop the operation of a positioning motors or, by operating a ...

International Nuclear Information System (INIS)

Inputs on radiological conditions forms the basis of implementation of effective exposure control to plant personnel in nuclear power station. Radiation monitoring system provides this input to the plant operator as well as to health physics group. Several design modifications have been incorporated in the Radiation Monitoring System at Tarapur Atomic Power Station (TAPS 3 and 4) over the similar systems at Kakrapar Atomic Power Station (KAPS) and Kaiga Generating Station (KGS). The radiological monitoring systems installed at TAPS unit 3 and 4 includes on line Radiation Data Acquisition System (RADAS), Emergency sampling system, effluent monitoring system and environmental monitoring system. The design changes and the versatile use of these systems are presented in this paper. (author)

International Nuclear Information System (INIS)

This paper presents case studies of economic feasibility of solar photovoltaic systems using the software AVES-F (Analysis of Economic Feasibility of Photovoltaic Systems), developed by the authors, considering cases of stand-alone and grid-connected systems. The software takes into account several factors that can influence the economic feasibility of these kind of systems, like load to be supplied, distance to the grid, the use regime of the system, applied subsidies and others. The main goal of this paper is to analyze some of these factors and to observe how they can affect the economics of PV systems for electricity generation. (authors)

British Library Electronic Table of Contents (United Kingdom)

The term biological motion is often used by researchers studying the patterns of movement generated by living forms and in sports. We studied a pattern recognition system of motion in sport using biological motion data. Biological motion data are acquired using a 3D motion capture system. However, 3D motion capture systems are very expensive. In this article, a biological motion capture system was built using acceleration sensors. Our proposed system uses the technique of Gaussian fitting and regression analysis. We tested our proposed system in pattern recognition of outdoor tennis and its evaluations.

Energy Technology Data Exchange (ETDEWEB)

This guide is intended to provide the necessary guidance to successfully manage the NAVMED Navy Occupational Health Information Management System (NOHIMS) at NAVMED sites and the NAVSEA Occupational Safety and Health Record Keeping System (OSHRKS) at NAVSEA sites. Outlines procedures to manage system operations, procedures to resolve hardware, software and communications problems, and procedures outside the realm of system operations that are required for a successful system. This guide is intended for the System and Functional Managers use. The System Manager is the individual designated to provide overall ADP management to the entire local configuration. Usually responsible for file backup, daily operations of the CPU, security, supplies, equipment, operating software and technical ADP guidance to the local functional users.

International Nuclear Information System (INIS)

The Reliability Data Management System (RDMS) for safety systems of PHWR type plants has been developed and utilized in the reliability analysis of the special safety systems of Wolsong Unit 1 with plant overhaul period lengthened. The RDMS is developed for the periodic efficient reliability analysis of the safety systems of Wolsong Unit 1. In addition, this system provides the function of analyzing the effects on safety system unavailability if the test period of a test procedure changes as well as the function of optimizing the test periods of safety-related test procedures. The RDMS can be utilized in handling the requests of the regulatory institute actively with regard to the reliability validation of safety systems.

Energy Technology Data Exchange (ETDEWEB)

A novel adaptive stabilizer, called an Adaptive Governor Power System Stabilizer (AGPSS), which operated on the governor turbine system, was described. There has been extensive research on adaptive excitation control of generators in power systems with the goal of achieving better dynamic performance. AGPSS tracks the frequency and damping of oscillations in a power system, and adjusts to ensure that there is always sufficient damping in the system. There is no interaction between stabilizers on different generating units, and each one acts independently, consuming oscillation energy locally. These stabilizers are easy to design and this facilitates their use in multimachine systems. Results obtained by nonlinear simulation of a single-machine and a three-machine power system were discussed, illustrating the effectiveness of the stabilizers ...

Energy Technology Data Exchange (ETDEWEB)

A decoupled characteristic between the damping of a specific swing mode and the stabilizer gain of the corresponding machine in multimachine power systems is identified. Using this decoupled characteristic a power system stabilizer (PSS) synthesis approach which is based on the phase compensation concept is verified on a 9-machine system and the dynamic performance of this system is significantly improved. This method is proved to be effective, simple and it can provide useful guidance for the PSS field tuning.

Energy Technology Data Exchange (ETDEWEB)

A semi-automatic system which considers operation in a face by monitoring technological parameters of an extraction vehicle and a longwall conveyor is examined. The system records in tabular form the location, progress made, operating and down time of an extraction vehicle and operating and down time of the conveyor. A description of the operating principle system and systems for arrangement of the remote sensing and central recording device are presented. (Note: extraction vehicle not identified: LTN)

International Nuclear Information System (INIS)

This book contains the proceedings of the International Topical Meeting on Remote Systems and Robotics in Hostile Environments. It is organized under the following sessions: Worldwide Applications Overview; Operating Mobile Systems; Sensors and Control Systems; Space Applications; Reactor Operations and Surveillance; Remote Equipment for Hazardous Operations; Future Mobile System; Mining and Construction Operations; Special Applications; Hot Cell Applications; Processing; Reactor Operations and Maintenance; Decontamination and Waste Handling; Remote Handling Development and Demonstration.

Energy Technology Data Exchange (ETDEWEB)

The basic design of a system installed in the Columbus, Ohio Zoo is described. The distribution system is described in detail. The control system is microprocessor controlled, with about 50 monitoring points. Preliminary evaluations have indicated that the system can operate with an overall coefficient of performance in excess of 3.5. 1 figure.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe instrumentation and control (I&C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I&C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I&C systems of the next generation of liquid metal reactor (LMR) plants.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe the embedded computer systems approach taken at Experimental Breeder Reactor II (EBR-II) for non-safety related systems. The hardware and software structures for typical embedded systems are presented The embedded systems development process is described. Three examples are given which illustrate typical embedded computer applications in EBR-II.

Energy Technology Data Exchange (ETDEWEB)

Using the Philips DRM distributed real-time multiprocessing system, designers can implement high-performance computer systems using VME hardware and the C programming language. The system provides a virtual-processing environment in which several 68000 CPUs share the workload. There are no centralized components, and tasks can be assumed by the rest of a system in the event of an individual processor's failure.