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1

Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and  

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

An Intriguing Twist in the Structure of a Cobalt Oxide Catalyst An Intriguing Twist in the Structure of a Cobalt Oxide Catalyst Breaking Records in Neurological Microradiology Exposing Valence-Bond Model Inadequacies Plants' Rapid Response System Revealed Rewriting the Organofluorine Playbook Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and Coherence AUGUST 21, 2012 Bookmark and Share Fabry-Perot resonance spectra (right) of a single-cavity resonator, two cascaded resonators, and a monolithic two-cavity resonator, respectively. Note the significant background of T1 as the Bragg reflectivity from a 10-μm diamond plate is only 59%. By comparison, spectra T2 and T3 are very

2

A Single Crystal Niobium RF Cavity of the TESLA Shape  

DOE Green Energy (OSTI)

A fabrication method for single crystal niobium cavities of the TESLA shape was proposed on the basis of metallographic investigations and electron beam welding tests on niobium single crystals. These tests showed that a cavity can be produced without grain boundaries even in the welding area. An appropriate annealing allows the outgassing of hydrogen and stress relaxation of the material without destruction of the single crystal. A prototype single crystal single cell cavity was built. An accelerating gradient of 37.5 MV/m was reached after approximately 110 mu-m of Buffered Chanical Polishing (BCP) and in situ baking at 120°C for 6 hrs with a quality factor exceeding 2x1010 at 1.8 K. The developed fabrication method can be extended to fabrication of multi cell cavities.

W. Singer; X. Singer; P. Kneisel

2007-09-01T23:59:59.000Z

3

Nanobeam Photonic Crystal Cavity Light-Emitting Diodes  

E-Print Network (OSTI)

We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2011-01-01T23:59:59.000Z

4

Three orders of magnitude cavity-linewidth narrowing by slow light in a rare-earth-ion-doped crystal cavity  

E-Print Network (OSTI)

Three orders of magnitude cavity-linewidth narrowing in a rare-earth-ion-doped crystal cavity, induced by strong intra-cavity dispersion caused by off-resonant interaction with dopant ions is demonstrated. The strong dispersion is created by semi-permanent but rapidly reprogrammable changes of the rare earth absorption profiles using optical pumping techniques. Several cavity modes are shown within the spectral transmission window. Potential applications are discussed.

Sabooni, Mahmood; Rippe, Lars; Kröll, Stefan

2013-01-01T23:59:59.000Z

5

Design of an efficient terahertz source using triply resonant nonlinear photonic crystal cavities  

E-Print Network (OSTI)

We propose a scheme for efficient cavity-enhanced nonlinear THz generation via difference-frequency generation (DFG) processes using a triply resonant system based on photonic crystal cavities. We show that high nonlinear ...

Burgess, Ian B.

6

Collective strong coupling between ion Coulomb crystals and an optical cavity field: Theory and experiment  

E-Print Network (OSTI)

A detailed description and theoretical analysis of experiments achieving coherent coupling between an ion Coulomb crystal and an optical cavity field are presented. The various methods used to measure the coherent coupling ...

Albert, M.

7

Deterministic nano-assembly of a coupled quantum emitter - photonic crystal cavity system  

E-Print Network (OSTI)

The interaction of a single quantum emitter with its environment is a central theme in quantum optics. When placed in highly confined optical fields, such as those created in optical cavities or plasmonic structures, the optical properties of the emitter can change drastically. In particular, photonic crystal (PC) cavities show high quality factors combined with an extremely small mode volume. Efficiently coupling a single quantum emitter to a PC cavity is challenging because of the required positioning accuracy. Here, we demonstrate deterministic coupling of single Nitrogen-Vacancy (NV) centers to high-quality gallium phosphide PC cavities, by deterministically positioning their 50 nm-sized host nanocrystals into the cavity mode maximum with few-nanometer accuracy. The coupling results in a 25-fold enhancement of NV center emission at the cavity wavelength. With this technique, the NV center photoluminescence spectrum can be reshaped allowing for efficient generation of coherent photons, providing new opportunities for quantum science.

T. van der Sar; J. Hagemeier; W. Pfaff; E. C. Heeres; S. M. Thon; H. Kim; P. M. Petroff; T. H. Oosterkamp; D. Bouwmeester; R. Hanson

2010-08-24T23:59:59.000Z

8

T-542: SAP Crystal Reports Server Multiple Vulnerabilities | Department of  

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

2: SAP Crystal Reports Server Multiple Vulnerabilities 2: SAP Crystal Reports Server Multiple Vulnerabilities T-542: SAP Crystal Reports Server Multiple Vulnerabilities January 25, 2011 - 2:30pm Addthis PROBLEM: SAP Crystal Reports Server Multiple Vulnerabilities. PLATFORM: Crystal Reports Server 2008 ABSTRACT: Multiple vulnerabilities in SAP Crystal Reports Server 2008, which can be exploited by malicious users to disclose potentially sensitive information and by malicious people to conduct cross-site scripting attacks, manipulate certain data, and compromise a user's system. reference LINKS: Secunia Advisory SA43060 Vulnerability Report: Crystal Reports Server 2008 IMPACT ASSESSMENT: High Discussion: 1) Input passed to the "actId" parameter in InfoViewApp/jsp/common/actionNav.jsp, "backUrl" parameter in

9

T-542: SAP Crystal Reports Server Multiple Vulnerabilities | Department of  

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

2: SAP Crystal Reports Server Multiple Vulnerabilities 2: SAP Crystal Reports Server Multiple Vulnerabilities T-542: SAP Crystal Reports Server Multiple Vulnerabilities January 25, 2011 - 2:30pm Addthis PROBLEM: SAP Crystal Reports Server Multiple Vulnerabilities. PLATFORM: Crystal Reports Server 2008 ABSTRACT: Multiple vulnerabilities in SAP Crystal Reports Server 2008, which can be exploited by malicious users to disclose potentially sensitive information and by malicious people to conduct cross-site scripting attacks, manipulate certain data, and compromise a user's system. reference LINKS: Secunia Advisory SA43060 Vulnerability Report: Crystal Reports Server 2008 IMPACT ASSESSMENT: High Discussion: 1) Input passed to the "actId" parameter in InfoViewApp/jsp/common/actionNav.jsp, "backUrl" parameter in

10

Dynamics of cavity fields with dissipative and amplifying couplings through multiple quantum two-state systems  

SciTech Connect

We consider simultaneous dissipative and amplifying coupling of cavity fields to multiple two-state systems. We derive a master equation for optical field in a leaky cavity coupled to a reservoir through multiple two-state systems. In our previous works we have limited our study to systems where the reservoir either solely absorbs energy (detector setup) or adds energy (amplifying setup) to the cavity through a single two-state system. In this work we allow both interactions simultaneously and derive a reduced dynamic model for the optical field. We also generalize our model to cover the coupling of the field to several two state systems and discuss its connection to macroscopic interaction, e.g., in semiconductors. Our model includes four physical parameters: the field two-state system coupling {gamma}, the excitation and deexcitation couplings of the two-state system by the reservoir {lambda}{sub A} and {lambda}{sub D}, respectively, and the mirror losses of the cavity C. We solve the steady-state fields at different regimes of these physical parameters. Furthermore, we show that, depending on the parameters, our model can describe the operation of a detector, a light emitting diode, or a laser.

Haeyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka [Department of Biomedical Engineering and Computational Science, Aalto University School of Science and Technology, P. O. Box 12200, FI-00076 AALTO (Finland)

2011-01-15T23:59:59.000Z

11

Atom-light crystallization of Bose-Einstein condensates in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration  

Science Conference Proceedings (OSTI)

The self-organization of a Bose-Einstein condensate (BEC) in a transversely pumped optical cavity is a process akin to crystallization: when pumped by a laser of sufficient intensity, the coupled matter and light fields evolve, spontaneously, into a spatially modulated pattern, or crystal, whose lattice structure is dictated by the geometry of the cavity. In cavities having multiple degenerate modes, the quasicontinuum of possible lattice arrangements, and the continuous symmetry breaking associated with the adoption of a particular lattice arrangement, give rise to phenomena such as phonons, defects, and frustration, which have hitherto been unexplored in ultracold atomic settings involving neutral atoms. The present work develops a nonequilibrium field-theoretic approach to explore the self-organization of a BEC in a pumped, lossy optical cavity. We find that the transition is well described, in the regime of primary interest, by an effective equilibrium theory. At nonzero temperatures, the self-organization occurs via a fluctuation-driven first-order phase transition of the Brazovskii class; this transition persists to zero temperature and crosses over into a quantum phase transition. We make further use of our field-theoretic description to investigate the role of nonequilibrium fluctuations in the self-organization transition, as well as to explore the nucleation of ordered-phase droplets, the nature and energetics of topological defects, supersolidity in the ordered phase, and the possibility of frustration controlled by the cavity geometry. In addition, we discuss the range of experimental parameters for which we expect the phenomena described here to be observable, along with possible schemes for detecting ordering and fluctuations via either atomic correlations or the correlations of the light emitted from the cavity.

Gopalakrishnan, Sarang; Goldbart, Paul M. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States); Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States); Lev, Benjamin L. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States)

2010-10-15T23:59:59.000Z

12

Efficient Method for Analyzing Leaky Cavities in Two-dimensional Photonic Crystals  

E-Print Network (OSTI)

and homogeneous media, Dirichlet-to-Neumann maps of the unit cells to reduce the problem to the cell edges. Cavities are also used in many filters, since they can be used to alter the transmission of light through solution can be quite limited, if the grid size is not small enough to accurately resolve the material

Lu, Ya Yan

13

Multiple solutions of gravity and surface shear driven thin film flows over a rectangular cavity  

Science Conference Proceedings (OSTI)

The effect of surface shear stress on the two-dimensional flow of a thin film over a rectangular cavity is investigated by the numerical simulation of the problem in terms of its corresponding Stokes formulation. The integral representation of the problem is numerically solved by a direct boundary element method(BEM) with primitive variables of velocity and surface traction. For cases in which the applied surface shear and the gravity act in opposite directions

N. H. Shuaib; H. Power; S. Hibberd

2006-01-01T23:59:59.000Z

14

Design of photonic crystals with multiple and combined band gaps  

E-Print Network (OSTI)

We present and use an algorithm based on convex conic optimization to design two-dimensional photonic crystals with large absolute band gaps. Among several illustrations we show that it is possible to design photonic ...

Men, H.

15

The mystery of ice crystal multiplication in a laboratory experiment  

Science Conference Proceedings (OSTI)

The paper addresses the problem of the large discrepancies between ice crystal concentrations in clouds and the number of ice nuclei in nearby clear air reported in published papers. Such discrepancies cannot always be explained, even by taking ...

Gianni Santachiara; Franco Belosi; Franco Prodi

16

Optically pumped InxGa?â??xN/InyGa?â??yN multiple quantum well vertical cavity surface emitting laser operating at room temperature.  

E-Print Network (OSTI)

Room temperature vertical cavity lasing at the wavelength of 433nm has been successfully realized in InxGa?â??xN/InyGa?â??yN multiple quantum well without Bragg mirrors under photo-excitation. At high excitation intensity, ...

Chen, Zhen

17

Final LDRD report : enhanced spontaneous emission rate in visible III-nitride LEDs using 3D photonic crystal cavities.  

Science Conference Proceedings (OSTI)

The fundamental spontaneous emission rate for a photon source can be modified by placing the emitter inside a periodic dielectric structure allowing the emission to be dramatically enhanced or suppressed depending on the intended application. We have investigated the relatively unexplored realm of interaction between semiconductor emitters and three dimensional photonic crystals in the visible spectrum. Although this interaction has been investigated at longer wavelengths, very little work has been done in the visible spectrum. During the course of this LDRD, we have fabricated TiO{sub 2} logpile photonic crystal structures with the shortest wavelength band gap ever demonstrated. A variety of different emitters with emission between 365 nm and 700 nm were incorporated into photonic crystal structures. Time-integrated and time-resolved photoluminescence measurements were performed to measure changes to the spontaneous emission rate. Both enhanced and suppressed emission were demonstrated and attributed to changes to the photonic density of states.

Fischer, Arthur Joseph; Subramania, Ganapathi S.; Coley, Anthony J.; Lee, Yun-Ju; Li, Qiming; Wang, George T.; Luk, Ting Shan; Koleske, Daniel David; Fullmer, Kristine Wanta

2009-09-01T23:59:59.000Z

18

Cavity state preparation using adiabatic transfer  

E-Print Network (OSTI)

We show how to prepare a variety of cavity field states for multiple cavities. The state preparation technique used is related to the method of stimulated adiabatic Raman passage or STIRAP. The cavity modes are coupled by atoms, making it possible to transfer an arbitrary cavity field state from one cavity to another, and also to prepare non-trivial cavity field states. In particular, we show how to prepare entangled states of two or more cavities, such as an EPR state and a W state, as well as various entangled superpositions of coherent states in different cavities, including Schrodinger cat states. The theoretical considerations are supported by numerical simulations.

Jonas Larson; Erika Andersson

2005-03-14T23:59:59.000Z

19

Thermoelectric material including a multiple transition metal-doped type I clathrate crystal structure  

DOE Patents (OSTI)

A thermoelectric material includes a multiple transition metal-doped type I clathrate crystal structure having the formula A.sub.8TM.sub.y.sub.1.sup.1TM.sub.y.sub.2.sup.2 . . . TM.sub.y.sub.n.sup.nM.sub.zX.sub.46-y.sub.1.sub.-y.sub.2.sub.- . . . -y.sub.n.sub.-z. In the formula, A is selected from the group consisting of barium, strontium, and europium; X is selected from the group consisting of silicon, germanium, and tin; M is selected from the group consisting of aluminum, gallium, and indium; TM.sup.1, TM.sup.2, and TM.sup.n are independently selected from the group consisting of 3d, 4d, and 5d transition metals; and y.sub.1, y.sub.2, y.sub.n and Z are actual compositions of TM.sup.1, TM.sup.2, TM.sup.n, and M, respectively. The actual compositions are based upon nominal compositions derived from the following equation: z=8q.sub.A-|.DELTA.q.sub.1|y.sub.1-|.DELTA.q.sub.2|y.sub.2- . . . -|.DELTA.q.sub.n|y.sub.n, wherein q.sub.A is a charge state of A, and wherein .DELTA.q.sub.1, .DELTA.q.sub.2, .DELTA.q.sub.n are, respectively, the nominal charge state of the first, second, and n-th TM.

Yang, Jihui (Lakeshore, CA); Shi, Xun (Troy, MI); Bai, Shengqiang (Shanghai, CN); Zhang, Wenqing (Shanghai, CN); Chen, Lidong (Shanghai, CN); Yang, Jiong (Shanghai, CN)

2012-01-17T23:59:59.000Z

20

STUDY OF LIQUID CRYSTAL CONFORMATION BY MULTIPLE QUANTUM NMR: n-PENTYL CYANOBIPHENYL  

E-Print Network (OSTI)

The proton::. and to of twist NMR spectrum of Proton The toCONFORMATION BY MULTIPLE QUANTUM NMR: n-PENTYL CYANOBIPHENYLCONFORMATION BY MULTIPLE QUANTUM NMR: n~PENTYL CYANOBIPHENYL

Sinton, S.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Cavity-locked ring down spectroscopy  

DOE Patents (OSTI)

Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.

Zare, Richard N. (Stanford, CA); Paldus, Barbara A. (Stanford, CA); Harb, Charles C. (Palo Alto, CA); Spence, Thomas (Union City, CA)

2000-01-01T23:59:59.000Z

22

CEBAF Center - Cavity Display  

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

CEBAF Center - Cavity Display Building Exterior 1st Floor Cafeteria Cavity Display CEBAF Center Auditorium Eating Area UserInternational Liaison Office 2nd Floor Computer Center...

23

RESONANT CAVITY EXCITATION SYSTEM  

DOE Patents (OSTI)

A cavity excitation circuit is described for rapidly building up and maintaining high-level oscillations in a resonant cavity. The circuit overcomes oscillation buildup slowing effects such as ion locking in the cavity by providing for the selective application of an amplified accelerating drive signal to the main cavity exciting oscillator during oscillation buildup and a direct drive signal to the oscillator thereafter.

Baker, W.R.

1959-08-01T23:59:59.000Z

24

Enhancing cavity cooling with cavity driving  

E-Print Network (OSTI)

Cavity-mediated cooling has the potential to become one of the most efficient techniques to cool molecular species down to very low temperatures. However, theoretical schemes with single-laser driving require relatively strong trapping potentials and relatively long cavity photon life times which are hard to realise experimentally. In this paper we therefore consider an alternative cavity cooling scenario with double-laser driving. It is shown that the second laser can enhance the phonon-photon coherence which governs the time evolution of the mean phonon number, thereby resulting in higher cooling rates and a lower final temperature, when the cavity decay rate kappa is four or more times larger than the phonon frequency nu of the trapped particle.

Blake, Tony; Beige, Almut

2010-01-01T23:59:59.000Z

25

Electromagnetic SCRF Cavity Tuner  

SciTech Connect

A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab

2009-05-01T23:59:59.000Z

26

Optically measuring interior cavities  

DOE Patents (OSTI)

A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

Stone, Gary Franklin (Livermore, CA)

2009-11-03T23:59:59.000Z

27

Optically measuring interior cavities  

SciTech Connect

A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

Stone, Gary Franklin (Livermore, CA)

2008-12-21T23:59:59.000Z

28

A terahertz plasmon cavity detector  

Science Conference Proceedings (OSTI)

Sensitivity of a plasmonic detector is enhanced by integrating a broadband log-periodic antenna with a two-dimensional plasma cavity that is defined by source, drain, and multiple gates of a GaAs/AlGaAs high electron mobility transistor. Both narrow-band terahertz detection and a rich harmonic spectrum are evident. With a bolometric sensor in the channel, we report responsivity, on resonance at 235-240 GHz and at 20 K, of up to 7 kV/W and a noise equivalent power of 5x10{sup -10} W/Hz{sup 1/2}.

Dyer, G. C.; Vinh, N. Q.; Allen, S. J. [Institute for Terahertz Science and Technology, UC Santa Barbara, Santa Barbara, California 93106 (United States); Aizin, G. R.; Mikalopas, J. [Kingsborough College, City University of New York, Brooklyn, New York 11235 (United States); Reno, J. L.; Shaner, E. A. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)

2010-11-08T23:59:59.000Z

29

Windowed versus windowless solar energy cavity receivers  

DOE Green Energy (OSTI)

A model for a windowed, high-temperature cavity receiver of the heated-air type is developed and used to evaluate the greenhouse effect as a method for obtaining high receiver operating efficiencies. The effects on receiver efficiency of varying the window cutoff wavelength, the amount of absorption in the window pass-band, the cavity operating temperature, and the number of windows are determined. Single windowed cavities are found to offer theoretical efficiencies comparable to windowless ones, while multiple windowed units are found to suffer from low operating efficiencies due to losses resulting from reflections at each window/air interface. A ''first order'' examination is made of the feasibility of air cooling the window to assure its survival. This appears possible if a proper combination of cooling technique and window material characteristics is selected.

Jarvinen, P. O.

1976-09-01T23:59:59.000Z

30

Ring resonant cavities for spectroscopy  

DOE Patents (OSTI)

Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

1999-06-15T23:59:59.000Z

31

Video Toroid Cavity Imager  

DOE Patents (OSTI)

A video toroid cavity imager for in situ measurement of electrochemical properties of an electrolytic material sample includes a cylindrical toroid cavity resonator containing the sample and employs NMR and video imaging for providing high-resolution spectral and visual information of molecular characteristics of the sample on a real-time basis. A large magnetic field is applied to the sample under controlled temperature and pressure conditions to simultaneously provide NMR spectroscopy and video imaging capabilities for investigating electrochemical transformations of materials or the evolution of long-range molecular aggregation during cooling of hydrocarbon melts. The video toroid cavity imager includes a miniature commercial video camera with an adjustable lens, a modified compression coin cell imager with a fiat circular principal detector element, and a sample mounted on a transparent circular glass disk, and provides NMR information as well as a video image of a sample, such as a polymer film, with micrometer resolution.

Gerald, Rex E. II; Sanchez, Jairo; Rathke, Jerome W.

2004-08-10T23:59:59.000Z

32

Cryogenic Optimization for Cavity Systems  

SciTech Connect

Accelerator systems are being built with superconducting Nb cavities at 350, 500, 1500 and 2860 MHz; in addition cavities previously have been built at 1000 MHz. Cavity heat loads are a strong function of frequency and operating temperature, varying by more than an order of magnitude.

Claus Rode; Dieter Proch

1989-03-20T23:59:59.000Z

33

Recent Studies of RF Breakdown Physics in Normal Conducting Cavities  

SciTech Connect

The operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The behavior of the rf breakdown depends on multiple parameters, including the input rf power, rf circuit, cavity shape and material. Here we discuss recent experimental data and theoretical studies of rf breakdown physics.

Dolgashev, Valery; /SLAC

2012-06-11T23:59:59.000Z

34

Quench studies of ILC cavities  

SciTech Connect

Quench limits accelerating gradient in SRF cavities to a gradient lower than theoretically expected for superconducting niobium. Identification of the quenching site with thermometry and OST, optical inspection, and replica of the culprit is an ongoing effort at Jefferson Lab aimed at better understanding of this limiting phenomenon. In this contribution we present our finding with several SRF cavities that were limited by quench.

Eremeev, Grigory; Geng, Rongli; Palczewski, Ari; Dai, Jin

2011-07-01T23:59:59.000Z

35

Pyrochemical multiplicity counter development  

Science Conference Proceedings (OSTI)

Impure plutonium-bearing materials from pyrochemical processes often display both significant self-multiplication and variable ({alpha},n) reaction rates. Standard neutron coincidence counting techniques usually fail to accurately measure these materials. Neutron multiplicity counters measure the third moment of the neutron multiplicity distribution and thus make it possible to deduce the fertile plutonium mass of a sample even when both the self-multiplication and the ({alpha},n) reaction rate are unknown. A multiplicity counter suitable for measuring pyrochemical materials has been designed and built. This paper describes the results of characterization studies for the new counter. The counter consists of 126 helium-3 tubes arranged in 4 concentric rings in a polyethylene moderator; the average spacing between the tubes is 1.59 cm. The end plugs for the counter are made of graphite, and the 24.1- by 37.5-cm sample cavity is cadmium lined. The counter consists of two distinct halves from which the neutron counts are summed. The counter is capable of operation in either a freestanding mode with the two halves coupled together by an external cabinet or in a glove-box mode with the two halves placed around a glovebox well and then mated. For a {sup 252}Cf source centered in the sample cavity, the measured efficiency of the new multiplicity counter is 57.7% and its die-away time is 47.2{mu}s. 8 refs., 9 figs.

Langner, D.G.; Dytlewski, N.; Krick, M.S.

1991-01-01T23:59:59.000Z

36

Toroid cavity/coil NMR multi-detector  

DOE Patents (OSTI)

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

Gerald, II, Rex E. (Brookfield, IL); Meadows, Alexander D. (Indianapolis, IN); Gregar, Joseph S. (Naperville, IL); Rathke, Jerome W. (Homer Glen, IL)

2007-09-18T23:59:59.000Z

37

Shape Determination for Deformed Cavities  

SciTech Connect

A realistic superconducting RF cavity has its shape deformed comparing to its designed shape due to the loose tolerance in the fabrication process and the frequency tuning for its accelerating mode. A PDE-constrained optimization problem is proposed to determine the deformation of the cavity. A reduce space method is used to solve the PDE-constrained optimization problem where design sensitivities were computed using a continuous adjoint approach. A proof-of-concept example is given in which the deformation parameters of a single cavity-cell with two different types of deformation were computed.

Lee, Lie-Quan; Akcelik, Volkan; Chen, Sheng; Ge, Lixin; Li, Zenghai; Ng, Cho; Xiao, Liling; Ko, Kwok; /SLAC; Ghattas, Omar; /Texas U.

2006-10-04T23:59:59.000Z

38

Prospects for Strong Cavity Quantum Electrodynamics with Superconducting Circuits  

E-Print Network (OSTI)

We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling of cavity photons to quantized excitations of an adjacent electrical circuit (qubit) can easily exceed the damping rates of both the cavity and the qubit. This architecture is attractive for quantum computing and control, since it provides strong inhibition of spontaneous emission, potentially leading to greatly enhanced qubit lifetimes, allows high-fidelity quantum non-demolition measurements of the state of multiple qubits, and has a natural mechanism for entanglement of qubits separated by centimeter distances. In addition it would allow production of microwave photon states of fundamental importance for quantum communication.

S. M. Girvin; Ren-Shou Huang; Alexandre Blais; Andreas Wallraff; R. J. Schoelkopf

2003-10-28T23:59:59.000Z

39

A process for separation by semi-continuous counter-current crystallization  

E-Print Network (OSTI)

A process is proposed to perform separations via crystallization by using multiple tanks and constraining crystal growth to solid surfaces. Multiple tanks allow multiple recrystallizations to improve product purity and to ...

Aumock, Nathan M. (Nathan Micheal)

2011-01-01T23:59:59.000Z

40

Channeling through Bent Crystals  

Science Conference Proceedings (OSTI)

Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump, thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal lengths, were compared and it was seen that multiple scattering decreases with the length of the crystal therefore allowing for cleaner detection of the channeled particles. The input beam was then modified and only a portion of the beam sent through the crystal. With the majority of the beam not affected by the crystal, most particles were not deflected and after propagation the channeled particles were seen to be deflected approximately 5mm. After a portion of the beam travels through the crystal, the entire beam was then sent through a quadrupole magnet, which increased the separation of the channeled particles from the remainder of the beam to a distance of around 20mm. A different code, which was developed at SLAC, was used to create an angular profile plot which was compared to what was produced by Yazynin's code for a beam with no multiple scattering. The results were comparable, with volume reflection and channeling effects observed and the range of crystal orientations at which volume reflection is seen was about 1 mrad in both simulations.

Mack, Stephanie; /Ottawa U. /SLAC

2012-09-07T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Hybrid Microwave Cavity Heat Engine  

E-Print Network (OSTI)

We propose and analyze the use of hybrid microwave cavities as quantum heat engines. A possible realization consists of two macroscopically separated quantum dot conductors coupled capacitively to the fundamental mode of a microwave cavity. We demonstrate that an electrical current can be induced in one conductor through cavity-mediated processes by heating up the other conductor. The heat engine can reach Carnot efficiency with optimal conversion of heat to work. When the system delivers the maximum power, the efficiency can be a large fraction of the Carnot efficiency. The heat engine functions even with moderate electronic relaxation and dephasing in the quantum dots. We provide detailed estimates for the electrical current and output power using realistic parameters.

Christian Bergenfeldt; Peter Samuelsson; Björn Sothmann; Christian Flindt; Markus Büttiker

2013-07-18T23:59:59.000Z

42

Photonic crystal cavity based architecture for optical interconnects.  

E-Print Network (OSTI)

??Today’s information and communication industry is confronted with a serious bottleneck due to the prohibitive energy consumption and limited transmission bandwidth of electrical interconnects. Silicon… (more)

Debnath, Kapil

2013-01-01T23:59:59.000Z

43

Cavity-water interface is polar  

E-Print Network (OSTI)

We present the results of numerical simulations of the electrostatics and dynamics of water hydration shells surrounding Kihara cavities given by a Lennard-Jones (LJ) layer at the surface of a hard-sphere cavity. The local dielectric response of the hydration layer substantially exceeds that of bulk water, with the magnitude of the dielectric constant peak in the shell increasing with the growing cavity size. The polar shell propagates into bulk water to approximately the cavity radius. The statistics of the electrostatic field produced by water inside the cavity follow linear response and approach the prediction of continuum electrostatics with increasing cavity size.

Allan D. Friesen; Dmitry V. Matyushov

2010-04-10T23:59:59.000Z

44

Laser-frequency multiplication  

SciTech Connect

A high quality mode locked pulse train was obtained at 9.55 micrometers, the CO2 wavelength chosen for frequency doubling into the atmospheric window at 4.8 micrometers. The pulse train consists of a 3 micro sec burst of 1.5 nsec pulses separated by 40 nsec, in a TEM(00) mode and with a total energy of 100 mJ. The pulse intensity without focussing is about 3 MW/sq.cm., already quite close to the target intensity of 10 MW/sq.cm. for frequency doubling in a AgGaSe2 crystal. The mode-locked train is obtained by intracavity modulation at 12.5 MHz using a germanium crystal driven with a power of about 30 Watts. Line selection is achieved firstly by the use of a 0.92 mm thick CaF2 plate at the Brewster angle within the cavity, which completely suppresses 10.6 micrometer band radiation. Secondly, a particular rotational line, the P20 at 9.55 micrometers, is selected by the injection of a continuous beam is mode-matched to the pulsed laser cavity using a long focal length lens, and for best line-locking it is necessary to fine tune the length of the pulsed laser resonator. Injection causes substantial depression of the gain switched spike.

Not Available

1991-11-01T23:59:59.000Z

45

Breakdown of Bose-Einstein distribution in photonic crystals  

E-Print Network (OSTI)

In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced non-Markovian dynamics, we discover that cavity photons in photonic crystals do not obey the standard Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine nontrivial quantum dissipation with thermal fluctuations to form photon states that can memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger than the photonic band gap.

Ping-Yuan Lo; Heng-Na Xiong; Wei-Min Zhang

2013-11-21T23:59:59.000Z

46

Multipacting analysis for JLAB ampere class cavities  

SciTech Connect

JLAB's ampere class 5-cell cavities require a moderate accelerating gradient (16.7 {approx} 20MV/m). Electron multipacting activity in the machine operating range can degrade the expected performance. A survey was conducted in the area of multipacting analysis for beta=1 electron cavity shapes, including options for the new high current cavity shape. The results obtained provided useful guidance to the final cavity shape adopted and to its expected performance.

Genfa Wu; Mircea Stirbet; Haipeng Wang; Robert Rimmer; Evan Donoghue

2005-07-10T23:59:59.000Z

47

Design of the spoke cavity ED&D input coupler.  

DOE Green Energy (OSTI)

The current design of the Accelerator Driven Test Facility (ADTF) accelerator contains multiple {beta}, superconducting, resonant cavities. Spoke-type resonators ({beta} = 0.175 and {beta} = 0.34) are proposed for the low energy linac immediately following the radio frequency quadrupole. A continuous wave power requirement of 8.5 - 211.8 kW, 350 MHz has been established for the input couplers of these spoke cavities. The coupler design approach was to have a single input coupler design for beam currents of 13.3 mA and 100 mA and both cavity {beta}'s. The baseline design consists of a half-height WR2300 waveguide section merged with a shorted coaxial conductor. At the transition is a 4.8-mm thick cylindrical ceramic window creating the air/vacuum barrier. The coax is 103-mm inner diameter, 75 Ohm. The coax extends from the short through the waveguide and terminates with an antenna tip in the sidewall of the cavity. A full diameter pumping port is located in the quarter-wave stub to facilitate good vacuum. The coaxial geometry chosen was based on multipacting and thermal design considerations. The coupling coefficient is adjusted by statically adjusting the outer conductor length. The RF-physics, thermal, vacuum, and structural design considerations will be discussed in this paper, in addition to future room temperature testing plans.

Schmierer, E. N. (Eric N.); Chan, K. D. (Kwok-Chi D.); Gentzlinger, R.C. (Robert C.); Haynes, W. B. (William B.); Krawczyk, F. L. (Frank L.); Montoya, D. I. (Debbie I.); Roybal, P. L. (Phillip L.); Schrage, D. L. (Dale L.); Tajima, T. (Tsuyoshi)

2001-01-01T23:59:59.000Z

48

Status of the ILC Crab Cavity Development  

SciTech Connect

The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

Burt, G.; Dexter, A.; /Cockcroft Inst. Accel. Sci. Tech.; Beard, C.; Goudket, P.; McIntosh, P.; /Daresbury; Bellantoni, L.; /Fermilab; Grimm, T.; Li, Z.; Xiao, L.; /SLAC

2011-10-20T23:59:59.000Z

49

Vented Cavity Radiant Barrier Assembly And Method  

DOE Patents (OSTI)

A vented cavity radiant barrier assembly (2) includes a barrier (12), typically a PV module, having inner and outer surfaces (18, 22). A support assembly (14) is secured to the barrier and extends inwardly from the inner surface of the barrier to a building surface (14) creating a vented cavity (24) between the building surface and the barrier inner surface. A low emissivity element (20) is mounted at or between the building surface and the barrier inner surface. At least part of the cavity exit (30) is higher than the cavity entrance (28) to promote cooling air flow through the cavity.

Dinwoodie, Thomas L. (Piedmont, CA); Jackaway, Adam D. (Berkeley, CA)

2000-05-16T23:59:59.000Z

50

Shape Determination for Deformed Electromagnetic Cavities  

SciTech Connect

The measured physical parameters of a superconducting cavity differ from those of the designed ideal cavity. This is due to shape deviations caused by both loose machine tolerances during fabrication and by the tuning process for the accelerating mode. We present a shape determination algorithm to solve for the unknown deviations from the ideal cavity using experimentally measured cavity data. The objective is to match the results of the deformed cavity model to experimental data through least-squares minimization. The inversion variables are unknown shape deformation parameters that describe perturbations of the ideal cavity. The constraint is the Maxwell eigenvalue problem. We solve the nonlinear optimization problem using a line-search based reduced space Gauss-Newton method where we compute shape sensitivities with a discrete adjoint approach. We present two shape determination examples, one from synthetic and the other from experimental data. The results demonstrate that the proposed algorithm is very effective in determining the deformed cavity shape.

Akcelik, Volkan; Ko, Kwok; Lee, Lie-Quan; Li, Zhenghai; Ng, Cho-Kuen; Xiao, Liling; /SLAC

2007-12-10T23:59:59.000Z

51

Scattering Phase Function of Bullet Rosette Ice Crystals  

Science Conference Proceedings (OSTI)

Ice crystals in cirrus frequently exhibit the shape of a bullet rosette composed of multiple bullets that radiate from a junction center. The scattering phase function of these ice crystals, pertinent to the radiation budget of cirrus, may differ ...

Jean Iaquinta; Harumi Isaka; Pascal Personne

1995-05-01T23:59:59.000Z

52

Coupled-cavity drift-tube linac  

DOE Patents (OSTI)

A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

Billen, James H. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

53

Electro-optic harmonic conversion to switch a laser beam out of a cavity  

DOE Patents (OSTI)

The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.

Haas, Roger A. (Pleasanton, CA); Henesian, Mark A. (Livermore, CA)

1987-01-01T23:59:59.000Z

54

Resonant-cavity antenna for plasma heating  

SciTech Connect

Disclosed is a resonant coil cavity wave launcher for energizing a plasma immersed in a magnetic field. Energization includes launching fast Alfven waves to excite ion cyclotron frequency resonances in the plasma. The cavity includes inductive and capacitive reactive members spaced no further than one-quarter wavelength from a first wall confinement chamber of the plasma. The cavity wave launcher is energized by connection to a waveguide or transmission line carrying forward power from a remote radio frequency energy source.

Perkins, Jr., Francis W. (Princeton, NJ); Chiu, Shiu-Chu (San Diego, CA); Parks, Paul (San Diego, CA); Rawls, John M. (Del Mar, CA)

1987-01-01T23:59:59.000Z

55

Compact Superconducting Crabbing and Deflecting Cavities  

SciTech Connect

Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM{sub 110} cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

De Silva, Payagalage Subashini Uddika [JLAB, Old Dominion U.

2012-09-01T23:59:59.000Z

56

Physics Out Loud - SRF Accelerator Cavities  

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

Short-range Correlations Previous Video (Short-range Correlations) Physics Out Loud Main Index Next Video (User Facility) User Facility SRF Accelerator Cavities Charlie Reece, an...

57

Cavity-water interface is polar  

E-Print Network (OSTI)

We present the results of numerical simulations of the electrostatics and dynamics of water hydration shells surrounding Kihara cavities given by a Lennard-Jones (LJ) layer at the surface of a hard-sphere cavity. The local dielectric response of the hydration layer substantially exceeds that of bulk water, with the magnitude of the dielectric constant peak in the shell increasing with the growing cavity size. The polar shell propagates into bulk water to approximately the cavity radius. The statistics of the electrostatic fluctuations produced by the interfacial waters do not follow the predictions of continuum electrostatics and the continuum limit is not reached for hydrated nano-size solutes.

Friesen, Allan D

2010-01-01T23:59:59.000Z

58

LARGE-SCALE FLOWS IN PROMINENCE CAVITIES  

Science Conference Proceedings (OSTI)

Regions of rarefied density often form cavities above quiescent prominences. We observed two different cavities with the Coronal Multichannel Polarimeter on 2005 April 21 and with Hinode/EIS on 2008 November 8. Inside both of these cavities, we find coherent velocity structures based on spectral Doppler shifts. These flows have speeds of 5-10 km s{sup -1}, occur over length scales of tens of megameters, and persist for at least 1 hr. Flows in cavities are an example of the nonstatic nature of quiescent structures in the solar atmosphere.

Schmit, D. J. [Department of Astrophysical and Planetary Sciences, University of Colorado-Boulder, UCB 391, Boulder, CO 80309 (United States); Gibson, S. E.; Tomczyk, S. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States); Reeves, K. K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 58, Cambridge, MA 02138 (United States); Sterling, Alphonse C. [NASA Marshall Space Flight Center, Space Science Office, VP62, Huntsville, AL 35805 (United States); Brooks, D. H. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Williams, D. R. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Tripathi, D. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2009-08-01T23:59:59.000Z

59

Design of the ILC Crab Cavity System  

SciTech Connect

The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.

Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B.; Church, M.; Dexter, A.; Dykes, M.; Edwards, H.; Goudket, P; Jenkins, R.; Jones, R.M.; Kalinin, A.; Khabiboulline, T.; Ko, K.; Latina, A.; Li, Z.; Ma, L.; McIntosh, P.; Ng, C.; /SLAC /Daresbury /Fermilab /Cockcroft Inst. Accel. Sci. Tech. /CERN

2007-08-15T23:59:59.000Z

60

Free energy screening of small ligands binding to an artificial protein cavity  

Science Conference Proceedings (OSTI)

The ?-dynamics simulation method was used to study the binding of 10 five-member ring heterocycle derivatives to an artificial cavity created inside cytochrome C peroxidase by mutagenesis. Application of ? dynamics using a multiple topology approach resulted in trapping in local minima. To extend the method to these cases

Shinichi Banba; Charles L. Brooks III

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Femtosecond Laser Micromachining of Single-Crystal Superalloys  

Science Conference Proceedings (OSTI)

scale features in multi-layer material systems for aerospace and power generation components. Introduction. Multiple generations of single crystal superalloys ...

62

Mode suppression means for gyrotron cavities  

DOE Patents (OSTI)

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

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

1983-08-09T23:59:59.000Z

63

Large grain cavities from pure niobium ingot  

DOE Patents (OSTI)

Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

Myneni, Ganapati Rao (Yorktown, VA); Kneisel, Peter (Williamsburg, VA); Cameiro, Tadeu (McMurray, PA)

2012-03-06T23:59:59.000Z

64

Cavity-enhanced absorption for optical refrigeration  

E-Print Network (OSTI)

A 20-fold increase over the single path optical absorption is demonstrated with a low loss medium placed in a resonant cavity. This has been applied to laser cooling of Yb:ZBLAN glass resulting in 90% absorption of the incident pump light. A coupled-cavity scheme to achieve active optical impedance matching is analyzed.

Seletskiy, Denis V; Sheik-Bahae, Mansoor

2009-01-01T23:59:59.000Z

65

Cavity cooling of a single atom  

E-Print Network (OSTI)

All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping and spontaneous emission of a photon by the atom. Spontaneous emission in a random direction is the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been proposed for a single atom strongly coupled to a high-finesse cavity; the role of spontaneous emission is replaced by the escape of a photon from the cavity. Application of such cooling schemes would improve the performance of atom cavity systems for quantum information processing. Furthermore, as cavity cooling does not rely on spontaneous emission, it can be applied to systems that cannot be laser-cooled by conventional methods; these include molecules (which do not have a closed transition) and collective excitations of Bose condensates, which are destroyed by randomly directed recoil kicks. Here we demonstrate cavity cooling of single rubidium atoms stored in an intracavity dipole trap. The cooling mechanism res...

Maunz, P; Schuster, I; Syassen, N; Pinkse, P W H; Rempe, G

2004-01-01T23:59:59.000Z

66

Automated Hydroforming of Seamless Superconducting RF Cavity  

SciTech Connect

We are studying the possibility of automated hydroforming process for seamless superconducting RF cavities. Preliminary hydroforming tests of three-cell cavities from seamless tubes made of C1020 copper have been performed. The key point of an automated forming is to monitor and strictly control some parameters such as operation time, internal pressure and material displacements. Especially, it is necessary for our studies to be able to control axial and radial deformation independently. We plan to perform the forming in two stages to increase the reliability of successful forming. In the first stage hydroforming by using intermediate constraint dies, three-cell cavities were successfully formed in less than 1 minute. In parallel, we did elongation tests on cavity-quality niobium and confirmed that it is possible to achieve an elongation of >64% in 2 stages that is required for our forming of 1.3 GHz cavities.

Nagata, Tomohiko [ULVAC, Inc.; Shinozawa, Seiichi [ULVAC, Inc.; Abe, Noriyuki [ULVAC, Inc.; Nagakubo, Junki [ULVAC, Inc.; Murakami, Hirohiko [ULVAC, Inc.; Tajima, Tsuyoshi [Los Alamos National Laboratory; Inoue, Hitoshi [High Energy Accelerator Research Organization, KEK; Yamanaka, Masashi [High Energy Accelerator Research Organization, KEK; Ueno, Kenji [High Energy Accelerator Research Organization, KEK

2012-07-31T23:59:59.000Z

67

Fast thermometry for superconducting rf cavity testing  

SciTech Connect

Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several resistance temperature detectors (RTDs) were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of the fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.

Orris, Darryl; Bellantoni, Leo; Carcagno, Ruben H.; Edwards, Helen; Harms, Elvin Robert; Khabiboulline, Timergali N.; Kotelnikov, Sergey; Makulski, Andrzej; Nehring, Roger; Pischalnikov, Yuriy; /Fermilab

2007-06-01T23:59:59.000Z

68

Temperature distributions in electron beam welding cavities  

SciTech Connect

Surface temperatures in electron beam welding cavities in stainless steel 304 and aluminum 1100, 2024, and 6061 were measured with a narrow band infrared radiation pyrometer. A special device was designed for mounting the radiation-sensing probe next to the electron beam gun in the welding chamber. This mounting device included a mechanism for oscillating the probe so as to scan the cavity region both perpendicular and parallel to the welding direction. At the center of its movement the probe viewed almost directly down into the welding cavity. The effect of interreflections occurring in the welding cavity were accounted for by the use of an apparent spectral cavity emittance. Typical measured cavity temperature distributions for SS-304 ranged from 1950/sup 0/C at the mouth to a peak of 2350/sup 0/C at the cavity base and from 1300 to 1650/sup 0/C for A1-1100. First approximation predictions of the cavity surface temperatures were determined by assuming a quasi-steady-state condition. The surface temperature is then a function of the vapor pressure, which is required to balance the surface tension and the hydrostatic pressure both of which tend to collapse the cavity. Base temperatures thus predicted were about 5% and 10% higher than measured for SS-304 and A1-1100, respectively. It was determined that EB welding cavity base surface temperatures are relatively constant with varying penetration depth because they are more strongly dependent on the curvature at the base than on the penetration depth. Average peak temperatures for SS-304, A1-1100, A1-6061, and A1-2024 were measured to be approximately 2300, 1700, 1525, and 1475/sup 0/C, respectively. The peak temperatures were lower for A1-6061 and A1-2024 than for A1-1100 because they contained a significant amount of magnesium and zinc, both of which have comparatively high vapor pressures.

Shintaku, S.M.

1976-07-15T23:59:59.000Z

69

Cavity and Continuous Insulation in REScheck | Building Energy...  

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

Cavity and Continuous Insulation in REScheck Insulation should be installed to fill the entire cavity. REScheck(tm) uses nominal insulation R-values. The assemblies listed in...

70

Electrically driven photonic crystal nanocavity devices  

E-Print Network (OSTI)

Interest in photonic crystal nanocavities is fueled by advances in device performance, particularly in the development of low-threshold laser sources. Effective electrical control of high performance photonic crystal lasers has thus far remained elusive due to the complexities associated with current injection into cavities. A fabrication procedure for electrically pumping photonic crystal membrane devices using a lateral p-i-n junction has been developed and is described in this work. We have demonstrated electrically pumped lasing in our junctions with a threshold of 181 nA at 50K - the lowest threshold ever demonstrated in an electrically pumped laser. At room temperature we find that our devices behave as single-mode light-emitting diodes (LEDs), which when directly modulated, have an ultrafast electrical response up to 10 GHz corresponding to less than 1 fJ/bit energy operation - the lowest for any optical transmitter. In addition, we have demonstrated electrical pumping of photonic crystal nanobeam LEDs...

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Majumdar, Arka; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2012-01-01T23:59:59.000Z

71

Fano Resonance in GaAs 2D Photonic Crystal Nanocavities  

SciTech Connect

We report the results of polarization resolved reflectivity experiments in GaAs air-bridge photonic crystals with L3 cavities. We show that the fundamental L3 cavity mode changes, in a controlled way, from a Lorentzian symmetrical lineshape to an asymmetrical form when the linear polarization of the incident light is rotated in the plane of the crystal. The different lineshapes are well fitted by the Fano asymmetric equation, implying that a Fano resonance is present in the reflectivity. We use the scattering matrix method to model the Fano interference between a localized discrete state (the cavity fundamental mode) and a background of continuum states (the light reflected from the crystal slab in the vicinity of the cavity) with very good agreement with the experimental data.

Valentim, P. T.; Guimaraes, P.S. S. [Departamento de Fisica, Universidade Federal de Minas Gerais, Belo Horizonte (Brazil); Instituto Nacional de Ciencia e Tecnologia de Nanodispositivos Semicondutores - INCT-DISSE (Brazil); Luxmoore, I. J.; Szymanski, D.; Whittaker, D. M.; Fox, A. M.; Skolnick, M. S. [Department of Physics and Astronomy, University of Sheffield, Sheffield (United Kingdom); Vasco, J. P. [Instituto de Fisica, Universidad de Antioquia, Medellin (Colombia); Vinck-Posada, H. [Departamento de Fisica, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia)

2011-12-23T23:59:59.000Z

72

Wakefield Damping for the CLIC Crab Cavity  

Science Conference Proceedings (OSTI)

A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

Ambattu, P.K.; Burt, G.; Dexter, A.C.; Carter, R.G.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Khan, V.; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Dolgashev, V.; /SLAC

2011-12-01T23:59:59.000Z

73

Cavity cooling of a single atom  

E-Print Network (OSTI)

All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping and spontaneous emission of a photon by the atom. Spontaneous emission in a random direction is the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been proposed1, 2 for a single atom strongly coupled to a high-finesse cavity; the role of spontaneous emission is replaced by the escape of a photon from the cavity. Application of such cooling schemes would improve the performance of atom cavity systems for quantum information processing3, 4. Furthermore, as cavity cooling does not rely on spontaneous emission, it can be applied to systems that cannot be laser-cooled by conventional methods; these include molecules2 (which do not have a closed transition) and collective excitations of

P. Maunz; I. Schuster; N. Syassen; P. W. H. Pinkse; G. Rempe

2004-01-01T23:59:59.000Z

74

Degreasing and cleaning superconducting RF Niobium cavities  

Science Conference Proceedings (OSTI)

The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

Rauchmiller, Michael; Kellett, Ron; /Fermilab

2011-09-01T23:59:59.000Z

75

Resonant cavity light?emitting diode  

Science Conference Proceedings (OSTI)

A novel concept of a light?emitting diode(LED) is proposed and demonstrated in which the active region of the device is placed in a resonantoptical cavity. As a consequence

E. F. Schubert; Y.?H. Wang; A. Y. Cho; L.?W. Tu; G. J. Zydzik

1992-01-01T23:59:59.000Z

76

Plasma Treatment of Niobium SRF Cavity Surfaces  

SciTech Connect

Plasma based surface modification provides an excellent opportunity to eliminate non- superconductive pollutants in the penetration depth region of the SRF cavity surface and to remove mechanically damaged surface layer improving surface roughness. We have demonstrated on flat samples that plasma etching in Ar / Cl2 of bulk Nb is a viable alternative surface preparation technique to BCP and EP methods, with comparable etching rates. The geometry of SRF cavities made of bulk Nb defines the use of asymmetric RF discharge configuration for plasma etching. In a specially designed single cell cavity with sample holders, discharge parameters are combined with etched surface diagnostics to obtain optimum combination of etching rates, roughness and homogeneity in a variety of discharge types, conditions, and sequences. The optimized experimental conditions will ultimately be applied to single cell SRF cavities.

J. Upadhyay, M. Raskovic, L. Vuskovic, S. Popovic, A.-M. Valente-Feliciano, L. Phillips

2010-05-01T23:59:59.000Z

77

Constant field gradient planar cavity structure  

DOE Patents (OSTI)

A cavity structure is described having at least two opposing planar housing members spaced apart to accommodate the passage of a particle beam through the structure between the members. Each of the housing members have a plurality of serially aligned hollows defined therein, and also passages, formed in the members, which interconnect serially adjacent hollows to provide communication between the hollows. The opposing planar housing members are spaced and aligned such that the hollows in one member cooperate with corresponding hollows in the other member to form a plurality of resonant cavities aligned along the particle beam within the cavity structure. To facilitate the obtaining of a constant field gradient within the cavity structure, the passages are configured so as to be incrementally narrower in the direction of travel of the particle beam. In addition, the spacing distance between the opposing housing members is configured to be incrementally smaller in the direction of travel of the beam.

Kang, Yoon W.; Kustom, R.L.

1997-12-01T23:59:59.000Z

78

Radiation properties of cavity Cerenkov radiation  

SciTech Connect

Cerenkov radiation from cavities has been analyzed by quantum electrodynamic theory. Analytical expressions of basic radiation properties such as the Einstein's A and B coefficients are derived and shown to be directly modified by the cavities. The analysis leads to the conclusion that the coherent radiation from the Cerenkov radiation devices is due to super radiance of spontaneous emission instead of stimulated emission. Coherent and incoherent radiations are analyzed in the THz radiation range.

Gao Ju; Shen Fang [Electrical and Computer Engineering Department, University of Illinois, Urbana, Illinois 61801 (United States)

2006-04-15T23:59:59.000Z

79

Fabrication and characterization of fibers with built-in liquid crystal channels and electrodes for transverse incident-light modulation  

E-Print Network (OSTI)

We report on an all-in-fiber liquid crystal (LC) structure designed for the modulation of light incident transverse to the fiber axis. A hollow cavity flanked by viscous conductors is introduced into a polymer matrix, and ...

Wei, Lei

80

Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation  

E-Print Network (OSTI)

We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling of cavity photons to quantized excitations of an adjacent electrical circuit (qubit) can easily exceed the damping rates of both the cavity and the qubit. This architecture is attractive both as a macroscopic analog of atomic physics experiments and for quantum computing and control, since it provides strong inhibition of spontaneous emission, potentially leading to greatly enhanced qubit lifetimes, allows high-fidelity quantum non-demolition measurements of the state of multiple qubits, and has a natural mechanism for entanglement of qubits separated by centimeter distances. In addition it would allow production of microwave photon states of fundamental importance for quantum communication.

Alexandre Blais; Ren-Shou Huang; Andreas Wallraff; S. M. Girvin; R. J. Schoelkopf

2004-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

"Fine grain Nb tube for SRF cavities"  

SciTech Connect

Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

Robert E. Barber

2012-07-08T23:59:59.000Z

82

Compound parabolic concentrator with cavity for tubular absorbers  

DOE Patents (OSTI)

A compond parabolic concentrator with a V-shaped cavity is provided in which an optical receiver is emplaced. The cavity redirects all energy entering between the receiver and the cavity structure onto the receiver, if the optical receiver is emplaced a distance from the cavity not greater than 0.27 r (where r is the radius of the receiver).

Winston, Roland (5217C S. University Ave., Chicago, IL 60615)

1983-01-01T23:59:59.000Z

83

JLab SRF Cavity Fabrication Errors, Consequences and Lessons Learned  

Science Conference Proceedings (OSTI)

Today, elliptical superconducting RF (SRF) cavities are preferably made from deep-drawn niobium sheets as pursued at Jefferson Laboratory (JLab). The fabrication of a cavity incorporates various cavity cell machining, trimming and electron beam welding (EBW) steps as well as surface chemistry that add to forming errors creating geometrical deviations of the cavity shape from its design. An analysis of in-house built cavities over the last years revealed significant errors in cavity production. Past fabrication flaws are described and lessons learned applied successfully to the most recent in-house series production of multi-cell cavities.

Frank Marhauser

2011-09-01T23:59:59.000Z

84

Cavity cooling of a single atom  

E-Print Network (OSTI)

All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping and spontaneous emission of a photon by the atom. Spontaneous emission in a random direction is the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been proposed for a single atom strongly coupled to a high-finesse cavity; the role of spontaneous emission is replaced by the escape of a photon from the cavity. Application of such cooling schemes would improve the performance of atom cavity systems for quantum information processing. Furthermore, as cavity cooling does not rely on spontaneous emission, it can be applied to systems that cannot be laser-cooled by conventional methods; these include molecules (which do not have a closed transition) and collective excitations of Bose condensates, which are destroyed by randomly directed recoil kicks. Here we demonstrate cavity cooling of single rubidium atoms stored in an intracavity dipole trap. The cooling mechanism results in extended storage times and improved localization of atoms. We estimate that the observed cooling rate is at least five times larger than that produced by free-space cooling methods, for comparable excitation of the atom.

P. Maunz; T. Puppe; I. Schuster; N. Syassen; P. W. H. Pinkse; G. Rempe

2004-03-03T23:59:59.000Z

85

Enhanced Method for Cavity Impedance Calculations  

Science Conference Proceedings (OSTI)

With the proposal of medium to high average current accelerator facilities the demand for cavities with extremely low Higher Order Mode (HOM) impedances is increasing. Modern numerical tools are still under development to more thoroughly predict impedances that need to take into account complex absorbing boundaries and lossy materials. With the usually large problem size it is preferable to utilize massive parallel computing when applicable and available. Apart from such computational issues, we have developed methods using available computer resources to enhance the information that can be extracted from a cavities? wakefield computed in time domain. In particular this is helpful for a careful assessment of the extracted RF power and the mitigation of potential beam break-up or emittance diluting effects, a figure of merit for the cavity performance. The method is described as well as an example of its implementation.

Frank Marhauser, Robert Rimmer, Kai Tian, Haipeng Wang

2009-05-01T23:59:59.000Z

86

1.3 GHz superconducting RF cavity program at Fermilab  

SciTech Connect

At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

2011-03-01T23:59:59.000Z

87

Accommodation of liquid metal by cavity liners  

Science Conference Proceedings (OSTI)

Present liquid metal breeder reactor cell liner designs appear adequate to contain postulated leakages of lithium-lead alloy in an air or steam atmosphere and to contain lithium when inert atmospheres are present. If an air or steam atmosphere may be present in a cavity where lithium amy accumulate under postulated accident conditions, then consideration of stainless steel liners and further testing is recommended. Lithium testing of faulted liners should also be considered. SOFIRE II and WATRe computer codes may be useful in establishing liner design requirements and in determining water release from concrete behind the liners (potential hydrogen production) for postulated leakages to steel-lined concrete cavities.

Jeppson, D.W.

1989-03-01T23:59:59.000Z

88

Fundamental Research in Superconducting RF Cavity Design  

Science Conference Proceedings (OSTI)

This is a 3-year SRF R&D proposal with two main goals: 1) to benefit near term high gradient SRF applications by understanding the causes of quench at high fields in present-day niobium cavities 2) to open the long-range prospects for SRF applications by experimentally verifying the recent exciting theoretical predication for new cavity materials such as Nb3Sn and MgB2. These predictions shwo that ultimately gradients of 100Mv/m to 200MV/m may become possible as material imperfections are overcome.

Georg Hoffstaetter

2012-11-13T23:59:59.000Z

89

Coupled Geomechanical Simulations of UCG Cavity Evolution  

Science Conference Proceedings (OSTI)

This paper presents recent work from an ongoing project to develop predictive tools for cavity/combustion-zone growth and to gain quantitative understanding of the processes and conditions (both natural and engineered) affecting underground coal gasification (UCG). In this paper we will focus upon the development of coupled geomechanical capabilities for simulating the evolution of the UCG cavity using discrete element methodologies. The Discrete Element Method (DEM) has unique advantages for facilitating the prediction of the mechanical response of fractured rock masses, such as cleated coal seams. In contrast with continuum approaches, the interfaces within the coal can be explicitly included and combinations of both elastic and plastic anisotropic response are simulated directly. Additionally, the DEM facilitates estimation of changes in hydraulic properties by providing estimates of changes in cleat aperture. Simulation of cavity evolution involves a range of coupled processes and the mechanical response of the host coal and adjoining rockmass plays a role in every stage of UCG operations. For example, cavity collapse during the burn has significant effect upon the rate of the burn itself. In the vicinity of the cavity, collapse and fracturing may result in enhanced hydraulic conductivity of the rock matrix in the coal and caprock above the burn chamber. Even far from the cavity, stresses due to subsidence may be sufficient to induce new fractures linking previously isolated aquifers. These mechanical processes are key in understanding the risk of unacceptable subsidence and the potential for groundwater contamination. These mechanical processes are inherently non-linear, involving significant inelastic response, especially in the region closest to the cavity. In addition, the response of the rock mass involves both continuum and discrete mechanical behavior. We have recently coupled the LDEC (Livermore Distinct Element Code) and NUFT (Non-isothermal Unsaturated Flow and Transport) codes to investigate the interaction between combustion, water influx and mechanical response. The modifications to NUFT are described in detail in a companion paper. This paper considers the extension of the LDEC code and the application of the coupled tool to the simulation of cavity growth and collapse. The distinct element technology incorporated into LDEC is ideally suited to simulation of the progressive failure of the cleated coal mass by permitting the simulation of individual planes of weakness. We will present details of the coupling approach and then demonstrate the capability through simulation of several test cases.

Morris, J P; Buscheck, T A; Hao, Y

2009-07-13T23:59:59.000Z

90

Cavity Loss Induced Generation of Entangled Atoms  

E-Print Network (OSTI)

We discuss the generation of entangled states of two two-level atoms inside an optical resonator. When the cavity decay is continuously monitored, the absence of photon-counts is associated with the presence of an atomic entangled state. In addition to being conceptually simple, this scheme could be demonstrated with presently available technology. We describe how such a state is generated through conditional dynamics, using quantum jump methods, including both cavity damping and spontaneous emission decay, and evaluate the fidelity and relative entropy of entanglement of the generated state compared with the target entangled state.

M. B. Plenio; S. F. Huelga; A. Beige; P. L. Knight

1998-11-02T23:59:59.000Z

91

Cavity Loss Induced Generation of Entangled Atoms  

E-Print Network (OSTI)

We discuss the generation of entangled states of two two-level atoms inside an optical resonator. When the cavity decay is continuously monitored, the absence of photon-counts is associated with the presence of an atomic entangled state. In addition to being conceptually simple, this scheme could be demonstrated with presently available technology. We describe how such a state is generated through conditional dynamics, using quantum jump methods, including both cavity damping and spontaneous emission decay, and evaluate the fidelity and relative entropy of entanglement of the generated state compared with the target entangled state.

Plenio, M B; Beige, A; Knight, P L

1999-01-01T23:59:59.000Z

92

Superconducting RF cavity R&D for future accelerators  

E-Print Network (OSTI)

High-beta superconducting radiofrequency (SRF) elliptical cavities are being developed for several accelerator projects including Project X, the European XFEL, and the International Linear Collider (ILC). Fermilab has recently established an extensive infrastructure for SRF cavity R&D for future accelerators, including cavity surface processing and testing and cavity assembly into cryomodules. Some highlights of the global effort in SRF R&D toward improving cavity performance, and Fermilab SRF cavity R&D in the context of global projects are reviewed.

C. M. Ginsburg

2009-10-22T23:59:59.000Z

93

Time-bin modulated polarization-entangled biphotons from cavity-enhanced down-conversion  

E-Print Network (OSTI)

We have generated a new type of biphoton state by cavity-enhanced down-conversion in a type-II phase-matched, periodically-poled KTiOPO_4 (PPKTP) crystal. By introducing a weak intracavity birefringence, the polarization-entangled output was modulated between the singlet and triplet states according to the arrival-time difference of the signal and idler photons. This cavity-enhanced biphoton source is spectrally bright, yielding a single-mode fiber-coupled coincidence rate of 0.7 pairs/s per mW of pump power per MHz of down-conversion bandwidth. Its novel biphoton behavior may be utilized in sensitive measurements of weak intracavity birefringence.

Christopher E. Kuklewicz; Franco N. C. Wong; Jeffrey H. Shapiro

2006-05-10T23:59:59.000Z

94

Eccentric superconducting RF cavity separator structure  

DOE Patents (OSTI)

Accelerator apparatus having an eccentric-shaped, iris-loaded deflecting cavity for an rf separator for a high energy high momentum, charged particle accelerator beam. In one embodiment, the deflector is superconducting, and the apparatus of this invention provides simplified machining and electron beam welding techniques. Model tests have shown that the electrical characteristics provide the desired mode splitting without adverse effects.

Aggus, John R. (Shoreham, NY); Giordano, Salvatore T. (Port Jefferson, NY); Halama, Henry J. (Shoreham, NY)

1976-01-01T23:59:59.000Z

95

Measuring the speed of light using beating longitudinal modes in an open-cavity HeNe laser  

E-Print Network (OSTI)

We describe an undergraduate laboratory that combines an accurate measurement of the speed of light, a fundamental investigation of a basic laser system, and a nontrivial use of statistical analysis. Students grapple with the existence of longitudinal modes in a laser cavity as they change the cavity length of an adjustable-cavity HeNe laser and tune the cavity to produce lasing in the TEM$_{00}$ mode. For appropriate laser cavity lengths, the laser gain curve of a HeNe laser allows simultaneous operation of multiple longitudinal modes. The difference frequency between the modes is measured using a self-heterodyne detection with a diode photodetector and a radio frequency spectrum analyzer. Asymmetric effects due to frequency pushing and frequency pulling, as well as transverse modes, are minimized by simultaneously monitoring and adjusting the mode structure as viewed with a Fabry-Perot interferometer. The frequency spacing of longitudinal modes is proportional to the inverse of the cavity length with a prop...

D'Orazio, Daniel J; Schultz, Justin T; Sidor, Daniel; Best, Micheal; Goodfellow, Kenneth; Scholten, Robert E; White, James D; 10.1119/1.3299281

2010-01-01T23:59:59.000Z

96

Tubular RF cage field confinement cavity - Energy Innovation ...  

An RF cavity is provided with a plurality of tubes that are formed into a tubular cage in a predefined shape to define the RF cavity. A selected number of tubes and a ...

97

An improved RF cavity search for halo axions  

E-Print Network (OSTI)

The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with ...

Yu, D. B. (Daniel Byungyoon), 1976-

2004-01-01T23:59:59.000Z

98

Hom dampers for ALS storage ring RF cavities  

E-Print Network (OSTI)

of the HOM dampers on ALS rf cavities was an immediatesuccess. Now, the ALS storage ring can operate with the 312The cross-section of the ALS third harmonic cavity with two

2003-01-01T23:59:59.000Z

99

STUDY OF HELIUM RETENTION IN NANO-CAVITY ...  

Science Conference Proceedings (OSTI)

STUDY OF HELIUM RETENTION IN NANO-CAVITY TUNGSTEN AS A FIRST WALL IN A FUSION CHAMBER USING NEUTRON DEPTH ...

100

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center_dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

102

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, Christopher A. (Livermore, CA); Davis, Laura E. (Manteca, CA); Webb, Mark (Salida, CA)

1992-01-01T23:59:59.000Z

103

TESLA Report 2003-32 FPGA based TESLA cavity SIMCON  

E-Print Network (OSTI)

TESLA Report 2003-32 FPGA based TESLA cavity SIMCON DOOCS server design, implementation of the laboratory solution of the FPGA based TESLA cavity simulator and controller (SIMCON) is presented. The major is a first description of the working DOOCS server for the FPGA based TESLA cavity SIMCON (which is a part

104

Crystallization process  

DOE Patents (OSTI)

An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Adler, Robert J. (Shaker Heights, OH); Brown, William R. (Brecksville, OH); Auyang, Lun (Highland Heights, OH); Liu, Yin-Chang (Richmond Heights, OH); Cook, W. Jeffrey (Cleveland Heights, OH)

1986-01-01T23:59:59.000Z

105

Effect of Cavity Wall Temperature and Opening Ratio on the Natural Convection Heat Loss Characteristics of a Solar Cavity Receiver  

Science Conference Proceedings (OSTI)

The natural convection heat loss characteristics of a solar cavity receiver have been investigated by numerical simulation method. The results show that, the natural convection heat loss, the convection heat transfer coefficient and Nusselt number increase ... Keywords: solar cavity receiver, cavity wall temperature, opening ratio, natural convection heat loss

Lan Xiao; Shuang-Ying Wu; You-Rong Li

2011-02-01T23:59:59.000Z

106

Dielectric supported radio-frequency cavities  

DOE Patents (OSTI)

A device which improves the electrical and thermomechanical performance of an RF cavity, for example, in a disk-loaded accelerating structure. A washer made of polycrystalline diamond is brazed in the middle to a copper disk washer and at the outer edge to the plane wave transformer tank wall, thus dissipating heat from the copper disk to the outer tank wall while at the same time providing strong mechanical support to the metal disk. The washer structure eliminates the longitudinal connecting rods and cooling channels used in the currently available cavities, and as a result minimizes problems such as shunt impedance degradation and field distortion in the plane wave transformer, and mechanical deflection and uneven cooling of the disk assembly.

Yu, David U. L. (Rancho Palos Verdes, CA); Lee, Terry G. (Cupertino, CA)

2000-01-01T23:59:59.000Z

107

Heat loss from an open cavity  

DOE Green Energy (OSTI)

Cavity type receivers are used extensively in concentrating solar thermal energy collecting systems. The Solar Total Energy Project (STEP) in Shenandoah, Georgia is a large scale field test for the collection of solar thermal energy. The STEP experiment consists of a large field array of solar collectors used to supplement the process steam, cooling and other electrical power requirements of an adjacent knitwear manufacturing facility. The purpose of the tests, conducted for this study, was to isolate and quantify the radiative, conductive, and convective components of total heat loss, and to determine the effects of operating temperature, receiver angle, and aperture size on cavity heat loss. An analytical model for radiative heat loss was developed and compared with two other methods used to determine radiative heat loss. A proposed convective heat loss correlation, including effects of aperture size, receiver operating temperature, and receiver angle is presented. The resulting data is a source to evaluate the STEP measurements.

McDonald, C.G. [California State Polytechnic Univ., Pomona, CA (United States). Coll. of Engineering

1995-12-01T23:59:59.000Z

108

Accommodation of liquid metal by cavity liners  

Science Conference Proceedings (OSTI)

Present liquid metal breeder reactor cell liner designs appear adequate to contain postulated leakages of lithium-lead alloy in an air or steam atmosphere and to contain lithium when inert atmospheres are present. If an air or steam atmosphere may be present in a cavity where lithium may accumulate under postulated accident conditions, then consideration of stainless steel liners and further testing is recommended. Lithium testing of faulted liners should also be considered. SOFIRE II and WATRE computer codes may be useful in establishing liner design requirements and in determining water release from concrete behind the liners (potential hydrogen production) for postulated leakages to steel-lined concrete cavities. 1 ref., 10 figs.

Jeppson, D.W.

1988-10-01T23:59:59.000Z

109

Final Report for "Compact Crab Cavity Design"  

SciTech Connect

The goal of this project is to provide an innovative, new crab cavity design relevant to the MEIC. Through this work, we will provide comprehensive modeling of this new cavity design, including electromagnetic, thermal, and microphonic effects. One most likely candidate configuration is the design put forward by JLab and Lancaster University, UK, researchers known as the four-rod configuration. In the Phase I, Tech-X Corporation researchers performed analysis and design optimization and iteration, utilizing their state-of-the art time-domain particle-in-cell software, on a 400 MHz design for the LHC by JLab and Lancaster University, UK, researchers known as the four-rod design.

Smithe, David N

2012-11-08T23:59:59.000Z

110

Atomic Layer Deposition for SRF Cavities  

SciTech Connect

We have begun using Atomic Layer Deposition (ALD) to synthesize a variety of surface coatings on coupons and cavities as part of an effort to produce rf structures with significantly better performance and yield than those obtained from bulk niobium, The ALD process offers the possibility of conformally coating complex cavity shapes with precise layered structures with tightly constrained morphology and chemical properties. Our program looks both at the metallurgy and superconducting properties of these coatings, and also their performance in working structures. Initial results include: 1) evidence from point contact tunneling showing magnetic oxides can be a significant limitation to high gradient operation, 2) experimental results showing the production sharp niobium/oxide interfaces from a high temperature bake of ALD coated Al2O3 on niobium surfaces, 3) results from ALD coated structures.

Norem, J; Pellin, M J; Antoine, C Z; Ciovati, G; Kneisel, P; Reece, C E; Rimmer, R A; Cooley, L; Gurevich, A V; Ha, Y; Proslier, Th

2009-05-01T23:59:59.000Z

111

Capillary toroid cavity detector for high pressure NMR  

DOE Patents (OSTI)

A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity contains an elongated central conductor extending within the toroid cavity. The toroid cavity and central conductor generate an RF magnetic field for NMR analysis. A flow-through capillary sample container is located within the toroid cavity adjacent to the central conductor to subject a sample material flowing through the capillary to a static magnetic field and to enable NMR spectra to be recorded of the material in the capillary under a temperature and high pressure environment.

Gerald, II, Rex E. (Brookfield, IL); Chen, Michael J. (Downers Grove, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Honer Glen, IL); ter Horst, Marc (Chapel Hill, NC)

2007-09-11T23:59:59.000Z

112

Dissipative hydride precipitates in superconducting niobium cavities  

Science Conference Proceedings (OSTI)

We report the first direct observation of the microstructural features exhibiting RF losses at high surface magnetic fields of above 100 mT in field emission free superconducting niobium cavities. The lossy areas were identified by advanced thermometry. Surface investigations using different techniques were carried out on cutout samples from lossy areas and showed the presence of dendritic niobium hydrides. This finding has possible implications to the mechanisms of RF losses in superconducting niobium at all field levels.

Romanenko, A.; Cooley, L.D.; /Fermilab; Ciovati, G.; / /Jefferson Lab; Wu, G.; /Argonne

2011-10-01T23:59:59.000Z

113

MULTIPLE TORNADO  

E-Print Network (OSTI)

The purpose of this note is to call attention to a preferred 1,000-500-mb. thickness line that in the mean accompanies multiple tornado outbreaks in the United States. Studies by Sutcliffe [I] and others have suggested that thickness patterns are a suitable synoptic tool for obtaining a picture of the three-dimensional structure of the atmosphere. SutclifFe and Forsdyke [2] have placed particular emphasis on charts showing the pattern of thickness of the 1,000-500-mb. layer. The contribution of the thickness pattern and the synoptic pressure patterns to the vorticity of the tornado is outside the scope of the present study. However, though much has been written concerning the value of such patterns in the evaluation of vertical motion and synoptic development, there has

Conrad P. Mook

1954-01-01T23:59:59.000Z

114

Handbook for Gas Filled RF Cavity Aficionados'  

DOE Green Energy (OSTI)

The use of hydrogen gas filled RF cavities in muon cooling channels has been proposed by Rolland Johnson. Impressive results have been obtained toward attaining high voltage gradients and rapid training in preliminary tests done at the FNAL MTA facility. However, so far it has not been possible to test them under conditions where they were subject to the transversal of a high intensity particle beam. This note is an attempt to bring together a description of some of the pertinent physical processes that take place in the dilute plasma that is generated in the hydrogen gas by the beam. Two effects dominate. The first is that the free electrons generated can load down the cavity and transfer its energy to heating the gas. The second is a question of what happens to the plasma in the longer term. There is an enormous literature on the subject of the subject of dilute hydrogen plasmas and we can tap into this information in order to understand and predict the behavior of the cavity.

Tollestrup, A.V.; Chung, Moses; Yonehara, Katsuya; /Fermilab

2009-05-01T23:59:59.000Z

115

Nano Positioning of Single Atoms in a Micro Cavity  

E-Print Network (OSTI)

The coupling of individual atoms to a high-finesse optical cavity is precisely controlled and adjusted using a standing-wave dipole-force trap, a challenge for strong atom-cavity coupling. Ultracold Rubidium atoms are first loaded into potential minima of the dipole trap in the center of the cavity. Then we use the trap as a conveyor belt that we set into motion perpendicular to the cavity axis. This allows us to repetitively move atoms out of and back into the cavity mode with a repositioning precision of 135 nm. This makes possible to either selectively address one atom of a string of atoms by the cavity, or to simultaneously couple two precisely separated atoms to a higher mode of the cavity.

Stefan Nussmann; Markus Hijlkema; Bernhard Weber; Felix Rohde; Gerhard Rempe; Axel Kuhn

2005-06-10T23:59:59.000Z

116

Recent Progress of RF Cavity Study at Mucool Test Area  

DOE Green Energy (OSTI)

Summar of presentation is: (1) MTA is a multi task working space to investigate RF cavities for R&D of muon beam cooling channel - (a) Intense 400 MeV H{sup -} beam, (b) Handle hydrogen (flammable) gas, (c) 5 Tesla SC solenoid magnet, (d) He cryogenic/recycling system; (2) Pillbox cavity has been refurbished to search better RF material - Beryllium button test will be happened soon; (3) E x B effect has been tested in a box cavity - Under study (result seems not to be desirable); (4) 201 MHz RF cavity with SRF cavity treatment has been tested at low magnetic field - (a) Observed some B field effect on maximum field gradient and (b) Further study is needed (large bore SC magnet will be delivered end of 2011); and (5) HPRF cavity beam test has started - (a) No RF breakdown observed and (b) Design a new HPRF cavity to investigate more plasma loading effect.

Yonehara, Katsuya; /Fermilab

2011-12-02T23:59:59.000Z

117

The Origin and Concentration of Ice Crystals in Clouds  

Science Conference Proceedings (OSTI)

Ice crystals in supercooled clouds may form upon ice nuclei, or they may arise through secondary processes. Two of these secondary ice “multiplication” mechanisms are discussed in some detail: the rime-splintering process and the mechanical ...

S. C. Mossop

1985-03-01T23:59:59.000Z

118

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

Kuzay, T.M.

1990-06-29T23:59:59.000Z

119

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

A method is disclosed for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N[sub 2] is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation. 7 figs.

Kuzay, T.M.

1992-06-23T23:59:59.000Z

120

Superconducting RF Cavities Past, Present and Future  

E-Print Network (OSTI)

In the last two decades many laboratories around the world, notably Argonne (ANL), TJNAF (formerly CEBAF), CERN, DESY and KEK, decided to develop the technology of superconducting (SC) accelerating cavities. The aim was either to increase the accelerator energy or to save electrical consumption or both. This technology has been used extensively in the operating machines showing good performances and strong reliability. At present, the technology using bulk niobium (Nb) or Nb coated on copper (Cu) is mature enough to be applied for many different applications, such as synchrotron light sources and spallation neutron drivers. Results, R&D work and future projects will be presented with emphasis on application to linear accelerators.

Chiaveri, Enrico

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

SRF Cavity Surface Topography Characterization Using Replica Techniques  

Science Conference Proceedings (OSTI)

To better understand the roll of topography on SRF cavity performance, we seek to obtain detailed topographic information from the curved practical cavity surfaces. Replicas taken from a cavity interior surface provide internal surface molds for fine Atomic Force Microscopy (AFM) and stylus profilometry. In this study, we confirm the replica resolution both on surface local defects such as grain boundary and etching pits and compare the surface uniform roughness with the aid of Power Spectral Density (PSD) where we can statistically obtain roughness parameters at different scales. A series of sampling locations are at the same magnetic field chosen at the same latitude on a single cell cavity to confirm the uniformity. Another series of sampling locations at different magnetic field amplitudes are chosen for this replica on the same cavity for later power loss calculation. We also show that application of the replica followed by rinsing does not adversely affect the cavity performance.

C. Xu, M.J. Kelley, C.E. Reece

2012-07-01T23:59:59.000Z

122

Electrically injected visible vertical cavity surface emitting laser diodes  

DOE Patents (OSTI)

Visible laser light output from an electrically injected vertical cavity surface emitting laser (VSCEL) diode is enabled by the addition of phase-matching spacer layers on either side of the active region to form the optical cavity. The spacer layers comprise InAlP which act as charge carrier confinement means. Distributed Bragg reflector layers are formed on either side of the optical cavity to act as mirrors. 5 figs.

Schneider, R.P.; Lott, J.A.

1994-09-27T23:59:59.000Z

123

Turbine inter-disk cavity cooling air compressor  

DOE Patents (OSTI)

The inter-disk cavity between turbine rotor disks is used to pressurize cooling air. A plurality of ridges extend radially outwardly over the face of the rotor disks. When the rotor disks are rotated, the ridges cause the inter-disk cavity to compress air coolant flowing through the inter-disk cavity en route to the rotor blades. The ridges eliminate the need for an external compressor to pressurize the air coolant.

Chupp, Raymond E. (Oviedo, FL); Little, David A. (Oviedo, FL)

1998-01-01T23:59:59.000Z

124

Turbine inter-disk cavity cooling air compressor  

DOE Patents (OSTI)

The inter-disk cavity between turbine rotor disks is used to pressurize cooling air. A plurality of ridges extend radially outwardly over the face of the rotor disks. When the rotor disks are rotated, the ridges cause the inter-disk cavity to compress air coolant flowing through the inter-disk cavity en route to the rotor blades. The ridges eliminate the need for an external compressor to pressurize the air coolant. 5 figs.

Chupp, R.E.; Little, D.A.

1998-01-06T23:59:59.000Z

125

Ring cavity for a Raman capillary waveguide amplifier  

DOE Patents (OSTI)

Disclosed is a regenerative ring amplifier and regenerative ring oscillator which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO[sub 2] laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplifier Stokes signal is synchronous with the mode-locked spikes of the incoming CO[sub 2] laser pump signal. 6 figs.

Kurnit, N.A.

1983-07-19T23:59:59.000Z

126

Ring cavity for a Raman capillary waveguide amplifir  

DOE Patents (OSTI)

A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

Kurnit, N.A.

1981-01-27T23:59:59.000Z

127

Cavity-stabilized laser with acceleration sensitivity below 10 g  

Science Conference Proceedings (OSTI)

... Typically, lasers for such applications are stabilized by locking them to a Fabry-Pérot cavity such that the fractional frequency stability of the laser is ...

2013-04-02T23:59:59.000Z

128

Ring cavity for a Raman capillary waveguide amplifier  

DOE Patents (OSTI)

A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

Kurnit, N.A.

1981-01-27T23:59:59.000Z

129

Diagnostic resonant cavity for a charged particle accelerator  

DOE Patents (OSTI)

Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.

Barov, Nikolai (San Diego, CA)

2007-10-02T23:59:59.000Z

130

Superconducting spoke cavities for high-velocity applications  

SciTech Connect

To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to {beta}{sub 0}~0.6, but there is a growing interest in possible applications of multispoke cavities for high-velocity applications. We have explored the design parameter space for low-frequency, high-velocity, double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. We present detailed design for cavities operating at 325 and 352 MHz and optimized for {beta}{sub 0}~=0.82 and 1.

Hopper, Christopher S. [Old Dominion U.; Delayen, Jean R. [Old Dominion U., JLAB

2013-10-01T23:59:59.000Z

131

HOM Survey of the First CEBAF Upgrade Style Cavity Pair  

SciTech Connect

The planned upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Laboratory (JLab) requires ten new superconducting rf (SRF) cavity cryomodules to double the beam energy to the envisaged 12 GeV. Adequate cavity Higher Order Mode (HOM) suppression is essential to avoid multipass, multibunch beam break-up (BBU) instabilities of the recirculating beam. We report on detailed HOM surveys performed for the first two upgrade style cavities tested in a dedicated cavity pair cryomodule at 2K. The safety margin to the BBU threshold budget at 12 GeV has been assessed.

Marhauser, Frank; Davis, G; Drury, Michael; Grenoble, Christiana; Hogan, John; Manus, Robert; Preble, Joseph; Reece, Charles; Rimmer, Robert; Tian, Kai

2009-05-01T23:59:59.000Z

132

Sublimation of Ice Crystals  

Science Conference Proceedings (OSTI)

Recent experiments on the sublimation of single crystals of ice in an atmosphere of air indicate that the sublimation rate is diffusion limited and initially solid prismatic crystals evolve into time-independent shapes similar to confocal ...

Jon Nelson

1998-03-01T23:59:59.000Z

133

Cavity cooling of an ensemble spin system  

E-Print Network (OSTI)

We describe how sideband cooling techniques, prevalent in quantum optics, may be applied to large spin ensembles in magnetic resonance. Using the Tavis-Cummings model in the presence of a Rabi drive, we solve a Markovian master equation describing the joint spin-cavity dynamics to derive cooling rates as a function of ensemble size. Our calculations indicate that a spin ensemble containing roughly $10^{11}$ electron spins may be polarized to a non-thermal equilibrium state in a time many orders of magnitude shorter than the typical thermal relaxation time. The described techniques permit the efficient removal of entropy for spin-based quantum information processors and fast polarization of spin samples. The proposed application of a standard technique in quantum optics to magnetic resonance also serves to reinforce the connection between the two fields, which has only recently begun to be explored in detail due to the development of hybrid designs for manufacturing noise-resilient quantum devices.

Christopher J. Wood; Troy W. Borneman; David G. Cory

2013-05-05T23:59:59.000Z

134

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, Jim J. (Dublin, CA); Bass, Isaac L. (Castro Valley, CA); Zapata, Luis E. (Livermore, CA)

1999-01-01T23:59:59.000Z

135

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, J.J.; Bass, I.L.; Zapata, L.E.

1999-11-02T23:59:59.000Z

136

Monochromator Crystal Glitch Library  

DOE Data Explorer (OSTI)

Users can view glitch spectra online, list specific crystal orientations, and download PDF files of the glitch spectra. (Specialized Interface)

137

Crystal Lattice Structures - TMS  

Science Conference Proceedings (OSTI)

Feb 7, 2007 ... This resource contains 273 common crystal lattice structures indexed by Strukturbericht designation, Pearson symbol, space group, prototype, ...

138

Crystal oriented (Bi  

Science Conference Proceedings (OSTI)

The remnant polarization and piezoelectric constant of crystal oriented BNBT ... Energy Landscape in Frustrated Systems: Cation Hopping and Relaxation in ...

139

Apparatus for mounting crystal  

DOE Patents (OSTI)

A thickness monitor useful in deposition or etching reactor systems comprising a crystal-controlled oscillator in which the crystal is deposited or etched to change the frequency of the oscillator. The crystal rests within a thermally conductive metallic housing and arranged to be temperature controlled. Electrode contacts are made to the surface primarily by gravity force such that the crystal is substantially free of stress otherwise induced by high temperature.

Longeway, Paul A. (East Windsor, NJ)

1985-01-01T23:59:59.000Z

140

TESLA Report 2003-08 Cavity control system  

E-Print Network (OSTI)

TESLA Report 2003-08 Cavity control system essential modeling for TESLA linear accelerator Tomasz of Technology, Poland Stefan Simrock DESY, TESLA, Hamburg, Germany ABSTRACT The pioneering TESLA linear are proposed. Keywords: TESLA, free electron laser, accelerator, high power microwave cavity, vector and phasor

Note: This page contains sample records for the topic "multiple crystal cavities" 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

STANDARDIZATION OF CEBAF 12 GEV UPGRADE CAVITY TESTING  

SciTech Connect

CEBAF 12GeV upgrade project includes 80 new 7-cell cavities to form 10 cryomodules. Each cavity underwent RF qualification at 2.07K using a high power accelerating gradient test and an HOM survey in Jefferson Lab's Vertical Testing Area (VTA) before cavity string assembly. In order to ensure consistently high quality data, updated cavity testing procedures and analysis were implemented and used by a group of VTA operators. For high power tests, a cavity testing procedure was developed and used in conjunction with a LabVIEW program to collect the test data. Additionally while the cavity was at 2.07K, an HOM survey was performed using a network analyzer and a combination of Excel and Mathematica programs. Data analysis was standardized and an online logbook, Pansophy, was used for data storage and mining. The Pansophy system allowed test results to be easily summarized and searchable across all cavity tests. In this presentation, the CEBAF 12GeV upgrade cavity testing procedure, method for data analysis, and results reporting results will be discussed.

Tiffany Bass, G. Davis, Christiana Wilson, Mircea Stirbet

2012-07-01T23:59:59.000Z

142

Four cavity efficiency enhanced magnetically insulated line oscillator  

DOE Patents (OSTI)

This invention relates to magnetically insulated line oscillators (MILOs), and more particularly to a four cavity MILO that is ultra compact and displays enhanced efficiency as a result of the four cavity configuration that incorporates an RF choke and electron dump region to obtain high power microwaves with lower voltage requirements than typically required in the microwave field for gigawatt output from microwave sources.

Lemke, R.W.; Clark, M.C.; Calico, S.E.

1996-07-10T23:59:59.000Z

143

High-R Walls for Remodeling: Wall Cavity Moisture Monitoring  

Science Conference Proceedings (OSTI)

The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

Wiehagen, J.; Kochkin, V.

2012-12-01T23:59:59.000Z

144

RF cavity using liquid dielectric for tuning and cooling  

SciTech Connect

A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

2012-04-17T23:59:59.000Z

145

Cavity Quantum Electrodynamics (CQED)-Based Quantum LDPC  

E-Print Network (OSTI)

Cavity Quantum Electrodynamics (CQED)-Based Quantum LDPC Encoders and Decoders Volume 3, Number 4-0655/$26.00 ©2011 IEEE #12;Cavity Quantum Electrodynamics (CQED)-Based Quantum LDPC Encoders and Decoders Ivan B: Quantum information processing (QIP) relies on delicate superposition states that are sensitive

Djordjevic, Ivan B.

146

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities  

E-Print Network (OSTI)

2001. Heat transfer in window frames with internal cavities.Simulations of Internal Window Frame Cavities Validatedin Three-Dimensional Window Frames with Internal Cavities. ”

Gustavsen, Arlid

2008-01-01T23:59:59.000Z

147

Lab Breakthrough: Record-Setting Cavities | Department of Energy  

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

Record-Setting Cavities Record-Setting Cavities Lab Breakthrough: Record-Setting Cavities April 24, 2012 - 2:34pm Addthis At Jefferson Lab, researchers have fabricated a niobium cavity for particle accelerators that has set a world record for energy efficiency. Gianluigi "Gigi" Ciovati, a superconducting radiofrequency scientist, discusses how scientists at the Jefferson Lab developed the technology, and how it will be used to impact the energy industry. Michael Hess Michael Hess Former Digital Communications Specialist, Office of Public Affairs What does this project do? With more powerful accelerators, researchers can someday build new power plants that produce little or no nuclear waste. At Jefferson Lab, researchers have fabricated a niobium cavity for particle accelerators that has set a world record for energy efficiency. Gianluigi

148

Proposal for high pressure RF cavity test in the MTA  

DOE Green Energy (OSTI)

In order to demonstrate the feasibility of high pressure hydrogen gas filled RF (HPRF) cavities for muon ionization cooling, an HPRF cavity must be tested with a high intensity charged beam. When an HPRF cavity is irradiated with an intense beam each incident particle generates about 1000 electrons and ions per cubic centimeter in a high pressure cavity via ionization. These ionization electrons are influenced by the RF field and the RF quality factor goes down. This Q factor reduction will be a problem with a multi bunch beam, e.g., a muon beam for a muon collider consists of a 12 to 20 bunch train beam with 5 ns timing gap. Thus, the RF field must recover in few nano seconds. We propose to use a 400 MeV proton beam in the MTA and measure a beam loading effect in the HPRF cavity and study the recovery mechanism of the RF field.

Yonehara, K.; /Fermilab

2010-09-01T23:59:59.000Z

149

Thermal Performance of Uninsulated and Partially Filled Wall Cavities: Preprint  

SciTech Connect

Low-rise, wood-framed homes are the most common type of residential structures in the United States. Wood wall construction supports roofs efficiently and provides a stable frame for attaching interior and exterior wall coverings. Wall cavities are prevalent and increase thermal resistance, particularly when they are filled with insulating material. This paper describes detailed computational fluid dynamics modeling to evaluate the thermal performance of uninsulated or partially filled wall cavities and accounts for conduction through framing, convection, and radiation. Parameters are ambient outdoor temperature, cavity surface emissivity, cavity aspect ratio, and insulation height. Understanding the thermal performance of uninsulated or partially insulated wall cavities is essential for conserving energy in residential buildings. The results can serve as input for building energy simulation tools such as DOE2 and EnergyPlus for modeling the temperature dependent energy performance of new and older homes with uninsulated or partially insulated walls.

Ridouane, E. H.; Bianchi, M.

2011-08-01T23:59:59.000Z

150

Compact, low power radio frequency cavity for femtosecond electron microscopy  

Science Conference Proceedings (OSTI)

Reported here is the design, construction, and characterization of a small, power efficient, tunable dielectric filled cavity for the creation of femtosecond electron bunches in an existing electron microscope without the mandatory use of femtosecond lasers. A 3 GHz pillbox cavity operating in the TM{sub 110} mode was specially designed for chopping the beam of a 30 keV scanning electron microscope. The dielectric material used is ZrTiO{sub 4}, chosen for the high relative permittivity ({epsilon}{sub r}= 37 at 10 GHz) and low loss tangent (tan {delta}= 2 x 10{sup -4}). This allows the cavity radius to be reduced by a factor of six, while the power consumption is reduced by an order of magnitude compared to a vacuum pillbox cavity. These features make this cavity ideal as a module for existing electron microscopes, and an alternative to femtosecond laser systems integrated with electron microscopes.

Lassise, A.; Mutsaers, P. H. A.; Luiten, O. J. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2012-04-15T23:59:59.000Z

151

Enhancement of accelerating field of microwave cavities by magnetic insulation  

Science Conference Proceedings (OSTI)

Limitations on the maximum achievable accelerating gradient of microwave cavities can strongly influence the performance, length, and cost of particle accelerators. Gradient limitations are widely believed to be initiated by electron emission from the cavity surfaces. Here, we show that the deleterious effects of field emission are effectively suppressed by applying a tangential magnetic field to the cavity walls. With the aid of numerical simulations we compute the field strength required to insulate an 805 MHz cavity and estimate the cavity's tolerances to typical experimental errors such as magnet misalignments and positioning errors. Then, we review an experimental program, currently under progress, to further study the concept. Finally, we report on two specific examples that illustrate the feasibility of magnetic insulation into prospective particle accelerator applications.

Stratakis, D.; Gallardo, J.; Palmer, R.B.

2011-04-15T23:59:59.000Z

152

Thermal Performance of Uninsulated and Partially Filled Wall Cavities  

SciTech Connect

Wall cavities are widely present in the construction of low rise homes since wood framing is the most common type of construction for residential buildings in the United States. The primary function of such wall construction is to provide a stable frame to which interior and exterior wall coverings can be attached and by which a roof can be supported. The existence of wall cavities increases the thermal resistance of the enclosure, particularly when they are filled with insulating material. Several design guides provide data for prediction of the thermal resistance of uninsulated wall cavities of varying internal geometries. However, U-value coefficients provided in these guides do not account for partially insulated cavities or for variations in aspect ratio. Whole building energy simulation tools, like DOE2 or Energy Plus, use simplified, 1-D characterization of building envelopes. For the most part, this characterization assumes a fixed thermal resistance over the range of temperatures experienced by the enclosure. In reality, the thermal resistance is dominated by convection and radiation and is a function of several parameters, including the temperatures and emissivities of the cavity surfaces and the aspect ratio of the cavity. This study describes detailed CFD modeling to evaluate the thermal performance of uninsulated or partially filled wall cavities accounting for conduction through framing, convection, and radiation. The resulting correlations can serve as input for DOE2 and Energy Plus modeling of older homes, where the walls are either uninsulated or partially insulated due to the settling of the insulating material. Parameters of the study are the ambient temperature outdoors, emissivity of the cavity surfaces, cavity aspect ratio, and height of the insulation level. The outcomes of this study provide: An understanding of the thermal performance of uninsulated or partially insulated wall cavities, which is an essential aspect of energy conservation in residential buildings. Accurate input for whole building simulations models like DOE2 and Energy Plus in various climate zones. Recommendations on retrofit measures.

Ridouane, E.H.; Bianchi, M. V. A.

2011-01-01T23:59:59.000Z

153

Slow light enhanced correlated photon pair generation in photonic-crystal coupled-resonator optical waveguides  

E-Print Network (OSTI)

We demonstrate the generation of quantum-correlated photon pairs from a Si photonic-crystal coupled-resonator optical waveguide. A slow-light supermode realized by the collective resonance of high-Q and small-mode-volume photonic-crystal cavities successfully enhanced the efficiency of the spontaneous four-wave mixing process. The generation rate of photon pairs was improved by two orders of magnitude compared with that of a photonic-crystal line defect waveguide without a slow-light effect.

Matsuda, Nobuyuki; Shimizu, Kaoru; Tokura, Yasuhiro; Kuramochi, Eiichi; Notomi, Masaya; 10.1364/OE.21.008596

2013-01-01T23:59:59.000Z

154

Control of acoustics and store separation in a cavity in supersonic flow  

E-Print Network (OSTI)

The supersonic flight community is currently faced with two cavity-under-cross-flow related problems, one being the high noise levels inside the cavity and the other being the return of a store into the cavity after being ...

Sahoo, Debashis, 1976-

2005-01-01T23:59:59.000Z

155

Photonic crystal light source  

DOE Patents (OSTI)

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27T23:59:59.000Z

156

Effect of low temperature baking on niobium cavities  

DOE Green Energy (OSTI)

A low temperature (100 C-150 C) ''in situ'' baking under ultra-high vacuum has been successfully applied as final preparation of niobium RF cavities by several laboratories over the last few years. The benefits reported consist mainly of an improvement of the cavity quality factor and a recovery from the so-called ''Q-drop'' without field emission at high field. A series of experiments with a CEBAF single cell cavity have been carried out at Jefferson Lab to carefully investigate the effect of baking at progressively higher temperatures for a fixed time on all the relevant material parameters. Measurements of the cavity quality factor in the temperature range 1.37K-280K and resonant frequency shift between 6K-9.3K provide information about the surface resistance, energy gap, penetration depth and mean free path. The experimental data have been analyzed with the complete BCS theory of superconductivity using a modified version of the computer code originally written by J. Halbritter [1] . Small niobium samples inserted in the cavity during its surface preparation were analyzed with respect to their hydrogen content with a Nuclear Reaction Analysis (NRA). The single cell cavity has been tested at three different temperatures before and after baking to gain some insight on thermal conductivity and Kapitza resistance and the data are compared with different models. This paper describes the results from these experiments and comments on the existing models to explain the effect of baking on the performance of niobium RF cavities.

Peter Kneisel; Ganapati Myneni; William Lanford; Gianluigi Ciovati

2003-09-01T23:59:59.000Z

157

Method for filling the cavities of cells with a chromogenic fluid  

DOE Patents (OSTI)

A method and apparatus are disclosed for filling a cell cavity positioned between a first substrate and a second substrate with a cell filling liquid. The method entails forming at least one evacuation cavity encompassing at least a portion of an outer surface of each of the first and second substrates of a cell containing a cell cavity and isolating the cell cavity from the evacuation cavity; reducing a pressure in each of the evacuation cavity and the cell cavity; and dispensing the cell filling fluid into the cell cavity.

Tonazzi, Juan C. Lopez (Tucson, AZ); Kucharczyk, Jr., Joseph E. (Tucson, AZ); Agrawal, Anoop (Tucson, AZ)

1999-01-01T23:59:59.000Z

158

Apparatus for filling the cavities of cells and laminated substrates with a fluid  

DOE Patents (OSTI)

A method and apparatus are disclosed for filling a cell cavity positioned between a first substrate and a second substrate with a cell filling liquid. The method entails forming at least one evacuation cavity encompassing at least a portion of an outer surface of each of the first and second substrates of a cell containing a cell cavity and isolating the cell cavity from the evacuation cavity; reducing a pressure in each of the evacuation cavity and the cell cavity; and dispensing the cell filling fluid into the cell cavity.

Lopez Tonazzi, Juan C. (Tucson, AZ); Kucharczyk, Jr., Joseph E. (Tucson, AZ); Agrawal, Anoop (Tucson, AZ)

2001-01-01T23:59:59.000Z

159

Method for filling the cavities of cells with a chromogenic fluid  

DOE Patents (OSTI)

A method and apparatus are disclosed for filling a cell cavity positioned between a first substrate and a second substrate with a cell filling liquid. The method entails forming at least one evacuation cavity encompassing at least a portion of an outer surface of each of the first and second substrates of a cell containing a cell cavity and isolating the cell cavity from the evacuation cavity; reducing a pressure in each of the evacuation cavity and the cell cavity; and dispensing the cell filling fluid into the cell cavity. The application is to the fabrication of electrochromic windows. 22 figs.

Tonazzi, J.C.L.; Kucharczyk, J.E. Jr.; Agrawal, A.

1999-01-05T23:59:59.000Z

160

Sequential generation of matrix-product states in cavity QED  

Science Conference Proceedings (OSTI)

We study the sequential generation of entangled photonic and atomic multiqubit states in the realm of cavity QED. We extend the work of C. Schoen et al. [Phys. Rev. Lett. 95, 110503 (2005)], where it was shown that all states generated in a sequential manner can be classified efficiently in terms of matrix-product states. In particular, we consider two scenarios: photonic multiqubit states sequentially generated at the cavity output of a single-photon source and atomic multiqubit states generated by their sequential interaction with the same cavity mode.

Schoen, C. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom); Hammerer, K. [Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck (Austria); Wolf, M. M.; Cirac, J. I. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru)

2007-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

static green's functions for a bisected coaxial cavity  

E-Print Network (OSTI)

This paper deals with the three-dimensional potential equation in cylindrical coordinates and its Green's function for geometry close to a rather uncommon Time Projection Chamber field-cage, namely a bisected coaxial cavity. The methods used to derive the Green's function for a coaxial cavity (see [CERN-OPEN-2009-003]) were adapted to deduce novel representations for a bisected geometry, where the additional Dirichlet conditions in phi have to be fulfilled. The necessary modifications are described in detail. In combination, these three novel representations allow fast converging calculations of the electric field components and therefore for any desired space charge configuration within this cavity.

Rossegger, S

2009-01-01T23:59:59.000Z

162

Predictions of convective losses from a solar cavity receiver  

SciTech Connect

Convective losses arising from buoyancy driven flow were calculated for a two-dimensional model simulating a solar cavity receiver. The TEMPEST code, capable of fully three-dimensional coupled thermal-hydraulic transient calculations, was used for the simulation. Predicted velocity and temperature results for a 2.59 m deep by 2.88 m high rectangular cavity with an aperture opening of 1.72 m were used to determine convective losses for prescribed interior wall temperatures and cavity orientation. Velocity vector and temperature isotherm plots were used to analyze flow characteristics.

Eyler, L.L.

1979-12-01T23:59:59.000Z

163

Frequency-doubled vertical-external-cavity surface-emitting laser  

DOE Patents (OSTI)

A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.

Raymond, Thomas D. (Edgewood, NM); Alford, William J. (Albuquerque, NM); Crawford, Mary H. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

164

Method for pressure modulation of turbine sidewall cavities  

DOE Patents (OSTI)

A method is provided for controlling cooling air flow for pressure modulation of turbine components, such as the turbine outer sidewall cavities. The pressure at which cooling and purge air is supplied to the turbine outer side wall cavities is modulated, based on compressor discharge pressure (Pcd), thereby to generally maintain the back flow margin (BFM) so as to minimize excessive leakage and the consequent performance deterioration. In an exemplary embodiment, the air pressure within the third stage outer side wall cavity and the air pressure within the fourth stage outer side wall cavity are each controlled to a respective value that is a respective prescribed percentage of the concurrent compressor discharge pressure. The prescribed percentage may be determined from a ratio of the respective outer side wall pressure to compressor discharge pressure at Cold Day Turn Down (CDTD) required to provide a prescribed back flow margin.

Leone, Sal Albert (Scotia, NY); Book, Matthew David (Altamont, NY); Banares, Christopher R. (Schenectady, NY)

2002-01-01T23:59:59.000Z

165

Optomechanics with molecules in a strongly pumped ring cavity  

E-Print Network (OSTI)

Cavity cooling of an atom works best on a cyclic optical transition in the strong coupling regime near resonance, where small cavity photon numbers suffice for trapping and cooling. Due to the absence of closed transitions a straightforward application to molecules fails: optical pumping can lead the particle into uncoupled states. An alternative operation in the far off-resonant regime generates only very slow cooling due to the reduced field-molecule coupling. We predict to overcome this by using a strongly driven ring-cavity operated in the sideband cooling regime. As in the optomechanical setups one takes advantage of a collectively enhanced field-molecule coupling strength using a large photon number. A linearized analytical treatment confirmed by full numerical quantum simulations predicts fast cooling despite the off-resonant small single molecule - single photon coupling. Even ground state cooling can be obtained by tuning the cavity field close to the Anti-stokes sideband for sufficiently high trappi...

Schulze, R J; Ritsch, H

2010-01-01T23:59:59.000Z

166

Commissioning the New LCLS X-Band Transverse Deflecting Cavity...  

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

Commissioning the New LCLS X-Band Transverse Deflecting Cavity with Femtosecond Resolution Wednesday, July 31, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Yuantao Ding...

167

Physical and mechanical metallurgy of high purity Nb accelerator cavities.  

Science Conference Proceedings (OSTI)

In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

Wright, N. T.; Bieler, T. R.; Pourgoghart , F.; Compton, C.; Hartwig, K. T.; Baars, D.; Zamiri, A.; Chandrasekaran, S.; Darbandi, P.; Jiang, H.; Skoug, E.; Balachandran, S.; Ice, G. E.; Liu, W.; Michigan State Univ.; Texas A & M Univ.; ORNL

2010-01-01T23:59:59.000Z

168

Two-beam detuned-cavity electron accelerator structure  

SciTech Connect

Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.

Jiang, Y.; Hirshfield, J. L. [Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States); Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States) and Omega-P, Inc., New Haven, CT 06510 (United States)

2012-12-21T23:59:59.000Z

169

System for pressure modulation of turbine sidewall cavities  

DOE Patents (OSTI)

A system and method are provided for controlling cooling air flow for pressure modulation of turbine components, such as the turbine outer sidewall cavities. The pressure at which cooling and purge air is supplied to the turbine outer side wall cavities is modulated, based on compressor discharge pressure (Pcd), thereby to generally maintain the back flow margin (BFM) so as to minimize excessive leakage and the consequent performance deterioration. In an exemplary embodiment, the air pressure within the third stage outer side wall cavity and the air pressure within the fourth stage outer side wall cavity are each controlled to a respective value that is a respective prescribed percentage of the concurrent compressor discharge pressure. The prescribed percentage may be determined from a ratio of the respective outer side wall pressure to compressor discharge pressure at Cold Day Turn Down (CDTD) required to provide a prescribed back flow margin.

Leone, Sal Albert (Scotia, NY); Book, Matthew David (Altamont, NY); Banares, Christopher R. (Schenectady, NY)

2002-01-01T23:59:59.000Z

170

Phononic crystal devices  

DOE Patents (OSTI)

Phononic crystals that have the ability to modify and control the thermal black body phonon distribution and the phonon component of heat transport in a solid. In particular, the thermal conductivity and heat capacity can be modified by altering the phonon density of states in a phononic crystal. The present invention is directed to phononic crystal devices and materials such as radio frequency (RF) tags powered from ambient heat, dielectrics with extremely low thermal conductivity, thermoelectric materials with a higher ratio of electrical-to-thermal conductivity, materials with phononically engineered heat capacity, phononic crystal waveguides that enable accelerated cooling, and a variety of low temperature application devices.

El-Kady, Ihab F. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2012-01-10T23:59:59.000Z

171

Coaxial Coupling Scheme for TESLA/ILC-type Cavities  

Science Conference Proceedings (OSTI)

This paper reports about our efforts to develop a flangeable coaxial coupler for both HOM and fundamental coupling for 9-cell TESLA/ILC-type cavities. The cavities were designed in early 90‘s for pulsed operation with a low duty factor, less than 1 %. The proposed design of the coupler has been done in a way, that the magnetic flux B at the flange connection is minimized and only a field of TESLA/ILC operation conditions.

J.K. Sekutowicz, P. Kneisel

2010-05-01T23:59:59.000Z

172

Development of high-power gyrotrons with gradually tapered cavity  

Science Conference Proceedings (OSTI)

In high power gyrotrons, the parasitic modes coupled with the operating mode cannot be avoided in the beam-wave interaction. These parasitic modes will decrease the efficiency of the gyrotrons. The purity of the operating mode affected by different tapers should be carefully studied. The steady-state self-consistent nonlinear theory for gyrotron with gradually tapered cavity is developed in this paper. A steady-state calculation code including 'cold cavity' and 'hot cavity' is designed. By comparison, a time-domain model analysis of gyrotron operation is also studied by particle-in-cell (PIC). It is found that the tapers of gyrotron have different influences on the modes coupling between the operating mode and the parasitic modes. During the study, an example of 94 GHz gyrotron with pure operating mode TE{sub 03} has been designed. The purity of the operating mode in the optimized cavity is up to -77 dB, and in output waveguide of the cavity is up to -76 dB. At the same time, the beam-wave interaction in the designed cavity has been simulated, too. An output power of 120 kW, corresponding to 41.6% efficiency and an oscillation frequency of 94.099 GHz have been achieved with a 50 kV, 6 A helical electron beam at a guiding magnetic field of 3.5485 T. The results show that the power in spurious modes of the optimized cavity may be kept far below than that of the traditional tapered cavity.

Lei Chaojun [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China); The Chinese People's Armed Police Force Academy, Langfang 065000 (China); Yu Sheng; Niu Xinjian; Liu Yinghui; Li Hongfu; Li Xiang [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China)

2012-12-15T23:59:59.000Z

173

Ultra-Gradient Test Cavity for Testing SRF Wafer Samples  

SciTech Connect

A 1.3 GHz test cavity has been designed to test wafer samples of superconducting materials. This mushroom shaped cavity, operating in TE01 mode, creates a unique distribution of surface fields. The surface magnetic field on the sample wafer is 3.75 times greater than elsewhere on the Niobium cavity surface. This field design is made possible through dielectrically loading the cavity by locating a hemisphere of ultra-pure sapphire just above the sample wafer. The sapphire pulls the fields away from the walls so the maximum field the Nb surface sees is 25% of the surface field on the sample. In this manner, it should be possible to drive the sample wafer well beyond the BCS limit for Niobium while still maintaining a respectable Q. The sapphire's purity must be tested for its loss tangent and dielectric constant to finalize the design of the mushroom test cavity. A sapphire loaded CEBAF cavity has been constructed and tested. The results on the dielectric constant and loss tangent will be presented

N.J. Pogue, P.M. McIntyre, A.I. Sattarov, C. Reece

2010-11-01T23:59:59.000Z

174

The Casimir Forces in a Single Conducting Cylindrical Cavity  

E-Print Network (OSTI)

We want to study the Casimir effect for a single conducting microscopic cylindrical cavity. The mathematical technique is based on the Green function of the geometry of the inside of the cavity, and the integral regularization is based on the plasma frequency cutoff for real conductors. Using the symmetric electromagnetic energy-momentum tensor, in terms of four potential, the total Casimir energy for the inside of the Cavity is calculated. Considering the fundamental cutoff applied by the uncertainty relations' limit on virtual particles' frequency in the quantum vacuum, it is shown that the contribution of the external (outside of the cavity) Casimir energy is negligible. Finally, the forces experienced by the lateral surface of the cavity and its circular bases are calculated. The resulting expressions show that these forces are repulsive. The numerical computation is done for the real problem of a cavity with a basis of a radius in the same order of its height at the scale of 100 nanometers made of the best conducting materials already known.

H. Razmi; S. M. Shirazi

2013-07-30T23:59:59.000Z

175

Modeling Coupled Evaporation and Seepage in Ventilated Cavities  

SciTech Connect

Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small.

T. Ghezzehei; R. Trautz; S. Finsterle; P. Cook; C. Ahlers

2004-07-01T23:59:59.000Z

176

Camera assembly design proposal for SRF cavity image collection  

SciTech Connect

This project seeks to collect images from the inside of a superconducting radio frequency (SRF) large grain niobium cavity during vertical testing. These images will provide information on multipacting and other phenomena occurring in the SRF cavity during these tests. Multipacting, a process that involves an electron buildup in the cavity and concurrent loss of RF power, is thought to be occurring near the cathode in the SRF structure. Images of electron emission in the structure will help diagnose the source of multipacting in the cavity. Multipacting sources may be eliminated with an alteration of geometric or resonant conditions in the SRF structure. Other phenomena, including unexplained light emissions previously discovered at SLAC, may be present in the cavity. In order to effectively capture images of these events during testing, a camera assembly needs to be installed to the bottom of the RF structure. The SRF assembly operates under extreme environmental conditions: it is kept in a dewar in a bath of 2K liquid helium during these tests, is pumped down to ultra-high vacuum, and is subjected to RF voltages. Because of this, the camera needs to exist as a separate assembly attached to the bottom of the cavity. The design of the camera is constrained by a number of factors that are discussed.

Tuozzolo, S.

2011-10-10T23:59:59.000Z

177

Learning from multiple heuristics  

Science Conference Proceedings (OSTI)

Heuristic functions for single-agent search applications estimate the cost of the optimal solution. When multiple heuristics exist, taking their maximum is an effective way to combine them. A new technique is introduced for combining multiple heuristic ...

Mehdi Samadi; Ariel Felner; Jonathan Schaeffer

2008-07-01T23:59:59.000Z

178

Optimization of beam injection into the first accelerating module at TTF with cavity dipole mode signals  

E-Print Network (OSTI)

Optimization of beam injection into the first accelerating module at TTF with cavity dipole mode signals

Baboi, N; Kreps, G; McCormick, D; Napoly, O; Paparella, R G; Ross, M; Schlarb, H; Smith, T; Wendt, M

2005-01-01T23:59:59.000Z

179

Predicting Deformation of Single Crystal Niobium Using Crystal ...  

Science Conference Proceedings (OSTI)

... Nb. Crystal plasticity models capable of predicting shape changes in single crystal Nb dog bone samples having different orientations have been developed,  ...

180

Design and Development of Superconducting Parallel-Bar Deflecting/Crabbing Cavities  

SciTech Connect

The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties that is being considered for a number of applications. We present the designs of a 499 MHz deflecting cavity developed for the Jefferson Lab 12 GeV Upgrade and a 400 MHz crabbing cavity for the LHC High Luminosity Upgrade. Prototypes of these two cavities are now under development and fabrication.

Payagalage Subashini Uddi De Silva, Jean Delayen

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Quartz crystal growth  

DOE Patents (OSTI)

A process for growing single crystals from an amorphous substance that can undergo phase transformation to the crystalline state in an appropriate solvent. The process is carried out in an autoclave having a lower dissolution zone and an upper crystallization zone between which a temperature differential (.DELTA.T) is maintained at all times. The apparatus loaded with the substance, solvent, and seed crystals is heated slowly maintaining a very low .DELTA.T between the warmer lower zone and cooler upper zone until the amorphous substance is transformed to the crystalline state in the lower zone. The heating rate is then increased to maintain a large .DELTA.T sufficient to increase material transport between the zones and rapid crystallization. .alpha.-Quartz single crystal can thus be made from fused quartz in caustic solvent by heating to 350.degree. C. stepwise with a .DELTA.T of 0.25.degree.-3.degree. C., increasing the .DELTA.T to about 50.degree. C. after the fused quartz has crystallized, and maintaining these conditions until crystal growth in the upper zone is completed.

Baughman, Richard J. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

182

Optimization of the Low Loss SRF Cavity for the ILC  

SciTech Connect

The Low-Loss shape cavity design has been proposed as a possible alternative to the baseline TESLA cavity design for the ILC main linacs. The advantages of this design over the TESLA cavity are its lower cryogenic loss, and higher achievable gradient due to lower surface fields. High gradient prototypes for such designs have been tested at KEK (ICHIRO) and TJNAF (LL). However, issues related to HOM damping and multipacting still need to be addressed. Preliminary numerical studies of the prototype cavities have shown unacceptable damping factors for some higher-order dipole modes if the typical TESLA HOM couplers are directly adapted to the design. The resulting wakefield will dilute the beam emittance thus reducing the machine luminosity. Furthermore, high gradient tests on a 9-cell prototype at KEK have experienced multipacting barriers although a single LL cell had achieved a high gradient. From simulations, multipacting activities are found to occur in the end-groups of the cavity. In this paper, we will present the optimization results of the end-groups for the Low-Loss designs for effective HOM damping and alleviation of multipacting.

Sekutowicz, J.S.; /DESY; Kneisel, P.; /Jefferson Lab; Higo, T.; Morozumi, Y.; Saito, K.; /KEK, Tsukuba; Ge, L.; Ko, Yong-kyu; Lee, L.; Li, Z.; Ng, C.K.; Schussman, G.L.; Xiao, L.; /SLAC

2008-01-18T23:59:59.000Z

183

Lessons learned on closed cavity thermophotovoltaic system efficiency measurements  

DOE Green Energy (OSTI)

Previous efficiency measurements have highlighted that to accurately measure and predict thermophotovoltaic (TPV) integrated cell or array efficiencies, a thorough understanding of the system is required. This includes knowledge of intrinsic diode and filter characteristics, radiative surface properties of all materials used within the cavity, and an intimate knowledge of the radiator/photon source. As a result of these and other lessons learned, the cavity test fixture used in earlier experiments was redesigned. To reduce radiator temperature gradients, the radiator was oversized and thickened, cavity walls were eliminated, the diode heat sink and shielding material were separated, and the cold side was redesigned to incorporate a steady state heat absorbed measurement technique. This redesigned test fixture provides an isothermal radiator and significantly enhances calorimetry capabilities. This newly designed cavity test fixture, in conjunction with the Monte Carlo Photon Transport code RACER-X, was used to improve and demonstrate the understanding of in-cavity TPV diode/module system efficiency testing. A single TPV diode was tested in this new fixture and yielded good agreement between measurements and predictions.

Gethers, C.K.; Ballinger, C.T.; DePoy, D.M. [Lockheed Martin Corp., Schenectady, NY (United States)

1998-10-01T23:59:59.000Z

184

COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS  

Science Conference Proceedings (OSTI)

The transverse focusing effect in RF cavities plays a considerable role in beam dynamics for low-energy beamline sections and can contribute to beam breakup (BBU) instability. The purpose of this analysis is to examine RF cavity models in simulation codes which will be used for BBU experiments at Jefferson Lab and improve BBU simulation results. We review two RF cavity models in the simulation codes elegant and TDBBU (a BBU simulation code developed at Jefferson Lab). elegant can include the Rosenzweig-Serafini (R-S) model for the RF focusing effect. Whereas TDBBU uses a model from the code TRANSPORT which considers the adiabatic damping effect, but not the RF focusing effect. Quantitative comparisons are discussed for the CEBAF beamline. We also compare the R-S model with the results from numerical simulations for a CEBAF-type 5-cell superconducting cavity to validate the use of the R-S model as an improved low-energy RF cavity transport model in TDBBU. We have implemented the R-S model in TDBBU. It will improve BBU simulation results to be more matched with analytic calculations and experimental results.

Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

2011-03-01T23:59:59.000Z

185

Quantum extended crystal PDE's  

E-Print Network (OSTI)

Our recent results on {\\em extended crystal PDE's} are generalized to PDE's in the category $\\mathfrak{Q}_S$ of quantum supermanifolds. Then obstructions to the existence of global quantum smooth solutions for such equations are obtained, by using algebraic topologic techniques. Applications are considered in details to the quantum super Yang-Mills equations. Furthermore, our geometric theory of stability of PDE's and their solutions, is also generalized to quantum extended crystal PDE's. In this way we are able to identify quantum equations where their global solutions are stable at finite times. These results, are also extended to quantum singular (super)PDE's, introducing ({\\em quantum extended crystal singular (super) PDE's}).

Agostino Prástaro

2011-05-01T23:59:59.000Z

186

Tensile tests of niobium material for SRF cavities  

DOE Green Energy (OSTI)

Mechanical tests of cavity-grade niobium samples were conducted to provide engineering information for the certification of 3rd-harmonic superconducting radio-frequency cavities and cryomodules. Large changes of mechanical properties occur throughout the cavity fabrication process due to the cold work introduced by forming, the heating introduced by electron beam welding, and the recovery of cold work during the anneal used to degas hydrogen after chemical processing. Data is provided here to show the different properties at various stages of fabrication, including both weld regions and samples from the bulk niobium far away from the weld. Measurements of RRR were used to assure that any contamination during annealing was negligible.

Wu, G.; Dhanaraj, N.; Cooley, L.; Hicks, D.; Hahn, E.; Burk, D.; Muranyi, W.; Foley, N.; Edwards, H.; Harms, E.; Champion, M.; /Fermilab /Michigan State U.

2009-06-01T23:59:59.000Z

187

Tomographic Analysis of SRF Cavities as Asymmetric Plasma Reactors  

SciTech Connect

The tomographic reconstruction of local plasma parameters for nonequilibrium plasma sources is a developing approach, which has a great potential in understanding the fundamental processes and phenomena during plasma processing of SRF cavity walls. Any type of SRF cavity presents a plasma rector with limited or distorted symmetry and possible presence of high gradients. Development of the tomographic method for SRF plasma analysis consists of several steps. First, we define the method based on the inversion of the Abel integral equation for a hollow spherical reactor. Second step is application of the method for the actual elliptical cavity shape. Third step consists of study of the effects of various shapes of the driven electrode. Final step consists of testing the observed line-integrated optical emission data. We will show the typical results in each step and the final result will be presented in the form of correlation between local plasma parameter distributions and local etching characteristics.

M. Nikoli?, A.L. Godunov, S. Popovi?, A. Samolov, J. Upadhyay, L. Vuškovi?, H.L. Phillips, A-M. Valente-Feliciano

2010-05-01T23:59:59.000Z

188

Beam Fields in an Integrated Cavity, Coupler and Window Configuration  

SciTech Connect

In a multi-bunch high current storage ring, beam generated fields couple strongly into the RF cavity coupler structure when beam arrival times are in resonance with cavity fields. In this study the integrated effect of beam fields over several thousand RF periods is simulated for the complete cavity, coupler, window and waveguide system of the PEP-II B-factory storage ring collider. We show that the beam generated fields at frequencies corresponding to several bunch spacings for this case gives rise to high field strength near the ceramic window which could limit the performance of future high current storage rings such as PEP-X or Super B-factories.

Weathersby, Stephen; Novokhatski, Alexander; /SLAC

2010-02-10T23:59:59.000Z

189

Cirrus Crystal Terminal Velocities  

Science Conference Proceedings (OSTI)

Cirrus crystal terminal velocities are of primary importance in determining the rate of transport of condensate from upper- to middle-tropospheric levels and profoundly influence the earth’s radiation balance through their effect on the rate of ...

Andrew J. Heymsfield; Jean Iaquinta

2000-04-01T23:59:59.000Z

190

Crystals and Plants  

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

Crystals and Plants Crystals and Plants Name: Diab Location: N/A Country: N/A Date: N/A Question: What will the likely effects of crystallized filaments in plant cells be? I had noticed that moth balls (para dichlorbenzene) tends within a very short temperature range to transform from a solid to gas and back to solid in the form of crystal filaments. I been wondering about the likely effects of an experiment in which a plant is placed in a chamber saturated with the fumes of a substance that had the same transformation properties of its state but none of the toxic effects be on the plants and will such filaments form inside the cell and rearrange its DNA strands or kill it outright? Replies: The following might be helpful: http://biowww.clemson.edu/biolab/mitosis.html http://koning.ecsu.ctstateu.edu/Plant_Physiology/osmosis.html

191

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

KOETZLE,T.F.

2001-03-13T23:59:59.000Z

192

Cavity Cooling of a Mechanical Resonator in Amorphous Systems  

E-Print Network (OSTI)

Cavity cooling via quantum back-action force can extract thermal fluctuations from a mechanical resonator to reach the quantum ground state. The two-level system (TLS) defects in the surface of a mechanical resonator couple to the mechanical mode via deformation potential and can affect the cooling process significantly. Here, we develop a theory to study the cavity cooling of a mechanical mode in the presence of a TLS defect using the adiabatic elimination technique. Our result shows that the cooling process depends strongly on the resonance and damping rate of the TLS.

Tian, L

2010-01-01T23:59:59.000Z

193

Multiple density layered insulator  

DOE Patents (OSTI)

A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

Alger, T.W.

1994-09-06T23:59:59.000Z

194

Multiple density layered insulator  

DOE Patents (OSTI)

A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

195

Effects of mode degeneracy in the LIGO Livingston Observatory recycling cavity  

E-Print Network (OSTI)

We analyze the electromagnetic fields in a Pound-Drever-Hall locked, marginally unstable, Fabry-Perot cavity as a function of small changes in the cavity length during resonance. More specifically, we compare the results of a detailed numerical model with the behavior of the recycling cavity of the Laser Interferometer Gravitational-wave Observatory (LIGO) detector that is located in Livingston, Louisiana. In the interferometer's normal mode of operation, the recycling cavity is stabilized by inducing a thermal lens in the cavity mirrors with an external CO2 laser. During the study described here, this thermal compensation system was not operating, causing the cavity to be marginally optically unstable and cavity modes to become degenerate. In contrast to stable optical cavities, the modal content of the resonating beam in the uncompensated recycling cavity is significantly altered by very small cavity length changes. This modifies the error signals used to control the cavity length in such a way that the zero crossing point is no longer the point of maximum power in the cavity nor is it the point where the input beam mode in the cavity is maximized.

Andri M. Gretarsson; Erika D'Ambrosio; Valery Frolov; Brian O'Reilly; Peter K. Fritschel

2007-08-26T23:59:59.000Z

196

Steam exit flow design for aft cavities of an airfoil  

DOE Patents (OSTI)

Turbine stator vane segments have inner and outer walls with vanes extending therebetween. The inner and outer walls have impingement plates. Steam flowing into the outer wall passes through the impingement plate for impingement cooling of the outer wall surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. A skirt or flange structure is provided for shielding the steam cooling impingement holes adjacent the inner wall aerofoil fillet region of the nozzle from the steam flow exiting the aft nozzle cavities. Moreover, the gap between the flash rib boss and the cavity insert is controlled to minimize the flow of post impingement cooling media therebetween. This substantially confines outflow to that exiting via the return channels, thus furthermore minimizing flow in the vicinity of the aerofoil fillet region that may adversely affect impingement cooling thereof.

Storey, James Michael (Clifton Park, NY); Tesh, Stephen William (Simpsonville, SC)

2002-01-01T23:59:59.000Z

197

Coaxial Coupling Scheme for TESLA/ILC-type Cavities  

SciTech Connect

This paper reports about our efforts to develop a flangeable coaxial coupler for both HOM and fundamental coupling for 9-cell TESLA/ILC-type cavities. The cavities were designed in early 90‘s for pulsed operation with a low duty factor, less than 1 %. The proposed design of the coupler has been done in a way, that the magnetic flux B at the flange connection is minimized and only a field of <5 mT would be present at the accelerating field Eacc of ~ 36 MV/m (B =150 mT in the cavity). Even though we achieved reasonably high Q-values at low field, the cavity/coupler combination was limited in the cw mode to only ~ 7 MV/m, where a thermally initiated degradation occurred. We have improved the cooling conditions by initially drilling radial channels every 30 degrees, then every 15 degrees into the shorting plate. The modified prototype performed well up to 9 MV/m in cw mode. This paper reports about our experiences with the further modified coaxial coupler and about test results in cw and low duty cycle pulsed mode, similar to the TESLA/ILC operation conditions.

J.K. Sekutowicz, P. Kneisel

2010-05-01T23:59:59.000Z

198

Optomechanics with molecules in a strongly pumped ring cavity  

E-Print Network (OSTI)

Cavity cooling of an atom works best on a cyclic optical transition in the strong coupling regime near resonance, where small cavity photon numbers suffice for trapping and cooling. Due to the absence of closed transitions a straightforward application to molecules fails: optical pumping can lead the particle into uncoupled states. An alternative operation in the far off-resonant regime generates only very slow cooling due to the reduced field-molecule coupling. We predict to overcome this by using a strongly driven ring-cavity operated in the sideband cooling regime. As in the optomechanical setups one takes advantage of a collectively enhanced field-molecule coupling strength using a large photon number. A linearized analytical treatment confirmed by full numerical quantum simulations predicts fast cooling despite the off-resonant small single molecule - single photon coupling. Even ground state cooling can be obtained by tuning the cavity field close to the Anti-stokes sideband for sufficiently high trapping frequency. Numerical simulations show quantum jumps of the molecules between the lowest two trapping levels, which can be be directly and continuously monitored via scattered light intensity detection.

R. J. Schulze; C. Genes; H. Ritsch

2010-03-02T23:59:59.000Z

199

CAVITY LIKE COMPLETIONS IN WEAK SANDS PREFERRED UPSTREAM MANAGEMENT PRACTICES  

SciTech Connect

The technology referred to as Cavity Like Completions (CLC) offers a new technique to complete wells in friable and unconsolidated sands. A successfully designed CLC provides significant increases in well PI (performance index) at lower costs than alternative completion techniques. CLC technology is being developed and documented by a partnership of major oil and gas companies through a GPRI (Global Petroleum Research Institute) joint venture. Through the DOE-funded PUMP program, the experiences of the members of the joint venture will be described for other oil and gas producing companies. To date six examples of CLC completions have been investigated by the JV. The project was performed to introduce a new type of completion (or recompletion) technique to the industry that, in many cases, offers a more cost effective method to produce oil and gas from friable reservoirs. The project's scope of work included: (1) Further develop theory, laboratory and field data into a unified model to predict performance of cavity completion; (2) Perform at least one well test for cavity completion (well provided by one of the sponsor companies); (3) Provide summary of geo-mechanical models for PI increase; and (4) Develop guidelines to evaluate success of potential cavity completion. The project tracks the experiences of a joint industry consortium (GPRI No. 17) over a three year period and compiles results of the activities of this group.

Ian Palmer; John McLennan

2004-04-30T23:59:59.000Z

200

Cryogenic vertical test facility for the SRF cavities at BNL  

SciTech Connect

A vertical test facility has been constructed to test SRF cavities and can be utilized for other applications. The liquid helium volume for the large vertical dewar is approximate 2.1m tall by 1m diameter with a clearance inner diameter of 0.95m after the inner cold magnetic shield installed. For radiation enclosure, the test dewar is located inside a concrete block structure. The structure is above ground, accessible from the top, and equipped with a retractable concrete roof. A second radiation concrete facility, with ground level access via a labyrinth, is also available for testing smaller cavities in 2 smaller dewars. The cryogenic transfer lines installation between the large vertical test dewar and the cryo plant's sub components is currently near completion. Controls and instrumentations wiring are also nearing completion. The Vertical Test Facility will allow onsite testing of SRF cavities with a maximum overall envelope of 0.9 m diameter and 2.1 m height in the large dewar and smaller SRF cavities and assemblies with a maximum overall envelope of 0.66 m diameter and 1.6 m height.

Than, R.; Liaw, CJ; Porqueddu, R.; Grau, M.; Tuozzolo, J.; Tallerico, T.; McIntyre, G.; Lederle, D.; Ben-Zvi, I.; Burrill, A.; Pate, D.

2011-03-28T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Material-Point Simulation to Cavity Collapse Under Shock  

E-Print Network (OSTI)

The collapse of cavities under shock is a key problem in various fields ranging from erosion of material, ignition of explosive, to sonoluminescence, etc. We study such processes using the material-point-method developed recently in the field of solid physics. The main points of the research include the relations between symmetry of collapsing and the strength of shock, other coexisting interfaces, as well as hydrodynamic and thermal-dynamic behaviors ignored by the pure fluid models. In the case with strong shock, we study the procedure of jet creation in the cavity; in the case with weak shock, we found that the cavity can not be collapsed completely by the shock and the cavity may collapse in a nearly isotropic way. The history of collapsing significantly influences the distribution of "hot spots" in the shocked material. The change in symmetry of collapsing is investigated. Since we use the Mie-Gr% \\"{u}neisen equation of state and the effects of strain rate are not taken into account, the behavior is the same if one magnifies the spatial and temporal scales in the same way.

Aiguo Xu; X. F. Pan; Guangcai Zhang; Jianshi Zhu

2007-06-18T23:59:59.000Z

202

FREEZING WATER CLEANING A POSSIBLE IMPROVEMENT IN SRF CAVITY RINSING*  

E-Print Network (OSTI)

the cavity to be rinsed. Expansion of water in the phase transition to ice can lift particles from the surface and overcome van der Waals forces. Different expansion coefficients of ice and niobium make the ice surface unstable and self- removing. The ice crust falls off together with trapped surface

203

Calibration of the ERL cavity FPC and PU couplers  

Science Conference Proceedings (OSTI)

The performance parameters of a superconducting cavity, notably accelerating field and quality factor, are first obtained in a cryogenic vertical test Dewar, and again after the final assembly in its cryostat. The tests involve Network Analyzer (NA) measurements in which the cavity is excited through an input coupler and the properties are obtained from the reflected signal at the input and the transmitted signal from the output coupler. The interpretation of the scattering coefficients in terms of field strength requires the knowledge of the Fundamental Power Coupler (FPC) and Pick-Up (PU) coupler strength, as expressed by their 'external' and Q{sub FPC} Q{sub PU}. The coupler strength is independent of the field level or cavity losses and thus can be determined at low levels with the scattering coefficients S{sub 11} and S{sub 21}, assuming standard 50 {Omega} terminations in the network analyzer. Also needed is the intrinsic cavity parameter, R{sub a} /Q{sub 0} {triple_bond} {l_brace}R/Q{r_brace}, a quantity independent of field or losses which must be obtained from simulation programs, such as the Microwave Studio.

Hahn, H.; Johnson, E.; Kayran, D.

2010-04-05T23:59:59.000Z

204

Effective cavity pumping from weakly coupled quantum dots  

E-Print Network (OSTI)

We derive the effective cavity pumping and decay rates for the master equation of a quantum dot-microcavity system in presence of $N$ weakly coupled dots. We show that the in-flow of photons is not linked to the out-flow by thermal equilibrium relationships.

del Valle, E

2010-01-01T23:59:59.000Z

205

Power efficiency for very high temperature solar thermal cavity receivers  

DOE Patents (OSTI)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatures are attained.

McDougal, Allan R. (LaCanada-Flintridge, CA); Hale, Robert R. (Upland, CA)

1984-01-01T23:59:59.000Z

206

Four cavity efficiency enhanced magnetically insulated line oscillator  

SciTech Connect

A four cavity, efficient magnetically insulated line oscillator (C4-E MILO) having seven vanes and six cavities formed within a tube-like structure surrounding a cathode. The C4-E MILO has a primary slow wave structure which is comprised of four vanes and the four cavities located near a microwave exit end of the tube-like structure. The primary slow wave structure is the four cavity (C4) portion of the magnetically insulated line oscillator (MILO). An RF choke is provided which is comprised of three of the vanes and two of the cavities. The RF choke is located near a pulsed power source portion of the tube-like structure surrounding the cathode. The RF choke increases feedback in the primary slow wave structure, prevents microwaves generated in the primary slow wave structure from propagating towards the pulsed power source and modifies downstream electron current so as to enhance microwave power generation. A beam dump/extractor is located at the exit end of the oscillator tube for extracting microwave power from the oscillator, and in conjunction with an RF extractor vane, which comprises the fourth vane of the primary slow wave structure (nearest the exit) having a larger gap radius than the other vanes of the primary SWS, comprises an RF extractor. Uninsulated electron flow is returned downstream towards the exit along an anode/beam dump region located between the beam dump/extractor and the exit where the RF is radiated at said RF extractor vane located near the exit and the uninsulated electron flow is disposed at the beam dump/extractor.

Lemke, Raymond W. (Albuquerque, NM); Clark, Miles C. (Albuquerque, NM); Calico, Steve E. (Albuquerque, NM)

1998-04-21T23:59:59.000Z

207

Four cavity efficiency enhanced magnetically insulated line oscillator  

DOE Patents (OSTI)

A four cavity, efficient magnetically insulated line oscillator (C4-E MILO) having seven vanes and six cavities formed within a tube-like structure surrounding a cathode is disclosed. The C4-E MILO has a primary slow wave structure which is comprised of four vanes and the four cavities located near a microwave exit end of the tube-like structure. The primary slow wave structure is the four cavity portion of the magnetically insulated line oscillator (MILO). An RF choke is provided which is comprised of three of the vanes and two of the cavities. The RF choke is located near a pulsed power source portion of the tube-like structure surrounding the cathode. The RF choke increases feedback in the primary slow wave structure, prevents microwaves generated in the primary slow wave structure from propagating towards the pulsed power source and modifies downstream electron current so as to enhance microwave power generation. A beam dump/extractor is located at the exit end of the oscillator tube for extracting microwave power from the oscillator, and in conjunction with an RF extractor vane, which comprises the fourth vane of the primary slow wave structure (nearest the exit) having a larger gap radius than the other vanes of the primary SWS, comprises an RF extractor. Uninsulated electron flow is returned downstream towards the exit along an anode/beam dump region located between the beam dump/extractor and the exit where the RF is radiated at said RF extractor vane located near the exit and the uninsulated electron flow is disposed at the beam dump/extractor. 34 figs.

Lemke, R.W.; Clark, M.C.; Calico, S.E.

1998-04-21T23:59:59.000Z

208

RF, Thermal and Structural Analysis of the 201.25 MHz Muon Ionization Cooling Cavity  

E-Print Network (OSTI)

THERMAL AND STRUCTURAL ANALYSIS OF THE 201.25 MHZ MUON IONIZATION COOLINGthe thermal performance of the cavity, including the coolingthermal and structural behavior of the prototype 201.25 MHz cavity for a muon ionization cooling

Virostek, S.; Li, D.

2005-01-01T23:59:59.000Z

209

Photothermal nano-cavities for ultra-sensitive chem-bio detection  

E-Print Network (OSTI)

Nano-cavity photothermal spectroscopy is a novel technique for ultra-sensitive chem-bio detection. We illustrate that through simultaneous localization of optical and thermal interactions in a planar nano-cavity, detection ...

Hu, Juejun

210

Numerical Investigation of Turbulent Natural Convection in Differentially Heated Square Cavities  

Science Conference Proceedings (OSTI)

This paper deals with the numerical simulation of turbulent natural convection in cavities heated from the side. Three cases are considered: an air?filled square cavity of size 0.75 m

Sonja Schmelter; Gert Lindner; Gudrun Wendt; Regine Model

2011-01-01T23:59:59.000Z

211

Progress on the high-current 704 MHz superconducting RF cavity at BNL  

Science Conference Proceedings (OSTI)

The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups and results for the copper prototype. The progress with the niobium cavity fabrication will also be described.

Xu W.; Astefanous, C.; Belomestnykh, S.; Ben-Zvi, I.; et al

2012-05-20T23:59:59.000Z

212

Multiple piece turbine engine airfoil with a structural spar  

DOE Patents (OSTI)

A multiple piece turbine airfoil having an outer shell with an airfoil tip that is attached to a root with an internal structural spar is disclosed. The root may be formed from first and second sections that include an internal cavity configured to receive and secure the one or more components forming the generally elongated airfoil. The internal structural spar may be attached to an airfoil tip and place the generally elongated airfoil in compression. The configuration enables each component to be formed from different materials to reduce the cost of the materials and to optimize the choice of material for each component.

Vance, Steven J. (Orlando, FL)

2011-10-11T23:59:59.000Z

213

The Ties that Bind Metals to Proteins | Advanced Photon Source  

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

Nanobio Catalyst for Biofuels Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and Coherence An Intriguing Twist in the Structure of a Cobalt Oxide Catalyst Breaking...

214

Dynamics of Polymer Chains Atop Different Materials | Advanced...  

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

Tuberculosis The Ties that Bind Metals to Proteins A Novel Nanobio Catalyst for Biofuels Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and Coherence An...

215

Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN-05-107)  

Scientists at Argonne National Laboratory have created innovations in the design and fabrication of radio frequency (RF) cavities that improve ...

216

Multiple shell fusion targets  

DOE Patents (OSTI)

Multiple shell fusion targets for use with electron beam and ion beam implosion systems are described. The multiple shell targets are of the low-power type and use a separate relatively low Z, low density ablator at large radius for the outer shell, which reduces the focusing and power requirements of the implosion system while maintaining reasonable aspect ratios. The targets use a high Z, high density pusher shell placed at a much smaller radius in order to obtain an aspect ratio small enough to protect against fluid instability. Velocity multiplication between these shells further lowers the power requirements. Careful tuning of the power profile and intershell density results in a low entropy implosion which allows breakeven at low powers. For example, with ion beams as a power source, breakeven at 10-20 Terrawatts with 10 MeV alpha particles for imploding a multiple shell target can be accomplished.

Lindl, J.D.; Bangerter, R.O.

1975-10-31T23:59:59.000Z

217

Photovoltaics: Separating Multiple Excitons  

Science Conference Proceedings (OSTI)

Scientists have demonstrated an efficient process for generating multiple excitons in adjacent silicon nanocrystals from a single high-energy photon. Their findings could prove useful for a wide range of photovoltaic applications.

Nozik, A. J.

2012-05-01T23:59:59.000Z

218

Learning from Multiple Outlooks  

E-Print Network (OSTI)

We consider semi-supervised learning from multiple outlooks of the same learning task, that is, learning from different representations of the same type of data. As opposed to learning from multiple views where it is assumed that the exact same instances have multiple representations, we only assume the availability of samples of the same learning task in different domains. We develop an algorithmic framework that is based on mapping the (unlabeled) data followed by adjusting the mapping using the scarcer labeled data. The mapped data from all the outlooks can then be used for a generic classification algorithm. We further provide sample complexity results under the assumption that the different outlooks are inherently low dimension Gaussian mixtures. Experiments with real-world data indicate the performance boost from using multiple outlooks.

Gal-on, Maayan

2010-01-01T23:59:59.000Z

219

Crystallization of Lipids, Nucleation to Application  

Science Conference Proceedings (OSTI)

Archive of Crystallization of Lipids, Nucleation to Application Crystallization of Lipids, Nucleation to Application Toronto, Canada Crystallization of Lipids, Nucleation to Application ...

220

Multiple stage multiple filter hydrate store  

DOE Patents (OSTI)

An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means for separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means. 7 figs.

Bjorkman, H.K. Jr.

1983-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Study of etching rate uniformity in SRF cavities  

Science Conference Proceedings (OSTI)

Plasma based surface modification is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. The crucial aspect of the technology development is dependence of the etching rate and surface roughness on the frequency of the power supply, pressure, power level, driven electrode shape and chlorine concentration in the gas mixture during plasma processing. To optimize the plasma parameters, we are using a single cell cavity with 20 sample holders symmetrically distributed over the cell. These holders are used as diagnostic ports for the measurement of the plasma parameters and as holders for the samples to be etched. The plasma properties are highly correlated with the shape of the driven electrode and chlorine concentration in the Argon/Chlorine gas mixtures.

Janardan Upadhyay, Svetozar Popovic, Leposova Vuskovic, H. Phillips, Anne-Marie Valente

2012-07-01T23:59:59.000Z

222

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

Science Conference Proceedings (OSTI)

Design, analysis, and low-power tests are described on a ferroelectric tuner concept that could be used for controlling external coupling to RF cavities for the superconducting Energy Recovery Linac (ERL) in the electron cooler of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The tuner configuration utilizes several small donut-shaped ferroelectric assemblies, which allow the design to be simpler and more flexible, as compared to previous designs. Design parameters for 704 and 1300 MHz versions of the tuner are given. Simulation results point to efficient performance that could reduce by a factor-of-ten the RF power levels required for driving superconducting cavities in the BNL ERL.

Jay L. Hirshfield

2012-07-03T23:59:59.000Z

223

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

Science Conference Proceedings (OSTI)

Analysis and modeling is presented for a fast microwave tuner to operate at 700 MHz which incorporates ferroelectric elements whose dielectric permittivity can be rapidly altered by application of an external voltage. This tuner could be used to correct unavoidable fluctuations in the resonant frequency of superconducting cavities in accelerator structures, thereby greatly reducing the RF power needed to drive the cavities. A planar test version of the tuner has been tested at low levels of RF power, but at 1300 MHz to minimize the physical size of the test structure. This test version comprises one-third of the final version. The tests show performance in good agreement with simulations, but with losses in the ferroelectric elements that are too large for practical use, and with issues in bonding of ferroelectric elements to the metal walls of the tuner structure.

Jay L. Hirshfield

2011-03-01T23:59:59.000Z

224

High power tests of dressed supconducting 1.3 GHz RF cavities  

SciTech Connect

A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted ('dressed') with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

Hocker, A.; Harms, E.R.; Lunin, A.; Sukhanov, A.; /Fermilab

2011-03-01T23:59:59.000Z

225

Fabrication of a Demountable TM{sub 020} Cavity from Large Grain Ingot Methods  

Science Conference Proceedings (OSTI)

A novel TM{sub 020} demountable test cavity has been fabricated by the Spallation Neutron Source (SNS) from large grain niobium ingot sheets. This TM{sub 020} cavity is designed to have a demountable test plate at the base of the cavity to allow for measuring RF properties as well as performing surface science analysis in an aim to develop plasma processing as a cleaning method for niobium cavities. Large grain ingot sheet fabrication methods were chosen to reduce the cost of the cavity and to produce smooth surfaces at high electric field locations with standard chemistry techniques, i.e. buffered chemical polish.

Mammosser, John [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Kim, Sang-Ho [Oak Ridge National Lab, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States)

2011-03-31T23:59:59.000Z

226

Photon - Axion Conversion Cross Sections in a Resonant Cavity  

E-Print Network (OSTI)

Photon - axion conversions in the resonant cavity with the lowest mode are considered in detail by the Feynman diagram method. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process, in which the conversion cross sections are much larger than those of the wave guide in the same conditions. Some estimates for experimental conditions are given from our results.

Dang Van Soa; Hoang Ngoc Long; Le Nhu Thuc

2006-11-20T23:59:59.000Z

227

Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications  

SciTech Connect

Laser-produced plasmas have many applications for which detailed characterization of the plume is requested. Cavity ring-down spectroscopy is a versatile absorption method which provides data on the plume and its surroundings, with spatial and temporal resolution. The measured absorption line shapes contain information about angular and velocity distributions within the plume. In various plasmas we have observed molecules or metastable atoms which were not present in the emission spectra.

Milosevic, S. [Institute of Physics, Zagreb (Croatia)

2012-05-25T23:59:59.000Z

228

TPV efficiency measurements and predictions for a closed cavity geometry  

DOE Green Energy (OSTI)

A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry effects. The overall efficiency of the TPV device is controlled by the TP cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4 x 4 configuration) in a cavity geometry. The first code, subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell electrical output performance predictions (assuming infinite parallel plates). The second code, utilizes a Monte Carlo Photon Transport code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays were fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F.

1997-05-01T23:59:59.000Z

229

TPV efficiency predictions and measurements for a closed cavity geometry  

DOE Green Energy (OSTI)

A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry affects. The overall efficiency of the TPV device is controlled by the TPV cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4x4 configuration) in a cavity geometry. The first code subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell performance predictions (assuming infinite parallel plates). The second utilizes a Monte Carlo Ray-Tracing code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays are fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

230

Development of a superconducting connection for niobium cavities  

Science Conference Proceedings (OSTI)

Several, partially successful attempts have been made in the past to develop a superconducting connection between adjacent niobium cavities with the capability to carry up to 30 mT of the magnetic flux. Such a connection would be particularly of great benefit to layouts of long accelerators like ILC because it would shorten the distances between structures and therefore the total length of an accelerator with the associated cost reductions. In addition the superconducting connection would be ideal for a super-structure – two multi-cell cavities connected through a half wavelength long beam pipe providing the coupling. Two welded prototypes of super-structure have been successfully tested with the beam at DESY. The chemical treatment and water rinsing was rather complicated for these prototypes because of the length of the assembly. We have engaged in a program to develop such a connection, initially based on the Nb55Ti material. Several options are pursued such as e.g. a two-cell cavity is being used to explore the reachable magnetic flux for the TESLA like connection with a squeezed niobium gasket between the flanges. Other materials, such as NbZr or NbN are also being considered. In this contribution, we will report about the progress of our investigations.

Peter Kneisel; Gianluigi Ciovati; Jacek Sekutowicz; Waldemar Singer; Xenia Singer; Axel Matheisen

2007-06-18T23:59:59.000Z

231

Development of a superconducting connection for niobium cavities  

Science Conference Proceedings (OSTI)

Several, partially successful attempts have been made in the past to develop a superconducting connection between adjacent niobium cavities with the capability to carry up to 30 mT of the magnetic flux. Such a connection would be particularly of great benefit to layouts of long accelerators like ILC because it would shorten the distances between structures and therefore the total length of an accelerator with the associated cost reductions. In addition the superconducting connection would be ideal for a super-structure – two multi-cell cavities connected through a half wavelength long beam pipe providing the coupling. Two welded prototypes of super-structure have been successfully tested with the beam at DESY. The chemical treatment and water rinsing was rather complicated for these prototypes because of the length of the assembly. We have engaged in a program to develop such a connection, initially based on the Nb55Ti material. Several options are pursued such as e.g. a two-cell cavity is being used to explore the reachable magnetic flux for the TESLA like connection with a squeezed niobium gasket between the flanges. Other materials, such as NbZr or NbN are also being considered. In this contribution, we will report about the progress of our investigations.

Peter Kneisel; Gianluigi Ciovati; Jacek Sekutowicz; Waldemar Singer; Xenia Singer; Axel Matheisen

2007-06-22T23:59:59.000Z

232

Dual-etalon, cavity-ring-down, frequency comb spectroscopy.  

Science Conference Proceedings (OSTI)

The 'dual etalon frequency comb spectrometer' is a novel low cost spectometer with limited moving parts. A broad band light source (pulsed laser, LED, lamp ...) is split into two beam paths. One travels through an etalon and a sample gas, while the second arm is just an etalon cavity, and the two beams are recombined onto a single detector. If the free spectral ranges (FSR) of the two cavities are not identical, the intensity pattern at the detector with consist of a series of heterodyne frequencies. Each mode out of the sample arm etalon with have a unique frequency in RF (radio-frequency) range, where modern electronics can easily record the signals. By monitoring these RF beat frequencies we can then determine when an optical frequencies is absorbed. The resolution is set by the FSR of the cavity, typically 10 MHz, with a bandwidth up to 100s of cm{sup -1}. In this report, the new spectrometer is described in detail and demonstration experiments on Iodine absorption are carried out. Further we discuss powerful potential next generation steps to developing this into a point sensor for monitoring combustion by-products, environmental pollutants, and warfare agents.

Strecker, Kevin E.; Chandler, David W.

2010-10-01T23:59:59.000Z

233

Cavity Beam Position Monitor System for ATF2  

SciTech Connect

The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 38 C and S band resonant cavity beam position monitors (CBPM) with associated mixer electronics and digitizers. The current status of the BPM system is described, with a focus on operational techniques and performance. The ATF2 C-band system is performing well, with individual CBPM resolution approaching or at the design resolution of 50 nm. The changes in the CBPM calibration observed over three weeks can probably be attributed to thermal effects on the mixer electronics systems. The CW calibration tone power will be upgraded to monitor changes in the electronics gain and phase. The four S-band CBPMs are still to be investigated, the main problem associated with these cavities is a large cross coupling between the x and y ports. This combined with the large design dispersion in that degion makes the digital signal processing difficult, although various techniques exist to determine the cavity parameters and use these coupled signals for beam position determination.

Boogert, Stewart; /Oxford U., JAI; Boorman, Gary; /Oxford U., JAI; Swinson, Christina; /Oxford U., JAI; Ainsworth, Robert; /Royal Holloway, U. of London; Molloy, Stephen; /Royal Holloway, U. of London; Aryshev, Alexander; /KEK, Tsukuba; Honda, Yosuke; /KEK, Tsukuba; Tauchi, Toshiaki; /KEK, Tsukuba; Terunuma, Nobuhiro; /KEK, Tsukuba; Urakawa, Junji; /KEK, Tsukuba; Frisch, Josef; /SLAC; May, Justin; /SLAC; McCormick, Douglas; /SLAC; Nelson, Janice; /SLAC; Smith, Tonee; /SLAC; White, Glen; /SLAC; Woodley, Mark; /SLAC; Heo, Ae-young; /Kyungpook Natl. U.; Kim, Eun-San; /Kyungpook Natl. U.; Kim, Hyoung-Suk; /Kyungpook Natl. U.; Kim, Youngim; /Kyungpook Natl. U. /University Coll. London /Kyungpook Natl. U. /Fermilab /Pohang Accelerator Lab.

2012-07-09T23:59:59.000Z

234

FOURIER TRANSFORM MULTIPLE QUANTUM NMR  

E-Print Network (OSTI)

TRANSFORM MULTIPLE QUANTUM NMR G. Drobny, A. Pines, S.TRANSFO~~ MULTIPLE QUANTUM NMR G. Drobny, A. Pines, S.

Drobny, G.

2011-01-01T23:59:59.000Z

235

Method for determining hydrogen mobility as a function of temperature in superconducting niobium cavities  

DOE Patents (OSTI)

A method for determining the mobility of hydrogen as a function of temperature in superconducting niobium cavities comprising: 1) heating a cavity under test to remove free hydrogen; 2) introducing hydrogen-3 gas into the cavity; 3) cooling the cavity to allow absorption of hydrogen-3; and 4) measuring the amount of hydrogen-3 by: a) cooling the cavity to about 4.degree. K while flowing a known and regulated amount of inert carrier gas such as argon or helium into the cavity; b) allowing the cavity to warm at a stable rate from 4.degree. K to room temperature as it leaves the chamber; and c) directing the exit gas to an ion chamber radiation detector.

May, Robert (Virginia Beach, VA)

2008-03-11T23:59:59.000Z

236

Collapses of underground cavities and soil-structure interactions: influences of the position of the structure relative to the cavity  

E-Print Network (OSTI)

This paper is focused on soil subsidence of small extend and amplitude caused by tunnel boring or the collapse of underground cavities, whether natural or man-made. The impact of the movements of the ground on existing structures is generally dramatic. It is therefore necessary to accurately predict these movements (settlements and horizontal extension or compression displacements). Even though it is obvious that the overall stiffness and weight of the structure influences the size and shape of the soil movement, the main features of this soil-structure interaction phenomenon are not well established. Caudron et al. (2006) developed an original small-scale physical model to take the soil-structure interaction into account. It is based on the use of the frictional Schneebeli material (assembly of small diameter rods) and a modified version including cohesion in order to reproduce a cohesive layer above a cavity. The displacements of the soil are obtained from digital images processing by particle image velocim...

Caudron, Matthieu; Emeriault, Fabrice

2008-01-01T23:59:59.000Z

237

Silicon crystal growing by oscillating crucible technique  

DOE Patents (OSTI)

A process for growing silicon crystals from a molten melt comprising oscillating the container during crystal growth is disclosed.

Schwuttke, G.H.; Kim, K.M.; Smetana, P.

1983-08-03T23:59:59.000Z

238

Hydrodynamic sweepout thresholds in BWR Mark III reactor cavity interactions  

DOE Green Energy (OSTI)

Simulant-material experiments and related analysis are described which investigated hydrodynamics aspects of ex-vessel interactions following postulated core meltdown with subsequent meltthrough of the vessel lower head and ejection of molten corium from the vessel into the containment region beneath the vessel. Objectives were to examine the possible sweepout of water and corium from the cavity by the steam/H/sub 2/ flow. The dispersal pathways in this containment design include a single manway and four CRD penetrations in the cylindrical pedestal wall connecting to the drywell with a combined cross-sectional area of approx. 10 m/sup 2/. These openings range from 3.4 to 6.3 m in elevation off the concrete floor of the cavity. The experiments were performed using a 1:34 scale mock-up of the RPV/pedestal region. The first tests were quasi-steady tests. Tests were also performed using molten Wood's metal (WM). Some tests were performed with water on the cavity floor, and one test was performed using steel shot. The test results indicated that threshold gas flowrates existed beyond which dispersal of water and/or corium from the cavity can be expected. The predominant dispersal flow regime observed in the experiments involved fluidization of the water or molten WM by the gas flowrate through the system and sweepout of the fluidized liquid droplets as the gas exited the cavity through the openings in the wall. The superficial gas velocity at the onset of water sweepout ranged from 0.87 to 1.04 m/s in the tests which agrees very closely to the calculated fluidization threshold of 0.96 m/s. Application of the fluidization model for prediction of sweepout for the full-size system suggests that sweepout of water and corium can occur if the breach size in the RPV lower head exceeds approx. 10 and 17 cm dia, respectively, for steam blowdown at a vessel initial pressure of 1000 psi.

Spencer, B.W.; Baronowsky, S.P.; Kilsdonk, D.J.

1984-04-01T23:59:59.000Z

239

Plenum type crystal growth chamber  

DOE Patents (OSTI)

Crystals are grown in a tank which is divided by a baffle into a crystal growth region above the baffle and a plenum region below the baffle. A turbine blade or stirring wheel is positioned in a turbine tube which extends through the baffle to generate a flow of solution from the crystal growing region to the plenum region. The solution is pressurized as it flows into the plenum region. The pressurized solution flows back to the crystal growing region through return flow tubes extending through the baffle. Growing crystals are positioned near the ends of the return flow tubes to receive a direct flow of solution.

Montgomery, K.E.

1990-12-31T23:59:59.000Z

240

Cracks Cleave Crystals  

E-Print Network (OSTI)

The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provide here a specific case where this rule fails. The example is of a crack in a crystal. It fractures along a crystal plane, rather than in the direction normally predicted to release the most energy. Thus, a correct equation of motion for brittle cracks must take into account both energy flows that are described in conventional continuum theories and details of the environment near the tip that are not.

Michael Marder

2004-03-05T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Multiple sort flow cytometer  

DOE Patents (OSTI)

A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane.

Van den Engh, Ger (Seattle, WA); Esposito, Richard J. (Seattle, WA)

1996-01-01T23:59:59.000Z

242

Radionuclide Partitioning in an Underground Nuclear Test Cavity  

SciTech Connect

In 2004, a borehole was drilled into the 1983 Chancellor underground nuclear test cavity to investigate the distribution of radionuclides within the cavity. Sidewall core samples were collected from a range of depths within the re-entry hole and two sidetrack holes. Upon completion of drilling, casing was installed and a submersible pump was used to collect groundwater samples. Test debris and groundwater samples were analyzed for a variety of radionuclides including the fission products {sup 99}Tc, {sup 125}Sb, {sup 129}I, {sup 137}Cs, and {sup 155}Eu, the activation products {sup 60}Co, {sup 152}Eu, and {sup 154}Eu, and the actinides U, Pu, and Am. In addition, the physical and bulk chemical properties of the test debris were characterized using Scanning Electron Microscopy (SEM) and Electron Microprobe measurements. Analytical results were used to evaluate the partitioning of radionuclides between the melt glass, rubble, and groundwater phases in the Chancellor test cavity. Three comparative approaches were used to calculate partitioning values, though each method could not be applied to every nuclide. These approaches are based on: (1) the average Area 19 inventory from Bowen et al. (2001); (2) melt glass, rubble, and groundwater mass estimates from Zhao et al. (2008); and (3) fission product mass yield data from England and Rider (1994). The U and Pu analyses of the test debris are classified and partitioning estimates for these elements were calculated directly from the classified Miller et al. (2002) inventory for the Chancellor test. The partitioning results from this study were compared to partitioning data that were previously published by the IAEA (1998). Predictions of radionuclide distributions from the two studies are in agreement for a majority of the nuclides under consideration. Substantial differences were noted in the partitioning values for {sup 99}Tc, {sup 125}Sb, {sup 129}I, and uranium. These differences are attributable to two factors: chemical volatility effects that occur during the initial plasma condensation, and groundwater remobilization that occurs over a much longer time frame. Fission product partitioning is very sensitive to the early cooling history of the test cavity because the decay of short-lived (t{sub 1/2} < 1 hour) fission-chain precursors occurs on the same time scale as melt glass condensation. Fission product chains that include both volatile and refractory elements, like the mass 99, 125, and 129 chains, can show large variations in partitioning behavior depending on the cooling history of the cavity. Uranium exhibits similar behavior, though the chemical processes are poorly understood. The water temperature within the Chancellor cavity remains elevated (75 C) more than two decades after the test. Under hydrothermal conditions, high solubility chemical species such as {sup 125}Sb and {sup 129}I are readily dissolved and transported in solution. SEM analyses of melt glass samples show clear evidence of glass dissolution and secondary hydrothermal mineral deposition. Remobilization of {sup 99}Tc is also expected during hydrothermal activity, but moderately reducing conditions within the Chancellor cavity appear to limit the transport of {sup 99}Tc. It is recommended that the results from this study should be used together with the IAEA data to update the range in partitioning values for contaminant transport models at the Nevada National Security Site (formerly known as the Nevada Test Site).

Rose, T P; Hu, Q; Zhao, P; Conrado, C L; Dickerson, R; Eaton, G F; Kersting, A B; Moran, J E; Nimz, G; Powell, B A; Ramon, E C; Ryerson, F J; Williams, R W; Wooddy, P T; Zavarin, M

2009-01-09T23:59:59.000Z

243

V-094: IBM Multiple Products Multiple Vulnerabilities | Department of  

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

94: IBM Multiple Products Multiple Vulnerabilities 94: IBM Multiple Products Multiple Vulnerabilities V-094: IBM Multiple Products Multiple Vulnerabilities February 19, 2013 - 1:41am Addthis PROBLEM: IBM Multiple Products Multiple Vulnerabilities PLATFORM: IBM Maximo Asset Management versions 7.5, 7.1, and 6.2 IBM Maximo Asset Management Essentials versions 7.5, 7.1, and 6.2 IBM SmartCloud Control Desk version 7.5 IBM Tivoli Asset Management for IT versions 7.2, 7.1, and 6.2 IBM Tivoli Change and Configuration Management Database versions 7.2 and 7.1 IBM Tivoli Service Request Manager versions 7.2, 7.1, and 6.2 ABSTRACT: A weakness and multiple vulnerabilities have been reported in multiple IBM products. REFERENCE LINKS: IBM Reference #:1625624 IBM Product Security Incident Response Blog Secunia Advisory SA52132

244

Qualification of the Second Batch Production 9-Cell Cavities Manufactured by AES and Validation of the First US Industrial Cavity Vendor for ILC  

SciTech Connect

One of the major goals of ILC SRF cavity R&D is to develop industrial capabilities of cavity manufacture and processing in all three regions. In the past several years, Jefferson Lab, in collaboration with Fermi National Accelerator Laboratory, has processed and tested all the 9-cell cavities of the first batch (4 cavities) and second batch (6 cavities) production cavities manufactured by Advanced Energy Systems Inc. (AES). Over the course, close information feedback was maintained, resulting in changes in fabrication and processing procedures. A light buffered chemical polishing was introduced, removing the weld splatters that could not be effectively removed by heavy EP alone. An 800 Celsius 2 hour vacuum furnace heat treatment procedure replaced the original 600 Celsius 10 hour procedure. Four out of the six 9-cell cavities of the second production bath achieved a gradient of 36-41 MV/m at a Q0 of more than 8·109 at 35 MV/m. This result validated AES as the first “ILC certified” industrial vendor in the US for ILC cavity manufacture.

Geng, R L; Golden, B A; Kushnick, P; Overton, R B; Calderaro, M; Peterson, E; Rathke, J; Champion, M S; Follkie, J

2011-07-01T23:59:59.000Z

245

Multiple gap photovoltaic device  

DOE Patents (OSTI)

A multiple gap photovoltaic device having a transparent electrical contact adjacent a first cell which in turn is adjacent a second cell on an opaque electrical contact, includes utilizing an amorphous semiconductor as the first cell and a crystalline semiconductor as the second cell.

Dalal, Vikram L. (Newark, DE)

1981-01-01T23:59:59.000Z

246

Fabrication of a Demountable TM020 Cavity from Large Grain Ingot Methods  

Science Conference Proceedings (OSTI)

A novel TM020 demountable test cavity has been fabricated by the Spallation Neutron Source (SNS) from large grain niobium ingot sheets. This TM020 cavity is designed to have a demountable test plate at the base of the cavity to allow for measuring RF properties as well as performing surface science analysis in an aim to develop plasma processing as a cleaning method for niobium cavities. Large grain ingot sheet fabrication methods were chosen to reduce the cost of the cavity and to produce smooth surfaces at high electric field locations with standard chemistry techniques, i.e. buffered chemical polish. A novel TM020 demountable test cavity has been fabricated by the Spallation Neutron Source (SNS) from large grain niobium ingot sheets. This TM020 cavity is designed to have a demountable test plate at the base of the cavity to allow for measuring RF properties as well as performing surface science analysis in an aim to develop plasma processing as a cleaning method for niobium cavities. Large grain ingot sheet fabrication methods were chosen to reduce the cost of the cavity and to produce smooth surfaces at high electric field locations with standard chemistry techniques, i.e. buffered chemical polish.

John Mammosser, Sang-Ho Kim

2011-03-01T23:59:59.000Z

247

Fast 704 MHz Ferroelectric Tuner for Superconducting Cavities  

SciTech Connect

The Omega-P SBIR project described in this Report has as its goal the development, test, and evaluation of a fast electrically-controlled L-band tuner for BNL Energy Recovery Linac (ERL) in the Electron Ion Collider (EIC) upgrade of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The tuner, that employs an electrically-controlled ferroelectric component, is to allow fast compensation to cavity resonance changes. In ERLs, there are several factors which significantly affect the amount of power required from the wall-plug to provide the RF-power level necessary for the operation. When beam loading is small, the power requirements are determined by (i) ohmic losses in cavity walls, (ii) fluctuations in amplitude and/or phase for beam currents, and (iii) microphonics. These factors typically require a substantial change in the coupling between the cavity and the feeding line, which results in an intentional broadening of the cavity bandwidth, which in turn demands a significant amount of additional RF power. If beam loading is not small, there is a variety of beam-drive phase instabilities to be managed, and microphonics will still remain an issue, so there remain requirements for additional power. Moreover ERL performance is sensitive to changes in beam arrival time, since any such change is equivalent to phase instability with its vigorous demands for additional power. In this Report, we describe the new modular coaxial tuner, with specifications suitable for the 704 MHz ERL application. The device would allow changing the RF-coupling during the cavity filling process in order to effect significant RF power savings, and also will provide rapid compensation for beam imbalance and allow for fast stabilization against phase fluctuations caused by microphonics, beam-driven instabilities, etc. The tuner is predicted to allow a reduction of about ten times in the required power from the RF source, as compared to a compensation system with narrower bandwidth. It is planned to build a 704 MHz version of the tuner, to check its underlying principles, and to make high-power tests at power densities aimed towards controlling 50 kW of average power. Steps towards this goal will be limited by, among other factors, losses in the actual ferroelectric elements in the ferroelectric assemblies. As the ferroelectric material loss tangent is reduced through efforts by the supplier Euclid TechLabs LLC, the concomitant power loss in its ferroelectric assemblies will drop, and the average power-handling capability of the Omega-P tuner will rise. It can thus be anticipated that the Phase II development project of the 704 MHz tuner will be iterative, but the pace and ultimate power-handling level of the tuner is difficult to predict at this early stage in Euclid's development program. Fortunately, since Omega-P's conceptual tuner is a simple module (nominally rated for 5 kW), so that the number of modules required in each tuner can be chosen, depending upon the cavity power level needed, plus the power for tuner losses.

Jay L. Hirshfield

2012-04-12T23:59:59.000Z

248

A Single Atom as a Mirror of an Optical Cavity  

E-Print Network (OSTI)

By tightly focussing a laser field onto a single cold ion trapped in front of a far-distant dielectric mirror, we could observe a quantum electrodynamic effect whereby the ion behaves as the optical mirror of a Fabry-P\\'erot cavity. We show that the amplitude of the laser field is significantly altered due to a modification of the electromagnetic mode structure around the atom in a novel regime in which the laser intensity is already changed by the atom alone. e propose a direct application of this system as a quantum memory for single photons.

G. Hétet; L. Slodi?ka; M. Hennrich; R. Blatt

2011-05-10T23:59:59.000Z

249

Photovoltaic Probe of Cavity Polaritons in a Quantum Cascade Structure  

E-Print Network (OSTI)

The strong coupling between an intersubband excitation in a quantum cascade structure and a photonic mode of a planar microcavity has been detected by angle-resolved photovoltaic measurements. A typical anticrossing behavior, with a vacuum-field Rabi splitting of 16 meV at 78K, has been measured, for an intersubband transition at 163 meV. These results show that the strong coupling regime between photons and intersubband excitations can be engineered in a quantum cascade opto-electronic device. They also demonstrate the possibility to perform angle-resolved mid-infrared photodetection and to develop active devices based on intersubband cavity polaritons.

Luca Sapienza; Raffaele Colombelli; Angela Vasanelli; Cristiano Ciuti; Christophe Manquest; Ulf Gennser; Carlo Sirtori

2007-03-07T23:59:59.000Z

250

Combination ring cavity and backward Raman waveguide amplifier  

DOE Patents (OSTI)

A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO/sub 2/ laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO/sub 2/ laser pump signal for conversion to Stokes radiation.

Kurnit, N.A.

1981-03-13T23:59:59.000Z

251

Radionuclide Partitioning in an Underground Nuclear Test Cavity  

Science Conference Proceedings (OSTI)

In 2004, a borehole was drilled into the 1983 Chancellor underground nuclear test cavity to investigate the distribution of radionuclides within the cavity. Sidewall core samples were collected from a range of depths within the re-entry hole and two sidetrack holes. Upon completion of drilling, casing was installed and a submersible pump was used to collect groundwater samples. Test debris and groundwater samples were analyzed for a variety of radionuclides including the fission products {sup 99}Tc, {sup 125}Sb, {sup 129}I, {sup 137}Cs, and {sup 155}Eu, the activation products {sup 60}Co, {sup 152}Eu, and {sup 154}Eu, and the actinides U, Pu, and Am. In addition, the physical and bulk chemical properties of the test debris were characterized using Scanning Electron Microscopy (SEM) and Electron Microprobe measurements. Analytical results were used to evaluate the partitioning of radionuclides between the melt glass, rubble, and groundwater phases in the Chancellor test cavity. Three comparative approaches were used to calculate partitioning values, though each method could not be applied to every nuclide. These approaches are based on: (1) the average Area 19 inventory from Bowen et al. (2001); (2) melt glass, rubble, and groundwater mass estimates from Zhao et al. (2008); and (3) fission product mass yield data from England and Rider (1994). The U and Pu analyses of the test debris are classified and partitioning estimates for these elements were calculated directly from the classified Miller et al. (2002) inventory for the Chancellor test. The partitioning results from this study were compared to partitioning data that were previously published by the IAEA (1998). Predictions of radionuclide distributions from the two studies are in agreement for a majority of the nuclides under consideration. Substantial differences were noted in the partitioning values for {sup 99}Tc, {sup 125}Sb, {sup 129}I, and uranium. These differences are attributable to two factors: chemical volatility effects that occur during the initial plasma condensation, and groundwater remobilization that occurs over a much longer time frame. Fission product partitioning is very sensitive to the early cooling history of the test cavity because the decay of short-lived (t{sub 1/2} data to update the range in partitioning values for contaminant transport models at the Nevada National Security Site (formerly known as the Nevada Test Site).

Rose, T P; Hu, Q; Zhao, P; Conrado, C L; Dickerson, R; Eaton, G F; Kersting, A B; Moran, J E; Nimz, G; Powell, B A; Ramon, E C; Ryerson, F J; Williams, R W; Wooddy, P T; Zavarin, M

2009-01-09T23:59:59.000Z

252

Doped H(2)-Filled RF Cavities for Muon Beam Cooling  

DOE Green Energy (OSTI)

RF cavities pressurized with hydrogen gas may provide effective muon beam ionization cooling needed for muon colliders. Recent 805 MHz test cell studies reported below include the first use of SF{sub 6} dopant to reduce the effects of the electrons that will be produced by the ionization cooling process in hydrogen or helium. Measurements of maximum gradient in the Paschen region are compared to a simulation model for a 0.01% SF{sub 6} doping of hydrogen. The observed good agreement of the model with the measurements is a prerequisite to the investigation of other dopants.

Yonehara, K.; Chung, M.; Jansson, A.; Hu, M.; Moretti, A.; Popovic, M.; /Fermilab; Alsharo'a, M.; Johnson, R.P.; Neubauer, M.; Sah, R.; /Muons Inc., Batavia; Rose, D.V.; /Voss Sci., Albuquerque

2009-05-01T23:59:59.000Z

253

Progressive cavity pumps prove more efficient in mature waterflood tests  

Science Conference Proceedings (OSTI)

For mature waterflood wells, field tests in the Permian basin indicate that progressive cavity (PC) pumps provide greater mechanical efficiency and use less electricity than beam and electric submersible pumps (ESP). The field tests are being conducted in wells that produce 500--1,000 b/d from 3,800--5,000 ft. The testing started in 1991 and will continue through 1993. The paper describes the environment of a mature waterflood, test objectives, primary and secondary concerns, test design, and three of the four phases of the test.

Wright, D.W. (Amoco Production Co., Odessa, TX (United States)); Adair, R.L. (Highland Pump Co., Odessa, TX (United States))

1993-08-09T23:59:59.000Z

254

Cavity availability and use in hardwood forests with emphasis on wood ducks  

E-Print Network (OSTI)

The availability and use of cavities were examined on Tony Houseman State Park and Wildlife Management Area at Blue Elbow Swamp (HWMA), Orange County, Texas, during 1999. Random 0.25-ha plots were used to inventory cavities by size and estimate cavity use by vertebrates. Tree species, number of cavities by entrance size, stems per ha, basal area, and total cavities were recorded in 23, 15, and 15 plots in the cypress-tupelo (Taxodium distichum-Nyssa aquatica), mixed hardwood, and pine-oak (Pinus spp.-Quercus spp.) forest stands, respectively. Cavities with entrance dimensions suitable for entry by wood ducks (Aix sponsa) were inspected for suitability as wood duck nesting sites. Total cavity densities were similar between forest stands, but cypress-tupelo contained significantly (P = 0.000) more large-size cavities and mixed hardwoods produced the greatest density of small cavities. Tree species important for cavity production varied by forest stand. Regardless of species or stand, larger diameter and dead trees provided cavities in greater proportions than their availability in forest stands. Suitable wood duck nesting cavities were found at densities (0.0-26.7 cavities/100 ha) comparable to other forest stands at similar latitudes. Wood ducks were captured using grain-baited, swim-in traps. Backpack (n = 13) and implant (n = 20) radio-transmitters were attached to wood duck hens in 1999 and 2000, respectively. A combined total of 404 hen locations was obtained over 1,352 days. No active nests were located at HWMA during this study and hens used forest stands differently between years. Seasonal activity ranges were 246.1 ha ± 187.9 ha and 437.0 ha ± 117.6 ha in 1999 and 2000, respectively, and were different between years (P = 0.032). Water levels were significantly (P = 0.000) different between years and were suspected to have influenced hen activity. This study proposes that managers inventory cavity availability in forest stands to identify important cavity producing trees. Low cavity densities exist in forest stands at lower latitudes and sound management must be implemented to promote and retain cavity trees. Additional research is needed to quantify the effect of water levels and habitat conditions on wood duck use of forest stands.

Wolter, Derrick Wayne

2002-01-01T23:59:59.000Z

255

Multiple System Rate Process  

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

DSW Multiple System Transmission Rate Process DSW Multiple System Transmission Rate Process Federal Register Notice Withdrawing Rate Proposal (PDF) Formal Process Extension Federal Register Notice (PDF) Customer Savings Under Various MSTR (XLS) Public Information Forum March 29, 2005 Customer Meeting Overview (Power Point) Customer Meeting Overview (PDF) Customer Meeting Transcript (PDF) Public Comment Forum April 6, 2005 Customer Meeting Transcript (PDF) Response Letter 5-17-05 (PDF) Customer Letters Tonopah ID-5/25/05 (PDF) APS-5/26/05 (PDF) SRP-5/27/05 (PDF) RSLynch-6/1/05 (PDF) KRSaline-6/1/05 (PDF) Formal Process Federal Register Notice (Word) Federal Register Notice (PDF) Brochure (Word) Appendices to Brochure: A B C D E1 E2 F1 F2 GH Public Information Forum July 14, 2004 Customer Meeting Overview (Power Point)

256

Portable multiplicity counter  

DOE Patents (OSTI)

A portable multiplicity counter has signal input circuitry, processing circuitry and a user/computer interface disposed in a housing. The processing circuitry, which can comprise a microcontroller integrated circuit operably coupled to shift register circuitry implemented in a field programmable gate array, is configured to be operable via the user/computer interface to count input signal pluses receivable at said signal input circuitry and record time correlations thereof in a total counting mode, coincidence counting mode and/or a multiplicity counting mode. The user/computer interface can be for example an LCD display/keypad and/or a USB interface. The counter can include a battery pack for powering the counter and low/high voltage power supplies for biasing external detectors so that the counter can be configured as a hand-held device for counting neutron events.

Newell, Matthew R. (Los Alamos, NM); Jones, David Carl (Los Alamos, NM)

2009-09-01T23:59:59.000Z

257

Microwave sintering of multiple articles  

DOE Patents (OSTI)

Apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

Blake, Rodger D. (Santa Fe, NM); Katz, Joel D. (Los Alamos, NM)

1993-01-01T23:59:59.000Z

258

Microwave sintering of multiple aritcles  

DOE Patents (OSTI)

Disclosed are apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

Blake, R.D.; Katz, J.D.

1992-12-31T23:59:59.000Z

259

Multi-purpose 805 MHz Pillbox RF Cavity for Muon Acceleration Studies  

SciTech Connect

An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques. The cavity can operate at vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity is designed for easy assembly and disassembly with bolted construction using aluminum seals. The surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. Different surface treatments such as electro polished, high-pressure water cleaned, and atomic layer deposition are being considered for testing. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. Current status of the cavity prepared for initial conditioning and operation in the external magnetic field is discussed.

Kurennoy, Sergey S. [Los Alamos National Laboratory; Chan, Kwok-Chi Dominic [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Turchi, Peter J. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

260

Preparation and Testing of the SRF Cavities for the CEBAF 12 GeV Upgrade  

SciTech Connect

Eighty new 7-cell, low-loss cell-shaped cavities are required for the CEBAF 12 GeV Upgrade project. In addition to ten pre-production units fabricated at JLab, the full set of commercially-produced cavities have been delivered. An efficient processing routine, which includes a controlled 30 micron electropolish, has been established to transform these cavities into qualified 8-cavity strings. This work began in 2010 and will run through the end of 2011. The realized cavity performance consistently exceeds project requirements and also the maximum useful gradient in CEBAF: 25 MV/m. We will describe the cavity processing and preparation protocols and summarize test results obtained to date.

Reilly, A. V.; Bass, T.; Burrill, A.; Davis, G. K.; Marhauser, F.; Reece, C. E.; Stirbet, M.

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Multiple sclerosis and interferon  

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

Multiple sclerosis and interferon Multiple sclerosis and interferon Name: iguanajoe Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 Question: I have recently read that interferon is being used as a treatment for multiple sclerosis. Please explain how it affects the nerve tissue and how effective it is. Replies: Interferon is a cell to cell chemical messenger which essentially protects cells from viruses. That is, when a virus infects a cell, it sends out interferon, which is received by neighboring cells. A biochemical reaction then follows which builds the cells resistance viruses, and hopefully, it will be enough to prevent the virus from spreading. If there is work with interferon and MS, perhaps some researchers believe that MS is caused by a viral infection that destroys nervous tissue. r, that viruses cause some genetic mutation which compromises the maintenance of healthy nervous tissue. By the way, the genetic cause for another muscular-nervous disorder, Lou Gherigs Disease or ALS, was recently found to be a hereditary genetic disorder. People susceptible to ALS did not have a gene which codes for a certain superoxide dismutase antioxidant enzyme, necessary to maintain healthy nervous tissue and prevent it from free radical destruction. Maybe the cause of MS is similar.

262

Producing KDP and DKDP crystals for the NIF laser  

SciTech Connect

The cost and physics requirements of the NIF have established two important roles for potassium dihydrogen phosphate (KDP) crystals. 1. To extract more laser energy per unit of flashlamp light and laser glass, the NIF has adopted a multipass architecture as shown in Figure 1. Light is injected in the transport spatial filter, first traverses the power amplifiers, and then is directed to main amplifiers, where it makes four passes before being redirected through the power amplifiers towards the target. To enable the multipass of the main amplifiers, a KDP-containing Pockels cell rotates the polarization of the beam to make it either transmit through or reflect off a polarizer held at Brewster's angle within the main laser cavity. If transmitted, the light reflects off a mirror and makes another pass through the cavity. If reflected, it proceeds through the power amplifier to the target. the original seed crystal as the pyramid faces grow. Unfortunately, this pyramidal growth is very slow, and it takes about two years to grow a crystal to NIF size. To provide more programmatic flexibility and reduce costs in the long run, we have developed an alternative technology commonly called rapid growth. Through a combination of higher temperatures and higher supersaturation of the growth solution, a NIF-size boule can be grown in 1 to 2 months from a small ''point'' seed. However, growing boules of adequate size is not sufficient. Care must be taken to prevent inclusions of growth solution and incorporation of atomically substituted 2. Implosions for ICF work far better at shorter wavelengths due to less generation of hot electrons, which preheat the fuel and make it harder to compress. Compromising between optic lifetime and implosion efficiency, both Nova and the NIF operate at a tripled frequency of the 1053-nm fundamental frequency of a neodymium glass laser. This tripling is accomplished by two crystals, one made of KDP and one made of deuterated KDP (DKDP). The first one mixes two 1053-nm photons to make 526-nm light, and the second one combines a residual 1053-nm photon with a 526-nm photon to make 351-nm light.

Atherton, L J; Burnham, A K; Combs, R C; Couture, S A; De Yoreo, J J; Hawley-Fedder, R A; Montesant, R C; Robey, H F; Runkel, M; Staggs, M; Wegner, P J; Yan, M; Zaitseva, N P

1999-09-02T23:59:59.000Z

263

VISUALS: Crystal Structure Animations - TMS  

Science Conference Proceedings (OSTI)

Jul 2, 2008 ... This site contains animated ball and stick models of anhydrite, aragonite, barite, beryl, biotite, calcite, ... "Crystal Structure Animations.

264

Florida Nuclear Profile - Crystal River  

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

Crystal River1" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

265

Nepheline Crystallization from Aluminosilicate Melts  

Al-limited and Al/Na-limited Hanford HLW. Figure 3. Crystallization during canister coolingis principal waste loading limiting factor . Current Nepheline Discriminator.

266

BY SILICON CRYSTALS  

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

c October 29, 1942 a 1 1 _MIGH aECTgFXCATIOH - BY SILICON CRYSTALS . . c .. I n. The excellent pesformmce of Brftieh "red dot" c r y s t a l s f e explained R R due t o the kgife edge contact i n a t A polfehod ~ X ' f l i C B o H i g h frequency m c t l f f c n t f o n 8ependre c r i t i c a l l y on the ape%e;y of the rectifytnc boundary layer o f the crystal, C, For hl#$ comvere~on e f f i c i e n c y , the product c d t h i ~ capacity m a o f ' t h e @forward" (bulk) re-. sistance Rb o f the crystnl must b@ sm%P, depende primarily on the breadth of tha b f f e edge i t s lbngth. The contact am &harefore ~ E L V Q a rather large area wMQh prevents burn-out, thh3 t h e breadth of &h@ knife edge should be bdt8~1 than E~$O$B% % f I - ' amo For a knife edge, this produet very 14ttle upom For a wavsIL~n+3tih of PO emo the eowp,o%a%8sne 4

267

Results of Cavity Series Fabrication at Jefferson Laboratory for the Cryomodule “R100”  

SciTech Connect

A series production of eight superconducting RF cavities for the cryomodule R100 was conducted at JLab in 2010. The cavities underwent chemical post-processing prior to vertical high power testing and routinely exceeded the envisaged performance specifications. After cryomodule assembly, cavities were successfully high power acceptance tested. In this paper, we present the achievements paving the way for the first demonstration of 100 MV (and beyond) in a single cryomodule to be operated at CEBAF.

F. Marhauser, W.A. Clemens, M.A. Drury, D. Forehand, J. Henry, S. Manning, R.B. Overton, R.S. Williams

2011-09-01T23:59:59.000Z

268

Nuclear resonance tomography with a toroid cavity detector  

DOE Patents (OSTI)

A toroid cavity detection system for determining the spectral properties and distance from a fixed point for a sample using Nuclear Magnetic Resonance. The detection system consists of a toroid with a central conductor oriented along the main axis of the toroidal cylinder and perpendicular to a static uniform magnetic field oriented along the main axis of the toroid. An rf signal is inputted to the central conductor to produce a magnetic field perpendicular to the central axis of the toroid and whose field strength varies as the inverse of the radius of the toroid. The toroid cavity detection system can be used to encapsulate a sample, or the detection system can be perforated to allow a sample to flow into the detection device or to place the samples in specified sample tubes. The central conductor can also be coated to determine the spectral property of the coating and the coating thickness. The sample is then subjected to the respective magnetic fields and the responses measured to determine the desired properties.

Woelk, K.; Rathke, J.W.; Klingler, R.J.

1994-12-31T23:59:59.000Z

269

Analysis of a Fabric/Desiccant Window Cavity Dehumidifier  

E-Print Network (OSTI)

This paper presents the results of an exploratory study of a fabric/desiccant window cavity dehumidifier system for possible use in commercial buildings. The objective was to evaluate fabrics commonly used in buildings, and system concepts that employ these fabrics, which can be used to dehumidify room air. We developed a first-order energy/mass balance model to determine the performance of a window cavity dehumidifier that uses silica gel encapsulated in a fabric matrix rotating on a belt alternately through dehumidification and regeneration chambers; the modeling effort was supplemented by environmental chamber measurements of the moisture absorption characteristics of 16 fabric/desiccant combinations. We ran the model for a typical office building module, for outside air design conditions characteristic of the most difficult humidity regime in Texas. Two flow configurations, outside air and return air, were evaluated to determine the capability of such a system to dehumidify the air streams under consideration. Issues addressed included the physical limitations on the amount of desiccant that can be included in this configuration and the degree of dehumidification achievable.

Hunn, B. D.; Grasso, M. M.; Vadlamani, V.

1994-01-01T23:59:59.000Z

270

Visible light emitting vertical cavity surface emitting lasers  

DOE Patents (OSTI)

A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of {lambda}/2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In{sub z}(Al{sub y}Ga{sub 1{minus}y}){sub 1{minus}z}P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m {lambda}/2n{sub eff} where m is an integer and n{sub eff} is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of {lambda}/n, typically within the green to red portion of the visible spectrum. 10 figs.

Bryan, R.P.; Olbright, G.R.; Lott, J.A.; Schneider, R.P. Jr.

1995-06-27T23:59:59.000Z

271

EXPERIMENTAL RESULTS FROM A MICROWAVE CAVITY BEAM POSITION MONITOR.  

Science Conference Proceedings (OSTI)

Future Linear Colliders have hard requirements for the beam transverse position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0.1 micron in the single bunch regime is needed to control the stability of the beam position along the linac. Proposed BPM is based on the measurement of the asymmetrical mode excited by single bunch in the cavity. Four stages of signal processing (space-, time-, frequency- and phase-filtering providing the required signal-to-noise ratio) are used to obtain extremely high resolution. The measurement set-up was designed by BINP and installed at ATF/BNL to test experimentally this concept. The set-up includes three two-coordinates BPM's at the frequency of 13.566 GHz, and reference intensity/phase cavity. BPM's were mounted on support table. The two-coordinates movers allow to move and align BPM's along the straight line, using the signals from the beam. The position of each monitor is controlled by the sensors with the accuracy 0.03 micron. The information from three monitors allows to exclude angle and position jitter of the beam and measure BPM resolution. In the experiments the resolution of about 0.15 micron for 0.25 nC beam intensity was obtained, that is close to the value required.

BALAKIN,V.; BAZHAN,A.; LUNEV,P.; SOLYAK,N.; VOGEL,V.; ZHOGOLEV,P.; LISITSYN,A.; YAKIMENKO,V.

1999-03-29T23:59:59.000Z

272

Nuclear resonance tomography with a toroid cavity detector  

DOE Patents (OSTI)

A toroid cavity detection system is described for determining the spectral properties and distance from a fixed point for a sample using Nuclear Magnetic Resonance. The detection system consists of a toroid with a central conductor oriented along the main axis of the toroidal cylinder and perpendicular to a static uniform magnetic field oriented along the main axis of the toroid. An rf signal is input to the central conductor to produce a magnetic field perpendicular to the central axis of the toroid and whose field strength varies as the inverse of the radius of the toroid. The toroid cavity detection system can be used to encapsulate a sample, or the detection system can be perforated to allow a sample to flow into the detection device or to place the samples in specified sample tubes. The central conductor can also be coated to determine the spectral property of the coating and the coating thickness. The sample is then subjected to the respective magnetic fields and the responses measured to determine the desired properties. 4 figs.

Woelk, K.; Rathke, J.W.; Klingler, R.J.

1996-11-12T23:59:59.000Z

273

Designs of Superconducting Parallel-Bar Deflecting Cavities for Deflecting/Crabbing Applications  

Science Conference Proceedings (OSTI)

The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties, compared to other conventional designs, that is currently being considered for a number of applications. The new parallel-bar design with curved loading elements and circular or elliptical outer conductors have improved properties compared to the designs with rectangular outer conductors. We present the designs proposed as deflecting cavities for the Jefferson Lab 12 GeV upgrade and for Project-X and as crabbing cavities for the proposed LHC luminosity upgrade and electron-ion collider at Jefferson Lab.

J.R. Delayen, S.U. De Silva

2011-07-01T23:59:59.000Z

274

Dielectric-Loaded Microwave Cavity for High-Gradient Testing of Superconducting Materials  

E-Print Network (OSTI)

A superconducting microwave cavity has been designed to test advanced materials for use in the accelerating structures contained within linear colliders. The electromagnetic design of this cavity produces surface magnetic fields on the sample wafer exceeding the critical limit of Niobium. The ability of this cavity to push up to 4 times the critical field provides, for the first time, a short sample method to reproducibly test these thin films to their ultimate limit. In order for this Wafer Test cavity to function appropriately, the large sapphire at the heart of the cavity must have specific inherent qualities. A second cavity was constructed to test these parameters: dielectric constant, loss tangent, and heat capacity. Several tests were performed and consistent values were obtained. The consequences of these measurements were then applied to the Wafer Cavity, and its performance was evaluated for different power inputs. The Q_0 of the cavity could be as low as 10^7 because of the sapphire heating, therefore removing the ability to measure nano-resistances. However, with additional measurements in a less complex environment, such as the Wafer Test Cavity, the Q_0 could be higher than 10^9.

Pogue, Nathaniel Johnston

2011-05-01T23:59:59.000Z

275

3D simulations of multipacting in the 56 MHz SRF cavity  

SciTech Connect

The 56 MHz SRF Quarter-Wave Resonator (QWR) is designed for RHIC as a storage cavity to improve the collider performance. 2D multipacting simulation has been done for the cavity alone. Ripples were added to the outer body of the cavity for multipacting suppression based on the simulation findings. During operation, there will be four higher order mode (HOM) couplers. All of these components will be exposed to high RF fields. In this paper we compare 2D and 3D codes simulation results for multipacting in the cavity. We also report 3D simulation results for multipacting simulation at the couplers.

Wu Q.; Belomestnykh, S.; Ge, L.; Ko, K.; Li, Z.; Ng, C.; Xiao, L.

2012-05-20T23:59:59.000Z

276

Energy Recovery Linac cavity at BNL | U.S. DOE Office of Science...  

Office of Science (SC) Website

Energy Recovery Linac cavity at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIRSTTR...

277

Quantum dynamics of an optical cavity coupled to a thin semitransparent membrane: Effect of membrane absorption  

Science Conference Proceedings (OSTI)

We study the quantum dynamics of the cavity optomechanical system formed by a Fabry-Perot cavity with a thin vibrating membrane at its center. We determine in particular to what extent optical absorption by the membrane hinders reaching a quantum regime for the cavity-membrane system. We show that even though membrane absorption may significantly lower the cavity finesse and also heat the membrane, one can still simultaneously achieve ground state cooling of a vibrational mode of the membrane and stationary optomechanical entanglement with state-of-the-art apparatuses.

Biancofiore, C.; Karuza, M.; Galassi, M.; Natali, R.; Vitali, D. [School of Science and Technology, Physics Division, University of Camerino, via Madonna delle Carceri, 9, I-62032 Camerino (Italy) and INFN, Sezione di Perugia (Italy); Tombesi, P.; Di Giuseppe, G. [School of Science and Technology, Physics Division, University of Camerino, via Madonna delle Carceri, 9, I-62032 Camerino (Italy) and INFN, Sezione di Perugia (Italy); CriptoCam S.r.l., via Madonna delle Carceri 9, I-62032 Camerino (Italy)

2011-09-15T23:59:59.000Z

278

Design of Electron and Ion Crabbing Cavities for an Electron-Ion Collider  

SciTech Connect

Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) has been considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present to-date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and higher-order mode separation will be presented. Keywords: super conducting, deflecting cavity, crab cavity.

Alejandro Castilla Loeza, Geoffrey Krafft, Jean Delayen

2012-07-01T23:59:59.000Z

279

Recent progress in large grain/single crystal high RRR niobium  

DOE Green Energy (OSTI)

High RRR bulk niobium Superconducting Radio Frequency (SRF) cavity technology is chosen for the International Linear Collider (ILC). The SRF community was convinced until now that fine grain polycrystalline RRR niobium sheets obtained via forging and cross rolling are essential for forming the SRF Cavities. However, it was recently discovered under a joint Reference Metals Company, Inc., - JLAB CRADA that large grain/single crystal RRR niobium sliced directly from ingots is highly ductile reaching 100 percent elongation. This discovery led to the successful fabrication of several SRF single and/or multi cell structures, formed with sliced RRR discs from the ingots, operating at 2.3, 1.5 and 1.3 GHz. This new exciting development is expected to offer high performance accelerator structures not only at reduced costs but also with simpler fabrication and processing conditions. As a result there is a renewed interest in the evaluation and understanding of the large grain and single crystal niobium with respect to their mechanical & physical properties as well as the oxidation behavior and the influence of impurities such as hydrogen and Ta. In this paper the results of many collaborative studies on large grain and single crystal high RRR niobium between JLAB, Universities and Industry are presented.

Ganapati Rao Myneni; Peter Kneisel; Tadeu Carneiro; S.R. Agnew; F. Stevie

2005-11-07T23:59:59.000Z

280

REACTOR FUEL WASTE DISPOSAL PROJECT DEVELOPMENT OF DESIGN PRINCIPLE FOR DISPOSAL OF REACTOR FUEL WASTE INTO UNDERGROUND SALT CAVITIES  

SciTech Connect

Waste disposal in underground salt cavities is considered. Theoretical Investigations for spherical and cylindrical cavities included analysis of elastic stress, thermal stress, and stress redistribution due to the development of a plastic zone around the cavity. The problems of temperature distribution and accompanying thermal stress, due to heat emission from the waste, were also studied. The reduction of the cavity volume, the development of the plastic zone, and the resulting stress redistribution around the cavity are presented as functions of cavity depth, internal pressure of cavity, strenzth of salt, and cavity teraperature rise. It is shown that a salt cavity can be designed such that it is structurally stable as a storage container assuming a chemical equilibrium can be established between the liquid waste and salt. (W.D.M.)

Serata, S.; Gloyna, E.F.

1959-01-01T23:59:59.000Z

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


281

Lamella settler crystallizer  

DOE Patents (OSTI)

A crystallizer which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities.

Maimoni, Arturo (Orinda, CA)

1990-01-01T23:59:59.000Z

282

Lamella settler crystallizer  

DOE Patents (OSTI)

A crystallizer is described which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities. 3 figs.

Maimoni, A.

1990-12-18T23:59:59.000Z

283

A SYSTEMATIC SEARCH FOR X-RAY CAVITIES IN THE HOT GAS OF GALAXY GROUPS  

SciTech Connect

We have performed a systematic search for X-ray cavities in the hot gas of 51 galaxy groups with Chandra archival data. The cavities are identified based on two methods: subtracting an elliptical beta-model fitted to the X-ray surface brightness, and performing unsharp masking. Thirteen groups in the sample ({approx}25%) are identified as clearly containing cavities, with another 13 systems showing tentative evidence for such structures. We find tight correlations between the radial and tangential radii of the cavities, and between their size and projected distance from the group center, in quantitative agreement with the case for more massive clusters. This suggests that similar physical processes are responsible for cavity evolution and disruption in systems covering a large range in total mass. We see no clear association between the detection of cavities and the current 1.4 GHz radio luminosity of the central brightest group galaxy, but there is a clear tendency for systems with a cool core to be more likely to harbor detectable cavities. To test the efficiency of the adopted cavity detection procedures, we employ a set of mock images designed to mimic typical Chandra data of our sample, and find that the model-fitting approach is generally more reliable than unsharp masking for recovering cavity properties. Finally, we find that the detectability of cavities is strongly influenced by a few factors, particularly the signal-to-noise ratio of the data, and that the real fraction of X-ray groups with prominent cavities could be substantially larger than the 25%-50% suggested by our analysis.

Dong Ruobing [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Rasmussen, Jesper; Mulchaey, John S., E-mail: rdong@princeton.ed [Observatories of Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2010-04-01T23:59:59.000Z

284

Equilibrium Crystal Shape of Nickel  

SciTech Connect

The crystal shape of Ni particles, dewetted in the solid state on sapphire substrates, was examined as a function of the partial pressure of oxygen (P(O2)) and iron content using scanning and transmission electron microscopy. The chemical composition of the surface was characterized by atom-probe tomography. Unlike other FCC equilibrium crystal shapes, the Ni crystals containing little or no impurities exhibited a facetted shape, indicating large surface anisotropy. In addition to the {111}, {100} and {110} facets, which are usually present in the equilibrium crystal shape of FCC metals, high index facets were identified such as {135} and {138} at low P(O2), and {012} and {013} at higher P(O2). The presence of iron altered the crystal shape into a truncated sphere with only facets parallel to denser planes. The issue of particle equilibration is discussed specifically for the case of solid-state dewetting.

Meltzman, Hila [Technion, Israel Institute of Technology; Chatain, Dominique [Universite d'Aix-Marseille; Avizemer, Dan [Technion, Israel Institute of Technology; Besmann, Theodore M [ORNL; Kaplan, Prof. Wayne D. [Technion, Israel Institute of Technology

2011-01-01T23:59:59.000Z

285

Phase-multiplication holography  

DOE Patents (OSTI)

This disclosure relates generally to nondestructive testing for identifying structural characteristics of an object by scanned holographic techniques using a known source of radiation, such as electromagnetic or acoustical radiation. It is an object of this invention to provide an apparatus and method for synthetic aperture expansion in holographic imaging applications to construct fringe patterns capable of holographic reproduction where aperture restrictions in nondestructive testing applications would conventionally make such imaging techniques impossible. The apparatus and method result in the production of a sharply defined frontal image of structural characteristics which could not otherwise be imaged because they occur either near the surface of the object or are confined by geometry restricting aperture dimensions available for scanning purposes. The depth of the structural characteristic below the surface of the object can also be determined by the reconstruction parameters which produce the sharpest focus. Lateral resolution is established by simulated reduction in the radiation wavelength and may easily be an order of magnitude less than the electromagnetic wavelength in the material or 2 times the standard depth of penetration. Since the phase multiplication technique is performed on the detected data, the penetration depth available due to the longer wavelength signals applied to the test object remains unchanged. The phase multiplication technique can also be applied to low frequency acoustic holography, resulting in a test which combines excellent penetration of difficult materials with high resolution images.

Collins, H.D.; Prince, J.M.; Davis, T.J.

1982-01-25T23:59:59.000Z

286

Multiple capillary biochemical analyzer  

DOE Patents (OSTI)

A multiple capillary analyzer allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed, using a modified sheath flow cuvette. A linear or rectangular array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system. The retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries. The optical system utilizes optic fibers to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands. 21 figs.

Dovichi, N.J.; Zhang, J.Z.

1995-08-08T23:59:59.000Z

287

Combination ring cavity and backward Raman waveguide amplifier  

DOE Patents (OSTI)

A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO.sub.2 laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO.sub.2 laser pump signal for conversion to Stokes radiation. Additionally, the backward Raman amplifier configuration produces a Stokes radiation signal which has a high intensity and a short duration. Adjustment of the position of overlap of the Stokes signal and the CO.sub.2 laser pump signal in the backward Raman waveguide amplifiers alters the amount of pulse compression which can be achieved.

Kurnit, Norman A. (Santa Fe, NM)

1983-01-01T23:59:59.000Z

288

Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities  

SciTech Connect

We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2?10{sup 10} at 2K.

Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Clemens, William A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Follkie, James E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harris, Teena M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kushnick, Peter W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Machie, Danny [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Martin, Robert E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, Ari D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Perry, Era A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Slack, Gary L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Williams, R. S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Adolphsen, C. [SLAC, Menlo Park, California, (United States); Li, Z. [SLAC, Menlo Park, California, (United States); Hao, J. K. [Peking University, Beijing (China); Li, Y. M. [Peking University, Beijing (China); Liu, K. X. [Peking University, Beijing (China)

2013-06-01T23:59:59.000Z

289

TESLA Report 2003-28 TESLA cavity modeling and digital implementation  

E-Print Network (OSTI)

TESLA Report 2003-28 TESLA cavity modeling and digital implementation with FPGA technology solution, Warsaw University of Technology Stefan Simrock TESLA, DESY, Hamburg ABSTRACT The cavity resonator modeling for the TESLA - TeV­Energy Superconducting Linear Accelerator project is initially introduced

290

Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Accelerator  

E-Print Network (OSTI)

1 Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Hamburg, Germany Abstract For the long term successful operation of the superconducting TESLA accelerator The beam vacuum system of the TESLA main linear accelerators contains about 20.000 superconducting cavities

291

Achievement of 35 MV/m in the Superconducting Nine-Cell Cavities for TESLA 1  

E-Print Network (OSTI)

Achievement of 35 MV/m in the Superconducting Nine-Cell Cavities for TESLA 1 L. Lilje2 , D. Kostin Electronvolt Superconducting Linear Accelerator TESLA is the only linear electron-positron collider project reliably achieved in the cavities of the TESLA Test Facility (TTF) accelerator. The upgrade of TESLA to 800

292

Electrical axes of TESLA-type cavities (Theoretical background, development of measurement equipment, measurement results)  

E-Print Network (OSTI)

- 1 - Electrical axes of TESLA-type cavities (Theoretical background, development of measurement equipment, measurement results) Anton Labanc, MHF-SL, DESY, January 2008 Abstract Cells in TESLA cavities. A short overview was already published at the TESLA Report 2007-01. This paper brings more details about

293

Study of the Variation of Transverse Voltage in the 4 Rod Crab Cavity for LHC  

Science Conference Proceedings (OSTI)

The planned high luminosity upgrade to LHC will utilise crab cavities to rotate the beam in order to increase the luminosity in the presence of a finite crossing angle. A compact design is required in order for the cavities to fit between opposing beam-lines. In this paper we discuss we discuss one option for the LHC crab cavity based on a 4 rod TEM deflecting cavity. Due to the large transverse size of the LHC beam the cavity is required to have a large aperture while maintaining a constant transverse voltage across the aperture. The cavity has been optimised to minimise the variation of the transverse voltage while keeping the peak surface electric and magnetic fields low for a given kick. This is achieved while fitting within the strict design space of the LHC. The variation of deflecting voltage across the aperture has been studied numerically and compared with numerical and analytical estimates of other deflecting cavity types. Performance measurements an aluminium prototype of this cavity are presented and compared to the simulated design.

B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

2011-04-01T23:59:59.000Z

294

Quantum entanglement and Bell violation of two coupled cavity fields in dissipative environment  

E-Print Network (OSTI)

We study the quantum entanglement between two coupled cavities, in which one is initially prepared in a mesoscopic superposition state and the other is in the vacuum in dissipative environment and show how the entanglement between two cavities can arise in the dissipative environment. The dynamic behavior of the nonlocality for the system is also investigated.

Shang-Bin Li; Jing-Bo Xu

2004-01-08T23:59:59.000Z

295

DYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION  

E-Print Network (OSTI)

-tracing study of the heat flux distribution inside the steam receiver is used to spatially refine the modelDYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION José Zapata 1 , John dish has been in operation since 2010 with a mono-tube steam cavity receiver, the SG4 system

296

Dynamics of a single trapped ion inside a nonideal QED cavity at zero temperature  

SciTech Connect

We consider a system consisting of a single ion in a Paul trap coupled to a cavity electromagnetic field mode. We analyze the fidelity of a scheme for quantum swapping between vibrational and cavity field states, when the system is in contact with a reservoir at zero temperature.

Rangel, R.; Zagury, N. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Massoni, E. [Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2004-02-01T23:59:59.000Z

297

TEMPERATURE AND EXTREME-ULTRAVIOLET INTENSITY IN A CORONAL PROMINENCE CAVITY AND STREAMER  

Science Conference Proceedings (OSTI)

We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of the streamer and cavity. We also compare model predictions to the EIS EUV line intensities and polarized brightness (pB) data from the Mauna Loa Solar Observatory (MLSO) Mark 4 K-coronameter. This work builds on earlier analysis using the same model to determine geometry of and density in the same cavity and streamer. The fit to the data with altitude-dependent temperature profiles indicates that both the streamer and cavity have temperatures in the range 1.4-1.7 MK. However, the cavity exhibits substantial substructure such that the altitude-dependent temperature profile is not sufficient to completely model conditions in the cavity. Coronal prominence cavities are structured by magnetism so clues to this structure are to be found in their plasma properties. These temperature substructures are likely related to structures in the cavity magnetic field. Furthermore, we find that the model overestimates the EUV line intensities by a factor of 4-10, without overestimating pB. We discuss this difference in terms of filling factors and uncertainties in density diagnostics and elemental abundances.

Kucera, T. A. [NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States); Gibson, S. E.; Schmit, D. J. [HAO/NCAR, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Landi, E. [Department of Atmospheric, Oceanic and Space Science, Space Research Building, University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109-2143 (United States); Tripathi, D. [Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune University Campus, Pune 411 007 (India)

2012-09-20T23:59:59.000Z

298

The standing wave FEL/TBA: Realistic cavity geometry and energy extraction  

SciTech Connect

A set of parameters for standing wave free electron laser two beam accelerators (SWFEL/TBA) is evaluated for realistic cavity geometry taking into account beam-break-up and the sensitivity of output power to imperfections. Also given is a power extraction system using cavity coupled wave guides.

Kim, Jin-Soo, Henke, H.; Sessler, A.M.; Sharp, W.M.

1993-05-01T23:59:59.000Z

299

Design study on very low Beta spoke cavity for China-ADS  

E-Print Network (OSTI)

Very low Beta superconducting spoke cavity is one of the key challenges for China-ADS project. In this paper, a new structure of 3*Beta*lamda/2 spoke cavity is first presented. Its RF and mechanical properties are simulated using CST-MWS and ANSYS, and compared with the traditional Beta*lamda/2 spoke structure.

Han, Li; Jianping, Dai; Hong, Huang; Qunyao, Wang

2013-01-01T23:59:59.000Z

300

High power RF test of an 805 MHz RF cavity for a muon cooling channel  

SciTech Connect

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

2002-05-30T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Large-Volume Resonant Microwave Discharge for Plasma Cleaning of a CEBAF 5-Cell SRF Cavity  

SciTech Connect

We report the preliminary results on plasma generation in a 5-cell CEBAF superconducting radio-frequency (SRF) cavity for the application of cavity interior surface cleaning. CEBAF currently has {approx}300 of these five cell cavities installed in the Jefferson Lab accelerator which are mostly limited by cavity surface contamination. The development of an in-situ cavity surface cleaning method utilizing a resonant microwave discharge could lead to significant CEBAF accelerator performance improvement. This microwave discharge is currently being used for the development of a set of plasma cleaning procedures targeted to the removal of various organic, metal and metal oxide impurities. These contaminants are responsible for the increase of surface resistance and the reduction of RF performance in installed cavities. The CEBAF five cell cavity volume is {approx} 0.5 m2, which places the discharge in the category of large-volume plasmas. CEBAF cavity has a cylindrical symmetry, but its elliptical shape and transversal power coupling makes it an unusual plasma application, which requires special consideration of microwave breakdown. Our preliminary study includes microwave breakdown and optical spectroscopy, which was used to define the operating pressure range and the rate of removal of organic impurities.

J. Mammosser, S. Ahmed, K. Macha, J. Upadhyay, M. Nikoli, S. Popovi, L. Vuakovi

2012-07-01T23:59:59.000Z

302

Dosimetry of I-125 seeds implanted on the surface of a cavity  

SciTech Connect

Dosimetry of a new implant technique to treat brain tumors is presented. High grade gliomas or astrocytomas are surgically removed, and radioactive I-125 seeds are implanted on the surface of the cavity. A computational model is presented to determine the number of seeds and the activity of the seeds for a given dose and cavity size.

Prasad, S.C.; Bassano, D.A.; Fear, P.I.; King, G.A. (SUNY, Syracuse (USA))

1990-12-01T23:59:59.000Z

303

Crystal Solar Inc | Open Energy Information  

Open Energy Info (EERE)

Crystal Solar Inc Jump to: navigation, search Name Crystal Solar Inc. Place Santa Clara, California Zip 94054 Sector Solar Product California-based developer of silicon solar...

304

Multiple layer insulation cover  

DOE Patents (OSTI)

A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

Farrell, James J. (Livingston Manor, NY); Donohoe, Anthony J. (Ovid, NY)

1981-11-03T23:59:59.000Z

305

Towards improved CZT crystals.  

Science Conference Proceedings (OSTI)

Past experimental efforts to improve CZT crystals for gamma spectrometer applications have been focused on reducing micron-scale defects such as tellurium inclusions and precipitates. While these micron-scale defects are important, experiments have shown that the micron-scale variations in transport can be caused by the formation and aggregation of atomic-scale defects such as dislocations and point defect clusters. Moreover, dislocation cells have been found to act as nucleation sites that cause the formation of large precipitates. To better solve the uniformity problem of CZT, atomic-scale defects must be understood and controlled. To this end, we have begun to develop an atomistic model that can be used to reveal the effects of small-scale defects and to guide experiments for reducing both atomic- and micron-scale (tellurium inclusions and precipitates) defects. Our model will be based upon a bond order potential (BOP) to enable large-scale molecular dynamics simulations of material structures at a high-fidelity level that was not possible with alternative methods. To establish how BOP improves over existing approaches, we report here our recent work on the assessment of two representative literature CdTe interatomic potentials that are currently widely used: the Stillinger-Weber (SW) potential and the Tersoff-Rockett (TR) potential. Careful examinations of phases, defects, and surfaces of the CdTe system were performed. We began our study by using both potentials to evaluate the lattice constants and cohesive energies of various Cd, Te, and CdTe phases including dimer, trimer, chain, square, rhomboid, tetrahedron, diamond-cubic (dc), simple-cubic (sc), body-centered-cubic (bcc), face-centered cubic (fcc), hexagonal-close-packed (hcp), graphite-sheet, A8, zinc-blende (zb), wurtzite (wz), NaCl, CsCl, etc. We then compared the results with our calculations using the density functional theory (DFT) quantum mechanical method. We also evaluated the suitability of the two potentials to predict the surface reconstructions and surface energies, various defect configurations and defect energies (interstitials and voids), elastic constants, and melting temperatures of different phases. We found that both potentials predicted incorrect energy trends as compared with those predicted by the DFT method. Most seriously, both potentials predicted incorrect lowest energy phases. These studies clearly showed that the existing potentials are not sufficient for correctly predicting the charge transport properties of CdTe demonstrating the need for a new potential. We anticipate that our BOP method will overcome this problem and will accelerate the discovery of a synthesis approach to produce improved CZT crystals.

Zimmerman, Jonathan A.; Ward, Donald K.; Doty, F. Patrick; Wong, Bryan Matthew; Zhou, Xiao Wang

2010-03-01T23:59:59.000Z

306

Impurity gettering in silicon using cavities formed by helium implantation and annealing  

DOE Patents (OSTI)

Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer.

Myers, Jr., Samuel M. (Albuquerque, NM); Bishop, Dawn M. (Albuquerque, NM); Follstaedt, David M. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

307

Impurity gettering in silicon using cavities formed by helium implantation and annealing  

DOE Patents (OSTI)

Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer. 4 figs.

Myers, S.M. Jr.; Bishop, D.M.; Follstaedt, D.M.

1998-11-24T23:59:59.000Z

308

Flow and heat transfer in gas turbine disk cavities subject to nonuniform external pressure field  

SciTech Connect

Ingestion of hot gas from the main-stream gas path into turbine disk cavities, particularly the first-stage disk cavity, has become a serious concern for the next-generation industrial gas turbines features high rotor inlet temperature. Fluid temperature in the cavities increases further due to windage generated by fluid drag at the rotating and stationary surfaces. The resulting problem of rotor disk heat-up is exacerbated by the high disk rim temperature due to adverse (relatively flat) temperature profile of the mainstream gas in the annular flow passage of the turbine. This describes an investigation into local convective heat transfer coefficient and cooling effectiveness of the rotor disk, flow field in the disk cavity, computation of the flow field and heat transfer in the disk cavity, and mainstream gas injection and rotor disk cooling effectiveness by mass transfer analogy.

Roy, R.P.; Kim, Y.W.; Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering

1995-12-31T23:59:59.000Z

309

An equivalent circuit model and power calculations for the APS SPX crab cavities.  

SciTech Connect

An equivalent parallel resistor-inductor-capacitor (RLC) circuit with beam loading for a polarized TM110 dipole-mode cavity is developed and minimum radio-frequency (rf) generator requirements are calculated for the Advanced Photon Source (APS) short-pulse x-ray (SPX) superconducting rf (SRF) crab cavities. A beam-loaded circuit model for polarized TM110 mode crab cavities was derived. The single-cavity minimum steady-state required generator power has been determined for the APS SPX crab cavities for a storage ring current of 200mA DC current as a function of external Q for various vertical offsets including beam tilt and uncontrollable detuning. Calculations to aid machine protection considerations were given.

Berenc, T. (Accelerator Systems Division (APS))

2012-03-21T23:59:59.000Z

310

Traits and Multiple Genes  

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

Traits and Multiple Genes Traits and Multiple Genes Name: Frank Location: N/A Country: N/A Date: N/A Question: Please, could you give me an example of how human traits are controlled by more than one pair of alleles? Replies: Your question is just a bit vague, there are different answers depending on just what your question is. I will answer it in terms of polygenic traits also known as additive alleles. When you think of traits such as skin color, hair color and eye color, or traits where there is a wide range of phenotypes they are usually under the control of more than one pair of alleles. These alleles can even be on different chromosomes! Each pair of additive alleles adds to the phenotype. For instance in the case of skin color, scientists now believe that 3 genes control skin color. You then get 3 sets from your mother and 3 from your father for 6 possibilities. If all 6 of the alleles are for dark skin, you will have the darkest possible skin. If you have 5 dark alleles and one light, you will have very dark skin. If you have all 6 light alleles then you will have the lightest skin possible. Is it possible to have a child that is light skinned when both parents are dark-skinned? Well, not if both have all 6 dark alleles, but if they have some light alleles and the child inherits all of the possible light alleles available, then yes, the child could have lighter skin than either parent. It is now believed that eye color is not simply brown being dominant over blue because how many people do you know that have the same shade of brown or blue eyes? Eye color must also be polygenic.

311

Creation of multiple identical single photon emitters in diamond  

E-Print Network (OSTI)

Emitters of indistinguishable single photons are crucial for the growing field of quantum technologies. To realize scalability and increase the complexity of quantum optics technologies, multiple independent yet identical single photon emitters are also required. However typical solid-state single photon sources are dissimilar, necessitating the use of electrical feedback or optical cavities to improve spectral overlap between distinct emitters. Here, we present controllable growth of bright silicon-vacancy (SiV-) centres in bulk diamond which intrinsically show almost identical emission (spectral overlap of up to 83%) and near transform-limited excitation linewidths. We measure the photo-physical properties of defects at room and cryogenic temperatures, and demonstrate incorporation into a solid immersion lens (SIL). Our results have impact upon the application of single photon sources for quantum optics and cryptography, and the production of next generation fluorophores for bio-imaging.

Lachlan J. Rogers; Kay D. Jahnke; Luca Marseglia; Christoph. Müller; Boris Naydenov; Hardy Schauffert; C. Kranz; T. Teraji; Junichi Isoya; Liam P. McGuinness; Fedor Jelezko

2013-10-14T23:59:59.000Z

312

The Effects of Variations in Buffer Gas Mixing Ratios on Commercial Carbon Dioxide Cavity Ring-Down Spectroscopy Sensors  

Science Conference Proceedings (OSTI)

Primary gas standards, gas chromatography, and frequency-stabilized cavity ring-down spectroscopy measurements have been used to assess the effect of variations in the argon mixing ratio on the CO2 mixing ratios reported by commercial cavity ring-...

D. A. Long; L. Gameson; G.-W. Truong; K. Bielska; A. Cygan; J. T. Hodges; J. R. Whetstone; R. D. van Zee

313

The trouble with crystal polymorphism  

Science Conference Proceedings (OSTI)

Crystal polymorphism is one of the most widely studied structural characteristics of fats used in spreads, shortening, and confectionery applications. Simply put, polymorphism refers to the fact that triacylglycerols (TAG), and other lipids, can crystalliz

314

PREPARATION OF REFRACTORY OXIDE CRYSTALS  

DOE Patents (OSTI)

A method is given for preparing uranium dioxide, thorium oxide, and beryllium oxide in the form of enlarged individual crystals. The surface of a fused alkali metal halide melt containing dissolved uranium, thorium, or beryllium values is contacted with a water-vapor-bearing inert gas stream at a rate of 5 to 10 cubic centimeters per minute per square centimeter of melt surface area. Growth of individual crystals is obtained by prolonged contact. Beryllium oxide-coated uranium dioxide crystals are prepared by disposing uranium dioxide crystals 5 to 20 microns in diameter in a beryllium-containing melt and contacting the melt with a water-vapor-bearing inert gas stream in the same manner. (AEC)

Grimes, W.R.; Shaffer, J.H.; Watson, G.M.

1962-11-13T23:59:59.000Z

315

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

E-Print Network (OSTI)

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

Chae, Y C; Dolgashev, V

2007-01-01T23:59:59.000Z

316

Adaptive Liquid Crystal Windows  

SciTech Connect

Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft × 1ft prototype panels for the world’s first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicron’s patented e-Tint® technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of power consumption by ALCWs allows for on-board power electronics for automatic matching of transmission through windows to varying climate conditions without drawing the power from the power grid. ALCWs are capable of transmitting more sunlight in winters to assist in heating and less sunlight in summers to minimize overheating. As such, they can change the window from being a source of energy loss to a source of energy gain. In addition, the scalable AMI’s roll-to-roll process, proved by making 1ft × 1ftALCW prototype panels, allows for cost-effective production of large-scale window panels along with capability to change easily their color and shape. In addition to architectural glazing in houses and commercial buildings, ALCWs can be used in other applications where control of sunlight is needed, such as green houses, used by commercial produce growers and botanical gardens, cars, aircrafts, etc.

Taheri, Bahman; Bodnar, Volodymyr

2011-12-31T23:59:59.000Z

317

Multiple stage railgun  

DOE Patents (OSTI)

A multiple stage magnetic railgun accelerator (10) for accelerating a projectile (15) by movement of a plasma arc (13) along the rails (11,12). The railgun (10) is divided into a plurality of successive rail stages (10a-n) which are sequentially energized by separate energy sources (14a-n) as the projectile (15) moves through the bore (17) of the railgun (10). Propagation of energy from an energized rail stage back towards the breech end (29) of the railgun (10) can be prevented by connection of the energy sources (14a-n) to the rails (11,12) through isolation diodes (34a-n). Propagation of energy from an energized rail stage back towards the breech end of the railgun can also be prevented by dividing the rails (11,12) into electrically isolated rail sections (11a-n, 12a-n). In such case means (55a-n) are used to extinguish the arc at the end of each energized stage and a fuse (31) or laser device (61) is used to initiate a new plasma arc in the next energized rail stage.

Hawke, Ronald S. (Livermore, CA); Scudder, Jonathan K. (Pleasanton, CA); Aaland, Kristian (Livermore, CA)

1982-01-01T23:59:59.000Z

318

Higher Order Modes Damping Analysis for the SPX Deflecting Cavity Cyromodule  

Science Conference Proceedings (OSTI)

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

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

2012-06-06T23:59:59.000Z

319

Higher Order Modes Damping Analysis for the SPX Deflecting Cavity Cryomodule  

Science Conference Proceedings (OSTI)

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

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

2012-07-01T23:59:59.000Z

320

Electromagnetic and mechanical design of gridded radio-frequency cavity windows  

SciTech Connect

Electromagnetic, thermal and structural analyses of radio-frequency (RF) cavities were performed as part of a developmental RF cavity program for muon cooling. RF cavities are necessary to provide longitudinal focusing of the muons and to compensate for their energy loss. Closing the cavity ends by electrically conducting windows reduces the power requirement and increases the on-axis electric field for a given maximum surface electric field. Many factors must be considered in the design of RF cavity windows. RF heating can cause the windows to deform in the axial direction of the cavity. The resulting thermal stresses in the window must be maintained below the yield stress of the window material. The out-of-plane deflection must be small enough so that the consequent frequency shift is tolerable. For example, for an 805 MHz cavity, the out-of-plane deflection must be kept below 25 microns to prevent the frequency of the cavity from shifting more than 10 kHz. In addition, the window design should yield smooth electric and magnetic fields, terminate field leakage beyond the window, and minimize beam scattering. In the present thesis, gridded-tube window designs were considered because of their high structural integrity. As a starting point in the analysis, a cylindrical pillbox cavity was considered as a benchmark problem. Analytical and finite element solutions were obtained for the electric and magnetic fields, power loss density, and temperature profile. Excellent agreement was obtained between the analytical and finite element results. The finite element method was then used to study a variety of gridded-tube windows. It was found that cooling of the gridded-tube windows by passing helium gas inside the tubes significantly reduces the out-of-plane deflection and the thermal stresses. Certain tube geometries and grid patterns were found to satisfy all of the design requirements.

Alsharoa, Mohammad M.; /IIT, Chicago /Fermilab

2004-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

CRYSTAL Research Plan January 2000  

E-Print Network (OSTI)

climates. The planned study includes participation by multiple agencies and international organizations IS AVAILABLE FROM: Robert J. Curran, Radiation Science Program NASA Headquarters, Washington DC rcurran@hq

322

Cryogenic controls for Fermilab's SRF cavities and test facility  

Science Conference Proceedings (OSTI)

A new superconducting radio frequency (SRF) cavities test facility is now operational at Fermilab's Meson Detector Building (MDB). The facility is supplied cryogens from the Cryogenic Test Facility (CTF) located in a separate building 500-m away. The design incorporates ambient temperature pumping for super-fluid helium production, as well as three 0.6-kW at 4.5-K refrigerators, five screw compressors, a helium purifier, helium and nitrogen inventory, cryogenic distribution system, and a variety of test cryostats. To control and monitor the vastly distributed cryogenic system, a flexible scheme has been developed. Both commercial and experimental physics tools are used. APACS+{trademark}, a process automation control system from Siemens-Moore, is at the heart of the design. APACS+{trademark} allows engineers to configure an ever evolving test facility while maintaining control over the plant and distribution system. APACS+{trademark} nodes at CTF and MDB are coupled by a fiber optic network. DirectLogic205 PLC's by KOYO{reg_sign} are used as the field level interface to most I/O. The top layer of this system uses EPICS (Experimental Physics and Industrial Control System) as a SCADA/HMI. Utilities for graphical display, control loop setting, real time/historical plotting and alarming have been implemented by using the world-wide library of applications for EPICS. OPC client/server technology is used to bridge across each different platform. This paper presents this design and its successful implementation.

Norris, B.; Bossert, R.; Klebaner, A.; Lackey, S.; Martinez, A.; Pei, L.; Soyars, W.; Sirotenko, V.; /Fermilab

2007-07-01T23:59:59.000Z

323

X-Band Crab Cavities for the CLIC Beam Delivery System  

Science Conference Proceedings (OSTI)

The CLIC machine incorporates a 20 mrad crossing angle at the IP to aid the extraction of spent beams. In order to recover the luminosity lost through the crossing angle a crab cavity is proposed to rotate the bunches prior to collision. The crab cavity is chosen to have the same frequency as the main linac (11.9942 GHz) as a compromise between size, phase stability requirements and beam loading. It is proposed to use a HE11 mode travelling wave structure as the CLIC crab cavity in order to minimise beam loading and mode separation. The position of the crab cavity close to the final focus enhances the effect of transverse wake-fields so effective wake-field damping is required. A damped detuned structure is proposed to suppress and de-cohere the wake-field hence reducing their effect. Design considerations for the CLIC crab cavity will be discussed as well as the proposed high power testing of these structures at SLAC. Design of a crab cavity for CLIC is underway at the Cockcroft Institute in collaboration with SLAC. This effort draws on a large degree of synergy with the ILC crab cavity developed at the Cockcroft Institute and other deflecting structure development at SLAC. A study of phase and amplitude variations in the cavity suggests that the tolerances are very tight and require a 'beyond state of the art' LLRF control system. A study of cavity geometry and its effect on the cavity fields has been performed using Microwave studio. This study has suggested that for our cavity an iris radius between 4-5 mm is optimum with an iris thickness of 2-3 mm based on group velocity and peak fields. A study of the cavity wakefields show that the single bunch wakes are unlikely to be a problem but the short bunch spacing may cause the multi-bunch wakefields to be an issue. This will require some of the modes to be damped strongly so that the wake is damped significantly before any following bunch arrives. Various methods of damping have been investigated and suggest that waveguide damping in the cells should provide sufficient damping in the vertical plane, which is the most sensitive.

Burt, G.; Ambattu, P.K.; Dexter, A.C.; Abram, T.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Dolgashev, V.; Tantawi, S.; /SLAC; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.

2011-11-22T23:59:59.000Z

324

Superconducting accelerator cavity with a heat affected zone having a higher RRR  

DOE Patents (OSTI)

An improved method for welding accelerator cavities without the need for time consuming and expensive faying surface treatments comprising electron beam welding such cavities in a vacuum welding chamber within a vacuum envelope and using the following welding parameters: a beam voltage of between about 45 KV and 55 KV; a beam current between about 38 ma and 47 ma; a weld speed of about 15 cm/min; and a sharp focus and a rhombic raster of between about 9 KHz and 10 Khz. A welded cavity made according to the method of the present invention is also described.

Brawley, John (Grafton, VA); Phillips, H. Lawrence (Hayes, VA)

2000-01-01T23:59:59.000Z

325

Quantum-information processing in decoherence-free subspace with low-Q cavities  

SciTech Connect

We consider the input-output process with low-Q cavities confining atoms for quantum-information processing, based on a general expression for reflection coefficient of the single photon. Focusing on the qubit encoding in decoherence-free subspace (DFS), we propose entanglement generation, universal quantum computing, and multiqubit controlled phase flip, using individual photon input and output from the cavities. Because of the DFS and no requirement for high-Q cavities, our schemes are not only immune to dephasing but also feasible with currently available technology.

Chen Qiong; Feng Mang [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

2010-11-15T23:59:59.000Z

326

Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities  

SciTech Connect

The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

De Silva, Payagalage Subashini Uddika [JLAB, Old Dominion U.; Delayen, Jean Roger [Old Dominion U.

2012-09-01T23:59:59.000Z

327

Cooling of a mirror in cavity optomechanics with a chirped pulse  

SciTech Connect

We investigate the response of a harmonically confined mirror to an optical pulse in cavity optomechanics. We show that when the pulsed coupling strength takes the form of a chirped pulse, thermal fluctuations of the mirror can be significantly transferred to the cavity field. In addition, the frequency modulation of the pulse could enable a better cooling performance by suppressing the sensitivity of the dependence of detuning and pulse areas. Using numerical investigations, we find that the pulsed cooling is mainly limited by the cavity-field decay rate.

Liao, Jie-Qiao; Law, C. K. [Department of Physics and Institute of Theoretical Physics, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region (China)

2011-11-15T23:59:59.000Z

328

Higher Order Modes HOM___s in Coupled Cavities of the Flash Module ACC39  

Science Conference Proceedings (OSTI)

We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

Shinton, I.R.R.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech.; Jones, R.M.; /Manchester U. /DESY; Li, Z.; /SLAC; Zhang, P.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech. /DESY

2012-09-14T23:59:59.000Z

329

Plasma etching of cavities into diamond anvils for experiments at high pressures and high temperatures  

Science Conference Proceedings (OSTI)

We describe a method for precisely etching small cavities into the culets of diamond anvils for the purpose of providing thermal insulation for samples in experiments at high pressures and high temperatures. The cavities were fabricated using highly directional oxygen plasma to reactively etch into the diamond surface. The lateral extent of the etch was precisely controlled to micron accuracy by etching the diamond through a lithographically fabricated tungsten mask. The performance of the etched cavities in high-temperature experiments in which the samples were either laser heated or electrically heated is discussed.

Weir, S.T.; Cynn, H.; Falabella, S.; Evans, W.J.; Aracne-Ruddle, C.; Farber, D.; Vohra, Y.K. (LLNL); (UAB)

2012-10-23T23:59:59.000Z

330

An experimental study of free convection in compound parabolic concentrator (CPC) cavities  

SciTech Connect

An experimental study of the free convection heat transfer between the cylindrical absorber and the flat top of a compound parabolic concentrator (CPC) is described. Results are obtained for a range of absorber temperatures and four CPC cavity heights. For similar conditions of operating temperature, the heat transfer from a cylinder in free air is about 30 to 50 percent higher than in a CPC cavity. Two correlations for Nusselt and Grashof numbers have been obtained using the equivalent length and the cavity height as the characteristic length of the system.

Chew, T.C.; Wijeysundera, N.E.; Tay, A.O.

1988-11-01T23:59:59.000Z

331

Usability in multiple monitor displays  

Science Conference Proceedings (OSTI)

An experimental study was conducted to examine the impact of multiple monitors on user performance and multitasking. Forty-three participants were assigned to two groups - a multi-monitor group and a singlemonitor group - to carry out a series of tasks. ... Keywords: large display monitor, multiple monitors, multitasking, usability, user performance

Jacob M. Truemper; Hong Sheng; Michael G. Hilgers; Richard H. Hall; Morris Kalliny; Basanta Tandon

2008-10-01T23:59:59.000Z

332

Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity  

SciTech Connect

A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here using the computer program.

J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, A. D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Geng, R. L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhao, K. [Institute of Heavy Ion Physics, Peking University, Beijing (China)

2011-07-01T23:59:59.000Z

333

New Accessory for Cleaning the Inside of the Machine Tool Cavity  

SciTech Connect

The best way to extend the life of a metalworking fluid (MWF) is to make sure the machine tool and MWF delivery system are properly cleaned at least once per year. The dilemma the MWF manager is faced with is: How does one clean the machine tool and the MWF system on a large machine tool with an enclosure in a timely manner without impacting production schedules? Remember the walls and roof of the machine enclosure are coated with a film of dried contaminated MWF that must also be removed. If not removed, the deposits on these surfaces can recontaminate the fresh charge of MWF. I have found a product that with this revised procedure helps to shorten the machine tool down time involved with machine cleaning. (1) Discuss with your MWF supplier if they have a machine cleaning product that can be used with your current water based MWF during normal machining operations. Most MWF manufacturers have a machine cleaner that can be used at a lower concentration (1-2% vs. 5%) and can be used while still making production parts for a short period of time (usually 24-48 hours). (2) Make sure this machine cleaner is compatible with the work-piece material you are machining into product. Most cleaners are compatible with ferrous alloys. Because of the increased alkalinity of the fluid you might experience staining if you are machining copper or aluminum alloys. (3) Remove the chips from the chips pans and fluid channels. (4) During off shift hours circulate the MWF using a new product marketed by Rego-Fix called a 'Hydroball'. This device has a 5/8 inch diameter straight shank which allows it to be installed in any collet or solid quick change tool holder. It has multiple nozzles so that the user can control the spray pattern generated when the MWF is circulated. It allows the user to utilize the high pressure, through spindle MWF delivery capability of your machine tool for cleaning purposes. The high pressure MWF system can now be effectively used for cleaning purposes. This will also work with standard pressure system but you must reduce the number of nozzles utilized. By combining the movement of the machine axis around the operating envelope and the MWF circulation you can do a reasonably effective job of washing the inside of the machine tool operating cavity. Way covers will be moved and surfaces exposed because of axis movement. Spray direction will change to better wash fixtures and machine tool components. Deposits will start to breakdown and be washed into the machine tool sump. Since the cycle will run four or more hours it can be done with a weaker cleaning solution. The distributor states that the unit can be rotated up to 50 RPM. When running it has the same effect as the washing rotor inside of your home dishwasher. Inside the cavity on a machining center there is a lot of splash. During normal operations, MWF deposits buildup on the walls and roof of the enclosures. If these deposits (containing bacteria, mold and other contaminants) are not removed they will inoculate the fresh charge of MWF when they are resaturated. When you clean the inside of machine tool cavity, time is spent removing these deposits on the walls and roof of the enclosure. Getting to these surfaces is very difficult usually requiring that a member of the cleaning crew get inside the machine tool to reach them. The Hydro ball is effective in distributing the cleaning solution on all surfaces of the enclosure under high pressure. The only negative we have found is you get to find all the gaps and leaks in your machine tool enclosure. By running the hydro ball with the machine cleaner enriched MWF during off shift (4-8 hours) you can effectively remove these deposits and buildups on the internal surfaces of the cavity of the machine tool and wash them down into the sump. You also clean the internal components of the MWF system without interrupting normal scheduled work. (5) Pump out the spent MWF. You will have found that most of the deposits have been washed from the internal surfaces of the enclosure. For extremely dirty machines you might have to

Lazarus, Lloyd

2009-04-21T23:59:59.000Z

334

Nonlinear Cerenkov Radiation in Nonlinear Photonic Crystal Waveguides  

SciTech Connect

We study nonlinear Cerenkov radiation generated from a nonlinear photonic crystal waveguide where the nonlinear susceptibility tensor is modulated by the ferroelectric domain. Nonlinear polarization driven by an incident light field may emit coherently harmonic waves at new frequencies along the direction of Cerenkov angles. Multiple radiation spots with different azimuth angles are simultaneously exhibited from such a hexagonally poled waveguide. A scattering involved nonlinear Cerenkov arc is also observed for the first time. Cerenkov radiation associated with quasi-phase matching leads to these novel nonlinear phenomena.

Zhang, Y.; Gao, Z. D.; Qi, Z.; Zhu, S. N.; Ming, N. B. [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210093 (China)

2008-04-25T23:59:59.000Z

335

Flux pinning characteristics in cylindrical ingot niobium used in superconducting radio frequency cavity fabrication  

Science Conference Proceedings (OSTI)

We present the results of from DC magnetization and penetration depth measurements of cylindrical bulk large-grain (LG) and fine-grain (FG) niobium samples used for the fabrication of superconducting radio frequency (SRF) cavities. The surface treatment consisted of electropolishing and low temperature baking as they are typically applied to SRF cavities. The magnetization data were fitted using a modified critical state model. The critical current density Jc and pinning force Fp are calculated from the magnetization data and their temperature dependence and field dependence are presented. The LG samples have lower critical current density and pinning force density compared to FG samples which implies a lower flux trapping efficiency. This effect may explain the lower values of residual resistance often observed in LG cavities than FG cavities.

Dhavale Ashavai, Pashupati Dhakal, Anatolii A Polyanskii, Gianluigi Ciovati

2012-04-01T23:59:59.000Z

336

OPTIMIZING CENTRIFUGAL BARREL POLISHING FOR MIRROR FINISH SRF CAVITY AND RF TESTS AT JEFFERSON LAB  

SciTech Connect

We performed Centrifugal Barrel Polishing (CBP) on a 1.3 GHz fine grain TESLA single cell cavity and 1.5 GHz fine grain CEBAF high gradient superconducting radio frequency (SRF) single cell cavity following a modified recipe originally developed at Fermi National Accelerator Lab (FNAL). We were able to obtain a mirror like surface similar to that obtained at FNAL, while reducing the number of CBP steps and total processing time. This paper will discuss the change in surface and subsequent cavity performance post CBP, after a 800 C bake (no pre-bake chemistry) and minimal controlled electro-polishing (10 micron). In addition to Q vs. E{sub ACC} thermometry mapping with preheating characteristics and optical inspection of the cavity after CBP will also be shown.

Ari Palczewski, Rongli Geng, Hui Tian

2012-07-01T23:59:59.000Z

337

High gain proportional rf control stability at TESLA cavities Elmar Vogel  

E-Print Network (OSTI)

High gain proportional rf control stability at TESLA cavities Elmar Vogel Deutsches Elektronen) based on TESLA technology. Additional control loops improve the field regulation by treating repetitive loops is desirable for the strong suppression of nonpredictive and nonrepetitive disturbances. TESLA

338

Energy Recovery Linac cavity at BNL | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Energy Recovery Linac cavity at BNL Energy Recovery Linac cavity at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Energy Recovery Linac cavity at BNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Energy Recovery Linac cavity Developed at: Brookhaven National Laboratory, New York and Advanced Energy Systems, New York Developed in:

339

Optical Injection Locking of Vertical Cavity Surface-Emitting Lasers: Digital and Analog Applications  

E-Print Network (OSTI)

and high gain resonance peak of an OIL VCSEL is demonstratedemission peaks. This phenomenon has enabled OIL MM VCSELs topeak under direct modulation. Moreover, the cavity mode of the OIL

Parekh, Devang

2012-01-01T23:59:59.000Z

340

The Measurement of Aerosol Optical Properties Using Continuous Wave Cavity Ring-Down Techniques  

Science Conference Proceedings (OSTI)

Large uncertainties in the effects that aerosols have on climate require improved in situ measurements of extinction coefficient and single-scattering albedo. This paper describes the use of continuous wave cavity ring-down (CW-CRD) technology to ...

Anthony W. Strawa; Rene Castaneda; Thomas Owano; Douglas S. Baer; Barbara A. Paldus

2003-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Parallel Computation of Intergrated Electronmagnetic, Thermal and Structural Effects for Accelerator Cavities  

Science Conference Proceedings (OSTI)

The successful operation of accelerator cavities has to satisfy both rf and mechanical requirements. It is highly desirable that electromagnetic, thermal and structural effects such as cavity wall heating and Lorentz force detuning in superconducting rf cavities can be addressed in an integrated analysis. Based on the SLAC parallel finite-element code infrastructure for electromagnetic modeling, a novel multi-physics analysis tool has been developed to include additional thermal and mechanical effects. The parallel computation enables virtual prototyping of accelerator cavities on computers, which would substantially reduce the cost and time of a design cycle. The multi-physics tool is applied to the LCLS rf gun for electromagnetic, thermal and structural analyses.

Akcelik, V.; Candel, A.; Kabel, A.; Lee, L-Q.; Li, Z.; Ng, C-K.; Xiao, L.; Ko, K.

2008-07-02T23:59:59.000Z

342

Casimir potential of a compact object enclosed by a spherical cavity  

E-Print Network (OSTI)

We study the electromagnetic Casimir interaction of a compact object contained inside a closed cavity of another compact object. We express the interaction energy in terms of the objects’ scattering matrices and translation ...

Zaheer, Saad

343

Field Testing of Cavity Ring-Down Spectroscopy Analyzers Measuring Carbon Dioxide and Water Vapor  

Science Conference Proceedings (OSTI)

Prevalent methods for making high-accuracy tower-based measurements of the CO2 mixing ratio, notably nondispersive infrared spectroscopy (NDIR), require frequent system calibration and sample drying. Wavelength-scanned cavity ring-down ...

Scott J. Richardson; Natasha L. Miles; Kenneth J. Davis; Eric R. Crosson; Chris W. Rella; Arlyn E. Andrews

2012-03-01T23:59:59.000Z

344

RF Cavity R&D at LBNL for the NLC Damping Rings, FY 1999  

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

3 031299 RF Cavity R&D at LBNL for the NLC Damping Rings, FY1999 December 3, 1999 R. Rimmer, J.N. Corlett, G. Koehler, D. Li, N. Hartmann, J. Rasson, T.Saleh Lawrence Berkeley...

345

NREL's Optical Cavity Furnace Brings Together a Myriad of Advances for Processing Solar Cells (Fact Sheet)  

DOE Green Energy (OSTI)

Fact sheet on 2011 R&D 100 Award winner, the Optical Cavity Furnace. The innovative furnace uses light and unique light-induced effects to make higher-efficiency solar cells at lower cost.

Not Available

2011-08-01T23:59:59.000Z

346

SRF CAVITY PERFORMANCE OVERVIEW FOR THE 12 GeV UPGRADE  

Science Conference Proceedings (OSTI)

The CEBAF accelerator, a recirculating CW electron accelerator that is currently operating at Jefferson Laboratory, is in the process of having 10 new cryomodules installed to allow for the maximum beam energy to be increased from 6 GeV to 12 GeV. This upgrade required the fabrication, processing and RF qualification of 80, seven cell elliptical SRF cavities, a process that was completed in February 2012. The RF performance achieve in the vertical testing dewars has exceeded the design specification by {approx}25% and is a testament to the cavity design and processing cycle that has been implemented. This paper will provide a summary of the cavity RF performance in the vertical tests, as well as review the overall cavity processing cycle and duration for the project.

A. Burrill, G.K. Davis, C.E. Reece, A.V. Reilly, M. Stirbet

2012-07-01T23:59:59.000Z

347

Entanglement and bistability in coupled quantum dots inside a driven cavity  

SciTech Connect

Generation and dissipation of entanglement between two coupled quantum dots (QDs) in a cavity driven by a coherent field is studied. We find that it is possible to generate and sustain a large amount of entanglement between the quantum dots in the steady state, even in the presence of strong decay in both the cavity and the dots. We investigate the effect of different parameters (decay rates, coupling strengths, and detunings) on entanglement. We find that the cavity field shows bistability and study the effect of relevant parameters on the existence of this bistable behavior. We also study the correlation between the cavity field and the entanglement between the dots. The experimental viability of the proposed scheme is discussed.

Mitra, Arnab; Vyas, Reeta [Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

2010-01-15T23:59:59.000Z

348

Physical and mechanical metallurgy of high purity Nb for accelerator cavities  

SciTech Connect

In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

Bieler, T. R. [Michigan State University, East Lansing; Wright, N. T. [Michigan State University, East Lansing; Pourboghrat, F. [Michigan State University, East Lansing; Compton, C. [Michigan State University, East Lansing; Hartwig, K. T. [Texas A& M University; Baars, D. [Michigan State University, East Lansing; Zamiri, A. [Michigan State University, East Lansing; Chandrasekaran, S. [Michigan State University, East Lansing; Darbandi, P. [Michigan State University, East Lansing; Jiang, H. [Michigan State University, East Lansing; Skoug, E. [Michigan State University, East Lansing; Balachandran, S. [Texas A& M University; Ice, Gene E [ORNL; Liu, W. [Argonne National Laboratory (ANL)

2010-01-01T23:59:59.000Z

349

Method and device for generating microwaves using a split cavity modulator  

DOE Patents (OSTI)

This invention consists of a compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves as that frequency and through a series of sequential extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Clark, M.C.; Coleman, P.D.; Marder, B.M.

1990-01-01T23:59:59.000Z

350

Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields  

DOE Patents (OSTI)

A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Clark, M.C.; Coleman, P.D.; Marder, B.M.

1993-08-10T23:59:59.000Z

351

Method and device for generating microwaves using a split cavity modulator  

DOE Patents (OSTI)

This invention consists of a compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves as that frequency and through a series of sequential extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Clark, M.C.; Coleman, P.D.; Marder, B.M.

1990-12-31T23:59:59.000Z

352

Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields  

DOE Patents (OSTI)

A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Clark, M. Collins (Albuquerque, NM); Coleman, P. Dale (Albuquerque, NM); Marder, Barry M. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

353

New waveguide-type HOM damper for ALS storage ring cavities.  

E-Print Network (OSTI)

WAVEGUIDE-TYPE HOM DAMPER FOR ALS STORAGE RING CAVITIES*.CA, 94720, USA Abstract The ALS storage ring 500 MHz RFoperations issue at the ALS. During three consecutive

Kwiatkowski, Slawomir; Baptiste, Kenneth; Julian, James

2004-01-01T23:59:59.000Z

354

Measurements of the Higher Order Modes of the ALS 500 MHz Accelerating Cavities  

E-Print Network (OSTI)

2] "Coupled-bunch Stability at the ALS", J. M. Byrd and J.this conference. [3] "The ALS Storage Ring RF System", B.Higher Order Modes of the ALS 500 MHz Accelerating Cavities

Corlett, J.N.

2011-01-01T23:59:59.000Z

355

An improved model for natural convection heat loss from modified cavity receiver of solar dish concentrator  

Science Conference Proceedings (OSTI)

A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of inclinations (60 {solar dish collector, when compared with other well known models. (author)

Reddy, K.S.; Sendhil Kumar, N. [Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, Tamilnadu 600036 (India)

2009-10-15T23:59:59.000Z

356

Long-external-cavity distributed Bragg reflector laser with subkilohertz intrinsic linewidth  

E-Print Network (OSTI)

We report on a simple, compact, and robust 780 nm distributed Bragg reflector laser with subkilohertz intrinsic linewidth. An external cavity with optical path length of 3.6 m, implemented with an optical fiber, reduces ...

Lin, Qian

357

Hyperspectral microscopy using an external cavity quantum cascade laser and its applications for explosives detection  

Science Conference Proceedings (OSTI)

A hyperspectral infrared microscope using external cavity quantum cascade laser illumination and a microbolometer focal plane array is used to characterize nanogram-scale particles of the explosives RDX, tetryl, and PETN at fast acquisition rates.

Phillips, Mark C.; Suter, Jonathan D.; Bernacki, Bruce E.

2012-04-01T23:59:59.000Z

358

Production and Testing Experience with the SRF Cavities for the CEBAF 12 GeV Upgrade  

Science Conference Proceedings (OSTI)

The CEBAF recirculating CW electron linear accelerator at Jefferson Lab is presently undergoing a major upgrade to 12 GeV. This project includes the fabrication, preparation, and testing of 80 new 7-cell SRF cavities, followed by their incorporation into ten new cryomodules for subsequent testing and installation. In order to maximize the cavity Q over the full operable dynamic range in CEBAF (as high as 25 MV/m), the decision was taken to apply a streamlined preparation process that includes a final light temperature-controlled electropolish of the rf surface over the vendor-provided bulk BCP etch. Cavity processing work began at JLab in September 2010 and will continue through December 2011. The excellent performance results are exceeding project requirements and indicate a fabrication and preparation process that is stable and well controlled. The cavity production and performance experience to date will be summarized and lessons learned reported to the community.

A. Burrill, G.K. Davis, F. Marhauser, C.E. Reece, A.V. Reilly, M. Stirbet

2011-09-01T23:59:59.000Z

359

Measurement of Individual Hydrometeor Absorption Cross Sections Utilizing Microwave Cavity Perturbation Techniques  

Science Conference Proceedings (OSTI)

A technique for measurement of individual hydrometeor absorption cross sections is presented. Cross sections are inferred by inserting the hydrometeor into a high Q resonant cavity and measuring the Q perturbation. Tests were conducted in a 10.64 ...

Robert John Hansman Jr.

1984-12-01T23:59:59.000Z

360

Emergence of multipartite optomechanical entanglement in microdisk cavities coupled to nanostring waveguide  

Science Conference Proceedings (OSTI)

In this paper, we propose a scheme to show signatures of multipartite optomechanical entanglement, which is based on two high quality factor (high- $$Q$$ ) silicon ... Keywords: Microdisk cavities, Nanostring waveguide, Optomechanical entanglement

Zhi-Cheng Shi, Yan Xia, Jie Song

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Crystal Systems | Open Energy Information  

Open Energy Info (EERE)

Crystal Systems Crystal Systems Name Crystal Systems Address 27 Congress Street Place Salem, Massachusetts Zip 01970 Sector Solar Product Silicon producer Year founded 1971 Website http://www.crystalsystems.com/ Coordinates 42.5190384°, -70.8896271° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.5190384,"lon":-70.8896271,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

362

Generation and purification of maximally entangled atomic states in optical cavities  

Science Conference Proceedings (OSTI)

We present a probabilistic scheme for generating and purifying maximally entangled states of two atoms inside an optical cavity via no-photon detection at the cavity output, where ideal detectors are not required. The intermediate mixed states can be continuously purified so as to violate Bell inequalities in a parametrized manner. The scheme relies on an additional strong-driving field that realizes, atypically, simultaneous Jaynes-Cummings and anti-Jaynes-Cummings interactions.

Lougovski, P.; Walther, H. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Solano, E. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2005-01-01T23:59:59.000Z

363

Rotational Cooling of Polar Molecules by Stark-tuned Cavity Resonance  

E-Print Network (OSTI)

A general scheme for rotational cooling of diatomic heteronuclear molecules is proposed. It uses a superconducting microwave cavity to enhance the spontaneous decay via Purcell effect. Rotational cooling can be induced by sequentially tuning each rotational transition to cavity resonance, starting from the highest transition level to the lowest using an electric field. Electrostatic multipoles can be used to provide large confinement volume with essentially homogeneous background electric field.

C. H. Raymond Ooi

2003-06-04T23:59:59.000Z

364

Generation of fan-states of radiation field in a cavity  

E-Print Network (OSTI)

A scheme of generating recently introduced fan-states | \\alpha, 2k>_F (\\alpha is complex, k=1,2,3,...) is proposed basing on a \\Lambda-type atom-cavity field interaction. We show that with suitable atomic preparations and measurements a passage of a sequence of N atoms through a cavity may transform an initial field coherent state | \\alpha> to a fan-state | \\alpha, 2k>_F with k=2^{N-2}.

Nguyen Ba An; Truong Minh Duc

2001-11-30T23:59:59.000Z

365

Fluid Dynamic and Performance Behavior of Multiphase Progressive Cavity Pumps  

E-Print Network (OSTI)

It is common for an oil well to produce a mixture of hydrocarbons that flash when exposed to atmospheric pressure. The separation of oil and gas mixtures on site may prove expensive and lead to higher infrastructure and maintenance costs as well. A multiphase pump offers a good alternative with a lower capital cost and increased overall production. A Progressive Cavity Pump (PCP) is a positive displacement pump type that can be used to pump a wide range of multiphase mixtures, including high viscosity fluids with entrained gas and solid particles in suspension. Despite its advantages, a PCP has a reduced ability to handle high gas-liquid ratios due to limitations of its elastomeric stator material required to overcome thermo and mechanical effects. Also the efficiency decreases significantly with increases in gas volume fractions and reduced differential pressures. The current study focuses on studying the behavior of this unique pump in a wide range of GVFs and studying the effect of this ratio on overall efficiency, temperature and pressure distribution on the stator. The pump exhibits vibration issues at specific differential pressures and they have been studied in this work. This can be of critical value as severe vibration issues can damage the pump components such as couplings and bearings leading to high maintenance costs. Another important issue addressed by this research is the behavior of this pump in transient conditions. Oil well production is highly unpredictable with unexpected rises and drops in GVFs. These transient conditions have been simulated by varying the GVF over wide ranges and studying the pump's behavior in terms of load, temperature rises and instantaneous pressure profiles on the pump stator. This thesis provides a comprehensive study of this pump, its operating ranges and behavior in off-design conditions to assist oil and gas exploration ventures in making an informed choice in pump selection for their applications based on field conditions.

Narayanan, Shankar Bhaskaran

2011-08-01T23:59:59.000Z

366

Enhancing extraordinary transmission of light through a metallic nano slit with a nano cavity antenna  

E-Print Network (OSTI)

The extraordinary transmission of light through a nano slit in a metal film is enhanced by introducing a nano cavity antenna formed by a nearby metallic nano-strip over the slit opening. For a fixed wavelength, the width of the metallic nano-strip should be chosen to make the horizontal metal-insulator-metal waveguide of finite length resonant as a Fabry-Perot cavity. When such a cavity antenna is used to enhance the transmission through a non-resonant nano slit, the slit should be opened at a position with maximal magnetic field in the horizontal resonant cavity. It is shown that an optimized cavity antenna can enhance greatly the transmission of light through a non-resonant nano slit (by about 20 times) or a resonant nano slit (by 124%). The transmission spectrum of the nano slit can also be tuned by adjusting the width of the metallic nano-strip. Such a transmission enhancement with a nano cavity antenna is studied for the first time and the physical mechanism is explained.

Cui, Yanxia

2008-01-01T23:59:59.000Z

367

Design Parameters and Commissioning of Vertical Inserts Used for Testing the XFEL Superconducting Cavities  

E-Print Network (OSTI)

The European XFEL is a new research facility currently under construction at DESY in the Hamburg area in Germany. From 2015 on, it will generate extremely intense X-ray flashes that will be used by researchers from all over the world. The superconducting XFEL linear accelerator consists of 100 accelerator modules with more than 800 RF-cavities inside. The accelerator modules, superconducting magnets and cavities will be tested in the accelerator module test facility (AMTF). This paper gives an overview of the design parameters and the commissioning of the vertical insert, used in two cryostats (XATC) of the AMTF-hall. The Insert serves as a holder for 4 nine-cell cavities. This gives the possibility to cool down 4 cavities to 2K in parallel and, consequently, to reduce the testing time. The following RF measurement, selected as quality check, will be done separately for each cavity. Afterwards the cavities will be warmed up again and will be sent to the accelerator module assembly.

J. Schaffran; Y. Bozhko; B. Petersen; D. Meissner; M. Chorowski; J. Polinski

2013-06-26T23:59:59.000Z

368

Cryogenic sub-system for the 56 MHz SRF storage cavity for RHIC  

Science Conference Proceedings (OSTI)

A 56 MHz Superconducting RF Storage Cavity is being constructed for the RHIC collider. This cavity is a quarter wave resonator that will be operated in a liquid helium bath at 4.4 K. The cavity requires an extremely quiet environment to maintain its operating frequency. The cavity, besides being engineered for a mechanically quiet system, also requires a quiet cryogenic system. The helium is taken from RHIC's main helium supply header at 3.5 atm, 5.3K at a phase separator tank. The boil-off is sent back to the RHIC refrigeration system to recover the cooling. To acoustically separate the RHIC helium supply and return lines, a condenser/boiler heat exchanger condenses the helium vapor generated in the RF cavity bath. A system description and operating parameters are given about the cryogen delivery system. The 56 MHz superconducting storage RF cavity project is making progress. The cryogenic system design is in its final stage. The helium supply lines have been tapped into the RHIC helium distribution lines. The plate-and-fin heat exchanger design is near completion and specification will be sent out for bid soon. The cold helium vapor heating system design will start soon as well. A booster compressor specification is underway. The first phase separator and transfer line design work is near completion and will be sent out for bid soon.

Huang, Y.; Than, R.; Orfin, P.; Lederle, D.; Tallerico, T.; Masi L.; Talty, P.; Zhang, Y.

2011-03-28T23:59:59.000Z

369

Generalized Interpolation Material Point Approach to High Melting Explosive with Cavities Under Shock  

E-Print Network (OSTI)

Criterion for contacting is critically important for the Generalized Interpolation Material Point(GIMP) method. We present an improved criterion by adding a switching function. With the method dynamical response of high melting explosive(HMX) with cavities under shock is investigated. The physical model used in the present work is an elastic-to-plastic and thermal-dynamical model with Mie-Gr\\"uneissen equation of state. We mainly concern the influence of various parameters, including the impacting velocity $v$, cavity size $R$, etc, to the dynamical and thermodynamical behaviors of the material. For the colliding of two bodies with a cavity in each, a secondary impacting is observed. Correspondingly, the separation distance $D$ of the two bodies has a maximum value $D_{\\max}$ in between the initial and second impacts. When the initial impacting velocity $v$ is not large enough, the cavity collapses in a nearly symmetric fashion, the maximum separation distance $D_{\\max}$ increases with $v$. When the initial shock wave is strong enough to collapse the cavity asymmetrically along the shock direction, the variation of $D_{\\max}$ with $v$ does not show monotonic behavior. Our numerical results show clear indication that the existence of cavities in explosive helps the creation of ``hot spots''.

X. F. Pan; Aiguo Xu; Guangcai Zhang; Jianshi Zhu

2007-10-11T23:59:59.000Z

370

Fabrication, Treatment and Testing of a 1.6 Cell Photo-injector Cavity for HZB  

SciTech Connect

As part of a CRADA (Cooperative Research and Development Agreement) between Forschungszentrum Dresden (FZD) and JLab we have fabricated and tested after appropriate surface treatment a 1.5 cell, 1300 MHz RRR niobium photo-injector cavity to be used in a demonstration test at BESSY*. Following a baseline test at JLab, the cavity received a lead spot coating of ~8 mm diameter deposited with a cathode arc at the Soltan Institute on the endplate made from large grain niobium. It had been demonstrated in earlier tests with a DESY built 1.5 cell cavity ? the original design ? that a lead spot of this size can be a good electron source, when irradiated with a laser light of 213 nm . In the initial test with the lead spot we could measure a peak surface electric field of ~ 29 MV/m; after a second surface treatment, carried out to improve the cavity performance, but which was not done with sufficient precaution, the lead spot was destroyed and the cavity had to be coated a second time. This contribution reports about the experiences and results obtained with this cavity.

P. Kneisel, T. Kamps, J. Knobloch, O. Kugeler, A. Neumann, R. Nietubyc, J.K. Sekutowicz

2011-03-01T23:59:59.000Z

371

DESIGN AND PRELIMINARY TEST OF THE 1500 MHZ NSLS-II PASSIVE SUPERCONDUCTING RF CAVITY  

SciTech Connect

NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed. A passive SRF 3rd harmonic cavity consisting of two tightly coupled cells has been designed and fabricated for NSLS-II. Initial cold tests of this cavity are very promising. These tests have verified that the cavity frequency and mode separation between the 0 and {pi}-modes can be set at manufacture. Further, the frequency separation can be maintained over wide tuning ranges necessary for operation. Future work includes HOM damper and motorized tuner development.

Rose, J.; Gash, W.; Kosciuk, B.; Ravindranath, V.; Sikora, B.; Sharma, S.; Towne, N.; Grimm, T.L.; Boulware, C.H.; Krizmanich, C.; Kuhlman, B.; Miller, N.; Siegel, B.; Winowski, M.

2011-03-28T23:59:59.000Z

372

Manufacturing method of photonic crystal  

DOE Patents (OSTI)

A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.

Park, In Sung; Lee, Tae Ho; Ahn, Jin Ho; Biswas, Rana; Constant, Kristen P.; Ho, Kai-Ming; Lee, Jae-Hwang

2013-01-29T23:59:59.000Z

373

Crystallization and Solidification Properties of LipidsChapter 11 Ultrasonic Characterization of Lipid Crystallization  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 11 Ultrasonic Characterization of Lipid Crystallization Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Press  

374

Crystallization and Solidification Properties of LipidsChapter 2 Molecular Modeling Applications in Lipid Crystallization  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 2 Molecular Modeling Applications in Lipid Crystallization Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Press   ...

375

Anomaly Detection at Multiple Scales  

Science Conference Proceedings (OSTI)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Anomaly Detection at Multiple Scales, or ADAMS, is a $35 million DARPA project designed to identify patterns and anomalies ...

Alain Sren Mikhayhu

2012-06-01T23:59:59.000Z

376

Multiple Specialization of WAM Code  

Science Conference Proceedings (OSTI)

Program specialization is normally supported by global analysis of the program. Compilers use the information deduced to generate more efficient, specialized implementations of the program. This specialization can be single or multiple, depending if ...

Michel Ferreira; Luís Damas

1999-01-01T23:59:59.000Z

377

Parallel progressive multiple sequence alignment  

Science Conference Proceedings (OSTI)

Multiple Sequence Alignment is an essential tool in the analysis and comparison of biological sequences. Unfortunately, the complexity of this problem is exponential. Currently feasible methods are, therefore, only approximations. The progressive ...

Erik Pitzer

2005-02-01T23:59:59.000Z

378

Charge Delocalization Induces Multiple Reaction within an ...  

Science Conference Proceedings (OSTI)

Chemical Synthesis and Structural Analysis of Gd2O3 Nanoparticles for Optical Applications · Complex Crystallization Dynamics in Amorphous Germanium ...

379

ARM - Field Campaign - CRYSTAL-FACE  

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

govCampaignsCRYSTAL-FACE govCampaignsCRYSTAL-FACE Campaign Links CRYSTAL-FACE Website Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : CRYSTAL-FACE 2002.06.26 - 2002.08.01 Lead Scientist : James Mather Data Availability Data is available to the general public at the ARM Archive. Questions regarding CRYSTAL-FACE or the PARSL data set may be directed to Jim Mather at the Pacific Northwest National Laboratory (Jim.Mather@pnl.gov) or visit the CRYSTAL-FACE web site at http://cloud1.arc.nasa.gov/crystalface/ For data sets, see below. Description From July 3-29, 2002 ARM took part in CRYSTAL-FACE (The Cirrus Regional Study of Tropical Anvils and Cirrus Layers -Florida Area Cirrus Experiment). CRYSTAL-FACE was organized by NASA but many agencies and

380

SLAC National Accelerator Laboratory - Bendable Crystals Resolve...  

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

Bendable Crystals Resolve Properties of X-ray Pulses By Glenn Roberts Jr. September 12, 2012 A frustrating flaw in a set of custom crystals for an instrument at SLAC National...

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Ice Crystal Production by Mountain Surfaces  

Science Conference Proceedings (OSTI)

Evidence is presented for a process of ice crystal generation in supercooled orographic clouds in contact with snow-covered mountain surfaces. Comparisons of the crystal concentrations at the surface with aircraft sampling indicate that the “...

David C. Rogers; Gabor Vali

1987-09-01T23:59:59.000Z

382

Aggregation of Ice Crystals in Cirrus  

Science Conference Proceedings (OSTI)

Results are given from analysis of the aggregation of thick plate, columnar, and bullet rosette ice crystals in cirrus. Data were obtained from PMS 2D-C images, oil coated slides, and aircraft meteorological measurements. Crystal size ranged from ...

Masahiro Kajikawa; Andrew J. Heymsfield

1989-10-01T23:59:59.000Z

383

Ice Crystal Replication with Common Plastic Solutions  

Science Conference Proceedings (OSTI)

Use of common plastics, i.e., polystyrene, Plexiglas (polymethyl methacrylate) and Lexan (polycarbonate), was investigated for ice crystal replication. The results suggest that all common plastics tested are usable for ice crystal replication ...

Tsuneya Takahashi; Norihiko Fukuta

1988-02-01T23:59:59.000Z

384

Crystallization and Solidification Properties of Lipids  

Science Conference Proceedings (OSTI)

A basic understanding of lipid crystallization and solidification is fundamental to understanding and optimizing products or systems containing lipids. Crystallization and Solidification Properties of Lipids Health acid analysis aocs april articles chlor

385

Light Scattering by Single Natural Ice Crystals  

Science Conference Proceedings (OSTI)

During the South Pole Ice Crystal Experiment, angular scattering intensities (ASIs) of single ice crystals formed in natural conditions were measured for the first time with the polar nephelometer instrument. The microphysical properties of the ...

Valery Shcherbakov; Jean-François Gayet; Brad Baker; Paul Lawson

2006-05-01T23:59:59.000Z

386

Crystal structure of a novel non-Pfam protein PF2046 solved using low resolution B-factor sharpening and multi-crystal averaging methods  

SciTech Connect

Sometimes crystals cannot diffract X-rays beyond 3.0 {angstrom} resolution due to the intrinsic flexibility associated with the protein. Low resolution diffraction data not only pose a challenge to structure determination, but also hamper interpretation of mechanistic details. Crystals of a 25.6 kDa non-Pfam, hypothetical protein, PF2046, diffracted X-rays to 3.38 {angstrom} resolution. A combination of Se-Met derived heavy atom positions with multiple cycles of B-factor sharpening, multi-crystal averaging, restrained refinement followed by manual inspection of electron density and model building resulted in a final model with a R value of 23.5 (R{sub free} = 24.7). The asymmetric unit was large and consisted of six molecules arranged as a homodimer of trimers. Analysis of the structure revealed the presence of a RNA binding domain suggesting a role for PF2046 in the processing of nucleic acids.

Su, Jing; Li, Yang; Shaw, Neil; Zhou, Weihong; Zhang, Min; Xu, Hao; Wang, Bi-Cheng; Liu, Zhi-Jie (Ankara); (Nankai); (Chinese Aca. Sci.); (Georgia)

2012-11-13T23:59:59.000Z

387

Program on Technology Innovation: Crystal Habit Modifiers  

Science Conference Proceedings (OSTI)

This report presents the results of a review of the scientific and technical literature pertaining to the potential use of crystal habit modifiers to control the formation or consequent effects of deposits in nuclear plant systems. Crystal habit modifiers (CHMs) could potentially be added to the primary or secondary circuits of a pressurized water reactor (PWR) or to boiling water reactor (BWR) coolant as a means of controlling the crystal habit (shape) of the crystals that comprise primary and secondary...

2007-12-17T23:59:59.000Z

388

Crystal of GTP Cyclohydrolase Type IB  

Science Conference Proceedings (OSTI)

This invention relates to a novel, bacterial GTP Cyclohydrolase Type IB enzyme, and the crystal structure thereof.

Swairjo, Manal A.; Iwata-Reuyl, Dirk; de Crecy-Lagard, Valerie

2012-12-11T23:59:59.000Z

389

Estimating Flexoelectric Properties of Piezoelectric Crystals  

Science Conference Proceedings (OSTI)

Energy Harvesting Utilized Resonance Phenomena of Piezoelectric Unimorph · Estimating Flexoelectric Properties of Piezoelectric Crystals: Utilization of a ...

390

Quartz Crystal Microbalances Enable New Microscale Analytic ...  

Science Conference Proceedings (OSTI)

... The technique measures the reaction energy needed to decompose, oxidize ... quartz crystal microbalance, essentially a small piezoelectric disk of ...

2012-10-15T23:59:59.000Z

391

Polymer Crystallization in 25 nm Spheres  

E-Print Network (OSTI)

Crystallization within the discrete spheres of a block copolymer mesophase was studied by time-resolved x-ray scattering. The cubic packing of microdomains, established by self-assembly in the melt, is preserved throughout crystallization by strong interblock segregation even though the amorphous matrix block is well above its glass transition temperature. Homogeneous nucleation within each sphere yields isothermal crystallizations which follow first-order kinetics, contrasting with the sigmoidal kinetics normally exhibited in the quiescent crystallization of bulk polymers.

Yueh-Lin Loo; Richard A. Register; Anthony J. Ryan

2000-03-30T23:59:59.000Z

392

The Next Generation of Crystal Detectors  

E-Print Network (OSTI)

Heavy crystal scintillators are used widely in HEP experiments for precision measurements of photons and electrons. Future HEP experiments, however, require crystal scintillators of more bright, more fast, more radiation hard and less cost. This paper discusses several R&D directions for the next generation of crystal detectors for future HEP experiments.

Ren-Yuan Zhu

2013-08-22T23:59:59.000Z

393

Light output simulation of LYSO single crystal  

E-Print Network (OSTI)

We used the Geant4 simulation toolkit to estimate the light collection in a LYSO crystal by using cosmic muons and E=105 MeV electrons. The light output as a function of the crystal length is studied. Significant influence of the crystal wrapping in the reflective paper and optical grease coupling to the photodetectors on the light output is demonstrated.

Usubov, Zafar

2013-01-01T23:59:59.000Z

394

Cloud Ice Crystal Classification Using a 95-GHz Polarimetric Radar  

Science Conference Proceedings (OSTI)

Two algorithms are presented for ice crystal classification using 95-GHz polarimetric radar observables and air temperature (T). Both are based on a fuzzy logic scheme. Ice crystals are classified as columnar crystals (CC), planar crystals (PC), ...

K. Aydin; J. Singh

2004-11-01T23:59:59.000Z

395

Federal Energy Management Program: Multiple Motivations Institutional  

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

Multiple Multiple Motivations Institutional Change Principle to someone by E-mail Share Federal Energy Management Program: Multiple Motivations Institutional Change Principle on Facebook Tweet about Federal Energy Management Program: Multiple Motivations Institutional Change Principle on Twitter Bookmark Federal Energy Management Program: Multiple Motivations Institutional Change Principle on Google Bookmark Federal Energy Management Program: Multiple Motivations Institutional Change Principle on Delicious Rank Federal Energy Management Program: Multiple Motivations Institutional Change Principle on Digg Find More places to share Federal Energy Management Program: Multiple Motivations Institutional Change Principle on AddThis.com... Sustainable Buildings & Campuses

396

CRITICAL INFRASTRUCTURE PROTECTION Multiple Efforts to Secure...  

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

CRITICAL INFRASTRUCTURE PROTECTION Multiple Efforts to Secure Control Systems Are Under Way, but Challenges Remain CRITICAL INFRASTRUCTURE PROTECTION Multiple Efforts to Secure...

397

Robust Multiple Car Tracking With Occlusion Reasoning  

E-Print Network (OSTI)

BERKELEY Robust Multiple Car Tracking with OcclusionAND HIGHWAYS Robust Multiple Car Tracking with Occlusiondraws decisions like "stalled car in lane 2 detected", "high

Koler, Dieter; Weber, Joseph; Malik, Jitendra

1994-01-01T23:59:59.000Z

398

Optimization of the Low-Loss SRF Cavity for the ILC  

SciTech Connect

The Low-Loss shape cavity design has been proposed as a possible alternative to the baseline TESLA cavity design for the ILC. The advantages of this design over the TESLA cavity are its lower cryogenic loss, and higher achievable gradient due to lower surface fields. High gradient prototypes for such designs have been tested at KEK (ICHIRO) and JLab (LL). However, issues related to HOM damping and multipacting (MP) still need to be addressed. Preliminary numerical studies of the prototype cavities have shown unacceptable damping for some higher-order dipole modes if the typical TESLA HOM couplers are directly adapted to the design. The resulting wakefield will dilute the beam emittance thus reduces the machine luminosity. Furthermore, high gradient tests on a 9-cell prototype at KEK have experienced MP barriers although a single LL cell had achieved a high gradient. From simulations, MP activities are found to occur in the end-groups of the cavity. In this paper, we will present the optimization results of the end-groups for the Low-Loss shape for effective HOM damping and alleviation of multipacting. Comparisons of simulation results with measurements will also be presented.

Z. Li; L. Ge; K. Ko; L. Lee; C.-K. Ng; G. L. Schussman; L. Xiao; T. Higo; Y. Morozumi; K. Saito; P. Kneisel; J. S. Sekutowicz

2007-08-01T23:59:59.000Z

399

Two-photon-driven nonlinear dynamics and entanglement of an atom in a nonuniform cavity  

Science Conference Proceedings (OSTI)

In this paper we study the dynamics in the general case for a Tavis-Cummings atom in a nonuniform cavity. In addition to the dynamical Stark shift, the center-of-mass motion of the atom and the recoil effect are considered in both the weak and the strong cavity-atom coupling regimes. It is shown that the spatial motion of the atom inside the cavity in the resonant case leads to a transition between topologically different solutions. This effect is manifested by a singularity in the interlevel transition spectrum. In the nonresonant case, the spatial motion of the atom leads to a switching of the spin orientation. In both effects, the key factor is the relation between the values of the Stark shift and the cavity-field coupling constant. We also investigate the entanglement of an atom in the cavity with the radiation field. It is shown that the entanglement between the atom and the field, usually quantified in terms of purity, decreases with increasing Stark shift.

Chotorlishvili, L. [Institut fuer Physik, Martin-Luther Universitaet Halle-Wittenberg, Heinrich-Damerow-Strasse 4, D-06120 Halle (Germany); Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany); Toklikishvili, Z. [Physics Department of the Tbilisi State University, Chavchavadze Avenue 3, 0128 Tbilisi (Georgia); Wimberger, S. [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany); Berakdar, J. [Institut fuer Physik, Martin-Luther Universitaet Halle-Wittenberg, Heinrich-Damerow-Strasse 4, D-06120 Halle (Germany)

2011-07-15T23:59:59.000Z

400

Thermal performance simulation of a solar cavity receiver under windy conditions  

SciTech Connect

Solar cavity receiver plays a dominant role in the light-heat conversion. Its performance can directly affect the efficiency of the whole power generation system. A combined calculation method for evaluating the thermal performance of the solar cavity receiver is raised in this paper. This method couples the Monte-Carlo method, the correlations of the flow boiling heat transfer, and the calculation of air flow field. And this method can ultimately figure out the surface heat flux inside the cavity, the wall temperature of the boiling tubes, and the heat loss of the solar receiver with an iterative solution. With this method, the thermal performance of a solar cavity receiver, a saturated steam receiver, is simulated under different wind environments. The highest wall temperature of the boiling tubes is about 150 C higher than the water saturation temperature. And it appears in the upper middle parts of the absorbing panels. Changing the wind angle or velocity can obviously affect the air velocity inside the receiver. The air velocity reaches the maximum value when the wind comes from the side of the receiver (flow angle {alpha} = 90 ). The heat loss of the solar cavity receiver also reaches a maximum for the side-on wind. (author)

Fang, J.B.; Wei, J.J.; Dong, X.W.; Wang, Y.S. [State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049 (China)

2011-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

High conversion efficiency pumped-cavity second harmonic generation of a diode laser  

Science Conference Proceedings (OSTI)

To investigate the feasibility of producing a compact, efficient blue laser source, pumped-cavity second harmonic generation of diode lasers was explored. It is desirable to have such lasers to increase optical disk storage density, for color displays and for under-the-sea green-blue optical signal transmission. Based on assumed cavity losses, a cavity was designed and numerical analysis predicted an overall conversion efficiency to the second harmonic wavelength of 76% from a 75 mW diode laser. The diode laser used in these experiments had a single longitudinal and a single transverse mode output at 860 nm. The best conversion efficiency obtained (26%) was less than optimum due to the 2.5% single-pass linear losses associated with the cavity. However, calculations based on these higher losses are in good agreement with the experimentally determined values. In additions, a factor of 1.65 increase in the second harmonic output power is anticipated by reducing the input mirror reflectivity to better impedance-match the cavity. With this relatively low second harmonic conversion, the power to light conversion is 7.8%.

Keicher, D.M.

1994-01-01T23:59:59.000Z

402

Generation of GHZ-type and \\emph{W}-type entangled coherent states of three-cavity fields  

E-Print Network (OSTI)

We present experimental schemes to prepare the three-cavity GHZ-type and \\emph{W}-type entangled coherent states in the context of dispersive cavity quantum electrodynamics. The schemes can be easily generalized to prepare the GHZ-type and \\emph{W}-type entangled coherent states of $n$-cavity fields. The discussion of our schemes indicates that it can be realized by current technologies.

Chun-Hua Yuan; Yong-Cheng Ou; Zhi-Ming Zhang

2005-09-11T23:59:59.000Z

403

Normalized Compression Distance of Multiples  

E-Print Network (OSTI)

Normalized compression distance (NCD) is a parameter-free similarity measure based on compression. The NCD between pairs of objects is not sufficient for all applications. We propose an NCD of finite multisets (multiples) of objacts that is metric and is better for many applications. Previously, attempts to obtain such an NCD failed. We use the theoretical notion of Kolmogorov complexity that for practical purposes is approximated from above by the length of the compressed version of the file involved, using a real-world compression program. We applied the new NCD for multiples to retinal progenitor cell questions that were earlier treated with the pairwise NCD. Here we get significantly better results. We also applied the NCD for multiples to synthetic time sequence data. The preliminary results are as good as nearest neighbor Euclidean classifier.

Cohen, Andrew R

2012-01-01T23:59:59.000Z

404

Constraining multiple systems with GAIA  

E-Print Network (OSTI)

GAIA will provide observations of some multiple asteroid and dwarf systems. These observations are a way to determine and improve the quantification of dynamical parameters, such as the masses and the gravity fields, in these multiple systems. Here we investigate this problem in the cases of Pluto's and Eugenia's system. We simulate observations reproducing an approximate planning of the GAIA observations for both systems, as well as the New Horizons observations of Pluto. We have developed a numerical model reproducing the specific behavior of multiple asteroid system around the Sun and fit it to the simulated observations using least-square method, giving the uncertainties on the fitted parameters. We found that GAIA will improve significantly the precision of Pluto's and Charon's mass, as well as Petit Prince's orbital elements and Eugenia's polar oblateness.

Beauvalet, L; Arlot, J -E; Bancelin, D; Binzel, R P; Marchis, F

2012-01-01T23:59:59.000Z

405

Superdense Crystal Packings of Ellipsoids  

E-Print Network (OSTI)

Particle packing problems have fascinated people since the dawn of civilization, and continue to intrigue mathematicians and scientists. Resurgent interest has been spurred by the recent proof of Kepler's conjecture: the face-centered cubic lattice provides the densest packing of equal spheres with a packing fraction $\\phi\\approx0.7405$ \\cite{Kepler_Hales}. Here we report on the densest known packings of congruent ellipsoids. The family of new packings are crystal (periodic) arrangements of nearly spherically-shaped ellipsoids, and always surpass the densest lattice packing. A remarkable maximum density of $\\phi\\approx0.7707$ is achieved for both prolate and oblate ellipsoids with aspect ratios of $\\sqrt{3}$ and $1/\\sqrt{3}$, respectively, and each ellipsoid has 14 touching neighbors. Present results do not exclude the possibility that even denser crystal packings of ellipsoids could be found, and that a corresponding Kepler-like conjecture could be formulated for ellipsoids.

Aleksandar Donev; Frank H. Stillinger; P. M. Chaikin; Salvatore Torquato

2004-03-10T23:59:59.000Z

406

Fast Crystals and Strong Glasses  

SciTech Connect

This talk describes new results on model colloid systems that provide insight into the behavior of fundamental problems in colloid physics, and more generally, for other materials as well. By visualizing the nucleation and growth of colloid crystals, we find that the incipient crystallites are much more disordered than expected, leading to a larger diversity of crystal morphologies. When the entropic contribution of these diverse morphologies is included in the free energy, we are able to describe the behavior very well, and can predict the nucleation rate surprisingly accurately. The talk also describes the glass transition in deformable colloidal particles, and will show that when the internal elasticity of the particles is included, the colloidal glass transition mimics that of molecular glass formers much more completely. These results also suggest that the elasticity at the scale of the fundamental unit, either colloid particle or molecule, determines the nature of the glass transition, as described by the "fragility."

Weitz, David [Harvard

2009-11-04T23:59:59.000Z

407

Characteristics and fabrication of a 499 MHz superconducting deflecting cavity for the Jefferson Lab 12 geV Upgrade  

Science Conference Proceedings (OSTI)

A 499 MHz parallel bar superconducting deflecting cavity has been designed and optimized for a possible implementation at the Jefferson Lab. Previously the mechanical analysis, mainly stress, was performed. Since then pressure sensitivity was studied further and the cavity parts were fabricated. The prototype cavity is not completed due to the renovation at Jefferson Lab which resulted in the temporary shutdown of the electron beam welding facility. This paper will present the analysis results and facts encountered during fabrication. The unique geometry of the cavity and its required mechanical strength present interesting manufacturing challenges.

HyeKyoung Park, S.U. De Silva, J.R. Delayen

2012-07-01T23:59:59.000Z

408

RF optimization and analysis of the 805-MHz cavity for the MuCool program using ACE3P  

SciTech Connect

An 805 MHz pillbox cavity tested at Fermilab's MTA facility showed significant degradation in gradient when operated in a several Tesla solenoidal magnetic field. We have used the advanced ACE3P simulation codes developed at SLAC to study the cavity dark current and multipacting characteristics to gain more insight into the gradient limitations. We also checked whether there is an optimal cavity length that minimizes the dark current impact energy. Finally, we have improved on the cavity design, significantly lowering the fields outside the beam area. These and other results are presented in this paper.

Li Zenghai; Ge Lixin; Adolphsen, Chris; Li Derun; Bowring, Daniel [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2012-12-21T23:59:59.000Z

409

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

410

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, E.M.; Nunnally, W.C.

1985-06-19T23:59:59.000Z

411

Cavity-QED models of switches for attojoule-scale nanophotonic logic  

E-Print Network (OSTI)

Quantum optical input-output models are described for a class of optical switches based on cavity quantum electrodynamics (cavity QED) with a single multilevel atom (or comparable bound system of charges) coupled simultaneously to several resonant field modes. A recent limit theorem for quantum stochastic differential equations is used to show that such models converge to a simple scattering matrix in a type of strong coupling limit that seems natural for nanophotonic systems. Numerical integration is used to show that the behavior of the pre-limit model approximates that of the simple scattering matrix in a realistic regime for the physical parameters, and that it is possible in the proposed cavity-QED configuration for low power optical signals to switch higher-power signals at attojoule energy scales.

Hideo Mabuchi

2009-07-15T23:59:59.000Z

412

A new approach to calculate the transport matrix in RF cavities  

SciTech Connect

A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code. A realistic approach to calculate the transport matrix in RF cavities is developed. Complete agreement for tracking results with existed code ASTRA is achieved. New algorithm will be implemented into MARS15 code.

Eidelman, Yu.; /Novosibirsk, IYF; Mokhov, N.; Nagaitsev, S.; Solyak, N.; /Fermilab

2011-03-01T23:59:59.000Z

413

Electro-optic harmonic conversion to switch a laser beam out of a cavity  

DOE Patents (OSTI)

The present invention relates to switching laser beams out of laser cavities, and more particularly, it relates to the use of generating harmonics of the laser beam to accomplish the switching. When laser light is generatd in a laser cavity the problem arises of how to switch the laser light out of the cavity in order to make use of the resulting laser beam in a well known multitude of ways. These uses include range finding, communication, remote sensing, medical surgery, laser fusion applications and many more. The switch-out problem becomes more difficult as the size of the laser aperture grows such as in laser fusion applications. The final amplifier stages of the Nova and Novette lasers at Lawrence Livermore National Laboratory are 46 centimeters with the laser beam expanded to 74 centimeters thereafter. Larger aperture lasers are planned.

Haas, R.A.; Henesian, M.A.

1984-10-19T23:59:59.000Z

414

Coupling interaction between the power coupler and the third harmonic superconducting cavity  

SciTech Connect

Fermilab has developed a third harmonic superconducting cavity operating at the frequency of 3.9 GHz to improve the beam performance for the FLASH user facility at DESY. It is interesting to investigate the coupling interaction between the SRF cavity and the power coupler with or without beam loading. The coupling of the power coupler to the cavity needs to be determined to minimize the power consumption and guarantee the best performance for a given beam current. In this paper, we build and analyze an equivalent circuit model containing a series of lumped elements to represent the resonant system. An analytic solution of the required power from the generator as a function of the system parameters has also been given based on a vector diagram.

Li, Jianjian; Solyak, Nikolay; /Fermilab; Wong, Thomas; /IIT, Chicago

2007-06-01T23:59:59.000Z

415

Fundamental and HOM Coupler Design for the Superconducting Parallel-Bar Cavity  

Science Conference Proceedings (OSTI)

The superconducting parallel-bar cavity is currently being considered as a deflecting system for the Jefferson Lab 12 GeV upgrade and as a crabbing cavity for a possible LHC luminosity upgrade. Currently the designs are optimized to achieve lower surface fields within the dimensional constraints for the above applications. A detailed analysis of the fundamental input power coupler design for the parallel-bar cavity is performed considering beam loading and the effects of microphonics. For higher beam loading the damping of the HOMs is vital to reduce beam instabilities generated due to the wake fields. An analysis of threshold impedances for each application and impedances of the modes that requires damping are presented in this paper with the design of HOM couplers.

S.U. De Silva, J.R. Delayen,

2011-03-01T23:59:59.000Z

416

Monitoring atom-atom entanglement and decoherence in a solvable tripartite open system in cavity QED  

E-Print Network (OSTI)

We solve exactly the dynamics of two strongly-driven two-level atoms resonantly coupled to a dissipative cavity field mode. Starting with the cavity field vacuum state, we show that the entanglement of the atom-atom subsystem cannot be created or increased. On the other hand, when the atoms are initially entangled the atomic Hilbert space divides into two subspaces. One of them is decoherence free so that the initial atomic entanglement remains available for applications, even in presence of a low enough atomic decay rate. In the other subspace a measure of entanglement, decoherence, and also purity, are described by a similar functional behavior that can be monitored by joint atomic measurements. Furthermore, we show the possible generation of Schr\\"odinger-cat-like states for the whole system in the transient regime, as well as of entanglement for the cavity field and the atom-atom subsystems conditioned by measurements on the complementary subsystem.

Bina, Matteo; Lulli, Alfredo; Solano, Enrique

2007-01-01T23:59:59.000Z

417

Method for constructing a lined underground cavity by underreaming, grouting, and boring through the grouting  

DOE Patents (OSTI)

A method is described for constructing a lined underground cavity. The process includes the steps of securing a casing in a borehole by grouting, underreaming the casing, filling the underreamed region with additional grouting, and then drilling through and underreaming the added grouting, thereby forming a room having a lining formed of the grouting. By using a structurally strong grouting that is impervious to water, the resulting room is waterproof and is suitable for on-site storage of an atomic device and its associated equipment prior to an underground atomic event. Such cavities also have other uses; for example, the cavities may be made very deep and used for storage of various fluids such as natural gas storage. (5 claims)

Johnson, W.H.

1971-02-02T23:59:59.000Z

418

Nonlinear harmonic generation and devices in doubly-resonant Kerr cavities  

E-Print Network (OSTI)

We describea theoretical analysis of the nonlinear dynamics of third-harmonic generation ($\\omega\\to3\\omega$) via Kerr ($\\chithree$) nonlinearities in a resonant cavity with resonances at both $\\omega$ and $3\\omega$. Such a doubly resonant cavity greatly reduces the required power for efficient harmonic generation, by a factor of $\\sim V/Q^2$ where $V$ is the modal volume and $Q$ is the lifetime, and can even exhibit 100% harmonic conversion efficiency at a critical input power. However, we show that it also exhibits a rich variety of nonlinear dynamics, such as multistable solutions and long-period limit cycles.We describe how to compensate for self/cross-phase modulation (which otherwise shifts the cavity frequencies out of resonance), and how to excite the different stable solutions (and especially the high-efficiency solutions) by specially modulated input pulses.

Hashemi, Hila; Joannopoulos, J D; SoljačiÄ?, Marin; Johnson, Steven G

2008-01-01T23:59:59.000Z

419

Design and Fabrication of the RHIC Electron-Cooling Experiment High Beta Cavity and Cryomodule  

Science Conference Proceedings (OSTI)

The summary of this report is: (1) A high-current SRF cavity for an Energy Recovery Linac (ERL) has been designed by BNL and AES and fabricated by AES; (2) The cavity was cleaned and tested by JLAB with BNL personnel support; (3) Cavity performance exceeded goal of 20 MV/m at Q{sub 0} > 1 x 10{sup 10} and far exceeded requirement of 15 MV/m at Q{sub 0} > 1 x 10{sup 10}; (4) Hermetic String assembled at JLAB with BNL personnel support and shipped to BNL; and (5) BNL has recently completed Cryomodule assembly and unit is ready for installation in the ERL vault.

Holmes,D.; Calderaro, M.; Cole, M.; Falletta, M.; Peterson, E.; Rathke, J.; Schultheiss, T.; Wong, R.; Ben-Zvi, I.; Burrill, A.; Calaga, R.; McIntyre, G.

2008-11-17T23:59:59.000Z

420

EVALUATION OF SILICON DIODES AS IN-SITU CRYOGENIC FIELD EMISSION DETECTORS FOR SRF CAVITY DEVELOPMENT  

Science Conference Proceedings (OSTI)

We performed in-situ cryogenic testing of four silicon diodes as possible candidates for field emission (FE) monitors of superconducting radio frequency (SRF) cavities during qualification testing and in accelerator cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S1223-01; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near the top of a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and the directionality of S1223-01 in such environments. We will also present calibration curves between the diodes and JLab's standard radiation detector placed above the Dewar's top plate.

Ari Palczewski, Rongli Geng

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Additional Losses in High Purity Niobium Cavities related to Slow Cooldown and Hydrogen Segregation  

DOE Green Energy (OSTI)

Several years ago the SRF--community was unpleasantly surprised by the discovery that superconducting RF-cavities made from high purity niobium showed significant degradations of the Q-values when kept for longer periods of time at intermediate temperatures around 100 K. The first temperature map taken on such a degraded cavity showed a rather uniform distribution of the additional losses. This fact and the roughly 100 K holding temperature resulted in the hypothesis of precipitation of hydride phases in niobium. A large number of investigations in several laboratories followed this discovery and the results supported the initial explanation of hydride precipitation. It was experimentally verified that the Q-degradation could be avoided, if the cavities were quickly cooled down through the dangerous temperature region; hydrogen degassing at elevated temperatures eliminated the cavity deterioration, but subsequent extensive chemical surface treatment seemed to reverse the process. A summary of the recent experimental observations has been given, but the detrimental effect of hydrogen precipitation in niobium cavities has been known for many years. For large scale accelerator projects like CEBAF the cryogenic system might prefer certain cooldown cycles and it is important to know the cooling conditions under which the cavity performance is not effected. Such investigations were done in the past and have extended to other temperature regimes. The results and the analysis of these experiments are reported in the following based on a model of weak links between hydrogen segregates and the niobium matrix, which has been developed by one of the authors (JH) for high T{sub c} and classical superconductors.

J. Halbritter; Peter Kneisel; Kenji Saito

1993-10-01T23:59:59.000Z

422

Multiple Partonic Interactions in Herwig++  

E-Print Network (OSTI)

We review the implementation of a model for multiple partonic interactions in Herwig++. Moreover, we show how recent studies on the colour structure of events in Herwig++ led to a significant improvement in the description of soft inclusive observables in pp interactions at the LHC.

Stefan Gieseke; Christian Rohr; Andrzej Siodmok

2013-02-20T23:59:59.000Z

423

Method for accurate growth of vertical-cavity surface-emitting lasers  

DOE Patents (OSTI)

We report a method for accurate growth of vertical-cavity surface-emitting lasers (VCSELs). The method uses a single reflectivity spectrum measurement to determine the structure of the partially completed VCSEL at a critical point of growth. This information, along with the extracted growth rates, allows imprecisions in growth parameters to be compensated for during growth of the remaining structure, which can then be completed with very accurate critical dimensions. Using this method, we can now routinely grow lasing VCSELs with Fabry-Perot cavity resonance wavelengths controlled to within 0.5%.

Chalmers, Scott A. (Albuquerque, NM); Killeen, Kevin P. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

424

Quantum memories with electrically controlled storage and retrieval in an opto- and electro-mechanical cavity  

E-Print Network (OSTI)

We propose a novel scheme to realize electrically controlled quantum memories in the opto- and electro-mechanical (OEM) cavity. Combining this OEM cavity with the mechanism of Electromagnetically Induced Transparency (EIT) we find that the quantum interference, arising from the two optical transitions of the $\\Lambda$ type three-level atomic ensembles, can be manipulated electrically. Numerical calculations show that the probe photon state can be well stored into the atomic spin state by sending an electric current pulse and retrieved with time-reverse symmetry by sending the other current pulse with opposite direction. The quantum interference with electric controlling is expected to apply to other quantum control aspects.

Li-Guo Qin; Zhong-Yang Wang; Gong-Wei Lin; Jing-Yun Zhao; Shang-Qing Gong

2013-09-12T23:59:59.000Z

425

Beam losses due to abrupt crab cavity failures in the LHC  

SciTech Connect

A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting beam impact on LHC collimators and on sensitive components around the ring. Results for the nominal LHC lattice is presented.

Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B.; Zimmermann, F.

2011-03-28T23:59:59.000Z

426

CONTAINED NUCLEAR DETONATIONS IN FOUR MEDIA-GEOLOGICAL FACTORS IN CAVITY AND CHIMNEY FORMATION  

SciTech Connect

Underground nuclear tests in tuff, alluvium, rock salt, and granite have yielded data essential to the evaluation of the effects of contained nuclear detonations. The data indicate that for these mediums the cavity radius is predictable within plus or minus 20% without regard to the physical or chemical properties of the rock in the immediate shot environment. Properties of the chimney of broken rock resulting from collapse of the cavity, on the other hand, were found to be related to the physical properties of the rock and to preshot structural weaknesses within the rock. (auth)

Boardman, C.R.; Rabb, D.D.; McArthur, R.D.

1964-02-01T23:59:59.000Z

427

Phase gate of one superconducting qubit simultaneously controlling n qubits in a cavity  

E-Print Network (OSTI)

We propose how to realize a three-step controlled-phase gate of one superconducting qubit simultaneously controlling n qubits selected from N qubits in a cavity (1nN). The operation time of this gate is independent of the number n of qubits involved in the gate operation. This phase gate controlling at once n qubits is insensitive to the initial state of the cavity mode and can be used to produce an analogous CNOT gate simultaneously acting on n qubits.

Chui-Ping Yang; Yu-xi Liu; Franco Nori

2009-07-24T23:59:59.000Z

428

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source  

SciTech Connect

We review the single-cell, superconducting crab cavity designs for the short-pulse x-ray (SPX) project at the Advanced Photon Source (APS). The 'on-cell' waveguide scheme is expected to have a more margin for the impedance budget of the APS storage ring, as well as offering a more compact design compared with the original design consisting of a low order mode damping waveguide on the beam pipe. We will report recent fabrication progress, cavity test performance on original and alternate prototypes, and concept designs and analysis for various cryomodule components.

Wang, H; Ciovati, G; Clemens, W A; Henry, J; Kneisel, P; Kushnick, P; Macha, K; Mammosser, J D; Rimmer, R A; Slack, G; Turlington, L; Nassiri, R; Waldschmidt, G J

2011-03-01T23:59:59.000Z

429

Phonon manipulation with phononic crystals.  

Science Conference Proceedings (OSTI)

In this work, we demonstrated engineered modification of propagation of thermal phonons, i.e. at THz frequencies, using phononic crystals. This work combined theoretical work at Sandia National Laboratories, the University of New Mexico, the University of Colorado Boulder, and Carnegie Mellon University; the MESA fabrication facilities at Sandia; and the microfabrication facilities at UNM to produce world-leading control of phonon propagation in silicon at frequencies up to 3 THz. These efforts culminated in a dramatic reduction in the thermal conductivity of silicon using phononic crystals by a factor of almost 30 as compared with the bulk value, and about 6 as compared with an unpatterned slab of the same thickness. This work represents a revolutionary advance in the engineering of thermoelectric materials for optimal, high-ZT performance. We have demonstrated the significant reduction of the thermal conductivity of silicon using phononic crystal structuring using MEMS-compatible fabrication techniques and in a planar platform that is amenable to integration with typical microelectronic systems. The measured reduction in thermal conductivity as compared to bulk silicon was about a factor of 20 in the cross-plane direction [26], and a factor of 6 in the in-plane direction. Since the electrical conductivity was only reduced by a corresponding factor of about 3 due to the removal of conductive material (i.e., porosity), and the Seebeck coefficient should remain constant as an intrinsic material property, this corresponds to an effective enhancement in ZT by a factor of 2. Given the number of papers in literature devoted to only a small, incremental change in ZT, the ability to boost the ZT of a material by a factor of 2 simply by reducing thermal conductivity is groundbreaking. The results in this work were obtained using silicon, a material that has benefitted from enormous interest in the microelectronics industry and that has a fairly large thermoelectric power factor. In addition, the techniques and scientific understanding developed in the research can be applied to a wide range of materials, with the caveat that the thermal conductivity of such a material be dominated by phonon, rather than electron, transport. In particular, this includes several thermoelectric materials with attractive properties at elevated temperatures (i.e., greater than room temperature), such as silicon germanium and silicon carbide. It is reasonable that phononic crystal patterning could be used for high-temperature thermoelectric devices using such materials, with applications in energy scavenging via waste-heat recovery and thermoelectric cooling for high-performance microelectronic circuits. The only part of the ZT picture missing in this work was the experimental measurement of the Seebeck coefficient of our phononic crystal devices. While a first-order approximation indicates that the Seebeck coefficient should not change significantly from that of bulk silicon, we were not able to actually verify this assumption within the timeframe of the project. Additionally, with regards to future high-temperature applications of this technology, we plan to measure the thermal conductivity reduction factor of our phononic crystals as elevated temperatures to confirm that it does not diminish, given that the nominal thermal conductivity of most semiconductors, including silicon, decreases with temperature above room temperature. We hope to have the opportunity to address these concerns and further advance the state-of-the-art of thermoelectric materials in future projects.

Kim Bongsang; Hopkins, Patrick Edward; Leseman, Zayd C.; Goettler, Drew F.; Su, Mehmet F. (University of New Mexico, Albuquerque, NM); El-Kady, Ihab Fathy; Reinke, Charles M.; Olsson, Roy H., III

2012-01-01T23:59:59.000Z

430

Molecular Cell Crystal Structures of the TRAF2: cIAP2  

E-Print Network (OSTI)

. They are crit- ical for canonical and noncanonical NF-kB signaling pathways. Here, we report the crystal-associated factors (TRAFs) in NF-kB and MAP kinase activation pathways in the signaling of multiple receptor families and the noncanon- ical NF-kB signaling pathways. In the noncanonical NF-kB signaling pathway, TRAF2 and cIAP1

Wu, Hao

431

How Spherical Plasma Crystals Form  

Science Conference Proceedings (OSTI)

The correlation buildup and the formation dynamics of the shell structure in a spherically confined one-component plasma are studied. Using Langevin dynamics simulations the relaxation processes and characteristic time scales and their dependence on the pair interaction and dissipation in the plasma are investigated. While in systems with Coulomb interaction (e.g., trapped ions) in a harmonic confinement shell formation starts at the plasma edge and proceeds inward, this trend is significantly weakened for dusty plasmas with Yukawa interaction. With a suitable change of the confinement conditions the crystallization scenario can be externally controlled.

Kaehlert, H.; Bonitz, M. [Institut fuer Theoretische Physik und Astrophysik, Christian-Albrechts Universitaet zu Kiel, 24098 Kiel (Germany)

2010-01-08T23:59:59.000Z

432

Ideal quantum gas in expanding cavity: nature of non-adiabatic force  

E-Print Network (OSTI)

We consider a quantum gas of non-interacting particles confined in the expanding cavity, and investigate the nature of the non-adiabatic force which is generated from the gas and acts on the cavity wall. Firstly, with use of the time-dependent canonical transformation which transforms the expanding cavity to the non-expanding one, we can define the force operator. Secondly, applying the perturbative theory which works when the cavity wall begins to move at time origin, we find that the non-adiabatic force is quadratic in the wall velocity and thereby does not break the time-reversal symmetry, in contrast with the general belief. Finally, using an assembly of the transitionless quantum states, we obtain the nonadiabatic force exactly. The exact result justifies the validity of both the definition of force operator and the issue of the perturbative theory. The mysterious mechanism of nonadiabatic transition with use of transitionless quantum states is also explained. The study is done on both cases of the hard-wall and soft-wall confinement with the time-dependent confining length.

K. Nakamura; S. K. Avazbaev; Z. A. Sobirov; D. U. Matrasulov; T. Monnai

2011-05-21T23:59:59.000Z

433

Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field  

Science Conference Proceedings (OSTI)

In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

2012-05-01T23:59:59.000Z

434

Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities  

DOE Green Energy (OSTI)

There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; /Fermilab; Norem, J.; /Argonne; Li, D.; Zisman, M.; /LBL, Berkeley; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Errede,; /Illinois U., Urbana

2005-10-01T23:59:59.000Z

435

Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities  

SciTech Connect

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.

Bane, K.L.F.; Adolphsen, C.; Li, Z.; /SLAC; Dohlus, M.; Zagorodnov, I.; /DESY; Gonin, I.; Lunin, A.; Solyak, N.; Yakovlev, V.; /Fermilab; Gjonaj, E.; Weiland, T.; /Darmstadt, Tech. Hochsch.

2008-07-07T23:59:59.000Z

436

Optomechanical approach to cooling of small polarizable particles in a strongly pumped ring cavity  

Science Conference Proceedings (OSTI)

Cavity cooling of an atom works best on a cyclic optical transition in the strong coupling regime near resonance, where small-cavity photon numbers suffice for trapping and cooling. A straightforward application to the cooling of the translational motion of other polarizable particles without sharply defined two-level transitions (such as molecules) fails as optical pumping transfers the particle into uncoupled states. An alternative operation in the far-off-resonant regime generates only very slow cooling due to the reduced field-particle coupling. We suggest one can overcome this by using a strongly driven ring cavity operated in the sideband cooling regime. The dynamics can be mapped onto the optomechanics setup with a movable mirror and allows one to take advantage of a collectively enhanced field-particle coupling by large photon numbers. A linearized analytical treatment confirmed by full numerical quantum simulations predicts fast cooling despite the off-resonant small single-particle-single-photon coupling. Even ground-state translational cooling (in the external potential) can be obtained by tuning the cavity field close to the Anti-stokes sideband for sufficiently high trapping frequency. Numerical simulations show quantum jumps of the particle between the lowest two trapping levels, which can be directly and continuously monitored via scattered light intensity detection.

Schulze, R. J.; Genes, C.; Ritsch, H. [Institute for Theoretical Physics, University of Innsbruck, and Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Technikerstrasse 25, A-6020 Innsbruck (Austria)

2010-06-15T23:59:59.000Z

437

Development of fundamental power coupler for high-current superconducting RF cavity  

SciTech Connect

Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

2012-05-20T23:59:59.000Z

438

Intracavity Sensing via Compliance Voltage in an External Cavity Quantum Cascade Laser  

SciTech Connect

We demonstrate a technique for gas phase spectroscopy and sensing by detecting changes in compliance voltage of an external cavity quantum cascade laser due to intracavity absorption. The technique is characterized and used to measure the absorption spectrum of water vapor and Freon-134a.

Phillips, Mark C.; Taubman, Matthew S.

2012-07-01T23:59:59.000Z

439

Fabrication and Testing Status of CEBAF 12 GeV Upgrade Cavities  

Science Conference Proceedings (OSTI)

The 12 GeV upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory (JLab) is under way. All cavities have been built by industry and are presently undergoing post-processing and final low and high power qualification before cryomodule assembly. The status is reported including fabrication-related experiences, observations and issues throughout production, post-processing and qualification.

Marhauser, F; Davis, G K; Forehand, D; Grenoble, C; Hogan, J; Overton, R B; Reilly, A V; Rimmer, R A

2011-09-01T23:59:59.000Z

440

Improved power efficiency for very-high-temperature solar-thermal-cavity receivers  

DOE Patents (OSTI)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatues are attained.

McDougal, A.R.; Hale, R.R.

1982-04-14T23:59:59.000Z

Note: This page contains sample records for the topic "multiple crystal cavities" 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

Plasmonic Nanolasers Without Cavity, Threshold and Diffraction Limit using Stopped Light  

E-Print Network (OSTI)

We present a plasmonic waveguide where light pulses are stopped at well-accessed complex-frequency zero-group-velocity points. Introducing gain at such points results in cavity-free, "thresholdless" nanolasers beating the diffraction limit via a novel, stopped-light mode-locking mechanism.

Tsakmakidis, Kosmas L; Pickering, Tim W; Hess, Ortwin

2013-01-01T23:59:59.000Z

442

Model for Naturally Ventilated Cavities on the Exteriors of Opaque Building Thermal Envelopes  

SciTech Connect

This paper describes a model for naturally ventilated cavities on the exterior of opaque building thermal envelopes that are formed by the presence of a lightweight baffle. The model can be used for building components that are slightly detached from the main envelope (but do not connect to the interior).

Griffith, B.

2006-11-01T23:59:59.000Z

443

Study of nonlinear interaction between bunched beam and intermediate cavities in a relativistic klystron amplifier  

Science Conference Proceedings (OSTI)

In intermediate cavities of a relativistic klystron amplifier (RKA) driven by intense relativistic electron beam, the equivalent circuit model, which is widely adopted to investigate the interaction between bunched beam and the intermediate cavity in a conventional klystron design, is invalid due to the high gap voltage and the nonlinear beam loading in a RKA. According to Maxwell equations and Lorentz equation, the self-consistent equations for beam-wave interaction in the intermediate cavity are introduced to study the nonlinear interaction between bunched beam and the intermediate cavity in a RKA. Based on the equations, the effects of modulation depth and modulation frequency of the beam on the gap voltage amplitude and its phase are obtained. It is shown that the gap voltage is significantly lower than that estimated by the equivalent circuit model when the beam modulation is high. And the bandwidth becomes wider as the beam modulation depth increases. An S-band high gain relativistic klystron amplifier is designed based on the result. And the corresponding experiment is carried out on the linear transformer driver accelerator. The peak output power has achieved 1.2 GW with an efficiency of 28.6% and a gain of 46 dB in the corresponding experiment.

Wu, Y. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Science and Technology on High Power Microwave Laboratory, Mianyang 621900 (China); Xu, Z.; Li, Z. H. [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Tang, C. X. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

2012-07-15T23:59:59.000Z

444

Improvements in Field Emission: An Updated Statistical Model for Electropolished Baked Cavities  

E-Print Network (OSTI)

values of Q, producing a yield profile for various degrees of field emission loading (see Figure 2 of cavities as a function of the accelerating electric field. They compared the simulated success rates of emitters that must be processed to reach accelerating gradients of 35 MV/m. Thus the analysis here looks

445

Numerical simulation of melting in two-dimensional cavity using adaptive grid  

Science Conference Proceedings (OSTI)

This paper presents a numerical simulation of melting of chemically pure material in two-dimensional square cavity. A single-domain model is used which does not require interface tracking and allows the use of a fixed grid in order to solve governing ... Keywords: adaptive moving grid, grid generation, melting

Jure Mencinger

2004-07-01T23:59:59.000Z

446

Convection heat loss from cavity receiver in parabolic dish solar thermal power system: A review  

SciTech Connect

The convection heat loss from cavity receiver in parabolic dish solar thermal power system can significantly reduce the efficiency and consequently the cost effectiveness of the system. It is important to assess this heat loss and subsequently improve the thermal performance of the receiver. This paper aims to present a comprehensive review and systematic summarization of the state of the art in the research and progress in this area. The efforts include the convection heat loss mechanism, experimental and numerical investigations on the cavity receivers with varied shapes that have been considered up to date, and the Nusselt number correlations developed for convection heat loss prediction as well as the wind effect. One of the most important features of this paper is that it has covered numerous cavity literatures encountered in various other engineering systems, such as those in electronic cooling devices and buildings. The studies related to those applications may provide valuable information for the solar receiver design, which may otherwise be ignored by a solar system designer. Finally, future development directions and the issues that need to be further investigated are also suggested. It is believed that this comprehensive review will be beneficial to the design, simulation, performance assessment and applications of the solar parabolic dish cavity receivers. (author)

Wu, Shuang-Ying; Xiao, Lan; Li, You-Rong [College of Power Engineering, Chongqing University, Chongqing 400044 (China); Cao, Yiding [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

2010-08-15T23:59:59.000Z

447

Adsorption of biological macromolecules into mesocage cavities of cubic Pm3n aluminosilica monoliths  

Science Conference Proceedings (OSTI)

With the remarkable progress in the field of gene technology, proteins take an important place in the field of disease diagnosis and treatment. Adsorption of biomolecules on the surface of inorganic materials is an important technique for diagnostic ... Keywords: adsorption, mesocage cavities, monoliths, protein, three-dimensional aluminosilica

Sherif A. El-Safty; Mohamed A. Shenashen

2012-02-01T23:59:59.000Z

448

Exploring Surfaces and Cavities in Lipoxygenase and Other Proteins by Hyperpolarized Xenon-129 NMR  

E-Print Network (OSTI)

Exploring Surfaces and Cavities in Lipoxygenase and Other Proteins by Hyperpolarized Xenon-129 NMR different proteins in the solution and solid states using both conventional and hyperpolarized 129Xe NMR of magnitude of its NMR signal. As a result, it is possible to observe Xe directly bound to the surface

Ronquist, Fredrik

449

Long-distance entanglement and quantum teleportation in coupled cavity arrays  

E-Print Network (OSTI)

We introduce quantum spin models whose ground states allow for sizeable entanglement between distant spins. We discuss how spin models with global end-to-end entanglement realize quantum teleportation channels with optimal compromise between scalability and resilience to thermal decoherence, and can be implemented straightforwardly in suitably engineered arrays of coupled optical cavities.

Salvatore M. Giampaolo; Fabrizio Illuminati

2009-06-15T23:59:59.000Z

450

Multiple target laser ablation system  

DOE Patents (OSTI)

A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film.

Mashburn, Douglas N. (Knoxville, TN)

1996-01-01T23:59:59.000Z

451

Multiple Uses of Substation Data  

Science Conference Proceedings (OSTI)

This report describes a suite of modules developed under the Multiple Uses of Substation Data project. The modules are aimed at the integration and automated analysis of data coming from several Intelligent Electronic Devices (IEDs) such as Digital Protective Relays, Digital Fault Recorders and Circuit Breaker Monitors. Once data are collected, automated analysis processes the files to extract relevant information. The modules convert non-operational data to information that may be used by variety of app...

2008-06-30T23:59:59.000Z

452

Anomalous ring-down effects and breakdown of the decay rate concept in optical cavities with negative group delay  

E-Print Network (OSTI)

Propagation of light pulses through negative group velocity media is known to give rise to a number of paradoxical situations that seem to violate causality. The solution of these paradoxes has triggered the investigation of a number of interesting and unexpected features of light propagation. Here we report a combined theoretical and experimental study of the ring-down oscillations in optical cavities filled with a medium with such a strongly negative frequency dispersion to give a negative round-trip group delay time. We theoretically anticipate that causality imposes the existence of additional resonance peaks in the cavity transmission, resulting in a non-exponential decay of the cavity field and in a breakdown of the cavity decay rate concept. Our predictions are validated by simulations and by an experiment using a room-temperature gas of metastable helium atoms in the detuned electromagnetically induced transparency regime as the cavity medium.

T. Lauprêtre; S. Schwartz; R. Ghosh; I. Carusotto; F. Goldfarb; F. Bretenaker

2011-07-22T23:59:59.000Z

453

Silicon Nano-Crystal Waveguide (SNOW) Laser  

Silicon Nano-Crystal Waveguide (SNOW) Laser Note: The technology described above is an early stage opportunity. Licensing rights to this intellectual property may

454

Livermore scientists capture crystallization of materials in...  

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

The team used multi-frame, nanosecond-scale imaging in the dynamic transmission electron microscope (DTEM) to create movies of the crystallization of phase change...

455

PHASE-FIELD CRYSTAL MODELING OF NANOCRYSTAL ...  

Science Conference Proceedings (OSTI)

PHASE-FIELD CRYSTAL MODELING OF NANOCRYSTAL GROWTH. Edwin J. Schwalbach, James A. Warren, Kuo-An Wu, and Peter W. Voorhees. ...

456

Mul%crystal diffrac%on  

Science Conference Proceedings (OSTI)

Page 1. Mul%crystal diffrac%on DTU, Denmark: C. Gundlach, PC Hansen, D. Juul Jensen, EM Lauridsen, L. Margulies, J. Oddershede, ...

2013-06-07T23:59:59.000Z

457

Mechanical Deformation of Single Crystal and Nanocrystalline ...  

Science Conference Proceedings (OSTI)

... hexagonal crystal structure and is commonly used as a solid lubricant and liquid lubricant additive. The objective of this work is to use atomistic simulations to ...

458

Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation  

Science Conference Proceedings (OSTI)

Limitations on the maximum achievable accelerating gradient of microwave cavities can influence the performance, length, and cost of particle accelerators. Gradient limitations are believed to be initiated by electron emission from the cavity surfaces. Here, we show that field emission is effectively suppressed by applying a tangential magnetic field to the cavity walls, so higher gradients can be achieved. Numerical simulations indicate that the magnetic field prevents electrons leaving these surfaces and subsequently picking up energy from the electric field. Our results agree with current experimental data. Two specific examples illustrate the implementation of magnetic insulation into prospective particle accelerator applications. The ultimate goal of several research efforts is to integrate high-gradient radio-frequency (rf) structures into next generation particle accelerators. For instance, the Muon Accelerator Program is looking at developing low-frequency cavities for muon cooling, and the International Linear Collider is optimizing the performance of 1.3 GHz rf structures aimed at designing a 1 TeV electron-positron collider. Furthermore, the High Gradient RF Collaboration is examining high frequency (f > 10 GHz) structures intended for an electron-positron collider operating at energies in the TeV range. In all this research, the accelerating gradient will be one of the crucial parameters affecting their design, construction, and cost. Limitations from rf breakdown strongly influence the development of accelerators since it limits the machine's maximum gradient. The emission of electrons from the cavity surfaces seemingly is a necessary stage in the breakdown process, acting either as a direct cause of breakdown or as precursor for other secondary effects. Typically, electron currents arise from sharp edges or cracks on the cavities surfaces, where the strength of the electric field is strongly enhanced compared to that of the nominal field when the surfaces of the cavity are perfect planes. Subsequently, a stream of emitted electrons can be accelerated by the rf electric field toward the opposing cavity walls. Upon impact, they heat a localized region, resulting in the eventual breakdown by a variety of secondary mechanisms. Therefore, it is advantageous to develop techniques that could suppress field emission within rf cavities. It has been proposed that high voltages up to about a gigavolt range may be sustained in voltage transformers, by adopting the principle of magnetic insulation in ultrahigh vacuum. The basic idea is to suppress field emission by applying a suitably directed magnetic field of sufficient strength to force the electrons orbits back on to the rf emitting surface. More recently, it was shown that magnetic insulation could be very effective in suppressing field emission and multipacting in rectangular coupler waveguides. Hence, the question arises whether the same principle is applicable to rf accelerating structures. In this Letter, we shall consider application of the concept to low-frequency (201-805 MHz) muon accelerator cavities.

Stratakis, D.; Gallardo, J.; Palmer, R.B.

2011-03-28T23:59:59.000Z

459

RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab  

SciTech Connect

We report recent high power RF tests on an 805 MHz RF pillbox cavity with demountable windows for beam apertures at Lab G of Fermilab, a dedicated facility for testing of MUCOOL (muon cooling) components. The cavity is installed inside a superconducting solenoidal magnet. A 12 MW peak RF power klystron is used for the tests. The cavity has been processed both with and without magnetic field. Without magnetic field, a gradient of 34 MV/m was reached rather quickly with very low sparking rate. In a 2.5 T solenoidal field, a 16 MV/m gradient was achieved, and it had to take many weeks of conditioning. Strong multipacting effects associated with high radiation levels were measured during the processing with the magnetic field. More recently Be windows with TiN-coated surface have been installed and tested at conditions of with and without the external magnetic field. A conservative 16 MV/m gradient without magnetic field was reached quickly as planned. Less multipacting was observed during the conditioning, it indicated that the TiN-coated surface on the windows had indeed helped to reduce the secondary electron emissions significantly. A modest gradient of 16.5 MV/m was finally achieved with magnet on in solenoidal mode and the field up to 4 T. Preliminary inspection on Be windows surface found no damage at all, in comparison with Cu windows where substantial surface damage was found. Preliminary understanding of conditioning cavity in a strong magnetic field has been developed. More through window and cavity surface inspection is under way.

Li, Derun; Corlett, J.; MacGill, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian , Z.; Wu, V.; Rimmer, R.; Norem, J.; Torun, Y.

2003-05-01T23:59:59.000Z

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Dislocation nucleation in bcc Ta single crystals studied by nanoindentation  

SciTech Connect

The study of dislocation nucleation in closed-packed metals by nanoindentation has recently attracted much interest. Here, we address the peculiarities of the incipient plasticity in body centered cubic (bcc) metals using low index Ta single-crystals as a model system. The combination of nanoindentation with high-resolution atomic force microscopy provides us with experimental atomic-scale information on the process of dislocation nucleation and multiplication. Our results reveal a unique deformation behavior of bcc Ta at the onset of plasticity which is distinctly different from that of closed-packed metals. Most noticeable, we observe only one rather than a sequence of discontinuities in the load-displacement curves. This and other differences are discussed in context of the characteristic plastic deformation behavior of bcc metals.

Biener, M M; Biener, J; Hodge, A M; Hamza, A V

2007-08-08T23:59:59.000Z