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1

Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

Enhanced photodetection in graphene-integrated photonic crystal cavity  

SciTech Connect (OSTI)

We demonstrate the controlled enhancement of photoresponsivity in a graphene photodetector by coupling to slow light modes in a long photonic crystal linear defect cavity. Near the Brillouin zone (BZ) boundary, spectral coupling of multiple cavity modes results in broad-band photocurrent enhancement from 1530?nm to 1540?nm. Away from the BZ boundary, individual cavity resonances enhance the photocurrent eight-fold in narrow resonant peaks. Optimization of the photocurrent via critical coupling of the incident field with the graphene-cavity system is discussed. The enhanced photocurrent demonstrates the feasibility of a wavelength-scale graphene photodetector for efficient photodetection with high spectral selectivity and broadband response.

Shiue, Ren-Jye; Englund, Dirk, E-mail: englund@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Gan, Xuetao; Li, Luozhou; Yao, Xinwen [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)] [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Gao, Yuanda; Hone, James [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States)] [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Szep, Attila; Walker, Dennis [Air Force Research Laboratory, Sensors Directorate, WPAFB, Dayton, Ohio 45433 (United States)] [Air Force Research Laboratory, Sensors Directorate, WPAFB, Dayton, Ohio 45433 (United States)

2013-12-09T23:59:59.000Z

3

Performance of Large grain and Single Crystal Niobium Cavities  

SciTech Connect (OSTI)

We have fabricated and tested several single and one multi-cell cavity made from large grain niobium of four different ingots. Two cavities at a frequency of ~ 2.2 GHz were made from single crystal sheets. Large grain material was used for four single cell cavities of the HG â and OC shapes, a 7-cell cavity of the HG â shape â all resonating at 1500 MHz â and an ILC_LL single cell cavity at 1300 MHz. We began to explore also different chemical polishing baths such as a 1:1:1 and a 1:1:2 buffered solution and explored the change of cavity performance as a function of material removal. The results from these preliminary investigations are reported in this contribution.

Kneisel, Peter; Ciovati, Gianluigi; Sekutowicz, Jacek

2006-07-01T23:59:59.000Z

4

Photonic Crystal Cavities in Cubic Polytype Silicon Carbide Films  

E-Print Network [OSTI]

We present the design, fabrication, and characterization of high quality factor and small mode volume planar photonic crystal cavities from cubic (3C) thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1250 - 1600 nm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.

Radulaski, Marina; Buckley, Sonia; Rundquist, Armand; Provine, J; Alassaad, Kassem; Ferro, Gabriel; Vu?kovi?, Jelena

2013-01-01T23:59:59.000Z

5

Novel photonic crystal cavities and related structures.  

SciTech Connect (OSTI)

The key accomplishment of this project is to achieve a much more in-depth understanding of the thermal emission physics of metallic photonic crystal through theoretical modeling and experimental measurements. An improved transfer matrix technique was developed to enable incorporation of complex dielectric function. Together with microscopic theory describing emitter radiative and non-radiative relaxation dynamics, a non-equilibrium thermal emission model is developed. Finally, experimental methodology was developed to measure absolute emissivity of photonic crystal at high temperatures with accuracy of +/-2%. Accurate emissivity measurements allow us to validate the procedure to treat the effect of the photonic crystal substrate.

Luk, Ting Shan

2007-11-01T23:59:59.000Z

6

SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES  

SciTech Connect (OSTI)

The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory’s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it

MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno

2013-02-28T23:59:59.000Z

7

Silicon Carbide Photonic Crystal Cavities with Integrated Color Centers  

E-Print Network [OSTI]

The recent discovery of color centers with optically addressable spin states in 3C silicon carbide (SiC) similar to the negatively charged nitrogen vacancy center in diamond has the potential to enable the integration of defect qubits into established wafer scale device architectures for quantum information and sensing applications. Here we demonstrate the design, fabrication, and characterization of photonic crystal cavities in 3C SiC films with incorporated ensembles of color centers and quality factor (Q) to mode volume ratios similar to those achieved in diamond. Simulations show that optimized H1 and L3 structures exhibit Q as high as 45,000 and mode volumes of approximately (\\lambda/n). We utilize the internal color centers as a source of broadband excitation to characterize fabricated structures with resonances tuned to the color center zero phonon line and observe Q in the range of 900-1,500 with narrowband photoluminescence collection enhanced by up to a factor of 10. By comparing the Q factors obser...

Calusine, Greg; Awschalom, David D

2014-01-01T23:59:59.000Z

8

Silicon Carbide Photonic Crystal Cavities with Integrated Color Centers  

E-Print Network [OSTI]

The recent discovery of color centers with optically addressable spin states in 3C silicon carbide (SiC) similar to the negatively charged nitrogen vacancy center in diamond has the potential to enable the integration of defect qubits into established wafer scale device architectures for quantum information and sensing applications. Here we demonstrate the design, fabrication, and characterization of photonic crystal cavities in 3C SiC films with incorporated ensembles of color centers and quality factor (Q) to mode volume ratios similar to those achieved in diamond. Simulations show that optimized H1 and L3 structures exhibit Q as high as 45,000 and mode volumes of approximately $(\\lambda/n)^{3}$. We utilize the internal color centers as a source of broadband excitation to characterize fabricated structures with resonances tuned to the color center zero phonon line and observe Q in the range of 900-1,500 with narrowband photoluminescence collection enhanced by up to a factor of 10. By comparing the Q factors observed for different geometries with finite-difference time-domain simulations, we find evidence that nonvertical sidewalls are likely the dominant source of discrepancies between our simulated and measured Q factors. These results indicate that defect qubits in 3C SiC thin films show clear promise as a simple, scalable platform for interfacing defect qubits with photonic, optoelectronic, and optomechanical devices.

Greg Calusine; Alberto Politi; David D. Awschalom

2014-05-20T23:59:59.000Z

9

Radio frequency regenerative oscillations in monolithic high-Q/V heterostructured photonic crystal cavities  

E-Print Network [OSTI]

of the radio frequency tones by laser-cavity detuning and laser power levels, confirmed by the CMT simulations crystal cavity is removed by buffered oxide wet etching. Inverse tapered couplers with an oxide over-cladding the CW coherent transverse-electric light from a tunable laser onto chip through polarization control

Hone, James

10

Deterministic coupling of delta-doped NV centers to a nanobeam photonic crystal cavity  

E-Print Network [OSTI]

The negatively-charged nitrogen vacancy center (NV) in diamond has generated significant interest as a platform for quantum information processing and sensing in the solid state. For most applications, high quality optical cavities are required to enhance the NV zero-phonon line (ZPL) emission. An outstanding challenge in maximizing the degree of NV-cavity coupling is the deterministic placement of NVs within the cavity. Here, we report photonic crystal nanobeam cavities coupled to NVs incorporated by a delta-doping technique that allows nanometer-scale vertical positioning of the emitters. We demonstrate cavities with Q up to ~24,000 and mode volume V ~ $0.47({\\lambda}/n)^{3}$ as well as resonant enhancement of the ZPL of an NV ensemble with Purcell factor of ~20. Our fabrication technique provides a first step towards deterministic NV-cavity coupling using spatial control of the emitters.

Jonathan C. Lee; David O. Bracher; Shanying Cui; Kenichi Ohno; Claire A. McLellan; Xingyu Zhang; Paolo Andrich; Benjamin Aleman; Kasey J. Russell; Andrew P. Magyar; Igor Aharonovich; Ania Bleszynski Jayich; David Awschalom; Evelyn L. Hu

2014-11-03T23:59:59.000Z

11

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

Broader source: Energy.gov (indexed) [DOE]

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

12

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

Broader source: Energy.gov (indexed) [DOE]

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

13

Photonic Crystal Cavities in Cubic (3C) Polytype Silicon Carbide Films  

E-Print Network [OSTI]

We present the design, fabrication, and characterization of high quality factor and small mode volume planar photonic crystal cavities from cubic (3C) thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1,250 - 1,600 nm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.

Marina Radulaski; Thomas M. Babinec; Sonia Buckley; Armand Rundquist; J Provine; Kassem Alassaad; Gabriel Ferro; Jelena Vu?kovi?

2013-11-30T23:59:59.000Z

14

A picogram and nanometer scale photonic crystal opto-mechanical cavity  

E-Print Network [OSTI]

We describe the design, fabrication, and measurement of a cavity opto-mechanical system consisting of two nanobeams of silicon nitride in the near-field of each other, forming a so-called "zipper" cavity. A photonic crystal patterning is applied to the nanobeams to localize optical and mechanical energy to the same cubic-micron-scale volume. The picrogram-scale mass of the structure, along with the strong per-photon optical gradient force, results in a giant optical spring effect. In addition, a novel damping regime is explored in which the small heat capacity of the zipper cavity results in blue-detuned opto-mechanical damping.

Eichenfield, M; Chan, J; Vahala, K J; Painter, O

2008-01-01T23:59:59.000Z

15

Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi-Naeini, Jeff T. Hill, Sen Meenehan, and Oskar Painter  

E-Print Network [OSTI]

Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi://apl.aip.org/about/rights_and_permissions #12;Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi

Painter, Oskar

16

Surface-Enhanced Raman Scattering with Ag Nanoparticles Optically Trapped by a Photonic Crystal Cavity  

E-Print Network [OSTI]

on the chemical to be sensed. Figure 1a shows a schematic diagram of the trapping-assisted SERS platform we) platform by optically trapping Ag nanoparticles with a photonic crystal cavity integrated, unattended systems for the continual monitoring of chemicals in air and water. A high- performance substrate

17

Relativistic electron Wigner crystal formation in a cavity for electron acceleration  

E-Print Network [OSTI]

It is known that a gas of electrons in a uniform neutralizing background can crystallize and form a lattice if the electron density is less than a critical value. This crystallization may have two- or three-dimensional structure. Since the wake field potential in the highly-nonlinear-broken-wave regime (bubble regime) has the form of a cavity where the background electrons are evacuated from and only the positively charged ions remain, it is suited for crystallization of trapped and accelerated electron bunch. However, in this case, the crystal is moving relativistically and shows new three-dimensional structures that we call relativistic Wigner crystals. We analyze these structures using a relativistic Hamiltonian approach. We also check for stability and phase transitions of the relativistic Wigner crystals.

Thomas, Johannes; Pukhov, Alexander

2014-01-01T23:59:59.000Z

18

Quantitative crystal structure descriptors from multiplicative congruential generators  

Science Journals Connector (OSTI)

Certain number-theoretic relations, known as multiplicative congruential generators, are developed into quantitative crystal structure descriptors, facilitating a linearization procedure that eventually allows for a concise, fully reconstructable representation of structural information. Potential applications are related to the computational storage, retrieval and analysis of crystal structures, their algorithmic generation in the first place, and their combinatorial enumeration and classification.

Hornfeck, W.

2012-01-12T23:59:59.000Z

19

Second harmonic generation in photonic crystal cavities in (111)-oriented GaAs  

SciTech Connect (OSTI)

We demonstrate second harmonic generation at telecommunications wavelengths in photonic crystal cavities in (111)-oriented GaAs. We fabricate 30 photonic crystal structures in both (111)- and (100)-oriented GaAs and observe an increase in generated second harmonic power in the (111) orientation, with the mean power increased by a factor of 3, although there is a large scatter in the measured values. We discuss possible reasons for this increase, in particular, the reduced two photon absorption for transverse electric modes in (111) orientation, as well as a potential increase due to improved mode overlap.

Buckley, Sonia, E-mail: bucklesm@stanford.edu; Radulaski, Marina; Vu?kovi?, Jelena [E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States)] [E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States); Biermann, Klaus [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany)] [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany)

2013-11-18T23:59:59.000Z

20

Mitigation of optical bistability in Si-based mid-infrared photonic crystal cavities using surface treatments  

Science Journals Connector (OSTI)

We present evidence of optical bistability in our mid-infrared photonic crystal cavities operating at 4.5 µm. Surface treatments are used to mitigate bistability and improve device...

Shankar, Raji; Bulu, Irfan; Leijssen, Rick; Kogos, Leonard; Loncar, Marko

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-enhanced laser cooling for Yb3+-doped fluoride crystal using a low-power diode laser  

Science Journals Connector (OSTI)

A diode laser with a power of 178 mW is used to pump a 2.2% (wt.) Yb3+-doped YLiF4 crystal in an optical extracavity, and a resonant cavity-enhanced laser...

Zhong, Biao; Jia, Youhua; Chen, Lin; Deng, Yingchao; Chen, Yangqin; Yin, Jianping

2014-01-01T23:59:59.000Z

22

Dynamically controlling the emission of single excitons in photonic crystal cavities  

E-Print Network [OSTI]

Single excitons in semiconductor microcavities represent a solid-state and scalable platform for cavity quantum electrodynamics (c-QED), potentially enabling an interface between flying (photon) and static (exciton) quantum bits in future quantum networks. While both single-photon emission and the strong coupling regime have been demonstrated, further progress has been hampered by the inability to control the coherent evolution of the c-QED system in real time, as needed to produce and harness charge-photon entanglement. Here, using the ultrafast electrical tuning of the exciton energy in a photonic crystal (PhC) diode, we demonstrate the dynamic control of the coupling of a single exciton to a PhC cavity mode on a sub-ns timescale, faster than the natural lifetime of the exciton, for the first time. This opens the way to the control of single-photon waveforms, as needed for quantum interfaces, and to the real-time control of solid-state c-QED systems.

Francesco Pagliano; YongJin Cho; Tian Xia; Frank van Otten; Robert Johne; Andrea Fiore

2014-11-03T23:59:59.000Z

23

Dynamically controlling the emission of single excitons in photonic crystal cavities  

E-Print Network [OSTI]

Single excitons in semiconductor microcavities represent a solid-state and scalable platform for cavity quantum electrodynamics (c-QED), potentially enabling an interface between flying (photon) and static (exciton) quantum bits in future quantum networks. While both single-photon emission and the strong coupling regime have been demonstrated, further progress has been hampered by the inability to control the coherent evolution of the c-QED system in real time, as needed to produce and harness charge-photon entanglement. Here, using the ultrafast electrical tuning of the exciton energy in a photonic crystal (PhC) diode, we demonstrate the dynamic control of the coupling of a single exciton to a PhC cavity mode on a sub-ns timescale, faster than the natural lifetime of the exciton, for the first time. This opens the way to the control of single-photon waveforms, as needed for quantum interfaces, and to the real-time control of solid-state c-QED systems.

Pagliano, Francesco; Xia, Tian; van Otten, Frank; Johne, Robert; Fiore, Andrea

2014-01-01T23:59:59.000Z

24

Photonic crystal heterostructures and interfaces  

Science Journals Connector (OSTI)

Photonic crystal heterostructures, like their semiconductor quantum electronic counterparts, generate complex function from simple, well-understood building blocks. They have led to compact photonic crystal-based waveguides and record-quality-factor resonant cavities. Here the progress on the experimental realization of photonic crystal heterostructure devices, and on the development of convenient, intuitive, and computationally efficient models of devices that unite multiple finite-sized photonic crystal media to engineer photon localization and guidance is summarized.

Emanuel Istrate and Edward H. Sargent

2006-05-16T23:59:59.000Z

25

A proposal for the implementation of quantum gates with photonic-crystal coupled cavity waveguides  

E-Print Network [OSTI]

Quantum computers require technologies that offer both sufficient control over coherent quantum phenomena and minimal spurious interactions with the environment. We show, that photons confined to photonic crystals, and in particular to highly efficient waveguides formed from linear chains of defects doped with atoms can generate strong non-linear interactions which allow to implement both single and two qubit quantum gates. The simplicity of the gate switching mechanism, the experimental feasibility of fabricating two dimensional photonic crystal structures and integrability of this device with optoelectronics offers new interesting possibilities for optical quantum information processing networks.

Dimitris G. Angelakis; Marcelo Franca Santos; Vassilis Yannopapas; Artur Ekert

2007-04-12T23:59:59.000Z

26

Design and Performance of a Sensor System for Detection of Multiple Chemicals Using an External Cavity Quantum Cascade Laser  

SciTech Connect (OSTI)

We describe the performance of a sensor system designed for simultaneous detection of multiple chemicals with both broad and narrow absorption features. The sensor system consists of a broadly tunable external cavity quantum cascade laser (ECQCL), multi-pass Herriott cell, and custom low-noise electronics. The ECQCL features a rapid wavelength tuning rate of 2265 cm 1/s (15660 nm/s) over its tuning range of 1150-1270 cm 1 (7.87-8.70 ?m), which permits detection of molecules with broad absorption features and dynamic concentrations, while the 0.2 cm-1 spectral resolution of the ECQCL system allows measurement of small molecules with atmospherically broadened absorption lines. High-speed amplitude modulation and low-noise electronics are used to improve the ECQCL performance for direct absorption measurements. We demonstrate simultaneous detection of Freon-134a (1,1,1,2-tetrafluoroethane), ammonia (NH3), and nitrous oxide (N2O) at low-ppb concentrations in field measurements of atmospheric chemical releases from a point source.

Phillips, Mark C.; Taubman, Matthew S.; Bernacki, Bruce E.; Cannon, Bret D.; Schiffern, John T.; Myers, Tanya L.

2010-01-23T23:59:59.000Z

27

Fabrication of Niobium sheet for RF cavities  

E-Print Network [OSTI]

..................................................................................... 18 2 Fabrication of Niobium SRF Cavities............................................. 20 3 Fine Grain Cavities versus Single Crystal and Large Grain........... Cavities... typical to that of RF cavities in comparison with Cu at 77 and 300K. Nb has low surface resistance in the operating range of 1GHz among the metals. [27]. 2. Fabrication of Niobium SRF Cavities There are different approaches involved in making...

Balachandran, Shreyas

2009-05-15T23:59:59.000Z

28

The effect of photo-generated carriers on the spectral diffusion of a quantum dot coupled to a photonic crystal cavity  

E-Print Network [OSTI]

We experimentally observe the effect of photo-generated carriers on the spectral diffusion of a quantum dot (QD) coupled to a photonic crystal (PC) cavity. In this system, spectral diffusion arises in part from charge fluctuations on the etched surfaces of the PC. We find that these fluctuations may be suppressed by photo-generated carriers, leading to a reduction of the measured QD linewidth by a factor of ~2 compared to the case where the photo-generated carriers are not present. This result demonstrates a possible means of countering the effects of spectral diffusion in QD-PC cavity systems and thus may be useful for quantum information applications where narrow QD linewidths are desired.

Arka Majumdar; Erik D. Kim; Jelena Vuckovic

2011-07-24T23:59:59.000Z

29

Room temperature spontaneous emission enhancement from quantum dots in photonic crystal slab cavities in the telecommunications C-band  

E-Print Network [OSTI]

We report on the control of the spontaneous emission dynamics from InAsP self-assembled quantum dots emitting in the telecommunications C-band and weakly coupled to the mode of a double heterostructure cavity etched on a suspended InP membrane at room temperature. The quality factor of the cavity mode is 44x10^3 with an ultra-low modal volume of the order of 1.2 lambda/n)^3, inducing an enhancement of the spontaneous emission rate of up a factor of 2.8 at 300 K.

Richard Hostein; Rémy Braive; Matthieu Larqué; Ko-Hsin Lee; Anne Talneau; Luc Le Gratiet; Isabelle Robert-Philip; Isabelle Sagnes; Alexios Beveratos

2009-03-25T23:59:59.000Z

30

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

31

Multiple exposure holographic interferometry with sillenite crystals applied to vibration measurement  

Science Journals Connector (OSTI)

A holographic camera is presented, which uses a sillenite crystal as dynamic recording medium. The camera operates in a pulse regime and is used to provide vibration analysis of an...

Georges, Marc P; Thizy, Cédric; Lemaire, Philippe C; Pauliat, Gilles; Roosen, Gérald

32

Optical cavity furnace for semiconductor wafer processing  

DOE Patents [OSTI]

An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

Sopori, Bhushan L.

2014-08-05T23:59:59.000Z

33

A New Method for Simultaneous Measurement of the Integrated Reflectivity of Crystals at Multiple Orders of Reflection and Comparison with New Theoretical Calculations  

SciTech Connect (OSTI)

This paper describes a new method for the simultaneous measurement of the integrated reflectivity of a crystal for multiple orders of reflection at a predefined Bragg angle. The technique is demonstrated with a mica crystal for Bragg angles of 43{sup o}, 47{sup o}, and 50{sup o}. The measured integrated reflectivity for Bragg reflections up to the 24th order is compared with new theoretical predictions, which are also presented in this paper.

S.G. Lee; J.G. Bak; Y.S. Jung; M. Bitter; K.W. Hill; G. Hoelzer; O. Wehrhan; E. Foerster

2003-04-09T23:59:59.000Z

34

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

SciTech Connect (OSTI)

The multiple quantum NMR spectrum of 4-cyano-4'-n-pentyl-d{sub 11}-biphenyl in the nematic phase is presented. The sub-spectra of the higher quantum transitions are easier to interpret than the single quantum spectrum. A preliminary analysis of the biphenyl conformation indicates that the dihedral angle is 32° ± 1°.

Sinton, S.; Pines, A.

1980-09-01T23:59:59.000Z

35

3600210 IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 19, NO. 2, MARCH/APRIL 2013 Photonic Crystal Nanobeam Cavities for Tunable  

E-Print Network [OSTI]

as ultrahigh quality factor resonances that they sup- port, nanobeam cavities are attractive candidates interconnects account for more than 50 % of the consumed energy causing excessive heating [1]. As technology technology [8]). However, the latter demands new breakthroughs in technology due to its on-chip requirements

Loncar, Marko

36

Design of Plasmon Cavities for Solid-State Cavity QED Applications  

E-Print Network [OSTI]

Research on photonic cavities with low mode volume and high quality factor garners much attention because of applications ranging from optoelectronics to cavity quantum electrodynamics (QED). We propose a cavity based on surface plasmon modes confined by metallic distributed Bragg reflectors. We analyze the structure with Finite Difference Time Domain simulations and obtain modes with quality factor 1000 (including losses from metals), reduced mode volume relative to photonic crystal cavities, Purcell enhancements of hundreds, and even the capability of enabling cavity QED strong coupling.

Yiyang Gong; Jelena Vuckovic

2006-11-25T23:59:59.000Z

37

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

38

Optimal feedback in efficient single-cavity optical parametric oscillators  

SciTech Connect (OSTI)

An approach based on the description of competition of quadratic processes of merging and decomposition of quanta resulting in the formation of cnoidal waves on an effective cascade cubic Kerr-type nonlinearity is used to optimise the scheme of a single-cavity optical parametric oscillator. It is shown that the use of a feedback circuit (cavity) decreases the period of cnoidal waves produced in a nonlinear crystal, while the optimisation procedure of the transfer constant of this circuit (reflectivity of the output mirror of the cavity) is reduced to matching this period with the nonlinear crystal length. (optical parametric oscillators)

Petnikova, V M; Shuvalov, Vladimir V [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2010-09-10T23:59:59.000Z

39

WAFER TEST CAVITY -Linking Surface Microstructure to RF Performance: a ‘Short-­?Sample Test Facility’ for characterizing superconducting materials for SRF cavities.  

SciTech Connect (OSTI)

The Wafer Test cavity was designed to create a short sample test system to determine the properties of the superconducting materials and S?I?S hetero?structures. The project, funded by ARRA, was successful in accomplishing several goals to achieving a high gradient test system for SRF research and development. The project led to the design and construction of the two unique cavities that each severed unique purposes: the Wafer test Cavity and the Sapphire Test cavity. The Sapphire Cavity was constructed first to determine the properties of large single crystal sapphires in an SRF environment. The data obtained from the cavity greatly altered the design of the Wafer Cavity and provided the necessary information to ascertain the Wafer Test cavity’s performance.

Pogue, Nathaniel; Comeaux, Justin; McIntyre, Peter

2014-05-30T23:59:59.000Z

40

Specimen illumination apparatus with optical cavity for dark field illumination  

DOE Patents [OSTI]

An illumination apparatus with a specimen slide holder, an illumination source, an optical cavity producing multiple reflection of illumination light to a specimen comprising a first and a second reflective surface arranged to achieve multiple reflections of light to a specimen is provided. The apparatus can further include additional reflective surfaces to achieve the optical cavity, a slide for mounting the specimen, a coverslip which is a reflective component of the optical cavity, one or more prisms for directing light within the optical cavity, antifading solutions for improving the viewing properties of the specimen, an array of materials for analysis, fluorescent components, curved reflective surfaces as components of the optical cavity, specimen detection apparatus, optical detection equipment, computers for analysis of optical images, a plane polarizer, fiberoptics, light transmission apertures, microscopic components, lenses for viewing the specimen, and upper and lower mirrors above and below the specimen slide as components of the optical cavity. Methods of using the apparatus are also provided.

Pinkel, Daniel (Walnut Creek, CA); Sudar, Damir (Walnut Creek, CA); Albertson, Donna (Lafayette, CA)

1999-01-01T23:59:59.000Z

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.


41

Enhanced optical power of GaN-based light-emitting diode with compound photonic crystals by multiple-exposure nanosphere-lens lithography  

SciTech Connect (OSTI)

The light-emitting diodes (LEDs) with single, twin, triple, and quadruple photonic crystals (PCs) on p-GaN are fabricated by multiple-exposure nanosphere-lens lithography (MENLL) process utilizing the focusing behavior of polystyrene spheres. Such a technique is easy and economical for use in fabricating compound nano-patterns. The optimized tilted angle is decided to be 26.6° through mathematic calculation to try to avoid the overlay of patterns. The results of scanning electron microscopy and simulations reveal that the pattern produced by MENLL is a combination of multiple ovals. Compared to planar-LED, the light output power of LEDs with single, twin, triple, and quadruple PCs is increased by 14.78%, 36.03%, 53.68%, and 44.85% under a drive current 350?mA, respectively. Furthermore, all PC-structures result in no degradation of the electrical properties. The stimulated results indicate that the highest light extraction efficiency of LED with the clover-shape triple PC is due to the largest scattering effect on propagation of light from GaN into air.

Zhang, Yonghui; Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Xiong, Zhuo; Shang, Liang; Tian, Yingdong; Zhao, Yun; Zhou, Pengyu; Wang, Junxi; Li, Jinmin [Semiconductor Lighting Technology Research and Development Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

2014-07-07T23:59:59.000Z

42

The LHC superconducting cavities  

E-Print Network [OSTI]

The LHC RF system, which must handle high intensity (0.5 A d.c.) beams, makes use of superconducting single-cell cavities, best suited to minimizing the effects of periodic transient beam loading. There will be eight cavities per beam, each capable of delivering 2 MV (5 MV/m accelerating field) at 400 MHz. The cavities themselves are now being manufactured by industry, using niobium-on-copper technology which gives full satisfaction at LEP. A cavity unit includes a helium tank (4.5 K operating temperature) built around a cavity cell, RF and HOM couplers and a mechanical tuner, all housed in a modular cryostat. Four-unit modules are ultimately foreseen for the LHC (two per beam), while at present a prototype version with two complete units is being extensively tested. In addition to a detailed description of the cavity and its ancillary equipment, the first test results of the prototype will be reported.

Boussard, Daniel; Häbel, E; Kindermann, H P; Losito, R; Marque, S; Rödel, V; Stirbet, M

1999-01-01T23:59:59.000Z

43

Cavity enhanced terahertz modulation  

SciTech Connect (OSTI)

We present a versatile concept for all optical terahertz (THz) amplitude modulators based on a Fabry-Pérot semiconductor cavity design. Employing the high reflectivity of two parallel meta-surfaces allows for trapping selected THz photons within the cavity and thus only a weak optical modulation of the semiconductor absorbance is required to significantly damp the field within the cavity. The optical switching yields to modulation depths of more than 90% with insertion efficiencies of 80%.

Born, N., E-mail: norman.born@physik.uni-marburg.de [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States); Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany); Scheller, M.; Moloney, J. V. [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States)] [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States); Koch, M. [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)] [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)

2014-03-10T23:59:59.000Z

44

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)

2008-12-21T23:59:59.000Z

45

Vibration insensitive optical cavity  

Science Journals Connector (OSTI)

An optical cavity is designed and implemented that is insensitive to vibration in all directions. The cavity is mounted with its optical axis in the horizontal plane. A minimum response of 0.1 (3.7)kHz?ms?2 is achieved for low-frequency vertical (horizontal) vibrations.

S. A. Webster; M. Oxborrow; P. Gill

2007-01-09T23:59:59.000Z

46

Passivated niobium cavities  

DOE Patents [OSTI]

A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

Myneni, Ganapati Rao (Yorktown, VA); Hjorvarsson, Bjorgvin (Lagga Arby, SE); Ciovati, Gianluigi (Newport News, VA)

2006-12-19T23:59:59.000Z

47

CRYSTALLIZATION IN MULTICOMPONENT GLASSES  

SciTech Connect (OSTI)

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

KRUGER AA; HRMA PR

2009-10-08T23:59:59.000Z

48

Tuned optical cavity magnetometer  

DOE Patents [OSTI]

An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

Okandan, Murat (Edgewood, NM); Schwindt, Peter (Albuquerque, NM)

2010-11-02T23:59:59.000Z

49

Generating multipartite entangled states of qubits distributed in different cavities  

E-Print Network [OSTI]

Cavity-based large-scale quantum information processing (QIP) needs a large number of qubits and placing all of them in a single cavity quickly runs into many fundamental and practical problems such as the increase of cavity decay rate and decrease of qubit-cavity coupling strength. Therefore, future QIP most likely will require quantum networks consisting of a large number of cavities, each hosting and coupled to multiple qubits. In this work, we propose a way to prepare a $W$-class entangled state of spatially-separated multiple qubits in different cavities, which are connected to a coupler qubit. Because no cavity photon is excited, decoherence caused by the cavity decay is greatly suppressed during the entanglement preparation. This proposal needs only one coupler qubit and one operational step, and does not require using a classical pulse, so that the engineering complexity is much reduced and the operation is greatly simplified. As an example of the experimental implementation, we further give a numerical analysis, which shows that high-fidelity generation of the $W$ state using three superconducting phase qubits each embedded in a one-dimensional transmission line resonator is feasible within the present circuit QED technique. The proposal is quite general and can be applied to accomplish the same task with other types of qubits such as superconducting flux qubits, charge qubits, quantum dots, nitrogen-vacancy centers and atoms.

Xiao-Ling He; Qi-Ping Su; Feng-Yang Zhang; Chui-Ping Yang

2014-10-12T23:59:59.000Z

50

Superconducting Radiofrequency (SRF) Accelerator Cavities  

SciTech Connect (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2013-05-03T23:59:59.000Z

51

Superconducting Radiofrequency (SRF) Accelerator Cavities  

ScienceCinema (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2014-05-22T23:59:59.000Z

52

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

53

Multimode optomechanical dynamics in a cavity with avoided crossings  

E-Print Network [OSTI]

Cavity optomechanics offers powerful methods for controlling optical fields and mechanical motion. A number of proposals have predicted that this control can be extended considerably in devices where multiple cavity modes couple to each other via the motion of a single mechanical oscillator. Here we study the dynamical properties of such a multimode optomechanical device, in which the coupling between cavity modes results from mechanically-induced avoided crossings in the cavity's spectrum. Near the avoided crossings we find that the optical spring shows distinct features that arise from the interaction between cavity modes. Precisely at an avoided crossing, we show that the particular form of the optical spring provides a classical analog of a quantum-nondemolition measurement of the intracavity photon number. The mechanical oscillator's Brownian motion, an important source of noise in these measurements, is minimized by operating the device at cryogenic temperature (500 mK).

D. Lee; M. Underwood; D. Mason; A. B. Shkarin; S. W. Hoch; J. G. E. Harris

2014-09-10T23:59:59.000Z

54

Copper waveguide cavities with reduced surface loss for coupling to superconducting qubits  

E-Print Network [OSTI]

Significant improvements in superconducting qubit coherence times have been achieved recently with three-dimensional microwave waveguide cavities coupled to transmon qubits. While many of the measurements in this direction have utilized superconducting aluminum cavities, other recent work has involved qubits coupled to copper cavities with coherence times approaching 0.1 ms. The copper provides a good path for thermalizing the cavity walls and qubit chip, although the substantial cavity loss makes conventional dispersive qubit measurements challenging. We are exploring various approaches for improving the quality factor of three-dimensional copper cavities, including electropolishing and coating with superconducting layers of tin. We have characterized these cavities on multiple cooldowns and found the tin-plating to be robust. In addition, we have performed coherence measurements on transmon qubits in these cavities and observed promising performance.

Daniela F. Bogorin; D. T. McClure; Matthew Ware; B. L. T. Plourde

2014-09-10T23:59:59.000Z

55

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

56

RF Cavity Characterization with VORPAL  

SciTech Connect (OSTI)

When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

C. Nieter, C. Roark, P. Stoltz, C.D. Zhou, F. Marhauser

2011-03-01T23:59:59.000Z

57

Plasma Treatment of Single-Cell Niobium SRF Cavities  

SciTech Connect (OSTI)

Superconducting radio frequency cavities of bulk Niobium are integral components of particle accelerators based on superconducting technology. Wet chemical processing is the commonly used procedure for impurities and surface defects removal and surface roughness improvement , both required to improve the RF performance of the cavity. We are studying plasma etching as an alternate technique to process these cavities. The uniformity of the plasma sheath at the inner wall of the cavity is one prerequisite for its uniform etching. We are developing electro-optic diagnostic techniques to assess the plasma uniformity. Multiple electro-optical probes are placed at different locations of the single cell cavity to diagnose the electrical and optical properties of the plasma. The electrical parameters are required to understand the kinetic nature of the plasma and the optical emission spectroscopy provides the spatial distribution of radicals in the plasma. The spatial variation of the plasma parameters inside the cavity and their effect on the etching of niobium samples placed at different locations in the cavity will be presented.

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

2011-03-01T23:59:59.000Z

58

Optimization of an External Cavity Quantum Cascade Laser for Chemical Sensing Applications  

SciTech Connect (OSTI)

We describe and characterize an external cavity quantum cascade laser designed for detection of multiple airborne chemicals, and used with a compact astigmatic Herriott cell for sensing of acetone and hydrogen peroxide.

Phillips, Mark C.; Bernacki, Bruce E.; Taubman, Matthew S.; Cannon, Bret D.; Schiffern, John T.; Myers, Tanya L.

2010-03-01T23:59:59.000Z

59

Plasmon resonant cavities in vertical nanowire arrays  

DOE Patents [OSTI]

Tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides are presented. Resonances can be observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides can satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors of over 10.sup.3 are possible due to plasmon focusing in the inter-wire space.

Bora, Mihail; Bond, Tiziana C.; Fasenfest, Benjamin J.; Behymer, Elaine M.

2014-07-15T23:59:59.000Z

60

Design of wide-angle selective absorbers/emitters with dielectric filled metallic photonic crystals for energy applications  

Science Journals Connector (OSTI)

The design and simulation of a wide angle, spectrally selective absorber/emitter metallic photonic crystal (MPhC) is presented. By using dielectric filled cavities, the angular,...

Chou, Jeffrey B; Yeng, Yi Xiang; Lenert, Andrej; Rinnerbauer, Veronika; Celanovic, Ivan; Solja?i?, Marin; Wang, Evelyn N; Kim, Sang-Gook

2014-01-01T23:59:59.000Z

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

Pyrochemical multiplicity counter development  

SciTech Connect (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

62

A compact chaotic laser device with a two-dimensional external cavity structure  

SciTech Connect (OSTI)

We propose a compact chaotic laser device, which consists of a semiconductor laser and a two-dimensional (2D) external cavity for delayed optical feedback. The overall size of the device is within 230??m?×?1?mm. A long time delay sufficient for chaos generation can be achieved with the small area by the multiple reflections at the 2D cavity boundary, and the feedback strength is controlled by the injection current to the external cavity. We experimentally demonstrate that a variety of output properties, including chaotic output, can be selectively generated by controlling the injection current to the external cavity.

Sunada, Satoshi, E-mail: sunada@se.kanazawa-u.ac.jp; Adachi, Masaaki [Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Fukushima, Takehiro [Department of Information and Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja, Okayama 719-1197 (Japan); Shinohara, Susumu; Arai, Kenichi [NTT Communication Science Laboratories, NTT Corporation, 2-4 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Harayama, Takahisa [NTT Communication Science Laboratories, NTT Corporation, 2-4 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Department of Mechanical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 (Japan)

2014-06-16T23:59:59.000Z

63

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

64

Quench studies of ILC cavities  

SciTech Connect (OSTI)

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

65

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

66

Microwave pulse compression from a storage cavity with laser-induced switching  

DOE Patents [OSTI]

A laser-induced switch and a multiple cavity configuration are disclosed for producing high power microwave pulses. The microwave pulses are well controlled in wavelength and timing, with a quick rise time and a variable shape and power of the pulse. In addition, a method of reducing pre-pulse leakage to a low level is disclosed. Microwave energy is directed coherently to one or more cavities that stores the energy in a single mode, represented as a standing wave pattern. In order to switch the stored microwave energy out of the main cavity and into the branch waveguide, a laser-actuated switch is provided for the cavity. The switch includes a laser, associated optics for delivering the beam into the main cavity, and a switching gas positioned at an antinode in the main cavity. When actuated, the switching gas ionizes, creating a plasma, which becomes reflective to the microwave energy, changing the resonance of the cavity, and as a result the stored microwave energy is abruptly switched out of the cavity. The laser may directly pre-ionize the switching gas, or it may pump an impurity in the switching gas to an energy level which switches when a pre-selected cavity field is attained. Timing of switching the cavities is controlled by varying the pathlength of the actuating laser beam. For example, the pathlengths may be adjusted to output a single pulse of high power, or a series of quick lower power pulses.

Bolton, Paul R. (Menlo Park, CA)

1992-01-01T23:59:59.000Z

67

Channeling through Bent Crystals  

SciTech Connect (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

68

Information dynamics in cavity QED  

Science Journals Connector (OSTI)

A common experimental setup in cavity quantum electrodynamics consists of a single two-level atom interacting with a single mode of the electromagnetic field inside an optical cavity. The cavity is externally driven and the output is continuously monitored via homodyne measurements. We derive formulas for the optimal rates at which these measurements provide information about (i) the quantum state of the system composed of atom and electromagnetic field, and (ii) the coupling strength between atom and field. We find that the two information rates are anticorrelated.

Andrei N. Soklakov and Rüdiger Schack

2003-03-13T23:59:59.000Z

69

The ESS spoke cavity cryomodules  

SciTech Connect (OSTI)

The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today’s leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. This paper introduces the thermo-mechanical design and expected operation of the ESS spoke cavity cryomodules. These cryomodules contain two double spoke bulk Niobium cavities operating at 2 K and at a frequency of 352.21 MHz. The superconducting section of the Spoke Linac accelerates the beam from 90 MeV to 220 MeV. A Spoke Cavity Cryomodule Technology Demonstrator will be built and tested in order to validate the ESS series production.

Bousson, Sebastien; Duthil, Patxi; Reynet, Denis; Thermeau, Jean-Pierre [CNRS/IN2P3, IPN Orsay (France); Darve, Christine; Elias, Nuno; Molloy, Steve [ESS, 22100, Lund (Sweden)

2014-01-29T23:59:59.000Z

70

The ESS elliptical cavity cryomodules  

SciTech Connect (OSTI)

The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today’s leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. The superconducting section of the Linac accelerates the beam from 80 MeV to 2.0 GeV. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. These cryomodules contain four elliptical Niobium cavities operating at 2 K and at a frequency of 704.42 MHz. This paper introduces the thermo-mechanical design, the prototyping and the expected operation of the ESS elliptical cavity cryomodules. An Elliptical Cavity Cryomodule Technology Demonstrator (ECCTD) will be built and tested in order to validate the ESS series production.

Darve, Christine [ESS, 22100, Lund (Sweden); Bosland, Pierre; Devanz, Guillaume; Renard, Bertrand [CEA-Saclay, 91191 Gif-sur-Yvette (France); Olivier, Gilles; Thermeau, Jean-Pierre [CNRS/IN2P3, IPN Orsay (France)

2014-01-29T23:59:59.000Z

71

Design of flexible ultrahigh-Q microcavities in diamond-based photonic crystal slabs  

E-Print Network [OSTI]

We design extremely flexible ultrahigh-Q diamond-based double-heterostructure photonic crystal slab cavities by modifying the refractive index of the diamond. The refractive index changes needed for ultrahigh-Q cavities with $Q ~ 10^7$, are well within what can be achieved ($\\Delta n \\sim 0.02$). The cavity modes have relatively small volumes $Vdesign is flexible because the range of parameters, cavity length and the index changes, that enables an ultrahigh-Q is quite broad. Furthermore as the index modification is post-processed, an efficient technique to generate cavities around defect centres is achievable, improving prospects for defect-tolerant quantum architectures.

Snjezana Tomljenovic-Hanic; Andrew D. Greentree; C. Martijn de Sterke; Steven Prawer

2008-12-10T23:59:59.000Z

72

Holographic Graphene in a Cavity  

E-Print Network [OSTI]

The effective strength of EM interactions can be controlled by confining the fields to a cavity and these effects might be used to push graphene into a strongly coupled regime. We study the similar D3/probe D5 system on a compact space and discuss the gravity dual for a cavity between two mirrors. We show that the introduction of a conformal symmetry breaking length scale introduces a mass gap on a single D5 sheet. Bilayer configurations display exciton condensation between the sheets. There is a first order phase transition away from the exciton condensate if a strong enough magnetic field is applied. We finally map out the phase structure of these systems in a cavity with the presence of mirror reflections of the probes - a mass gap may form through exciton condensation with the mirror image.

Nick Evans; Peter A. R. Jones

2014-07-11T23:59:59.000Z

73

Holographic Graphene in a Cavity  

E-Print Network [OSTI]

The effective strength of EM interactions can be controlled by confining the fields to a cavity and these effects might be used to push graphene into a strongly coupled regime. We study the similar D3/probe D5 system on a compact space and discuss the gravity dual for a cavity between two mirrors. We show that the introduction of a conformal symmetry breaking length scale introduces a mass gap on a single D5 sheet. Bilayer configurations display exciton condensation between the sheets. There is a first order phase transition away from the exciton condensate if a strong enough magnetic field is applied. We finally map out the phase structure of these systems in a cavity with the presence of mirror reflections of the probes - a mass gap may form through exciton condensation with the mirror image.

Evans, Nick

2014-01-01T23:59:59.000Z

74

Progress on a Be Cavity Design  

SciTech Connect (OSTI)

Previous RF experiments with normal-conducting cavities have demonstrated that there is a significant degradation in maximum gradient when the cavity is subjected to a strong axial magnetic field. We have developed a model suggesting that a cavity with beryllium walls may perform better than copper cavities. In this paper we outline the issues that led us to propose fabricating a Be-wall cavity. We also discuss a concept for fabricating such a cavity and mention some of the manufacturing issues we expect to face.

Li, D.; Palmer, R.; Stratakis, D.; Virostek, S.; Zisman, Michael S.

2010-12-24T23:59:59.000Z

75

High efficiency SHG of orbital angular momentum light in an external cavity  

E-Print Network [OSTI]

Traditional methods for generating orbital angular momentum (OAM) light include holographic diffraction gratings, vortex phase plate and spatial light modulator. In this article, we report a new method for high efficient OAM light generation. By pumping an external cavity contains a quasi phase matching nonlinear crystal with a fundamental OAM carrying light and properly aligning the cavity, mode matching between the pump light and the cavitys higher order Laguerre-Gaussian (LG) mode is achieved, conversion efficiency up to 10.3 percentage have been obtained. We have demonstrated that the cavity can stably operate at its higher order LG mode just as Gaussian mode for the first time. The SHG light possesses a doubled OAM value with respect to the pump light. The parameters that affect the beam quality and conversion efficiency are discussed in detail. Our work opens a brand new field in laser optics, and makes the first step toward high efficiency OAM light processing.

Zhi-Yuan Zhou; Yan Li; Dong-Sheng Ding; Yun-Kun Jiang; Wei Zhang; Shuai Shi; Bao-Sen Shi; Guang-Can Guo

2014-05-12T23:59:59.000Z

76

Foundations for quantitative microstructural models to track evolution of the metallurgical state during high purity Nb cavity fabrication  

SciTech Connect (OSTI)

The goal of the Materials Science SRF Cavity Group of Michigan State University and the National Superconducting Cyclotron has been (and continues to be) to understand quantitatively the effects of process history on functional properties. These relationships were assessed via studies on Nb samples and cavity parts, which had various combinations of forming processes, welding, heat treatments, and surface preparation. A primary focus was on large-grain cavity building strategies. Effects of processing operations and exposure to hydrogen on the thermal conductivity has been identified in single and bi-crystal samples, showing that the thermal conductivity can be altered by a factor of 5 depending on process history. Characterization of single crystal tensile samples show a strong effect of crystal orientation on deformation resistance and shape changes. Large grain half cells were examined to characterize defect content and surface damage effects, which provided quantitative information about the depth damage layers from forming.

Bieler, Thomas R [Michigan State University; Wright, Neil T [Michigan State University; Compton, Chris C [Facility for Rare Isotope Beams

2014-03-15T23:59:59.000Z

77

Spontaneous Photon Emission in Cavities  

E-Print Network [OSTI]

We investigate spontaneous photon emission processes of two-level atoms in parabolic and ellipsoidal cavities thereby taking into account the full multimode scenario. In particular, we calculate the excitation probabilities of the atoms and the energy density of the resulting few-photon electromagnetic radiation field by using semiclassical methods for the description of the multimode scenario. Based on this approach photon path representations are developed for relevant transition probability amplitudes which are valid in the optical frequency regime where the dipole and the rotating-wave approximations apply. Comparisons with numerical results demonstrate the quality of these semiclassical results even in cases in which the wave length of a spontaneously emitted photon becomes comparable or even larger than characteristic length scales of the cavity. This is the dynamical regime in which diffraction effects become important so that geometric optical considerations are typically not applicable.

Gernot Alber; Nils Trautmann

2014-12-04T23:59:59.000Z

78

Cooling molecules in optical cavities  

SciTech Connect (OSTI)

We have studied theoretically and numerically the cooling of CN molecules in a high-finesse optical cavity and show that these molecules can be cooled from 100 mK temperatures to submillikelvin temperatures in less than 1 ms. We establish that the cooling time does not change significantly with molecular numbers and initial temperatures over a wide range. We have further studied the scaling of the system for extending the current results for hundreds of molecules to a very large molecular ensemble. The results indicate that a gas of 10{sup 9} molecules can be cooled in the cavity by use of a far-off-resonant and high-intensity pump source.

Lu Weiping; Zhao Yongkai; Barker, P. F. [Physics, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

2007-07-15T23:59:59.000Z

79

Adaptive frequency comb illumination for interferometry in the case of nested two-beam cavities  

SciTech Connect (OSTI)

The homogeneity test of glass plates in a Fizeau interferometer is hampered by the superposition of multiple interference signals coming from the surfaces of the glass plate as well as the empty Fizeau cavity. To evaluate interferograms resulting from such nested cavities, various approaches such as the use of broadband light sources have been applied. In this paper, we propose an adaptive frequency comb interferometer to accomplish the cavity selection. An adjustable Fabry-Perot resonator is used to generate a variable frequency comb that can be matched to the length of the desired cavity. Owing to its flexibility, the number of measurements needed for the homogeneity test can be reduced to four. Furthermore, compared to approaches using a two-beam interferometer as a filter for the broadband light source, the visibility of the fringe system is considerably higher if a Fabry-Perot filter is applied.

Harder, Irina; Leuchs, Gerd; Mantel, Klaus; Schwider, Johannes

2011-09-01T23:59:59.000Z

80

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. 5 figs.

Billen, J.H.

1996-11-26T23:59:59.000Z

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

Resonant-cavity antenna for plasma heating  

DOE Patents [OSTI]

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

82

Mechanical Properties of Ingot Nb Cavities  

SciTech Connect (OSTI)

This contribution presents the results of measurements of the resonant frequency and of strain along the contour of a single-cell cavity made of ingot Nb subjected to increasing uniform differential pressure, up to 6 atm. The data were used to infer mechanical properties of this material after cavity fabrication, by comparison with the results from simulation calculations done with ANSYS. The objective is to provide useful information about the mechanical properties of ingot Nb cavities which can be used in the design phase of SRF cavities intended to be built with this material.

Ciovati, Gianluigi; Dhakal, Pashupati; Kneisel, Peter; Mammosser, John; Matalevich, Joseph; Rao Myneni, Ganapati

2014-07-01T23:59:59.000Z

83

An Overfilled Cavity Problem for Maxwell's Equations  

E-Print Network [OSTI]

plane is of great interest to the engineering community due to its significant industrial and ... ground plane and the cavity wall are perfect electrical conductors.

2011-12-23T23:59:59.000Z

84

Fano Resonance in GaAs 2D Photonic Crystal Nanocavities  

SciTech Connect (OSTI)

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

85

Breakthrough: Record-Setting Cavity  

ScienceCinema (OSTI)

Gianluigi "Gigi" Ciovati, a superconducting radiofrequency scientist, discusses how scientists at the U.S. Department of Energy's Jefferson Lab in Newport News, VA, used ARRA funds to fabricate a niobium cavity for superconducting radiofrequency accelerators that has set a world record for energy efficiency. Jefferson Lab's scientists developed a new, super-hot treatment process that could soon make it possible to produce cavities more quickly and at less cost, benefitting research and healthcare around the world. Accelerators are critical to our efforts to study the structure of matter that builds our visible universe. They also are used to produce medical isotopes and particle beams for diagnosing and eradicating disease. And they offer the potential to power future nuclear power plants that produce little or no radioactive waste.around the world. Accelerators are critical to our efforts to study the structure of matter that builds our visible universe. They also are used to produce medical isotopes and particle beams for diagnosing and eradicating disease. And they offer the potential to power future nuclear power plants that produce little or no radioactive waste.

Ciovati, Gianluigi

2014-05-21T23:59:59.000Z

86

Chapter 13 - Progressing cavity pumps  

Science Journals Connector (OSTI)

Publisher Summary Progressing cavity pumps (PCPs) have the advantage of being able to easily pump solids, liquids, and gasses. With comparatively the lowest capital cost and highest operating efficiencies of any ALS, \\{PCPs\\} are the preferred artificial lift system for many CBM operations. Dewatering CBM wells with \\{PCPs\\} is a relatively routine operation that has been deployed successfully since the mid-1980s. The PC pump is composed of two components, the rotor and the stator. The rotor is manufactured from high strength steel and covered with a chrome layer 0.010 to 0.020 inches thick. The rotor is the only moving component of the pump. The stator has an internal helix shape molded into an elastomer compound that is chemically bonded to the inside of a steel tube. When the rotor is inserted into the stator, it creates a continuous seal line (compression/interference fit between the rotor and stator elastomer) that extends from the pump suction to discharge. This creates a series of identical, but separate, cavities that progress from the pump suction to the discharge as the rotor turns. Water production handling, gas production handling, critical tubing flow velocity, and pump landing depth are briefly discussed in this chapter

James F. Lea; Henry V. Nickens; Mike R. Wells

2008-01-01T23:59:59.000Z

87

Generating multipartite entangled states of qubits distributed in different cavities  

Science Journals Connector (OSTI)

Cavity-based large-scale quantum information processing (QIP) needs a large number of qubits, and placing all of them in a single cavity quickly runs into many fundamental and practical problems such as the increase in cavity decay rate and decrease ... Keywords: $$W$$W state, Cavity, Cavity QED, Coupler qubit, Entanglement

Xiao-Ling He, Qi-Ping Su, Feng-Yang Zhang, Chui-Ping Yang

2014-06-01T23:59:59.000Z

88

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

89

Large Grain Superconducting RF Cavities at DESY  

SciTech Connect (OSTI)

The DESY R and D program on cavities fabricated from large grain niobium explores the potential of this material for the production of approx. 1000 nine-cell cavities for the European XFEL. The program investigates basic material properties, comparing large grain material to standard sheet niobium, as well as fabrication and preparation aspects. Several single-cell cavities of TESLA shape have been fabricated from large grain niobium. A gradient up to 41 MV/m at Q0 = 1.4{center_dot}1010 (TB = 2K) was measured after electropolishing. The first three large grain nine-cell cavities worldwide have been produced under contract of DESY with ACCEL Instruments Co. The first tests have shown that all three cavities reach an accelerating gradient up to 30 MV/m after BCP (Buffered Chemical Polishing) treatment, what exceeds the XFEL requirements for RF test in the vertical cryostat.

Singer, W.; Brinkmann, A.; Ermakov, A.; Iversen, J.; Kreps, G.; Matheisen, A.; Proch, D.; Reschke, D.; Singer, X.; Spiwek, M.; Wen, H.; Brokmeier, H. G. [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); GKSS, Max-Planck-Strasse, D-21502 Geesthacht (Germany)

2007-08-09T23:59:59.000Z

90

External cavity quantum cascade laser  

Science Journals Connector (OSTI)

In this paper we review the progress of the development of mid-infrared quantum cascade lasers (QCLs) operated in an external cavity configuration. We concentrate on QCLs based on the bound-to-continuum design, since this design is especially suitable for broadband applications. Since they were first demonstrated, these laser-based tunable sources have improved in performance in terms of output power, duty cycle, operation temperature and tuneability. Nowadays they are an interesting alternative to FTIRs for some applications. They operate at room temperature, feature a high spectral resolution while being small in size. They were successfully used in different absorption spectroscopy techniques. Due to their vast potential for applications in industry, medicine, security and research, these sources enjoy increasing interest within the research community as well as in industry.

Andreas Hugi; Richard Maulini; Jérôme Faist

2010-01-01T23:59:59.000Z

91

Control of light polarization using optically spin-injected vertical external cavity surface emitting lasers  

SciTech Connect (OSTI)

We fabricated and characterized an optically pumped (100)-oriented InGaAs/GaAsP multiple quantum well Vertical External Cavity Surface Emitting Laser (VECSEL). The structure is designed to allow the integration of a Metal-Tunnel-Junction ferromagnetic spin-injector for future electrical injection. We report here the control at room temperature of the electromagnetic field polarization using optical spin injection in the active medium of the VECSEL. The switching between two highly circular polarization states had been demonstrated using an M-shaped extended cavity in multi-modes lasing. This result witnesses an efficient spin-injection in the active medium of the LASER.

Frougier, J., E-mail: julien.frougier@thalesgroup.com; Jaffrès, H.; Deranlot, C.; George, J.-M. [Unité Mixte de Physique CNRS-Thales and Université Paris Sud 11, 1 av. Fresnel, 91767 Palaiseau (France)] [Unité Mixte de Physique CNRS-Thales and Université Paris Sud 11, 1 av. Fresnel, 91767 Palaiseau (France); Baili, G.; Dolfi, D. [Thales Research and Technology, 1 av. Fresnel, 91767 Palaiseau (France)] [Thales Research and Technology, 1 av. Fresnel, 91767 Palaiseau (France); Alouini, M. [Institut de Physique de Rennes, 263 Avenue Général Leclerc, 35042 Rennes (France)] [Institut de Physique de Rennes, 263 Avenue Général Leclerc, 35042 Rennes (France); Sagnes, I. [Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis (France)] [Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis (France); Garnache, A. [Institut d'électronique du Sud CNRS UMR5214, Université Montpellier 2 Place Eugene Bataillon, 34095 Montpellier (France)] [Institut d'électronique du Sud CNRS UMR5214, Université Montpellier 2 Place Eugene Bataillon, 34095 Montpellier (France)

2013-12-16T23:59:59.000Z

92

Generation of 20 GHz, sub-40 fs pulses at 960 nm via repetition-rate multiplication  

E-Print Network [OSTI]

Generation of 20 GHz, sub-40 fs pulses at 960 nm via repetition-rate multiplication M. S. Kirchner of Physics, University of Colorado, 2000 Colorado Avenue, Boulder, Colorado 80309, USA 2 National Institute­Pérot cavity in a double-pass configuration provides a broad cavity coupling bandwidth / 10% and large

Purdue University

93

allosteric regulatory cavity: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

coherence. We demonstrate such quantum bath engineering for a superconducting artificial atom coupled to a microwave frequency cavity. Cavity-assisted cooling of the atom is...

94

Cavity cooling of an optically trapped nanoparticle  

Science Journals Connector (OSTI)

We study the cooling of a dielectric nanoscale particle trapped in an optical cavity. We derive the frictional force for motion in the cavity field and show that the cooling rate is proportional to the square of oscillation amplitude and frequency. Both the radial and axial components of the center-of-mass motion of the trapped particle, which are coupled by the cavity field, are cooled. This motion is analogous to two coupled but damped pendulums. Our simulations show that the nanosphere can be cooled to e-1 of its initial momentum over time scales of hundredths of milliseconds.

P. F. Barker and M. N. Shneider

2010-02-23T23:59:59.000Z

95

Plasma Treatment of Niobium SRF Cavity Surfaces  

SciTech Connect (OSTI)

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

96

Reentrant Klystron Cavity as an Electromechanical Transducer  

E-Print Network [OSTI]

Reentrant Klystron Cavity as an Electromechanical Transducer J. J. Barroso, P. J. Castro, L. A coaxial line. Joaquim J. Barroso, barroso@plasma.inpe.br, Pedro J. de Castro, castro

97

Ultrastable lasers based on vibration insensitive cavities  

SciTech Connect (OSTI)

We present two ultrastable lasers based on two vibration insensitive cavity designs, one with vertical optical axis geometry, the other horizontal. Ultrastable cavities are constructed with fused silica mirror substrates, shown to decrease the thermal noise limit, in order to improve the frequency stability over previous designs. Vibration sensitivity components measured are equal to or better than 1.5x10{sup -11}/m s{sup -2} for each spatial direction, which shows significant improvement over previous studies. We have tested the very low dependence on the position of the cavity support points, in order to establish that our designs eliminate the need for fine tuning to achieve extremely low vibration sensitivity. Relative frequency measurements show that at least one of the stabilized lasers has a stability better than 5.6x10{sup -16} at 1 s, which is the best result obtained for this length of cavity.

Millo, J.; Magalhaes, D. V.; Mandache, C.; Le Coq, Y.; English, E. M. L.; Westergaard, P. G.; Lodewyck, J.; Bize, S.; Lemonde, P.; Santarelli, G. [LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 Avenue de l'Observatoire, 75014 Paris (France)

2009-05-15T23:59:59.000Z

98

Resonantly pumped optical pumping injection cavity lasers  

E-Print Network [OSTI]

An optical parametric oscillator is tuned to the resonance wavelength of the etalon in an optical pumping injection cavity (OPIC) laser with a type-II "W" active region, thereby minimizing the threshold pump intensity and ...

Santilli, Michael Robert; McAlpine, T. C.; Greene, K. R.; Olafsen, L. J.; Bewley, W. W.; Felix, C. L.; Vurgaftman, I.; Meyer, J. R.; Lee, H.; Martinelli, R. U.

2004-11-01T23:59:59.000Z

99

Hybrid cavity mechanics with doped systems  

E-Print Network [OSTI]

We investigate the dynamics of a mechanical resonator in which is embedded an ensemble of two-level systems interacting with an optical cavity field. We show that this hybrid approach to optomechanics allows for enhanced effective interactions between the mechanics and the cavity field, leading for instance to ground state cooling of the mechanics, even in regimes, like the unresolved sideband regime, in which standard radiation pressure cooling would be inefficient.

Aurelien Dantan; Bhagya Nair; Guido Pupillo; Claudiu Genes

2014-06-27T23:59:59.000Z

100

"Fine grain Nb tube for SRF cavities"  

SciTech Connect (OSTI)

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

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

Behavior of a bipartite system in a cavity  

SciTech Connect (OSTI)

We study the time evolution of a superposition of product states of two dressed atoms in a spherical cavity in the situations of an arbitrarily large cavity (free space) and a small one. In the large-cavity case, the system dissipates, whereas, for the small cavity, the system evolves in an oscillating way and never completely decays. We verify that the von Neumann entropy for such a system does depends neither on time nor the size of the cavity.

Granhen, E. R. [Centro Brasileiro de Pesquisas Fisicas/MCT, 22290-180 Rio de Janeiro, RJ (Brazil); Faculdade de Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil); Linhares, C. A. [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20559-900 Rio de Janeiro, RJ (Brazil); Malbouisson, A. P. C. [Centro Brasileiro de Pesquisas Fisicas/MCT, 22290-180 Rio de Janeiro, RJ (Brazil); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340 Salvador, BA (Brazil)

2010-05-15T23:59:59.000Z

102

Ray chaos in optical cavities based upon standard laser mirrors  

E-Print Network [OSTI]

We present a composite optical cavity made of standard laser mirrors; the cavity consists of a suitable combination of stable and unstable cavities. In spite of its very open nature the composite cavity shows ray chaos, which may be either soft or hard, depending on the cavity configuration. This opens a new, convenient route for experimental studies of the quantum aspects of a chaotic wave field.

A. Aiello; M. P. van Exter; J. P. Woerdman

2003-07-17T23:59:59.000Z

103

RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES  

SciTech Connect (OSTI)

Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

Johnson, Rolland

2014-09-21T23:59:59.000Z

104

Gravitational Wave Detection with High Frequency Phonon Trapping Acoustic Cavities  

E-Print Network [OSTI]

There are a number of theoretical predictions for astrophysical and cosmological objects, which emit high frequency ($10^6-10^9$~Hz) Gravitation Waves (GW) or contribute somehow to the stochastic high frequency GW background. Here we propose a new sensitive detector in this frequency band, which is based on existing cryogenic ultra-high quality factor quartz Bulk Acoustic Wave cavity technology, coupled to near-quantum-limited SQUID amplifiers at $20$~mK. We show that spectral strain sensitivities reaching $10^{-22}$ per $\\sqrt{\\text{Hz}}$ per mode is possible, which in principle can cover the frequency range with multiple ($>100$) modes with quality factors varying between $10^6-10^{10}$ allowing wide bandwidth detection. Due to its compactness and well established manufacturing process, the system is easily scalable into arrays and distributed networks that can also impact the overall sensitivity and introduce coincidence analysis to ensure no false detections.

Goryachev, Maxim

2014-01-01T23:59:59.000Z

105

Gravitational Wave Detection with High Frequency Phonon Trapping Acoustic Cavities  

E-Print Network [OSTI]

There are a number of theoretical predictions for astrophysical and cosmological objects, which emit high frequency ($10^6-10^9$~Hz) Gravitation Waves (GW) or contribute somehow to the stochastic high frequency GW background. Here we propose a new sensitive detector in this frequency band, which is based on existing cryogenic ultra-high quality factor quartz Bulk Acoustic Wave cavity technology, coupled to near-quantum-limited SQUID amplifiers at $20$~mK. We show that spectral strain sensitivities reaching $10^{-22}$ per $\\sqrt{\\text{Hz}}$ per mode is possible, which in principle can cover the frequency range with multiple ($>100$) modes with quality factors varying between $10^6-10^{10}$ allowing wide bandwidth detection. Due to its compactness and well established manufacturing process, the system is easily scalable into arrays and distributed networks that can also impact the overall sensitivity and introduce coincidence analysis to ensure no false detections.

Maxim Goryachev; Michael E. Tobar

2014-10-09T23:59:59.000Z

106

Single transverse mode selectively oxidized vertical cavity lasers  

SciTech Connect (OSTI)

Vertical cavity surface emitting lasers (VCSELs) which operate in multiple transverse optical modes have been rapidly adopted into present data communication applications which rely on multi-mode optical fiber. However, operation only in the fundamental mode is required for free space interconnects and numerous other emerging VCSEL applications. Two device design strategies for obtaining single mode lasing in VCSELs based on mode selective loss or mode selective gain are reviewed and compared. Mode discrimination is attained with the use of a thick tapered oxide aperture positioned at a longitudinal field null. Mode selective gain is achieved by defining a gain aperture within the VCSEL active region to preferentially support the fundamental mode. VCSELs which exhibit greater than 3 mW of single mode output power at 850 nm with mode suppression ratio greater than 30 dB are reported.

CHOQUETTE,KENT D.; GEIB,KENT M.; BRIGGS,RONALD D.; ALLERMAN,ANDREW A.; HINDI,JANA JO

2000-04-26T23:59:59.000Z

107

Self-frequency summing in quantum dot photonic crystal nanocavity lasers  

SciTech Connect (OSTI)

We demonstrate self-frequency summing in photonic crystal nanocavity lasers with quantum dot gain. Two dipole modes and a hexapole mode, supported in the cavity, simultaneously showed lasing oscillation in the near infrared wavelength region under optical carrier injection. Meanwhile, within the same laser cavity, the internally generated three laser fields are up-converted to exhibit sharp visible emission lines via intra-cavity nonlinear frequency summing (and doubling) processes. This self-frequency summing process in active nanocavities will pave the way for developing nanoscale nonlinear optical light sources.

Ota, Yasutomo; Watanabe, Katsuyuki [Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)] [Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Iwamoto, Satoshi; Arakawa, Yasuhiko [Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan) [Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

2013-12-09T23:59:59.000Z

108

Interaction of copper with cavities in silicon  

SciTech Connect (OSTI)

Copper in Si was shown to be strongly bound at cavities formed by He ion implantation and annealing. Evolution of this system during heating was observed by Rutherford backscattering spectrometry and transmission electron microscopy. Results were mathematically modeled to characterize quantitatively the binding of Cu in the cavities and, for comparison, in precipitates of the equilibrium silicide, {eta}-Cu{sub 3}Si. Binding of Cu to cavities occurred by chemisorption on the walls, and the binding energy was determined to be 2.2{plus_minus}0.2 eV relative to solution in Si. The heat of solution from the silicide was found to be 1.7 eV, consistent with the published phase diagram. These findings suggest the use of cavities for metal-impurity gettering in Si devices. Hydrogen in solution in equilibrium with external H{sub 2} gas displaced Cu atoms from cavity walls, a mechanistically illuminating effect that is also of practical concern for gettering applications.

Myers, S.M.; Follstaedt, D.M. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1056 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1056 (United States)

1996-02-01T23:59:59.000Z

109

Cavity cooling of an atomic array  

E-Print Network [OSTI]

While cavity cooling of a single trapped emitter was demonstrated, cooling of many particles in an array of harmonic traps needs investigation and poses a question of scalability. This work investigates the cooling of a one dimensional atomic array to the ground state of motion via the interaction with the single mode field of a high-finesse cavity. The key factor ensuring the cooling is found to be the mechanical inhomogeneity of the traps. Furthermore it is shown that the pumped cavity mode does not only mediate the cooling but also provides the necessary inhomogeneity if its periodicity differs from the one of the array. This configuration results in the ground state cooling of several tens of atoms within a few milliseconds, a timescale compatible with current experimental conditions. Moreover, the cooling rate scaling with the atom number reveals a drastic change of the dynamics with the size of the array: atoms are either cooled independently, or via collective modes. In the latter case the cavity mediated atom interaction destructively slows down the cooling as well as increases the mean occupation number, quadratically with the atom number. Finally, an order of magnitude speed up of the cooling is predicted as an outcome the optimization scheme based on the adjustment of the array versus the cavity mode periodicity.

Oxana Mishina

2014-04-16T23:59:59.000Z

110

Source flow chemical laser cavity performance  

SciTech Connect (OSTI)

The flow field in chemical optical cavities with source flow injectors is investigated. The 2-D coupled gasdynamics, chemical-vibrational-rotational kinetics, and multiline laser radiation equations are solved by using a stable implicit numerical method. The flow field-resonator interaction through the gain-intensity relations is calculated by linearization of the kinetics equations and application of an interative procedure. Calculated small signal gain distributions, closed cavity power variation with mode width, and intracavity spectral content are shown to be in close agreement with experimental measurements. A parametric study has also been conducted, and the potential improvements in performance are illustrated. The results indicate a strong dependency of optical power potential on fluid mechanical interactions with the injector cavity hardware.

Quan, V.; Vieceli, J.J.; Yang, T.T.

1984-05-01T23:59:59.000Z

111

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

2014-02-27T23:59:59.000Z

112

Vertical-cavity surface-emitting laser device  

DOE Patents [OSTI]

A vertical-cavity surface-emitting laser device. The vertical-cavity surface-emitting laser (VCSEL) device comprises one or more VCSELs with each VCSEL having a mode-control region thereabout, with the mode-control region forming an optical cavity with an effective cavity length different from the effective cavity length within each VCSEL. Embodiments of the present invention can be formed as single VCSELs and as one- or two-dimensional arrays of VCSELs, with either an index-guided mode of operation or an index anti-guided mode of operation being defined by a sign of the difference in the two effective cavity lengths.

Hadley, G. Ronald (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM); Awyoung, Adelbert (Albuquerque, NM); Choquette, Kent D. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

113

Cavity-QED-based quantum phase gate  

E-Print Network [OSTI]

are detuned by an amount D from the cavity mode 1, i.e., vbc5n11D . A quantum phase gate with a p phase shift is implemented if the atom in its ground state uc& passes through the cavity such that ~1! the detuning D is equal to g2, and ~2! the interaction...- lowing. The effective Hamiltonian for the interaction, in the di- pole and rotating-wave approximations, is H5H01H1 , ~3! where H05\

Zubairy, M. Suhail; Kim, M.; Scully, Marlan O.

2003-01-01T23:59:59.000Z

114

A single ion inside a miniature cavity  

E-Print Network [OSTI]

understanding of nature. For instance, Joseph von Fraunhofer’s observation of absorption-lines in the optical spectrum of the Sun was crucial for the development of Rydberg’s formula and Bohr’s atomic model. However, under normal conditions the light... the prescribed word limit of 60’000 words. Abstract A Single Ion Inside a Miniature Cavity This thesis describes the first experimentally achieved coupling of a single atomic ion to an optical fibre-cavity as well as the first photonic interaction between a...

Steiner, Matthias

2014-04-08T23:59:59.000Z

115

Monochromator Crystal Glitch Library  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

SSRL's Monochromator Crystal Glitch Library allows users to view glitch spectra online, list specific crystal orientations, and download PDF files of the glitch spectra. (Specialized Interface)

116

Cavity Field Reconstruction at Finite Temperature  

E-Print Network [OSTI]

We present a scheme to reconstruct the quantum state of a field preparedinside a lossy cavity at finite temperature. Quantum coherences are normallydestroyed by the interaction with an environment, but we show that it ispossible to recover complete information about the initial state (beforeinteraction with its environment), making possible to reconstruct any$s$-parametrized quasiprobability distribution, in particular, the Wignerfunction.

Moya-Cessa, H; Tombesi, P; Roversi, J A

2000-01-01T23:59:59.000Z

117

Cavity QED implementation of the discrete quantum Fourier transform  

E-Print Network [OSTI]

We present a scheme for the implementation of the discrete quantum Fourier transform using cavity quantum electrodynamics. In the proposed scheme a series of atoms whose atomic coherence carries the input state passes through a series of cavities...

Scully, Marlan O.; Zubairy, M. Suhail

2002-01-01T23:59:59.000Z

118

Estimation of GMRFs by Recursive Cavity Jason K. Johnson  

E-Print Network [OSTI]

Estimation of GMRFs by Recursive Cavity Modeling by Jason K. Johnson Submitted to the Department by Recursive Cavity Modeling by Jason K. Johnson Submitted to the Department of Electrical Engineering

Willsky, Alan S.

119

Defect- and Strain-enhanced Cavity Formation and Au Precipitation...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Defect- and Strain-enhanced Cavity Formation and Au Precipitation at nano-crystalline ZrO2SiO2Si Interfaces . Defect- and Strain-enhanced Cavity Formation and Au Precipitation at...

120

Long-Range Order of Dilute Rare-Earth Spin Ensemble Revealed with Cavity QED  

E-Print Network [OSTI]

This work demonstrates strong coupling regime between an Erbium ion spin ensemble and Hybrid Cavity-Whispering Gallery Modes in a Yttrium Aluminium Garnet dielectric crystal. Coupling strengths of $220$~MHz and mode quality factors in excess of $10^6$ are demonstrated. The spin ensemble exhibits memory effects as well as remnant magnetisation. A qualitative change of system magnetic field response between 190 and 445mK is interpreted as a phase transition. This work is the first observation of the long range order in an ensemble of dilute Rare-Earth impurities similar to the phenomenon of dilute ferromagnetism in semiconductors.

W. G. Farr; M. Goryachev; J. M. le Floch; P. Bushev; M. E. Tobar

2014-11-29T23:59:59.000Z

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

Crystallography of Quasiperiodic Crystals  

Science Journals Connector (OSTI)

A unified description is given of modulated crystals and quasicrystals based on higher-dimensional crystallography.

Yamamoto, A.

1996-07-01T23:59:59.000Z

122

Superconducting multicell cavity development program at Los Alamos  

SciTech Connect (OSTI)

The superconducting rf (SCRF) cavity Development Program at Los Alamos has designed, fabricated, and tested single-cell niobium cavities at 3-GHz and 805-MHz. This work is being done in preparation for procuring and testing a multicell niobium cavity. The multicell cavity is designed to accelerate protons at [beta] = 0.9; initial tests will be without beam. Progammmatic changes have required us to modify our plans to install a 6800-liter helium cryostat and a 12.8-g/s helium pump. We will use an installed cryostat to test the multicell cavity. Also, the cavity will be modified from a seven-cell to a four-cell structure to match the dimensions of the installed cryostat. Previous reports concentrated on 3-GHz results. In this paper, some of the latest results of the 805-MHz cavity tests are presented. Modifications to allow high pulsed power (HPP) testing on 805-MHz single- and four-cell cavities are proceeding. Glow discharge cleaning of an 805-MHz niobium cavity resulted in a decrease in cavity performance. The cavity was restored to previous performance levels with buffered chemical polishing (bcp). Initial results with high-pressure water cleaning show the process is useful in restoring cavity performance.

Rusnak, B.; Spalek, G.: Gray, E.; DiMarco, J.N.; DeHaven, R.; Novak, J.; Walstrom, P.; Zumbro, J.; Thiessen, H.A. (Los Alamos National Lab., NM (United States)); Langenbrunner, J. (Minnesota Univ., Minneapolis, MN (United States))

1993-01-01T23:59:59.000Z

123

Superconducting multicell cavity development program at Los Alamos  

SciTech Connect (OSTI)

The superconducting rf (SCRF) cavity Development Program at Los Alamos has designed, fabricated, and tested single-cell niobium cavities at 3-GHz and 805-MHz. This work is being done in preparation for procuring and testing a multicell niobium cavity. The multicell cavity is designed to accelerate protons at {beta} = 0.9; initial tests will be without beam. Progammmatic changes have required us to modify our plans to install a 6800-liter helium cryostat and a 12.8-g/s helium pump. We will use an installed cryostat to test the multicell cavity. Also, the cavity will be modified from a seven-cell to a four-cell structure to match the dimensions of the installed cryostat. Previous reports concentrated on 3-GHz results. In this paper, some of the latest results of the 805-MHz cavity tests are presented. Modifications to allow high pulsed power (HPP) testing on 805-MHz single- and four-cell cavities are proceeding. Glow discharge cleaning of an 805-MHz niobium cavity resulted in a decrease in cavity performance. The cavity was restored to previous performance levels with buffered chemical polishing (bcp). Initial results with high-pressure water cleaning show the process is useful in restoring cavity performance.

Rusnak, B.; Spalek, G.: Gray, E.; DiMarco, J.N.; DeHaven, R.; Novak, J.; Walstrom, P.; Zumbro, J.; Thiessen, H.A. [Los Alamos National Lab., NM (United States); Langenbrunner, J. [Minnesota Univ., Minneapolis, MN (United States)

1993-06-01T23:59:59.000Z

124

Dirk Lipka, MDI, DESY Hamburg Status Cavity BPM's  

E-Print Network [OSTI]

Dirk Lipka, MDI, DESY Hamburg Status Cavity BPM's for E-XFEL #12;2 08.12.2009, FLASH seminar D. Lipka, MDI, DESY Hamburg Status Cavity BPM's Content 1. Requirements 2. Overview (all BPM's) 3. In kind contribution (Saclay, DESY, PSI) 4. Cavity BPM: principle 5. Design 6. Measurements: a. Laboratory measurements

125

Enhanced cooling of atoms within an optical cavity  

SciTech Connect (OSTI)

We study enhanced cooling of atoms within an optical cavity using feedback and a time-dependent pump source. The two approaches operate on the same principle by increasing the modulation of the optical potential induced by atomic motion in the cavity. We show that cooling time can be reduced by up to two orders of magnitude over conventional cavity cooling.

Lu, W.; Barker, P.F. [Physics, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, Scotland, EH14 4AS (United Kingdom)

2005-08-15T23:59:59.000Z

126

Quantum phase gate for optical qubits with cavity quantum optomechanics  

E-Print Network [OSTI]

We show that a cavity optomechanical system formed by a mechanical resonator simultaneously coupled to two modes of an optical cavity can be used for the implementation of quantum phase gate between optical qubits associated with the two intracavity modes. The scheme is realizable for sufficiently strong single-photon optomechanical coupling in the resolved sideband regime, and is robust against cavity losses.

Muhammad Asjad; Paolo Tombesi; David Vitali

2015-01-16T23:59:59.000Z

127

Research Article Modeling Nest Survival of Cavity-Nesting  

E-Print Network [OSTI]

Research Article Modeling Nest Survival of Cavity-Nesting Birds in Relation to Postfire Salvage forests often have direct effects on species associated with dead trees, particularly cavity-nesting birds. As such, evaluation of postfire management practices on nest survival rates of cavity nesters is necessary

128

Mixed crystal organic scintillators  

DOE Patents [OSTI]

A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

2014-09-16T23:59:59.000Z

129

Nonlinear optical tuning of photonic crystal microcavities by near-field probe  

SciTech Connect (OSTI)

We report on a nonlinear way to control and tune the dielectric environment of photonic crystal microcavities exploiting the local heating induced by near-field laser excitation at different excitation powers. The temperature gradient due to the optical absorption results in an index of refraction gradient which modifies the dielectric surroundings of the cavity and shifts the optical modes. Reversible tuning can be obtained either by changing the excitation power density or by exciting in different points of the photonic crystal microcavity.

Vignolini, Silvia; Zani, Margherita; Riboli, Francesco; Vinattieri, Anna; Wiersma, Diederik S.; Gurioli, Massimo [LENS and Department of Physics, University of Florence, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Intonti, Francesca [LENS and Department of Physics, University of Florence, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); CNISM, Unita di Ricerca di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Balet, Laurent; Li, Lianhe [Ecole Polytechnique Federale de Lausanne, Institute of Photonics and Quantum Electronics, Station 3, CH-1015 Lausanne (Switzerland); Colocci, Marcello [CNISM, Unita di Ricerca di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Francardi, Marco; Gerardino, Annamaria [Institute of Photonics and Nanotechnology, CNR, via del Cineto Romano 42, 00156 Roma (Italy); Fiore, Andrea [COBRA Research Institute, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

2008-07-14T23:59:59.000Z

130

Inverted and multiple nematic emulsions  

Science Journals Connector (OSTI)

We investigate experimentally the structures that form when small colloidal particles are suspended in a nematic solvent. These structures are anisotropic, and their formation is driven by interactions arising from the orientational elasticity of the nematic solvent. By using inverted and multiple nematic emulsions composed of water droplets dispersed in a thermotropic liquid crystal, we identify the nature of these interactions, and demonstrate that they can be controlled by the anchoring of the liquid crystal molecules at the surfaces of the droplets. When the anchoring is normal, the droplets form linear chains, suggesting a long-range dipole-dipole attraction between the particles. By contrast, the interactions are repulsive at short range, and prevent contact of the droplets, thereby stabilizing them against coalescence. When the anchoring is planar, the droplets generate distortions that have a quadrupolar character. The resultant elastic interactions lead to more compact, but still anisotropic, clusters.

P. Poulin and D. A. Weitz

1998-01-01T23:59:59.000Z

131

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

132

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

133

Final Report for "Compact Crab Cavity Design"  

SciTech Connect (OSTI)

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

134

GHz Resonant Cavity Enhanced Schottky Photodiodes  

E-Print Network [OSTI]

Resonant Cavity Enhanced (RCE) photodiodes are promising candidates for applications in optical communications and interconnects where ultrafast high-efficiency detection is desirable. We have designed and fabricated RCE Schottky photodiodes in the (Al,In)GaAs material system for 900nm wavelength. The observed temporal response with 10 ps pulse width was limited by the measurement setup and a conservative estimation of the bandwidth corresponds to more than 100 GHz. A direct comparison of RCE versus conventional detector performance was performed by high speed measurements under optical excitation at resonant wavelength (895 nm) and at 840 nm where the device functions as a single pass conventional photodiode. A more than two-fold bandwidth enhancement with the RCE detection scheme was demonstrated. Index Terms--- Resonant cavity enhancement, high-speed, photodetector, Schottky photodiode. 1 I. INTRODUCTION High speed photodetectors for today's high performance optical co...

Onat Gokkavas Ozbay; B. M. Onat; M. Gokkavas; E. P. Ata; E. Towe; M. S

135

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

136

Control of multiatom entanglement in a cavity  

SciTech Connect (OSTI)

We propose a general formalism for analytical description of multiatomic ensembles interacting with a single-mode quantized cavity field under the assumption that most atoms remain unexcited on average. By combining the obtained formalism with the nilpotent technique for the description of multipartite entanglement we are able to overview in a unified fashion different probabilistic control scenarios of entanglement among atoms or examine atomic ensembles. We then apply the proposed control schemes to the creation of multiatom states useful for quantum information.

Mandilara, Aikaterini; Akulin, Vladimir M.; Kolar, Michal; Kurizki, Gershon [Laboratoire Aime Cotton, CNRS, Campus d'Orsay, 91405 Orsay (France); Weizmann Institute of Science, 76100 Rehovot (Israel)

2007-02-15T23:59:59.000Z

137

Dissipative hydride precipitates in superconducting niobium cavities  

SciTech Connect (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

138

Single-atom cavity QED and optomicromechanics  

SciTech Connect (OSTI)

In a recent publication [K. Hammerer, M. Wallquist, C. Genes, M. Ludwig, F. Marquardt, P. Treutlein, P. Zoller, J. Ye, and H. J. Kimble, Phys. Rev. Lett. 103, 063005 (2009)] we have shown the possibility to achieve strong coupling of the quantized motion of a micron-sized mechanical system to the motion of a single trapped atom. In the proposed setup the coherent coupling between a SiN membrane and a single atom is mediated by the field of a high finesse cavity and can be much larger than the relevant decoherence rates. This makes the well-developed tools of cavity quantum electrodynamics with single atoms available in the realm of cavity optomechanics. In this article we elaborate on this scheme and provide detailed derivations and technical comments. Moreover, we give numerical as well as analytical results for a number of possible applications for transfer of squeezed or Fock states from atom to membrane as well as entanglement generation, taking full account of dissipation. In the limit of strong-coupling the preparation and verification of nonclassical states of a mesoscopic mechanical system is within reach.

Wallquist, M.; Hammerer, K.; Zoller, P.; Genes, C.; Ludwig, M.; Marquardt, F.; Treutlein, P.; Ye, J.; Kimble, H. J. [Institute for Theoretical Physics, University of Innsbruck, and Institute for Quantum Optics and Quantum Communication, Austrian Academy of Sciences, Technikerstrasse 25, 6020 Innsbruck, Austria and Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, California 91125 (United States); Institute for Theoretical Physics, University of Innsbruck, and Institute for Quantum Optics and Quantum Communication, Austrian Academy of Sciences, Technikerstrasse 25, 6020 Innsbruck (Austria); Department of Physics, Center for NanoScience, and Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universitaet Muenchen, Theresienstr. 37, D-80333 Munich (Germany); Max-Planck-Institute of Quantum Optics and Department of Physics, Ludwig-Maximilians-Universitaet Muenchen, Schellingstr. 4, D-80799 Munich (Germany); JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA and Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, California 91125 (United States); Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, California 91125 (United States)

2010-02-15T23:59:59.000Z

139

Handbook for Gas Filled RF Cavity Aficionados'  

SciTech Connect (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

140

Crystal structure and chemistry of a complex indium phosphate framework material, (ethylenediammonium)In{sub 3}P{sub 3}O{sub 12}(OH){sub 2}  

SciTech Connect (OSTI)

The chemistry and structure of a novel indium phosphate material (RIPS-4), (H{sub 3}NCH{sub 2}CH{sub 2}NH{sub 3})In{sub 3}-P{sub 3}O{sub 12}(OH){sub 2}, are described. RIPS-4 was synthesized using ethylene diamine as a structure-directing organic agent. The X-ray crystal structure was determined from a 12 Multiplication-Sign 12 Multiplication-Sign 42 {mu}m{sup 3} crystal in space group C2/m with a=18.662(4) A, b=6.600(2) A, c=12.573(3) A and {beta}=120.92(1) Degree-Sign . The structure consists of a complex edge- and vertex-shared open framework of InO{sub 6} octahedra and PO{sub 4} tetrahedra enclosing cavities occupied by ethylenediamonium ions. One set of octahedra share opposing edges to form chains along the b-axis matching the structural unit in rutile (TiO{sub 2}). This rutile edge-shared chain has its projecting oxygen atoms shared with the vertexes of either a PO{sub 4} tetrahedron or a second type of InO{sub 6} octahedron. The O atoms are 2-connected, each to one In and one P, except for two protonated O atoms (hydroxyl groups) that connect to two and three In atoms, giving three- and four-coordinate O atoms, respectively. - Graphical abstract: The unique topology contains an unusual 4-connected oxygen atom (O{sub 1}) in a complex edge- and vertex-shared open framework of InO{sub 6} octahedra (blue) and PO{sub 4} tetrahedra (yellow) that encloses cavities occupied by ethylenediammonium ions. Highlights: Black-Right-Pointing-Pointer The structure has a unique open-framework topology. Black-Right-Pointing-Pointer The framework contains an unusual 4-connected oxygen atom. Black-Right-Pointing-Pointer Hydrogen bonds hold the ethylenediammonium ions in the cavities.

Broach, Robert W., E-mail: robert.broach@uop.com [UOP, a Honeywell Co., 50 E. Algonquin Rd., Des Plaines, IL 60017 (United States); Bedard, Robert L. [UOP, a Honeywell Co., 50 E. Algonquin Rd., Des Plaines, IL 60017 (United States)] [UOP, a Honeywell Co., 50 E. Algonquin Rd., Des Plaines, IL 60017 (United States); King, Lisa M., E-mail: lisa.king@uop.com [UOP, a Honeywell Co., 50 E. Algonquin Rd., Des Plaines, IL 60017 (United States); Pluth, Joseph J., E-mail: pluth@cars.uchicago.edu [The University of Chicago, Department of the Geophysical Sciences, Consortium for Advanced Radiation Sources, Chicago, IL 60637 (United States); The University of Chicago, The Materials Research Science and Engineering Center, Chicago, IL 60637 (United States); Smith, Joseph V. [The University of Chicago, Department of the Geophysical Sciences, Consortium for Advanced Radiation Sources, Chicago, IL 60637 (United States)] [The University of Chicago, Department of the Geophysical Sciences, Consortium for Advanced Radiation Sources, Chicago, IL 60637 (United States); Kirchner, Richard M., E-mail: richard.kirchner@manhattan.edu [Manhattan College, Chemistry Department, Bronx, NY 10471 (United States)

2012-12-15T23:59:59.000Z

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.


141

CRYSTAL Simulation Code and New Coherent Effects in Bent Crystal at the LHC  

E-Print Network [OSTI]

The LHC crystal-based collimation system is mainly addressed. A CRYSTAL simulation code for particle tracking in crystals is introduced. Its essence consists in both adequate and fast sampling of proton trajectories in crystals which is crucial for both correct description of experiments and quantitative prediction of new effects. The H8 single-pass experiment at the CERN SPS as well as 7 TeV proton deflection by a bent crystal at the LHC are simulated. We predict the existence of dechanneling peaks corresponding to the planar channeling oscillations as well as describe the possibility of their observation at high energies, specifically in the LHC crystal-assisted collimation experiment planned on 2015. An effect of excess over the amorphous level of ionization losses in the channeling mode was also found for the LHC energy. In addition, the LHC crystal-based collimation system is simulated as well as its possible improved layouts with application of a crystal with the cut and multiple volume reflection in on...

Sytov, Alexei I

2014-01-01T23:59:59.000Z

142

Phasing tiny crystals  

Science Journals Connector (OSTI)

For tiny crystals, their diffraction intensities at and between the Bragg peaks become measurable due to the limited number of the unit cells, which can in principle be used to directly phase the crystal structures.

Miao, J.

2013-12-31T23:59:59.000Z

143

Growing Giant Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

kids Growing Giant Crystals A new process similar to making rock candy was developed at NIF to rapidly grow very large crystals that are about 2 cubic feet in size and weigh up to...

144

Automation in biological crystallization  

Science Journals Connector (OSTI)

Automation is the response to overcoming the crystallization bottleneck in biological crystallography. This review provides a summary of the current methods and technologies applied in automated platforms for the setup of initial and follow-up crystallization experiments.

Shaw Stewart, P.

2014-05-28T23:59:59.000Z

145

Vertical-cavity surface-emitting laser device  

DOE Patents [OSTI]

A vertical-cavity surface-emitting laser device is disclosed. The vertical-cavity surface-emitting laser (VCSEL) device comprises one or more VCSELs with each VCSEL having a mode-control region thereabout, with the mode-control region forming an optical cavity with an effective cavity length different from the effective cavity length within each VCSEL. Embodiments of the present invention can be formed as single VCSELs and as one- or two-dimensional arrays of VCSELs, with either an index-guided mode of operation or an index anti-guided mode of operation being defined by a sign of the difference in the two effective cavity lengths. 10 figs.

Hadley, G.R.; Lear, K.L.; Awyoung, A.; Choquette, K.D.

1999-05-11T23:59:59.000Z

146

Quench dynamics in SRF cavities: can we locate the quench origin with 2nd sound?  

SciTech Connect (OSTI)

A newly developed method of locating quenches in SRF cavities by detecting second-sound waves has been gaining popularity in SRF laboratories. The technique is based on measurements of time delays between the quench as determined by the RF system and arrival of the second-sound wave to the multiple detectors placed around the cavity in superfluid helium. Unlike multi-channel temperature mapping, this approach requires only a few sensors and simple readout electronics; it can be used with SRF cavities of almost arbitrary shape. One of its drawbacks is that being an indirect method it requires one to solve an inverse problem to find the location of a quench. We tried to solve this inverse problem by using a parametric forward model. By analyzing the data we found that the approximation where the second-sound emitter is a near-singular source does not describe the physical system well enough. A time-dependent analysis of the quench process can help us to put forward a more adequate model. We present here our current algorithm to solve the inverse problem and discuss the experimental results.

Maximenko, Yulia; /Moscow, MIPT; Segatskov, Dmitri A.; /Fermilab

2011-03-01T23:59:59.000Z

147

Stable fiber-based Fabry-Perot cavity  

SciTech Connect (OSTI)

The development of a fiber-based, tunable optical cavity with open access is reported. The cavity is of the Fabry-Perot type and is formed with miniature spherical mirrors positioned on the end of single- or multimode optical fibers by a transfer technique, which involves lifting a high-quality mirror from a smooth convex substrate, either a ball lens or microlens. The cavities typically have a finesse of {approx}1000 and a mode volume of 600 {mu}m{sup 3}. The detection of small ensembles of cold Rb atoms guided through such a cavity on an atom chip is demonstrated.

Steinmetz, T.; Colombe, Y.; Hunger, D.; Haensch, T. W.; Balocchi, A.; Warburton, R. J.; Reichel, J. [Department fuer Physik, Ludwig-Maximilians-Universitaet, Schellingstrasse 4/III, 80799 Munich (Germany); School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Laboratoire Kastler Brossel de l'E.N.S., 24 rue Lhomond, 75231 Paris Cedex 05 (France)

2006-09-11T23:59:59.000Z

148

Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds  

SciTech Connect (OSTI)

We consider an axisymmetric microwave cavity for an accelerator structure whose eigenfrequency for its second lowest TM-like axisymmetric mode is twice that of the lowest such mode, and for which the fields are asymmetric along its axis. In this cavity, the peak amplitude of the rf electric field that points into either longitudinal face can be smaller than the peak field which points out. Computations show that a structure using such cavities might support an accelerating gradient about 47% greater than that for a structure using similar single-mode cavities, without an increase in breakdown probability.

Kuzikov, S. V. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov Street, Nizhny Novgorod, 603950 (Russian Federation); Kazakov, S. Yu. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Jiang, Y. [Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States); Hirshfield, J. L. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States)

2010-05-28T23:59:59.000Z

149

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

150

Physical simulations of cavity closure in a creeping material  

SciTech Connect (OSTI)

The finite element method has been used extensively to predict the creep closure of underground petroleum storage cavities in rock salt. Even though the numerical modeling requires many simplifying assumptions, the predictions have generally correlated with field data from instrumented wellheads, however, the field data are rather limited. To gain an insight into the behavior of three-dimensional arrays of cavities and to obtain a larger data base for the verification of analytical simulations of creep closure, a series of six centrifuge simulation experiments were performed using a cylindrical block of modeling clay, a creeping material. Three of the simulations were conducted with single, centerline cavities, and three were conducted with a symmetric array of three cavities surrounding a central cavity. The models were subjected to body force loading using a centrifuge. For the single cavity experiments, the models were tested at accelerations of 100, 125 and 150 g's for 2 hours. For the multi-cavity experiments, the simulations were conducted at 100 g's for 3.25 hours. The results are analyzed using dimensional analyses. The analyses illustrate that the centrifuge simulations yield self-consistent simulations of the creep closure of fluid-filled cavities and that the interaction of three-dimensional cavity layouts can be investigated using this technique.

Sutherland, H.J.; Preece, D.S.

1985-09-01T23:59:59.000Z

151

Cavity Microwave Searches for Cosmological Axions  

SciTech Connect (OSTI)

This chapter will cover the search for dark matter axions based on microwave cavity experiments proposed by Pierre Sikivie. We will start with a brief overview of halo dark matter and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described as well as practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of this chapter will be the two complementary strategies for ultra-low noise detection of the microwave photons--the 'photon-as-wave' approach (i.e. conventional heterojunction amplifiers and soon to be quantum-limited SQUID devices), and 'photon-as-particle' (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The section will conclude with a discussion of future plans and challenges for the microwave cavity experiment.

Carosi, G; van Bibber, K

2007-01-22T23:59:59.000Z

152

Trace formula for dielectric cavities III: TE modes  

E-Print Network [OSTI]

The construction of the semiclassical trace formula for the resonances with the transverse electric (TE) polarization for two-dimensional dielectric cavities is discussed. Special attention is given to the derivation of the two first terms of Weyl's series for the average number of such resonances. The obtained formulas agree well with numerical calculations for dielectric cavities of different shapes.

E. Bogomolny; R. Dubertrand

2012-06-15T23:59:59.000Z

153

Optical-cavity tests of higher-order Lorentz violation  

E-Print Network [OSTI]

The effects of Lorentz-violating operators of nonrenormalizable dimension in optical resonate cavities are studied. Optical-frequency experiments are shown to provide sensitivity to nondispersive nonbirefringent violations that is many orders of magnitude beyond current constraints from microwave cavities. Existing experiments based on Fabry-Perot and ring resonators are considered as illustrations.

Matthew Mewes

2012-06-22T23:59:59.000Z

154

Analytical Shape Computation of Macromolecules: II. Inaccessible Cavities in Proteins  

E-Print Network [OSTI]

that cavities in proteins could contain disordered water molecules not apparent in the X-ray structural data.9Analytical Shape Computation of Macromolecules: II. Inaccessible Cavities in Proteins Jie Liang,1-Champaign, Urbana, Illinois ABSTRACT The structures of proteins are well-packed, yet they contain numerous cavi

Dai, Yang

155

RF cavity using liquid dielectric for tuning and cooling  

DOE Patents [OSTI]

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

156

NEST-SITESELECTIONAND NESTINGSUCCESSOF CAVITY-NESTINGBIRDSIN HIGH ELEVATION  

E-Print Network [OSTI]

NEST-SITESELECTIONAND NESTINGSUCCESSOF CAVITY-NESTINGBIRDSIN HIGH ELEVATION FORESTDRAINAGES that characterized successful and unsuccessful nest sites, nest sites vs. random sites, and differences among coexisting species of cavity- nesting birds for 356 nests in central Arizona. Live and, more commonly, dead

Martin, Thomas E.

157

Wave Generation from Explosions in Rock Cavities CANGLI LIU1  

E-Print Network [OSTI]

Wave Generation from Explosions in Rock Cavities CANGLI LIU1 and THOMAS J. AHRENS1 Abstract Ð We have developed a measurement method to monitor P- and S-waves generated from laboratory diameter cavities. Stress waves generated by the explosions were recorded within a radius of 25 cm

Stewart, Sarah T.

158

Lab Breakthrough: Record-Setting Cavities | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

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

159

Apparatus and process for passivating an SRF cavity  

DOE Patents [OSTI]

An apparatus and process for the production of a niobium cavity exhibiting high quality factors at high gradients is provided. The apparatus comprises a first chamber positioned within a second chamber, an RF generator and vacuum pumping systems. The process comprises placing the niobium cavity in a first chamber of the apparatus; thermally treating the cavity by high temperature in the first chamber while maintaining high vacuum in the first and second chambers; and applying a passivating thin film layer to a surface of the cavity in the presence of a gaseous mixture and an RF field. Further a niobium cavity exhibiting high quality factors at high gradients produced by the method of the invention is provided.

Myneni, Ganapati Rao; Wallace, John P

2014-12-02T23:59:59.000Z

160

Hydrogen-filled RF Cavities for Muon Beam Cooling  

SciTech Connect (OSTI)

Ionization cooling requires low-Z energy absorbers immersed in a strong magnetic field and high-gradient, large-aperture RF cavities to be able to cool a muon beam as quickly as the short muon lifetime requires. RF cavities that operate in vacuum are vulnerable to dark-current- generated breakdown, which is exacerbated by strong magnetic fields, and they require extra safety windows that degrade cooling, to separate RF regions from hydrogen energy absorbers. RF cavities pressurized with dense hydrogen gas will be developed that use the same gas volume to provide the energy absorber and the RF acceleration needed for ionization cooling. The breakdown suppression by the dense gas will allow the cavities to operate in strong magnetic fields. Measurements of the operation of such a cavity will be made as functions of external magnetic field and charged particle beam intensity and compared with models to understand the characteristics of this technology and to develop mitigating strategies if necessary.

CHARLES, Ankenbrandt

2009-04-17T23:59:59.000Z

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

A new microphonics measurement method for superconducting RF cavities  

SciTech Connect (OSTI)

Mechanical vibrations of the superconducting cavity, also known as microphonics, cause shifts in the resonant frequency of the cavity. In addition to requiring additional RF power, these frequency shifts can contribute to errors in the closed loop phase and amplitude regulation. In order to better understand these effects, a new microphonics measurement method was developed, and the method was successfully used to measure microphonics on the half-wave superconducting cavity when it was operated in a production style cryostat. The test cryostat held a single ?=0.1 half-wave cavity which was operated at 162.5 MHz [1] and [2]. It's the first time that the National Instruments PXIe-5641R intermediate frequency transceiver has been used for microphonics measurements in superconducting cavities. The new microphonics measurement method and results will be shown and analyzed in this paper.

Gao,Zheng; He,Yuan; Chang,Wei; Powers, Tom [JLAB; Yue,Wei-ming; Zhu,Zheng-long; Chen,Qi

2014-09-01T23:59:59.000Z

162

Enhancement of accelerating field of microwave cavities by magnetic insulation  

SciTech Connect (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

163

Fabrication and Testing of Deflecting Cavities for APS  

SciTech Connect (OSTI)

Jefferson Lab (Newport News, Virginia) in collaboration with Argonne National Laboratory (Argonne, IL) has fabricated and tested four first article, 2.8 GHz, deflecting SRF cavities, for Argonne's Short-Pulse X-ray (SPX) project. These cavities are unique in many ways including the fabrication techniques in which the cavity cell and waveguides were fabricated. These cavity subcomponents were milled from bulk large grain niobium ingot material directly from 3D CAD files. No forming of sub components was used with the exception of the beam-pipes. The challenging cavity and helium vessel design and fabrication results from the stringent RF performance requirements required by the project and operation in the APS ring. Production challenges and fabrication techniques as well as testing results will be discussed in this paper.

Mammosser, John; Wang, Haipeng; Rimmer, Robert; Jim, Henry; Katherine, Wilson; Dhakal, Pashupati; Ali, Nassiri; Jim, Kerby; Jeremiah, Holzbauer; Genfa, Wu; Joel, Fuerst; Yawei, Yang; Zenghai, Li

2013-09-01T23:59:59.000Z

164

AGN Heating through Cavities and Shocks  

E-Print Network [OSTI]

Three comments are made on AGN heating of cooling flows. A simple physical argument is used to show that the enthalpy of a buoyant radio lobe is converted to heat in its wake. Thus, a significant part of ``cavity'' enthalpy is likely to end up as heat. Second, the properties of the repeated weak shocks in M87 are used to argue that they can plausibly prevent gas close to the AGN from cooling. As the most significant heating mechanism at work closest to the AGN, shock heating probably plays a critical role in the feedback mechanism. Third, results are presented from a survey of AGN heating rates in nearby giant elliptical galaxies. With inactive systems included, the overall AGN heating rate is reasonably well matched to the total cooling rate for the sample. Thus, intermittent AGN outbursts are energetically capable of preventing the hot atmospheres of these galaxies from cooling and forming stars.

P. E. J. Nulsen; C. Jones; W. R. Forman; L. P. David; B. R. McNamara; D. A. Rafferty; L. Birzan; M. W. Wise

2006-11-04T23:59:59.000Z

165

Cavity optomechanics in gallium phosphide microdisks  

SciTech Connect (OSTI)

We demonstrate gallium phosphide (GaP) microdisk optical cavities with intrinsic quality factors >2.8?×?10{sup 5} and mode volumes <10(?/n){sup 3}, and study their nonlinear and optomechanical properties. For optical intensities up to 8.0?×?10{sup 4} intracavity photons, we observe optical loss in the microcavity to decrease with increasing intensity, indicating that saturable absorption sites are present in the GaP material, and that two-photon absorption is not significant. We observe optomechanical coupling between optical modes of the microdisk around 1.5??m and several mechanical resonances, and measure an optical spring effect consistent with a theoretically predicted optomechanical coupling rate g{sub 0}/2??30?kHz for the fundamental mechanical radial breathing mode at 488?MHz.

Mitchell, Matthew; Barclay, Paul E., E-mail: pbarclay@ucalgary.ca [Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); National Institute for Nanotechnology, 11421 Saskatchewan Dr. NW, Edmonton, Alberta T6G 2M9 (Canada); Hryciw, Aaron C. [National Institute for Nanotechnology, 11421 Saskatchewan Dr. NW, Edmonton, Alberta T6G 2M9 (Canada)

2014-04-07T23:59:59.000Z

166

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

167

The crystal structure of wild-type human brain neuroglobin reveals flexibility of the disulfide bond that regulates oxygen affinity  

Science Journals Connector (OSTI)

The crystal structure of wild-type human neuroglobin reveals two distinct conformations of the CD loop that contains an internal disulfide bridge. The increased affinity for oxygen upon disulfide-bond formation may be explained by the flexibility of the CD loop and the remodelling of the internal cavities.

Guimar?es, B.G.

2014-03-19T23:59:59.000Z

168

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum cascade laser  

E-Print Network [OSTI]

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum: Faraday Rotation Spectroscopy, external-cavity quantum cascade laser, nitrogen dioxide, trace

169

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

170

THE CRYSTAL CLOCK  

Science Journals Connector (OSTI)

...crystal are connected between the grid and filament of the oscillator tube, a grid leak being connected across the crystal to provide the proper grid bias. A parallel resonant circuit...cycles, and a mercury damped flywheel used to reduce hunting. As...

W. A. Marrison

1930-01-01T23:59:59.000Z

171

Optical bistability and free carrier dynamics in graphenesilicon photonic crystal cavities  

E-Print Network [OSTI]

is the electron charge, and is the permittivity of graphene at the drive frequency. For our 1550 nm wavelengths material for integrated photonic devices. Graphene has been examined for its gate-variable optical

Hone, James

172

Nano-mechanical tuning and imaging of a photonic crystal micro-cavity resonance  

Science Journals Connector (OSTI)

We show that nano-mechanical interaction using atomic force microscopy (AFM) can be used to map out mode-patterns of an optical micro-resonator with high spatial accuracy....

Hopman, W C L; van der Werf, K O; Hollink, A J F; Bogaerts, W; Subramaniam, V; de Ridder, R M

2006-01-01T23:59:59.000Z

173

Roughening transition and helium crystals  

Science Journals Connector (OSTI)

Crystal shapes or crystal growth mechanisms depend drastically on whether the crystal surface is smooth or rough, i.e. whether the temperature is lower or higher than its roughening temperature. Helium appeared r...

S. Balibar; F. Gallet; E. Rolley; P. E. Wolf

1985-01-01T23:59:59.000Z

174

Binding of cobalt and iron to cavities in silicon  

SciTech Connect (OSTI)

The chemisorption binding of Co and Fe to cavity walls in Si was quantitatively characterized in the temperature range 973{endash}1273 K in order to evaluate the efficacy of cavities for impurity gettering. The cavities were formed by He ion implantation and annealing. Then, with the solution concentration of Co or Fe being held at the solid solubility through prior formation of excess metal-silicide phase, the equilibrium number of metal atoms bound to the cavities was measured. Using this information in conjunction with published solubilities, a binding free energy relative to interstitial solution was extracted. The binding free energies for cavity-wall chemisorption of Co and Fe were found to be less than those for precipitation of the respective silicide phases, a reversal of the ordering previously observed by us for Cu and Au. Nevertheless, model calculations indicate that the chemisorption mechanism is important together with silicide precipitation for cavity gettering of all four elements. The results of this work, taken with the known thermal stability and the anticipated device-side compatibility of cavities, suggest that these sinks will prove attractive for gettering.

Myers, S.M.; Petersen, G.A.; Seager, C.H. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1056 (United States)] [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1056 (United States)

1996-10-01T23:59:59.000Z

175

Tests of a prototype magnetostrictive tuner for superconducting cavities  

SciTech Connect (OSTI)

The Continuous Electron Beam Accelerator (CEBA) uses mechanical tuners at 2 K driven by room temperature stepping motors in a feedback loop to maintain cavity frequency at 1497 MHz. Modification of the system was designed, replacing a passive section of the mechanical tuner with a magnetostrictive tuning element consisting of a Ni rod and an industrially supplied 0.25 T superconducting solenoid. This assembly was tested with several magnetic shield configurations designed to keep the stray flux at the Nb cavity below 1 {mu}T when the cavity was normal, to maintain cavity Q. Results of the tests, including change in cavity performance when the cavity was locally quenched near the end of the solenoid, showed that the a multi-layer shield of 6mm steel, with sheets of mu metal, niobium and my metal spaced appropriately outside the thick steel, was effective in containing the flux, both remanent and current-driven, preventing any change in cavity Q upon cooldown or quench with an external heater near the solenoid end. Hysteresis attributed to the Ni magnetostrictive element was observed.

Benesch, J.F.; Wiseman, M. [Thomas Jefferson National Accelerator facility, Newport News, VA (United States)

1996-10-01T23:59:59.000Z

176

Low-Threshold Surface-Passivated Photonic Crystal Nanocavity Laser  

E-Print Network [OSTI]

The efficiency and operating range of a photonic crystal laser is improved by passivating the InGaAs quantum well (QW) gain medium and GaAs membrane using an (NH4)S treatment. The passivated laser shows a four-fold reduction in nonradiative surface recombination rate, resulting in a four-fold reduction in lasing threshold. A three-level carrier dynamics model explains the results and shows that lasing threshold is as much determined by surface recombination losses as by the cavity quality factor (Q). Surface passivation therefore appears crucial in operating such lasers under practical conditions.

Dirk Englund; Hatice Altug; Jelena Vuckovic

2007-03-21T23:59:59.000Z

177

Neutron Diffraction Performance Based on Multiple Reflection Monochromator for High-Resolution Neutron Radiography  

Science Journals Connector (OSTI)

The effects of multiple Bragg reflections in single crystal can be observed when more than one set of planes are simultaneously operative for a given wavelength i.e. when more than two reciprocal lattice point...

Pavel Mikula; Miroslav Vrana

2007-01-01T23:59:59.000Z

178

A top loading 2 Kelvin test cryostat for SRF cavities.  

SciTech Connect (OSTI)

A new large 2 Kelvin test cryostat is being commissioned at Argonne National Laboratory. This system will have a full time connection to the 4.5 Kelvin ATLAS refrigerator and, with integrated J-T heat exchanger, will allow continuous 2 Kelvin operation. The large diameter was chosen to accommodate essentially all of today's superconducting cavities and the top loading design facilitates clean room assembly. The commissioning run will be with a coaxial half wave cavity to be followed by testing with 1.3 GHz single-cell elliptical cavities. Details of the initial engineering cool down on the cryostat are presented.

Kedzie, M.; Kelly, M. P.; Gerbick, S. M.; Fuerst, J. D.; Shepard, K. W.; Physics

2009-01-01T23:59:59.000Z

179

Thermal effects on the stability of excited atoms in cavities  

SciTech Connect (OSTI)

An atom, coupled linearly to an environment, is considered in a harmonic approximation in thermal equilibrium inside a cavity. The environment is modeled by an infinite set of harmonic oscillators. We employ the notion of dressed states to investigate the time evolution of the atom initially in the first excited level. In a very large cavity (free space) for a long elapsed time, the atom decays and the value of its occupation number is the physically expected one at a given temperature. For a small cavity the excited atom never completely decays and the stability rate depends on temperature.

Khanna, F. C.; Malbouisson, A. P. C.; Malbouisson, J. M. C.; Santana, A. E. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada) and TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Centro Brasileiro de Pesquisas Fisicas/MCT, 22290-180 Rio de Janeiro, Rio de Janeiro (Brazil); Instituto de Fisica, Universidade Federal da Bahia, 40.210-310 Salvador, Bahia (Brazil); Instituto de Fisica, Universidade de Brasilia, 70910-900 Brasilia, Distrito Federal (Brazil) and Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)

2010-03-15T23:59:59.000Z

180

Three-qubit phase gate based on cavity quantum electrodynamics  

E-Print Network [OSTI]

- mentation, such as linear ion traps #4;1#5;, liquid-state nuclear magnetic resonance #1;NMR#2; #4;2#5;, and cavity QED systems #4;3,4#5;. There are three requirements for implementing a quantum computer: Efficient manipulation and read out of an indi.... #4;6#5;, a scheme to implement a two-qubit quantum phase gate and one-qubit unitary operation implementation based on cavity QED was described. They choose the Fock states #6;0#7; and #6;1#7; of a high Q cavity mode as the two logical states of a...

Chang, Jun-Tao; Zubairy, M. Suhail

2008-01-01T23:59:59.000Z

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.


181

Computational analysis of crystallization trials  

Science Journals Connector (OSTI)

A system for the automatic classification of images from crystallization trials for use in conjunction with a high-throughput robotic crystallization platform is described.

Spraggon, G.

2002-10-21T23:59:59.000Z

182

High sensitivity gas sensor based on high-Q suspended polymer photonic crystal nanocavity  

SciTech Connect (OSTI)

We present high-sensitivity, multi-use optical gas sensors based on a one-dimensional photonic crystal cavity. These devices are implemented in versatile, flexible polymer materials which swell when in contact with a target gas, causing a measurable cavity length change. This change causes a shift in the cavity resonance, allowing precision measurements of gas concentration. We demonstrate suspended polymer nanocavity sensors and the recovery of sensors after the removal of stimulant gas from the system. With a measured quality factor exceeding 10{sup 4}, we show measurements of gas concentration as low as 600 parts per million (ppm) and an experimental sensitivity of 10?ppm; furthermore, we predict detection levels in the parts-per-billion range for a variety of gases.

Clevenson, Hannah, E-mail: hannahac@mit.edu; Desjardins, Pierre; Gan, Xuetao; Englund, Dirk, E-mail: englund@mit.edu [Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-06-16T23:59:59.000Z

183

Quantum measurements of atoms using cavity QED  

SciTech Connect (OSTI)

Generalized quantum measurements are an important extension of projective or von Neumann measurements in that they can be used to describe any measurement that can be implemented on a quantum system. We describe how to realize two nonstandard quantum measurements using cavity QED. The first measurement optimally and unambiguously distinguishes between two nonorthogonal quantum states. The second example is a measurement that demonstrates superadditive quantum coding gain. The experimental tools used are single-atom unitary operations effected by Ramsey pulses and two-atom Tavis-Cummings interactions. We show how the superadditive quantum coding gain is affected by errors in the field-ionization detection of atoms and that even with rather high levels of experimental imperfections, a reasonable amount of superadditivity can still be seen. To date, these types of measurements have been realized only on photons. It would be of great interest to have realizations using other physical systems. This is for fundamental reasons but also since quantum coding gain in general increases with code word length, and a realization using atoms could be more easily scaled than existing realizations using photons.

Dada, Adetunmise C.; Andersson, Erika [SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Jones, Martin L.; Kendon, Vivien M. [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Everitt, Mark S. [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda ku, Tokyo 101-8430 (Japan)

2011-04-15T23:59:59.000Z

184

Raman scattering in crystals  

SciTech Connect (OSTI)

A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

Edwards, D.F.

1988-09-30T23:59:59.000Z

185

Sintering behavior of two roughened crystals just after contact  

E-Print Network [OSTI]

We consider two spherical, roughened crystals with approximately isotropic surface free energy which are brought into contact and begin to sinter. We argue that the geometry immediately post-contact is two dimensional and Cartesian and can be approximated by the evolution of a slot-shaped cavity. On this basis, we construct travelling wave solutions for the crystal shape in the limits of bulk diffusion limited and surface diffusion limited kinetics. These solutions are then used to calculate novel scalings for the neck size as a function of time $t$ after contact: We predict that neck size is proportional to $t^{1/4}$ for the bulk diffusion limited case and (following a single pinch-off event) approximately proportional to $t^{1/3}$ for the surface diffusion limited case.

R. S. Farr; M. J. Izzard

2010-01-22T23:59:59.000Z

186

A Cavity QED Implementation of Deutsch-Jozsa Algorithm  

E-Print Network [OSTI]

The Deutsch-Jozsa algorithm is a generalization of the Deutsch algorithm which was the first algorithm written. We present schemes to implement the Deutsch algorithm and the Deutsch-Jozsa algorithm via cavity QED.

E. S. Guerra

2004-10-23T23:59:59.000Z

187

Intermittency in an Optomechanical Cavity Near a Subcritical Hopf Bifurcation  

E-Print Network [OSTI]

We experimentally study an optomechanical cavity consisting of an oscillating mechanical resonator embedded in a superconducting microwave transmission line cavity. Tunable optomechanical coupling between the mechanical resonator and the microwave cavity is introduced by positioning a niobium-coated single mode optical fi?ber above the mechanical resonator. The capacitance between the mechanical resonator and the coated fi?ber gives rise to optomechanical coupling, which can be controlled by varying the ?fiber-resonator distance. We study radiation pressure induced self-excited oscillations as a function of microwave driving parameters (frequency and power). Intermittency between limit cycle and steady state behaviors is observed with blue-detuned driving frequency. The experimental results are accounted for by a model that takes into account the Duffi?ng-like nonlinearity of the microwave cavity. A stability analysis reveals a subcritical Hopf bifurcation near the region where intermittency is observed.

Suchoi, Oren; Shtempluk, Oleg; Buks, Eyal

2014-01-01T23:59:59.000Z

188

Intermittency in an Optomechanical Cavity Near a Subcritical Hopf Bifurcation  

E-Print Network [OSTI]

We experimentally study an optomechanical cavity consisting of an oscillating mechanical resonator embedded in a superconducting microwave transmission line cavity. Tunable optomechanical coupling between the mechanical resonator and the microwave cavity is introduced by positioning a niobium-coated single mode optical fiber above the mechanical resonator. The capacitance between the mechanical resonator and the coated fiber gives rise to optomechanical coupling, which can be controlled by varying the fiber-resonator distance. We study radiation pressure induced self-excited oscillations as a function of microwave driving parameters (frequency and power). Intermittency between limit cycle and steady state behaviors is observed with blue-detuned driving frequency. The experimental results are accounted for by a model that takes into account the Duffing-like nonlinearity of the microwave cavity. A stability analysis reveals a subcritical Hopf bifurcation near the region where intermittency is observed.

Oren Suchoi; Lior Ella; Oleg Shtempluk; Eyal Buks

2014-05-15T23:59:59.000Z

189

Cavity dynamics in water entry at low Froude numbers  

E-Print Network [OSTI]

The dynamics of the air cavity created by vertical water entry of a three-dimensional body is investigated theoretically, computationally and experimentally. The study is focused in the range of relatively low Froude ...

Yan, Hongmei

190

Design criterion for tubed solar-heated cavity receivers  

Science Journals Connector (OSTI)

Solar energy can be economically converted into electrical ... small and medium power outputs. A typical solar power plant consists of a parabolic dish, cavity receiver and gas turbine. To obtain high gas turbine

Prof. Dr.-Ing. Karl Bammert; Dr.-Ing. Ahmed Hegazy

1986-01-01T23:59:59.000Z

191

Analysis of Direct and Inverse Cavity Scattering Prob- lems  

E-Print Network [OSTI]

problem is to determine the shape of the cavity from the measurement of the field on ... can be efficiently stored and solved, especially for three-dimensional .... In addition, standard jump conditions are satisfied for the fields across an interface.

2011-02-15T23:59:59.000Z

192

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...

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

1994-01-01T23:59:59.000Z

193

Single-molecule controlled emission in planar plasmonic cavities  

Science Journals Connector (OSTI)

We study the fluorescence emission from single dye molecules in coplanar plasmonic cavities composed of a thin gold film surrounded by two in-plane surface plasmon Bragg mirrors. We first discuss the effect of the presence of Bragg mirrors on the radiation diagram of surface plasmon coupled emission. Then, we investigate the role of the planar cavity size by single-molecule fluorescence lifetime imaging. Experimental data are compared to numerical simulations of the decay rates calculated as a function of the molecule orientation and position within the cavity. The creation of new decay channels by coupling to the cavity modes is also discussed. We measure a plasmonic Purcell factor up to five, attributed to the enhancement of the radiative rate.

S. Derom; A. Bouhelier; A. Kumar; A. Leray; J-C. Weeber; S. Buil; X. Quélin; J. P. Hermier; G. Colas des Francs

2014-01-02T23:59:59.000Z

194

Cavity-enhanced optical bottle beam as a mechanical amplifier  

Science Journals Connector (OSTI)

We analyze the resonant cavity enhancement of a hollow “optical bottle beam” for the dipole-force trapping of dark-field-seeking species. We first improve upon the basic bottle beam by adding further Laguerre-Gaussian components to deepen the confining potential. Each of these components itself corresponds to a superposition of transverse cavity modes, which are then enhanced simultaneously in a confocal cavity to produce a deep optical trap needing only a modest incident power. The response of the trapping field to displacement of the cavity mirrors offers an unusual form of mechanical amplifier in which the Gouy phase shift produces an optical Vernier scale between the Laguerre-Gaussian beam components.

Tim Freegarde and Kishan Dholakia

2002-07-30T23:59:59.000Z

195

State of the art of multicell SC cavities and perspectives  

SciTech Connect (OSTI)

Superconducting cavity technology has made major progresses in the last decade with the introduction of high purity niobium on an industrial scale and, at the same time, by an improved understanding of the limiting processes in cavity performance, such as multipacting, field emission loading and thermal break-down. Multicell niobium cavities for beta = 1 particle acceleration, e.g. for the TESLA project, are routinely exceeding gradients of Eacc = 20 MV/m after the application of surface preparation techniques such as buffered chemical polishing or electropolishing, high pressure ultrapure water rinsing, UHV heat treatment and clean room assembly. The successes of the technology for beta = 1 accelerators has triggered a whole set of possible future applications for beta < 1 particle acceleration such as spallation neutron sources (SNS, ESS), transmutation of nuclear waste (TRASCO, ASH) or rare isotopes (RIA). The most advanced of these projects is SNS now under construction at Oak Ridge National Laboratory. This paper will review the technical solutions adopted to advance SRF technology and their impact on cavity performance, based on the SNS prototyping efforts. 2K at these high gradients are no longer out of reach. For the accelerator builder the challenge remains to come up with a good and reasonable design, which takes into account the status of the technology and does not over-estimate the achievable cavity performances in a large assembly such as, e.g., a multi-cavity cryo-module. In the following the criteria for multi-cell sc cavity design are reviewed and it is attempted to give a snapshot of the present status of multi-cell cavity performances.

Peter Kneisel

2002-08-01T23:59:59.000Z

196

From Josephson junction metamaterials to tunable pseudo-cavities  

E-Print Network [OSTI]

The scattering through a Josephson junction interrupting a superconducting line is revisited including power leakage. We discuss also how to make tunable and broadband resonant mirrors by concatenating junctions. As an application, we show how to construct cavities using these mirrors, thus connecting two research fields: JJ quantum metamaterials and coupled cavity arrays. We finish by discussing the first non-linear corrections to the scattering and their measurable effects.

D. Zueco; C. Fernández-Juez; J. Yago; U. Naether; B. Peropadre; J. J. García-Ripoll; J. J. Mazo

2013-05-21T23:59:59.000Z

197

A high resolution cavity BPM for the CLIC Test Facility  

E-Print Network [OSTI]

In frame of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.

Chritin, N; Soby, L; Lunin, A; Solyak, N; Wendt, M; Yakovlev, V

2012-01-01T23:59:59.000Z

198

Damping of unwanted modes in SRF deflecting/crabbing cavities  

SciTech Connect (OSTI)

As deflecting and crab cavities do not use the fundamental acceleration mode for their operation, the spectrum of unwanted modes is significantly different from that of accelerating cavities. The fundamental acceleration mode is now unwanted and can cause energy spread in the beam; in addition this mode frequency is often close to or lower than that of the deflecting mode, making it difficult to damp. This is made more complex in some of the compact crab cavities as there small beampipes often attenuate the fields very sharply. In addition in some crab cavities there can be an orthogonal transverse mode similar to the deflecting mode, known as the same order mode. The degeneracy of these modes must be split by polarising the cavity and if the polarisation is not large enough, dampers should be placed at either an electric or magnetic field null of the crabbing mode to effectively damp the unwanted polarisation. Various concepts for dealing with unwanted modes in various SRF deflecting cavities will be reviewed.

Burt, Graeme [University of Lancaster (United Kingdom); Wang, Haipeng [JLAB, Newport News, VA (United States)

2014-01-01T23:59:59.000Z

199

Modeling Coupled Evaporation and Seepage in Ventilated Cavities  

SciTech Connect (OSTI)

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

200

Crystals and Plants  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

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

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect (OSTI)

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

202

A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment  

SciTech Connect (OSTI)

MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beamâ s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

Li, D.; DeMello, A.J.; Virostek, Steve; S. Zisman, Michael; Rimmer, Robert

2008-07-01T23:59:59.000Z

203

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

SciTech Connect (OSTI)

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

204

The Ties that Bind Metals to Proteins | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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 Records in...

205

Infrared hyperspectral imaging using a broadly tunable external cavity quantum cascade laser and microbolometer focal plane array  

SciTech Connect (OSTI)

A versatile mid-infrared hyperspectral imaging system is demonstrated by combining a broadly tunable external cavity quantum cascade laser and a microbolometer focal plane array. The tunable mid-infrared laser provided high brightness illumination over a tuning range from 985 cm-1 to 1075 cm-1 (9.30-10.15 ?m). Hypercubes containing images at 300 wavelengths separated by 0.3 cm 1 were obtained in 12 s. High spectral resolution chemical imaging of methanol vapor was demonstrated for both static and dynamic systems. The system was also used to image and characterize multiple component liquid and solid samples.

Phillips, Mark C.; Ho, Nicolas

2008-02-04T23:59:59.000Z

206

Reversed Doppler Effect in Photonic Crystals  

Science Journals Connector (OSTI)

Nonrelativistic reversed Doppler shifts have never been observed in nature and have only been speculated to occur in pathological systems with simultaneously negative effective permittivity and permeability. This Letter presents a different, new physical phenomenon that leads to a nonrelativistic reversed Doppler shift in light. It arises when light is reflected from a moving shock wave propagating through a photonic crystal. In addition to reflection of a single frequency, multiple discrete reflected frequencies or a 10 GHz periodic modulation can also be observed when a single carrier frequency of wavelength 1????m is incident.

Evan J. Reed; Marin Solja?i?; John D. Joannopoulos

2003-09-23T23:59:59.000Z

207

Thoracic cavity segmentation algorithm using multiorgan extraction and surface fitting in volumetric CT  

SciTech Connect (OSTI)

Purpose: To develop and validate a semiautomatic segmentation method for thoracic cavity volumetry and mediastinum fat quantification of patients with chronic obstructive pulmonary disease. Methods: The thoracic cavity region was separated by segmenting multiorgans, namely, the rib, lung, heart, and diaphragm. To encompass various lung disease-induced variations, the inner thoracic wall and diaphragm were modeled by using a three-dimensional surface-fitting method. To improve the accuracy of the diaphragm surface model, the heart and its surrounding tissue were segmented by a two-stage level set method using a shape prior. To assess the accuracy of the proposed algorithm, the algorithm results of 50 patients were compared to the manual segmentation results of two experts with more than 5 years of experience (these manual results were confirmed by an expert thoracic radiologist). The proposed method was also compared to three state-of-the-art segmentation methods. The metrics used to evaluate segmentation accuracy were volumetric overlap ratio (VOR), false positive ratio on VOR (FPRV), false negative ratio on VOR (FNRV), average symmetric absolute surface distance (ASASD), average symmetric squared surface distance (ASSSD), and maximum symmetric surface distance (MSSD). Results: In terms of thoracic cavity volumetry, the mean ± SD VOR, FPRV, and FNRV of the proposed method were (98.17 ± 0.84)%, (0.49 ± 0.23)%, and (1.34 ± 0.83)%, respectively. The ASASD, ASSSD, and MSSD for the thoracic wall were 0.28 ± 0.12, 1.28 ± 0.53, and 23.91 ± 7.64 mm, respectively. The ASASD, ASSSD, and MSSD for the diaphragm surface were 1.73 ± 0.91, 3.92 ± 1.68, and 27.80 ± 10.63 mm, respectively. The proposed method performed significantly better than the other three methods in terms of VOR, ASASD, and ASSSD. Conclusions: The proposed semiautomatic thoracic cavity segmentation method, which extracts multiple organs (namely, the rib, thoracic wall, diaphragm, and heart), performed with high accuracy and may be useful for clinical purposes.

Bae, JangPyo [Interdisciplinary Program, Bioengineering Major, Graduate School, Seoul National University, Seoul 110-744, South Korea and Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)] [Interdisciplinary Program, Bioengineering Major, Graduate School, Seoul National University, Seoul 110-744, South Korea and Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Kim, Namkug, E-mail: namkugkim@gmail.com; Lee, Sang Min; Seo, Joon Beom [Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)] [Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Kim, Hee Chan [Department of Biomedical Engineering, College of Medicine and Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of)] [Department of Biomedical Engineering, College of Medicine and Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of)

2014-04-15T23:59:59.000Z

208

Cavity quantum electrodynamics with a Rydberg-blocked atomic ensemble  

SciTech Connect (OSTI)

The realization of a Jaynes-Cummings model in the optical domain is proposed for an atomic ensemble. The scheme exploits the collective coupling of the atoms to a quantized cavity mode and the nonlinearity introduced by coupling to high-lying Rydberg states. A two-photon transition resonantly couples the single-atom ground state |g> to a Rydberg state |e> via a nonresonant intermediate state |i>, but due to the interaction between Rydberg atoms only a single atom can be resonantly excited in the ensemble. This restricts the state space of the ensemble to the collective ground state |G> and the collectively excited state |E> with a single Rydberg excitation distributed evenly on all atoms. The collectively enhanced coupling of all atoms to the cavity field with coherent coupling strengths which are much larger than the decay rates in the system leads to the strong coupling regime of the resulting effective Jaynes-Cummings model. We use numerical simulations to show that the cavity transmission can be used to reveal detailed properties of the Jaynes-Cummings ladder of excited states and that the atomic nonlinearity gives rise to highly nontrivial photon emission from the cavity. Finally, we suggest that the absence of interactions between remote Rydberg atoms may, due to a combinatorial effect, induce a cavity-assisted excitation blockade whose range is larger than the typical Rydberg dipole-dipole interaction length.

Guerlin, Christine [Institute for Quantum Electronics, ETH Zuerich, CH-8093 Zuerich (Switzerland); Thales Research and Technology, Campus Polytechnique, 1 avenue Augustin Fresnel, F-91767 Palaiseau Cedex (France); Brion, Etienne [Laboratoire Aime Cotton, CNRS, Campus d'Orsay, F-91405, Orsay (France); Esslinger, Tilman [Institute for Quantum Electronics, ETH Zuerich, CH-8093 Zuerich (Switzerland); Moelmer, Klaus [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 (Denmark)

2010-11-15T23:59:59.000Z

209

Cavity quantum electrodynamics with a Rydberg-blocked atomic ensemble  

Science Journals Connector (OSTI)

The realization of a Jaynes-Cummings model in the optical domain is proposed for an atomic ensemble. The scheme exploits the collective coupling of the atoms to a quantized cavity mode and the nonlinearity introduced by coupling to high-lying Rydberg states. A two-photon transition resonantly couples the single-atom ground state |g? to a Rydberg state |e? via a nonresonant intermediate state |i?, but due to the interaction between Rydberg atoms only a single atom can be resonantly excited in the ensemble. This restricts the state space of the ensemble to the collective ground state |G? and the collectively excited state |E? with a single Rydberg excitation distributed evenly on all atoms. The collectively enhanced coupling of all atoms to the cavity field with coherent coupling strengths which are much larger than the decay rates in the system leads to the strong coupling regime of the resulting effective Jaynes-Cummings model. We use numerical simulations to show that the cavity transmission can be used to reveal detailed properties of the Jaynes-Cummings ladder of excited states and that the atomic nonlinearity gives rise to highly nontrivial photon emission from the cavity. Finally, we suggest that the absence of interactions between remote Rydberg atoms may, due to a combinatorial effect, induce a cavity-assisted excitation blockade whose range is larger than the typical Rydberg dipole-dipole interaction length.

Christine Guerlin; Etienne Brion; Tilman Esslinger; Klaus Mølmer

2010-11-29T23:59:59.000Z

210

MagLab Audio Dictionary: Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

What are Crystals? Now Playing: What are Crystals? Enable Javascript and Flash to stream the Magnet Minute Chris Wiebe Associated Links Quantum Materials Group New Crystal Growth...

211

Demazure Crystals, Kirillov-Reshetikhin Crystals, and the Energy Function  

E-Print Network [OSTI]

It has previously been shown that, at least for non-exceptional Kac-Moody Lie algebras, there is a close connection between Demazure crystals and tensor products of Kirillov-Reshetikhin crystals. In particular, certain ...

Schilling, Anne

212

Single-Photon Absorption in Coupled Atom-Cavity Systems  

E-Print Network [OSTI]

We show how to capture a single photon of arbitrary temporal shape with one atom coupled to an optical cavity. Our model applies to Raman transitions in three-level atoms with one branch of the transition controlled by a (classical) laser pulse, and the other coupled to the cavity. Photons impinging on the cavity normally exhibit partial reflection, transmission, and/or absorption by the atom. Only a control pulse of suitable temporal shape ensures impedance matching throughout the pulse, which is necessary for complete state mapping from photon to atom. For most possible photon shapes, we derive an unambiguous analytic expression for the shape of this control pulse, and we discuss how this relates to a quantum memory.

Jerome Dilley; Peter Nisbet-Jones; Bruce W. Shore; Axel Kuhn

2012-03-01T23:59:59.000Z

213

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

214

Numerical study of natural convection in fully open tilted cavities  

SciTech Connect (OSTI)

A numerical simulation of two-dimensional laminar natural convection in a fully open tilted square cavity with an isothermally heated back wall is conducted. The remaining two walls of the cavity are adiabatic. Steady-state solutions are presented for Grashof numbers between 10{sup 2} and 10{sup 5} and for tilt angles ranging from {minus}60{degree} to 90{degree} (where 90{degree} represents a cavity with the opening facing down). The fluid properties are assumed to be constant except for the density variation with temperature that gives rise to the buoyancy forces, which is treated by the Boussinesq approximation. The fluid concerned is air with Prandtl number fixed at 0.71. The governing equations are expressed in a normalized primitive variables formulation. Numerical predictions of the velocity and temperature fields are obtained using the finite-volume-based power law (SIMPLER: Semi-Implicit Method for Pressure-Linked Equations Revised) algorithm. For a vertical open cavity ({alpha} = 0{degree}), the algorithm generated results that were in good agreement with those previously published. Flow patterns and isotherms are shown in order to give a better understanding of the heat transfer and flow mechanisms inside the cavity. Effects of the controlling parameters-Grashof number and tilt angle-on the heat transfer (average Nusselt number) are presented and analyzed. The results also revealed that the open-cavity Nusselt number approaches the flat-plate solution when either Grashof number or tilt angle increases. In addition, a correlation of the Nusselt number in terms of the Grashof number and tilt angle is developed and presented; a comparison is made with available data from other literature.

Elsayed, M.M.; Al-Najem, N.M.; El-Refaee, M.M.; Noor, A.A.

1999-09-01T23:59:59.000Z

215

Phonon-cavity-enhanced low-temperature thermal conductance of a semiconductor nanowire with narrow constrictions  

Science Journals Connector (OSTI)

We study the effect of the phonon cavity lying in a narrow constriction of a semiconductor nanowire on the ballistic phonon thermal conductance at low temperatures. At higher temperatures, the thermal conductance of the nanowire with phonon cavity is lower than that of the nanowire without phonon cavity since more discontinuous interfaces scatter phonons. On the contrary, it is found that the cavity can enhance the thermal conductance at very low temperatures despite phonons are scattered by its interfaces. The enhancement originates from the coupling between more excited cavity modes in the phonon cavity and phonon modes in the constrictions.

Wei-Qing Huang; Gui-Fang Huang; Ling-Ling Wang; Bai-Yun Huang

2007-06-27T23:59:59.000Z

216

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

217

Time evolution of entangled biatomic states in a cavity  

SciTech Connect (OSTI)

We study the time evolution of entangled states of a pair of identical atoms, considered in the harmonic approximation, coupled to an environment represented by an infinite set of free oscillators, with the whole system confined within a spherical cavity of radius R. Taking the center-of-mass and the relative-position coordinates, and using the dressed-state approach, we present the time evolution of some quantities measuring the entanglement for both limits of a very large and a small cavity; the chosen examples are simple and illustrate these very distinct behaviors.

Figueiredo, E. G. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil); Centro de Cie circumflex ncias Exatas e Tecnologicas, Universidade Federal do Reco circumflex ncavo da Bahia, 44380-000, Cruz das Almas, BA (Brazil); Linhares, C. A. [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20559-900, Rio de Janeiro, RJ (Brazil); Malbouisson, A. P. C. [Centro Brasileiro de Pesquisas Fisicas/MCT, 22290-180, Rio de Janeiro, RJ (Brazil); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil)

2011-10-15T23:59:59.000Z

218

A New Cavity Design For Medium Beta Acceleration  

SciTech Connect (OSTI)

Heavy duty or cw, superconducting proton and heavy ion accelerators are being proposed and constructed worldwide. The total length of the machine is one of the main drivers in terms of cost. Thus hwr and spoke cavities at medium beta are usually optimized to achieve low surface field and high gradient. A novel accelerating structure at beta=0.5 evolved from spoke cavity is proposed, with lower surface fields but slightly higher heat load. It would be an interesting option for pulsed and cw accelerators with beam energy of more than 200mev/u.

He, Feisi [Peking University, Beijing (China); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-02-01T23:59:59.000Z

219

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network [OSTI]

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Parker, Stephen R; Povey, Rhys G; Tobar, Michael E

2014-01-01T23:59:59.000Z

220

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network [OSTI]

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2014-10-20T23:59:59.000Z

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

Cryogenic resonant microwave cavity searches for hidden sector photons  

Science Journals Connector (OSTI)

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment, where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53???eV, we limit the hidden photon kinetic mixing parameter ?cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2013-12-03T23:59:59.000Z

222

On the possible optical resonance in carbon nanotubes based cavities  

Science Journals Connector (OSTI)

An enhanced interference phenomenon in the IR absorbance-wavenumber profiles of ship-shaped carbon nanotubes powder has been observed by attenuated total reflection at room temperature. This room temperature interference phenomenon was considered as possibly originating from an optical resonance effect and that single carbon nanotubes could act as individual Fabry-Perot or Lummer-Gehrcke resonant cavities. It is demonstrated that this interference phenomenon could be an Anderson type localisation phenomenon due to resonant modes in the semi-disordered ship-shaped carbon nanotubes nanopowder which could form a plausible resonant cavity.

M. Maaza; T. Mhlungu; M.O. Ndwandwe; N. Cingo; A.C. Beye; A. Govindaraj; C.N.R. Rao

2007-01-01T23:59:59.000Z

223

Crystallization of Congo Red  

Science Journals Connector (OSTI)

... It has been confirmed that the potassium salt of Congo Red will crystallize as needles from various ethyl alcohol-water mixtures, but only with ... observation during a trial of various salting-out procedures, however, the potassium salt of Congo Red has been found to be precipitated in crystalline form by salting out with potassium ...

PETER MITCHELL

1950-05-13T23:59:59.000Z

224

Multiplicative congruential generators, their lattice structure, its relation to lattice-sublattice trans­formations and applications in crystallography  

Science Journals Connector (OSTI)

An analysis of certain types of multiplicative congruential generators - otherwise known for their application to the sequential generation of pseudo-random numbers - reveals their relation to lattice-sublattice transformations and the coordinate description of crystal structures.

Hornfeck, W.

2009-10-17T23:59:59.000Z

225

Crystals of Platinum and Palladium  

Science Journals Connector (OSTI)

... will be found partially fused. The ribbon upon which crystals have been formed presents a roughened appearance.

J. JOLY

1891-04-09T23:59:59.000Z

226

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

227

Ultraslow growth rates of giant gypsum crystals  

Science Journals Connector (OSTI)

...gypsum crystals of Naica ore mines in Chihuahua, Mexico, a challenging subject in mineral...gypsum crystals of Naica ore mines in Chihuahua, Mexico, a challenging subject in...geological timescale. age anhydrite Chihuahua Mexico cooling crystal growth crystallization...

A. E. S. Van Driessche; J. M. García-Ruíz; K. Tsukamoto; L. D. Patiño-Lopez; H. Satoh

2011-01-01T23:59:59.000Z

228

Quantum ferroelectrics of mixed crystals  

Science Journals Connector (OSTI)

The inverse dielectric susceptibility for quantum ferroelectrics in mixed crystals is computed. As in the perfect crystals we find a logarithmic correction to the quantum mean-field theory. For mixed crystals the correction increases faster in the vicinity of the critical point.

D. Schmeltzer

1984-03-01T23:59:59.000Z

229

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

230

Laser Frequency Stabilization with Optical Cavities Anya M. Davis  

E-Print Network [OSTI]

Laser Frequency Stabilization with Optical Cavities Anya M. Davis Walla Walla University University Effective laser cooling requires the laser's frequency to be precise, with a frequency drift of no more than lasers for correcting frequency drift. In the University of Washington Quantum Computing with Trapped

Blinov, Boris

231

Toroid cavities as NMR detectors in high pressure probes  

SciTech Connect (OSTI)

A cylindrical toroid cavity has been developed for application as an NMR detector for high sensitivity and high resolution spectroscopy in metal vessel probes. Those probes are used for in situ investigations at high temperature and pressure. Since the transmitted r.f. field is completely confined within the torus, the cavity can be placed inside the pressurized system without magnetic coupling to the metal vessel. Resonance frequencies up to 400 MHz make the toroid cavity detector especially suited for use in {sup 1}H and {sup 19}F spectroscopy. Typically achieved static {sup 1}H linewidths, measured on CHCl{sub 3} using cavities in Be-Cu pressure vessels, are 2.0 Hz. On the basis of theoretical considerations that include the radial dependence of the r.f. field within cylindrical or circular toroid detectors, equations were evolved to predict the signal intensity as a function of the pulse width. The equations precisely describe the deviations from the sinusoidal approximation, which is generally used for signal intensities derived from Helmholtz or solenoid coils.

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

1993-03-01T23:59:59.000Z

232

State of the art of multicell SC Cavities and Perspectives  

SciTech Connect (OSTI)

Superconducting cavity technology has made major progresses in the last decade with the introduction of high purity niobium on an industrial scale and, at the same time, by an improved understanding of the limiting processes in cavity performance, such as multipacting, field emission loading and thermal breakdown. Multicell niobium cavities for Beta=1 particle acceleration, e.g. for the TESLA project, are routinely exceeding gradients of E{sub acc}=20 MV/m after the application of surface preparation techniques such as buffered chemical polishing or electropolishing, high pressure ultrapure water rinsing, UHV heat treatment and clean-room assembly. The successes of the technology for Beta=1 accelerators has triggered a whole set of possible future applications for Beta < 1 particle acceleration such as spallation neutron sources (SNS, ESS), transmutation of nuclear waste (TRASCO, ASH) or rare isotopes (RIA). The most advanced of these projects is SNS now under construction at Oak Ridge National Laboratory. This paper will review the technical solutions adopted to advance SRF technology and their impact on cavity performance, based on the SNS prototyping efforts. Work supported by U.S. DOE contract DE-AC05-84ER40150

Peter Kneisel

2002-06-01T23:59:59.000Z

233

COMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES  

E-Print Network [OSTI]

of muons passing through matter. PHYSICAL MODEL We start our study with a classical scattering of muonsCOMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES A. Samolov, A. Godunov, and to validate a technical design of these new accelerating facilities, accu- rate and comprehensive simulations

Godunov, Alexander L.

234

Cavity resonances in engine combustion chambers and some applications  

Science Journals Connector (OSTI)

Cavity resonances in engine cylinders are caused by combustion events such as the rapid rate of pressure rise that occurs during compression ignition in diesels or from knock in gasoline engines. These resonances generally occur at frequencies greater than 4 to 5 kHz where the engine structure is not an efficient acoustical radiator. However when they occur at lower frequencies such as in engines with a large bore or in indirect injection diesels they can be important in the noise generation process. They are also important for knock detection in gasoline engines. Current knock detection systems are tuned to the frequency band of the lowest cavity resonance in the combustion chamber. It is shown in the paper that higher order resonances can also be detected by a knock vibration sensor on the surface of the engine. Another use for the cavity resonances is to determine the bulk temperature of the gas in the combustion chamber as a function of crank angle. This technique is demonstrated in the paper for a heavy?duty two?stroke diesel. Also the results of several fundamental investigations of cavity resonances in engine combustion chambers are reported briefly. Good agreement is obtained between theoretical prediction of the resonant frequencies and experimental observation. The splitting of degenerate modes into two components is discussed.

Robert Hickling; Douglas A. Feldmaier; Francis H. K. Chen; Josette S. Morel

1983-01-01T23:59:59.000Z

235

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

236

E-Print Network 3.0 - addressable vertical-cavity laser Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

vertical-cavity laser Search Powered by Explorit Topic List Advanced Search Sample search results for: addressable vertical-cavity laser Page: << < 1 2 3 4 5 > >> 1 J. Phys. III...

237

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

E-Print Network [OSTI]

-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...

Wolter, Derrick Wayne

2002-01-01T23:59:59.000Z

238

E-Print Network 3.0 - air-containing cavities blast Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences 83 200MHz superconducting RF cavity development for RLAs1 Summary: 200MHz superconducting RF cavity development for RLAs1 R.L. Geng , H. Padamsee , D. Hartill ,...

239

Engineering the internal cavity of neuroglobin demonstrates the role of the haem-sliding mechanism  

Science Journals Connector (OSTI)

Mutants have been produced that reduce the volume of the large internal cavity of murine neuroglobin. Their structural and functional characterization sheds light on the role of the cavity itself and of the structural transitions of the haem upon binding.

Avella, G.

2014-05-29T23:59:59.000Z

240

Quantum discord dynamics of two qubits in the single-mode cavities  

E-Print Network [OSTI]

The dynamics of the quantum discord for two identical qubits in both two independent single-mode cavities and a common single-mode cavity are discussed. For the initial Bell state with correlated spins, while the entanglement sudden death can occur, the quantum discord vanishes only at discrete moments in the independent cavities and never vanishes in the common cavity. Interestingly, quantum discord and entanglement show opposite behaviors in the common cavity, unlike in the independent cavities. For the initial Bell state with anti-correlated spins, quantum discord and entanglement behave in the same way for both independent cavities and a common cavity. It is found that the detunnings always stabilize the quantum discord.

Chen Wang; Qing-Hu Chen

2012-02-27T23:59:59.000Z

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

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

242

Scheme for implementing the Deutsch-Jozsa algorithm in cavity QED  

SciTech Connect (OSTI)

We propose a scheme for realizing the Deutsch-Jozsa algorithm in cavity QED. The scheme is based on the resonant interaction of atoms with a cavity mode. The required experimental techniques are within the scope of what can be obtained in the microwave cavity QED setup. The experimental implementation of the scheme would be an important step toward more complex quantum computation in cavity QED.

Zheng Shibiao [Department of Electronic Science and Applied Physics, Fuzhou University, Fuzhou 350002 (China)

2004-09-01T23:59:59.000Z

243

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

E-Print Network [OSTI]

an energy distribution. Data was taken from the CRC Handbook 90th edition [13]. : : : : : : : : : : : : : : : : : : : : 17 10 Current state of high gradient cavities in the SRF world. Note these points are champion cavities, the average gradient of all... an energy distribution. Data was taken from the CRC Handbook 90th edition [13]. : : : : : : : : : : : : : : : : : : : : 17 10 Current state of high gradient cavities in the SRF world. Note these points are champion cavities, the average gradient of all...

Pogue, Nathaniel Johnston

2011-08-08T23:59:59.000Z

244

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

245

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. 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

246

Photon Emission from a Cavity-Coupled Double Quantum Dot Y.-Y. Liu,1  

E-Print Network [OSTI]

,1 J. M. Taylor,2 and J. R. Petta1, 3 1 Department of Physics, Princeton University, Princeton, New emission from the cavity at a rate of 10 MHz. With a small cavity drive field, we observe a gain of up for single Rydberg atoms passing through a superconducting mi- crowave cavity [2], and a single Ca atom

Petta, Jason

247

High resolution pulsed infrared cavity ringdown spectroscopy: Application to laser ablated carbon clusters  

E-Print Network [OSTI]

pass fractional absorption is 1 ppm. We observe a frequency dependent ringdown cavity transmission of 5 in molecular beams. © 2002 American Institute of Physics. DOI: 10.1063/1.1461825 INTRODUCTION Cavity ringdown rate of light trapped in a high finesse optical cavity. Since the decay rate is directly proportional

Cohen, Ronald C.

248

Cavity-induced two-photon absorption in unidentical atoms M. S. Kim1,  

E-Print Network [OSTI]

Cavity-induced two-photon absorption in unidentical atoms M. S. Kim1, * and G. S. Agarwal1,2 1 Max-photon absorption in unidentical atoms, and demonstrate the nonclassical character of this two-photon absorption. We-photon absorption in two unidentical atoms in a cavity. In a cavity the atoms interact with a common quantized

Kim, Myungshik

249

24 Jan 2007 Institute of Photonics, University of Strathclyde, 2007 1 Laser Intra-cavity  

E-Print Network [OSTI]

As GaInP InGaAs GaInNAs InGaAsP GaInAsSb · Intra-cavity power up to ~100W Pump Pump optics Mirror and intraVECSEL and intra--cavity sensingcavity sensing · Intra-Cavity Laser Absorption Spectroscopy (ICLAS

Strathclyde, University of

250

Copper waveguide cavities with reduced surface loss for coupling to superconducting qubits  

E-Print Network [OSTI]

Copper waveguide cavities with reduced surface loss for coupling to superconducting qubits Daniela, other recent work has involved qubits coupled to copper cavities with coherence times approaching 0.1 ms. The copper provides a good path for thermalizing the cavity walls and qubit chip, although the substantial

Plourde, Britton L. T.

251

Tensile strained $In_{x}Ga_{1-x}P$ membranes for cavity optomechanics  

E-Print Network [OSTI]

We investigate the optomechanical properties of tensile-strained ternary InGaP nanomembranes grown on GaAs. This material system combines the benefits of highly strained membranes based on stoichiometric silicon nitride, with the unique properties of thin-film semiconductor single crystals, as previously demonstrated with suspended GaAs. Here we employ lattice mismatch in epitaxial growth to impart an intrinsic tensile strain to a monocrystalline thin film (approximately 30 nm thick). These structures exhibit mechanical quality factors of 2*10^6 or beyond at room temperature and 17 K for eigenfrequencies up to 1 MHz, yielding Q*f products of 2*10^12 Hz for a tensile stress of ~170 MPa. Incorporating such membranes in a high finesse Fabry-Perot cavity, we extract an upper limit to the total optical loss (including both absorption and scatter) of 40 ppm at 1064 nm and room temperature. Further reductions of the In content of this alloy will enable tensile stress levels of 1 GPa, with the potential for a significant increase in the Q*f product, assuming no deterioration in the mechanical loss at this composition and strain level. This materials system is a promising candidate for the integration of strained semiconductor membrane structures with low-loss semiconductor mirrors and for realizing stacks of membranes for enhanced optomechanical coupling.

G. D. Cole; P. -L. Yu; C. Gärtner; K. Siquans; R. Moghadas Nia; J. Schmöle; J. Hoelscher-Obermaier; T. P. Purdy; W. Wieczorek; C. A. Regal; M. Aspelmeyer

2014-03-31T23:59:59.000Z

252

Influence of the multiple scattering of relativistic electrons on the line width of backward Parametric X-ray Radiation in the absence of photo absorption  

E-Print Network [OSTI]

The multiple scattering effect on the line width of backward Parametric X-ray Radiation (PXR) in the extremely Bragg geometry, produced by low energy relativistic electrons traversing a single crystal, is discussed. It is shown that there exist conditions, when the influence of photo absorption on the line width can be neglected, and the only multiple scattering process of relativistic electrons in crystal leads to the broadening of backward PXR lines. Based on the obtained theoretical results, the line width broadening of backward PXR, caused by the multiple scattering of 30 MeV and 50 MeV relativistic electrons in a Si crystal of varying thicknesses, is numerically obtained.

Tabrizi, Mehdi

2015-01-01T23:59:59.000Z

253

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

254

Multiple Rankine topping cycles  

SciTech Connect (OSTI)

The efficiency of a Rankine cycle is primarily determined by the temperatures of heat addition and rejection. However, no working fluid has been identified which will operate in a Rankine cycle over an extremely wide temperature range. Multiple Rankine topping cycles offer a technique for achieving high thermal efficiencies in power plants by allowing the use of several working fluids. This paper gives a history of Rankine topping cycles, presents an analysis for the calculation of the overall efficiency of a three-module multiple Rankine cycle, and presents results from a case study for a sodium-mercury-water cycle.

McWhirter, J.D. [Argonne National Lab., Idaho Falls, ID (United States). Engineering Div.]|[Idaho State Univ., Pocatello, ID (United States). Coll. of Engineering

1995-07-01T23:59:59.000Z

255

32 - Fundamentals of Industrial Crystallization  

Science Journals Connector (OSTI)

Abstract Industrial crystallization processes aim at the large-scale production of crystalline products through the formation of involving a suspension of growing particles in a solution. The product quality is defined by the kind of crystalline phase produced, the crystal size distribution, the crystal morphology, and the product purity. These product quality aspects are determined by the subprocesses of crystallization of which crystal nucleation and growth are usually of main importance. The driving force for these subprocesses is usually established either by evaporating solvent to increase the concentration or cooling the solution to decrease the solubility. The recent pharmaceutical research interest in continuous crystallization processes is fortified by claims of improved product quality, efficient use of materials and energy resources, and waste stream reductions.

Joop H. ter Horst; Christiane Schmidt; Joachim Ulrich

2015-01-01T23:59:59.000Z

256

Cavity-Modified Super- and Subradiant Rayleigh Scattering of Two Atoms  

E-Print Network [OSTI]

We report on the observation of cooperative radiation of exactly two neutral atoms strongly coupled to the single mode field of an optical cavity in the good cavity limit. Monitoring the cavity output power, we observe super- and subradiant Rayleigh scattering into the cavity mode for certain relative distances between the two atoms. Surprisingly, due to cavity backaction onto the atoms, the cavity output power for superradiant scattering is almost equal to the single emitter case. These effects are quantitatively explained by a classical model as well as by a quantum mechanical model based on Dicke states. We extract information on the relative phases of the light fields at the atom positions and employ advanced cooling to reduce the jump rate between super- and subradiant configurations. Thereby we improve the control over the system to a level where the realization of two-atom entanglement schemes involving optical cavities becomes feasible.

René Reimann; Wolfgang Alt; Tobias Kampschulte; Tobias Macha; Lothar Ratschbacher; Natalie Thau; Seokchan Yoon; Dieter Meschede

2014-08-25T23:59:59.000Z

257

Towards measuring variations of Casimir energy by a superconducting cavity  

E-Print Network [OSTI]

We consider a Casimir cavity, one plate of which is a thin superconducting film. We show that when the cavity is cooled below the critical temperature for the onset of superconductivity, the sharp variation (in the far infrared) of the reflection coefficient of the film engenders a variation in the value of the Casimir energy. Even though the relative variation in the Casimir energy is very small, its magnitude can be comparable to the condensation energy of the superconducting film, and this gives rise to a number of testable effects, including a significant increase in the value of the critical magnetic field, required to destroy the superconductivity of the film. The theoretical ground is therefore prepared for the first experiment ever aimed at measuring variations of the Casimir energy itself.

Giuseppe Bimonte; Enrico Calloni; Giampiero Esposito; Leopoldo Milano; Luigi Rosa

2005-04-07T23:59:59.000Z

258

Beam Dynamics Studies of Parallel-Bar Deflecting Cavities  

SciTech Connect (OSTI)

We have performed three-dimensional simulations of beam dynamics for parallel-bar transverse electromagnetic mode (TEM) type RF separators: normal- and super-conducting. The compact size of these cavities as compared to conventional TM$_{110}$ type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a one- or two-cell superconducting structure are enough to produce the required vertical displacement at the Lambertson magnet. Both the normal and super-conducting structures show very small emittance dilution due to the vertical kick of the beam.

S. Ahmed, G. Krafft, K. Detrick, S. Silva, J. Delayen, M. Spata ,M. Tiefenback, A. Hofler ,K. Beard

2011-03-01T23:59:59.000Z

259

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS  

E-Print Network [OSTI]

The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a ?nal energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron ?ux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide suf?cient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

Ainsworth, R; Calaga, R

2012-01-01T23:59:59.000Z

260

Circuit cavity electromechanics in the strong coupling regime  

E-Print Network [OSTI]

Demonstrating and exploiting the quantum nature of larger, more macroscopic mechanical objects would help us to directly investigate the limitations of quantum-based measurements and quantum information protocols, as well as test long standing questions about macroscopic quantum coherence. The field of cavity opto- and electro-mechanics, in which a mechanical oscillator is parametrically coupled to an electromagnetic resonance, provides a practical architecture for the manipulation and detection of motion at the quantum level. Reaching this quantum level requires strong coupling, interaction timescales between the two systems that are faster than the time it takes for energy to be dissipated. By incorporating a free-standing, flexible aluminum membrane into a lumped-element superconducting resonant cavity, we have increased the single photon coupling strength between radio-frequency mechanical motion and resonant microwave photons by more than two orders of magnitude beyond the current state-of-the-art. A par...

Teufel, J D; Allman, M S; Cicak, K; Sirois, A J; Whittaker, J D; Simmonds, R W

2010-01-01T23:59:59.000Z

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.


261

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

SciTech Connect (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

262

Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications  

SciTech Connect (OSTI)

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

263

Addendum to 'Behavior of a bipartite system in a cavity'  

SciTech Connect (OSTI)

This note is an Addendum to our previous article [Phys. Rev. A 81, 053820 (2010)]. We show that under the assumption of a Bose-Einstein distribution for the thermal reservoir, zero-temperature properties of the entangled states considered there are not changed by heating, for temperatures up to the order of room temperatures. In this case, the system is dissipative in free space and presents stability for a small cavity, both for T=0 and for finite temperature.

Linhares, C. A. [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20559-900 Rio de Janeiro, RJ (Brazil); Malbouisson, A. P. C. [Centro Brasileiro de Pesquisas Fisicas/MCT, 22290-180 Rio de Janeiro, RJ (Brazil); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340 Salvador, BA (Brazil)

2010-11-15T23:59:59.000Z

264

Plasma Treatment of Bulk Niobium Surface for SRF Cavities  

SciTech Connect (OSTI)

Pulsed electric discharges were used to demonstrate the validity of plasma surface treatment of superconducting radio-frequency cavities. The experiments were performed on disc-shaped Nb samples and compared with identical samples treated with buffer chemical polishing techniques. The results of several standard surface analytical techniques indicate that plasma-treated samples have comparable or superior properties regarding the surface roughness and composition.

Marija Raskovic; H. Phillips; Anne-Marie Valente

2006-08-16T23:59:59.000Z

265

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"...

266

Aperiodic crystals and superspace concepts  

Science Journals Connector (OSTI)

Aperiodic crystals may conveniently be described in a higher dimensional `superspace'. An overview of the method and applications to various families is given.

Janssen, T.

2014-07-31T23:59:59.000Z

267

Invisible defects in complex crystals  

E-Print Network [OSTI]

We show that invisible localized defects, i.e. defects that can not be detected by an outside observer, can be realized in a crystal with an engineered imaginary potential at the defect site. The invisible defects are synthesized by means of supersymmetric (Darboux) transformations of an ordinary crystal using band-edge wave functions to construct the superpotential. The complex crystal has an entire real-valued energy spectrum and Bragg scattering is not influenced by the defects. An example of complex crystal synthesis is presented for the Mathieu potential.

S. Longhi; G. Della Valle

2013-06-04T23:59:59.000Z

268

Uppsala High Power Test Stand for ESS Spoke Cavities  

E-Print Network [OSTI]

The European Spallation Source (ESS) is one of the world’s most powerful neutron source. The ESS linac will accelerate 50mA pulse current of protons to 2.5GeV in 2.86 ms long pulses at a repetition rate of 14 Hz. It produces a beam with 5MW average power and 125MW peak power. ESS Spoke Linac consist of 28 superconducting spoke cavities, which will be developed by IPN Orsay, France. These Spoke Cavities will be tested at low power at IPN Orsay and high power testing will be performed in a high power test stand at Uppsala University. The test stand consists of tetrode based RF amplifier chain (352MHz, 350 kW) power and related RF distribution. Outputs of two tetrodes shall be combined with the hybrid coupler to produce 350 kW power. Preamplifier for a tetrode shall be solid state amplifier. As the spoke cavities are superconducting, the test stand also includes horizontal cryostat, Helium liquefier, test bunker etc. The paper describes features of the test stand in details.

Yogi, RA; Dancila, D; Gajewski, K; Hermansson, L; Noor, M; Wedberg, R; Santiago-Kern, R; Ekelöf, T; Lofnes, T; Ziemann, V; Goryashko, V; Ruber, R

2013-01-01T23:59:59.000Z

269

Development of a superconducting connection for niobium cavities  

SciTech Connect (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

270

Development of a superconducting connection for niobium cavities  

SciTech Connect (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

271

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

SciTech Connect (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

272

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

273

BY SILICON CRYSTALS  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

274

NMR STUDIES OF LIQUID CRYSTALS AND MOLECULES DISSOLVED IN LIQUID CRYSTAL SOLVENTS  

SciTech Connect (OSTI)

This thesis describes several studies in which nuclear magnetic resonance (nmr) spectroscopy has been used to probe the structure, orientation and dynamics of liquid crystal mesogens and molecules dissolved in liquid crystalline phases. In addition, a modern high field nmr spectrometer is described which has been used to perform such nmr studies. Chapter 1 introduces the quantum mechanical formalisms used throughout this thesis and briefly reviews the fundamentals of nuclear spin physics and pulsed nmr spectroscopy. First the density operator is described and a specific form for the canonical ensemble is derived. Then Clebsch-Gordon coefficients, Wigner rotation matrices, and irreducible tensor operators are reviewed. An expression for the equilibrium (Curie) magnetization is obtained and the linear response of a spin system to a strong pulsed r.f. irradiation is described. Finally, the spin interaction Hamiltonians relevant to this work are reviewed together with their truncated forms. Chapter 2 is a deuterium magnetic resonance study of two 'nom' liquid crystals which possess several low temperature mesomorphic phases. Specifically, deuterium quadrupolar echo spectroscopy is used to determine the orientation of the liquid crystal molecules in smectic phases, the changes in molecular orientation and motion that occur at smectic-smectic phase transitions, and the order of the phase transitions. For both compounds, the phase sequence is determined to be isotropic, nematic, smectic A, smectic C, smectic B{sub A}, smectic B{sub C}, and crystalline. The structure of the smectic A phase is found to be consistent with the well-known model of a two dimensional liquid in which molecules are rapidly rotating about their long axes and oriented at right angles to the plane of the layers. Molecules in the smectic C phase are found to have their long axes tilted with respect to the layer normal, and the tilt angle is temperature dependent, increasing from zero at the smectic A - smectic C transition and reaching a maximum at 9{sup o} at the smectic C - smectic B{sub A} transition. This finding contradicts the results of X-ray diffraction studies which indicate that the tilt angle is 18{sup o} and temperature independent. The smectic B{sub A} - smectic B{sub C} phase transition is observed for the first time, and is found to be first order, a result that contradicts the prediction of a mean theory by McMillian. Chapter 3 is a multiple quantum nmr study of n-hexane oriented in a nematic liquid crystal solvent. The basic three pulse multiple quantum experiment is discussed which enables the observation of transitions for which |{Delta}m|>1, and then the technique of the separation of multiple quantum orders by phase incrementation in the multiple quantum evolution period is reviewed (TPPI). An explicit example of multiple quantum nmr is given by the calculation of the multiple quantum spectrum of an oriented methyl group.

Drobny, G.P.

1982-11-01T23:59:59.000Z

275

Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. Large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities made from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.

Kneisel, Peter [JLAB; Ciovati, Gianluigi [JLAB; Dhakal, Pashupati [JLAB; Saito, Kenji; Singer, W.; Singer, X.; Myneni, Ganapati Rao [JLAB

2015-02-01T23:59:59.000Z

276

Cascade atom in high-Q cavity: The spectrum for non-Markovian decay  

E-Print Network [OSTI]

The spontaneous emission spectrum for a three level cascade configuration atom in a single mode high-Q cavity coupled to a zero temperature reservoir of continuum external modes is determined from the atom-cavity mode master equation using the quantum regression theorem. Initially the atom is in its upper state and the cavity mode empty of photons. Following Glauber, the spectrum is defined via the response of a detector atom. Spectra are calculated for the detector located inside the cavity (case A), outside the cavity end mirror (Case B-end emission), or placed for emission out the side of the cavity (Case C). The spectra for case A and case B are found to be essentially the same. In all the cases the predicted lineshapes are free of instrumental effects and only due to cavity decay. Spectra are presented for intermediate and strong coupling regime situations (where both atomic transitions are resonant with the cavity frequency), for cases of non-zero cavity detuning, and for cases where the two atomic transition frequencies differ. The spectral features for Cases B(A) and C are qualitatively similar, with six spectral peaks for resonance cases and eight for detuned cases. These general features of the spectra can be understood via the dressed atom model. However, Case B and C spectra differ in detail, with the latter exhibiting a deep spectral hole at the cavity frequency due to quantum interference effects.

B. J. Dalton; B. M. Garraway

2007-07-08T23:59:59.000Z

277

Ultraslow growth rates of giant gypsum crystals  

Science Journals Connector (OSTI)

...gypsum crystals of Naica ore mines in Chihuahua, Mexico, a challenging subject in mineral...gypsum crystals of Naica ore mines in Chihuahua, Mexico, a challenging subject...gypsum crystals of Naica ore mines in Chihuahua, Mexico, a challenging subject...

A. E. S. Van Driessche; J. M. García-Ruíz; K. Tsukamoto; L. D. Patiño-Lopez; H. Satoh

2011-01-01T23:59:59.000Z

278

Multiple System Rate Process  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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)

279

Photon-pair generation in photonic crystal fibrebre with a 1.5GHz modelocked VECSEL  

E-Print Network [OSTI]

Four-wave mixing (FWM) in optical fibre is a leading technique for generating high-quality photon pairs. We report the generation of photon pairs by spontaneous FWM in photonic crystal fibre pumped by a 1.5 GHz repetition-rate vertical-external-cavity surface-emitting laser (VECSEL). The photon pairs exhibit high count rates and a coincidence-to-accidental ratio of over 80. The VECSEL's high repetition-rate, high average power, tunability, and small footprint make this an attractive source for quantum key distribution and photonic quantum-state engineering.

Oliver J. Morris; Robert J. A. Francis-Jones; Keith G. Wilcox; Anne C. Tropper; Peter J. Mosley

2014-09-09T23:59:59.000Z

280

Multiple sclerosis and interferon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

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

Laser Crystallization of Phase Change Material  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Geoffrey Campbell is the Principal Investigator for Laser Crystallization of Phase Change Material LLNL BES Programs Highlight Laser Crystallization of Phase Change Material False...

282

Fast 704 MHz Ferroelectric Tuner for Superconducting Cavities  

SciTech Connect (OSTI)

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

283

Cryogenic test of a proof-of-principle superconducting rf-dipole deflecting and crabbing cavity  

Science Journals Connector (OSTI)

Recent applications in need of compact low-frequency deflecting and crabbing cavities have initiated the design and development of new superconducting structures operating at high gradients with low losses. Previously, TM110-type deflecting and crabbing cavities were developed and have also been operated successfully. However, these geometries are not favorable designs for low operating frequencies. The superconducting rf-dipole cavity is the first compact deflecting and crabbing geometry that has demonstrated high gradients and high shunt impedance. Since the fundamental operating mode is the lowest mode and is widely separated from the nearest higher order mode, the rf-dipole design is an attractive geometry for effective damping of the higher order modes in high current applications. A 400 MHz rf-dipole cavity was designed, fabricated, and tested as a proof-of-principle cavity. The cavity achieved high operating gradients, and the multipacting levels were easily processed and did not reoccur.

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

2013-08-16T23:59:59.000Z

284

Investigation Of Breakdown Induced Surface Damage On 805 Mhz Pillbox Cavity Interior Surfaces  

E-Print Network [OSTI]

The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested two 805 MHz vacuum RF cavities in a multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanisms and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for quantitative estimation of spark damage spot distribution on cavity interior surfaces. The distribution is compared with the electric field distribution predicted by a computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with ...

Jana, M R; Leonova, M; Moretti, A; Tollestrup, A; Yonehara, K; Freemire, B; Torun, Y; Bowring, D; Flanagan, G

2014-01-01T23:59:59.000Z

285

Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties  

DOE Patents [OSTI]

An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

Pipino, Andrew C. R. (Gaithersburg, MD); Hudgens, Jeffrey W. (Rockville, MD)

1999-08-24T23:59:59.000Z

286

Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties  

DOE Patents [OSTI]

An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

Pipino, Andrew Charles Rule (Gaithersburg, MD)

1999-11-16T23:59:59.000Z

287

Microwave cavity searches for dark-matter axions  

Science Journals Connector (OSTI)

Recent determinations of cosmological parameters point to a flat Universe, whose total energy density is composed of about two-thirds vacuum energy and one-third matter. Ordinary baryonic matter is relegated to a small fraction of the latter, within which the luminous part is an order of magnitude smaller yet. Particle dark matter, i.e., one or more relic particle species from the big bang, is thus strongly suggested as the dominant component of matter in the Universe. The axion, a hypothetical elementary pseudoscalar arising from the Peccei-Quinn solution to the strong-CP problem, is a well-motivated candidate. If the axion exists, it must be extremely light, in the mass range of 10-6–10-3 eV, and possess extraordinarily feeble couplings to matter and radiation. Nevertheless, as proposed by Sikivie in 1983, the axion’s two-photon coupling lends itself to a feasible search strategy with currently available technology. In this scheme, axions resonantly convert to single microwave photons by a Primakoff interaction, in a tunable microwave cavity permeated by a strong magnetic field. Present experiments utilizing heterostructure transistor microwave amplifiers have achieved total system noise temperatures of ?3 K and represent the world’s quietest spectral radio receivers. Exclusion regions have already been published well into the band of realistic axion model couplings, within the lowest decade of mass range. Recent breakthroughs in the development of near-quantum-limited superconducting quantum interference device amplifiers should reduce the system noise temperature to ?100 mK or less. Ongoing research into using Rydberg-atom single-quantum detectors as the detector in a microwave cavity experiment could further reduce the effective noise temperature. In parallel with improvements in amplifier technology, promising concepts for higher-frequency cavity resonators are being explored to open up the higher decades in mass range. Definitive experiments to find or exclude the axion may therefore be at hand in the next few years. As the microwave cavity technique measures the total energy of the axion, a positive discovery could well reveal fine structure of the signal due to flows of nonthermalized axions. Manifesting diurnal and sidereal modulation, such detailed features would contain a wealth of information about the history, structure, and dynamics of our Milky Way galaxy.

Richard Bradley; John Clarke; Darin Kinion; Leslie J Rosenberg; Karl van Bibber; Seishi Matsuki; Michael Mück; Pierre Sikivie

2003-06-12T23:59:59.000Z

288

Upgrading EMMA to Use Low-frequency RF Cavities  

SciTech Connect (OSTI)

EMMA is an experiment to study beam dynamics in fixed field alternating gradient accelerators (FFAGs). It accelerates the beam in about 10 turns using 1.3 GHz cavities in a mode like that used for muon accelerators. Many applications of FFAGs prefer to have slower acceleration, typically thousands of turns. To do so in EMMA would require the RF system to be replaced with a low-frequency, high-gradient system. This paper describes the motivation for studying slow acceleration in EMMA and the required parameters for an RF system to do that. It then describes the technology needed for the RF system.

Ohmori, C.; Berg, J.

2011-04-30T23:59:59.000Z

289

Spectroscopic properties of inhomogeneously broadened spin ensembles in a cavity  

SciTech Connect (OSTI)

The enhanced collective coupling to weak quantum fields may turn atomic or spin ensembles into an important component in quantum information processing architectures. Inhomogeneous broadening can, however, significantly reduce the coupling and the lifetime of the collective excitation that represent the quantum information. In this paper we show that the width and shape of the inhomogeneous broadening have a striking influence on the dynamics of the cavity-ensemble system and may lead to narrowing of the linewidth of the collective states. We underpin our findings with the examples of a Gaussian and a Lorentzian profile of the inhomogeneity.

Kurucz, Z.; Moelmer, K. [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Wesenberg, J. H. [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore)

2011-05-15T23:59:59.000Z

290

Note: Flowing ion population from a resonance cavity source  

SciTech Connect (OSTI)

The experimental low energy plasma for hemispherical analyzers nominal testing thermal plasma facility of Dartmouth College uses a microwave plasma source which generates an ionosphere-like plasma through a two-step process. The plasma is initially generated inside a cylindrical, insulated, resonance cavity. This initial plasma must pass through a sheath in order to enter the main experimental region. This process imparts a significant flow velocity to the ions which has been neglected in previous analysis of this plasma source. We predict the flow energy of the ions to be between 12-15 eV depending on conservation laws and show agreement with experimental results.

Gayetsky, Lisa E.; Lynch, Kristina A. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)

2011-04-15T23:59:59.000Z

291

Diffraction from oxide confinement apertures in vertical-cavity lasers  

SciTech Connect (OSTI)

Direct measurement of scattered fields from oxide confinement apertures in vertical-cavity lasers is presented. Diffraction fringes associated with each transverse lasing mode are detected in the far field from devices with varying oxide aperture dimensions and with quantum efficiencies as high as 48{percent}. The diffracted pattern symmetries match the rectangular symmetry of the oxide apertures present in the devices and fringe locations are compared to Fraunhofer theory. The fraction of power diffracted from the lasing mode remains roughly constant as a function of relative pump rate, but is shown to depend on both transverse mode order and oxide aperture size. {copyright} {ital 1999 American Institute of Physics.}

Roos, P.A.; Carlsten, J.L. [Montana State University, Department of Physics, Bozeman, Montana 59717 (United States)] [Montana State University, Department of Physics, Bozeman, Montana 59717 (United States); Kilper, D.C. [University of North Carolina at Charlotte, Department of Physics, Charlotte, North Carolina 28223 (United States)] [University of North Carolina at Charlotte, Department of Physics, Charlotte, North Carolina 28223 (United States); Lear, K.L. [MicroOptical Devices Inc., 5601C Midway Park Pl. NE, Albuquerque, New Mexico 87109 (United States)] [MicroOptical Devices Inc., 5601C Midway Park Pl. NE, Albuquerque, New Mexico 87109 (United States)

1999-08-01T23:59:59.000Z

292

PHOTOCATALYTIC AND PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS  

E-Print Network [OSTI]

HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS F.HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS

Wagner, F.T.

2012-01-01T23:59:59.000Z

293

Electromagnetic design of the RF cavity beam position monitor for the LCLS.  

SciTech Connect (OSTI)

A high-resolution X-band cavity BPM has been developed for the LCLS. A dipole mode cavity and a monopole mode reference cavity have been designed in order to achieve micron-level accuracy of the beam position. The rf properties of the BPM as well as beam interaction with the cavities will be discussed including output power and tuning. In addition, methods will be presented for improving the isolation of the output ports to differentiate between horizontal/vertical beam motion and to reject extraneous modes from affecting the output signal. The predicted simulation results will be compared to data collected from low-power experimental tests.

Waldschmidt, G.; Lill, B.; Morrison, L.

2008-01-01T23:59:59.000Z

294

Cryogenic Performance of Double-Fused 1.5-m Vertical Cavity Lasers  

Science Journals Connector (OSTI)

The low-temperature performance of vertical cavity lasers (VCL's) is of interest for high-speed data transmission from superconducting and cryogenic semiconductor circuits. Our...

Zhang, Y M; Piprek, J; Margalit, N; Anzlowar, M; Bowers, J

1999-01-01T23:59:59.000Z

295

Spatially correlated light emission from a resonant-cavity light-emitting diode  

Science Journals Connector (OSTI)

We present the angular-resolved intensity noise characteristics of a resonant-cavity light-emitting diode under quiet pumping conditions. Measurements by a sensitivity-enhanced...

Kappe, Philip; Kaiser, Joachim; Elsässer, Wolfgang

2003-01-01T23:59:59.000Z

296

3D simulations of multipacting in the 56 MHz SRF cavity  

SciTech Connect (OSTI)

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

297

The Development of Cavity Ringdown Spectroscopy as a Toxic Metal Continuous Emission Monitor  

SciTech Connect (OSTI)

Innovative program to explore the viability of using Cavity Ringdown Spectroscopy (CRDS) for trace analysis and monitoring of remediation processes for hazardous and radioactive wastes. Cavity ringdown spectroscopy is a measurement of the rate of absorption of a sample within a closed optical cavity rather than the standard measurement of the avsorved signal strength over a given sample path. It is a technique capable of providing ultra-sensitive absorption measurements in hostile environments using commercially available easy-to-use pulsed lasers. The inherent high sensitivity stems from both the long effective sample pathlengths possible and the relaxed constraints on the accuracy of the measurement of the cavity decay time.

Dr. Goeroge P. Miller; Dr. Christopher B. Winstead

2001-12-04T23:59:59.000Z

298

External Cavity Quantum Cascade Lasers: Recent Advances, Applications, and Comparisons with Alternative Sources in the MIR  

Science Journals Connector (OSTI)

The performance of external cavity quantum/interband cascade lasers (ECqcL/ECicL) in molecular detection and imaging applications will be discussed. Alternative MIR laser technologies...

Day, Timothy

299

Focused ion beam engineered whispering gallery mode resonators with open cavity structure  

Science Journals Connector (OSTI)

We report the realization of an open cavity whispering gallery mode optical resonator, in which the circulating light traverses a free space gap. We utilize focused ion beam...

Aveline, David C; Baumgartel, Lukas; Ahn, Byungmin; Yu, Nan

2012-01-01T23:59:59.000Z

300

Development of superconducting crossbar-H-mode cavities for proton and ion accelerators  

Science Journals Connector (OSTI)

The crossbar-H-mode (CH) structure is the first superconducting multicell drift tube cavity for the low and medium energy range operated in the H21 mode. Because of the large energy gain per cavity, which leads to high real estate gradients, it is an excellent candidate for the efficient acceleration in high power proton and ion accelerators with fixed velocity profile. A prototype cavity has been developed and tested successfully with a gradient of 7??MV/m. A few new superconducting CH cavities with improved geometries for different high power applications are under development at present. One cavity (f=325??MHz, ?=0.16, seven cells) is currently under construction and studied with respect to a possible upgrade option for the GSI UNILAC. Another cavity (f=217??MHz, ?=0.059, 15 cells) is designed for a cw operated energy variable heavy ion linac application. Furthermore, the EUROTRANS project (European research program for the transmutation of high level nuclear waste in an accelerator driven system, 600 MeV protons, 352 MHz) is one of many possible applications for this kind of superconducting rf cavity. In this context a layout of the 17 MeV EUROTRANS injector containing four superconducting CH cavities was proposed by the Institute for Applied Physics (IAP) Frankfurt. The status of the cavity development related to the EUROTRANS injector is presented.

F. Dziuba; M. Busch; M. Amberg; H. Podlech; C. Zhang; H. Klein; W. Barth; U. Ratzinger

2010-04-26T23:59:59.000Z

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

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 Applications of Nuclear Science Applications of Nuclear...

302

Disorder-induced transparency in a one-dimensional waveguide side coupled with optical cavities  

SciTech Connect (OSTI)

Disorder influence on photon transmission behavior is theoretically studied in a one-dimensional waveguide side coupled with a series of optical cavities. For this sake, we propose a concept of disorder-induced transparency appearing on the low-transmission spectral background. Two kinds of disorders, namely, disorders of optical cavity eigenfrequencies and relative phases in the waveguide side coupled with optical cavities are considered to show the disorder-induced transparency. They both can induce the optical transmission peaks on the low-transmission backgrounds. The statistical mean value of the transmission also increases with increasing the disorders of the cavity eigenfrequencies and relative phases.

Zhang, Yongyou, E-mail: yyzhang@bit.edu.cn; Dong, Guangda; Zou, Bingsuo [Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems and School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

2014-05-07T23:59:59.000Z

303

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

SciTech Connect (OSTI)

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

304

Cavity dumping versus stationary output coupling in repetitively Q-switched solid-state lasers  

Science Journals Connector (OSTI)

A comparative theoretical analysis of continuously pumped actively Q-switched solid-state lasers differing in output coupling methods (cavity dumping versus a partially transmitting...

Grishin, Mikhail

2011-01-01T23:59:59.000Z

305

E-Print Network 3.0 - axisymmetric-fold-combination cavity adapting...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

INTERNATIONAL ERL CRYOMODULE AT DARESBURY LABORATORY Summary: . The design of the cavity string is carefully laid out to fit inside the module. TUNER Figure 4: Adaptation... ,...

306

X-Ray Crystallography What do you need? A crystal. But not just any crystal a well ordered crystal  

E-Print Network [OSTI]

X-Ray Crystallography What do you need? A crystal. But not just any crystal­ a well ordered crystal that will diffract x-rays strongly. A crystal handedness. This reduces number to 6- 12. #12;#12;Generally X-ray beam

Cavanagh, John

307

Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demsy and Sajeev John  

E-Print Network [OSTI]

Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demésy and Sajeev by the American Institute of Physics. Related Articles Solar power conversion efficiency in modulated silicon utilizing multiple carrier generation via singlet exciton fission Appl. Phys. Lett. 101, 153507 (2012) Light

John, Sajeev

308

Effect on cavity optomechanics of the interaction between a cavity field and a one-dimensional interacting bosonic gas  

SciTech Connect (OSTI)

We investigate optomechanical coupling between one-dimensional interacting bosons and the electromagnetic field in a high-finesse optical cavity. We show that by tuning interatomic interactions, one can realize effective optomechanics with mechanical resonators ranging from side-mode excitations of a Bose-Einstein condensate (BEC) to particle-hole excitations of a Tonks-Girardeau (TG) gas. We propose that this unique feature can be formulated to detect the BEC-TG gas crossover and measure the sine-Gordon transition continuously and nondestructively.

Sun Qing [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Center of Theoretical Physics, Department of Physics, Capital Normal University, Beijing 100048 (China); Hu Xinghua; Liu, W. M. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Xie, X. C. [International Center for Quantum Materials, Peking University, Beijing 100871 (China); Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States); Ji Anchun [Center of Theoretical Physics, Department of Physics, Capital Normal University, Beijing 100048 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2011-08-15T23:59:59.000Z

309

Design and test of SX-FEL cavity BPM  

E-Print Network [OSTI]

This paper reports the design and cold test of the cavity beam position monitor (CBPM) for SX-FEL to fulfill the requirement of beam position measurement resolution of less than 1{\\mu}m, even 0.1{\\mu}m. The CBPM was optimized by using a coupling slot to damp the TM010 mode in the output signal. The isolation of TM010 mode is about 117dB, and the shunt impedance is about 200{\\Omega}@4.65GHz with the quality factor 80 from MAFIA simulation and test result. A special antenna was designed to load power for reducing excitation of other modes in the cavity. The resulting output power of TM110 mode was about 90mV/mm when the source was 6dBm, and the accomplishable minimum voltage was about 200{\\mu}V. The resolution of the CBPM was about 0.1{\\mu}m from the linear fitting result based on the cold test.

Yuan, Renxian; Chen, Zhichu; Yu, Luyang; Wang, Baopen; Leng, Yongbin

2013-01-01T23:59:59.000Z

310

Integrable Aspects of Universal Quantum Transport in Chaotic Cavities  

E-Print Network [OSTI]

The Painlev\\'e transcendents discovered at the turn of the XX century by pure mathematical reasoning, have later made their surprising appearance -- much in the way of Wigner's "miracle of appropriateness" -- in various problems of theoretical physics. The notable examples include the two-dimensional Ising model, one-dimensional impenetrable Bose gas, corner and polynuclear growth models, one dimensional directed polymers, string theory, two dimensional quantum gravity, and spectral distributions of random matrices. In the present contribution, ideas of integrability are utilized to advocate emergence of an one-dimensional Toda Lattice and the fifth Painlev\\'e transcendent in the paradigmatic problem of conductance fluctuations in quantum chaotic cavities coupled to the external world via ballistic point contacts. Specifically, the cumulants of the Landauer conductance of a cavity with broken time-reversal symmetry are proven to be furnished by the coefficients of a Taylor-expanded Painlev\\'e V function. Further, the relevance of the fifth Painlev\\'e transcendent for a closely related problem of sample-to-sample fluctuations of the noise power is discussed. Finally, it is demonstrated that inclusion of tunneling effects inherent in realistic point contacts does not destroy the integrability: in this case, conductance fluctuations are shown to be governed by a two-dimensional Toda Lattice.

Eugene Kanzieper

2014-10-02T23:59:59.000Z

311

Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.  

SciTech Connect (OSTI)

This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank

Warne, Larry K.; Jorgenson, Roy E.

2014-10-01T23:59:59.000Z

312

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, Klaus (Hinsdale, IL); Rathke, Jerome W. (Lockport, IL); Klingler, Robert J. (Westmont, IL)

1996-01-01T23:59:59.000Z

313

Noise-like pulse based on dissipative four-wave-mixing with photonic crystal fiber filled by reduced graphene oxide  

E-Print Network [OSTI]

A noise-like pulse based on dissipative four-wave-mixing in a fiber cavity with photonic crystal fiber filled by reduced graphene oxide is proposed. Due to large evanescent field provided by 3 cm photonic crystal fiber and ultrahigh nonlinearity of reduced graphene oxide, this mixed structure provides excellent saturable absorption and high nonlinearity, which are necessary for generating four-wave-mixing (FWM). We experimentally prove that the mode-locked laser transfers its energy from center wavelength to sidebands through degenerate FWM, and new frequencies are generated via cascaded FWM among those sidebands. During this process, the frequencies located in various orders of longitudinal modes of the ring cavity are supported, and others are suppressed due to destructive interference. As the longitudinal modes of the cavity with a spacing of 6.874 MHz are partially supported, the loosely fixed phase relationship results in noise-like pulse with a coherent peak of 530 fs locating on a pedestal of 730.693 p...

Gao, Lei; Huang, Wei

2014-01-01T23:59:59.000Z

314

Heat transport through ion crystals  

E-Print Network [OSTI]

We study the thermodynamical properties of crystals of trapped ions which are laser cooled to two different temperatures in two separate regions. We show that these properties strongly depend on the structure of the ion crystal. Such structure can be changed by varying the trap parameters and undergoes a series of phase transitions from linear to zig-zag or helicoidal configurations. Thus, we show that these systems are ideal candidates to observe and control the transition from anomalous to normal heat transport. All structures behave as `heat superconductors', with a thermal conductivity increasing linearly with system size and a vanishing thermal gradient inside the system. However, zig-zag and helicoidal crystals turn out to be hyper sensitive to disorder having a linear temperature profile and a length independent conductivity. Interestingly, disordered 2D ion crystals are heat insulators. Sensitivity to disorder is much smaller in the 1D case.

Nahuel Freitas; Esteban Martinez; Juan Pablo Paz

2013-12-23T23:59:59.000Z

315

Crystal-Like geometric modeling  

E-Print Network [OSTI]

faces, symmetry, and fractal geometry. The techniques have also been implemented in software, as a proof of concept. They are used in an interactive geometric modeling system, in which users can use these techniques to create crystal-like shapes...

Landreneau, Eric Benjamin

2006-08-16T23:59:59.000Z

316

Crystal Growth of Oxide and Sulphide  

Science Journals Connector (OSTI)

......film. The hexagonal shaped crystal was often formed on a needle crystals. One of the electron diffraction...the diffraction patterns of bent crystals, the unit cell of this crystal...was often observed that the spherical particles like dew drops......

Hatsujiro HASHIMOTO

1960-01-01T23:59:59.000Z

317

Graphene-based polaritonic crystal  

Science Journals Connector (OSTI)

It is shown that monolayer graphene deposited on a spatially periodic gate behaves as a polaritonic crystal. Its band structure depending on the applied gate voltage is studied. The scattering of electromagnetic radiation from such a crystal is presented calculated and its spectral dependence is analyzed in terms of Fano-type resonances between the reflected continuum and plasmon-polariton modes forming narrow bands.

Yu. V. Bludov; N. M. R. Peres; M. I. Vasilevskiy

2012-06-05T23:59:59.000Z

318

Functional 2D nanoparticle/polymer array : interfacial assembly, transfer, characterization, and coupling to photonic crystal cavities.  

E-Print Network [OSTI]

??We developed a universal, facile and robust method to prepare free-standing, ordered and patternable nanoparticle/polymer monolayer arrays by evaporation-induced self-assembly at a fluid interface. The… (more)

Xiong, Shisheng

2011-01-01T23:59:59.000Z

319

Neutron diffraction by perfect crystals  

Science Journals Connector (OSTI)

The dynamical theory of neutron diffraction has been formulated to include the reflected waves from the boundaries of a crystal. This formulation allows a unified treatment of the neutron optical and diffraction phenomena in crystals. It is shown that the neutron propagation in the crystal is determined by two structure factors characterizing the lattice: the total structure factor and the structure factor of the neutron-spin-neutron-orbit interaction. Diffraction by a parallel crystal plate has been studied in considerable detail. It has been found that for a definite neutron-spin orientation, the diffracted and transmitted beams are modulated by six terms periodic in the thickness of the crystal. The period of the dominant term, in this Pendellösung fringe structure, has been calculated in several cases of experimental importance. If the glancing angle of incidence substantially exceeds the critical angle for total reflection, the results are identical with those obtained by a simple extension, to the neutron case, of the x-ray dynamical theory. The diffraction by a magnetized crystal has been examined in some detail and it is shown that measurement of the Pendellösung periods for the two neutron-spin orientations may be used to determine both the nuclear and magnetic neutron scattering amplitude.

C. Stassis and J. A. Oberteuffer

1974-12-15T23:59:59.000Z

320

Cavity-enhanced optical feedback-assisted photo-acoustic spectroscopy with a 10.4 ?m external cavity quantum cascade laser  

Science Journals Connector (OSTI)

An ultra-sensitive photo-acoustic spectrometer using a 10.4 ?m broadly tunable mid-IR external cavity quantum cascade laser (EC-QCL) coupled with optical feedback ... reflectivity mirrors was developed and tested...

A. Kachanov; S. Koulikov; F. K. Tittel

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.


321

A Cavity Ring-Down Spectroscopy Mercury Continuous Emission Monitor  

SciTech Connect (OSTI)

The Sensor Research & Development Corporation (SRD) has undertaken the development of a Continuous Emissions Monitor (CEM) for mercury based on the technique of Cavity Ring-Down Spectroscopy (CRD). The project involved building an instrument for the detection of trace levels of mercury in the flue gas emissions from coal-fired power plants. The project has occurred over two phases. The first phase concentrated on the development of the ringdown cavity and the actual detection of mercury. The second phase dealt with the construction and integration of the sampling system, used to carry the sample from the flue stack to the CRD cavity, into the overall CRD instrument. The project incorporated a Pulsed Alexandrite Laser (PAL) system from Light Age Incorporated as the source to produce the desired narrow band 254 nm ultra-violet (UV) radiation. This laser system was seeded with a diode laser to bring the linewidth of the output beam from about 150 GHz to less than 60 MHz for the fundamental beam. Through a variety of non-linear optics the 761 nm fundamental beam is converted into the 254 nm beam needed for mercury detection. Detection of the mercury transition was verified by the identification of the characteristic natural isotopic structure observed at lower cavity pressures. The five characteristic peaks, due to both natural isotopic abundance and hyperfine splitting, provided a unique identifier for mercury. SRD scientists were able to detect mercury in air down below 10 parts-per-trillion by volume (pptr). This value is dependent on the pressure and temperature within the CRD cavity at the time of detection. Sulfur dioxide (SO{sub 2}) absorbs UV radiation in the same spectral region as mercury, which is a significant problem for most mercury detection equipment. However, SRD has not only been able to determine accurate mercury concentrations in the presence of SO{sub 2}, but the CRD instrument can in fact determine the SO{sub 2} concentration as well. Detection of mercury down to the low hundreds of pptr has been accomplished in the presence of SO{sub 2} at concentration levels much higher than that found in typical flue gas emissions. SRD scientists extended the interferent testing to each individual component found in flue gas. It was found that only SO{sub 2} had a significant effect on the ring-down decay curve. Upon completion of testing the components of flue gas individually a simulated flue gas stream was used to test to the CRD instrument. The result showed accurate detection of mercury down to levels below 100 pptr in a simulated flue gas stream with the concentrations of the various components above that found in a typical untreated flue gas. A sampling system was designed and integrated into the CRD instrument to carry the sample from the flue gas stack to the CRD cavity. The sampling system was constructed so that it could be placed very close to the sampling port. SRD scientists were able to couple the UV laser light into an optical fiber, which is then sent to the sampling system. This allows the laser system to be isolated from the sampling system. Initial long-term testing revealed a couple of problems related to the stability of the output frequency of the laser system. These problems have been successfully dealt with by incorporating specific software solutions into the overall data acquisition program. The project culminated in a field test conducted at the DOE/NETL pilot plant facility in Pittsburgh, Pennsylvania. The object of the test was the evaluation of a cavity ringdown spectrometer constructed for the detection of TOTAL vapor phase mercury as a continuous emission monitor (CEM). Although there is the potential for the instrument to determine the amount of speciation between neutral elemental mercury (Hg{sup (o)}) and oxidized mercury (Hg{sup (+2)}), the initial test plan was to concentrate on the measurement of the total mercury. Another added benefit is that the measurements will report the sulfur dioxide (SO 2) concentration throughout the test. This report concludes the technical work asso

Christopher C. Carter

2004-12-15T23:59:59.000Z

322

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

323

Cryogenic spectroscopy of ultra-low density colloidal lead chalcogenide quantum dots on chip-scale optical cavities towards single quantum dot near-infrared cavity QED  

E-Print Network [OSTI]

We present evidence of cavity quantum electrodynamics from a sparse density of strongly quantum-confined Pb-chalcogenide nanocrystals (between 1 and 10) approaching single-dot levels on moderately high-Q mesoscopic silicon optical cavities. Operating at important near-infrared (1500-nm) wavelengths, large enhancements are observed from devices and strong modifications of the QD emission are achieved. Saturation spectroscopy of coupled QDs is observed at 77K, highlighting the modified nanocrystal dynamics for quantum information processing.

Ranojoy Bose; Jie Gao; James F. McMillan; Alex D. Williams; Chee Wei Wong

2008-12-01T23:59:59.000Z

324

Design and Operating Characteristics of a Lead-lined Hexagonal Neutron-Multiplicity Counter  

SciTech Connect (OSTI)

A high-efficiency Hexagonal Neutron-Multiplicity Counter (HNMC) has been developed for measurement of non-contact handleable power plant decommissioning and dismantling wastes. The HNMC counter was originally designed for nuclear stockpile safeguards measurements, but the unique challenges of the present application required significant adaptations to the design. The counter consists of six detector modules, each containing two parallel rows of 11 He-3 tubes embedded in high-density polyethylene and arranged in a hexagonal pattern around a central cavity. Graphite reflectors are located above and below the cavity to improve the axial linearity of the response and increase the overall efficiency, which is measured to be 39% for a centrally located Cf-252 source. The HNMC also includes an add-a-source feature by which a known Cf-252 source can be introduced near the bottom of the cavity. The perturbation of the count rate due to the Cf-252 is used to estimate the efficiency loss due to the moderator content of the drum matrix. Unusual to similar large volume multiplicity counters is the addition of a 6.4 mm lead lining on the inner walls of the cavity. This addition results in a suitably low value for the minimum detectable Pu-240-effective mass in drums with as much as 10 mSv.h{sup -1} gamma-ray dose rates when operated in a properly shielded bunker to suppress the background production of neutrons in the lead by cosmic rays. The details of the design and operating characteristics of the HNMC are presented and discussed. (authors)

Mueller, W.F.; Croft, S.; McElroy, R.D.; Venkataraman, R.; Zhu, H. [Canberra Industries, Inc., 800 Research Parkway, Meriden, Connecticut 06450 (United States)

2006-07-01T23:59:59.000Z

325

Traits and Multiple Genes  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

326

AM with Multiple Merlins  

E-Print Network [OSTI]

We introduce and study a new model of interactive proofs: AM(k), or Arthur-Merlin with k non-communicating Merlins. Unlike with the better-known MIP, here the assumption is that each Merlin receives an independent random challenge from Arthur. One motivation for this model (which we explore in detail) comes from the close analogies between it and the quantum complexity class QMA(k), but the AM(k) model is also natural in its own right. We illustrate the power of multiple Merlins by giving an AM(2) protocol for 3SAT, in which the Merlins' challenges and responses consist of only n^{1/2+o(1)} bits each. Our protocol has the consequence that, assuming the Exponential Time Hypothesis (ETH), any algorithm for approximating a dense CSP with a polynomial-size alphabet must take n^{(log n)^{1-o(1)}} time. Algorithms nearly matching this lower bound are known, but their running times had never been previously explained. Brandao and Harrow have also recently used our 3SAT protocol to show quasipolynomial hardness for approximating the values of certain entangled games. In the other direction, we give a simple quasipolynomial-time approximation algorithm for free games, and use it to prove that, assuming the ETH, our 3SAT protocol is essentially optimal. More generally, we show that multiple Merlins never provide more than a polynomial advantage over one: that is, AM(k)=AM for all k=poly(n). The key to this result is a subsampling theorem for free games, which follows from powerful results by Alon et al. and Barak et al. on subsampling dense CSPs, and which says that the value of any free game can be closely approximated by the value of a logarithmic-sized random subgame.

Scott Aaronson; Russell Impagliazzo; Dana Moshkovitz

2014-01-27T23:59:59.000Z

327

THERMAL PROPERTIES OF A SOLAR CORONAL CAVITY OBSERVED WITH THE X-RAY TELESCOPE ON HINODE  

SciTech Connect (OSTI)

Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during 2008 July that contains bright X-ray emission in its center. Using ratios of XRT filters, we find evidence for elevated temperatures in the cavity center. The area of elevated temperature evolves from a ring-shaped structure at the beginning of the observation, to an elongated structure two days later, finally appearing as a compact round source four days after the initial observation. We use a morphological model to fit the cavity emission, and find that a uniform structure running through the cavity does not fit the observations well. Instead, the observations are reproduced by modeling several short cylindrical cavity 'cores' with different parameters on different days. These changing core parameters may be due to some observed activity heating different parts of the cavity core at different times. We find that core temperatures of 1.75 MK, 1.7 MK, and 2.0 MK (for July 19, July 21, and July 23, respectively) in the model lead to structures that are consistent with the data, and that line-of-sight effects serve to lower the effective temperature derived from the filter ratio.

Reeves, Katharine K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS 58, Cambridge, MA 02138 (United States); Gibson, Sarah E. [HAO/NCAR, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Kucera, Therese A. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Hudson, Hugh S. [Space Sciences Laboratories, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Kano, Ryouhei, E-mail: kreeves@cfa.harvard.edu [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2012-02-20T23:59:59.000Z

328

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

SciTech Connect (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

329

COMMUNICATIONS Polarization-resolved linewidth-power product of a vertical-cavity  

E-Print Network [OSTI]

when the lasing mode passes through threshold, and ii that the polarization fluctuations in a VCSEL Institute of Physics. DOI: 10.1063/1.1352673 The vertical-cavity semiconductor laser VCSEL is not a true c is the cavity loss rate, i.e., the sum of the mirror loss rate m and the internal loss rate i , h

Exter, Martin van

330

Field synergy principle analysis for reducing natural convection heat loss of a solar cavity receiver  

Science Journals Connector (OSTI)

Abstract Due to the operating temperature from 900 K to 1300 K produced by the concentrating ratio over 2000 in solar parabolic dish-engine system, the natural convection heat loss driven by the buoyancy force of air contributes an important role in the energy loss of cavity receiver. 3-D numerical simulations were performed and the results are analyzed from the novel viewpoint of field synergy principle (FSP) in order to study the heat transfer and fluid flow characteristics in natural convection heat loss of cavity receiver. The effects of geometric parameters, including the inclination angle, aperture size, aperture position and cavity geometric shape on the natural convection heat loss of cavity receiver were examined. The FSP analysis on the simulation results demonstrates that FSP can well explain the reduction mechanism for natural convection heat loss of cavity receiver because the smaller inner production of velocity vector and temperature gradient always corresponds to the lower Nusselt number occurred in the cases with lager inclination angle, smaller aperture size, lower aperture position and frustum-cylinder cavity, respectively. Therefore, the reducing natural convection heat loss attributes to the weakening synergy between velocity vector and temperature gradient. In addition, the local heat transfer performance is studied by the presented distributions of heat transferred via fluid motion, where more interesting natural convection heat loss characteristics of cavity receiver and the detailed explanations were provided. The results of this work offer benefits for the development of theory and technique about reducing natural convection heat loss of cavity receiver.

Yuqiang Li; Gang Liu; Zhenghua Rao; Shengming Liao

2015-01-01T23:59:59.000Z

331

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

SciTech Connect (OSTI)

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

332

Three-dimensional finite difference time domain modeling of the Earth-ionosphere cavity resonances  

E-Print Network [OSTI]

domain (FDTD) model of Schumann resonances (SR) with a set of classical eigenfrequency and quality factorThree-dimensional finite difference time domain modeling of the Earth-ionosphere cavity resonances-dimensional finite difference time domain modeling of the Earth-ionosphere cavity resonances, Geophys. Res. Lett., 32

Pasko, Victor

333

THREE-DIMENSIONAL FLUX PREDICTION FOR A DISH CONCENTRATOR CAVITY RECEIVER  

E-Print Network [OSTI]

, for a particular cavity geometry, affects the temperature distribution on the cavity walls, and the location-dimensional flux distribution in the focal region, in particular as an aid to receiver design. Inputs to the ray error on the completed dish. On-sun flux mapping of the image produced by individual mirror panels gave

334

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

Boyer, Edmond

335

Characterization and Fabrication of Spoke Cavities for High-Velocity Applications  

SciTech Connect (OSTI)

A 500 MHz, velocity-of-light, two-spoke cavity has been designed and optimized for possible use in a compact light source. Here we present the mechanical analysis and steps taken in fabrication of this cavity at Jefferson Lab.

Hopper, Christopher S. [Old Dominion University, Norfolk, VA (United States); Park, HyeKyoung [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Delayen, Jean R. [Old Dominion University, Norfolk, VA (United States)

2014-02-01T23:59:59.000Z

336

Active galactic nuclei-induced cavities in NGC 1399 and NGC 4649  

Science Journals Connector (OSTI)

......in the range of 10 MHz to 10 GHz and f is...filling factor of the plasma in the cavity. We...low-density relativistic plasma, and are a consequence...hot gas from the atmosphere of the host galaxy...in the range of 10 MHz to 10 GHz, and f...the relativistic plasma in the cavity. The......

K. Shurkin; R. J. H. Dunn; G. Gentile; G. B. Taylor; S. W. Allen

2008-01-21T23:59:59.000Z

337

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

SciTech Connect (OSTI)

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

338

Cavity-nesting Bird Use of Nest Boxes in Vineyards of Central-Coast California1  

E-Print Network [OSTI]

Cavity-nesting Bird Use of Nest Boxes in Vineyards of Central-Coast California1 Daniel P. Mummert,2 by vineyards in many areas of central- coastal California. Oak woodlands are home to many insectivorous, cavity-nesting birds that would be beneficial in and around vineyards. During March to June 2001, we used bluebird nest

Standiford, Richard B.

339

Nest Defense Behaviors of Native Cavity-Nesting Birds to European Starlings1  

E-Print Network [OSTI]

457 Nest Defense Behaviors of Native Cavity- Nesting Birds to European Starlings1 Rodney G. Olsen,2 for nest sites and the extent to which European Starlings (Sturnus vulgaris) are seen as a threat by native of aggressive behavior of four species of native cavity-nesting birds to starlings at active nests in trees

Standiford, Richard B.

340

Proposal for the award of a contract for the supply of electronics for the temperature control of cavity windows and helium gas return lines for the superconducting cavities of the LEP200 radio frequency system  

E-Print Network [OSTI]

Proposal for the award of a contract for the supply of electronics for the temperature control of cavity windows and helium gas return lines for the superconducting cavities of the LEP200 radio frequency system

1991-01-01T23:59:59.000Z

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.


341

Mode-locking external-cavity laser-diode sensor for displacement measurements of technical surfaces  

SciTech Connect (OSTI)

A novel laser sensor for position measurements of technical solid-state surfaces is proposed. An external Fabry-Perot laser cavity is assembled by use of an antireflection-coated laser diode together with the technical surface. Mode locking results from pumping the laser diode synchronously to the mode spacing of the cavity. The laser cavity length, i.e., the distance to the measurement object, is determined by evaluation of the modulation transfer function of the cavity by means of a phase-locked loop. The mode-locking external-cavity laser sensor incorporates a resonance effect that results in highly resolving position and displacement measurements. More than a factor-of-10 higher resolution than with conventional nonresonant sensing principles is achieved. Results of the displacement measurements of various technical surfaces are reported. Experimental and theoretical investigations are in good agreement.

Czarske, Juergen; Moebius, Jasper; Moldenhauer, Karsten

2005-09-01T23:59:59.000Z

342

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

SciTech Connect (OSTI)

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

343

Tunneling dynamics of bosonic Josephson junctions assisted by a cavity field  

E-Print Network [OSTI]

We study the interplay between the dynamics of a Bose-Einstein condensate in a double-well potential and that of an optical cavity mode. The cavity field is superimposed to the double-well potential and affects the atomic tunneling processes. The cavity field is driven by a laser red detuned from the bare cavity resonance; the dynamically changing spatial distribution of the atoms can shift the cavity in and out of resonance. At resonance the photon number is hugely enhanced and the atomic tunneling becomes amplified. The Josephson junction equations are revisited and the phase diagram is calculated. We find new solutions with finite imbalance and at the same time a lack of self-trapping solutions due to the emergence of a new separatrix resulting from enhanced tunneling.

G. Szirmai; G. Mazzarella; L. Salasnich

2015-01-13T23:59:59.000Z

344

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

345

Calibration of a Solar Absolute Cavity Radiometer with Traceability to the World Radiometric Reference  

SciTech Connect (OSTI)

This report describes the present method of establishing traceability of absolute cavity radiometers to the World Radiometric Reference (WRR) through the process employed in the International Pyrheliometer Comparisons (IPC). This method derives the WRR reduction factor for each of the participating cavity radiometers. An alternative method is proposed, described, and evaluated as a way to reduce the uncertainty in the comparison process. The two methods are compared using a sample of data from the recent IPC-VIII conducted from September 25th to October 13th, 1995 at the World Radiation Center in Davos, Switzerland. A description of absolute cavity radiometers is also included, using a PMO-6 as an example of active cavity radiometers, and a HF as an example of passive cavity radiometers.

Reda, I.

1996-01-01T23:59:59.000Z

346

Emission from dielectric cavities in terms of invariant sets of the chaotic ray dynamics  

E-Print Network [OSTI]

In this paper, the chaotic ray dynamics inside dielectric cavities is described by the properties of an invariant chaotic saddle. I show that the localization of the far field emission in specific directions is related to the filamentary pattern of the saddle's unstable manifold, along which the energy inside the cavity is distributed. For cavities with mixed phase space, the chaotic saddle is divided in hyperbolic and non-hyperbolic components, related, respectively, to the intermediate exponential (tt_c) decay of the energy inside the cavity. The alignment of the manifolds of the two components of the saddle explains why even if the energy concentration inside the cavity dramatically changes from tt_c, the far field emission changes only slightly. Simulations in the annular billiard confirm and illustrate the predictions.

Eduardo G. Altmann

2009-02-02T23:59:59.000Z

347

Failure of man-made cavities in salt and surface subsidence due to sulfur mining  

SciTech Connect (OSTI)

An engineering data base relevant to subsidence due to sulfur mining and to structural failure of cavities in salt is established, evaluated and documented. Nineteen failure events are discussed. Based on these documented failure events, capabilities of and inputs to a mathematical model of cavity failure are determined. Two failure events are adequately documented for use in model verification studies. A conclusion of this study that is pertinent to the Strategic Petroleum Reserve is that cavity failures in dome salt are fairly rare, but that as the number of large cavities (especially those having large roof spans) increases, failures will probably be more common unless stability and failure mechanisms of cavities are better understood.

Coates, G.K.; Lee, C.A.; McClain, W.C.; Senseny, P.E.

1981-01-01T23:59:59.000Z

348

Network for transfer of an arbitrary $n$-qubit atomic state via cavity QED  

E-Print Network [OSTI]

I show a scheme which allows a perfect transfer of an unknown single-qubit atomic state from one atom to another by letting two atoms interact simultaneously with a cavity QED. During the interaction between atom and cavity, the cavity is only virtually excited and accordingly the scheme is insensitive to the cavity field states and cavity decay. Based on this scheme, a network for transfer of an arbitrary single-qubit atomic state between atoms is engineered. Then the scheme is generalized to perfectly transfer an arbitrary 2-qubit atomic state and accordingly a network for transfer of an arbitrary 2-qubit atomic state is designed. At last, it is proven that the schemes can be generalized to an arbitrary $n(n\\ge 3)$-qubit atomic state transfer case and a corresponding network is also proposed.

Zhan-jun Zhang

2005-04-29T23:59:59.000Z

349

Adiabatic transfer of light in a double cavity and the optical Landau-Zener problem  

SciTech Connect (OSTI)

We analyze the evolution of an electromagnetic field inside a double cavity when the difference in length between the two cavities is changed, e.g., by translating the common mirror. We find that this allows photons to be moved deterministically from one cavity to the other. We are able to obtain the conditions for adiabatic transfer by first mapping the Maxwell wave equation for the electric field onto a Schroedinger-like wave equation and then using the Landau-Zener result for the transition probability at an avoided crossing. Our analysis reveals that this mapping only rigorously holds when the two cavities are weakly coupled (i.e., in the regime of a highly reflective common mirror) and that, generally speaking, care is required when attempting a Hamiltonian description of cavity electrodynamics with time-dependent boundary conditions.

Miladinovic, N.; Hasan, F.; Linnington, I. E.; O'Dell, D. H. J. [Department of Physics and Astronomy, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4M1 (Canada); Chisholm, N. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Hinds, E. A. [Centre for Cold Matter, Imperial College, Prince Consort Road, London SW7 2AZ (United Kingdom)

2011-10-15T23:59:59.000Z

350

Improved "Position Squared" Readout of a Mechanical Resonator in an Optical Cavity Using Degenerate Optical Modes  

E-Print Network [OSTI]

Optomechanical devices in which a flexible SiN membrane is placed inside an optical cavity allow for very high finesse and mechanical quality factor in a single device. They also provide fundamentally new functionality: the cavity detuning can be a quadratic function of membrane position. This enables a measurement of "position squared" ($x^2$) and in principle a QND phonon number readout of the membrane. However, the readout achieved using a single transverse cavity mode is not sensitive enough to observe quantum jumps between phonon Fock states. Here we demonstrate an $x^2$-sensitivity that is orders of magnitude stronger using two transverse cavity modes that are nearly degenerate. We derive a first-order perturbation theory to describe the interactions between nearly-degenerate cavity modes and achieve good agreement with our measurements using realistic parameters. We also demonstrate theoretically that the $x^2$-coupling should be easily tunable over a wide range.

Jack C. Sankey; Andrew M. Jayich; Benjamin M. Zwickl; Cheng Yang; Jack G. E. Harris

2008-11-09T23:59:59.000Z

351

Fabrication of High-Speed Resonant Cavity Enhanced Schottky Photodiodes  

E-Print Network [OSTI]

Abstract — We report the fabrication and testing of a GaAsbased high-speed resonant cavity enhanced (RCE) Schottky photodiode. The top-illuminated RCE detector is constructed by integrating a Schottky contact, a thin absorption region (InHXHVGaHXWPAs) and a distributed AlAs–GaAs Bragg mirror. The Schottky contact metal serves as a high-reflectivity top mirror in the RCE detector structure. The devices were fabricated by using a microwave-compatible fabrication process. The resulting spectral photo response had a resonance around 895 nm, in good agreement with our simulations. The full-widthat-half-maximum (FWHM) was 15 nm, and the enhancement factor was in excess of 6. The photodiode had an experimental setup limited temporal response of 18 ps FWHM, corresponding to a 3-dB bandwidth of 20 GHz. Index Terms—High-speed circuits/devices, photodetectors, photodiodes, resonant caity enhancement, Schottky diodes.

Ekmel Özbay; M. Saiful Islam; Bora Onat; Student Member; Mutlu Gökkavas; Orhan Aytür; Gary Tuttle; Elias Towe; R. H. Henderson; M. Selim Ünlü; Senior Member

352

Complex Dynamics of Nano-Mechanical Membrane in Cavity Optomechanics  

E-Print Network [OSTI]

Theoretical analysis of a suspended nano-mechanical membrane subject to an optical driving field in cavity optomechanics is presented, which is confirmed through numerical simulations. In the presence of an optical field between its mirrors a high finesse nano-mechanical resonator acts as an oscillator driven by radiation pressure force. The periodic nature of the radiation pressure force makes the nano-mechanical membrane in the optomechanical system as kicked harmonic oscillator. Mathematically the physical system displays a stochastic web map that helps to understand several properties of the kicked membrane in classical phase space. We find that our web map is area preserving, and displays quasi-periodic symmetrical structures in phase space which we express as q-fold symmetry. It is shown that under appropriate control of certain parameters, namely the frequency ratio (q) and the kicking strength (K), the dynamics of kicked membrane exhibits chaotic dynamics. We provide the stability analysis by means of...

Akram, Muhammad Javed

2014-01-01T23:59:59.000Z

353

Toward photonic-crystal metamaterials: Creating magnetic emitters in photonic crystals  

E-Print Network [OSTI]

Toward photonic-crystal metamaterials: Creating magnetic emitters in photonic crystals M. L Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge explore the possibility of designing photonic crystals to act as magnetic metamaterials: structures

354

Hadron multiplicities at the LHC  

E-Print Network [OSTI]

We present the predictions for hadron multiplicities in pp, pA and AA collisions at the LHC based on our approach to the Color Glass Condensate.

D. Kharzeev; E. Levin; M. Nardi

2007-07-05T23:59:59.000Z

355

SC Beta Graded Cavity Design for a Proposed 350 MHZ Linac for Waste Transmutation and Energy Production  

E-Print Network [OSTI]

SC Beta Graded Cavity Design for a Proposed 350 MHZ Linac for Waste Transmutation and Energy Production

Barni, D; Pagani, C; Pierini, P; Visona, S; Gemme, G; Parodi, R

1998-01-01T23:59:59.000Z

356

Smart Materials Based System Operated at 2K Used as a Superconducting Cavity Tuner for VUV-fel Purpose  

E-Print Network [OSTI]

Smart Materials Based System Operated at 2K Used as a Superconducting Cavity Tuner for VUV-fel Purpose

Sekalski, P; Simrock, S; Albrecht, C; Lilje, L; Bosland, P; Fouaidy, M; Bosotti, A; Paparella, R

2006-01-01T23:59:59.000Z

357

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":""}]}

358

PHYSICAL REVIEW E 86, 046204 (2012) Impedance and power fluctuations in linear chains of coupled wave chaotic cavities  

E-Print Network [OSTI]

cavities takes place through a small port, and electromagnetic energy flows in a single propagation mode of electromagnetic wave energy through a chain of coupled cavities is considered. The cavities are assumed that can be characterized as an enclosed region with ports for the ingress and egress of waves, less work

Anlage, Steven

359

Calibrating Curved Crystals Used for Plasma Spectroscopy  

SciTech Connect (OSTI)

The throughput and resolving power of an X-ray spectrometer that uses a curved crystal as the diffraction element is determined primarily by the crystal X-ray reflectivity properties. This poster presents a measurement technique for these crystal parameters using a simple diode source to produce a narrow spectral band. The results from measurements on concave elliptical polyethylene terephthalate (PET) crystals and convex potassium acid phthalate (KAP) crystals show large variations in the key parameters compared to those from the flat crystal.

Haugh, M. J., Jacoby, K. D., Ross, P. W., Rochau, G. Wu, M., Regan, S. P., Barrios, M. A.

2012-10-29T23:59:59.000Z

360

Precision Crystal Calorimeters in High Energy Physics  

ScienceCinema (OSTI)

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal?s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

Ren-Yuan Zhu

2010-01-08T23:59:59.000Z

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

Progress on a Cavity with Beryllium Walls for Muon Ionization Cooling Channel R&D.  

SciTech Connect (OSTI)

The Muon Accelerator Program (MAP) collaboration is working to develop an ionization cooling channel for muon beams. An ionization cooling channel requires the operation of high-gradient, normal-conducting RF cavities in multi-Tesla solenoidal magnetic fields. However, experiments conducted at Fermilab?s MuCool Test Area (MTA) show that increasing the solenoidal field strength reduces the maximum achievable cavity gradient. This gradient limit is characterized by an RF breakdown process that has caused significant damage to copper cavity interiors. The damage may be caused by field-emitted electrons, focused by the solenoidal magnetic field onto small areas of the inner cavity surface. Local heating may then induce material fatigue and surface damage. Fabricating a cavity with beryllium walls would mitigate this damage due to beryllium?s low density, low thermal expansion, and high electrical and thermal conductivity. We address the design and fabrication of a pillbox RF cavity with beryllium walls, in order to evaluate the performance of high-gradient cavities in strong magnetic fields.

Bowring, D.L.; DeMello, A.J.; Lambert, A.R.; Li, D.; Virostek,, S.; Zisman, M.; Kaplan, D.; Palmer, R.B.

2012-05-20T23:59:59.000Z

362

Results of two LANL [beta]=0.175, 350-MHZ, 2-GAP spoke cavities  

SciTech Connect (OSTI)

Two {beta} = 0.175, 350 MHz, 2-gap superconducting (SC) spoke cavities were fabricated in industry under the Advanced Accelerator Applications (AAA) project for the transmutation of nuclear waste. These cavities are promising candidates for the accelerating structures between a RFQ and the elliptical SC cavities for proton and heavy ion linacs. Since their delivery in July 2002, they have been tested in terms of mechanical properties, low-temperature performance, i.e., Qo-Eaccc urves at 4 K and 2 K, surface resistance dependence on temperature and for multipacting (MP). The two cavities achieved accelerating fields of 13.5 MV/m and 13.0 MV/m as compared to the required field of 7.5 MV/m with enough margin for the quality factor. These cavities seem to need more time to condition away MP than elliptical cavities, but MP does not occur once the cavity is conditioned and kept at 4 K. The length of the 103 mm-diameter nominal coupler port was found to be too short for the penetrating field.

Tajima, T. (Tsuyoshi); Edwards, R. L. (Randall L.); Gentzlinger, R.C. (Robert C.); Krawczyk, F. L. (Frank L.); Ledford, J. E. (John E.); Liu, Jianfei; Montoya, D. I. (Debbie I.); Roybal, R. J. (Raymond J.(Ray); Schrage, D. L. (Dale L.); Shapiro, A. H. (Alan H.); Barni, D.; Bosotti, A.; Pagani, C. D.

2003-01-01T23:59:59.000Z

363

Quantum Fisher information of fermionic cavity modes in an accelerated motion  

E-Print Network [OSTI]

We investigate the effect of the inertial and non-inertial segments of relativistic motion on the quantum Fisher information of (1+1) Dirac field modes confined to cavities. %For this purpose, a bipartite system comprising of Alice's and Rob's cavities with appropriate boundary conditions is prepared. For the purpose, we consider the situation that Rob's cavity, initially inertial, accelerates uniformly with respect to its proper time and then again becomes inertial while Alice's cavity remains inertial. The acceleration is assumed to be very small and its effects were analyzed in a perturbative regime. For analysis, we consider $\\theta$ parameterized two-qubit pure entangled state and a Werner state. In contrast to the degradation of entanglement due to the relativistic motion between the cavities, the quantum Fisher information of the pure composite system $\\mathcal{F}_\\theta$ with respect to parameter $\\theta$ is found to be invariant under the same conditions. However, in the case of the Werner state, the quantum Fisher information displays periodic degradation, due to the inertial and non-inertial segments of motion. Further, we investigate how this evolution process affects the quantum Fisher information distribution over the subsystems of Alice's and Rob's cavities. We find that the quantum Fisher information over the Rob's cavity shows the periodic degradation behavior depending upon the parameter $\\theta$ as well as the uniform acceleration for both the two qubit pure state and Werner state. The quantum Fisher information over Alice's cavity remains invariant throughout the motion of Rob's cavity for the two qubit pure state whereas for Werner state it is affected by the mixing parameter of the Werner state.

Zahid Hussain Shamsi; DaiGyoung Kim; Younghun Kwon

2014-09-24T23:59:59.000Z

364

Experimental investigation of pressure loss and heat transfer in a rotor–stator cavity with two outlets  

Science Journals Connector (OSTI)

Abstract This article presented detailed measurements of the pressure distribution and heat transfer in a rotor–stator cavity with inlet of orifices on the rotating disk and two outlets at both low radius and high radius. Transient thermochromic liquid crystal (TLC) technique was employed to determine the convective heat transfer characteristics on the test surface of the rotating disk. Rotational Reynolds numbers (Re?) ranging from 4.9 × 105 to 2.47 × 106 and dimensionless flow rate (Cw) between 6.9 × 103 and 2.72 × 104 were considered. Experimental results indicated that the characteristics of the pressure loss coefficient between the inlet and the outlet was strongly dependent on the Re? and Cw. Under the current operating conditions, the heat transfer on the surface of the rotating disk was weakened at both in the upper and lower edges for the case of r/R = 0.775 due to the existence of the recirculation. Whereas the heat transfer were enhanced near the upper radius with relatively low flow rate and high rotational speed, as well as on the middle radius with relatively high flow rate and low rotational speed.

X. Luo; G. Han; H. Wu; L. Wang; G. Xu

2014-01-01T23:59:59.000Z

365

Simple scheme for implementing the Deutsch-Jozsa algorithm in thermal cavity  

E-Print Network [OSTI]

We present a simple scheme to implement the Deutsch-Jozsa algorithm based on two-atom interaction in a thermal cavity. The photon-number-dependent parts in the evolution operator are canceled with the strong resonant classical field added. As a result, our scheme is immune to thermal field, and does not require the cavity to remain in the vacuum state throughout the procedure. Besides, large detuning between the atoms and the cavity is not necessary neither, leading to potential speed up of quantum operation. Finally, we show by numerical simulation that the proposed scheme is equal to demonstrate the Deutsch-Jozsa algorithm with high fidelity.

Wen-Xing Yang; Zhe-Xuan Gong

2006-11-22T23:59:59.000Z

366

Nano- and microscale particles and global electromagnetic resonances in the Earth-ionosphere cavity  

SciTech Connect (OSTI)

The influence of nano-and microscale particles (dust grains) on the global electromagnetic (Schumann) cavity has been studied in the context of two possible mechanisms. First, the presence of charged microscale particles in the ionospheric plasma modifies the dispersion properties of the upper boundary of the Schumann cavity and, thus, affects its eigenfrequencies and quality factor. Second, there is a relation between the dust concentration in the atmosphere and lightning discharges, which excite Schumann resonances. Therefore, dust grains can enhance the energy pumping of the cavity, thereby increasing the amplitude of electromagnetic oscillations in it.

Besedina, Yu. N.; Popel, S. I. [Russian Academy of Sciences, Institute of Geosphere Dynamics (Russian Federation)

2007-02-15T23:59:59.000Z

367

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

SciTech Connect (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

368

Enhancement in Quality Factor of SRF Niobium Cavities by Material Diffusion  

E-Print Network [OSTI]

An increase in the quality factor of superconducting radiofrequency cavities is achieved by minimizing the surface resistance during processing steps. The surface resistance is the sum of temperature independent residual resistance and temperature/material dependent Bardeen-Cooper-Schrieffer (BCS) resistance. High temperature heat treatment usually reduces the impurities concentration from the bulk niobium, lowering the residual resistance. The BCS part can be reduced by selectively doping non-magnetic impurities. The increase in quality factor, termed as Q-rise, was observed in cavities when titanium or nitrogen thermally diffused in the inner cavity surface.

Dhakal, Pashupati; Kneisel, Peter; Myneni, Ganapati Rao

2014-01-01T23:59:59.000Z

369

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

370

Fast ground-state cooling of mechanical resonators with time-dependent optical cavities  

SciTech Connect (OSTI)

We propose a feasible scheme to cool down a mechanical resonator (MR) in a three-mirror cavity optomechanical system with controllable external optical driving fields. Under the Born-Oppenheimer approximation, the whole dynamics of the mechanical resonator and cavities is reduced to that of a time-dependent harmonic oscillator, whose effective frequency can be controlled through the optical driving fields. The fast cooling of the MR can be realized by controlling the amplitude of the optical driving fields. Significantly, we further show that the ground-state cooling may be achieved via the three-mirror cavity optomechanical system without the resolved sideband condition.

Li Yong [Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Beijing Computational Science Research Center, Beijing 100084 (China); Wu Lianao [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), P.O. Box 644, ES-48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, ES-48011 Bilbao (Spain); Wang, Z. D. [Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

2011-04-15T23:59:59.000Z

371

Cavity optomechanics with Si3N4 membranes at cryogenic temperatures  

E-Print Network [OSTI]

We describe a cryogenic cavity-optomechanical system that combines Si3N4 membranes with a mechanically-rigid Fabry-Perot cavity. The extremely high quality-factor frequency products of the membranes allow us to cool a MHz mechanical mode to a phonon occupation of less than 10, starting at a bath temperature of 5 kelvin. We show that even at cold temperatures thermally-occupied mechanical modes of the cavity elements can be a limitation, and we discuss methods to reduce these effects sufficiently to achieve ground state cooling. This promising new platform should have versatile uses for hybrid devices and searches for radiation pressure shot noise.

T. P. Purdy; R. W. Peterson; P. -L. Yu; C. A. Regal

2012-08-31T23:59:59.000Z

372

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

SciTech Connect (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

373

Ray-wave correspondence in the nonlinear description of stadium-cavity lasers  

E-Print Network [OSTI]

We show that the solution of fully nonlinear lasing equations for stadium cavities exhibits a highly directional emission pattern. This directionality can be well explained by a ray-dynamical model, where the dominant ray-escape dynamics is governed by the unstable manifolds of the unstable short periodic orbits for the stadium cavity. Investigating the cold-cavity modes relevant for the lasing, we found that all of the high-Q modes have the emission directionality corresponding to that of the ray-dynamical model.

Susumu Shinohara; Takahisa Harayama; Hakan E. Tureci; A. Douglas Stone

2006-09-28T23:59:59.000Z

374

Atomic spatial coherence with spontaneous emission in a strong-coupling cavity  

SciTech Connect (OSTI)

The role of spontaneous emission in the interaction between a two-level atom and a pumped microcavity in the strong-coupling regime is discussed. In particular, using a quantum Monte Carlo simulation, we investigate atomic spatial coherence. It is found that atomic spontaneous emission destroys the coherence between neighboring lattice sites, while cavity decay does not. Furthermore, our computation of the spatial coherence function shows that the in-site locality is little affected by the cavity decay but greatly depends on the cavity pump amplitude.

Fang Zhen; Guo Rui; Zhou Xiaoji; Chen Xuzong [School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

2010-07-15T23:59:59.000Z

375

A CAVITY RING-DOWN SPECTROSCOPY MERCURY CONTINUOUS EMISSION MONITOR  

SciTech Connect (OSTI)

The construction of the sampling system was completed during the past quarter. The sampling system has been built on a 3 feet x 4 feet x 2 inch breadboard table. The laser system, all the associated optics, and the mounts and hardware needed to couple the UV light into the fiber optic have also been condensed and placed on an identical 3 feet x 4 feet x 2 inch breadboard table. This reduces the footprint of each system for ease of operation at a field test facility. The two systems are only connected with a fiber optic, to bring the UV light to the CRD cavity, and a single coaxial cable used to apply a voltage to the diode seed laser to scan the frequency over the desired mercury transition. SRD software engineers applied a couple of software fixes to correct the problems of the diode seed laser drifting or mode hopping. Upon successful completion of the software fixes another long-term test was conducted. A nearly 3 day long, 24 hours/day, test was run to test out the new subroutines. Everything appeared to work as it should and the mercury concentrations were accurately reported for the entire test, with the exception of a small interval of time when the intensity of the UV light dropped low enough that the program was no longer triggering properly. After adjusting the power of the laser the program returned to proper operation. With the successful completion of a relatively long test SRD software engineer incorporated the new subroutine into an entirely new program. This program operates the CRD instrument automatically as a continuous emissions monitor for mercury. In addition the program also reports the concentration of SO{sub 2} determined in the sample flue gas stream. Various functions, operation of, and a description of the new program have been included with this report. This report concludes the technical work associated with Phase II of the Cavity Ring-Down project for the continuous detection of trace levels of mercury. The project is presently gearing up for additional testing in preparation for a field test to be conducted at the DOE/NETL pilot plant facility in Pittsburgh, Pennsylvania.

Christopher C. Carter

2004-03-31T23:59:59.000Z

376

ARM - Field Campaign - CRYSTAL-FACE  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

377

IR laser-induced protein crystal transformation  

Science Journals Connector (OSTI)

A novel method and the associated instrumentation for improving crystalline order (higher resolution of X-ray diffraction and reduced mosaicity) of protein crystals by precisely controlled heating is demonstrated. Crystal transformation is optically controlled by a video system.

Kiefersauer, R.

2014-04-26T23:59:59.000Z

378

Photon tunnelling microscopy of polyethylene single crystals  

E-Print Network [OSTI]

Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

Srinivasarao, Mohan

379

Fluid Inclusions in Hydrothermally Synthesized Brucite Crystals  

Science Journals Connector (OSTI)

Brucite crystals were grown hydrothermally from Mg(OH)2 powder in 7.5 and 15 mol% NaOH solutions. It is established from the observation of the surface microtopographs that the crystals grew by the spiral mechani...

Kazuo Nakamura; Shin-Ichi Hirano…

1989-01-01T23:59:59.000Z

380

Crystallization of the crenarchaeal SRP core  

Science Journals Connector (OSTI)

The conserved ribonucleoprotein core of the signal recognition particle (SRP) has been crystallized. Both crystal forms are highly twinned and an explanation for the possible tetartohedral twinning is presented.

Rosendal, K.R.

2003-12-18T23:59:59.000Z

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.


381

Nanopatterned anchoring layers for liquid crystals  

E-Print Network [OSTI]

This thesis describes the theory and fabrication of inhomogeneous Liquid Crystal anchoring layers. While chemical anchoring techniques have proved useful for many applications, especially Liquid Crystal Displays, they have ...

Gear, Christopher S. (Christopher Stanwood)

2014-01-01T23:59:59.000Z

382

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

SciTech Connect (OSTI)

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

383

Crystal structure of guggulsterone Z  

SciTech Connect (OSTI)

The crystal structure of the title compound (4,17(20)-trans-pregnadiene-3,16-dione, C{sub 21}H{sub 28}O{sub 2}) has been determined by direct methods using single-crystal X-ray diffraction data. The compound crystallizes into the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} with the unit cell parameters a = 7.908(2) A, b = 13.611(3) A, c = 16.309(4) A, and Z = 4. The structure has been refined to R = 0.058 for 3667 observed reflections. The bond distances and angles are in good agreement with guggulsterone E and other related steroid molecules. Ring A exists in the distorted sofa conformation, while rings B and C adopt the distorted chair conformation. Five-membered ring D is intermediate between the half-chair and envelope conformations. The A/B ring junction is quasi-trans, while ring systems B/C and C/D are trans fused about the C(8)-C(9) and C(13)-C(14) bonds, respectively. The steroid nucleus has a small twist, as shown by the C(19)-C(10)...C(13)-C(18) pseudo-torsion angle of 7.2{sup o}. The crystal structure is stabilized by intra-and intermolecular C-H...O hydrogen bonds.

Gupta, V. K., E-mail: vivek_gupta2k2@hotmail.com; Bandhoria, P. [University of Jammu, Post Graduate Department of Physics (India); Gupta, B. D.; Gupta, K. K. [Regional Research Laboratory (India)

2006-03-15T23:59:59.000Z

384

Crystal Engineering: Strategies and Architectures  

Science Journals Connector (OSTI)

This review takes a look at some of the strategies that have been devised for research in crystal engineering, in particular, those based around hydrogen-bonded architectures. In addition, some of the history and possibilites of the field itself are alluded to.

Aakeröy, C.B.

1997-08-01T23:59:59.000Z

385

Generation of vector beams with liquid crystal disclination lines  

E-Print Network [OSTI]

We report that guiding light beams, ranging from continuous beams to femtosecond pulses, along liquid crystal defect lines can transform them into vector beams with various polarization profiles. Using Finite Difference Time Domain numerical solving of Maxwell equations, we confirm that the defect in the orientational order of the liquid crystal induces a defect in the light field with twice the winding number of the liquid crystal defect, coupling the topological invariants of both fields. For example, it is possible to transform uniformly-polarized light into light with a radial polarization profile. Our approach also correctly yields a zero-intensity region near the defect core, which is always present in areas of discontinuous light polarization or phase. Using circularly polarized incident light, we show that defects with non-integer winding numbers can be obtained, where topological constants are preserved by phase vortices, demonstrating coupling between the light's spin, orbital angular momentum and polarization profile. Further, we find an ultrafast femtosecond laser pulse travelling along a defect line splits into multiple intensity regions, again depending on the defect's winding number, allowing applications in beam steering and filtering. Finally, our approach describing generation of complex optical fields via coupling with topological defect lines in optically birefringent nematic fluids can be easily extended to high-intensity beams that affect nematic ordering.

Miha ?an?ula; Miha Ravnik; Slobodan Žumer

2014-08-12T23:59:59.000Z

386

Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ferromagnetic Amorphous Ribbons: A Multimodal Characterization and Thermal Model Study. Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons: A Multimodal...

387

Ames Lab 101: Growing Crystals in Space  

SciTech Connect (OSTI)

Rohit Trivedi, distinguished professor of materials science and engineering, discusses his research with NASA to grow crystals in space.

Trivedi, Rohit

2011-01-01T23:59:59.000Z

388

Crystal of GTP Cyclohydrolase Type IB  

DOE Patents [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

Robotic CCD microscope for enhanced crystal recognition  

DOE Patents [OSTI]

A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

Segelke, Brent W. (San Ramon, CA); Toppani, Dominique (Livermore, CA)

2007-11-06T23:59:59.000Z

390

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals  

E-Print Network [OSTI]

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals of lamellar single crystals of polyethylene (PE). We obtain thickness, diffraction, and calorimetry data

Allen, Leslie H.

391

Cavity induced modifications to the resonance fluorescence and probe absorption of a laser-dressed V atom  

E-Print Network [OSTI]

A cavity-modified master equation is derived for a coherently driven, V-type three-level atom coupled to a single-mode cavity in the bad cavity limit. We show that population inversion in both the bare and dressed-state bases may be achieved, originating from the enhancement of the atom-cavity interaction when the cavity is resonant with an atomic dressed-state transition. The atomic populations in the dressed state representation are analysed in terms of the cavity-modified transition rates. The atomic fluorescence spectrum and probe absorption spectrum also investigated, and it is found that the spectral profiles may be controlled by adjusting the cavity frequency. Peak suppression and line narrowing occur under appropriate conditions.

Jin-Sheng Peng; Gao-Xiang Li; Peng Zhou; S. Swain

2000-03-20T23:59:59.000Z

392

New Accessory for Cleaning the Inside of the Machine Tool Cavity  

SciTech Connect (OSTI)

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

393

Cryogenic controls for Fermilab's SRF cavities and test facility  

SciTech Connect (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

394

Complex Dynamics of Nano-Mechanical Membrane in Cavity Optomechanics  

E-Print Network [OSTI]

Theoretical analysis of a suspended nano-mechanical membrane subject to an optical driving field in cavity optomechanics is presented, which is confirmed through numerical simulations. In the presence of an optical field between its mirrors a high finesse nano-mechanical resonator acts as an oscillator driven by radiation pressure force. The periodic nature of the radiation pressure force makes the nano-mechanical membrane in the optomechanical system as kicked harmonic oscillator. Mathematically the physical system displays a stochastic web map that helps to understand several properties of the kicked membrane in classical phase space. We find that our web map is area preserving, and displays quasi-periodic symmetrical structures in phase space which we express as q-fold symmetry. It is shown that under appropriate control of certain parameters, namely the frequency ratio (q) and the kicking strength (K), the dynamics of kicked membrane exhibits chaotic dynamics. We provide the stability analysis by means of Lyapunov exponent and survival probability.

Muhammad Javed Akram; Farhan Saif

2014-11-03T23:59:59.000Z

395

Transition from Irradiation-Induced Amorphization to Crystallization...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

from Irradiation-Induced Amorphization to Crystallization in Nanocrystalline Silicon Carbide. Transition from Irradiation-Induced Amorphization to Crystallization in...

396

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:

397

A 674 nm external cavity diode laser for a ??Sr? ion trap  

E-Print Network [OSTI]

Atomic ion traps are a promising candidate for scalable quantum information processing. In this thesis, a 674 nm extended cavity diode laser is built to address an optical quantum bit in ??Sr? with the goal of testing such ...

Thon, Susanna M. (Susanna Mitrani)

2005-01-01T23:59:59.000Z

398

Solid state cavity QED : practical applications of strong coupling of light and matter  

E-Print Network [OSTI]

J-aggregates of cyanine dyes are the excitonic materials of choice for realizing polariton devices that operate in strong coupling at room temperature. Since the earliest days of cavity QED, there has been a major desire ...

Tischler, Jonathan Randall, 1977-

2007-01-01T23:59:59.000Z

399

Industrial Fabrication of Medium-Beta SCRF Cavities for a High-Intensity Proton Linac  

E-Print Network [OSTI]

During 1999, four 700-MHz, medium-beta (b = 0.64), superconducting radio frequency (SCRF) cavities for a high-intensity proton linac project at Los Alamos National Laboratory (LANL) were manufactured by industry. The SCRF cavities were designed by a LANL team in Los Alamos, New Mexico, USA, and manufactured at a CERCA plant in Romans, France. The cavities were made of 4-mm-thick, solid niobium sheets with a residual resistivity ratio (RRR) greater than 250. These niobium sheets were supplied by Wah Chang (USA), Heraeus AG (Germany), and Tokyo Denkai (Japan). The SCRF cavities were shipped to LANL for performance testing. This paper describes the experience gained during the manufacturing process at CERCA.

Kuzminski, J; Gentzlinger, R C; Maccioni, P

2000-01-01T23:59:59.000Z

400

Aft-body loading function for penetrators based on the spherical cavity-expansion approximation.  

SciTech Connect (OSTI)

In this paper we develop an aft-body loading function for penetration simulations that is based on the spherical cavity-expansion approximation. This loading function assumes that there is a preexisting cavity of radius a{sub o} before the expansion occurs. This causes the radial stress on the cavity surface to be less than what is obtained if the cavity is opened from a zero initial radius. This in turn causes less resistance on the aft body as it penetrates the target which allows for greater rotation of the penetrator. Results from simulations are compared with experimental results for oblique penetration into a concrete target with an unconfined compressive strength of 23 MPa.

Longcope, Donald B., Jr.; Warren, Thomas Lynn; Duong, Henry

2009-12-01T23:59:59.000Z

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.


401

Lattice Boltzmann Simulation of Mixed Convection in a Driven Cavity Packed with Porous Medium  

Science Journals Connector (OSTI)

The problem of mixed convection in a driven cavity packed with porous medium is studied with lattice Boltzmann method. A lattice Boltzmann model for incompressible flow in porous media and another thermal lattice

Zhenhua Chai; Zhaoli Guo; Baochang Shi

2007-01-01T23:59:59.000Z

402

Dynamics of rising magnetized cavities and UHECR acceleration in clusters of galaxies  

E-Print Network [OSTI]

We study the expansion of low density cavities produced by Active Galactic Nuclei jets in clusters of galaxies. The long term stability of these cavities requires the presence of linked magnetic fields. We find solutions describing the self-similar expansion of structures containing large-scale electromagnetic fields. Unlike the force-free spheromak-like configurations, these solutions have no surface currents and, thus, are less susceptible to resistive decay. The cavities are internally confined by external pressure, with zero gradient at the surface. If the adiabatic index of the plasma within the cavity is $\\Gamma>4/3$, the expansion ultimately leads to the formation of large-scale current sheets. The resulting dissipation of the magnetic field can only partially offset the adiabatic and radiative losses of radio emitting electrons. We demonstrate that if the formation of large-scale current sheets is accompanied by explosive reconnection of the magnetic field, the resulting reconnection layer can acceler...

Gourgouliatos, Konstantinos N

2011-01-01T23:59:59.000Z

403

Novel Organic Solar Cell Design To Enhance The Efficiency Using An Optical Cavity Control  

Science Journals Connector (OSTI)

We fabricated an organic solar cell where the electrodes are metallic layers that form an optical cavity. To be able to optically enhance the efficiency, we used a high fluorescence...

Betancur Lopera, Rafael A; Elias, Xavier; Vuong, Luat T; Martorell, Jordi

404

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

Science Journals Connector (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

405

Two-photon absorption and emission by Rydberg atoms in coupled cavities  

E-Print Network [OSTI]

We study the dynamics of a system composed of two coupled cavities, each containing a single Rydberg atom. The interplay between Rydberg-Rydberg interaction and photon hopping enables the transition of the atoms from the collective ground state to the double Rydberg excitation state by individually interacting with the hybrid cavity modes and suppressing the up conversion process between them. The atomic transition is accompanied by the two-photon absorption and emission of the hybrid modes. Since the energy level structure of the atom-cavity system is photon number dependent, there is only a pair of states being in the two-photon resonance. Therefore, the system can act as a quantum nonlinear absorption filter through the nonclassical quantum process, converting coherent light field into a non-classical state. Meanwhile, the vacuum field in the cavity inspires the Rydberg atoms to simultaneously emit two photons into the hybrid mode, resulting in obvious emission enhancement of the mode.

Huaizhi Wu; Zhen-Biao Yang; Shi-Biao Zheng

2013-10-10T23:59:59.000Z

406

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

407

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

SciTech Connect (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

408

One-dimensional array of ion chains coupled to an optical cavity  

E-Print Network [OSTI]

We present a novel system where an optical cavity is integrated with a microfabricated planar-electrode ion trap. The trap electrodes produce a tunable periodic potential allowing the trapping of up to 50 separate ion ...

Cetina, Marko

409

INDUCED SEISMICITY MONITORING OF AN UNDERGROUND SALT CAVITY UNDER A TRANSIENT PRESSURE EXPERIMENT  

E-Print Network [OSTI]

to 125 m in cemented boreholes drilled in thé vicinity of thé study area. The underground cavity under and Monitoring, Seismic Introduction A large research project within thé GISOS1 program has been launched

Paris-Sud XI, Université de

410

RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab  

E-Print Network [OSTI]

PILLBOX CAVITY AT LAB G OF FERMILAB* Derun Li, J. Corlett,apertures at Lab G of Fermilab, a dedicated facility forwas shipped to Lab G of Fermilab for high power tests in

2003-01-01T23:59:59.000Z

411

Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider  

SciTech Connect (OSTI)

On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

Castilla Loeza, Alejandro [ODU, JLAB; Delayen, Jean R. [ODU, JLAB

2013-12-01T23:59:59.000Z

412

Closed Path Approach to Casimir Effect in Rectangular Cavities and Pistons  

E-Print Network [OSTI]

We study thoroughly Casimir energy and Casimir force in a rectangular cavity and piston with various boundary conditions, for both scalar field and electromagnetic (EM) field. Using the cylinder kernel approach, we find the Casimir energy exactly...

Liu, Zhonghai

2010-07-14T23:59:59.000Z

413

Experimental and Computational Study of a Scaled Reactor Cavity Cooling System  

E-Print Network [OSTI]

The Very High Temperature Gas-Cooled Reactor (VHTR) is one of the next generation nuclear reactors designed to achieve high temperatures to support industrial applications and power generation. The Reactor Cavity Cooling System (RCCS) is a passive...

Vaghetto, Rodolfo

2013-11-25T23:59:59.000Z

414

Bow shocks formed by plasma collisions in laser irradiated semi-cylindrical cavities  

E-Print Network [OSTI]

the axis to form a dense bright plasma focus. Later in time a long lasting bow shock is observed to develop a location near the cavity axis, where it collides forming a bright high density plasma focus

Rocca, Jorge J.

415

High-Gradient Tests of the Single-Cell SC Cavity with a Feedback Waveguide  

SciTech Connect (OSTI)

Use of a superconducting (SC) traveling-wave accelerating (STWA) structure with a small phase advance per cell, rather than a standing-wave structure, may provide a significant increase in the accelerating gradient in the ILC linac [1]. For the same surface electric and magnetic fields, the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing-wave cavities. In addition, the STWA allows longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed and manufactured to demonstrate the possibility of proper processing to achieve a high accelerating gradient. The first results of high-gradient tests of a prototype 1.3 GHz single-cell cavity with feedback waveguide will be presented.

Yakovlev, V.; Solyak, N.; Wu, G.; Ge, M.; Gonin, I.; Khabiboulline, T.; Ozelis, J.; Rowe, A. [Fermilab, Batavia, IL 60510 (United States); Avrakhov, P.; Kanareykin, A. [Euclid TechLabs, LLC, Solon, Ohio 44139 (United States); Rathke, J. [AES, Medford, NY 11763 (United States)

2010-11-04T23:59:59.000Z

416

Computational and experimental investigations into cavity receiver heat loss for solar thermal concentrators  

E-Print Network [OSTI]

of the total, though the losses depend on solar elevation angle; at higher angles, and in low-wind conditions in inclination, temperature and cavity geometry on convective and radiative heat loss. Secondly, a water

417

Testing and Simulation of the SRF Wafer Test Cavity for the Characterization of Superconductors and Heterostructures  

E-Print Network [OSTI]

The wafer test cavity, designed at Texas A&M University, has been constructed and tested at Thomas Jefferson National Accelerator Facility. The mode structure, quality factor and coupling methods have been investigated. The TE_(011) mode has been...

Comeaux, Justin

2014-08-07T23:59:59.000Z

418

Realizing Three-Qubit Quantum-Gate Operation in a Cavity-QED System  

Science Journals Connector (OSTI)

Three-qubit quantum phase-gate and C2-NOT gate realization in a cavity-QED system is proposed where highly detuned field modes interact with a four-level system in an...

Joshi, Amitabh; Xiao, Min

419

Quantum Efficiency of Organic Solar Cells: Electro-Optical Cavity Considerations  

Science Journals Connector (OSTI)

Quantum Efficiency of Organic Solar Cells: Electro-Optical Cavity Considerations ... The authors kindly thank SJPC, Canada, for providing sample PCDTBT material and for performing the high-temperature GPC analyses. ...

Ardalan Armin; Marappan Velusamy; Pascal Wolfer; Yuliang Zhang; Paul L Burn; Paul Meredith; Almantas Pivrikas

2014-02-13T23:59:59.000Z

420

Light polymerization during cavity filling: influence of total energy density on shrinkage and marginal adaptation  

Science Journals Connector (OSTI)

Volumetric contraction during light cured polymerization of methacrylate based dental composites...1]. If the material is adhesively fixed to a tooth cavity, these stresses will be transferred to the margins and ...

Tissiana Bortolotto; Federico Prando; Didier Dietschi; Ivo Krejci

2014-07-01T23:59:59.000Z

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

Cavity-Enhanced IR Absorption in Planar Chalcogenide Glass Microdisk Resonators: Experiment and Analysis  

E-Print Network [OSTI]

Planar microdisk optical resonators fabricated from Ge[subscript 23]Sb[subscript 7]S[subscript 70] chalcogenide glass on a silicon substrate are applied for cavity-enhanced spectroscopic measurement of chemical molecular ...

Kimerling, Lionel C.

422

Effect of External Magnetic Fields on the Operation of RF Cavities  

SciTech Connect (OSTI)

Recent experiments have shown severe surface damage and a reduction of the maximum accelerating gradient for an rf cavity that is operating under external magnetic fields. This implies that serious problems may occur in lattices where rf cavities and external magnetic fields coexist, such as those of the proposed neutrino factory and muon collider. Although existing data suggest that this magnetic field dependent breakdown is associated with the emission of electrons from locally enhanced field regions on the cavity surface, the mechanism that drives this effect is not yet well understood. Here, we show that such field emitted electrons are accelerated by the cavity and focused by the magnetic field to the other side of the cavity where they heat its surface. We show that if the magnetic field is strong, significant surface deformation can occur that eventually could limit the accelerating gradient of the cavity. Results of our model are compared to the existing experimental data from an 805 MHz cavity. The geometry of the pillbox cavity in our case is more complicated, and the analysis depends on the electron energies, focused dimensions, and angle of impact, but damage may reasonably be expected with similar cyclical heating above 40 C. However, it is not yet known what the mechanism is for such surface damage to cause a cavity to breakdown. One possibility is that if electrons are focused on a location with a high surface gradient, then the local damage will generate new asperities with higher FN enhancement factors, thus initiating breakdown. While our preliminary analysis offers some quantification on the effects of the magnetic fields on the cavity's operation, other theoretical issues were not addressed. For instance, emission from secondary electrons was disregarded, the asperity was placed on axis, the magnetic field was assumed as uniform, the thermal-diffusion calculation ignored the shape of the rise time, and adopted an approximate calculation. On the theoretical level, it will be interesting to pursue additional simulations exploring these effects in detail. Experimentally, there is a clear need for more well-designed experiments to study, systematically, the effect of external fields on the cavity's operation.

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

2010-12-01T23:59:59.000Z

423

Parallel progressive multiple sequence alignment  

Science Journals Connector (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

424

Multiple Motivations Institutional Change Principle  

Broader source: Energy.gov [DOE]

The multiple motivations principle suggests that a portfolio approach—rather than a single strategy—may be required to achieve change. Research demonstrates that people and institutions adopt new...

425

Multiple hypothesis evaluation in auditing  

E-Print Network [OSTI]

In many audit tasks, auditors evaluate multiple hypotheses to diagnose the situation. Research suggests this is a complex task that individuals have difficulty performing. Further, there is little guidance in professional ...

Srivastava, Rajendra P.; Wright, Arnold; Mock, Theodore J.

2002-11-01T23:59:59.000Z

426

Multiple matching of parameterized patterns  

Science Journals Connector (OSTI)

We extend Baker's theory of parameterized pattern matching [Proc. 25th Annual STOC, 1993, pp. 71–80] to algorithms that match multiple patterns in a text. We first consider the case where the patterns are fixed a...

Ramana M. Idury; Alejandro A. Schäffer

1994-01-01T23:59:59.000Z

427

Design And Commissioning Status Of New Cylindrical HiPIMS Nb Coating System for SRF Cavities  

SciTech Connect (OSTI)

For the past 19 years Jefferson Lab has sustained a program studying niobium films deposited on small samples in order to develop an understanding of the correlation between deposition parameters, film micro-structure, and RF performance. A new cavity deposition system employing a cylindrical cathode using the HiPIMS technique has been developed to apply this work to cylindrical cavities. The status of this system will be presented.

Phillips, H. Lawrence; Macha, Kurt M.; Valente-Feliciano, Anne-Marie

2014-02-01T23:59:59.000Z

428

Segregation gettering by implantation-formed cavities and B-Si precipitates in silicon  

SciTech Connect (OSTI)

The authors show that Fe, Co, Cu, and Au in Si undergo strong segregation gettering to cavities and B-Si precipitates formed by He or B ion implantation and annealing. The respective mechanisms are argued to be chemisorption on the cavity walls and occupation of solution sites within the disordered, B-rich, B-Si phase. The strengths of the reactions are evaluated, enabling prediction of gettering performance.

Myers, S.M.; Petersen, G.A.; Follstaedt, D.M. [Sandia National Lab., Albuquerque, NM (United States)] [and others

1998-01-01T23:59:59.000Z

429

Integration of photoactive and electroactive components with vertical cavity surface emitting lasers  

DOE Patents [OSTI]

A monolithically integrated optoelectronic device is provided which integrates a vertical cavity surface emitting laser and either a photosensitive or an electrosensitive device either as input or output to the vertical cavity surface emitting laser either in parallel or series connection. Both vertical and side-by-side arrangements are disclosed, and optical and electronic feedback means are provided. Arrays of these devices can be configured to enable optical computing and neural network applications. 9 figs.

Bryan, R.P.; Esherick, P.; Jewell, J.L.; Lear, K.L.; Olbright, G.R.

1997-04-29T23:59:59.000Z

430

Integration of photoactive and electroactive components with vertical cavity surface emitting lasers  

DOE Patents [OSTI]

A monolithically integrated optoelectronic device is provided which integrates a vertical cavity surface emitting laser and either a photosensitive or an electrosensitive device either as input or output to the vertical cavity surface emitting laser either in parallel or series connection. Both vertical and side-by-side arrangements are disclosed, and optical and electronic feedback means are provided. Arrays of these devices can be configured to enable optical computing and neural network applications.

Bryan, Robert P. (12700 Indian School Rd. NE., Apt. 604, Albuquerque, NM 87112); Esherick, Peter (1105 Sagebrush Trail SE., Albuquerque, NM 87123); Jewell, Jack L. (12 Timberline Dr., Bridgewater, NJ 08807); Lear, Kevin L. (13713 Vic Rd. NE., Albuquerque, NM 87112); Olbright, Gregory R. (3875 Orange Ct., Boulder, CO 80304)

1997-01-01T23:59:59.000Z

431

Low noise cryogenic system for the measurement of Casimir energy in rigid cavities  

E-Print Network [OSTI]

We report on preliminary results on the measurement of variations of the Casimir energy in rigid cavities through its influence on the superconducting transition of in-cavity aluminium (Al) thin films. After a description of the experimental apparatus we report on a measurement made with thermal photons, discussing its implications for the zero-point photons case. Finally we show the preliminary results for the zero-point case.

Giuseppe Bimonte; Detlef Born; Enrico Calloni; Giampiero Esposito; Uwe Huebner; Evgeni Il'ichev; Luigi Rosa; Francesco Tafuri; Ruggero Vaglio

2007-10-22T23:59:59.000Z

432

On the analogy between vehicle and vehicle-like cavities with reverberation chambers  

E-Print Network [OSTI]

of this paper. For a characterisation of the time variation and Doppler spread of in-vehicle wireless communication channels, we refer the reader to our previous work [8]. The paper is organised as follows: Details of the experimen- tal methods undertaken... vehicles is minimal [12]–[14]. During the measurement process the vehicle-like cavity was located in the UK National Physical Laboratory Small Antenna Radiated Testing (SMART) range, enabling us to isolate the cavity from the effects of external objects...

Herbert, Steven; Loh, Tian-Hong; Wassell, Ian; Rigelsford, Jonathan

2014-01-01T23:59:59.000Z

433

The INEL beryllium multiplication experiment  

SciTech Connect (OSTI)

The experiment to measure the multiplication of 14-MeV neutrons in bulk beryllium has been completed. The experiment consists of determining the ratio of {sup 56}Mn activities induced in a large manganese bath by a central 14-MeV neutron source, with and without a beryllium sample surrounding the source. In the manganese bath method a neutron source is placed at the center of a totally-absorbing aqueous solution of MnSo{sub 4}. The capture of neutrons by Mn produces a {sup 56}Mn activity proportional to the emission rate of the source. As applied to the measurement of the multiplication of 14- MeV neutrons in bulk beryllium, the neutron source is a tritium target placed at the end of the drift tube of a small deuteron accelerator. Surrounding the source is a sample chamber. When the sample chamber is empty, the neutrons go directly to the surrounding MnSO{sub 4} solution, and produce a {sup 56}Mn activity proportional to the neutron emission rate. When the chamber contains a beryllium sample, the neutrons first enter the beryllium and multiply through the (n,2n) process. Neutrons escaping from the beryllium enter the bath and produce a {sup 56}Mn activity proportional to the neutron emission rate multiplied by the effective value of the multiplication in bulk beryllium. The ratio of the activities with and without the sample present is proportional to the multiplication value. Detailed calculations of the multiplication and all the systematic effects were made with the Monte Carlo program MCNP, utilizing both the Young and Stewart and the ENDF/B-VI evaluations for beryllium. Both data sets produce multiplication values that are in excellent agreement with the measurements for both raw and corrected values of the multiplication. We conclude that there is not real discrepancy between experimental and calculated values for the multiplication of neutrons in bulk beryllium. 12 figs., 11 tabs., 18 refs.

Smith, J.R.; King, J.J.

1991-03-01T23:59:59.000Z

434

Frequency-feedback tuning for single-cell cavity under rf heating  

SciTech Connect (OSTI)

A tuning system is described that is being used to match the source frequency of a high-power klystron on the resonant frequency of the prototype single-cell cavity for the 7-GeV Advance Photon Source (APS) storage ring. Typically a water-cooled piston tuner is required to adjust the reactive component of the cavity`s impedance to minimize reflected power back to the RF drive source. As the cavity watts expand due to RF heating, the resonant frequency decreases. Adjusting the source frequency to follow the cavity resonant frequency is a convenient method used to condition the cavity (for vacuum) at high power levels, in this case, 1 MV gap voltage at 100 kW power level. The tuning system consists of two coupling ports, a phase detector, a digitizing I/O system, and a DC coupled FM-modulated RF source. Proportional Integral Derivative (PID) loop parameters for the Experimental Physics and Industrial Control System (EPICS) software are calculated, and data is presented showing the damped response to peturbations on the loop. The timing system presented here does not need water-cooling, has no moving parts to wear out, and has an inherently faster response time. Its one limitation is the digitizing sampling rate. The only limitation in tuning range is the bandwidth of the RF source.

Stepp, J.D.; Bridges, J.F.

1993-08-01T23:59:59.000Z

435

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

SciTech Connect (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

436

INVESTIGATION OF BREAKDOWN INDUCED SURFACE DAMAGE ON 805 MHZ PILLBOX CAVITY INTERIOR SURFACES  

SciTech Connect (OSTI)

The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested two 805 MHz vacuum RF cavities in a multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanisms and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for quantitative estimation of spark damage spot distribution on cavity interior surfaces. The distribution is compared with the electric field distribution predicted by a computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with the dark current calculated from the Fowler-Nordheim equation.

Jana, M.R.; Chung, M.; Leonova, M.; Moretti, A.; Tollestrup,A.; Yonehara, K.; Freemire, B.; Torun, Y.; Bowring, D.; Flanagan, G.

2013-09-25T23:59:59.000Z

437

CO gas inside the protoplanetary disk cavity in HD 142527: disk structure from ALMA  

E-Print Network [OSTI]

Inner cavities and annular gaps in circumstellar disks are possible signposts of giant planet formation. The young star HD 142527 hosts a massive protoplanetary disk with a large cavity that extends up to 140 au from the central star, as seen in continuum images at infrared and millimeter wavelengths. Estimates of the survival of gas inside disk cavities are needed to discriminate between clearing scenarios. We present a spatially and spectrally resolved carbon monoxide isotopologue observations of the gas-rich disk HD 142527, in the J=2-1 line of 12CO, 13CO and C18O, obtained with the Atacama Large Millimeter Array (ALMA). We detect emission coming from inside the dust-depleted cavity in all three isotopologues. Based on our analysis of the gas in the dust cavity, the 12CO emission is optically thick, while 13CO and C18O emission are both optically thin. The total mass of residual gas inside the cavity is about 1.5-2 Jupiter masses. We model the gas with an axisymmetric disk model. Our best fit model shows t...

Perez, Sebastian; Ménard, F; Roman, P; van der Plas, G; Cieza, L; Pinte, C; Christiaens, V; Hales, A S

2014-01-01T23:59:59.000Z

438

Vacuum energy densities of a field in a cavity with a mobile boundary  

E-Print Network [OSTI]

We consider the zero-point field fluctuations, and the related field energy densities, inside a one-dimensional and a three-dimensional cavity with a mobile wall. The mechanical degrees of freedom of the mobile wall are described quantum mechanically and they are fully included in the overall system dynamics. In this optomechanical system, the field and the wall can interact with each other through the radiation pressure on the wall, given by the photons inside the cavity or even by vacuum fluctuations. We consider two cases: the one-dimensional electromagnetic field and the three-dimensional scalar field, and use the Green's functions formalism, which allows extension of the results obtained for the scalar field to the electromagnetic field. We show that the quantum fluctuations of the position of the cavity's mobile wall significantly affect the field energy density inside the cavity, in particular at the very proximity of the mobile wall. The dependence of this effect from the ultraviolet cutoff frequency, related to the plasma frequency of the cavity walls, is discussed. We also compare our new results for the one-dimensional electromagnetic field and the three-dimensional massless scalar field to results recently obtained for the one-dimensional massless scalar field. We show that the presence of a mobile wall also changes the Casimir-Polder force on a polarizable body placed inside the cavity, giving the possibility to detect experimentally the new effects we have considered.

Federico Armata; Roberto Passante

2015-01-15T23:59:59.000Z

439

A Study of the Filling of Wall Cavities With Retrofit Wall Insulation.  

SciTech Connect (OSTI)

The Pacific Northwest Power Marketing Agency, the Bonneville Power Administration (BPA), conducted a retrofit wall insulation study to determine the effects of various obstructions within a wall cavity, where voids are likely to occur, and preferred filling methods and material types. The insulation test structure was composed of four 8-foot /times/ 12-foot walls, and was built using standard construction practices. The inside walls were clear plastic glazing, instead of gypsum board, to enable viewing of the filling process. A total of eight tests were performed: four cellulose, two rockwool, and two fiberglass. One- and two-hole filling methods were observed. All insulations were found to perform in the same basic manner with all experiencing the same problem areas. Common installer problems were empty spaces at the tops of cavities and missed cavities, especially above headers. Wiring and lath and plaster consistently caused reduced insulation densities in cavities. The problems with wiring, lath and plaster, and other features in the wall cavities were avoided with the use of a filler tube. The filler tube also provided a more consistent fill along the length of the entire cavity. 2 figs., 3 tabs.

Flores, Joseph A.; Grill, Alan R.

1988-08-01T23:59:59.000Z

440

Fast-light enhancement of an optical cavity by polarization mode coupling  

Science Journals Connector (OSTI)

We present an entirely linear all-optical method of cavity scale factor enhancement that relies on mode coupling between the orthogonal polarization modes of a single optical cavity, eliminating the necessity of using an atomic medium to produce the required anomalous dispersion, which decreases the dependence of the scale factor on temperature and increases signal-to-noise ratio by reducing absorption and nonlinear effects. The use of a single cavity results in common mode rejection of the noise and drift that would be present in a system of two coupled cavities. We show that the scale-factor-to-mode-width ratio is increased above unity for this system, and demonstrate tuning of the scale factor by (i) directly varying the polarization mode coupling via rotation of an intracavity half-wave plate, and (ii) coherent control of the cavity reflectance which is achieved simply by varying the incident polarization superposition. These tuning methods allow us to closely approach the critical anomalous dispersion condition and achieve unprecedented enhancements in scale factor and in the scale-factor-to-mode-width ratio. Based on these findings, we propose an adaptation of the traditional optical cavity gyroscope that takes advantage of polarization mode coupling to enhance the gyro scale factor, and demonstrate how the bandwidth of the scale factor enhancement for this gyroscope can be effectively broadened in comparison with fast-light gyroscopes based on atomic media.

David D. Smith; H. Chang; Krishna Myneni; A. T. Rosenberger

2014-05-05T23:59:59.000Z

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.


441

Vacuum Energy Densities of a Field in a Cavity with a Mobile Boundary  

E-Print Network [OSTI]

We consider the zero-point field fluctuations, and the related field energy densities, inside a one-dimensional and a three-dimensional cavity with a mobile wall. The mechanical degrees of freedom of the mobile wall are described quantum-mechanically and they are fully included in the overall system dynamics. In this optomechanical system, the field and the wall can interact with each other through the radiation pressure on the wall, given by the photons inside the cavity or even by vacuum fluctuations. We consider two cases: the 1D electromagnetic field and the 3D scalar field, and use the Green's functions formalism, that allows extension of the results obtained for the scalar field to the electromagnetic field. We show that the quantum fluctuations of the position of the cavity's mobile wall significantly affect the field energy density inside the cavity, in particular at the very proximity of the mobile wall. The dependence of this effect from the ultraviolet cut-off frequency, related to the plasma frequency of the cavity walls, is discussed. We also compare our new results for the 1D electromagnetic field and the 3D massless scalar field to results recently obtained for the 1D massless scalar field. We show that the presence of a mobile wall also changes the Casimir-Polder force on a polarizable body placed inside the cavity, giving possibility to detect experimentally the new effects we have considered.

Federico Armata; Roberto Passante

2014-11-19T23:59:59.000Z

442

Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities  

SciTech Connect (OSTI)

Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6?1.6 MV/m, 21?34 MV/m, 32?35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6?13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP?s predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.

Li, Y. M. [Peking University, Beijing (China); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Liu, Kexin [Peking University, Beijing (China); Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-02-01T23:59:59.000Z

443

Design parameters and commissioning of vertical inserts used for testing the XFEL superconducting cavities  

SciTech Connect (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.

Schaffran, J.; Bozhko, Y.; Petersen, B.; Meissner, D. [Deutsches Elektronen Synchrotron DESY, Notkestr. 85, D-22607 Hamburg (Germany); Chorowski, M.; Polinski, J. [Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

2014-01-29T23:59:59.000Z

444

Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator  

SciTech Connect (OSTI)

Microwave plasma ion source with rectangular cavity resonator has been examined to improve ion beam current by changing wave launcher type from single-port to double-port. The cavity resonators with double-port and single-port wave launchers are designed to get resonance effect at TE-103 mode and TE-102 mode, respectively. In order to confirm that the cavities are acting as resonator, the microwave power for breakdown is measured and compared with the E-field strength estimated from the HFSS (High Frequency Structure Simulator) simulation. Langmuir probe measurements show that double-port cavity enhances central density of plasma ion source by modifying non-uniform plasma density profile of the single-port cavity. Correspondingly, beam current from the plasma ion source utilizing the double-port resonator is measured to be higher than that utilizing single-port resonator. Moreover, the enhancement in plasma density and ion beam current utilizing the double-port resonator is more pronounced as higher microwave power applied to the plasma ion source. Therefore, the rectangular cavity resonator utilizing the double-port is expected to enhance the performance of plasma ion source in terms of ion beam extraction.

Lee, Yuna; Park, Yeong-Shin; Jo, Jong-Gab; Yang, J. J.; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2012-02-15T23:59:59.000Z

445

1500 MHZ Passive SRF Cavity for Bunch Lengthening in the NSLS-II Storage Ring  

SciTech Connect (OSTI)

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. After an extensive investigation of different cavity geometries, a passive, superconducting two-cell cavity has been selected for prototyping. The cavity is HOM damped with ferrite absorbers on the beam pipes. The two-cell cavity simplifies the tuner design, compared to having two independent cells. Tradeoffs between the damping of the higher order modes, thermal isolation associated with the large beam tubes, and overall cavity length are described. A copper prototype has been constructed, and measurements of fundamental and higher order modes will be compared to calculated values.

Yanagisawa,T.; Rose, J.; Grimm, T.; Bogle, A.

2009-05-04T23:59:59.000Z

446

Invisibility in PT-symmetric complex crystals  

E-Print Network [OSTI]

Bragg scattering in sinusoidal PT-symmetric complex crystals of finite thickness is theoretically investigated by the derivation of exact analytical expressions for reflection and transmission coefficients in terms of modified Bessel functions of first kind. The analytical results indicate that unidirectional invisibility, recently predicted for such crystals by coupled-mode theory [Z. Lin et al., Phys. Rev. Lett. 106, 213901 (2011)], breaks down for crystals containing a large number of unit cells. In particular, for a given modulation depth in a shallow sinusoidal potential, three regimes are encountered as the crystal thickness is increased. At short lengths the crystal is reflectionless and invisible when probed from one side (unidirectional invisibility), whereas at intermediate lengths the crystal remains reflectionless but not invisible; for longer crystals both unidirectional reflectionless and invisibility properties are broken.

Stefano Longhi

2011-11-15T23:59:59.000Z

447

Fair capacity sharing of multiple aperiodic servers  

E-Print Network [OSTI]

For handling multiple aperiodic tasks with different temporal requirements, multiple aperiodic servers are used. Since capacity is partitioned statically among the multiple servers, they suffer from heavy capacity exhaustions. Bernat and Burns...

Melapudi, Vinod Reddy

2002-01-01T23:59:59.000Z

448

Photonic crystals with controlled disorder  

SciTech Connect (OSTI)

Photonic crystals are extremely sensitive to structural disorder even to the point of completely losing their functionalities. While, on one side, this can be detrimental for applications in traditional optical devices, on the other side, it gives also rise to very interesting new physics and maybe even new applications. We propose a route to introduce disorder in photonic crystals in a controlled way by creating a certain percentage of vacancies in the lattice. We show how the method works and what type of materials can be obtained this way. Also, we use this system to probe the role of disorder on the resulting transport properties from various points of view, including measurements of the transport and scattering mean free path and the diffusion constant.

Garcia, P. D.; Sapienza, R.; Lopez, C. [Instituto de Ciencia de Materiales de Madrid (CSIC) and Unidad Asociada CSIC-UVigo, Cantoblanco E-28049, Madrid (Spain); Toninelli, C.; Wiersma, D. S. [European Laboratory for Nonlinear Spectroscopy and CNR-INO, 50019 Sesto Fiorentino, Florence (Italy)

2011-08-15T23:59:59.000Z

449

Experimental Studies of NGNP Reactor Cavity Cooling System With Water  

SciTech Connect (OSTI)

This project will investigate the flow behavior that can occur in the reactor cavity cooling system (RCCS) with water coolant under the passive cooling-mode of operation. The team will conduct separate-effects tests and develop associated scaling analyses, and provide system-level phenomenological and computational models that describe key flow phenomena during RCCS operation, from forced to natural circulation, single-phase flow and two-phase flow and flashing. The project consists of the following tasks: Task 1. Conduct separate-effects, single-phase flow experiments and develop scaling analyses for comparison to system-level computational modeling for the RCCS standpipe design. A transition from forced to natural convection cooling occurs in the standpipe under accident conditions. These tests will measure global flow behavior and local flow velocities, as well as develop instrumentation for use in larger scale tests, thereby providing proper flow distribution among standpipes for decay heat removal. Task 2. Conduct separate-effects experiments for the RCCS standpipe design as two-phase flashing occurs and flow develops. As natural circulation cooling continues without an ultimate heat sink, water within the system will heat to temperatures approaching saturation , at which point two-phase flashing and flow will begin. The focus is to develop a phenomenological model from these tests that will describe the flashing and flow stability phenomena. In addition, one could determine the efficiency of phase separation in the RCCS storage tank as the two-phase flashing phenomena ensues and the storage tank vents the steam produced. Task 3. Develop a system-level computational model that will describe the overall RCCS behavior as it transitions from forced flow to natural circulation and eventual two-phase flow in the passive cooling-mode of operation. This modeling can then be used to test the phenomenological models developed as a function of scale.

Michael Corradini; Mark Anderson; Yassin Hassan; Akira Tokuhiro

2013-01-16T23:59:59.000Z

450

Abstract crystals Department of Mathematics  

E-Print Network [OSTI]

is a normal crystal define a bijection si : B B by sib = ~f wti(b) i b, if wti(b) 0, ~e -wti(b) i b, if wti, b2 B2} with wti(b1 b2) = wti(b1) + wti(b2), i(b1 b2) = max{i(b1), i(b2) - wt(b1), i }, i(b1 b2

Ram, Arun

451

Federal Energy Management Program: Multiple Motivations Institutional  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

452

Modularization to Support Multiple Brand Platforms  

E-Print Network [OSTI]

Methods to determine acceptable architecture for multiple platforms supporting multiple brands must represent both platform cost saving commonization as well as revenue enhancing brand distinctions. Functional architecting ...

Agus, Sudjianto

2001-09-09T23:59:59.000Z

453

Quench propagation in the HOM damper of the 56 MHz cavity  

SciTech Connect (OSTI)

The aim of this report is to summarize a study of the propagation of a quench in a HOM damper probe of the 56 MHz superconducting storage cavity for RHIC and provide guidance for machine protection. The 56 MHz cavity [1] is designed to operate as a beam-driven superconducting quarter-wave resonator in the RHIC ring. Four Higher Order Mode (HOM) dampers [2] are used to prevent beam instabilities [3] in RHIC. These are inserted in the back wall of the cavity (the high magnetic field region) through ports that also serve for rinsing the cavity with high-pressure deionized water as well as the fundamental power coupler and pick-up ports. Figure 1 shows the outline of the cavity [4,5]. The HOM damper probe has a magnetic coupling loop which penetrates the cavity as shown in Figure 2 [5]. The loop is cooled by conduction to the 4.3K helium system, thus any sudden, significant amount of heat dumped on the loop will cause local heating. The peak magnetic field on the loop can reach about 7.4 x 10{sup 4} amperes per meter at a cavity voltage of 2.5 MV [5]. The scenario we present here is that a small region on the loop quenches. We can calculate the current driving the cavity using the RHIC parameters and get the magnetic field as a function of the current, the cavity's intrinsic Q and detuning parameter, however it turns out that within the time relevant for the quench development (a fraction of a second) the cavity field does not change sufficiently to warrant this extra computation. Thus we can assume that the field over the loop is constant. The damper loop dimensions are not so important, however its cross section is. In the following we assume that the loop's cross-section is 2 cm by 0.3 cm. It is actually rounded in cross section (sharp corners avoided) but we will approximate it as square. The material parameters taken for the niobium loop (assuming high RRR of about 200) are given in the following stepwise linear approximations. The surface resistivity in ohms as a function of temperature in degrees Kelvin is given in Figure 3, the thermal conductivity in watt per degree meter as a function of temperature is given in Figure 4 and the heat capacity in Joule per kg as a function of temperature is given in Figure 5.

Ben-Zvi,I.

2009-08-01T23:59:59.000Z

454

Multiple smart weapons employment mechanism  

SciTech Connect (OSTI)

A digital communications armament network adaptor is described for carrying multiple smart weapons on a single wing pylon station of an aircraft, comprising: an aircraft having a weapons controller configured in compliance with MIL-STD 1553; multiple wing-mounted pylons on said aircraft, each providing a weapons station with communications and ejection and release mechanisms electrically connected to said controller for the airborne launch of smart weapons; a multiple ejector rack affixed to at least one pylon, said rack holding a plurality of smart weapons; and an electronic digital network connected between the controller and said rack-mounted smart weapons, said network located in said rack and including circuitry which receives coded digital communications from said controller and selectively rebroadcasts said communications to one of said smart weapons on said rack designated by said coded communications, thereby controlling all required functions of said designated smart weapon.

McGlynn, M.P.; Meiklejohn, W.D.

1993-07-20T23:59:59.000Z

455

Information transfer at multiple scales  

Science Journals Connector (OSTI)

In the study of complex systems a fundamental issue is the mapping of the networks of interaction between constituent subsystems of a complex system or between multiple complex systems. Such networks define the web of dependencies and patterns of continuous and dynamic coupling between the system’s elements characterized by directed flow of information spanning multiple spatial and temporal scales. Here, we propose a wavelet-based extension of transfer entropy to measure directional transfer of information between coupled systems at multiple time scales and demonstrate its effectiveness by studying (a) three artificial maps, (b) physiological recordings, and (c) the time series recorded from a chaos-controlled simulated robot. Limitations and potential extensions of the proposed method are discussed.

Max Lungarella; Alex Pitti; Yasuo Kuniyoshi

2007-11-27T23:59:59.000Z

456

Interactive Multiple Scale Small Multiples Andrew S. Forsberg  

E-Print Network [OSTI]

-dependent, include thousands of time steps, and have multiple fields. While mathematical modeling helps users? Motivated by the complex data generated from bat flight simulations in a wind tunnel [8], we designed datasets (e.g., kinematics, anatomical structures, and the wake structure behind bat wings). The views

Laidlaw, David

457

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

458

Single-crystal sapphire tubes as economical probes for optical pyrometry in harsh environments  

SciTech Connect (OSTI)

One-end-sealed single-crystal sapphire tubes are presented as a simple, robust, and economical alternative for bulky lightpipe probes. Thermal radiation from a blackbody cavity created at the inner surface of the sealed end is gathered by a simple lens-based collecting system and transmitted via optical fiber to the remote detection unit. Simplicity and applicability of the concept are demonstrated by the combination of commercially available sapphire tubes with a common optical pyrometer. Radiation thermometers with sapphire tubes as invasive probes can be useful for applications requiring immunity to electromagnetic interference, resistance to harsh environments, simple replacement in the case of failure, and enhanced mechanical firmness, enabling wider range probe positioning inside the medium of interest.

Ruzicka, Jakub; Houzvicka, Jindrich; Bok, Jiri; Praus, Petr; Mojzes, Peter

2011-12-20T23:59:59.000Z

459

Flowing Liquid Crystal Simulating the Schwarzschild Metric  

E-Print Network [OSTI]

We show how to simulate the equatorial section of the Schwarzschild metric through a flowing liquid crystal in its nematic phase. Inside a liquid crystal in the nematic phase, a traveling light ray feels an effective metric, whose properties are linked to perpendicular and parallel refractive indexes, $n_o$ e $n_e$ respectively, of the rod-like molecule of the liquid crystal. As these indexes depend on the scalar order parameter of the liquid crystal, the Beris-Edwards hydrodynamic theory is used to connect the order parameter with the velocity of a liquid crystal flow at each point. This way we calculate a radial velocity profile that simulates the equatorial section of the Schwarzschild metric, in the region outside of Schwarzschild's radius, in the nematic phase of the liquid crystal. In our model, the higher flow velocity can be of the order of some meters per second.

Erms R. Pereira; Fernando Moraes

2010-11-21T23:59:59.000Z

460

Phonon manipulation with phononic crystals.  

SciTech Connect (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

Note: This page contains sample records for the topic "multiple crystal cavities" from the National Library of EnergyBeta (NLEBeta).
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461

Status of the mechanical design of the 650 MHz cavities for Project X  

SciTech Connect (OSTI)

In the high-energy section of the Project X Linac, acceleration of H{sup -} ions takes place in superconducting cavities operating at 650 MHz. Two families of five-cell elliptical cavities are planned: beta = 0.61 and beta = 0.9. A specific feature of the Project X Linac is low beam loading, and thus, low bandwidth and higher sensitivity to microphonics. Efforts to optimize the mechanical design of the cavities to improve their mechanical stability in response to the helium bath pressure fluctuations will be presented. These efforts take into account constraints such as cost and ease of fabrication. Also discussed will be the overall design status of the cavities and their helium jackets. The proposed design of the 3 GeV Project X superconducting (SC) Linac employs 650 MHz five-cell elliptical cavities to accelerate 1.0 mA of average H-beam current in the 160-3000 MeV energy range. The 650 MHz region of the Linac is divided into two sections with two different geometric phase velocity factors: beta = 0.61 to cover the 160-520 MeV range and beta = 0.9 to cover the 520-3000 MeV range. Approximately 40 beta = 0.61 and 150 beta = 0.9 cavities are currently planned for the project. An R&D program is in progress at FNAL, in collaboration with TJNAF and India, to develop the 650 MHz cavities for the proposed Linac design. This R&D program includes the design and fabrication of several beta = 0.61 and beta = 0.9 single-cell prototypes for evaluation prior to production of the five-cell cavities. FNAL has contracted AES to fabricate the beta = 0.9 prototypes, while TJNAF is building beta = 0.61 prototypes of their own design. In the remainder of this paper we will restrict our discussion to the five-cell beta = 0.9 cavities.

Barbanotti, S.; Grimm, C.; Champion, M.; Foley, M.; Ginsburg, C.M.; Gonin, I.; Peterson, T.; Ristori, L.; Yakovlev, V.; /Fermilab

2011-03-01T23:59:59.000Z

462

Crystallization of niobium germanosilicate glasses  

SciTech Connect (OSTI)

Niobium germanosilicate glasses are potential candidates for the fabrication of transparent glass ceramics with interesting non-linear optical properties. A series of glasses in the (Ge,Si)O{sub 2}-Nb{sub 2}O{sub 5}-K{sub 2}O system were prepared by melting and casting and their characteristic temperatures were determined by differential thermal analysis. Progressive replacement of GeO{sub 2} by SiO{sub 2} improved the thermal stability of the glasses. Depending on the composition and the crystallization heat-treatment, different nanocrystalline phases-KNbSi{sub 2}O{sub 7}, K{sub 3}Nb{sub 3}Si{sub 2}O{sub 13} and K{sub 3.8}Nb{sub 5}Ge{sub 3}O{sub 20.4} could be obtained. The identification and characterization of these phases were performed by X-ray diffraction and Raman spectroscopy. The 40 GeO{sub 2}-10 SiO{sub 2}-25 Nb{sub 2}O{sub 5}-25 K{sub 2}O (mol%) composition presented the higher ability for volume crystallization and its nucleation temperature was determined by the Marotta's method. An activation energy for crystal growth of {approx}529 kJ/mol and a nucleation rate of 9.7x10{sup 18} m{sup -3} s{sup -1} was obtained, for this composition. Transparent glass ceramics with a crystalline volume fraction of {approx}57% were obtained after a 2 h heat-treatment at the nucleation temperature, with crystallite sizes of {approx}20 nm as determined by transmission electron microscopy. - Abstract: TEM image and XRD pattern of the glass ceramic produced (circles indicate nanocrystals).

Santos, Rodrigo [Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Tecnico/TU Lisbon, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Santos, Luis F., E-mail: luis.santos@ist.utl.p [Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Tecnico/TU Lisbon, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Almeida, Rui M. [Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Tecnico/TU Lisbon, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Deubener, Joachim [Institute of Non-Metallic Materials, Clausthal University of Technology, Clausthal-Zellerfeld (Germany); Wondraczek, Lothar [Department of Materials Science, Glass and Ceramics, University of Erlangen-Nuremberg, 91058 Erlangen (Germany)

2010-01-15T23:59:59.000Z

463

Resonant-frequency discharge in a multi-cell radio frequency cavity  

SciTech Connect (OSTI)

We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency (SRF) cryomodule (in situ operation). This discharge offers an efficient mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the problems related to generation and sustaining the multi-cell cavity plasma, which are breakdown and resonant detuning. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

Popovic, S; Upadhyay, J.; Mammosser, J.; Nikolic, M; Vuskovic, L

2014-11-07T23:59:59.000Z

464

Third harmonic cavity design and RF measurements for the Frascati DA?NE collider  

Science Journals Connector (OSTI)

Third harmonic passive RF cavities have been proposed for installation in both rings of the DA?NE factory collider to improve the Touschek lifetime and to increase the Landau damping. This paper illustrates the design of the harmonic cavities. The main requirements were to obtain a relatively low R/Q factor and a quality factor Q as high as possible to satisfy beam dynamics requirements and to damp all the higher order mode (HOM) to a harmless level in order to avoid multibunch instabilities. A spherical shape of the cavity central body has been chosen as an optimum compromise between a high Q resonator and a low R/Q factor. HOM suppression has been provided by a ferrite ring damper designed for the superconducting cavities of the high energy ring of the KEK-B factory. The design and electromagnetic properties of the resonant modes have been studied with MAFIA and HFSS codes. Cavities have been made of aluminum and the RF measurements have been performed to characterize them. The measurements are in a good agreement with numerical simulations results, demonstrating a satisfactory HOM damping.

David Alesini; Roberto Boni; Alessandro Gallo; Fabio Marcellini; Mikhail Zobov; Mauro Migliorati; Luigi Palumbo

2004-09-07T23:59:59.000Z

465

Pressurized H_{2} rf Cavities in Ionizing Beams and Magnetic Fields  

SciTech Connect (OSTI)

A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10?18 to 10?16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

Chung, M.; et al.

2013-10-01T23:59:59.000Z

466

Anomalous electron loading in SLAC 5045 klystron and relativistic klystron input cavities  

SciTech Connect (OSTI)

Recent studies of RF breakup and instability in the SLAC 5045 klystrons have revealed that many production klystrons show loading of the input cavity by low energy electrons even under cold cathode no beam conditions. Sometime after the onset of the RF drive pulse, the input cavity absorbs a portion of the incident RF drive that would otherwise be reflected from the not-beam-loaded cavity. This power absorption is a function of drive level, and of axial magnetic field surrounding the cavity. No power absorption is present when the axial magnetic field is zero. This same phenomenon has been observed in the input cavity of relativistic klystron experiments being conducted as part of the SLAC-LBL-LLNL development program. The phenomenon may be associated with RF breakup and RF instability in SLAC 5045 klystrons, and with unstable pulse shortening in the relativistic klystron experiments. This paper outlines some old and new observations of microwave beam device malfunctions that probably are associated with low energy electron fluxes in the vacuum environments of microwave power devices. 2 refs., 5 figs.

Koontz, R.F.; Fowkes, R.W.; Lavine, T.L.; Miller, R.H.; Vlieks, A.E.

1989-03-01T23:59:59.000Z

467

Binding of copper and nickel to cavities in silicon formed by helium ion implantation  

SciTech Connect (OSTI)

Cavities formed in Si by He ion implantation and annealing are shown to be strong traps for Cu and Ni impurities. Experiments utilizing ion-beam analysis and transmission electron microscopy indicate that Cu is trapped at the internal surfaces of cavities up to {approximately}1 monolayer coverage with a binding energy of 2.2{plus_minus}0.2 eV relative to solution. This is greater than the heat of solution from the precipitated Cu{sub 3}Si phase, determined to be 1.7 eV in agreement with earlier work. Copper at cavity-wall sites is reversibly replaced by H during heating in H{sub 2} gas, indicating the relative stability of the two surface terminations. Initial results for Ni impurities indicate that trapping at cavities is again energetically preferred to silicide formation. The saturation coverage of Ni on the internal surfaces, however, is an order of magnitude smaller for Ni than Cu, consistent with published studies of external-surface adsorption. These results suggest that cavity trapping may getter metallic impurities in Si more effectively than methods based on silicide precipitation.

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

1993-12-01T23:59:59.000Z

468

Field Emission in CEBAF's SRF Cavities and Implications for Future Accelerators  

SciTech Connect (OSTI)

Field emission is one of the key issues in superconducting RF for particle accelerators. When present, it limits operating gradient directly or via induced heat load at 2K. In order to minimize particulate contamination of and thus field emission in the CEBAF SRF cavities during assembly, a cold ceramic RF window was placed very close to the accelerating cavity proper. As an unintended consequence of this, the window is charged by field-emitted electrons, making it possible to monitor and model field emission in the CEBAF cavities since in-tunnel operation began. From January 30, 1995, through February 10, 2003, there were 64 instances of spontaneous onset or change in cavity field emission with a drop in usable gradient averaging 1.4 ({sigma} 0.8) MV/m at each event. Fractional loss averaged 0.18 ({sigma} 0.12) of pre-event gradient. This event count corresponds to 2.4 events per century per cavity, or 8 per year in CEBAF. It is hypothesized that changes in field emission are due to adsorbed gas accumulation. The possible implications of this and other observations for the International Linear Collider (ILC) and other future accelerators will be discussed.

Jay Benesch

2006-02-15T23:59:59.000Z

469

Study of high pressure gas filled RF cavities for muon collider  

E-Print Network [OSTI]

Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

Yonehara, Katsuya

2015-01-01T23:59:59.000Z

470

Bose-glass phases of ultracold atoms due to cavity backaction  

E-Print Network [OSTI]

We determine the quantum ground-state properties of ultracold bosonic atoms interacting with the mode of a high-finesse resonator. The atoms are confined by an external optical lattice, whose period is incommensurate with the cavity mode wave length, and are driven by a transverse laser, which is resonant with the cavity mode. While for pointlike atoms photon scattering into the cavity is suppressed, for sufficiently strong lasers quantum fluctuations can support the build-up of an intracavity field, which in turn amplifies quantum fluctuations. The dynamics is described by a Bose-Hubbard model where the coefficients due to the cavity field depend on the atomic density at all lattice sites. Quantum Monte Carlo simulations and mean-field calculations show that for large parameter regions cavity backaction forces the atoms into clusters with a checkerboard density distribution. Here, the ground state lacks superfluidity and possesses finite compressibility, typical of a Bose-glass. This system constitutes a novel setting where quantum fluctuations give rise to effects usually associated with disorder.

Hessam Habibian; André Winter; Simone Paganelli; Heiko Rieger; Giovanna Morigi

2012-06-22T23:59:59.000Z

471

Observation of Motion Dependent Nonlinear Dispersion with Narrow Linewidth Atoms in an Optical Cavity  

E-Print Network [OSTI]

As an alternative to state-of-the-art laser frequency stabilisation using ultra-stable cavities, it has been proposed to exploit the non-linear effects from coupling of atoms with a narrow atomic transition to an optical cavity. Here we have constructed such a system and observed non-linear phase shifts of a narrow optical line by strong coupling of a sample of strontium-88 atoms to an optical cavity. The sample temperature of a few mK provides a domain where the Doppler energy scale is several orders of magnitude larger than the narrow linewidth of the optical transition. This makes the system sensitive to velocity dependent multi-photon scattering events (Dopplerons) that affect the cavity transmission significantly while leaving the phase signature relatively unaffected. By varying the number of atoms and the intra-cavity power we systematically study this non-linear phase signature which displays roughly the same features as for much lower temperature samples. This demonstration in a relatively simple sys...

Westergaard, Philip G; Tieri, David; Matin, Rastin; Cooper, John; Holland, Murray; Ye, Jun; Thomsen, Jan W

2014-01-01T23:59:59.000Z

472

Integrated system modeling analysis of a cryogenic multi-cell deflecting-mode cavity resonator  

SciTech Connect (OSTI)

A deflecting mode cavity is the integral element for six-dimensional phase-space beam control in bunch compressors and emittance transformers at high energy beam test facilities. RF performance of a high-Q device is, however, highly sensitive to operational conditions, in particular in a cryo-cooling environment. Using analytic calculations and RF simulations, we examined cavity parameters and deflecting characteristics of TM{sub 110,?} mode of a 5 cell resonator in a liquid nitrogen cryostat, which has long been used at the Fermilab A0 Photoinjector (A0PI). The sensitivity analysis indicated that the cavity could lose 30%–40% of deflecting force due to defective input power coupling accompanying non-uniform field distribution across the cells with 40 ? 50 MeV electron beam and 70–80 kW klystron power. Vacuum-cryomodules of the 5 cell cavity are planned to be installed at the Fermilab Advanced Superconducting Test Accelerator facility. Comprehensive modeling analysis integrated with multi-physics simulation tools showed that RF loading of 1 ms can cause a ?5 K maximum temperature increase, corresponding to a ?4.3 ?m/ms deformation and a 1.32 MHz/K maximum frequency shift. The integrated system modeling analysis will improve design process of a high-Q cavity with more accurate prediction of cryogenic RF performance under a high power pulse operation.

Shin, Young-Min [Department of Physics, Northern Illinois University, Dekalb, Illinois 60115 (United States) [Department of Physics, Northern Illinois University, Dekalb, Illinois 60115 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Church, Michael [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

2013-09-15T23:59:59.000Z

473

Reconstruction of an entangled state in a cavity via Autler-Townes spectroscopy RID A-4660-2010  

E-Print Network [OSTI]

#. Most of these schemes are for the quantum state recon- struction of a single-mode field in high-Q cavities. There are atom initially prepared in level ua&, which interacts with two modes of the cavity field. The atomic transition uc1&2ua...& is resonant with cavity mode A while transition uc 2&2ua& is resonant with cavity mode B. The interaction time t of the atom with the field is kept large as compared to the inverse of decay rate g of the atom so that during the passage of the atom through...

Ikram, M.; Zubairy, M. Suhail.

2002-01-01T23:59:59.000Z

474

Low threshold vertical cavity surface emitting lasers integrated onto Si-CMOS ICs using novel hybrid assembly techniques  

E-Print Network [OSTI]

A new heterogeneous integration technique has been developed and demonstrated to integrate vertical cavity surface emitting lasers (VCSELs) on silicon CMOS integrated circuits for optical interconnect applications. Individual ...

Perkins, James Michael, 1978-

2007-01-01T23:59:59.000Z

475

Journal of Crystal Growth 250 (2003) 499515 Induction time in crystallization of gas hydrates  

E-Print Network [OSTI]

for revealing how additives in the solution that act as kinetic inhibitors of hydrate crystallization can affect to prevent hydrate crystallization. These options include heating, insulation, water removal, and the use

Firoozabadi, Abbas