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Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
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1

Single mode pulsed dye laser oscillator  

DOE Patents (OSTI)

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

Hackel, R.P.

1992-11-24T23:59:59.000Z

2

Fundamental modes of a trapped probe photon in optical fibers conveying periodic pulse trains  

SciTech Connect

Wave modes induced by cross-phase reshaping of a probe photon in the guiding structure of a periodic train of temporal pulses are investigated theoretically with emphasis on exact solutions to the wave equation for the probe. The study has direct connection with recent advances on the issue of light control by light, the focus being on the trapping of a low-power probe by a temporal sequence of periodically matched high-power pulses of a dispersion-managed optical fiber. The problem is formulated in terms of the nonlinear optical fiber equation with averaged dispersion, coupled to a linear equation for the probe including a cross-phase modulation term. Shape-preserving modes which are robust against the dispersion are shown to be induced in the probe, they form a family of mutually orthogonal solitons the characteristic features of which are determined by the competition between the self-phase and cross-phase effects. Considering a specific context of this competition, the theory predicts two degenerate modes representing a train of bright signals and one mode which describes a train of dark signals. When the walk-off between the pump and probe is taken into consideration, these modes have finite-momentum envelopes and none of them is totally transparent vis-a-vis the optical pump soliton.

Dikande, Alain M. [Laboratory of Research on Advanced Materials and Nonlinear Sciences (LaRAMaNS), Department of Physics, Faculty of Science, University of Buea, P.O. Box 63, Buea (Cameroon)

2010-01-15T23:59:59.000Z

3

Pulse mode readout techniques for use with non-gridded industrial ionization chambers  

SciTech Connect

Highly sensitive readout technique for precision long-term radiation measurements has been developed and tested in the Radiation Control Department at Jefferson Lab. The new electronics design is used to retrieve ionization data in a pulse mode. The dedicated data acquisition system works with M=Audio Audiophile 192 High-Definition 24-bit/192 kHz audio cards, taking data in continuous waveform recording mode. The on-line data processing algorithms extract signals of the ionization events from the data flow and measure the ionization value for each event. Two different ion chambers are evaluated. The first is a Reuter-Stokes Argon-filled (at 25 atm) High Pressure Ionization Chamber (HPIC), commonly used as a detector part in many GE Reuter-Stokes instruments of the RSS series. The second is a VacuTec Model 70181, 5 atm Xenon-filled ionization chamber. Results for both chambers indicate that the techniques allow using industrial ICs for high sensitivity and precision long-term radiation measurements, while at the same time providing information about spectral characteristics of the radiation fields.

Popov, Vladimir E. [JLAB; Degtiarenko, Pavel V. [JLAB

2011-10-01T23:59:59.000Z

4

Maximum relative excitation of a specific vibrational mode via optimum laser-pulse duration  

E-Print Network (OSTI)

For molecules and materials responding to femtosecond-scale optical laser pulses, we predict maximum relative excitation of a Raman-active vibrational mode with period T when the pulse has a full-width-at-halfmaximum duration tau approximate to 0.42T. This result follows from a general analytical model, and is precisely confirmed by detailed density-functional-based dynamical simulations for C(60) and a carbon nanotube, which include anharmonicity, nonlinearity, no assumptions about the polarizability tensor, and no averaging over rapid oscillations within the pulse. The mode specificity is, of course, best at low temperature and for pulses that are electronically off-resonance, and the energy deposited in any mode is proportional to the fourth power of the electric field.

Zhou, Xiang; Lin, Zhibin; Jiang, Chenwei; Gao, Meng; Allen, Roland E.

2010-01-01T23:59:59.000Z

5

Electromagnetic vacuum energy for two parallel slabs in terms of surface, wave guide and photonic modes  

E-Print Network (OSTI)

The formulation of the Lisfshitz formula in terms of real frequencies is reconsidered for half spaces described by the plasma model. It is shown that besides the surface modes (for the TM polarization), and the photonic modes, also waveguide modes must be considered.

Bordag, M

2011-01-01T23:59:59.000Z

6

Electromagnetic vacuum energy for two parallel slabs in terms of surface, wave guide and photonic modes  

E-Print Network (OSTI)

The formulation of the Lifshitz formula in terms of real frequencies is reconsidered for half spaces described by the plasma model. It is shown that besides the surface modes (for the TM polarization), and the photonic modes, also waveguide modes must be considered.

M. Bordag

2011-11-28T23:59:59.000Z

7

Experimental Investigation of the Reflection Mode Micro Laser Propulsion under Highly Frequent and Multi Pulse Laser  

SciTech Connect

Micro laser propulsion used for some space tasks of micro-satellites are preferred to providing small thrust and high specific impulse while keeping power consumption low. Most previous work on micro laser propulsion are about transmission mode (T-mode) using a CW laser. In this article, a pulsed fiber laser is used to study the micro laser propulsion performance under reflection mode. Multi pulse (ranged from 100 to 2000) tests are conducted on a double base propellant with the vacuum less than 10 Pa. The laser frequency is 20 kHz and two kinds of instantaneous power density 4.77x10{sup 6} W/cm{sup 2} and 2.39x10{sup 7} W/cm{sup 2} are used. It is found that the momentum coupling coefficient C{sub m} and the mean thrust F increases with the increasing pulse numbers, which is different to the previous work. By adjusting the irradiation time T, it is easy to get a large mean thrust, up to mN. When the energy density is the same, C{sub m}, I{sub sp}, F and {eta} increase with the increasing power density. Also I{sub sp} and {eta} are very low, laser ablation is insufficiently under the current condition. 3D Morphology of the ablation hole is obtained by confocal microscope for the first time.

Zhang Xinghua; Cai Jian [Microelectronic Equipment Technology Department, Institute of Microelectronics of the Chinese Academy of Sciences, Beijing, 100029 (China); Li Long [Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 (China)

2011-11-10T23:59:59.000Z

8

LONG-TERM MONITORING OF MODE SWITCHING FOR PSR B0329+54  

SciTech Connect

The mode-switching phenomenon of PSR B0329+54 is investigated based on the long-term monitoring from 2003 September to 2009 April made with the Urumqi 25 m radio telescope at 1540 MHz. At that frequency, the change of relative intensity between the leading and trailing components is the predominant feature of mode switching. The intensity ratios between the leading and trailing components are measured for the individual profiles averaged over a few minutes. It is found that the ratios follow normal distributions, where the abnormal mode has a greater typical width than the normal mode, indicating that the abnormal mode is less stable than the normal mode. Our data show that 84.9% of the time for PSR B0329+54 was in the normal mode and 15.1% was in the abnormal mode. From the two passages of eight-day quasi-continuous observations in 2004, supplemented by the daily data observed with the 15 m telescope at 610 MHz at Jodrell Bank Observatory, the intrinsic distributions of mode timescales are constrained with the Bayesian inference method. It is found that the gamma distribution with the shape parameter slightly smaller than 1 is favored over the normal, log-normal, and Pareto distributions. The optimal scale parameters of the gamma distribution are 31.5 minutes for the abnormal mode and 154 minutes for the normal mode. The shape parameters have very similar values, i.e., 0.75{sup +0.22}{sub -0.17} for the normal mode and 0.84{sup +0.28}{sub -0.22} for the abnormal mode, indicating that the physical mechanisms in both modes may be the same. No long-term modulation of the relative intensity ratios was found for either mode, suggesting that the mode switching was stable. The intrinsic timescale distributions, constrained for this pulsar for the first time, provide valuable information to understand the physics of mode switching.

Chen, J. L.; Wang, N.; Liu, Z. Y.; Yuan, J. P. [Xinjiang Astronomical Observatory, 150, Science-1 Street, Urumqi, Xinjiang, 830011 (China); Wang, H. G. [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China); Lyne, A. [University of Manchester, Jodrell Bank (United Kingdom); Jessner, A.; Kramer, M., E-mail: hgwang@gzhu.edu.cn [Max-Planck Institute for Radio Astronomy, Bonn 53121 (Germany)

2011-11-01T23:59:59.000Z

9

Enhanced production of ECR plasma by using pulse mode microwaves on a large bore ECRIS with permanent magnets  

Science Conference Proceedings (OSTI)

In order to enhance the efficiency of an electron cyclotron resonance (ECR) plasma for a broad and dense ion beam source at low pressure, the magnetic field configuration is constructed by all permanent magnets. By using the pulse mode, we aim at the generation of plasma with parameters that cannot be achieved in the CW mode at microwave frequencies of 11-13GHz, under the constraint of the same average incident microwave powers. It is found that the total beam currents are increased by the pulse mode operation compared with the case of the CW mode. According to probe measurements of the ECR plasma, it is found that the electron density in the pulse mode is larger than that in the CW mode, while the electron temperatures in the pulse mode are lower than that in the CW mode. These results are discussed from the viewpoint of relaxation times obtained on plasma parameters and ECR efficiency. The cause of the beam current increment and operational windows spread due to the pulse mode are also discussed on these parameters suitable to production of molecular/cluster ions.

Kato, Yushi; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Sato, Fuminobu; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ., 2-1 Ymadaoka, Suita-shi, Osaka, 565-0871 (Japan)

2012-11-06T23:59:59.000Z

10

Evolution of the shape and spectrum of ultrashort pulses upon active mode locking  

SciTech Connect

Time sweeps of the autocorrelation function and the emission spectrum of an actively mode-locked Nd:YAG laser are recorded during the development of quasi-continuous pre-lasing maintained by a negative feedback loop. It is found that higher Hermitian-Gaussian supermodes are present at the transient stage of radiation, and the ultrashort pulse shortening is accompanied by the shift of the lasing spectrum to the red wing of the gain band of the active medium. (control of laser radiation parameters)

Zaporozhchenko, V A [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

2003-11-30T23:59:59.000Z

11

New regime of single-pulse lasing in fibre lasers with mode locking by nonlinear polarisation evolution  

Science Conference Proceedings (OSTI)

A new lasing regime has been obtained experimentally and as a result of numerical simulation of fibre lasers with mode locking by nonlinear polarisation evolution. This regime differs radically from the previously known regimes of stable single-pulse lasing and generation of wave packets with quasi-stochastic filling. The spectral and temporal features of the pulses generated in the new regime, as well as the possibilities of pulse compression, have been investigated. Simple criteria are formulated, which make it possible to identify rapidly the new lasing regime in experiment. (optical fibres, lasers and amplifiers. properties and applications)

Smirnov, Sergei V; Kobtsev, Sergey M; Kukarin, S V; Ivanenko, A V [Novosibirsk State University, Novosibirsk (Russian Federation)

2012-09-30T23:59:59.000Z

12

Synchronization and cell search algorithms in 3GPP long term evolution systems (FDD mode)  

Science Conference Proceedings (OSTI)

In this paper initial downlink synchronization (sync) and cell identification algorithms for the 3rd generation partnership project (3GPP) long term evolution (LTE) systems are presented. The frequency division duplex (FDD) mode is used in the downlink ... Keywords: 3GPP LTE, MIMO, OFDM, cell search, frequency and time synchronization

Abdo N. Gaber; Loay D. Khalaf; Ahmad M. Mustafa

2012-02-01T23:59:59.000Z

13

Design and optimization of 6li neutron-capture pulse mode ion chamber  

E-Print Network (OSTI)

The purpose of this research is to design and optimize the performance of a unique, inexpensive 6Li neutron-capture pulse-mode ion chamber (LiPMIC) for neutron detection that overcomes the fill-gas contamination stemming from outgas of detector components. This research also provides a demonstration of performance of LiPMICs. Simulations performed with GARFIELD, a drift-chamber simulation package for ion transport in an electrostatic field, have shown that argon-methane mixtures of fill-gas allow maintenance of electron drift velocity through a surprisingly wide range of fill-gas content. During the design stage of LiPMIC development, the thicknesses of lithium metallization layer, the neutron energy conversion site of the detector, and the thickness of neutron moderator, the high-density polyethylene body, are optimized through analytical and MCNPX calculations. Also, a methodology of obtaining the suitable combination of electric field strength, electron drift velocity, and fill-gas mixtures has been tested and simulated using argon-methane gas mixtures. The LiPMIC is shown to have comparable efficiency to 3He proportional counters at a fraction of cost. Six-month long baseline measurements of overall detector performance shows there is a 3% reduction in total counts for 252Cf sources, which provides a good indicator for the longevity of the detector.

Chung, Kiwhan

2008-08-01T23:59:59.000Z

14

Improved performance of Li-ion cells under pulsed load using double-layer capacitors in a hybrid circuit mode  

DOE Green Energy (OSTI)

Electrical characteristics of hybrid power sources consisting of Li-ion cells and double-layer capacitors were studied at 25 C and {minus}20 C. The cells were initially evaluated for pulse performance and then measured in hybrid modes of operation where they were coupled with the high-power capacitors. Cells manufactured by Panasonic measured at 25 C delivered full capacities of 0.76 Ah for pulses up to 3A and cells from A and T delivered full capacities of 0.73 Ah for pulses up to 4A. Measured cell resistances were 0.15 ohms and 0.12 ohms, respectively. These measurements were repeated at {minus}20 C. Direct coupling of the cells and capacitors (coupled hybrid) using 10F Panasonic capacitors in a 8F series/parallel combination extended the full capacity pulse limits (3.0V threshold) to 5.6A for the Panasonic cells and to 9A for the A and T cells. A similar arrangement using 100F capacitors from Elna in a 60F combination increased the Panasonic cell limit to 10 A. Operation in an uncoupled hybrid mode using uncoupled cell/capacitor discharge allowed fill cell capacity usage at 25 C up to the capacitor discharge limit and showed a factor of 5 improvement in delivered capacity at {minus}20 C.

ROTH,EMANUEL P.; NAGASUBRAMANIAN,GANESAN

2000-02-07T23:59:59.000Z

15

Nonlinear Normal Mode Initialization of a Limited-Area Model: Inclusion of All Beta Terms in the Linearized Model Equations  

Science Conference Proceedings (OSTI)

A nonlinear normal mode initialization method with all of the beta terms included in the linearized model equations is formulated for a limited-area model. It is the extension of an earlier method examining the sensitivity of nonlinear normal ...

S. J. Bijlsma

1991-04-01T23:59:59.000Z

16

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17

Negative ion rich plasmas in continuous and pulsed wave modes in a minimum-B magnetic field  

Science Conference Proceedings (OSTI)

Generation of hydrogen negative ion rich plasmas is investigated in continuous wave (CW) and pulse modulated (PM) wave modes of 2.45 GHz in a minimum-B magnetic field. The waves are launched directly into the plasma device and utilize wave particle resonances for high density plasma generation. In CW operation, the chamber is divided into two sections, namely, the source and downstream region, separated by a transverse magnetic field that allows only cold electrons ({approx}1 eV) into the downstream region helpful for the generation of negative ions. The H{sup -} density is measured by the second derivative beat method and is compared with the values obtained from a steady state model and the extracted current density. In the pulsed mode, temporal filtering generates negative ion rich plasmas in the afterglow phase. The H{sup -} density in the afterglow is estimated using saturation current ratio method and the results are compared with a time dependent model using particle balance equations. The essential idea in both the filtering techniques is to assist generation of negative ions and prevent its destruction by hot electrons.

Sahu, Debaprasad; Pandey, Shail; Aneja, Jyoti; Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

2012-12-15T23:59:59.000Z

18

Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes  

SciTech Connect

This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

Dr. Anatoly Shteynberg, PhD

2006-08-17T23:59:59.000Z

19

Non-Normal Mode Initialization: Formulation and Application to Inclusion of the ?-Terms in the Linearization  

Science Conference Proceedings (OSTI)

The non-normal mode initialization, i.e., an initialization scheme which does not require an explicit computation of the eigenmodes of the linearized equations, is reviewed. The formulation of such a scheme is given in abstract form, in the case ...

Régis Juvanon Du Vachat

1988-10-01T23:59:59.000Z

20

Microsoft PowerPoint - Arseneau_EIA_ShortTermDriversofEnergyPrices.ppt [Compatibility Mode]  

U.S. Energy Information Administration (EIA) Indexed Site

SHORT-TERM ENERGY PRICES: SHORT-TERM ENERGY PRICES: WHAT DRIVERS MATTER MOST? DAVID M. ARSENEAU FEDERAL RESERVE BOARD U.S. Energy Information Administration & Johns Hopkins University - SAIS FEDERAL RESERVE BOARD Johns Hopkins University SAIS 2010 Energy Conference Washington, D.C., U.S.A. A il 6 2010 April 6, 2010 BROAD COMMODITY PRICES SINCE 2000 Short-term Energy Prices: What Drivers Matters Most? BROAD COMMODITY PRICES SINCE 2000 April 6, 2010 Seminar: 2010 EIA/SAIS Energy Conference 2 A (GROSSLY OVERSIMPLIFIED) FRAMEWORK Short-term Energy Prices: What Drivers Matters Most? A (GROSSLY OVERSIMPLIFIED) FRAMEWORK ...  Two candidate explanations:  "Fundamentals"  Fundamentals  Trend price movements appear broadly interpretable through lens of fundamental market developments...

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Petterssen's “Type B”Cyclogenesis in Terms of Discrete, Neutral Eady Modes  

Science Conference Proceedings (OSTI)

We investigate B. Farrell's hypothesis that the development of a surface cyclone with the passage of an upper trough, as observed by S. Pettessen and coworkers, may be understood in terms of an initial-value problem on the Eady model. We consider ...

Richard Rotunno; Maurizio Fantini

1989-12-01T23:59:59.000Z

22

Coherent propagation of a single photon in a lossless medium: $0?$ pulse formation, slow photon, storage and retrieval in multiple temporal modes  

E-Print Network (OSTI)

Single-photon coherent optics represents a fundamental importance for the investigation of quantum light-matter interactions. While most work has considered the interaction in the steady-state regime, here we demonstrate that a single-photon pulse shorter than any relaxation time in a medium propagates without energy loss and is consistently transformed into a zero-area pulse. A general analytical solution is found for photon passage through a cold ensemble of $\\Lambda$-type atoms confined inside a hollow core of a single-mode photonic-crystal fiber. We use the robust far off-resonant Raman scheme to control the pulse reshaping by an intense control laser beam and show that in the case of cw control field, for exact two-photon resonance, the outgoing photon displays an oscillating temporal distribution, which is the quantum counterpart of a classical field ringing, while for nonzero two-photon detuning a slow photon is produced. We demonstrate also that a train of readout control pulses coherently recalls the stored photon in many well-separated temporal modes, thus producing time-bin entangled single-photon states. Such states, which allow sharing quantum information among many users, are highly demanded for applications in long-distance quantum communication.

Shushan Petrosyan; Yuri Malakyan

2013-10-04T23:59:59.000Z

23

LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE  

DOE Green Energy (OSTI)

Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.

J. E. O'Brien; R. C. O'Brien; X. Zhang; G. Tao; B. J. Butler

2011-11-01T23:59:59.000Z

24

Long-Term Variation of the Principal Mode of Boreal Spring Hadley Circulation Linked to SST over the Indo-Pacific Warm Pool  

Science Conference Proceedings (OSTI)

The variability of the boreal spring [March–May (MAM)] Hadley circulation (HC) is investigated, focusing on the long-term variation of the first principal mode for 1951–2008, which is an equatorially asymmetric mode (AM) with the rising branch ...

Juan Feng; Jianping Li; Fei Xie

2013-01-01T23:59:59.000Z

25

Pulse-shape discrimination of scintillation from alpha and beta particles with liquid scintillator and Geiger-mode multipixel avalanche diodes  

E-Print Network (OSTI)

A successfull application of Geiger-mode multipixel avalanche diodes (GMAPDs) for pulse-shape discrimination in alpha-beta spectrometry using organic liquid scintillator is described in this paper. Efficient discrimination of alpha and beta components in the emission of radioactive isotopes is achieved for alpha energies above 0.3 MeV. The ultra-compact design of the scintillating detector helps to efficiently suppress cosmic-ray and ambient radiation background. This approach allows construction of hand-held robust devices for monitoring of radioactive contamination in various environmental conditions.

I. Kreslo; I. Badhrees; S. Delaquis; A. Ereditato; S. Janos; M. Messina; U. Moser; B. Rossi; M. Zeller

2011-05-23T23:59:59.000Z

26

Improved long-term electrical stability of pulsed high-power diodes using dense carbon fiber velvet cathodes  

Science Conference Proceedings (OSTI)

The influence of fibrous velvet cathodes on the electrical stability of a planar high-power diode powered by a {approx}230 kV, {approx}110 ns pulse has been investigated. The current density was on the order of {approx}123 A/cm{sup 2}. A combination of time-resolved electrical and optical diagnostics has been employed to study the basic phenomenology of the temporal and spatial evolution of the diode plasmas. Additionally, an impedance model was used to extract information about this plasma from voltage and current profiles. The results from the two diagnostics were compared. By comparison with commercial polymer velvet cathode, the dense carbon fiber velvet cathode showed superior long-term electrical stability as judged by the change in cathode turn-on field, ignition delays, diode impedance, and surface plasma characteristics during the voltage flattop, a promising result for applications where reliable operation at high power is required. Finally, it was shown that the interaction of the electron beam with the stainless steel anode did not lead to the formation of anode plasma. These results may be of interest to the high power microwave systems with cold cathodes.

Yang Jie; Shu Ting; Wang Hui [College of Opto-Electric Science and Engineering, National University of Defense Technology, Hunan 410073 (China)

2012-07-15T23:59:59.000Z

27

Three XMM-Newton observations of the Anomalous X-ray Pulsar 1E 1048.1-5937: long term variations in spectrum and pulsed fraction  

E-Print Network (OSTI)

We report the results of a recent (July 2004) XMM-Newton Target of Opportunity observation of the Anomalous X-ray pulsar 1E 1048.1-5937, together with a detailed re-analysis of previous observations carried out in 2000 and 2003. In July 2004 the source had a 2-10 keV flux of 6.2$\\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$ and a pulsed fraction P$_F$=0.68. The comparison of the three data sets shows the presence of an anti-correlation between flux and pulsed fraction, implying that previous estimates of the source energetics based on the assumption of a large and constant pulsed fraction might be significantly underestimated. The source spectrum is well described by a power law plus blackbody model (kT~0.63 keV, photon index $\\Gamma$~2.7-3.5) or, alternatively, by the sum of two blackbodies of which the hotter is Comptonized by relativistic electrons. In this case the temperatures are kT${_1}$~0.2-0.3 keV and kT${_2}$~0.4-0.5 keV and the emitting area of the cooler component is consistent with the whole neutron star surface. The long term luminosity variation of a factor >~2 is accompanied by relatively small variations in the spectral shape. Phase resolved spectroscopy indicates a harder spectrum in correspondence of the pulse maximum. No spectral features have been detected with 4$\\sigma$ limits on the equivalent width in the range ~10-220 eV, depending on line energy and width.

A. Tiengo; S. Mereghetti; R. Turolla; S. Zane; N. Rea; L. Stella; G. L. Israel

2005-03-17T23:59:59.000Z

28

Feasibility and Calculated Performance of Near-Term Pulse Energy Storage Components for Use in Mass Transit Vehicles  

Science Conference Proceedings (OSTI)

Electrically driven mass transit vehicles—trams, light rail, and buses—are typically powered from the utility grid via third-rail or overhead catenary mechanisms. These feed systems supply adequate traction power, but they limit vehicle flexibility and, for safety and aesthetic reasons, are generally undesirable. Electric vehicles can carry their own onboard batteries, but existing and projected near-term battery systems are too bulky for most day-long mass transit uses. Enhancing third-rail ...

2003-07-31T23:59:59.000Z

29

Novel concept for pulse compression via structured spatial energy distribution  

E-Print Network (OSTI)

We present a novel concept for pulse compression scheme applicable at RF, microwave and possibly to optical frequencies based on structured energy distribution in cavities supporting degenerate band-edge (DBE) modes. For such modes a significant fraction of energy resides in a small fraction of the cavity length. Such energy concentration provides a basis for superior performance for applications in microwave pulse compression devices (MPC) when compared to conventional cavities. The novel design features: far larger loaded quality factor of the cavity and stored energy compared to conventional designs, energy feeding and extraction at the cavity center, substantial reduction of the cavity size by use of equivalent lumped circuits for low energy sections of the cavity, controlled pulse shaping via engineered extraction techniques. The presented concepts are general, in terms of equivalent transmission lines, and can be applied to a variety of realistic guiding structures.

Tamma, Venkata Ananth; Capolino, Filippo

2013-01-01T23:59:59.000Z

30

Pulsed-neutron monochromator  

DOE Patents (OSTI)

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, H.A. Jr.

1984-01-01T23:59:59.000Z

31

Method to calibrate fission chambers in Campbelling mode  

Science Conference Proceedings (OSTI)

Fission chambers are neutron detectors which are widely used to instrument experimental reactors such as material testing reactors or zero power reactors. In the presence of a high level mixed gamma and neutron flux, fission chambers can be operated in Campbelling mode (also known as 'fluctuation mode' or 'mean square voltage mode') to provide reliable and precise neutron related measurements. Fission chamber calibration in Campbelling mode (in terms of neutron flux) is usually done empirically using a calibrated reference detector. A major drawback of this method is that calibration measurements have to be performed in a neutron environment very similar to the one in which the calibrated detector will be used afterwards. What we propose here is a different approach based on characterizing the fission chamber response in terms of fission rate. This way, the detector calibration coefficient is independent from the neutron spectrum and can be determined prior to the experiment. The fissile deposit response to the neutron spectrum can then be assessed independently by other means (experimental or numerical). In this paper, the response of CEA made miniature fission chambers in Campbelling mode is studied. We use a theoretical model of the signal to calculate the calibration coefficient. Input parameters of the model come from statistical distribution of individual pulses. Supporting measurements have been made in the CEA Cadarache zero power reactor MINERVE. Results are compared to an empirical Campbelling mode calibration.

Benoit Geslot; Troy C. Unruh; Philippe Filliatre; Christian Jammes; Jacques Di Salvo; Stéphane Bréaud; Jean-François Villard

2011-06-01T23:59:59.000Z

32

A compact high voltage pulse generator  

SciTech Connect

A compact, easily transportable, pulse generator has been developed for a variety of applications that require a pulse duration in the range of 1 {mu} sec., voltages from 150 to 300 KV and current levels from 2,000 to 3,000 amps. The generator has a simple cylindrical configuration and modular construction to facilitate assembly and service. The generator may be operated single-pulse or repetitively at pulse repetition rates to 50 Hz in a burst mode.

Rohwein, G.J.; Babcock, S.R.

1994-07-01T23:59:59.000Z

33

Passive mode locking of a XeCl laser  

SciTech Connect

Passive mode locking of a 20-ns pulse duration XeCl laser was achieved. A modulation of 90% and less than 2-ns pulses are reported using Coumarin 1 and Auramine-0 dyes as saturable absorbers.

Efthimiopoulos, T.

1984-08-15T23:59:59.000Z

34

Storage Ring Operation Modes  

NLE Websites -- All DOE Office Websites (Extended Search)

Longitudinal bunch profile and Up: APS Storage Ring Parameters Longitudinal bunch profile and Up: APS Storage Ring Parameters Previous: Source Parameter Table Storage Ring Operation Modes Standard Operating Mode, top-up Fill pattern: 102 mA in 24 singlets (single bunches) with a nominal current of 4.25 mA and a spacing of 153 nanoseconds between singlets. Lattice configuration: Low emittance lattice with effective emittance of 3.1 nm-rad and coupling of 1%. Bunch length (rms): 33.5 ps. Refill schedule: Continuous top-up with single injection pulses occurring at a minimum of two minute intervals, or a multiple of two minute intervals. Special Operating Mode - 324 bunches, non top-up Fill pattern: 102 mA in 324 uniformly spaced singlets with a nominal single bunch current of 0.31 mA and a spacing of 11.37 nanoseconds between singlets.

35

Group velocity and pulse lengthening of mismatched laser pulses in plasma channels  

SciTech Connect

Analytic solutions are presented to the non-paraxial wave equation describing an ultra-short, low-power, laser pulse propagating in aplasma channel. Expressions for the laser pulse centroid motion and laser group velocity are derived, valid for matched and mismatchedpropagation in a parabolic plasma channel, as well as in vacuum, for an arbitrary Laguerre-Gaussian laser mode. The group velocity of amismatched laser pulse, for which the laser spot size is strongly oscillating, is found to be independent of propagation distance andsignificantly less than that of a matched pulse. Laser pulse lengthening of a mismatched pulse owing to laser mode slippage isexamined and found to dominate over that due to dispersive pulse spreading for sufficiently long pulses. Analytic results are shown tobe in excellent agreement with numerical solutions of the full Maxwell equations coupled to the plasma response. Implications for plasmachannel diagnostics are discussed.

Schroeder, Carl; Benedetti, Carlo; Esarey, Eric; van Tilborg, Jeroen; Leemans, Wim

2011-07-07T23:59:59.000Z

36

Pulsed Power Technology and Application -- North America  

Science Conference Proceedings (OSTI)

This report describes pulsed power technologies and applications along with a market assessment of near-term market opportunities. Recommendations for initial activities also are presented.

1999-11-23T23:59:59.000Z

37

PULSE AMPLIFIER  

DOE Patents (OSTI)

The improvement of pulse amplifiers used with scintillation detectors is described. The pulse amplifier circuit has the advantage of reducing the harmful effects of overloading cause by large signal inputs. In general the pulse amplifier circuit comprises two amplifier tubes with the input pulses applied to one amplifier grid and coupled to the second amplifier tube through a common cathode load. The output of the second amplifier is coupled from the plate circuit to a cathode follower tube grid and a diode tube in connected from grid to cathode of the cathode follower tube. Degenerative feedback is provided in the second amplifier by coupling a signal from the cathode follower cathode to the second amplifier grid. The circuit proqides moderate gain stability, and overload protection for subsequent pulse circuits.

Johnstone, C.W.

1958-06-17T23:59:59.000Z

38

Advanced tokamak operating modes in TPX and ITER  

SciTech Connect

A program is described to develop the advanced tokamak physics required for an economic steady-state fusion reactor on existing (short-pulse) tokamak experiments; to extend these operating modes to long-pulse on TPX; and finally to demonstrate them in a long-pulse D-T plasma on ITER.

Nevins, W.M.

1994-12-31T23:59:59.000Z

39

Low-noise pulse conditioner  

DOE Patents (OSTI)

A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits. This circuit may be used for conditioning the sensor signal from the Fidler coil in a gas centrifuge for separation of isotopic gaseous mixtures.

Bird, D.A.

1981-06-16T23:59:59.000Z

40

Gating A 911 with a 412 using Mode 1 in Recycle Mode John Wertenbaker 5/8/07  

E-Print Network (OSTI)

is in Mode 1. The intent of this is to output 25 pulses, 100uSec apart. In reality, though, there will be a 5uSec interval between the pulse at address 4 and the next pulse at address 0. Not only does an interval between CE pulses of at least 50uSec. If it is clocked any faster than that, it will ignore

Princeton Plasma Physics Laboratory

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Mode trap  

DOE Patents (OSTI)

This report discusses a mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around it`s aperture and extending radially out toward it`s absorbing material layer.

Chojnacki, E.P.

1992-12-31T23:59:59.000Z

42

Experiments with Non-Normal-Mode Initialization of a Shallow-Water Limited-Area Model: Impact of Relaxation, Orography, and of an Extended Linearization Including Most of the ? Terms  

Science Conference Proceedings (OSTI)

A non-normal-mode initialization scheme, that is, an initialization scheme that does not require an explicit computation of the normal modes of the linearized equations, is considered. Such a scheme is applied to a shallow-water limited-area ...

Régis Juvanon Du Vachat

1992-09-01T23:59:59.000Z

43

Design and testing of high power, repetitively pulsed solid-state closing switches  

DOE Green Energy (OSTI)

Repetitively pulsed closing switches are often required in high-power physics experiments. Traditionally, ignitrons have been used for these applications. There are reasons why ignitrons have undesirable features, such as the high trigger current which causes electromagnetic interference, the arc instability and environmental concern with the mercury used in the switches. With the development of ever increasing power rating of solid-state switches, in particular thyristors, the designer has the tools to replace ignitrons with solid-state devices. Using as an example a recently designed and tested 10 kV, 80 kA high-power switch, the design philosophy for repetitively pulsed switches is developed. The parameters which impose the greatest challenge on the device, such as di/dt, temperature rise and reverse blocking voltage are investigated with respect to their capability when operating in the pulsed mode. Starting with the available device data sheet information and published results of the dependency of the number of life cycles as a function of the device temperature, it is shown how the overload capability of a device for short term pulsed applications can be exploited. The detailed design of a 2 Hz, 10{sup 8} cycle, 12.5 kV, 80 kA, 3 ms switch, with a short circuit capability of 250 kA, is presented. The paper concludes with a short summary about device limits in voltage, current amplitude and pulse length ratings for repetitively pulsed switches using available thyristors.

Boenig, H.J. [Los Alamos National Lab., NM (United States); Schwartzenberg, J.W.; Willinger, L.J.; Piccone, D.E. [Silicon Power Corp., Malvern, PA (United States); Lopez, D.A.; Smolleck, H.A. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Electrical and Computer Engineering

1997-04-01T23:59:59.000Z

44

Spatial hole burning in actively mode-locked quantum cascade lasers  

E-Print Network (OSTI)

A theoretical study of active mode-locking in quantum cascade lasers including spatial hole-burning is presented. It is found that spatial hole-burning reduces the pulse duration at the expense of slight pulse instability ...

Kartner, Franz X.

45

Active/passive mode-locked laser oscillator  

DOE Patents (OSTI)

A Q-switched/mode-locked Nd:YAG laser oscillator employing simultaneous active (electro-optic) and passive (saturable absorber) loss modulation within the optical cavity is described. This "dual modulation" oscillator can produce transform-limited pulses of duration ranging from about 30 psec to about 5 nsec with greatly improved stability compared to other mode-locked systems. The pulses produced by this system lack intrapulse frequency or amplitude modulation, and hence are idealy suited for amplification to high energies and for other applications where well-defined pulses are required. Also, the pulses of this system have excellent interpulse characteristics, wherein the optical noise between the individual pulses of the pulse train has a power level well below the power of the peak pulse of the train.

Fountain, William D. (Fremont, CA); Johnson, Bertram C. (Palo Alto, CA)

1977-01-01T23:59:59.000Z

46

Pulsed hydrojet  

DOE Patents (OSTI)

An underwater pulsed hydrojet propulsion system is provided for accelerating and propelling a projectile or other vessel. A reactant, such as lithium, is fluidized and injected into a water volume. The resulting reaction produces an energy density in a time effective to form a steam pocket. Thrust flaps or baffles direct the pressure from the steam pocket toward an exit nozzle for accelerating a water volume to create thrust. A control system regulates the dispersion of reactant to control thrust characteristics.

Bohachevsky, I.O.; Torrey, M.D.

1986-06-10T23:59:59.000Z

47

High-power pulse modulator with ignitron discharger  

SciTech Connect

The high-power pulse modulator described here is used to produce spatial gaseous discharges and has an improved, controllable charging circuit, which permits a type ITR-4 ignitron discharger to be employed in a frequency mode as the basic commutator. The modulator is utilized in two modes: at a pulse repetition frequency of 50 Hz pulses are formed that have a duration of 25 usec and energies up to 3.5 kJ and at a frequency of 200 Hz, the pulses have a duration of -2 usec and energies up to 600 J. In all conditions the modulator operated stably with a wide range of load changes.

Anisimova, T.E.; Akkuratov, E.V.; Artemov, V.A.; Gromovenko, V.M.; Kalinin, V.P.; Nikonov, V.P.

1985-10-01T23:59:59.000Z

48

Fast pulsed excitation wiggler or undulator  

DOE Patents (OSTI)

A fast pulsed excitation, electromagnetic undulator or wiggler, employing geometrically alternating substacks of thin laminations of ferromagnetic material, together with a single turn current loop excitation of the composite assembly, of such shape and configuration that intense, spatially alternating, magnetic fields are generated; for use as a pulsed mode undulator or wiggler radiator, for use in a Free Electron Laser (FEL) type radiation source or, for use in an Inverse Free Electron Laser (IFEL) charged particle accelerator.

Van Steenbergen, A.

1989-06-20T23:59:59.000Z

49

Fast pulsed excitation wiggler or undulator  

DOE Patents (OSTI)

A fast pulsed excitation, electromagnetic undulator or wiggler, employing geometrically alternating substacks of thin laminations of ferromagnetic material, together with a single turn current loop excitation of the composite assembly, of such shape and configuration that intense, spatially alternating, magnetic fields are generated; for use as a pulsed mode undulator or wiggler radiator, for use in a Free Electron Laser (FEL) type radiation source or, for use in an Inverse Free Electron Laser (IFEL) charged particle accelerator.

van Steenbergen, Arie (Shoreham, NY)

1990-01-01T23:59:59.000Z

50

Isolated trigger pulse generator  

DOE Patents (OSTI)

A trigger pulse generation system capable of delivering a multiplicity of isolated 100 kV trigger pulses with picosecond simultaneity. 2 figs.

Aaland, K.

1980-02-19T23:59:59.000Z

51

Mode conversion studies in TFTR  

SciTech Connect

Mode converted Ion Bernstein Waves (IBW) have important potential applications in tokamak reactors. These applications include on or off axis electron heating and current drive and the channeling of alpha particle power for both current drive and increased reactivity. Efficient mode conversion electron heating with a low field side antenna, with both on and off axis power deposition, has been demonstrated for the first time in TFTR in D{sup 3}He-{sup 4}He plasmas. Up to 80% of the Ion Cyclotron Range of Frequency (ICRF) power is coupled to electrons at the mode conversion surface. Experiments during deuterium and tritium neutral beam injection (NBI) indicate that good mode conversion efficiency can be maintained during NBI if sufficient {sup 3}He is present. No evidence of strong alpha particle heating by the IBW is seen. Recent modeling indicates that if the mode converted IBW is preferentially excited off the horizontal midplane then the resultant high poloidal mode number wave may channel alpha particle power to either electrons or ions. In TFTR both the propagation of the IBW and its effect on the alpha particle population is being investigated. Experiments with 2 MW of ICRF power launched with {+-} 90{degree} antenna phasing for current drive show that electron heating and sawtooth activity depend strongly on the direction of the launched wave. The noninductively driven current could not be experimentally determined in these relatively high plasma current, short pulse discharges. Experiments at higher RF power and lower plasma current are planned to determine on and off axis current drive efficiency.

Majeski, R.; Fisch, N.J.; Adler, H.

1995-03-01T23:59:59.000Z

52

Clouds Height and Aerosol Dynamic Monitoring by Micro Pulse Backscattering Eye-safe Lidar  

E-Print Network (OSTI)

Real-time, clouds height monitoring, attenuation length measurement and remote atmospheric homogeneity sensing by micro pulse Lidar (MPL) is proposed for use together with UV-laser slant-path extinction measurements in the Pierre Auger experiment. The goal of the research reported here is to determine the feasibility of such a sensor for quatitative measurements during an experiment in autonomous mode regardless of weather. Preliminary results of an atmosphere sensing at the Pierre Auger site in Nov.1998 by micro pulse Lidar are presented and discussed. 1 Introduction The long term measurements of the atmospheric turbidity, meteovisibility, haze optical thickness and cloud base height are very important for the surface radiation budget and for climate modeling in general. These data are necessary both, for scientic use, as in the detection of extremely high energy cosmic rays by the uorescence technique [1], and for applied environmental monitoring, as in air trac control for...

Pershin And Lyash

1999-01-01T23:59:59.000Z

53

Cluster Compatibility Mode  

NLE Websites -- All DOE Office Websites (Extended Search)

Cluster Compatibility Mode Cluster Compatibility Mode Edison compute nodes run a stripped down Linux operating system called Compute Node Linux (CNL). Some standard Linux services,...

54

DIFFERENTIAL PULSE HEIGHT DISCRIMINATOR  

DOE Patents (OSTI)

Pulse-height discriminators are described, specifically a differential pulse-height discriminator which is adapted to respond to pulses of a band of amplitudes, but to reject pulses of amplitudes greater or less than tbe preselected band. In general, the discriminator includes a vacuum tube having a plurality of grids adapted to cut off plate current in the tube upon the application of sufficient negative voltage. One grid is held below cutoff, while a positive pulse proportional to the amplltude of each pulse is applled to this grid. Another grid has a negative pulse proportional to the amplitude of each pulse simultaneously applied to it. With this arrangement the tube will only pass pulses which are of sufficlent amplitude to counter the cutoff bias but not of sufficlent amplitude to cutoff the tube.

Test, L.D.

1958-11-11T23:59:59.000Z

55

H-Mode Turbulence, Power Threshold, ELM, and Pedestal Studies in NSTX  

SciTech Connect

High-confinement mode (H-mode) operation plays a crucial role in NSTX [National Spherical Torus Experiment] research, allowing higher beta limits due to reduced plasma pressure peaking, and long-pulse operation due to high bootstrap current fraction. Here, new results are presented in the areas of edge localized modes (ELMs), H-mode pedestal physics, L-H turbulence, and power threshold studies. ELMs of several other types (as observed in conventional aspect ratio tokamaks) are often observed: (1) large, Type I ELMs, (2) ''medium'' Type II/III ELMs, and (3) giant ELMs which can reduce stored energy by up to 30% in certain conditions. In addition, many high-performance discharges in NSTX have tiny ELMs (newly termed Type V), which have some differences as compared with ELM types in the published literature. The H-mode pedestal typically contains between 25-33% of the total stored energy, and the NSTX pedestal energy agrees reasonably well with a recent international multi-machine scaling. We find that the L-H transition occurs on a {approx}100 {micro}sec timescale as viewed by a gas puff imaging diagnostic, and that intermittent quiescent periods precede the final transition. A power threshold identity experiment between NSTX and MAST shows comparable loss power at the L-H transition in balanced double-null discharges. Both machines require more power for the L-H transition as the balance is shifted toward lower single null. High field side gas fueling enables more reliable H-mode access, but does not always lead to a lower power threshold e.g., with a reduction of the duration of early heating. Finally the edge plasma parameters just before the L-H transition were compared with theories of the transition. It was found that while some theories can separate well-developed L- and H-mode data, they have little predictive value.

R. Maingi; C.E. Bush; E.D. Fredrickson; D.A. Gates; S.M. Kaye; B.P. LeBlanc; J.E. Menard; H. Meyer; D. Mueller; N. Nishino; A.L. Roquemore; S.A. Sabbagh; K. Tritz; S.J. Zweben; M.G. Bell; R.E. Bell; T. Biewer; J.A. Boedo; D.W. Johnson; R. Kaita; H.W. Kugel; R.J. Maqueda; T. Munsat; R. Raman; V.A. Soukhanovskii; T. Stevenson; D. Stutman

2004-10-28T23:59:59.000Z

56

Laser pulse stacking method  

DOE Patents (OSTI)

A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

Moses, E.I.

1992-12-01T23:59:59.000Z

57

Laser pulse stacking method  

DOE Patents (OSTI)

A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter.

Moses, Edward I. (Livermore, CA)

1992-01-01T23:59:59.000Z

58

Electrical pulse generator  

DOE Patents (OSTI)

A technique for generating high-voltage, wide dynamic range, shaped electrical pulses in the nanosecond range. Two transmission lines are coupled together by resistive elements distributed along the length of the lines. The conductance of each coupling resistive element as a function of its position along the line is selected to produce the desired pulse shape in the output line when an easily produced pulse, such as a step function pulse, is applied to the input line.

Norris, Neil J. (Santa Barbara, CA)

1979-01-01T23:59:59.000Z

59

Optically pulsed electron accelerator  

DOE Patents (OSTI)

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

60

Optically pulsed electron accelerator  

DOE Patents (OSTI)

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Performances of Induction System for Nanosecond Mode Operation  

SciTech Connect

An induction system comprises an array of single turn pulse transformers. Ferromagnetic cores of transformers are toroids that are stacked along the longitudinal core axis. Another name for this array is a fraction transformer or an adder. The primary and secondary windings of such a design have one turn. The step up mode is based on the number of primary pulse sources. The secondary windings are connected in series. Performances of such a system for the nanosecond range mode operation are different in comparison to the performances of traditional multi-turn pulse transformers, which are working on a 100+ nanosecond mode operation. In this paper, the author discusses which aspects are necessary to take into account for the high power nanosecond fractional transformer designs. The engineering method of the nanosecond induction system design is presented.

Krasnykh, Anatoly; /SLAC

2006-05-16T23:59:59.000Z

62

Laser fusion pulse shape controller  

DOE Patents (OSTI)

An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

Siebert, Larry D. (Ann Arbor, MI)

1977-01-01T23:59:59.000Z

63

Stress pulse phenomena  

Science Conference Proceedings (OSTI)

This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

McGlaun, M.

1993-08-01T23:59:59.000Z

64

Gaussian pulse generators for subbanded Ultra-Wideband transmitters  

E-Print Network (OSTI)

Abstract—This paper presents calculations for approximating the measured spectrum of pulsed signals in the high and low pulserepetition-frequency (PRF) region. Experimentally verified peak and average power calculations are presented for pulse trains with no modulation and when modulated by random data using binary phase-shift keying (BPSK). A pulse generator is presented that is built using commercially available discrete components. BPSK pulses are generated at a PRF of 50 MHz. The output spectrum has a center frequency of 5.355 GHz and a 10-dB bandwidth of 550 MHz. A technique for pulse shaping is presented that approximates a Gaussian pulse by exploiting the exponential behavior of a bipolar junction transistor. This technique is demonstrated by a pulse generator fabricated in a 0.18- m SiGe BiCMOS process. BPSK pulses are generated by inverting a local oscillator signal as opposed to the reference pulse, improving matching. Pulses are transmitted at a PRF of 100 MHz and centered in 528-MHz-wide channels equally spaced within the 3.1–10.6-GHz ultra-wideband band. Measurement results for both transmitters match well with calculated values. Index Terms—Gaussian, pulse analysis, pulse generation, transmitter, ultra-wideband (UWB). I.

David D. Wentzloff; Anantha P. Ch

2006-01-01T23:59:59.000Z

65

PULSE RATE DIVIDER  

DOE Patents (OSTI)

A compact pulse-rate divider circuit affording low impedance output and high input pulse repetition rates is described. The circuit features a single secondary emission tube having a capacitor interposed between its dynode and its control grid. An output pulse is produced at the anode of the tube each time an incoming pulse at the control grid drives the tube above cutoff and the duration of each output pulse corresponds to the charging time of the capacitor. Pulses incoming during the time the grid bias established by the discharging capacitor is sufficiently negative that the pulses are unable to drive the tube above cutoff do not produce output pulses at the anode; these pulses are lost and a dividing action is thus produced by the circuit. The time constant of the discharge path may be vanied to vary in turn the division ratio of the circuit; the time constant of the charging circuit may be varied to vary the width of the output pulses. (AEC)

McDonald, H.C. Jr.

1962-12-18T23:59:59.000Z

66

PULSE AMPLITUDE ANALYZER  

DOE Patents (OSTI)

A pulse-height analyzer system of improved design for sorting and counting a series of pulses, such as provided by a scintillation detector in nuclear radiation measurements, is described. The analyzer comprises a main transmission line, a cathode-ray tube for each section of the line with its deflection plates acting as the line capacitance; means to bias the respective cathode ray tubes so that the beam strikes a target only when a prearranged pulse amplitude is applied, with each tube progressively biased to respond to smaller amplitudes; pulse generating and counting means associated with each tube to respond when the beam is deflected; a control transmission line having the same time constant as the first line per section with pulse generating means for each tube for initiating a pulse on the second transmission line when a pulse triggers the tube of corresponding amplitude response, the former pulse acting to prevent successive tubes from responding to the pulse under test. This arrangement permits greater deflection sensitivity in the cathode ray tube and overcomes many of the disadvantages of prior art pulse-height analyzer circuits.

Gray, G.W.; Jensen, A.S.

1957-10-22T23:59:59.000Z

67

PULSE AMPLITUDE ANALYZER  

DOE Patents (OSTI)

This patent pertains to pulse amplitude analyzers for sorting and counting a serles of pulses, and specifically discloses an analyzer which ls simple in construction and presents the puise height distribution visually on an oscilloscope screen. According to the invention, the pulses are applied to the vertical deflection plates of an oscilloscope and trigger the horizontal sweep. Each pulse starts at the same point on the screen and has a maximum amplitude substantially along the same vertical line. A mask is placed over the screen except for a slot running along the line where the maximum amplitudes of the pulses appear. After the slot has been scanned by a photocell in combination with a slotted rotating disk, the photocell signal is displayed on an auxiliary oscilloscope as vertical deflection along a horizontal time base to portray the pulse amplitude distribution.

Greenblatt, M.H.

1958-03-25T23:59:59.000Z

68

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Stringfield, R.M.; Wheat, R.M. Jr.

1989-02-21T23:59:59.000Z

69

PULSED INDICATOR CIRCUIT  

DOE Patents (OSTI)

A system is given for detecting incremental changes in a transducer impedance terminating a transmission line. Principal novelty resides in the transducer impedance terminating the line in a mismatch and a pulse generator being provided to apply discrete pulses to the input end of the line. The amplitudes of the pulses reflected to the input end of the line from the mismatched transducer impedance are then observed as a very accurate measure of the instantaneous value of the latter.

Linlor, W.I.; Kerns, Q.A.

1960-11-15T23:59:59.000Z

70

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

71

PULSE at Stanford University  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Science @ SLAC - LCLS - LUSI - SSRL - PULSE - Stanford University Go Search Home Publications Atomic & Molecular Physics Condensed Matter Physics Single Molecule Imaging...

72

OpenEI - mode  

Open Energy Info (EERE)

http:en.openei.orgdatasetstaxonomyterm3930 en Transportation Sector Energy Use by Fuel Type Within a Mode from EIA AEO 2011 Early Release http:en.openei.orgdatasetsnode...

73

Efficient photoassociation with a train of asymmetric laser pulses  

SciTech Connect

The photoassociation (PA) dynamics implemented by a train of asymmetric slowly turned-on and rapidly turned-off (STRT) laser pulses is investigated theoretically with Cs{sub 2} as an example. A higher PA efficiency is achieved by optimizing the parameters of the STRT pulse train. The PA reaction goes partly beyond the scope of the PA window. Numerical calculations show that an efficient population accumulation in the PA process can be realized with the STRT laser-pulse train which is available in the current experiment based on laser mode-lock and shaping technology.

Zhang Wei; Wang Gaoren; Cong Shulin [School of Physics and Optoelectronic Technology, Dalian University of Technology, 116024 Dalian (China)

2011-04-15T23:59:59.000Z

74

MHK Technologies/Pulse Stream 100 | Open Energy Information  

Open Energy Info (EERE)

Pulse Stream 100 Pulse Stream 100 < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Pulse Stream 100.jpg Technology Profile Primary Organization Pulse Tidal Ltd Project(s) where this technology is utilized *MHK Projects/Pulse Stream 100 Demonstration Project Technology Resource Click here Wave Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 5/6: System Integration and Technology Laboratory Demonstration Technology Description The 100kW Humber prototype system uses tidal streams to oscillate horizontal blades rather than extracting energy in the same way as a wind turbine through rotary blades. This mode of operation is the key to the device's unique access to shallow water and has so far shown that it can harness enough energy to power 70 homes. The device is connected to the national grid through nearby industrial process plant Millennium Inorganic Chemicals and Ethernet connected through neighbouring resin manufacturing company Cray Valley.

75

PULSE AMPLITUDE DISTRIBUTION RECORDER  

DOE Patents (OSTI)

A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

Cowper, G.

1958-08-12T23:59:59.000Z

76

Pulsed wave interconnect  

Science Conference Proceedings (OSTI)

Pulsed wave interconnect is proposed for global interconnect applications. Signals are represented by localized wavepackets that propagate along the interconnect lines at the local speed of light to trigger the receivers. Energy consumption is reduced ... Keywords: CMOS, VLSI, high-speed interconnect, nonlinear transmission line, pulse compression, soliton, wafer-scale-integration

Pingshan Wang; Gen Pei; Edwin Chih-Chuan Kan

2004-05-01T23:59:59.000Z

77

PULSE HEIGHT ANALYZER  

DOE Patents (OSTI)

An anticoincidence device is described for a pair of adjacent channels of a multi-channel pulse height analyzer for preventing the lower channel from generating a count pulse in response to an input pulse when the input pulse has sufficient magnitude to reach the upper level channel. The anticoincidence circuit comprises a window amplifier, upper and lower level discriminators, and a biased-off amplifier. The output of the window amplifier is coupled to the inputs of the discriminators, the output of the upper level discriminator is connected to the resistance end of a series R-C network, the output of the lower level discriminator is coupled to the capacitance end of the R-C network, and the grid of the biased-off amplifier is coupled to the junction of the R-C network. In operation each discriminator produces a negative pulse output when the input pulse traverses its voltage setting. As a result of the connections to the R-C network, a trigger pulse will be sent to the biased-off amplifier when the incoming pulse level is sufficient to trigger only the lower level discriminator.

Johnstone, C.W.

1958-01-21T23:59:59.000Z

78

Pulsed electron beam precharger  

Science Conference Proceedings (OSTI)

Florida State University is investigating the concept of pulsed electron beams for fly ash precipitation. This report describes the results and data on three of the subtasks of this project and preliminary work only on the remaining five subtasks. Described are the modification of precharger for pulsed and DC energization of anode; installation of the Q/A measurement system; and modification and installation of pulsed power supply to provide both pulsed and DC energization of the anode. The other tasks include: measurement of the removal efficiency for monodisperse simulated fly ash particles; measurement of particle charge; optimization of pulse energization schedule for maximum removal efficiency; practical assessment of results; and measurement of the removal efficiency for polydisperse test particles. 15 figs., 1 tab. (CK)

Finney, W.C. (ed.); Shelton, W.N.

1990-01-01T23:59:59.000Z

79

Actively mode-locked/Q-switched Nd:phosphate glass laser oscillator  

SciTech Connect

Good stability and reliability is achieved in the operation of a laser oscillator with Nd-doped phosphate glass that is actively mode-locked, as well as actively Q-switched. It delivers a single pulse at 1.053 microns with an energy of 140 microJ. Pulse duration is variable between 150 ps and 1.1 ns. The system offers a TTL trigger well related to the single pulse. 9 references.

Roschger, E.W.; Schwarzenbach, A.P.; Balmer, J.E.; Weber, H.P.

1985-05-01T23:59:59.000Z

80

Mode Initialization for On-line Estimation of Power System Electromechanical Modes  

SciTech Connect

Measurement-based mode estimation methods are utilized to estimate electromechanical modes of a power system using phasor measurement units (PMU) data. These methods need to extract a certain amount of information before they can give useable mode estimation. Traditionally, the information is gathered solely from measurement data. Priori mode information from other resources (e.g. model eigenvalue analysis, engineering knowledge) are not fully utilized. For real time application, this means that mode estimation takes time to converge. By adding a mode regularization term in the objective function, this paper proposes a mode initialization method to include priori mode information in a regularized robust recursive least squares (R3LS) algorithm for on-line mode estimation. The proposed method is tested using a simple model, a 17 machine model and is shown to be able to shorten the convergence period of the R3LS algorithm. The proposed method is also applied on the measurement data recorded right before a major power outage in the western North American Grid on August 10th 1996 to show its potential applica-tion in detecting an approaching small signal stability problem.

Zhou, Ning; Trudnowski, Daniel; Pierre, John W.

2009-03-18T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Laser breakdown in air at ultrahigh laser pulse repetition rates  

SciTech Connect

Some specific features of interaction of intense femtosecond laser pulses with air at ultrahigh pulse repetition rates have been experimentally studied. Data on the dynamics of plasma cloud expansion and the plasma electron density on time intervals no longer than 10 ns are obtained by femtosecond interferometry. These data are interpreted in terms of the most likely mechanisms of ionised gas recombination. The effect of ultrahigh-frequency laser radiation on a medium was modelled by double-pulse irradiation with a short delay {Delta}t between the pulses: from 1 ps to 11 ns. A nonmonotonic dependence of the degree of air ionisation by the second pulse on the delay time {Delta}t is found; possible mechanisms of these dependences are discussed in terms of the processes of femtosecond radiation absorption in the residual plasma. (extreme light fields and their applications)

Kononenko, Vitalii V; Kononenko, Taras V; Pashinin, V P; Gololobov, V M; Konov, Vitalii I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-04-30T23:59:59.000Z

82

Gear Tooth Failure Modes  

Science Conference Proceedings (OSTI)

Table 1   Basic failure modes of gear teeth...Rolling Bruising Peening Brinelling Rippling (fish scaling) Ridging Bending (yielding) Tip-to-root interference Bending fatigue Low-cycle

83

mode | OpenEI  

Open Energy Info (EERE)

mode mode Dataset Summary Description Supplemental Table 46 of EIA AEO 2011 Early Release Source EIA Date Released December 08th, 2010 (4 years ago) Date Updated Unknown Keywords AEO Annual Energy Outlook EIA Energy Information Administration Fuel mode TEF transportation Transportation Energy Futures Data text/csv icon Transportation_Sector_Energy_Use_by_Fuel_Type_Within_a_Mode.csv (csv, 144.3 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually Time Period 2008-2035 License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access Average vote Your vote Overall rating Average vote Your vote

84

The electron geodesic acoustic mode  

Science Conference Proceedings (OSTI)

In this report, a novel new mode, named the electron geodesic acoustic mode, is presented. This mode can occur in toroidal plasmas like the conventional geodesic acoustic mode (GAM). The frequency of this new mode is much larger than that of the conventional GAM by a factor equal to the square root of the ion to electron mass ratio.

Chakrabarti, N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064 (India); Guzdar, P. N. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Kaw, P. K. [Institute for Plasma Research Bhat, Gandhinagar 382428 (India)

2012-09-15T23:59:59.000Z

85

Pulsed Power for a Dynamic Transmission Electron Microscope  

Science Conference Proceedings (OSTI)

Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

2009-06-25T23:59:59.000Z

86

Pulse measurement apparatus and method  

DOE Patents (OSTI)

An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses. An embodiment of the invention is directed to a method for increasing the dynamic range of a pulse measurement by a repetitively-gated electronic sampling device having a rated dynamic range capability, beyond the rated dynamic range of the sampling device; e.g., enhancing the dynamic range of an oscilloscope. The embodied technique can improve the SNR from about 300:1 to 1000:1. A dynamic range enhancement of four to seven bits may be achieved.

Marciante, John R. (Webster, NY); Donaldson, William R. (Pittsford, NY); Roides, Richard G. (Scottsville, NY)

2011-10-25T23:59:59.000Z

87

Highly stable pulse stretchers  

SciTech Connect

Highly stable pulse stretchers are described that are designed for fine control of pulse duration in digital pulse shapers of nuclear magnetic resonance spectrometers with a quantization step of 0.1 ..mu..sec. The fine-control range is 20-150 nsec. The stretchers employ a circuit to compensate for the logic-0 voltage and the time delays of the logic elements. The instability of the trailing-edge delay for a supply variation of +/- 0.5 V is less than 0.1%, and the temperature instability in the range of 20-80/sup 0/C is not over (60/t/sub d/)-0.3%, where t/sub d/ is the trailing-edge delay. The inputs and outputs of the pulse stretchers are matcher to TTL and Schottky TTL levels.

Svintenok, V.A.; Nikiforov, E.A.

1988-02-01T23:59:59.000Z

88

Pulse combustion: Commercial, industrial, and residential applications. (Latest citations from the NTIS Bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the evolution of pulse combustion, the types of pulse combustion burners and their applications, and selected fuels utilized. Topics include fuel combustion efficiency, energy conversion and utilization technologies, modeling of chemical kinetics, and dynamics and thermal characteristics of pulse combustors. Pulse combustion systems for water heaters, gas furnaces, industrial and residential boilers, commercial cooking equipment, and space heating devices are presented. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-10-01T23:59:59.000Z

89

Pulse magnetic welder  

DOE Patents (OSTI)

A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.

Christiansen, D.W.; Brown, W.F.

1984-01-01T23:59:59.000Z

90

The Signature of the Annular Modes in the Moisture Budget  

Science Conference Proceedings (OSTI)

The mid- and high-latitude variations of mass and momentum, variously termed the Arctic and Antarctic oscillations and/or the Northern and Southern Annular Modes also have a signature in the moisture budget. This is investigated, using associated ...

G. J. Boer; S. Fourest; B. Yu

2001-09-01T23:59:59.000Z

91

PULSE COLUMN DESIGN  

SciTech Connect

A stagewise approach was used in a theoretical analysis of pulse columns. In the analysis the column was arbitrarily divided into discrete stages comprising that part of the column between two adjacent perforated plates. The operation of the pulse column was described mathematically using material balance equations, and a design method was derived which used two stage lines and two operating lines, one set for the pulse generator upstroke and one set for the downstroke. Assuming equilibrium contact, the effect of recycle in a pulse column was shown to cause a large decrease in the separation obtained as the pulse frequency was increased. Hold-up studies were made using isoamyl alcohol- water, and methyl isobutyl ketone water. The hold-up per cycle of the dispersed phase for both systems was found to be equal to the interstage flow per cycle of the dispersed phase. Hold-up behavior at high frequencies was different for the two systems. Extraction runs were also made using the system methyl isobutyl ketone - acetic acid-water. The effects of recycle were found to result in a drop in column separation efficiency with increased pulse frequency. It was found to be theoretically possible for a column to operate in a pinched-in region even though this is not apparert from an examination of the superficial flow ratio of the two streams being fed to the column Techniques for sampling interstage flow streams in a colurm operating in the mixer-settler region are described. (J.R.D.)

Burkhart, L.E.; Fahien, R.W.

1958-11-01T23:59:59.000Z

92

Pulse shaping with transmission lines  

DOE Patents (OSTI)

A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

Wilcox, R.B.

1985-08-15T23:59:59.000Z

93

Pulse shaping with transmission lines  

DOE Patents (OSTI)

A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

Wilcox, Russell B. (Oakland, CA)

1987-01-01T23:59:59.000Z

94

Efficient optical pulse stacker system  

SciTech Connect

Method and apparatus for spreading and angle-encoding each pulse of a multiplicity of small area, short pulses into several temporally staggered pulses by use of appropriate beam splitters, with the optical elements being arranged so that each staggered pulse is contiguous with one or two other such pulses, and the entire sequence of stacked pulses comprising a single, continuous long pulse. The single long pulse is expanded in area, and then doubly passed through a nonstorage laser amplifier such as KrF. After amplification, the physically separated, angle-encoded and temporally staggered pulses are recombined into a single pulse of short duration. This high intensity output beam is well collimated and may be propagated over long distance, or used for irradiating inertial confinement fusion targets.

Seppala, Lynn G. (Pleasanton, CA); Haas, Roger A. (Pleasanton, CA)

1982-01-01T23:59:59.000Z

95

High energy mode locked fiber oscillators for high contrast, high energy petawatt laser seed sources  

Science Conference Proceedings (OSTI)

In a high-energy petawatt laser beam line the ASE pulse contrast is directly related to the total laser gain. Thus a more energetic input pulse will result in increased pulse contrast at the target. We have developed a mode-locked fiber laser with high quality pulses and energies exceeding 25nJ. We believe this 25nJ result is scalable to higher energies. This oscillator has no intra-cavity dispersion compensation, which yields an extremely simple, and elegant laser configuration. We will discuss the design of this laser, our most recent results and characterization of all the key parameters relevant to it use as a seed laser. Our oscillator is a ring cavity mode-locked fiber laser [1]. These lasers operate in a self-similar pulse propagation regime characterized by a spectrum that is almost square. This mode was found theoretically [2] to occur only in the positive dispersion regime. Further increasing positive dispersion should lead to increasing pulse energy [2]. We established that the positive dispersion required for high-energy operation was approximately that of 2m of fiber. To this end, we constructed a laser cavity similar to [1], but with no gratings and only 2m of fiber, which we cladding pumped in order to ensure sufficient pump power was available to achieve mode-locked operation. A schematic of the laser is shown in figure 1 below. This laser produced low noise 25nJ pulses with a broad self similar spectrum (figure 2) and pulses that could be de-chirped to <100fs (figure 3). Pulse contrast is important in peta-watt laser systems. A major contributor to pulse contrast is amplified spontaneous emission (ASE), which is proportional to the gain in the laser chain. As the oscillator strength is increased, the required gain to reach 1PW pulses is decreased, reducing ASE and improving pulse contrast. We believe these lasers can be scaled in a stable fashion to pulse energies as high as 100nJ and have in fact seen 60nJ briefly in our lab, which is work still in progress. At this level, even if the pulses are not perfect, post-oscillator pulse cleaning can be used to create a clean high energy pulse for injection into a peta-watt laser beam line.

Dawson, J W; Messerly, M J; An, J; Kim, D; Barty, C J

2006-06-15T23:59:59.000Z

96

HydroPulse Drilling  

Science Conference Proceedings (OSTI)

Tempress HydroPulse{trademark} tool increases overbalanced drilling rates by generating intense suction pulses at the drill bit. This report describes the operation of the tool; results of pressure drilling tests, wear tests and downhole drilling tests; and the business case for field applications. The HydroPulse{trademark} tool is designed to operate on weighted drilling mud at conventional flow rates and pressures. Pressure drilling tests confirm that the HydroPulse{trademark} tool provides 33% to 200% increased rate of penetration. Field tests demonstrated conventional rotary and mud motor drilling operations. The tool has been operated continuous for 50 hours on weighted mud in a wear test stand. This level of reliability is the threshold for commercial application. A seismic-while-drilling version of the tool was also developed and tested. This tool was used to demonstrate reverse vertical seismic profiling while drilling an inclined test well with a PDC bit. The primary applications for the HydroPulse{trademark} tool are deep onshore and offshore drilling where rate of penetration drives costs. The application of the seismic tool is vertical seismic profiling-while-drilling and look-ahead seismic imaging while drilling.

J.J. Kolle

2004-04-01T23:59:59.000Z

97

Pulse power linac  

DOE Patents (OSTI)

A linear acceleration for charged particles is constructed of a plurality of transmission line sections that extend between a power injection region and an accelerating region. Each line section is constructed of spaced plate-like conductors and is coupled to an accelerating gap located at the accelerating region. Each gap is formed between a pair of apertured electrodes, with all of the electrode apertures being aligned along a particle accelerating path. The accelerating gaps are arranged in series, and at the injection region the line sections are connected in parallel. At the injection region a power pulse is applied simultaneously to all line sections. The line sections are graduated in length so that the pulse reaches the gaps in a coordinated sequence whereby pulse energy is applied to particles as they reach each of the gaps along the accelerating path.

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

98

Pulse shaping system  

DOE Patents (OSTI)

Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses. 8 figs.

Skeldon, M.D.; Letzring, S.A.

1999-03-23T23:59:59.000Z

99

Pulse shaping system  

DOE Patents (OSTI)

Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses.

Skeldon, Mark D. (Penfield, NY); Letzring, Samuel A. (Jemez Springs, NM)

1999-03-23T23:59:59.000Z

100

Pulsed neutron detector  

DOE Patents (OSTI)

A pulsed neutron detector and system for detecting low intensity fast neutron pulses has a body of beryllium adjacent a body of hydrogenous material the latter of which acts as a beta particle detector, scintillator, and moderator. The fast neutrons (defined as having En>1.5 MeV) react in the beryllium and the hydrogenous material to produce larger numbers of slow neutrons than would be generated in the beryllium itself and which in the beryllium generate hellium-6 which decays and yields beta particles. The beta particles reach the hydrogenous material which scintillates to yield light of intensity related to the number of fast neutrons. A photomultiplier adjacent the hydrogenous material (scintillator) senses the light emission from the scintillator. Utilization means, such as a summing device, sums the pulses from the photo-multiplier for monitoring or other purposes.

Robertson, deceased, J. Craig (late of Albuquerque, NM); Rowland, Mark S. (Livermore, CA)

1989-03-21T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Micro-joule sub-10-fs VUV pulse generation by MW pump pulse using highly efficient chirped-four-wave mixing in hollow-core photonic crystal fibers  

E-Print Network (OSTI)

We theoretically study chirped four-wave mixing for VUV pulse generation in hollow-core photonic crystal fibers. We predict the generation of sub-10-fs VUV pulses with energy of up to hundreds of microjoule by broad-band chirped idler pulses at 830 nm and MW pump pulses with narrow-band at 277 nm. MW pump could be desirable to reduce the complexity of the laser system or use a high repetition rate-laser system. The energy conversion efficiency from pump pulse to VUV pulse reaches to 30%. This generation can be realized in kagome-lattice hollow-core PCF filled with noble gas of high pressure with core-diameter less than 40 micrometers which would enable technically simple or highly efficient coupling to fundamental mode of the fiber.

Im, Song-Jin

2013-01-01T23:59:59.000Z

102

Pulse compression with a high-energy Nd:YAG regenerative amplifier system  

Science Conference Proceedings (OSTI)

We describe a method for the generation of readily synchronizable, near-transform-limited, 1064-nm, 6-mJ pulses with {lt}20-ps duration at a repetition rate of 20 Hz. The method employs chirped pulse amplification of spectrally broadened and temporally stretched pulses from a cw mode-locked Nd:YAG laser in a commercial Nd:YAG regenerative amplifier followed by pulse compression with a grating pair. Linear amplification subsequent to regenerative amplification is not required with this method, although higher energies would be easily obtained. {copyright} 1997 Optical Society of America

Venturo, V.A.; Joly, A.G.; Ray, D. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999 K2-14, Richland, Washington 99352 (United States)

1997-07-01T23:59:59.000Z

103

Passive and active pulse stacking scheme for pulse shaping  

DOE Patents (OSTI)

Apparatus and method for producing a sequence of radiation pulses with a pulse envelope of time variation which is controllable by an external electromagnetic signal applied to an active medium or by a sectored reflector, through which the radiation passes.

Harney, Robert C. (Livermore, CA); Schipper, John F. (Palo Alto, CA)

1977-01-01T23:59:59.000Z

104

Adaptive feedforward and feedback control schemes for sliding mode controlled power converters  

E-Print Network (OSTI)

Abstract—A major disadvantage of applying sliding mode control to dc/dc converters is that the steady-state switching frequency is affected by line and load variations. This is undesirable as it complicates the design of the input and output filters. To reduce switching frequency deviation in the events of line and load variations, an adaptive feedforward control scheme that varies the hysteresis band according to the change of line input voltage and an adaptive feedback control scheme that varies the control parameter (i.e., sliding coefficient) according to the change of the output load are proposed. This paper presents a thorough investigation into the problem and the effectiveness of the proposed solutions. In addition, methods of implementing the proposed adaptive control strategies are discussed. Experimental results confirm that the adaptive control schemes are capable of reducing the switching frequency variations caused by both line and load variations. Index Terms—Adaptive feedback control, adaptive feedforward control, buck converter, hysteresis modulation, pulse-width-modulation (PWM), sliding mode (SM)control. I.

Siew-chong Tan; Y. M. Lai; Chi K. Tse; Martin K. H. Cheung; Student Member

2006-01-01T23:59:59.000Z

105

Molecular pulses: Population inversion with positively chirped short pulses  

E-Print Network (OSTI)

Molecular pulses: Population inversion with positively chirped short pulses Jianshu Cao of molecular systems can be achieved with intense positively chirped broadband laser pulses. To provide and a four-level model is designed to demonstrate for molecular systems the correlation between the sign

Cao, Jianshu

106

Efficient and long-lived field-free orientation of molecules by a single hybrid short pulse  

E-Print Network (OSTI)

We show that a combination of a half-cycle pulse and a short nonresonant laser pulse produces a strongly enhanced postpulse orientation. Robust transients that display both efficient and long-lived orientation are obtained. The mechanism is analyzed in terms of optimal oriented target states in finite Hilbert subspaces and shows that hybrid pulses can prove useful for other control issues.

Daems, D; Sugny, D; Jauslin, H R

2005-01-01T23:59:59.000Z

107

Efficient and long-lived field-free orientation of molecules by a single hybrid short pulse  

E-Print Network (OSTI)

We show that a combination of a half-cycle pulse and a short nonresonant laser pulse produces a strongly enhanced postpulse orientation. Robust transients that display both efficient and long-lived orientation are obtained. The mechanism is analyzed in terms of optimal oriented target states in finite Hilbert subspaces and shows that hybrid pulses can prove useful for other control issues.

D. Daems; S. Guérin; D. Sugny; H. R. Jauslin

2005-07-08T23:59:59.000Z

108

Dual-Mode Hybrid/Two-Mode Hybrid Accomplishment  

NLE Websites -- All DOE Office Websites (Extended Search)

Dual-Mode Hybrid/Two-Mode Hybrid Accomplishment Dual-Mode Hybrid/Two-Mode Hybrid Accomplishment DOE-funded research, in collaboration with Allison Buses and General Motors Corporation has led to the commercialization of a dramatically different hybrid transmission system for heavy-duty and light-duty applications. The Dual-Mode or Two-Mode hybrid system is an infinitely variable speed hybrid transmission that works with the engine and battery system and automatically chooses to operate in a parallel or series hybrid path to maximize efficiency and minimize emissions, fuel consumption and noise. Parallel and Series hybrid configurations are found on most hybrid vehicles today, both with their own pluses and minuses. The Dual- Mode/Two-Mode systems uses the positive characteristics from both systems to maximize fuel

109

Pulsed gas laser  

DOE Patents (OSTI)

A pulsed gas laser is constituted by Blumlein circuits wherein space metal plates function both as capacitors and transmission lines coupling high frequency oscillations to a gas filled laser tube. The tube itself is formed by spaced metal side walls which function as connections to the electrodes to provide for a high frequency, high voltage discharge in the tube to cause the gas to lase. Also shown is a spark gap switch having structural features permitting a long life.

Anderson, Louis W. (Madison, WI); Fitzsimmons, William A. (Madison, WI)

1978-01-01T23:59:59.000Z

110

Downhole pulse radar  

DOE Patents (OSTI)

A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

Chang, Hsi-Tien

1987-09-28T23:59:59.000Z

111

Downhole pulse radar  

DOE Patents (OSTI)

A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

Chang, Hsi-Tien (Albuquerque, NM)

1989-01-01T23:59:59.000Z

112

International magnetic pulse compression workshop: (Proceedings)  

SciTech Connect

A few individuals have tried to broaden the understanding of specific and salient pulsed-power topics. One such attempt is this documentation of a workshop on magnetic switching as it applies primarily to pulse compression (power transformation), affording a truly international perspective by its participants under the initiative and leadership of Hugh Kirbie and Mark Newton of the Lawrence Livermore National Laboratory (LLNL) and supported by other interested organizations. During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card--its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

1991-04-01T23:59:59.000Z

113

MULTICHANNEL PULSE-HEIGHT ANALYZER  

DOE Patents (OSTI)

This patent deals with electronic computing circuits and more particularly to pulse-height analyzers used for classifying variable amplitude pulses into groups of different amplitudes. The device accomplishes this pulse allocation by by converting the pulses into frequencies corresponding to the amplitudes of the pulses, which frequencies are filtered in channels individually pretuned to a particular frequency and then detected and recorded in the responsive channel. This circuit substantially overcomes the disadvantages of prior annlyzers incorporating discriminators pre-set to respond to certain voltage levels, since small variation in component values is not as critical to satisfactory circuit operation.

Russell, J.T.; Lefevre, H.W.

1958-01-21T23:59:59.000Z

114

Petawatt pulsed-power accelerator  

DOE Patents (OSTI)

A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

Stygar, William A. (Albuquerque, NM); Cuneo, Michael E. (Albuquerque, NM); Headley, Daniel I. (Albuquerque, NM); Ives, Harry C. (Albuquerque, NM); Ives, legal representative; Berry Cottrell (Albuquerque, NM); Leeper, Ramon J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Olson, Craig L. (Albuquerque, NM); Porter, John L. (Sandia Park, NM); Wagoner; Tim C. (Albuquerque, NM)

2010-03-16T23:59:59.000Z

115

High-speed pulse-shape generator, pulse multiplexer  

DOE Patents (OSTI)

The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

Burkhart, Scott C. (Livermore, CA)

2002-01-01T23:59:59.000Z

116

Heralding Single Photons from Pulsed Parametric Down-Conversion  

E-Print Network (OSTI)

We describe an experiment in which photon pairs from a pulsed parametric down-conversion source were coupled into single-mode fibers. Detecting one of the photons heralded the presence of the other photon in its fiber with a probability of 83%. The heralded photons were then used in a simple multi-photon interference experiment to illustrate their potential for quantum information applications.

T. B. Pittman; B. C Jacobs; J. D. Franson

2004-08-13T23:59:59.000Z

117

Coiled transmission line pulse generators  

DOE Patents (OSTI)

Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

McDonald, Kenneth Fox (Columbia, MO)

2010-11-09T23:59:59.000Z

118

Resonance Excitation of Longitudinal High Order Modes in Project X Linac  

SciTech Connect

Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

Khabiboulline, T.N.; Sukhanov, A.AUTHOR = Awida, M.; Gonin, I.; Lunin, A.AUTHOR = Solyak, N.; Yakovlev, V.; /Fermilab

2012-05-01T23:59:59.000Z

119

Partial core pulse transformer  

DOE Patents (OSTI)

A light-weight partial-core pule transformer is provided for generating high voltage output pulses with low distortion. The transformer includes sets of ferrite bars arranged so as to extend longitudinally along the inside and outside surfaces of a high frequency cylindrical coil winding-pair. The ferrite bars are arranged in pairs with the bars of each pair being located on opposite sides of winding-pair. The bars are preferably disposed in a radially symmetric arrangement around the winding-pair, and each has a length at least equal to the width of the winding-pair.

Lawson, R.N.; Rohwein, G.J.

1991-12-31T23:59:59.000Z

120

PULSE SYNTHESIZING GENERATOR  

DOE Patents (OSTI)

>An electronlc circuit for synthesizing electrical current pulses having very fast rise times includes several sinewave generators tuned to progressively higher harmonic frequencies with signal amplitudes and phases selectable according to the Fourier series of the waveform that is to be synthesized. Phase control is provided by periodically triggering the generators at precisely controlled times. The outputs of the generators are combined in a coaxial transmission line. Any frequency-dependent delays that occur in the transmission line can be readily compensated for so that the desired signal wave shape is obtained at the output of the line. (AEC)

Kerns, Q.A.

1963-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Green Light Pulse Oximeter  

DOE Patents (OSTI)

A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

Scharf, John Edward (Oldsmar, FL)

1998-11-03T23:59:59.000Z

122

High harmonic attosecond pulse train amplification in a free electron laser  

SciTech Connect

It is shown using three-dimensional simulations that the temporal structure of an attosecond pulse train, such as that generated via high harmonic generation in noble gases, may be retained in a free electron laser amplifier through to saturation using a mode-locked optical klystron configuration. At wavelengths of {approx}12 nm, a train of attosecond pulses of widths {approx}300 as with peak powers in excess of 1 GW are predicted.

McNeil, B.W.; Sheehy, B.; Thompson, N.R.; Dunning, D.J.

2011-03-04T23:59:59.000Z

123

High power pulsed plasma MHD experiments. Annual report 1 Jan 81-30 Sep 82  

SciTech Connect

Results of high power pulsed plasma MHD experiments are reported. An explosively driven plasma source is used to drive a Faraday mode MHD generator with an externally applied B-field of several tesla. The highest power achieved was 6 gigawatts in a 140 kJ electrical pulse delivered to a resistive load. The experimentally observed scaling relationships of power with applied B-field and electrode area are also presented.

Baum, D.W.; Gill, S.P.; Shimmin, W.L.; Watson, J.D.

1982-09-30T23:59:59.000Z

124

PSR 2303+30: A single system of drifting subpulses, moding and nulling  

E-Print Network (OSTI)

Analyses of multiple pulse sequences of B2303+30 reveal that this pulsar has two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically weak, but has intermittent driftbands with a periodicity of approximately 3 P/cycles, and nulls much more frequently than the B mode. Both modes occur with roughly equal frequency and their profiles have a similar single-humped form with a slight asymmetry. Our observations and analyses strongly suggest that the subpulse driftrates in both modes are linked in a series of cycles, which can be modelled as relaxing oscillations in the underlying circulation rate.

Stephen L. Redman; Geoffrey A. E. Wright; Joanna M. Rankin

2004-07-27T23:59:59.000Z

125

Electron geodesic acoustic modes in electron temperature gradient mode turbulence  

Science Conference Proceedings (OSTI)

In this work, the first demonstration of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared to the mixing length estimate.

Anderson, Johan; Nordman, Hans [Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Singh, Raghvendra; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2012-08-15T23:59:59.000Z

126

Switching power pulse system  

DOE Patents (OSTI)

A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

Aaland, K.

1983-08-09T23:59:59.000Z

127

Compensated pulsed alternator  

DOE Patents (OSTI)

This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak outout. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit.

Weldon, William F. (Austin, TX); Driga, Mircea D. (Austin, TX); Woodson, Herbert H. (Austin, TX)

1980-01-01T23:59:59.000Z

128

Fiber Laser Front Ends for High Energy, Short Pulse Lasers  

SciTech Connect

We are developing a fiber laser system for short pulse (1-10ps), high energy ({approx}1kJ) glass laser systems. Fiber lasers are ideal for these systems as they are highly reliable and enable long term stable operation.

Dawson, J; Messerly, M; Phan, H; Siders, C; Beach, R; Barty, C

2007-06-21T23:59:59.000Z

129

Short-Term Energy Outlook  

Gasoline and Diesel Fuel Update (EIA)

(83/3Q) (83/3Q) Short-Term Energy Outlook iuarterly Projections August 1983 Energy Information Administration Washington, D.C. 20585 t rt jrt- .ort- iort- iort- iort- nort- lort- '.ort- ort- Tt- .-m .erm -Term -Term -Term -Term -Term -Term -Term -Term -Term -Term -Term -Term Term .-Term -Term xrm Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy Energy ^nergy -OJ.UUK Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Outlook Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term Short-Term

130

Ultrafast Accelerators for Pulse Radiolysis  

NLE Websites -- All DOE Office Websites (Extended Search)

in this area agreed that it would be useful to organize a specialist's conference on ultrafast accelerators for pulse radiolysis, to discuss the common experiences and problems...

131

Ultra-short pulse generator  

DOE Patents (OSTI)

An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shock wave diode, which increases and sharpens the pulse even more. 5 figures.

McEwan, T.E.

1993-12-28T23:59:59.000Z

132

Pulsed helium ionization detection system  

DOE Patents (OSTI)

A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

Ramsey, R.S.; Todd, R.A.

1985-04-09T23:59:59.000Z

133

Pulse-to-Pulse Coherent Doppler Sonar Signal Processing Techniques  

Science Conference Proceedings (OSTI)

In this paper we present and discuss techniques for the computation of the mean and spectral variance of a pulse-to-pulse coherent sonar signal, leading to the measurement of mean water velocity and turbulence. The use of an autocovariance ...

Roger Lhermitte; Robert Serafin

1984-12-01T23:59:59.000Z

134

Design and testing of an internal mode converter for a 1.5 MW, 110 GHz gyrotron with a depressed collector  

E-Print Network (OSTI)

We report experimental results on a 1.5 MW, 110 GHz, 3 microsecond pulsed gyrotron with a single-stage depressed collector. A simplified mode converter with smooth mirror surfaces has been installed in the tube. The converter ...

Tax, David Samuel

135

Two stroke homogenous charge compression ignition engine with pulsed air supplier  

DOE Patents (OSTI)

A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

Clarke, John M. (Chillicothe, IL)

2003-08-05T23:59:59.000Z

136

Hydraulic Pulse Drilling  

NLE Websites -- All DOE Office Websites (Extended Search)

REV DATE DESCRIPTION ORIGINATOR REVIEWED DATE REV DATE DESCRIPTION ORIGINATOR REVIEWED DATE 0 4/13/2004 Final Report Author: J. Kolle Hunter/Theimer 4/13/2004 Document No.: TR- 053 HydroPulse(tm) Drilling Final Report Prepared by J.J. Kolle April 2004 U.S. Department of Energy Cooperative Development Agreement No. DE-FC26-FT34367 Tempress Technologies, Inc. 18858 - 72 ND Ave S. Kent, WA 98032 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not

137

Switching power pulse system  

DOE Patents (OSTI)

A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

Aaland, Kristian (Livermore, CA)

1983-01-01T23:59:59.000Z

138

Fiber Optic Picosecond Laser Pulse Transmission Line for Hydrogen Ion Beam Profile Measurement  

Science Conference Proceedings (OSTI)

We present a fiber optic laser pulse transmission line for non-intrusive longitudinal profile measurement of the hydrogen ion (H-) beam at the front-end of the Spallation Neutron Source (SNS) accelerator. The 80.5 MHz, 2.5 ps, multi-killowatt optical pulses are delivered to the accelerator beam line through a large mode area polarization maintaining optical fiber to ensure a high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter and pulse width broadening over a 100-ft fiber line are experimentally investigated. A successful measurement of the H- beam microbunch (~130 ps) profile is obtained. Our experiment is the first demonstration of particle beam profile diagnostics using fiber optic laser pulse transmission line.

Liu, Yun [ORNL; Huang, Chunning [ORNL; Aleksandrov, Alexander V [ORNL

2013-01-01T23:59:59.000Z

139

Reheating induced by competing decay modes  

SciTech Connect

We address the problem of studying the decay of the inflaton field {phi} to another scalar field {chi} through parametric resonance in the case of a coupling that involves several decay modes. This amounts to the presence of extra harmonic terms in the perturbation of the {chi} field dynamics. For the case of two frequencies we compute the geometry of the resonance regions, which is significantly altered due to the presence of noncuspidal resonance regions associated to higher harmonics and to the emergence of instability 'pockets'. We discuss the effect of this change in the efficiency of the energy transfer process for the simplest case of a coupling given by a combination of the two interaction terms of homogeneous degree usually considered in the literature. We find that the presence of higher harmonics has limited cosmological implications.

Charters, T. [Departamento de Engenharia Mecanica/Area Cientifica de Matematica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, P-1949-014 Lisbon, Portugal and Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal); Nunes, A.; Mimoso, J. P. [Departamento de Fisica, Faculdade de Ciencias da Universidade de Lisboa, Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal)

2008-10-15T23:59:59.000Z

140

Radiation pressure excitation of test mass ultrasonic modes via three mode opto-acoustic interactions in a suspended Fabry-Perot cavity  

E-Print Network (OSTI)

Three-mode parametric-instabilities risk stable operation of gravitational-wave detectors. Instabilities occur through time varying radiation-pressure distributions, derived from beating between two optical modes, exciting mirror acoustic modes in Fabry-Perot cavities. Here we report the first demonstration of radiation-pressure driving of ultrasonic-acoustic modes via pairs of optical modes in gravitational-wave type optical cavities. In this experiment ~0.4W of TEM01 mode and ~1kW of TEM00 mode circulated inside the cavity, an ~181.6kHz excitation was observed with amplitude ~5E-13m. The results verify the driving force term in Braginsky's parametric instability feedback model. The interaction parametric gain was (3.8+/-0.5)E-3 and mass-ratio scaled opto-acoustic overlap 2.7+/-0.4.

Blair, Carl; Zhao, Chunnong; Qi, Fang; Ju, Li; Blair, David

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

A wide bandwidth free-electron laser with mode locking using current modulation.  

SciTech Connect

A new scheme for mode locking a free-electron laser amplifier is proposed based on electron beam current modulation. It is found that certain properties of the original concept, based on the energy modulation of electrons, are improved including the spectral brightness of the source and the purity of the series of short pulses. Numerical comparisons are made between the new and old schemes and between a mode-locked free-electron laser and self-amplified spontaneous emission free-electron laser. Illustrative examples using a hypothetical mode-locked free-electron laser amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated.

Kur, E.; Dunning, D. J.; McNeil, B. W. J.; Wurtele, J.; Zholents, A. A. (Accelerator Systems Division (APS)); (Univ. of California at Berkeley); (Univ. of Strathclyde); (STFC Daresbury Lab.); (LBNL)

2011-01-20T23:59:59.000Z

142

Mode coupling of electron plasma waves  

SciTech Connect

The driven coupled mode equations are derived for a two fluid, unequal temperature (T/sub e/ much greater than T/sub i/) plasma in the one-dimensional, electrostatic model and applied to the coupling of electron plasma waves. It is assumed that the electron to ion mass ratio identical with m/sub e/M/sub i// much less than 1 and eta$sup 2$/sub ko/k lambda/sub De/ less than 1 where eta$sup 2$/ sub ko/ is the pump wave's power normalized to the plasma thermal energy, k the mode wave number and lambda/sub De/ the electron Debye length. Terms up to quadratic in pump power are retained. The equations describe the linear plasma modes oscillating at the wave number k and at $omega$/sub ek/, the Bohn Gross frequency, and at $Omega$/sub k/, the ion acoustic frequency, subject to the damping rates $nu$/sub ek/ and $nu$/sub ik/ for electrons and ions and their interactions due to intense high frequency waves E/sub k//sup l/. n/sub o/ is the background density, n/sub ik/ the fluctuating ion density, $omega$/sub pe/ the plasma frequency. (auth)

Harte, J.A.

1975-10-31T23:59:59.000Z

143

Explain Spires Terms  

NLE Websites -- All DOE Office Websites (Extended Search)

Spires terms Enter term below Example:   index :: Browse Examples Search Help :: About Explain SPIRES TopCites HEP Reviews SPIRES News Playground Preprint listings Resources...

144

Glossary Term - Tritium  

NLE Websites -- All DOE Office Websites (Extended Search)

Titans Previous Term (Titans) Glossary Main Index Next Term (Uranus) Uranus Tritium Discovered in 1934, tritium is an unstable isotope of the element hydrogen. An atom of tritium...

145

Glossary Term - Pluto  

NLE Websites -- All DOE Office Websites (Extended Search)

Pallas Previous Term (Pallas) Glossary Main Index Next Term (Positron) Positron Pluto A computer enhanced image of Pluto made from Hubble Space Telescope images taken in 1994....

146

Glossary Term - Cloud Chamber  

NLE Websites -- All DOE Office Websites (Extended Search)

Ceres Previous Term (Ceres) Glossary Main Index Next Term (Composition of the Earth's Atmosphere) Composition of the
Earth's Atmosphere Cloud Chamber A cloud chamber showing the...

147

Glossary Term - Beta Particle  

NLE Websites -- All DOE Office Websites (Extended Search)

Decay Previous Term (Beta Decay) Glossary Main Index Next Term (Bohr Radius) Bohr Radius Beta Particle Beta particles are either electrons or positrons ejected from the nucleus....

148

Glossary Term - Alpha Particle  

NLE Websites -- All DOE Office Websites (Extended Search)

Decay Previous Term (Alpha Decay) Glossary Main Index Next Term (Atomic Number) Atomic Number Alpha Particle alphaparticle.gif Produced during alpha decay, an alpha particle is a...

149

Glossary Term - Deuterium  

NLE Websites -- All DOE Office Websites (Extended Search)

Cyclotron Previous Term (Cyclotron) Glossary Main Index Next Term (Deuteron) Deuteron Deuterium Discovered in 1932 by Harold C. Urey, deuterium is a stable isotope of the element...

150

Glossary Term - Pallas  

NLE Websites -- All DOE Office Websites (Extended Search)

Nucleus Previous Term (Nucleus) Glossary Main Index Next Term (Pluto) Pluto Pallas Pallas is an asteroid located between the orbits of Mars and Jupiter. Discovered on March 28,...

151

Glossary Term - Prometheus  

NLE Websites -- All DOE Office Websites (Extended Search)

Positron Previous Term (Positron) Glossary Main Index Next Term (Proton) Proton Prometheus In Greek mythology, Promethus was the son of the Titan Iapetus. He fought with Zeus...

152

Glossary Term - Neutron Emission  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Previous Term (Neutron) Glossary Main Index Next Term (Niobe) Niobe Neutron Emission After neutron emission, an atom contains one less neutron. Neutron emission is one...

153

Glossary Term - Atomic Number  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Previous Term (Alpha Particle) Glossary Main Index Next Term (Avogadro's Number) Avogadro's Number Atomic Number Silver's atomic number is 47 The atomic number is equal to...

154

Glossary Term - Proton Emission  

NLE Websites -- All DOE Office Websites (Extended Search)

Proton Previous Term (Proton) Glossary Main Index Next Term (Quark) Quark Proton Emission After proton emission, an atom contains one less proton. Proton emission is one process...

155

Glossary Term - Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

of the
Earth's Atmosphere Previous Term (Composition of the Earth's Atmosphere) Glossary Main Index Next Term (Deuterium) Deuterium Cyclotron A cyclotron is a device used to...

156

Glossary Term - Proton  

NLE Websites -- All DOE Office Websites (Extended Search)

Prometheus Previous Term (Prometheus) Glossary Main Index Next Term (Proton Emission) Proton Emission Proton A Proton Protons are positively charged particles found within atomic...

157

Glossary Term - Alpha Decay  

NLE Websites -- All DOE Office Websites (Extended Search)

Universe Previous Term (10 Most Abundant Elements in the Universe) Glossary Main Index Next Term (Alpha Particle) Alpha Particle Alpha Decay Alpha Decay Diagram Alpha decay is one...

158

Glossary Term - Neutron  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutrino Previous Term (Neutrino) Glossary Main Index Next Term (Neutron Emission) Neutron Emission Neutron A Neutron Neutrons are uncharged particles found within atomic nuclei....

159

Glossary Term - Isotope  

NLE Websites -- All DOE Office Websites (Extended Search)

Helios Previous Term (Helios) Glossary Main Index Next Term (Joule) Joule Isotope The Three Isotopes of Hydrogen - Protium, Deuterium and Tritium Atoms that have the same number of...

160

Glossary Term - Positron  

NLE Websites -- All DOE Office Websites (Extended Search)

Pluto Previous Term (Pluto) Glossary Main Index Next Term (Prometheus) Prometheus Positron A Positron The antimatter counterpart of the electron, positrons were discovered in 1932...

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Glossary Term - Niobe  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Emission Previous Term (Neutron Emission) Glossary Main Index Next Term (Nucleus) Nucleus Niobe In Greek mythology, Niobe was the daughter of Tantalus. She was punished by...

162

Glossary Term - Lepton  

NLE Websites -- All DOE Office Websites (Extended Search)

Joule Previous Term (Joule) Glossary Main Index Next Term (Liquid Nitrogen) Liquid Nitrogen Lepton Leptons are particles with little mass that interact through the electromagnetic...

163

Status Company Terminal Term  

NLE Websites -- All DOE Office Websites (Extended Search)

Status of Short-Term Applications to Export Previously Imported LNG (as of March 5, 2013) Status Company Terminal Term (Years) Authorized Volume (Equivalent Bcf in natural gas)...

164

Enhanced modeling and control of VSIs in microgrids operating in grid-connected mode  

Science Conference Proceedings (OSTI)

This paper focus on the influence of filter dynamics on the performance and stability of current control loops of three-phase, pulse-width modulation (PWM) voltage source inverters (VSIs) in grid-connected operating mode. The analysis considers the application ...

Leonardo Rese; Antonio Simoes Costa; Aguinaldo S. e Silva

2012-01-01T23:59:59.000Z

165

Geiger-mode avalanche photodiodes for three-dimensional imaging  

E-Print Network (OSTI)

? We discuss the properties of Geiger-mode avalanche photodiodes (APDs) and their use in developing an imaging laser radar (ladar). This type of photodetector gives a fast electrical pulse in response to the detection of even a single photon, allowing for sub-nsec-precision photon-flight-time measurement. We present ongoing work at Lincoln Laboratory on three-dimensional (3D) imaging with arrays of these diodes, and the integration of the arrays with fast complementary metal-oxide semiconductor (CMOS) digital timing circuits. Lincoln laboratory has long been involved with the development of laser radar (ladar) systems, which, like their microwave counterparts, measure the flight time of transmitted pulses of radiation to determine the distance to an object of interest. Real-time acquisition of such range information is central to a wide variety of remote-sensing applications. The optical radar, because of its shorter

Brian F. Aull; Andrew H. Loomis; Douglas J. Young; Richard M. Heinrichs; Bradley J. Felton; Peter J. Daniels; Deborah J. L

2002-01-01T23:59:59.000Z

166

CHEMICAL ENGINEERING Fall Term Spring Term  

E-Print Network (OSTI)

CHEMICAL ENGINEERING CURRICULUM Fall Term Spring Term EGGG 101 Introduction to Engineering (FYE) 2 CHEG 112 Introduction to Chemical Engineering 3 CHEM 111 General Chemistry 3 CHEM 112 General Chemistry and Writing 3 Breadth Requirement Elective 1 3 15 17 CHEG 231 Chemical Engineering Thermodynamics 3 CHEG 325

Lee, Kelvin H.

167

CHEMICAL ENGINEERING Fall Term Spring Term  

E-Print Network (OSTI)

CHEMICAL ENGINEERING CURRICULUM FALL 2010 Fall Term Spring Term EGGG 101 Introduction to Chemical Engineering 3 MATH 242 Analytic Geometry & Calculus B 4 MATH 243 Analytic Geometry & Calculus C 4 Critical Reading and Writing 3 Breadth Requirement Elective 1 3 15 17 CHEG 231 Chemical Engineering

Lee, Kelvin H.

168

Stress Induced Degradation Modes in CIGSS Minimodules (Presentation)  

DOE Green Energy (OSTI)

The experimental objectives of this report are: (1) compare the performance of modules exposed to high temperature and humidity; (2) determine the effects of different encapsulants on long term stability of CIGSS modules; and (3) analyze failure modes to determine areas in need of improvement.

Kempe, M. D.; Terwilliger, K.; Tarrant, D.

2008-05-01T23:59:59.000Z

169

Subtropical Mode Water in the 137°E Section  

Science Conference Proceedings (OSTI)

The subtropics mode water (STMW) in the North Pacific Ocean has been investigated based on the data of long-term observations along the 137°E meridian, which have been performed by the Japan Meteorological Agency since 1967 for winter and since ...

Toshio Suga; Kimio Hanawa; Yoshiaki Toba

1989-10-01T23:59:59.000Z

170

Critical {delta}{sup '} for stability of viscoresistive tearing modes  

Science Conference Proceedings (OSTI)

An analytic expression for the stability threshold of linear tearing modes is derived. The magnetized plasma is described in terms of a standard viscoresistive magnetohydrodynamic model. The analytic derivation requires an extension of the standard layer equation that represents an approximation of the full model in the vicinity of the reconnecting layer. The analytic result is checked against numerical simulations, showing excellent agreement.

Grasso, D.; Hastie, R. J.; Porcelli, F. [Burning Plasma Research Group, Dipartimento di Energetica, Politecnico di Torino, Torino (Italy); Tebaldi, C. [Burning Plasma Research Group, Dipartimento di Energetica, Politecnico di Torino, Torino (Italy); Dipartimento di Matematica, Politecnico di Torino, Torino (Italy)

2008-07-15T23:59:59.000Z

171

Glossary of Terms  

Science Conference Proceedings (OSTI)

...Glossary of Terms, Surface Engineering, Vol 5, ASM Handbook, ASM International, 1994, p 944â??973...

172

Financial and Economic Terms  

E-Print Network (OSTI)

This publication lists and defines many financial and economic terms with which producers should be familiar.

McCorkle, Dean; Klinefelter, Danny A.

2008-12-05T23:59:59.000Z

173

Pulsed Power Technology at Sandia National Laboratories  

NLE Websites -- All DOE Office Websites (Extended Search)

are some specific sites on Pulsed Power MAGPIE Pulsed Power Facility, Imperial College NIF Naval Research Laboratory, Plasma Physics Division Reviews of U.S. Fusion Policy UKAEA...

174

Dielectric liquid pulsed-power switch  

DOE Patents (OSTI)

This disclosure identifies dielectric liquids for use as opening and closing switching media in pulsed power technology, and describes a dielectric-liquid-pulsed-power switch empolying flashlamps.

Christophorou, Loucas G. (Oak Ridge, TN); Faidas, Homer (Knoxville, TN)

1990-01-01T23:59:59.000Z

175

Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser  

E-Print Network (OSTI)

This paper describes the modeling of quantum dots lasers with the aim of assessing the conditions for stable cw dual-mode operation when the mode separation lies in the THz range. Several possible models suited for InAs quantum dots in InP barriers are analytically evaluated, in particular quantum dots electrically coupled through a direct exchange of excitation by the wetting layer or quantum dots optically coupled through the homogeneous broadening of their optical gain. A stable dual-mode regime is shown possible in all cases when quantum dots are used as active layer whereas a gain medium of quantum well or bulk type inevitably leads to bistable behavior. The choice of a quantum dots gain medium perfectly matched the production of dual-mode lasers devoted to THz generation by photomixing.

Chusseau, Laurent; Viktorovitch, P; Letartre, Xavier

2013-01-01T23:59:59.000Z

176

Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method  

SciTech Connect

A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

2011-04-01T23:59:59.000Z

177

Hyper dispersion pulse compressor for chirped pulse amplification systems  

Science Conference Proceedings (OSTI)

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

Barty, Christopher P. J. (Hayward, CA)

2011-11-29T23:59:59.000Z

178

Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner  

DOE Patents (OSTI)

An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

Veligdan, James T. (Manorville, NY)

1994-01-01T23:59:59.000Z

179

Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive  

DOE Patents (OSTI)

A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

Konrad, Charles E. (Roanoke, VA); Boothe, Richard W. (Roanoke, VA)

1994-01-01T23:59:59.000Z

180

Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive  

DOE Patents (OSTI)

A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

Konrad, Charles E. (Roanoke, VA); Boothe, Richard W. (Roanoke, VA)

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

ccsd00001714, Nonlinear dynamics of electromagnetic pulses in cold relativistic plasmas  

E-Print Network (OSTI)

ccsd­00001714, version 2 ­ 19 Oct 2004 Nonlinear dynamics of electromagnetic pulses in cold particle and photon accel- eration, nonlinear optics, laser fusion, and others [1{6]. Intense of coupled electromagnetic and electrostatic modes in cold relativistic electron-ion plas- mas to conclude

182

Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive  

DOE Patents (OSTI)

A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figs.

Konrad, C.E.; Boothe, R.W.

1996-01-23T23:59:59.000Z

183

Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive  

DOE Patents (OSTI)

A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figures.

Konrad, C.E.; Boothe, R.W.

1994-02-15T23:59:59.000Z

184

Prefire identification for pulse power systems  

DOE Patents (OSTI)

Prefires in a high-power, high-frequency, multi-stage pulse generator are detected by a system having an EMI shielded pulse timing transmitter associated with and tailored to each stage of the pulse generator. Each pulse timing transmitter upon detection of a pulse triggers a laser diode to send an optical signal through a high frequency fiber optic cable to a pulse timing receiver which converts the optical signal to an electrical pulse. The electrical pulses from all pulse timing receivers are fed through an OR circuit to start a time interval measuring device and each electrical pulse is used to stop an individual channel in the measuring device thereby recording the firing sequence of the multi-stage pulse generator.

Longmire, Jerry L. (Los Alamos, NM); Thuot, Michael E. (Espanola, NM); Warren, David S. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

185

Ultrasonic flowmetering with reflected pulses  

E-Print Network (OSTI)

A transit time type ultrasonic flowmeter was tested with two different reflected pulse trajectories in flowing air at ambient conditions against an orifice meter. The flowmeter was designed to be highly accurate, to require ...

Hoyle, David C.

1984-01-01T23:59:59.000Z

186

Pulsed operation of a segmented longitudinal discharge CO/sub 2/ laser without ballast impedance  

SciTech Connect

It is shown that a longitudinal CO/sub 2/ laser with two discharge tubes electrically coupled in parallel can be operated in pulsed mode without ballast impedance. This scheme not only yields much higher efficiency (up to 13% at the maximum output energy) and eliminates component failure at high pulse repetition frequency (prf) but also facilitates short pulse availability. In the absence of ballast, current and laser pulse width decrease on increasing the voltage applied to the discharge tubes but these quantities remain unaffected on varying the value of the energy storage capacitor. This enables an independent control of the laser pulse duration and energy. Threshold energy for the onset of nonuniformities in the glow discharge reduces almost exponentially on increasing the discharge current pulse duration but rises on decreasing the operating value of E/N, the electric field to neutral gas density ratio. The maximum output laser energy of about 1 J/pulse, adjustable pulse duration from 30 ..mu..s to about 2 ms, and prf up to 50 Hz have been obtained.

Kukreja, L.M.; Sehgal, S.K.; Chatterjee, U.K.

1985-11-01T23:59:59.000Z

187

Lithium batteries for pulse power  

DOE Green Energy (OSTI)

New designs of lithium batteries having bipolar construction and thin cell components possess the very low impedance that is necessary to deliver high-intensity current pulses. The R D and understanding of the fundamental properties of these pulse batteries have reached an advanced level. Ranges of 50--300 kW/kg specific power and 80--130 Wh/kg specific energy have been demonstrated with experimental high-temperature lithium alloy/transition-metal disulfide rechargeable bipolar batteries in repeated 1- to 100-ms long pulses. Other versions are designed for repetitive power bursts that may last up to 20 or 30 s and yet may attain high specific power (1--10 kW/kg). Primary high-temperature Li-alloy/FeS{sub 2} pulse batteries (thermal batteries) are already commercially available. Other high-temperature lithium systems may use chlorine or metal-oxide positive electrodes. Also under development are low-temperature pulse batteries: a 50-kW Li/SOCl{sub 2} primary batter and an all solid-state, polymer-electrolyte secondary battery. Such pulse batteries could find use in commercial and military applications in the near future. 21 refs., 8 figs.

Redey, L.

1990-01-01T23:59:59.000Z

188

Pulsed CO laser for isotope separation of uranium  

SciTech Connect

This article proposes a technical solution for using a CO laser facility for the industrial separation of uranium used in the production of fuel for nuclear power plants, employing a method of laser isotope separation of uranium with condensation repression in a free jet. The laser operation with nanosecond pulse irradiation can provide an acceptable efficiency in the separating unit and a high efficiency of the laser with the wavelength of 5.3 {mu}m. In the present work we also introduce a calculation model and define the parameters of a mode-locked CO laser with a RF discharge in the supersonic stream. The average pulsed CO laser power of 3 kW is sufficient for efficient industrial isotope separation of uranium in one stage.

Baranov, Igor Y.; Koptev, Andrey V. [Rocket-Space Technics Department, Baltic State Technical University, 1, 1st Krasnoarmeyskaya st.,St. Petersburg, 190005 (Russian Federation)

2012-07-30T23:59:59.000Z

189

Icelandic Coastal Sea Surface Temperature Records Constructed: Putting the Pulse on Air–Sea–Climate Interactions in the Northern North Atlantic. Part I: Comparison with HadISST1 Open-Ocean Surface Temperatures and Preliminary Analysis of Long-Term Patterns and Anomalies of SSTs around Iceland  

Science Conference Proceedings (OSTI)

A new comprehensive record of long-term Icelandic sea surface temperature measurements, which have been updated and filled in with reference to air temperature records, is presented. The new SST series reveal important features of the variability ...

Edward Hanna; Trausti Jónsson; Jon Ólafsson; Hedinn Valdimarsson

2006-11-01T23:59:59.000Z

190

Glossary Term - Avogadro's Number  

NLE Websites -- All DOE Office Websites (Extended Search)

Atomic Number Previous Term (Atomic Number) Glossary Main Index Next Term (Beta Decay) Beta Decay Avogadro's Number Avogadro's number is the number of particles in one mole of a...

191

Glossary Term - Vanadis  

NLE Websites -- All DOE Office Websites (Extended Search)

Van de Graaff Generator Previous Term (Van de Graaff Generator) Glossary Main Index Next Term (10 Most Abundant Compounds in the Earth's Crust) 10 Most Abundant Compounds
in the...

192

Glossary Term - Liquid Nitrogen  

NLE Websites -- All DOE Office Websites (Extended Search)

Lepton Previous Term (Lepton) Glossary Main Index Next Term (Mercury) Mercury Liquid Nitrogen Liquid nitrogen boils in a frying pan on a desk. The liquid state of the element...

193

Glossary Term - Mercury  

NLE Websites -- All DOE Office Websites (Extended Search)

Liquid Nitrogen Previous Term (Liquid Nitrogen) Glossary Main Index Next Term (Mole) Mole Mercury Mercury as seen by the Mariner 10 spacecraft on March 24, 1974. Mercury is the...

194

Glossary Term - Mole  

NLE Websites -- All DOE Office Websites (Extended Search)

Mercury Previous Term (Mercury) Glossary Main Index Next Term (Neptune) Neptune Mole A mole of a substance is the mass, in grams, that is numerically equal to that substance's...

195

Glossary Term - Helios  

NLE Websites -- All DOE Office Websites (Extended Search)

Half-life Previous Term (Half-life) Glossary Main Index Next Term (Isotope) Isotope Helios The sun seen in Hydrogen-alpha light. In Greek mythology, Helios was god of the sun....

196

Glossary Term - Nucleus  

NLE Websites -- All DOE Office Websites (Extended Search)

Niobe Previous Term (Niobe) Glossary Main Index Next Term (Pallas) Pallas Nucleus The nucleus of a nitrogen-14 atom. Discovered by Ernest Rutherford in 1911, the nucleus is the...

197

Glossary Term - Deuteron  

NLE Websites -- All DOE Office Websites (Extended Search)

Deuterium Previous Term (Deuterium) Glossary Main Index Next Term (Dry Ice) Dry Ice Deuteron A Deuteron The nucleus of a deuterium atom. A deuteron consists of one proton and one...

198

Glossary Term - Joule  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotope Previous Term (Isotope) Glossary Main Index Next Term (Lepton) Lepton Joule A joule is the amount of work done when a force of one Newton is applied through a distance of...

199

Glossary Term - Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Bohr Radius Previous Term (Bohr Radius) Glossary Main Index Next Term (Ceres) Ceres Catalyst A catalyst is a substance that increases the speed of a chemical reaction without being...

200

Glossary Term - Thor  

NLE Websites -- All DOE Office Websites (Extended Search)

Tantalus Previous Term (Tantalus) Glossary Main Index Next Term (Titans) Titans Thor In Norse mythology, Thor is the god of thunder and the son of Odin and Earth. Thor possesses a...

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Glossary Term - Titans  

NLE Websites -- All DOE Office Websites (Extended Search)

Thor Previous Term (Thor) Glossary Main Index Next Term (Tritium) Tritium Titans In Greek mythology, the Titans are the offspring of Earth and Sky and ruled before being overthrown...

202

Glossary Term - Gluon  

NLE Websites -- All DOE Office Websites (Extended Search)

Volt (eV) Previous Term (Electron Volt (eV)) Glossary Main Index Next Term (Half-life) Half-life Gluon Gluons are the particles responsible for binding quarks to each other....

203

Glossary Term - Dry Ice  

NLE Websites -- All DOE Office Websites (Extended Search)

Deuteron Previous Term (Deuteron) Glossary Main Index Next Term (Electron) Electron Dry Ice A block of dry ice sublimating on a table. Dry ice is the solid form of carbon dioxide...

204

Narrow linewidth picosecond pulsed laser with mega-watt peak power at UV wavelength  

Science Conference Proceedings (OSTI)

We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system to generate 66 ps/402.5 MHz pulses with mega-watt peak power at 355 nm. The seed laser is based on a direct electro-optic modulation of a fiber laser output. A very high extinction ratio (45 dB) has been achieved by using an adaptive bias control. The multi-stage Nd:YAG amplifier system allows a uniformly temporal shaping of macropulses with tunable pulse duration. The light output form the amplifier is converted to 355 nm and over 1 MW UV peak power is obtained when the laser is operating in a 5- s/10-Hz macropulse mode. The laser output has a transform limited spectrum bandwidth with a very narrow linewidth of individual laser mode. The immediate application of the laser system is the laser assisted hydrogen ion beam stripping for the Spallation Neutron Source (SNS).

Liu, Yun [ORNL; Huang, Chunning [ORNL; Deibele, Craig Edmond [ORNL

2013-01-01T23:59:59.000Z

205

Glossary of Sewing Terms  

E-Print Network (OSTI)

This publication lists common terms used in sewing. It includes definitions of garment types, fabric qualities, notions and construction procedures.

2006-05-01T23:59:59.000Z

206

Short pulse free electron laser amplifier  

DOE Patents (OSTI)

Method and apparatus for amplification of a laser pulse in a free electron laser amplifier where the laser pulse duration may be a small fraction of the electron beam pulse duration used for amplification. An electron beam pulse is passed through a first wiggler magnet and a short laser pulse to be amplified is passed through the same wiggler so that only the energy of the last fraction, f, (f<1) of the electron beam pulse is consumed in amplifying the laser pulse. After suitable delay of the electron beam, the process is repeated in a second wiggler magnet, a third, . . . , where substantially the same fraction f of the remainder of the electron beam pulse is consumed in amplification of the given short laser pulse in each wiggler magnet region until the useful electron beam energy is substantially completely consumed by amplification of the laser pulse.

Schlitt, Leland G. (Livermore, CA); Szoke, Abraham (Fremont, CA)

1985-01-01T23:59:59.000Z

207

Pulse compression and prepulse suppression apparatus  

DOE Patents (OSTI)

A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).

Dane, C.B.; Hackel, L.A.; George, E.V.; Miller, J.L.; Krupke, W.F.

1993-11-09T23:59:59.000Z

208

Nuclear Excitation by a Strong Short Laser Pulse  

Science Conference Proceedings (OSTI)

We derive the conditions on laser energy and photon number under which a short strong laser pulse excites a collective nuclear mode. We use the Giant Dipole Resonance as a representative example, and a random-matrix description of the fine-structure states and perturbation theory as tools. We identify the relevant observable as the nuclear time-decay function. That function is the Fourier transform of the autocorrelation function of the associated scattering matrix and contains information not otherwise available. We evaluate that function in specific cases and show that it may deviate significantly from an exponential.

Weidenmueller, Hans A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

2011-05-06T23:59:59.000Z

209

Occupant satisfaction in mixed-mode buildings  

E-Print Network (OSTI)

Environmental Quality in Green Buildings”. Indoor Air; 14 (Strategies for Mixed-Mode Buildings, Summary Report, CenterCBE). 2006. Website: Mixed-Mode Building Case Studies.

Brager, Gail; Baker, Lindsay

2009-01-01T23:59:59.000Z

210

Occupant satisfaction in mixed-mode buildings.  

E-Print Network (OSTI)

Strategies for Mixed-Mode Buildings, Summary Report, CenterCBE). 2006. Website: Mixed-Mode Building Case Studies.Department of Environmental Building Research Establishment

Brager, Gail; Baker, Lindsay

2008-01-01T23:59:59.000Z

211

Mixed-Mode Ventilation and Building Retrofits  

E-Print Network (OSTI)

November 1994, ENTPE, Lyon. [CIBSE] Chartered Institution ofMixed-mode ventilation. CIBSE Applications Manual AM13.incorporated by the design. CIBSE, 2000 Mixed-mode

Brager, Gail; Ackerly, Katie

2010-01-01T23:59:59.000Z

212

Method and apparatus for pulse stacking  

DOE Patents (OSTI)

An active pulse stacking system including an etalon and an electro-optical modulator apparatus combined with a pulse-forming network capable of forming and summing a sequence of time-delayed optical waveforms arising from, for example, a single laser pulse. The Pockels cell pulse stacker may attain an efficiency of about 2.6% while providing a controllable faster-than-exponential time rise in transmitted pulse intensity.

Harney, Robert C. (Livermore, CA)

1977-01-01T23:59:59.000Z

213

Analytical modeling of pulse-pileup distortion using the true pulse shape; applications to Fermi-GBM  

E-Print Network (OSTI)

Pulse-pileup affects most photon counting systems and occurs when photon detections occur faster than the detector's registration and recovery time. At high input rates, shaped pulses interfere and the source spectrum, as well as intensity information, get distorted. For instruments using bipolar pulse shaping there are two aspects to consider: `peak' and `tail' pileup effects, which raise and lower the measured energy, respectively. Peak effects have been extensively modeled in the past. Tail effects have garnered less attention due to the increased complexity: bipolar tails mean the tail pulse-height measurement depends on events in more than one time interval. We leverage previous work to derive an accurate, semi-analytical prediction for peak and tail pileup, up to high orders. We use the true pulse shape from the detectors of the Fermi Gamma-ray Burst Monitor. The measured spectrum is calculated by writing exposure time as a state-space expansion of overlapping pileup states and is valid up to very high rates. This expansion models losses due to fixed and extendable deadtime by averaging overlap configurations. Additionally, the model correctly predicts energy-dependent losses due to tail subtraction (sub-threshold) effects. We discuss pileup losses in terms of the true rate of photon detections versus the recorded count rate.

Vandiver Chaplin; Narayana Bhat; Michael Briggs; Valerie Connaughton

2012-11-28T23:59:59.000Z

214

Kinematic study of the effect of dispersion in quantum vacuum emission from strong laser pulses  

E-Print Network (OSTI)

A strong light pulse propagating in a nonlinear medium causes an effective change in the local refractive index. With a suitable tuning of the pulse velocity, the leading and trailing edge of the pulse were predicted to behave as analogue black and white horizons in the limit of a dispersionless medium. In this paper, we study a more realistic situation where the frequency dispersion of the medium is fully taken into account. As soon as positive frequency modes with negative norm are present in the comoving frame, spontaneous emission of quantum vacuum radiation is expected to arise independently of the presence of horizons. We finally investigate the kinematic constraints put on the emission and we show that the optimal directions to observe Hawking-like emission form a narrow angle with the direction of propagation of the pulse.

Stefano Finazzi; Iacopo Carusotto

2012-04-16T23:59:59.000Z

215

Inverse Faraday Effect with Linearly Polarized Laser Pulses  

Science Conference Proceedings (OSTI)

The inverse Faraday effect is usually associated with circularly polarized radiation; here, we show that it can also occur for linearly polarized radiation. The quasistatic axial magnetic field generated by a laser propagating in plasma can be calculated by considering both the spin and the orbital angular momenta of the laser pulse. A net spin is present when the radiation is circularly polarized and a net orbital angular momentum is present if there is any deviation from perfect rotational symmetry. The orbital angular momentum gives an additional contribution to the axial magnetic field that can enhance or reduce the effect usually attributed to circular polarization and strongly depends on the intensity profile of the Laguerre-Gaussian modes involving the azimuthal and radial mode numbers.

Ali, S. [Instituto de Plasmas e Fusao Nuclear--Laboratorio Associado, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Davies, J. R.; Mendonca, J. T. [Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

2010-07-16T23:59:59.000Z

216

Deterministic source of a train of indistinguishable single-photon pulses with single-atom-cavity system  

E-Print Network (OSTI)

We present a mechanism to produce indistinguishable single-photon pulses on demand from an optical cavity. The sequences of two laser pulses generate, at the two Raman transitions of a four-level atom, the same cavity-mode photons without repumping of the atom between photon generations. Photons are emitted from the cavity with near-unit efficiency in well-defined temporal modes of identical shapes controlled by the laser fields. The second order correlation function reveals the single-photon nature of the proposed source. A realistic setup for the experimental implementation is presented.

A. Gogyan; S. Guérin; H. -R. Jauslin; Yu. Malakyan

2010-05-01T23:59:59.000Z

217

Pulse combustor with controllable oscillations  

DOE Patents (OSTI)

A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive ignition and combustion of sequentially introduced fuel-air charges without the assistance of the spark plug and the rapid quenching of the flame after each ignition in a controlled manner so as to provide a selective control over the oscillation frequency and amplitude. Additional control over the heat transfer in the combustion chamber is provided by employing heat exchange mechanisms for selectively heating or cooling the elongated ceramic body or bodies and/or the walls of the combustion chamber.

Richards, George A. (Morgantown, WV); Welter, Michael J. (Columbiana, OH); Morris, Gary J. (Morgantown, WV)

1992-01-01T23:59:59.000Z

218

Pulse combustor with controllable oscillations  

DOE Patents (OSTI)

A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive ignition and combustion of sequentially introduced fuel-air charges without the assistance of the spark plug and the rapid quenching of the flame after each ignition in a controlled manner so as to provide a selective control over the oscillation frequency and amplitude. Additional control over the heat transfer in the combustion chamber is provided by employing heat exchange mechanisms for selectively heating or cooling the elongated ceramic body or bodies and/or the walls of the combustion chamber.

Richards, G.A.; Morris, G.J.; Welter, M.J.

1991-12-31T23:59:59.000Z

219

Mach 5 bow shock control by a nanosecond pulse surface dielectric barrier discharge  

Science Conference Proceedings (OSTI)

Bow shock perturbations in a Mach 5 air flow, produced by low-temperature, nanosecond pulse, and surface dielectric barrier discharge (DBD), are detected by phase-locked schlieren imaging. A diffuse nanosecond pulse discharge is generated in a DBD plasma actuator on a surface of a cylinder model placed in air flow in a small scale blow-down supersonic wind tunnel. Discharge energy coupled to the actuator is 7.3-7.8 mJ/pulse. Plasma temperature inferred from nitrogen emission spectra is a few tens of degrees higher than flow stagnation temperature, T = 340 {+-} 30 K. Phase-locked Schlieren images are used to detect compression waves generated by individual nanosecond discharge pulses near the actuator surface. The compression wave propagates upstream toward the baseline bow shock standing in front of the cylinder model. Interaction of the compression wave and the bow shock causes its displacement in the upstream direction, increasing shock stand-off distance by up to 25%. The compression wave speed behind the bow shock and the perturbed bow shock velocity are inferred from the Schlieren images. The effect of compression waves generated by nanosecond discharge pulses on shock stand-off distance is demonstrated in a single-pulse regime (at pulse repetition rates of a few hundred Hz) and in a quasi-continuous mode (using a two-pulse sequence at a pulse repetition rate of 100 kHz). The results demonstrate feasibility of hypersonic flow control by low-temperature, repetitive nanosecond pulse discharges.

Nishihara, M.; Takashima, K.; Rich, J. W.; Adamovich, I. V. [Michael A. Chaszeyka Nonequilibrium Thermodynamics Laboratories, Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2011-06-15T23:59:59.000Z

220

High-resolution single-pulse studies of the Vela Pulsar  

E-Print Network (OSTI)

We present high-resolution multi-frequency single-pulse observations of the Vela pulsar, PSR B0833-45, aimed at studying micro-structure, phase-resolved intensity fluctuations and energy distributions at 1.41 and 2.30 GHz. We show that the micro-pulse width in pulsars has a period dependence. Like individual pulses, Vela's micro-pulses are highly elliptically polarized. There is a strong correlation between Stokes parameters V and I in the micro-structure. We show that the V/I distribution is Gaussian with a narrow width and that this width appears to be constant as a function of pulse phase. The phase-resolved intensity distributions of I are best fitted with log-normal statistics. Extra emission components, i.e.``bump'' and ``giant micro-pulses'', discovered by Johnston et al.(2001) are also present at 2.3 GHz. The bump component seems to be an extra component superposed on the main pulse profile but does not appear periodically. The giant micro-pulses are time-resolved and have significant jitter in their arrival times. Their flux density distribution is best fitted by a power-law, indicating a link between these features and ``classical'' giant pulses as observed for the Crab pulsar, (PSR B0531+21), PSR B1937+21 and PSR B1821-24. We find that Vela contains a mixture of emission properties representing both ``classical'' properties of radio pulsars (e.g. micro-structure, high degree of polarization, S-like position angle swing, orthogonal modes) and features which are most likely related to high-energy emission (e.g. extra profile components, giant micro-pulses). It hence represents an ideal test case to study the relationship between radio and high-energy emission in significant detail.

M. Kramer; S. Johnston; W. van Straten

2002-03-08T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Synchronization of Sub-Picosecond Electron and Laser Pulses  

SciTech Connect

Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is subpicosecond, with tens of femtosecond synchronization implied for next-generation experiments. Typically, an RF electron accelerator is synchronized to a short pulse laser system by detecting the repetition signal of a laser oscillator, adjusted to an exact subharmonic of the linac RF frequency, and multiplying or phase locking this signal to produce the master RF clock. Pulse-to-pulse jitter characteristic of self-mode-locked laser oscillators represents a direct contribution to the ultimate timing jitter between a high intensity laser focus and electron beam at the interaction point, or a photocathode drive laser in an RF photoinjector. This timing jitter problem has been addressed most seriously in the context of the RF photoinjector, where the electron beam properties are sensitive functions of relative timing jitter. The timing jitter achieved in synchronized photocathode drive laser systems is near, or slightly below one picosecond. The ultimate time of arrival jitter of the beam at the photoinjector exit is typically a bit smaller than the photocathode drive-laser jitter due to velocity compression effects in the first RF cell of the gun. This tendency of the timing of the electron beam arrival at a given spatial point to lock to the RF lock is strongly reinforced by use of magnetic compression.

Rosenzweig, J.B.; Le Sage G.P.

2000-08-15T23:59:59.000Z

222

Terms and Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Terms and Conditions Terms and Conditions Terms and Conditions As a premier national research and development laboratory, LANL seeks to do business with qualified companies that offer value and high quality products and services. Contact Small Business Office (505) 667-4419 Email Use information below as guideline to doing business An "Appendix SFA-1" contains FAR and DEAR Clauses that are incorporated by reference into a particular subcontract. "Exhibit A General Conditions" are the general terms and conditions applicable to a particular subcontract. Note: The contents of the SFA-1 and Exhibit A (below) are not the only terms and conditions that will be in a LANS subcontract but represent the terms that generally do not change in a particular type of procurement. The

223

Failure Modes and Effects Analysis  

Science Conference Proceedings (OSTI)

Table 1   Glossary of terms used in reliability-centered maintenance...containment, comfort, appearance, energy efficiency, and structural

224

Long-Term Surveillance  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Long-Term Surveillance Long-Term Surveillance Operations and Maintenance Fiscal Year 2013 Year-End Summary Report September 2013 LMS/ESL/S10692 ESL-RPT-2013-03 This page intentionally left blank LMS/ESL/S10692 ESL-RPT-2013-03 Long-Term Surveillance Operations and Maintenance Fiscal Year 2013 Year-End Summary Report September 2013 This page intentionally left blank U.S. Department of Energy Long-Term Surveillance Operations and Maintenance FY 2013 Year-End Summary Report September 2013 Doc. No. S10692 Page i Contents Abbreviations .................................................................................................................................. ii 1.0 Introduction ............................................................................................................................1

225

Toward single-cycle optical pulses  

E-Print Network (OSTI)

Single-cycle optical pulses, the never-before-achieved regime, have a great potential for attosecond science and phase-sensitive nonlinear optics. To achieve single-cycle optical pulses by active synchronization, three ...

Kim, Jung-Won, 1976-

2004-01-01T23:59:59.000Z

226

Dielectric liquid pulsed-power switch  

DOE Patents (OSTI)

This disclosure identifies dielectric liquids for use as opening and closing switching media in pulsed power technology, and describes a dielectric-liquid-pulsed-power switch employing flashlamps. 2 figs.

Christophorou, L.; Faidas, H.

1989-08-30T23:59:59.000Z

227

Femto-Second Pulses of Synchrotron Radiation  

E-Print Network (OSTI)

Pulses of Synchrotron Radiation" A. A. Zholents 1) and M. S.Pulses of Synchrotron Radiation' I) A. A. Zholents l , andpulses of syn- chrotron radiation is proposed. It is based

Zholents, A.A.

2011-01-01T23:59:59.000Z

228

Pulsed Power Technology and Applications -- Scandinavia  

Science Conference Proceedings (OSTI)

Pulsed power is a new and promising technology with a large number of potential applications. In addition to existing and future pulsed power supply and technology in Scandinavia and Europe, this report also describes present and future applications.

1999-04-19T23:59:59.000Z

229

Irregular term courses (These do not roll to future terms) Irregular term courses are allowed only in fall and spring terms. Irregular term courses  

E-Print Network (OSTI)

Irregular term courses (These do not roll to future terms) · Irregular term courses are allowed only in fall and spring terms. Irregular term courses in spring term cannot roll into summer term(s), no exceptions. · A course ending one day or more beyond the last final exam day for the fall term is considered

Bolding, M. Chad

230

Current Sheet Canting in Pulsed Electromagnetic Accelerators  

E-Print Network (OSTI)

Current Sheet Canting in Pulsed Electromagnetic Accelerators Thomas Edward Markusic A DISSERTATION #12;Current Sheet Canting in Pulsed Electromagnetic Accelerators Prepared by: Thomas Edward Markusic of current sheet canting in pulsed electromagnetic accelerators is the de- parture of the plasma sheet

Choueiri, Edgar

231

Pulsed energy storage in fusion devices  

DOE Green Energy (OSTI)

Research and development on pulsed energy technologies, primarily for pulsed high-beta fusion systems, is described. Systems studies at Los Alamos and elsewhere have served to define these required technologies, which include fast discharging homopolar machines, pulsed superconducting coils, and the associated switching technology. Programs at the Los Alamos Scientific Laboratory, Westinghouse, and The University of Texas are described here.

Thomassen, K.I.; Rogers, J.D.; Ribe, F.L.

1976-01-01T23:59:59.000Z

232

Library Terms That Users Understand  

E-Print Network (OSTI)

data resources about Library Terms That Users Understand ©terminology is a major factor. Terms most often cited asHumanities    or Social Sciences Terms most often cited as

Kupersmith, John

2012-01-01T23:59:59.000Z

233

Cornman's definition of observation terms  

Science Conference Proceedings (OSTI)

reconcile what is described in mentalistic terms with materialism. ... It is clearly important that the observation terms should not include terms which are ...

234

Linearizer for pulse-shaping of received pulse in ultra-wideband radio systems  

Science Conference Proceedings (OSTI)

This paper presents a novel concept of pulse-shaping in an ultra-wide band radio system. Instead of attempting to design an antenna with flat group delay, the emphasis has been shifted to the signal processing aspect of pulse shaping. The received pulse ... Keywords: Group delay, Linearizer, Pulse shaping, Radar, Radio systems, Ultra-wideband

Ajay K. Singh; Pradeep Kumar; G. Singh; T. Chakravarty

2010-03-01T23:59:59.000Z

235

Pulsed Power for Solid-State Lasers  

SciTech Connect

Beginning in the early 1970s, a number of research and development efforts were undertaken at U.S. National Laboratories with a goal of developing high power lasers whose characteristics were suitable for investigating the feasibility of laser-driven fusion. A number of different laser systems were developed and tested at ever larger scale in pursuit of the optimum driver for laser fusion experiments. Each of these systems had associated with it a unique pulsed power option. A considerable amount of original and innovative engineering was carried out in support of these options. Ultimately, the Solid-state Laser approach was selected as the optimum driver for the application. Following this, the Laser Program at the Lawrence Livermore National Laboratory and the University of Rochester undertook aggressive efforts directed at developing the technology. In particular, at Lawrence Livermore National Laboratory, a series of laser systems beginning with the Cyclops laser and culminating in the present with the National Ignition Facility were developed and tested. As a result, a large amount of design information for solid-state laser pulsed power systems has been documented. Some of it is in the form of published papers, but most of it is buried in internal memoranda, engineering reports and LLNL annual reports. One of the goals of this book is to gather this information into a single useable format, such that it is easily accessed and understood by other engineers and physicists for use with future designs. It can also serve as a primer, which when seriously studied, makes the subsequent reading of original work and follow-up references considerably easier. While this book deals only with the solid-state laser pulsed power systems, in the bibliography we have included a representative cross section of papers and references from much of the very fine work carried out at other institutions in support of different laser approaches. Finally, in recent years, there has been a renewed interest in high-average-power solid-state glass lasers. Much of the prime power technology developed in support of this has definite applications in the long term for fusion power plant scenarios.

Gagnon, W; Albrecht, G; Trenholme, J; Newton, M

2007-04-19T23:59:59.000Z

236

Flu Terms Defined  

NLE Websites -- All DOE Office Websites (Extended Search)

Flu Terms Defined H1N1 Influenza is a respiratory disease of pigs caused by type A influenza viruses that causes regular outbreaks in pigs. People do not normally get H1N1 flu, but...

237

Terms and Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Terms and Conditions Terms and Conditions R&D Overview 100G Testbed Testbed Description Testbed Results Current Testbed Research Proposal Process Terms and Conditions Virtual Circuits (OSCARS) Performance (perfSONAR) Tools Development Green Networking Authentication & Trust Federation (ATF) Partnerships Contact Us Technical Assistance: 1 800-33-ESnet (Inside the US) 1 800-333-7638 (Inside the US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Terms and Conditions Researchers must provide ESnet copies of any articles, presentations, and publications based on testbed research for posting on the ESnet Testbed web site. All publications based on work conducted on the testbed must include the following statement:

238

High current pulse transmission cable  

DOE Patents (OSTI)

This invention is comprised of a transmission cable for carrying high current pulses in which an even numbered plurality of electrical conductors surrounds a central ground conductor. Each electrical conductor is connected so that it at any instant in time it will carry current of opposite polarity to the polarity carried by adjacent conductors. This arrangement cancels practically all of the external fields generated by current in the conductors.

Parsons, W.M.

1990-09-28T23:59:59.000Z

239

Adaptive control system for pulsed megawatt klystrons  

DOE Patents (OSTI)

The invention provides an arrangement for reducing waveform errors such as errors in phase or amplitude in output pulses produced by pulsed power output devices such as klystrons by generating an error voltage representing the extent of error still present in the trailing edge of the previous output pulse, using the error voltage to provide a stored control voltage, and applying the stored control voltage to the pulsed power output device to limit the extent of error in the leading edge of the next output pulse.

Bolie, Victor W. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

240

Filtering of Gravity Modes in Atmospheric Models  

Science Conference Proceedings (OSTI)

The impact of gravity modes in atmospheric model predictions is assessed quantitatively by comparing integrations with a normal mode initialized primitive equation model and its corresponding pseudogeostrophic form to document some generally ...

F. Baer; J. J. Tribbia

1984-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Waveguide mode converter and method using same  

DOE Patents (OSTI)

A waveguide mode converter converts electromagnetic power being transmitted in a TE.sub.0n or a TM.sub.0n mode, where n is an integer, to an HE.sub.11 mode. The conversion process occurs in a single stage without requiring the power to pass through any intermediate modes. The converter comprises a length of circular corrugated waveguide formed in a multiperiod periodic curve. The period of the curve is selected to couple the desired modes and decouple undesired modes. The corrugation depth is selected to control the phase propagation constant, or wavenumbers, of the input and output modes, thereby preventing coherent coupling to competing modes. In one embodiment, both the period and amplitude of the curve may be selectively adjusted, thereby allowing the converter to be tuned to maximize the conversion efficiency.

Moeller, Charles P. (Del Mar, CA)

1990-01-01T23:59:59.000Z

242

Performance of the intense pulsed neutron source accelerator system  

Science Conference Proceedings (OSTI)

The Intense Pulsed Neutron Source (IPNS) facility has now been operating in a routine way for outside users since November 1, 1981. From that date through December of 1982, the accelerator system was scheduled for neutron science for 4500 hours. During this time the accelerator achieved its short-term goals by delivering about 380,000,000 pulses of beam totaling over 6 x 10/sup 20/ protons. The changes in equipment and operating practices that evolved during this period of intense running are described. The intensity related instability threshold was increased by a factor of two and the accelerator beam current has been ion source limited. Plans to increase the accelerator intensity are also described. Initial operating results with a new H/sup -/ ion source are discussed.

Potts, C.; Brumwell, F.; Rauchas, A.; Stipp, V.; Volk, G.

1983-01-01T23:59:59.000Z

243

Pulsed power drivers for ICF and high energy density physics  

SciTech Connect

Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to ICF and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application to x-ray laser and radiation effects science research. Saturn is the most powerful of these sources to date. It generates {approximately}500 kilojoules of x-rays from a magnetically driven implosion (Z-pinch). This paper describes results of x-ray physics experiments performed on Saturn, plans for a new Z-pinch drive capability for PBFA-II, and a design concept for the proposed {approximately}15 MJ Jupiter facility. The opportunities for ICF-relevant research using these facilities will also be discussed.

Ramirez, J.J.; Matzen, M.K.; McDaniel, D.H.

1995-12-31T23:59:59.000Z

244

New Modes of Nuclear Excitations  

E-Print Network (OSTI)

We present a theoretical approach based on density functional theory supplemented by a microscopic multi-phonon model which is applied for investigations of pygmy resonances and other excitations of different multipolarities in stable and exotic nuclei. The possible relation of low-energy modes to the properties of neutron or proton skins is systematically studied in isotonic and isotopic chains. The fine structure of nuclear electric and magnetic response functions is analyzed and compared to experimental data. Their relevance to nuclear astrophysics is discussed.

Nadia Tsoneva; Horst Lenske

2013-09-30T23:59:59.000Z

245

The Wakefield Effects of Pulsed Crab Cavities at the Advanced Photon Source for Short-X-ray Pulse Generation  

E-Print Network (OSTI)

The Wakefield Effects of Pulsed Crab Cavities at the Advanced Photon Source for Short-X-ray Pulse Generation

Chae, Y C; Dolgashev, V

2007-01-01T23:59:59.000Z

246

Nuclear Excitation by a Zeptosecond Multi--MeV Laser Pulse  

E-Print Network (OSTI)

A zeptosecond multi--MeV laser pulse may either excite a "plasma" of strongly interacting nucleons or a collective mode. We derive the conditions on laser energy and photon number such that either of these scenarios is realized. We use the nuclear Giant Dipole Resonance as a representative example, and a random--matrix description of the fine--structure states and perturbation theory as tools.

Hans A. Weidenmueller

2010-09-30T23:59:59.000Z

247

High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor  

SciTech Connect

Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5–9 MW level of incident power. The compressed pulses observed had powers of 50–70 MW and durations of 40–70 ns. Peak power gains were measured to be in the range of 7:1–11:1 with efficiency in the range of 50–63%.

Jay L. Hirshfield

2010-03-04T23:59:59.000Z

248

Developments in Normal Mode Initialization. Part II: A New Method and its Comparison with Currently Used Schemes  

Science Conference Proceedings (OSTI)

The analysis of Part I suggested that the temporal characteristics of the nonlinear terms in the equations of motion could introduce convergence problems in currently used schemes for normal mode initialization (NMI). In Part II we 1) introduce a ...

Philip J. Rasch

1985-10-01T23:59:59.000Z

249

On the Theory of the Long-Term Variability of the Atmosphere  

Science Conference Proceedings (OSTI)

Much of the atmosphere's long-term variability is contained in the planetary modes with zonal wavenumber m?5. It is proposed that a considerable fraction of this variability is induced by the nonlinear interaction of synoptic-scale modes (m>5) ...

Joseph Egger; Heinz-Dieter Schilling

1983-05-01T23:59:59.000Z

250

Propagation of femtosecond terawatt laser pulses in N{sub 2} gas including higher-order Kerr effects  

Science Conference Proceedings (OSTI)

Propagation characteristic of femtosecond terawatt laser pulses in N{sub 2} gas with higher-order Kerr effect (HOKE) is investigated. Theoretical analysis shows that HOKE acting as Hamiltonian perturbation can destroy the coherent structure of a laser field and result in the appearance of incoherent patterns. Numerical simulations show that in this case two different types of complex structures can appear. It is found that the high-order focusing terms in HOKE can cause continuous phase shift and off-axis evolution of the laser fields when irregular homoclinic orbit crossings of the field in phase space take place. As the laser propagates, small-scale spatial structures rapidly appear and the evolution of the laser field becomes chaotic. The two complex patterns can switch between each other quasi-periodically. Numerical results show that the two complex patterns are associated with the stochastic evolution of the energy contained in the higher-order shorter-wavelength Fourier modes. Such complex patterns, associated with small-scale filaments, may be typical for laser propagation in a HOKE medium.

Huang, T. W. [HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zhou, C. T.; He, X. T. [HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

2012-12-15T23:59:59.000Z

251

Real-time multi-mode neutron multiplicity counter  

DOE Patents (OSTI)

Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms. The detector includes a multi-mode counter that executes a number of different count algorithms in parallel to determine different attributes of the count data.

Rowland, Mark S; Alvarez, Raymond A

2013-02-26T23:59:59.000Z

252

Collective modes in the color flavor-locked phase.  

SciTech Connect

We study the low-energy effective action for some collective modes of the color flavor-locked (CFL) phase of QCD. This phase of matter has long been known to be a superfluid because by picking a phase its order parameter breaks the quark-number U(1){sub B} symmetry spontaneously. We consider the modes describing fluctuations in the magnitude of the condensate, namely the Higgs mode, and in the phase of the condensate, namely the Nambu-Goldstone (NG) (or Anderson-Bogoliubov) mode associated with the breaking of U(1){sub B}. By employing as microscopic theory the Nambu-Jona-Lasinio model, we reproduce known results for the Lagrangian of the NG field to the leading order in the chemical potential and extend such results evaluating corrections due to the gap parameter. Moreover, we determine the interaction terms between the Higgs and the NG field. This study paves the way for a more reliable study of various dissipative processes in rotating compact stars with a quark matter core in the CFL phase.

Anglani, R.; Mannarelli, M.; Ruggieri, M. (Physics); (Univ. of Barcelona); (Kyoto Univ.); (Italian National Research Council)

2011-05-17T23:59:59.000Z

253

Higher Order Modes Damping Analysis for the SPX Deflecting Cavity Cryomodule  

Science Conference Proceedings (OSTI)

A single-cell superconducting deflecting cavity operating at 2.812 GHz has been proposed and designed for the Short Pulse X-ray (SPX) project for the Advanced Photon Source upgrade. A cryomodule of 4 such cavities will be needed to produce the required 2-MV deflecting voltage. Each deflecting cavity is equipped with one fundamental power coupler (FPC), one lower order mode (LOM) coupler, and two higher order mode (HOM) couplers to achieve the stringent damping requirements for the unwanted modes. The damping of the HOM/LOM modes below the beampipe cutoff has been analyzed in the single cavity geometry and shown to meet the design requirements. The HOMs above beam pipe cutoff in the 4-cavity cyromodule, however, may result in cross coupling which may affect the HOM damping and potentially trapped modes between the cavities which could produce RF heating to the beamline bellows and even be detrimental to the beam. We have evaluated the HOM damping and trapped modes in the 4-cavity cryomodule using the parallel finite element EM code ACE3P developed at SLAC. We will present the results of the cryomodule analysis in this paper.

L. Xiao, Z. Li, C.-K. Ng, A. Nassiri, G.J. Waldschmidt, G. Wu, R.A. Rimmer, H. Wang

2012-07-01T23:59:59.000Z

254

Dictionary of petroleum terms  

Science Conference Proceedings (OSTI)

Terms included in the dictionary come from writers and contributors of the Petroleum Extension Service of Texas (PETEC), which constantly revises and updates the material to keep it current. Over 170 pages of petroleum-related words include those involving exploration, production, processing, transport, marketing, and use. Lists of abbreviations, units, and metric equivalents and prefixes follow the dictionary.

Leecraft, J. (ed.)

1983-01-01T23:59:59.000Z

255

Train of high-power femtosecond pulses: Probe wave in a gas of prepared atoms  

E-Print Network (OSTI)

We present a new method for generating a regular train of ultrashort optical pulses in a prepared two-level medium. The train develops from incident monochromatic probe radiation travelling in a medium of atoms, which are in a quantum mechanical superposition of dressed internal states. In the frame of used linear theory for the probe radiation, the energy of individual pulses is an exponentially growing function of atom density and of interaction cross section. Pulse repetition rate is determined by the generalized Rabi frequency and can be around 1 THz and greater. We also show that the terms, extra to the dipole approximation, endow the gas by a new property: non-saturating dependence of refractive index on the dressing monochromatic field intensity. Contribution of these nonsaturating terms can be compatible with the main dipole approximation in the wavelength region of about ten micrometers (the range of CO_2 laser) or larger.

Gevorg Muradyan; A. Zh. Muradyan

2009-03-15T23:59:59.000Z

256

Vehicle Technologies Office: Long-Term Exploratory Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Long-Term Exploratory Research Long-Term Exploratory Research Long-term research addresses the chemical instabilities that impede the development of advanced batteries. Researchers focus on synthesizing novel components into battery cells and determining failure modes, while maintaining strengths in materials synthesis and evaluation, advanced diagnostics, and improved electrochemical model development. Goals include developing a better understanding of why systems fail, creating models that predict system failure and permit system optimization, and investigating new and promising materials. The work concentrates on six research areas: Advanced cell chemistry, Non-carbonaceous anodes, New electrolytes, Novel cathode materials, Advanced diagnostics and analytical methods, and Phenomenological modeling.

257

Mirror Modes in the Heliosheath  

SciTech Connect

Mirror mode (MM) structures are identified in the Voyager 1 heliosheath magnetic field data. Their characteristics are: (1) quasiperiodic structures with a typical scale size of {approx}57 {rho}{sub p}(proton gyroradii), (2) little or no angular changes across the structures ({approx}3 deg. longitude and {approx}3 deg. latitude), and (3) a lack of sharp boundaries at the magnetic dip edges. It is proposed that the pickup of interstellar neutrals in the upstream region of the termination shock (TS) is the likely cause of MM instability during intervals when the IMF is nearly orthogonal to the solar wind flow direction. Concomitant (quasiperpendicular) shock compression of the MM structures at the TS and additional injection of pickup ions (PUIs) throughout the heliosheath will enhance MM growth.

Tsurutani, B. T. [Jet Propulsion Lab., Calif. Inst. Tech., Pasadena, CA (United States); Guarnieri, F. L. [UNIVAP, Sao Jose dos Campos, SP (Brazil); Echer, E. E. [INPE, Sao Jose dos Campos, SP (Brazil); Lakhina, G. S. [Indian Institute of Geomagnetism, Navi Mumbai (India); Verkhoglyadova, O. P. [CSPAR, Univ. Alabama, Huntsville, AL (United States)

2011-01-04T23:59:59.000Z

258

Representation of Ideal Magnetohydrodynamic Modes  

SciTech Connect

One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through ? ? = ? X (xi X B) ensures that ? B • ? ? = 0 at a resonance, with ? labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation ? ? = ? X ?B. These two representations are equivalent, but the vanishing of ? B • ?? at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in xi to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed

Roscoe B. White

2013-01-15T23:59:59.000Z

259

Attachment J TERMS AND CONDITIONS  

E-Print Network (OSTI)

Attachment J TERMS AND CONDITIONS AWARD # PON-10-603 #12;TERMS AND CONDITIONS TABLE OF CONTENTS ............................................................................... 24 i #12;TERMS AND CONDITIONS 1. Grant Agreement This project is being funded with a grant from is comprised of the grant funding award, the Terms and Conditions, and all attachments. These Terms

260

Attachment K TERMS AND CONDITIONS  

E-Print Network (OSTI)

Attachment K TERMS AND CONDITIONS AWARD # #12;TERMS AND CONDITIONS TABLE OF CONTENTS SECTION PAGE ............................................................................... 24 i #12;TERMS AND CONDITIONS 1. Grant Agreement This project is being funded with a grant from, the Terms and Conditions, and all attachments. These Terms and Conditions are standard requirements

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Pulsed source ion implantation apparatus and method  

DOE Patents (OSTI)

A new pulsed plasma-immersion ion-implantation apparatus that implants ions in large irregularly shaped objects to controllable depth without overheating the target, minimizing voltage breakdown, and using a constant electrical bias applied to the target. Instead of pulsing the voltage applied to the target, the plasma source, for example a tungsten filament or a RF antenna, is pulsed. Both electrically conducting and insulating targets can be implanted.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

262

Pulsed source ion implantation apparatus and method  

DOE Patents (OSTI)

A new pulsed plasma-immersion ion-implantation apparatus that implants ions in large irregularly shaped objects to controllable depth without overheating the target, minimizing voltage breakdown, and using a constant electrical bias applied to the target. Instead of pulsing the voltage applied to the target, the plasma source, for example a tungsten filament or a RF antenna, is pulsed. Both electrically conducting and insulating targets can be implanted. 16 figs.

Leung, K.N.

1996-09-24T23:59:59.000Z

263

ShortShort--Term Energy Outlook Term Energy Outlook  

U.S. Energy Information Administration (EIA)

U.S. Energy Information Administration Independent Statistics & Analysis ShortShort--Term Energy Outlook Term Energy Outlook Chart Gallery for Chart Gallery for ...

264

Effect of pulse intensity distributions on fragment internal energy in the infrared multiphoton dissociation of vinyl  

E-Print Network (OSTI)

Effect of pulse intensity distributions on fragment internal energy in the infrared multiphoton the rovibra- tional energy distributions of fragmentsl formed in the infrared multiphoton dissociation (IRMPD energies of the frag- ment can be well characterized in terms of a Boltzmann distribution with a single

Zare, Richard N.

265

Analytical solutions for a two-level system driven by a class of chirped pulses  

Science Conference Proceedings (OSTI)

We present analytical solutions for the problem of a two-level atom driven by a class of chirped pulses. The solutions are given in terms of Heun functions. By use of the appropriate chirping parameters, an enhancement of four orders of magnitude in the population transfer is obtained.

Jha, Pankaj K. [Institute for Quantum Science and Engineering and Department of Physics, Texas A and M University, College Station, Texas 77843 (United States); Rostovtsev, Yuri V. [Institute for Quantum Science and Engineering and Department of Physics, Texas A and M University, College Station, Texas 77843 (United States); Department of Physics, University of North Texas, 1155 Union Circle 311427, Denton, Texas 76203 (United States)

2010-07-15T23:59:59.000Z

266

The APS direct-drive pulsed septum magnets  

Science Conference Proceedings (OSTI)

The Advanced Photon Source (APS) consists of four separate machines: linac, booster, positron accumulator ring (PAR) and storage ring (SR), plus three transfer lines interconnecting the machines. At least one thin, pulsed septum magnet is located at each splice joint. The stray field tolerances for two of these septum magnets are very stringent. As an example, for clean operation during the proposed top-up mode in the storage ring, the stray fields from the septum magnet must not exceed 1 G-m. The septum wall thickness must also not exceed 2.4 mm. To meet these requirements, direct-drive septum magnets with magnetic shield pipe around the stored beam region were developed and built. These magnets have now been tested and installed, and are used in daily operation. We describe the magnet(s) design, the measurement results, the actual operation, and performance.

Sheynin, S.; Lopez, F.; Milton, S.V.

1995-07-01T23:59:59.000Z

267

Processed by Pulsed Electric Current Sintering (PECS)  

Science Conference Proceedings (OSTI)

Presentation Title, Bulk Nanoceramics and Nanocomposites: Processed by Pulsed Electric Current Sintering (PECS). Author(s), Omer Van der Biest, Kim ...

268

Microcomputer-controlled two-pulse generator  

SciTech Connect

The two-pulse generator generates trains of pulses whose parameters are specified by an Elektronika D3-28 microcomputer. The pulse durations are 1-128 usec, the intervals are 1-2048 usec, and the repetition periods are from 4 msec to 16 sec. In conjunction with an automated system, the generator allows automatic measurement of spin-spin and spin-lattice relaxation times in nuclear quadrupole resonance, setting of optimum pulse-train parameters (90-180 degrees), etc.

Boguslavskii, A.A.; Ermilov, V.V.; Pechenov, V.V.; Semin, G.K.; Shapiro, G.Y.

1986-07-01T23:59:59.000Z

269

PARALYZER FOR PULSE HEIGHT DISTRIBUTION ANALYZER  

DOE Patents (OSTI)

A paralyzer circuit is described for use with a pulseheight distribution analyzer to prevent the analyzer from counting overlapping pulses where they would serve to provide a false indication. The paralyzer circuit comprises a pair of cathode-coupled amplifiers for amplifying pulses of opposite polarity. Diodes are provided having their anodes coupled to the separate outputs of the amplifiers to produce only positive signals, and a trigger circuit is coupled to the diodes ior operation by input pulses of either polarity from the amplifiers. A delay network couples the output of the trigger circuit for delaying the pulses.

Fairstein, E.

1960-01-19T23:59:59.000Z

270

Glossary Term - Uranus  

NLE Websites -- All DOE Office Websites (Extended Search)

Tritium Tritium Previous Term (Tritium) Glossary Main Index Next Term (Van de Graaff Generator) Van de Graaff Generator Uranus Uranus as seen by the Voyager II spacecraft. Uranus is the seventh planet from the sun and takes 84 years to orbit the sun once. Uranus is about 4 times larger than the Earth and is about 14.5 times as massive. Uranus was discovered on March 13, 1781 by William Herschel. In greek mythology, Uranus was Father Sky. Planetary Data Distance from Sun Length of Day Length of Year Radius Mass 19.191 AU 17.2 hours 84.01 years 25,559 km 8.68*1025 kg Known Satellites Name Distance from Uranus Rotational Period Orbital Period Radius Cordelia 49,770 km -unknown- 0.335034 days 21 km Ophelia 53,790 km -unknown- 0.376400 days 23 km Bianca 59,170 km -unknown- 0.434579 days 27 km

271

Glossary Term - Neptune  

NLE Websites -- All DOE Office Websites (Extended Search)

Mole Mole Previous Term (Mole) Glossary Main Index Next Term (Neutrino) Neutrino Neptune Neptune as seen by the Voyager II spacecraft on August 14, 1989. Neptune is the eighth planet from the sun and takes 165 years to orbit the sun once. Neptune is about 4 times larger than the Earth and is about 17 times as massive. Neptune was discovered on September 23, 1846 based on calculations done by the French astronomer Urbain LeVerrier and the English astronomer John Adams. Neptune is also the Roman name for Poseidon, the god of the sea and earthquakes. Neptune was the son of Chronus and Rhea and carries the trident, a three pronged spear. Planetary Data Distance from Sun Length of Day Length of Year Radius Mass 30.069 AU 16.1 hours 164.79 years 24,764 km 1.02*1026 kg Known Satellites

272

Glossary Term - Beta Decay  

NLE Websites -- All DOE Office Websites (Extended Search)

Avogadro's Number Avogadro's Number Previous Term (Avogadro's Number) Glossary Main Index Next Term (Beta Particle) Beta Particle Beta Decay Beta decay results in the emission of an electron and antineutrino, or a positron and neutrino. Beta decay is one process that unstable atoms can use to become more stable. There are two types of beta decay, beta-minus and beta-plus. During beta-minus decay, a neutron in an atom's nucleus turns into a proton, an electron and an antineutrino. The electron and antineutrino fly away from the nucleus, which now has one more proton than it started with. Since an atom gains a proton during beta-minus decay, it changes from one element to another. For example, after undergoing beta-minus decay, an atom of carbon (with 6 protons) becomes an atom of nitrogen (with 7 protons).

273

Glossary Term - Electron Capture  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Electron Previous Term (Electron) Glossary Main Index Next Term (Electron Volt (eV)) Electron Volt (eV) Electron Capture After electron capture, an atom contains one less proton and one more neutron. Electron capture is one process that unstable atoms can use to become more stable. During electron capture, an electron in an atom's inner shell is drawn into the nucleus where it combines with a proton, forming a neutron and a neutrino. The neutrino is ejected from the atom's nucleus. Since an atom loses a proton during electron capture, it changes from one element to another. For example, after undergoing electron capture, an atom of carbon (with 6 protons) becomes an atom of boron (with 5 protons). Although the numbers of protons and neutrons in an atom's nucleus change

274

Glossary Term - Ceres  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalyst Catalyst Previous Term (Catalyst) Glossary Main Index Next Term (Cloud Chamber) Cloud Chamber Ceres Ceres is an asteroid located between the orbits of Mars and Jupiter. Discovered on January 1, 1801 by Giuseppi Piazzi, Ceres was the first asteroid ever discovered. With a diameter of 1025 kilometers (637 miles), Ceres is also the largest known asteroid. Ceres is also the Roman name for the Greek goddess Demeter, the elder sister of Zeus and daughter of Cronus and Rhea. Demeter was the goddess of grain and helped the crops grow. One day her daughter, Persephone, was abducted by Hades. While Demeter searched for her missing daughter, no crops grew and people starved. Persephone was eventually found, but Hades refused to let her leave the underworld. As a compromise, Persephone is

275

Long Term Innovative Technologies  

NLE Websites -- All DOE Office Websites (Extended Search)

DOE's Hydrogen and DOE's Hydrogen and Fuel Cell Technologies, Fuel Cell Presolicitation Workshop Bryan Pivovar With Input/Feedback from Rod Borup (LANL), Debbie Myers (ANL), DOE and others as noted in presentation Lakewood, CO March 16, 2010 Long Term Innovative Technologies National Renewable Energy Laboratory Innovation for Our Energy Future Innovative/Long Term and RELEVANT Mission of DOE Mission of EERE (Applied Program) Mission of HFCT To enable the widespread commercialization of hydrogen and fuel cells in diverse sectors of the economy-with emphasis on applications that will most effectively strengthen the nation's energy security and improve our stewardship of the environment-through research, development, and demonstration of critical improvements in the technologies, and through diverse activities to overcome

276

High Resolution Measurements of Turbulence, Velocity and Stress Using a Pulse-to-Pulse Coherent Sonar  

Science Conference Proceedings (OSTI)

Considered are the capabilities of a recently developed pulse-to-pulse coherent sonar called the High Resolution Current Profiler (HRCP). Special emphasis is placed on methods whereby reliable and accurate vertical profiles of turbulence ...

Atle Lohrmann; Bruce Hackett; Lars Petter Røed

1990-02-01T23:59:59.000Z

277

Pulse-to-Pulse Coherent Doppler Measurements of Waves and Turbulence  

Science Conference Proceedings (OSTI)

This paper presents laboratory and field testing of a pulse-to-pulse coherent acoustic Doppler profiler for the measurement of turbulence in the ocean. In the laboratory, velocities and wavenumber spectra collected from Doppler and digital ...

Fabrice Veron; W. Kendall Melville

1999-11-01T23:59:59.000Z

278

Aperiodic dynamical decoupling sequences in the presence of pulse errors  

SciTech Connect

Dynamical decoupling (DD) is a promising tool for preserving the quantum states of qubits. However, small imperfections in the control pulses can seriously affect the fidelity of decoupling, and qualitatively change the evolution of the controlled system at long times. Using both analytical and numerical tools, we theoretically investigate the effect of the pulse error accumulation for two aperiodic DD sequences, Uhrig's DD (UDD) protocol (Uhrig 2007 Phys. Rev. Lett. 98 100504), and the quadratic DD (QDD) protocol (West et al 2010 Phys. Rev. Lett. 104 130501). We consider the implementation of these sequences using the electron spins of phosphorus donors in silicon, where DD sequences are applied to suppress dephasing of the donor spins. The dependence of the decoupling fidelity on different initial states of the spins is the focus of our study. We investigate in detail the initial drop in the DD fidelity, and its long-term saturation. We also demonstrate that by applying the control pulses along different directions, the performance of QDD protocols can be noticeably improved, and explain the reason for such an improvement. Our results can be useful for future implementations of the aperiodic decoupling protocols, and for better understanding of the impact of errors on quantum control of spins.

Wang, Zhi-Hui; Dobrovitski, V. V.

2011-01-12T23:59:59.000Z

279

Crop Insurance Terms and Definitions  

E-Print Network (OSTI)

This publication is a glossary of terms used by the crop insurance industry. There are definitions for terms used in crop insurance documents and for terms pertaining to coverage levels, farming, reports, units and parties to contracts.

Stokes, Kenneth; Waller, Mark L.; Outlaw, Joe; Barnaby, G. A. Art

2008-10-17T23:59:59.000Z

280

X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure  

Science Conference Proceedings (OSTI)

This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30-40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Tarasenko, Victor; Kostyrya, Igor D. [Institute of High Current Electronics, Russian Academy of Science, Tomsk 634055 (Russian Federation); Ma Hao [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yan Ping [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China)

2012-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

FY07 LDRD Final Report Precision, Split Beam, Chirped-Pulse, Seed Laser Technology  

Science Conference Proceedings (OSTI)

The goal of this LDRD ER was to develop a robust and reliable technology to seed high-energy laser systems with chirped pulses that can be amplified to kilo-Joule energies and recompressed to sub-picosecond pulse widths creating extremely high peak powers suitable for petawatt class physics experiments. This LDRD project focused on the development of optical fiber laser technologies compatible with the current long pulse National Ignition Facility (NIF) seed laser. New technologies developed under this project include, high stability mode-locked fiber lasers, fiber based techniques for reduction of compressed pulse pedestals and prepulses, new compact stretchers based on chirped fiber Bragg gratings (CFBGs), new techniques for manipulation of chirped pulses prior to amplification and new high-energy fiber amplifiers. This project was highly successful and met virtually all of its goals. The National Ignition Campaign has found the results of this work to be very helpful. The LDRD developed system is being employed in experiments to engineer the Advanced Radiographic Capability (ARC) front end and the fully engineered version of the ARC Front End will employ much of the technology and techniques developed here.

Dawson, J W; Messerly, M J; Phan, H H; Crane, J K; Beach, R J; Siders, C W; Barty, C J

2009-11-12T23:59:59.000Z

282

Collective Modes of Quantum Hall Stripes  

E-Print Network (OSTI)

The collective modes of striped phases in a quantum Hall system are computed using the time-dependent Hartree-Fock approximation. Uniform stripe phases are shown to be unstable to the formation of modulations along the stripes, so that within the Hartree-Fock approximation the groundstate is a stripe crystal. Such crystalline states are generically gapped at any finite wavevector; however, in the quantum Hall system the interactions of modulations among different stripes is found to be remarkably weak, leading to an infinite collection of collective modes with immeasurably small gaps. The resulting long wavelength behavior is derivable from an elastic theory for smectic liquid crystals. Collective modes for the phonon branch are computed throughout the Brillouin zone, as are spin wave and magnetoplasmon modes. A soft mode in the phonon spectrum is identified for partial filling factors sufficiently far from 1/2, indicating a second order phase transition. The modes contain several other signatures that should be experimentally

R. Côté; H. A. Fertig

2008-01-01T23:59:59.000Z

283

DRAFT Glossary of AFIS Terms  

Science Conference Proceedings (OSTI)

Page 1. DRAFT Glossary of AFIS Terms Latent Print AFIS Interoperability Working Group Page 2. DRAFT Glossary of AFIS Terms 2 ...

2012-05-04T23:59:59.000Z

284

Glossary of nuclear criticality terms  

SciTech Connect

This is a glossary of terms generally encountered in the literature of nuclear criticality and criticality safety. Terms sometimes misused are emphasized. 7 refs.

Paxton, H.C.

1989-10-01T23:59:59.000Z

285

Short-Term Energy Outlook  

U.S. Energy Information Administration (EIA) Indexed Site

U.S. Energy Information Administration Independent Statistics & Analysis Short Short- -Term Energy Outlook Term Energy Outlook Chart Gallery for Chart Gallery for November...

286

A Summary of Taxonomies of Digital System Failure Modes Provided by the DigRel Task Group  

SciTech Connect

Recently, the CSNI directed WGRisk to set up a task group called DIGREL to initiate a new task on developing a taxonomy of failure modes of digital components for the purposes of PSA. It is an important step towards standardized digital I&C reliability assessment techniques for PSA. The objective of this paper is to provide a comparison of the failure mode taxonomies provided by the participants. The failure modes are classified in terms of their levels of detail. Software and hardware failure modes are discussed separately.

Chu T. L.; Yue M.; Postma, W.

2012-06-25T23:59:59.000Z

287

Eigenoscillations of the Differentially Rotating Sun: I. 22-year, 4000-year, and quasi-biennial modes  

E-Print Network (OSTI)

Retrograde waves with frequencies much lower than the rotation frequency become trapped in the solar radiative interior. The eigenfunctions of the compressible, nonadiabatic, Rossby-like modes ($\\epsilon$-mechanism and radiative losses taken into account) are obtained by an asymptotic method assuming a very small latitudinal gradient of rotation, without an arbitrary choice of other free parameters. An integral dispersion relation for the complex eigenfrequencies is derived as a solution of the boundary value problem. The discovered resonant cavity modes (called R-modes) are fundamentally different from the known r-modes: their frequencies are functions of the solar interior structure, and the reason for their existence is not related to geometrical effects. The most unstable R-modes are those with periods of 1--3 yr, 18--30 yr, and 1500--20000 yrs; these three separate period ranges are known from solar and geophysical data. The growing times of those modes which are unstable with respect to the $\\epsilon$-mechanism are $\\approx 10^2, 10^3,$ and $10^5$ years, respectively. The amplitudes of the R-modes are growing towards the center of the Sun. We discuss some prospects to develop the theory of R-modes as a driver of the dynamics in the convective zone which could explain, e.g., observed short-term fluctuations of rotation, a control of the solar magnetic cycle, and abrupt changes of terrestrial climate in the past.

N. S. Dzhalilov; J. Staude; V. N. Oraevsky

2002-01-09T23:59:59.000Z

288

Statistical properties of giant pulses from the Crab pulsar  

E-Print Network (OSTI)

We have studied the statistics of giant pulses from the Crab pulsar for the first time with particular reference to their widths. We have analyzed data collected during 3.5 hours of observations conducted with the Westerbork Synthesis Radio Telescope operated in a tied-array mode at a frequency of 1200 MHz. The PuMa pulsar backend provided voltage recording of X and Y linear polarization states in two conjugate 10 MHz bands. We restricted the time resolution to 4 microseconds to match the scattering on the interstellar inhomogeneities. In total about 18000 giant pulses (GP) were detected in full intensity with a threshold level of 6 sigma. Cumulative probability distributions (CPD) of giant pulse energies were analyzed for groups of GPs with different effective widths in the range 4 to 65 microseconds. The CPDs were found to manifest notable differences for the different GP width groups. The slope of a power-law fit to the high-energy portion of the CPDs evolves from -1.7 to -3.2 when going from the shortest to the longest GPs. There are breaks in the CPD power-law fits indicating flattening at low energies with indices varying from -1.0 to -1.9 for the short and long GPs respectively. The GPs with a stronger peak flux density were found to be of shorter duration. We compare our results with previously published data and discuss the importance of these peculiarities in the statistical properties of GPs for the heoretical understanding of the emission mechanism responsible for GP generation.

M. V. Popov; B. Stappers

2007-04-10T23:59:59.000Z

289

Entanglement of Pure Two-Mode Gaussian States  

E-Print Network (OSTI)

The entanglement of general pure Gaussian two-mode states is examined in terms of the coefficients of the quadrature components of the wavefunction. The entanglement criterion and the entanglement of formation are directly evaluated as a function of these coefficients, without the need for deriving local unitary transformations. These reproduce the results of other methods for the special case of symmetric pure states which employ a relation between squeezed states and Einstein-Podolsky-Rosen correlations. The modification of the quadrature coefficients and the corresponding entanglement due to application of various optical elements is also derived.

R. W. Rendell; A. K. Rajagopal

2005-02-09T23:59:59.000Z

290

Normal Modes of Black Hole Accretion Disks  

SciTech Connect

This paper studies the hydrodynamical problem of normal modes of small adiabatic oscillations of relativistic barotropic thin accretion disks around black holes (and compact weakly magnetic neutron stars). Employing WKB techniques, we obtain the eigen frequencies and eigenfunctions of the modes for different values of the mass and angular momentum of the central black hole. We discuss the properties of the various types of modes and examine the role of viscosity, as it appears to render some of the modes unstable to rapid growth.

Ortega-Rodriguez, Manuel; /Stanford U., Appl. Phys. Dept. /Costa Rica U.; Silbergleit, Alexander S.; /Stanford U., HEPL; Wagoner, Robert V.; /Stanford U., Phys. Dept.

2006-11-07T23:59:59.000Z

291

Definition: Mode Meter | Open Energy Information  

Open Energy Info (EERE)

oscillatory mode information from ambient noise.1 References https:www.smartgrid.govcategorytechnologymodemeter Ret LikeLike UnlikeLike You like this.Sign Up to...

292

Analytic theory of stable resistive magnetohydrodynamic modes  

SciTech Connect

The spectrum of stable resistive magnetohydrodynamic modes is shown to be determined by the geometry of anti-Stokes lines. Behavior of the eigenfunctions is also examined.

Pao, Y.; Kerner, W.

1985-01-01T23:59:59.000Z

293

Generation of Femtosecond Electron Pulses  

SciTech Connect

At the Fast Neutron Research Facility (FNRF), Chiang Mai University (Thailand), the SURIYA project has been established aiming to produce femtosecond electron pulses utilizing a combination of an S-band thermionic rf gun and a magnetic bunch compressor ({alpha}-magnet). A specially designed rf-gun has been constructed to obtain optimum beam characteristics for the best bunch compression. Simulation results show that bunch lengths as short as about 50 fs rms can be expected at the experimental station. The electron bunch lengths will be determined using autocorrelation of coherent transition radiation (TR) through a Michelson interferometer. The paper discusses beam dynamics studies, design, fabrication and cold tests of the rf-gun as well as presents the project current status and forth-coming experiments.

Jinamoon, V.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Thongbai, C.; Vilaithong, T.; /Chiang Mai U.; Rhodes, M.W.; Wichaisirimongkol, P.; /Chiang Mai U.; Chumphongphan,; /Mae Fah Luang U.; Wiedemann, H.; /SLAC, SSRL

2005-05-09T23:59:59.000Z

294

Laser system using ultra-short laser pulses  

DOE Patents (OSTI)

A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

Dantus, Marcos (Okemos, MI); Lozovoy, Vadim V. (Okemos, MI); Comstock, Matthew (Milford, MI)

2009-10-27T23:59:59.000Z

295

Fission modes of mercury isotopes  

E-Print Network (OSTI)

Background: Recent experiments on beta-delayed fission in the mercury-lead region and the discovery of asym- metric fission in 180 Hg [1] have stimulated theoretical interest in the mechanism of fission in heavy nuclei. Purpose: We study fission modes and fusion valleys in 180 Hg and 198 Hg to reveal the role of shell effects in pre-scission region and explain the experimentally observed fragment mass asymmetry and its variation with A. Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals. Results: The potential energy surfaces in multi-dimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180 Hg and 198 Hg. The asymmetric fission valleys - well separated from fusion valleys associated with nearly spherical fragments - are found in in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits. Conclusions: The energy density functionals SkM\\ast and D1S give a very consistent description of the fission process in 180 Hg and 198 Hg. We predict a transition from asymmetric fission in 180 Hg towards more symmetric distribution of fission fragments in 198 Hg. For 180 Hg, both models yield 100 Ru/80 Kr as the most probable split. For 198 Hg, the most likely split is 108 Ru/90 Kr in HFB-D1S and 110 Ru/88 Kr in HFB-SkM\\ast.

M. Warda; A. Staszczak; W. Nazarewicz

2012-05-25T23:59:59.000Z

296

Fission Modes of Mercury Isotopes  

Science Conference Proceedings (OSTI)

Background: Recent experiments on -delayed fission in the mercury-lead region and the discovery of asymmetric fission in 180Hg [A. N. Andreyev et al., Phys. Rev. Lett. 105, 252502 (2010)] have stimulated theoretical interest in the mechanism of fission in heavy nuclei. Purpose: We study fission modes and fusion valleys in 180Hg and 198Hg to reveal the role of shell effects in the prescission region and explain the experimentally observed fragment mass asymmetry and its variation with A. Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals. Results: The potential energy surfaces in multidimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180Hg and 198Hg. The asymmetric fission valleys well separated from fusion valleys associated with nearly spherical fragments are found in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits. Conclusions: The energy density functionals SkM and D1S give a very consistent description of the fission process in 180Hg and 198Hg. We predict a transition from asymmetric fission in 180Hg toward a more symmetric distribution of fission fragments in 198Hg. For 180Hg, both models yield 100Ru/80Kr as the most probable split. For 198Hg, the most likely split is 108Ru/90Kr in HFB-D1S and 110Ru/88Kr in HFB-SkM .

Warda, M. [Maria Curie-Sk?odowska University-Poland; Staszczak, A. [Maria Curie-Sklodowska University; Nazarewicz, Witold [UTK/ORNL/University of Warsaw

2012-01-01T23:59:59.000Z

297

Long-Term Risk From Actinides in the Environment: Modes of Mobility  

Science Conference Proceedings (OSTI)

Laboratory soil column experiments were conducted to investigate the migration of plutonium in soils from the Waste Isolation Pilot Plant (WIPP) and the Rocky Flats Environmental Technology Site.

Shawki Ibrahim, Ph.D.

2001-05-24T23:59:59.000Z

298

An Investigation of Precipitator Pulse Energization  

Science Conference Proceedings (OSTI)

With the guidelines developed in this study, utility engineers can make informed evaluations of such competing technologies as flue gas conditioning and pulsing, on the basis of their site-specific requirements and costs. The data collection and analyses on which the guidelines are based have eliminated many uncertainties about the benefits and limitations of pulsing.

1986-09-19T23:59:59.000Z

299

Heart Physiology Lab Part 1: Pulse Rate  

E-Print Network (OSTI)

Heart Physiology Lab Part 1: Pulse Rate Measure your pulse in each of the following conditions (in in the class. You may use Table 1 in the Heart Physiology Worksheet for this, if you wish. Once you have all of the class averages for each measurement. You may use Graph 1 in the Heart Physiology Worksheet for this

Loughry, Jim

300

Stably operating pulse combustor and method  

DOE Patents (OSTI)

A pulse combustor apparatus is described which is adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation. 4 figs.

Zinn, B.T.; Reiner, D.

1990-05-29T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Stably operating pulse combustor and method  

DOE Patents (OSTI)

A pulse combustor apparatus adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation.

Zinn, Ben T. (Atlanta, GA); Reiner, David (Haifa, IL)

1990-01-01T23:59:59.000Z

302

Nanosecond component in a femtosecond laser pulse  

Science Conference Proceedings (OSTI)

Experimental and computational results show that the coherent microwave scattering from a laser-induced plasma can be used for measuring the quality of a fs laser pulse. The temporal dynamics of the microwave scattered signal from the fs-laser induced plasma can be related to the effect of nanosecond tail of the fs laser pulse.

Shneider, M. N. [Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Semak, V. V. [ARL, Pennsylvania State University, University Park, Pennsylvania 16801 (United States); Zhang Zhili [Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

2012-11-15T23:59:59.000Z

303

High reliability low jitter pulse generator  

SciTech Connect

A method and concomitant apparatus for generating pulses comprising providing a laser light source, disposing a voltage electrode between ground electrodes, generating laser sparks using the laser light source via laser spark gaps between the voltage electrode and the ground electrodes, and outputting pulses via one or more insulated ground connectors connected to the voltage electrode.

Savage, Mark E.; Stoltzfus, Brian S.

2013-01-01T23:59:59.000Z

304

Coherence as ultrashort pulse train generator  

E-Print Network (OSTI)

Intense, well-controlled regular light pulse trains start to play a crucial role in many fields of physics. We theoretically demonstrate a very simple and robust technique for generating such periodic ultrashort pulses from a continuous probe wave which propagates in a dispersive thermal gas media.

Gevorg Muradyan; Mariam Hovhannisyan

2010-07-08T23:59:59.000Z

305

Production of Picosecond, Kilojoule, and Petawatt Laser Pulses via Raman Amplification of Nanosecond Pulses  

Science Conference Proceedings (OSTI)

Raman amplification in plasma has been promoted as a means of compressing picosecond optical laser pulses to femtosecond duration to explore the intensity frontier. Here we show for the first time that it can be used, with equal success, to compress laser pulses from nanosecond to picosecond duration. Simulations show up to 60% energy transfer from pump pulse to probe pulse, implying that multikilojoule ultraviolet petawatt laser pulses can be produced using this scheme. This has important consequences for the demonstration of fast-ignition inertial confinement fusion.

Trines, R. M. G. M.; Bingham, R.; Norreys, P. A. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX (United Kingdom); Fiuza, F.; Fonseca, R. A.; Silva, L. O. [GoLP/Instituto de Plasmas e Fusao Nuclear--Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal); Cairns, R. A. [University of St. Andrews, St. Andrews, Fife KY16 9AJ (United Kingdom)

2011-09-02T23:59:59.000Z

306

AN UPDATE ON NIF PULSED POWER  

SciTech Connect

The National Ignition Facility (NIF) is a 192-beam laser fusion driver operating at Lawrence Livermore National Laboratory. NIF relies on three large-scale pulsed power systems to achieve its goals: the Power Conditioning Unit (PCU), which provides flashlamp excitation for the laser's injection system; the Power Conditioning System (PCS), which provides the multi-megajoule pulsed excitation required to drive flashlamps in the laser's optical amplifiers; and the Plasma Electrode Pockels Cell (PEPC), which enables NIF to take advantage of a fourpass main amplifier. Years of production, installation, and commissioning of the three NIF pulsed power systems are now complete. Seven-day-per-week operation of the laser has commenced, with the three pulsed power systems providing routine support of laser operations. We present the details of the status and operational experience associated with the three systems along with a projection of the future for NIF pulsed power.

Arnold, P A; James, G F; Petersen, D E; Pendleton, D L; McHale, G B; Barbosa, F; Runtal, A S; Stratton, P L

2009-06-22T23:59:59.000Z

307

Generation of Femtosecond Electron And Photon Pulses  

SciTech Connect

Femtosecond (fs) electron and photon pulses become a tool of increasing importance to study dynamics in ultrafast processes. Such short electron pulses can be generated from a system consisting of a thermionic-cathode RF-gun and a magnetic bunch compressor. The fs electron pulses can be used directly or used as a source to produce equally short electromagnetic radiation pulses via certain kind of radiation production processes. At the Fast Neutron Research Facility (FNRF), Thailand, we are especially interested in production of radiation in Farinfrared and X-ray regime. In the far-infrared wavelengths, the radiation emitted from fs electron pulses is emitted coherently resulting high intensity radiation. In the X-ray regime, development of fs X-ray sources is crucial for application in ultrafast sciene.

Thongbai, C.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; /Chiang Mai U.; Wiedemann, H.; /SLAC

2006-03-17T23:59:59.000Z

308

Filters for High Rate Pulse Processing  

E-Print Network (OSTI)

We introduce a filter-construction method for pulse processing that differs in two respects from that in standard optimal filtering, in which the average pulse shape and noise-power spectral density are combined to create a convolution filter for estimating pulse heights. First, the proposed filters are computed in the time domain, to avoid periodicity artifacts of the discrete Fourier transform, and second, orthogonality constraints are imposed on the filters, to reduce the filtering procedure's sensitivity to unknown baseline height and pulse tails. We analyze the proposed filters, predicting energy resolution under several scenarios, and apply the filters to high-rate pulse data from gamma-rays measured by a transition-edge-sensor microcalorimeter.

B. K. Alpert; R. D. Horansky; D. A. Bennett; W. B. Doriese; J. W. Fowler; A. S. Hoover; M. W. Rabin; J. N. Ullom

2012-12-07T23:59:59.000Z

309

Flu Terms Defined  

NLE Websites -- All DOE Office Websites (Extended Search)

Flu Terms Defined Flu Terms Defined H1N1 Influenza is a respiratory disease of pigs caused by type A influenza viruses that causes regular outbreaks in pigs. People do not normally get H1N1 flu, but human infections can and do happen. H1N1 flu viruses have been reported to spread from person-to-person, but in the past, this transmission was limited and not sustained beyond three people. Avian flu (AI) is caused by influenza viruses that occur naturally among wild birds. Low pathogenic AI is common in birds and causes few problems. Highly pathogenic H5N1 is deadly to domestic fowl, can be transmitted from birds to humans, and is deadly to humans. There is virtually no human immunity and human vaccine availability is very limited. Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person. Currently, there is no pandemic flu.

310

Pulse-excited, auto-zeroing multiple channel data transmission system  

DOE Patents (OSTI)

A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

Fasching, G.E.

1985-02-22T23:59:59.000Z

311

Pulse-excited, auto-zeroing multiple channel data transmission system  

SciTech Connect

A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

Fasching, George E. (Morgantown, WV)

1987-01-01T23:59:59.000Z

312

Mo-containing tetrahedral amorphous carbon deposited by dualfiltered cathodic vacuum arc with selective pulsed bias voltage  

SciTech Connect

Metal-containing tetrahedral amorphous carbon films were produced by dual filtered cathodic vacuum arc (FCVA) plasma sources operated in sequential pulsed mode. A negatively pulsed bias was applied to the substrate only when carbon plasma was generated. Films thickness was measured after deposition by profilometry. Glass slides with silver pads were used as substrate for the of the measurement sheet resistance. The microstructure and composition of the films were characterized by Raman spectroscopy and Rutherford backscattering, respectively. It found that the electrical resistivity decreases with an increase of the Mo content, which can be ascribed to an increase of sp2 content and an increase of the sp2 cluster size.

Pasaja, Nitisak; Sansongsiri, Sakon; Anders, Andre; Vilaithong,Thiraphat; Intasiri, Sawate

2006-09-10T23:59:59.000Z

313

Mo-containing tetrahedral amorphous carbon deposited by dualfiltered cathodic vacuum arc with selective pulsed bias voltage  

SciTech Connect

Metal-containing tetrahedral amorphous carbon films wereproduced by dual filtered cathodic vacuum arc plasma sources operatedinsequentially pulsed mode. Negatively pulsed bias was applied to thesubstrate when carbon plasma was generated, whereas it was absentwhen themolybdenum plasma was presented. Film thickness was measured afterdeposition by profilometry. Glass slides with silver padswere used assubstrates for the measurement of the sheet resistance. Themicrostructure and composition of the films were characterizedbyRamanspectroscopy and Rutherford backscattering, respectively. It was foundthat the electrical resistivity decreases with an increaseof the Mocontent, which can be ascribed to an increase of the sp2 content and anincrease of the sp2 cluster size.

Pasaja, Nitisak; Sansongsiri, Sakon; Intasiri, Sawate; Vilaithong, Thiraphat; Anders, Andre

2007-01-24T23:59:59.000Z

314

Mode suppression means for gyrotron cavities  

DOE Patents (OSTI)

In a gyrotron electron tube of the gyro-klystron or gyro-monotron type, having a cavity supporting an electromagnetic mode with circular electric field, spurious resonances can occur in modes having noncircular electric field. These spurious resonances are damped and their frequencies shifted by a circular groove in the cavity parallel to the electric field.

Chodorow, Marvin (Stanford, CA); Symons, Robert S. (Los Altos, CA)

1983-08-09T23:59:59.000Z

315

Spatial mode properties of plasmon assisted transmission  

E-Print Network (OSTI)

Orbital angular momentum of photons is explored to study the spatial mode properties of plasmon assisted transmission process. We found that photons carrying different orbital angular momentums have different transmission efficiencies, while the coherence between these spatial modes can be preserved.

Xi-Feng Ren; Guo-Ping Guo; Yun-Feng Huang; Zhi-Wei Wang; Guang-Can Guo

2006-03-03T23:59:59.000Z

316

Proxying location update for idle mode interfaces  

Science Conference Proceedings (OSTI)

In cellular networks it is the mobile node's responsibility to update the network about its location change, especially when this one enters idle mode. We developed a new framework [8] where the idle interface is powered-off to save energy and thus could ... Keywords: MIH services, idle/active mode, location-update, proxied interface, proxied multi-radio interface, proxy entity

Hicham Mahkoum; Abdelhakim S. Hafid; Behcet Sarikaya

2010-06-01T23:59:59.000Z

317

Running Modes in a Dataflow Language: Mode-Automata and their Implementation  

E-Print Network (OSTI)

this paper, modes are simply hierarchical and concurrent states like in Argos [Mar92]. In Modecharts, modes seem to be similar to the notion of task in Esterel, but they are not dealt with in the language itself; the mode structure of a reactive system may be described in Modecharts, but the behavior of the system in a particular mode is left to some host language that has no formal semantics.

Florence Maraninchi; Yann Rémond; Yannick Raoul; Yannick Raoul

1998-01-01T23:59:59.000Z

318

Sliding mode control of quantum systems  

E-Print Network (OSTI)

This paper proposes a new robust control method for quantum systems with uncertainties involving sliding mode control (SMC). Sliding mode control is a widely used approach in classical control theory and industrial applications. We show that SMC is also a useful method for robust control of quantum systems. In this paper, we define two specific classes of sliding modes (i.e., eigenstates and state subspaces) and propose two novel methods combining unitary control and periodic projective measurements for the design of quantum sliding mode control systems. Two examples including a two-level system and a three-level system are presented to demonstrate the proposed SMC method. One of main features of the proposed method is that the designed control laws can guarantee desired control performance in the presence of uncertainties in the system Hamiltonian. This sliding mode control approach provides a useful control theoretic tool for robust quantum information processing with uncertainties.

Daoyi Dong; Ian R. Petersen

2009-10-31T23:59:59.000Z

319

Multiple Oscillatory Modes of the Argentine Basin. Part II: The Spectral Origin of Basin Modes  

Science Conference Proceedings (OSTI)

In this paper the spectrum of barotropic basin modes of the Argentine Basin is shown to be connected to the classical Rossby basin modes of a flat-bottom (constant depth), rectangular basin. First, the spectrum of basin modes is calculated for ...

Wilbert Weijer; Frédéric Vivier; Sarah T. Gille; Henk A. Dijkstra

2007-12-01T23:59:59.000Z

320

2 MW Active Bouncer Converter Design for Long Pulse Klystron Modulators  

E-Print Network (OSTI)

This paper presents some design issues of a 2 MW interleaved buck converter which is used as an active bouncer droop compensator for a 5.5MW long pulse klystron modulator. This novel design concept presents many challenges in terms of voltage ripple versus pulse rise-time. Issues related to the voltage ripple specification versus output filter design are discussed in detail. The design study is analyzed analytically, simulated numerically and is validated by experimental results obtained from a full power prototype.

Aguglia, D

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

R modes of slowly pulsating B stars  

E-Print Network (OSTI)

We examine pulsational stability of low $m$ $r$ modes in SPB stars by calculating fully nonadiabatic oscillations of uniformly rotating stars, where $m$ is an integer representing the azimuthal wave number around the rotation axis. $R$ modes are rotationally induced, non-axisymmetric, oscillation modes, whose oscillation frequency strongly depends on the rotation frequency $\\Omega$ of the star. They are conveniently classified by using two integer indices $m$ and $l^\\prime\\ge |m|$ that define the asymptotic oscillation frequency $2m\\Omega/[l^\\prime(l^\\prime+1)]$ in the limit of $\\Omega\\to 0$. We find low $m$, high radial order, odd $r$ modes with $l^\\prime=m$ in SPB stars are excited by the same iron opacity bump mechanism that excites low frequency $g$ modes of the variables, when the rotation frequency $\\Omega$ is sufficiently high. No even $r$ modes with low $m$ are found to be pulsationally unstable. Since the surface pattern of the temperature perturbation of odd modes is antisymmetric about the equator of the star, observed photometric amplitudes caused by the unstable odd $r$ modes with $l^\\prime=m$ are strongly dependent on the inclination angle between the axis of rotation and the line of sight. Applying the wave-meanflow interaction formalism to nonadiabatic $r$ modes in rapidly rotating SPB models, we find that because of the $r\\phi$ component of the Reynolds stress and the radial transport of the eddy fluctuation of density in the rotating star, the surface rotation is accelerated by the forcing due to the low $l^\\prime=m$ unstable $r$ modes.

Umin Lee

2005-09-12T23:59:59.000Z

322

Calibration Service for Low-level Pulsed-Laser Radiometers ...  

Science Conference Proceedings (OSTI)

... be noted that not all pulse energies or peak ... both the peak-power and pulse-energy radiometers ... a single radiometer has not been reserved for NIST ...

2012-10-31T23:59:59.000Z

323

Electric Pulse Method for Compaction of the Mononitride Uranium ...  

Science Conference Proceedings (OSTI)

Presentation Title, Electric Pulse Method for Compaction of the Mononitride ... reactors and also the advantages of the electric pulse compaction method.

324

Measurement and Mapping of Pulse Combustion Impingement Heat Transfer Rates .  

E-Print Network (OSTI)

??Current research shows that pulse combustion impingement drying is an improvement over the steady impingement drying currently in commercial use. Pulse combustion impingement has higher… (more)

Hagadorn, Charles C., III

2005-01-01T23:59:59.000Z

325

Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes  

Science Conference Proceedings (OSTI)

The current paper investigates stimulated Raman scattering (SRS) when laser-induced plasma is formed in heavy water by focusing an intense pulsed 532 nm Nd:YAG laser beam at room temperature. An unexpected low-frequency SRS line attributed to the lattice translational modes of ice-VII (D{sub 2}O) is observed. The pressure of the plasma shockwave is estimated using low-frequency SRS line shift.

Li Zhanlong [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); College of Physics, Jilin University, Changchun 130012 (China); Shan Xiaoning; Li Zuowei; Zhou Mi; Men Zhiwei [College of Physics, Jilin University, Changchun 130012 (China); Cao Junsheng [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Wang Yiding [College of Electronic Science and Engineering and Key Laboratory on Integrated Optoelectronics, Jilin University, Changchun 130012 (China); Sun Chenglin [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)

2012-07-09T23:59:59.000Z

326

Femto-second pulses of synchrotron radiation  

SciTech Connect

A method capable of producing femto-second pulses of synchrotron radiation is proposed. It is based on the interaction of femto-second light pulses with electrons in a storage ring. The application of the method to the generation of ultra-short x-ray pulses at the Advance Light Source of Lawrence Berkeley National Laboratory has been considered. The same method can also be used for extraction of electrons from a storage ring in ultra-short series of microbunches spaced by the periodicity of light wavelength.

Zholents, A.A. [Lawrence Berkeley Lab., CA (United States); Zolotorev, M.S. [Stanford Univ., CA (United States)

1995-07-01T23:59:59.000Z

327

Nox reduction system utilizing pulsed hydrocarbon injection  

DOE Patents (OSTI)

Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

Brusasco, Raymond M. (Livermore, CA); Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA); Merritt, Bernard T. (Livermore, CA)

2001-01-01T23:59:59.000Z

328

Preservice teachers' knowledge of linear functions within multiple representation modes  

E-Print Network (OSTI)

This study examines preservice teachers’ knowledge in the case of linear functions. Teachers’ knowledge in general consists of their subject matter knowledge and their pedagogical content knowledge. In this study, teachers’ subject matter knowledge is examined by looking at their ability to adapt to different representation modes. The framework for subject matter content knowledge consists of five components: (1) flexibility across formal mathematical symbolisms; (2) flexibility between visual and algebraic representations; (3) flexibility within visual representations; (4) flexibility with real-life situations, and (5) procedural skills. In terms of pedagogical content knowledge, two aspects were examined across five corresponding components. These two aspects were knowledge of students’ conceptions and misconceptions, and teachers’ teaching strategies. The primary source of data for the study was from two tests and six interviews. The results showed preservice teachers performed poorly in terms of representation flexibility. Furthermore, most of the preservice teachers had limited knowledge of the nature and sources of students’ mistakes as well as effective teaching strategies to help students with their misconceptions. In terms of knowledge structure, representation flexibility was found to be significant in both CK and PCK compared to procedural skills. Moreover, the representational flexibility in terms of CK seemed to strongly predict the overall PCK performance. Representational flexibility seemed to be related to the use of instructional representations. Overall, there was a strong relationship between various components of CK and PCK.

You, Zhixia

2006-08-01T23:59:59.000Z

329

Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode  

DOE Green Energy (OSTI)

An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. Results presented in this paper were obtained from single cells, with an active area of 16 cm{sup 2} per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes ({approx}10 {mu}m thick), nickel-YSZ steam/hydrogen electrodes ({approx}1400 {mu}m thick), and modified LSM or LSCF air-side electrodes ({approx}90 {mu}m thick). The purpose of the present study is to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of an improved single-cell test apparatus developed specifically for these experiments.

X. Zhang; J. E. O'Brien; R. C. O'Brien; N. Petigny

2011-11-01T23:59:59.000Z

330

Guiding Center Equations for Ideal Magnetohydrodynamic Modes  

SciTech Connect

Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through ?~B = ? X (? X B) however perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement ? are derived which perserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

Roscoe B. White

2013-02-21T23:59:59.000Z

331

Glossary of Terms  

E-Print Network (OSTI)

Fiscal Year – The Council operates on a federal fiscal year (FFY) that begins on October 1 and ends on September 30. Focus Area – The Council has selected five areas on which to focus the remaining funds, four of which are addressed in this Invitation: herring, long-term monitoring of marine conditions and injured resources, harbor protection and marine restoration and lingering oil. Plan – is a multi-year program request for funding that includes all administrative and costs to run each program area. Preferred Proposer – after reviewing proposals submitted under this Invitation, the Council will identify a Preferred Proposer for each focus area and direct Council staff to work with each Preferred Proposer to revise the subject proposals to satisfy any scientific, technical or programmatic concerns. This identification is not a commitment to fund. Program – is a 20-year plan for spending the funds for each program area. Program Science Panel – a panel of scientific experts to review potential projects and give guidance and oversight on the direction of the program; is not required to be independent from the program.

unknown authors

2010-01-01T23:59:59.000Z

332

Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner  

DOE Patents (OSTI)

An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90[degree] angle of incidence. 8 figures.

Veligdan, J.T.

1994-03-08T23:59:59.000Z

333

Quadridirectional mode expansion modeling in integrated optics  

E-Print Network (OSTI)

.6 0.8 1 [µm] PR,T PR P T 1-P R -P T BEP, b.c. E y = 0 x [-4, 2] µm, 60 modes (QUEP, BEP Ey = 0 b,T PR P T 1-P R -P T QUEP BEP, b.c. E y = 0 x [-4, 2] µm, 60 modes (QUEP, BEP Ey = 0 b.c.), z [-1,T PR P T 1-P R -P T QUEP BEP, PML b.c.* x [-4, 2] µm, 60 modes (QUEP, BEP Ey = 0 b.c.), z [-1.8, 10

Al Hanbali, Ahmad

334

Mixed Mode Fuel Injector And Injection System  

DOE Patents (OSTI)

A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set that are controlled respectively by first and second three way needle control valves. Each fuel injector includes first and second concentric needle valve members. One of the needle valve members moves to an open position for a homogenous charge injection event, while the other needle valve member moves to an open position for a conventional injection event. The fuel injector has the ability to operate in a homogenous charge mode with a homogenous charge spray pattern, a conventional mode with a conventional spray pattern or a mixed mode.

Stewart, Chris Lee (Normal, IL); Tian, Ye (Bloomington, IL); Wang, Lifeng (Normal, IL); Shafer, Scott F. (Morton, IL)

2005-12-27T23:59:59.000Z

335

Tests of Four PT-415 Coolers Installed in the Drop-in Mode  

DOE Green Energy (OSTI)

The superconducting magnets and absorbers for MICE will be cooled using PT415 pulse tube coolers. The cooler 2nd stage will be connected to magnets and the absorbers through a helium or hydrogen re-condensing system. It was proposed that the coolers be connected to the magnets in such a way that the cooler can be easily installed and removed, which permits the magnets to be shipped without the coolers. The drop-in mode requires that the cooler 1st stage be well connected to the magnet shields and leads through a low temperature drop demountable connection. The results of the PT415 drop-in cooler tests are presented.

Green, Michael A.; Wang, S.T.

2008-07-08T23:59:59.000Z

336

Short-Term Energy Outlook  

U.S. Energy Information Administration (EIA)

U.S. Energy Information Administration | Short-Term Energy Outlook July 2013 1 July 2013 Short-Term Energy Outlook (STEO) Highlights The U.S. Energy Information ...

337

Pulsed Power Technology at Sandia National Laboratories  

NLE Websites -- All DOE Office Websites (Extended Search)

largest pulsed laser in the world. It provides x-ray images of imploding capsules and wire-array dynamics on Z experiments. Saturn Accelerator Saturn is a modular,...

338

Modeling Pulsed Laser Melting of Embedded Nanoparticles  

E-Print Network (OSTI)

2 Model of Pulsed Laser Melting 2.1 Experimental Systemto be Modeled 2.2 Laser Absorption . . . . . . . . . . .a prototypical 0.3 J/cm 2 laser ?uence PLM at 0.5 J/m 2 Ge-

Sawyer, Carolyn Anne

2013-01-01T23:59:59.000Z

339

Review of long-pulse laser development  

Science Conference Proceedings (OSTI)

A brief review of some present techniques to obtain long-pulse laser action in excimer discharge devices will be presented. An attempt will be made to point out the strengths and weaknesses of these techniques. 18 refs., 15 figs.

Sze, R.C.

1989-01-01T23:59:59.000Z

340

Electromagnetic Pulse (EMP) and the Power Grid  

Science Conference Proceedings (OSTI)

This document provides background and an introduction to the topic of electromagnetic pulse (EMP, including high-altitude EMP or HEMP) for stakeholders concerned about potential damage to power grid infrastructures.

2013-08-21T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Glossary of Terms in TDE  

Science Conference Proceedings (OSTI)

Glossary of Terms used in ThermoData Engine (TDE): Alternative Equations (Navigation Tree item): For most properties ...

2012-10-19T23:59:59.000Z

342

Long-term testing  

SciTech Connect

Land-based gas turbines are significantly different from automotive gas turbines in that they are designed to operate for 50,000 h or greater (compared to 5,000--10,000 h). The primary goal of this research is to determine the long-term survivability of ceramic materials for industrial gas turbine applications. Research activities in this program focus on the evaluation of the static tensile creep and stress rupture (SR) behavior of three commercially available structural ceramics which have been identified by the gas turbine manufacturers as leading candidates for use in industrial gas turbines. For each material investigated, a minimum of three temperatures and four stresses will be used to establish the stress and temperature sensitivities of the creep and SR behavior. Because existing data for many candidate structural ceramics are limited to testing times less than 2,000 h, this program will focus on extending these data to times on the order of 10,000 h, which represents the lower limit of operating time anticipated for ceramic blades and vanes in gas turbine engines. A secondary goal of the program will be to investigate the possibility of enhancing life prediction estimates by combining interrupted tensile SR tests and tensile dynamic fatigue tests in which tensile strength is measured as a function of stressing rate. The third goal of this program will be to investigate the effects of water vapor upon the SR behavior of the three structural ceramics chosen for the static tensile studies by measuring the flexural strength as a function of stressing rate at three temperatures.

Ferber, M.; Graves, G.A. Jr.

1994-12-31T23:59:59.000Z

343

ATTACHMENT E TERMS AND CONDITIONS  

E-Print Network (OSTI)

ATTACHMENT E TERMS AND CONDITIONS TABLE OF CONTENTS SECTION PAGE NO. 1. Vehicle Buy-Down Incentive Program Agreement................................................ 1 2. Term of the Agreement..................................................................................................... 14 #12;TERMS AND CONDITIONS 1. Vehicle Buy-Down Incentive Program Agreement The Vehicle Buy

344

Assessment and Mitigation of Electromagnetic Pulse (EMP) Impacts at Short-pulse Laser Facilities  

SciTech Connect

The National Ignition Facility (NIF) will be impacted by electromagnetic pulse (EMP) during normal long-pulse operation, but the largest impacts are expected during short-pulse operation utilizing the Advanced Radiographic Capability (ARC). Without mitigation these impacts could range from data corruption to hardware damage. We describe our EMP measurement systems on Titan and NIF and present some preliminary results and thoughts on mitigation.

Brown, Jr., C G; Bond, E; Clancy, T; Dangi, S; Eder, D C; Ferguson, W; Kimbrough, J; Throop, A

2010-02-04T23:59:59.000Z

345

Assessment and Mitigation of Electromagnetic Pulse (EMP) Impacts at Short-pulse Laser Facilities  

SciTech Connect

The National Ignition Facility (NIF) will be impacted by electromagnetic pulse (EMP) during normal long-pulse operation, but the largest impacts are expected during short-pulse operation utilizing the Advanced Radiographic Capability (ARC). Without mitigation these impacts could range from data corruption to hardware damage. We describe our EMP measurement systems on Titan and NIF and present some preliminary results and thoughts on mitigation.

Brown, Jr., C G; Bond, E; Clancy, T; Dangi, S; Eder, D C; Ferguson, W; Kimbrough, J; Throop, A

2009-10-02T23:59:59.000Z

346

Spectral Measurements of Pulse Solar Simulators  

DOE Green Energy (OSTI)

Spectral measurements of pulse solar simulators are used to quantify the wavelength-dependant characteristics of the light. Because every PV device has a unique spectral response, it is important to know the spectral irradiance and to periodically monitor the spectra for changes. Measurements are made at the National Renewable Energy Laboratory (NREL) using several different techniques including the NREL-developed Pulse Analysis Spectroradiometer System (PASS).

Cannon, T. W.

1998-11-12T23:59:59.000Z

347

Cold moderators for pulsed neutron sources  

SciTech Connect

This paper reviews cold moderators in pulsed neutron sources and provides details of the performance of different cold moderator materials and configurations. Analytical forms are presented which describe wavelength spectra and emission time distributions. Several types of cooling arrangements used in pulsed source moderators are described. Choices of materials are surveyed. The author examines some of the radiation damage effects in cold moderators, including the phenomenon of burping'' in irradiated cold solid methane. 9 refs., 15 figs., 4 tabs.

Carpenter, J.M.

1990-01-01T23:59:59.000Z

348

Multiple laser pulse ignition method and apparatus  

DOE Patents (OSTI)

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures. 18 figs.

Early, J.W.

1998-05-26T23:59:59.000Z

349

Multiple laser pulse ignition method and apparatus  

DOE Patents (OSTI)

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

Early, James W. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

350

Pulsed, Photonuclear-induced, Neutron Measurements of Nuclear Materials with Composite Shielding  

SciTech Connect

Active measurements were performed using a 10-MeV electron accelerator with inspection objects containing various nuclear and nonnuclear materials available at the Idaho National Laboratory’s Zero Power Physics Reactor (ZPPR) facility. The inspection objects were assembled from ZPPR reactor plate materials to evaluate the measurement technologies for the characterization of plutonium, depleted uranium or highly enriched uranium shielded by both nuclear and non-nuclear materials. A series of pulsed photonuclear, time-correlated measurements were performed with unshielded calibration materials and then compared with the more complex composite shield configurations. The measurements used multiple 3He detectors that are designed to detect fission neutrons between pulses of an electron linear accelerator. The accelerator produced 10-MeV bremsstrahlung X-rays at a repetition rate of 125 Hz (8 ms between pulses) with a 4-us pulse width. All inspected objects were positioned on beam centerline and 100 cm from the X-ray source. The time-correlated data was collected in parallel using both a Los Alamos National Laboratory-designed list-mode acquisition system and a commercial multichannel scaler analyzer. A combination of different measurement configurations and data analysis methods enabled the identification of each object. This paper describes the experimental configuration, the ZPPR inspection objects used, and the various measurement and analysis results for each inspected object.

James Jones; Kevin Haskell; Rich Waston; William Geist; Jonathan Thron; Corey Freeman; Martyn Swinhoe; Seth McConchie; Eric Sword; Lee Montierth; John Zabriskie

2011-07-01T23:59:59.000Z

351

Note: A portable pulsed neutron source based on the smallest sealed-type plasma focus device  

Science Conference Proceedings (OSTI)

Development and operation of a portable and compact pulsed neutron source based on sealed-type plasma focus (PF) device are reported. The unit is the smallest sealed-type neutron producing PF device. The effective volume of the PF unit is 33 cm{sup 3} only. A compact size single capacitor (4 {mu}F) is used as the energy driver. A battery based power supply unit is used for charging the capacitor and triggering the spark gap. The PF unit is operated at 10 kV (200 J) and at a deuterium gas filling pressure of 8 mb. The device is operated over a time span of 200 days and the neutron emissions have been observed for 200 shots without changing the gas in between the shots. The maximum yield of this device is 7.8 x 10{sup 4} neutrons/pulse. Beyond 200 shots the yield is below the threshold (1050 neutrons/pulse) of our {sup 3}He detector. The neutron energy is evaluated using time of flight technique and the value is (2.49 {+-} 0.27) MeV. The measured neutron pulse width is (24 {+-} 5) ns. Multishot and long duration operations envisage the potentiality of such portable device for repetitive mode of operation.

Niranjan, Ram; Rout, R. K.; Srivastava, Rohit; Rawool, A. M.; Kaushik, T. C.; Gupta, Satish C. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, Prabhat [Materials Processing Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2011-02-15T23:59:59.000Z

352

Pulse propagation through a dispersive intracavity medium  

E-Print Network (OSTI)

In this paper, we study theoretically the behavior of a pulse as it propagates through an intracavity fast-light medium. The method of using a transfer function to determine a pulse after it passes through a cavity is well known. However, this approach cannot be used to determine the behavior of the pulse inside the cavity. To circumvent this constraint, we use an approach that starts by finding a self-consistent solution for a monochromatic field of infinite spatial and temporal extents, and determine its amplitudes before, inside, and after the cavity. We then construct a Gaussian input pulse by adding a set of these waves, properly phased and weighted, to represent a moving pulse before the cavity. Adding these waves at various time intervals then yields the complete spatial profile everywhere, including before, inside and after the cavity. We first confirm the prediction of this model by analyzing the behavior of a pulse passing through an empty cavity, and comparing the prediction of the output with the ...

Yum, Honam; Shahriar, Selim

2010-01-01T23:59:59.000Z

353

Tunable pulsed narrow bandwidth light source  

DOE Patents (OSTI)

A tunable pulsed narrow bandwidth light source and a method of operating a light source are provided. The light source includes a pump laser, first and second non-linear optical crystals, a tunable filter, and light pulse directing optics. The method includes the steps of operating the pump laser to generate a pulsed pump beam characterized by a nanosecond pulse duration and arranging the light pulse directing optics so as to (i) split the pulsed pump beam into primary and secondary pump beams; (ii) direct the primary pump beam through an input face of the first non-linear optical crystal such that a primary output beam exits from an output face of the first non-linear optical crystal; (iii) direct the primary output beam through the tunable filter to generate a sculpted seed beam; and direct the sculpted seed beam and the secondary pump beam through an input face of the second non-linear optical crystal such that a secondary output beam characterized by at least one spectral bandwidth on the order of about 0.1 cm.sup.-1 and below exits from an output face of the second non-linear optical crystal.

Powers, Peter E. (Dayton, OH); Kulp, Thomas J. (Livermore, CA)

2002-01-01T23:59:59.000Z

354

Pulse width modulation inverter with battery charger  

SciTech Connect

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin [theta], where [theta] is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120[degree] at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback'' DC-DC converter circuit for recharging the battery. 11 figs.

Slicker, J.M.

1985-01-01T23:59:59.000Z

355

Pulse width modulation inverter with battery charger  

SciTech Connect

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

Slicker, James M. (Union Lake, MI)

1985-01-01T23:59:59.000Z

356

Normal Mode Initialization with Elementary Surface Friction  

Science Conference Proceedings (OSTI)

Various normal-mode initialization techniques are applied to a simple 12-level linear model with boundary layer friction, and results are compared to exact solutions of the model. It is found that Machenhauer's initialization scheme gives an ...

Bradley A. Ballish; Ferdinand Baer

1985-02-01T23:59:59.000Z

357

Organizational Modes of Midlatitude Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

This paper discusses common modes of mesoscale convective organization. Using 2-km national composite reflectivity data, the authors investigated linear mesoscale convective systems (MCSs) that occurred in the central United States during May ...

Matthew D. Parker; Richard H. Johnson

2000-10-01T23:59:59.000Z

358

Engine control system for multiple combustion modes  

Science Conference Proceedings (OSTI)

To reduce the emission by Diesel-engine in railway traction, continuous development and innovation in combustion, sensing net, control method and strategies are required to met the legal requirements. Multiple combustion modes by Diesel engines can reduce ...

D. Bonta; V. Tulbure; Cl. Festila

2008-05-01T23:59:59.000Z

359

Coupling between Tropospheric and Stratospheric Leading Modes  

Science Conference Proceedings (OSTI)

Coupling between tropospheric and stratospheric leading modes in anomaly fields is investigated. By using daily data at many levels in addition to monthly mean data, the transition of spatial patterns and the direction and speed of the vertical ...

Hisanori Itoh; Ken-ichi Harada

2004-01-01T23:59:59.000Z

360

Mixed mode execution with context threading  

Science Conference Proceedings (OSTI)

Interpreters are widely used to implement portable language runtime environments. Programs written in these languages may benefit from performance beyond that obtainable by optimizing interpretation alone. A modern high-performance mixed-mode virtual ...

Mathew Zaleski; Marc Berndl; Angela Demke Brown

2005-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Coexistence of Equatorial Coupled Modes of ENSO  

Science Conference Proceedings (OSTI)

To study the regimes of leading ocean–atmosphere coupled modes of relevance to the El Niño–Southern Oscillation (ENSO) phenomenon, a comprehensive eigenmode analysis of an intermediate coupled model linearized with respect to an array of basic ...

Luis Bejarano; Fei-Fei Jin

2008-06-01T23:59:59.000Z

362

Fundamental Moist Modes of the Equatorial Troposphere  

Science Conference Proceedings (OSTI)

Raymond's diabatic parameterizations are combined with a three-dimensional channel model on an equatorial beta plane. The equatorially symmetric moist modes of this model for an atmosphere initially at rest are “nonlinear WISHE” (wind-induced ...

David J. Raymond; David J. Torres

1998-05-01T23:59:59.000Z

363

Westward Intensified and Topographically Modified Planetary Modes  

Science Conference Proceedings (OSTI)

The process study presented in this note originates from the interest in investigating the existence of barotropic planetary Rossby modes in Mediterranean subbasins that have relatively small length scales and include extensive topographic ...

Stefano Pierini

1997-07-01T23:59:59.000Z

364

Nonlinear Normal Mode Initialization with Physics  

Science Conference Proceedings (OSTI)

The nonlinear normal mode initialization with physics was applied for analyses in FGGE IIIb data of the European Center for Medium Range Weather Forecasting (ECMWF). A convergence of the iteration in the initialization was attained by modifying ...

Takeo Kitade

1983-11-01T23:59:59.000Z

365

Vertical Normal Mode Transforms: Theory and Application  

Science Conference Proceedings (OSTI)

The separation of the vertical structure of the, solutions of the primitive (hydrostatic) meteorological equations is formalized as a vertical normal-mode transform. The transform is implemented for arbitrary static stability profiles by the ...

Scott R. Fulton; Wayne H. Schubert

1985-04-01T23:59:59.000Z

366

Rotary Mode Core Sample System availability improvement  

SciTech Connect

The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2.

Jenkins, W.W.; Bennett, K.L.; Potter, J.D. [Westinghouse Hanford Co., Richland, WA (United States); Cross, B.T.; Burkes, J.M.; Rogers, A.C. [Southwest Research Institute (United States)

1995-02-28T23:59:59.000Z

367

Dissociative ionization of H{sub 2} in an attosecond pulse train and delayed laser pulse  

SciTech Connect

The ionization of H{sub 2} in a single attosecond extreme ultraviolet (XUV) pulse generates a nuclear wave packet in H{sub 2}{sup +}, which is entangled with the emitted photoelectron wave packet. The nuclear wave-packet dynamics can be observed by dissociating H{sub 2}{sup +} in a delayed IR laser pulse. If H{sub 2} is ionized by a sequence of XUV pulses of an attosecond pulse train, whether or not the corresponding sequence of nuclear wave packets in H{sub 2}{sup +} is detected as a coherent or incoherent superposition depends on whether and how the photoelectrons are observed. We simulate the nuclear dynamics in this XUV-pump-IR-probe scenario and analyze our numerical results for both single attosecond pump pulses and pump-pulse trains of different lengths and temporal spacings between individual XUV pulses. By superimposing nuclear wave packets in H{sub 2}{sup +} generated by individual pulses in the pump-pulse train incoherently, we calculate proton kinetic energy release spectra that are in good qualitative agreement with the recent experiment of Kelkensberg et al. [Phys. Rev. Lett. 103, 123005 (2009)].

He Feng; Thumm, Uwe [James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506-2604 (United States)

2010-05-15T23:59:59.000Z

368

Quasi-exactly solvable quasinormal modes  

SciTech Connect

We consider quasinormal modes with complex energies from the point of view of the theory of quasi-exactly solvable (QES) models. We demonstrate that it is possible to find new potentials which admit exactly solvable or QES quasinormal modes by suitable complexification of parameters defining the QES potentials. Particularly, we obtain one QES and four exactly solvable potentials out of the five one-dimensional QES systems based on the sl(2) algebra.

Ho, C.-L.; Cho, H.-T. [Department of Physics, Tamkang University, Tamsui 25137, Taiwan (China)

2007-11-20T23:59:59.000Z

369

Guiding of 35 TW laser pulses in ablative capillary discharge waveguides  

Science Conference Proceedings (OSTI)

An ablatively driven capillary discharge plasma waveguide has been used to demonstrate guiding of 30 fs, 35 TW laser pulses over distances up to 3 cm with incident intensity in excess of 4x10{sup 18} W/cm{sup 2}. The plasma density range over which good guiding was observed was 1-3x10{sup 18} cm{sup -3}. The quality of the laser spot at the exit mode was observed to be similar to that at the entrance and the transmitted energy was {approx}25% at input powers of 35 TW. The transmitted laser spectrum typically showed blueshifting due to ionization of carbon and hydrogen atoms in the capillary plasma by the high intensity laser pulse. The low plasma density regime in which these capillaries operate makes these devices attractive for use in single stage electron accelerators to multi-GeV energies driven by petawatt class laser systems.

McGuffey, C.; Matsuoka, T.; Chvykov, V.; Kalintchenko, G.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Levin, M.; Zigler, A. [Hebrew University, Jerusalem 91904 (Israel)

2009-11-15T23:59:59.000Z

370

Long-Term Stewardship Study  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Office of Long Term Stewardship Office of Long Term Stewardship LONG-TERM STEWARDSHIP STUDY Volume I - Report Prepared to comply with the terms of a settlement agreement: Natural Resources Defense Council, et al. v. Richardson, et al., Civ. No. 97-936 (SS) (D.D.C. Dec. 12, 1998). Final Study October 2001 - i - Foreword The Department of Energy (DOE) has prepared this Long-term Stewardship Study ("Study" or "Final Study") to comply with the terms of a settlement agreement between DOE, the Natural Resources Defense Council, and 38 other plaintiffs [Natural Resources Defense Council, et al. v. Richardson, et al., Civ. No. 97-936 (SS) (D.D.C. Dec. 12, 1998)]. The Study describes and analyzes several issues and a variety of information associated with long-term stewardship. The Study

371

Pulse combustion: an assessment of opportunities for increased efficiency  

SciTech Connect

The results of a literature review on pulse combustion are discussed. Current, near-future, and potential opportunities for pulse combustion applications are summarized, and the barriers to developing and using pulse combustion technology are discussed, along with research and development needs. Also provided are the proceedings of a pulse combustion workshop held in May, 1984 in Seattle, Washington. (LEW)

Brenchley, D.L.; Bomelburg, H.J.

1984-12-01T23:59:59.000Z

372

Generation of parabolic pulses and applications for optical telecommunications  

E-Print Network (OSTI)

Generation of parabolic pulses and applications for optical telecommunications Christophe Finot 1.Finot@u-bourgogne.fr ABSTRACT Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review amplifiers, optical pulse processing techniques 1. INTRODUCTION Parabolic pulse generation and propagation

Paris-Sud XI, Université de

373

An experimental comparison of triggered and random pulse train uncertainties  

SciTech Connect

In this paper we present an experimental comparison of signal-triggered and randomly triggered based analysis algorithms of neutron multiplicity data. Traditional shift register type signal-triggered multiplicity analysis of singles, doubles and triples rates is compared with analysis using randomly triggered gates. Two methods of random gate generation are explored - non-overlapping gates (Feyrunan approach) and periodic overlapping gates (fast accidentals). Using californium sources with low, medium and high rate in combination with AmLi sources (as a surrogate for plutonium) we investigate relative standard deviation (RSD) of data in order to determine if there are parameter spaces in which one of the measurement methods should be preferred. Neutron correlation analysis is a commonly used NDA technique to assay plutonium mass. The data can be collected in two distinct ways: using signal-triggered or randomly triggered counting gates. Analysis algorithms were developed for both approaches to determine singles (S), doubles (D) and triples (7) rates from the measured sample. Currently the most commonly implemented technique to collect neutron coincidence data utilizes shift register based electronics. Shift register uses signal-triggered counting gates to generate foreground multiplicity distribution of correlated+accidental events and a random gate (opened after a predefined long delay following the signal trigger) to generate background multiplicity distribution of accidental events. Modern shift registers include fast accidental option to sample data with a fixed clock frequency. This way a set of overlapping gates is used to generate background multiplicity distributions in order to improve the measurement precision. In parallel to shift register approach the Feynman variance technique is frequently used, which utilizes set of consecutive non-overlapping gates. In general, different user communities (e.g. safeguards, nuclear material accountancy, emergency response) have used only one of the two analysis methods for the nuclear material assay. The aim of this study is to provide a systematic comparison of the precision of the measured S, D, T rates and {sup 240}Pu effective mass obtained using the above mentioned pulse train sampling techniques. In order to perform this task, a LANL developed list mode based data acquisition system is used, where the entire pulse train is recorded and subsequently analyzed. The list mode acquisition brings an essential advantage for this type of comparison, since the very same pulse train can be analyzed using signal-triggered as well as randomly triggered counting gates. The aim of this study is not only to compare the precision of signal-triggered versus random triggered sampling techniques, but also to investigate the influence of fast accidental sampling on the precision of signal-triggered results. In addition the different random sampling techniques used in safeguards are investigated. For this purpose we implement two types of random sampling - non-overlapping gates (Feynrnan approach) and periodic overlapping gates (fast accidentals). In the following sections the equations utilized in the pulse train analysis are described, experimental setup and measurement techniques are discussed and finally the results are summarized and discussed.

Henzlova, Daniela [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

374

The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems  

SciTech Connect

In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

Guo, Jiquan; /SLAC

2009-03-20T23:59:59.000Z

375

ARE PULSING SOLITARY WAVES RUNNING INSIDE THE SUN?  

SciTech Connect

A precise sequence of frequencies-detected four independent ways-is interpreted as a system of solitary waves below the Sun's convective envelope. Six future observational or theoretical tests of this idea are suggested. Wave properties (rotation rates, radial energy distribution, nuclear excitation strength) follow from conventional dynamics of global oscillation modes after assuming a localized nuclear term strong enough to perturb and hold mode longitudes into alignments that form 'families'. To facilitate future tests, more details are derived for a system of two dozen solitary waves 2 {<=} l {<=} 25. Wave excitation by {sup 3}He and {sup 14}C burning is complex. It spikes by factors M{sub 1} {<=} 10{sup 3} when many waves overlap in longitude but its long-time average is M{sub 2} {<=} 10. Including mixing can raise overall excitation to {approx}50 times that in a standard solar model. These spikes cause tiny phase shifts that tend to pull wave rotation rates toward their ideal values {proportional_to}[l(l + 1)]{sup -1}. A system like this would generate some extra nuclear energy in two spots at low latitude on opposite sides of the Sun. Each covers about 20 Degree-Sign of longitude. Above a certain wave amplitude, the system starts giving distinctly more nuclear excitation to some waves (e.g., l = 9, 14, and 20) than to neighboring l values. The prominence of l = 20 has already been reported. This transition begins at temperature amplitudes {Delta}T/T = 0.03 in the solar core for a typical family of modes, which corresponds to {delta}T/T {approx} 0.001 for one of its many component oscillation modes.

Wolff, Charles L., E-mail: charles.l.wolff@nasa.gov [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

376

Spotlight-Mode Synthetic Aperture Radar: A Signal Processing Approach  

Science Conference Proceedings (OSTI)

From the Publisher:Spotlight-mode Synthetic Aperture Radar: A Signal Processing Approach describes an important mode of synthetic aperture radar (SAR) imaging, known as spotlight-mode SAR. By treating the subject via the principles of signal processing, ...

Paul Thompson; Daniel E. Wahl; Paul H. Eichel; Dennis C. Ghiglia; Charles V. Jakowatz

1996-01-01T23:59:59.000Z

377

Distinct Modes of the East Asian Winter Monsoon  

Science Conference Proceedings (OSTI)

Two distinct modes of the East Asian winter monsoon (EAWM) have been identified, and they correspond to real and imaginary parts of the leading mode of the EAWM, respectively. Analyses of these modes used the National Centers for Environment ...

Bingyi Wu; Renhe Zhang; Rosanne D’Arrigo

2006-08-01T23:59:59.000Z

378

Discrete sliding-mode control of a PWM inverter for sinusoidal output waveform synthesis with optimal sliding curve  

SciTech Connect

This paper presents a discrete sliding-mode control scheme with feedforward compensation for the closed-loop regulation of the pulse-width modulated (PWM) inverter used in an uninterruptible power supply (UPS). The proposed feedforward controller can effectively improve the tracking performance of the PWM inverter. In designing the sliding-mode controller, the authors have taken load disturbance into consideration to enhance the robustness of the PWM inverter. Moreover, the upper bound of the load disturbance under which the sliding condition can be maintained has also been derived. The sliding curve of the sliding-mode controller is designed such that the behavior of the controlled PWM inverter is optimal subject to the selected cost function. Due to the coordinate transformation proposed in this paper, only the output voltage needs to be measured as feedback for the purpose of closed-loop regulation. Simulation and experimental results are given to show the effectiveness of the proposed control scheme.

Jung, S.L.; Tzou, Y.Y. [National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Control Engineering

1996-07-01T23:59:59.000Z

379

Hidden explosives detector employing pulsed neutron and x-ray interrogation  

DOE Green Energy (OSTI)

Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

Schultz, Frederick J. (Oak Ridge, TN); Caldwell, John T. (Los Alamos, NM)

1993-01-01T23:59:59.000Z

380

Hidden explosives detector employing pulsed neutron and x-ray interrogation  

DOE Patents (OSTI)

Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

Schultz, F.J.; Caldwell, J.T.

1993-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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381

Injection locked oscillator system for pulsed metal vapor lasers  

SciTech Connect

An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

1988-01-01T23:59:59.000Z

382

CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES  

SciTech Connect

This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.

Professor Bruce R. Kusse; Professor David A. Hammer

2007-04-18T23:59:59.000Z

383

Laser damage by ns and sub-ps pulses on hafnia/silica anti-reflection coatings on fused silica double-sided polished using zirconia or ceria and washed with or without an alumina wash step.  

SciTech Connect

Sandia's Large Optics Coating Operation has extensive results of laser induced damage threshold (LIDT) testing of its anti-reflection (AR) and high reflection coatings on substrates pitch polished using ceria and washed in a process that includes an alumina wash step. The purpose of the alumina wash step is to remove residual polishing compound to minimize its role in laser damage. These LIDT tests are for multi longitudinal mode, ns class pulses at 1064 nm and 532 nm (NIF-MEL protocol) and mode locked, sub-ps class pulses at 1054 nm (Sandia measurements), and show reasonably high and adequate laser damage resistance for coatings in the beam trains of Sandia's Z-Backlighter terawatt and petawatt lasers. An AR coating in addition to coatings of our previous reports confirms this with LIDTs of 33.0 J/cm{sup 2} for 3.5 ns pulses and 1.8 J/cm{sup 2} for 350 fs pulses. In this paper, we investigate both ceria and zirconia in doublesided polishing (common for large flat Z-Backlighter laser optics) as they affect LIDTs of an AR coating on fused silica substrates washed with or without the alumina wash step. For these AR coated, double-sided polished surfaces, ceria polishing in general affords better resistance to laser damage than zirconia polishing and laser damage is less likely with the alumina wash step than without it. This is supported by specific results of laser damage tests with 3.5 ns, multi longitudinal mode, single shot pulses at 1064 nm and 532 nm, with 7.0 ns, single and multi longitudinal mode, single and multi shot pulses at 532 nm, and with 350 fs, mode-locked, single shot pulses at 1054 nm.

Bellum, John Curtis; Rambo, Patrick K.; Schwarz, Jens; Kletecka, Damon; Atherton, Briggs W.; Kimmel, Mark W.; Smith, Ian Craig; Smith, Douglas (Plymouth Grating Laboratory, Carver, MA); Hobbs, Zachary (Sydor Optics, Inc., Rochester, NY)

2010-10-01T23:59:59.000Z

384

Term Appointments | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Term Appointments Term Appointments Term Appointments A term appointment is a non-permanent time limited appointment for a period of more than 1 year but not more than 4 years. The appointment allows eiligibility for benefits and retirement coverage. Reasons for making a term appointment include but are not limited to: project work, extraordinary workload, scheduled abolishment, reorganization, uncertainty of future funding, or the need to maintain permanent positions for placement of employees who would otherwise be displaced from other parts of the organization. OPM may authorize exceptions beyond the 4-year limit when the extension is appropriately justifiable. For example, if the deadline of a major project is extended and the employee's term appointment is at the end of its time

385

Rail Access Modes and Catchment Areas for the BART System  

E-Print Network (OSTI)

parking supplies), ridership (e.g. , rail modal splits), andof California at Berkeley Rail Access Modes and CatchmentHypothesized Distributions of Rail Station Access Modes as a

Cervero, Robert

1995-01-01T23:59:59.000Z

386

Ultrasonic-Based Mode-Synthesizing Atomic Force Microscopy  

In a single run and without damaging the sample, ORNL’s mode-synthesizingatomic force microscopy (MSAFM), along with mode-synthesizing sensing, ...

387

Thyristor stack for pulsed inductive plasma generation  

Science Conference Proceedings (OSTI)

A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 {mu}s and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/{mu}s.

Teske, C.; Jacoby, J.; Schweizer, W.; Wiechula, J. [Plasmaphysics Group, Institute of Applied Physics, Johann-Wolfgang-Goethe University, 60438 Frankfurt am Main (Germany)

2009-03-15T23:59:59.000Z

388

Radiographic X-Ray Pulse Jitter  

Science Conference Proceedings (OSTI)

The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

2011-01-15T23:59:59.000Z

389

Performances Analysis of Main Components Used in 60 MW Pulsed Supply for Particle Accelerator  

E-Print Network (OSTI)

The Proton-Synchrotron (PS) accelerator at CERN will be supplied by a new power system. The pulsed operation of the PS accelerator requires a specific design of the main components of the power system. This paper presents some key elements of the design of DC/DC power converters in terms of aging of power semiconductors, the strategy of harmonics voltage suppression and the design of the output filters. Finally, the performance of this new power system is presented.

Peron, R; Pouliquen, JL; Gollentz, B; Bordry, F; Burnet, JP

2010-01-01T23:59:59.000Z

390

RENEWABLE ENERGY Medium-Term  

E-Print Network (OSTI)

Please note that this PDF is subject to specific restrictions that limit its use and distribution. The terms and conditions are available online at

unknown authors

2012-01-01T23:59:59.000Z

391

H-mode fueling optimization with the supersonic deuterium jet in NSTX  

SciTech Connect

High-performance, long-pulse 0.7-1.2 MA 6-7 MW NBI-heated small-ELM H-mode plasma discharges are developed in the National Spherical Torus Experiment (NSTX) as prototypes for confinement and current drive extrapolations to future spherical tori. It is envisioned that innovative lithium coating techniques for H-mode density pumping and a supersonic deuterium jet for plasma refueling will be used to achieve the low pedestal collisionality and low n{sub e}/n{sub G} fractions (0.3-0.6), both of which being essential conditions for maximizing the non-inductive (bootstrap and beam driven) current fractions. The low field side supersonic gas injector (SGI) on NSTX consists of a small converging-diverging graphite Laval nozzle and a piezoelectric gas valve. The nozzle is capable of producing a deuterium jet with Mach number M {le} 4, estimated gas density at the nozzle exit n {le} 5 x 10{sup 23} m{sup -3}, estimated temperature T {ge} 70 K, and flow velocity v = 2:4 km/s. The nozzle Reynolds number Reis {approx_equal} 6000. The nozzle and the valve are enclosed in a protective carbon fiber composite shroud and mounted on a movable probe at a midplane port location. Despite the beneficial L-mode fueling experience with supersonic jets in limiter tokamaks, there is a limited experience with fueling of high-performance H-mode divertor discharges and the associated density, MHD stability, and MARFE limits. In initial supersonic deuterium jet fueling experiments in NSTX, a reliable H-mode access, a low NBI power threshold, P{sub LH} {le} 2 MW, and a high fueling efficiency (0.1-0.4) have been demonstrated. Progress has also been made toward a better control of the injected fueling gas by decreasing the uncontrolled high field side (HFS) injector fueling rate by up to 95 % and complementing it with the supersonic jet fueling. These results motivated recent upgrades to the SGI gas delivery and control systems. The new SGI-Upgrade (SGI-U) capabilities include multi-pulse ms-scale controls and a reservoir gas pressure up to P{sub 0} = 5000 Torr. In this paper we summarize recent progress toward optimization of H-mode fueling in NSTX using the SGI-U.

Soukhanovskii, V A; Bell, M G; Bell, R E; Gates, D A; Kaita, R; Kugel, H W; LeBlanc, B P; Lundberg, D P; Maingi, R; Menard, J E; Raman, R; Roquemore, A L; Stotler, D P

2008-06-18T23:59:59.000Z

392

Spatiotemporal reconstruction of list-mode PET data  

Science Conference Proceedings (OSTI)

We describe a method for computing a continuous time estimate of tracer density using list-mode positron emission tomography data. The rate function in each voxel is modeled as an inhomogeneous Poisson process whose rate function can be represented using a cubic B-spline basis. The rate functions are estimated by maximizing the likelihood of the arrival times of detected photon pairs over the control vertices of the spline, modified by quadratic spatial and temporal smoothness penalties and a penalty term to enforce nonnegativity. Randoms rate functions are estimated by assuming independence between the spatial and temporal randoms distributions. Similarly, scatter rate functions are estimated by assuming spatiotemporal independence and that the temporal distribution of the scatter is proportional to the temporal distribution of the trues. A quantitative evaluation was performed using simulated data and the method is also demonstrated in a human study using 11C-raclopride.

Nichols, Thomas E.; Qi, Jinyi; Asma, Evren; Leahy, Richard M.

2002-03-01T23:59:59.000Z

393

Resistive Wall Mode Stabilization Studies at DIII-D  

Science Conference Proceedings (OSTI)

The effort to understand the physics of the resistive wall mode (RWM) and develop methods to control this magnetohydrodynamic mode to allow achievement of higher pressure in advanced tokamak plasmas has been an example of successful multi-institutional collaboration at the DIII-D National Fusion Facility in San Diego, California. DIII-D research in this area has produced several advances and breakthroughs following a coordinated research plan involving a sequence of measurements, development of new analysis tools, and the installation of new diagnostic and feedback stabilization hardware: Suppression of the RWM by active magnetic feedback has been demonstrated using the DIII-D six-element error field correction coil, rotational stabilization of the RWM has been demonstrated and sustained for all values of the plasma pressure from the no-wall to the ideal-wall stability limits, improved RWM feedback stabilization has been shown using a new set of 12 internal control coils, and newly developed models of feedback have shown good agreement with the measurements. By so doing, the DIII-D work on RWM stabilization has become a cornerstone of the long-term advanced tokamak program and is having impact on the world fusion program. Presently both ITER and FIRE are including plans for RWM stabilization in their programs.

Garofalo, A.M. [Columbia University (United States)

2005-10-15T23:59:59.000Z

394

Pulsed LASER for testing silicon strip detectors  

SciTech Connect

This DO Note describes a pulsed LASER setup for testing silicon strip detectors at the Silicon Detector Facility (SiDet) of Fermilab supporting the related projects and, in particular, the DO Silicon Tracker Upgrade. It will be used in the measurements of the efficiency of individual strips and their coupling. The LASER wavelength is 1060 nm, at which the absorption length in silicon is about 2 mm. The LASER setup is capable of producing light pulses with rise time of less than 1 ns, allowing the measurement of charge pulse shaping at individual strips and their capacitive couplings. Due to the high power output of the LASER, safety considerations are included. Also discussed are precautions for the safety of the LASER itself, and how to limit the light to an area smaller than 50,pm of diameter.

Vaz, M.; Cihangir, S.; Rapidis, P.

1993-07-01T23:59:59.000Z

395

Stabilizing windings for tilting and shifting modes  

DOE Patents (OSTI)

This invention provides simple, inexpensive, independent and passive, conducting loops for stabilizing a plasma ring having externally produced equilibrium fields on opposite sides of the plasma ring and internal plasma currents that interact to tilt and/or shift the plasma ring relative to the externally produced equilibrium field so as to produce unstable tilting and/or shifting modes in the plasma ring. More particularly this invention provides first and second passive conducting loops for containing first and second induced currents in first and second directions corresponding to the amplitude and directions of the unstable tilting and/or shifting modes in the plasma ring. To this end, the induced currents provide additional magnetic fields for producing restoring forces and/or restoring torques for counteracting the tilting and/or shifting modes when the conducting loops are held fixed in stationary positions relative to the externally produced equilibrium fields on opposite sides of the plasma ring.

Jardin, S.C.; Christensen, U.R.

1982-02-26T23:59:59.000Z

396

Contained Modes In Mirrors With Sheared Rotation  

SciTech Connect

In mirrors with E × B rotation, a fixed azimuthal perturbation in the lab frame can appear as a wave in the rotating frame. If the rotation frequency varies with radius, the plasma-frame wave frequency will also vary radially due to the Doppler shift. A wave that propagates in the high rotation plasma region might therefore be evanescent at the plasma edge. This can lead to radially localized Alfven eigenmodes with high azimuthal mode numbers. Contained Alfven modes are found both for peaked and non-peaked rotation profiles. These modes might be useful for alpha channeling or ion heating, as the high azimuthal wave number allows the plasma wave frequency in the rotating frame to exceed the ion cyclotron frequency. __________________________________________________

Abraham J. Fetterman and Nathaniel J. Fisch

2010-10-08T23:59:59.000Z

397

Search for global f-modes and p-modes in the 8B neutrino flux  

E-Print Network (OSTI)

The impact of global acoustic modes on the 8B neutrino flux time series is computed for the first time. It is shown that the time fluctuations of the 8B neutrino flux depend on the amplitude of acoustic eigenfunctions in the region where the 8B neutrino flux is produced: modes with low n (or order) that have eigenfunctions with a relatively large amplitude in the Sun's core, strongly affect the neutrino flux; conversely, modes with high n that have eigenfunctions with a minimal amplitude in the Sun's core have a very small impact on the neutrino flux. It was found that the global modes with a larger impact on the 8B neutrino flux have a frequency of oscillation in the interval 250 \\mu Hz to 500 \\mu Hz (or a period in the interval 30 minutes to 70 minutes), such as the f-modes (n=0) for the low degrees, radial modes of order n smaller or equal to 3, and the dipole mode of order n=1. Their corresponding neutrino eigenfunctions are very sensitive to the solar inner core and are unaffected by the variability of the external layers of the solar surface. If time variability of neutrinos is observed for these modes, it will lead to new ways of improving the sound speed profile inversion in the central region of the Sun.

Ilidio Lopes

2013-10-13T23:59:59.000Z

398

Hydrogen local vibrational modes in semiconductors  

DOE Green Energy (OSTI)

Following, a review of experimental techniques, theory, and previous work, the results of local vibrational mode (LVM) spectroscopy on hydrogen-related complexes in several different semiconductors are discussed. Hydrogen is introduced either by annealing in a hydrogen ambient. exposure to a hydrogen plasma, or during growth. The hydrogen passivates donors and acceptors in semiconductors, forming neutral complexes. When deuterium is substituted for hydrogen. the frequency of the LVM decreases by approximately the square root of two. By varying the temperature and pressure of the samples, the microscopic structures of hydrogen-related complexes are determined. For group II acceptor-hydrogen complexes in GaAs, InP, and GaP, hydrogen binds to the host anion in a bond-centered orientation, along the [111] direction, adjacent to the acceptor. The temperature dependent shift of the LVMs are proportional to the lattice thermal energy U(T), a consequence of anharmonic coupling between the LVM and acoustical phonons. In the wide band gap semiconductor ZnSe, epilayers grown by metalorganic chemical vapor phase epitaxy (MOCVD) and doped with As form As-H complexes. The hydrogen assumes a bond-centered orientation, adjacent to a host Zn. In AlSb, the DX centers Se and Te are passivated by hydrogen. The second, third, and fourth harmonics of the wag modes are observed. Although the Se-D complex has only one stretch mode, the Se-H stretch mode splits into three peaks. The anomalous splitting is explained by a new interaction between the stretch LVM and multi-phonon modes of the lattice. As the temperature or pressure is varied, and anti-crossing is observed between LVM and phonon modes.

McCluskey, M.D. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States)

1997-06-01T23:59:59.000Z

399

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

Tailored Terahertz Pulses from a Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Wednesday, 29 November 2006 00:00 Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. Interaction of the ALS electron beam with a femtosecond laser pulse as they co-propagate through a wiggler modulates the electron energies within a short slice of the electron bunch with about the same duration as the laser pulse. This causes a dispersion of the electron trajectories, and the bunch develops a hole that emits short pulses of temporally and spatially coherent terahertz pulses synchronized to the laser. The technique allows tremendous flexibility in shaping the terahertz pulses by appropriate modulation of the laser pulse.

400

Lovelock Terms and BRST Cohomology  

E-Print Network (OSTI)

Lovelock terms are polynomial scalar densities in the Riemann curvature tensor that have the remarkable property that their Euler-Lagrange derivatives contain derivatives of the metric of order not higher than two (while generic polynomial scalar densities lead to Euler-Lagrange derivatives with derivatives of the metric of order four). A characteristic feature of Lovelock terms is that their first nonvanishing term in the expansion of the metric around flat space is a total derivative. In this paper, we investigate generalized Lovelock terms defined as polynomial scalar densities in the Riemann curvature tensor and its covariant derivatives (of arbitrarily high but finite order) such that their first nonvanishing term in the expansion of the metric around flat space is a total derivative. This is done by reformulating the problem as a BRST cohomological one and by using cohomological tools. We determine all the generalized Lovelock terms. We find, in fact, that the class of nontrivial generalized Lovelock terms contains only the usual ones. Allowing covariant derivatives of the Riemann tensor does not lead to new structure. Our work provides a novel algebraic understanding of the Lovelock terms in the context of BRST cohomology.

S. Cnockaert; M. Henneaux

2005-04-20T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Pulsed Power Technology at Sandia National Laboratories  

NLE Websites -- All DOE Office Websites (Extended Search)

Z-Machine Time-exposure photograph of electrical flashover arcs produced over the surface of the water in the accelerator tank as a byproduct of Z operation. These flashovers are much like strokes of lightning Related links Electromagnetic Technology at Sandia National Laboratories Pulsed Power Technology Published Papers Inertial Fusion Energy C. L. Olson, "Inertial Fusion Energy with Pulsed Power," 2000 Codes: ALEGRA K. C. Cochrane, "Aluminum Equation of State Validation and Verification for the ALEGRA HEDP Simulation Code," 2006 T. Trucano, "ALEGRA-HEDP Validation Strategy," 2005 C. Garasi , "Multi-dimensional high energy density physics modeling and simulation of wire array z-pinch physics," 2003 Equation of State (EOS)

402

Dispersion compensation for attosecond electron pulses  

Science Conference Proceedings (OSTI)

We propose a device to compensate for the dispersion of attosecond electron pulses. The device uses only static electric and magnetic fields and therefore does not require synchronization to the pulsed electron source. Analogous to the well-known optical dispersion compensator, an electron dispersion compensator separates paths by energy in space. Magnetic fields are used as the dispersing element, while a Wien filter is used for compensation of the electron arrival times. We analyze a device with a size of centimeters, which can be applied to ultrafast electron diffraction and microscopy, and fundamental studies.

Hansen, Peter; Baumgarten, Cory; Batelaan, Herman; Centurion, Martin [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

2012-08-20T23:59:59.000Z

403

Device for generation of pulsed corona discharge  

DOE Patents (OSTI)

The invention is a method and system for the generation of high voltage, pulsed, periodic corona discharges capable of being used in the presence of conductive liquid droplets. The method and system can be used, for example, in different devices for cleaning of gaseous or liquid media using pulsed corona discharge. Specially designed electrodes and an inductor increase the efficiency of the system, permit the plasma chemical oxidation of detrimental impurities, and increase the range of stable discharge operations in the presence of droplets of water or other conductive liquids in the discharge chamber.

Gutsol, Alexander F. (San Ramon, CA); Fridman, Alexander (Marlton, NJ); Blank, Kenneth (Philadelphia, PA); Korobtsev, Sergey (Moscow, RU); Shiryaevsky, Valery (Moscow, RU); Medvedev, Dmitry (Moscow, RU)

2012-05-08T23:59:59.000Z

404

Long-Term Environmental Stewardship  

NLE Websites -- All DOE Office Websites (Extended Search)

Long-Term Environmental Stewardship Long-Term Environmental Stewardship The Long-Term Environmental Stewardship Program ensures protection of human health and the environment, following site remediations. Contact Environmental Communication & Public Involvement P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email Continuing environmental commitment Long-term stewardship activities are designed to prevent exposures to residual contamination and waste including groundwater monitoring ongoing pump-and-treatment activities maintenance of barriers and other contaminant structures periodic inspections control of site access posted signs Long-term environmental stewardship (LTES) data access DOE requires that data used to make decisions concerning LTES conditions be readily accessible to the public. To accomplish this, sample analysis data

405

A NEW METHOD OF PULSE-WISE SPECTRAL ANALYSIS OF GAMMA-RAY BURSTS  

SciTech Connect

Time-resolved spectral analysis, though a very promising method to understand the emission mechanism of gamma-ray bursts (GRBs), is difficult to implement in practice because of poor statistics. We present a new method for pulse-wise time-resolved spectral study of the individual pulses of GRBs, using the fact that many spectral parameters are either constants or smooth functions of time. We use this method for the two pulses of GRB 081221, the brightest GRB with separable pulses. We choose, from the literature, a set of possible models that includes the Band model, blackbody with a power law (BBPL), and a collection of blackbodies with a smoothly varying temperature profile, along with a power law (mBBPL), and two blackbodies with a power law (2BBPL). First, we perform a time-resolved study to confirm the spectral parameter variations, and then we construct the new model to perform a joint spectral fit. We find that any photospheric emission in terms of blackbodies is required mainly in the rising parts of the pulses and the falling part can be adequately explained in terms of the Band model, with the low-energy photon index within the regime of synchrotron model. Interestingly, we find that 2BBPL is comparable or sometimes even better, though marginally, than the Band model, in all episodes. Consistent results are also obtained for the brightest GRB of Fermi era-GRB 090618. We point out that the method is generic enough to test any spectral model with well-defined parameter variations.

Basak, Rupal; Rao, A. R., E-mail: rupalb@tifr.res.in, E-mail: arrao@tifr.res.in [Tata Institute of Fundamental Research, Mumbai-400005 (India)

2013-05-10T23:59:59.000Z

406

Isolated sub-100-attosecond pulse generation via controlling electron dynamics  

E-Print Network (OSTI)

A new method to coherently control the electron dynamics is proposed using a few-cycle laser pulse in combination with a controlling field. It is shown that this method not only broadens the attosecond pulse bandwidth, but also reduces the chirp, then an isolated 80-as pulse is straightforwardly obtained and even shorter pulse is achievable by increasing the intensity of the controlling field. Such ultrashort pulses allow one to investigate ultrafast electronic processes which have never be achieved before. In addition, the few-cycle synthesized pulse is expected to manipulate a wide range of laser-atom interactions.

Lan, Pengfei; Cao, Wei; Li, Yuhua; Wang, Xinlin

2007-01-01T23:59:59.000Z

407

Nuclear vorticity in isoscalar E1 modes: Skyrme-RPA analysis  

E-Print Network (OSTI)

Two basic concepts of nuclear vorticity, hydrodynamical (HD) and Rawenthall-Wambach (RW), are critically inspected. As a test case, we consider the interplay of irrotational and vortical motion in isoscalar electric dipole E1(T=0) modes in $^{208}$Pb, namely the toroidal and compression modes. The modes are described in a self-consistent random-phase-approximation (RPA) with the Skyrme force SLy6. They are examined in terms of strength functions, transition densities, current fields, and formfactors. It is shown that the RW conception (suggesting the upper component of the nuclear current as the vorticity indicator) is not robust. The HD vorticity is not easily applicable either because the definition of a velocity field is too involved in nuclear systems. Instead, the vorticity is better characterized by the toroidal strength which closely corresponds to HD treatment and is approximately decoupled from the continuity equation.

P. -G. Reinhard; V. O. Nesterenko; A. Repko; J. Kvasil

2013-12-27T23:59:59.000Z

408

Voltage Pulse Profile Characteristics with Space Charge of a Loaded Pulsed Ionization Chamber  

Science Conference Proceedings (OSTI)

An analytical model describing the voltage pulse profile of a pulsed ionization chamber and its relationship to the electron density in a field drift dominated plasma is formulated. The differential equation derived from the equations of motion and conservation of electron density combined with Poisson's equation for the electric space?charge field in the system is solved analytically for the cylindrical?electrode geometry with an external RC circuit. The numerical analysis for the given initial and boundary conditions yields the anode voltage?signal pulse profiles for the period of electron collection as a function of the initial electron density

S.H. Kim; W.H. Ellis

1972-01-01T23:59:59.000Z

409

MHD mode conversion in a stratified atmosphere  

E-Print Network (OSTI)

Mode conversion in the region where the sound and Alfven speeds are equal is a complex process, which has been studied both analytically and numerically, and has been seen in observations. In order to further the understanding of this process we set up a simple, one-dimensional model, and examine wave propagation through this system using a combination of analytical and numerical techniques. Simulations are carried out in a gravitationally stratified atmosphere with a uniform, vertical magnetic field for both isothermal and non-isothermal cases. For the non-isothermal case a temperature profile is chosen to mimic the steep temperature gradient encountered at the transition region. In all simulations, a slow wave is driven on the upper boundary, thus propagating down from low-beta to high-beta plasma across the mode-conversion region. In addition, a detailed analytical study is carried out where we predict the amplitude and phase of the transmitted and converted components of the incident wave as it passes through the mode-conversion region. A comparison of these analytical predictions with the numerical results shows good agreement, giving us confidence in both techniques. This knowledge may be used to help determine wave types observed and give insight into which modes may be involved in coronal heating.

A. M. Dee McDougall; Alan W. Hood

2008-08-01T23:59:59.000Z

410

Models for Short-Term Production Planning of Cogeneration Plants  

E-Print Network (OSTI)

The short-term production planning problem for a district heating system is a well-known but difficult optimization problem. In a district heating plant several types of energy producing units are used, the most important being the cogeneration unit, which produces both heat and electricity. The net electricity is sold at the electricity market. Most plants also have a heat water storage. Finding the optimal production of both heat and electricity and the optimal use of the heat water storage is a challenging mixed optimization problem. The production planning may be divided into two sub-problems. The unit commitment problem determines which units should be on or off and in which different mode the unit should run. The economic dispatch problem finds the optimal production plan given the units on and running modes. In this paper we formulate a new approach for the mathematical modeling of the economic dispatch problem. The model objective function is nonlinear, with nonlinear constrain...

Erik Dotzauer; Kenneth Holmström

1997-01-01T23:59:59.000Z

411

Experimental investigations of the TE{sub 11} mode radiation from a relativistic magnetron with diffraction output  

Science Conference Proceedings (OSTI)

Directly radiating microwaves at TE{sub 11} mode, a relativistic magnetron with diffraction output (MDO) is experimentally investigated. Two important factors, transition section and working condition, significantly affecting the microwave powers, efficiencies, and pulse durations are analyzed. The experimental results on our designed MDO show that the optimized transition section with the parameters, 46 mm in height and 70 mm in length, is beneficial for producing high power TE{sub 11} mode microwaves. Under the low applied voltage condition (less than 650 kV), the power conversion efficiency will be higher than that obtained from the high applied voltage condition. {approx}24 ns of the microwave duration is a typical value under the voltage duration of 56 ns. Pulse shortens will happen if the applied voltage is higher than 650 kV. When the applied voltage reaches 880 kV, the microwave duration is only just {approx}12 ns. Impendence mismatch between the accelerator and the diode is the chief reason causing the pulse shortens.

Li Wei; Liu Yonggui; Zhang Jun; Yang Hanwu; Qian Baoliang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)

2012-11-15T23:59:59.000Z

412

Pulse thermal energy transport/storage system  

DOE Patents (OSTI)

A pulse-thermal pump having a novel fluid flow wherein heat admitted to a closed system raises the pressure in a closed evaporator chamber while another interconnected evaporator chamber remains open. This creates a large pressure differential, and at a predetermined pressure the closed evaporator is opened and the opened evaporator is closed. This difference in pressure initiates fluid flow in the system.

Weislogel, Mark M. (23133 Switzer Rd., Brookpark, OH 44142)

1992-07-07T23:59:59.000Z

413

Combinatorial Pulsed Electrodeposition Approach for Development ...  

Science Conference Proceedings (OSTI)

Symposium, J. Materials and Processes for Enhanced Performance ... Separation and Recovery Process of Rare Metals from Oil Desulfurization Spent Catalyst ... Pulsed Laser Evaporation: An Enabling Technology for Organic Thin Films ... Redox Investigation of NiFe2O4 Supported on Al2O3 and Yttria-Stabilized Zirconia ...

414

Entanglement manipulation by a local magnetic pulse  

E-Print Network (OSTI)

A scheme for controlling the entanglement of a two-qubit system by a local magnetic pulse is proposed. We show that the entanglement of the two-qubit system can be increased by sacrificing the coherence in ancillary degree of freedom, which is induced by a local manipulation.

Shi-Jian Gu; Hai-Qing Lin

2005-03-15T23:59:59.000Z

415

The Use of Topographic Wave Modes to Solve for the Barotropic Mode of a Rigid-Lid Ocean Model  

Science Conference Proceedings (OSTI)

Topographic wave modes are defined for the barotropic mode of a rigid-lid ocean, and the question is asked whether these might form an efficient basis for a description of the barotropic mode of a general ocean flow. The modes are shown to be ...

C. W. Hughes

1996-06-01T23:59:59.000Z

416

The Effect of a Pulsed Electric Current on the Compressive Behavior ...  

Science Conference Proceedings (OSTI)

Quasi-static compressive tests with multiple pulses of electric current with a constant pulse period are conducted. Two different electric pulse conditions, ...

417

Plasma Modes Along the Open Field Lines of a Neutron Star  

E-Print Network (OSTI)

We consider electrostatic plasma modes along the open field lines of a rotating neutron star. Goldreich-Julian charge density in general relativity is analyzed for the neutron star with zero inclination. It is found that the charge density is maximum at the polar cap and it remains almost same in certain extended region of the pole. For a steady state Goldreich-Julian charge density we found the usual plasma oscillation along the field lines; plasma frequency resembles to the gravitational redshift close to the Schwarzschild radius. We study the nonlinear plasma mode along the field lines. From the system of equations under general relativity, a second order differential equation is derived. The equation contains a term which describes the growing plasma modes near Schwarzschild radius in a black hole environment. The term vanishes with the distance far away from the gravitating object. For initially zero potential and field on the surface of a neutron star, Goldreich-Julian charge density is found to create the plasma mode, which is enhanced and propagates almost without damping along the open field lines. We briefly outline our plan to extend the work for studying soliton propagation along the open field lines of strongly gravitating objects.

U. A. Mofiz; B. J. Ahmedov

2007-05-30T23:59:59.000Z

418

Short-Term Energy Outlook  

U.S. Energy Information Administration (EIA)

DOE/EIA-0202(98/3Q) Distribution Category UC-950 Short-Term Energy Outlook July 1998 Energy Information Administration Office of Energy Markets and End Use

419

More on the term Fission?  

NLE Websites -- All DOE Office Websites (Extended Search)

information, and he certainly did. His insight into the origin of the term "fission" expanded greatly on the mere mention I had made of it in the Y-12 history column he...

420

Interpretations of the JEBAR Term  

Science Conference Proceedings (OSTI)

In diagnostic calculations of the ocean's circulation, the so-called JEBAR (joint effect of baroclinicity and relief) term may induce a significant depth-average current field, as has been noted in the oceanographic literature. Here we present ...

Gordon Mertz; Daniel G. Wright

1992-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Does the term structure forecast  

E-Print Network (OSTI)

provides more accurate forecasts of real consumption growth14. Harvey, C.R. (1989): \\Forecasts of economic growth fromC.R. (1993): \\Term structure forecasts economic growth", Fi-

Berardi, Andrea; Torous, Walter

2002-01-01T23:59:59.000Z

422

Long-Term Surveillance Plan  

E-Print Network (OSTI)

NRC in the referenced letter have been addressed and are reflected in this submittal. This Long Term Surveillance Plan (LTSP) is intended to satisfy the requirements set forth in 10 CFR 40.28 whereby the long-term custodian must provide an LTSP to the NRC as a step in the licensing/license termination process. Please call me at (970) 248-6037 if you have questions. Sincerely, Enclosures cc w/enclosure:

Mail Stop Ta; M. Plessinger Mactec-ers

2001-01-01T23:59:59.000Z

423

Higher Order Modes Damping Analysis for the SPX Deflecting Cavity Cyromodule  

Science Conference Proceedings (OSTI)

A single-cell superconducting deflecting cavity operating at 2.815 GHz has been proposed and designed for the Short Pulse X-ray (SPX) project for the Advanced Photon Source (APS) upgrade. A cryomodule of 4 such cavities will be needed to produce the required 2-MV deflecting voltage. Each deflecting cavity is equipped with one fundamental power coupler (FPC), one lower order mode (LOM) coupler, and two higher order mode (HOM) couplers to achieve the stringent damping requirements for the unwanted modes. The damping of the LOM/HOM below the beampipe cutoff has been analyzed in the single cavity geometry and shown to meet the design requirements. The HOM above the beampipe cutoff in the 4-cavity cyromodule, however, may result in cross coupling which may affect the HOM damping and potentially be trapped between the cavities which could produce RF heating to the beamline bellows. We have evaluated the HOM damping in the 4-cavity cryomodule using the parallel finite element EM code suite ACE3P developed at SLAC. We will present the results of the cryomodule analysis in this paper.

Xiao, L; Li, Z.; Ng, C.; /SLAC; Nassiri, A.; Waldschmidt, G.; Wu, G.; /Argonne; Wang, H.; Rimmer, R.; /Jefferson Lab

2012-06-06T23:59:59.000Z

424

Isothermal Bainite Transformation of Cr5 Steel under Pulsed Current ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The pulsed current and pulsed magnetic field had been applied ... Solubility in the CaO-SiO2-FeOt Based Welding Flux System Containing NaF.

425

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. Interaction of the ALS electron beam with a femtosecond laser pulse as they co-propagate through a wiggler modulates the electron energies within a short slice of the electron bunch with about the same duration as the laser pulse. This causes a dispersion of the electron trajectories, and the bunch develops a hole that emits short pulses of temporally and spatially coherent terahertz pulses synchronized to the laser. The technique allows tremendous flexibility in shaping the terahertz pulses by appropriate modulation of the laser pulse.

426

Non-dimensional Performance Trends of a Pulsed Plasma Accelerator  

E-Print Network (OSTI)

of Current Sheet Canting in a Pulsed Electromagnetic Accelerator," Physics of Plasmas, Vol. 11, No. 10, 2004, Princeton University, 2005. 5Markusic, T., Current Sheet Canting in Pulsed Electromagnetic Accelerators, Ph

Choueiri, Edgar

427

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. Interaction of the ALS electron beam with a femtosecond laser pulse as they co-propagate through a wiggler modulates the electron energies within a short slice of the electron bunch with about the same duration as the laser pulse. This causes a dispersion of the electron trajectories, and the bunch develops a hole that emits short pulses of temporally and spatially coherent terahertz pulses synchronized to the laser. The technique allows tremendous flexibility in shaping the terahertz pulses by appropriate modulation of the laser pulse.

428

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. Interaction of the ALS electron beam with a femtosecond laser pulse as they co-propagate through a wiggler modulates the electron energies within a short slice of the electron bunch with about the same duration as the laser pulse. This causes a dispersion of the electron trajectories, and the bunch develops a hole that emits short pulses of temporally and spatially coherent terahertz pulses synchronized to the laser. The technique allows tremendous flexibility in shaping the terahertz pulses by appropriate modulation of the laser pulse.

429

Optical state engineering, quantum communication, and robustness of entanglement promiscuity in three-mode Gaussian states  

E-Print Network (OSTI)

We present a novel, detailed study on the usefulness of three-mode Gaussian states states for realistic processing of continuous-variable quantum information, with a particular emphasis on the possibilities opened up by their genuine tripartite entanglement. We describe practical schemes to engineer several classes of pure and mixed three-mode states that stand out for their informational and/or entanglement properties. In particular, we introduce a simple procedure -- based on passive optical elements -- to produce pure three-mode Gaussian states with {\\em arbitrary} entanglement structure (upon availability of an initial two-mode squeezed state). We analyze in depth the properties of distributed entanglement and the origin of its sharing structure, showing that the promiscuity of entanglement sharing is a feature peculiar to symmetric Gaussian states that survives even in the presence of significant degrees of mixedness and decoherence. Next, we discuss the suitability of the considered tripartite entangled states to the implementation of quantum information and communication protocols with continuous variables. This will lead to a feasible experimental proposal to test the promiscuous sharing of continuous-variable tripartite entanglement, in terms of the optimal fidelity of teleportation networks with Gaussian resources. We finally focus on the application of three-mode states to symmetric and asymmetric telecloning, and single out the structural properties of the optimal Gaussian resources for the latter protocol in different settings. Our analysis aims to lay the basis for a practical quantum communication with continuous variables beyond the bipartite scenario.

Gerardo Adesso; Alessio Serafini; Fabrizio Illuminati

2006-09-09T23:59:59.000Z

430

Green Bank Telescope Studies of Giant Pulses from Millisecond Pulsars  

E-Print Network (OSTI)

We have conducted a search for giant pulses from four millisecond pulsars using the 100m Green Bank Telescope. Coherently dedispersed time-series from PSR J0218+4232 were found to contain giant pulses of very short intrinsic duration whose energies follow power-law statistics. The giant pulses are in phase with the two minima of the radio integrated pulse profile but are phase aligned with the peaks of the X-ray profile. Historically, individual pulses more than 10-20 times the mean pulse energy have been deemed to be ``giant pulses''. As only 4 of the 155 pulses had energies greater than 10 times the mean pulse-energy, we argue the emission mechanism responsible for giant pulses should instead be defined through: (a) intrinsic timescales of microsecond or nanosecond duration; (b) power-law energy statistics; and (c) emission occurring in narrow phase-windows coincident with the phase windows of non-thermal X-ray emission. Four short-duration pulses with giant-pulse characteristics were also observed from PSR B1957+20. As the inferred magnetic fields at the light cylinders of the millisecond pulsars that emit giant pulses are all very high, this parameter has previously been considered to be an indicator of giant pulse emissivity. However, the frequency of giant pulse emission from PSR~B1957+20 is significantly lower than for other millisecond pulsars that have similar magnetic fields at their light cylinders. This suggests that the inferred magnetic field at the light cylinder is a poor indicator of the rate of emission of giant pulses.

H. S. Knight; M. Bailes; R. N. Manchester; S. M. Ord; B. A. Jacoby

2005-12-13T23:59:59.000Z

431

CURRENT SHEET MASS LEAKAGE IN A PULSED PLASMA ACCELERATOR  

E-Print Network (OSTI)

in this dissertation was performed in a pulsed electromagnetic accelerator. 1 #12;Figure 1.1: Diagram of a gas

Choueiri, Edgar

432

Discrete-Time Poles and Dynamics of Discontinuous Mode Boost and Buck Converters Under Various Control Schemes  

E-Print Network (OSTI)

Nonlinear systems, such as switching DC-DC boost or buck converters, have rich dynamics. A simple one-dimensional discrete-time model is used to analyze the boost or buck converter in discontinuous conduction mode. Seven different control schemes (open-loop power stage, voltage mode control, current mode control, constant power load, constant current load, constant-on-time control, and boundary conduction mode) are analyzed systematically. The linearized dynamics is obtained simply by taking partial derivatives with respect to dynamic variables. In the discrete-time model, there is only a single pole and no zero. The single closed-loop pole is a linear combination of three terms: the open-loop pole, a term due to the control scheme, and a term due to the non-resistive load. Even with a single pole, the phase response of the discrete-time model can go beyond -90 degrees as in the two-pole average models. In the boost converter with a resistive load under current mode control, adding the compensating ramp has no effect on the pole location. Increasing the ramp slope decreases the DC gain of control-to-output transfer function and increases the audio-susceptibility. Similar analysis is applied to the buck converter with a non-resistive load or variable switching frequency. The derived dynamics agrees closely with the exact switching model and the past research results.

Chung-Chieh Fang

2012-11-19T23:59:59.000Z

433

Generator of pumping pulses for powerful semiconductor lasers  

Science Conference Proceedings (OSTI)

The generator of electric and optic pulses are built using powerful MOS transistors and an ILPI-103 semiconductor laser generates pumping pulses with an amplitude of 15 A and optic pulses with a duration of 9 to 30 nsec at a repetition rate of up to 90 kHz. The output signal is TTL. The device is designed for open optic communication lines.

An, V.I.; Kolesnikov, Yu.Yu. [Voronezh Scientific Research Institute of Communications, Voronezh (Russian Federation)

1995-06-01T23:59:59.000Z

434

Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators  

E-Print Network (OSTI)

Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators T of current sheet canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that - canting angle [degrees] 5 - plasma frequency [rad/s] 1 Introduction Pulsed electromagnetic accelerators

Choueiri, Edgar

435

CHARACTERIZATION OF CURRENT SHEET EVOLUTION IN A PULSED  

E-Print Network (OSTI)

CHARACTERIZATION OF CURRENT SHEET EVOLUTION IN A PULSED ELECTROMAGNETIC ACCELERATOR J.W. Berkery evolution in a pulsed electromagnetic accelerator is presented based on temporally and spatially resolved field in a pulsed electromagnetic accelerator has been presented. The magnetic field measurements have

Choueiri, Edgar

436

Measurements of current sheet canting in a pulsed electromagnetic accelerator  

E-Print Network (OSTI)

Measurements of current sheet canting in a pulsed electromagnetic accelerator T. E. Markusic, E. Y canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that carries in an experimental pulsed electromagnetic accelerator, using a variety of propellants and pressure levels

Choueiri, Edgar

437

Physics and Dynamics of Current Sheets in Pulsed Plasma Thrusters  

E-Print Network (OSTI)

canting in pulsed electromagnetic accelerators is the departure of the plasma sheet that carries Pulsed electromagnetic accelerators are devices which use intense bursts of elec- trical current (O(104 to improve the performance of pulsed electromagnetic accelerators in the context of plasma propulsion

Choueiri, Edgar

438

Theory of parabolic pulse generation in tapered Anton I. Latkin  

E-Print Network (OSTI)

Theory of parabolic pulse generation in tapered fiber Anton I. Latkin Institute of Automation and differences between high-power parabolic pulse generation in an active me- dium and in tapered fiber of parabolic pulse generation without an external pump and determine the limita- tions of this approach. © 2007

Turitsyn, Sergei K.

439

Disordered Optical Modes for Photon Management  

E-Print Network (OSTI)

Wave transport in disordered systems is a vast research topic, ranging from electrons in semiconductors, to light in random dielectrics, to cold atoms in laser speckles. In optics, light transport is conveyed by random electromagnetic modes and the wave can be localized about a point or extended throughout the system, depending on disorder strength, structural correlations and dimensionality of the system. Light localization phenomena are more dominantly present in two-dimensional systems than in three-dimensional ones and their optical modes can be tailored to a greater extent. Here, we show that it is possible to make use of the properties of lower-dimensional disordered structures to obtain photon management in three-dimensional space. More particularly, we argue that two-dimensional disorder and wave interferences can be exploited to improve the performance of light absorbers or emitters. Our findings have direct applications for enhancing the absorption efficiency of third-generation solar cells in a rel...

Vynck, Kevin; Riboli, Francesco; Wiersma, Diederik S

2012-01-01T23:59:59.000Z

440

Stabilizing windings for tilting and shifting modes  

DOE Patents (OSTI)

This invention relates to passive conducting loops for stabilizing a plasma ring against unstable tilting and/or shifting modes. To this end, for example, plasma ring in a spheromak is stabilized by a set of four figure-8 shaped loops having one pair on one side of the plasma and one pair on the other side with each pair comprising two loops whose axes are transverse to each other.

Jardin, Stephen C. (Princeton, NJ); Christensen, Uffe R. (Princeton, NJ)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Neoclassical tearing modes in a tokamak  

SciTech Connect

Linear tearing instability is studied in the banana collisionality regime in tokamak geometry. Neoclassical effects produce significant modifications of Ohm's law and the vorticity equation so that the growth rate of tearing modes driven by ..delta..' is dramatically reduced compared to the usual resistive MHD value. Consequences of this result, regarding the presence of pressure-gradient-driven neoclassical resistive interchange instabilities and the evolution of magnetic islands in the Rutherford regime, are discussed. 10 refs.

Hahm, T.S.

1988-08-01T23:59:59.000Z

442

Method and apparatus for ultrasonic doppler velocimetry using speed of sound and reflection mode pulsed wideband doppler  

DOE Patents (OSTI)

According to the present invention, a method and apparatus rely upon tomographic measurement of the speed of sound and fluid velocity in a pipe. The invention provides a more accurate profile of velocity within flow fields where the speed of sound varies within the cross-section of the pipe. This profile is obtained by reconstruction of the velocity profile from the local speed of sound measurement simultaneously with the flow velocity. The method of the present invention is real-time tomographic ultrasonic Doppler velocimetry utilizing a to plurality of ultrasonic transmission and reflection measurements along two orthogonal sets of parallel acoustic lines-of-sight. The fluid velocity profile and the acoustic velocity profile are determined by iteration between determining a fluid velocity profile and measuring local acoustic velocity until convergence is reached.

Shekarriz, Alireza (Kennewick, WA); Sheen, David M. (Richland, WA)

2000-01-01T23:59:59.000Z

443

LONG PULSE ADVANCED TOKAMAK DISCHARGES IN THE DIII-D TOKAMAK  

SciTech Connect

One of the main goals for the DIII-D research program is to establish an advanced tokamak plasma with high bootstrap current fraction that can be sustained in-principle steady-state. Substantial progress has been made in several areas during the last year. The resistive wall mode stabilization has been done with spinning plasmas in which the plasma pressure has been extended well above the no-wall beta limit. The 3/2 neoclassical tearing mode has been stabilized by the injection of ECH into the magnetic islands, which drives current to substitute the missing bootstrap current. In these experiments either the plasma was moved or the toroidal field was changed to overlap the ECCD resonance with the location of the NTMs. Effective disruption mitigation has been obtained by massive noble gas injection into shots where disruptions were deliberately triggered. The massive gas puff causes a fast and clean current quench with essentially all the plasma energy radiated fairly uniformly to the vessel walls. The run-away electrons that are normally seen accompanying disruptions are suppressed by the large density of electrons still bound on the impurity nuclei. Major elements required to establish integrated, long-pulse, advanced tokamak operations have been achieved in DIII-D: {beta}{sub T} = 4.2%, {beta}{sub p} = 2, f{sub BS} = 65%, and {beta}{sub N}H{sub 89} = 10 for 600 ms ({approx} 4{tau}{sub E}). The next challenge is to integrate the different elements, which will be the goal for the next five years when additional control will be available. Twelve resistive wall mode coils are scheduled to be installed in DIII-D during the summer of 2003. The future plans include upgrading the tokamak pulse length capability and increasing the ECH power, to control the current profile evolution.

P.I. PETERSEN

2002-06-01T23:59:59.000Z

444

Impact of Remote Reemergence of the Subtropical Mode Water on Winter SST Variation in the Central North Pacific  

Science Conference Proceedings (OSTI)

Using long-term datasets of sea surface temperature (SST), core-layer temperature (CLT) of the North Pacific subtropical mode water (NPSTMW), and the North Pacific index, an impact of remote reemergence of NPSTMW on winter SST variation in the ...

Shusaku Sugimoto; Kimio Hanawa

2007-01-01T23:59:59.000Z

445

Thermodynamics, Optical Properties and Coordination Modes of Np(V) with Dipicolinic Acid  

E-Print Network (OSTI)

Thermodynamics, Optical Properties and Coordination Modes ofacid, complexation, thermodynamics, coordination mode 1.

Tian, Guoxin

2010-01-01T23:59:59.000Z

446

Pulse Combustor Design, A DOE Assessment  

NLE Websites -- All DOE Office Websites (Extended Search)

Pulse Combustor Design Pulse Combustor Design A DOE Assessment DOE/NETL-2003/1190 July 2003 U.S. Department of Energy National Energy Technology Laboratory P.O. Box 880, 3610 Collins Ferry Road Morgantown, WV 26507-0880 P.O. Box 10940, 626 Cochrans Mill Road Pittsburgh, PA 15236-0940 West Third Street, Suite 1400 Tulsa, OK 74103-3519 website: www.netl.doe.gov 2 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or

447

Sandia National Laboratories: Z Pulsed Power Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

Z-Machine Z-Machine About Z Z Research Z News Contact Us Facebook Twitter YouTube Flickr RSS Z-Machine Z Pulsed Power Facility Science serving the nation Created to validate nuclear weapons models, the Z machine is also in the race for viable fusion energy. Z-Machine From Earth's Core to Black Holes Contributing to discovery science by studying matter at conditions found nowhere else on Earth Center of Z About Z Sandia's Z machine is the world's most powerful and efficient laboratory radiation source. It uses high magnetic fields associated with high electrical currents to produce high temperatures, high pressures, and powerful X-rays for research in high energy density science. The Z machine creates conditions found nowhere else on Earth. Z is part of Sandia's Pulsed Power program, which began in the 1960s.

448

Pulsed Power Technology at Sandia National Laboratories  

NLE Websites -- All DOE Office Websites (Extended Search)

News and Reviews News and Reviews Pulsed Power in the News Nuclear fusion simulation shows high-gain energy output (March 2012) Rapid-fire pulse brings Sandia Z method closer to goal of high-yield fusion reactor (April 2007) Ice created in nanoseconds by Sandia's Z machine (March 2007) Z-Machine Shockwaves Melt Diamond (November 2006) Phase diagram of water revised by Sandia researchers (October 2006) Z fires objects faster than Earth moves through space (June 6, 2005) Sandia imagists view imploding wire arrays on Z (November 10, 2004) Z's $61.7 million refurbishment to advance capabilities (October 21, 2004) Z produces fusion neutrons (April 7, 2003) Former shock physics manager (Asay) elected to NAE (February 20, 2003) Z-Beamlet image shows Z evenly compresses pellet (August 30, 2001)

449

Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt laser system  

E-Print Network (OSTI)

Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced of liquid water using electron pulses produced by a table-top terawatt laser system (T3 ). The results

Umstadter, Donald

450

Long Term World Oil Supply  

Gasoline and Diesel Fuel Update (EIA)

0 0 Notes: The following pages summarize a recent EIA presentation on estimates of the world conventional oil resource base and the year when production from it will peak and then begin to decline. A version of this presentation was given by former EIA Administrator Jay Hakes to the April 18, 2000 meeting of the American Association of Petroleum Geologists in New Orleans, Louisiana. Specific information about this presentation may be obtained from John Wood (john.wood@eia.doe.gov), Gary Long (gary.long@eia.doe.gov) or David Morehouse (david.morehouse@eia.doe.gov). Long Term World Oil Supply http://www.eia.doe.gov/pub/oil_gas/petroleum/presentations/2000/long_term_supply/sld001.htm [8/10/2000 4:56:23 PM] Slide 2 of 20 http://www.eia.doe.gov/pub/oil_gas/petroleum/presentations/2000/long_term_supply/sld002.htm [8/10/2000 4:56:24 PM]

451

Carbon-14 Bomb-Pulse Dating  

Science Conference Proceedings (OSTI)

Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the concentration of carbon-14 atmosphere and created a pulse that labeled everything alive in the past 50 years as carbon moved up the food chain. The variation in carbon-14 concentration in time is well-documented and can be used to chronologically date all biological materials since the mid-1950s.

Buchholz, B A

2007-12-16T23:59:59.000Z

452

2XII-B pulse coil design  

SciTech Connect

The design of the 2XII-B pulse coil system is presented. Development of the coil geometry is given as well as the results of magnetic field calculations. A discussion of the forces developed by this high-energy coil set and the electrical stress on the magnet insulation is presented. The results of materials selection for both the coil insulation and structure are included, and also a description of the fabrication procedure. (auth)

Bulmer, R.H.; Harvey, A.R.

1973-08-20T23:59:59.000Z

453

Pulsed atmospheric fluidized bed combustor apparatus  

DOE Patents (OSTI)

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.

Mansour, Momtaz N. (Columbia, MD)

1993-10-26T23:59:59.000Z

454

Dynamics of similariton pulses in length-inhomogeneous active fibres  

SciTech Connect

The possibility of producing self-similar frequency-modulated (FM) optical wave packets in length-inhomogeneous active fibres is studied for optical pulses with the initial Gaussian, hyperbolic-secant or parabolic shape. The conditions for converting these pulses into stable parabolic-type pulses with a constant frequency-modulation rate are considered. It is shown that the use of FM pulses of parabolic shape in active and length-inhomogeneous fibres can ensure the creation of an all-fibre generator-amplifier-compressor system with peak powers up to 1 MW and higher in the generated pulses. (nonlinear optical phenomena)

Zolotovskii, Igor' O; Sementsov, Dmitrii I; Yavtushenko, M S [Ulyanovsk State University, Ulyanovsk (Russian Federation); Senatorov, A K; Sysolyatin, A A [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

2010-05-26T23:59:59.000Z

455

EPAct Transportation Regulatory Activities: Key Terms  

NLE Websites -- All DOE Office Websites (Extended Search)

Key Terms Key Terms to someone by E-mail Share EPAct Transportation Regulatory Activities: Key Terms on Facebook Tweet about EPAct Transportation Regulatory Activities: Key Terms on Twitter Bookmark EPAct Transportation Regulatory Activities: Key Terms on Google Bookmark EPAct Transportation Regulatory Activities: Key Terms on Delicious Rank EPAct Transportation Regulatory Activities: Key Terms on Digg Find More places to share EPAct Transportation Regulatory Activities: Key Terms on AddThis.com... Home About Covered Fleets Compliance Methods Alternative Fuel Petitions Resources Guidance Documents Statutes & Regulations Program Annual Reports Fact Sheets Newsletter Case Studies Workshops Tools Key Terms FAQs Key Terms The Energy Policy Act (EPAct) includes specific terminology related to

456

Strain sensors for high field pulse magnets  

Science Conference Proceedings (OSTI)

In this paper we present an investigation into several strain sensing technologies that are being considered to monitor mechanical deformation within the steel reinforcement shells used in high field pulsed magnets. Such systems generally operate at cryogenic temperatures to mitigate heating issues that are inherent in the coils of nondestructive, high field pulsed magnets. The objective of this preliminary study is to characterize the performance of various strain sensing technologies at liquid nitrogen temperatures (-196 C). Four sensor types are considered in this investigation: fiber Bragg gratings (FBG), resistive foil strain gauges (RFSG), piezoelectric polymers (PVDF), and piezoceramics (PZT). Three operational conditions are considered for each sensor: bond integrity, sensitivity as a function of temperature, and thermal cycling effects. Several experiments were conducted as part of this study, investigating adhesion with various substrate materials (stainless steel, aluminum, and carbon fiber), sensitivity to static (FBG and RFSG) and dynamic (RFSG, PVDF and PZT) load conditions, and sensor diagnostics using PZT sensors. This work has been conducted in collaboration with the National High Magnetic Field Laboratory (NHMFL), and the results of this study will be used to identify the set of sensing technologies that would be best suited for integration within high field pulsed magnets at the NHMFL facility.

Martinez, Christian [Los Alamos National Laboratory; Zheng, Yan [Los Alamos National Laboratory; Easton, Daniel [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

457

Materials processing with intense pulsed ion beams  

SciTech Connect

We review research investigating the application of intense pulsed ion beams (IPIBs) for the surface treatment and coating of materials. The short range (0.1-10 {mu}m) and high-energy density (1-50 J/cm{sup 2}) of these short-pulsed ({le} 1 {mu}s) beams (with ion currents I = 5 - 50 kA, and energies E = 100 - 1000 keV) make them ideal to flash-heat a target surface, similar to the more familiar pulsed laser processes. IPIB surface treatment induces rapid melt and solidification at up to 10{sup 10} K/s to cause amorphous layer formation and the production of non-equilibrium microstructures. At higher energy density the target surface is vaporized, and the ablated vapor is condensed as coatings onto adjacent substrates or as nanophase powders. Progress towards the development of robust, high-repetition rate IPIB accelerators is presented along with economic estimates for the cost of ownership of this technology.

Rej, D.J.; Davis, H.A.; Olson, J.C. [and others

1996-12-31T23:59:59.000Z

458

Diagnostics on the COBRA pulsed power generator  

Science Conference Proceedings (OSTI)

The COBRA pulsed power generator has a variable current pulse wave form and amplitude (95-180 ns rise time, up to 1 MA peak current). It was designed to study wire array Z pinches and X pinches, including plasma formation, pinch implosion dynamics, and pinch plasma parameters as a function of current rise time. These loads have been studied using an extensive set of diagnostics with spatial and/or temporal resolution. The set of electrical diagnostics on the COBRA generator includes Rogowski coils to monitor the total load current and the current through individual return current posts, and there is also an inductive voltage monitor. A set of extreme ultraviolet and x-ray detectors is used to study the load radiation. Wire array and X pinch plasma formation and dynamics are studied using two-frame, point projection X-pinch x-ray imaging as well as with multiframe laser probing. Flat potassium acid phtalate crystal (KAP), convex, extreme luminosity imaging conical spectrograph, and focusing spectrograph with spatial resolution with mica crystal, pinhole cameras, and a camera with a slit and a step filter set (slip step-wedge camera) can be used in each pulse to monitor the x-ray emission from the X pinch(es) and arrays in several spectral bands.

Shelkovenko, T. A.; Chalenski, D. A.; Chandler, K. M.; Douglass, J. D.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; McBride, R. D.; Pikuz, S. A. [Laboratory of Plasma Studies, Cornell University, Rhodes Hall, Ithaca, New York 14853 (United States)

2006-10-15T23:59:59.000Z

459

Ablation driven by hot electrons generated during the ignitor laser pulse in shock ignition  

SciTech Connect

An analytical model for the ablation driven by hot electrons is presented. The hot electrons are assumed to be generated during the high intensity laser spike used to produce the ignitor shock wave in the shock ignition driven inertial fusion concept, and to carry on the absorbed laser energy in its totality. Efficient energy coupling requires to keep the critical surface sufficiently close to the ablation front and this goal can be achieved for high laser intensities provided that the laser wavelength is short enough. Scaling laws for the ablation pressure and the other relevant magnitudes of the ablation cloud are found in terms of the laser and target parameters. The effect of the preformed plasma assembled by the compression pulse, previous to the ignitor, is also discussed. It is found that a minimum ratio between the compression and the ignitor pulses would be necessary for the adequate matching of the corresponding scale lengths.

Piriz, A. R.; Rodriguez Prieto, G. [E.T.S.I. Industriales, Universidad de Castilla-La Mancha and Instituto de Investigaciones Energeticas, 13071 Ciudad Real (Spain); Tahir, N. A. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Zhang, Y. [School of Physics and Optoelectronic Technology, Dalian University of Technology, 116024 Dalian (China); Liu, S. D.; Zhao, Y. T. [Institute of Modern Physics, Chinese Academy of Science, 730000 Lanzhou (China)

2012-12-15T23:59:59.000Z

460

Singular Modes and Low-Frequency Atmospheric Variability  

Science Conference Proceedings (OSTI)

Recently, it has been shown that the EOFs (empirical orthogonal functions) of the solutions of a stationary linear model to an ensemble of white noise forcing fields are the Schmidt modes (singular modes) of the model' linear operator. If the ...

Werner Metz

1994-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Empirical Normal Modes versus Empirical Orthogonal Functions for Statistical Prediction  

Science Conference Proceedings (OSTI)

The theory of empirical normal modes (ENMs) for a shallow water fluid is developed. ENMs are basis functions that both have the statistical properties of empirical orthogonal functions (EOFs) and the dynamical properties of normal modes. In fact, ...

Gilbert Brunet; Robert Vautard

1996-12-01T23:59:59.000Z

462

Mode conversion current drive experiments on Alcator C-Mod  

E-Print Network (OSTI)

In tokamak plasmas with multiple ion species, fast magnetosonic waves (FW) in the Ion Cyclotron Range of Frequency can mode convert to shorter wavelength modes at the Ion-Ion hybrid layer, leading to localized electron ...

Parisot, Alexandre, 1979-

2007-01-01T23:59:59.000Z

463

Vehicle Technologies Office: Fact #287: September 29, 2003 Modes...  

NLE Websites -- All DOE Office Websites (Extended Search)

7: September 29, 2003 Modes of Transport, May 2003 to someone by E-mail Share Vehicle Technologies Office: Fact 287: September 29, 2003 Modes of Transport, May 2003 on Facebook...

464

Hybrid Rossby-Shelf Modes in a Laboratory Ocean  

Science Conference Proceedings (OSTI)

Idealized laboratory experiments reveal the existence of forced–dissipative hybrid Rossby-shelf modes. The laboratory ocean consists of a deeper ocean (accommodating basin-scale Rossby modes) and a coastal step shelf (accommodating trapped shelf ...

Onno Bokhove; Vijaya Ambati

2009-10-01T23:59:59.000Z

465

Normal-Mode Decomposition of Small-Scale Oceanic Motions  

Science Conference Proceedings (OSTI)

Small-scale oceanic motions consist of vortical motion and internal waves. In a linear or weakly nonlinear system these two types of motions can be unambiguously separated using normal-mode decomposition in which the vortical mode carries the ...

Ren-Chieh Lien; Peter Müller

1992-12-01T23:59:59.000Z

466

Topographic Vorticity-Mode Mesoscale-? (TVM) Model. Part I: Formulation  

Science Conference Proceedings (OSTI)

The three-dimensional, flat-terrain, finite-difference URBMET vorticity, mode mesoscale-? model has been modified to include topographic effects. The resulting topographic vorticity-mode mesoscale-? (TVM) model is hydrostatic, Boussinesq, and ...

G. Schayes; P. Thunis; R. Bornstein

1996-10-01T23:59:59.000Z

467

Nonlinear tearing mode interactions and mode locking in reversed field pinches  

SciTech Connect

The nonlinear interaction of a set of tearing instabilities and plasma flow is studied in a cylindrical plasma. An analytic theory of mode locking is developed which includes the effects of the localized electromagnetic torques, plasma inertia and cross-field viscosity. The calculation is specialized for the case of mode locking on the Madison Symmetric Torus (MST) reversed field pinch. In MST plasmas, a set of m = 1 tearing instabilities become phase locked and form a toroidally localized, rotating magnetic disturbance. An evolution equation for the phase velocity of this magnetic disturbance is derived which accounts for two types of electromagnetic torques. The external torques describe the interaction of the tearing modes with static magnetic perturbations located outside the plasma region. The interior torques describe the nonlinear interaction of three tearing modes which satisfy a wave number resonance condition. For conditions typical of MST, the internal torques dominate the external torques, which suggest the nonlinear interaction of tearing instabilities play a prominent role in the momentum degradation and mode locking.

Hegna, C.C.

1996-06-01T23:59:59.000Z

468

Special purpose modes in photonic band gap fibers - Energy ...  

Solar Thermal; Startup ... Partners (27) Visual Patent Search; Success Stories; News; Events; Special purpose modes in ... Issued: April 2, 2013: ...

469

Viscoelastic modes in a strongly coupled, cold, magnetized dusty plasma  

SciTech Connect

A generalized hydrodynamical model has been used to study the low frequency modes in a strongly coupled, cold, magnetized dusty plasma. Such plasmas exhibit elastic properties due to the strong correlations among dust particles and the tensile stresses imparted by the magnetic field. It has been shown that longitudinal compressional Alfven modes and elasticity modified transverse shear mode exist in such a medium. The features of these collective modes are established and discussed.

Banerjee, Debabrata; Mylavarapu, Janaki Sita; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, I/AF Bidhannagar, Calcutta 700 064 (India)

2010-11-15T23:59:59.000Z

470

Extracting Operating Modes from Building Electrical Load Data: Preprint  

Science Conference Proceedings (OSTI)

Empirical techniques for characterizing electrical energy use now play a key role in reducing electricity consumption, particularly miscellaneous electrical loads, in buildings. Identifying device operating modes (mode extraction) creates a better understanding of both device and system behaviors. Using clustering to extract operating modes from electrical load data can provide valuable insights into device behavior and identify opportunities for energy savings. We present a fast and effective heuristic clustering method to identify and extract operating modes in electrical load data.

Frank, S.; Polese, L. G.; Rader, E.; Sheppy, M.; Smith, J.

2012-01-01T23:59:59.000Z

471

Multidimensional study of a 50-MeV, 1500-rad/pulse radiographic linac, using the stagger-tuning concept  

Science Conference Proceedings (OSTI)

Stagger tuning of accelerator cavities, or blocks of cavities, can significantly enhance the achievable charge transfer through an electron linac operating in the stored-energy mode. The output bremsstrahlung flux can be increased over a conventional approach by an order of magnitude without any significant degradation in emittance growth or energy spread. Given a suitable injector, a 1500-rad/pulse, 50-MeV radiographic linac appears to be practical at a 400-MHz operating frequency; a 150-rad/pulse, 50-MeV radiographic linac will operate at 1300 MHz. A multidimensional study was made using the PARMELA code where several parameters, including beam current, synchronous phase angle, and beam radius, were varied while observing the effects on emittance and transmission efficiency.

Owen, R.K.; Fazio, M.V.; Boyd, T.J.

1983-01-01T23:59:59.000Z

472

First test of a power-pulsed electronics system on a GRPC detector in a 3-Tesla magnetic field  

E-Print Network (OSTI)

An important technological step towards the realization of an ultra-granular hadronic calorimeter to be used in the future International Linear Collider (ILC) experiments has been made. A 33X50 cm2 GRPC detector equipped with a power-pulsed electronics board offering a 1cm2 lateral segmentation was successfully tested in a 3-Tesla magnet operating at the H2 beam line of the CERN SPS. An important reduction of power consumption with no deterioration of the detector performance is obtained when the power-pulsing mode is applied. This important result shows that ultra-granular calorimeters for ILC experiments are not only an attractive but also a realistic option.

L. Caponetto; C. Combaret; C. de la Taille; F. Dulucq; R. Kieffer; I. Laktineh; N. Lumb; L. Mirabito; N. Seguin-Moreau

2011-11-23T23:59:59.000Z

473

Comparison of H-Mode Plasmas Diverted to Solid and Liquid Lithium Surfaces  

SciTech Connect

Experiments were conducted with a Liquid Lithium Divertor (LLD) in NSTX. Among the goals was to use lithium recoating to sustain deuterium (D) retention by a static liquid lithium surface, approximating the ability of flowing liquid lithium to maintain chemical reactivity. Lithium evaporators were used to deposit lithium on the LLD surface. Improvements in plasma edge conditions were similar to those with lithiated graphite plasma-facing components (PFCs), including an increase in confinement over discharges without lithiumcoated PFCs and ELM reduction during H-modes. With the outer strike point on the LLD, the D retention in the LLD was about the same as that for solid lithium coatings on graphite, or about two times that achieved without lithium PFC coatings. There were also indications of contamination of the LLD surface, possibly due erosion and redeposition of carbon from PFCs. Flowing lithium may thus be needed for chemically active PFCs during long-pulse operation.

R. Kaita, et. al.

2012-07-20T23:59:59.000Z

474

Two-atom system as a nano-antenna for mode switching and light routing  

E-Print Network (OSTI)

We determine how a system composed of two nonidentical two-level atoms with different resonance frequencies and different damping rates could work as a nano-antenna for controlled mode switching and light routing. We calculate the angular distribution of the emitted field detected in a far-field zone of the system including the direct interatomic interactions and arbitrary linear dimensions of the system. The calculation is carried out in terms of the symmetric and antisymmetric modes of the two atom system. We find that as long as the atoms are identical, the emission cannot be switched between the symmetric and antisymmetric modes. The switching may occur when the atoms are non-identical and the emission can then be routed to different modes by changing the relative ratio of the atomic frequencies, or damping rates or by a proper tuning of the laser frequency to the atomic resonance frequencies. It is shown that in the case of atoms of different resonance frequencies but equal damping rates, the light routing is independent of the frequency of the driving laser field. It depends only on the sign of the detuning between the atomic resonance frequencies. In the case of atoms of different damping rates, the emission can be switched between different modes by changing the laser frequency from the blue to red detuned from the atomic resonance. The effect of the interatomic interactions is also considered and it is found that in the case of unequal resonance frequencies of the atoms, the interactions slightly modify the visibility of the intensity pattern. The case of unequal damping rates of the atoms is affected rather more drastically, the light routing becoming asymmetric under the dipole-dipole interaction with the enhanced intensities of the modes turned towards the atom of smaller damping rate.

Vassilis E. Lembessis; Anwar Al Rsheed; Omar M. Aldossary; Zbigniew Ficek

2013-09-16T23:59:59.000Z

475

Optimal scheduling for constant-rate multi-mode systems  

Science Conference Proceedings (OSTI)

Constant-rate multi-mode systems are hybrid systems that can switch freely among a finite set of modes, and whose dynamics is specified by a finite number of real-valued variables with mode-dependent constant rates. The schedulability problem for such ... Keywords: cyber-physical systems, green scheduling, hybrid automata, peak minimization, switched systems

Rajeev Alur; Ashutosh Trivedi; Dominik Wojtczak

2012-04-01T23:59:59.000Z

476

Adaptive fuzzy sliding mode control for flexible satellite  

Science Conference Proceedings (OSTI)

The adaptive fuzzy sliding mode control is applied to the attitude stabilization of flexible satellite. The detailed design procedure of the fuzzy sliding mode control system is presented. The adaptive fuzzy control is utilized to approach the equivalent ... Keywords: Adaptive fuzzy control, Attitude control, Flexible satellite, Sliding mode control

Ping Guan; Xiang-Jie Liu; Ji-Zhen Liu

2005-06-01T23:59:59.000Z

477

Modeling reducibility on ground terms using constraints  

E-Print Network (OSTI)

Modeling reducibility on ground terms using constraints Isabelle GNAEDIGa , H´el`ene KIRCHNERb a on ground terms using (dis)equational constraints. We show in particular that innermost (ir)reducibility can on the ground term algebra that any rewriting chain starting from any term termi- nates, provided that terms

Paris-Sud XI, Université de

478

Asymptotically almost all -terms are strongly normalizing  

E-Print Network (OSTI)

Asymptotically almost all -terms are strongly normalizing Ren´e David, Christophe Raffalli) properties of random -terms. Our main results show that asymptotically, almost all terms are strongly normalizing and that any fixed closed term almost never appears in a random term. Surprisingly, in combinatory

Paris-Sud XI, Université de

479

Asymptotically almost all -terms are strongly normalizing  

E-Print Network (OSTI)

Asymptotically almost all -terms are strongly normalizing Ren´e David, Christophe Raffalli) properties of random -terms. Our main results are that asymptotically all the terms are strongly normalizing and that any fixed closed term almost never appears in a random term. Surprisingly, in combinatory logic (the

Paris-Sud XI, Université de

480

Helical mode conversion using conical reflector  

E-Print Network (OSTI)

In a recent paper, Mansuripur et al. [Phys. Rev. A 84, 033813 (2011)] indicated and numerically verified the generation of the helical wavefront of optical beams using a conical-shape reflector. Because the optical reflection is largely free from chromatic aberrations, the conical reflector has an advantage of being able to manipulate the helical wavefront with broadband light such as white light or short light pulses. In this study, we introduce geometrical understanding of the function of the conical reflector using the spatially-dependent geometric phase, or more specifically, the spin redirection phase. We also present a theoretical analysis based on three-dimensional matrix calculus and elucidate relationships of the spin, orbital, and total angular momenta between input and output beams. These analyses are very useful when designing other optical devices that utilize spatially-dependent spin redirection phases. Moreover, we experimentally demonstrate the generation of helical beams from an ordinary Gaussian beam using a metallic conical-shape reflector.

H. Kobayashi; K. Nonaka; M. Kitano

2012-04-23T23:59:59.000Z

Note: This page contains sample records for the topic "term pulse mode" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Predictions of Alpha Heating in ITER L-mode and H-mode Plasmas  

Science Conference Proceedings (OSTI)

Predictions of alpha heating in L-mode and H-mode DT plasmas in ITER are generated using the PTRANSP code. The baseline toroidal field of 5.3 T, plasma current ramped to 15 MA and a flat electron density profile ramped to Greenwald fraction 0.85 are assumed. Various combinations of external heating by negative ion neutral beam injection, ion cyclotron resonance, and electron cyclotron resonance are assumed to start half-way up the density ramp. The time evolution of plasma temperatures and, for some cases, toroidal rotation are predicted assuming GLF23 and boundary parameters. Significant toroidal rotation and flow-shearing rates are predicted by GLF23 even in the L-mode phase with low boundary temperatures, and the alpha heating power is predicted to be significant if the power threshold for the transition to H-mode is higher than the planned total heating power. The alpha heating is predicted to be 8-76 MW in L-mode at full density. External heating mixes with higher beam injection power have higher alpha heating power. Alternatively if the toroidal rotation is predicted assuming that the ratio of the momentum to thermal ion energy conductivity is 0.5, the flow-shearing rate is predicted to have insignificant effects on the GLF23- predicted temperatures, and alpha heating is predicted to be 8-20 MW. In H-mode plasmas the alpha heating is predicted to depend sensitively on the assumed pedestal temperatures. Cases with fusion gain greater than 10 are predicted to have alpha heating greater than 80 MW.

R.V. Budny

2011-01-06T23:59:59.000Z

482

A thyratron-based pulse generator for fundamental studies of NO{sub x} removal in nonthermal plasmas  

DOE Green Energy (OSTI)

In collaboration with the Army Research Laboratory (ARL), the National Institute of Standards and Technology (NIST), and McMaster University, the authors are investigating the removal of NOx from engine exhaust streams using nonthermal plasmas (NTPs). The near-term experiments focus on measuring temperature distributions and reactive species concentrations in electric discharge NTP reactors using laser induced fluorescence (LIF) and tunable diode laser absorption spectroscopy (TDLAS), with first experiments on LIF measurements of OH in a pulsed dielectric-barrier discharge. Because the self extinguishing microdischarges in a conventional (low frequency driven) barrier discharge are both short lived (a few to a few tens of nanoseconds) and randomly distributed in the process volume, it is difficult to measure the time-varying properties of the species produced by the plasma. To synchronize the plasma ignition with the optical diagnostics, a thyratron switched, high voltage pulse generator has been constructed to drive a small dielectric-barrier plasma cell. A fast rise time thyratron tube is used in a low inductance geometry to deliver a negative high voltage pulse to the cell. The output voltage pulse has a rise time of 6.5 ns, a peak voltage of 40 kV, and a repetition rate of 20 Hz. A microdischarge streamer occurs between the pin electrode and the glass barrier during the rise time of the voltage pulse. The delay between the input signal and the microdischarge is 250 ns with a jitter of 4 ns, thus allowing repetitive initiation of a microdischarge with low temporal jitter. The energy per pulse is obtained from the voltage and current versus time, v(t) and i(t), measured at the cell. The fast rising pulse also produces a higher E/N at breakdown in the discharge than in conventional NTP cells, which may affect the removal efficiency of pollutants.

Korzekwa, R.A.; Rosocha, L.A.

1997-09-01T23:59:59.000Z

483

THE 5 hr PULSE PERIOD AND BROADBAND SPECTRUM OF THE SYMBIOTIC X-RAY BINARY 3A 1954+319  

SciTech Connect

We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries (SyXBs), i.e., systems composed of a neutron star accreting from the inhomogeneous medium around an M-giant star. The extremely long pulse period of {approx}5.3 hr is directly visible in the 2008 INTEGRAL-ISGRI outburst light curve. The pulse profile is double peaked and generally not significantly energy dependent although there is an indication of possible softening during the main pulse. During the outburst a strong spin-up of -1.8 Multiplication-Sign 10{sup -4} hr hr{sup -1} occurred. Between 2005 and 2008 a long-term spin-down trend of 2.1 Multiplication-Sign 10{sup -5} hr hr{sup -1} was observed for the first time for this source. The 3-80 keV pulse peak spectrum of 3A 1954+319 during the 2008 flare could be well described by a thermal Comptonization model. We interpret the results within the framework of a recently developed quasi-spherical accretion model for SyXBs.

Marcu, Diana M.; Pottschmidt, Katja [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Fuerst, Felix; Grinberg, Victoria; Mueller, Sebastian; Wilms, Joern [Dr. Karl Remeis-Observatory and ECAP, University of Erlangen-Nuremberg, 96049 Bamberg (Germany); Postnov, Konstantin A. [Sternberg Astronomical Institute, 119992 Moscow (Russian Federation); Corbet, Robin H. D. [CRESST and University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Markwardt, Craig B. [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 662, Greenbelt, MD 20771 (United States); Cadolle Bel, Marion [European Space Agency, European Space Astronomy Centre, 28691 Villanueva de la Canada, 28692 Madrid (Spain)

2011-11-20T23:59:59.000Z

484

Long-Term Surveillance Plan...  

NLE Websites -- All DOE Office Websites (Extended Search)

AL/62350-235 AL/62350-235 REV. 1 LONG-TERM SURVEILLANCE PLAN FOR THE ESTES GULCH DISPOSAL SITE NEAR RIFLE, COLORADO November 1997 DOE and DOE contractors can obtain copies of this report from: Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831 (615) 576-8401 This report is publicly available from: National Technical Information Service Department of Commerce 5285 Port Royal Road Springfield, VA 22161 (703) 487-4650 Long-Term Surveillance Plan for the Estes Gulch Disposal Site Near Rifle... http://lts1.lm.doe.gov/documents/rfl/ltsp.html 1 of 25 5/20/2009 1:38 PM Prepared for U.S. Department of Energy Environmental Restoration Division UMTRA Project Team Albuquerque, New Mexico Prepared by Jacobs Engineering Group Inc. Albuquerque, New Mexico

485

Short-Term Energy Outlook  

Gasoline and Diesel Fuel Update (EIA)

3 3 1 Short-Term Energy Outlook April 2003 Overview World Oil Markets. Crude oil prices fell sharply at the onset of war in Iraq, but the initial declines probably overshot levels that we consider to be generally consistent with fundamental factors in the world oil market. Thus, while near-term price averages are likely to be below our previous projections, the baseline outlook for crude oil prices (while generally lower) is not drastically different and includes an average for spot West Texas Intermediate (WTI) that is close to $30 per barrel in 2003 (Figure 1). The mix of uncertainties related to key oil production areas has changed since last month, as Venezuelan production has accelerated beyond previous estimates while Nigerian output has been reduced due to internal conflict.

486

Hydrodynamic modes in a confined granular fluid  

E-Print Network (OSTI)

Confined granular fluids, placed in a shallow box that is vibrated vertically, can achieve homogeneous stationary states thanks to energy injection mechanisms that take place throughout the system. These states can be stable even at high densities and inelasticities allowing for a detailed analysis of the hydrodynamic modes that govern the dynamics of granular fluids. Analyzing the decay of the time correlation functions it is shown that there is a crossover between a quasielastic regime in which energy evolves as a slow mode, to a inelastic regime, with energy slaved to the other conserved fields. The two regimes have well differentiated transport properties and, in the inelastic regime, the dynamics can be described by a reduced hydrodynamics with modified longitudinal viscosity and sound speed. The crossover between the two regimes takes place at a wavevector that is proportional to the inelasticity. A two dimensional granular model, with collisions that mimic the energy transfers that take place in a confined system is studied by means of microscopic simulations. The results show excellent agreement with the theoretical framework and allows the validation of hydrodynamic-like models.

Ricardo Brito; Dino Risso; Rodrigo Soto

2013-01-17T23:59:59.000Z