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1

Ion beam energy spectrum calculation via dosimetry data deconvolution.  

SciTech Connect

The energy spectrum of a H{sup +} beam generated within the HERMES III accelerator is calculated from dosimetry data to refine future experiments. Multiple layers of radiochromic film are exposed to the beam. A graphic user interface was written in MATLAB to align the film images and calculate the beam's dose depth profile. Singular value regularization is used to stabilize the unfolding and provide the H{sup +} beam's energy spectrum. The beam was found to have major contributions from 1 MeV and 8.5 MeV protons. The HERMES III accelerator is typically used as a pulsed photon source to experimentally obtain photon impulse response of systems due to high energy photons. A series of experiments were performed to explore the use of Hermes III to generate an intense pulsed proton beam. Knowing the beam energy spectrum allows for greater precision in experiment predictions and beam model verification.

Harper-Slaboszewicz, Victor Jozef; Sharp, Andrew Clinton (A& M University, College Station, TX)

2010-10-01T23:59:59.000Z

2

Coating thermal noise for arbitrary shaped beams  

E-Print Network (OSTI)

Advanced LIGO's sensitivity will be limited by coating noise. Though this noise depends on beam shape, and though nongaussian beams are being seriously considered for advanced LIGO, no published analysis exists to compare the quantitative thermal noise improvement alternate beams offer. In this paper, we derive and discuss a simple integral which completely characterizes the dependence of coating thermal noise on shape. The derivation used applies equally well, with minor modifications, to all other forms of thermal noise in the low-frequency limit.

Richard O'Shaughnessy

2006-10-13T23:59:59.000Z

3

Thermal stresses in laminated beams  

E-Print Network (OSTI)

24. Normal Stress Distribution for a Cantilever Laminated Beam, T-Z sinzx/L --------------- 58 m. i 25. Axial Stress Distribution for a Cantilever Laminated Bearq, T-T (2z/8+1) 2 mi 27. Normal Stress Distribution for ("/L) ? ---- 6 O 2 a... 80 100 Stress o (psi) xz. i Fig. 14. Normal Stress Distribution for a Simply-Supported Laminated Beam, T=z (2z/H+1) (x/L) 2 2 m. 1 6 4 x Classical Solution o Present Solution Load: Sinusoidal I F 0 100 200 300 400 Stress c (ps&) XX. 1 500...

Marcano, Victor Manuel

2012-06-07T23:59:59.000Z

4

Thermal equilibrium theory of periodically focused charged-particle beams  

E-Print Network (OSTI)

A thermal equilibrium theory of periodically focused charged-particle beams is presented in the framework of both warm-fluid and kinetic descriptions. In particular, the thermal beam equilibria are discussed for paraxial ...

Samokhvalova, Ksenia R

2008-01-01T23:59:59.000Z

5

Energy Spectrum of Neutrons from Thermal Fission of U235  

Science Journals Connector (OSTI)

A proton recoil counter has been used to determine the neutron spectrum, in the energy range 3.3-17 Mev, of a beam produced by irradiating 95 percent U235 (metal) in the central experimental hole of the Los Alamos Homogeneous Reactor. Most of the fissions were induced by slow neutrons. The data are combined with those obtained by D. Hill and by T. W. Bonner, R. A. Ferrell and M. C. Rinehart; the composite spectrum so obtained extends from 0.075 to 17 Mev. Fits with two general formulas are discussed.

B. E. Watt

1952-09-15T23:59:59.000Z

6

Full Spectrum Diffused and Beamed Solar Energy Application Using Optical Fibre  

E-Print Network (OSTI)

Existing solar energy application systems use small fraction of full spectrum of solar energy. So attempts are made to show how full spectrum solar energy can be used for diffused and beamed form of incident solar energy. Luminescent Solar Concentrator (LSC) principle with optical fibre in diffused sun light and dielectric mirror separation technique with optical fibre in beamed form are discussed. Comparison of both the cases are done. Keywords: full spectrum, solar photonics, diffused solar energy, beamed solar energy, LSC, dielectric mirror, optical fibre, Photo-Voltaic

Dutta Majumdar, M R

2007-01-01T23:59:59.000Z

7

Applications of heat pipes for high thermal load beam lines  

SciTech Connect

The high flux beam produced by insertion devices often requires special heat removal techniques. For the optical elements used in such high thermal load beam lines, the required precision demands a highly accurate design. Heat pipe cooling of critical elements of the X-1 beam line at the National Synchrotron Light Source is described. This method reduces vibrations caused by water cooling systems and simplifies the design. In some of these designs, deposited heat must be transferred through unbonded contact interfaces. A pinhole assembly and a beam position monitor designed for the X-1 beam line both transfer heat through such interfaces in an ultrahigh vacuum environment. The fundamental design objective is that of removing the heat with minimal interface thermal resistance. We present our test method and results for measuring the thermal resistance across metallic interfaces as a function of contact pressure. The design of some devices which utilize both heat pipes and thermal contact interfaces will also be described. 12 refs., 8 figs.

Shu, D.; Mortazavi, P.; Rarback, H.; Howells, M.R.

1985-01-01T23:59:59.000Z

8

Effect of space charge on the energy spectrum of a multispecies ion beam  

SciTech Connect

The parameters of a multispecies metal ion beam extracted with the help of a set of grids from a plasma jet of a pulsed vacuum arc are studied experimentally. It is shown that the beam contains ions with energies that are both significantly lower and higher than the expected energy E{sub Z} = Z-bar eU{sub acc}, where Z-bar is the average ion charge number and U{sub acc} is the extracting voltage. As a result, the mean ion energy is lower than E{sub Z} and the ion energy spectrum is substantially wider than that in the plasma jet. It is found that this effect weakens with decreasing discharge current amplitude and that the shape of the spectrum depends on the accelerating voltage. Probe measurements show that, at accelerating voltages higher than 1 kV, a positive space charge forms in the drift gap, due to which the electric potential in the drift gap increases to a few hundred electronvolts. Analysis of experimental data indicates that the observed features of the ion spectrum can be attributed to the effect of the unsteady electric field of the space charge of the ion beam transported through the drift gap.

Paperny, V. L.; Chernykh, A. A. [Irkutsk State University (Russian Federation); Shklyaev, V. A. [Russian Academy of Sciences, Institute of High-Current Electronics, Siberian Branch (Russian Federation)

2009-02-15T23:59:59.000Z

9

Spectrum bandwidth narrowing of Thomson scattering X-rays with energy chirped electron beams from laser wakefield acceleration  

SciTech Connect

We study incoherent Thomson scattering between an ultrashort laser pulse and an electron beam accelerated from a laser wakefield. The energy chirp effects of the accelerated electron beam on the final radiation spectrum bandwidth are investigated. It is found that the scattered X-ray radiation has the minimum spectrum width and highest intensity as electrons are accelerated up to around the dephasing point. Furthermore, it is proposed that the electron acceleration process inside the wakefield can be studied by use of 90° Thomson scattering. The dephasing position and beam energy chirp can be deduced from the intensity and bandwidth of the scattered radiation.

Xu, Tong; Chen, Min, E-mail: minchen@sjtu.edu.cn; Li, Fei-Yu; Yu, Lu-Le [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)] [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sheng, Zheng-Ming, E-mail: zmsheng@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, Jie [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

2014-01-06T23:59:59.000Z

10

Sheet beam model for intense space-charge: with application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam  

SciTech Connect

A one-dimensional Vlasov-Poisson model for sheet beams is reviewed and extended to provide a simple framework for analysis of space-charge effects. Centroid and rms envelope equations including image charge effects are derived and reasonable parameter equivalences with commonly employed 2D transverse models of unbunched beams are established. This sheet beam model is then applied to analyze several problems of fundamental interest. A sheet beam thermal equilibrium distribution in a continuous focusing channel is constructed and shown to have analogous properties to two- d three-dimensional thermal equilibrium models in terms of the equilibrium structure and Deybe screening properties. The simpler formulation for sheet beams is exploited to explicitly calculate the distribution of particle oscillation frequencies within a thermal equilibrium beam. It is shown that as space-charge intensity increases, the frequency distribution becomes broad, suggesting that beams with strong space-charge can have improved stability.

Lund, Steven M.; Friedman, Alex; Bazouin, Guillaume

2011-01-10T23:59:59.000Z

11

Constraining the intra-cluster pressure profile from the thermal SZ power spectrum  

E-Print Network (OSTI)

The angular power spectrum of the thermal Sunyaev-Zel'dovich (tSZ) effect is highly sensitive to cosmological parameters such as sigma8 and OmegaM, but its use as a precision cosmological probe is hindered by the astrophysical uncertainties in modeling the gas pressure profile in galaxy groups and clusters. In this paper we assume that the relevant cosmological parameters are accurately known, and explore the ability of current and future tSZ power spectrum measurements to constrain the intra-cluster gas pressure or the evolution of the gas mass fraction, f_gas. We use the CMB bandpower measurements from the South Pole Telescope and a Bayesian MCMC method to quantify deviations from the standard, universal gas pressure model. We explore analytical model extensions that bring the predictions for the tSZ power in agreement with experimental data. We find that a steeper pressure profile in the cluster outskirts or an evolving f_gas have mild to severe conflicts with experimental data or simulations. Varying more...

Ramos-Ceja, M E; Pacaud, F; Bertoldi, F

2014-01-01T23:59:59.000Z

12

Contamination of Cluster Radio Sources in the Measurement of the Thermal Sunyaev-Zel'dovich Angular Power Spectrum  

E-Print Network (OSTI)

We present a quantitative estimate of the confusion of cluster radio halos and galaxies in the measurement of the angular power spectrum of the thermal Sunyaev-Zel'dovich (SZ) effect. To achieve the goal, we use a purely analytic approach to both radio sources and dark matter of clusters by incorporating empirical models and observational facts together with some theoretical considerations. It is shown that the correction of cluster radio halos and galaxies to the measurement of the thermal SZ angular power spectrum is no more than 20% at $l>2000$ for observing frequencies $\

Wei Zhou; Xiang-Ping Wu

2003-09-26T23:59:59.000Z

13

Assessment of Failure Mechanisms for Thermal Barrier Coatings by Photoluminescence, Electrochemical Impedance and Focused Ion Beam  

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

H. Sohn, B. Jayaraj and V.H. Desai H. Sohn, B. Jayaraj and V.H. Desai SCIES Project 02- 01- SR103 DOE COOPERATIVE AGREEMENT DE-FC26-02NT41431 Tom J. George, Program Manager, DOE/NETL Richard Wenglarz, Manager of Research, SCIES Project Awarded (May 1, 2002, 36 Month Duration) $249,766 Total Contract Value ($208,228 DOE UTSR) Assessment of Failure Mechanisms for Thermal Barrier Coatings by Photoluminescence, Electrochemical Impedance and Focused Ion Beam YHS@UCF,10/17/05 Gas Turbine Needs: Reliable and Durable Thermal Barrier Coatings (TBCs) TBCs Provide Thermal Protection of Hot Components in Advanced Gas Turbine Engines Increase in Performance, Efficiency, Reliability and Maintainability. Reduction Life Cycle Costs. Reliable and Durable TBCs Needed as An Integral Part of Component Design.

14

Thermal Acoustic Sensor for High Pulse Energy X-ray FEL Beams  

SciTech Connect

The pulse energy density of X-ray FELs will saturate or destroy conventional X-ray diagnostics, and the use of large beam attenuation will result in a beam that is dominated by harmonics. We present preliminary results at the LCLS from a pulse energy detector based on the thermal acoustic effect. In this type of detector an X-ray resistant material (boron carbide in this system) intercepts the beam. The pulse heating of the target material produces an acoustic pulse that can be detected with high frequency microphones to produce a signal that is linear in the absorbed energy. The thermal acoustic detector is designed to provide first- and second-order calorimetric measurement of X-ray FEL pulse energy. The first-order calorimetry is a direct temperature measurement of a target designed to absorb all or most of the FEL pulse power with minimal heat leak. The second-order measurement detects the vibration caused by the rapid thermoelastic expansion of the target material each time it absorbs a photon pulse. Both the temperature change and the amplitude of the acoustic signal are directly related to the photon pulse energy.

Smith, T.J.; Frisch, J.C.; Kraft, E.M.; Loos, J.; /SLAC; Bentsen, G.S.; /Rochester U.

2011-12-13T23:59:59.000Z

15

Stability properties of free-electron laser in Raman regime with thermal electron beam  

SciTech Connect

In the context of kinetic theory an expression for the growth rate of a free-electron laser, under the weak resonance instability condition, for full dispersion relation has been obtained. The space-charge potential is included in the analysis and the expression for growth rate reduces to that of the Compton regime under the low density condition. With the assumption of a spread in the longitudinal momentum in the form of a Gaussian distribution function, the effect of the thermal electron beam on the growth rate is studied. The results are compared to another linear theory, a computer simulation, and an experiment.

Chakhmachi, A. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of); Department of Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

2009-04-15T23:59:59.000Z

16

Measurements of gamma dose and thermal neutron fluence in phantoms exposed to a BNCT epithermal beam with TLD-700  

Science Journals Connector (OSTI)

......epithermal neutron beam for boron neutron capture therapy...separation. INTRODUCTION Boron neutron capture therapy...accumulation of the isotope 10B in tumour tissue...necessary and that for the determination of the ratio R n, a...Carrara M., Borroni M. Determination of gamma dose and thermal......

G. Gambarini; D. Magni; V. Regazzoni; M. Borroni; M. Carrara; E. Pignoli; J. Burian; M. Marek; V. Klupak; L. Viererbl

2014-10-01T23:59:59.000Z

17

The thermal-neutron-induced alpha-accompanied fission of235U investigation of the low energy part of the alpha spectrum  

Science Journals Connector (OSTI)

The energy spectrum of the ?-particles emitted in the thermal-neutron induced fission of235U was measured from 11.5 MeV down to 2 MeV using the parabola mass spectrometer Lohengrin at the I.L.L. high flux reactor...

F. Caïtucoli; B. Leroux; G. Barreau; N. Cârjan…

1980-01-01T23:59:59.000Z

18

A toolkit for epithermal neutron beam characterisation in BNCT  

Science Journals Connector (OSTI)

......neutron fluence spectra calculated...function of neutron energy, data from...USA (new fission converter...free-beam spectrum and dose...beam and neutron and gamma...water phantom thermal and epithermal...The MnRR is induced basically......

Iiro Auterinen; Tom Serén; Jouni Uusi-Simola; Antti Kosunen; Sauli Savolainen

2004-08-01T23:59:59.000Z

19

10 MW/sub e/ Solar Thermal Central Receiver Pilot Plant heliostat and beam characterization system evaluation, November 1981-December 1986  

SciTech Connect

Test and evaluation results for the heliostats and beam characterization system at the 10 MW/sub e/ Solar Thermal Central Receiver Pilot Plant are described in this report. Southern California Edison operated and maintained the plant during the five years covered by this evaluation. Therefore, the results represent what can be expected from a large number of heliostats that are operated over a long period of time in a power plant environment. The heliostats and beam characterization system were evaluated for their ability to meet performance and survival requirements. Heliostat evaluation results are reported for mirror soiling rates, mirror corrosion, wind loads, availability, maintenance requirements, tracking accuracy, beam quality, component temperatures, and operating power requirements. The heliostat beam characterization system accuracy is given for the measurement of beam quality, heliostat tracking accuracy, and power in the reflected beam. The heliostat technical specifications and design description are provided, and a detailed design description of the beam characterization system is included. 41 refs.

Mavis, C.L.

1988-05-01T23:59:59.000Z

20

Energy spectrum and angular distribution of muons from the decay of heavy leptons produced in colliding electron-positron beams  

Science Journals Connector (OSTI)

On the basis of an arbitrary (V, A) structure of the neutral weak ¯ee and LL currents (L=??, M0) a study is made of the processes of production in colliding electron-positron beams of pairs of heavy leptons with ...

T. M. Aliev; N. A. Guliev; I. G. Dzhafarov; F. T. Khalil-Zade

1981-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Beam characterization at the Neutron Radiography Reactor  

SciTech Connect

The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

2013-12-01T23:59:59.000Z

22

Development of a compact thermal lithium atom beam source for measurements of electron velocity distribution function anisotropy in electron cyclotron resonance plasmas  

SciTech Connect

The anisotropy of the electron velocity distribution function (EVDF) in plasmas can be deduced from the polarization of emissions induced by anisotropic electron-impact excitation. In this paper, we develop a compact thermal lithium atom beam source for spatially resolved measurements of the EVDF anisotropy in electron cyclotron resonance (ECR) plasmas. The beam system is designed such that the ejected beam has a slab shape, and the beam direction is variable. The divergence and flux of the beam are evaluated by experiments and calculations. The developed beam system is installed in an ECR plasma device with a cusp magnetic field, and the LiI 2s–2p emission (670.8 nm) is observed in low-pressure helium plasma. The two-dimensional distributions of the degree and direction of the polarization in the LiI emission are measured by a polarization imaging system. The evaluated polarization distribution suggests the spatial variation of the EVDF anisotropy.

Nishioka, T.; Shikama, T.; Nagamizo, S.; Fujii, K.; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan)] [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan); Zushi, H. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan)] [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan); Uchida, M.; Tanaka, H.; Maekawa, T. [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan)] [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan); Iwamae, A. [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)] [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)

2013-07-15T23:59:59.000Z

23

Characterization of a thermal neutron beam monitor based on gas electron multiplier technology  

Science Journals Connector (OSTI)

......from gadolinium isotopes (which adsorb neutrons...about 3980b and boron and thermal neutrons...Experimental details Boron carbide (B C...view allows the determination of the coating thickness...Simulation of different isotopes is obtained with...High-voltage scan and determination of working point......

Gabriele Croci; Carlo Cazzaniga; Gerardo Claps; Marco Tardocchi; Marica Rebai; Fabrizio Murtas; Espedito Vassallo; Roberto Caniello; Enrico Perelli Cippo; Giovanni Grosso; Valentino Rigato; Giuseppe Gorini

2014-08-01T23:59:59.000Z

24

Increasing the upper-limit intensity and temperature range for thermal self-focusing of a laser beam by using plasma density ramp-up  

SciTech Connect

This work is devoted to improving relativistic and ponderomotive thermal self-focusing of the intense laser beam in an underdense plasma. It is shown that the ponderomotive nonlinearity induces a saturation mechanism for thermal self-focusing. Therefore, in addition to the well-known lower-limit critical intensity, there is an upper-limit intensity for thermal self-focusing above which the laser beam starts to experience ponderomotive defocusing. It is indicated that the upper-limit intensity value is dependent on plasma and laser parameters such as the plasma electron temperature, plasma density, and laser spot size. Furthermore, the effect of the upward plasma density ramp profile on the thermal self-focusing is studied. Results show that by using the plasma density ramp-up, the upper-limit intensity increases and the self-focusing temperature range expands.

Bokaei, B.; Niknam, A. R., E-mail: a-niknam@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)

2014-03-15T23:59:59.000Z

25

LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS  

E-Print Network (OSTI)

LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS Miguel A. Furman, Center for Beam Physics, LBNL, Berkeley, CA 94720 Abstract We present beam-beam simulation results from a strong- strong gaussian code for separated beams for the LHC and RHIC. The frequency spectrum produced

Furman, Miguel

26

Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning, The Spectrum of Clean Energy Innovation (Fact Sheet)  

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

Innovative Evaporative and Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning Researchers at the National Renewable Energy Laboratory (NREL) invented a breakthrough technology that improves air conditioning in a novel way-with heat. NREL combined desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90% less electricity and up to 80% less total energy than traditional air conditioning (AC). This solution, called the desiccant enhanced evaporative air conditioner (DEVap), also controls humidity more effectively to improve the comfort of people in buildings. Desiccants are an example of a thermally activated technology (TAT) that relies on heat instead

27

Self aligning electron beam gun having enhanced thermal and mechanical stability  

DOE Patents (OSTI)

A compact, high power electron gun having enhanced thermal and mechanical stability which incorporates a mechanically coupled, self aligning structure for the anode and cathode. The enhanced stability, and reduced need for realignment of the cathode to the anode and downstream optics during operation are achieved by use of a common support structure for the cathode and anode which requires no adjustment screws or spacers. The electron gun of the present invention also incorporates a modular design for the cathode, in which the electron emitter, its support structure, and the hardware required to attach the emitter assembly to the rest of the gun are a single element. This modular design makes replacement of the emitter simpler and requires no realignment after a new emitter has been installed. Compactness and a reduction in the possibility of high voltage breakdown are achieved by shielding the "triple point" where the electrode, insulator, and vacuum meet. The use of electric discharge machining (EDM) for fabricating the emitter allows for the accurate machining of the emitter into intricate shapes without encountering the normal stresses developed by standard emitter fabrication techniques.

Scarpetti, Jr., Raymond D. (Livermore, CA); Parkison, Clarence D. (Livermore, CA); Switzer, Vernon A. (Livermore, CA); Lee, Young J. (Sunnyvale, CA); Sawyer, William C. (Manteca, CA)

1995-01-01T23:59:59.000Z

28

Self aligning electron beam gun having enhanced thermal and mechanical stability  

DOE Patents (OSTI)

A compact, high power electron gun is disclosed having enhanced thermal and mechanical stability which incorporates a mechanically coupled, self aligning structure for the anode and cathode. The enhanced stability, and reduced need for realignment of the cathode to the anode and downstream optics during operation are achieved by use of a common support structure for the cathode and anode which requires no adjustment screws or spacers. The electron gun of the present invention also incorporates a modular design for the cathode, in which the electron emitter, its support structure, and the hardware required to attach the emitter assembly to the rest of the gun are a single element. This modular design makes replacement of the emitter simpler and requires no realignment after a new emitter has been installed. Compactness and a reduction in the possibility of high voltage breakdown are achieved by shielding the ``triple point`` where the electrode, insulator, and vacuum meet. The use of electric discharge machining (EDM) for fabricating the emitter allows for the accurate machining of the emitter into intricate shapes without encountering the normal stresses developed by standard emitter fabrication techniques. 12 Figs.

Scarpetti, R.D. Jr.; Parkison, C.D.; Switzer, V.A.; Lee, Y.J.; Sawyer, W.C.

1995-05-16T23:59:59.000Z

29

Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U  

SciTech Connect

We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

Selby, H.D., E-mail: hds@lanl.go [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-12-15T23:59:59.000Z

30

Optical properties across the solar spectrum and indoor thermal performance of cool white coatings for building energy efficiency  

Science Journals Connector (OSTI)

Abstract Two single-layer, waterborne cool white coatings for building envelopes were recently developed for use in improving building energy efficiency. After the coatings were manufactured, their optical properties over the solar spectrum and their indoor temperature reduction effect were systematically investigated using appropriate tools, and the advantages/disadvantages of single layer cool white coatings over multilayer ones were discussed in detail. The preparation process enables these two coatings to integrate multiple cooling principles and thereby exhibit high solar heat reflectance and good indoor temperature reduction. The predicted industrial limit of solar heat reflectance for practical reflective cool white coatings is 0.91. Use of cool white coatings significantly reduces radiant heat flux. The temperature reduction effects evaluated by a self-developed device cannot describe adequately the indoor cooling performance of cool coatings.

Zhongnan Song; Weidong Zhang; Yunxing Shi; Jianrong Song; Jian Qu; Jie Qin; Tao Zhang; Yanwen Li; Hongqiang Zhang; Rongpu Zhang

2013-01-01T23:59:59.000Z

31

Response to “Comment on ‘Stationary self-focusing of Gaussian laser beam in relativistic thermal quantum plasma’” [Phys. Plasmas 21, 064701 (2014)  

SciTech Connect

Habibi and Ghamari have presented a Comment on our paper [Phys. Plasmas 20, 072703 (2013)] by examining quantum dielectric response in thermal quantum plasma. They have modeled the relativistic self-focusing of Gaussian laser beam in cold and warm quantum plasmas and reported that self-focusing length does not change in both situations. In this response, we have reached the following important conclusions about the comment itself.

Patil, S. D., E-mail: sdpatil-phy@rediffmail.com [Department of Physics, Devchand College, Arjunnagar, Kolhapur 591 269 (India); Takale, M. V. [Department of Physics, Doodhsakhar Mahavidyalaya, Bidri, Kolhapur 416 208 (India)

2014-06-15T23:59:59.000Z

32

Prompt fission neutron multiplicity and spectrum calculations for thermal and fast neutron induced reactions on 233,231Pa nuclei  

Science Journals Connector (OSTI)

The prompt fission neutron multiplicity and spectra of 233Pa(n, f) and 231Pa(n, f) were calculated for incident neutron energies up to 50 MeV and 30 MeV, respectively using refined neutron evaporation models. Those models have been already successfully applied to calculate the prompt neutron multiplicities and spectra for many actinides. The unique experimental data concerning the fission fragment mass distribution and total kinetic energy for the 234,233,232Pa fissioning nuclei were exploited in the frame of the Point-by-Point treatment. The total average prompt neutron multiplicity, the fission fragment pair multiplicity and the multiplicity dependence on fragment mass (sawtooth) for the reactions 233,232,231Pa(nth, f) and the average values of the model parameters for 234-232Pa fissioning nuclei were calculated. For the other Pa fissioning nuclei involved in the studied reactions relevant parameters were established following systematic trends. Due to a total lack of experimental prompt fission neutron multiplicity and spectrum data for Pa isotopes, the present results were compared with systematic trends following from neighboring actinides. The calculated prompt fission neutron multiplicity as well as the prompt ?-ray energy of the 233,231Pa(n, f) reactions are obtained in very good agreement with all systematic trends.

Anabella Tudora; G. Vladuca; F.-J. Hambsch; D. Filipescu; S. Oberstedt

2008-01-01T23:59:59.000Z

33

An Analysis of the Broadband (22-3900 MHz) Radio Spectrum of HB3 (G132.7+1.3): The Detection of Thermal Radio Emission from an Evolved Supernova Remnant?  

E-Print Network (OSTI)

We present an analysis of the broadband radio spectrum (from 22 to 3900 MHz) of the Galactic supernova remnant (SNR) HB3 (G132.7+1.3). Published observations have revealed that a curvature is present in the radio spectrum of this SNR, indicating that a single synchrotron component appears is insufficient to adequately fit the spectrum. We present here a fit to this spectrum using a combination of a synchrotron component and a thermal bremsstrahlung component. We discuss properties of this latter component and estimate the ambient density implied by the presence of this component to be n \\~ 10 cm^-3. We have also analyzed extracted X-ray spectra from archived {\\it ASCA} GIS observations of different regions of HB3 to obtain independent estimates of the density of the surrounding interstellar medium (ISM). From this analysis, we have derived electron densities of 0.1-0.4 f^-1/2 cm^-3 for the ISM for the three different regions of the SNR, where f is the volume filling factor. By comparing these density estimates with the estimate derived from the thermal bremsstrahlung component, we argue that the radio thermal bremsstrahlung emission is emitted from a thin shell enclosing HB3. The presence of this thermal bremsstrahlung component in the radio spectrum of HB3 suggests that this SNR is in fact interacting with an adjacent molecular cloud associated with the HII region W3. By extension, we argue that the presence of thermal emission at radio wavelengths may be a useful tool for identifying interactions between SNRs and molecular clouds, and for estimating the ambient density near SNRs using radio continuum data.

D. Urosevic; T. Pannuti; D. Leahy

2006-12-22T23:59:59.000Z

34

A comparative study of the electrical properties of Pd/ZnO Schottky contacts fabricated using electron beam deposition and resistive/thermal evaporation techniques  

SciTech Connect

A systematic investigation to check the quality of Pd Schottky contacts deposited on ZnO has been performed on electron beam (e-beam) deposited and resistively/thermally evaporated samples using current-voltage, IV, and conventional deep level transient spectroscopy (DLTS) measurements. Room temperature IV measurements reveal the dominance of pure thermionic emission on the resistively evaporated contacts, while the e-beam deposited contacts show the dominance of generation recombination at low voltages, <0.30 V, and the dominance of pure thermionic emission at high voltages, greater than 0.30 V. The resistively evaporated contacts have very low reverse currents of the order of 10{sup -10} A at a reverse voltage of 1.0 V whereas the e-beam deposited contacts have reverse currents of the order of 10{sup -6} A at 1.0 V. Average ideality factors have been determined as (1.43 {+-} 0.01) and (1.66 {+-} 0.02) for the resistively evaporated contacts and e-beam deposited contacts, respectively. The IV barrier heights have been calculated as (0.721 {+-} 0.002) eV and (0.624 {+-} 0.005) eV for the resistively evaporated and e-beam deposited contacts, respectively. Conventional DLTS measurements reveal the presence of three prominent defects in both the resistive and e-beam contacts. Two extra peaks with energy levels of 0.60 and 0.81 eV below the conduction band minimum have been observed in the e-beam deposited contacts. These have been explained as contributing to the generation recombination current that dominates at low voltages and high leakage currents. Based on the reverse current at 1.0 V, the degree of rectification, the dominant current transport mechanism and the observed defects, we conclude that the resistive evaporation technique yields better quality Schottky contacts for use in solar cells and ultraviolet detectors compared to the e-beam deposition technique. The 0.60 eV has been identified as possibly related to the unoccupied level for the doubly charged oxygen vacancy, V{sub o}{sup 2+}.

Mtangi, W.; Auret, F. D.; Janse van Rensburg, P. J.; Coelho, S. M. M.; Legodi, M. J.; Nel, J. M.; Meyer, W. E.; Chawanda, A. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield, 0028 (South Africa)

2011-11-01T23:59:59.000Z

35

Reduction of Ion Thermal Diffusivity Associated with the Transition of the Radial Electric Field in Neutral-Beam-Heated Plasmas in the Large Helical Device  

Science Journals Connector (OSTI)

Recent large helical device experiments revealed that the transition from ion root to electron root occurred for the first time in neutral-beam-heated discharges, where no nonthermal electrons exist. The measured values of the radial electric field were found to be in qualitative agreement with those estimated by neoclassical theory. A clear reduction of ion thermal diffusivity was observed after the mode transition from ion root to electron root as predicted by neoclassical theory when the neoclassical ion loss is more dominant than the anomalous ion loss.

K. Ida et al.

2001-06-04T23:59:59.000Z

36

Measurements of gamma dose and thermal neutron fluence in phantoms exposed to a BNCT epithermal beam with TLD-700  

Science Journals Connector (OSTI)

......parameters utilised for the analysis of TLD-700 chips...after exposure (a) at reactor and (b) at the 60Co...beam of the LVR-15 reactor, dedicated to BNCT...Pirola L. Study of reliability of TLFs for the photon dose mapping in reactor neutron fields for BNCT......

G. Gambarini; D. Magni; V. Regazzoni; M. Borroni; M. Carrara; E. Pignoli; J. Burian; M. Marek; V. Klupak; L. Viererbl

2014-10-01T23:59:59.000Z

37

The energy spectrum of delayed neutrons from thermal neutron induced fission of sup 2 sup 3 sup 5 U and its analytical approximation  

E-Print Network (OSTI)

The energy spectrum of the delayed neutrons is the poorest known of all input data required in the calculation of the effective delayed neutron fractions. In addition to delayed neutron spectra based on the aggregate spectrum measurements there are two different approaches for deriving the delayed neutron energy spectra. Both of them are based on the data related to the delayed neutron spectra from individual precursors of delayed neutrons. In present work these two different data sets were compared with the help of an approximation by gamma-function. The choice of this approximation function instead of the Maxwellian or evaporation type of distribution is substantiated.

Doroshenko, A Y; Tarasko, M Z

2001-01-01T23:59:59.000Z

38

Beam History  

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

Beam Status Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and...

39

Beam-Gas  

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

Gas Gas and Thermal Photon Scattering in the NLC Main Linac as a Source of Beam Halo P. Tenenbaum LCC-Note-0051 12-JAN-2001 Abstract Scattering of primary beam electrons off of residual gas molecules or blackbody radiation photons in the NLC main linac has been identified as a potential source of beam haloes which must be collimated in the beam delivery system. We consider the contributions from four scat- tering mechanisms: inelastic thermal-photon scattering, elastic beam-gas (Coulomb) scattering inelastic beam-gas (Bremsstrahlung) scattering, and atomic-electron scattering. In each case we develop the formalism necessary to estimate the backgrounds generated in the main linac, and determine the expected number of off-energy or large-amplitude particles from each process, assuming a main linac injection energy of 8 GeV and extraction energy of 500 GeV. 1 Introduction The

40

A LINGERING NON-THERMAL COMPONENT IN THE GAMMA-RAY BURST PROMPT EMISSION: PREDICTING GeV EMISSION FROM THE MeV SPECTRUM  

SciTech Connect

The high-energy GeV emission of gamma-ray bursts (GRBs) detected by Fermi/LAT has a significantly different morphology compared to the lower energy MeV emission detected by Fermi/GBM. Though the late-time GeV emission is believed to be synchrotron radiation produced via an external shock, this emission as early as the prompt phase is puzzling. A meaningful connection between these two emissions can be drawn only by an accurate description of the prompt MeV spectrum. We perform a time-resolved spectroscopy of the Gamma-ray Burst Monitor (GBM) data of long GRBs with significant GeV emission, using a model consisting of two blackbodies and a power law. We examine in detail the evolution of the spectral components and find that GRBs with high GeV emission (GRB 090902B and GRB 090926A) have a delayed onset of the power-law component in the GBM spectrum, which lingers at the later part of the prompt emission. This behavior mimics the flux evolution in the Large Area Telescope (LAT). In contrast, bright GBM GRBs with an order of magnitude lower GeV emission (GRB 100724B and GRB 091003) show a coupled variability of the total and the power-law flux. Further, by analyzing the data for a set of 17 GRBs, we find a strong correlation between the power-law fluence in the MeV and the LAT fluence (Pearson correlation: r = 0.88 and Spearman correlation: ? = 0.81). We demonstrate that this correlation is not influenced by the correlation between the total and the power-law fluences at a confidence level of 2.3?. We speculate the possible radiation mechanisms responsible for the correlation.

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)

2013-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Beam History  

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

Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and day, then...

42

Study on thermal properties and crystallization behavior of electron beam irradiated ethylene vinyl acetate (EVA)/waste tyre dust (WTD) blends in the presence of polyethylene graft maleic anhydride (PEgMAH)  

SciTech Connect

The aim of this article is to show the effects of the electron beam irradiation dose and presence of a compatibiliser on the thermal properties and crystallinity of EVA/WTD blends. The purpose of applying electron beam radiation with doses range 50 to 200 kGy and adding a compatibiliser was to enhance the compatibility of the studied blends and at the same time to investigate the possibility of using this technique in the process of recycling polymeric materials. As the compatibilisers, the polyethylene grafted maleic anhydride (PEgMAH) was utilized, they were added at the amounts of 1-5 phr respectively. The enhancement of thermal properties was accompanied by the following effects, discussed in this article: i) an irradiated EVA/WTD blend at 200kGy was found to improve the thermal properties of EVA, ii) the addition of PEgMAH in EVA/WTD blends and the subsequent irradiation allowed prevention of degradation mechanism. iii) the ?H{sub f} and crystallinity percentage decrease at higher PEgMAH content.

Ramli, Syuhada; Ahmad, S. H. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan (Malaysia); Ratnam, C. T. [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang (Malaysia); Athirah, Nurul [School of Materials and Mineral Resources, USM Engineering Campus (Malaysia)

2013-11-27T23:59:59.000Z

43

Exact kinetic theory for the instability of an electron beam in a hot magnetized plasma  

SciTech Connect

Efficiency of collective beam-plasma interaction strongly depends on the growth rates of dominant instabilities excited in the system. Nevertheless, exact calculations of the full unstable spectrum in the framework of relativistic kinetic theory for arbitrary magnetic fields and particle distributions were unknown until now. In this paper, we give an example of such a calculation answering the question whether the finite thermal spreads of plasma electrons are able to suppress the fastest growing modes in the beam-plasma system. It is shown that nonrelativistic temperatures of Maxwellian plasmas can stabilize only the oblique instabilities of relativistic beam. On the contrary, non-Maxwellian tails typically found in laboratory beam-plasma experiments are able to substantially reduce the growth rate of the dominant longitudinal modes affecting the efficiency of turbulent plasma heating.

Timofeev, I. V.; Annenkov, V. V. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia Novosibirsk State University, Novosibirsk (Russian Federation)] [Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia Novosibirsk State University, Novosibirsk (Russian Federation)

2013-09-15T23:59:59.000Z

44

Polymer-Ceramic MEMS Bimorphs as Thermal Infrared Sensors.  

E-Print Network (OSTI)

??Thermal infrared detectors based on MEMS bimorph beams have the potential to exceed the performance of current uncooled thermal infrared cameras both in terms of… (more)

Warren, Clinton Gregory

2010-01-01T23:59:59.000Z

45

Microelectromechanical (MEM) thermal actuator  

DOE Patents (OSTI)

Microelectromechanical (MEM) buckling beam thermal actuators are disclosed wherein the buckling direction of a beam is constrained to a desired direction of actuation, which can be in-plane or out-of-plane with respect to a support substrate. The actuators comprise as-fabricated, linear beams of uniform cross section supported above the substrate by supports which rigidly attach a beam to the substrate. The beams can be heated by methods including the passage of an electrical current through them. The buckling direction of an initially straight beam upon heating and expansion is controlled by incorporating one or more directional constraints attached to the substrate and proximal to the mid-point of the beam. In the event that the beam initially buckles in an undesired direction, deformation of the beam induced by contact with a directional constraint generates an opposing force to re-direct the buckling beam into the desired direction. The displacement and force generated by the movement of the buckling beam can be harnessed to perform useful work, such as closing contacts in an electrical switch.

Garcia, Ernest J. (Albuquerque, NM); Fulcher, Clay W. G. (Sandia Park, NM)

2012-07-31T23:59:59.000Z

46

High flux photon beam monitor  

SciTech Connect

We have designed two photon beam position monitors for use on our x-ray storage ring beam lines. In both designs, a pair of tungsten blades, separated by a pre-determined gap, intercepts a small fraction of the incoming beam. Due to photoemission, an electrical signal is generated which is proportional to the amount of beam intercepted. The thermal load deposited in the blade is transferred by a heat pipe to a heat exchanger outside the vacuum chamber. A prototype monitor with gap adjustment capability was fabricated and tested at a uv beam line. The results show that the generated electrical signal is a good measurement of the photon beam position. In the following sections, design features and test results are discussed.

Mortazavi, P.; Woodle, M.; Rarback, H.; Shu, D.; Howells, M.

1985-01-01T23:59:59.000Z

47

Rhodium self-powered neutron detector as a suitable on-line thermal neutron flux monitor in BNCT treatments  

SciTech Connect

Purpose: A rhodium self-powered neutron detector (Rh SPND) has been specifically developed by the Comision Nacional de Energia Atomica (CNEA) of Argentina to measure locally and in real time thermal neutron fluxes in patients treated with boron neutron capture therapy (BNCT). In this work, the thermal and epithermal neutron response of the Rh SPND was evaluated by studying the detector response to two different reactor spectra. In addition, during clinical trials of the BNCT Project of the CNEA, on-line neutron flux measurements using the specially designed detector were assessed. Methods: The first calibration of the detector was done with the well-thermalized neutron spectrum of the CNEA RA-3 reactor thermal column. For this purpose, the reactor spectrum was approximated by a Maxwell-Boltzmann distribution in the thermal energy range. The second calibration was done at different positions along the central axis of a water-filled cylindrical phantom, placed in the mixed thermal-epithermal neutron beam of CNEA RA-6 reactor. In this latter case, the RA-6 neutron spectrum had been well characterized by both calculation and measurement, and it presented some marked differences with the ideal spectrum considered for SPND calibrations at RA-3. In addition, the RA-6 neutron spectrum varied with depth in the water phantom and thus the percentage of the epithermal contribution to the total neutron flux changed at each measurement location. Local (one point-position) and global (several points-positions) and thermal and mixed-field thermal neutron sensitivities were determined from these measurements. Thermal neutron flux was also measured during BNCT clinical trials within the irradiation fields incident on the patients. In order to achieve this, the detector was placed on patient's skin at dosimetric reference points for each one of the fields. System stability was adequate for this kind of measurement. Results: Local mixed-field thermal neutron sensitivities and global thermal and mixed-field thermal neutron sensitivities derived from measurements performed at the RA-6 were compared and no significant differences were found. Global RA-6-based thermal neutron sensitivity showed agreement with pure thermal neutron sensitivity measurements performed in the RA-3 spectrum. Additionally, the detector response proved nearly unchanged by differences in neutron spectra from real (RA-6 BNCT beam) and ideal (considered for calibration calculations at RA-3) neutron source descriptions. The results confirm that the special design of the Rh SPND can be considered as having a pure thermal response for neutron spectra with epithermal-to-thermal flux ratios up to 12%. In addition, the linear response of the detector to thermal flux allows the use of a mixed-field thermal neutron sensitivity of 1.95 {+-} 0.05 x 10{sup -21} A n{sup -1}{center_dot}cm{sup 2}{center_dot}s. This sensitivity can be used in spectra with up to 21% epithermal-to-thermal flux ratio without significant error due to epithermal neutron and gamma induced effects. The values of the measured fluxes in clinical applications had discrepancies with calculated results that were in the range of -25% to +30%, which shows the importance of a local on-line independent measurement as part of a treatment planning quality control system. Conclusions: The usefulness of the CNEA Rh SPND for the on-line local measurement of thermal neutron flux on BNCT patients has been demonstrated based on an appropriate neutron spectra calibration and clinical applications.

Miller, Marcelo E.; Sztejnberg, Manuel L.; Gonzalez, Sara J.; Thorp, Silvia I.; Longhino, Juan M.; Estryk, Guillermo [Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429 (Argentina); Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429, Argentina and CONICET, Av. Rivadavia 1917, Ciudad de Buenos Aires 1033 (Argentina); Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429 (Argentina)

2011-12-15T23:59:59.000Z

48

Apparatus for synthesis of a solar spectrum  

DOE Patents (OSTI)

A xenon arc lamp and a tungsten filament lamp provide light beams that together contain all the wavelengths required to accurately simulate a solar spectrum. Suitable filter apparatus selectively direct visible and ultraviolet light from the xenon arc lamp into two legs of a trifurcated randomized fiber optic cable. Infrared light selectively filtered from the tungsten filament lamp is directed into the third leg of the fiber optic cable. The individual optic fibers from the three legs are brought together in a random fashion into a single output leg. The output beam emanating from the output leg of the trifurcated randomized fiber optic cable is extremely uniform and contains wavelengths from each of the individual filtered light beams. This uniform output beam passes through suitable collimation apparatus before striking the surface of the solar cell being tested. Adjustable aperture apparatus located between the lamps and the input legs of the trifurcated fiber optic cable can be selectively adjusted to limit the amount of light entering each leg, thereby providing a means of "fine tuning" or precisely adjusting the spectral content of the output beam. Finally, an adjustable aperture apparatus may also be placed in the output beam to adjust the intensity of the output beam without changing the spectral content and distribution of the output beam.

Sopori, Bhushan L. (Denver, CO)

1993-01-01T23:59:59.000Z

49

Characterization of Dosimetry of the BMRR Horizontal Thimble Tubes and Broad Beam Facility.  

SciTech Connect

The Brookhaven Medical Research Reactor was a 5 mega-watt, light-water cooled and heavy-graphite moderated research facility. It has two shutter-equipped treatment rooms, three horizontally extended thimble tubes, and an ex-core broad beam facility. The three experimental thimbles, or activation ports, external to the reactor tank were designed for several uses, including the investigations on diagnostic and therapeutic methods using radioactive isotopes of very short half-life, the analysis of radiation exposure on tissue-equivalent materials using a collimated neutron beam, and the evaluation of dose effects on biological cells to improve medical treatment. At the broad beam facility where the distribution of thermal neutrons was essential uniform, a wide variety of mammalian whole-body exposures were studied using animals such as burros or mice. Also studied at the broad beam were whole-body phantom experiments, involving the use of a neutron or photon beam streaming through a screen to obtain the flux spectrum suitable for dose analysis on the sugar-urea-water mixture, a tissue-equivalent material. Calculations of the flux and the dose at beam ports based on Monte Carlo particle-transport code were performed, and measurements conducted at the same tally locations were made using bare or cadmium-covered gold foils. Analytical results, which show good agreement with measurement data, are presented in the paper.

Hu,J.P.; Reciniello, R.N.; Holden, N.E.

2008-05-05T23:59:59.000Z

50

Effects of thermal motion on electromagnetically induced absorption  

E-Print Network (OSTI)

We describe the effect of thermal motion and buffer-gas collisions on a four-level closed N system interacting with strong pump(s) and a weak probe. This is the simplest system that experiences electromagnetically induced absorption (EIA) due to transfer of coherence via spontaneous emission from the excited to ground state. We investigate the influence of Doppler broadening, velocity-changing collisions (VCC), and phase-changing collisions (PCC) with a buffer gas on the EIA spectrum of optically active atoms. In addition to exact expressions, we present an approximate solution for the probe absorption spectrum, which provides physical insight into the behavior of the EIA peak due to VCC, PCC, and wave-vector difference between the pump and probe beams. VCC are shown to produce a wide pedestal at the base of the EIA peak, which is scarcely affected by the pump-probe angular deviation, whereas the sharp central EIA peak becomes weaker and broader due to the residual Doppler-Dicke effect. Using diffusion-like equations for the atomic coherences and populations, we construct a spatial-frequency filter for a spatially structured probe beam and show that Ramsey narrowing of the EIA peak is obtained for beams of finite width.

E. Tilchin; O. Firstenberg; A. D. Wilson-Gordon

2011-07-04T23:59:59.000Z

51

Beam Characterization at the Neutron Radiography Facility  

SciTech Connect

The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

Sarah Morgan; Jeffrey King

2013-01-01T23:59:59.000Z

52

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT  

E-Print Network (OSTI)

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D­22607#erential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass measurement possible impact of the beam related systematic errors on the Higgs boson mass measurement is discussed

53

Carbon Fiber Damage in Accelerator Beam  

E-Print Network (OSTI)

Carbon fibers are commonly used as moving targets in Beam Wire Scanners. Because of their thermomechanical properties they are very resistant to particle beams. Their strength deteriorates with time due to radiation damage and low-cycle thermal fatigue. In case of high intensity beams this process can accelerate and in extreme cases the fiber is damaged during a single scan. In this work a model describing the fiber temperature, thermionic emission and sublimation is discussed. Results are compared with fiber damage test performed on SPS beam in November 2008. In conclusions the limits of Wire Scanner operation on high intensity beams are drawn.

Sapinski, M; Guerrero, A; Koopman, J; Métral, E

2009-01-01T23:59:59.000Z

54

THE COMPACT STEEP SPECTRUM AND GHZ PEAKED SPECTRUM RADIO SOURCES  

E-Print Network (OSTI)

THE COMPACT STEEP SPECTRUM AND GHZ PEAKED SPECTRUM RADIO SOURCES Christopher P. O'Dea Space@stsci.edu ABSTRACT I review the radio to X­ray properties of GHz Peaked Spectrum (GPS) and Compact Steep Spectrum The GHz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources make up significant fractions

55

SPECTRUM OPPORTUNITY AND INTERFERENCE CONSTRAINT IN OPPORTUNISTIC SPECTRUM ACCESS  

E-Print Network (OSTI)

of the radio spec- trum? Actual spectrum usage measurements obtained by the FCC's Spectrum Policy Task Force [1SPECTRUM OPPORTUNITY AND INTERFERENCE CONSTRAINT IN OPPORTUNISTIC SPECTRUM ACCESS Qing Zhao@ece.ucdavis.edu ABSTRACT In this paper, we study two important concepts in opportunis- tic spectrum access: spectrum

Islam, M. Saif

56

Paraxial Light Beams with Angular Momentum  

E-Print Network (OSTI)

Fundamental and applied concepts concerning the ability of light beams to carry a certain mechanical angular momentum with respect to the propagation axis are reviewed and discussed. Following issues are included: Historical reference; Angular momentum of a paraxial beam and its constituents; Spin angular momentum and paradoxes associated with it; Orbital angular momentum; Circularly-spiral beams: examples and methods of generation; Orbital angular momentum and the intensity moments; Symmetry breakdown and decomposition of the orbital angular momentum; Mechanical models of the vortex light beams; Mechanical action of the beam angular momentum; Rotational Doppler effect, its manifestation in the image rotation; Spectrum of helical harmonics and associated problems; Non-collinear rotational Doppler effect; Properties of a beam forcedly rotating around its own axis. Research prospects and ways of practical utilization of optical beams with angular momentum.

A. Bekshaev; M. Soskin; M. Vasnetsov

2008-01-15T23:59:59.000Z

57

Intelligent Spectrum Sensor Radio.  

E-Print Network (OSTI)

??A cognitive radio is a radio with built-in intelligence that makes it able to utilize the radio frequency spectrum more efficiently by adapting to the… (more)

Mian, Omer

2008-01-01T23:59:59.000Z

58

Halpha with Heating by Particle Beams  

E-Print Network (OSTI)

Using 1D NLTE radiative hydrodynamics we model the influence of the particle beams on the Halpha line profile treating the beam propagation and the atmosphere evolution self-consistently. We focus on the influence of the non-thermal collisional rates and the return current. Based on our results, we propose a diagnostic method for determination of the particle beam presence in the formation regions of the Halpha line.

J. Kasparova; M. Varady; M. Karlicky; P. Heinzel; Z. Moravec

2007-03-30T23:59:59.000Z

59

Computational characterization and experimental validation of the thermal neutron source for neutron capture therapy research at the University of Missouri  

SciTech Connect

Parameter studies, design calculations and neutronic performance measurements have been completed for a new thermal neutron beamline constructed for neutron capture therapy cell and small-animal radiobiology studies at the University of Missouri Research Reactor. The beamline features the use of single-crystal silicon and bismuth sections for neutron filtering and for reduction of incident gamma radiation. The computational models used for the final beam design and performance evaluation are based on coupled discrete-ordinates and Monte Carlo techniques that permit detailed modeling of the neutron transmission properties of the filtering crystals with very few approximations. Validation protocols based on neutron activation spectrometry measurements and rigorous least-square adjustment techniques show that the beam produces a neutron spectrum that has the anticipated level of thermal neutron flux and a somewhat higher than expected, but radio-biologically insignificant, epithermal neutron flux component. (authors)

Broekman, J. D. [University of Missouri, Research Reactor Center, 1513 Research Park Drive, Columbia, MO 65211-3400 (United States); Nigg, D. W. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Hawthorne, M. F. [University of Missouri, International Institute of Nano and Molecular Medicine, 1514 Research Park Dr., Columbia, MO 65211-3450 (United States)

2013-07-01T23:59:59.000Z

60

Radiation detector spectrum simulator  

DOE Patents (OSTI)

A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

Wolf, Michael A. (Los Alamos, NM); Crowell, John M. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Radiation detector spectrum simulator  

DOE Patents (OSTI)

A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

Wolf, M.A.; Crowell, J.M.

1985-04-09T23:59:59.000Z

62

Thermodynamic and optical analysis for a CPV/T hybrid system with beam splitter and fully tracked linear Fresnel reflector concentrator utilizing sloped panels  

Science Journals Connector (OSTI)

Abstract Spectral splitting technology that separates solar spectrum into several parts and enables different energy conversions such as photovoltaic (PV) conversion and photo-thermal conversion aims to utilize the full spectrum solar energy efficiently. A novel concentrating PV/Thermal (CPV/T) hybrid system with beam splitter and fully tracked linear Fresnel reflector concentrator utilizing sloped panels was proposed in this study. The relations between the structural parameters and the optical performances of the system were investigated. The concentrated radiation distribution on the PV device surface was simulated by taking into account the main optical errors and shows a good uniformity. Based on the experimental data of the components, thermodynamic analysis on the CPV/T hybrid system was carried out and the results reveal that the overall energy conversion efficiencies of the proposed CPV/T hybrid system is higher than that of the CPV system under the same conditions.

Yang Liu; Peng Hu; Qian Zhang; Zeshao Chen

2014-01-01T23:59:59.000Z

63

Thermal and non-thermal energies in solar flares  

E-Print Network (OSTI)

The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in the spectrum. The turnover or cutoff in the low-energy distribution of electrons has been studied by simulation and fitting, yielding a reliable lower limit to the non-thermal energy. It remains the largest contribution to the error budget. Other effects, such as albedo, non-uniform target ionization, hot target, and cross-sections on the spectrum have been studied. The errors of the thermal energy are about equally as large. They are due to the estimate of the flare volume, the assumption of the filling factor, and energy losses. Within a flare, the non-thermal/thermal ratio increases with accumulation time, as expected from loss of thermal energy due to radiative cooling or heat conduction. Our analysis suggests that the thermal and non-thermal energies are of the same magnitude. This surprising result may be interpreted by an efficient conversion of non-thermal energy to hot flare plasma.

Pascal Saint-Hilaire; Arnold O. Benz

2005-03-03T23:59:59.000Z

64

Hardening neutron spectrum for advanced actinide transmutation experiments in the ATR  

Science Journals Connector (OSTI)

......constant neutron-flux field, the fission power is...over the neutron energy range 0...the neutron spectrum such that all the thermal neutrons...Nuclear Energy-Engineering...fraction of neutron induced gamma-heat...Hardening neutron spectrum for advanced...shorter-lived fission products...performed in a thermal test reactor......

G. S. Chang; R. G. Ambrosek

2005-12-20T23:59:59.000Z

65

Parametric Adaptive Spectrum Sensing Framework for Dynamic Spectrum Access Networks  

E-Print Network (OSTI)

- ture for dynamic spectrum sensing. In our approach, the radio learns the statistics of the channel Spectrum Sensing Architecture The proposed PASS architecture enables the radio to adapt its spectrumParametric Adaptive Spectrum Sensing Framework for Dynamic Spectrum Access Networks Dinesh Datla

Kansas, University of

66

Tuning energy transport in solar thermal systems using nanostructured materials  

E-Print Network (OSTI)

Solar thermal energy conversion can harness the entire solar spectrum and theoretically achieve very high efficiencies while interfacing with thermal storage or back-up systems for dispatchable power generation. Nanostructured ...

Lenert, Andrej

2014-01-01T23:59:59.000Z

67

Background-subtraction using contour-based fusion of thermal and visible imagery  

E-Print Network (OSTI)

rights reserved. Keywords: Background-subtraction; Fusion; Thermal imagery; Infrared; FLIR; Contour of the electromagnetic spectrum, long-wave infrared (thermal) and visible light. Thermal (FLIR) and color video cameras

Davis, James W.

68

BNL | ICS Spectrum  

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

Demonstration of Mass-shift and High Harmonics in ICS X-ray Spectrum The recent improvements in the ATF's CO2 laser, in particular, using CO2 isotopes for the picosecond pulse...

69

Thermomechanical measurements on thermal microactuators.  

SciTech Connect

Due to the coupling of thermal and mechanical behaviors at small scales, a Campaign 6 project was created to investigate thermomechanical phenomena in microsystems. This report documents experimental measurements conducted under the auspices of this project. Since thermal and mechanical measurements for thermal microactuators were not available for a single microactuator design, a comprehensive suite of thermal and mechanical experimental data was taken and compiled for model validation purposes. Three thermal microactuator designs were selected and fabricated using the SUMMiT V{sup TM} process at Sandia National Laboratories. Thermal and mechanical measurements for the bent-beam polycrystalline silicon thermal microactuators are reported, including displacement, overall actuator electrical resistance, force, temperature profiles along microactuator legs in standard laboratory air pressures and reduced pressures down to 50 mTorr, resonant frequency, out-of-plane displacement, and dynamic displacement response to applied voltages.

Baker, Michael Sean; Epp, David S.; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

2009-01-01T23:59:59.000Z

70

Thermal and non-thermal energies in solar flares  

E-Print Network (OSTI)

The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in the spectrum. The turnover or cutoff in the low-energy distribution of electrons has been studied by simulation and fitting, yielding a reliable lower limit to the non-thermal energy. It remains the largest contribution to the error budget. Other effects, such as albedo, non-uniform target ionization, hot target, and cross-sections on the spectrum have been studied. The errors of the thermal energy are about equally as large. They are due to the estimate of the flare volume, the assumption of the filling factor, and energy losses. Within a flare, the non-thermal/thermal ratio increases with accumulation time, as expected from loss of thermal energy due to radiative cooling or heat conduction. Our analysis suggests that the thermal and non-thermal energies are of the same m...

Saint-Hilaire, P; Saint-Hilaire, Pascal; Benz, Arnold O.

2005-01-01T23:59:59.000Z

71

Utilization and Fairness in Spectrum Assignment for Opportunistic Spectrum Access  

E-Print Network (OSTI)

. INTRODUCTION Wireless devices are becoming ubiquitous, placing increas­ ing stress on the fixed radio spectrum by software defined radio (SDR) technology [5], [15], [23], Open Spectrum allows unlicensed (secondary) users1 Utilization and Fairness in Spectrum Assignment for Opportunistic Spectrum Access Chunyi Peng

Zhao, Ben Y.

72

Utilization and Fairness in Spectrum Assignment for Opportunistic Spectrum Access  

E-Print Network (OSTI)

. INTRODUCTION Wireless devices are becoming ubiquitous, placing increas- ing stress on the fixed radio spectrum by software defined radio (SDR) technology [5], [16], [24], Open Spectrum allows unlicensed (secondary) users1 Utilization and Fairness in Spectrum Assignment for Opportunistic Spectrum Access Chunyi Peng

Almeroth, Kevin C.

73

An Approximate Truthfulness Motivated Spectrum Auction for Dynamic Spectrum Access  

E-Print Network (OSTI)

Radio Spectrum is a critical but scarce resource for wireless communications. Traditionally of spectrum allocation approach, each licensed user has exclusive right for the allocated spectrum, thus facilities as well as the explosive growth of novel wireless services, the demand for radio spectrum

Zhou, Yuanyuan

74

Efficient Dynamic Spectrum Sharing Through Rate Compensation and Spectrum Handoff  

E-Print Network (OSTI)

Abstract--In this work, we propose a heuristic for dynamic spectrum sharing in cognitive radio networks licensed channels available for opportunistic spectrum access. Each SU is equipped with n wEfficient Dynamic Spectrum Sharing Through Rate Compensation and Spectrum Handoff Adisorn

Paris-Sud XI, Université de

75

BEAM LINE  

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

BEAM LINE BEAM LINE 45 W ILHELM ROENTGEN'S INITIAL DISCOVERY of X-radiation in 1895 led immediately to practical applications in medicine. Over the next few decades X rays proved to be an invaluable tool for the investigation of the micro-world of the atom and the development of the quantum theory of matter. Almost a century later, telescopes designed to detect X-radiation are indispensable for understanding the structure and evolution of the macro-world of stars, galaxies, and the Universe as a whole. The X-Ray Universe by WALLACE H. TUCKER X-ray images of the Universe are strikingly different from the usual visible-light images. 46 SUMMER 1995 did not think: I investigated." Undeterred by NASA's rejection of a proposal to search for cosmic X-radiation, Giacconi persuaded the

76

Radio and Spectrum Management | Department of Energy  

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

Radio and Spectrum Management Radio and Spectrum Management DOE Radio and Spectrum Workshop 43.pdf More Documents & Publications ICAM Workshop Ad Hoc Meetings Spectrum Technology...

77

Broad spectrum solar cell  

DOE Patents (OSTI)

An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In.sub.1-xGa.sub.xN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA); Wu, Junqiao (Richmond, CA); Schaff, William J. (Ithaca, NY)

2007-05-15T23:59:59.000Z

78

Electron energy-loss spectrum of nanowires G. F. Bertsch  

E-Print Network (OSTI)

Electron energy-loss spectrum of nanowires G. F. Bertsch Institute of Nuclear Theory and Department, Cornell University, Ithaca, New York 14853 Received 8 May 1998 The electronic properties of nanoscale-size fibers can be studied by electron energy-loss spectroscopy with electron beams that pass near the fiber

Bertsch George F.

79

NREL Spectrum of Innovation  

SciTech Connect

There are many voices calling for a future of abundant clean energy. The choices are difficult and the challenges daunting. How will we get there? The National Renewable Energy Laboratory integrates the entire spectrum of innovation including fundamental science, market relevant research, systems integration, testing and validation, commercialization and deployment. The innovation process at NREL is interdependent and iterative. Many scientific breakthroughs begin in our own laboratories, but new ideas and technologies come to NREL at any point along the innovation spectrum to be validated and refined for commercial use.

None

2011-01-01T23:59:59.000Z

80

arXiv:hepex/0111033 An O -Axis Neutrino Beam  

E-Print Network (OSTI)

to that of the proton beam. 5. At what energy E #23;;peak does the neutrino spectrum peak for #18; = 0? 6. Compare by the \\horn". The main source of neutrinos is then the decay #25; + ! #22; + #23; #22; . 1. Give a simple estimate of the relative number of other types of neutrinos than #23; #22; in the beam. 2. If the decay

McDonald, Kirk

Note: This page contains sample records for the topic "beam spectrum thermal" 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

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT  

E-Print Network (OSTI)

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D-22607 and differential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass such as Higgs boson mass, decay branching fractions and production rate. However, most of these studies did

82

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect

Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

2004-10-16T23:59:59.000Z

83

Beam-Bem interactions  

SciTech Connect

In high energy storage-ring colliders, the nonlinear effect arising from beam-beam interactions is a major source that leads to the emittance growth, the reduction of beam life time, and limits the collider luminosity. In this paper, two models of beam-beam interactions are introduced, which are weak-strong and strong-strong beam-beam interactions. In addition, space-charge model is introduced.

Kim, Hyung Jin; /Fermilab

2011-12-01T23:59:59.000Z

84

Laser systems configured to output a spectrally-consolidated laser beam and related methods  

DOE Patents (OSTI)

A laser apparatus includes a plurality of pumps each of which is configured to emit a corresponding pump laser beam having a unique peak wavelength. The laser apparatus includes a spectral beam combiner configured to combine the corresponding pump laser beams into a substantially spatially-coherent pump laser beam having a pump spectrum that includes the unique peak wavelengths, and first and second selectively reflective elements spaced from each other to define a lasing cavity including a lasing medium therein. The lasing medium generates a plurality of gain spectra responsive to absorbing the pump laser beam. Each gain spectrum corresponds to a respective one of the unique peak wavelengths of the substantially spatially-coherent pump laser beam and partially overlaps with all other ones of the gain spectra. The reflective elements are configured to promote emission of a laser beam from the lasing medium with a peak wavelength common to each gain spectrum.

Koplow, Jeffrey P. (San Ramon, CA)

2012-01-10T23:59:59.000Z

85

Hawking spectrum and high frequency dispersion  

Science Journals Connector (OSTI)

We study the spectrum of created particles in two-dimensional black hole geometries for a linear, Hermitian scalar field satisfying a Lorentz noninvariant field equation with higher spatial derivative terms that are suppressed by powers of a fundamental momentum scale k0. The preferred frame is the "free-fall frame" of the black hole. This model is a variation of Unruh's sonic black hole analogy. We find that there are two qualitatively different types of particle production in this model: a thermal Hawking flux generated by "mode conversion" at the black hole horizon, and a nonthermal spectrum generated via scattering off the background into negative free-fall frequency modes. This second process has nothing to do with black holes and does not occur for the ordinary wave equation because such modes do not propagate outside the horizon with positive Killing frequency. The horizon component of the radiation is astonishingly close to a perfect thermal spectrum: for the smoothest metric studied, with Hawking temperature TH?0.0008k0, agreement is of order (THk0)3 at frequency ?=TH, and agreement to order THk0 persists out to ?TH?45 where the thermal number flux is ?10-20. The flux from scattering dominates at large ? and becomes many orders of magnitude larger than the horizon component for metrics with a "kink," i.e., a region of high curvature localized on a static world line outside the horizon. This nonthermal flux amounts to roughly 10% of the total luminosity for the kinkier metrics considered. The flux exhibits oscillations as a function of frequency which can be explained by interference between the various contributions to the flux.

Steven Corley and Ted Jacobson

1996-07-15T23:59:59.000Z

86

Spectrum Mobility Games Richard Southwell  

E-Print Network (OSTI)

by allowing cognitive radio devices to opportunisti- cally access underutilized licensed spectrum while With the unprecedented growth in the number of mobile devices and wireless services, the radio frequency spectrum are widely underutilized. Cognitive radio technology has the great potential to alleviate spectrum scarcity

Huang, Jianwei

87

Hybrid spread spectrum radio system  

DOE Patents (OSTI)

Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

2010-02-09T23:59:59.000Z

88

Discrete multiwavelength spectrum created  

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

Supramolecular structure of polymer blends Supramolecular structure of polymer blends * Macroscale self-similarity of rocks * Structure of colloidal crystals and alloys * Hydration of cement pastes * Aggregation in colloidal dispersions * Self-assembling of polymers * Mesoscopic structure of natural composites * Structure of granular powders * Morphology of colloidal reinforcing fillers * Structure and morphology of complex fluids * Rheology and morphology of hydrogels 06-G01637F/gim Moderator Decoupled poisoned hydrogen Source- detector distance 30 m Focusing premono- chromator Cooper mosaic Cu(111) crystals Monochro- mator and analyzer Si(220) channel-cut, triple-bounce crystals Bragg angle 70° Wavelength spectrum 4 Bragg

89

Plasma Heating by High-Current Relativistic Electron Beams  

Science Journals Connector (OSTI)

A mechanism is proposed for the heating of a plasma with a high-current relativistic electron beam which makes essential use of the plasma return current induced by the beam. From overall energy conservation it is concluded that a large fraction of the beam energy is converted into plasma thermal energy. For reasonable parameters the heating occurs through ion sound turbulence generated by the plasma return current.

R. V. Lovelace and R. N. Sudan

1971-11-08T23:59:59.000Z

90

Inertial Confinement Fusion with Light Ion Beams  

Science Journals Connector (OSTI)

...plasma can be formed without significant contribution of the ion thermal velocity to the beam divergence. The large ionization energy...3. P. L. Dreike, C. Eichenberger, S. Humphries, R. Sudan, J. Appi. Phys. 47, 85 (1986). 4. J. D. Lindi and...

J. PACE VANDEVENDER; DONALD L. COOK

1986-05-16T23:59:59.000Z

91

Ortho- and para-hydrogen in neutron thermalization  

SciTech Connect

The large difference in neutron scattering cross-section at low neutron energies between ortho- and para-hydrogen was recognized early on. In view of this difference (more than an order of magnitude), one might legitimately ask whether the ortho/para ratio has a significant effect on the neutron thermalization properties of a cold hydrogen moderator. Several experiments performed in the 60`s and early 70`s with a variety of source and (liquid hydrogen) moderator configurations attempted to investigate this. The results tend to show that the ortho/para ratio does indeed have an effect on the energy spectrum of the neutron beam produced. Unfortunately, the results are not always consistent with each other and much unknown territory remains to be explored. The problem has been approached from a computational standpoint, but these isolated efforts are far from having examined the ortho/para-hydrogen problem in neutron moderation in all its complexity. Because of space limitations, the authors cannot cover, even briefly, all the aspects of the ortho/para question here. This paper will summarize experiments meant to investigate the effect of the ortho/para ratio on the neutron energy spectrum produced by liquid hydrogen moderators.

Daemen, L. L.; Brun, T. O.

1998-01-01T23:59:59.000Z

92

Spectrum sharing in cognitive radio networks.  

E-Print Network (OSTI)

??Years of growth in wireless communication services and conservative spectrum allocation policies by government regulators have led to spectrum scarcity. On the other hand, spectrum… (more)

Ahmed, Waqas

2012-01-01T23:59:59.000Z

93

Spectrum Policy Seminar | Department of Energy  

Energy Savers (EERE)

Policy Seminar Spectrum Policy Seminar Slide show from FCC's Public Safety and Homeland Security Bureau's presenation on spectrum policy. Spectrum Policy Seminar More Documents &...

94

Thermal Spectrum of Uranus: Implications for Large Helium Abundance  

Science Journals Connector (OSTI)

...Modelprocedure. Recovery ofthe tempera-ture...for telluric water vapor absorption...simultaneous with recovery of the tempera-ture...its nominal condensation lev-el...appealing to atmospheric cloud and...ionic ocean of water existed in...1 for dear atmospheric conditions...dose to the condensation level for...

GLENN S. ORTON

1986-02-21T23:59:59.000Z

95

NREL: Innovation Spectrum - NREL Spectrum of Innovation Video...  

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

are many...and the challenges are daunting. How will we get there? The National Renewable Energy Laboratory integrates the entire spectrum of innovation, including Fundamental...

96

LANSCE beam current limiter  

SciTech Connect

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.

Gallegos, F.R.

1996-06-01T23:59:59.000Z

97

Auger spectrum of the LiF molecule  

Science Journals Connector (OSTI)

The Auger spectrum of LiF vapor has been measured in the energy region 600-680 eV by means of electron-beam excitation. The assignment of the peak structure is based on theoretical ab initio calculations with the use of the multiconfigurational complete-active-space self-consistent-field method and by comparison with the corresponding spectra of the neon atom and the hydrogen fluoride molecule.

Matti Hotokka; Hans Ågren; Helena Aksela; Seppo Aksela

1984-10-01T23:59:59.000Z

98

Federal Spectrum Management at the National Telecommunications...  

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

Federal Spectrum Management at the National Telecommunications and Information Administration Federal Spectrum Management at the National Telecommunications and Information...

99

Horizontal Beam Tubes - HFIR Technical Parameters | ORNL Neutron Sciences  

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

Horizontal Beam Tubes Horizontal Beam Tubes The reactor has four horizontal beam tubes that supply the neutrons to the neutron scattering instruments. Details for each beam tube and instrument can be found on the HFIR instrument page. Each of the beam tubes that supply these instruments with neutrons is described subsequently. HB-1 and HB-3 The HB-1 and HB-3 thermal neutron beam tube designs are identical except for the length. Both are situated tangential to the reactor core so that the tubes point at reflector material and do not point directly at the fuel. An internal collimator is installed at the outboard end. This collimator is fabricated out of carbon steel and is plated with nickel. The collimator provides a 2.75-in by 5.5-in. rectangular aperture. A rotary shutter is located outboard of each of these beam tubes. The

100

Spectrum Sensing and Reconstruction for Cognitive Radio  

E-Print Network (OSTI)

Spectrum Sensing and Reconstruction for Cognitive Radio Amanpreet S Saini, Zhen Hu, Robert Qiu with spectrum sensing and spectrum reconstruction under the umbrella of cognitive radio which is the smart radio to explore and exploit the free spectrum. Spectrum analyzer is used to emulate cognitive radio to do spectrum

Qiu, Robert Caiming

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Normal Conducting CW RF Gun Design for High Performance Electron Beams  

SciTech Connect

High repetition rate (>1 MHz), high charge (1 nC), low emittance (1 micron) electron beams are an important enabling technology for next generation light sources. Advanced Energy Systems has begun the development of an advanced, continuous-wave, normal-conducting radio frequency electron gun. This gun is designed to minimize thermal stress, allowing fabrication in copper, while providing low emittance electron beams. Beam dynamics performance will be presented along with thermal and stress analysis of the gun cavity design.

Bluem, Hans; Schultheiss, Tom; Young, L.M.; Rimmer, Robert

2008-07-01T23:59:59.000Z

102

Scission neutron emission and prompt fission neutron spectrum  

E-Print Network (OSTI)

The mass, energy and angular integrated spectra of prompt fission neutrons for sup 2 sup 3 sup 5 U induced fission in the energy range from thermal to 5 MeV were analyzed. It allows assume that about 0.362+-0.025 neutrons per fission are emitted due to another mechanism then neutron emission from excited fragments after full acceleration. The spectrum of scission neutrons consists of two components with average energy 0.98 MeV and 2.74 MeV. The share of scission neutrons and their spectrum shape estimated in this work does not contradict to results of differential experiments analyzed in previous papers.

Kornilov, N V

2001-01-01T23:59:59.000Z

103

NREL: Innovation Spectrum Home Page  

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

Innovation Spectrum Innovation Spectrum Te xt version The scope of NREL's capabilities emulates the nature of the innovation process itself. Moving new technologies from initial concept to commercial application requires a breadth of expertise across the innovation spectrum, encompassing: Fundamental science Market-relevant research Systems integration Testing and validation Commercialization Deployment The NREL innovation spectrum is highly interactive within the laboratory and across other research institutions and private industry. NREL provides the scientific and analytical leadership to guide the innovation process, contributing knowledge and expertise at each stage. Innovation Success Stories Learn more about the spectrum of clean energy innovation and how NREL is creating a future of sustainable energy systems based on clean,

104

Thermal treatment  

Science Journals Connector (OSTI)

Thermal treatment can be regarded as either a pre-treatment of waste prior to final disposal, or as a means of valorising waste by recovering energy. It includes both the burning of mixed MSW in municipal inciner...

Dr. P. White; Dr. M. Franke; P. Hindle

1995-01-01T23:59:59.000Z

105

Thermal Processes  

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

Some thermal processes use the energy in various resources, such as natural gas, coal, or biomass, to release hydrogen, which is part of their molecular structure. In other processes, heat, in...

106

BEAMS3D Neutral Beam Injection Model  

SciTech Connect

With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

Lazerson, Samuel

2014-04-14T23:59:59.000Z

107

ATA diagnostic beam dump conceptual design  

SciTech Connect

A diagnostic beam dump, able to withstand 72,000 pulses (10 kA, 50 MeV/pulse) per shift was designed and analyzed. The analysis shows that the conceptual beam dump design consisting of 80 vitreous carbon plate-foam elements is able to withstand the thermal and mechanical stresses generated. X-rays produced by bremsstrahlung are absorbed by a three element copper plate-foam x-ray absorber. Cooling between bursts of electron pulses is provided by pressurized helium.

Not Available

1981-09-01T23:59:59.000Z

108

A TALE OF TWO BEAMS: GAUSSIAN BEAMS AND BESSEL BEAMS ROBERT L. NOWACK  

E-Print Network (OSTI)

A TALE OF TWO BEAMS: GAUSSIAN BEAMS AND BESSEL BEAMS ROBERT L. NOWACK Abstract. An overview is given of two types of focused beams, Gaussian beams and Bessel beams. First I describe some of the basic properties of Gaussian beams in homogeneous media which stay collimated over a certain distance range after

Nowack, Robert L.

109

LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC  

E-Print Network (OSTI)

LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC M. A. Furman, W. C. Turner, Center for Beam Physics, LBNL, Berkeley, CA 94720, USA Abstract We present beam-beam simulation results from a strong- strong gaussian code for separated beams for the LHC. We focus on the possible

Furman, Miguel

110

Monochromatic short pulse laser produced ion beam using a compact passive magnetic device  

SciTech Connect

High-intensity laser accelerated protons and ions are emerging sources with complementary characteristics to those of conventional sources, namely high charge, high current, and short bunch duration, and therefore can be useful for dedicated applications. However, these beams exhibit a broadband energy spectrum when, for some experiments, monoenergetic beams are required. We present here an adaptation of conventional chicane devices in a compact form (10 cm × 20 cm) which enables selection of a specific energy interval from the broadband spectrum. This is achieved by employing magnetic fields to bend the trajectory of the laser produced proton beam through two slits in order to select the minimum and maximum beam energy. The device enables a production of a high current, short duration source with a reproducible output spectrum from short pulse laser produced charged particle beams.

Chen, S. N.; Gauthier, M.; Higginson, D. P.; Dorard, S.; Marquès, J.-R.; Fuchs, J. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France)] [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Mangia, F.; Atzeni, S. [Dipartimento SBAI, Università di Roma “La Sapienza,” Roma (Italy)] [Dipartimento SBAI, Università di Roma “La Sapienza,” Roma (Italy); Riquier, R. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France) [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); CEA, DAM, DIF, F-91297 Arpajon (France)

2014-04-15T23:59:59.000Z

111

BEAMS: Curiosity | Jefferson Lab  

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

BEAMS: Curiosity January 9, 2013 BEAMS, Becoming Excited About Math and Science, is one of our education programs. In particular, it is the only one in which I participate with...

112

Prompt Fission Neutron Spectrum of Pu241  

Science Journals Connector (OSTI)

The energy distribution of prompt neutrons resulting from the thermal-neutron-induced fission of Pu241 is measured. Fast time-of-flight techniques are employed in the neutron energy range 0.3 to 6.0 Mev. Proton recoils in emulsions are utilized for the measurement of neutron energies from 1.6 to 7.0 Mev. The experimentally determined Pu241 fission neutron spectrum is well represented by the Maxwellian distribution, N(E)?E12e-ET, where E is the neutron energy in Mev, N(E) the number of neutrons per unit energy interval, and T=1.335±0.034 Mev. The measured average Pu241 fission neutron energy is 2.002±0.051 Mev.

A. B. Smith; R. K. Sjoblom; J. H. Roberts

1961-09-15T23:59:59.000Z

113

NREL: Innovation Spectrum - NREL Spectrum of Innovation Video (Text  

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

Spectrum of Innovation Video (Text Version) Spectrum of Innovation Video (Text Version) Below is the text version of the NREL Spectrum of Innovation video. "...renewable energy is a national imperative..." "...This breakthrough technology will..." "...we are still looking for an innovative material that will..." "...we need a study to determine..." "...the right people need to work together..." "...competing priorities mean we cannot..." There are many voices calling for a future of abundant, clean energy. The choices are many...and the challenges are daunting. How will we get there? The National Renewable Energy Laboratory integrates the entire spectrum of innovation, including Fundamental Science, Market-Relevant Research, Systems Integration, Testing and Validation, Commercialization, and

114

Ion Beams - Radiation Effects Facility / Cyclotron Institute...  

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

Ion Beams Available Beams Beam Change Times Measurements Useful Graphs Various ion beams have been developed specifically for the Radiation Effects Facility. These beams...

115

ATA beam director experiment  

SciTech Connect

This report describes beam director elements for an experiment at the Advanced Test Accelerator. The elements described include a vernier magnet for beam aiming, an achromat magnet, and an isolation system for the beam interface. These components are built at small scale for concept testing. (JDH)

Lee, E.P.; Younger, F.C.; Cruz, G.E.; Nolting, E.

1986-06-23T23:59:59.000Z

116

Inexpensive dual beam turbidimeter  

Science Journals Connector (OSTI)

...Articles Articles Inexpensive dual beam turbidimeter Cathie Lubell Thomas Barry Edward Brody Gregory Hearn This dual beam turbidimeter...74D728B5-2B21-11D7-8648000102C1865D Inexpensive dual beam turbidimeter Lubell Cathie Author Barry Thomas Author Brody Edward Author Hearn...

Cathie Lubell; Thomas Barry; Edward Brody; Gregory Hearn

117

Neutral beam monitoring  

DOE Patents (OSTI)

Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

Fink, Joel H. (Livermore, CA)

1981-08-18T23:59:59.000Z

118

Raman Spectrum of Heavy Water  

Science Journals Connector (OSTI)

... . of 99.2 gm./lOO gm. D2O ( 1.1049) supplied by the Norsk Hydro-Elektrisk Kvaelstofaktieselskab. The Raman spectrum of the substance was photographed with a Hilger ...

R. ANANTHAKRISHNAN

1935-10-05T23:59:59.000Z

119

Spectrum of C_heart  

E-Print Network (OSTI)

Spectrum of C_heart where 1 + z + 2\\sqrt{1 - z^2} heart(z)= ------------------------- 3 - z + 2\\sqrt{1 - z^2}. Figure 7.1, page 303, of "Composition Operators on Spaces ...

120

Comparison of thermal neutron distributions within shield materials obtained by experiments, SN and monte carlo code calculations  

Science Journals Connector (OSTI)

......The TLDs for thermal neutrons, which consist...measurements of induced activity of gold...measurement of thermal neutron fluence was...region of the energy range 5.04...Watt neutron fission spectrum of 252Cf and......

Yoshihiro Asano; Takeshi Sugita; Takenori Suzaki; Hideyuki Hirose

2005-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Spectrum Clouds: A Session Based Spectrum Trading System for Multi-hop Cognitive Radio Networks  

E-Print Network (OSTI)

of opportunistic using licensed spectrum bands has initiated the spectrum trading in multi-hop cognitive radioSpectrum Clouds: A Session Based Spectrum Trading System for Multi-hop Cognitive Radio Networks in the demand for radio spectrum. In parallel with that, current static spectrum allocation policy of Federal

Latchman, Haniph A.

122

Spectrum Technology Workshop | Department of Energy  

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

Technology Workshop Spectrum Technology Workshop Agenda.pdf More Documents & Publications Radio and Spectrum Management Transuranic Waste Transportation Working Group Agenda...

123

Spectrum sensing through implementation of USRP2.  

E-Print Network (OSTI)

??Scarcity of the wireless spectrum has led to the development of new techniques for better utilization of the wireless spectrum. Demand for high data rates… (more)

Aftab, Adnan

2011-01-01T23:59:59.000Z

124

Compressive Spectrum Sensing for Cognitive Radio Networks.  

E-Print Network (OSTI)

??Spectrum sensing is the most important part in cognitive radios. Wideband spectrum sensing requires high speed and large data samples. It makes sampling process challenging… (more)

Nakarmi, Ukash

2011-01-01T23:59:59.000Z

125

WTB & Spectrum Access Overview | Department of Energy  

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

WTB & Spectrum Access Overview More Documents & Publications An Introduction to Spectrum Engineering NBP RFI: Communications Requirements Reply Comments of Southern Company...

126

Progress toward a microsecond duration, repetitive, intense-ion beam for active spectroscopic measurements on ITER  

SciTech Connect

The authors describe the design of an intense, pulsed, repetitive, neutral beam based on magnetically insulated diode technology for injection into ITER for spectroscopic measurements of thermalizing alpha particle and thermal helium density profiles, ion temperature, plasma rotation, and low Z impurity concentrations in the confinement region. The beam is being developed to enhance low signal-to-noise ratios expected with conventional steady-state ion beams because of severe beam attenuation and intense bremstrahlung emission. A 5 GW (e.g., 100 keV, 50 kA) one-microsecond-duration beam would increase the signal by 10{sup 3} compared to a conventional 5 MW beam with signal-to-noise ratios comparable to those from a chopped conventional beam in one second.

Davis, H.A.; Bartsch, R.R.; Barnes, C.W. [and others

1996-06-01T23:59:59.000Z

127

Perfect light trapping in nanoscale thickness semiconductor films with resonant back reflector and spectrum-splitting structures  

E-Print Network (OSTI)

The optical absorption of nanoscale thickness semiconductor films on top of light-trapping structures based on optical interference effects combined with spectrum-splitting structures is theoretically investigated. Nearly perfect absorption over a broad spectrum range can be achieved in $solar absorption and low carrier thermalization loss can be achieved when the light-trapping structures with wedge-shaped spacer layer or semiconductor films are combined with spectrum-splitting structures.

Liu, Jiang-Tao; Yang, Wen; Li, Jun

2014-01-01T23:59:59.000Z

128

Nanoscale thermal transport. II. 2003–2012  

SciTech Connect

A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ?1?nm, the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interfaces between materials. Major advances in the physics of phonons include first principles calculation of the phonon lifetimes of simple crystals and application of the predicted scattering rates in parameter-free calculations of the thermal conductivity. Progress in the control of thermal transport at the nanoscale is critical to continued advances in the density of information that can be stored in phase change memory devices and new generations of magnetic storage that will use highly localized heat sources to reduce the coercivity of magnetic media. Ultralow thermal conductivity—thermal conductivity below the conventionally predicted minimum thermal conductivity—has been observed in nanolaminates and disordered crystals with strong anisotropy. Advances in metrology by time-domain thermoreflectance have made measurements of the thermal conductivity of a thin layer with micron-scale spatial resolution relatively routine. Scanning thermal microscopy and thermal analysis using proximal probes has achieved spatial resolution of 10?nm, temperature precision of 50 mK, sensitivity to heat flows of 10 pW, and the capability for thermal analysis of sub-femtogram samples.

Cahill, David G., E-mail: d-cahill@illinois.edu; Braun, Paul V. [Department of Materials Science and Engineering and the Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States); Chen, Gang [Department of Mechanical Engineering, MIT, Cambridge, Massachusetts 02139 (United States); Clarke, David R. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Fan, Shanhui [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Goodson, Kenneth E. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Keblinski, Pawel [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); King, William P. [Department of Mechanical Sciences and Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Mahan, Gerald D. [Department of Physics, Penn State University, University Park, Pennsylvania 16802 (United States); Majumdar, Arun [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States); Maris, Humphrey J. [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States); Phillpot, Simon R. [Department of Materials Science and Engineering, University of Florida, Gainseville, Florida 32611 (United States); Pop, Eric [Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Shi, Li [Department of Mechanical Engineering, University of Texas, Autin, Texas 78712 (United States)

2014-03-15T23:59:59.000Z

129

Ion Beam Materials Lab  

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

Facilities » Facilities » Ion Beam Materials Lab Ion Beam Materials Lab A new research frontier awaits! Our door is open and we thrive on mutually beneficial partnerships, collaborations that drive innovations and new technologies. April 12, 2012 Ion Beam Danfysik Implanter High Voltage Terminal. Contact Yongqiang Wang (505) 665-1596 Email Devoted to the characterization and modification of surfaces through the use of ion beams The Ion Beam Materials Laboratory (IBML) is a Los Alamos National Laboratory resource devoted to the characterization and modification of surfaces through the use of ion beams. The IBML provides and operates the core facilities, while supporting the design and implementation of specific apparati needed for experiments requested by users of the facility. The result is a facility with

130

Noninterceptive beam diagnostics  

SciTech Connect

The need for accurate real-time diagnostics is critical for high-power particle beams. This paper describes the present level of development of noninterceptive devices for these beams. Discussion will be related to diagnostic measurements as they occur along the beamline, from ion-source performance through presentation to an RFQ and measures of the RFQ output, using the cw beam at Los Alamos as a guide. 23 refs.

Chamberlin, D.D.

1985-01-01T23:59:59.000Z

131

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network (OSTI)

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

132

Kicked surface muon beams  

Science Journals Connector (OSTI)

The possibility of splitting a surface muon beam into three separate components using an ... and could be very effectively used to provide muons to time differential ?SR experiments.

J. L. Beveridge

1992-01-01T23:59:59.000Z

133

Measurements and simulations of focused beam for orthovoltage therapy  

SciTech Connect

Purpose: Megavoltage photon beams are typically used for therapy because of their skin-sparing effect. However, a focused low-energy x-ray beam would also be skin sparing, and would have a higher dose concentration at the focal spot. Such a beam can be produced with polycapillary optics. MCNP5 was used to model dose profiles for a scanned focused beam, using measured beam parameters. The potential of low energy focused x-ray beams for radiation therapy was assessed. Methods: A polycapillary optic was used to focus the x-ray beam from a tungsten source. The optic was characterized and measurements were performed at 50 kV. PMMA blocks of varying thicknesses were placed between optic and the focal spot to observe any variation in the focusing of the beam after passing through the tissue-equivalent material. The measured energy spectrum was used to model the focused beam in MCNP5. A source card (SDEF) in MCNP5 was used to simulate the converging x-ray beam. Dose calculations were performed inside a breast tissue phantom. Results: The measured focal spot size for the polycapillary optic was 0.2 mm with a depth of field of 5 mm. The measured focal spot remained unchanged through 40 mm of phantom thickness. The calculated depth dose curve inside the breast tissue showed a dose peak several centimeters below the skin with a sharp dose fall off around the focus. The percent dose falls below 10% within 5 mm of the focus. It was shown that rotating the optic during scanning would preserve the skin-sparing effect of the focused beam. Conclusions: Low energy focused x-ray beams could be used to irradiate tumors inside soft tissue within 5 cm of the surface.

Abbas, Hassan, E-mail: Hassan.Abbas@Yale.Edu [Department of Therapeutic Radiology, Yale University School of Medicine, Yale-New Haven Hospital, New Haven, 344 Lane Street Hamden, Connecticut 06514 (United States)] [Department of Therapeutic Radiology, Yale University School of Medicine, Yale-New Haven Hospital, New Haven, 344 Lane Street Hamden, Connecticut 06514 (United States); Mahato, Dip N., E-mail: dip.n.mahato@intel.com [Intel Corporation, Mail-Stop RA3-410, 2501 NW 229th Avenue, Hillsboro, Oregon 97124 (United States); Satti, Jahangir, E-mail: sattij@mail.amc.edu [Department of Radiation Oncology, Albany Medical Center, 43 New Scotland Avenue, Albany, New York 12208 (United States)] [Department of Radiation Oncology, Albany Medical Center, 43 New Scotland Avenue, Albany, New York 12208 (United States); MacDonald, C. A., E-mail: c.macdonald@albany.edu [Department of Physics, University at Albany, SUNY, 1400 Washington Avenue, Albany, New York 12222 (United States)

2014-04-15T23:59:59.000Z

134

Thermality of the Hawking flux  

E-Print Network (OSTI)

Is the Hawking flux "thermal"? Unfortunately, the answer to this seemingly innocent question depends on a number of often unstated, but quite crucial, technical assumptions built into modern (mis-)interpretations of the word "thermal". The original 1850's notions of thermality --- based on classical thermodynamic reasoning applied to idealized "black bodies" or "lamp black surfaces" --- when supplemented by specific basic quantum ideas from the early 1900's, immediately led to the notion of the black-body spectrum, (the Planck-shaped spectrum), but "without" any specific assumptions or conclusions regarding correlations between the quanta. Many (not all) modern authors (often implicitly and unintentionally) add an extra, and quite unnecessary, assumption that there are no correlations in the black-body radiation; but such usage is profoundly ahistorical and dangerously misleading. Specifically, the Hawking flux from an evaporating black hole, (just like the radiation flux from a leaky furnace or a burning lump of coal), is only "approximately" Planck-shaped over a bounded frequency range. Standard physics (phase space and adiabaticity effects) explicitly bound the frequency range over which the Hawking flux is "approximately" Planck-shaped from both above and below --- the Hawking flux is certainly not exactly Planckian, and there is no compelling physics reason to assume the Hawking photons are uncorrelated.

Matt Visser

2014-09-27T23:59:59.000Z

135

Small beam nonparaxiality arrests selffocusing of optical beams Gadi Fibich  

E-Print Network (OSTI)

Small beam nonparaxiality arrests self­focusing of optical beams Gadi Fibich Department­focusing in the presence of small beam nonparaxiality is derived. Analysis of this equation shows that nonparaxiality remains small as the beam propa­ gates. Nevertheless, nonparaxiality arrests self­focusing when the beam

Soatto, Stefano

136

Electromagnetic Spectrum of Radium D  

Science Journals Connector (OSTI)

The electromagnetic spectrum of RaD has been studied by the proportional counter spectrometry technique. The work of the Curie Laboratory on the gamma-ray spectrum has been generally confirmed. However, the presumed K x-ray lines are of much lower intensity and occur at a lower energy than previously reported. The L x-ray intensity is 22 per hundred disintegrations, indicating 0.63 conversion per disintegration and a conversion coefficient of 18.3 for the principal gamma-ray.

P. E. Damon and R. R. Edwards

1953-04-15T23:59:59.000Z

137

Spectrum Sensing Techniques in Cognitive Radio Communications  

E-Print Network (OSTI)

1 Spectrum Sensing Techniques in Cognitive Radio Communications Mario Bkassiny*, Yang Li, Georges for CR's. Index Terms-- Cognitive radio, cooperative spectrum sensing, dynamic spectrum access, energy, jayaweera, christos}@ece.unm.edu Abstract-- In this paper, we review some of the recent patents on spectrum

Jayaweera, Sudharman K.

138

Coalition Formation Games for Collaborative Spectrum Sensing  

E-Print Network (OSTI)

demand on the radio spectrum. However, the spectrum resources are scarce and most of them have been already licensed to existing operators. Various studies have shown that the actual licensed spectrum remains unoccupied for large periods [1]. For efficiently exploiting these spectrum holes, cognitive radio

Paris-Sud XI, Université de

139

Smart Radio Spectrum Management for Cognitive Radio  

E-Print Network (OSTI)

Today's wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm to exploit the existing wireless spectrum opportunistically. Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. In this work, a fuzzy logic based system for spectrum management is proposed where the radio can share unused spectrum depending on some parameters like distance, signal strength, node velocity and availability of unused spectrum. The system is simulated and is found to give satisfactory results.

Bhattacharya, Partha Pratim; Gera, Rishita; Agarwal, Anjali

2011-01-01T23:59:59.000Z

140

Caborane beam from ITEP Bernas ion source for semiconductor implanters  

SciTech Connect

A joint research and development of steady state intense boron ion sources for hundreds of electron-volt ion implanters has been in progress for the past 5 years. The difficulties of extraction and transportation of low energy boron beams can be solved by implanting clusters of boron atoms. In Institute for Theoretical and Experimental Physics (ITEP) the Bernas ion source successfully generated the beam of decaborane ions. The carborane (C{sub 2}B{sub 10}H{sub 12}) ion beam is more attractive material due to its better thermal stability. The results of carborane ion beam generation are presented. The result of the beam implantation into the silicon wafer is presented as well.

Seleznev, D.; Hershcovitch, A.; Kropachev, G.; Kozlov, A.; Kuibeda, R.; Koshelev, V.; Kulevoy, T.; Jonson, B.; Poole, J.; Alexeyenko, O.; Gurkova, E.; Oks, E.; Gushenets, V.; Polozov, S.; Masunov, E.

2010-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Stabilization of beam-weibel instability by equilibrium density ripples  

SciTech Connect

In this paper, we present an approach to achieve suppression/complete stabilization of the transverse electromagnetic beam Weibel instability in counter streaming electron beams by modifying the background plasma with an equilibrium density ripple, shorter than the skin depth; this weakening is more pronounced when thermal effects are included. On the basis of a linear two stream fluid model, it is shown that the growth rate of transverse electromagnetic instabilities can be reduced to zero value provided certain threshold values for ripple parameters are exceeded. We point out the relevance of the work to recent experimental investigations on sustained (long length) collimation of fast electron beams and integral beam transport for laser induced fast ignition schemes, where beam divergence is suppressed with the assistance of carbon nano-tubes.

Mishra, S. K., E-mail: nishfeb@gmail.com; Kaw, Predhiman; Das, A.; Sengupta, S. [Institute for Plasma Research (IPR), Gandhinagar 382428 (India)] [Institute for Plasma Research (IPR), Gandhinagar 382428 (India); Ravindra Kumar, G. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)] [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

2014-01-15T23:59:59.000Z

142

Chevron beam dump for ITER edge Thomson scattering system  

SciTech Connect

This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.

Yatsuka, E.; Hatae, T.; Bassan, M.; Itami, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)] [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Vayakis, G. [ITER Organization, 13115 St Paul Lez Durance Cedex (France)] [ITER Organization, 13115 St Paul Lez Durance Cedex (France)

2013-10-15T23:59:59.000Z

143

Optimal Light Beams and Mirror Shapes for Future LIGO Interferometers  

E-Print Network (OSTI)

We report the results of a recent search for the lowest value of thermal noise that can be achieved in LIGO by changing the shape of mirrors, while fixing the mirror radius and maintaining a low diffractional loss. The result of this minimization is a beam with thermal noise a factor of 2.32 (in power) lower than previously considered Mesa Beams and a factor of 5.45 (in power) lower than the Gaussian beams employed in the current baseline design. Mirrors that confine these beams have been found to be roughly conical in shape, with an average slope approximately equal to the mirror radius divided by arm length, and with mild corrections varying at the Fresnel scale. Such a mirror system, if built, would impact the sensitivity of LIGO, increasing the event rate of observing gravitational waves in the frequency range of maximum sensitivity roughly by a factor of three compared to an Advanced LIGO using Mesa beams (assuming all other noises remain unchanged). We discuss the resulting beam and mirror properties and study requirements on mirror tilt, displacement and figure error, in order for this beam to be used in LIGO detectors.

Mihai Bondarescu; Oleg Kogan; Yanbei Chen

2008-06-14T23:59:59.000Z

144

Beam director design report  

SciTech Connect

A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 30/sup 0/ beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project. (LEW)

Younger, F.C.

1986-08-01T23:59:59.000Z

145

Design and Testing of a Boron Carbide Capsule for Spectral Tailoring in Mixed-Spectrum Reactors  

SciTech Connect

A boron carbide capsule has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. Irradiations were conducted in pulsed mode and in continuous operation for up to 4 hours. A cadmium cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in good agreement with reactor dosimetry measurements using the STAY'SL computer code. The neutron spectrum resembles that of a fast reactor. Design of a capsule using boron carbide enriched in {sup 10}B shows that it is possible to produce a neutron spectrum similar to {sup 235}U fission.

Greenwood, Lawrence R.; Wittman, Richard S.; Pierson, Bruce D.; Metz, Lori A.; Payne, Rosara F.; Finn, Erin C.; Friese, Judah I.

2012-03-01T23:59:59.000Z

146

Measurements - Ion Beams - Radiation Effects Facility / Cyclotron...  

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

Ion Beams Available Beams Beam Change Times Measurements Useful Graphs Measurements The beam uniformity and flux are determined using an array of five detectors. Each...

147

Neutrino Factories and Beta Beams  

E-Print Network (OSTI)

a Neutrino Factory Based on Muon Beams,” Proc. 2001 ParticleMD. [19] C. Rubbia et al. , “Beam Cooling with Ionisationthe required unstable ion beams has recently been suggested

Zisman, Michael S.

2006-01-01T23:59:59.000Z

148

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC  

SciTech Connect

to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B.; Toth, C.

2009-05-04T23:59:59.000Z

149

Thermal behavior in the LENS process  

SciTech Connect

Direct laser metal deposition processing is a promising manufacturing technology which could significantly impact the length of time between initial concept and finished part. For adoption of this technology in the manufacturing environment, further understanding is required to ensure robust components with appropriate properties are routinely fabricated. This requires a complete understanding of the thermal history during part fabrication and control of this behavior. This paper will describe research to understand the thermal behavior for the Laser Engineered Net Shaping (LENS) process, where a component is fabricated by focusing a laser beam onto a substrate to create a molten pool in which powder particles are simultaneously injected to build each layer. The substrate is moved beneath the laser beam to deposit a thin cross section, thereby creating the desired geometry for each layer. After deposition of each layer, the powder delivery nozzle and focusing lens assembly is incremented in the positive Z-direction, thereby building a three dimensional component layer additively. It is important to control the thermal behavior to reproducibly fabricate parts. The ultimate intent is to monitor the thermal signatures and to incorporate sensors and feedback algorithms to control part fabrication. With appropriate control, the geometric properties (accuracy, surface finish, low warpage) as well as the materials` properties (e.g., strength, ductility) of a component can be dialed into the part through the fabrication parameters. Thermal monitoring techniques will be described, and their particular benefits highlighted. Preliminary details in correlating thermal behavior with processing results will be discussed.

Griffith, M.L.; Schlienger, M.E.; Harwell, L.D. [and others

1998-08-01T23:59:59.000Z

150

Energy Production Demonstrator for Megawatt Proton Beams  

E-Print Network (OSTI)

A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however, a number of approaches (a beam rastering, in first place) are suggested to mitigate the issue. The efficiency of the considered EPD as a Materials Test Station (MTS) is also evaluated in this study.

Vitaly S. Pronskikh; Nikolai Mokhov; Igor Novitski; Sergey I. Tyutyunnikov

2014-07-16T23:59:59.000Z

151

Challenges in Accelerator Beam Instrumentation  

SciTech Connect

The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

Wendt, M.

2009-12-01T23:59:59.000Z

152

Beta-beams  

E-Print Network (OSTI)

Beta-beams is a new concept for the production of intense and pure neutrino beams. It is at the basis of a proposed neutrino facility, whose main goal is to explore the possible existence of CP violation in the lepton sector. Here we briefly review the original scenario and the low energy beta-beam. This option would offer a unique opportunity to perform neutrino interaction studies of interest for particle physics, astrophysics and nuclear physics. Other proposed scenarios for the search of CP violation are mentioned.

C. Volpe

2008-02-22T23:59:59.000Z

153

Towards Cognitive Radio Networks: Spectrum Utilization Measurements in Suburb Environment  

E-Print Network (OSTI)

Towards Cognitive Radio Networks: Spectrum Utilization Measurements in Suburb Environment Václav in an opportunistic way. Cognitive radio concept for better spectrum utilization is introduced here along -- Cognitive radio, radio spectrum management, spectrum sensing, spectrum utilization. I. INTRODUCTION

Paris-Sud XI, Université de

154

Quasi-monoenergetic neutron reference fields in the energy range from thermal to 200 MeV  

Science Journals Connector (OSTI)

......NEUTRON BEAM The thermal reference beam(5) is installed at the research reactor FRG-1 of the GKSS research centre at Geesthacht, Germany. A bent neutron guide is used to transport thermal neutrons from the reactor to the experimental station. The......

R. Nolte; M. S. Allie; R. Böttger; F. D. Brooks; A. Buffler; V. Dangendorf; H. Friedrich; S. Guldbakke; H. Klein; J. P. Meulders; D. Schlegel; H. Schuhmacher; F. D. Smit

2004-08-01T23:59:59.000Z

155

Neutral particle beam intensity controller  

DOE Patents (OSTI)

The neutral beam intensity controller is based on selected magnetic defocusing of the ion beam prior to neutralization. The defocused portion of the beam is dumped onto a beam dump disposed perpendicular to the beam axis. Selective defocusing is accomplished by means of a magnetic field generator disposed about the neutralizer so that the field is transverse to the beam axis. The magnetic field intensity is varied to provide the selected partial beam defocusing of the ions prior to neutralization. The desired focused neutral beam portion passes along the beam path through a defining aperture in the beam dump, thereby controlling the desired fraction of neutral particles transmitted to a utilization device without altering the kinetic energy level of the desired neutral particle fraction. By proper selection of the magnetic field intensity, virtually zero through 100% intensity control of the neutral beam is achieved.

Dagenhart, W.K.

1984-05-29T23:59:59.000Z

156

Courses on Beam Physics  

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

Beam Physics Beam Physics The following is an incomplete listing of course available for beam physics. United States Particle Accelerator School The US Particle Accelerator School provides educational programs in the field of beams and their associated accelerator technologies not otherwise available to the community of science and technology. Joint Universities Accelerator School Each year JUAS provides a foundation course on accelerator physics and associated technologies. The US-CERN-Japan-Russia Joint Accelerator School The purpose of the US-CERN-Japan-Russia joint school is to better our relations by working together on an advanced topical course every two years, alternating between the U.S., western Europe, Japan and Russia. The last set of courses focused on the frontiers of accelerator technology in

157

Focused ion beam system  

DOE Patents (OSTI)

A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

1999-08-31T23:59:59.000Z

158

BNL | ATF Beam Diagnostics  

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

Beamline Spectrometry Both ATF beam lines have dipoles, which serve as spectrometers, the vacuum chambers on of these dipoles also have zero degree ports that may be covered with a...

159

Electron Beam Ion Sources  

E-Print Network (OSTI)

Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

Zschornacka, G; Thorn, A

2013-01-01T23:59:59.000Z

160

BNL | ATF Beam Schedule  

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

Beam Schedule (pdf) Beam Schedule (pdf) Sunday Monday Tuesday Wednesday Thursday Friday Saturday 22 1/2 Holiday Holiday 28 January Holiday 4 5 Maintenance 11 12 Maintenance 18 19 Holiday AE52 - DWFA (Euclid), BL2 25 February AE52 - DWFA (Euclid), BL2 1 2 AE50 - PWFA in QNR (UCLA), BL2 8 9 AE50 - PWFA in QNR (UCLA), BL2 15 16 Holiday AE50 - PWFA in QNR (UCLA), BL2 22 March 1 2 AE53 - Nonlinear Compton (UCLA) 8 9 AE53 - Nonlinear Compton (UCLA) 15 16 AE53 - Nonlinear Compton (UCLA) 22 23 29 Sunday Monday Tuesday Wednesday Thursday Friday Saturday User operations (E-beam in use) Ions - Ion generation User operations (laser in use) PWFA - Plasma Wakefield Acceleration User operations (E-beam and laser in use)

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Small Spot, Brighter Beam  

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

Small Spot, Brighter Beam Small Spot, Brighter Beam Small Spot, Brighter Beam Print Do you notice the brighter beam? During the most recent shutdown, all of the corrector magnets were replaced with sextupoles, reducing the horizontal emittance and increasing beam brightness. "This is part of ongoing improvement to keep the ALS on the cutting edge," says Alastair MacDowell, a beamline scientist on Beamline 12.2.2. The brightness has increased by a factor of about three in the storage ring. Beamlines on superbend or center-bend magnets will see the most noticeable increase in brightness, but the horizontal beam size and divergence have been substantially reduced at all beamlines. "We are starting to approach the resolution of many beamlines. Therefore, not every beamline will be able to resolve the full improvement," says Christoph Steier, project leader of the brightness upgrade. Though superbend and center-bend magnet source sizes are reduced by roughly a factor of three, "measured improvements so far range from a factor of 2-2.5," Steier says. He and MacDowell agree that the beamline optics are likely the limiting factor in resolving the full improvement at the beamlines.

162

Ion-beam superpinch  

Science Journals Connector (OSTI)

Intense nonrelativistic light-ion beams generated in magnetically insulated diodes can reach total beam currents large enough to confine charged fusion products within pinch channels which are formed by these beams if they are projected onto thermonuclear material. Furthermore, since the required beam currents are still below the critical Alfvén current, these pinch channels are magnetohydrodynamically stable. However, because the time these beams last is very short and of the order of 10 nsec, the thermonuclear target must have a density at least as large as solid-state density to satisfy the Lawson criterion. This large target density makes it necessary that the beam be focused down to a radius less than ? 10-2 cm, to balance the plasma pressure against the magnetic pressure. To make this focusing possible a new kind of a low-emittance intense ion source is proposed. It consists of pointlike pulsed dense plasma positioned in the field-free space behind a meshlike anode. The focusing itself can be done in three steps, first by sufficiently good ion optics, second by wall focusing, and third by radiation cooling. This inertial-confinement fusion concept avoids the problems of reaching this goal through highdensity target compression by ablative implosion.

F. Winterberg

1981-10-01T23:59:59.000Z

163

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development  

SciTech Connect

The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

2012-05-15T23:59:59.000Z

164

Public safety radios must pool spectrum  

E-Print Network (OSTI)

The dynamic-spectrum-access research and development community is maturing technologies that will enable radios to share RF spectrum much more intensively. The adoption of DSA technologies by the public-safety community ...

Lehr, William Herndon

165

Fluctuations of Beams of Quantum Particles  

Science Journals Connector (OSTI)

A beam of noninteracting particles, bosons or fermions, is described by the superposition of stochastic wave packets. This description allows in each case (bosons or fermions) the determination of the detection process of the particles. This process is defined by the set of the p-order coincidence probability densities, a general formulation of which is given. In the case of a stationary and weak incoherent beam, these coincidence probability densities are studied thoroughly and several results are obtained. The well-known bunching effect for bosons and the "antibunching effect" for fermions are shown to come from the detection of indistinguishable particles. In the boson case, all the well-known results for thermal light are found. In the fermion case, the detection process is, under certain conditions, identical to a renewal process.

Christine Bénard

1970-11-01T23:59:59.000Z

166

Single element laser beam shaper  

DOE Patents (OSTI)

A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

2005-09-13T23:59:59.000Z

167

REVIEW ARTICLE Taming molecular beams  

E-Print Network (OSTI)

REVIEW ARTICLE Taming molecular beams The motion of neutral molecules in a beam can be manipulated time-varying fields can be used to decelerate or accelerate beams of molecules to any desired velocity. We review the possibilities that this molecular-beam technology offers, ranging from ultrahigh

Loss, Daniel

168

Spectrum Characterization for Opportunistic Cognitive Radio Systems  

E-Print Network (OSTI)

1 Spectrum Characterization for Opportunistic Cognitive Radio Systems Tevfik Y¨ucek and H challenging problems in cognitive radio systems. The spectrum of interest needs to be characterized and unused initial network entry is also discussed as a case study. Index Terms-- Cognitive radio, spectrum sensing

Arslan, Hüseyin

169

Primary proton beam line at the J-PARC hadron experimental facility  

Science Journals Connector (OSTI)

......water passage, the insulation reliability and...improved as ceramic insulation pipes are not required...the results of a thermal and mechanical...radiation-hard specifications. In the SY, almost...included. The main specifications of the optics are...reduce beam loss and thermal stress. Aluminum......

Keizo Agari; Erina Hirose; Masaharu Ieiri; Masami Iio; Yoji Katoh; Akio Kiyomichi; Michifumi Minakawa; Ryotaro Muto; Megumi Naruki; Hiroyuki Noumi; Yoshinori Sato; Shin?ya Sawada; Yoshihisa Shirakabe; Yoshihiro Suzuki; Hitoshi Takahashi; Minoru Takasaki; Kazuhiro H. Tanaka; Akihisa Toyoda; Hiroaki Watanabe; Yutaka Yamanoi

2012-01-01T23:59:59.000Z

170

Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab  

SciTech Connect

A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.

Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S.; Rakhno, I.; /Fermilab

2012-05-10T23:59:59.000Z

171

Light beam frequency comb generator  

DOE Patents (OSTI)

A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics.

Priatko, Gordon J. (Cupertino, CA); Kaskey, Jeffrey A. (Livermore, CA)

1992-01-01T23:59:59.000Z

172

Susceptor heating device for electron beam brazing  

DOE Patents (OSTI)

A brazing device and method are provided which locally apply a controlled amount of heat to a selected area, within a vacuum. The device brazes two components together with a brazing metal. A susceptor plate is placed in thermal contact with one of the components. A serrated pedestal supports the susceptor plate. When the pedestal and susceptor plate are in place, an electron gun irradiates an electron beam at the susceptor plate such that the susceptor plate is sufficiently heated to transfer heat through the one component and melt the brazing metal.

Antieau, Susan M. (Pittsburgh, PA); Johnson, Robert G. R. (Trafford, PA)

1999-01-01T23:59:59.000Z

173

Hybrid spread spectrum radio system  

DOE Patents (OSTI)

Systems and methods are described for hybrid spread spectrum radio systems. A method includes modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control an amplification circuit that provides a gain to the signal. Another method includes: modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control a fast hopping frequency synthesizer; and fast frequency hopping the signal with the fast hopping frequency synthesizer, wherein multiple frequency hops occur within a single data-bit time.

Smith, Stephen F. (London, TN); Dress, William B. (Camas, WA)

2010-02-02T23:59:59.000Z

174

Thermal effects testing at the National Solar Thermal Test Facility  

SciTech Connect

The National Solar Thermal Test Facility is operated by Sandia National Laboratories and located on Kirkland Air Force Base in Albuquerque, New Mexico. The permanent features of the facility include a heliostat field and associated receiver tower, two solar furnaces, two point-focus parabolic concentrators, and Engine Test Facility. The heliostat field contains 220 computer-controlled mirrors, which reflect concentrated solar energy to test stations on a 61-m tower. The field produces a peak flux density of 250 W/cm{sup 2} that is uniform over a 15-cm diameter with a total beam power of over 5 MW{sub t}. The solar beam has been used to simulate aerodynamic heating for several customers. Thermal nuclear blasts have also been simulated using a high-speed shutter in combination with heliostat control. The shutter can accommodate samples up to 1 m {times} 1 m and it has been used by several US and Canadian agencies. A glass-windowed wind tunnel is also available in the Solar Tower. It provides simultaneous exposure to the thermal flux and air flow. Each solar furnace at the facility includes a heliostat, an attenuator, and a parabolic concentrator. One solar furnace produces flux levels of 270 W/cm{sup 2} over and delivers a 6-mm diameter and total power of 16 kW{sub t}. A second furnace produces flux levels up to 1000 W/cm{sup 2} over a 4 cm diameter and total power of 60 kW{sub t}. Both furnaces include shutters and attenuators that can provide square or shaped pulses. The two 11 m diameter tracking parabolic point-focusing concentrators at the facility can each produce peak flux levels of 1500 W/cm{sup 2} over a 2.5 cm diameter and total power of 75 kW{sub t}. High-speed shutters have been used to produce square pulses.

Ralph, M.E.; Cameron, C.P. [Sandia National Labs., Albuquerque, NM (United States); Ghanbari, C.M. [Technadyne Engineering Consultants, Inc., Albuquerque, NM (United States)

1992-12-31T23:59:59.000Z

175

Thermal effects testing at the National Solar Thermal Test Facility  

SciTech Connect

The National Solar Thermal Test Facility is operated by Sandia National Laboratories and located on Kirkland Air Force Base in Albuquerque, New Mexico. The permanent features of the facility include a heliostat field and associated receiver tower, two solar furnaces, two point-focus parabolic concentrators, and Engine Test Facility. The heliostat field contains 220 computer-controlled mirrors, which reflect concentrated solar energy to test stations on a 61-m tower. The field produces a peak flux density of 250 W/cm[sup 2] that is uniform over a 15-cm diameter with a total beam power of over 5 MW[sub t]. The solar beam has been used to simulate aerodynamic heating for several customers. Thermal nuclear blasts have also been simulated using a high-speed shutter in combination with heliostat control. The shutter can accommodate samples up to 1 m [times] 1 m and it has been used by several US and Canadian agencies. A glass-windowed wind tunnel is also available in the Solar Tower. It provides simultaneous exposure to the thermal flux and air flow. Each solar furnace at the facility includes a heliostat, an attenuator, and a parabolic concentrator. One solar furnace produces flux levels of 270 W/cm[sup 2] over and delivers a 6-mm diameter and total power of 16 kW[sub t]. A second furnace produces flux levels up to 1000 W/cm[sup 2] over a 4 cm diameter and total power of 60 kW[sub t]. Both furnaces include shutters and attenuators that can provide square or shaped pulses. The two 11 m diameter tracking parabolic point-focusing concentrators at the facility can each produce peak flux levels of 1500 W/cm[sup 2] over a 2.5 cm diameter and total power of 75 kW[sub t]. High-speed shutters have been used to produce square pulses.

Ralph, M.E.; Cameron, C.P. (Sandia National Labs., Albuquerque, NM (United States)); Ghanbari, C.M. (Technadyne Engineering Consultants, Inc., Albuquerque, NM (United States))

1992-01-01T23:59:59.000Z

176

Far-IR and radio thermal continua in solar flares  

E-Print Network (OSTI)

With the invention of new far-infrared (FIR) and radio mm and sub-mm instruments (DESIR on SMESE satellite, ESO-ALMA), there is a growing interest in observations and analysis of solar flares in this so far unexplored wavelength region. Two principal radiation mechanisms play a role: the synchrotron emission due to accelerated particle beams moving in the magnetic field and the thermal emission due to the energy deposit in the lower atmospheric layers. In this contribution we explore the time-dependent effects of beams on thermal FIR and radio continua. We show how and where these continua are formed in the presence of time dependent beam heating and non-thermal excitation/ionisation of the chromospheric hydrogen plasma.

Kašparová, J; Karlický, M; Moravec, Z; Varady, M

2009-01-01T23:59:59.000Z

177

Seasonal thermal energy storage  

SciTech Connect

This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

1984-05-01T23:59:59.000Z

178

Expanded beam deflection method for simultaneous measurement of displacement and vibrations of multiple microcantilevers  

SciTech Connect

Here we present an extension of optical beam deflection (OBD) method for measuring displacement and vibrations of an array of microcantilevers. Instead of focusing on the cantilever, the optical beam is either focused above or below the cantilever array, or focused only in the axis parallel to the cantilevers length, allowing a wide optical line to span multiple cantilevers in the array. Each cantilever reflects a part of the incident beam, which is then directed onto a photodiode array detector in a manner allowing distinguishing between individual beams. Each part of reflected beam behaves like a single beam of roughly the same divergence angle in the bending sensing axis as the incident beam. Since sensitivity of the OBD method depends on the divergence angle of deflected beam, high sensitivity is preserved in proposed expanded beam deflection (EBD) method. At the detector, each spot's position is measured at the same time, without time multiplexing of light sources. This provides real simultaneous readout of entire array, unavailable in most of competitive methods, and thus increases time resolution of the measurement. Expanded beam can also span another line of cantilevers allowing monitoring of specially designed two-dimensional arrays. In this paper, we present first results of application of EBD method to cantilever sensors. We show how thermal noise resolution can be easily achieved and combined with thermal noise based resonance frequency measurement.

Nieradka, K.; MaloziePc, G.; Kopiec, D.; Gotszalk, T. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroclaw 50-372 (Poland); Grabiec, P.; Janus, P.; Sierakowski, A. [Division of Silicon Microsystem and Nanostructure Technology, Institute of Electron Technology, Lotnikow 32/46, Warsaw 02-668 (Poland)

2011-10-15T23:59:59.000Z

179

SPARTA: Stable and Efficient Spectrum Access in Next Generation Dynamic Spectrum Networks  

E-Print Network (OSTI)

and development require easy and reliable access to radio spectrum. However, exist- ing regulations allocateSPARTA: Stable and Efficient Spectrum Access in Next Generation Dynamic Spectrum Networks Lili Cao.S.A Abstract--Future wireless infrastructure networks will dynam- ically access spectrum for maximum

Almeroth, Kevin C.

180

Joint Spectrum Allocation and Scheduling for Fair Spectrum Sharing in Cognitive Radio  

E-Print Network (OSTI)

Joint Spectrum Allocation and Scheduling for Fair Spectrum Sharing in Cognitive Radio Wireless University, Tempe, AZ 85287-8809. Email:{misra,xue}@asu.edu Abstract Cognitive radio and Dynamic Spectrum joint spectrum alloca- tion and scheduling problems in cognitive radio wireless networks with the objec

Misra, Satyajayant

Note: This page contains sample records for the topic "beam spectrum thermal" 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

SLC beam dynamics issues  

SciTech Connect

The Stanford Linear Collider (SLC){sup 1,2} accelerates single bunches of electrons and positrons to 47 GeV per beam and collides them with small beam sizes and at high currents. The beam emittances and intensities required for present operation have significantly extended traditional beam quality limits. The electron source produces over 10{sup 11} e{sup {minus}} in each of two bunches. The damping rings provide coupled invariant emittances of 1.8 {times} 10{sup {minus}5} r-m at 4.5 {times} 10{sup 10} particles. The 50 GeV linac has successfully accelerated over 3 {times} 10{sup 10} particles with design invariant emittances of 3 {times} 10{sup {minus}5} r-m. The collider arcs are now sufficiently decoupled and matched in betatron space, so that the final focus can be chromatically corrected, routinely producing spot sizes ({sigma}{sub x}, {sigma}{sub y}) of 2.5 {mu}m at the interaction point. Spot sizes below 2 {mu}m have been made during tests. Instrumentation and feedback systems are well advanced, providing continuous beam monitoring and considerable pulse-by-pulse control. The luminosity reliability is about 60%. Overviews of the recent accelerator physics achievements used to obtain these parameters and the present limiting phenomena are described for each accelerator subsystem.

Seeman, J.T.

1991-12-01T23:59:59.000Z

182

Apparatus and methods for continuous beam fourier transform mass spectrometry  

DOE Patents (OSTI)

A continuous beam Fourier transform mass spectrometer in which a sample of ions to be analyzed is trapped in a trapping field, and the ions in the range of the mass-to-charge ratios to be analyzed are excited at their characteristic frequencies of motion by a continuous excitation signal. The excited ions in resonant motions generate real or image currents continuously which can be detected and processed to provide a mass spectrum.

McLuckey, Scott A. (Oak Ridge, TN); Goeringer, Douglas E. (Oak Ridge, TN)

2002-01-01T23:59:59.000Z

183

Thermal unobtainiums? The perfect thermal conductor and  

E-Print Network (OSTI)

contribute to thermal resistance · Isotopically pure diamond has highest thermal conductivity of any material materials: disordered layered crystals Conclude with some thoughts on promising, high-risk, research even in a computer model. #12;Thermal resistance is created by Umklapp scattering (U

Braun, Paul

184

Determination of a mutational spectrum  

DOE Patents (OSTI)

A method of resolving (physically separating) mutant DNA from nonmutant DNA and a method of defining or establishing a mutational spectrum or profile of alterations present in nucleic acid sequences from a sample to be analyzed, such as a tissue or body fluid. The present method is based on the fact that it is possible, through the use of DGGE, to separate nucleic acid sequences which differ by only a single base change and on the ability to detect the separate mutant molecules. The present invention, in another aspect, relates to a method for determining a mutational spectrum in a DNA sequence of interest present in a population of cells. The method of the present invention is useful as a diagnostic or analytical tool in forensic science in assessing environmental and/or occupational exposures to potentially genetically toxic materials (also referred to as potential mutagens); in biotechnology, particularly in the study of the relationship between the amino acid sequence of enzymes and other biologically-active proteins or protein-containing substances and their respective functions; and in determining the effects of drugs, cosmetics and other chemicals for which toxicity data must be obtained.

Thilly, William G. (Winchester, MA); Keohavong, Phouthone (Cambridge, MA)

1991-01-01T23:59:59.000Z

185

On the Spectrum of Superspheres  

E-Print Network (OSTI)

Sigma models on coset superspaces, such as odd dimensional superspheres, play an important role in physics and in particular the AdS/CFT correspondence. In this work we apply recent general results on the spectrum of coset space models and on supergroup WZNW models to study the conformal sigma model with target space S^{3|2}. We construct its vertex operators and provide explicit formulas for their anomalous dimensions, at least to leading order in the sigma model coupling. The results are used to revisit a non-perturbative duality between the supersphere and the OSP(4|2) Gross-Neveu model that was conjectured by Candu and Saleur. With the help of powerful all-loop results for 1/2 BPS operators in the Gross-Neveu model we are able to recover the entire zero mode spectrum of the sigma model at a certain finite value of the Gross-Neveu coupling. In addition, we argue that the sigma model constraints and equations of motion are implemented correctly in the dual Gross-Neveu description. On the other hand, high(er) gradient operators of the sigma model are not all accounted for. It is possible that this discrepancy is related to an instability from high gradient operators that has previously been observed in the context of Anderson localization.

Alessandra Cagnazzo; Volker Schomerus; Vaclav Tlapak

2014-08-28T23:59:59.000Z

186

On the Spectrum of Superspheres  

E-Print Network (OSTI)

Sigma models on coset superspaces, such as odd dimensional superspheres, play an important role in physics and in particular the AdS/CFT correspondence. In this work we apply recent general results on the spectrum of coset space models and on supergroup WZNW models to study the conformal sigma model with target space S^{3|2}. We construct its vertex operators and provide explicit formulas for their anomalous dimensions, at least to leading order in the sigma model coupling. The results are used to revisit a non-perturbative duality between the supersphere and the OSP(4|2) Gross-Neveu model that was conjectured by Candu and Saleur. With the help of powerful all-loop results for 1/2 BPS operators in the Gross-Neveu model we are able to recover the entire zero mode spectrum of the sigma model at a certain finite value of the Gross-Neveu coupling. In addition, we argue that the sigma model constraints and equations of motion are implemented correctly in the dual Gross-Neveu description. On the other hand, high(er...

Cagnazzo, Alessandra; Tlapak, Vaclav

2014-01-01T23:59:59.000Z

187

Mode-selective thermal radiation from a microparticle  

SciTech Connect

We experimentally demonstrate that thermal radiation from a micron-sized dielectric particle depends sensitively on its size and shape through the cavity quantum-electrodynamic effect. Our laser trapping technique levitated a high-temperature microsphere of Al{sub 2}O{sub 3} and enabled emission spectroscopy of the single particle. As the particle becomes smaller, a blackbodylike spectrum turns into a spectrum dominated by multiple peaks resonant with whispering gallery modes of the spherical resonator. The observed sharp frequency selectivity is applicable to spectral control of thermal radiation.

Odashima, Hitoshi; Tachikawa, Maki; Takehiro, Kei [Department of Physics, Meiji University, Kawasaki 214-8571 (Japan)

2009-10-15T23:59:59.000Z

188

Precision control of thermal transport in cryogenic single-crystal silicon devices  

E-Print Network (OSTI)

We report on the diffusive-ballistic thermal conductance of multi-moded single-crystal silicon beams measured below 1 K. It is shown that the phonon mean-free-path $\\ell$ is a strong function of the surface roughness characteristics of the beams. This effect is enhanced in diffuse beams with lengths much larger than $\\ell$, even when the surface is fairly smooth, 5-10 nm rms, and the peak thermal wavelength is 0.6 $\\mu$m. Resonant phonon scattering has been observed in beams with a pitted surface morphology and characteristic pit depth of 30 nm. Hence, if the surface roughness is not adequately controlled, the thermal conductance can vary significantly for diffuse beams fabricated across a wafer. In contrast, when the beam length is of order $\\ell$, the conductance is dominated by ballistic transport and is effectively set by the beam area. We have demonstrated a uniformity of $\\pm$8% in fractional deviation for ballistic beams, and this deviation is largely set by the thermal conductance of diffuse beams tha...

Rostem, Karwan; Colazo, Felipe A; Crowe, Erik J; Denis, Kevin L; Lourie, Nathan P; Moseley, Samuel H; Stevenson, Thomas R; Wollack, Edward J

2014-01-01T23:59:59.000Z

189

Injection Locking Techniques for Spectrum Analysis  

SciTech Connect

Wideband spectrum analysis supports future communication systems that reconfigure and adapt to the capacity of the spectral environment. While test equipment manufacturers offer wideband spectrum analyzers with excellent sensitivity and resolution, these spectrum analyzers typically cannot offer acceptable size, weight, and power (SWAP). CMOS integrated circuits offer the potential to fully integrate spectrum analysis capability with analog front-end circuitry and digital signal processing on a single chip. Unfortunately, CMOS lacks high-Q passives and wideband resonator tunability that is necessary for heterodyne implementations of spectrum analyzers. As an alternative to the heterodyne receiver architectures, two nonlinear methods for performing wideband, low-power spectrum analysis are presented. The first method involves injecting the spectrum of interest into an array of injection-locked oscillators. The second method employs the closed loop dynamics of both injection locking and phase locking to independently estimate the injected frequency and power.

Gathma, Timothy D.; Buckwalter, James F. [Department of Electrical and Computer Engineering, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 9209 (United States)

2011-04-19T23:59:59.000Z

190

Measurement of Hyperfine Structure in the Infrared Rotation-Vibration Spectrum of NH-  

Science Journals Connector (OSTI)

Hyperfine structure (hfs) has been observed in the P, Q, and R branches of the fundamental rotation-vibration spectrum of the X?2 electronic state of the molecular anion NH-. A coaxial ion-beam-laser-beam spectrometer is employed in which rotation-vibration transitions are induced by a color-center laser operating near 3000 cm-1. The vibrationally excited ions autodetach, and the fast neutral NH is detected. The structure has been analyzed and the magnetic dipole hfs parameters obtained in both N14H- and N15H-. This is the first analyzed case of hfs in any molecular anion.

Harold C. Miller; Mohammad Al-Za'al; John W. Farley

1987-05-18T23:59:59.000Z

191

Thermal Control & System Integration  

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

The thermal control and system integration activity focuses on issues such as the integration of motor and power control technologies and the development of advanced thermal control technologies....

192

Beam Profile Monitor With Accurate Horizontal And Vertical Beam Profiles  

DOE Patents (OSTI)

A widely used scanner device that rotates a single helically shaped wire probe in and out of a particle beam at different beamline positions to give a pair of mutually perpendicular beam profiles is modified by the addition of a second wire probe. As a result, a pair of mutually perpendicular beam profiles is obtained at a first beamline position, and a second pair of mutually perpendicular beam profiles is obtained at a second beamline position. The simple modification not only provides more accurate beam profiles, but also provides a measurement of the beam divergence and quality in a single compact device.

Havener, Charles C [Knoxville, TN; Al-Rejoub, Riad [Oak Ridge, TN

2005-12-26T23:59:59.000Z

193

Beam-Based Alignment  

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

One: One: Single-Bunch Comparative Study of Three Algorithms Peter Tenenbaum LCC-Note-0013 17-February-1999 Abstract We describe the results of a series of simulation studies of beam-based alignment of the NLC main linacs using the program LIAR. Three algorithms for alignment of quadrupoles and girders are consid- ered: the algorithm used in the ZDR, the ZDR algorithm combined with a post-alignment MICADO operation, and an algorithm which requires no steering dipoles but requires twice as many alignment segments per linac as the ZDR algorithm. The third algorithm appears to be the most robust, based on convergence time, required quad mover step sizes, and variation in extracted beam emittance as a function of BNS profile. We also study the effect of structure BPM resolution and ATL misalignments during the alignment process. 1 Introduction Beam-based alignment and steering of the

194

Single Crystal Diamond Beam Position Monitors with Radiofrequency Electronic Readout  

SciTech Connect

Over the energy range 5{approx}30 keV a suitably contacted, thin ({approx}100 {mu}m) diamond plate can be operated in situ as a continuous monitor of X-ray beam intensity and position as the diamond absorbs only a small percentage of the incident beam. Single crystal diamond is a completely homogeneous material showing fast (ns), spatially uniform signal response and negligible (thermal conductivity, it is the only semiconductor material that can be used in intense synchrotron white beams. We report on tests made at ESRF and DESY using diamond beam position monitors of simple quadrant electrode designs with metal contacts, operated using wideband electronic readout corresponding to the RF accelerator frequency. The instrumentation for these monitors must cover a large range of operating conditions: different beam sizes, fluxes, energies and time structure corresponding to the synchrotron fill patterns. Sophisticated new RF sampling electronics can satisfy most requirements: using a modified Libera Brilliance readout system, we measured the center of gravity position of a 25 {mu}m beam at the DORIS III F4 beam line at a rate of 130 Msample/s with narrowband filtering of a few MHz bandwidth. Digitally averaging the signal further provided a spatial resolution {approx}20 nm.

Solar, B.; Graafsma, H.; Potdevin, G.; Trunk, U. [Hasylab, Deutsches Elektronen Synchroton, Hamburg (Germany); Morse, J.; Salome, M. [Instrumentation Services and Development Division, European Synchroton Radiation Facility, Grenoble (France)

2010-06-23T23:59:59.000Z

195

Colliding neutrino beams  

E-Print Network (OSTI)

From several neutrino oscillation experiments, we understand now that neutrinos have mass. However, we really don't know what mechanism is responsible for producing this neutrino mass. Current or planned neutrino experiments utilize neutrino beams and long-baseline detectors to explore flavor mixing but do not address the question of the origin of neutrino mass. In order to answer that question, neutrino interactions need to be explored at much higher energies. This paper outlines a program to explore neutrinos and their interactions with various particles through a series of experiments involving colliding neutrino beams.

Reinhard Schwienhorst

2007-11-08T23:59:59.000Z

196

System and method for delivery of neutron beams for medical therapy  

DOE Patents (OSTI)

A neutron delivery system that provides improved capability for tumor control during medical therapy is disclosed. The system creates a unique neutron beam that has a bimodal or multi-modal energy spectrum. This unique neutron beam can be used for fast-neutron therapy, boron neutron capture therapy (BNCT), or both. The invention includes both an apparatus and a method for accomplishing the purposes of the invention. 5 figs.

Nigg, D.W.; Wemple, C.A.

1999-07-06T23:59:59.000Z

197

System and method for delivery of neutron beams for medical therapy  

DOE Patents (OSTI)

A neutron delivery system that provides improved capability for tumor control during medical therapy. The system creates a unique neutron beam that has a bimodal or multi-modal energy spectrum. This unique neutron beam can be used for fast-neutron therapy, boron neutron capture therapy (BNCT), or both. The invention includes both an apparatus and a method for accomplishing the purposes of the invention.

Nigg, David W. (Idaho Falls, ID); Wemple, Charles A. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

198

Non-Paraxial Accelerating Beams  

E-Print Network (OSTI)

We present the spatially accelerating solutions of the Maxwell equations. Such non-paraxial beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams. For both TE and TM polarizations, the beams exhibit shape-preserving bending with sub-wavelength features, and the Poynting vector of the main lobe displays a turn of more than 90 degrees. We show that these accelerating beams are self-healing, analyze their properties, and compare to the paraxial Airy beams. Finally, we present the new family of periodic accelerating beams which can be constructed from our solutions.

Ido Kaminer; Rivka Bekenstein; Jonathan Nemirovsky; Mordechai Segev

2012-02-03T23:59:59.000Z

199

Antineutrino spectra from 241Pu and 239Pu thermal neutron fission products  

Science Journals Connector (OSTI)

The antineutrino spectrum of fission products from thermal neutron induced fission of 241Pu was derived from a measurement of the correlated beta spectrum. The energy range 1.5 MeV to 9 MeV was covered and a precision of 4% was achieved at 4 MeV. A revised version of the antineutrino spectrum from 239Pu fission is also presented.

A.A. Hahn; K. Schreckenbach; W. Gelletly; F. von Feilitzsch; G. Colvin; B. Krusche

1989-01-01T23:59:59.000Z

200

Apparatus and method for transient thermal infrared spectrometry of flowable enclosed materials  

DOE Patents (OSTI)

A method and apparatus for enabling analysis of a flowable material enclosed in a transport system having an infrared transparent wall portion. A temperature differential is transiently generated between a thin surface layer portion of the material and a lower or deeper portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material, and the altered thermal infrared emission spectrum is detected through the infrared transparent portion of the transport system while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower or deeper portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation. By such detection, the detected altered thermal infrared emission spectrum is indicative of characteristics relating to molecular composition of the material.

McClelland, John F. (Ames, IA); Jones, Roger W. (Ames, IA)

1993-03-02T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Collisionless relaxation in beam-plasma systems  

SciTech Connect

This thesis reports the results from the theoretical investigations, both numerical and analytical, of collisionless relaxation phenomena in beam-plasma systems. Many results of this work can also be applied to other lossless systems of plasma physics, beam physics and astrophysics. Different aspects of the physics of collisionless relaxation and its modeling are addressed. A new theoretical framework, named Coupled Moment Equations (CME), is derived and used in numerical and analytical studies of the relaxation of second order moments such as beam size and emittance oscillations. This technique extends the well-known envelope equation formalism, and it can be applied to general systems with nonlinear forces. It is based on a systematic moment expansion of the Vlasov equation. In contrast to the envelope equation, which is derived assuming constant rms beam emittance, the CME model allows the emittance to vary through coupling to higher order moments. The CME model is implemented in slab geometry in the absence of return currents. The CME simulation yields rms beam sizes, velocity spreads and emittances that are in good agreement with particle-in-cell (PIC) simulations for a wide range of system parameters. The mechanism of relaxation is also considered within the framework of the CME system. It is discovered that the rapid relaxation or beam size oscillations can be attributed to a resonant coupling between different modes of the system. A simple analytical estimate of the relaxation time is developed. The final state of the system reached after the relaxation is complete is investigated. New and accurate analytical results for the second order moments in the phase-mixed state are obtained. Unlike previous results, these connect the final values of the second order moments with the initial beam mismatch. These analytical estimates are in good agreement with the CME model and PIC simulations. Predictions for the final density and temperature are developed that show main important features of the spatial dependence of the profiles. Different aspect of the final coarse-grained state such as its non-thermal nature, the appearance of 'hot' regions on the periphery and the core-halo character of the density are investigated.

Backhaus, Ekaterina Yu.

2001-05-01T23:59:59.000Z

202

Pulsed ion beam source  

DOE Patents (OSTI)

An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

Greenly, J.B.

1997-08-12T23:59:59.000Z

203

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

Kuchnir, M.; Mills, F.E.

1984-09-28T23:59:59.000Z

204

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

1987-01-01T23:59:59.000Z

205

Isolating the thermal degree of freedom in nuclear multifragmentation.  

SciTech Connect

Multifragmentation studies induced by GeV light-ion beams permit investigation of the influence of intrinsic thermal properties of hot nuclear matter, with minimal interference from the compression/decompression cycle and rotational instabilities. We summarize recent results obtained with {sup 3}He, proton and pion beams up to 15 GeV/c and present the initial results from a recent experiment with 8 GeV/c antiproton and pion beams. The results are compared with INC simulations coupled to EES and SMM models and the caloric curve for the {sup 3}He data will also be discussed.

Back, B.; Beaulieu, L.; Breuer, H.; Gushue, S.; Hsi, W.-C.; Korteling, R. G.; Kwiatkowski, K.; Laforest, R.; Lefort, T.; Martin, E.; Pienkowski, L.; Ramakrishnan, E.; Remsberg, L. P.; Rowland, D.; Ruangma, A.; Viola, V. E.; Winchester, E.; Yennello, S. J.

1999-05-03T23:59:59.000Z

206

Neutral particle beam intensity controller  

DOE Patents (OSTI)

A neutral beam intensity controller is provided for a neutral beam generator in which a neutral beam is established by accelerating ions from an ion source into a gas neutralizer. An amplitude modulated, rotating magnetic field is applied to the accelerated ion beam in the gas neutralizer to defocus the resultant neutral beam in a controlled manner to achieve intensity control of the neutral beam along the beam axis at constant beam energy. The rotating magnetic field alters the orbits of ions in the gas neutralizer before they are neutralized, thereby controlling the fraction of neutral particles transmitted out of the neutralizer along the central beam axis to a fusion device or the like. The altered path or defocused neutral particles are sprayed onto an actively cooled beam dump disposed perpendicular to the neutral beam axis and having a central open for passage of the focused beam at the central axis of the beamline. Virtually zero therough 100% intensity control is achieved by varying the magnetic field strength without altering the ion source beam intensity or its species yield.

Dagenhart, William K. (Oak Ridge, TN)

1986-01-01T23:59:59.000Z

207

Spectrum Auction Framework for Access Allocation in Cognitive Radio Networks  

E-Print Network (OSTI)

1 Spectrum Auction Framework for Access Allocation in Cognitive Radio Networks Gaurav S. Kasbekar does not exist. Index Terms Cognitive Radio Networks, Spectrum Auctions, Algorithms I. INTRODUCTION, Wireless Meteropolitan Area networks etc., demand for radio spectrum is increasing. Currently, spectrum

Sarkar, Saswati

208

Thermal Management of Solar Cells  

E-Print Network (OSTI)

a better thermal conductance and when ceramic particles areor ceramic fillers that enhances thermal conductivity. Solid

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

209

Thermal radiation from magnetic neutron star surfaces  

E-Print Network (OSTI)

We investigate the thermal emission from magnetic neutron star surfaces in which the cohesive effects of the magnetic field have produced the condensation of the atmosphere and the external layers. This may happen for sufficiently cool atmospheres with moderately intense magnetic fields. The thermal emission from an isothermal bare surface of a neutron star shows no remarkable spectral features, but it is significantly depressed at energies below some threshold energy. However, since the thermal conductivity is very different in the normal and parallel directions to the magnetic field lines, the presence of the magnetic field is expected to produce a highly anisotropic temperature distribution, depending on the magnetic field geometry. In this case, the observed flux of such an object looks very similar to a BB spectrum, but depressed in a nearly constant factor at all energies. This results in a systematic underestimation of the area of the emitter (and therefore its size) by a factor 5-10 (2-3).

J. F. Perez--Azorin; J. A. Miralles; J. A. Pons

2004-10-27T23:59:59.000Z

210

The radio spectrum of Sgr A*  

E-Print Network (OSTI)

We discuss the radio spectrum of Sgr A* \\index{Sgr A*, radio spectrum} in the frequency range between $\\approx 1\\,{\\rm GHz}$ and $\\approx 1\\,000\\,{\\rm GHz}$, show that it can be explained by optically thin synchrotron radiation \\index{Sgr A*, synchrotron radiation, optically thin} of relativistic electrons, and point toward a possible correlation between the spectrum of Sgr A* and larger-scale ($\\la 50\\,{\\rm pc}$) radio emission from the Galactic Center \\index{Galactic Center} region.

Wolfgang J. Duschl; Harald Lesch

1994-11-03T23:59:59.000Z

211

Femtosecond-tunable measurement of electron thermalization in gold  

Science Journals Connector (OSTI)

Femtosecond electron thermalization in metals was investigated using transient thermomodulation transmissivity and reflectivity. Studies were performed using a tunable multiple-wavelength femtosecond pump-probe technique in optically thin gold films in the low perturbation limit. An IR pump beam is used to heat the electron distribution and changes in electron temperature are measured with a visible probe beam at the d band to Fermi-surface transition. We show that the subpicosecond optical response of gold is dominated by delayed thermalization of the electron gas. This effect is particularly important far off the spectral peak of the reflectivity or transmissivity changes, permitting a direct and sensitive access to the internal thermalization of the electron gas. Using a simple rate-equation model, line-shape analysis of the transient reflectivity and transmissivity indicates a thermalization time of the order of 500 fs. At energies close to the Fermi surface, longer thermalization times ?1–2 ps are observed. These results are in agreement with a more sophisticated model based on calculations of the electron-thermalization dynamics by numerical solutions of the Boltzmann equation. This model quantitatively describes the measured transient optical response during the full thermalization time of electron gas, of the order of 1.5 ps, and gives new insight into electron thermalization in metals.

C.-K. Sun; F. Vallée; L. H. Acioli; E. P. Ippen; J. G. Fujimoto

1994-11-15T23:59:59.000Z

212

Cognitive radio networks for dynamic spectrum management.  

E-Print Network (OSTI)

??A fundamental evolution is witnessed in recent research and development of wireless communications: much effort is put on shifting from the current static spectrum management… (more)

Jia, Juncheng

2009-01-01T23:59:59.000Z

213

Proceedings of the IEEE, vol. 97, no. 4, pp. 708-19, April 2009. Sharing Spectrum through Spectrum Policy Reform  

E-Print Network (OSTI)

Spectrum Policy Reform and Cognitive Radio1 Jon M. Peha Carnegie Mellon University Abstract Traditionally inefficient use of spectrum. Cognitive radio along with software radio, spectrum sensors, mesh networks sharing, spectrum policy, cognitive radio, band manager, unlicensed, etiquette, opportunistic access

Peha, Jon M.

214

Thermal conductance of metal-metal interfaces  

Science Journals Connector (OSTI)

The thermal conductance of interfaces between Al and Cu is measured in the temperature range 78beam mixing using 1MeV Kr ions. The thermal conductance of the as-deposited Al-Cu interface is 4GWm?2K?1 at room temperature, an order-of-magnitude larger than the phonon-mediated thermal conductance of typical metal-dielectric interfaces. The magnitude and the linear temperature dependence of the conductance are described well by a diffuse-mismatch model for electron transport at interfaces.

Bryan C. Gundrum; David G. Cahill; Robert S. Averback

2005-12-30T23:59:59.000Z

215

Investment and Pricing with Spectrum Uncertainty: A Cognitive Operator's Perspective  

E-Print Network (OSTI)

" of licensed bands and dynamically leasing from the spectrum owner. As a result, a C-MVNO can make flexible--Cognitive radio, spectrum trading, spectrum sensing, dynamic spectrum leasing, spectrum pricing, Stackelberg game affecting the normal oper- ation of the spectrum owner who serves the primary (licensed) users. Dynamic

Huang, Jianwei

216

Gaussian Beams Enrique J. Galvez  

E-Print Network (OSTI)

Gaussian Beams Enrique J. Galvez Department of Physics and Astronomy Colgate University Copyright 2009 #12;ii #12;Contents 1 Fundamental Gaussian Beams 1 1.1 Spherical Wavefront in the Paraxial region . . . . . . . . . . . . . . . 1 1.2 Formal Solution of the Wave Equation . . . . . . . . . . . . . . . . . 3 1.2.1 Beam Spot w

Galvez, Enrique J. "Kiko"

217

Algorithm for Building a Spectrum for NREL's One-Sun Multi-Source Simulator: Preprint  

SciTech Connect

Historically, the tools used at NREL to compensate for the difference between a reference spectrum and a simulator spectrum have been well-matched reference cells and the application of a calculated spectral mismatch correction factor, M. This paper describes the algorithm for adjusting the spectrum of a 9-channel fiber-optic-based solar simulator with a uniform beam size of 9 cm square at 1-sun. The combination of this algorithm and the One-Sun Multi-Source Simulator (OSMSS) hardware reduces NREL's current vs. voltage measurement time for a typical three-junction device from man-days to man-minutes. These time savings may be significantly greater for devices with more junctions.

Moriarty, T.; Emery, K.; Jablonski, J.

2012-06-01T23:59:59.000Z

218

Thermal characterization of submicron polyacrylonitrile fibers based on optical heating and electrical thermal sensing  

SciTech Connect

In this work, the thermal diffusivity of single submicron ({approx}800 nm) polyacrylonitrile (PAN) fibers is characterized using the recently developed optical heating and electrical thermal sensing technique. In the experiment, a thin Au film (approximately in the nanometer range) is coated on the surface of nonconductive PAN fibers. A periodically modulated laser beam is used to irradiate suspended individual fibers to achieve noncontact periodical heating. The periodical temperature response of the sample is monitored by measuring the electrical resistance variation of the thin Au coating. The experimental results for three different synthesized PAN fibers with varying Au coating thickness are presented and discussed.

Hou Jinbo; Wang Xinwei; Zhang Lijun [Department of Mechanical Engineering, N104 Walter Scott Engineering Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0656 (United States)

2006-10-09T23:59:59.000Z

219

Electron Cloud in Steel Beam Pipe vs Titanium Nitride Coated and Amorphous Carbon Coated Beam Pipes in Fermilab's Main Injector  

SciTech Connect

This paper documents the use of four retarding field analyzers (RFAs) to measure electron cloud signals created in Fermilab’s Main Injector during 120 GeV operations. The first data set was taken from September 11, 2009 to July 4, 2010. This data set is used to compare two different types of beam pipe that were installed in the accelerator. Two RFAs were installed in a normal steel beam pipe like the rest of the Main Injector while another two were installed in a one meter section of beam pipe that was coated on the inside with titanium nitride (TiN). A second data run started on August 23, 2010 and ended on January 10, 2011 when Main Injector beam intensities were reduced thus eliminating the electron cloud. This second run uses the same RFA setup but the TiN coated beam pipe was replaced by a one meter section coated with amorphous carbon (aC). This section of beam pipe was provided by CERN in an effort to better understand how an aC coating will perform over time in an accelerator. The research consists of three basic parts: (a) continuously monitoring the conditioning of the three different types of beam pipe over both time and absorbed electrons (b) measurement of the characteristics of the surrounding magnetic fields in the Main Injector in order to better relate actual data observed in the Main Injector with that of simulations (c) measurement of the energy spectrum of the electron cloud signals using retarding field analyzers in all three types of beam pipe.

Backfish, Michael

2013-04-01T23:59:59.000Z

220

THE SPECTRUM OF Fe II  

SciTech Connect

The spectrum of singly ionized iron (Fe II) has been recorded using high-resolution Fourier transform (FT) and grating spectroscopy over the wavelength range 900 A to 5.5 {mu}m. The spectra were observed in high-current continuous and pulsed hollow cathode discharges using FT spectrometers at the Kitt Peak National Observatory, Tucson, AZ and Imperial College, London and with the 10.7 m Normal Incidence Spectrograph at the National Institute of Standards and Technology. Roughly 12,900 lines were classified using 1027 energy levels of Fe II that were optimized to measured wavenumbers. The wavenumber uncertainties of lines in the FT spectra range from 10{sup -4} cm{sup -1} for strong lines around 4 {mu}m to 0.05 cm{sup -1} for weaker lines around 1500 A. The wavelength uncertainty of lines in the grating spectra is 0.005 A. The ionization energy of (130,655.4 {+-} 0.4) cm{sup -1} was estimated from the 3d{sup 6}({sup 5}D)5g and 3d{sup 6}({sup 5}D)6h levels.

Nave, Gillian [National Institute of Standards and Technology, Gaithersburg, MD 20899-8422 (United States); Johansson, Sveneric, E-mail: gillian.nave@nist.gov [Lund Observatory, University of Lund, Box 43, SE-22100 Lund (Sweden)

2013-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Design and Testing of a 10B4C Capsule for Spectral-Tailoring in Mixed-Spectrum Reactors  

SciTech Connect

A boron carbide capsule highly enriched in 10B has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. New experiments show that enriching the boron to 96% B-10 results in additional absorption of neutrons in the resonance region thereby producing a neutron spectrum that is much closer to a pure 235U fission spectrum. A cadmium outer cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in very good agreement with measured activation rates from neutron fluence monitors.

Greenwood, Lawrence R.; Wittman, Richard S.; Metz, Lori A.; Finn, Erin C.; Friese, Judah I.

2014-04-11T23:59:59.000Z

222

Measurement of the Betatron Radiation Spectrum Coming From a Laser Wakefield Accelerator  

SciTech Connect

A Laser Wakefield Accelerator (LWFA) is under development at Lawrence Livermore National Laboratory (LLNL) to produce electron bunches with GeV class energy and energy spreads of a few-percent. The ultimate goal is to provide a bright and compact photon source for high energy density physics. The interaction of a high power (200 TW), short pulse (50 fs) laser with neutral He gas can generate quasi-monoenergetic electron beams at energies up to 1 GeV. The laser pulse can be self-guided over a dephasing length of 1 cm (for a plasma density of 1.5 x 10{sup 18} cm{sup -3}) overcoming the limitation of vacuum diffraction. Betatron radiation is emitted while the accelerated electrons undergo oscillations in the wakefield electrostatic field. Here we present electron spectra measurements with a two screen spectrometer allowing to fix the ambiguities due to electron deflections at the plasma exit. They have measured monoenergetic electron beams above 300 MeV. Furthermore a forward directed x-ray beam is observed. The measured betatron spectrum agrees well with the calculated spectrum in the synchrotron asymptotic limit (SAL) using the measured electron beam parameters.

Leurent, V; Michel, P; Clayton, C E; Pollock, B; Doeppner, T; Wang, T L; Ralph, J; Pak, A; Marsh, K; Joshi, C; Tynan, G R; Divol, L; Palastro, J P; Glenzer, S H; Froula, D H

2008-08-12T23:59:59.000Z

223

H-mode accelerating structures with PMQ focusing for low-beta ion beams  

SciTech Connect

We are developing high-efficiency normal-conducting RF accelerating structures based on inter-digital H-mode (IH) cavities and the transverse beam focusing with permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. Such IH-PMQ accelerating structures following a short RFQ can be used in the front end of ion linacs or in stand-alone applications, e.g. a compact deuteron-beam accelerator up to the energy of several MeV. Results of combined 3-D modeling for a full IH-PMQ accelerator tank - electromagnetic computations, beam-dynamics simulations with high currents, and thermal-stress analysis - are presented. The accelerating field profile in the tank is tuned to provide the best beam propagation using coupled iterations of electromagnetic and beam-dynamics modeling. A cold model of the IH-PMQ tank is being manufactured.

Kurennoy, Sergey S [Los Alamos National Laboratory; O' Hara, James F [Los Alamos National Laboratory; Olivas, Eric R [Los Alamos National Laboratory; Rybarcyk, Lawrence J [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

224

LSST beam simulator  

Science Journals Connector (OSTI)

It is always important to test new imagers for a mosaic camera before device acceptance and constructing the mosaic. This is particularly true of the LSST CCDs due to the fast beam illumination: at long wavelengths there can be significant beam divergence (defocus) inside the silicon because of the long absorption length for photons near the band gap. Moreover, realistic sky scenes need to be projected onto the CCD focal plane Thus, we need to design and build an f/1.2 re-imaging system. The system must simulate the entire LSST1 operation, including a sky with galaxies and stars with approximately black-body spectra superimposed on a spatially diffuse night sky emission with its complex spectral features.

J A Tyson; J Sasian; C Claver; G Muller; K Gilmor; M Klint

2014-01-01T23:59:59.000Z

225

Hardening Neutron Spectrum for Advanced Actinides Transmutation Experiments in the ATR  

SciTech Connect

The most effective method for transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products is in a fast neutron spectrum reactor. In the absence of a fast rest reactor in the United States, initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. Such a test facility, with a spectrum similar but somewhat softer than that of the liquid-metal fast breeder reactor (LMFBR), has been constructed in the INEEL's Advanced Test Reactor (ATR). The radial fission power distribution of the actinide fuel pin, which is an important parameter in fission gas released modelling, needs to be accurately predicted and the hardened neturon spectrum in the ATR and the LMFBR fast neutron spectrum is compared. The comparison analyses in this study are peformed using MCWO, a well-developed tool that couples the Monte Carlo transport code MCNP with the isotope depletion and build-up code ORIGEN-2. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations and detailed radial fission power profile calculations for a typical fast reactor (LMFBR) neutron spectrum and the hardened neturon spectrum test region in the ATR. The MCWO-calculated results indicate that the cadmium basket used in the advanced fuel test assembly in the ATR can effectively depress the linear heat generation rate in the experimental fuels and harden the neutron spectrum in the test region.

G. S. Chang; R. G. Ambrosek

2004-05-01T23:59:59.000Z

226

Chapter 12 - Assessment of Thermal Energy Storage Systems  

Science Journals Connector (OSTI)

Abstract The foremost challenges of energy supply in meeting the energy demand apply to the development of energy efficient technologies to achieve energy security and environmental emissions. In the spectrum of energy-efficient technologies, thermal energy storage systems offer huge potential to bridge the mismatch between energy supply and energy demand. The overall operational performance of thermal storage systems depends on the quality of energy content and the energy degradation effects exhibited during the cyclic charging and discharging processes. The assessment pertaining to the exergy efficiency in addition to energy efficiency can have a pivotal role to enable thermal storage systems to outperform on a long-term basis.

S. Kalaiselvam; R. Parameshwaran

2014-01-01T23:59:59.000Z

227

SSRL BEAM PORT SCHEDULE  

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

1-5 1-5 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 7-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled FACI FACI FACI FACI FACI FACI

228

SSRL BEAM PORT SCHEDULE  

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

4 4 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 1-5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN

229

SSRL BEAM PORT SCHEDULE  

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

5-1 5-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 5-2 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA FACI FACI FACI FACI FACI FACI

230

SSRL BEAM PORT SCHEDULE  

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

1-5 1-5 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 7-1 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN FACI FACI FACI FACI FACI FACI

231

All Beams 2013.xls  

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

1598 29 1079 9 1070 3.8 3.8 20.1 78 Kr 77.920 40 3117 140 622 20 602 14.2 14.4 41.4 Proton 1.007 40 40 0.1 8148 1.2 8147 0.012 0.012 0.56 Available Beams 40 A MeV 25 A MeV 15 A MeV...

232

Axion beams at HERA?  

E-Print Network (OSTI)

If the recently observed anomaly in the PVLAS experiment is due to the axion, then the powerful beams of synchrotron photons, propagating through high magnetic field of the HERA beamline, become strong axion sources. This gives a unique opportunity of detection of the axion-photon interactions by installing a small detector in the HERA tunnel, and to corroborate the axion hypothesis within a few days of running.

K. Piotrzkowski

2007-01-09T23:59:59.000Z

233

Proton beam therapy facility  

SciTech Connect

It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs.

Not Available

1984-10-09T23:59:59.000Z

234

Human segmentation by geometrically fusing visible-light and thermal imageries  

Science Journals Connector (OSTI)

From depth sensors to thermal cameras, the increased availability of camera sensors beyond the visible spectrum has created many exciting applications. Most of these applications require combining information from these hyperspectral cameras with a regular ... Keywords: Human segmentation, Multi-camera fusion, Sensor fusion, Thermal cameras

Jian Zhao, Sen-Ching S. Cheung

2014-11-01T23:59:59.000Z

235

Potential Impact of ZT = 4 Thermoelectric Materials on Solar Thermal Energy Conversion Technologies  

Science Journals Connector (OSTI)

Photovoltaic and solar-thermal are two conversion technologies receiving a great deal of attention. ... Solar-thermal conversion uses the full solar spectrum and generates electricity by conventional electromagnetic induction methods. ... Resource and environmental impact considerations will play an increasingly important role in reaching decisions concerning the practicality of thermoelectric power generation systems. ...

Ming Xie; Dieter M. Gruen

2010-03-02T23:59:59.000Z

236

Wavelet Spectrum Analysis and Ocean Wind Waves  

E-Print Network (OSTI)

Wavelet Spectrum Analysis and Ocean Wind Waves Paul C. Liu Abstract. Wavelet spectrum analysis is applied to a set of measured ocean wind waves data collected during the 1990 SWADE {Surface Wave Dynamics Experi- ment) program. The results reveal significantly new and previously unexplored Insights on wave

237

HEATS: Thermal Energy Storage  

SciTech Connect

HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

None

2012-01-01T23:59:59.000Z

238

Holographic thermalization patterns  

E-Print Network (OSTI)

We investigate the behaviour of various correlators in N=4 super Yang Mills theory, taking finite coupling corrections into account. In the thermal limit we investigate the flow of the quasinormal modes as a function of the 't Hooft coupling. Then by using a specific model of holographic thermalization we investigate the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the various plasma constituents of different energies approach their final thermal distribution as the coupling constant decreases from the infinite coupling limit. All results point towards the weakening of the usual top down thermalization pattern.

Stefan Stricker

2014-03-11T23:59:59.000Z

239

Holographic thermalization patterns  

E-Print Network (OSTI)

We investigate the behaviour of various correlators in N=4 super Yang Mills theory, taking finite coupling corrections into account. In the thermal limit we investigate the flow of the quasinormal modes as a function of the 't Hooft coupling. Then by using a specific model of holographic thermalization we investigate the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the various plasma constituents of different energies approach their final thermal distribution as the coupling constant decreases from the infinite coupling limit. All results point towards the weakening of the usual top down thermalization pattern.

Stricker, Stefan

2014-01-01T23:59:59.000Z

240

Drilling Large Diameter Holes in Rocks Using Multiple Laser Beams  

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

Drilling Large Diameter Holes in Rocks Using Multiple Laser Beams (504) Drilling Large Diameter Holes in Rocks Using Multiple Laser Beams (504) Richard Parker,. Parker Geoscience Consulting, LLC, Arvada, Colorado, USA; Zhiyue Xu and Claude Reed, Argonne National Laboratory, Argonne, Illinois, USA; Ramona Graves, Department of Petroleum Engineering, Colorado School of Mines, Golden, Colorado, USA; Brian Gahan and Samih Batarseh, Gas Technology Institute, Des Plaines, Illinois, USA ABSTRACT Studies on drilling petroleum reservoir rocks with lasers show that modern infrared lasers have the capability to spall (thermally fragment), melt and vaporize natural earth materials with the thermal spallation being the most efficient rock removal mechanism. Although laser irradiance as low as 1000 W/cm 2 is sufficient to spall rock, firing the

Note: This page contains sample records for the topic "beam spectrum thermal" 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

A high power beam-on-target test of liquid lithium target for RIA.  

SciTech Connect

Experiments were conducted to demonstrate the stable operation of a windowless liquid lithium target under extreme thermal loads that are equivalent to uranium beams from the proposed Rare Isotope Accelerator (RIA) driver linac. The engineering and safety issues accompanying liquid lithium systems are first discussed. The liquid metal technology knowledge base generated primarily for fast reactors, and liquid metal cooled fusion reactors, was applied to the development of these systems in a nuclear physics laboratory setting. The use of a high energy electron beam for simulating a high power uranium beam produced by the RIA driver linac is also described. Calculations were performed to obtain energy deposition profiles produced by electron beams at up to a few MeV to compare with expected uranium beam energy deposition profiles. It was concluded that an experimental simulation using a 1-MeV electron beam would be a valuable tool to assess beam-jet interaction. In the experiments, the cross section of the windowless liquid lithium target was 5 mm x 10 mm, which is a 1/3rd scale prototype target, and the velocity of the liquid lithium was varied up to 6 m/s. Thermal loads up to 20 kW within a beam spot diameter of 1mm were applied on the windowless liquid lithium target by the 1-MeV electron beam. The calculations showed that the maximum power density and total power deposited within the target, from the electron beam, was equivalent to that of a 200-kW, 400-MeV/u uranium beam. It was demonstrated that the windowless liquid lithium target flowing at velocities as low as 1.8 m/s stably operated under beam powers up to 20 kW without disruption or excessive vaporization.

Nolen, J.; Reed, C.; Novick, V.; Specht, J.; Plotkin, P.; Momozaki,Y.; Gomes, I.

2005-08-29T23:59:59.000Z

242

A compact molecular beam machine  

SciTech Connect

We have developed a compact, low cost, modular, crossed molecular beam machine. The new apparatus utilizes several technological advancements in molecular beams valves, ion detection, and vacuum pumping to reduce the size, cost, and complexity of a molecular beam apparatus. We apply these simplifications to construct a linear molecular beam machine as well as a crossed-atomic and molecular beam machine. The new apparatus measures almost 50 cm in length, with a total laboratory footprint less than 0.25 m{sup 2} for the crossed-atomic and molecular beam machine. We demonstrate the performance of the apparatus by measuring the rotational temperature of nitric oxide from three common molecular beam valves and by observing collisional energy transfer in nitric oxide from a collision with argon.

Jansen, Paul [Vrije Universiteit, 1081 HV Amsterdam (Netherlands); Chandler, David W.; Strecker, Kevin E. [Sandia National Laboratories, Livermore, California 94551 (United States)

2009-08-15T23:59:59.000Z

243

Spectrum Energy Inc SEI | Open Energy Information  

Open Energy Info (EERE)

Energy Inc SEI Energy Inc SEI Jump to: navigation, search Name Spectrum Energy Inc (SEI) Place Elk Grove, California Zip 95758 Sector Efficiency, Services, Solar Product US-based solar and energy services company that installs PV systems on a turnkey-basis; also provides evaluations of energy efficiency. References Spectrum Energy Inc (SEI)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Spectrum Energy Inc (SEI) is a company located in Elk Grove, California . References ↑ "Spectrum Energy Inc (SEI)" Retrieved from "http://en.openei.org/w/index.php?title=Spectrum_Energy_Inc_SEI&oldid=351613" Categories: Clean Energy Organizations Companies Organizations

244

NREL Spectrum of Clean Energy Innovation (Brochure)  

SciTech Connect

This brochure describes the NREL Spectrum of Clean Energy Innovation, which includes analysis and decision support, fundamental science, market relevant research, systems integration, testing and validation, commercialization and deployment. Through deep technical expertise and an unmatched breadth of capabilities, the National Renewable Energy Laboratory (NREL) leads an integrated approach across the spectrum of renewable energy innovation. From scientific discovery to accelerating market deployment, NREL works in partnership with private industry to drive the transformation of our nation's energy systems. NREL integrates the entire spectrum of innovation, including fundamental science, market relevant research, systems integration, testing and validation, commercialization, and deployment. Our world-class analysis and decision support informs every point on the spectrum. The innovation process at NREL is inter-dependent and iterative. Many scientific breakthroughs begin in our own laboratories, but new ideas and technologies may come to NREL at any point along the innovation spectrum to be validated and refined for commercial use.

Not Available

2011-09-01T23:59:59.000Z

245

Visible Spectrum Incandescent Selective Emitter  

SciTech Connect

The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination was initially projected. The work performed provided answers to a number of important questions. The first is that, with the investigated approaches, the maximum sustained emitter efficiencies are about 1.5 times that of a standard incandescent bulb. This was seen to be the case for both thick and thin emitters, and for both mono-layer and bi-layer designs. While observed VIS/NIR ratios represent improvements over standard incandescent bulbs, it does not appear sufficient to overcome higher cost (i.e. up to five times that of the standard bulb) and ensure commercial success. Another result is that high temperatures (i.e. 2650 K) are routinely attainable without platinum electrodes. This is significant for reducing material costs. A novel dual heating arrangement and insulated electrodes were used to attain these temperatures. Another observed characteristic of the emitter was significant grain growth soon after attaining operating temperatures. This is an undesirable characteristic that results in substantially less optical scattering and spectral selectivity, and which significantly limits emitter efficiencies to the values reported. Further work is required to address this problem.

Sonsight Inc.

2004-04-30T23:59:59.000Z

246

Non-thermal Plasma Chemistry Non-thermal Thermal  

E-Print Network (OSTI)

automotive industry optics biomedical technology environmental technology Plasma Technology Quote from: Pla-thermal Plasma Chemical Flow Reactor #12;Werner von Siemens ,, ... construction of an apparatus generation (1857) pollution control volatile organic components, NOx reforming, ... radiation sources excimer

Greifswald, Ernst-Moritz-Arndt-Universität

247

Nondestructive Damage Detection in General Beams  

E-Print Network (OSTI)

is to provide NDE methodologies that simultaneously identify the location, the extent, and the severity of damage in general beams. By general beams, we mean beyond Euler-Bernoulli beams (i.e. slender beams) to deep beams and stubby beams whose response may...

Dincal, Selcuk

2010-12-08T23:59:59.000Z

248

Thermal oxidation as a simple method to increase resolution in nanoimprint lithography  

Science Journals Connector (OSTI)

We introduce a simple thermal oxidation technique for decreasing feature sizes of nanoimprint lithography (NIL) masters. During oxidation, the dimensions of negative features are reduced (e.g., gaps become narrower), and the dimensions of positive features ... Keywords: Electron beam lithography, Master fabrication, Nanoimprint lithography, Resolution, Thermal oxidation

Andrew P. Bonifas; Richard L. McCreery; Kenneth D. Harris

2011-11-01T23:59:59.000Z

249

In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research  

E-Print Network (OSTI)

The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without sup 1 sup 0 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of sup 1 sup 0 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99+-0.24, 3.04+-0.19 and 1.43+-0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50+-0.32, 2.34+-0.30 and 2.17+-0.28 for EN...

Yamamoto, T; Horiguchi, Y; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Yamamoto, K

2002-01-01T23:59:59.000Z

250

Thermal contact resistance  

E-Print Network (OSTI)

This work deals with phenomena of thermal resistance for metallic surfaces in contact. The main concern of the work is to develop reliable and practical methods for prediction of the thermal contact resistance for various ...

Mikic, B. B.

1966-01-01T23:59:59.000Z

251

Solar Thermal Processes  

Science Journals Connector (OSTI)

The use of solar energy for desalination purposes was one of ... The process is based on the use of solar thermal energy to evaporate water, thus separating pure ... brine. In this chapter an overview of solar thermal

M.T. Chaibi; Ali M. El-Nashar

2009-01-01T23:59:59.000Z

252

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

253

Measurement of neutron spectrum in an AGN-201 reactor using a semiconductor neutron spectrometer  

E-Print Network (OSTI)

safely exceed the maximum triton range. The detectors could be refined for the specific application. A detector pair may be miniaturized 29 30 for in-core reactor spectra measurements between fuel-bearing plates and between elements. Low flux..., this point is considered to be essentially valid and free from thermal and low epi- thermal event overlap. Figure 11 presents the result of this research. The reactor core flux spectrum is believed to be valid from 0. 25 Mev to 3. 0 Mev. The measurement...

Stephenson, S. E

2012-06-07T23:59:59.000Z

254

Beam-Beam Interaction Simulations with Guinea Pig  

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

5 5 SLAC-TN-03-070 September 2003 Beam-Beam Interaction Simulations with Guinea Pig C. Sramek, T. O. Raubenheimer, A. Seryi, M. Woods, J. Yu Stanford Linear Accelerator Center Stanford University Stanford, CA Abstract: At the interaction point of a particle accelerator, various phenomena occur that are known as beam-beam effects. Incident bunches of electrons (or positrons) experience strong electromagnetic fields from the opposing bunches, which leads to electron deflection, beamstrahlung and the creation of electron/positron pairs and hadrons due to two-photon exchange. In addition, the beams experience a "pinch effect" which focuses each beam and results in either a reduction or expansion of their vertical size. Finally, if a

255

Simulation of beam-beam effects in tevatron  

SciTech Connect

The Fermilab accelerator complex is in the middle of an upgrade plan Fermilab III. In the last phase of this upgrade the luminosity of the Tevatron will increase by at least one order of magnitude. In order to keep the number of interactions per crossing manageable for experiments, the number of bunches will be increased from 6 {times} 6 to 36 {times} 36 and finally to {approximately}100 {times} 100 bunches. The beam dynamics of the Tevatron has been studied from Beam-Beam effect point of view in a ``Strong-Weak`` representation with a single particle being tracked in presence of other beam. This paper describes the beam-beam effect in 6 {times} 6 operation of Tevatron.

Mishra, C.S.; Assadi, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Talman, R. [Cornell Univ., Ithaca, NY (United States)

1995-08-01T23:59:59.000Z

256

Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum  

E-Print Network (OSTI)

We revisit the scenario where inflation is preceded by a radiation era by considering that the inflaton too could have been in thermal equilibrium early in the radiation era. Hence we take into account not only the effect of a pre-inflationary era on the inflaton mode functions but also that of a frozen thermal distribution of inflaton quanta. We initially discuss in detail the issues relevant to our scenario of a pre-inflationary radiation dominated era and then obtain the scalar power spectrum for this scenario. We find that the power spectrum is free from infrared divergences. We then use the WMAP and Planck data to determine the constraints on the inflaton comoving `temperature' and on the duration of inflation. We find that the best fit value of the duration of inflation is less than 1 e-folding more than what is required to solve cosmological problems, while only an upper bound on the inflaton temperature can be obtained.

Das, Suratna; Prasad, Jayanti; Rangarajan, Raghavan

2014-01-01T23:59:59.000Z

257

146 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 9, NO. 1, MARCH 2000 Self-Buckling of Micromachined Beams Under  

E-Print Network (OSTI)

electrical current is applied, joule-heating effects trigger the thermal expansion of beam structures, starting from the electrical inputs that provides the joule-heating energy to the mechanical actuation with the heating of microstructures by the electrical power. An electro-thermal model for heavily doped polysilicon

Lin, Liwei

258

Thermal neutron detection system  

DOE Patents (OSTI)

According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

2000-01-01T23:59:59.000Z

259

Thermal Performance Benchmarking (Presentation)  

SciTech Connect

This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

Moreno, G.

2014-11-01T23:59:59.000Z

260

Multiwavelength Thermal Emission  

E-Print Network (OSTI)

Multiwavelength Astronomy NASA #12;Thermal Emission #12;Thermal Emission Non-thermal p-p collisions Optical IR Radio/ Microwave sources of emission massive stars, WHIM, Ly many dust, cool objects-ray ~GeV Gamma-ray ~TeV sources of emission AGN, clusters, SNR, binaries, stars AGN (obscured), shocks

California at Santa Cruz, University of

Note: This page contains sample records for the topic "beam spectrum thermal" 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

SSRL BEAM PORT SCHEDULE  

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

1-4 1-4 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled BEAM LINE 2-1 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON

262

SSRL BEAM PORT SCHEDULE  

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

5 5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 9-1 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 Unscheduled CHANGE/8837 A.COHE 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN

263

Distillation by repeated measurements: Continuous spectrum case  

SciTech Connect

Repeated measurements on one part of a bipartite system strongly affect the other part that is not measured, the dynamics of which is regulated by an effective contracted evolution operator. When the spectrum of this operator is discrete, the nonmeasured system is driven into a pure state, irrespective of the initial state, provided that the spectrum satisfies certain conditions. We show here that, even in the case of continuous spectrum, an effective distillation can occur under rather general conditions. We confirm it by applying our formalism to a simple model.

Bellomo, Bruno; Compagno, Giuseppe [CNISM and Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, via Archirafi 36, IT-90123 Palermo (Italy); Nakazato, Hiromichi [Department of Physics, Waseda University, Tokyo 169-8555 (Japan); Yuasa, Kazuya [Waseda Institute for Advanced Study, Waseda University, Tokyo 169-8050 (Japan)

2010-12-15T23:59:59.000Z

264

Cadmium Depletion Impacts on Hardening Neutron6 Spectrum for Advanced Fuel Testing in ATR  

SciTech Connect

For transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products effectively is in a fast neutron spectrum reactor. In the absence of a fast spectrum test reactor in the United States of America (USA), initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. A test region is achieved with a Cadmium (Cd) filter which can harden the neutron spectrum to a spectrum similar (although still somewhat softer) to that of the liquid metal fast breeder reactor (LMFBR). A fuel test loop with a Cd-filter has been installed within the East Flux Trap (EFT) of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). A detailed comparison analyses between the cadmium (Cd) filter hardened neutron spectrum in the ATR and the LMFBR fast neutron spectrum have been performed using MCWO. MCWO is a set of scripting tools that are used to couple the Monte Carlo transport code MCNP with the isotope depletion and buildup code ORIGEN-2.2. The MCWO-calculated results indicate that the Cd-filter can effectively flatten the Rim-Effect and reduce the linear heat rate (LHGR) to meet the advanced fuel testing project requirements at the beginning of irradiation (BOI). However, the filtering characteristics of Cd as a strong absorber quickly depletes over time, and the Cd-filter must be replaced for every two typical operating cycles within the EFT of the ATR. The designed Cd-filter can effectively depress the LHGR in experimental fuels and harden the neutron spectrum enough to adequately flatten the Rim Effect in the test region.

Gray S. Chang

2011-05-01T23:59:59.000Z

265

Magnetically operated beam dump for dumping high power beams in a neutral beamline  

DOE Patents (OSTI)

It is an object of this invention to provide a beam dump system for a neutral beam generator which lowers the time-averaged power density of the beam dump impingement surface. Another object of this invention is to provide a beam dump system for a neutral particle beam based on reionization and subsequent magnetic beam position modulation of the beam onto a beam dump surface to lower the time-averaged power density of the beam dump ion impingement surface.

Dagenhart, W.K.

1984-01-27T23:59:59.000Z

266

Active beam position stabilization of pulsed lasers for long-distance ion profile diagnostics at the Spallation Neutron Source (SNS)  

SciTech Connect

A high peak-power Q-switched laser has been used to monitor the ion beam profiles in the superconducting linac at the Spallation Neutron Source (SNS). The laser beam suffers from position drift due to movement, vibration, or thermal effects on the optical components in the 250-meter long laser beam transport line. We have designed, bench-tested, and implemented a beam position stabilization system by using an Ethernet CMOS camera, computer image processing and analysis, and a piezo-driven mirror platform. The system can respond at frequencies up to 30 Hz with a high position detection accuracy. With the beam stabilization system, we have achieved a laser beam pointing stability within a range of 2 rad (horizontal) to 4 rad (vertical), corresponding to beam drifts of only 0.5 mm 1 mm at the furthest measurement station located 250 meters away from the light source.

Hardin, Robert A [ORNL; Liu, Yun [ORNL; Long, Cary D [ORNL; Aleksandrov, Alexander V [ORNL; Blokland, Willem [ORNL

2011-01-01T23:59:59.000Z

267

LANL: Ion Beam Materials Laboratory  

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

Ion Beam Materials Laboratory (IBML) is a Los Ion Beam Materials Laboratory (IBML) is a Los Alamos National Laboratory resource devoted to materi- als research through the use of ion beams. Current major research areas include surface characterization through ion beam analysis techniques, surface modification and materials synthesis through ion implantation technology, and radiation damage stud- ies in gases, liquids, and solids. The laboratory's core is a 3.2 MV tandem ion accelerator and a 200 kV ion implanter together with several beam lines. Attached to each beam line is a series of experimental stations that support various research programs. The operation of IBML and its interactions with users are organized around core facilities and experimental stations. The IBML provides and operates the core facilities as well as supports

268

Survey on Spectrum Utilization in Europe: Measurements, Analyses and Observations  

E-Print Network (OSTI)

major results and comparisons of radio spectrum utilization measurements that have been carried out and physical aspects that will have to be considered in the future radio spectrum management to assure efficient spectrum utilization. Keywords-cognitive radio, dynamic spectrum access, spectrum utilization

Paris-Sud XI, Université de

269

Cooperation and Learning in Multiuser Opportunistic Spectrum Access  

E-Print Network (OSTI)

for the efficient utilization of the radio frequency spectrum is opportunistic spectrum access (OSA), whereCooperation and Learning in Multiuser Opportunistic Spectrum Access Hua Liu§ , Bhaskar spectrum access net- work where spectrum opportunities are time varying and spatially inhomogeneous

Islam, M. Saif

270

MAP: Multiauctioneer Progressive Auction for Dynamic Spectrum Access  

E-Print Network (OSTI)

to access the licensed spectrum, and dynamic spectrum access (DSA) is one of the fundamental functions of CR solution according to the length of step. Index Terms--Cognitive radio, dynamic spectrum access, auction from scarcity in spectrum resource and inefficiency in spectrum usage. Cognitive radio (CR) or dynamic

Wang, Xinbing

271

ON THE EXISTENCE OF 'RADIO THERMALLY ACTIVE' GALACTIC SUPERNOVA REMNANTS  

SciTech Connect

In this paper, we investigate the possibility of significant production of thermal bremsstrahlung radiation at radio continuum frequencies that could be linked to some Galactic supernova remnants (SNRs). The main targets for this investigation are SNRs expanding in high-density environments. There are several indicators of radio thermal bremsstrahlung radiation from SNRs, such as a flattening at higher frequencies and thermal absorption at lower frequencies intrinsic to an SNR. In this work, we discuss the radio continuum properties of three SNRs that are the best candidates for testing our hypothesis of significant thermal emission. In the case of SNRs IC 443 and 3C 391, thermal absorption has been previously detected. For IC 443, the contribution of thermal emission at 1 GHz, from our model fit is 3%-57%. It is similar to the estimate obtained from the thermal absorption properties (10%-40% at 1 GHz). In the case of the 3C 391 the conclusions are not so clear. The results from our model fit (thermal emission contribution of 10%-25% at 1 GHz) and results obtained from the low-frequency absorption (thermal contribution of 0.15%-7% at 1 GHz) do not overlap. For the SNR 3C 396 we suggest that if previously detected thermal absorption could be intrinsic to the SNR then the thermal emission (<47% at 1 GHz from our model fit) could be significant enough to shape the radio continuum spectrum at high frequencies. Polarization observations for these SNRs can constrain the strength of a thermal component. Reliable observations at low frequencies (<100 MHz) are needed as well as more data at high radio frequencies (>1 GHz), in order to make stronger conclusions about the existence of 'radio thermally active' SNRs.

Onic, D.; Urosevic, D.; Arbutina, B. [Department of Astronomy, Faculty of Mathematics, University of Belgrade (Serbia); Leahy, D. [Department of Physics and Astronomy, University of Calgary (Canada)

2012-09-01T23:59:59.000Z

272

Particle Detector / Beam Current Transformer  

E-Print Network (OSTI)

Particle Detector / Beam Current Transformer Analysis December 8, 2009 Harold G. Kirk #12;ShotSignal,A.U. Proton Bunch Number Beam Current Transformer - 17011 0 2 4 6 8 0 2 4 6 8 10 12 14 16 18 20 Integrated Transformer Pump 187829 (au) Probe 196504 (au) Ratios: Beam Current 1.046 SF 1.019 2.9% difference #12;Shot

McDonald, Kirk

273

Thermal Insulation in Solar Thermal Devices  

Science Journals Connector (OSTI)

Thermal Insulation is a device or a practice which is used in a system for minimising heat losses caused due to transfer of heat from hotter to colder regions. It is one of the cheapest methods of energy conse...

B. C. Raychaudhuri

1986-01-01T23:59:59.000Z

274

A pencil beam algorithm for helium ion beam therapy  

SciTech Connect

Purpose: To develop a flexible pencil beam algorithm for helium ion beam therapy. Dose distributions were calculated using the newly developed pencil beam algorithm and validated using Monte Carlo (MC) methods. Methods: The algorithm was based on the established theory of fluence weighted elemental pencil beam (PB) kernels. Using a new real-time splitting approach, a minimization routine selects the optimal shape for each sub-beam. Dose depositions along the beam path were determined using a look-up table (LUT). Data for LUT generation were derived from MC simulations in water using GATE 6.1. For materials other than water, dose depositions were calculated by the algorithm using water-equivalent depth scaling. Lateral beam spreading caused by multiple scattering has been accounted for by implementing a non-local scattering formula developed by Gottschalk. A new nuclear correction was modelled using a Voigt function and implemented by a LUT approach. Validation simulations have been performed using a phantom filled with homogeneous materials or heterogeneous slabs of up to 3 cm. The beams were incident perpendicular to the phantoms surface with initial particle energies ranging from 50 to 250 MeV/A with a total number of 10{sup 7} ions per beam. For comparison a special evaluation software was developed calculating the gamma indices for dose distributions. Results: In homogeneous phantoms, maximum range deviations between PB and MC of less than 1.1% and differences in the width of the distal energy falloff of the Bragg-Peak from 80% to 20% of less than 0.1 mm were found. Heterogeneous phantoms using layered slabs satisfied a {gamma}-index criterion of 2%/2mm of the local value except for some single voxels. For more complex phantoms using laterally arranged bone-air slabs, the {gamma}-index criterion was exceeded in some areas giving a maximum {gamma}-index of 1.75 and 4.9% of the voxels showed {gamma}-index values larger than one. The calculation precision of the presented algorithm was considered to be sufficient for clinical practice. Although only data for helium beams was presented, the performance of the pencil beam algorithm for proton beams was comparable. Conclusions: The pencil beam algorithm developed for helium ions presents a suitable tool for dose calculations. Its calculation speed was evaluated to be similar to other published pencil beam algorithms. The flexible design allows easy customization of measured depth-dose distributions and use of varying beam profiles, thus making it a promising candidate for integration into future treatment planning systems. Current work in progress deals with RBE effects of helium ions to complete the model.

Fuchs, Hermann; Stroebele, Julia; Schreiner, Thomas; Hirtl, Albert; Georg, Dietmar [Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); PEG MedAustron, 2700 Wiener Neustadt (Austria); Department of Nuclear Medicine, Medical University of Vienna, 1090 Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria)

2012-11-15T23:59:59.000Z

275

Broad-band beam buncher  

DOE Patents (OSTI)

A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

Goldberg, David A. (Walnut Creek, CA); Flood, William S. (Berkeley, CA); Arthur, Allan A. (Martinez, CA); Voelker, Ferdinand (Orinda, CA)

1986-01-01T23:59:59.000Z

276

Low energy beta-beams  

E-Print Network (OSTI)

The main goal of a beta-beam facility is to determine the possible existence of CP violation in the lepton sector, the value of the third neutrino mixing angle and the mass hierarchy. Here we argue that a much broader physics case can be covered since the beta-beam concept can also be used to establish a low energy beta-beam facility. We discuss that the availability of neutrino beams in the 100 MeV energy range offers a unique opportunity to perform neutrino scattering experiments of interest for nuclear physics, for the study of fundamental interactions and of core-collapse supernova physics.

Cristina Volpe

2009-11-13T23:59:59.000Z

277

ANL Beams and Applications Seminar  

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

Argonne Beams & Applications Seminar Search APS ... Search Argonne Home > Argonne Home > Advanced Photon Source > Seminar Archive 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003...

278

Decision Analysis of Dynamic Spectrum Access Rules  

SciTech Connect

A current trend in spectrum regulation is to incorporate spectrum sharing through the design of spectrum access rules that support Dynamic Spectrum Access (DSA). This paper develops a decision-theoretic framework for regulators to assess the impacts of different decision rules on both primary and secondary operators. We analyze access rules based on sensing and exclusion areas, which in practice can be enforced through geolocation databases. Our results show that receiver-only sensing provides insufficient protection for primary and co-existing secondary users and overall low social welfare. On the other hand, using sensing information between the transmitter and receiver of a communication link, provides dramatic increases in system performance. The performance of using these link end points is relatively close to that of using many cooperative sensing nodes associated to the same access point and large link exclusion areas. These results are useful to regulators and network developers in understanding in developing rules for future DSA regulation.

Juan D. Deaton; Luiz A. DaSilva; Christian Wernz

2011-12-01T23:59:59.000Z

279

ACTION SPECTRUM OF THE "SECOND EMERSON EFFECT"  

E-Print Network (OSTI)

at 670 mju in the action spectrum of the "second Emerson effect"' (22, 33), in the green alga Chlorella the fraction of total absorbed light absorbed by the accessory pigments (be it chlorophyll b in Chlorella

Govindjee

280

The 21-cm power spectrum after reionization  

Science Journals Connector (OSTI)

......spectrum (PS) following the completion of reionization. In contrast...uncertainty in the primordial PS index or through a running spectral index, which we have not considered...the 21-cm PS following the completion of reionization. Our approach......

J. Stuart B. Wyithe; Abraham Loeb

2009-08-21T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


281

Shape of the particulate beam attenuation spectrum and its inversion to obtain the shape of the  

E-Print Network (OSTI)

trans- port. Both particle settling rates and resuspension are dependent, to first order, on their size the predictive capabilities of sediment-transport models, since both resuspension and settling are size dependent

Boss, Emmanuel S.

282

Mass Spectrum, Actons and Cosmological Landscape  

E-Print Network (OSTI)

It is suggested that the properties of the mass spectrum of elementary particles could be related with cosmology. Solutions of the Klein-Gordon equation on the Friedmann type manifold with the finite action are constructed. These solutions (actons) have a discrete mass spectrum. We suggest that such solutions could select a universe from cosmological landscape. In particular the solutions with the finite action on de Sitter space are investigated.

V. V. Kozlov; I. V. Volovich

2006-12-13T23:59:59.000Z

283

Neutron energy spectrum from 120 GeV protons on a thick copper target  

E-Print Network (OSTI)

Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, proton-induced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30^{\\circ} and 5 m 90^{\\circ} with respect to the proton beam axis. The neutron energy was determined by time-of-flight technique using timing difference between the NE213 and a plastic scintillator located just before the target. Neutron detection efficiency of NE213 was determined on basis of experimental data from the high energy neutron beam line at Los Alamos National Laboratory. The neutron spectrum was compared with the results of multi-particle transport codes to validate the implemented theoretical models. The apparatus would be applied to future measurements to obtain a systematic data set for secondary particle production on various target materials.

Nobuhiro Shigyo; Toshiya Sanami; Tsuyoshi Kajimoto; Yosuke Iwamoto; Masayuki Hagiwara; Kiwamu Saito; Kenji Ishibashi; Hiroshi Nakashima; Yukio Sakamoto; Hee-Seock Lee; Erik Ramberg; Aria A. Meyhoefer; Rick Coleman; Doug Jensen; Anthony F. Leveling; David J. Boehnlein; Nikolai V. Mokhov

2012-02-07T23:59:59.000Z

284

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams  

SciTech Connect

Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

Siemann, R.H.; /SLAC

2011-10-24T23:59:59.000Z

285

H-Mode Accelerating Structures with PMQ Beam Focusing  

E-Print Network (OSTI)

We have developed high-efficiency normal-conducting RF accelerating structures by combining H-mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of inter-digital H-mode (IH-PMQ) structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. Results of the combined 3-D modeling - electromagnetic computations, multi-particle beam-dynamics simulations with high currents, and thermal-stress analysis - for an IH-PMQ accelerator tank are presented. The accelerating field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. H-PMQ accelerating structures following a short RFQ can be used both in the front end of ion linacs or ...

Kurennoy, Sergey S; O'Hara, James F; Olivas, Eric R; Wangler, Thomas P

2011-01-01T23:59:59.000Z

286

Absorption spectrum of Ca atoms attached to $^4$He nanodroplets  

E-Print Network (OSTI)

Within density functional theory, we have obtained the structure of $^4$He droplets doped with neutral calcium atoms. These results have been used, in conjunction with newly determined {\\it ab-initio} $^1\\Sigma$ and $^1\\Pi$ Ca-He pair potentials, to address the $4s4p$ $^1$P$_1 \\leftarrow 4s^2$ $^1$S$_0$ transition of the attached Ca atom, finding a fairly good agreement with absorption experimental data. We have studied the drop structure as a function of the position of the Ca atom with respect of the center of mass of the helium moiety. The interplay between the density oscillations arising from the helium intrinsic structure and the density oscillations produced by the impurity in its neighborhood plays a role in the determination of the equilibrium state, and hence in the solvation properties of alkaline earth atoms. In a case of study, the thermal motion of the impurity within the drop surface region has been analyzed in a semi-quantitative way. We have found that, although the atomic shift shows a sizeable dependence on the impurity location, the thermal effect is statistically small, contributing by about a 10% to the line broadening. The structure of vortices attached to the calcium atom has been also addressed, and its effect on the calcium absorption spectrum discussed. At variance with previous theoretical predictions, we conclude that spectroscopic experiments on Ca atoms attached to $^4$He drops will be likely unable to detect the presence of quantized vortices in helium nanodrops.

Alberto Hernando; Manuel Barranco; Marek Kro?nicki; Ricardo Mayol; Martí Pi

2007-11-12T23:59:59.000Z

287

Behavior of liquid lithium jet irradiated by 1 MeV electron beams up to 20 kW  

SciTech Connect

Experiments were conducted to demonstrate the stable operation of the windowless liquid lithium target under extreme thermal loads that are equivalent to uranium beams from the proposed Rare Isotope Accelerator (RIA) driver linac. The cross section of the windowless liquid lithium target was 5 mmx10 mm and the velocity of the liquid lithium was varied up to 6 m/s. Thermal loads up to 20 kW within a beam spot of 1 mm in diameter were applied on the windowless liquid lithium target by 1 MeV electron beams. The maximum power density and total power deposited within the target was equivalent to that of a 200 kW, 400 MeV/u uranium beam. It was demonstrated that the windowless liquid lithium target flowing at as low as 1.8 m/s stably operates at a beam energy deposition up to 20 kW without disruption or excess vaporization.

Nolen, J.A.; Reed, C.B.; Novick, V.J.; Specht, J.R.; Bogaty, J.M.; Plotkin, P.; Momozaki, Y. [Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Energy Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2005-07-15T23:59:59.000Z

288

Optimal Classifier Based Spectrum Sensing in Cognitive Radio Wireless Systems  

E-Print Network (OSTI)

Optimal Classifier Based Spectrum Sensing in Cognitive Radio Wireless Systems Siddharth Sharma tolerance. General Terms Algorithms, Theory, Reliability. Keywords Cognitive Radio; Cooperative Spectrum Cognitive radio (CR) networks have been proposed as a revolutionary breakthrough to enhance spectrum

Jagannatham, Aditya K.

289

High-power electron beam tests of a liquid-lithium target and characterization study of 7Li(p,n) near-threshold neutrons for accelerator-based boron neutron capture therapy  

Science Journals Connector (OSTI)

Abstract A compact Liquid-Lithium Target (LiLiT) was built and tested with a high-power electron gun at Soreq Nuclear Research Center (SNRC). The target is intended to demonstrate liquid-lithium target capabilities to constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals. The lithium target will produce neutrons through the 7Li(p,n)7Be reaction and it will overcome the major problem of removing the thermal power >5 kW generated by high-intensity proton beams, necessary for sufficient therapeutic neutron flux. In preliminary experiments liquid lithium was flown through the target loop and generated a stable jet on the concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power densities of more than 4 kW/cm2 and volumetric power density around 2 MW/cm3 at a lithium flow of ~4 m/s, while maintaining stable temperature and vacuum conditions. These power densities correspond to a narrow (?=~2 mm) 1.91 MeV, 3 mA proton beam. A high-intensity proton beam irradiation (1.91–2.5 MeV, 2 mA) is being commissioned at the SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator. In order to determine the conditions of LiLiT proton irradiation for BNCT and to tailor the neutron energy spectrum, a characterization of near threshold (~1.91 MeV) 7Li(p,n) neutrons is in progress based on Monte-Carlo (MCNP and Geant4) simulation and on low-intensity experiments with solid LiF targets. In-phantom dosimetry measurements are performed using special designed dosimeters based on CR-39 track detectors.

S. Halfon; M. Paul; A. Arenshtam; D. Berkovits; D. Cohen; I. Eliyahu; D. Kijel; I. Mardor; I. Silverman

2014-01-01T23:59:59.000Z

290

Useful Graphs and Charts - Ion Beams - Radiation Effects Facility...  

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

Ion Beams Available Beams Beam Change Times Measurements Useful Graphs Useful Graphs and Charts LET vs. Range in Si Graphs: 15 MeVu Beams 24.8 MeVu Beams 40 MeVu Beams...

291

SSRL BEAM PORT SCHEDULE  

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

1, 2002 Nov. 18, 2002 Nov. 25, 2002 Dec. 02, 2002 1, 2002 Nov. 18, 2002 Nov. 25, 2002 Dec. 02, 2002 Dec. 09, 2002 Dec. 16, 2002 Dec. 23, 2002 Dec. 30, 2002 Jan. 06, 2003 Jan. 13, 2003 Jan. 20, 2003 Jan. 27, 2003 Feb. 03, 2003 Feb. 10, 2003 Feb. 17, 2003 Feb. 24, 2003 Mar. 03, 2003 Mar. 10, 2003 Mar. 17, 2003 Mar. 24, 2003 Mar. 31, 2003 Back to Table of Contents WEEK OF Nov. 11, 2002 Nov. 11, 2002 Nov. 12, 2002 Nov. 13, 2002 Nov. 14, 2002 Nov. 15, 2002 Nov. 16, 2002 Nov. 17, 2002 BEAM LINE 1-4 Nov. 11, 2002 Nov. 12, 2002 Nov. 13, 2002 Nov. 14, 2002 Nov. 15, 2002 Nov. 16, 2002 Nov. 17, 2002 Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled

292

SSRL BEAM PORT SCHEDULE  

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

Nov. 04, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Nov. 04, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Back to Table of Contents WEEK OF Nov. 04, 2013 Ops Re-start Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 BEAM LINE 1-4 Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 DOWN DOWN DOWN 8891 C.TASSONE 8891 C.TASSONE 8891 C.TASSONE 8891 C.TASSONE

293

SSRL BEAM PORT SCHEDULE  

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

1-4 1-4 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled CHANGE/8051 M.TONE 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY BEAM LINE 2-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 3157* M.MONTERO-CA 3087 L.FUENTES-COB 3087 L.FUENTES-COB

294

SSRL BEAM PORT SCHEDULE  

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

1-5 1-5 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ BEAM LINE 7-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA DOWN DOWN DOWN DOWN DOWN DOWN

295

SSRL BEAM PORT SCHEDULE  

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

5-4 5-4 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU CHANGE/8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 8821 D.Brehmer 8821 D.Brehmer 8821 D.Brehmer 3064* S.SUN 3075 M.GARNER 3075 M.GARNER 3075 M.GARNER

296

SSRL BEAM PORT SCHEDULE  

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

4, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 4, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Back to Table of Contents WEEK OF Nov. 04, 2013 Ops Re-start Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 BEAM LINE 5-4 Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 DOWN DOWN DOWN DOWN DOWN DOWN DOWN

297

SSRL BEAM PORT SCHEDULE  

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

1-4 1-4 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE CHANGE/8840 J.POPL 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE BEAM LINE 2-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON

298

SSRL BEAM PORT SCHEDULE  

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

5-4 5-4 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 Unscheduled Unscheduled Unscheduled 3269 S.SUN 3269 S.SUN 3269 S.SUN 3269 S.SUN

299

Molecular-beam scattering  

SciTech Connect

The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

Vernon, M.F.

1983-07-01T23:59:59.000Z

300

Experimental optimization of the 6-dimentional electron beam emittance at the NSLS SDL  

SciTech Connect

Experimental optimization of the 6-dimensional electron beam emittance generated by a Magnesium (Mg) photocathode RF gun is presented in this report. A new electron beam optimization algorithm for a low charge (<100 pC) beam was experimentally demonstrated; where the electron beam velocity bunching inside the RF gun plays a critical role, and the transverse emittance as a function of the laser-RF timing jitter was experimentally characterized for the first time. A 20 pC electron beam was optimized to have a normalized slice emittance of 0.15 mm mrad and a longitudinal projected emittance of 3.9 ps keV. Furthermore, the upper limit of the measured thermal emittance - 0.5 mm mrad per mm of the rms laser size, is about 50% lower than the theoretical prediction for a Mg cathode (Qian et al., 2010) [1].

Qian, H.J.; Murphy, J.; Shen,Y.; Tang,C.X.; Wang,X.J.

2011-05-13T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Laser acceleration of ion beams  

E-Print Network (OSTI)

We consider methods of charged particle acceleration by means of high-intensity lasers. As an application we discuss a laser booster for heavy ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a cascade of crossed laser beams would be necessary to provide additional acceleration to gold ions of the order of GeV/nucleon.

I. A. Egorova; A. V. Filatov; A. V. Prozorkevich; S. A. Smolyansky; D. B. Blaschke; M. Chubaryan

2007-02-01T23:59:59.000Z

302

Broad-band beam buncher  

DOE Patents (OSTI)

A broad-band beam bunther is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-

Goldberg, D.A.; Flood, W.S.; Arthur, A.A.; Voelker, F.

1984-03-20T23:59:59.000Z

303

SciTech Connect: Broad Spectrum Photoelectrochemical Diodes for...  

Office of Scientific and Technical Information (OSTI)

Broad Spectrum Photoelectrochemical Diodes for Solar Hydrogen Generation Citation Details In-Document Search Title: Broad Spectrum Photoelectrochemical Diodes for Solar Hydrogen...

304

Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring  

SciTech Connect

In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G. [Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)] [Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Singh, P. [Bhabha Atomic Research Centre, Mumbai (India)] [Bhabha Atomic Research Centre, Mumbai (India)

2013-12-15T23:59:59.000Z

305

RF generation in the DARHT Axis-II beam dump  

SciTech Connect

We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

306

IonBeamMicroFab  

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

Ion Beam Manufacture of Microscale Ion Beam Manufacture of Microscale Tools and Components Manufacturing Technologies Sandia Manufacturing Science &Technology's Focused Ion Beam (FIB) laboratory provides an opportunity for research, development and prototyping. Currently, our scientists are devel- oping methods for ion beam sculpting microscale tools, components and devices. This includes shaping of specialty tools such as end-mills, turning tools and indenters. Many of these have been used in ultra-precision machining DOE applications. Additionally, staff are developing the capability to ion mill geo- metrically-complex features and substrates. This includes the ability to sputter predeter- mined curved shapes of various symmetries and periodicities. Capabilities and Expertise * Two custom-built focused ion beam sys-

307

Universal relation between thermal entropy and entanglement entropy in CFT  

E-Print Network (OSTI)

Inspired by the holographic computation of large interval entanglement entropy of two dimensional conformal field theory at high temperature, it was proposed that the thermal entropy is related to the entanglement entropy as $S_{th}=\\displaystyle{\\lim_{l \\to 0}(S_{EE}(R-l)-S_{EE}(l))}$. In this letter, we prove this relation for 2D CFT with discrete spectrum in two different ways. Moreover we show that this relation could break down for 2D noncompact free scalar, which is a CFT with continuous spectrum.

Chen, Bin

2014-01-01T23:59:59.000Z

308

Thermal comfort during surgery  

E-Print Network (OSTI)

THERMAL COMFORT DURING SURGERY A Thesis by DAVID HAROLD MANNING Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978 Major Subject: Industrial... Engineering THERMAL COMFORT DURING SURGERY A Thesis by DAVID HAROLD MANNING Approved as to style and content by: airman of C it ee Head of Department Member Me er December 1978 ABSTRACT Thermal Comfort During Surgery (December 1978) David Harold...

Manning, David Harold

1978-01-01T23:59:59.000Z

309

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network (OSTI)

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Vivian Poulin; Pasquale D. Serpico

2015-02-04T23:59:59.000Z

310

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network (OSTI)

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Poulin, Vivian

2015-01-01T23:59:59.000Z

311

Time Structure of the LANSCE Beam  

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

Beam One of the greatest strengths of the LANSCE facility is that it can produce proton beams with a wide range of time structures. Time Structure of the LANSCE Beam One of the...

312

Variable pressure thermal insulating jacket  

DOE Patents (OSTI)

A device for controlled insulation of a thermal device is disclosed. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communication with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket. 10 figs.

Nelson, P.A.; Malecha, R.F.; Chilenskas, A.A.

1994-09-20T23:59:59.000Z

313

NANO REVIEW Open Access Thermal conductivity and thermal boundary  

E-Print Network (OSTI)

NANO REVIEW Open Access Thermal conductivity and thermal boundary resistance of nanostructures and the thermal transport prop- erties is a key point to design materials with preferred thermal properties with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity

Boyer, Edmond

314

Multi-dimensional collective effects in high-current relativistic beams relevant to High Density Laboratory Plasmas  

SciTech Connect

In summary, an analytical model describing the self-pinching of a relativistic charge-neutralized electron beam undergoing the collisionless Weibel instability in an overdense plasma has been developed. The model accurately predicts the final temperature and size of the self-focused filament. It is found that the final temperature is primarily defined by the total beam’s current, while the filament’s radius is shown to be smaller than the collisionless skin depth in the plasma and primarily determined by the beam’s initial size. The model also accurately predicts the repartitioning ratio of the initial energy of the beam’s forward motion into the magnetic field energy and the kinetic energy of the surrounding plasma. The density profile of the final filament is shown to be a superposition of the standard Bennett pinch profile and a wide halo surrounding the pinch, which contains a significant fraction of the beam’s electrons. PIC simulations confirm the key assumption of the analytic theory: the collisionless merger of multiple current filaments in the course of the Weibel Instability provides the mechanism for Maxwellization of the beam’s distribution function. Deviations from the Maxwell-Boltzmann distribution are explained by incomplete thermalization of the deeply trapped and halo electrons. It is conjectured that the simple expression derived here can be used for understanding collsionless shock acceleration and magnetic field amplification in astrophysical plasmas.

Shvets, Gennady

2014-05-09T23:59:59.000Z

315

Investigation of properties of the TIARA neutron beam facility of importance for calibration applications  

Science Journals Connector (OSTI)

......former, the neutron spectra were measured...field of neutrons produced...to 2 MeV energy loss. Protons...and 232Th fission chambers...only to the thermal neutrons...of low-energy neutrons 20 MeV and...well the spectrum at the calibration...calculate induced radioactivity......

Y. Shikaze; Y. Tanimura; J. Saegusa; M. Tsutsumi; Y. Yamaguchi; Y. Uchita

2007-08-01T23:59:59.000Z

316

Reconnection of vortex filaments and Kolmogorov spectrum  

E-Print Network (OSTI)

The energy spectrum of the 3D velocity field, induced by collapsing vortex filaments is studied. One of the aims of this work is to clarify the appearance of the Kolmogorov type energy spectrum $E(k)\\varpropto k^{-5/3}$, observed in many numerical works on discrete vortex tubes (quantized vortex filaments in quantum fluids). Usually, explaining classical turbulent properties of quantum turbulence, the model of vortex bundles, is used. This model is necessary to mimic the vortex stretching, which is responsible for the energy transfer in classical turbulence. In our consideration we do not appeal to the possible "bundle arrangement" but explore alternative idea that the turbulent spectra appear from singular solution, which describe the collapsing line at moments of reconnection. One more aim is related to an important and intensively discussed topic - a role of hydrodynamic collapse in the formation of turbulent spectra. We demonstrated that the specific vortex filament configuration generated the spectrum $E...

Nemirovskii, Sergey K

2014-01-01T23:59:59.000Z

317

SSRL BEAM PORT SCHEDULE  

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

7-1 7-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ MC CHECKOUT/2B87 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA BEAM LINE 9-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV FACI FACI

318

SSRL BEAM PORT SCHEDULE  

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

Feb. 14, 2005 Feb. 21, 2005 Feb. 28, 2005 Mar. 07, 2005 Feb. 14, 2005 Feb. 21, 2005 Feb. 28, 2005 Mar. 07, 2005 Mar. 14, 2005 Mar. 21, 2005 Mar. 28, 2005 Apr. 04, 2005 Apr. 11, 2005 Apr. 18, 2005 Apr. 25, 2005 May 02, 2005 May 09, 2005 May 16, 2005 May 23, 2005 May 30, 2005 Jun. 06, 2005 Jun. 13, 2005 Jun. 20, 2005 Jun. 27, 2005 Jul. 04, 2005 Jul. 11, 2005 Jul. 18, 2005 Jul. 25, 2005 Aug. 01, 2005 Back to Table of Contents WEEK OF Feb. 14, 2005 Feb. 14, 2005 Feb. 15, 2005 Feb. 16, 2005 Feb. 17, 2005 Feb. 18, 2005 Feb. 19, 2005 Feb. 20, 2005 BEAM LINE 1-5 Feb. 14, 2005 Feb. 15, 2005 Feb. 16, 2005 Feb. 17, 2005 Feb. 18, 2005 Feb. 19, 2005 Feb. 20, 2005 8858 D.HARRINGTON 8858 D.HARRIN/DOWN 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON

319

SSRL BEAM PORT SCHEDULE  

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

1, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 1, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Feb. 10, 2014 Feb. 17, 2014 Feb. 24, 2014 Back to Table of Contents WEEK OF Nov. 11, 2013 Nov. 11, 2013 Nov. 12, 2013 Nov. 13, 2013 Nov. 14, 2013 Nov. 15, 2013 Nov. 16, 2013 Nov. 17, 2013 BEAM LINE 7-1 Nov. 11, 2013 Nov. 12, 2013 Nov. 13, 2013 Nov. 14, 2013 Nov. 15, 2013 Nov. 16, 2013 Nov. 17, 2013 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 4B02 A.Yeh 8050 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith Unscheduled MC CHECKOUT/8050 8050 C.Smith

320

SSRL BEAM PORT SCHEDULE  

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

7-1 7-1 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 CHANGE/8803* C.SMI 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH BEAM LINE 9-1 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 CHANGE/8861* I.MAT 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Molecular Beam Epitaxy, Multi-source | EMSL  

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

beam epitaxy, is examined using a combination... Self-corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. A...

322

Probing Organic Transistors with Infrared Beams  

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

Probing Organic Transistors with Infrared Beams Probing Organic Transistors with Infrared Beams Print Wednesday, 26 July 2006 00:00 Silicon-based transistors are well-understood,...

323

Electron beam machining using rotating and shaped beam power distribution  

DOE Patents (OSTI)

An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

Elmer, John W. (Pleasanton, CA); O'Brien, Dennis W. (Livermore, CA)

1996-01-01T23:59:59.000Z

324

Alight a beam and beaming light: A theme with variations  

SciTech Connect

The interaction of light (coherent and incoherent) with charged particle beams is explored in various configurations: incoherent scattering of coherent light (laser) from an incoherent particle beam (high temperature), coherent scattering of coherent light (laser) from a {open_quotes}cold{close_quotes} (bunched) beam, femtosecond generation of particle and light beams via {open_quotes}optical slicing{close_quotes} and Thomson/Compton scattering techniques, etc. The domains of ultrashort temporal duration (femtoseconds) as well as ultrashort wavelengths (x rays and shorter), with varying degrees of coherence, are explored. The relevance to a few critical areas of research in the natural sciences, e.g., ultrafast material, chemical and biological processes, protein folding, particle phase space cooling, etc. are touched upon. All the processes discussed involve proper interpretation and understanding of coherent states of matter and radiation, as well as the quality and quantity of information and energy embedded in them. {copyright} {ital 1998 American Institute of Physics.}

Chattopadhyay, S. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)] [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)

1998-05-01T23:59:59.000Z

325

Electron beam machining using rotating and shaped beam power distribution  

DOE Patents (OSTI)

An apparatus and method are disclosed for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: (1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and (2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

Elmer, J.W.; O`Brien, D.W.

1996-07-09T23:59:59.000Z

326

Diagnostic beam absorber in Mu2e beam line  

SciTech Connect

Star density, hadron flux, and residual dose distributions are calculated around the {mu}2e diagnostic beam absorber. Corresponding surface and ground water activation, and air activation are presented as well.

Rakhno, Igor; /Fermilab

2011-03-01T23:59:59.000Z

327

Broad Energy Spectrum of Laser-Accelerated Protons for Spallation-Related Physics  

Science Journals Connector (OSTI)

A beam of MeV protons, accelerated by ultraintense laser-pulse interactions with a thin target foil, is used to investigate nuclear reactions of interest for spallation physics. The laser-generated proton beam is shown (protons were measured) to have a broad energy distribution, which closely resembles the expected energy spectrum of evaporative protons (below 50 MeV) produced in GeV-proton-induced spallation reactions. The protons are used to quantify the distribution of residual radioisotopes produced in a representative spallation target (Pb), and the results are compared with calculated predictions based on spectra modeled with nuclear Monte Carlo codes. Laser-plasma particle accelerators are shown to provide data relevant to the design and development of accelerator driven systems.

P. McKenna; K. W. D. Ledingham; S. Shimizu; J. M. Yang; L. Robson; T. McCanny; J. Galy; J. Magill; R. J. Clarke; D. Neely; P. A. Norreys; R. P. Singhal; K. Krushelnick; M. S. Wei

2005-03-04T23:59:59.000Z

328

Thermal Insulation of Houses  

Science Journals Connector (OSTI)

... THE Thermal Insulation (Dwellings) Bill which Mr. G. Nabarro introduced into the House of Commons on ... , sponsored by members of both major political parties, extends the principle of the Thermal Insulation (Industrial Buildings) Act of July 1957 to all new dwelling houses built in the ...

1958-02-22T23:59:59.000Z

329

Mechanical Engineering & Thermal Group  

E-Print Network (OSTI)

Mechanical Engineering & Thermal Group The Mechanical Engineering (ME) & Thermal Group at LASP has, and ground- based mechanical systems. Instrument Design Building on decades of design experience that has evolved with the complexity of instrument design demands, LASP mechanical engineers develop advanced

Mojzsis, Stephen J.

330

Radiobiologic Significance of Response of Intratumor Quiescent Cells In Vivo to Accelerated Carbon Ion Beams Compared With {gamma}-Rays and Reactor Neutron Beams  

SciTech Connect

Purpose: To clarify the radiosensitivity of intratumor quiescent cells in vivo to accelerated carbon ion beams and reactor neutron beams. Methods and Materials: Squamous cell carcinoma VII tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine to label all intratumor proliferating cells. Next, they received accelerated carbon ion or {gamma}-ray high-dose-rate (HDR) or reduced-dose-rate (RDR) irradiation. Other tumor-bearing mice received reactor thermal or epithermal neutrons with RDR irradiation. Immediately after HDR and RDR irradiation or 12 h after HDR irradiation, the response of quiescent cells was assessed in terms of the micronucleus frequency using immunofluorescence staining for 5-bromo-2'-deoxyuridine. The response of the total (proliferating plus quiescent) tumor cells was determined from the 5-bromo-2'-deoxyuridine nontreated tumors. Results: The difference in radiosensitivity between the total and quiescent cell populations after {gamma}-ray irradiation was markedly reduced with reactor neutron beams or accelerated carbon ion beams, especially with a greater linear energy transfer (LET) value. Clearer repair in quiescent cells than in total cells through delayed assay or a decrease in the dose rate with {gamma}-ray irradiation was efficiently inhibited with carbon ion beams, especially with a greater LET. With RDR irradiation, the radiosensitivity to accelerated carbon ion beams with a greater LET was almost similar to that to reactor thermal and epithermal neutron beams. Conclusion: In terms of tumor cell-killing effect as a whole, including quiescent cells, accelerated carbon ion beams, especially with greater LET values, are very useful for suppressing the dependency on the heterogeneity within solid tumors, as well as depositing the radiation dose precisely.

Masunaga, Shin-ichiro [Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, Kumatori, Osaka (Japan)], E-mail: smasuna@rri.kyoto-u.ac.jp; Ando, Koichi; Uzawa, Akiko; Hirayama, Ryoichi; Furusawa, Yoshiya; Koike, Sachiko [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Sakurai, Yoshinori [Department of Physics, Faculty of Medicine, Sapporo Medical University, Sapporo (Japan); Nagata, Kenji; Suzuki, Minoru; Kashino, Genro [Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, Kumatori, Osaka (Japan); Kinashi, Yuko [Department of Radiation Safety and Control, Research Reactor Institute, Kyoto University, Kumatori, Osaka (Japan); Tanaka, Hiroki; Maruhashi, Akira [Department of Radiation Medical Physics, Research Reactor Institute, Kyoto University, Kumatori, Osaka (Japan); Ono, Koji [Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, Kumatori, Osaka (Japan)

2008-01-01T23:59:59.000Z

331

Thermal Recovery Methods  

SciTech Connect

Thermal Recovery Methods describes the basic concepts of thermal recovery and explains the injection patterns used to exploit reservoir conditions. Basic reservoir engineering is reviewed with an emphasis on changes in flow characteristics caused by temperature. The authors discuss an energy balance for steam and combustion drive, and they explain in situ reactions. Heat loss, combustion drive, and steam displacement also are examined in detail, as well as cyclic steam injection, downhole ignition, well heating, and low-temperature oxidation. Contents: Thermal processes; Formation and reservoir evaluations; Well patterns and spacing; Flow and process equations; Laboratory simulation of thermal recovery; Heat loss and transmission; Displacement and production; Equipment; Basic data for field selection; Laboratory evaluation of combustion characteristics; Thermal properties of reservoirs and fluids.

White, P.D.; Moss, J.T.

1983-01-01T23:59:59.000Z

332

Tunable thermal link  

DOE Patents (OSTI)

Disclosed is a device whereby the thermal conductance of a multiwalled nanostructure such as a multiwalled carbon nanotube (MWCNT) can be controllably and reversibly tuned by sliding one or more outer shells with respect to the inner core. As one example, the thermal conductance of an MWCNT dropped to 15% of the original value after extending the length of the MWCNT by 190 nm. The thermal conductivity returned when the tube was contracted. The device may comprise numbers of multiwalled nanotubes or other graphitic layers connected to a heat source and a heat drain and various means for tuning the overall thermal conductance for applications in structure heat management, heat flow in nanoscale or microscale devices and thermal logic devices.

Chang, Chih-Wei; Majumdar, Arunava; Zettl, Alexander K.

2014-07-15T23:59:59.000Z

333

Solar thermal aircraft  

DOE Patents (OSTI)

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Bennett, Charles L. (Livermore, CA)

2007-09-18T23:59:59.000Z

334

1 Spectrum Sharing Games of Network Operators and Cognitive Radios  

E-Print Network (OSTI)

Contents 1 Spectrum Sharing Games of Network Operators and Cognitive Radios Mohammad Hossein advances in radio technology, the spectrum regulators have opened some parts of the available spectrum operators and cognitive radios. Because of the dynamic nature of spectrum sharing, it is difficult

Bencsáth, Boldizsár

335

A Framework for Radio Frequency Spectrum Measurement and Analysis  

E-Print Network (OSTI)

A Framework for Radio Frequency Spectrum Measurement and Analysis V. Rory Petty ITTC-FY2008-TR allocation and the burgeoning problem of spectrum scarcity have prompted an examination of how the radio frequency spectrum is utilized. The radio frequency spectrum is an important national resource that impacts

Kansas, University of

336

Robust Performance of Spectrum Sensing in Cognitive Radio Networks  

E-Print Network (OSTI)

1 Robust Performance of Spectrum Sensing in Cognitive Radio Networks Shimin Gong, Ping Wang) in cognitive radio networks requires SUs to be spectrum aware and know which spectrum bands are occupied by PUs and reduces the system sensitivity on decision variables. Index Terms Cognitive radio network, spectrum

Huang, Jianwei

337

Reputation Aware Collaborative Spectrum Sensing for Mobile Cognitive Radio Networks  

E-Print Network (OSTI)

Reputation Aware Collaborative Spectrum Sensing for Mobile Cognitive Radio Networks Abstract ­ The task of spectrum sensing for Dynamic Spectrum Access in Cognitive Radio Networks (CRNs) is very of Cognitive Radio (CR) operation is the opportunistic utilization of licensed spectrum bands by the Secondary

Zou, Cliff C.

338

Cryptographic Link Signatures for Spectrum Usage Authentication in Cognitive Radio  

E-Print Network (OSTI)

Cryptographic Link Signatures for Spectrum Usage Authentication in Cognitive Radio Xi Tan, Kapil frequency spectrum was inefficiently utilized. To fully use these spectrums, cognitive radio networks have of cognitive radio is to enable the current fixed spectrum channels assigned by Federal Communica- tions

Du, Wenliang "Kevin"

339

Toward Secure Distributed Spectrum Sensing in Cognitive Radio Networks  

E-Print Network (OSTI)

1 Toward Secure Distributed Spectrum Sensing in Cognitive Radio Networks Ruiliang Chen, Jung}@vt.edu Abstract Cognitive radio (CR) is a revolutionary technology that promises to alleviate the spectrum shortage problem and to bring about remarkable improvement in spectrum utilization. Spectrum sensing is one

340

SAMER: Spectrum Aware Mesh Routing in Cognitive Radio Networks  

E-Print Network (OSTI)

SAMER: Spectrum Aware Mesh Routing in Cognitive Radio Networks SHORT PAPER Ioannis Pefkianakis1 in licensed bands, to meet the increasing demand for radio spectrum. The new open spectrum operation--Cognitive Radio, Spectrum Aware Routing I. INTRODUCTION Cognitive radio networks (CORNET) are an emerging multihop

Lu, Songwu

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Energy-efficient spectrum sensing for cognitive sensor networks  

E-Print Network (OSTI)

spectrum. Traditionally, radio spectrum allocation has been based on exclusive, licensed use of portions for newer wireless net- works and applications. Radio spectrum measurements [13] however indicate that large portions of spectrum licensed to wireless systems remain under-utilized. Consequently there is a growing

Leus, Geert

342

Scheduling Heterogeneous Wireless Systems for Efficient Spectrum Access  

E-Print Network (OSTI)

Radio approach for usage of the Virtual Unlicensed Spectrum (CORVUS) system exploits unoccupied licensed

Bao, Lichun; Liao, Shenghui

2010-01-01T23:59:59.000Z

343

Distributed Routing, Relay Selection, and Spectrum Allocation in Cognitive and  

E-Print Network (OSTI)

of the existing radio spectrum. Based on the reported evidence that static licensed spectrum allocation results--Throughput maximization is a key challenge in cognitive radio ad hoc networks, where the availability of local spectrum radio networks, dynamic spectrum allocation, routing, cross-layer de- sign. I. INTRODUCTION The need

Melodia, Tommaso

344

Federal Spectrum Management at the National Telecommunications and Information Administration  

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

Slides from National Telecommunications and Information Administration's presentation on Federal spectrum management.

345

MATERIAL R&D FOR HIGH-INTENSITY PROTON BEAM PROGRESS REPORT  

E-Print Network (OSTI)

MATERIAL R&D FOR HIGH-INTENSITY PROTON BEAM TARGETS PROGRESS REPORT Nicholas Simos, BNL January 4 strength, very low thermal expansion or high ductility #12;Experimentation with Graphite & Carbon-Carbon Targets (BNL E951) #12;Graphite vs. Carbon-Carbon ­ A Clear Choice ..... really? BNL E951 Target

McDonald, Kirk

346

A Survey on Dynamic Spectrum Access Techniques for Cognitive Radio  

E-Print Network (OSTI)

Cognitive radio (CR) is a new paradigm that utilizes the available spectrum band. The key characteristic of CR system is to sense the electromagnetic environment to adapt their operation and dynamically vary its radio operating parameters. The technique of dynamically accessing the unused spectrum band is known as Dynamic Spectrum Access (DSA). The dynamic spectrum access technology helps to minimize unused spectrum bands. In this paper, main functions of Cognitive Radio (CR) i.e. spectrum sensing, spectrum management, spectrum mobility and spectrum sharing are discussed. Then DSA models are discussed along with different methods of DSA such as Command and Control, Exclusive-Use, Shared Use of Primary Licensed User and Commons method. Game-theoretic approach using Bertrand game model, Markovian Queuing Model for spectrum allocation in centralized architecture and Fuzzy logic based method are also discussed and result are shown.

Garhwal, Anita

2012-01-01T23:59:59.000Z

347

Sandia National Laboratories: National Solar Thermal Testing...  

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

Beam Profiling On November 2, 2012, in Concentrating Solar Power, News, Renewable Energy, Solar On Thursday, June 7, we began beam profiling the NSTTF field heliostat beam....

348

The Beam | Open Energy Information  

Open Energy Info (EERE)

Zip: 2446 Product: The Beam is a start-up company that looks to establish an online retail portal that would market and sell clean energy-related products to consumers....

349

STOCHASTIC COOLING FOR BUNCHED BEAMS.  

SciTech Connect

Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.

BLASKIEWICZ, M.

2005-05-16T23:59:59.000Z

350

Center for Beam Physics, 1992  

SciTech Connect

This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities.

Not Available

1993-06-01T23:59:59.000Z

351

Neutron beam testing of triblades  

SciTech Connect

PowerXCell 8i processors and Opterons in four IBM Triblades were tested at LANSCE. The hazard rate when the beam was aimed at the Opterons was higher than when it was aimed at the Cell processors.

Michalak, Sarah E [Los Alamos National Laboratory; Du Bois, Andrew J [Los Alamos National Laboratory; Storlie, Curtis B [Los Alamos National Laboratory; Rust, William N [Los Alamos National Laboratory; Du Bois, David H [Los Alamos National Laboratory; Modl, David G [Los Alamos National Laboratory; Quinn, Heather M [Los Alamos National Laboratory; Blanchard, Sean P [Los Alamos National Laboratory; Manuzzato, Andrea [UNIV DEGLI STUDI DI PADOVA ITALY

2011-01-31T23:59:59.000Z

352

Neon Ion Beam Lithography (NIBL)  

E-Print Network (OSTI)

Existing techniques for electron- and ion-beam lithography, routinely employed for nanoscale device fabrication and mask/mold prototyping, do not simultaneously achieve efficient (low fluence) exposure and high resolution. ...

Winston, Donald

353

Simulation of the Beam Dump for a High Intensity Electron Gun  

E-Print Network (OSTI)

The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using Geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.

Doebert, S; Lefevre, T; Pepitone, K

2014-01-01T23:59:59.000Z

354

Beam bunch feedback  

SciTech Connect

When the electromagnetic fields that are excited by the passage of a bundle of charged particles persist to act upon bunches that follow, then the motions of the bunches are coupled. This action between bunches circulating on a closed orbit can generate growing patterns of bunch excursions. Such growth can often be suppressed by feedback systems that detect the excursion and apply corrective forces to the bunches. To be addressed herein is feedback that acts on motions of the bunch body centers. In addition to being useful for suppressing the spontaneous growth of coupled-bunch motions, such feedback can be used to damp transients in bunches injected into an accelerator or storage ring; for hadrons which lack strong radiation damping, feedback is needed to avoid emittance growth through decoherence. Motions excited by noise in magnetic fields or accelerating rf can also be reduced by using this feedback. Whether the action is on motions that are transverse to the closed orbit or longitudinal, the arrangement is the same. Bunch position is detected by a pickup and that signal is processed and directed to a kicker that may act upon the same bunch or some other portion of the collective beam pattern. Transverse motion is an oscillation with angular frequency {nu}{perpendicular}{omega}{sub o} where {omega}{sub o} is the orbital frequency 2{pi}{line_integral}o. Longitudinal synchrotron oscillation occurs at frequency {omega} {sub s} = {nu}{sub s}{omega}{sub o}. The former is much more rapid, {nu}{perpendicular} being on the order of 10 while {nu}{sub s} is typically about 10{sup minus 1} to 10 {sup minus 2}.

Lambertson, G.

1995-09-01T23:59:59.000Z

355

Economic Viability of Dynamic Spectrum Management  

E-Print Network (OSTI)

and Economics Lab Department of Information Engineering The Chinese University of Hong Kong #12;#12;1 EconomicEconomic Viability of Dynamic Spectrum Management Jianwei Huang Network Communications efficiently. Successful im- plementation of DSM is not a pure engineering issue. It is also a complicated

Huang, Jianwei

356

Energy spectrum of cosmic-ray muons  

Science Journals Connector (OSTI)

The energy spectrum of cosmic-ray muons at sea-level is calculated by the ... in good agreement with the observed data of muons with the zenith angles of 0° and ... the scaling model is valid up to the muon energy

H. Komori; K. Mitsui

357

Spectrum of the Flame of Ethylene  

Science Journals Connector (OSTI)

1 December 1934 research-article Spectrum of the Flame of Ethylene W. M. Vaidya The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. www.jstor.org

1934-01-01T23:59:59.000Z

358

Microwave Absorption Spectrum of ND3  

Science Journals Connector (OSTI)

The main J=K sequence of inversion lines of the ND3 absorption spectrum were observed and measured between 1589 and 2540 Mc. Quantum numbers up to J, K=18, 18 were assigned by the use of an approximate empirical formula.

R. G. Nuckolls; L. J. Rueger; Harold Lyons

1953-03-01T23:59:59.000Z

359

Diamond/aluminium nitride composites for efficient thermal management applications  

SciTech Connect

Synthetic diamond/AlN composite materials have been fabricated by a combination of microwave plasma-assisted chemical vapor deposition and molecular beam epitaxy. These wide band gap semiconductor heterojunctions show promises for many applications, including thermal management, deep ultraviolet light emitting devices, and high power and high temperature electronics. Here, we report results of an interface study of polycrystalline diamond layers grown on single crystal AlN(0001). High resolution transmission microscopy revealed atomically sharp interfaces between diamond and AlN. Temperature dependent Raman spectroscopy measurements showed reduced thermal resistance on diamond-coated AlN substrates compared to uncoated AlN at temperatures above 330 K.

Cervenka, J.; Dontschuk, N.; Prawer, S. [School of Physics, University of Melbourne, VIC (Australia); Ladouceur, F. [School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW (Australia); Duvall, S. G. [Silanna Semiconductor Pty Ltd., Sydney, NSW (Australia)

2012-07-30T23:59:59.000Z

360

Application of beam emission spectroscopy to NBI plasmas of Heliotron J  

SciTech Connect

This paper describes the application of the beam emission spectroscopy (BES) to Heliotron J, having the nonsymmetrical helical-magnetic-axis configuration. The spectral and spatial profile of the beam emission has been estimated by the numerical calculation taking the collisional excitation processes between plasmas (electrons/ions) and beam atoms. Two sets of the sightlines with good spatial resolution are presented. One is the optimized viewing chords which have 20 sightlines and observe the whole plasma region with the spatial resolution {Delta}{rho} less than {+-}0.055 using the newly designed viewing port. The other is 15 sightlines from the present viewing port of Heliotron J for the preliminary measurement to discuss the feasibility of the density fluctuation measurement by BES. The beam emission has been measured by a monochromator with a CCD camera. A good consistency has been obtained between the spectral profiles of the beam emission measured by the monochromator and the beam emission spectrum deduced by the model calculation. An avalanche photodiode with an interference filter system was also used to evaluate the signal-to-noise (S/N) ratio of the beam emission in the present experimental setup. The modification of the optical system is being planned to improve the S/N ratio, which will enable us to estimate the density fluctuation in Heliotron J.

Kobayashi, S.; Ohshima, S.; Mizuuchi, T.; Nagasaki, K.; Yamamoto, S.; Okada, H.; Minami, T.; Hanatani, K.; Konoshima, S.; Takeuchi, M.; Toushi, K.; Sano, F. [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kado, S. [School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); Oishi, T. [Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Kagawa, T.; Lee, H. Y.; Minami, T.; Nakamura, Y. [Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011 (Japan); Murakami, S. [Graduate School of Engineering, Kyoto University, Kyoto, Kyoto 606-8501 (Japan)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

EARS (Enhancing Access to the Radio Spectrum) PROGRAM: The radio spectrum is a finite but exceedingly valuable natural resource that  

E-Print Network (OSTI)

EARS (Enhancing Access to the Radio Spectrum) PROGRAM: The radio spectrum is a finite communications, among a multitude of others. During the last two decades, the use of the radio spectrum has on the topic of Enhancing Access to the Radio Spectrum. The charge to the workshop was "to identify

Cetiner, Bedri A.

362

High-Temperature Thermal Array for Next Generation Solar Thermal...  

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

Thermal Array for Next Generation Solar Thermal Power Production Award Number: DE-EE00025828 Report Date: March 15, 2013 PI: Stephen Obrey * Technical approach is focused on...

363

Ultrafast electron beam imaging of femtosecond laser-induced plasma  

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

Ultrafast electron beam imaging of femtosecond laser-induced plasma Ultrafast electron beam imaging of femtosecond laser-induced plasma dynamics Title Ultrafast electron beam imaging of femtosecond laser-induced plasma dynamics Publication Type Journal Article Year of Publication 2010 Authors Li, Junjie, Xuan Wang, Zhaoyang Chen, Richard Clinite, Samuel S. Mao, Pengfei Zhu, Zhengming Sheng, Jie Zhang, and Jianming Cao Journal Journal of Applied Physics Volume 107 Issue 8 Date Published 03/2010 Keywords copper, electron beam applications, high-speed optical techniques, laser ablation, plasma diagnostics, plasma production by laser Abstract Plasma dynamics in the early stage of laser ablation of a copper target are investigated in real time by making ultrafast electron shadow images and electron deflectometry measurements. These complementary techniques provide both a global view and a local perspective of the associated transient electric field and charge expansion dynamics. The results reveal that the charge cloud above the target surface is composed predominantly of thermally ejected electrons and that it is self-expanding, with a fast front-layer speed exceeding 107 m/s. The average electric field strength of the charge cloud induced by a pump fluence of 2.2 J/cm2 is estimated to be ∼ 2.4×105 V/m.

364

Fast ignition of inertial fusion targets by laser-driven carbon beams  

E-Print Network (OSTI)

Two-dimensional simulations of ion beam driven fast ignition are presented. Ignition energies of protons with Maxwellian spectrum and carbon ions with quasi-monoenergetic and Maxwellian energy distributions are evaluated. The effect of the coronal plasma surrounding the compressed Deuterium-Tritium is studied for three different fuel density distributions. It is found that quasi- monoenergetic ions have better coupling with the compressed Deuterium-Tritium and substantially lower ignition energies. Comparison of quasi-monoenergetic carbon ions and relativistic electrons as ignitor beams shows similar laser energy requirements, provided that a laser to quasi-monoenergetic carbon ion conversion efficiency around 10% can be achieved.

Honrubia, J J; Temporal, M; Hegelich, B M; Meyer-ter-Vehn, J

2009-01-01T23:59:59.000Z

365

A simplified approach to characterizing a kilovoltage source spectrum for accurate dose computation  

SciTech Connect

Purpose: To investigate and validate the clinical feasibility of using half-value layer (HVL) and peak tube potential (kVp) for characterizing a kilovoltage (kV) source spectrum for the purpose of computing kV x-ray dose accrued from imaging procedures. To use this approach to characterize a Varian Registered-Sign On-Board Imager Registered-Sign (OBI) source and perform experimental validation of a novel in-house hybrid dose computation algorithm for kV x-rays. Methods: We characterized the spectrum of an imaging kV x-ray source using the HVL and the kVp as the sole beam quality identifiers using third-party freeware Spektr to generate the spectra. We studied the sensitivity of our dose computation algorithm to uncertainties in the beam's HVL and kVp by systematically varying these spectral parameters. To validate our approach experimentally, we characterized the spectrum of a Varian Registered-Sign OBI system by measuring the HVL using a Farmer-type Capintec ion chamber (0.06 cc) in air and compared dose calculations using our computationally validated in-house kV dose calculation code to measured percent depth-dose and transverse dose profiles for 80, 100, and 125 kVp open beams in a homogeneous phantom and a heterogeneous phantom comprising tissue, lung, and bone equivalent materials. Results: The sensitivity analysis of the beam quality parameters (i.e., HVL, kVp, and field size) on dose computation accuracy shows that typical measurement uncertainties in the HVL and kVp ({+-}0.2 mm Al and {+-}2 kVp, respectively) source characterization parameters lead to dose computation errors of less than 2%. Furthermore, for an open beam with no added filtration, HVL variations affect dose computation accuracy by less than 1% for a 125 kVp beam when field size is varied from 5 Multiplication-Sign 5 cm{sup 2} to 40 Multiplication-Sign 40 cm{sup 2}. The central axis depth dose calculations and experimental measurements for the 80, 100, and 125 kVp energies agreed within 2% for the homogeneous and heterogeneous block phantoms, and agreement for the transverse dose profiles was within 6%. Conclusions: The HVL and kVp are sufficient for characterizing a kV x-ray source spectrum for accurate dose computation. As these parameters can be easily and accurately measured, they provide for a clinically feasible approach to characterizing a kV energy spectrum to be used for patient specific x-ray dose computations. Furthermore, these results provide experimental validation of our novel hybrid dose computation algorithm.

Poirier, Yannick; Kouznetsov, Alexei; Tambasco, Mauro [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy and Department of Oncology, University of Calgary and Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada)

2012-06-15T23:59:59.000Z

366

Electron beam diagnostic for profiling high power beams  

DOE Patents (OSTI)

A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA)

2008-03-25T23:59:59.000Z

367

Performance of multilayers in intense synchrotron x-ray beams  

SciTech Connect

The use of multilayer reflectors under intense synchroton x-ray beams requires to develop a new generation of multilayered materials that can withstand a high-power load in excess of 100 W/mm/sup 2/. Multilayers with the high-/ital Z/ layer consisting either of a pure element or of compounds such as carbides, nitrides, or silicides have been produced. Because the fabrication conditions are not yet optimized, thin films with satisfactory layer were not obtained leading to poor reflectivities. Such multilayers have been both thermally annealed in a furnace and exposed to a synchrotron beam with a power density of about 1 W/mm/sup 2/. The resulting damage ranges from the total destruction of the layering to a reduction of the reflectivity by typically 40%--60%. In some cases an only 1%--15% loss in reflectivity has been observed.

Ziegler, E.; Lepetre, Y.; Joksch, S.; Saile, V.; Mourikis, S.; Viccaro, P. J.; Rolland, G.; Laugier, F.

1989-07-01T23:59:59.000Z

368

Hybrid simulation of ion beams in background plasma  

SciTech Connect

We present a 2 1/2-dimensional (r, z,v/sub r/, v/sub theta/, v/sub z/; partial/partialtheta = 0) quasineutral hybrid code suitable for studying a broad class of plasma and beam-plasma and configurations. Ions are represented by particles and electrons by an inertialess thermal fluid which obeys a generalized Ohm's law. Fields are solved in the quasineutral Darwin approximation. Several collisional and atomic processes are also included in the model. The code has been applied to the problem of propagation of intense ion beams through performed z-pinch plasma channels, a scenario of interest for inertial confinement fusion devices. copyright 1987 Academic Press, Inc.

Mankofsky, A.; Sudan, R.N.; Denavit, J.

1987-05-01T23:59:59.000Z

369

An adaptive crystal bender for high power synchrotron radiation beams  

SciTech Connect

Perfect crystal monochromators cannot diffract x-rays efficiently, nor transmit the high source brightness available at synchrotron radiation facilities, unless surface strains within the beam footprint are maintained within a few arcseconds. Insertion devices at existing synchrotron sources already produce x-ray power density levels that can induce surface slope errors of several arcseconds on silicon monochromator crystals at room temperature, no matter how well the crystal is cooled. The power density levels that will be produced by insertion devices at the third-generation sources will be as much as a factor of 100 higher still. One method of restoring ideal x-ray diffraction behavior, while coping with high power levels, involves adaptive compensation of the induced thermal strain field. The design and performance, using the X25 hybrid wiggler beam line at the National Synchrotron Light Source (NSLS), of a silicon crystal bender constructed for this purpose are described.

Berman, L.E.; Hastings, J.B.

1992-01-01T23:59:59.000Z

370

An adaptive crystal bender for high power synchrotron radiation beams  

SciTech Connect

Perfect crystal monochromators cannot diffract x-rays efficiently, nor transmit the high source brightness available at synchrotron radiation facilities, unless surface strains within the beam footprint are maintained within a few arcseconds. Insertion devices at existing synchrotron sources already produce x-ray power density levels that can induce surface slope errors of several arcseconds on silicon monochromator crystals at room temperature, no matter how well the crystal is cooled. The power density levels that will be produced by insertion devices at the third-generation sources will be as much as a factor of 100 higher still. One method of restoring ideal x-ray diffraction behavior, while coping with high power levels, involves adaptive compensation of the induced thermal strain field. The design and performance, using the X25 hybrid wiggler beam line at the National Synchrotron Light Source (NSLS), of a silicon crystal bender constructed for this purpose are described.

Berman, L.E.; Hastings, J.B.

1992-10-01T23:59:59.000Z

371

Theory of delayed thermal fluorescence  

Science Journals Connector (OSTI)

A theory of nonradiative thermal activation involved in delayed thermal fluorescence has been developed from the viewpoint of the breakdown of the Born-Oppenheimer adiabatic approximation.

S. H. Lin

1971-01-01T23:59:59.000Z

372

Thermal insulations using vacuum panels  

DOE Patents (OSTI)

Thermal insulation vacuum panels are formed of an inner core of compressed low thermal conductivity powders enclosed by a ceramic/glass envelope evaluated to a low pressure.

Glicksman, Leon R. (Lynnfield, MA); Burke, Melissa S. (Pittsburgh, PA)

1991-07-16T23:59:59.000Z

373

Characterization of UHV E-beam Evaporated Low-Stress Thick Silicon Film for MEMS Application  

Science Journals Connector (OSTI)

This paper investigates various deposition and subsequent processing conditions on UHV e-beam evaporated silicon to obtain low stress film. They include substrate temperature, deposition rate, annealing, thermal oxidation and post-oxidation annealing. Film stress is measured for each condition and cantilever beams made from the films are released for evaluating stress-gradient. Films are also deposited on sloped step structures to observe step and corner coverage. The results indicate that as-deposited evaporated silicon exhibits tensile stress at substrate temperatures below 400?C and compressive stress as substrate temperature is increased above 400?C for a 100 nm/min deposition rate. For evaporated amorphous silicon films, performing thermal oxidation at 900?C and annealing at elevated temperatures has been found to be effective in reducing film stress. For fully crystallized poly-silicon films, however, annealing at 1000?C without thermal oxidation seems to be the more effective way of reducing stress in the film.

A. Michael; O. Kazuo; Y.W. Xu; C.Y. Kwok; T. Puzzer; S. Varlamov

2012-01-01T23:59:59.000Z

374

Thermally driven circulation  

E-Print Network (OSTI)

Several problems connected by the theme of thermal forcing are addressed herein. The main topic is the stratification and flow field resulting from imposing a specified heat flux on a fluid that is otherwise confined to a ...

Nelken, Haim

1987-01-01T23:59:59.000Z

375

Manipulation of Thermal Phonons  

E-Print Network (OSTI)

to manipulate the behavior of phonons is crucial for both energy applications and the cooling of integrated circuits. A novel class of artificially periodic structured materials — phononic crystals — might make manipulation of thermal phonons possible. In many...

Hsu, Chung-Hao

2013-03-28T23:59:59.000Z

376

Solar Thermal Energy Storage  

Science Journals Connector (OSTI)

Various types of thermal energy storage systems are introduced and their importance and desired characteristics are outlined. Sensible heat storage, which is one of the most commonly used storage systems in pract...

E. Paykoç; S. Kakaç

1987-01-01T23:59:59.000Z

377

Contact thermal lithography  

E-Print Network (OSTI)

Contact thermal lithography is a method for fabricating microscale patterns using heat transfer. In contrast to photolithography, where the minimum achievable feature size is proportional to the wavelength of light used ...

Schmidt, Aaron Jerome, 1979-

2004-01-01T23:59:59.000Z

378

Neutron stars - thermal emitters  

E-Print Network (OSTI)

Confronting theoretical models with observations of thermal radiation emitted by neutron stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the neutron stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized neutron stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized neutron stars to the observed thermally emitting objects.

Potekhin, A Y; Pons, J A

2014-01-01T23:59:59.000Z

379

Texas Thermal Comfort Report  

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

thermal comfort thermal comfort Too often, the systems in our houses are both physically and intellectually inaccessible. In the SNAP House, HVAC components are integrated into the overall structure, and act as an experiential threshold between public and private spaces. They are located in a central, structural chase that supports the clerestory and gives the systems a functional presence within the interior. Each individual component is contained within a single chase

380

Photovoltaic-thermal collectors  

DOE Patents (OSTI)

A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.

Cox, III, Charles H. (Carlisle, MA)

1984-04-24T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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.


381

The host galaxies of Compact Steep Spectrum and Gigahertz-Peaked Spectrum radio sources  

E-Print Network (OSTI)

I will review some of the developments in studies of the host galaxy properties of Compact Steep Spectrum (CSS) and GigaHertz-Peaked Spectrum (GPS) radio sources. In contrast to previous reviews structured around observational technique, I will discuss the host galaxy properties in terms of morphology, stellar content and warm gas properties and discuss how compact, young radio-loud AGN are key objects for understanding galaxy evolution.

J. Holt

2008-12-15T23:59:59.000Z

382

A Timoshenko beam theory with pressure corrections for layered orthotropic beams  

E-Print Network (OSTI)

A Timoshenko beam theory with pressure corrections for layered orthotropic beams Graeme J. Kennedya of Michigan, Ann Arbor, MI 48109, USA Abstract A Timoshenko beam theory for layered orthotropic beams and rotation variables that provide the kinematic description of the beam, stress and strain moments used

Papalambros, Panos

383

Physics Reach of the Beta Beam  

E-Print Network (OSTI)

Beta Beams are designed to produce pure (anti)electron neutrino beams and could be an elegant and powerful option for the search of leptonic CP violating processes. In this paper will be quantified the physics reach of a CERN based Beta Beam and of a Super Beam - Beta Beam combination. The CP phase $\\delta$ sensitivity results to be comparable to a Neutrino Factory for $\\sin^2{\\theta_{13}}$ values greater than $10^{-4}$.

Mauro Mezzetto

2003-02-07T23:59:59.000Z

384

Steps toward the power spectrum of matter. I.The mean spectrum of galaxies  

E-Print Network (OSTI)

We calculate the mean power spectrum of galaxies using published power spectra of galaxies and clusters of galaxies. On small scales we use the power spectrum derived from the 2-dimensional distribution of APM galaxies, on large scales we use power spectra derived from 3-dimensional data for galaxy and cluster samples. Spectra are reduced to real space and to the amplitude of the power spectrum of APM galaxies. Available data indicate the presence of two different populations in the nearby Universe. Clusters of galaxies sample a relatively large region in the Universe where rich, medium and poor superclusters are well represented. Their mean power spectrum has a spike on scale 120 h^{-1}Mpc, followed by an approximate power-law spectrum of index n = -1.9 towards small scales. The power spectrum found from LCRS and IRAS 1.2 Jy surveys is flatter around the maximum, which may represent regions of the Universe with medium-rich and poor superclusters.

J. Einasto; M. Einasto; E. Tago; A. A. Starobinsky; F. Atrio-Barandela; V. M"uller; A. Knebe; P. Frisch; R. Cen; H. Andernach; D. Tucker

1998-12-13T23:59:59.000Z

385

Time-dependent simulation of prebunched one and two-beam free electron laser  

SciTech Connect

A numerical simulation in one-dimension is conducted to study the slippage effects on prebunched free electron laser. A technique for the simulation of time dependent free electron lasers (FEL) to model the slippage effects is introduced, and the slowly varying envelope approximation in both z and t is used to illustrate the temporal behaviour in the prebunched FEL. Slippage effect on prebunched two-beam FEL is compared with the one-beam modeling. The evaluation of the radiation pulse energy, thermal and phase distribution, and radiation pulse shape in one-beam and two-beam modeling is studied. It was shown that the performance is considerably undermined when the slippage time is comparable to the pulse duration. However, prebunching reduces the slippage. Prebunching also leads to the radiation pulse with a single smooth spike.

Mirian, N. S., E-mail: najmeh.mirian@ipm.ir [School of Particle and Accelerator Physics, Institute for Research in Fundamental Sciences (IPM), Post code 19395-5531 Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, Post code 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, Post code 15875-4413 Tehran (Iran, Islamic Republic of)

2014-04-15T23:59:59.000Z

386

Demonstration of Cathode Emittance Dominated High Bunch Charge Beams in a DC gun-based Photoinjector  

E-Print Network (OSTI)

We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (greater than or equal to 100 pC) beams produced in the DC gun-based Cornell Energy Recovery Linac Photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittance measured at 9-9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs (ERLs) and Free Electron Lasers (FELs).

Gulliford, Colwyn; Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca

2015-01-01T23:59:59.000Z

387

Dynamic modelling for thermal micro-actuators using thermal networks  

E-Print Network (OSTI)

Dynamic modelling for thermal micro-actuators using thermal networks Beatriz L´opez-Wallea,1 and analytical calculations. Key words: Micro-actuators, Thermal modelling, Electrical analogy, Thermal network 1 and MicroMechatronic Systems Department (AS2M), 24 rue Alain Savary, 25000 Besan¸con, France Abstract

Paris-Sud XI, Université de

388

TMX-U thermal-barrier experiments  

SciTech Connect

This review of thermal-barrier experiments in the Tandem Mirror Experiment Upgrade (TMX-U) describes our progress at Lawrence Livermore National Laboratory in plasma confinement and central-cell heating. Thermal barriers in TMX-U improved axial confinement by two orders of magnitude over a limited range of densities, compared with confinement in single-cell mirrors at the same ion temperature. Our study shows that central-cell radial nonambipolar confinement scales as neoclassical theory and can be eliminated by floating the end walls. Radial ambipolar losses can also be measured and reduced. The electron energy balance is improved in tandem mirrors to near classical, resulting in T/sub e/ up to 0.28 keV. Electron cyclotron heating (ECH) efficiencies up to 42 percent, with low levels of electron microinstability, were achieved when hot electrons in the thermal barrier were heated to average betas as large as 15 percent. The hot-electron distribution is measured from X rays and is modeled by a Fokker-Planck code that includes heating from cavity radio-frequency (RF) fields. Neutral-beam injection in the central cell created average ion betas up to 5 percent with radial profiles of hot ions that are modeled accurately by a radial Fokker-Planck code. Gas fueling between two fundamental ion cyclotron heating (ICH) resonances resulted in symmetrical heating of passing ions toward both ends.

Simonen, T.C.; Allen, S.L.; Barter, J.D.; Casper, T.A.; Correll, D.L.; Carter, M.R.; Clauser, J.F.; Dimonte, G.; Foote, J.H.; Futch, A.H.

1988-02-01T23:59:59.000Z

389

PROSPECT - A precision oscillation and spectrum experiment  

E-Print Network (OSTI)

Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

T. J. Langford

2014-12-22T23:59:59.000Z

390

Energy Spectrum of Buoyancy-driven Turbulence  

E-Print Network (OSTI)

Using direct numerical simulation we demonstrate that stably stratified flows with large Richardson number follow Bolgiano-Obukhov scaling, i.e, the kinetic energy spectrum $E_u(k) \\sim k^{-11/5}$, the entropy spectrum $E_\\theta(k) \\sim k^{-7/5}$, and kinetic energy flux $\\Pi_u(k) \\sim k^{-4/5}$. This is due to the conversion of kinetic energy to potential energy because of buoyancy. We also demonstrate that $E_u(k) \\sim k^{-5/3}$ for stratified flow with weaker buoyancy or smaller Richardson number. We argue that due to the positive energy supply by buoyancy and non-decreasing $\\Pi_u(k)$, Rayleigh B\\'{e}nard convection should follow Kolmogorov-Obukhov scaling ($E_u(k) \\sim k^{-5/3}$).

Verma, Mahendra K; Chatterjee, Anando G

2014-01-01T23:59:59.000Z

391

PROSPECT - A precision oscillation and spectrum experiment  

E-Print Network (OSTI)

Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

,

2015-01-01T23:59:59.000Z

392

Machine and Beam Delivery Updates  

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

MAchine and Beam delivery Updates FY13 MAchine and Beam delivery Updates FY13 Summary of Beam Delivery: FACET Summary Feb_15_22.pdf FACET Summary Feb_15_22.pdf FACET Summary Feb_23_Mar_1.pdf FACET Summary Feb_23_Mar_1.pdf FACET Summary Mar_2_8.pdf FACET Summary Mar_2_8.pdf FACET Summary Mar_9_15.pdf FACET Summary Mar_9_15.pdf FACET Summary Mar_16_22.pdf FACET Summary Mar_16_22.pdf FACET Summary Mar_23_29.pdf FACET Summary Mar_23_29.pdf FACET Summary Mar_30_Apr_5.pdf FACET Summary Mar_30_Apr_5.pdf FACET Summary Apr_6_12.pdf FACET Summary Apr_6_12.pdf FACET Summary Apr_27_May_3.pdf FACET Summary Apr_27_May_3.pdf FACET Summary May_4_10.pdf FACET Summary May_4_10.pdf Emittance Stability in Sector 2_31513.pdf Emittance Stability in Sector 2_31513.pdf FACET beam operations readiness with R56.pdf FACET beam operations readiness with R56.pdf (6/19/2013)

393

Low-temperature grown graphene films by using molecular beam epitaxy  

SciTech Connect

Complete graphene film is prepared by depositing carbon atoms directly on Cu foils in a molecular beam epitaxy chamber at 300 Degree-Sign C. The Raman spectrum of the film has indicated that high-quality few-layer graphene is obtained. With back-gated transistor architecture, the characteristic current modulation of graphene transistors is observed. Following the similar growth procedure, graphitization is observed at room temperature, which is consistent with the molecular dynamics simulations of graphene growth.

Lin, Meng-Yu [Institute of Electronics, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Guo, Wei-Ching; Wang, Pro-Yao [Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan (China); Wu, Meng-Hsun [College of Photonics, National Chiao-Tung University, Tainan, Taiwan (China); Liu, Te-Huan; Chang, Chien-Cheng [Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan (China); Pao, Chun-Wei; Lin, Shih-Yen [Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Lee, Si-Chen [Institute of Electronics, National Taiwan University, Taipei, Taiwan (China)

2012-11-26T23:59:59.000Z

394

Power Spectrum in Krein Space Quantization  

E-Print Network (OSTI)

The power spectrum of scalar field and space-time metric perturbations produced in the process of inflation of universe, have been presented in this paper by an alternative approach to field quantization namely, Krein space quantization [1,2]. Auxiliary negative norm states, the modes of which do not interact with the physical world, have been utilized in this method. Presence of negative norm states play the role of an automatic renormalization device for the theory.

M. Mohsenzadeh; S. Rouhani; M. V. Takook

2008-11-06T23:59:59.000Z

395

Reconnection of vortex filaments and Kolmogorov spectrum  

E-Print Network (OSTI)

The energy spectrum of the 3D velocity field, induced by collapsing vortex filaments is studied. One of the aims of this work is to clarify the appearance of the Kolmogorov type energy spectrum $E(k)\\varpropto k^{-5/3}$, observed in many numerical works on discrete vortex tubes (quantized vortex filaments in quantum fluids). Usually, explaining classical turbulent properties of quantum turbulence, the model of vortex bundles, is used. This model is necessary to mimic the vortex stretching, which is responsible for the energy transfer in classical turbulence. In our consideration we do not appeal to the possible "bundle arrangement" but explore alternative idea that the turbulent spectra appear from singular solution, which describe the collapsing line at moments of reconnection. One more aim is related to an important and intensively discussed topic - a role of hydrodynamic collapse in the formation of turbulent spectra. We demonstrated that the specific vortex filament configuration generated the spectrum $E(k)$ close to the Kolmogorov dependence and discussed the reason for this as well as the reason for deviation. We also discuss the obtained results from point of view of the both classical and quantum turbulence.

Sergey K. Nemirovskii

2014-04-19T23:59:59.000Z

396

AFRD - Center for Beam Physics  

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

Center for Beam Physics Center for Beam Physics Home Organization Outreach and Diversity Highlights Safety Links Intramural Group photo of our staff CBP staff, May 2011 CBP in the News: Read about an innovation in super-precise timing and synchronization; and a look toward the next generation of electron guns with responsiveness and brightness needed by future free-electron lasers such as those in the Next Generation Light Source initiative. Who We Are and What We Do The Center for Beam Physics (CBP) is a resource for meeting the challenges of accelerator science, and a source of many innovative concepts, within the Accelerator and Fusion Research Division. We have core expertise in accelerator physics and theory, accelerator modeling using high performance computing, and instrumentation,

397

Atom penetration from a thin film into the substrate during sputtering by polyenergetic Ar{sup +} ion beam with mean energy of 9.4 keV  

SciTech Connect

Penetration of alien atoms (Be, Ni) into Be, Al, Zr, Si and diamond was investigated under Ar{sup +} ion bombardment of samples having thermally evaporated films of 30--50 nm. Sputtering was carried out using a wide energy spectrum beam of Ar{sup +} ions of 9.4 keV to dose D = 1 {times} 10{sup 16}--10{sup 19} ion/cm{sup 2}. Implanted atom distribution in the targets was measured by Rutherford backscattering spectrometry (RBS) of H{sup +} and He{sup +} ions with energy of 1.6 MeV as well as secondary ion mass-spectrometry (SIMS). During the bombardment, the penetration depth of Ar atoms increases with dose linearly. This depth is more than 3--20 times deeper than the projected range of bombarding ions and recoil atoms. This is a deep action effect. The analysis shows that the experimental data for foreign atoms penetration depth are similar to the data calculated for atom migration through the interstitial site in a field of internal (lateral) compressive stresses created in the near-surface layer of the substrate as a result of implantation. Under these experimental conditions atom ratio r{sub i}/r{sub m} (r{sub i} -- radius of dopant, r{sub m} -- radius target of substrate) can play a principal determining role.

Kalin, B.A.; Gladkov, V.P.; Volkov, N.V.; Sabo, S.E. [Moscow Engineering Physics Inst. (Russian Federation)

1995-12-31T23:59:59.000Z

398

The Beam Profile Calculation for Diagnostic Neutral Beam on HT-7 Tokamak  

Science Journals Connector (OSTI)

A new calculation method is introduced for convergence beam intensity. The program based on this method is prepared for beam intensity distribution and beam power calculation. Taking the HT-7 DNB as a referenc...

Lizhen Liang; Chundong Hu

2013-10-01T23:59:59.000Z

399

Effect of Beam-Beam Interactions on Stability of Coherent Oscillations in a Muon Collider  

SciTech Connect

In order to achieve peak luminosity of a muon collider in the 10{sup 34}/cm{sup 2}/s range the number of muons per bunch should be of the order of a few units of 10{sup 12} rendering the beam-beam parameter as high as 0.1 per IP. Such strong beam-beam interaction can be a source of instability if the working point is chosen close to a coherent beam-beam resonance. On the other hand, the beam-beam tunespread can provide a mechanism of suppression of the beam-wall driven instabilities. In this report the coherent instabilities driven by beam-beam and beam-wall interactions are studied with the help of BBSS code for the case of 1.5 TeV c.o.m muon collider.

Alexahin, Y.; /Fermilab; Ohmi, K.; /KEK, Tsukuba

2012-05-01T23:59:59.000Z

400

Survey of Collective Instabilities and Beam-Plasma Interactions in Intense Heavy Ion Beams  

E-Print Network (OSTI)

H. Qin, Phys. Rev. ST Accel. Beams 4, 104401 (2001). [30] S.Davidson, Phys. Rev. ST Accel. Beams 5, 021001 (2002). [31]Channell, Phys. Rev. ST Accel. Beams 2, 074401 (1999); [32

Davidson, Ronald C.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

TMX-U (Tandem Mirror Experiment-Upgrade) tandem-mirror thermal-barrier experiments  

SciTech Connect

Thermal-barrier experiments have been carried out in the Tandem Mirror Experiment-Upgrade (TMX-U). Measurements of nonambipolar and ambipolar radial transport show that these transport processes, as well as end losses, can be controlled at modest densities and durations. Central-cell heating methods using ion-cyclotron heating (ICH) and neutral-beam injection have been demonstrated. Potential mesurements with recently developed methods indicate that deep thermal barriers can be established.

Simonen, T.C.; Allen, S.L.; Baldwin, D.E.; Barter, J.D.; Berzins, L.V.; Carter, M.R.; Casper, T.A.; Clauser, J.F.; Coensgen, F.H.; Correll, D.L.

1986-10-29T23:59:59.000Z

402

Nonparaxial Mathieu and Weber accelerating beams  

E-Print Network (OSTI)

We demonstrate both theoretically and experimentally nonparaxial Mathieu and Weber accelerating beams, generalizing the concept of previously found accelerating beams. We show that such beams bend into large angles along circular, elliptical or parabolic trajectories but still retain nondiffracting and self-healing capabilities. The circular nonparaxial accelerating beams can be considered as a special case of the Mathieu accelerating beams, while an Airy beam is only a special case of the Weber beams at the paraxial limit. Not only generalized nonparaxial accelerating beams open up many possibilities of beam engineering for applications, but the fundamental concept developed here can be applied to other linear wave systems in nature, ranging from electromagnetic and elastic waves to matter waves.

Peng Zhang; Yi Hu; Tongcang Li; Drake Cannan; Xiaobo Yin; Roberto Morandotti; Zhigang Chen; Xiang Zhang

2012-10-23T23:59:59.000Z

403

Stochastic cooling of bunched beams  

SciTech Connect

Numerical simulation studies are presented for transverse and longitudinal stochastic cooling of bunched particle beams. Radio frequency buckets of various shapes (e.g. rectangular, parabolic well, single sinusoidal waveform) are used to investigate the enhancement of phase space cooling by nonlinearities of synchrotron motion. The connection between the notions of Landau damping for instabilities and mixing for stochastic cooling are discussed. In particular, the need for synchrotron frequency spread for both Landau damping and good mixing is seen to be comparable for bunched beams.

Bisognano, J.J.; Chattopadhyay, S.

1981-03-01T23:59:59.000Z

404

Statistical and evaporation models for the neutron emission energy spectrum in the center-of-mass system from fission fragments  

Science Journals Connector (OSTI)

Abstract The neutron emission energy spectra in the CMS (center-of-mass) frame from two compound nuclei produced by fission are studied. The neutron spectra calculated with the Hauser–Feshbach statistical model are compared with the evaporation theory, and the definition of the temperature is revisited. Using the Monte Carlo technique we average the CMS neutron spectra from many fission fragments to construct the representative CMS spectrum from both the light and heavy fragments. The CMS spectra for each fission fragment pair are also converted into the laboratory frame to calculate the total prompt fission neutron spectrum that can be observed experimentally. This is compared to measured laboratory data for thermal neutron induced fission on 235U. We show that the Hauser–Feshbach calculation gives a different spectrum shape than the Madland–Nix model calculation.

T. Kawano; P. Talou; I. Stetcu; M.B. Chadwick

2013-01-01T23:59:59.000Z

405

Design and testing of a boron carbide capsule for spectral-tailoring in mixed-spectrum reactors  

SciTech Connect

A boron carbide capsule has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State Univ.. Irradiations were conducted in pulsed mode and in continuous operation for up to 4 h. A cadmium cover was used to reduce thermal heating. The neutron spectrum calculated with the Monte Carlo N-particle transport code was found to be in good agreement with reactor dosimetry measurements using the STAY'SL computer code. The neutron spectrum resembles that of a fast reactor. The design of a capsule using boron carbide fully enriched in {sup 10}B shows that it is possible to produce a neutron spectrum similar to that of {sup 235}U fission. (authors)

Greenwood, L.R.; Wittman, R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Pierson, B.P. [Univ. of Michigan, Ann Arbor, MI 48109 (United States); Metz, L.A.; Payne, R.; Finn, E.C.; Friese, J.I. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

2011-07-01T23:59:59.000Z

406

1569003080 1 Characterization of Spectrum Activities in the  

E-Print Network (OSTI)

interference, and policy performance with local and cooperative sensing. We analyze the collected data. Jung is with the Electrical and Computer Engineering Department, The University of California, Davis and dynamic spectrum policies, including regulation recommendations, secondary market spectrum leasing rulings

Liu, Xin

407

Centralized Collaborative Compressed Sensing of Wideband Spectrum for Cognitive Radios  

E-Print Network (OSTI)

1 Centralized Collaborative Compressed Sensing of Wideband Spectrum for Cognitive Radios Hessam, spectrum sensing, cognitive radio, distri- bution discontinuities, algebraic detection, wideband. I technique for cognitive radio systems which combines algebraic tools and compressive sampling techniques

Paris-Sud XI, Université de

408

A day in the life of the RF spectrum  

E-Print Network (OSTI)

There is a misguided perception that RF spectrum space is fully allocated and fully used though even a superficial study of actual spectrum usage by measuring local RF energy shows it largely empty of radiation. Traditional ...

Cooley, James E. (James Edward)

2005-01-01T23:59:59.000Z

409

Temperature measurements using multicolor pyrometry in thermal radiation heating environments  

SciTech Connect

Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

Fu, Tairan, E-mail: trfu@mail.tsinghua.edu.cn [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China) [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of CO2 Utilization and Reduction Technology, Beijing 100084 (China); Liu, Jiangfan; Duan, Minghao; Zong, Anzhou [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)] [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)

2014-04-15T23:59:59.000Z

410

Air fluorescence measurements in the spectral range 300-420 nm using a 28.5 GeV electron beam  

E-Print Network (OSTI)

Measurements are reported of the yield and spectrum of fluorescence, excited by a 28.5 GeV electron beam, in air at a range of pressures of interest to ultra-high energy cosmic ray detectors. The wavelength range was 300 - 420 nm. System calibration has been performed using Rayleigh scattering of a nitrogen laser beam. In atmospheric pressure dry air at 304 K the yield is 20.8 +/- 1.6 photons per MeV.

R. Abbasi; T. Abu-Zayyad; K. Belov; J. Belz; Z. Cao; M. Dalton; Y. Fedorova; P. Huentemeyer; B. F. Jones; C. C. H. Jui; E. C. Loh; N. Manago; K. Martens; J. N. Matthews; M. Maestas; J. Smith; P. Sokolsky; R. W. Springer; J. Thomas; S. Thomas; P. Chen; C. Field; C. Hast; R. Iverson; J. S. T. Ng; A. Odian; K. Reil; D. Walz; D. R. Bergman; G. Thomson; A. Zech; F-Y. Chang; C-C. Chen; C-W. Chen; M. A. Huang; W-Y. P. Hwang; G-L. Lin

2007-08-23T23:59:59.000Z

411

Sequential Detection based Cooperative Spectrum Sensing Algorithms in Cognitive Radio  

E-Print Network (OSTI)

Sequential Detection based Cooperative Spectrum Sensing Algorithms in Cognitive Radio Arun considers the problem of Spectrum Sensing in Cognitive Radio Networks. For this we use a recently developed is not experienced by our algorithm. Keywords-Cognitive Radio, Cooperative Spectrum Sensing, Decentralized Sequential

Sharma, Vinod

412

Competitive Interference-aware Spectrum Access in Cognitive Radio Networks  

E-Print Network (OSTI)

Competitive Interference-aware Spectrum Access in Cognitive Radio Networks Jocelyne Elias, Fabio studies the spectrum access problem in cognitive radio networks from a game theoretical perspective. Finally, we provide numerical results of the proposed spectrum access game in several cognitive radio

Boyer, Edmond

413

High Throughput Spectrum-aware Routing for Cognitive Radio Networks  

E-Print Network (OSTI)

High Throughput Spectrum-aware Routing for Cognitive Radio Networks Ashwin Sampath, Lei Yang, Lili, wireless nodes equipped with cognitive radios [11] do not operate on statically as- signed spectrum who own the spectrum, e.g. analog TV broadcast stations. Such flexibility means cognitive radios can

Zhao, Ben Y.

414

Spectrum Leasing via Distributed Cooperation in Cognitive Radio  

E-Print Network (OSTI)

Spectrum Leasing via Distributed Cooperation in Cognitive Radio Igor Stanojev1 , Osvaldo Simeone1 for cognitive radio. I. INTRODUCTION Cognitive radio is a debated new paradigm for efficient spectrum or unlicensed model [1], requires secondary users to first sense the radio environment in search of spectrum

Yener, Aylin

415

Spectrum Leasing via Distributed Cooperation in Cognitive Radio  

E-Print Network (OSTI)

Spectrum Leasing via Distributed Cooperation in Cognitive Radio Igor Stanojev1, Osvaldo Simeone1 for cognitive radio. I. INTRODUCTION Cognitive radio is a debated new paradigm for efficient spectrum or unlicensed model [1], requires secondary users to first sense the radio environment in search of spectrum

Simeone, Osvaldo

416

Censored Truncated Sequential Spectrum Sensing for Cognitive Radio Networks  

E-Print Network (OSTI)

1 Censored Truncated Sequential Spectrum Sensing for Cognitive Radio Networks Sina Maleki Geert Leus Abstract Reliable spectrum sensing is a key functionality of a cognitive radio network. Cooperative spectrum sensing improves the detection reliability of a cognitive radio system but also increases

Leus, Geert

417

Collaborative Spectrum Sensing from Sparse Observations in Cognitive Radio Networks  

E-Print Network (OSTI)

1 Collaborative Spectrum Sensing from Sparse Observations in Cognitive Radio Networks Jia (Jasmine for the implementation of cognitive radio. Collaborative spectrum sensing among the cognitive radio nodes is expected to improve the ability of checking complete spectrum usage. Due to hardware limitations, each cognitive radio

Yin, Wotao

418

Demonstration of Real-time Spectrum Sensing for Cognitive Radio  

E-Print Network (OSTI)

Demonstration of Real-time Spectrum Sensing for Cognitive Radio Zhe Chen, Nan Guo, and Robert C sensing detects the availability of the radio frequency spectrum in a real-time fashion, which is essen Cognitive radio (CR) has been put forward to make effi- cient use of scarce radio frequency spectrum

Qiu, Robert Caiming

419

Two Phase Spectrum Sharing for Frequency-Agile Radio Networks  

E-Print Network (OSTI)

1 Two Phase Spectrum Sharing for Frequency-Agile Radio Networks Zhenhua Feng and Yaling Yang of modern radios. We solve a joint spectrum sharing and end-to-end rate control problems for general technologies (e.g. software defined radio and cognitive radios) enable more flexible spectrum access through

Ha, Dong S.

420

Throughput Enhancing Cooperative Spectrum Sensing Strategies for Cognitive Radios  

E-Print Network (OSTI)

Throughput Enhancing Cooperative Spectrum Sensing Strategies for Cognitive Radios Kyounghwan Lee growth of wireless services continues to accelerate the exhaustion of usable radio spectrum. The radio channels licensed to the primary users. A main chal- lenge in this case is to design a spectrum sensing

Yener, Aylin

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Quickest Spectrum Detection Using Hidden Markov Model for Cognitive Radio  

E-Print Network (OSTI)

Quickest Spectrum Detection Using Hidden Markov Model for Cognitive Radio Zhe Chen, Zhen Hu, Robert and recognition under the umbrella of cognitive radio. In the procedure of spectrum recognition, a frequency) opened free white space spectrum on November 4, 2008 [1]. Cognitive radio has been put forward as a more

Qiu, Robert Caiming

422

Partial Cooperation for Spectrum Sharing in Cognitive Radio Network  

E-Print Network (OSTI)

Partial Cooperation for Spectrum Sharing in Cognitive Radio Network Lok Man Law1, Fen Hou2, Jianwei that many licensed radio spectrums are heavily under-utilized. Cognitive radio technology can improve spectrum, without affecting the normal communications of the primary licensed users. In cognitive radio

Paris-Sud XI, Université de

423

Partial Cooperation for Spectrum Sharing in Cognitive Radio Network  

E-Print Network (OSTI)

that many licensed radio spectrums are heavily under-utilized. Cognitive radio technology can improve spectrum, without affecting the normal communications of the primary licensed users. In cognitive radioPartial Cooperation for Spectrum Sharing in Cognitive Radio Network Lok Man Law1, Fen Hou2, Jianwei

Huang, Jianwei

424

Competition and bargaining in wireless networks with spectrum leasing  

E-Print Network (OSTI)

which have bought a license, giving them the exclusive right to use a fixed part of the radio spectrum a license which gives it the right to use spectrum, while the MVNO is a Secondary Operator (SO), which leases a fraction of the spectrum licensed to the PO. The SO is assumed to have deployed a new technology

Paris-Sud XI, Université de

425

ICST Transactions Preprint Cooperation Scheme For Distributed Spectrum  

E-Print Network (OSTI)

ICST Transactions Preprint Cooperation Scheme For Distributed Spectrum Sensing In Cognitive Radio, Philadelphia, PA 19122 Abstract Spectrum sensing is an essential phase in cognitive radio networks (CRNs). It enables secondary users (SUs) to access licensed spectrum, which is temporarily not occupied

Wu, Jie

426

Robust Distributed Spectrum Sensing in Cognitive Radio Networks  

E-Print Network (OSTI)

unlicensed radios to operate in licensed spectrum, provided no harmful interference is expe- riencedRobust Distributed Spectrum Sensing in Cognitive Radio Networks Ruiliang Chen, Jung-Min Park {rlchen, jungmin, kgbian}@vt.edu Abstract--Distributed spectrum sensing (DSS) enables a Cog- nitive Radio

427

Cognitive Radio Networks: How much Spectrum Sharing is Optimal?  

E-Print Network (OSTI)

Cognitive Radio Networks: How much Spectrum Sharing is Optimal? Sudhir Srinivasa and Syed Ali Jafar the traditional `divide and set aside' approach to spectrum regulation ensures that the licensed (primary) users periodically monitors the radio spectrum, intelligently detects occupancy in the different frequency bands

Jafar, Syed A.

428

Spread-spectrum Cognitive Networking: Distributed Channelization and Routing  

E-Print Network (OSTI)

Mainstream cognitive radio proposals focus on opportunistic access to the licensed spectrum where the primary. Moreover, in cognitive radio networks with multi-hop communication requirements, spectrum occupancy or secondary users. In this way, the secondary users share the licensed spectrum with the primary users

Melodia, Tommaso

429

On the Characteristics of Spectrum-Agile Communication Networks  

E-Print Network (OSTI)

space" in radio spectrum, varying on frequency, time, and geographic locations. Thus, it is likely and general observations indicate that much of the radio spectrum is not in use for a significant amount on the opportunistic spectrum utilization by users other than the primary licensed ones on a non-interfering or leasing

Liu, Xin

430

Ensuring Trustworthy Spectrum Sensing in Cognitive Radio Networks  

E-Print Network (OSTI)

Ensuring Trustworthy Spectrum Sensing in Cognitive Radio Networks Ruiliang Chen and Jung-Min Park to coexist with incumbent users in licensed spectrum bands without inducing interference to incumbent--Cognitive Radio, Spectrum Sensing, Primary User Emulation Attack, Location Verification. I. INTRODUCTION The need

431

Spectrum Investment with Uncertainty Based on Prospect Theory  

E-Print Network (OSTI)

Spectrum Investment with Uncertainty Based on Prospect Theory Junlin Yu, Man Hon Cheung, and Jianwei Huang Abstract--We study a secondary wireless operator's spectrum investment problem under is uncertain. We formulate such a hybrid spectrum investment problem as a two-stage optimization prob- lem

Huang, Jianwei

432

Nonlinear Energy Transfer in a Narrow Gravity-Wave Spectrum  

Science Journals Connector (OSTI)

...research-article Nonlinear Energy Transfer in a Narrow Gravity-Wave Spectrum J. C...calculation of the rate of energy transfer due to...a narrow gravity wave spectrum according...typical narrow wind wave spectrum on the nonlinear energy transfer are very...

1979-01-01T23:59:59.000Z

433

Thermal ignition combustion system  

DOE Patents (OSTI)

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

434

Scattering Solar Thermal Concentrators  

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

"This fact sheet describes a scattering solar thermal concentrators project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pennsylvania State University, is working to demonstrate a new, scattering-based approach to concentrating sunlight that aims to improve the overall performance and reliability of the collector field. The research team aims to show that scattering solar thermal collectors are capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but with the added benefits of immunity to wind-load tracking error, more efficient land use, and utilization of stationary receivers."

435

Thermal ignition combustion system  

SciTech Connect

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

1988-01-01T23:59:59.000Z

436

Thermal ignition combustion system  

SciTech Connect

A thermal ignition combustion system adapted for use with an internal combustion engine is described comprising: (a) means for providing ignition chamber walls defining an ignition chamber, the chamber walls being made of a material having a thermal conductivity greater than 20 W/m/sup 0/C. and a specific heat greater than 480J/kg/sup 0/C., the ignition chamber being in constant communication with the main combustion chamber; (b) means for maintaining the temperature of the chamber walls above a threshold temperature capable of causing ignition of a fuel; and (c) means for conducting fuel to the ignition chamber.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

437

Thermal test options  

SciTech Connect

Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods.

Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

1993-02-01T23:59:59.000Z

438

High energy laser beam dump  

DOE Patents (OSTI)

The laser beam dump is positioned in a housing. An absorbing glass plate means is operatively connected to the housing. A heat sync means for extracting heat from the absorbing glass plate means is operatively connected to the housing and operatively connected to the absorbing glass plate means.

Halpin, John (Tracy, CA)

2004-09-14T23:59:59.000Z

439

Relativistic atomic beam spectroscopy II  

SciTech Connect

We are requesting support for a postdoctoral person to participate in H{sup -} studies at Los Alamos. In addition, we are requesting funding for a state-of-the-art YAG laser system that would allow us to obtain data at three times our present rate with improved beam quality.

NONE

1991-12-31T23:59:59.000Z

440

Optical Absorption Spectrum of AgF  

Science Journals Connector (OSTI)

The optical absorption of thin films of silver monofluoride has been investigated in the visible and ultraviolet region of the spectrum at room and low temperatures. Exciton peaks have been observed at 4.63 and 6.34 eV for samples at 4.8 °K. The first exciton peak is considerably lower in energy than might be expected on the basis of the trend set by the other silver halides. This unusually low energy has led us to speculate that the band structure of AgF may be quite different from those of the other silver halides.

Alfred P. Marchetti and G. L. Bottger

1971-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Raman Spectrum of Graphene and Graphene Layers  

Science Journals Connector (OSTI)

Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality. We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers. The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process. The G peak slightly down-shifts. This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.

A. C. Ferrari; J. C. Meyer; V. Scardaci; C. Casiraghi; M. Lazzeri; F. Mauri; S. Piscanec; D. Jiang; K. S. Novoselov; S. Roth; A. K. Geim

2006-10-30T23:59:59.000Z

442

Thermal expansion recovery microscopy: Practical design considerations  

SciTech Connect

A detailed study of relevant parameters for the design and operation of a photothermal microscope technique recently introduced is presented. The technique, named thermal expansion recovery microscopy (ThERM) relies in the measurement of the defocusing introduced by a surface that expands and recovers upon the heating from a modulated source. A new two lens design is presented that can be easily adapted to commercial infinite conjugate microscopes and the sensitivity to misalignment is analyzed. The way to determine the beam size by means of a focus scan and the use of that same scan to verify if a thermoreflectance signal is overlapping with the desired ThERM mechanism are discussed. Finally, a method to cancel the thermoreflectance signal by an adequate choice of a nanometric coating is presented.

Mingolo, N., E-mail: nmingol@fi.uba.ar; Martínez, O. E. [Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina)] [Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina)

2014-01-15T23:59:59.000Z

443

Thermal Dileptons as Fireball Thermometer and Chronometer  

E-Print Network (OSTI)

Thermal dilepton radiation from the hot fireballs created in high-energy heavy-ion collisions provides unique insights into the properties of the produced medium. We first show how the predictions of hadronic many-body theory for a melting $\\rho$ meson, coupled with QGP emission utilizing a modern lattice-QCD based equation of state, yield a quantitative description of dilepton spectra in heavy-ion collisions at the SPS and the RHIC beam energy scan program. We utilize these results to systematically extract the excess yields and their invariant-mass spectral slopes to predict the excitation function of fireball lifetimes and (early) temperatures, respectively. We thereby demonstrate that future measurements of these quantities can yield unprecedented information on basic fireball properties. Specifically, our predictions quantify the relation between the measured and maximal fireball temperatures, and the proportionality of excess yields and total lifetime. This information can serve as a "caloric" curve to ...

Rapp, Ralf

2014-01-01T23:59:59.000Z

444

The Broadband Spectrum of Galaxy Clusters  

E-Print Network (OSTI)

We examine whether nonthermal protons energized during a cluster merger are simultaneously responsible for the Coma cluster's diffuse radio flux (via secondary decay) and the departure of its intra-cluster medium (ICM) from a thermal profile via Coulomb collisions between the quasithermal electrons and the hadrons. Rather than approximating the influence of nonthermal proton/thermal electron collisions as extremely rare events which cause an injection of nonthermal, power-law electrons (the `knock-on' approximation), we self-consistently solve (to our knowledge, for the first time) the covariant kinetic equations for the two populations. The electron population resulting from these collisions is out of equilibrium, yet not a power law, and importantly displays a higher bremsstrahlung radiative efficiency than a pure power law. Observations with GLAST will test this model directly.

Brandon Wolfe; Fulvio Melia

2007-12-02T23:59:59.000Z

445

Design of titania nanotube structures by focused laser beam direct writing  

SciTech Connect

In this work, we report on electrochemical fabrication of titania films consisting of nanotubes (NTs) and their treatment by focused laser beam. The results of sample characterization by optical and scanning electron microscopy, cathodoluminescence imaging, and Raman scattering scanning spectroscopy are compared to those inherent to specimens subjected to thermal treatment in a furnace. The obtained data demonstrate possibilities for controlling crystallographic structure of TiO{sub 2} NTs by focused laser beam direct writing. These findings open new prospects for the design and fabrication of spatial architectures based on titania nanotubes.

Enachi, Mihai [National Center for Materials Study and Testing, Technical University of Moldova, Stefan cel Mare av. 168, Chisinau, MD-2004 (Moldova, Republic of); Stevens-Kalceff, Marion A. [School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Sarua, Andrei [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Ursaki, Veaceslav [Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau, MD-2028 (Moldova, Republic of); Tiginyanu, Ion, E-mail: tiginyanu@asm.md [National Center for Materials Study and Testing, Technical University of Moldova, Stefan cel Mare av. 168, Chisinau, MD-2004 (Moldova, Republic of); Institute of Electronic Engineering and Nanotechnologies, Academy of Sciences of Moldova, Chisinau, MD-2028 (Moldova, Republic of)

2013-12-21T23:59:59.000Z

446

Prototype photon position monitors for undulator beams at the Advanced Light Source  

SciTech Connect

Design criteria are described, and test results are presented, for prototype ALS undulator beam position monitors. The design is based on monitors presently in use at NSLS, with modifications to account for the widely varying and large K values of the undulators to be installed at the ALS. In particular, we have modified the design to simplify the thermal engineering and we have explored techniques to suppress the response of the monitors to soft photons, so that the beam position can be determined by measuring the higher energy photons which are better collimated. 4 refs., 8 figs.

Warwick, T.; Shu, D. (Lawrence Berkeley Lab., CA (United States)); Rodricks, B. (Argonne National Lab., IL (United States)); Johnson, E.D. (Brookhaven National Lab., Upton, NY (United States))

1990-10-17T23:59:59.000Z

447

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

ENERGY STORAGE FOR CONCENTRATING SOLAR POWER PLANTS,”Thermal Energy Storage in Concentrated Solar Thermal PowerThermal Energy Storage in Concentrated Solar Thermal Power

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

448

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

CHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLAR POWERfor Thermal Energy Storage in Concentrated Solar Thermalfor Thermal Energy Storage in Concentrated Solar Thermal

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

449

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

and Background Solar thermal energy collection is anCHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLAR POWERfor Thermal Energy Storage in Concentrated Solar Thermal

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

450

Beam Pipe HOM Absorber for 750 MHz RF Cavity Systems  

SciTech Connect

This joint project of Muons, Inc., Cornell University and SLAC was supported by a Phase I and Phase II grant monitored by the SBIR Office of Science of the DOE. Beam line HOM absorbers are a critical part of future linear colliders. The use of lossy materials at cryogenic temperatures has been incorporated in several systems. The design in beam pipes requires cylinders of lossy material mechanically confined in such a way as to absorb the microwave energy from the higher-order modes and remove the heat generated in the lossy material. Furthermore, the potential for charge build-up on the surface of the lossy material requires the conductivity of the material to remain consistent from room temperature to cryogenic temperatures. In this program a mechanical design was developed that solved several design constraints: a) fitting into the existing Cornell load vacuum component, b) allowing the use of different material compositions, c) a thermal design that relied upon the compression of the lossy ceramic material without adding stress. Coating experiments were performed that indicated the design constraints needed to fully implement this approach for solving the charge build-up problem inherent in using lossy ceramics. In addition, the ACE3P program, used to calculate the performance of lossy cylinders in beam pipes in general, was supported by this project. Code development and documentation to allow for the more wide spread use of the program was a direct result of this project was well.

Johnson, Rolland; Neubauer, Michael

2014-10-29T23:59:59.000Z

451

Electron Beam--21st Century Food Technology  

E-Print Network (OSTI)

This publication explains electron beam irradiation technology to consumers, industry professionals and government officials. Electron beam irradiation is a method of treating food and other products for pathogens that might jeopardize food safety....

Vestal, Andy

2003-03-07T23:59:59.000Z

452

Autogenerator of beams of charged particles  

DOE Patents (OSTI)

An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

1983-10-31T23:59:59.000Z

453

Fusion Reactions Involving Radioactive Beams at GANIL  

Science Journals Connector (OSTI)

......February 2004 research-article Articles Fusion Reactions Involving Radioactive Beams...been used to produce exotic nuclei via fusion evaporation or to study reaction mechanisms...Physics Supplement No. 154, 2004 113 Fusion Reactions Involving Radioactive Beams......

Gilles de France

2004-02-01T23:59:59.000Z

454

Autogenerator of beams of charged particles  

DOE Patents (OSTI)

An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

Adler, Richard J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Miller, Robert B. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM); Smith, David L. (Albuquerque, NM)

1986-01-01T23:59:59.000Z

455

Transport of elliptic intense charged -particle beams  

E-Print Network (OSTI)

The transport theory of high-intensity elliptic charged-particle beams is presented. In particular, the halo formation and beam loss problem associated with the high space charge and small-aperture structure is addressed, ...

Zhou, J. (Jing), 1978-

2006-01-01T23:59:59.000Z

456

Adaptive phase measurements for narrowband squeezed beams  

E-Print Network (OSTI)

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and hence can be significantly squeezed only over a limited frequency range. In this paper we analyze adaptive phase measurements of this type for a realistic model of a squeezed beam. We show that, provided it is possible to suitably choose the parameters of the beam, a mean-square phase uncertainty scaling as (N/kappa)^{-5/8} is possible, where kappa is the linewidth of the beam resulting from the fluctuating phase. This is an improvement over the (N/kappa)^{-1/2} scaling found previously for coherent beams. In the experimentally realistic case where there is a limit on the maximum squeezing possible, the variance will be reduced below that for coherent beams, though the scaling is unchanged.

Dominic W. Berry; Howard M. Wiseman

2006-03-22T23:59:59.000Z

457

MIS-1 electron-beam ion source  

Science Journals Connector (OSTI)

The Institute of Nuclear Physics (INP) has developed and produced electron-beam multiply charged ion sources. These ion sources give the electron beam its high density in the ionization...3 A/cm2.... They produce...

V. G. Abdulmanov; N. S. Dikansky

2010-12-01T23:59:59.000Z

458

Thermal barrier coating  

DOE Patents (OSTI)

A thermal barrier coating for hot gas path components of a combustion turbine based on a zirconia-scandia system. A layer of zirconium scandate having the hexagonal Zr.sub.3 Sc.sub.4 O.sub.12 structure is formed directly on a superalloy substrate or on a bond coat formed on the substrate.

Bowker, Jeffrey Charles (Gibsonia, PA); Sabol, Stephen M. (Orlando, FL); Goedjen, John G. (Oviedo, FL)

2001-01-01T23:59:59.000Z

459

Thermal management of nanoelectronics  

E-Print Network (OSTI)

-state thermoelectric on- spot cooling, requiring efficient thermoelectric materials that can be integrated with the IC are further complicated by the fact that the material's ability to conduct heat deteriorates when at the packaging level but also at the nanoscale materials and device levels. THERMAL CHALLENGES AT NANOSCALE One

460

Thermal Reactor Safety  

SciTech Connect

Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

Not Available

1980-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam spectrum thermal" 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

Probing the thermal character of analogue Hawking radiation for shallow water waves?  

E-Print Network (OSTI)

We study and numerically compute the scattering coefficients of shallow water waves blocked by a stationary counterflow. When the flow is transcritical, the coefficients closely follow Hawking's prediction according to which black holes should emit a thermal spectrum. We study how the spectrum deviates from thermality when reducing the maximal flow velocity, with a particular attention to subcritical flows since these have been recently used to test Hawking's prediction. For such flows, we show that the emission spectrum is strongly suppressed, and that its Planckian character is completely lost. For low frequencies, we also show that the scattering coefficients are dominated by elastic hydrodynamical channels. Our numerical results reproduce rather well the observations made by S. Weinfurtner {\\it et al.} in the Vancouver experiment. Nevertheless, we propose a new interpretation of what has been observed, as well as new experimental tests.

Florent Michel; Renaud Parentani

2014-09-15T23:59:59.000Z

462

The Optical Spectrum of the Vela Pulsar  

E-Print Network (OSTI)

Our knowledge of the optical spectra of Isolated Neutron Stars (INSs) is limited by their intrinsic faintness. Among the fourteen optically identified INSs, medium resolution spectra have been obtained only for a handful of objects. No spectrum has been published yet for the Vela pulsar (PSR B0833-45), the third brightest (V=23.6) INS with an optical counterpart. Optical multi-band photometry underlines a flat continuum.In this work we present the first optical spectroscopy observations of the Vela pulsar, performed in the 4000-11000 A spectral range.Our observations have been performed at the ESO VLT using the FORS2 instrument. The spectrum of the Vela pulsar is characterized by a flat power-law (alpha = -0.04 +/- 0.04), which compares well with the values obtained from broad-band photometry. This confirms, once more, that the optical emission of Vela is entirely of magnetospheric origin. The comparison between the optical spectral indeces of rotation-powered INSs does not show evidence for a spectral evolution suggesting that, as in the X-rays, the INS aging does not affect the spectral properties of the magnetospheric emission. At the same time, the optical spectral indeces are found to be nearly always flatter then the X-rays ones, clearly suggesting a general spectral turnover at lower energies.

R. P. Mignani; S. Zharikov; P. A. Caraveo

2007-07-13T23:59:59.000Z

463

Target design optimization for an electron accelerator driven subcritical facility with circular and square beam profiles.  

SciTech Connect

A subcritical facility driven by an electron accelerator is planned at the Kharkov Institute of Physics and Technology (KIPT) in Ukraine for medical isotope production, materials research, training, and education. The conceptual design of the facility is being pursued through collaborations between ANL and KIPT. As part of the design effort, the high-fidelity analyses of various target options are performed with formulations to reflect the realistic configuration and the three dimensional geometry of each design. This report summarizes the results of target design optimization studies for electron beams with two different beam profiles. The target design optimization is performed via the sequential neutronic, thermal-hydraulic, and structural analyses for a comprehensive assessment of each configuration. First, a target CAD model is developed with proper emphasis on manufacturability to provide a basis for separate but consistent models for subsequent neutronic, thermal-hydraulic, and structural analyses. The optimizations are pursued for maximizing the neutron yield, streamlining the flow field to avoid hotspots, and minimizing the thermal stresses to increase the durability. In addition to general geometric modifications, the inlet/outlet channel configurations, target plate partitioning schemes, flow manipulations and rates, electron beam diameter/width options, and cladding material choices are included in the design optimizations. The electron beam interactions with the target assembly and the neutronic response of the subcritical facility are evaluated using the MCNPX code. the results for the electron beam energy deposition, neutron generation, and utilization in the subcritical pile are then used to characterize the axisymmetric heat generation profiles in the target assembly with explicit simulations of the beam tube, the coolant, the clad, and the target materials. Both tungsten and uranium are considered as target materials. Neutron spectra from tungsten and uranium are very similar allowing the use of either material in the subcritical assembly without changing its characteristics. However, the uranium target has a higher neutron yield, which increases the neutron flux of the subcritical assembly. Based on the considered dimensions and heat generation profiles, the commercial CFD software Star-CD is used for the thermal-hydraulic analysis of each target design to satisfy a set of thermal criteria, the most limiting of which being to maintain the water temperature 50 below the boiling point. It is found that the turbulence in the inlet channels dissipates quickly in narrow gaps between the target plates and, as a result, the heat transfer is limited by the laminar flow conditions. On average, 3-D CFD analyses of target assemblies agree well with 1-D calculations using RELAP (performed by KIPT). However, the recirculation and stagnation zones predicted with the CFD models prove the importance of a 3-D analysis to avoid the resulting hotspots. The calculated temperatures are subsequently used for the structural analysis of each target configuration to satisfy the other engineering design requirements. The thermo-structural calculations are performed mostly with NASTRAN and the results occasionally compared with the results from MARC. Both, NASTRAN and MARC are commercially available structural-mechanics analysis software. Although, a significant thermal gradient forms in target elements along the beam direction, the high thermal stresses are generally observed peripherally around the edge of thin target disks/plates. Due to its high thermal conductivity, temperatures and thermal stresses in tungsten target are estimated to be significantly lower than in uranium target. The deformations of the target disks/plates are found to be insignificant, which eliminate concerns for flow blockages in narrow coolant channels. Consistent with the specifications of the KIPT accelerator to be used in this facility, the electron beam power is 100-kW with electron energy in the range of 100 to 200 MeV. As expected, the 100 MeV el

Gohar, M. Y. A; Sofu, T.; Zhong, Z.; Belch, H.; Naberezhnev, D.; Nuclear Engineering Division

2008-10-30T23:59:59.000Z

464

High-Temperature Thermal Array for Next Generation Solar Thermal...  

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

3 Q1 High-Temperature Thermal Array for Next Generation Solar Thermal Power Production - FY13 Q1 This document summarizes the progress of this Los Alamos National Laboratory...

465

Impact of Ageing on Thermal Efficiency of Solar Thermal Collectors  

Science Journals Connector (OSTI)

Today it is common practice to calculate the performance of solar thermal systems or solar collectors based on the results of a thermal performance test carried out with a new solar collector. However, for an int...

Elke Streicher; Stephan Fischer…

2009-01-01T23:59:59.000Z

466

Spectrum Management for Cognitive Radio based on Genetics Algorithm  

E-Print Network (OSTI)

Spectrum scarceness is one of the major challenges that the present world is facing. The efficient use of existing licensed spectrum is becoming most critical as growing demand of the radio spectrum. Different researches show that the use of licensed are not utilized inefficiently. It has been also shown that primary user does not use more than 70% of the licensed frequency band most of the time. Many researchers are trying to found the techniques that efficiently utilize the under-utilized licensed spectrum. One of the approaches is the use of "Cognitive Radio". This allows the radio to learn from its environment, changing certain parameters. Based on this knowledge the radio can dynamically exploit the spectrum holes in the licensed band of the spectrum. This paper w i l l focus on the performance of spectrum allocation technique, based on popular meta-heuristics Genetics Algorithm and analyzing the performance of this technique using Mat Lab.

Singh, Santosh Kumar; Pathak, Vibhakar; Roy, Dr Krishna Chandra

2011-01-01T23:59:59.000Z

467

Laser Telecommunication timeLaser beam  

E-Print Network (OSTI)

Laser Telecommunication Experiment Laser time Laser beam intensity timeLaser beam Laser battery Laser connected to a circuit without a modulator. Bottom graph illustrates what happen when a modulating signal is superimposed to the DC voltage driving the laser Laser beam intensity DC Input voltage DC

La Rosa, Andres H.

468

Physics with energetic radioactive ion beams  

SciTech Connect

Beams of short-lived, unstable nuclei have opened new dimensions in studies of nuclear structure and reactions. Such beams also provide key information on reactions that take place in our sun and other stars. Status and prospects of the physics with energetic radioactive beams are summarized.

Henning, W.F.

1996-12-31T23:59:59.000Z

469

Cyclotrons for the production of radioactive beams  

SciTech Connect

This paper describes the characteristics and design choices for modern cyclotrons. Cyclotrons can be used in 3 areas in the radioactive beam field: the production of high energy heavy ion beams for use in fragmentation, the spallation of targets with high energy protons, and the acceleration of radioactive beams from low energy to the MeV/u range. 16 refs., 6 figs.

Clark, D.J.

1990-01-01T23:59:59.000Z

470

Beam Dynamics and Instabilities in MEIC Design  

SciTech Connect

In this paper, we study the narrow and broadband impedance calculations and various instabilities generated by single and multiple bunches. We study the physical phenomena such as intra-beam scattering, touschek scattering, beam-gas scattering, ion trapping and fast beam-ion instability, etc. Details will be discussed in the paper.

S. Ahmed, G.A. Krafft, B.C. Yunn

2011-03-01T23:59:59.000Z

471

Gaussian beams in inhomogeneous anisotropic layered structures  

E-Print Network (OSTI)

Gaussian beams in inhomogeneous anisotropic layered structures Vlastislav Cerven´y 1 ) and Ivan@ig.cas.cz. Summary Gaussian beams concentrated close to rays of high-frequency seismic body waves prop- agating in an inhomogeneous anisotropic layered structure are studied. The amplitude profiles of the Gaussian beam along

Cerveny, Vlastislav

472

A Generalized Vlasov Theory for Composite Beams  

E-Print Network (OSTI)

A Generalized Vlasov Theory for Composite Beams Wenbin Yu, Department of Mechanical and Aerospace-0150 Abstract A generalized Vlasov theory for composite beams with arbitrary geometric and material sectional properties is developed based on the variational asymptotic beam sectional analysis. Instead of invoking ad

Yu, Wenbin

473

Stability design of long precast concrete beams  

E-Print Network (OSTI)

Stability design of long precast concrete beams T. J. Stratford, BA, MEng, C. J. Burgoyne BA, MSc needed for design engineers to check the stability of precast concrete beams when simply supported loads can be determined and how estimates can be made of the eect of imperfections both in the beam

Burgoyne, Chris

474

Lateral stability of long precast concrete beams  

E-Print Network (OSTI)

Lateral stability of long precast concrete beams T. J. Stratford, BA, BEng, and C. J. Burgoyne, BA, MSc, CEng, MICE & Modern precast concrete bridge beams are becoming increasingly long and slender, making them more susceptible to buckling failure. This paper shows that once the beam is positioned

Burgoyne, Chris

475

Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets.  

E-Print Network (OSTI)

??Electromagnetic spectrum is a natural resource and at present its use is regulated by fixed spectrum assignment policy. That is, spectrum is assigned to license… (more)

Manju Mathew.

2012-01-01T23:59:59.000Z

476

Preliminary requirements for thermal storage subsystems in solar thermal applications  

SciTech Connect

Methodologies for the analysis of value and comparing thermal storage concepts are presented. Value is a measure of worth and is determined by the cost of conventional fuel systems. Value data for thermal storage in large solar thermal electric power applications are presented. Thermal storage concepts must be compared when all are performing the same mission. A method for doing that analysis, called the ranking index, is derived. Necessary data to use the methodology are included.

Copeland, R.J.

1980-04-01T23:59:59.000Z

477

An electrostatically-focused beam for reemitted positron energy spectroscopy  

SciTech Connect

An ultrahigh vacuum system has been constructed in which 2 keV positrons are electrostatically transported and focused onto a solid surface which has been characterised by LEED and Auger spectroscopies. Slow positrons reemitted from the surface traverse a field-free region and enter the transport lens system of a hemispherical energy analyser. This last device potentially enables high-resolution measurements of the energy spectrum of the reemitted positrons. Preliminary low-resolution measurements of positron spectra from Cu(110) and polycrystalline W surfaces have been made under various conditions; the system is currently being developed and upgraded to improve the beam brightness as well as the energy and angular resolution.

Goodyear, A.; Farthing, I.R.; Coleman, P.G. (School of Physics, University of East Anglia, Norwich NR4 7TJ (U.K.))

1991-02-01T23:59:59.000Z

478

Chapter 9: Photovoltaic DevicesChapter 9: Photovoltaic Devices Solar energy spectrumSolar energy spectrum  

E-Print Network (OSTI)

Chapter 9: Photovoltaic DevicesChapter 9: Photovoltaic Devices Solar energy spectrumSolar energy Solar Energy? · Clean · Nearly unlimited PHYS5320 Chapter Nine 3 #12;S l ll l t PHYS5320 Chapter Nine 4 Solar cell plant #12;Cars powered by photovoltaic devices PHYS5320 Chapter Nine 5 #12;Solar Energy

Wang, Jianfang

479

Theory of Thermal Motion in Electromagnetically Induced Transparency: Diffusion, Doppler, Dicke and Ramsey  

E-Print Network (OSTI)

We present a theoretical model for electromagnetically induced transparency (EIT) in vapor, that incorporates atomic motion and velocity-changing collisions into the dynamics of the density-matrix distribution. Within a unified formalism we demonstrate various motional effects, known for EIT in vapor: Doppler-broadening of the absorption spectrum; Dicke-narrowing and time-of-flight broadening of the transmission window for a finite-sized probe; Diffusion of atomic coherence during storage of light and diffusion of the light-matter excitation during slow-light propagation; and Ramsey-narrowing of the spectrum for a probe and pump beams of finite-size.

O. Firstenberg; M. Shuker; R. Pugatch; D. R. Fredkin; N. Davidson; A. Ron

2008-01-30T23:59:59.000Z

480

HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS  

SciTech Connect

This technical progress report describes work performed from October 1 through December 31, 2002 , for the project ''Heavy and Thermal Oil Recovery Production Mechanisms.'' In this project, a broad spectrum of research is undertaken related to thermal and heavy-oil recovery. The research tools and techniques used are varied and span from pore-level imaging of multiphase fluid flow to definition of reservoir-scale features through streamline-based history-matching techniques. During this period, experimental data regarding multidimensional imbibition was analyzed to obtain shape factors appropriate for dual-porosity simulation. It is shown that the usual assumption of constant, time-independent shape factors is incorrect. In other work, we continued to study the mechanisms by which oil is produced from fractured media at high pressure and high temperature. High temperature significantly increased the apparent wettability and affected water relative permeability of cores used in previous experiments. A phenomenological and mechanistic cause for this behavior is sought. Our work in the area of primary production of heavy oil continues with field cores and crude oil. On the topic of reservoir definition, work continued on developing techniques that integrate production history into reservoir models using streamline-based properties.

Anthony R. Kovscek

2003-01-01T23:59:59.000Z

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481

HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS  

SciTech Connect

This technical progress report describes work performed from January 1 through March 31, 2003 for the project ''Heavy and Thermal Oil Recovery Production Mechanisms,'' DE-FC26-00BC15311. In this project, a broad spectrum of research is undertaken related to thermal and heavy-oil recovery. The research tools and techniques span from pore-level imaging of multiphase fluid flow to definition of reservoir-scale features through streamline-based history matching techniques. During this period, previous analysis of experimental data regarding multidimensional imbibition to obtain shape factors appropriate for dual-porosity simulation was verified by comparison among analytic, dual-porosity simulation, and fine-grid simulation. We continued to study the mechanisms by which oil is produced from fractured porous media at high pressure and high temperature. Temperature has a beneficial effect on recovery and reduces residual oil saturation. A new experiment was conducted on diatomite core. Significantly, we show that elevated temperature induces fines release in sandstone cores and this behavior may be linked to wettability. Our work in the area of primary production of heavy oil continues with field cores and crude oil. On the topic of reservoir definition, work continued on developing techniques that integrate production history into reservoir models using streamline-based properties.

Anthony R. Kovscek

2003-04-01T23:59:59.000Z

482

HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS  

SciTech Connect

This technical progress report describes work performed from April 1 through June 30, 2002, for the project ''Heavy and Thermal Oil Recovery Production Mechanisms.'' We investigate a broad spectrum of topics related to thermal and heavy-oil recovery. Significant results were obtained in the areas of multiphase flow and rock properties, hot-fluid injection, improved primary heavy oil recovery, and reservoir definition. The research tools and techniques used are varied and span from pore-level imaging of multiphase fluid flow to definition of reservoir-scale features through streamline-based history-matching techniques. Briefly, experiments were conducted to image at the pore level matrix-to-fracture production of oil from a fractured porous medium. This project is ongoing. A simulation studied was completed in the area of recovery processes during steam injection into fractured porous media. We continued to study experimentally heavy-oil production mechanisms from relatively low permeability rocks under conditions of high pressure and high temperature. High temperature significantly increased oil recovery rate and decreased residual oil saturation. Also in the area of imaging production processes in laboratory-scale cores, we use CT to study the process of gas-phase formation during solution gas drive in viscous oils. Results from recent experiments are reported here. Finally, a project was completed that uses the producing water-oil ratio to define reservoir heterogeneity and integrate production history into a reservoir model using streamline properties.

Anthony R. Kovscek

2002-07-01T23:59:59.000Z

483

HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS  

SciTech Connect

This technical progress report describes work performed from July 1 through September, 2003 for the project ''Heavy and Thermal Oil Recovery Production Mechanisms,'' DE-FC26-00BC15311. In this project, a broad spectrum of research is undertaken related to thermal and heavy-oil recovery. The research tools and techniques span from pore-level imaging of multiphase fluid flow to definition of reservoir-scale features through streamline-based history-matching techniques. During this period, work focused on completing project tasks in the area of multiphase flow and rock properties. The area of interest is the production mechanisms of oil from porous media at high temperature. Temperature has a beneficial effect on oil recovery and reduces residual oil saturation. Work continued to delineate how the wettability of reservoir rock shifts from mixed and intermediate wet conditions to more water-wet conditions as temperature increases. One mechanism for the shift toward water-wet conditions is the release of fines coated with oil-wet material from pore walls. New experiments and theory illustrate the role of temperature on fines release.

Anthony R. Kovscek; Louis M. Castanier

2004-03-01T23:59:59.000Z

484

Anisotropic thermal emission from magnetized neutron stars  

E-Print Network (OSTI)

The thermal emission from isolated neutron stars is not well understood. The X-ray spectrum is very close to a blackbody but there is a systematic optical excess flux with respect to the extrapolation to low energy of the best blackbody fit. This fact, in combination with the observed pulsations in the X-ray flux, can be explained by anisotropies in the surface temperature distribution.We study the thermal emission from neutron stars with strong magnetic fields in order to explain the origin of the anisotropy. We find (numerically) stationary solutions in axial symmetry of the heat transportequations in the neutron star crust and the condensed envelope. The anisotropy in the conductivity tensor is included consistently. The presence of magnetic fields of the expected strength leads to anisotropy in the surface temperature. Models with toroidal components similar to or larger than the poloidal field reproduce qualitatively the observed spectral properties and variability of isolated neutron stars. Our models also predict spectral features at energies between 0.2 and 0.6 keV.

J. F. Perez-Azorin; J. A. Miralles; J. A. Pons

2005-10-24T23:59:59.000Z

485

Electron beam diagnostic for space charge measurement of an ion beam  

SciTech Connect

A non-perturbing electron beam diagnostic system for measuring the charge distribution of an ion beam is developed for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but such diagnostics stop the beam, or significantly alter its properties. In this diagnostic a low energy, low current electron beam is swept transversely across the ion beam; the measured electron beam deflection is used to infer the charge density profile of the ion beam. The initial application of this diagnostic is to the Neutralized Transport Experiment (NTX), which is exploring the physics of space-charge-dominated beam focusing onto a small spot using a neutralizing plasma. Design and development of this diagnostic and performance with the NTX ion beamline is presented.

Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef; Bieniosek, Frank M.; Waldron, William L.; Greenway, Wayne G.; Vanecek, David L.; Hannink, Ryan; Amezcua, Monserrat

2004-09-25T23:59:59.000Z

486

Nanostructured ion beam-modified Ge films for high capacity Li ion battery N. G. Rudawski, B. L. Darby, B. R. Yates, K. S. Jones, R. G. Elliman et al.  

E-Print Network (OSTI)

Nanostructured ion beam-modified Ge films for high capacity Li ion battery anodes N. G. Rudawski, B718 (2012) Thermal properties of the hybrid graphene-metal nano-micro-composites: Applications://apl.aip.org/authors #12;Nanostructured ion beam-modified Ge films for high capacity Li ion battery anodes N. G. Rudawski,1

Florida, University of

487

Beam Time Allocation Committee (BAC)  

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

Time Allocation Committee (BAC) Time Allocation Committee (BAC) Charter Purpose: Allocates general user beam time by instrument to promote diverse and high- impact science and a broad-based user community to meet DOE and NSSD goals. Participants: BAC Chair (appointed by NSSD Director), Instrument Group Leaders, User Office Schedule: Tied to proposal calls - expected to meet at least 2 times/year with meetings scheduled about 6 weeks after the proposal call has closed and at least 1 month prior to scheduled operations. Process: 1. Instrument Group Leaders (with group members): a. Confirm feasibility (equipment requirements and instrument capabilities) and safe operations b. Review amount of beam time requested and adjust as needed with consideration for instrument and sample environment availability.

488

Center for Beam Physics, 1993  

SciTech Connect

The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993.

Not Available

1994-05-01T23:59:59.000Z

489

Oxygen ion-beam microlithography  

DOE Patents (OSTI)

A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used. 5 figures.

Tsuo, Y.S.

1991-08-20T23:59:59.000Z

490

Oxygen ion-beam microlithography  

DOE Patents (OSTI)

A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used.

Tsuo, Y. Simon (Lakewood, CO)

1991-01-01T23:59:59.000Z

491

Neutron beam testing of triblades  

SciTech Connect

Four IBM Triblades were tested in the Irradiation of Chips and Electronics facility at the Los Alamos Neutron Science Center. Triblades include two dual-core Opteron processors and four PowerXCell 8i (Cell) processors. The Triblades were tested in their field configuration while running different applications, with the beam aimed at the Cell processor or the Opteron running the application. Testing focused on the Cell processors, which were tested while running five different applications and an idle condition. While neither application nor Triblade was statistically important in predicting the hazard rate, the hazard rate when the beam was aimed at the Opterons was significantly higher than when it was aimed at the Cell processors. In addition, four Cell blades (one in each Triblade) suffered voltage shorts, leading to their inoperability. The hardware tested is the same as that in the Roadrunner supercomputer.

Michalak, Sarah E [Los Alamos National Laboratory; Du Bois, Andrew J [Los Alamos National Laboratory; Storlie, Curtis B [Los Alamos National Laboratory; Rust, William N [Los Alamos National Laboratory; Du Bois, David H [Los Alamos National Laboratory; Modl, David G [Los Alamos National Laboratory; Quinn, Heather M [Los Alamos National Laboratory; Blanchard, Sean P [Los Alamos National Laboratory; Manuzzato, Andrea [UNIV DEGLI STUDI DI PADOVA ITALY

2010-12-16T23:59:59.000Z

492

Thermal Storage of Solar Energy  

Science Journals Connector (OSTI)

Thermal storage is needed to improve the efficiency and usefulness of solar thermal systems. The paper indicates the main storage ... which would greatly increase the practical use of solar energy — is more diffi...

H. Tabor

1984-01-01T23:59:59.000Z

493

VAV Reheat Versus Active Chilled Beams and DOAS  

E-Print Network (OSTI)

Andrey. Don’t Turn Active Beams Into Expensive Diffusers,added costs of the piping and beams for ACBs are simply too1. Simmonds, Peter. To Beam or not To Beam? , Engineered

Stein, Jeff; Taylor, Steven

2013-01-01T23:59:59.000Z

494

X-ray beam finder  

DOE Patents (OSTI)

An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

Gilbert, H.W.

1983-06-16T23:59:59.000Z

495

H-mode accelerating structures with permanent-magnet quadrupole beam focusing  

We have developed high-efficiency normal-conducting rf accelerating structures by combining H -mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of interdigital H -mode (IH-PMQ) structures is 10–20 times higher than that of a conventional drift-tube linac, while the transverse size is 4–5 times smaller. Results of the combined 3D modeling—electromagnetic computations, multiparticle beam-dynamics simulations with high currents, and thermal-stress analysis—for an IH-PMQ accelerator tank are presented. The accelerating-field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. Examples of cross-bar H -mode structures with PMQ focusing for higher beam velocities are also presented. H -PMQ accelerating structures following a short radio-frequency quadrupole accelerator can be used both in the front end of ion linacs or in stand-alone applications.

Kurennoy, S. S.; Rybarcyk, L. J.; O’Hara, J. F.; Olivas, E. R.; Wangler, T. P.

2012-09-01T23:59:59.000Z

496

THERMAL ENERGY STORAGE IN AQUIFERS WORKSHOP  

E-Print Network (OSTI)

Survey of Thermal Energy Storage in Aquifers Coupled withLow Temperature Thermal Energy Storage Program of Oak Ridgefor Seasonal Thermal Energy Storage: An Overview of the DOE-

Authors, Various

2011-01-01T23:59:59.000Z

497

Electric Motor Thermal Management | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Merit Review and Peer Evaluation ape030bennion2011o.pdf More Documents & Publications Motor Thermal Control Electric Motor Thermal Management Electric Motor Thermal Management...

498

Power Electronic Thermal System Performance and Integration ...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

More Documents & Publications Motor Thermal Control Thermal Stress and Reliability for Advanced Power Electronics and Electric Machines Integrated Vehicle Thermal Management...

499

THERMAL ENERGY STORAGE IN AQUIFERS WORKSHOP  

E-Print Network (OSTI)

Scale Thermal Energy Storage for Cogeneration and Solarsolar captors, thermal effluents, low cost energy duringSeale Thermal Energy Storage for Cogeneration and Solar

Authors, Various

2011-01-01T23:59:59.000Z

500

Ocean Thermal Extractable Energy Visualization: Final Technical...  

Office of Environmental Management (EM)

Ocean Thermal Extractable Energy Visualization: Final Technical Report Ocean Thermal Extractable Energy Visualization: Final Technical Report Report about the Ocean Thermal...