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1

FINDING OF NO SIGNIFICANT IMPACT FOR LINAC COHERENT LIGHT SOURCE-Il  

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

FINDING FINDING OF NO SIGNIFICANT IMPACT FOR LINAC COHERENT LIGHT SOURCE-Il PROJECT SLAC NATIONAL ACCELERATOR LABORATORY AGENCY: U. S. Department of Energy (DOE) ACTION: Finding of No Significant Impact (FONSI) SUMMARY: The U. S. Department of Energy (DOE) has completed an Environmental Assessment (DOE/EA-1904) on a project to expand the existing Linac Coherent Light Source (LCLS) facility at the SLAC National Accelerator Laboratory (SLAC). One of SLAC's major scientific facilities is the LCLS, the world's first hard X-ray free electron laser. The LCLS X-ray laser beams enable the simultaneous investigation of a material's electronic and structural properties on the size (sub-nanometer) and time (femto-second) scales that determine their function. Research programs at SLAC include materials science, catalytic sciences, structural molecular biology, and molecular environmental

2

Linac Coherent Light Source Overview  

ScienceCinema (OSTI)

Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

None

2013-05-29T23:59:59.000Z

3

Measurements and modeling of coherent synchrotron radiation and its impact on the Linac Coherent Light Source electron beam  

Science Journals Connector (OSTI)

In order to reach the high peak current required for an x-ray free electron laser, two separate magnetic dipole chicanes are used in the Linac Coherent Light Source accelerator to compress the electron bunch length in stages. In these bunch compressors, coherent synchrotron radiation (CSR) can be emitted either by a short electron bunch or by any longitudinal density modulation that may be on the bunch. In this paper, we report detailed measurements of the CSR-induced energy loss and transverse emittance growth in these compressors. Good agreement is found between the experimental results and multiparticle tracking studies. We also describe direct observations of CSR at optical wavelengths and compare with analytical models based on beam microbunching.

K. L. F. Bane; F.-J. Decker; Y. Ding; D. Dowell; P. Emma; J. Frisch; Z. Huang; R. Iverson; C. Limborg-Deprey; H. Loos; H.-D. Nuhn; D. Ratner; G. Stupakov; J. Turner; J. Welch; J. Wu

2009-03-17T23:59:59.000Z

4

Linac Coherent Light SourCe  

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

Linac Linac Coherent Light SourCe after the Stanford Linear Accelerator Center (now the SLAC National Accelerator Laboratory) developed its two- mile-long linear accelerator (linac), it received approval from the Department of Energy to construct the Linac Coherent Light Source (LCLS), the first free electron laser (FEL) facility that would be able to produce x-rays short and bright enough that individual molecules could be imaged in their natural states. 40 years Genesis of the idea In 1992, Dr. Claudio Pellegrini, a professor at UCLA, first developed a proposal for a facility that would eventually become LCLS. The idea generated interest within the scientific community, and a design study report conducted by SLAC in the late 1990s led to the first

5

Science and Instrumentation for the Linac Coherent Light Source...  

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

of the proposed Linac Coherent Light Source (LCLS): subpicosecond time-structure, coherence and unprecedented high averagepeak brightness in the angstrom spectral region. The...

6

EA-1904: Linac Coherent Light Source II at Stanford Linear Accelerator  

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

04: Linac Coherent Light Source II at Stanford Linear 04: Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, California EA-1904: Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, California Summary This EA evaluates the environmental impacts of the proposed construction of the Linac Coherent Light Source at SLAC National Accelerator Laboratory, Menlo Park, California. Public Comment Opportunities None available at this time. For more information, contact: Mr. Dave Osugi DOE SLAC Site Office 2575 Sand Hill Road, MS8A Menlo Park, CA 94025 Electronic mail: dave.osugi@sso.science.doe.gov Documents Available for Download March 7, 2012 EA-1904: Finding of No Significant Impact Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, CA

7

EA-1904: Linac Coherent Light Source II at Stanford Linear Accelerator  

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

4: Linac Coherent Light Source II at Stanford Linear 4: Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, California EA-1904: Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, California Summary This EA evaluates the environmental impacts of the proposed construction of the Linac Coherent Light Source at SLAC National Accelerator Laboratory, Menlo Park, California. Public Comment Opportunities None available at this time. For more information, contact: Mr. Dave Osugi DOE SLAC Site Office 2575 Sand Hill Road, MS8A Menlo Park, CA 94025 Electronic mail: dave.osugi@sso.science.doe.gov Documents Available for Download March 7, 2012 EA-1904: Finding of No Significant Impact Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, CA

8

The Linac Coherent Light Source is  

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

Coherent Light Source is Coherent Light Source is a revolution in x-ray science. Just as the invention of x-ray machines a century ago astonishingly revealed the inside of our bodies and began new sciences, the world's first x-ray laser will open up unprecedented opportunities. Pioneering experiments will advance our understand ing of everything from the hidden physics inside planets, to how proteins function as the engines of life, to building nanotechnology devices for the backbone of future industry and technology. The applications are legion: medicine, electronics, biology, solid-state physics, nanotechnology, energy production, industry and fields that do not yet exist. Linac Coherent Light Source New Tools Create New Science The LCLS is dramatically different from any x-ray

9

SLAC Linac Coherent Light Source User Site  

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

Welcome to the LCLS User Resources Site Welcome to the LCLS User Resources Site User Portal | Agreements | Data Collection & Analysis | Logistics | Policies | Proposals | Safety | Schedules | Shipping The Linac Coherent Light Source (LCLS) encourages scientists from diverse fields to submit proposals for experiments that utilize the LCLS's unique capabilities. Interested scientists are encouraged to learn more about the latest developments by contacting LCLS staff scientists and by reviewing the instrument descriptions. Step-By-Step Instructions to Working at LCLS Review LCLS Policies Review Machine FAQ & Parameters Register and Submit Proposals Confirm User Agreement Reserve Accommodations Complete Safety Training Request Computer Account Establish User Account Ship Samples/Equipment Review Check-in Procedures

10

Linac Coherent Light Source Overview | Department of Energy  

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

Linac Coherent Light Source Overview Linac Coherent Light Source Overview Linac Coherent Light Source Overview Addthis Description Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall. Duration 5:50 Topic Physics Credit Energy Department Video MR. : The SLAC National Accelerator Laboratory is located in the heart of California's beautiful San Francisco Bay Area. Operated by Stanford University for the U.S. Department of Energy, SLAC has been home to the world's longest particle accelerator for nearly 50 years. In 2009 SLAC ushered in a new era in its long history of physics research with a new kind of laser called the Linac Coherent Light Source, or LCLS. The LCLS is the first laser in the world to produce hard X-rays, which can

11

Finding of No Significant Impact for the Construction and Operation of the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC), California (DOE/EA-1426) (2/28/03)  

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

U.S. Department of Energy (DOE) U.S. Department of Energy (DOE) Finding of No Significant Impact Construction and Operation of the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC), California. AGENCY: U.S. Department of Energy (DOE) ACTION: Finding of No Significant Impact (FONSI) SUMMARY: The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1426, evaluating the proposed action to construct and operate the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC). Based upon the information and analyses in the EA, the DOE has determined that the proposed federal action does not significantly affect the quality of the human environment within the meaning of the National Environmental Policy Act of 1969.

12

EA-1975: LINAC Coherent Light Source-Il, SLAC National Accelerator Laboratory, Menlo Park, California  

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

DOE is preparing an EA on the potential environmental impacts of a proposal to upgrade the existing LINAC Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. The proposed LCLS-II would extend the photon energy range, increase control over photon pulses, and enable two-color pump-probe experiments. The X-ray laser beams generated by LCLS-II would enable a new class of experiments: the simultaneous investigation of a material’s electronic and structural properties.

13

Linac Coherent Light Source Undulator RF BPM System  

SciTech Connect

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results.

Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; /Argonne; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; /SLAC

2007-04-17T23:59:59.000Z

14

The Development of the Linac Coherent Light Source RF Gun  

SciTech Connect

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of the emittance compensation solenoid are discussed in Section 1.1.7. The novel feature of the LCLS solenoid is the embedded quadrupole correctors. The thermo-mechanical engineering of the LCLS gun is discussed in Section 1.1.8, and the cold and hot RF tests are described in Section 1.1.9. The results of this work are summarized and concluding remarks are given in Section 1.1.10.

Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

2008-09-24T23:59:59.000Z

15

Beam-based Feedback for the Linac Coherent Light Source  

SciTech Connect

Beam-based feedback control loops are required by the Linac Coherent Light Source (LCLS) program in order to provide fast, single-pulse stabilization of beam parameters. Eight transverse feedback loops, a 6 x 6 longitudinal feedback loop, and a loop to maintain the electron bunch charge were successfully prototyped in MATLAB for the LCLS, and have been maintaining stability of the LCLS electron beam at beam rates up to 30Hz. In the final commissioning phase of LCLS the beam will be operating at up to 120Hz. In order to run the feedback loops at beam rate, the feedback loops will be implemented in EPICS IOCs with a dedicated ethernet multi-cast network. This paper will discuss the design of the beam-based Fast Feedback System for LCLS. Topics include MATLAB feedback prototyping, algorithm for 120Hz feedback, network design for fast data transport, actuator and sensor design for single-pulse control and sensor readback, and feedback configuration and runtime control.

Fairley, D.; Allison, S.; Chevtsov, S.; Chu, P.; Decker, F.J.; Emma, P.; Frisch, J.; Himel, T.; Kim, K.; Krejcik, P.; Loos, H.; Lahey, T.; Natampalli, P.; Peng, S.; Rogind, D.; Shoaee, H.; Straumann, T.; Williams, E.; White, G.; Wu, J.; Zelazney, M.; /SLAC

2010-02-11T23:59:59.000Z

16

Environmental Assessment for Linac Coherent Light Source Experimental Facility (12/02)  

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

Stanford Stanford Linear A ccelerator Center DOE/EA-1426 Environmental Assessment for Linac Coherent Light Source Experimental Facility LCLS December 2002 LCLS Environmental Assessment DOE/EA-1426 December 2002 Page - i - Environmental Assessment for LCLS Experimental Facility Table of Contents Preface ............................................................................................................................................ iii 1.0 Summary ................................................................................................................................... 1 2.0 Purpose and Need for LCLS ..................................................................................................... 6 3.0 Description of Proposed Action and Alternatives

17

Single shot spatial and temporal coherence properties of the SLAC linac coherent light source in the hard x-ray regime  

SciTech Connect

We measured the transverse and longitudinal coherence properties of the Linac Coherent Light Source (LCLS) at SLAC in the hard x-ray regime at 9 keV photon energy on a single shot basis. Speckle patterns recorded in the forward direction from colloidal nanoparticles yielded the transverse coherence properties of the focused LCLS beam. Speckle patterns from a gold nanopowder recorded with atomic resolution allowed us to measure the shot-to-shot variations of the spectral properties of the x-ray beam. The focused beam is in the transverse direction fully coherent with a mode number close to 1. The average number of longitudinal modes behind the Si(111) monochromator is about 14.5 and the average coherence time {tau}{sub c} = (2.0 {+-} 1.0) fs. The data suggest a mean x-ray pulse duration of (29 {+-} 14) fs behind the monochromator for (100 {+-} 14) fs long electron pulses.

Gutt, C.; Wochner, P.; Fischer, B.; Conrad, H.; Castro-Colin, M.; Lee, S.; Lehmkuhler, F.; Steinke, I.; Sprung, M.; Roseker, W.; Zhu, D.; Lemke, H.; Bogle, S.; Fuoss, P. H.; Stephenson, G. B.; Cammarata, M.; Fritz, D. M.; Robert, A.; Grubel, G. (Materials Science Division); (Deutsches Elektronen-Synchrotron); (Max-Planck-Institut fur Intelligene Systeme); (LCLS, SLAC Nat. Accelerator Lab.)

2012-01-01T23:59:59.000Z

18

X-RAY ACTIVE MATRIX PIXEL SENSORS BASEDON J-FET TECHNOLOGY DEVELOPED FOR THE LINAC COHERENT LIGHT SOURCE.  

SciTech Connect

An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.

CARINI,G.A.; CHEN, W.; LI, Z.; REHAK, P.; SIDDONS, D.P.

2007-10-29T23:59:59.000Z

19

Second and Third Harmonic Measurements at the Linac Coherent Light Source  

SciTech Connect

The Linac Coherent Light Source (LCLS) started user commissioning in October of 2009, producing Free Electron Laser (FEL) radiation between 800 eV and 8 keV [1]. The fundamental wavelength of the FEL dominates radiation in the beamlines, but the beam also produces nonnegligible levels of radiation at higher harmonics. The harmonics may be desirable as a source of harder X-rays, but may also contribute backgrounds to user experiments. In this paper we present preliminary measurements of the second and third harmonic content in the FEL. We also measure the photon energy cutoff of the soft X-ray mirrors to determine the extent to which higher harmonics reach the experimental stations. We present preliminary second and third harmonic measurements for LCLS. At low energies (below 1 keV fundamental) we measure less than 0.1% second harmonic content. The second harmonic will be present in the soft X-ray beam line for fundamental photon energies below approximately 1.1 keV. At low and high energies, we measure third harmonic content ranging from 0.5% to 3%, which is consistent with expectations. For both second and third harmonics, experimental work is ongoing. More rigorous analysis of the data will be completed soon.

Ratner, D.; /Stanford U., Phys. Dept.; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Fisher, A.; Frisch, J.; Gilevich, S.; Huang, Z.; Hering, P.; Iverson, R.; Krzywinski, J.; Loos, H.; Messerschmidt, M.; Nuhn, H.D.; Smith, T.; Turner, J.; Welch, J.; White, W.; Wu, J.; /SLAC

2011-01-03T23:59:59.000Z

20

Coherent Effects of High Current Beam in Project-X Linac  

SciTech Connect

Resonance excitation of longitudinal high order modes in superconducting RF structures of Project-X continuous wave linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of the linac, which is more suitable for high current operation.

Sukhanov, A.; Lunin, A.; Yakovlev, V.; Gonin, I.; Khabiboulline, T.; Saini, A.; Solyak, N.; Yostrikov, A.

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Creating an EPICS Based Test Stand Development System for a BPM Digitizer of the Linac Coherent Light Source  

SciTech Connect

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test the digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. Finally, logging of meaningful data into files has been added.

Not Available

2011-06-22T23:59:59.000Z

22

Monte Carlo Studies of the Radiation Fields in the Linac Coherent Light Source Undulators and of the Corresponding Signals in the Cerenkov Beam Loss Monitors  

SciTech Connect

In 2009 the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Center started free electron laser (FEL) operation. In order to continue to produce the bright and short-pulsed x-ray laser demanded by FEL scientists, this pioneer hard x-ray FEL requires a perfectly tailored magnetic field at the undulators, so that the photons generated at the electron wiggling path interact at the right phase with the electron beam. In such a precise system, small (>0.01%) radiation-induced alterations of the magnetic field in the permanent magnets could affect FEL performance. This paper describes the simulation studies of radiation fields in permanent magnets and the expected signal in the detectors. The transport of particles from the radiation sources (i.e. diagnostic insert) to the undulator magnets and to the beam loss monitors (BLM) was simulated with the intra nuclear cascade codes FLUKA and MARS15. In order to accurately reproduce the optics of LCLS, lattice capabilities and magnetic fields were enabled in FLUKA and betatron oscillations were validated against reference data. All electron events entering the BLMs were printed in data files. The paper also introduces the Radioactive Ion Beam Optimizer (RIBO) Monte Carlo 3-D code, which was used to read from the event files, to compute Cerenkov production and then to simulate the optical coupling of the BLM detectors, accounting for the transmission of light through the quartz.

Santana Leitner, Mario

2010-09-14T23:59:59.000Z

23

coherence  

Science Journals Connector (OSTI)

coherence [The property of wave trains being in phase. The coherence of adjacent seismic waves, along with an ... is the principal evidence for an event. Coherence is used qualitatively in picking ev...

2014-08-01T23:59:59.000Z

24

Linac Energy Management for LCLS  

SciTech Connect

Linac Energy Management (LEM) is a control system program that scales magnet field set-point settings following a change in beam energy. LEM is necessary because changes in the number, phase, and amplitude of the active klystrons change the beam's rigidity, and therefore, to maintain constant optics, one has to change focusing gradients and bend fields accordingly. This paper describes the basic process, the control system application programs we developed for LEM, and some of the implementation lessons learned at the Linac Coherent Light Source (LCLS).

Chu, Chungming; /SLAC; Iverson, Richard; /SLAC; Krejcik, Patrick; /SLAC; Rogind, Deborah; /SLAC; White, Greg; /SLAC; Woodley, Mark; /SLAC

2012-07-05T23:59:59.000Z

25

SAC - Linac Coherent Light Source  

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

SAC Home | Project Page | Contact Us | Visitor Information User Resources LUSI Cost & Schedule Glossary News LCLS SAC LCLS FAC LCLS Science LCLS Machine FEL Resources Stanford...

26

SLAC Linac Coherent Light Source  

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

for the U.S. Department of Energy by Stanford University. As the world's most powerful X-ray laser, the LCLS creates unique light that can see details down to the size of atoms...

27

Wakefields in SLAC linac collimators  

Science Journals Connector (OSTI)

When a beam travels near collimator jaws, it gets an energy loss and a transverse kick due to the backreaction of the beam field diffracted from the jaws. The effect becomes very important for an intense short bunch when a tight collimation of the background beam halo is required. In the Linac Coherent Light Source at SLAC a collimation system is used to protect the undulators from radiation due to particles in the beam halo. The halo is most likely formed from gun dark current or dark current in some of the accelerating sections. However, collimators are also responsible for the generation of wake fields. The wake field effect from the collimators not only brings an additional energy jitter and change in the trajectory of the beam, but it also rotates the beam on the phase plane, which consequently leads to a degradation of the performance of the Free Electron Laser at the Linac Coherent Light Source. In this paper, we describe a model of the wake field radiation in the SLAC linac collimators. We use the results of a numerical simulation to illustrate the model. Based on the model, we derive simple formulas for the bunch energy loss and the average kick. We also present results from experimental measurements that confirm our model.

A. Novokhatski; F.-J. Decker; H. Smith; M. Sullivan

2014-12-02T23:59:59.000Z

28

LCLS LLRF Upgrades to the SLAC Linac  

SciTech Connect

The Linac Coherent Light Source (LCLS) at SLAC will be the brightest X-ray laser in the world when it comes on line. In order to achieve the brightness a 200fS length electron bunch is passed through an undulator. To create the 200fS, 3kA bunch, a 10pS electron bunch, created from a photo cathode in an RF gun, is run off crest on the RF to set up a position to energy correlation. The bunch is then compressed by chicanes. The stability of the RF system is critical in setting up the position to energy correlation. Specifications derived from simulations require the RF system to be stable to below 200fS in several critical injector stations and the last kilometer of linac. The SLAC linac RF system is being upgraded to meet these requirements.

Akre, R.; Dowell, D.; Emma, P.; Frisch, J.; Hong, B.; Kotturi, K.; Krejcik, P.; Wu, J.; /SLAC; Byrd, J.; /LBL, Berkeley

2007-10-04T23:59:59.000Z

29

Instability issues for the ESS linac and rings  

SciTech Connect

Comments are made on beam instability issues in the ESS linac and rings. The topics of interest in the linac are halo generation in the absence and presence of machine imperfections, and also the stability of the momentum ramping of the output beam. In the case of the rings, the main concern is for fast coherent transverse instabilities due to the combined effect of coupled electron-proton oscillations and interaction with the wall impedances.

Rees, G. H. [Rutherford Appleton Laboratory, CLRC (United Kingdom)

1999-12-03T23:59:59.000Z

30

Simulation of large acceptance LINAC for muons  

SciTech Connect

There has been a recent need for muon accelerators not only for future Neutrino Factories and Muon Colliders but also for other applications in industry and medical use. We carried out simulations on a large-acceptance muon linac with a new concept 'mixed buncher/acceleration'. The linac can accept pions/muons from a production target with large acceptance and accelerate muon without any beam cooling which makes the initial section of muon-linac system very compact. The linac has a high impact on Neutrino Factory and Muon Collider (NF/MC) scenario since the 300-m injector section can be replaced by the muon linac of only 10-m length. The current design of the linac consists of the following components: independent 805-MHz cavity structure with 6- or 8-cm-radius aperture window; injection of a broad range of pion/muon energies, 10-100 MeV, and acceleration to 150 - 200 MeV. Further acceleration of the muon beam are relatively easy since the beam is already bunched.

Miyadera, H [Los Alamos National Laboratory; Kurennoy, S [Los Alamos National Laboratory; Jason, A J [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

31

SLAC Linac Coherent Light Source User Site  

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

User Logistics User Logistics Accommodations/Hours/Maps | Agreements | Check-In | Computing | Safety | Shipping | Supplies & Gases | User Feedback | Publications Proposal Submission and Scheduling Step-By-Step Instructions to Working at LCLS Review LCLS Policies Review Machine FAQ & Parameters Register and Submit Proposals Confirm User Agreement Reserve Accommodations Complete Safety Training Request Computer Account Establish User Account Ship Samples/Equipment Review Check-in Procedures Provide Feedback Inform us of Publications Participate in LCLS Users' Organization LCLS experiments start with submitting a proposal, usually due twice a year. Each proposal is for one specific experiment and each proposal is valid for one scheduling cycle only. There is no limit to the number of

32

SLAC Linac Coherent Light Source User Site  

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

Safety Safety Safety and Security Overview | Proposal Safety Review | Safety Training | Feedback Safety and Security Overview Step-By-Step Instructions to Working at LCLS Review LCLS Policies Review Machine FAQ & Parameters Register and Submit Proposals Confirm User Agreement Reserve Accommodations Complete Safety Training Request Computer Account Establish User Account Ship Samples/Equipment Review Check-in Procedures Provide Feedback Inform us of Publications Participate in LCLS Users' Organization Each person who works at LCLS is required to be familiar with and identify in advance the hazards associated with his/her work, the hazards associated with work areas, and to properly implement all necessary procedures and protocols for mitigation of those hazards. Each person is required to

33

SLAC Linac Coherent Light Source User Site  

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

Accommodations / Hours / Maps Accommodations / Hours / Maps Stanford Guest House This comfortable and convenient housing structure is located on SLAC's campus. Guests have access to in-room, high-speed Internet access, a fitness center, a 24-hour reception desk, laundry facilities, free parking, complimentary tea and coffee, and a 24-hour gift shop. The Guest House offers single as well as shared rooms, but all rooms have their own bathroom, and at very reasonable rates. All rooms are non-smoking only. Please reserve accommodations using their on-line form. If the Guest House is not available, additional accommodations may be made at local hotels/motels. For longer term visits, please contact the User Research Administration office. Gate Hours Maps & Directions SLAC Maps Directions to SLAC Security Gate 17

34

SLAC Linac Coherent Light Source User Site  

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

LCLS User Check-In Procedures LCLS User Check-In Procedures All users must check in at the User Research Administration (URA) offices upon arrival. Users must complete relevant training and return all forms to User Research Administration, Building 120, Room 211, prior to going to the LCLS Near Experimental Hall (NEH) or starting any experiments. The URA office is staffed Monday-Friday from 8 am to 4 pm. Many steps can and should be completed prior to your arrival: Automated access is now in operation 24/7 at Gate 17 and the Sector 30 Gate. Avoid delays by contacting us before arriving. If you have current safety training and an activated proximity card, your card will open the automated gate. Proceed to User Research Administration (URA) in Building 120 for check-in. However, you will need to first stop at SLAC Security IF you are a

35

SLAC Linac Coherent Light Source User Site  

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

not happen automatically and a re-submission will not receive preference during the review process. There is no limit to the number of proposals that can be submitted by a...

36

STANFORD SYNCHROTRON RADIATION LIGHTSOURCE LINAC COHERENT LIGHT...  

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

of any merchandise shipped or consigned by or to the FPPI and to receive or ship any merchandise on the FPPI's behalf. I hereby certify that all statements and...

37

Bioimaging Workshop - Linac Coherent Light Source  

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

Bioimaging Home | Project Page | Contact Us | Visitor Information User Resources LUSI Cost & Schedule Glossary News LCLS SAC LCLS FAC LCLS Science LCLS Machine FEL Resources...

38

SLAC Linac Coherent Light Source User Site  

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

in the following two documents: An Engineering Specification Document (ESD). An Interface Control Document (ICD). The end station builders must be available to commit the...

39

SLAC Linac Coherent Light Source User Site  

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

(2013-2016) Biology (BIO)Atomic, Molecular and Optical Science (AMO) Steve Johnson ETH Zurich (2013-2016) Materials Science - Hard Condensed Matter (HCM) Gianluca Gregori...

40

SLAC Linac Coherent Light Source User Site  

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

Schedules Schedules Schedule of Experiments for the Current Run | User Support Requests | Changes to the Operating Schedule LCLS Operations Schedules Step-By-Step Instructions to Working at LCLS Review LCLS Policies Review Machine FAQ & Parameters Register at User Portal Confirm User Agreement Reserve Accommodations Complete Safety Training Request Computer Account Establish User Account Ship Samples/Equipment Review Check-in Procedures Provide Feedback Inform us of Publications Participate in LCLS Users' Organization Tentative Long-Range Operating Plans Experiments Scheduled March to August 2014 Experiments Scheduled July 2013 to March 2014 Experiments Scheduled January to July 2013 Experiments Scheduled June to December 2012 Experiments Scheduled November 2011 to May 2012

Note: This page contains sample records for the topic "impact linac coherent" 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

NSLS Booster & Linac Ring  

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

Booster & Linac Ring Booster & Linac Ring Booster Operating Parameters (pdf) Lattice Information (pdf) Mechanical Drawing (pdf) Standard Operating Mode Electrons are injected into the NSLS storage rings from a 750 MeV booster synchrotron fed by a 120 MeV linac. The electrons are first produced in a 100 KeV triode electron gun. The gun is pulsed at the booster revolution period, 94.6 nsec, seven times per booster cycle. Each pulse is 5 nsec long and supplies about 17 microbunches in the linac. After acceleration in the linac, the beam is injected into the booster on seven successive turns. Multi-turn injection in the booster is accomplished in the following way: The beam is deflected into the booster by a septum magnet. The first linac pulse goes around the booster and returns to the injection point just as

42

Compact LINAC for deuterons  

SciTech Connect

We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

Kurennoy, S S [Los Alamos National Laboratory; O' Hara, J F [Los Alamos National Laboratory; Rybarcyk, L J [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

43

Optimization of SRF Linacs  

SciTech Connect

This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project.[1] The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. The work was first published in an ICFA Beam Dynamics News Letter.[2] More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so. Additionally, program changes now allow one to model the costs associated with a linac that makes use of energy recovery mode of operation.

Powers, Tom [JLAB

2013-09-01T23:59:59.000Z

44

EA-1904: Finding of No Significant Impact | Department of Energy  

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

Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, CA Based on the findings in the EA, DOE has determined that the proposed action to...

45

BNL | S-band Linac  

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

S-band Linac S-band Linac Some experiments at the ATF require higher energies than what is available from the photoinjector. We use two traveling wave linac structures, known as 'SLAC sections' (from the famous 2-mile SLAC linac). Each section provides an acceleration given by: Energy gain (in MeV) = 10.8*SQRT(Power in MW)-39.5*Current(in amps) The current to be used is an equivalent steady state current. The microwave drive power, at a frequency of 2856 MHz, is provided by a single XK5 klystron tube (the old SLAC klystron). This tube can provide up to 25 MW. The ATF modulator can provide the XK5 klystron with high voltage for about 3 microseconds. This 3 microsecond pulse is called the macropulse. The repetition rate for the macropulses is from 1 to 6 per second. Within each

46

SU?E?J?32: The Dosimetric Impact of Both a Rigid and a Flexible Radiofrequency Coil in a Hybrid 1.5T MRI and 6 MV Linac System for Online MR?Guided Radiotherapy  

Science Journals Connector (OSTI)

Purpose: To investigate the dosimetric impact of both a rigid and a flexible radiofrequency coil in a hybrid 1.5T MRI and 6 MV linac system for online MR?guided radiotherapy. Methods: We evaluated the dosimetric impact of a flexible Synergy MR coil (Philips Best) on both a simple and a complex irradiation strategy for treating spinal bone metastases by Monte?Carlo simulations. This tumor site in combination with this MR coil may be chosen for the first in?man treatments with the UMC Utrecht MRL?system. Second we investigated the dosimetric impact of a rigid pelvis coil as used in the interventional Philips MRI HIFU system. This coil consists of a hard plastic shell with the actual coil elements and electronics inside it. We took a separate look at the influence of the shell and the coil components on the dose distribution. Results: For the flexible coil the dose to the target volume was underestimated up to 2.2% as a Result of beam attenuation in the MR coil in case a single posterior?anterior field was applied (Figure 1). This underestimation however decreased to 1% when a stereotactic treatment strategy was employed (Figure 2). For the rigid HIFU coil the shell without electronic components introduced a homogenous 4% dose decrease when an anterior?posterior rectangular field was utilized. The dose to the skin however was increased dramatically as a Result of additional electrons generated inside the shell (figure 3). The shell with the electronic components yielded severe streaks in the dose distribution (figure 4). Conclusion: It is feasible to use the Flexible Synergy MR body coil for MR guided radiotherapy without any modification to the coil. The rigid HIFU pelvis coil however is with its current design unsuitable for MRgRT.

2013-01-01T23:59:59.000Z

47

Induction Linac Pulsers  

SciTech Connect

The pulsers used in most of the induction linacs evolved from the very large body of work that was done in the U.S. and Great Britain during the development of the pulsed magnetron for radar. The radar modulators started at {approx}100 kW and reached >10 MW by 1945. A typical pulse length was 1 {mu}s at a repetition rate of 1,000 pps. A very comprehensive account of the modulator development is Pulse Generators by Lebacqz and Glasoe, one of the Radiation Laboratory Series. There are many permutations of possible modulators, two of the choices being tube type and line type. In earlier notes I wrote that technically the vacuum tube pulser met all of our induction linac needs, in the sense that a number of tubes, in series and parallel if required, could produce our pulses, regulate their voltage, be useable in feed-forward correctors, and provide a low source impedance. At a lower speed, an FET array is similar, and we have obtained and tested a large array capable of >10 MW switching. A modulator with an electronically controlled output only needs a capacitor for energy storage and in a switched mode can transfer the energy from the capacitor to the load at high efficiency. Driving a full size Astron induction core and a simulated resistive 'beam load' we achieved >50% efficiency. These electronically controlled output pulses can produce the pulses we desire but are not used because of their high cost. The second choice, the line type pulser, visually comprises a closing switch and a distributed or a lumped element transmission line. The typical switch cannot open or stop conducting after the desired pulse has been produced, and consequently all of the initially stored energy is dissipated. This approximately halves the efficiency, and the original cost estimating program LIACEP used this factor of two, even though our circuits are usually worse, and even though our inveterate optimists often omit it. The 'missing' energy is that which is reflected back into the line from mismatches, the energy left in the accelerator module's capacitance, the energy lost in the switch during switching and during the pulse, and the energy lost in the pulse line charging circuit. For example, a simple resistor-limited power supply dissipates as much energy as it delivers to the pulse forming line, giving a factor if two by itself, therefore efficiency requires a more complicated charging system.

Faltens, Andris

2011-01-07T23:59:59.000Z

48

LINACS FOR FUTURE MUON FACILITIES  

SciTech Connect

Future Muon Colliders (MC) and Neutrino Factories (NF) based on muon storage rings will require innovative linacs to: produce the muons, cool them, compress longi-tudinally and ‘shape’ them into a beam and finally to rap-idly accelerate them to multi-GeV (NF) and TeV (MC) energies. Each of these four linac applications has new requirements and opportunities that follow from the na-ture of the muon in that it has a short lifetime (? = 2.2 ?sec) in its own rest frame, it is produced in a tertiary process into a large emittance, and its electron, photon, and neutrino decay products can be more than an annoy-ance. As an example, for optimum performance, the linac repetition rates should scale inversely with the laboratory lifetime of the muon in its storage ring, something as high as 1 kHz for a 40 GeV Neutrino Factory or as low as 20 Hz for a 5 TeV Muon Collider. A superconducting 8 GeV Linac capable of CW operation is being studied as a ver-satile option for muon production [1] for colliders, facto-ries, and muon beams for diverse purposes. A linac filled with high pressure hydrogen gas and imbedded in strong magnetic fields has been proposed to rapidly cool muon beams [2]. Recirculating Linear Accelerators (RLA) are possible because muons do not generate significant syn-chrotron radiation even at extremely high energy and in strong magnetic fields. We will describe the present status of linacs for muon applications; in particular the longitu-dinal bunch compression in a single pass linac and multi-pass acceleration in the RLA, especially the optics and technical requirements for RLA designs, using supercon-ducting RF cavities capable of simultaneous acceleration of both ?+ and ?? species, with pulsed linac quadrupoles to allow the maximum number of passes. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

Slawomir Bogacz, Rolland Johnson

2008-10-01T23:59:59.000Z

49

EA-1087: Proposed Induction Linac System Experiments in Building 51B at  

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

7: Proposed Induction Linac System Experiments in Building 7: Proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California EA-1087: Proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California SUMMARY This EA evaluates the environmental impacts of a proposal to modify existing Building 51B at the U.S. Department of Energy's Lawrence Berkeley National Laboratory to install and conduct experiments on a new Induction Linear Accelerator System. PUBLIC COMMENT OPPORTUNITIES None available at this time. DOCUMENTS AVAILABLE FOR DOWNLOAD September 8, 1995 EA-1087: Finding of No Significant Impact Proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California

50

Drift Tube Linac Conditioning of Tank1  

E-Print Network (OSTI)

Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

Shafqat, N; Toor, W A

2014-01-01T23:59:59.000Z

51

Source of coherent short wavelength radiation  

DOE Patents (OSTI)

An apparatus for producing coherent radiation ranging from X-rays to the far ultraviolet (i.e., 1 Kev to 10 eV) utilizing the Compton scattering effect. A photon beam from a laser is scattered on a high energy electron bunch from a pulse power linac. The short wavelength radiation produced by such scattering has sufficient intensity and spatial coherence for use in high resolution applications such as microscopy.

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

52

PROGRESS IN DESIGN OF THE SNS LINAC  

SciTech Connect

The Spallation Neutron Source (SNS) is a six-laboratory collaboration to build an intense pulsed neutron facility at Oak Ridge, TN. The linac design has evolved from the conceptual design presented in 1997 to achieve higher initial performance and to incorporate desirable upgrade features. The linac will initially produce 2-MW beam power using a combination of radio-frequency quadruple (RFQ) linac, drift-tube linac (DTL), coupled-cavity linac (CCL), and superconducting-cavity linac (SCL). Designs of each of these elements support the high peak intensity and high quality beam required for injection into the SNS accumulator ring. This paper will trace the evolution of the linac design, the cost and performance factors that drove architecture decisions, and the progress made in the R&D program.

R. HARDEKOPF

2000-11-01T23:59:59.000Z

53

LFSC - Linac Feedback Simulation Code  

SciTech Connect

The computer program LFSC (<Linac Feedback Simulation Code>) is a numerical tool for simulation beam based feedback in high performance linacs. The code LFSC is based on the earlier version developed by a collective of authors at SLAC (L.Hendrickson, R. McEwen, T. Himel, H. Shoaee, S. Shah, P. Emma, P. Schultz) during 1990-2005. That code was successively used in simulation of SLC, TESLA, CLIC and NLC projects. It can simulate as pulse-to-pulse feedback on timescale corresponding to 5-100 Hz, as slower feedbacks, operating in the 0.1-1 Hz range in the Main Linac and Beam Delivery System. The code LFSC is running under Matlab for MS Windows operating system. It contains about 30,000 lines of source code in more than 260 subroutines. The code uses the LIAR ('Linear Accelerator Research code') for particle tracking under ground motion and technical noise perturbations. It uses the Guinea Pig code to simulate the luminosity performance. A set of input files includes the lattice description (XSIF format), and plane text files with numerical parameters, wake fields, ground motion data etc. The Matlab environment provides a flexible system for graphical output.

Ivanov, Valentin; /Fermilab

2008-05-01T23:59:59.000Z

54

partial coherence  

Science Journals Connector (OSTI)

In an electromagnetic wave, or waves, coherence such that the electromagnetic fields at two ... of correlation, i.e., have a coherence degree that is below 0.88 but...See also coherence

2001-01-01T23:59:59.000Z

55

Coherence - 2014  

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

Coherence - 2014 International Workshop on Phase Retrieval and Coherent Scattering Argonne National Laboratory home program venue lodging exhibitors committees workshop Register...

56

Modeling of the ALS linac  

SciTech Connect

The ALS injector linac is used for the Beam Test Facility (BTF) and the Damping Experiments when it is available in between the ALS filings. These experiments usually require higher quality beams and a better characterization than is normally required for ALS operations. This paper focuses on the beam emittance, energy tilt, and especially the longitudinal variation of the beam parameters. For instance, the authors want to avoid longitudinal variations at the low beta section of the BTF. On the other hand, a large energy tilt is required for post-acceleration compression of the bunch using an alpha magnet. The PARMELA code was modified to calculate and display longitudinal variations of the emittance ellipse. Using the Microsoft Development Studio under Windows NT environment the code can handle a much larger number of particles than was previously possible.

Kim, C.H. [Lawrence Berkeley Lab., CA (United States). Advanced Light Source Center

1996-08-01T23:59:59.000Z

57

New Post-Linac Collimation System  

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

Post-Linac Post-Linac Collimation System for the Next Linear Collider NLC Post-Linac Collimation Task Force LCC-Note-0052 21-Feb-2001 Abstract We present a new design for the NLC post-linac collimation system. The new design sepa- rates the collimation of off-energy particles and particles with large betatron amplitudes. The energy collimation system achieves passive protection against damage by an errant bunch train via large horizontal dispersion and vertical betatron functions, and makes use of optical symme- tries to reduce jitter amplification. The betatron collimation system permits infrequent damage to the thin "spoiler" collimators, while the thick "absorber" collimators have a much larger aperture and are thus more difficult to hit. The physical phenomena which are relevant to the design and operation of the collimation system are reviewed, and

58

Quantifying Coherence  

Science Journals Connector (OSTI)

We introduce a rigorous framework for the quantification of coherence and identify intuitive and easily computable measures of coherence. We achieve this by adopting the viewpoint of coherence as a physical resource. By determining defining conditions for measures of coherence we identify classes of functionals that satisfy these conditions and other, at first glance natural quantities, that do not qualify as coherence measures. We conclude with an outline of the questions that remain to be answered to complete the theory of coherence as a resource.

T. Baumgratz; M. Cramer; M.?B. Plenio

2014-09-29T23:59:59.000Z

59

Quantifying Coherence  

E-Print Network (OSTI)

We introduce a rigorous framework for the quantification of coherence and identify intuitive and easily computable measures of coherence. We achieve this by adopting the viewpoint of coherence as a physical resource. By determining defining conditions for measures of coherence we identify classes of functionals that satisfy these conditions and other, at first glance natural quantities, that do not qualify as coherence measure. We conclude with an outline of the questions that remain to be answered to complete the theory of coherence as a resource.

T. Baumgratz; M. Cramer; M. B. Plenio

2013-11-01T23:59:59.000Z

60

EA-1426: Finding of No Significant Impact | Department of Energy  

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

DOE proposes to construct and operate a new research facility at SLAC, the Linac Coherent Light Source (LCLS), as a collaborative effort with other DOE facilities. U.S. Department...

Note: This page contains sample records for the topic "impact linac coherent" 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

EA-1904: Final Environmental Assessment | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, CA This EA evaluates the environmental impacts of the proposed construction of the Linac...

62

S-Band Loads for SLAC Linac  

SciTech Connect

The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.

Krasnykh, A.; Decker, F.-J.; /SLAC; LeClair, R.; /INTA Technologies, Santa Clara

2012-08-28T23:59:59.000Z

63

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

64

Remarks on the concept of dispersion in a curved linac  

SciTech Connect

A next-generation linear collider is expected to span tens of kilometers in length. For various reasons, it may be desirable to house such an accelerator in a tunnel that follows the earth's curvature rather that in a 'laser-straight' tunnel. One side effect of opting for a curved linac is the introduction of vertical dispersion. In recent years, much work has been dedicated to understand and evaluate the impact of the presence of dispersion on emittance preservation. While performing simulations with our in-house code (CHEF) we observed a discrepancy between the dispersion function it produces and that computed using other codes in use within the accelerator community. Understanding the origin and the meaning of this discrepancy required a re-examination of the meaning of the concept of dispersion in the context of a linac. The object of this note is to document our findings. We establish that the default dispersion algorithm used by CHEF corresponds to a different, and ultimately more appropriate, definition of the dispersion in presence of acceleration. Not surprisingly, a consistent definition of dispersion restores agreement between codes.

Ostiguy, Jean-Francois; /Fermilab

2009-01-01T23:59:59.000Z

65

Coherence holography  

Science Journals Connector (OSTI)

The principle of unconventional holography, called coherence holography, is proposed and experimentally demonstrated for the first time. An object recorded in a hologram is...

Takeda, Mitsuo; Wang, Wei; Duan, Zhihui; Miyamoto, Yoko

2005-01-01T23:59:59.000Z

66

A Stability of LCLS Linac Modulators  

SciTech Connect

Information concerning to a stability of LCLS RF linac modulators is allocated in this paper. In general a 'pulse-to-pulse' modulator stability (and RF phase as well) is acceptable for the LCLS commission and FEL programs. Further modulator stability improvements are possible and approaches are discussed based on our experimental results.

Decker, F.-J.; Krasnykh, A.; Morris, B.; Nguyen, M.; /SLAC

2012-06-13T23:59:59.000Z

67

Coherence Current, Coherence Vortex, and the Conservation Law of Coherence  

Science Journals Connector (OSTI)

Introducing scalar and vector densities for a mutual coherence function, we present a new conservation law for optical coherence of scalar wave fields in the form of a continuity equation. This coherence conservation law provides new insights into topological phenomena for the complex coherence function. Some properties related to the newly introduced coherence vector density, such as a circulating coherence current associated with a coherence vortex, are investigated both theoretically and experimentally for the first time.

Wei Wang and Mitsuo Takeda

2006-06-08T23:59:59.000Z

68

Transverse-coherence properties of the FEL at the LCLS  

SciTech Connect

The recently commissioned Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is now operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron sources. Understanding of coherence properties of the radiation from SASE FELs at LCLS is of great practical importance for some user experiments. We present the numerical analysis of the coherence properties at different wavelengths based on a fast algorithmusing ideal and start-end simulated FEL fields. The sucessful commissioning and operation of the linac coherent light source (LCLS) [1] has demonstrated that the x-ray free-electron laser (FEL) has come of age; these types of x-ray sources are poised to revolutionize the ultra-fast x-ray sciences. The LCLS and other hard x-ray FELs under construction are based on the principle of self-amplified spontaneous emission (SASE) [2, 3], where the amplification process starts from the shot noise in the electron beam. A large number of transverse radiation modes are also excited when the electron beam enters the undulator. The FEL collective instability in the electron beam causes the modulation of the electron density to increase exponentially, and after sufficient undulator distances, a single transverse mode starts to dominate. As a result, SASE FEL is almost fully coherent in the transverse dimension. Understanding of transverse coherence properties of the radiation from SASE FELs is of great practical importance. The longitudinal coherence properties of SASE FELs have been studied before [4]. Some studies on the transverse coherence can be found in previous papers, for example, in ref. [5, 6, 7, 8, 9]. In this paper, we first discuss a new numerical algorithm based on Markov chain Monte Carlo techniques to calculate the FEL transverse coherence. Then we focus on the numerical analysis of the LCLS FEL transverse coherence.

Ding, Yuantao

2010-09-02T23:59:59.000Z

69

Catalytic Coherence  

Science Journals Connector (OSTI)

Because of conservation of energy we cannot directly turn a quantum system with a definite energy into a superposition of different energies. However, if we have access to an additional resource in terms of a system with a high degree of coherence, as for standard models of laser light, we can overcome this limitation. The question is to what extent coherence gets degraded when utilized. Here it is shown that coherence can be turned into a catalyst, meaning that we can use it repeatedly without ever diminishing its power to enable coherent operations. This finding stands in contrast to the degradation of other quantum resources and has direct consequences for quantum thermodynamics, as it shows that latent energy that may be locked into superpositions of energy eigenstates can be released catalytically.

Johan Ĺberg

2014-10-07T23:59:59.000Z

70

Coherence waves  

Science Journals Connector (OSTI)

In 1955 Wolf noticed that the mutual coherence function ? obeys two wave equations [Proc. R. Soc. London230, 246 (1955)]. The physical optics of this finding is thoroughly presented in...

Lohmann, Adolf W; Mendlovic, David; Shabtay, Gal

1999-01-01T23:59:59.000Z

71

Photocathodes for the energy recovery linacs  

SciTech Connect

This paper presents an overview of existing and emerging technologies on electron sources that can service various Energy Recovering Linacs under consideration. Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed. Status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.

T. Rao; A. Burrill; X.Y. Chang; J. Smedley; T. Nishitani; C. Hernandez Garcia; M. Poelker; E. Seddon; F.E. Hannon; C.K. Sinclair; J. Lewellen; D. Feldman

2005-03-19T23:59:59.000Z

72

PHOTOCATHODES FOR THE ENERGY RECOVERY LINACS.  

SciTech Connect

This paper presents an overview of existing and emerging technologies on electron sources that can service various Energy Recovering Linacs under consideration. Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed. Status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.

RAO, T.; BURRILL, A.; CHANG, X.Y.; SMEDLEY, J.; ET AL.

2005-03-19T23:59:59.000Z

73

An overview of LINAC ion sources  

SciTech Connect

This paper discusses ion sources used in high-duty-factor proton and H{sup -} Linacs as well as in accelerators utilizing multi-charged heavy ions, mostly for nuclear physics applications. The included types are Electron Cyclotron Resonance (ECR) sources as well as filament and rf driven multicusp sources. The paper does not strive to attain encyclopedic character but rather to highlight major lines of development, peak performance parameters and type-specific limitations and problems of these sources. The main technical aspects being discussed are particle feed, plasma generation and ion production by discharges, and plasma confinement.

Keller, Roderich [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

74

WATER PURITY DEVELOPMENT FOR THE COUPLED CAVITY LINAC (CCL) AND DRIFT TUBE LINAC (DTL) STRUCTURES OF THE SPALLATION NEUTRON SOURCE (SNS) LINAC  

SciTech Connect

The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the proton beam. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems. One of the primary components in the DTL and CCL water cooling systems, is a water purification system that is responsible for minimizing erosion, corrosion, scaling, biological growth, and hardware activation. The water purification system consists of filters, ion exchange resins, carbon beds, an oxygen scavenger, a UV source, and diagnostic instrumentation. This paper reviews related issues associated with water purification and describes the mechanical design of the SNS Linac water purification system.

D. KATONAK; J. BERNARDIN; S. HOPKINS

2001-06-01T23:59:59.000Z

75

Design of the Prototypical Cryomodule for the EUROTRANS Superconducting Linac for Nuclear Waste Transmutation  

E-Print Network (OSTI)

Design of the Prototypical Cryomodule for the EUROTRANS Superconducting Linac for Nuclear Waste Transmutation

Barbanotti, S; Blache, P; Commeaux, C; Duthil, P; Panzeri, N; Pierini, P; Rampnoux, E; Souli, M

2008-01-01T23:59:59.000Z

76

PHYSICS RESULTS OF THE NSLS-II LINAC FRONT END TEST STAND  

SciTech Connect

The Linac Front End Test Stand (LFETS) was installed at the Source Development Laboratory (SDL) in the fall of 2011 in order to test the Linac Front End. The goal of these tests was to test the electron source against the specifications of the linac. In this report, we discuss the results of these measurements and the effect on linac performance.

Fliller R. P.; Gao, F.; Yang, X.; Rose, J.; Shaftan, T.; Piel, C

2012-05-20T23:59:59.000Z

77

Progress on an energy recovery linac upgrade to the Advanced Photon Source  

SciTech Connect

The Advanced Photon Source (APS) is a third-generation storage-ring-based x-ray source that has been operating for more than 13 years and is enjoying a long period of stable, reliable operation. However, major accelerator upgrades are being investigated in order to maintain scientific relevance into the future. One very promising possibility is the use of an energy recovery linac (ERL). In this option, APS would transition from a source based on a stored electron beam to one based on a continuously generated high-brightness electron beam from a linac. Such a source promises dramatically improved brightness and transverse coherence compared to third-generation storage rings. We present a new design for an ERL upgrade that incorporates very long insertion devices. We show that operation at high electron beam energy provides the promise of extremely high brightness for hard x-rays. We also show results of the first start-to-end simulations of an ERL-based x-ray source.

Borland, Michael; Dong Xiaowei; Li Yuelin [Argonne National Laboratory, Argonne, IL, 60439 (United States)

2010-06-23T23:59:59.000Z

78

The Linac4 DTL Prototype: Low and High Power Measurements  

E-Print Network (OSTI)

The prototype of the Linac4 Drift Tube Linac (DTL) has undergone low power measurements in order to verify the RF coupling and to adjust the post-coupler lengths based on bead-pull and spectrum measurements. Following the installation at the test stand, the cavity has been subjected to high power operation at Linac4 and SPL duty cycles. Saturation effects and multipacting have been observed and linked to X-ray emission. Voltage holding is reported in the presence of magnetic fields from permanent magnet quadrupoles (PMQ) installed in the first drift tubes.

De Michele, G; Marques-Balula, J; Ramberger, S

2012-01-01T23:59:59.000Z

79

High-Performance Beam Simulator for the LANSCE Linac  

SciTech Connect

A high performance multiparticle tracking simulator is currently under development at Los Alamos. The heart of the simulator is based upon the beam dynamics simulation algorithms of the PARMILA code, but implemented in C++ on Graphics Processing Unit (GPU) hardware using NVIDIA's CUDA platform. Linac operating set points are provided to the simulator via the EPICS control system so that changes of the real time linac parameters are tracked and the simulation results updated automatically. This simulator will provide valuable insight into the beam dynamics along a linac in pseudo real-time, especially where direct measurements of the beam properties do not exist. Details regarding the approach, benefits and performance are presented.

Pang, Xiaoying [Los Alamos National Laboratory; Rybarcyk, Lawrence J. [Los Alamos National Laboratory; Baily, Scott A. [Los Alamos National Laboratory

2012-05-14T23:59:59.000Z

80

Recirculating Linac Accelerators For Future Muon Facilities  

SciTech Connect

Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

2012-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

FRIB driver linac vacuum model and benchmarks  

Science Journals Connector (OSTI)

Abstract The Facility for Rare Isotope Beams (FRIB) is a superconducting heavy-ion linear accelerator that is to produce rare isotopes far from stability for low energy nuclear science. In order to achieve this, its driver linac needs to achieve a very high beam current (up to 400 kW beam power), and this requirement makes vacuum levels of critical importance. Vacuum calculations have been carried out to verify that the vacuum system design meets the requirements. The modeling procedure was benchmarked by comparing models of an existing facility against measurements. In this paper, we present an overview of the methods used for FRIB vacuum calculations and simulation results for some interesting sections of the accelerator.

Bojan Durickovic; Paul Gibson; Roberto Kersevan; Guillaume Machicoane

2014-01-01T23:59:59.000Z

82

Beam Measurements on Argonne Linac for Collider Injector Design  

Science Journals Connector (OSTI)

The 20 MeV electron linac at Argonne produces 5 × 1010 electrons in a single bunch. This amount of charge per bunch is required for the proposed single pass collider at SLAC. For this reason the characteristics o...

G. Mavrogenes; M. B. James; R. F. Koontz…

1980-01-01T23:59:59.000Z

83

BEAM DYNAMICS FOR A PHOTOINJECTED ENERGY RECOVERY LINAC AT THE...  

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

on a 3-7 GeV energy recovering superconducting linac initiated by a photo- injected RF gun 1. To be a competitive light source the photoinjector must provide high brightness...

84

End to End Beam Dynamics of the ESS Linac  

E-Print Network (OSTI)

The European Spallation Source, ESS, uses a linear accelerator to deliver the high intensity proton beam to the target station. The nominal beam power is 5 MW at an energy of 2.5 GeV. The individual accelerating structures in the linac and the transport lines are brie?y described, and the beam is tracked from the source throughout the linac to the target. This paper will present a review of the beam dynamics from the source to the target.

Eshraqi, M; Celona, L; Comunian, M; Danared, H; Holm, A S; Mřller, S P; Ponton, A; Stovall, J; Thomsen, H D

2012-01-01T23:59:59.000Z

85

Status and plans for Linac4 installation and commissioning  

E-Print Network (OSTI)

Linac4 is a normal conducting 160 MeV H? linear accelerator presently being installed and progressively commissioned at CERN. It will replace the ageing 50 MeV Linac2 as injector of the PS Booster (PSB), increasing at the same time its brightness by a factor of two thanks to the higher injection energy. This will be the first step of a program to increase the beam brightness in the LHC injectors for the needs of the High-Luminosity LHC project. After a series of beam measurements on a dedicated test stand the 3 MeV Linac4 front-end, including ion source, RFQ and a beam chopping line, has been recommissioned at its final position in the Linac4 tunnel. Commissioning of the following section, the Drift Tube Linac, is starting. Beam commissioning will take place in steps of increasing energy, to reach the final 160 MeV in 2015. An extended beam measurement phase including testing of stripping equipment for the PSB and a year-long test run to assess and improve Linac4 reliability will take place in 2016, prior to...

Vretenar, M; Arnaudon, L; Baudrenghien, P; Bellodi, G; Broere, J; Brunner, O; Comblin, J F; Coupard, J; Dimov, V A; Fuchs, J F; Funken, A; Gerigk, F; Granemann Souza, E; Hanke, K; Hansen, J; Yarmohammadi Satri, M; Kozsar, I; Lallement, J B; Lenardon, F; Lettry, J; Lombardi, A M; Maglioni, C; Midtun, O; Mikulec, B; Nisbet, D; Paoluzzi, M; Raich, U; Ramberger, S; Roncarolo, F; Rossi, C; Sanchez Alvarez, J L; Scrivens, R; Tan, J; Valerio-Lizarraga, C A; Vollaire, J; Wegner, R; Weisz, S; Zocca, F

2014-01-01T23:59:59.000Z

86

Classical versus quantum coherence  

Science Journals Connector (OSTI)

...M. Stoneham Classical versus quantum coherence P. T. Greenland Department of Physics...nanostructures| Classical versus quantum coherence. | Quantum dots are structures engineered...2002.1134 Classical versus quantum coherence By P. T. Greenland Department of Physics...

2003-01-01T23:59:59.000Z

87

Unexpected coherence and conservation  

Science Journals Connector (OSTI)

...December 2001 research-article Unexpected coherence and conservation Bernard Cazelles 1...out-of-phase synchrony| Unexpected coherence and conservation. | The effects of migration...Behavior Stochastic Processes Unexpected coherence and conservation Bernard Cazelles1...

2001-01-01T23:59:59.000Z

88

The Coherence Premium:.  

E-Print Network (OSTI)

??Evidence was found for the partial explanation of firm succes from a new point of view: coherence. A positive relationship was found between coherence, a… (more)

Van Braam Houckgeest, A.Q.

2012-01-01T23:59:59.000Z

89

Sense of coherence.  

E-Print Network (OSTI)

?? The aim of the study was to investigate the sense of coherence among students in Zambia. Sense of coherence was assessed with the questionnaire… (more)

Lennqvist, Susanne

2009-01-01T23:59:59.000Z

90

Understanding Causal Coherence Relations.  

E-Print Network (OSTI)

??The research reported in this dissertation focuses on the cognitive processes and representations involved in understanding causal coherence relations in text. Coherence relations are the… (more)

Mulder, G.

2008-01-01T23:59:59.000Z

91

Coherence in Oxygenic Photosynthesis  

Science Journals Connector (OSTI)

We report coherent dynamics in the photosystem II reaction center observed by two dimensional electronic spectroscopy. We discuss the physical nature of the coherences and their...

Fuller, Franklin D; Pan, Jie; Gelzinis, Andrius; Butkus, Vytautas; Senlik, Seckin; Wilcox, Daniel E; Valkunas, Leonas; Abramavicius, Darius; Ogilvie, Jennifer P

92

Electron gun system for NSC KIPT linac  

E-Print Network (OSTI)

In NSC KIPT linac, a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, the physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2A for the pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply which can provide a high voltage up to 150 kV. . Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture and operation of the new electron system are basically successful.

Zhou, Zusheng; Chi, Yunlong

2013-01-01T23:59:59.000Z

93

LINAC4, A New $H^{-}$ Linear Injector at CERN  

E-Print Network (OSTI)

Linac2, the present injector of the CERN PS Booster, limits the performance of the proton accelerator complex because of its low output energy (50 MeV). To remove this bottleneck, a higher energy linac is proposed (called â??Linac4â? ť) which will double the brightness and the intensity of the beam delivered by the PSB and ensure the â??ultimateâ?ť beam is available for LHC. Linac4 will deliver H- ions at a kinetic energy of 160 MeV. It is designed to be usable as the front-end of a future multi-GeV multi-MW linear accelerator, the â??Superconducting Proton Linacâ?ť (SPL). R&D for Linac4 is now actively taking place with the support of the European Union through the Joint Research Activity HIPPI (â??High Intensity Pulsed Proton Injectorsâ?ť), and of three ISTC projects involving three major Russian laboratories (BINP, IHEP and ITEP) and two nuclear centres (VNIIEF and VNIITF). The design of this new accelerator and the on-going developments are described.

Garoby, R; Hanke, K; Lombardi, A M; Rossi, C; Vretenar, M

2004-01-01T23:59:59.000Z

94

High Power Superconducting Continuous Wave Linacs for Protons and  

Office of Science (SC) Website

Power Superconducting Continuous Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions 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 High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions

95

Investigations of Slow Motions of the SLAC Linac Tunnel  

SciTech Connect

Investigations of slow transverse motion of the linac tunnel of the Stanford Linear Collider have been performed over period of about one month in December 1999--January 2000. The linac laser alignment system, equipped with a quadrant photodetector, allowed submicron resolution measurement of the motion of the middle of the linac tunnel with respect to its ends. Measurements revealed two major sources responsible for the observed relative motion. Variation of the external atmospheric pressure was found to be the most significant cause of short wavelength transverse motion of the tunnel. The long wavelength component of the motion has been also observed to have a large contribution from tidal effects. The measured data are essential for determination of parameters for the Next Linear Collider.

Seryi, Andrei

2000-08-31T23:59:59.000Z

96

1Mechanical, Aerospace and Nuclear Engineering nacThe Gaerttner Laboratory RPI LINAC Facility  

E-Print Network (OSTI)

1Mechanical, Aerospace and Nuclear Engineering nacThe Gaerttner Laboratory RPI LINAC Facility and Nuclear Engineering nacThe Gaerttner Laboratory Capabilities of the RPI LINAC · Pulsed Electron Beam ­ 7ns;4Mechanical, Aerospace and Nuclear Engineering nacThe Gaerttner Laboratory Capabilities of the RPI LINAC

Danon, Yaron

97

BEAM SIMULATIONS USING VIRTUAL DIAGNOSTICS FOR THE DRIVER LINAC  

SciTech Connect

End-to-end beam simulations for the driver linac have shown that the design meets the necessary performance requirements including having adequate transverse and longitudinal acceptances. However, to achieve reliable operational performance, the development of appropriate beam diagnostic systems and control room procedures are crucial. With limited R&D funding, beam simulations provide a cost effective tool to evaluate candidate beam diagnostic systems and to provide a critical basis for developing early commissioning and later operational activities. We propose to perform beam dynamic studies and engineering analyses to define the requisite diagnostic systems of the driver linac and through simulation to develop and test commissioning and operational procedures.

R. C. York; X. Wu; Q. Zhao

2011-12-21T23:59:59.000Z

98

The Coherence of Stoic Ontology  

E-Print Network (OSTI)

The Coherence of Stoic Ontology by Vanessa de Harven ALong Spring 2012 Abstract The Coherence of Stoic Ontology byof charity that seeks coherence in the Stoics and something

de Harven, Vanessa

2012-01-01T23:59:59.000Z

99

Status of the Project-X CW Linac Design  

SciTech Connect

Project-X is a proposed proton accelerator complex at Fermilab that would provide particle beams to support a diversified experimental program at the intensity frontier. As currently envisioned, the complex would employ a CW superconducting linac to accelerate a 1 mA average, 5 mA peak H{sup -} beam from 2.1 MeV to 3 GeV. A second superconducting linac, operating in pulsed mode would ultimately accelerate a small fraction of this beam up to 8 GeV. The CW linac is based on five families of resonators operating at three frequencies: half-wave (1 family at 162.5 MHz), spoke (2 families at 325 MHz) and elliptical (2 families at 650 MHz). Accelerating and focusing elements are assembled in cryomodules separated by short warm sections. A long open region ({approx} 15 m) allows beam extraction at 1 GeV in support of a nuclear experimental program. In this paper, we present the latest iteration of the CW linac baseline lattice. We also briefly compare it to an alternative where the 162.5 half-wave resonators are replaced with 325 MHz spoke resonators.

Ostiguy, J-F.; Solyak, N.; Berrutti, P.; Carneiro, J.P.; Lebedev, V.; Nagaitsev, S.; Saini, A.; Stheynas, B.; Yakovlev, V.P.; /Fermilab

2012-05-01T23:59:59.000Z

100

Maximal Privacy without Coherence  

E-Print Network (OSTI)

Privacy is a fundamental feature of quantum mechanics. A coherently transmitted quantum state is inherently private. Remarkably, coherent quantum communication is not a prerequisite for privacy: there are quantum channels ...

Leung, Debbie

Note: This page contains sample records for the topic "impact linac coherent" 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

Deductive coherence and norm adoption  

Science Journals Connector (OSTI)

......Issue: Normative Multiagent Systems Deductive coherence and norm adoption Sindhu Joseph Artificial Intelligence...contribution to the formalisation of Thagards coherence theory. The term coherence is defined as the quality or the state of cohering......

Sindhu Joseph; Carles Sierra; Marco Schorlemmer; Pilar Dellunde

2010-02-01T23:59:59.000Z

102

Linac Coherent Light Source (LCLS) | U.S. DOE Office of Science...  

Office of Science (SC) Website

Syncrotron Light Source (NSLS-II) Stanford Synchrotron Radiation Light Source (SSRL) Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Projects...

103

Coherence versus interferometric resolution  

Science Journals Connector (OSTI)

We examine the relation between second-order coherence and resolution in the interferometric detection of phase shifts. While for classical thermal light resolution and second-order coherence are synonymous, we show that for quantum light beams reaching optimum precision second-order coherence and resolution become antithetical.

Alfredo Luis

2010-06-30T23:59:59.000Z

104

Coherence versus interferometric resolution  

SciTech Connect

We examine the relation between second-order coherence and resolution in the interferometric detection of phase shifts. While for classical thermal light resolution and second-order coherence are synonymous, we show that for quantum light beams reaching optimum precision second-order coherence and resolution become antithetical.

Luis, Alfredo [Departamento de Optica, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid (Spain)

2010-06-15T23:59:59.000Z

105

Projected performance of rf-linac-driven free-electron lasers in the VUV and soft x-ray regions  

SciTech Connect

A multidisciplinary team of Los Alamos scientists, supported by the US Department of Energy, has been developing the requisite technologies to extend free-electron laser (FEL) operation from infrared and visible wavelengths into the extreme-ultraviolet below 100 nm using rf-linear accelerator technology. The goal is to establish an XUV Free-Electron Laser User Facility, the next-generation light source that will make available to researchers optical power more than one-million times greater than provided by synchroton light sources. Based primarily on a series of FEL oscillators driven by a single, rf-linac, the Los Alamos facility is designed to generate broadly tunable, picosecond-pulse, coherent radiation spanning the soft x-ray through the ultraviolet to the visible spectral ranges from 1 nm to 400 nm. The FEL facility design is discussed and performance predicted. 3 figs., 5 tabs.

Newnam, B.E.

1987-12-01T23:59:59.000Z

106

Status of high current R&D Energy Recovery LINAC at Brookhaven National Laboratory  

SciTech Connect

An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch ({approx} 5 nC) and low normalized emittance ({approx} 5 mm-mrad) at an energy of 20 MeV. Flexible lattice of ERL loop provides a test-bed for investigating issues of transverse and longitudinal instabilities, and diagnostics for intense CW e-beam. The superconducting 703 MHz RF photoinjector is considered as an electron source for such a facility. We will start with a straight pass (gun - 5 cell cavity - beam stop) test for the SRF Gun performance studies. Later, we will install and test a novel injection line concept for emittance preservation in a lower energy merger. In this paper we present the status and our plans for construction and commissioning of this facility.

Kayran, D.; Altinbas Z.; Beavis D.; Ben-Zvi I.; Calaga R.; Gassner D.M.; Hahn H.; Hammons L.; Jain A.; Jamilkowski J.; Lambiase R.; Lederle D.; Litvinenko V.N.; Laloudakis N.; Mahler G.; McIntyre G.; Meng W.; Oerter B.; Pate D.; Phillips D.; Reich J.; Roser T.; Schultheiss C.; Seda T.; Sheehy B.; Srinivasan-Rao T.; Than R.; Tuozzolo J.; Weiss D.; Xu W.; Zaltsman A.

2011-03-28T23:59:59.000Z

107

Linac4 Low Energy Beam Measurements with Negative Hydrogen  

E-Print Network (OSTI)

Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

2013-01-01T23:59:59.000Z

108

Multipass Arc Lattice Design for Recirculating Linac Muon Accelerators  

SciTech Connect

Recirculating linear accelerators (RLA) are the most likely means to achieve rapid acceleration of short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. A drawback of this scheme is that a separate return arc is required for each passage of the muons through the linac. In the work described here, a novel arc optics based on a Non-Scaling Fixed Field Alternating Gradient (NSFFAG) lattice is developed, which would provide sufficient momentum acceptance to allow multiple passes (two or more consecutive energies) to be transported in one string of magnets. An RLA with significantly fewer arcs will reduce the cost. We will develop the optics and technical requirements to allow the maximum number of passes by using an adjustable path length to accurately control the returned beam to synchronize with the linac RF phase.

G.M. Wang, R.P. Johnson, S.A. Bogacz, D. Trbojevic

2009-05-01T23:59:59.000Z

109

The Linac Injector For The ANL 7 Ge V Advanced Photon Source  

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

Injector For The ANL 7 Ge V Injector For The ANL 7 Ge V Advanced Photon Source A. Nassiri, W. Wesolowski, and G. Mavrogenes Argonne National Laboratory Submitted to the 1990 LINAC Conferece Albuquerque, New Mexico LS-154 9/28/90 TEE LINAC INJECTOR FOR TEE ANL 7 G<.iJ,V ADVANCED PHOTON SOORCE* A. Nassiri, W. Wesolowski, and G. Mavrogenes Argonne National Laboratory 9700 South Cass Avenue Argonne, IL 60439 USA Abstract The Argonne Advanced Photon Source (APS) linac system consists of a 200 MeV electron linac, a positron converter, and a 450 MeV positron linac. Design parameters and computer simulations of the two linac systems are presented. Introduction The Argonne Advanced Photon Source is a 7 GeV synchrotron X-Ray facility. The APS machine parameters have been described.

110

HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS  

SciTech Connect

It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

Deibele, Craig Edmond [ORNL] [ORNL; Curry, Douglas E [ORNL] [ORNL; Dickson, Richard W [ORNL] [ORNL

2012-01-01T23:59:59.000Z

111

Coherence of neutron fields  

Science Journals Connector (OSTI)

Glauber's definition of quantum coherence is used for neutron fields under the assumption that the complete occupation number space is a direct product of Fermi subspaces. As a result, completely coherent microfields are obtained which define a density operator in full analogy to Glauber's P representation of boson fields. For better physical significance, a transformation from the P representation to a momentum representation is performed. It is proved that the second-order coherence function in this representation is equivalent to Wolf's second-order coherence function of a classical Dirac field. Finally, the results of the theory are used to calculate explicitly the second-order coherence function and the coherence time of an ideally collimated neutron beam.

E. Ledinegg and E. Schachinger

1983-05-01T23:59:59.000Z

112

Generalized coherent states  

E-Print Network (OSTI)

In the coherent state of the harmonic oscillator, the probability density is that of the ground state subjected to an oscillation along a classical trajectory. Senitzky and others pointed out that there are states of the harmonic oscillator corresponding to an identical oscillatory displacement of the probability density of any energy eigenstate. These generalizations of the coherent state are rarely discussed, yet they furnish an interesting set of quantum states of light that combine features of number states and coherent states. Here we give an elementary account of the quantum optics of generalized coherent states.

T. G. Philbin

2013-12-18T23:59:59.000Z

113

Coherent Expanded-Aerogels  

Science Journals Connector (OSTI)

Coherent Expanded-Aerogels ... Hydrophobization of Silica Aerogels: Insights from Quantitative Solid-State NMR Spectroscopy ... Hydrophobization of Silica Aerogels: Insights from Quantitative Solid-State NMR Spectroscopy ...

S. S. Kistler

1931-01-01T23:59:59.000Z

114

Coherence-induced entanglement  

Science Journals Connector (OSTI)

We show how atomic coherence can lead to entanglement between two thermal fields at a temperature T. We first show that the passage of a three-level atom in V configuration without coherence cannot create entanglement. However, if the excited states are driven by a microwave field, the resulting atomic coherence can lead to entanglement between the thermal fields. We show that, no matter how high the temperature of the fields is, the thermal fields can always be entangled in the presence of atomic coherence.

Fu-li Li; Han Xiong; M. Suhail Zubairy

2005-07-19T23:59:59.000Z

115

E-Print Network 3.0 - acelerador lineal linac Sample Search Results  

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

linacs and arcs. The arcs are identical in the sense that each has the same Source: Berg, J. Scott - Department of Physics, Brookhaven National Laboratory Collection: Physics...

116

E-Print Network 3.0 - aps linac rf Sample Search Results  

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

the gradient... - cient use of the linacs and the RF power, at the cost ... Source: Berg, J. Scott - Department of Physics, Brookhaven National Laboratory Collection: Physics 4...

117

The Muon LINAC for the International Design Study of the Neutrino Factory  

SciTech Connect

The first stage of muon acceleration in the Neutrino Factory utilises a superconducting linac to accelerate muons from 244 MeV to 900 MeV. The linac was split into three types of cryomodules with decreasing magnetic fields and increasing amounts of RF voltage but with the design of the superconducting solenoid and RF cavities being the same for all cryomodules. The current status of the muon linac for the International Design Study for the Neutrino Factory will be presented including a final lattice design of the linac and tracking simulations.

A. Kurup, C. Bontoiu, Morteza Aslaninejad, J. Pozimski, A. Bogacz, V.S. Morozov, Y.R. Roblin, K.B. Beard

2011-09-01T23:59:59.000Z

118

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...

119

High Current Energy Recovery Linac at BNL | U.S. DOE Office of...  

Office of Science (SC) Website

High Current Energy Recovery Linac at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of...

120

Single-cycle terahertz pulses with >0.2 V/A field amplitudes via coherent transition radiation  

SciTech Connect

We demonstrate terahertz pulses with field amplitudes exceeding 0.2 V/A generated by coherent transition radiation. Femtosecond, relativistic electron bunches generated at the Linac Coherent Light Source are passed through a beryllium foil, and the emitted radiation is characterized as a function of the bunch duration and charge. Broadband pulses centered at a frequency of 10 THz with energies of 140 {mu}J are measured. These far-below-bandgap pulses drive a nonlinear optical response in a silicon photodiode, with which we perform nonlinear autocorrelations that yield information regarding the terahertz temporal profile. Simulations of the spatiotemporal profile agree well with experimental results.

Daranciang, Dan [Department of Chemistry, Stanford University, Stanford, California 94305 (United States); PULSE Institute for Ultrafast Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Goodfellow, John [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Fuchs, Matthias; Ghimire, Shambhu [PULSE Institute for Ultrafast Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Wen, Haidan [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Reis, David A. [PULSE Institute for Ultrafast Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Loos, Henrik; Fisher, Alan S. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Lindenberg, Aaron M. [PULSE Institute for Ultrafast Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

2011-10-03T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Single-cycle Terahertz Pulses with >0.2 V/A Field Amplitudes via Coherent Transition Radiation  

SciTech Connect

We demonstrate terahertz pulses with field amplitudes exceeding 0.2 V/{angstrom} generated by coherent transition radiation. Femtosecond, relativistic electron bunches generated at the Linac Coherent Light Source are passed through a beryllium foil, and the emitted radiation is characterized as a function of the bunch duration and charge. Broadband pulses centered at a frequency of 10 THz with energies of 140 {mu}J are measured. These far-below-bandgap pulses drive a nonlinear optical response in a silicon photodiode, with which we perform nonlinear autocorrelations that yield information regarding the terahertz temporal profile. Simulations of the spatiotemporal profile agree well with experimental results.

Daranciang, Dan; /Stanford U., Chem. Dept.; Goodfellow, John; /Stanford U. Materials Sci. Dept.; Fuchs, Matthias; /SIMES, Stanford /SLAC, PULSE; Wen, Haidan; /ANL, APS; Ghimire, Shambhu; /SLAC, PULSE; Reis, David A.; /SIMES, Sanford /SLAC, PULSE /Stanford U., Appl. Phys. Dept.; Loos, Henrik; Fisher, Alan S.; /SLAC, LCLS; Lindenberg, Aaron M.; /Stanford U. Materials Sci. Dept. /SIMES, Stanford /SLAC, PULSE

2012-02-15T23:59:59.000Z

122

Coherence vortices in Mie scattered nonparaxial partially coherent beams  

Science Journals Connector (OSTI)

We have previously demonstrated that Mie scattering of partially coherent plane waves can create coherence vortices, namely screw-type dislocations in the phase of the spectral degree...

Marasinghe, Madara L; Premaratne, Malin; Paganin, David M; Alonso, Miguel A

2012-01-01T23:59:59.000Z

123

Reverse Coherent Information  

Science Journals Connector (OSTI)

In this Letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This leads to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

Raúl García-Patrón; Stefano Pirandola; Seth Lloyd; Jeffrey H. Shapiro

2009-05-29T23:59:59.000Z

124

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

125

DESIGN FOR A 1.3 MW, 13 MEV BEAM DUMP FOR AN ENERGY RECOVERY LINAC*  

E-Print Network (OSTI)

DESIGN FOR A 1.3 MW, 13 MEV BEAM DUMP FOR AN ENERGY RECOVERY LINAC* Colin H. Smith+ , Yun He an Energy Recovery Linac (ERL) is dumped at an energy close to the injection energy. This energy is chosen to be as low as possible consistent with meeting the beam quality specifications. ERLs operate with high

126

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, Pavel [JLAB

2013-11-01T23:59:59.000Z

127

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, P., E-mail: Pavel.Evtushenko@jlab.org [Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2013-11-07T23:59:59.000Z

128

Coherence Holography and Spatial Frequency Comb for 3-D Coherence Imaging and Coherence Vortex Generation  

Science Journals Connector (OSTI)

The principle and the applications of a recently proposed unconventional holography technique, coherence holography, applied for coherence vortex generation, and a related technique...

Takeda, Mitsuo; Wang, Wei; Duan, Zhihui; Miyamoto, Yoko; Rosen, Joseph

129

Iris tilting and RF steering in the SLAC Linac  

SciTech Connect

For some time now, the sources of RF transverse beam steering in the SLAC Linac have been a mystery. The previously known sources, coupler asymmetries and survey misalignment, have predicted deflections which are frequently much smaller than the observed deflections. A new source of RF steering has been discovered: the tilting of accelerator irises. Measurements of iris tilting in a forty foot accelerator girder are compared with measurements of RF beam deflections and are found to be strongly correlated. 4 refs., 6 figs., 3 tabs.

Seeman, J.T.

1985-05-02T23:59:59.000Z

130

OPERATIONAL ASPECTS OF HIGH POWER ENERGY RECOVERY LINACS  

SciTech Connect

We have been operating a high-power energy-recovery linac (ERL) at Jefferson Lab for several years. In the process we have learned quite a bit about both technical and physics limitations in high power ERLs. Several groups are now considering new ERLs that greatly increase either the energy, the current or both. We will present some of our findings on what to consider when designing, building, and operating a high power ERL. Our remarks for this paper are limited to lattice design and setup, magnets, vacuum chamber design, diagnostics, and beam stability.

Stephen Benson; David Douglas; Pavel Evtushenko; Kevin Jordan; George Neil; Paul Powers

2006-08-21T23:59:59.000Z

131

Characterizing quantum coherence  

Science Journals Connector (OSTI)

For a system with canonical variables x and p, [x,p]=i?, we associate with each density operator ? an x coherence ?x and a p coherence ?p which specify, respectively, the characteristic distance and momentum range over which the underlying quantum-mechanical nature of the ensemble cannot be neglected. These coherences are less than or equal to the associated uncertainties ?x??x, ?p??p; so the ratios cx??x/?x, cp??p/?p give measures of the quantum character of the ensemble with respect to x and p. Examples are presented.

J. E. Sipe and N. Arkani-Hamed

1992-09-01T23:59:59.000Z

132

Workshop on scientific applications of short wavelength coherent light sources  

SciTech Connect

This report contains paper on the following topics: A 2 to 4nm High Power FEL On the SLAC Linac; Atomic Physics with an X-ray Laser; High Resolution, Three Dimensional Soft X-ray Imaging; The Role of X-ray Induced Damage in Biological Micro-imaging; Prospects for X-ray Microscopy in Biology; Femtosecond Optical Pulses ; Research in Chemical Physics Surface Science, and Materials Science, with a Linear Accelerator Coherent Light Source; Application of 10 GeV Electron Driven X-ray Laser in Gamma-ray Laser Research; Non-Linear Optics, Fluorescence, Spectromicroscopy, Stimulated Desorption: We Need LCLS' Brightness and Time Scale; Application of High Intensity X-rays to Materials Synthesis and Processing; LCLS Optics: Selected Technological Issues and Scientific Opportunities; Possible Applications of an FEL for Materials Studies in the 60 eV to 200 eV Spectral Region.

Spicer, W.; Arthur, J.; Winick, H.

1993-02-01T23:59:59.000Z

133

Workshop on scientific applications of short wavelength coherent light sources  

SciTech Connect

This report contains paper on the following topics: A 2 to 4nm High Power FEL On the SLAC Linac; Atomic Physics with an X-ray Laser; High Resolution, Three Dimensional Soft X-ray Imaging; The Role of X-ray Induced Damage in Biological Micro-imaging; Prospects for X-ray Microscopy in Biology; Femtosecond Optical Pulses?; Research in Chemical Physics Surface Science, and Materials Science, with a Linear Accelerator Coherent Light Source; Application of 10 GeV Electron Driven X-ray Laser in Gamma-ray Laser Research; Non-Linear Optics, Fluorescence, Spectromicroscopy, Stimulated Desorption: We Need LCLS` Brightness and Time Scale; Application of High Intensity X-rays to Materials Synthesis and Processing; LCLS Optics: Selected Technological Issues and Scientific Opportunities; Possible Applications of an FEL for Materials Studies in the 60 eV to 200 eV Spectral Region.

Spicer, W.; Arthur, J.; Winick, H.

1993-02-01T23:59:59.000Z

134

Compensating effect of the coherent synchrotron radiation in bunch compressors  

Typical bunch compression for a high-gain free-electron laser (FEL) requires a large compression ratio. Frequently, this compression is distributed in multiple stages along the beam transport line. However, for a high-gain FEL driven by an energy recovery linac (ERL), compression must be accomplished in a single strong compressor located at the beam line’s end; otherwise the electron beam would be affected severely by coherent synchrotron radiation (CSR) in the ERL’s arcs. In such a scheme, the CSR originating from the strong compressors could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressor that will limit the effect of CSR on the e-beam’s quality. We discuss our findings from a study of such a compressor, and detail its potential for an FEL driven by a multipass ERL developed for the electron-Relativistic Heavy Ion Collider.

Jing, Yichao; Hao, Yue; Litvinenko, Vladimir N.

2013-06-01T23:59:59.000Z

135

Library Cache Coherence  

E-Print Network (OSTI)

Directory-based cache coherence is a popular mechanism for chip multiprocessors and multicores. The directory protocol, however, requires multicast for invalidation messages and the collection of acknowledgement messages, ...

Shim, Keun Sup

2011-05-02T23:59:59.000Z

136

Linac4 45 keV Proton Beam Measurements  

E-Print Network (OSTI)

Linac4 is a 160 MeV normal-conducting H- linear accelerator, which will replace the 50 MeV proton Linac2 as injector for the CERN proton complex. Commissioning of the low energy part - comprising the H - source, a 45 keV Low Energy Beam Transport line (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) - will start in fall 2012 on a dedicated test stand installation. In preparation to this, preliminary measurements were taken using a 45 keV proton source and a temporary LEBT setup, with the aim of characterising the output beam by comparison with the predictions of simulations. At the same time this allowed a first verification of the functionalities of diagnostics instrumentation and acquisition software tools. Measurements of beam profile, emittance and intensity were taken in three different setups: right after the source, after the first and after the second LEBT solenoids respectively. Particle distributions were reconstructed from emittance scan...

Bellodi, G; Hein, L M; Lallement, J-B; Lombardi, A M; Midttun, O; Scrivens, R; Posocco, P A

2013-01-01T23:59:59.000Z

137

Superconducting RF Linac Technology for ERL Light Sources  

SciTech Connect

Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity�������¢����������������s Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

Chris Tennant

2005-08-01T23:59:59.000Z

138

Linac cryogenic distribution system maintenance and upgrades at JLab  

SciTech Connect

The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

Dixon, K.; Wright, M.; Ganni, V. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States)

2014-01-29T23:59:59.000Z

139

Linac cryogenic distribution system maintenance and upgrades at Jlab  

SciTech Connect

The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

Dixon, Kelly D. [JLAB; Wright, Mathew C. [JLAB; Ganni, Venkatarao [JLAB

2014-01-01T23:59:59.000Z

140

Coherence-driven effects in sentence and discourse processing  

E-Print Network (OSTI)

Intersentential CoherenceDiscussion of Coherence Results . . . . . . . . . . . . . .198 B Guidelines for Coherence

Rohde, Hannah

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

SAR image effects on coherence and coherence estimation.  

SciTech Connect

Radar coherence is an important concept for imaging radar systems such as synthetic aperture radar (SAR). This document quantifies some of the effects in SAR which modify the coherence. Although these effects can disrupt the coherence within a single SAR image, this report will focus on the coherence between separate images, such as for coherent change detection (CCD) processing. There have been other presentations on aspects of this material in the past. The intent of this report is to bring various issues that affect the coherence together in a single report to support radar engineers in making decisions about these matters.

Bickel, Douglas Lloyd

2014-01-01T23:59:59.000Z

142

ISAC SC-LINAC PHASE-II HELIUM REFRIGERATOR COMMISSIONING AND FIRST OPERATIONAL EXPERIENCE AT TRIUMF  

SciTech Connect

ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

Sekachev, I.; Kishi, D.; Laxdal, R. E. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada)

2010-04-09T23:59:59.000Z

143

Status of the Argonne heavy-ion-fusion low-beta linac  

SciTech Connect

The primary goal of the experimental program in heavy-ion fusion (HIF) at Argonne National Laboratory (ANL) during the next few years is to demonstrate many of the requirements of a RF linac driver for inertial-fusion power plants. So far, most of the construction effort has been applied to the front end. The ANL program has developed a high-intensity xenon source, a 1.5-MV preaccelerator, and the initial cavities of the low-beta linac. The design, initial tests, and status of the low-beta linac are described.

Watson, J.M.; Bogaty, J.M.; Moretti, A.; Sacks, R.A.; Sesol, N.Q.; Wright, A.J.

1981-01-01T23:59:59.000Z

144

Multi-Scale Optical Coherence Tomography Imaging  

E-Print Network (OSTI)

Fourier domain optical coherence tomography and methods forspeed spectral-domain optical coherence tomography at 1.3umJ. G. (1991). Optical coherence tomography. Science, 254(

Oliveira, Michael

2014-01-01T23:59:59.000Z

145

Sandia National Laboratories: Spontaneous Coherence and Spin...  

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

Spontaneous Coherence and Spin Texture Spontaneous Coherence and Spin Texture videobanner Spontaneous Coherence and Spin Texture in a Cold Exciton Gas (Watch Video) Speaker:...

146

THE SNS VACUUM CONTROL SYSTEM UPGRADE FOR THE SUPERCONDUCTING LINAC  

SciTech Connect

The superconducting linac of the Spallation Neutron Source (SNS) has 23 cryomodules whose vacuum system is monitored and controlled by custom built hardware. The original control hardware was provided by Thomas Jefferson National Accelerator Facility (JLab) and contained a variety of custom boards utilizing integrated circuits to perform logic. The need for control logic changes, a desire to increase maintainability, and a desire to increase flexibility to adapt for the future has led to a Programmable Logic Controller (PLC) based upgrade. This paper provides an overview of the commercial off-the-shelf (COTS) hardware being used in the superconducting vacuum control system. Details of the design and challenges to convert a control system during small windows of maintenance periods without disrupting beam operation will be covered in this paper.

Williams, Derrick C [ORNL] [ORNL

2009-01-01T23:59:59.000Z

147

Design study of a medical proton linac for neutron therapy  

SciTech Connect

This paper describes a design study which establishes the physical parameters of the low energy beam transport, radiofrequency quadrupole, and linac, using computer programs available at Fermilab. Beam dynamics studies verify that the desired beam parameters can be achieved. The machine described here meets the aforementioned requirements and can be built using existing technology. Also discussed are other technically feasible options which could be attractive to clinicians, though they would complicate the design of the machine and increase construction costs. One of these options would allow the machine to deliver 2.3 MeV protons to produce epithermal neutrons for treating brain tumors. A second option would provide 15 MeV protons for isotope production. 21 refs., 33 figs.

Machida, S.; Raparia, D.

1988-08-26T23:59:59.000Z

148

Ion optics of the Linac--LEB transfer line  

SciTech Connect

This report describes the ion optical properties of a proposed transfer line to inject a nominal 25 mA H{sup {minus}} beam at 600 MeV from the Linac into the Low Energy Booster (LEB) synchrotron. Ion optical investigations have been carried out in detail using the TRANSPORT, TURTLE and TRACE 3-D codes. The calculations take account of linear space charge effects of up to 50 mA average beam current. These effects have been found to be quite appreciable, especially on the longitudinal phase space. Procedure for their evaluation and optimization are described. Effects of some imperfections in the beam line magnets have been studied. 6 refs., 19 figs., 4 tabs.

Bhandari, R.K.; Penner, S.

1990-12-01T23:59:59.000Z

149

Maximal Privacy without Coherence  

Science Journals Connector (OSTI)

Privacy is a fundamental feature of quantum mechanics. A coherently transmitted quantum state is inherently private. Remarkably, coherent quantum communication is not a prerequisite for privacy: there are quantum channels that are too noisy to transmit any quantum information reliably that can nevertheless send private classical information. Here, we ask how much private classical information a channel can transmit if it has little quantum capacity. We present a class of channels Nd with input dimension d2, quantum capacity Q(Nd)?1, and private capacity P(Nd)=logd. These channels asymptotically saturate an interesting inequality P(N)?(1/2)[logdA+Q(N)] for any channel N with input dimension dA and capture the essence of privacy stripped of the confounding influence of coherence.

Debbie Leung; Ke Li; Graeme Smith; John A. Smolin

2014-07-16T23:59:59.000Z

150

Coherence in Microchip Traps  

Science Journals Connector (OSTI)

We report the coherent manipulation of internal states of neutral atoms in a magnetic microchip trap. Coherence lifetimes exceeding 1 s are observed with atoms at distances of 5–130????m from the microchip surface. The coherence lifetime in the chip trap is independent of atom-surface distance within our measurement accuracy and agrees well with the results of similar measurements in macroscopic magnetic traps. Because of the absence of surface-induced decoherence, a miniaturized atomic clock with a relative stability in the 10-13 range can be realized. For applications in quantum information processing, we propose to use microwave near fields in the proximity of chip wires to create potentials that depend on the internal state of the atoms.

Philipp Treutlein; Peter Hommelhoff; Tilo Steinmetz; Theodor W. Hänsch; Jakob Reichel

2004-05-21T23:59:59.000Z

151

Weighted Coherence: A More Effective Measure Than Average Coherence  

Science Journals Connector (OSTI)

In this study, we evaluated the effectiveness of the statistic, “Weighted Coherence” in relation to the average or mean coherence in a particular frequency band after cross- ... using cross-spectral analysis is r...

Vikram Kumar Yeragani; Arindam Barua…

2003-12-01T23:59:59.000Z

152

EA-1087: Finding of No Significant Impact | Department of Energy  

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

87: Finding of No Significant Impact 87: Finding of No Significant Impact EA-1087: Finding of No Significant Impact Proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California Based on the information and analysis in the EA, DOE has determined that the proposal to construct and operate the Induction Linac System Experiments project does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969. Therefore, a Finding of No Significant Impact is made and an Environmental Impact Statement is not required. EA-1087-FONSI-1995.pdf More Documents & Publications EA-1087: Final Environmental Assessment EA-1065: Finding of No Significant Impact

153

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:

154

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

Office of Science (SC) Website

High Current Energy Recovery Linac at High Current Energy Recovery Linac 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 High Current Energy Recovery Linac at BNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: High Current Energy Recovery Linac Developed at: Brookhaven National Laboratory, New York and Advanced Energy Systems, New

155

Beam energy spread in FERMI@elettra gun and linac induced by intrabeam scattering  

E-Print Network (OSTI)

spread in FERMI@elettra gun and linac induced by intrabeamcathode area in the electron guns know in the literature asmost visible within the electron gun where the electron beam

Zholents, Alexander A

2008-01-01T23:59:59.000Z

156

Beam Dynamics Studies for the First Muon Linac of the Neutrino Factory  

SciTech Connect

Within the Neutrino Factory Project the muon acceleration process involves a complex chain of accelerators including a (single-pass) linac, two recirculating linacs and an FFAG. The linac consists of RF cavities and iron shielded solenoids for transverse focusing and has been previously designed relying on idealized field models. However, to predict accurately the transport and acceleration of a high emittance 30 cm wide beam with 10 % energy spread requires detailed knowledge of fringe field distributions. This article presents results of the front-to-end tracking of the muon beam through numerically simulated realistic field distributions for the shielded solenoids and the RF fields. Real and phase space evolution of the beam has been studied along the linac and the results are presented and discussed.

C. Bontoiu,M. Aslaninejad,J. Pozimski,Alex Bogacz

2010-05-01T23:59:59.000Z

157

DESIGN OF THE PROTOTYPICAL CRYOMODULE FOR THE EUROTRANS SUPERCONDUCTING LINAC FOR NUCLEAR WASTE  

E-Print Network (OSTI)

DESIGN OF THE PROTOTYPICAL CRYOMODULE FOR THE EUROTRANS SUPERCONDUCTING LINAC FOR NUCLEAR WASTE of the accelerator workpackage of the EUROTRANS program for the design of a nuclear waste transmutation system

Boyer, Edmond

158

Beam diagnostics measurements at 3 MeV of the LINAC4 H- beam at CERN  

E-Print Network (OSTI)

As part of the CERN LHC injector chain upgrade, LINAC4 [1, 2] will accelerate H- ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been commissioned in the LINAC4 tunnel. Diagnostic devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

Zocca, F; Duraffourg, M; Focker, G J; Gerard, D; Kolad, B; Lenardon, F; Ludwig, M; Raich, U; Roncarolo, F; Sordet, M; Tan, J; Tassan-Viol, J; Vuitton, C; Feshenko, A

2014-01-01T23:59:59.000Z

159

HIGH INTENSITY LINAC DRIVER FOR THE SPIRAL-2 PROJECT : DESIGN OF SUPERCONDUCTING 88 MHZ QUARTER WAVE  

E-Print Network (OSTI)

HIGH INTENSITY LINAC DRIVER FOR THE SPIRAL-2 PROJECT : DESIGN OF SUPERCONDUCTING 88 MHZ QUARTER to the required energy. · Capability to accelerate ion beams of q/A=1/6 (up to 1 mA) in the future. The initial Abstract A superconducting linac driver, delivering deuterons with an energy up to 40 MeV (5 mA) and heavy

Paris-Sud XI, Université de

160

Quantum Coherence Engines  

E-Print Network (OSTI)

In a report published in Science, Scully et al propose to generate "phaseonium", and "extract work from a single heat bath via vanishing coherence" [1]. On the basis of the laws of physics, such a proposal is futile for at least two reasons.

Elias P. Gyftopoulos

2007-06-20T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Coherence in photoionization  

Science Journals Connector (OSTI)

We have detected coherence in a superposition of excited states by collecting photoelectrons. The superposition state is prepared by one laser pulse, and the photoelectrons are produced by a delayed laser pulse. We have described the experiment by the extension of a simple model and found the agreement with the data to be quite good.

Ting Shan Luk; Louis DiMauro; Mark Feldman; Harold Metcalf

1981-08-01T23:59:59.000Z

162

Nonlinear optics at maximum coherence  

Science Journals Connector (OSTI)

...D. Walls Nonlinear optics at maximum coherence S. E. Harris G. Y. Yin M. Jain H...optical processes which utilize maximum coherence of a non-allowed transition. The nonlinear...frequency. Nonlinear optics at maximum coherence B y S. E. Harris, G. Y. Yin, M...

1997-01-01T23:59:59.000Z

163

Coherence Transfer in Magnetic Fields  

Science Journals Connector (OSTI)

Some results recently discussed by Chiu for interatomic coherence transfer are shown to have a simple physical interpretation, to be independent of collision model assumed, and to be applicable also to intra -atomic coherence transfer. A derivation using density matrices is presented which takes both depolarizing collisions and backtransfer of coherence into account.

W. E. Baylis

1973-03-01T23:59:59.000Z

164

Coherent hybrid electromagnetic field imaging  

DOE Patents (OSTI)

An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.

Cooke, Bradly J. (Jemez Springs, NM); Guenther, David C. (Los Alamos, NM)

2008-08-26T23:59:59.000Z

165

Free electron laser amplifier driven by an induction linac  

SciTech Connect

This paper discusses the use of a free-electron laser amplifier as a means of converting the kinetic energy of an electron beam into coherent radiation. In particular, the use of an induction linear accelerator is discussed. The motion of the elections in the tapered and untapered wiggler magnets is discussed as well as the beam emittance, and the radiation fields involved. (LSP)

Neil, V.K.

1986-06-03T23:59:59.000Z

166

Preliminary Analysis on Linac Oscillation Data LI05-19 and Wake Field Energy Loss in FACET Commissioning 2012  

SciTech Connect

In this note, preliminary analysis on linac ocsillation data in FACET linac LI05-09 plus LI11-19 is presented. Several quadrupoles are identified to possibly have different strength, compared with their designed strength in the MAD optics model. The beam energy loss due to longitudinal wake fields in the S-band linac is also analytically calculated, also by LITRACK numerical simulations.

Sun, Yipeng; /SLAC

2012-07-23T23:59:59.000Z

167

Quantum correlation via quantum coherence  

E-Print Network (OSTI)

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative understanding of how quantum correlation is related to quantum coherence. We divide the coherence of a quantum state into several classes and find the complete coincidence between geometric (symmetric and asymmetric) quantum discords and some particular classes of quantum coherence. We propose a revised measure for total coherence and find that this measure can lead to a symmetric version of geometric quantum correlation which is analytic for two qubits. In particular, this measure can also arrive at a monogamy equality on the distribution of quantum coherence. Finally, we also quantify a remaining type of quantum coherence and find that for two qubits it is directly connected with quantum nonlocality.

Chang-shui Yu; Yang Zhang; Haiqing Zhao

2014-02-19T23:59:59.000Z

168

Coherence Controlled Soliton Interactions  

Science Journals Connector (OSTI)

We demonstrate theoretically and subsequently observe in experiment a novel type of soliton interaction when a pair of closely spaced spatial optical solitons as a whole is made partially incoherent. We explain how the character of the soliton interaction can be controlled by the total partial incoherence, and show a possibility to change the soliton interaction from attractive to repulsive, or vice versa, near a certain threshold in the coherence parameter.

Ting-Sen Ku; Ming-Feng Shih; Andrey A. Sukhorukov; Yuri S. Kivshar

2005-02-18T23:59:59.000Z

169

Breakdown of Coherence ?  

E-Print Network (OSTI)

In a recent paper, Albrecht Kyrieleis, Jeff Forshaw and I discovered a new tower of super-leading logarithms in gaps between jets cross sections. After discussions with the referee of our paper and further investigation, we have come to view this as a breakdown of naive coherence for initial state radiation. In this talk I illustrate this statement in a simple way, and show how it results in the super-leading logarithms.

Michael H. Seymour

2007-10-15T23:59:59.000Z

170

LANSCE Drift Tube Linac Water Control System Refurbishment  

SciTech Connect

There are several refurbishment projects underway at the Los Alamos National Laboratory LANSCE linear accelerator. Systems involved are: RF, water cooling, networks, diagnostics, timing, controls, etc. The Drift Tube Linac (DTL) portion of the accelerator consists of four DTL tanks, each with three independent water control systems. The systems are about 40 years old, use outdated and non-replaceable equipment and NIM bin control modules, are beyond their design life and provide unstable temperature control. Insufficient instrumentation and documentation further complicate efforts at maintaining system performance. Detailed design of the replacement cooling systems is currently in progress. Previous design experience on the SNS accelerator water cooling systems will be leveraged, see the SNS DTL FDR. Plans call for replacement of water piping, manifolds, pumps, valves, mix tanks, instrumentation (flow, pressure and temperature) and control system hardware and software. This presentation will focus on the control system design with specific attention on planned use of the National Instruments Compact RIO platform with the Experimental Physics and Industrial Control system (EPICS) software toolkit.

Marroquin, Pilar S. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

171

A Multi-MW Proton/Electron Linac at KEK  

E-Print Network (OSTI)

It is proposed that a multi-MW superconducting proton/electron linac (SCL) and a proton injector (PI) be built at KEK. The 3 GeV PI would serve both as an injector to the SCL and a source of proton beams that could be used to copiously produce neutrons and muons. Protons accelerated by the SCL to 20 GeV would be transferred through the KEK Tristan ring in order to create neutrino, kaon and muon beams for fixed-target experiments. At a later stage, a 60 GeV proton synchrotron could be installed inside the Tristan ring. The SCL, comprising 1.3 GHZ superconducting ILC-type rf cavities, could also accelerate polarized or unpolarized electron beams. After acceleration, electrons may traverse an XFEL undulator, or could be used to produce polarized positrons. An SCL-based synchrotron light source for applications in materials science and medicine is also envisaged. The proposed facility would be constructed using the existing KEK accelerator infrastructure.

Belusevic, Radoje

2014-01-01T23:59:59.000Z

172

MODEL AND BEAM BASED SETUP PROCEDURES FOR A HIGH POWER HADRON SUPERCONDUCTING LINAC  

SciTech Connect

This presentation will review methods for experimental determination of optimal operational set points in a multi-cavity superconducting high power hadron linac. A typical tuning process is based on comparison between measured data and the results of simulations from envelope and single-particle models. Presence of significant space charge effects requires simulation and measurement of bunch dynamics in 3 dimensions to ensure low loss beam transport. This is especially difficult in a superconducting linac where use of interceptive diagnostics is usually restricted because of the risk of SRF cavity surface contamination. The procedures discussed here are based on non-interceptive diagnostics such as beam position monitors and laser wires, and conventional diagnostics devices such as wire scanners and bunch shape monitors installed outside the superconducting linac. The longitudinal Twiss analysis based on the BPM signals will be described. The superconducting SNS linac tuning experience will be used to demonstrate problems and their solution for real world linac tune-up procedures

Shishlo, Andrei P [ORNL

2014-01-01T23:59:59.000Z

173

Progress update on cryogenic system for ARIEL E-linac at TRIUMF  

SciTech Connect

TRIUMF is involved in a major upgrade. The Advanced Rare IsotopeE Laboratory (ARIEL) has become a fully funded project in July 2010. A 10 mA 50 MeV SRF electron linac (e-linac) operating CW at 1.3 GHz is the key component of this initiative. This machine will serve as a second independent photo-fission driver for Rare Isotope Beams (RIB) production at TRIUMF's Isotope Separator and Accelerator (ISAC) facility. The cryogens delivery system requirements are driven by the electron accelerator cryomodule design [1, 2]. Since commencement of the project in 2010 the cryogenic system of e-linac has moved from the conceptual design phase into engineering design and procurement stage. The present document summarizes the progress in cryogenic system development and construction. Current status of e-linac cryogenic system including details of LN{sub 2} storage and delivery systems, and helium subatmospheric (SA) system is presented. The first phase of e-linac consisting of two cryomodules, cryogens storage, delivery, and distribution systems, and a 600 W class liquid helium cryoplant is scheduled for installation and commissioning by year 2014.

Koveshnikov, A.; Bylinskii, I.; Hodgson, G.; Yosifov, D. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada)

2014-01-29T23:59:59.000Z

174

7 Ĺ Resolution in Protein 2-Dimentional-Crystal X-Ray Diffraction at Linac Coherent Light Source  

SciTech Connect

Membrane proteins arranged as two-dimensional (2D) crystals in the lipid en- vironment provide close-to-physiological structural information, which is essential for understanding the molecular mechanisms of protein function. X-ray diffraction from individual 2D crystals did not represent a suitable investigation tool because of radiation damage. The recent availability of ultrashort pulses from X-ray Free Electron Lasers (X-FELs) has now provided a mean to outrun the damage. Here we report on measurements performed at the LCLS X-FEL on bacteriorhodopsin 2D crystals mounted on a solid support and kept at room temperature. By merg- ing data from about a dozen of single crystal diffraction images, we unambiguously identified the diffraction peaks to a resolution of 7 °A, thus improving the observable resolution with respect to that achievable from a single pattern alone. This indicates that a larger dataset will allow for reliable quantification of peak intensities, and in turn a corresponding increase of resolution. The presented results pave the way to further X-FEL studies on 2D crystals, which may include pump-probe experiments at subpicosecond time resolution.

Pedrini, Bill; Tsai, Ching-Ju; Capitani, Guido; Padeste, Celestino; Hunter, Mark; Zatsepin, Nadia A.; Barty, Anton; Benner, Henry; Boutet, Sebastien; Feld, Geoffrey K.; Hau-Riege, Stefan; Kirian, Rick; Kupitz, Christopher; Messerschmidt, Marc; Ogren, John I.; Pardini, Tommaso; Segelke, Brent; Williams, Garth J.; Spence , John C.; Abela, Rafael; Coleman, Matthew A.; Evans, James E.; Schertler, Gebhard; Frank, Matthias; Li, Xiao-Dan

2014-06-09T23:59:59.000Z

175

Quantum Privacy and Quantum Coherence  

Science Journals Connector (OSTI)

We derive a simple relation between a quantum channel's capacity to convey coherent (quantum) information and its usefulness for quantum cryptography.

Benjamin Schumacher and Michael D. Westmoreland

1998-06-22T23:59:59.000Z

176

Phase correlations and optical coherence  

Science Journals Connector (OSTI)

We examine the properties of the recently introduced degrees of coherence regarding the phase correlations of the optical field. It is seen that some of these quantities are...

Tervo, Jani; Setälä, Tero; Friberg, Ari T

2012-01-01T23:59:59.000Z

177

Coherence-induced entanglement  

E-Print Network (OSTI)

and these transitions are coupled resonantly with the asteriskmathReprinted with permission from Fuli Li, Han Xiong and M. Suhail Zubairy, Phys. Rev. A 72, 010303, (2005). Copyright (2005) by the American Physical Society. ?Readers may view, browse, and/or download... Zubairy Marlan O. Scully Committee Members, George R. Welch Goong Chen Head of Department, Edward Fry May 2006 Major Subject: Physics iii ABSTRACT Coherence-Induced Entanglement. (May 2006) Han Xiong, B.S., Peking University; M.S., Chinese Academy...

Xiong, Han

2006-08-16T23:59:59.000Z

178

Breakdown of QCD coherence ?  

E-Print Network (OSTI)

We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a sensitivity to emission at small angles and it leads to the appearance of super-leading logarithms. We use the `gaps between jets' cross-section as a concrete example and illustrate that the new logarithms are intimately connected with the presence of Coulomb gluon contributions. Numerical estimates of their potential phenomenological significance are presented.

A. Kyrieleis; J. R. Forshaw; M. H. Seymour

2006-12-16T23:59:59.000Z

179

Present and Future Optics Challenges at CHESS and for Proposed Energy Recovery Linac Source of Synchrotron Radiation  

E-Print Network (OSTI)

Present and Future Optics Challenges at CHESS and for Proposed Energy Recovery Linac Source-ray optics, energy-recovery linac, high brilliance 1. INTRODUCTION As one of the pioneer synchrotron in the area of high heat load and high x-ray flux optics [1-5] since the high critical-energy wigglers

Shen, Qun

180

Resonance Excitation of Longitudinal High Order Modes in Project X Linac  

SciTech Connect

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

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

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Design, Manufacture and Measurements of Permanent Quadrupole Magnets for Linac4  

E-Print Network (OSTI)

Compact quadrupole magnets are required for the CCDTL (Cell-Coupled Drift Tube Linac) of Linac 4, a 160 MeV linear accelerator of negative hydrogen ions which will replace the old 50 MeV proton Linac2 at CERN. The magnets, of an overall physical length of 140 mm and an aperture diameter of 45 mm, are based on Sm2Co17 blocks and can provide an integrated gradient of up to 1.6 Tesla. The magnetic field quality is determined by 4 ferromagnetic pole tips, aligned together with the permanent magnets blocks inside a structure made in a single piece. Tuning bars allow to individually trim the magnetic flux provided by each pole, to correct possible differences between blocks and to modify the field gradient intensity within about 20% of the nominal value. The paper describes and discusses the design, manufacture and magnetic measurements of a first prototype magnet.

Tommasini, D; Thonet, P; Vorozhtsov, A

2012-01-01T23:59:59.000Z

182

Commissioning of the CERN LINAC4 BPM System with 50 Mev Proton Beamns  

E-Print Network (OSTI)

The new Linac4 at CERN will provide a 160 MeV H- ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations.

Tan, J; Sřby, L; Sordet, M; Wendt, M

2013-01-01T23:59:59.000Z

183

Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center  

SciTech Connect

A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

2012-07-01T23:59:59.000Z

184

New beam-charge interlock system for radiation safety at the KEKB injector linac  

Science Journals Connector (OSTI)

A new beam-charge interlock system is under development for radiation safety and machine protection at the KEKB injector linac. A hardware-based interlock system is required instead of the present software-based interlock system in order to boost its reliability. This system restricts the integrated amount of beamcharges delivered to four different storage rings. The beamcharges are measured using wall-current monitors and detection electronics at six locations along the linac. The detection electronics independently transmits a beam-abort request through a twisted hardwire cable directly to the safetycontrol system of the linac when the integrated amount of beamcharges exceeds a certain threshold level prescribed for each location. We describe the characteristics and performance of the new beam-charge interlock system along with the details of the experimental tests.

T. Suwada; E. Kadokura; M. Satoh; K. Furukawa

2008-01-01T23:59:59.000Z

185

INCREASED UNDERSTANDING OF BEAM LOSSES FROM THE SNS LINAC PROTON EXPERIMENT  

SciTech Connect

Beam loss is a major concern for high power hadron accelerators such as the Spallation Neutron Source (SNS). An unexpected beam loss in the SNS superconducting linac (SCL) was observed during the power ramp up and early operation. Intra-beam-stripping (IBS) loss, in which interactions between H- particles within the accelerated bunch strip the outermost electron, was recently identified as a possible cause of the beam loss. A set of experiments using proton beam acceleration in the SNS linac was conducted, which supports IBS as the primary beam loss mechanism in the SNS SCL.

Aleksandrov, Alexander V [ORNL] [ORNL; Shishlo, Andrei P [ORNL] [ORNL; Plum, Michael A [ORNL] [ORNL; Lebedev, Valerie [FNAL] [FNAL; Laface, Emanuele [ESS] [ESS; Galambos, John D [ORNL] [ORNL

2013-01-01T23:59:59.000Z

186

On coherence in parametric density estimation  

Science Journals Connector (OSTI)

......1990 research-article Miscellanea On coherence in parametric density estimation J...KullbackLeibler directed divergence has this coherence property whereas the corresponding symmetric...estimation is also discussed. Admissibility|Coherence|Kullback-Leibler divergence|Predictive......

J. AITCHISON

1990-12-01T23:59:59.000Z

187

Coherence lengths and neutron optics  

Science Journals Connector (OSTI)

The dynamical diffraction of divergent beams and its application to neutron interferometry are considered. The coherence properties of thermal neutrons are studied, and it is shown that the extreme anisotropy of dynamically diffracted wave packets should be included in the discussion of coherence lengths. Finally, the mechanism leading to a nondispersive phase shift is investigated.

D. Petrascheck

1987-05-01T23:59:59.000Z

188

Ultrabroadband coherent supercontinuum frequency comb  

SciTech Connect

We present detailed studies of the coherence properties of an ultrabroadband supercontinuum, enabled by a comprehensive approach involving continuous-wave laser sources to independently probe both the amplitude and phase noise quadratures across the entire spectrum. The continuum coherently spans more than 1.5 octaves, supporting Hz-level comparison of ultrastable lasers at 698 nm and 1.54 {mu}m. We present a complete numerical simulation of the accumulated comb coherence in the limit of many pulses, in contrast to the single-pulse level, with systematic experimental verification. The experiment and numerical simulations reveal the presence of quantum-seeded broadband amplitude noise without phase coherence degradation, including the discovery of a dependence of the supercontinuum coherence on the fiber fractional Raman gain.

Ruehl, Axel; McKay, Hugh; Thomas, Brian; Dong, Liang; Fermann, Martin E.; Hartl, Ingmar [IMRA America Inc., 1044 Woodridge Avenue, Ann Arbor, Michigan 48105 (United States); Martin, Michael J.; Cossel, Kevin C.; Chen Lisheng; Benko, Craig; Ye Jun [JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, 440 UCB, Boulder, Colorado 80309 (United States); Dudley, John M. [Institute FEMTO-ST, CNRS-University of Franche-Comte UMR 6174, Besancon (France)

2011-07-15T23:59:59.000Z

189

Cluster-impact fusion  

Science Journals Connector (OSTI)

We present a model for the cluster-impact-fusion experiments of Buehler, Friedlander, and Friedman, Calculated fusion rates as a function of bombarding energy for constant cluster size agree well with experiment. The dependence of the fusion rate on cluster size at fixed bombarding energy is explained qualitatively. The role of correlated, coherent collisions in enhanced energy loss by clusters is emphasized.

P. M. Echenique; J. R. Manson; R. H. Ritchie

1990-03-19T23:59:59.000Z

190

Coherence in Classical Electromagnetism and Quantum Optics.  

E-Print Network (OSTI)

??This thesis is a study of coherence theory in light in classical electromagnetism and quantum optics. %The coherence is quantified Specifically two quantities are studied:… (more)

Mevik, Hanne-Torill

2009-01-01T23:59:59.000Z

191

Multiphoton Absorption and Coherence  

Science Journals Connector (OSTI)

We study the probability for multiphoton absorption processes induced by both laser and thermal light acting on an atomic system. When the thermal radiation, suitably filtered, has the same frequency spectrum and the same total energy as the laser packet, we find that the ratio between the relative probabilities for s-photon absorption can be expressed by (4?)-12(s-1)s!s12(?c?)s-1, where ? is the time during which the atomic system is illuminated by thermal radiation with coherence time ?c. This shows that multiphoton absorption processes depend on the statistical properties of the incident light, and that the probability induced by the laser packet is certainly greater than that induced by the thermal light if s

S. Carusotto; G. Fornaca; E. Polacco

1968-01-25T23:59:59.000Z

192

Coherence and Partial Coherence in Interacting Electron Systems  

Science Journals Connector (OSTI)

We study coherence of electron transport through interacting quantum dots and discuss the relation of the coherent part to the flux-sensitive conductance for three different types of Aharonov-Bohm interferometers. Contributions to transport in first and second order in the intrinsic linewidth of the dot levels are addressed in detail. We predict an asymmetry of the interference signal around resonance peaks as a consequence of incoherence associated with spin-flip processes. Furthermore, we show by strict calculation that first-order contributions can be partially or even fully coherent. This contrasts with the sequential-tunneling picture which describes first-order transport as a sequence of incoherent processes.

Jürgen König and Yuval Gefen

2001-04-23T23:59:59.000Z

193

Reliable-linac design for accelerator-driven subcritical reactor systems.  

SciTech Connect

Accelerator reliability corresponding to a very low frequency of beam interrupts is an important new accelerator requirement for accelerator-driven subcritical reactor systems. In this paper we review typical accelerator-reliability requirements and discuss possible methods for meeting these goals with superconducting proton-linac technology.

Wangler, Thomas P.,

2002-01-01T23:59:59.000Z

194

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC S. Schreiber. For this, an rf-gun based photoinjec- tor was installed late 1998 and is in operation since then gun [4] to match the beam charcteristics as close as pos- sible to the TESLA proposal. It is able

195

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber was produced by a sub-harmonic in- jector using a thermionic gun, a buncher cavity, and one standard Linear Collider, a laser driven rf gun has been de- veloped and been brought in operation late fall 1998

196

PHOTOINJECTED ENERGY RECOVERY LINAC UPGRADE FOR THE NATIONAL SYNCHROTRON LIGHT SOURCE *  

E-Print Network (OSTI)

PHOTOINJECTED ENERGY RECOVERY LINAC UPGRADE FOR THE NATIONAL SYNCHROTRON LIGHT SOURCE * Ilan Ben of the National Synchrotron Light Source (NSLS). This upgrade will be based on the Photoinjected Energy Recovering limitations. First, the emittance of a storage ring based light source is proportional to the energy

Brookhaven National Laboratory

197

Novel linac structures for low-beta ions and for muons  

SciTech Connect

Development of two innovative linacs is discussed. (1) High-efficiency normal-conducting accelerating structures for ions with beam velocities in the range of a few percent of the speed of light. Two existing accelerator technologies - the H-mode resonator cavities and transverse beam focusing by permanent-magnet quadrupoles (PMQ) - are merged to create efficient structures for light-ion beams of considerable currents. The inter-digital H-mode accelerator with PMQ focusing (IH-PMQ) has the shunt impedance 10-20 times higher than the standard drift-tube linac. Results of the combined 3-D modeling for an IH-PMQ accelerator tank - electromagnetic computations, beam-dynamics simulations, and thermal-stress analysis - are presented. H-PMQ structures following a short RFQ accelerator can be used in the front end of ion linacs or in stand-alone applications like a compact mobile deuteron-beam accelerator up to a few MeV. (2) A large-acceptance high-gradient linac for accelerating low-energy muons in a strong solenoidal magnetic field. When a proton beam hits a target, many low-energy pions are produced almost isotropically, in addition to a small number of high-energy pions in the forward direction. We propose to collect and accelerate copious muons created as the low-energy pions decay. The acceleration should bring muons to a kinetic energy of {approx}200 MeV in about 10 m, where both an ionization cooling of the muon beam and its further acceleration in a superconducting linac become feasible. One potential solution is a normal-conducting linac consisting of independently fed O-mode RF cavities with wide apertures closed by thin metal windows or grids. The guiding magnetic field is provided by external superconducting solenoids. The cavity choice, overall linac design considerations, and simulation results of muon acceleration are presented. Potential applications range from basic research to homeland defense to industry and medicine.

Kurennoy, Sergey S [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

198

A Proposal for First-Ever Measurement of Coherent Neutrino-Nucleus Scattering  

SciTech Connect

We propose to build and deploy a 10-kg dual-phase argon ionization detector for the detection of coherent neutrino-nucleus scattering, which is described by the reaction; {nu} + (Z,N) {yields} {nu} + (Z,N), where {nu} is the scattering neutrino, and (Z,N) is the target nucleus of atomic number Z and neutron number N. Its detection would validate central tenets of the Standard Model. We have built a gas-phase argon ionization detector to determine the feasibility of measuring the small recoil energies ({approx} 1keV) predicted from coherent neutrino scattering, and to characterize the recoil spectrum of the argon nuclei induced by scattering from medium-energy neutrons. We present calibrations made with 55-Fe, a low-energy X-ray source, and report on measurements to date of the recoil spectra from the 2-MeV LINAC Li-target neutron source at LLNL. A high signal-to-noise measurement of the recoil spectrum will not only serve as an important milestone in achieving the sensitivity necessary for measuring coherent neutrino-nucleus scattering, but will break new scientific ground on its own.

Winant, C D; Bernstein, A; Foxe, M P; Hagmann, C A; Jovanovic, I; Kazkaz, K M; Stoeffl, W S

2008-02-05T23:59:59.000Z

199

Coherence and destruction of coherence in mesoscopic rings  

Science Journals Connector (OSTI)

Recent investigations have shown that an important contribution to the magnetic response of an ensemble of mesoscopic normal metal rings at low temperatures is given by the coherent backscattering familiar fro...

Ulrich Eckern

1991-01-01T23:59:59.000Z

200

Coherence polarization filtering and relation with intrinsic degrees of coherence  

Science Journals Connector (OSTI)

It is demonstrated for stationary fields that when the polarization state of the electric field can be modified arbitrarily the maximal value of the modulus of the degree of coherence...

Réfrégier, Philippe; Roueff, Antoine

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

INJECTORS H. Hayano and M. Ross, Chairmen Presentations H. Hayano, "Linac Beam Stability"  

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

2 2 INJECTORS H. Hayano and M. Ross, Chairmen Presentations H. Hayano, "Linac Beam Stability" S. Takeda, "Injector Linac Performance" S. Kashiwagi, "ECS Performance" K. Kubo, "Lattice Diagnostic (Linear Optics and Beta-Match)" T. Naito, "Performance of SR Monitor" . . . H. Hayano, "Performance of Alignment Method" J. Urakawa, "Summary of Ring Circumference Issue (Including Wiggler Issue)" N. Terunuma, "Summary of Vacuum Chamber Design Including Ring Impedance" T. Okugi, "Performance of Orbit Measurement" J. Urakawa, "Summary of Emittance Tuning" T. Raubenheimer, "Parameters - Combined Session" D. Yeremian, "Bunching Stability" J. Turner, "Injector Linac Performance"

202

On Coherence Lengths of Wave Packets  

Science Journals Connector (OSTI)

......research-article Articles A60 A64 On Coherence Lengths of Wave Packets Kenzo Ishikawa...University, Sapporo 060-0810, Japan The coherence lengths of one-particle states described...finite spatial size that we call the coherence length. The coherence lengths in the......

Kenzo Ishikawa; Yutaka Tobita

2009-11-01T23:59:59.000Z

203

Coherence-controlled holographic microscope  

Science Journals Connector (OSTI)

Transmitted-light coherence-controlled holographic microscope (CCHM) based on an off-axis achromatic interferometer allows us to use light sources of arbitrary degree of temporal and...

Kolman, Pavel; Chmelík, Radim

2010-01-01T23:59:59.000Z

204

Quantum Coherence of Relic Neutrinos  

Science Journals Connector (OSTI)

We argue that in at least a portion of the history of the Universe the relic background neutrinos are spatially extended, coherent superpositions of mass states. We show that an appropriate quantum mechanical treatment affects the neutrino mass values derived from cosmological data. The coherence scale of these neutrino flavor wave packets can be an appreciable fraction of the causal horizon size, raising the possibility of spacetime curvature-induced decoherence.

George M. Fuller and Chad T. Kishimoto

2009-05-22T23:59:59.000Z

205

Coherence Holography: A Thought on Synthesis and Analysis of Optical Coherence Fields  

Science Journals Connector (OSTI)

Coherence plays fundamental role in holography and interferometry, and control of coherence is essential in an illumination system for...coherence holography..., which was developed recently for synthesis and ana...

Mitsuo Takeda; Wei Wang; Dinesh N. Naik

2009-01-01T23:59:59.000Z

206

Coherent quasiparticle approximation cQPA and nonlocal coherence  

E-Print Network (OSTI)

We show that the dynamical Wigner functions for noninteracting fermions and bosons can have complex singularity structures with a number of new solutions accompanying the usual mass-shell dispersion relations. These new shell solutions are shown to encode the information of the quantum coherence between particles and antiparticles, left and right moving chiral states and/or between different flavour states. Analogously to the usual derivation of the Boltzmann equation, we impose this extended phase space structure on the full interacting theory. This extension of the quasiparticle approximation gives rise to a self-consistent equation of motion for a density matrix that combines the quantum mechanical coherence evolution with a well defined collision integral giving rise to decoherence. Several applications of the method are given, for example to the coherent particle production, electroweak baryogenesis and study of decoherence and thermalization.

Matti Herranen; Kimmo Kainulainen; Pyry M. Rahkila

2009-12-14T23:59:59.000Z

207

Design Construction and Test Results of a HTS Solenoid for Energy Recovery Linac  

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

DESIGN CONSTRUCTION AND TEST RESULTS OF A HTS SOLENOID DESIGN CONSTRUCTION AND TEST RESULTS OF A HTS SOLENOID FOR ENERGY RECOVERY LINAC* R. Gupta # , M. Anerella, I. Ben-Zvi, G. Ganetis, D. Kayran, G. McIntyre, J. Muratore, S. Plate and W. Sampson, Brookhaven National Laboratory, Upton, NY, 11973 USA and M. Cole and D. Holmes, Advanced Energy Systems, Inc., Medord, NY, 11763 USA Abstract An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at ~77 K is simpler and cheaper than 4 K testing. This paper will present the

208

A versatile, high-power proton linac for accelerator driven transmutation technologies  

SciTech Connect

We are applying the new coupled-cavity drift-tube linac (CCDTL) to a conceptual design of a high-current, CW accelerator for transmutation applications. A 350-MHz RFQ followed by 700--MHz structures accelerates a 100-mA proton beam to I GeV. Several advantages stem from four key features: (1) a uniform focusing lattice from the start of the CCDTL at about 7 MeV to the end of the linac, (2) external location and separate mechanical support of the electromagnetic quadrupole magnets, (3) very flexible modular physics design and mechanical implementation, and (4) compact, high-frequency structures. These features help to reduce beam loss and, hence, also reduce potential radioactivation of the structure. They result in easy alignment, fast serviceability, and high beam availability. Beam funneling, if necessary, is possible at any energy after the RFQ.

Billen, J.H.; Nath, S.; Stovall, J.E.; Takeda, H.; Wood, R.L.; Young, L.M.

1995-05-01T23:59:59.000Z

209

Coherence Holography and Spatial Frequency Comb for 3-D Coherence Imaging  

Science Journals Connector (OSTI)

The principle and the applications of a recently proposed unconventional holography technique, called coherence holography, and a related technique for dispersion-free 3-D coherence...

Takeda, Mitsuo; Wang, Wei; Duan, Zhihui; Miyamoto, Yoko; Rosen, Joseph

210

Coherence and polarization properties of a radially polarized beam with variable spatial coherence  

Science Journals Connector (OSTI)

In a recent publication [Appl. Phys. Lett, 100, 051108 (2012)], a radially polarized (RP) beam with variable spatial coherence (i.e., partially coherent RP beam) was generated...

Wu, Gaofeng; Wang, Fei; Cai, Yangjian

2012-01-01T23:59:59.000Z

211

Coherence-Controlled Holographic Microscopy for Coherence-Gated Quantitative Phase Imaging  

Science Journals Connector (OSTI)

We show that the use of incoherent illumination in coherence-controlled holographic microscopy (CCHM) enables coherence-gated quantitative phase imaging of objects through turbid...

Slaby, Tomas; Kolman, Pavel; Dostal, Zbynek; Antos, Martin; Lostak, Martin; Krizova, Aneta; Collakova, Jana; Kollarova, Vera; Slaba, Michala; Vesely, Pavel; Chmelik, Radim

212

Quantum coherence and correlations in quantum system  

E-Print Network (OSTI)

Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we investigate the relative entropic measure of coherence. Based on its analytical expression, we give an operational interpretation of it with respect to the concept of quantum channel. On this basis, we derive the relation about the coherence and the coherent information in any quantum state. From the point of view of quantum measurement, we furthermore give three trade-offs among the coherence, discord-like and deficit-like quantum correlation quantities for any bipartite quantum state. As an application, we discuss the coherent property of the amplitude damping channel.

Zhengjun Xi; Yongming Li; Heng Fan

2014-08-14T23:59:59.000Z

213

Creating coherent animations from video  

Science Journals Connector (OSTI)

In this paper, different techniques for the creation of time coherent figurative animations from a video input are presented. The animations are generated using an analysis-synthesis approach. Information of the scene is extracted using only a 2D RGB image. No markers or depth planes are needed. After the analysis, the image is drawn again using the extracted information. To guarantee temporal coherence when redrawing the image, different alternatives have been explored: matching and interpolation on the parameters domain and gradient descent parameter update. All methods and variations are described and illustrated with images.

Javier Villegas; George Legrady

2014-01-01T23:59:59.000Z

214

Partial coherence with twin photons  

Science Journals Connector (OSTI)

An approach for calculating fourth-order coherence functions between fields produced in the parametric down-conversion process is proposed. It takes into account the transverse correlations between twin photons and is used to calculate the visibility of the interference patterns obtained in double-slit experiments with coincidence detection. The finite dimension of the light source and detectors are shown to be responsible for a kind of partial coherence which affects the visibility of the fringes. The results explain known features and predict other ones.

P. H. Souto Ribeiro

1997-11-01T23:59:59.000Z

215

Coherence Properties and Photon Correlation  

Science Journals Connector (OSTI)

An intensity-correlation experiment is proposed to test the second-order coherence of laser light from a cw-operated laser based on the Glauber formalism. The calculation utilizes the known form of the density matrix for radiation from a randomly excited source such as a discharge tube which is equivalent to filtered black-body radiation, and represents the laser radiation field by a coherent state. The intensity correlation calculated exhibits the standard Hanbury Brown-Twiss term and an extra term due to intensity interference between the Fourier components of the thermal field and the laser mode.

Hans Morawitz

1965-08-16T23:59:59.000Z

216

Coherence in Spontaneous Radiation Processes  

Science Journals Connector (OSTI)

By considering a radiating gas as a single quantum-mechanical system, energy levels corresponding to certain correlations between individual molecules are described. Spontaneous emission of radiation in a transition between two such levels leads to the emission of coherent radiation. The discussion is limited first to a gas of dimension small compared with a wavelength. Spontaneous radiation rates and natural line breadths are calculated. For a gas of large extent the effect of photon recoil momentum on coherence is calculated. The effect of a radiation pulse in exciting "super-radiant" states is discussed. The angular correlation between successive photons spontaneously emitted by a gas initially in thermal equilibrium is calculated.

R. H. Dicke

1954-01-01T23:59:59.000Z

217

Coherence length of neutron superfluids  

Science Journals Connector (OSTI)

The coherence length of superfluid neutron matter is calculated from the microscopic BCS wave function of a Cooper pair in momentum space making use of recent nucleon-nucleon potential models and including polarization (RPA) effects. We find as our main result that the coherence length is proportional to the Fermi momentum to pairing gap ratio, in good agreement with simple estimates used in the literature, with a nearly interaction independent constant of proportionality. Our calculations can be applied to the problem of inhomogeneous superfluidity of hadronic matter in the crust of a neutron star.

F. V. De Blasio; M. Hjorth-Jensen; Ř. Elgarřy; L. Engvik; G. Lazzari; M. Baldo; H.-J. Schulze

1997-10-01T23:59:59.000Z

218

Coherent scattering from a free gas  

E-Print Network (OSTI)

We investigate decoherence in atom interferometry due to scattering from a background gas and show that the supposition that residual coherence is due to near-forward scattering is incorrect. In fact, the coherent part is ...

Sanders, Scott N.

219

Phenotyping transgenic embryonic murine hearts using optical coherence tomography  

E-Print Network (OSTI)

Phenotyping transgenic embryonic murine hearts using optical coherence tomography Michael W optical coherence tomography (OCT) to characterize the morphological phenotype of embryonic murine hearts the etiology of heart defects. Optical coherence tomography (OCT)6,7 measures coherently gated backreflected

220

Heralded single-photon partial coherence  

Science Journals Connector (OSTI)

We study transverse spatial coherence of approximately localized single-photon states. We demonstrate nonlocal control over single-photon spatial coherence via projective measurements of an entangled twin and provide a theoretical interpretation from quantum coherence theory. Our results show that the spatial coherence of a single-photon state behaves similarly to that of a classical optical field, although the coincidence measurement adds a degree of freedom.

P. Ben Dixon; Gregory Howland; Mehul Malik; David J. Starling; R. W. Boyd; John C. Howell

2010-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Heralded single-photon partial coherence  

SciTech Connect

We study transverse spatial coherence of approximately localized single-photon states. We demonstrate nonlocal control over single-photon spatial coherence via projective measurements of an entangled twin and provide a theoretical interpretation from quantum coherence theory. Our results show that the spatial coherence of a single-photon state behaves similarly to that of a classical optical field, although the coincidence measurement adds a degree of freedom.

Dixon, P. Ben; Howland, Gregory; Starling, David J.; Howell, John C. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Malik, Mehul [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Boyd, R. W. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

2010-08-15T23:59:59.000Z

222

Chapter 4: Phenomenological Coherence Introduction  

E-Print Network (OSTI)

38 Chapter 4: Phenomenological Coherence Introduction The central thesis of this dissertation. In this chapter, I will highlight particular phenomenological aspects of this and other analogies. In following chapter, I will address the implications that these phenomenological properties have on cognitive

Maryland at College Park, University of

223

Scalar Diffraction in Terms of Coherence  

Science Journals Connector (OSTI)

...research-article Scalar Diffraction in Terms of Coherence W. H. Steel In scalar diffraction theory...correlation function, here called the 'coherence', rather than in quantities such as...diffraction is developed here based on the coherence between radiation at pairs of points...

1959-01-01T23:59:59.000Z

224

Coherence principles in dose-finding studies  

Science Journals Connector (OSTI)

......Trust December 2005 Article Articles Coherence principles in dose-finding studies...Revised April 2005. This paper studies the coherence conditions of dose-finding methods...toxic outcome has just been seen. The coherence conditions, motivated by ethical concerns......

Ying Kuen Cheung

2005-12-01T23:59:59.000Z

225

Coherence Frame, Entanglement Conservation, and Einselection  

E-Print Network (OSTI)

In this paper, the theory of coherence frame is developed. Two kinds of coherence frame are classified. Under coherence frame, the entanglement is conserved in the entanglement swapping process, without entanglement sudden death and birth. The einselection method for the preferred basis problem in the entangle process is shown as incomplete.

Dong-Sheng Wang

2011-04-29T23:59:59.000Z

226

Coherence Properties of Optical Fields  

Science Journals Connector (OSTI)

This article presents a review of coherence properties of electromagnetic fields and their measurements, with special emphasis on the optical region of the spectrum. Analyses based on both the classical and quantum theories are described. After a brief historical introduction, the elementary concepts which are frequently employed in the discussion of interference phenomena are summarized. The measure of second-order coherence is then introduced in connection with the analysis of a simple interference experiment and some of the more important second-order coherence effects are studied. Their uses in stellar interferometry and interference spectroscopy are described. Analysis of partial polarization from the standpoint of correlation theory is also outlined. The general statistical description of the field is discussed in some detail. The recently discovered universal "diagonal" representation of the density operator for free fields is also considered and it is shown how, with the help of the associated generalized phase-space distribution function, the quantum-mechanical correlation functions may be expressed in the same form as the classical ones. The sections which follow deal with the statistical properties of thermal and nonthermal light, and with the temporal and spatial coherence of blackbody radiation. Later sections, dealing with fourth- and higher-order coherence effects include a discussion of the photoelectric detection process. Among the fourth-order effects described in detail are bunching phenomena, the Hanbury Brown-Twiss effect and its application to astronomy. The article concludes with a discussion of various transient superposition effects, such as light beats and interference fringes produced by independent light beams.

L. MANDEL and E. WOLF

1965-04-01T23:59:59.000Z

227

Coherence vortices in one spatial dimension  

SciTech Connect

Coherence vortices are screw-type topological defects in the phase of Glauber's two-point degree of quantum coherence, associated with pairs of spatial points at which an ensemble-averaged stochastic quantum field is uncorrelated. Coherence vortices may be present in systems whose dimensionality is too low to support spatial vortices. We exhibit lattices of such quantum-coherence phase defects for a one-dimensional model quantum system. We discuss the physical meaning of coherence vortices and propose how they may be realized experimentally.

Simula, Tapio P.; Paganin, David M. [School of Physics, Monash University, Victoria 3800 (Australia)

2011-11-15T23:59:59.000Z

228

Measuring linac photon beam energy through EPID image analysis of physically wedged fields  

SciTech Connect

Purpose: Electronic portal imaging devices (EPIDs) have proven to be useful tools for measuring several parameters of interest in linac quality assurance (QA). However, a method for measuring linac photon beam energy using EPIDs has not previously been reported. In this report, such a method is devised and tested, based on fitting a second order polynomial to the profiles of physically wedged beams, where the metric of interest is the second order coefficient?. The relationship between ? and the beam quality index [percentage depth dose at 10 cm depth (PDD{sub 10})] is examined to produce a suitable calibration curve between these two parameters. Methods: Measurements were taken in a water-tank for beams with a range of energies representative of the local QA tolerances about the nominal value 6 MV. In each case, the beam quality was found in terms of PDD{sub 10} for 100 × 100 mm{sup 2} square fields. EPID images of 200 × 200 mm{sup 2} wedged fields were then taken for each beam and the wedge profile was fitted in MATLAB 2010b (The MathWorks, Inc., Natick, MA). ? was then plotted against PDD{sub 10} and fitted with a linear relation to produce the calibration curve. The uncertainty in ? was evaluated by taking five repeat EPID images of the wedged field for a beam of 6 MV nominal energy. The consistency of measuring ? was found by taking repeat measurements on a single linac over a three month period. The method was also tested at 10 MV by repeating the water-tank crosscalibration for a range of energies centered approximately about a 10 MV nominal value. Finally, the calibration curve from the test linac and that from a separate clinical machine were compared to test consistency of the method across machines in a matched fleet. Results: The relationship between? and PDD{sub 10} was found to be strongly linear (R{sup 2} = 0.979) while the uncertainty in ? was found to be negligible compared to that associated with measuring PDD{sub 10} in the water-tank (±0.3%). The repeat measurements over a three month period showed the method to be reasonably consistent (i.e., well within the limits defined by local QA tolerances). The measurements were repeated on a matched machine and the same linear relationship between ? and PDD{sub 10} was observed. The results for both machines were found to be indistinguishable across the energy range of interest (i.e., across and close to the thresholds defined by local QA tolerances), hence a single relation could be established across a matched fleet. Finally, the experiment was repeated on both linacs at 10 MV, where the linear relationship between ? and PDD{sub 10} was again observed. Conclusions: The authors conclude that EPID image analysis of physically wedged beam profiles can be used to measure linac photon beam energy. The uncertainty in such a measurement is dominated by that associated with measuring PDD{sub 10} in the water-tank; hence, the accuracies of these two methods are directly comparable. This method provides a useful technique for quickly performing energy constancy measurements while saving significant clinical downtime for QA.

Dawoud, S. M., E-mail: samir.dawoud@leedsth.nhs.uk; Weston, S. J.; Bond, I.; Ward, G. C.; Rixham, P. A.; Mason, J.; Huckle, A. [Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom)] [Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom); Sykes, J. R. [Institute of Medical Physics, School of Physics, The University of Sydney, New South Wales 2006, Australia and Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom)] [Institute of Medical Physics, School of Physics, The University of Sydney, New South Wales 2006, Australia and Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom)

2014-02-15T23:59:59.000Z

229

Development and reproducibility evaluation of a Monte Carlo-based standard LINAC model for quality assurance of multi-institutional clinical trials  

Science Journals Connector (OSTI)

......study, however, we plan to use mean values of...clinical institutions, and standard beam data for a variety...of other vendors. The standard LINAC model developed...archiving, retrieval and QA review of advanced technology...CONCLUSIONS An MC-based standard Varian LINAC model was......

Muhammad Nauman Usmani; Hideki Takegawa; Masaaki Takashina; Hodaka Numasaki; Masaki Suga; Yusuke Anetai; Keita Kurosu; Masahiko Koizumi; Teruki Teshima

2014-06-01T23:59:59.000Z

230

BEAM DYNAMICS STUDIES IN SPIRAL 2 LINAC R. Duperrier, D. Uriot, CEA Saclay, 91191 Gif sur Yvette; N. Pichoff , CEA Bruyres le Chtel, BP  

E-Print Network (OSTI)

to the LINAG driver. End-to-end simulations (low-energy beam lines, RFQ, medium-energy beam line, SC linac is proposed for the production of the radioactive ions, with the aim of at least 1013 fissions per second) and a superconducting linac with independent resonators (QWRs and/or HWRs). The accelerating optimisation has

Boyer, Edmond

231

Coherent Phase Argument for Inflation  

E-Print Network (OSTI)

Cosmologists have developed a phenomenally successful picture of structure in the universe based on the idea that the universe expanded exponentially in its earliest moments. There are three pieces of evidence for this exponential expansion -- {\\it inflation} -- from observations of anisotropies in the cosmic microwave background. First, the shape of the primordial spectrum is very similar to that predicted by generic inflation models. Second, the angular scale at which the first acoustic peak appears is consistent with the flat universe predicted by inflation. Here I describe the third piece of evidence, perhaps the most convincing of all: the phase coherence needed to account for the clear peak/trough structure observed by the WMAP satellite and its predecessors. I also discuss alternatives to inflation that have been proposed recently and explain how they produce coherent phases.

Scott Dodelson

2003-09-05T23:59:59.000Z

232

Intense slow positron production at the 15 MeV LINAC at Argonne National Laboratory  

Science Journals Connector (OSTI)

An intense slow positron beam using a 15 MeV LINAC (average current 1.25 × 1015 e?/s) at the Radiation and Photochemistry Group, Chemistry Division of Argonne National Laboratory (ANL) has been proposed and studied. Computer simulated results optimizing the positron yield and distribution of energy and angle show that a slow positron production at 1010 e+/s is possible. A proposed design of an intense slow positron beam with optimal conditions of incident electron, converter/moderator configurations, and extraction/transportation is presented.

H.M. Chen; Y.C. Jean; C.D. Jonah; S. Chemerisov; A.F. Wagner; D.M. Schrader; A.W. Hunt

2006-01-01T23:59:59.000Z

233

Measurements of Linac4 H Ion Source Beam with a Magnetized Einzel Lens Electron Dump  

E-Print Network (OSTI)

Linac4 is a part of the upgrade of CERN’s accelerator complex for increased luminosity in the LHC. A new system to extract the ion beam from the plasma generator has been designed and tested, in order to improve the reliability and beam optics of the pulsed H- ion source. This paper presents the successfully implemented extraction system and three different beam measurements. The simulations compare well to the measurements and show that the plasma density was too low for the extraction system design during the measurements.

Midttun, O; Scrivens, R

2013-01-01T23:59:59.000Z

234

Quantum coherence in two dimensions  

Science Journals Connector (OSTI)

The formation and evaporation of two-dimensional black holes are discussed. It is shown that if the radiation in minimal scalars has positive energy, there must be a global event horizon or a naked singularity. The former would imply loss of quantum coherence while the latter would lead to an even worse breakdown of predictability. CPT invariance would suggest that there ought to be past horizons as well. A way in which this could happen with wormholes is described.

S. W. Hawking and J. D. Hayward

1994-05-15T23:59:59.000Z

235

Coherence effects in neutrino oscillations  

Science Journals Connector (OSTI)

We study the effect of coherent and incoherent broadening on neutrino oscillations both in vacuum and in the presence of matter (the MSW effect). We show under very general assumptions that it is not possible to distinguish experimentally neutrinos produced in some region of space as wave packets from those produced in the same region of space as plane waves with the same energy distribution. © 1995 The American Physical Society.

Ken Kiers; Shmuel Nussinov; Nathan Weiss

1996-01-01T23:59:59.000Z

236

Pulsed spallation neutron source with an induction linac and a fixed-field alternating-gradient accelerator  

SciTech Connect

The paper describes an accelerator scenario of a Pulsed Spallation Neutron Source made of an Induction Linac injecting into a Fixed-Field Alternating-Gradient Accelerator (FFAG). The motivations underlying the proposal deal with the concern of removing technical risks peculiar to other scenarios involving RF Linacs, Synchrotrons and Accumulator Rings, which originate, for example, from the need of developing intense negative-ion sources and of multi-turn injection into the Compressor Rings. The system proposed here makes use of a positive-ion source of very short pulse duration, and of single-turn transfer into the circular accelerator.

Ruggiero, A.G. [Brookhaven National Lab., Upton, NY (United States); Bauer, G. [Paul Scherrer Institute, Villigen (Switzerland); Faltens, A. [Lawrence Berkeley National Lab., CA (United States)] [and others

1995-12-01T23:59:59.000Z

237

DEVELOPMENT OF A PRECISION TUNABLE GAMMA-RAY SOURCE DRIVEN BY A COMPACT X-BAND LINAC  

SciTech Connect

A precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development at LLNL. High-brightness, relativistic electron bunches produced by the linac interact with a Joule-class, 10 ps laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. The source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented.

Hartemann, F V; Albert, F; Anderson, G G; Anderson, S G; Bayramian, A J; Betts, S M; Chu, T S; Cross, R R; Ebbers, C A; Fisher, S E; Gibson, D J; Ladran, A S; Messerly, M J; Semenov, V A; Shverdin, M Y; Siders, C W; McNabb, D P; Barty, C J; Vlieks, A E; Jongewaard, E N; Tantawi, S G

2009-04-30T23:59:59.000Z

238

Simulations of Jitter Coupling due to Wakefields in the FACET Linac  

SciTech Connect

Facilities for Accelerator Science and Experimental Test Beams (FACET) is a proposed facility at SLAC that would use the initial two-thirds of the linac to transport e{sup +} and e{sup -} beams to an experimental region. A principal use of this facility is to identify the optimum method for accelerating positrons in a beam driven plasma wakefield accelerator. To study this, a positron bunch, followed an RF-cycle later by an electron bunch, will be accelerated to an asymmetric chicane designed to move the positrons behind the electrons, and then on to the plasma wakefield test stand. A major focus of study was the coupling of jitter of the positron bunch to the electron bunch via linac wakes. Lucretia is a Matlab toolbox for the simulation of electron beam transport systems, capable of multi-bunch tracking and wakefield calculations. With the exception of the lack of support for tracking of electrons and positrons within a single bunch train, it was well suited to the jitter coupling studies. This paper describes the jitter studies, including modifications made to Lucretia to correctly simulate tracking of mixed-species bunch trains through a lattice of magnetic elements and EM wakes.

Molloy, Stephen

2009-10-30T23:59:59.000Z

239

Compact X-ray Source using a High Repetition Rate Laser and Copper Linac  

E-Print Network (OSTI)

A design for a compact x-ray light source (CXLS) with flux and brilliance orders of magnitude beyond existing laboratory scale sources is presented. The source is based on inverse Compton scattering of a high brightness electron bunch on a picosecond laser pulse. The accelerator is a novel high-efficiency standing-wave linac and RF photoinjector powered by a single ultrastable RF transmitter at x-band RF frequency. The high efficiency permits operation at repetition rates up to 1 kHz, which is further boosted to 100 kHz by operating with trains of 100 bunches of 100 pC charge, each separated by 5 ns. The 100 kHz repetition rate is orders of magnitude beyond existing high brightness copper linacs. The entire accelerator is approximately 1 meter long and produces hard x-rays tunable over a wide range of photon energies. The colliding laser is a Yb:YAG solid-state amplifier producing 1030 nm, 100 mJ pulses at the same 1 kHz repetition rate as the accelerator. The laser pulse is frequency-doubled and stored for m...

Graves, W S; Brown, P; Carbajo, S; Dolgashev, V; Hong, K -H; Ihloff, E; Khaykovich, B; Lin, H; Murari, K; Nanni, E A; Resta, G; Tantawi, S; Zapata, L E; Kärtner, F X; Moncton, D E

2014-01-01T23:59:59.000Z

240

Does coherence enhance transport in photosynthesis?  

E-Print Network (OSTI)

Recent observations of coherence in photosynthetic complexes have led to the question of whether quantum effects can occur in vivo, not under femtosecond laser pulses but in incoherent sunlight and at steady state, and, if so, whether the coherence explains the high exciton transfer efficiency. We distinguish several types of coherence and show that although some photosynthetic pathways are partially coherent processes, photosynthesis in nature proceeds through stationary states. This distinction allows us to rule out several mechanisms of transport enhancement in sunlight. In particular, although they are crucial for understanding exciton transport, neither wavelike motion nor microscopic coherence, on their own, enhance the efficiency. By contrast, two partially coherent mechanisms---ENAQT and supertransfer---can enhance transport even in sunlight and thus constitute motifs for the optimisation of artificial sunlight harvesting. Finally, we clarify the importance of ultrafast spectroscopy in understanding incoherent processes.

Ivan Kassal; Joel Yuen-Zhou; Saleh Rahimi-Keshari

2012-10-18T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Does coherence enhance transport in photosynthesis?  

E-Print Network (OSTI)

Recent observations of coherence in photosynthetic complexes have led to the question of whether quantum effects can occur in vivo, not under femtosecond laser pulses but in incoherent sunlight and at steady state, and, if so, whether the coherence explains the high exciton transfer efficiency. We distinguish several types of coherence and show that although some photosynthetic pathways are partially coherent processes, photosynthesis in nature proceeds through stationary states. This distinction allows us to rule out several mechanisms of transport enhancement in sunlight. In particular, although they are crucial for understanding exciton transport, neither wavelike motion nor microscopic coherence, on their own, enhance the efficiency. By contrast, two partially coherent mechanisms---ENAQT and supertransfer---can enhance transport even in sunlight and thus constitute motifs for the optimisation of artificial sunlight harvesting. Finally, we clarify the importance of ultrafast spectroscopy in understanding i...

Kassal, Ivan; Rahimi-Keshari, Saleh

2012-01-01T23:59:59.000Z

242

Coherence delay augmented laser beam homogenizer  

DOE Patents (OSTI)

The geometrical restrictions on a laser beam homogenizer are relaxed by ug a coherence delay line to separate a coherent input beam into several components each having a path length difference equal to a multiple of the coherence length with respect to the other components. The components recombine incoherently at the output of the homogenizer, and the resultant beam has a more uniform spatial intensity suitable for microlithography and laser pantogography. Also disclosed is a variable aperture homogenizer, and a liquid filled homogenizer.

Rasmussen, P.; Bernhardt, A.

1993-06-29T23:59:59.000Z

243

Coherence delay augmented laser beam homogenizer  

DOE Patents (OSTI)

The geometrical restrictions on a laser beam homogenizer are relaxed by ug a coherence delay line to separate a coherent input beam into several components each having a path length difference equal to a multiple of the coherence length with respect to the other components. The components recombine incoherently at the output of the homogenizer, and the resultant beam has a more uniform spatial intensity suitable for microlithography and laser pantogography. Also disclosed is a variable aperture homogenizer, and a liquid filled homogenizer.

Rasmussen, Paul (Livermore, CA); Bernhardt, Anthony (Berkeley, CA)

1993-01-01T23:59:59.000Z

244

Low-coherence doppler lidar with multiple time coherence of reference and probe waves  

Science Journals Connector (OSTI)

The notion of multiple time coherence of optical beams is introduced and mathematically ... pulses (MFPs), which exhibit multiple time coherence, and the possibility of their application for ... is based on nanos...

G. G. Matvienko; S. N. Polyakov; V. K. Oshlakov

2007-11-01T23:59:59.000Z

245

Laser-induced "two-atom" coherence  

Science Journals Connector (OSTI)

Our analysis shows that if an electromagnetic field excites a coherent superposition of states of two different types of atoms, then the results of a collision of those two atoms can be quite different from the usual dephasing that a coherently excited atom suffers upon collision with another atom. We present the concept of "two-atom" coherence as one feature of this interaction where the field of a given wavelength may interact with the system coherently over a wide range of internuclear distances.

Munir H. Nayfeh and G. B. Hillard

1984-04-01T23:59:59.000Z

246

Coherent Control of Quantum Matter  

SciTech Connect

This talk addresses some recent work aimed at controlling the low-lying electrodynamics of quantum solids using strong field transients. The excitation of selected vibrational resonances to manipulate the many-body physics of one dimensional Mott Hubbard Insulators and to perturb competing orders in High-Tc superconductors is also covered. Finally, the speaker shows how the electrodynamics of layered superconductors can be driven through the orderparameter phase gradient, demonstrating ultrafast transistor action in a layered superconductor. Advances in the use of coherent optics, from tabletop sources to THz and x-ray free-electron lasers are also discussed.

Cavalleri, Andrea (Max Planck Institute) [Max Planck Institute

2011-10-05T23:59:59.000Z

247

Production and application of a novel energy-tunable X-ray source at the RPI LINAC  

E-Print Network (OSTI)

Production and application of a novel energy-tunable X-ray source at the RPI LINAC Bryndol Sones energy linewidth for example, Si(400) FWHM of 134 eV at 9.0 keV (2%). Per electron, the photon production-monochromatic, energy-tunable, and polarized X-ray source derived from the interaction of relativistic electrons

Danon, Yaron

248

coherence  

Science Journals Connector (OSTI)

1. Pertaining to a correlation between the phase points of two waves, such as lightwaves or radio waves, at the same instant or at the same point in space. 2. Pertaining to a correlation between the ...

2001-01-01T23:59:59.000Z

249

Coherence and Conservatism in the Dynamics of Belief II: Iterated Belief Change without Dispositional Coherence  

Science Journals Connector (OSTI)

......University Press 2003 Original Article Coherence and Conservatism in the Dynamics of Belief...Iterated Belief Change without Dispositional Coherence Hans Rott 1 1 Department of Philosophy...based on the conclusions of Rott, Coherence and Conservatism in the Dynamics of Belief......

Hans Rott

2003-02-01T23:59:59.000Z

250

Coherence and Flexibility in Dialogue Games for Argumentation  

Science Journals Connector (OSTI)

......2005 Original Article Original Articles Coherence and Flexibility in Dialogue Games for...particular, it allows for varying degrees of coherence and flexibility when it comes to maintaining...dialogue games, defeasible reasoning| Coherence and Flexibility in Dialogue Games for......

Henry Prakken

2005-12-01T23:59:59.000Z

251

Spin coherence transfer in chemical transformations monitored NMR  

E-Print Network (OSTI)

the transfer of spin coherence in non-equilibrium chemicalK. L. Pierce, A. Pines ? Spin coherence transfer in chemical10.1002/anie.200123456 Spin Coherence Transfer in Chemical

Anwar, Sabieh M.; Hilty, Christian; Chu, Chester; Bouchard, Louis-S.; Pierce, Kimberly L.; Pines, Alexander

2006-01-01T23:59:59.000Z

252

Coherence and Completeness of Population-based Family Cancer Reports  

Science Journals Connector (OSTI)

...research-article Research Articles Coherence and Completeness of Population-based...telephone survey in Connecticut examined coherence and completeness of reports from 1...household survey. This study describes the coherence and completeness of such reports in a...

Louise Wideroff; Anne O. Garceau; Mark H. Greene; Marsha Dunn; Timothy McNeel; Phuong Mai; Gordon Willis; Lou Gonsalves; Michael Martin; Barry I. Graubard

2010-03-01T23:59:59.000Z

253

COMMON KNOWLEDGE, COHERENT UNCERTAINTIES AND CONSENSUS  

E-Print Network (OSTI)

COMMON KNOWLEDGE, COHERENT UNCERTAINTIES AND CONSENSUS by Yakov Ben-Haim TECHNICAL REPORT ETR-2001 of Mechanical Engineering #12;Working Paper Common Knowledge, Coherent Uncertainties and Consensus Yakov Ben- and knowledge-functions, common knowledge and consensus. Our main results are that knowledge is constricted

Rimon, Elon

254

Time-optimal transfer of coherence  

Science Journals Connector (OSTI)

We provide exact analytical solutions for the problem of time-optimal transfer of coherence from one spin-polarization to a threefold coherence in a trilinear Ising chain with a fixed energy available and subject to local controls with a non-negligible time cost. The time of transfer is optimal and consistent with a previous numerical result obtained assuming instantaneous local controls.

Alberto Carlini and Tatsuhiko Koike

2012-11-26T23:59:59.000Z

255

The Fidelity and Trace Norm Distances for Quantifying Coherence  

E-Print Network (OSTI)

We investigate the coherence measures induced by fidelity and trace norm, based on the recent proposed coherence quantification in [Phys. Rev. Lett. 113, 140401, 2014]. We show that the fidelity of coherence does not in general satisfy the monotonicity requirement as a measure of coherence under the subselection of measurements condition. We find that the trace norm of coherence can act as a measure of coherence for qubit case and some special class of qutrits.

Lian-He Shao; Zhengjun Xi; Heng Fan; Yongming Li

2014-10-30T23:59:59.000Z

256

Half-Wave, beta=0.43 Cavity Prototyping for a Heavy Ion Linac  

SciTech Connect

A medium velocity half wave resonator has been designed and prototyped at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) for use in a heavy ion linac. The cavity is designed to provide 3.7 MV of accelerating voltage at an optimum beta = v/c = 0.53, with peak surface electric and magnetic fields of 32.5 MV/m and 79 mT, respectively. The cavity was designed for stiffness and tunability, as well as straightforward fabrication, assembly and cleaning. Measurements were performed to confirm Finite Element Analysis (FEA) predictions for modal analysis, bath pressure sensitivity, tuner stiffness and tuning range. A copper cavity prototype has been fabricated to confirm tolerances and formability. A tuner prototype has been built. The helium vessel and power coupler have been designed.

Popielarski, John [Michigan State University; Compton, Chris C. [Michigan State University; Hartung, Walter [Michigan State University; Johnson, Mat [Michigan State University; Oliva, John [Michigan State University; York, R. C. [Michigan State University; Marti, Felix [Michigan State University

2008-04-01T23:59:59.000Z

257

Postacceleration Of Laser-Generated High Energy Protons Through Conventional Accelerator Linacs  

SciTech Connect

The post-acceleration of laser-generated protons through conventional drift tube linear accelerators has been simulated with the particle code Parmela. The proton source is generated on the rear surface of a target irradiated by an high-intensity (10{sup 19} W{center_dot}cm{sup -2}) short-pulse (350 fs) laser and focused by a microlens that allows selecting collimated protons at 7{+-}0.1 MeV with rms unnormalized emittance of 0.180 mm.mrad. The simulations show that protons can be accelerated by one drift tube linac tank to more than 14 MeV with unnormalized emittance growth of 8 in x and 22.6 in y directions when considering a total proton charge of 0.112 mA. This result shows for the first time that coupling between laser-plasma accelerators with traditional accelerators is possible, allowing a luminosity gain for the final beam.

Fuchs, Julien; Audebert, Patrick [Laboratoire pour l'Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-Ecole Polytechnique-Universite Paris VI, Palaiseau (France); Antici, Patrizio [Laboratoire pour l'Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-Ecole Polytechnique-Universite Paris VI, Palaiseau (France); Dipartimento di Energetica, Universita di Roma 'La Sapienza', Via Scarpa 14-16, 00165 Roma (Italy); Fazi, Mauro; Migliorati, Mauro; Palumbo, Luigi [Dipartimento di Energetica, Universita di Roma 'La Sapienza', Via Scarpa 14-16, 00165 Roma (Italy); Lombardi, Augusto [ATreP via Perini 181, 38100, Trento (Italy)

2008-06-24T23:59:59.000Z

258

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

259

High Repetition Rate, LINAC-Based Nuclear Resonance Fluorescence FY 2008 Final Report  

SciTech Connect

This summarizes the first year of a multi-laboratory/university, multi-year effort focusing on high repetition rate, pulsed LINAC-based nuclear resonance fluorescence (NRF) measurements. Specifically, this FY2008 effort centered on experimentally assessing NRF measurements using pulsed linear electron accelerators, operated at various repetition rates, and identifying specific detection requirements to optimize such measurements. Traditionally, interest in NRF as a detection technology, which continues to receive funding from DHS and DOE/NA-22, has been driven by continuous-wave (CW), Van de Graff-based bremsstrahlung sources. However, in addition to the relatively sparse present-day use of Van de Graff sources, only limited NRF data from special nuclear materials has been presented; there is even less data available regarding shielding effects and photon source optimization for NRF measurements on selected nuclear materials.

Scott M Watson; Mathew T Kinlaw; James L Jones; Alan W. Hunt; Glen A. Warren

2008-12-01T23:59:59.000Z

260

Plasma ignition and steady state simulations of the Linac4 H$^{-}$ ion source  

E-Print Network (OSTI)

The RF heating of the plasma in the Linac4 H- ion source has been simulated using an Particle-in-Cell Monte Carlo Collision method (PIC-MCC). This model is applied to investigate the plasma formation starting from an initial low electron density of 1012 m-3 and its stabilization at 1018 m-3. The plasma discharge at low electron density is driven by the capacitive coupling with the electric field generated by the antenna, and as the electron density increases the capacitive electric field is shielded by the plasma and induction drives the plasma heating process. Plasma properties such as e-/ion densities and energies, sheath formation and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.

Mattei, S; Yasumoto, M; Hatayama, A; Lettry, J; Grudiev, A

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

The stripping foil test stand in the Linac4 transfer line  

E-Print Network (OSTI)

The 160 MeV H? beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H? charge-exchange injection system. It will include a stripping foil, to convert H? into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters.

Weterings, W; Noulibos, R; Sillanoli, Y; van Trappen, P

2015-01-01T23:59:59.000Z

262

Chromaticity of the lattice and beam stability in energy-recovery linacs  

SciTech Connect

Energy recovery linacs (ERLs) are an emerging generation of accelerators promising to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and hold the promise of delivering electron beams of unprecedented power and quality. Use of superconducting radio-frequency (SRF) cavities converts ERLs into nearly perfect 'perpetuum mobile' accelerators, wherein the beam is accelerated to a desirable energy, used, and then gives the energy back to the RF field. One potential weakness of these devices is transverse beam break-up instability that could severely limit the available beam current. In this paper, I present a method of suppressing these dangerous effects using a natural phenomenon in the accelerators, viz., the chromaticity of the transverse motion.

Litvinenko, V.N.

2011-12-23T23:59:59.000Z

263

Precision X-Band Linac Technologies for Nuclear Photonics Gamma-Ray Sources  

SciTech Connect

Nuclear photonics is an emerging field of research requiring new tools, including high spectral brightness, tunable gamma-ray sources; high photon energy, ultrahigh-resolution crystal spectrometers; and novel detectors. This presentation focuses on the precision linac technology required for Compton scattering gamma-ray light sources, and on the optimization of the laser and electron beam pulse format to achieve unprecedented spectral brightness. Within this context, high-gradient X-band technology will be shown to offer optimal performance in a compact package, when used in conjunction with the appropriate pulse format, and photocathode illumination and interaction laser technologies. The nascent field of nuclear photonics is enabled by the recent maturation of new technologies, including high-gradient X-band electron acceleration, robust fiber laser systems, and hyper-dispersion CPA. Recent work has been performed at LLNL to demonstrate isotope-specific detection of shielded materials via NRF using a tunable, quasi-monochromatic Compton scattering gamma-ray source operating between 0.2 MeV and 0.9 MeV photon energy. This technique is called Fluorescence Imaging in the Nuclear Domain with Energetic Radiation (or FINDER). This work has, among other things, demonstrated the detection of {sup 7}Li shielded by Pb, utilizing gamma rays generated by a linac-driven, laser-based Compton scattering gamma-ray source developed at LLNL. Within this context, a new facility is currently under construction at LLNL, with the goal of generating tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range, at a repetition rate of 120 Hz, and with a peak brightness in the 10{sup 20} photons/(s x mm{sup 2} x mrad{sup 2} x 0.1% bw).

Hartemann, F V; Albert, F; Anderson, S G; Bayramian, A J; Cross, R R; Ebbers, C A; Gibson, D J; Houck, T L; Marsh, R A; Messerly, M J; Siders, C W; McNabb, D P; Barty, C J; Adolphsen, C E; Chu, T S; Jongewaard, E N; Tantawi, S G; Vlieks, A E; Wang, F; Wang, J W; Raubenheimer, T O; Ighigeanu, D; Toma, M; Cutoiu, D

2011-08-31T23:59:59.000Z

264

Laser Seeding Yields High-Power Coherent Terahertz Radiation  

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

Laser Seeding Yields High-Power Coherent Terahertz Radiation Laser Seeding Yields High-Power Coherent Terahertz Radiation Print Wednesday, 25 April 2007 00:00 Researchers at...

265

Laser Seeding Yields High-Power Coherent Terahertz Radiation  

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

Laser Seeding Yields High-Power Coherent Terahertz Radiation Print Researchers at Berkeley Lab have been exploring the ways coherent synchrotron radiation (CSR) is generated in...

266

Coherence length tunable semiconductor laser with optical feedback  

Science Journals Connector (OSTI)

We report the experimental results to continuously tune the coherence length of a semiconductor laser using an optical feedback scheme. The coherence length can be controlled by...

Wang, Yuncai; Kong, Lingqin; Wang, Anbang; Fan, Linlin

2009-01-01T23:59:59.000Z

267

Coherence-Preserving Quantum Bits  

Science Journals Connector (OSTI)

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a Hamiltonian made up solely of two-body interactions between four two-level systems (qubits) which has a 2-fold degenerate ground state. This degenerate ground state has the property that any decoherence process acting on an individual physical qubit must supply energy from the bath to the system. Quantum information can be encoded into the degeneracy of the ground state and such coherence-preserving qubits will then be robust to local decoherence at low bath temperatures. We show how this quantum information can be universally manipulated and indicate how this approach may be applied to a quantum dot quantum computer.

Dave Bacon; Kenneth R. Brown; K. Birgitta Whaley

2001-11-26T23:59:59.000Z

268

STATISTICAL SIMULATIONS OF MACHINE ERRORS FOR LINAC4 M. Baylac, JM de Conto, E. Froidefond, LPSC (CNRS/IN2P3-UJF-INPG), Grenoble, France,  

E-Print Network (OSTI)

. It should replace the existing LINAC 2 as injector to the Proton Synchroton Booster and can also operate to validate the proposed design. INTRODUCTION At CERN, the Proton Synchroton Booster is injected by a linear

Paris-Sud XI, Université de

269

Coherent versus incoherent sequential quantum measurements  

SciTech Connect

We compare a trade-off between knowledge and decoherence for the incoherent and coherent partial sequential compatible measurements on single-qubit systems. The individual partial measurement nondestructively monitors basis states of the system by single-qubit meter. For the same decoherence caused by this unbiased measurement, the individual coherent measurement gives more knowledge than the incoherent one. For identical sequential coherent measurements, knowledge accumulated not additively increases more slowly than for the incoherent measurements. The overall knowledge can be accumulated using an adaptive measurement strategy on the meters if the single-qubit coherence of meters is kept. On the other hand, preservation of the mutual qubit coherence between the meters necessary for the collective measurement strategy is not required. A loss of single-qubit coherence degrades the coherent measurements back to the incoherent ones. Since the decoherence caused by the measurement process is a quadratic function of knowledge extracted by the individual measurement, Zeno-like behavior can be observed for repetitive weak compatible measurements. This unconditional universal effect does not depend on any dynamics of the qubit and it is a direct consequence of optimally controlled sequential evolution of quantum information.

Filip, Radim [Department of Optics, Palacky University, 17. listopadu 1192/12, CZ-771 46 Olomouc (Czech Republic)

2011-03-15T23:59:59.000Z

270

Kinetic transport theory with quantum coherence  

E-Print Network (OSTI)

We derive transport equations for fermions and bosons in spatially or temporally varying backgrounds with special symmetries, by use of the Schwinger-Keldysh formalism. In a noninteracting theory the coherence information is shown to be encoded in new singular shells for the 2-point function. Imposing this phase space structure to the interacting theory leads to a a self-consistent equation of motion for a physcial density matrix, including coherence and a well defined collision integral. The method is applied e.g. to demonstrate how an initially coherent out-of-equlibrium state approaches equlibrium through decoherence and thermalization.

Matti Herranen; Kimmo Kainulainen; Pyry M. Rahkila

2008-11-06T23:59:59.000Z

271

Coherence of magnetic resonators in a metamaterial  

SciTech Connect

The coherence of periodic magnetic resonators (MRs) under oblique incidence is studied using simulations. The correlated phase of interaction including both the retardation effect and relative phase difference between two MRs is defined, and it plays a key role in the MR interaction. The correlated phase is anisotropic, as is the coherence condition. The coherence condition is the same as the Wood's anomaly and verified by the Fano resonance. This study shows that the applications of the Fano resonance of periodic MRs will become widespread owing to achieving the Fano resonance simply by tuning the incident angle.

Hou, Yumin, E-mail: ymhou@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

2013-12-15T23:59:59.000Z

272

Cooling the ANL SC heavy-ion linac with two refrigerators in parallel. Preprint Paper G-26  

SciTech Connect

The Argonne Superconducting Heavy-Ion Linac consists of a series of niobium accelerating resonators grouped in cryostats. The resonators are cooled by a forced-circulation flow of liquid helium directly from a CTI Model 1400 refrigerator through a low-loss distribution line. Helium entering each cryostat is condensed to near liquid saturation by heat exchange with the colder, lower pressure return stream. As more resonators and cryostats have been added to the linac over the past few years, it has been necessary to increase the cooling capacity of the system without increasing the flow of helium through the outgoing primary side of the distribution line and the resonators. This has been accomplished by coupling the first operational CTI Model 2800 turbo-expander refrigerator in parallel with the Model 1400 in such a way as to avoid major modifications in the helium distribution system.

Nixon, J.M.; Bollinger, L.M.

1981-01-01T23:59:59.000Z

273

Stripping of H- beams by residual gas in the linac at the Los Alamos neutron science center  

SciTech Connect

The linear accelerator at the Los Alamos Neutron Science Center (LANSCE) accelerates both protons and H{sup -} ions using Cockroft-Walton-type injectors, a drift-tube linac and a coupled-cavity linac. The vacuum is maintained in the range of 10{sup -6} to 10{sup -7} Torr; the residual gas in the vacuum system results in some stripping of the electrons from the H{sup -} ions resulting in beam spill and the potential for unwanted proton beams delivered to experiments. We have measured the amount of fully-stripped H{sup -} beam (protons) that end up at approximately 800 MeV in the beam switchyard at LANSCE using image plates as very sensitive detectors. We present here the motivation for the measurement, the measurement technique and results.

Mccrady, Rodney C [Los Alamos National Laboratory; Ito, Takeyasu [Los Alamos National Laboratory; Cooper, Martin D [Los Alamos National Laboratory; Alexander, Saunders [Los Alamos National Laboratory

2010-09-07T23:59:59.000Z

274

Issues concerning high current lower energy electron beams required for ion cooling between EBIS LINAC and booster  

SciTech Connect

Some issues, regarding a low energy high current electron beam that will be needed for electron beam cooling to reduce momentum of gold ions exiting the EBIS LINAC before injection into the booster, are examined. Options for propagating such an electron beam, as well as the effect of neutralizing background plasma on electron and ion beam parameters are calculated. Computations and some experimental data indicate that none of these issues is a show stopper.

Hershcovitch,A.

2009-03-01T23:59:59.000Z

275

Enhancing photovoltaic power by Fano-induced coherence  

SciTech Connect

We show that coherence induced by Fano interference can enhance power generated by a photovoltaic device as compared to the same system with no coherence. No additional external energy source is necessary to create such induced coherence. In the present model, coherence increases the flow of electrons through the load, which reduces radiative recombination and enhances cell power.

Svidzinsky, Anatoly A.; Dorfman, Konstantin E.; Scully, Marlan O. [Texas A and M University, College Station, Texas 77843, USA and Princeton University, Princeton, New Jersey 08544 (United States)

2011-11-15T23:59:59.000Z

276

Managing coherence via put/get windows  

DOE Patents (OSTI)

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an area of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.

Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton on Hudson, NY); Coteus, Paul W. (Yorktown Heights, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk (Ossining, NY); Ohmacht, Martin (Yorktown Heights, NY)

2012-02-21T23:59:59.000Z

277

Photosynthetic light harvesting: excitons and coherence  

Science Journals Connector (OSTI)

...Delocalization-enhanced long-range energy transfer between cryptophyte...Scholes. 2012 Coherent energy transfer under incoherent...Oppenheimer, Jr.]. New York, NY: McGraw-Hill Book...162 ) 78 Kasha, M . 1963 Energy transfer mechanisms and...

2014-01-01T23:59:59.000Z

278

Coherence and emergence of classical spacetime  

Science Journals Connector (OSTI)

Using the coherent-state representation we show that the classical Einstein equation for the Friedmann-Robertson-Walker cosmological model with a general minimal scalar field can be derived from the semiclassical quantum Einstein equation.

Sang Pyo Kim; Jeong-Young Ji; Hak-Soo Shin; Kwang-Sup Soh

1997-09-15T23:59:59.000Z

279

Coherence and transitivity of subtyping as entailment  

Science Journals Connector (OSTI)

...Copyright 2000 Article Coherence and transitivity of subtyping as entailment G Longo A K Milsted A2 S Soloviev A3 A LIENS(CNRS) and DMI, Ecole Normale Superieure......

G Longo; K Milsted; S Soloviev

2000-08-01T23:59:59.000Z

280

Phase-Conjugate Optical Coherence Tomography  

E-Print Network (OSTI)

We demonstrate a new type of optical coherence tomography using only classical resources to achieve results that are typically associated with quantum-enhanced metrology: factor-of-two axial resolution enhancement and ...

Shapiro, Jeffrey H.

Note: This page contains sample records for the topic "impact linac coherent" 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

Managing coherence via put/get windows  

DOE Patents (OSTI)

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an area of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.

Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton on Hudson, NY); Coteus, Paul W. (Yorktown Heights, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk (Ossining, NY); Ohmacht, Martin (Yorktown Heights, NY)

2011-01-11T23:59:59.000Z

282

Coherence Momentum in Second-Order Vectorial Coherence Theory of Stationary Electromagnetic Fields  

Science Journals Connector (OSTI)

In analog to the electromagnetic momentum, we introduce vector and tensor densities to the general coherence theory of vector electromagnetic fields, and present new conservation...

Wang, Wei; Takeda, Mitsuo

283

Coherence Momentum in Second-Order Vectorial Coherence Theory of Stationary Electromagnetic Fields  

Science Journals Connector (OSTI)

In analog to the electromagnetic momentum, we introduce vector and tensor densities to the general coherence theory of vector electromagnetic fields, and present new conservation laws...

Wang, Wei; Takeda, Mitsuo

284

Measurement of optical emission from the hydrogen plasma of the Linac4 ion source and the SPL plasma generator  

SciTech Connect

At CERN, a non caesiated H{sup -} ion volume source derived from the DESY ion source is being commissioned. For a proposed High Power Superconducting Proton Linac (HP-SPL), a non caesiated plasma generator was designed to operate at the two orders of magnitude larger duty factor required by the SPL. The commissioning of the plasma generator test stand and the plasma generator prototype are completed and briefly described. The 2 MHz RF generators (100 kW, 50 Hz repetition rate) was successfully commissioned; its frequency and power will be controlled by arbitrary function generators during the 1 ms plasma pulse. In order to characterize the plasma, RF-coupling, optical spectrometer, rest gas analyzer and Langmuir probe measurements will be used. Optical spectrometry allows direct comparison with the currently commissioned Linac4 H{sup -} ion source plasma. The first measurements of the optical emission of the Linac4 ion source and of the SPL plasma generator plasmas are presented.

Lettry, J.; Bertolo, S.; Castel, A.; Chaudet, E.; Ecarnot, J.-F.; Favre, G.; Fayet, F.; Geisser, J.-M.; Haase, M.; Habert, A.; Hansen, J.; Joffe, S.; Kronberger, M.; Lombard, D.; Marmillon, A.; Balula, J. Marques; Mathot, S.; Midttun, O.; Moyret, P.; Nisbet, D. [CERN, 1211 Geneva 23 (Switzerland)

2011-09-26T23:59:59.000Z

285

Coherence Effects in Resonance Fluorescence  

Science Journals Connector (OSTI)

The crossed-level method of atomic spectroscopy is discussed and the angular distribution formula for both the incoherent and coherent resonance scattering is derived. The form of this distribution function, as given here, explicity displays the geometric factors depending on radiation propagation vectors. With the application to hydrogen in mind, the distribution function is expressed explicitly for single electron transitions with external fields possessing axial symmetry. The properties of the distribution function are discussed with emphasis on the case of unpolarized radiation. For the case of hydrogen there are two possible applications of major interest. The first concerns the possibility of a precision measurement of the 2p fine structure splitting and, hence, a determination of the fine structure constant. Explicit results for the shape and other properties of the resonance line with a uniform magnetic field obtained. The other application is concerned with the possibility of measuring the 2s-2p Lamb splitting. This requires an electric field parallel to the magnetic field. Unfortunately, the level crossings which are sensitive to the Lamb splitting cannot radiate sufficiently rapidly while those which do radiate appreciably occur at field strengths which are extremely insensitive to the Lamb splitting.

M. E. Rose and R. L. Carovillano

1961-05-15T23:59:59.000Z

286

Extended Coherence Time with Atom-Number Squeezed Sources  

E-Print Network (OSTI)

Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the decay of Bloch oscillations to probe the coherence time. We extend coherence times by a factor of 2 over those expected with coherent state BEC interferometry. We observe quantitative agreement with theory both for the degree of initial number squeezing as well as for prolonged coherence times.

Wei Li; Ari K. Tuchman; Hui-Chun Chien; Mark A. Kasevich

2006-09-02T23:59:59.000Z

287

Extended Coherence Time with Atom-Number Squeezed States  

SciTech Connect

Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the decay of Bloch oscillations to probe the coherence time. We extend coherence times by a factor of 2 over those expected with coherent state Bose-Einstein condensate interferometry. We observe quantitative agreement with theory both for the degree of initial number squeezing as well as for prolonged coherence times.

Li Wei; Tuchman, Ari K.; Chien, H.-C.; Kasevich, Mark A. [Physics Department, Stanford University, Stanford, California 94305 (United States)

2007-01-26T23:59:59.000Z

288

Insertion of coherence requests for debugging a multiprocessor  

DOE Patents (OSTI)

A method and system are disclosed to insert coherence events in a multiprocessor computer system, and to present those coherence events to the processors of the multiprocessor computer system for analysis and debugging purposes. The coherence events are inserted in the computer system by adding one or more special insert registers. By writing into the insert registers, coherence events are inserted in the multiprocessor system as if they were generated by the normal coherence protocol. Once these coherence events are processed, the processing of coherence events can continue in the normal operation mode.

Blumrich, Matthias A. (Ridgefield, CT); Salapura, Valentina (Chappaqua, NY)

2010-02-23T23:59:59.000Z

289

Quantum Coherence in a Superfluid Josephson Junction  

SciTech Connect

We report a new kind of experiment in which we take an array of nanoscale apertures that form a superfluid {sup 4}He Josephson junction and apply quantum phase gradients directly along the array. We observe collective coherent behaviors from aperture elements, leading to quantum interference. Connections to superconducting and Bose-Einstein condensate Josephson junctions as well as phase coherence among the superfluid aperture array are discussed.

Narayana, Supradeep; Sato, Yuki [Rowland Institute at Harvard, Harvard University, Cambridge, Massachusetts 02142 (United States)

2011-02-04T23:59:59.000Z

290

Two-Photon Absorption and Coherence  

Science Journals Connector (OSTI)

We study the probabilities for two-photon absorption processes induced by both coherent and thermal light when acting on an atomic system. Calculations are performed with quantum electrodynamics, and we find results similar to those obtained with semiclassical methods; that is, the two-photon absorption probability depends on the statistical properties of the light used. This probability assumes its maximum value for coherent light.

S. Carusotto; G. Fornaca; E. Polacco

1967-05-25T23:59:59.000Z

291

Coherence and Two-Photon Absorption  

Science Journals Connector (OSTI)

A kinetic theory of the two-photon absorption from a single mode of the radiation field is presented. It is found that, in general, the rate of two-photon absorption depends on certain correlation functions, and hence on the coherence properties, of the field. The results are applied to the case of a pure coherent state and the case of a chaotic field.

P. Lambropoulos; C. Kikuchi; R. K. Osborn

1966-04-29T23:59:59.000Z

292

Coherence condition for resonant neutrino oscillation  

Science Journals Connector (OSTI)

We study the coherence condition for a neutrino to keep coherence between the effective mass eigenstates in the presence of matter and examine whether or not resonant neutrino oscillation (RNO) happens in the cases of solar and SN 1987A neutrinos. As a result, it becomes evident that RNO is possible in the solar-neutrino case but impossible in the SN 1987A neutrino case.

Hajime Anada and Haruhiko Nishimura

1990-04-15T23:59:59.000Z

293

Restoration of Coherent Population Movement from Noise-Induced Chaos in the Chemotaxis of E. Coli: A Fractal Interpretation  

Science Journals Connector (OSTI)

Bacteria navigating in a chemically guided manner are under the impact of noise from at least three sources-inside the cells, at the binding sites between chemoattractants in the environment and corresponding receptors of the cells, and in the environment ... Keywords: Bacterial Chemotaxis, Chaotic Motions, Coherent Movement, Environmental Noise, Escherichia Coli, Fractal Dimensions, Intra-Cellular Noise, Noise Filters

Pratap R. Patnaik

2013-07-01T23:59:59.000Z

294

Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule  

SciTech Connect

The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ?1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. The unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.

Laxdal, R. E.; Ma, Y.; Harmer, P.; Kishi, D.; Koveshnikov, A.; Muller, N.; Vrielink, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); O'Brien, M. [University of British Columbia, Vancouver (Canada); Ahammed, M. [Variable Energy Cyclotron Center, Kolkata (India)

2014-01-29T23:59:59.000Z

295

A feasibility study of space-charge neutralized ion induction linacs: Final report  

SciTech Connect

Applications for high current (> 1 kA) ion beams are increasing. They include hardening of material surfaces, transmutation of radioactive waste, cancer treatment, and possibly driving fusion reactions to create energy. The space-charge of ions limits the current that can be accelerated in a conventional ion linear accelerator (linac). Furthermore, the accelerating electric field must be kept low enough to avoid the generation and acceleration of counter-streaming electrons. These limitations have resulted in ion accelerator designs that employ long beam lines and would be expensive to build. Space-charge neutralization and magnetic insulation of the acceleration gaps could substantially reduce these two limitations, but at the expense of increasing the complexity of the beam physics. We present theory and experiments to determine the degree of charge-neutralization that can be achieved in various environments found in ion accelerators. Our results suggest that, for high current applications, space-charge neutralization could be used to improve on the conventional ion accelerator technology. There are two basic magnetic field geometries that can be used to insulate the accelerating gaps, a radial field or a cusp field. We will present studies related to both of these geometries. We shall also present numerical simulations of {open_quotes}multicusp{close_quotes} accelerator that would deliver potassium ions at 400 MeV with a total beam power of approximately 40 TW. Such an accelerator could be used to drive fusion.

Slutz, S.A.; Primm, P.; Renk, T.; Johnson, D.J. [and others

1997-03-01T23:59:59.000Z

296

Simulations of coherent beam-beam effects with head-on compensation  

SciTech Connect

Electron lenses are under construction for installation in RHIC in order to mitigate the head-on beam-beam effects. This would allow operation with higher bunch intensity and result in a significant increase in luminosity. We report on recent strong-strong simulations and experiments that were carried out using the RHIC upgrade parameters to assess the impact of coherent beam-beam effects in the presence of head-on compensation.

White S.; Fischer, W.; Luo. Y.

2012-05-20T23:59:59.000Z

297

Transverse coherence saturation: A method to enhance the coherence of x-ray beams  

Science Journals Connector (OSTI)

A method is proposed to generate improved coherence in x-ray beams. The method leaves the photon source unchanged, and improves transverse coherence by reordering the emitted radiation through dynamical optical means (i.e., with at least one moving optical component). Since the method increases the transverse coherence of beams, it thus reduces the time needed to perform certain types of observations, such as in microscopy, and interference experiments such as holography. It does not increase the longitudinal coherence of beams. However, it can be supplemented by other means to increase longitudinal coherence. It does not increase the brightness, but allows one to more efficiently utilize beams of a given brightness. The use of this method with photons generated by pulsed electron beams, including those in storage rings, seems particularly appropriate.

Paul L. Csonka

1990-06-01T23:59:59.000Z

298

Optical Design in Phase-Space for the I13L X-Ray Imaging and Coherence Beamline at Diamond using XPHASY  

SciTech Connect

I13L is a 250 m long beamline for imaging and coherent diffraction currently under construction at the Diamond Light Source. For modeling the beamline optics the phase-space based ray-tracing code XPHASY was developed, as general ray-tracing codes for x-rays do not easily allow studying the propagation of coherence along the beamline. In contrast to computational intensive wave-front propagation codes, which fully describe the propagation of a photon-beam along a beamline but obscure the impact of individual optical components onto the beamline performance, this code allows to quickly calculate the photon-beam propagation along the beamline and estimate the impact of individual components.In this paper we will discuss the optical design of the I13L coherence branch from the perspective of phase-space by using XPHASY. We will demonstrate how the phase-space representation of a photon-beam allows estimating the coherence length at any given position along the beamline. The impact of optical components on the coherence length and the effect of vibrations on the beamline performance will be discussed. The paper will demonstrate how the phase-space representation of photon-beams allows a more detailed insight into the optical performance of a coherence beamline than ray-tracing in real space.

Wagner, Ulrich H. [Science, Diamond Light Source Ltd., Didcot, Oxon OX11 0DE (United Kingdom); Rau, Christoph [Science, Diamond Light Source Ltd., Didcot, Oxon OX11 0DE (United Kingdom); Northwestern University, Chicago (United States)

2010-06-23T23:59:59.000Z

299

Coherence techniques at extreme ultraviolet wavelengths  

SciTech Connect

The renaissance of Extreme Ultraviolet (EUV) and soft x-ray (SXR) optics in recent years is mainly driven by the desire of printing and observing ever smaller features, as in lithography and microscopy. This attribute is complemented by the unique opportunity for element specific identification presented by the large number of atomic resonances, essentially for all materials in this range of photon energies. Together, these have driven the need for new short-wavelength radiation sources (e.g. third generation synchrotron radiation facilities), and novel optical components, that in turn permit new research in areas that have not yet been fully explored. This dissertation is directed towards advancing this new field by contributing to the characterization of spatial coherence properties of undulator radiation and, for the first time, introducing Fourier optical elements to this short-wavelength spectral region. The first experiment in this dissertation uses the Thompson-Wolf two-pinhole method to characterize the spatial coherence properties of the undulator radiation at Beamline 12 of the Advanced Light Source. High spatial coherence EUV radiation is demonstrated with appropriate spatial filtering. The effects of small vertical source size and beamline apertures are observed. The difference in the measured horizontal and vertical coherence profile evokes further theoretical studies on coherence propagation of an EUV undulator beamline. A numerical simulation based on the Huygens-Fresnel principle is performed.

Chang, Chang

2002-10-01T23:59:59.000Z

300

High-resolution imaging of microvasculature in human skin in-vivo with optical coherence tomography  

E-Print Network (OSTI)

using swept-source optical coherence tomography,” Opt. Lett.J. G. Fujimoto, “Optical coherence tomography,” Science 254(volumes using optical coherence tomography,” Opt. Lett. 22(

Liu, Gangjun; Jia, Wangcun; Sun, Victor; Choi, Bernard; Chen, Zhongping

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Double common-path interferometer for flexible optical probe of optical coherence tomography  

E-Print Network (OSTI)

J. Fujimoto, “Optical coherence tomography,” Science 254(D. E. N. Davies, “Optical coherence-domain reflectometry: afiber common-path optical coherence tomography: sensitivity

Park, Jae Seok; Chen, Zhongping; Jeong, Myung Yung; Kim, Chang-Seok

2012-01-01T23:59:59.000Z

302

High-speed upper-airway imaging using full-range optical coherence tomography  

E-Print Network (OSTI)

Huang et al. , “Optical coherence tomography,” Science 254(endoscopic long-range optical coherence tomogra- phy,” Opt.tracking with optical coherence tomography: proof-of-

Jing, Joseph; Zhang, Jun; Loy, Anthony Chin; Wong, Brian F.; Chen, Zhongping

2012-01-01T23:59:59.000Z

303

Quantum Coherence and Energy Landscapes in Photosynthetic Systems Investigated with Two-Dimensional Electronic Spectroscopy  

E-Print Network (OSTI)

transfer through quantum coherence iii1.3.1 Excitonic Coherence . . . . . . . . 1.3.2 Electronic4 Quantum Coherence Enabled Determination scape in Light-

Calhoun, Tessa Rae

2010-01-01T23:59:59.000Z

304

Low-speckle holographic beam shaping of high-coherence EUV sources  

E-Print Network (OSTI)

beam shaping of high-coherence EUV sources Christopher N.and homogenize high-coherence extreme ultraviolet sourcesbe achieved. Keywords: Coherence, Uniformity, Homogenize,

Anderson, Christopher N.

2011-01-01T23:59:59.000Z

305

Reference spectrum extraction and fixed-pattern noise removal in optical coherence tomography  

E-Print Network (OSTI)

OCIS codes: (110.4500) Optical coherence tomography; (170.4500) Optical coherence tomography; (100.2000) Digitalvs. time domain optical coherence tomography,” Opt. Express

Moon, Sucbei; Lee, Sang-Won; Chen, Zhongping

2010-01-01T23:59:59.000Z

306

Pupil shaping and coherence control in an EUV mask-imaging microscope  

E-Print Network (OSTI)

Fourier—synthesis custom- coherence illuminator for extremeBhatnagar, “Effect of Partial Coherence on the Resolution offield. 2. PARTIAL COHERENCE AND CONTRAST The illumination

Mochi, Iacopo

2014-01-01T23:59:59.000Z

307

COHERENCE AND SELF-INDUCED TRANSPARENCY IN HIGH ENERGY HADRONIC COLLISIONS  

E-Print Network (OSTI)

to Physics Letters COHERENCE AND SELF-INDUCED TRANSPARENCYof California. LBL-12279 Coherence and self-inducedTwo consequences of coherence of mesonic fields have been

Fowler, G.N.

2014-01-01T23:59:59.000Z

308

Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography  

E-Print Network (OSTI)

J. G. Fujimoto. Optical coherence tomog- raphy. Science 254:spectral domain low coherence interferometry and retinalsedimentation on optical coherence tomography signals from

Xu, Xiangqun; Yu, Lingfeng; Chen, Zhongping

2010-01-01T23:59:59.000Z

309

In vivo three-dimensional microelectromechanical endoscopic swept source optical coherence tomography  

E-Print Network (OSTI)

with endoscopic optical coherence tomography”, Opt. Express,G. Fujimoto, "Optical coherence tomography," Science, 254,endoscope for optical coherence tomography”,Opt. Lett. 21,

Su, Jianping; Zhang, Jun; Yu, Linfeng; Chen, Zhongping

2007-01-01T23:59:59.000Z

310

HIGH RESOLUTION NMR IN INHOMOGENEOUS MAGNETIC FIELDS: APPLICATION OF TOTAL SPIN COHERENCE TRANSFER ECHOES  

E-Print Network (OSTI)

APPLICATION OF TOTAL SPIN COHERENCE TRANSFER ECHOES D.P.by total spin coherence transfer echo spectroscopy. (a) Thesequence to use total spin coherence transfer echoes to

Weitekamp, D.P.

2014-01-01T23:59:59.000Z

311

Store-operate-coherence-on-value  

DOE Patents (OSTI)

A system, method and computer program product for performing various store-operate instructions in a parallel computing environment that includes a plurality of processors and at least one cache memory device. A queue in the system receives, from a processor, a store-operate instruction that specifies under which condition a cache coherence operation is to be invoked. A hardware unit in the system runs the received store-operate instruction. The hardware unit evaluates whether a result of the running the received store-operate instruction satisfies the condition. The hardware unit invokes a cache coherence operation on a cache memory address associated with the received store-operate instruction if the result satisfies the condition. Otherwise, the hardware unit does not invoke the cache coherence operation on the cache memory device.

Chen, Dong; Heidelberger, Philip; Kumar, Sameer; Ohmacht, Martin; Steinmacher-Burow, Burkhard

2014-11-18T23:59:59.000Z

312

Global coherence of dust density waves  

SciTech Connect

The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

313

Control of coherence resonance in semiconductor superlattices  

E-Print Network (OSTI)

We study the effect of time-delayed feedback control and Gaussian white noise on the spatio-temporal charge dynamics in a semiconductor superlattice. The system is prepared in a regime where the deterministic dynamics is close to a global bifurcation, namely a saddle-node bifurcation on a limit cycle ({\\it SNIPER}). In the absence of control, noise can induce electron charge front motion through the entire device, and coherence resonance is observed. We show that with appropriate selection of the time-delayed feedback parameters the effect of coherence resonance can either be enhanced or destroyed, and the coherence of stochastic domain motion at low noise intensity is dramatically increased. Additionally, the purely delay-induced dynamics in the system is investigated, and a homoclinic bifurcation of a limit cycle is found.

Johanne Hizanidis; Eckehard Schoell

2008-09-01T23:59:59.000Z

314

Coherence and oscillations of cosmic neutrinos  

E-Print Network (OSTI)

For cosmic neutrinos we study the conditions and the effects of the coherence loss as well as coherent broadening of the spectrum. We evaluate the width of the neutrino wavepacket produced by charged particles under various circumstances: in an interaction-free environment, in a radiation-dominated medium (typical of the sources of the gamma ray bursts) and in the presence of a magnetic field. The effect of the magnetic field on the wavepacket size appears to be more important than the scattering. If the magnetic field at the source is larger than $\\sim$10 Gauss, the coherence of neutrinos will be lost while traveling over cosmological distances. Various applications of these results have been considered. We find that for large magnetic fields ($B> 10^9$ Gauss) and high energies ($E_\

Yasaman Farzan; Alexei Yu Smirnov

2008-03-04T23:59:59.000Z

315

Coherent Synchrotron Radiation: Theory and Simulations.  

SciTech Connect

The physics of coherent synchrotron radiation (CSR) emitted by ultra-relativistic electron bunches, known since the last century, has become increasingly important with the development of high peak current free electron lasers and shorter bunch lengths in storage rings. Coherent radiation can be described as a low frequency part of the familiar synchrotron radiation in bending magnets. As this part is independent of the electron energy, the fields of different electrons of a short bunch can be in phase and the total power of the radiation will be quadratic with the number of electrons. Naturally the frequency spectrum of the longitudinal electron distribution in a bunch is of the same importance as the overall electron bunch length. The interest in the utilization of high power radiation from the terahertz and far infrared region in the field of chemical, physical and biological processes has led synchrotron radiation facilities to pay more attention to the production of coherent radiation. Several laboratories have proposed the construction of a facility wholly dedicated to terahertz production using the coherent radiation in bending magnets initiated by the longitudinal instabilities in the ring. Existing synchrotron radiation facilities also consider such a possibility among their future plans. There is a beautiful introduction to CSR in the 'ICFA Beam Dynamics Newsletter' N 35 (Editor C. Biscari). In this paper we recall the basic properties of CSR from the theory and what new effects, we can get from the precise simulations of the coherent radiation using numerical solutions of Maxwell's equations. In particular, transverse variation of the particle energy loss in a bunch, discovered in these simulations, explains the slice emittance growth in bending magnets of the bunch compressors and transverse de-coherence in undulators. CSR may play same the role as the effect of quantum fluctuations of synchrotron radiation in damping rings. It can limit the minimum achievable emittance in the synchrotron light sources for short bunches.

Novokhatski, Alexander; /SLAC

2012-03-29T23:59:59.000Z

316

Cryogenic system for the Energy Recovery Linac and vertical test facility at BNL  

SciTech Connect

A small cryogenic system and warm helium vacuum pumping system provides cooling to either the Energy Recovery Linac's (ERL) cryomodules that consist of a 5-cell cavity and an SRF gun or a large Vertical Test Dewar (VTD) at any given time. The cryogenic system consists of a model 1660S PSI piston plant, a 3800 liter storage dewar, subcooler, a wet expander, a 50 g/s main helium compressor, and a 170 m{sup 3} storage tank. A system description and operating plan of the cryogenic plant and cryomodules is given. The cryogenic system for ERL and the Vertical Test Dewar has a plant that can produce the equivalent of 300W at 4.5K with the addition of a wet expander 350 W at 4.5K. Along with this system, a sub-atmospheric, warm compression system provides pumping to produce 2K at the ERL cryomodules or the Vertical Test Dewar. The cryogenic system for ERL and the Vertical Test Dewar makes use of existing equipment for putting a system together. It can supply either the ERL side or the Vertical Test Dewar side, but not both at the same time. Double valve isolation on the liquid helium supply line allows one side to be warmed to room temperature and worked on while the other side is being held at operating temperature. The cryogenic system maintain the end loads from 4.4K to 2K or colder depending on capacity. Liquid helium storage dewar capacity allows ERL or the VTD to operate above the plant's capacity when required and ERL cryomodules ballast reservoirs and VTD reservoir allows the end loads to operate on full vacuum pump capacity when required.

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

2011-03-28T23:59:59.000Z

317

Vector coherent states for nanoparticle Hamiltonians  

E-Print Network (OSTI)

The first part of this work deals with a formalism of vector coherent states construction for a system of $M$ Fermi-type modes associated with $N$ bosonic modes. Then follows a generalization to a Hamiltonian describing the translational motion of the center of mass of a nanoparticle. The latter gives rise to a new mechanism for the electronic energy relaxation in nanocrystals, intensively studied today in condensed matter physics. Finite degeneracies of the involved Hamiltonian systems are also investigated. The defined vector coherent states satisfy relevant mathematical properties of continuity, resolution of identity, temporal stability and action identity.

Isiaka Aremua; Mahouton Norbert Hounkonnou

2009-03-30T23:59:59.000Z

318

Coherence and anticoherence resonance tuned by noise  

Science Journals Connector (OSTI)

We present numerical evidence and a theoretical analysis of the appearance of anticoherence resonance induced by noise, not predicted in former analysis of coherence resonance. We have found that this phenomenon occurs for very small values of the intensity of the noise acting on an excitable system, and we claim that this is a universal signature of a nonmonotonous relaxational behavior near its oscillatory regime. Moreover, we demonstrate that this new phenomenon is totally compatible with the standard situation of coherence resonance appearing at intermediate values of noise intensity.

A. M. Lacasta; F. Sagués; J. M. Sancho

2002-10-24T23:59:59.000Z

319

Electromagnetically induced grating with maximal atomic coherence  

SciTech Connect

We describe theoretically an atomic diffraction grating that combines an electromagnetically induced grating with a coherence grating in a double-{Lambda} atomic system. With the atom in a condition of maximal coherence between its lower levels, the combined gratings simultaneously diffract both the incident probe beam as well as the signal beam generated through four-wave mixing. A special feature of the atomic grating is that it will diffract any beam resonantly tuned to any excited state of the atom accessible by a dipole transition from its ground state.

Carvalho, Silvania A.; Araujo, Luis E. E. de [Instituto de Fisica ''Gleb Wataghin'', Universidade Estadual de Campinas, Campinas-SP, 13083-859 Sao Paulo (Brazil)

2011-10-15T23:59:59.000Z

320

Coherence of phonon avalanches in ruby  

Science Journals Connector (OSTI)

Phonon avalanches resonant with the optically inverted Zeeman-split ?(2E) doublet of Cr3+ have been measured and analyzed in a single crystal of 500-at. ppm ruby (Al2O3:Cr3+) with a geometry adapted to the study of coherence. A set of coherent Bloch equations governing the interacting acoustic wave and spin polarizations is found to provide an excellent description of the results, and to be far superior to incoherent rate equations for the phonon and level populations. The dephasing time conforms with the width of the inhomogeneously broadened transition connecting the ?(2E) states, which indicates that dephasing primarily occurs by the spread in frequencies.

L. G. Tilstra; A. F. M. Arts; H. W. de Wijn

2003-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Spatial coherence resonance on diffusive and small-world networks of Hodgkin-Huxley neurons  

E-Print Network (OSTI)

Spatial coherence resonance in a spatially extended system that is locally modeled by Hodgkin-Huxley (HH) neurons is studied in this paper. We focus on the ability of additive temporally and spatially uncorrelated Gaussian noise to extract a particular spatial frequency of excitatory waves in the medium, whereby examining also the impact of diffusive and small-world network topology determining the interactions amongst coupled HH neurons. We show that there exists an intermediate noise intensity that is able to extract a characteristic spatial frequency of the system in a resonant manner provided the latter is diffusively coupled, thus indicating the existence of spatial coherence resonance. However, as the diffusive topology of the medium is relaxed via the introduction of shortcut links introducing small-world properties amongst coupled HH neurons, the ability of additive Gaussian noise to evoke ordered excitatory waves deteriorates rather spectacularly, leading to the decoherence of the spatial dynamics and with it related absence of spatial coherence resonance. In particular, already a minute fraction of shortcut links suffices to substantially disrupt coherent pattern formation in the examined system.

Xiaojuan Sun; Matjaz Perc; Qishao Lu; Jürgen Kurths

2008-03-01T23:59:59.000Z

322

Quantum Coherence Effects in Novel Quantum Optical Systems  

E-Print Network (OSTI)

Optical response of an active medium can substantially be modified when coherent superpositions of states are excited, that is, when systems display quantum coherence and interference. This has led to fascinating applications in atomic and molecular...

Sete, Eyob Alebachew

2012-10-19T23:59:59.000Z

323

Coherence Maps for Wind-Forced Quasigeostrophic Flows  

Science Journals Connector (OSTI)

Coherence maps are a useful tool to study the oceanic response to atmospheric forcing. For a specific frequency band these maps display the coherence between the oceanic current (or pressure) at a single mooring location and the atmospheric ...

Peter Müller

1997-09-01T23:59:59.000Z

324

Coherence of Electron Wave and Contrast of Electron Image  

Science Journals Connector (OSTI)

......other Symposium of the Society of Japanese Electron Microscopy Coherence of Electron Wave and Contrast of Electron Image Tadatoshi...Measurements, Tohoku University (21) 207 0 Jfc & ft* ffi Coherence of Electron Wave and Contrast of Electron Image Tadatoshi......

Tadatoshi HIBI; Shoichi Takahashi

1964-01-01T23:59:59.000Z

325

Coherence in natural language : data structures and applications .  

E-Print Network (OSTI)

??(cont.) baseline, and that some coherence-based approaches best predict the human data. However, coherence-based algorithms that operate on trees did not perform as well as… (more)

Wolf, Florian, 1975-

2005-01-01T23:59:59.000Z

326

Simultaneous sample and spatial coherence characterisation using diffractive imaging  

SciTech Connect

We demonstrate an algorithm that reconstructs the complex transmission function of an object from experimental X-ray diffraction data using partially coherent 1.4 keV X-rays that does not require a priori input of the coherence function. The quality of the reconstruction is significantly better than that obtained by assuming that the illumination is fully coherent. Our approach can be readily applied to diffraction imaging problems where a model for the spatial coherence can be assumed.

Clark, Jesse N.; Peele, Andrew G. (La Trobe)

2012-01-20T23:59:59.000Z

327

Simultaneous sample and spatial coherence characterisation using diffractive imaging  

SciTech Connect

We demonstrate an algorithm that reconstructs the complex transmission function of an object from experimental X-ray diffraction data using partially coherent 1.4 keV X-rays that does not require a priori input of the coherence function. The quality of the reconstruction is significantly better than that obtained by assuming that the illumination is fully coherent. Our approach can be readily applied to diffraction imaging problems where a model for the spatial coherence can be assumed.

Clark, Jesse N. [Department of Physics, La Trobe University, Victoria 3086 (Australia); Australian Research Council Centre of Excellence for Coherent X-Ray Science, Melbourne (Australia); Peele, Andrew G. [Department of Physics, La Trobe University, Victoria 3086 (Australia); Australian Research Council Centre of Excellence for Coherent X-Ray Science, Melbourne (Australia); Australian Synchrotron, Clayton 3168 (Australia)

2011-10-10T23:59:59.000Z

328

Electron Coherence in a Melting Lead Monolayer  

Science Journals Connector (OSTI)

...the Pb(1,0) spots in the LEED patterns of Fig. 1, B to D...azimuthal modulation of the LEED intensities above Tm is likely not a manifestation...associated with the particular LEED spot, and {xi} is the temperature-dependent...British Columbia V6T1Z4, Canada. Electron coherence in a melting...

F. Baumberger; W. Auwärter; T. Greber; J. Osterwalder

2004-12-24T23:59:59.000Z

329

Electron Coherence in a Melting Lead Monolayer  

Science Journals Connector (OSTI)

...azimuthal modulation of the LEED intensities above Tm is likely...sixfold symmetric elementary building blocks of the 2D liquid. The slight anisotropy...associated with the particular LEED spot, and {xi} is the temperature-dependent...British Columbia V6T1Z4, Canada. Electron coherence in a melting...

F. Baumberger; W. Auwärter; T. Greber; J. Osterwalder

2004-12-24T23:59:59.000Z

330

Testing nonlocal realism with entangled coherent states  

SciTech Connect

We investigate the violation of nonlocal realism using entangled coherent states (ECSs) under nonlinear operations and homodyne measurements. We address recently proposed Leggett-type inequalities, including a class of optimized incompatibility inequalities proposed by Branciard et al. [Nature Phys. 4, 681 (2008)], and thoroughly assess the effects of detection inefficiency.

Paternostro, Mauro [School of Mathematics and Physics, Queen's University, Belfast BT7 1NN (United Kingdom); Jeong, Hyunseok [Center for Subwavelength Optics, Department of Physics and Astronomy, Seoul National University, Seoul, 151-742 (Korea, Republic of)

2010-03-15T23:59:59.000Z

331

Modes of storage ring coherent instabilities  

SciTech Connect

Longitudinal impedance in a beam and various modes of longitudinal coherent instabilities are discussed. The coasting beam coherent instability, microwave instability, and single-bunch longitudinal coherent instabilities are considered. The Vlasov equation is formulated, and a method of solving it is developed. The synchrotron modes are treated, which take the possible bunch shape distortion fully into consideration. A method of treating the synchrotron mode coupling in the case of a small bunch is discussed which takes advantage of the fact that only a few of the synchrotron modes can contribute in such a case. The effect of many bunches on the coherent motion of the beam and the longitudinal symmetric coupled bunch modes are discussed. The transverse impedance is then introduced, and the transverse coasting beam instability is discussed. Various bunched beam instabilities are discussed, including both single bunch instabilities and coupled bunch instabilities. The Vlasov equation for transverse as well as longitudinal motion of particles is introduced as well as a method of solving it within a linear approximation. Head-tail modes and short bunch instabilities and strong coupling instabilities in the long bunch case are covered. (LEW)

Wang, J.M.

1986-12-01T23:59:59.000Z

332

Convex and coherent risk measures Hans FOLLMER  

E-Print Network (OSTI)

: Monetary risk measure, convex risk measure, coherent risk measure, acceptance set, Value at Risk. Section 3 briefly discusses the representation of monetary risk measures in terms of their acceptance sets-free manner, makes the position acceptable. The following axiomatic approach to such risk measures

Föllmer, Hans

333

Coherence of resonant tunneling in heterostructures  

Science Journals Connector (OSTI)

A simple argument is put forward to substantiate the rule that either coherent resonant tunneling or sequential tunneling will occur according to whether the natural energy width for the former (in frequency units) is large compared to or small compared to the scattering frequency for an electron in the quantum-well two-dimensional subband based on the resonant quasilevel.

Peter J. Price

1987-07-15T23:59:59.000Z

334

Coherence in Chaos and Caviton Turbulence  

Science Journals Connector (OSTI)

The chaotic nature of "caviton turbulence" is studied in one-dimensional, many-Fourier-mode numerical simulations of the driven dissipative Zakharov equations. Above the modulational instability threshold the system evolves into a variety of stable patterns of cavitons which become chaotic for stronger driving. The cavitons remain coherent for times long compared to the shortest Lyapunov time.

G. D. Doolen; D. F. DuBois; H. A. Rose; B. Hafizi

1983-08-01T23:59:59.000Z

335

Coherence and Incoherence in an Optical Comb  

Science Journals Connector (OSTI)

We demonstrate a coexistence of coherent and incoherent modes in the optical comb generated by a passively mode-locked quantum dot laser. This is experimentally achieved by means of optical linewidth, radio frequency spectrum, and optical spectrum measurements and confirmed numerically by a delay-differential equation model showing excellent agreement with the experiment. We interpret the state as a chimera state.

Evgeny A. Viktorov; Tatiana Habruseva; Stephen P. Hegarty; Guillaume Huyet; Bryan Kelleher

2014-06-02T23:59:59.000Z

336

Search for temporal coherence in the sky Erez N. Ribak  

E-Print Network (OSTI)

, related to longitudinal coherence by the speed of light c: c = lc / c. Generally, naturally occurring for naturally occurring coherence is in gravitational lensing by a small object, where the paths to the observer in astrophysical processes. Among others, synchrotron radiation, known to be polarized, can be also coherent over

Ribak, Erez

337

Coherence and discontinuity in the scaling of specie's distribution patterns  

Science Journals Connector (OSTI)

7 January 2004 research-article Coherence and discontinuity in the scaling of specie's...points Adobe PDF - rspb20032531s01.pdf Coherence and discontinuity in the scaling of species...2003 Published online 24 November 2003 Coherence and discontinuity in the scaling of species...

2004-01-01T23:59:59.000Z

338

Observable coherence theory for statistically periodic fields Brynmor J. Davis*  

E-Print Network (OSTI)

Observable coherence theory for statistically periodic fields Brynmor J. Davis* The Beckman processes is used to develop classical coherence theory for the measurement of statistically periodicRevA.76.043843 PACS number s : 42.25.Kb, 42.60.Mi, 42.65.Re I. INTRODUCTION Coherence theory 1

Bhargava, Rohit

339

Wavelength-dependent scattering in spectroscopic optical coherence tomography  

E-Print Network (OSTI)

Wavelength-dependent scattering in spectroscopic optical coherence tomography Chenyang Xu, P. Scott of light scattering spectroscopy (LSS) and the spatial localization of optical coherence tomography (OCT.4500) Optical coherence tomography; (290.0290) Scattering; (300.0300) Spectroscopy References and links 1. A

Bhargava, Rohit

340

Anti-coherence based molecular electronics: XOR-gate response  

E-Print Network (OSTI)

Anti-coherence based molecular electronics: XOR-gate response Roi Baera,*, Daniel Neuhauserb 90095-1569, USA Received 18 August 2001 Abstract We point out and simulate the possible utility of anti-coherence phase condition on the loop structure, the transfer would be anti- coherent. By applying one or two

Baer, Roi

Note: This page contains sample records for the topic "impact linac coherent" 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

Differential Entropy Dynamics: A Possible Cause of Coherence Resonance  

E-Print Network (OSTI)

Coherence resonance can be explained using differential entropy and mutual information. This theory explores the role of external noise in stabilising chaotic circuits such as the uni-junction transistor relaxation oscillator.The phenomenon of coherence resonance maximizes differential entropy and mutual information.Thus most natural chaotic oscillators show coherence resonance in the presence of an external driving noise.

Juhi Rajhans; A. N. Sekar Iyengar

2013-12-01T23:59:59.000Z

342

Control momentum entanglement with atomic spontaneously generated coherence  

E-Print Network (OSTI)

With atomic spontaneously generated coherence (SGC), we propose a novel scheme to coherently control the atom--photon momentum entanglement through atomic internal coherence. A novel phenomena of ``phase entanglement in momentum'' is proposed, and we found, under certain conditions, that super--high degree of momentum entanglement can be produced with this scheme.

Rui Guo; Hong Guo

2007-01-05T23:59:59.000Z

343

Inverse scattering for rotationally scanned optical coherence tomography  

E-Print Network (OSTI)

Inverse scattering for rotationally scanned optical coherence tomography Daniel L. Marks, Tyler S May 16, 2006; posted May 26, 2006 (Doc. ID 67358) Optical coherence tomography of luminal structures coherence tomography1,2 (OCT), is determined in large part by the degree to which the images provide

Bhargava, Rohit

344

FAP Coherent Laser System (Polarizer) Standard Operating Procedures  

E-Print Network (OSTI)

FAP Coherent Laser System (Polarizer) Standard Operating Procedures These safety training the 110V input power. C. Chemical: No. #12;FAP Coherent Laser System (Polarizer) Standard Operating Coherent Laser System as well as describes the normal operation of the laser and any hazards that may

Cohen, Ronald C.

345

Multiscale imaging of human thyroid pathologies using integrated Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM)  

E-Print Network (OSTI)

We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. Thirty four thyroid ...

Zhou, Chao

346

Application of Partially coherent Wavefront Propagation Calculations for Design of Coherence-Preserving Synchrotron Radiation Beamlines  

SciTech Connect

Ultra-low emittance third-generation synchrotron radiation (SR) sources, such as NSLS-II and MAX-IV, will offer excellent opportunities for further development of experimental techniques exploiting X-ray coherence. However, even in these new SR sources, the radiation produced by relativistic electrons (in undulators, wigglers and bending magnets) will remain only partially coherent in the X-ray spectral range. 'Extraction' of 'coherent portion' of the radiation flux and its transport to sample without loss of coherence must be performed by dedicated SR beamlines, optimized for particular types of experiments. Detailed quantitative prediction of partially coherent X-ray beam properties at propagation through optical elements, which is required for the optimization of such beamlines, can only be obtained from accurate and efficient physical-optics based numerical simulations. Examples of such simulations, made for NSLS-II beamlines, using 'Synchrotron Radiation Workshop' (SRW) computer code, are presented. Special attention is paid to the numerical analysis of the basic properties of partially coherent undulator radiation beam and its distinctions from the Gaussian beam. Performance characteristics of importance for particular beamlines, such as radiation spot size and flux at sample vs size of secondary source aperture for high-resolution microscopy beamlines, are predicted by the simulations.

O Chubar; Y Chu; K Kaznatcheev; h Yan

2011-12-31T23:59:59.000Z

347

Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals  

SciTech Connect

The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-{beta} Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of {beta}{sub 0} = 0.041 and 0.085 QWRs and {beta}{sub 0} = 0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-{beta} cavities nearly free from field emission. The first two cryostats of {beta}{sub 0} = 0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient, with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed.

Facco, A; Binkowski, J; Compton, C; Crisp, J L; Dubbs, L J; Elliot, K; Harle, L L; Hodek, M; Johnson, M J; Leitner, D; Leitner, M; Malloch, I M; Miller, S J; Oweiss, R; Popielarski, J; Popielarski, L; Saito, K; Wei, J; Wlodarczak, J; Xu, Y; Zhang, Y; Zheng, Z; Burrill, A; Davis, G K; Macha, K

2012-07-01T23:59:59.000Z

348

Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University  

SciTech Connect

Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam energy at ~5MeV. Simulation shows that in the 3+1/2 DC- C injector, there is a region the beam could be over focused by RF electromagnetic field and the transverse emittance in the transport line up to linac will increase instantly due to over focusing. In order to eliminate this effect on beam emittance, several solutions are investigated to avoid over focusing. This result is very important for beam loading experiment for low bunch charge operation. Meanwhile, different merger structures are compared in terms of error sensitivity and emittance increase with space charge effect. In recirculation beam line, a new symmetric 180{degree} arc structure is designed. It fulfills the achromatic condition and adjustable bunch compression. These two parameters are controlled by different Quads knob. With this novel structure, the recirculation lattice can achieve path length adjustment, bunch compression and decompression in a large range. With beamline error, the beam central orbit will deviate from the designed trajectory. An orbit correction system is optimized, which balances between cost and performance of orbit after correction at design level. Different methods are used to estimate its robustness. The BBU instability, especially multi-pass BBU imposed a potentially severe limitation to the average current that can be accelerated in an ERL. Simulation gives the harmful HOMs and predicts that the threshold average current in this machine is much higher than the possible operation current. This work is based on the existing facility in PKU, so it provides guidelines for the facility operation and upgrade in the future. The theoretical analysis of ERL requirement and FEL requirement on beam transport line and beam property paves the way for future ERL research.

Guimei Wang

2011-12-31T23:59:59.000Z

349

Coherent Time-Delayed Atom-Light Interferometer  

E-Print Network (OSTI)

We present experimental observations of interference between an atomic spin coherence and an optical field in a $\\Lambda$-type gradient echo memory. The interference is mediated by a strong classical field that couples a weak probe field to the atomic spin coherence through a resonant Raman transition. Interference can be observed between a prepared spin coherence and another propagating optical field, or between multiple $\\Lambda$ transitions driving a single spin coherence. In principle, the interference in each scheme can yield a near unity visibility and could be used as a coherent all-optical switch.

Campbell, G; Sparkes, B M; Lam, P K; Buchler, B C

2011-01-01T23:59:59.000Z

350

Measurements of the Vertical Coherence Length in Neutron Interferometry  

SciTech Connect

The study and use of macroscopic quantum coherence requires long coherence lengths. Here we describe an approach to measuring the vertical coherence length in neutron interferometry, along with improvements to the NIST interferometer that led to a measured coherence length of 790 A. The measurement is based on introducing a path separation and measuring the loss in contrast as this separation is increased. The measured coherence length is consistent with the momentum distribution of the neutron beam. Finally, we demonstrate that the loss in contrast with beam displacement in one leg of the interferometer can be recovered by introducing a corresponding displacement in the second leg.

Pushin, D. A.; Cory, D. G. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Huber, M. G. [Department of Physics, Tulane University, New Orleans, Louisiana (United States)

2008-06-27T23:59:59.000Z

351

Coherence resonance in an unijunction transistor relaxation oscillator  

E-Print Network (OSTI)

The phenomenon of coherence resonance (CR) is investigated in an unijunction transistor relaxation oscillator (UJT-RO) and quantified by estimating the normal variance (NV). Depending upon the measuring points two types of NV curves have been obtained. We have observed that the degradations in coherency at higher noise amplitudes in our system is probably the result of direct interference of coherent oscillations and the stochastic perturbation. Degradation of coherency may be minimal if this direct interference of noise and coherent oscillations is eliminated.

Md. Nurujjaman; P. S. Bhattacharya; A. N. Sekar Iyengar; Sandip Sarkar

2009-02-02T23:59:59.000Z

352

THE RF-GUN BASED INJECTOR FOR THE TESLA TESTFACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany  

E-Print Network (OSTI)

THE RF-GUN BASED INJECTOR FOR THE TESLA TESTFACILITY LINAC S. Schreiber for the TESLA Collaboration was produced by a subharmonic injector using a thermionic gun, a buncher cavity, and one standard Linear Collider, a laser driven RF gun is required. At present, two similar guns are under con- struction

353

Nonperturbative Coherent Population Trapping: An Analytic Model  

Science Journals Connector (OSTI)

Coherent population trapping is shown to occur in a driven symmetric double-well potential in the strong-field regime. The system parameters have been chosen to reproduce the 0-?3+ transition of the inversion mode of the ammonia molecule. For a molecule initially prepared in its lower doublet we find that, under certain circumstances, the 3+ level remains unpopulated, and this occurs in spite of the fact that the laser field is resonant with the 0-?3+ transition and intense enough so as to strongly mix the 0+ and 0- ground states. This counterintuitive result constitutes a coherent population trapping phenomenon of nonperturbative origin which cannot be accounted for with the usual models.

V. Delgado and J. M. Gomez Llorente

2002-01-23T23:59:59.000Z

354

Synchronization of extended systems from internal coherence  

E-Print Network (OSTI)

A condition for the synchronizability of a pair of PDE systems, coupled through a finite set of variables, is commonly the existence of internal synchronization or internal coherence in each system separately. The condition was previously illustrated in a forced-dissipative system, and is here extended to Hamiltonian systems, using an example from particle physics. Full synchronization is precluded by Liouville's theorem. A form of synchronization weaker than "measure synchronization" is manifest as the positional coincidence of coherent oscillations ("breathers" or "oscillons") in a pair of coupled scalar field models in an expanding universe with a nonlinear potential, and does not occur with a variant of the model that does not exhibit oscillons.

Gregory S. Duane

2008-12-02T23:59:59.000Z

355

Coherent Neutrino Scattering and Stellar Collapse  

Science Journals Connector (OSTI)

Freedman has shown that coherency and the neutral current theory of neutrinos imply a scattering cross section for neutrinos off heavy nuclei proportional to the square of the atomic weight. The collapse of an iron-core star produces a hot neutron star surrounded by a thin iron layer. Because of the large scattering rate in the outer layer, neutrinos from the hot neutron core are able to accelerate the iron layer to above escape velocity.

James R. Wilson

1974-04-15T23:59:59.000Z

356

Glauber coherence of single-electron sources  

Science Journals Connector (OSTI)

Recently demonstrated solid-state single-electron sources generate different quantum states depending on their operation condition. For adiabatic and nonadiabatic sources, we determine the Glauber correlation function in terms of the Floquet scattering matrix of the source. The correlation function provides full information on the shape of the state and on its time-dependent amplitude and phase. The coherence properties of single-electron states are therefore essential for the production of quantum multiparticle states.

G. Haack; M. Moskalets; M. Büttiker

2013-05-17T23:59:59.000Z

357

Coherent neutrino scattering in dark matter detectors  

Science Journals Connector (OSTI)

Coherent elastic neutrino-nucleus and weakly interacting massive particle-nucleus interaction signatures are expected to be quite similar. This paper discusses how a next-generation ton-scale dark matter detector could discover neutrino-nucleus coherent scattering, a precisely-predicted standard model process. A high-intensity pion- and muon- decay-at-rest neutrino source recently proposed for oscillation physics at underground laboratories would provide the neutrinos for these measurements. In this paper, we calculate raw rates for various target materials commonly used in dark matter detectors and show that discovery of this interaction is possible with a 2??ton·year GEODM exposure in an optimistic energy threshold and efficiency scenario. We also study the effects of the neutrino source on weakly interacting massive particle sensitivity and discuss the modulated neutrino signal as a sensitivity/consistency check between different dark matter experiments at the Deep Underground Science and Engineering Laboratory. Furthermore, we consider the possibility of coherent neutrino physics with a GEODM module placed within tens of meters of the neutrino source.

A. J. Anderson; J. M. Conrad; E. Figueroa-Feliciano; K. Scholberg; J. Spitz

2011-07-15T23:59:59.000Z

358

Emergence of non-zonal coherent structures  

E-Print Network (OSTI)

Planetary turbulence is observed to self-organize into large-scale structures such as zonal jets and coherent vortices. One of the simplest models that retains the relevant dynamics of turbulent self-organization is a barotropic flow in a beta-plane channel with turbulence sustained by random stirring. Non-linear integrations of this model show that as the energy input rate of the forcing is increased, the homogeneity of the flow is first broken by the emergence of non-zonal, coherent, westward propagating structures and at larger energy input rates by the emergence of zonal jets. The emergence of both non-zonal coherent structures and zonal jets is studied using a statistical theory, Stochastic Structural Stability Theory (S3T). S3T directly models a second-order approximation to the statistical mean turbulent state and allows the identification of statistical turbulent equilibria and study of their stability. Using S3T, the bifurcation properties of the homogeneous state in barotropic beta-plane turbulence ...

Bakas, Nikolaos A

2015-01-01T23:59:59.000Z

359

Quantum kinetic theory with nonlocal coherence  

E-Print Network (OSTI)

In this thesis we develop a novel approximation scheme (eQPA), where the effects of nonlocal coherence are included in the kinetic approach to nonequilibrium quantum dynamics. The key element in our formalism is the finding of new singular shell solutions, located at $k_{0,z} = 0$ in the phase space of 2-point Wightman function, which describe the nonlocal quantum coherence between the ``opposite'' mass-shell excitations for spatially homogeneous and static planar symmetric problems, respectively. This phase space structure leads to a closed set of transport equations for the corresponding on-shell distribution functions $f$, providing an extension to the standard quantum Boltzmann equation. We have considered a number of applications to demonstrate the use of our formalism, including the Klein problem, quantum reflection from a CP-violating mass wall and coherent production of (fermionic and scalar) particles in an oscillating background. Our formalism should be of relevance for many problems in particle physics and cosmology, including baryogenesis and neutrino flavour oscillations in an inhomogeneous background.

Matti Herranen

2009-06-17T23:59:59.000Z

360

Introduction of coherence in astrophysical spectroscopy  

E-Print Network (OSTI)

By confusing the radiance of a single mode light beam, constant in a transparent medium, with the irradiance which decreases away from the source, Menzel purports to show that coherent interactions of light with the diluted media of astrophysics, are negligible. Therefore, to study the interaction of light with gases, astrophysicists use Monte Carlo computations which work to study nuclear systems, but not optics: optical modes which may be defined in inhomogeneous media or for the emissions of single atoms interact coherently with these systems: a unique formula represents, according to the sign of a parameter, absorption and coherent emission. The optical and spectroscopic properties of a very simple model, an extremely hot source in an isotropic cloud of pure, low pressure, initially cold, huge hydrogen cloud are studied using Planck's and Einstein's theories. The similarities of the images and the spectra of this simple model with astronomical observations, for instance of SNR1987A, Einstein cross, lyman break galaxies, quasars,... is so large that this model may be an elementary first step in the study of many astrophysical objects. Adaptations of the model to complex astrophysical systems could represent them using only the old, standard theories of physics commonly used in laser spectroscopy.

Jacques Moret-Bailly

2010-02-08T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

California | Department of Energy  

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

February 28, 2003 February 28, 2003 EA-1426: Finding of No Significant Impact Linac Coherent Light Source Project, Stanford Linear Accelerator Center, Menlo Park, California February 3, 2003 EA-1441: Environmental Assessment Construction and Operation of the Molecular Foundry at Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California January 1, 2003 EA-1422: Final Site-wide Environmental Assessment Sandia National Laboratories December 2, 2002 EA-1426: Final Environmental Assessment Linac Coherent Light Source Experimental Facility December 2, 2002 EA-1442: Final Environmental Assessment Proposed Construction and Operation of a Biosafety Level 3 Facility at Lawrence Livermore National Laboratory, Livermore, CA November 1, 2002 EIS-0323: Final Environmental Impact Statement

362

Spatial coherence effect on layer thickness determination in narrowband full-field optical coherence tomography  

SciTech Connect

Longitudinal spatial coherence (LSC) is determined by the spatial frequency content of an optical beam. The use of lenses with a high numerical aperture (NA) in full-field optical coherence tomography and a narrowband light source makes the LSC length much shorter than the temporal coherence length, hence suggesting that high-resolution 3D images of biological and multilayered samples can be obtained based on the low LSC. A simplified model is derived, supported by experimental results, which describes the expected interference output signal of multilayered samples when high-NA lenses are used together with a narrowband light source. An expression for the correction factor for the layer thickness determination is found valid for high-NA objectives. Additionally, the method was applied to a strongly scattering layer, demonstrating the potential of this method for high-resolution imaging of scattering media.

Safrani, Avner; Abdulhalim, Ibrahim

2011-06-20T23:59:59.000Z

363

Equatorial spread {ital F} effects on an HF path: Doppler spread, spatial coherence, and frequency coherence  

SciTech Connect

In August 1990 we participated in the Equatorial Ionospheric Studies sounding rocket campaign near Kwajalein Atoll in the equatorial Pacific region. The campaign included measurements of plasma density using rocket probes and coherent and incoherent scatter radar. During the campaign we fielded high-frequency ionospheric sounders over a bistatic path between Maloelap Atoll and Bikini Atoll in the Marshall Islands. The distance between the transmitters and receivers was 700 km; the ionospheric-reflection region was at 10.18; {degree}N, 168.40;{degree}E, near the magnetic equator. We made three types of measurements: Doppler spread and spatial coherence for a single-frequency CW path; frequency coherence of multiple CW paths; and Doppler spread and time-delay spread for a 60-kHz bandwidth path. We obtained such data over a period of 2 weeks for approximately 2 hours each evening; during this period spread {ital F} was common. Fifty percent of the evenings showed Doppler spread of greater than 6 Hz at the {minus}10 dB level (relative to the peak signal power) and greater than 15 Hz at the {minus}30 dB level. Forty percent of the evenings showed spatial coherence distance of less than 180 m in the direction normal to the bistatic path; 40{percent} of the evenings showed spatial coherence of less than 75 m in the direction parallel to the path. Seventy-five percent of the evenings showed coherence bandwidths of less than 1.5 kHz. {copyright} 1999 American Geophysical Union

Fitzgerald, T.J.; Argo, P.E.; Carlos, R.C. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

1999-01-01T23:59:59.000Z

364

Proposal to search for a dark photon in $e^+$ on target collisions at DA$?$NE linac  

E-Print Network (OSTI)

Photon-like particles are predicted in many extensions of the Standard Model. They have interactions similar to the photon, are vector bosons, and can be produced together with photons. The present paper proposes a search for such particles in the $ e^+e^- \\to U\\gamma$ process in a positron-on-target experiment, exploiting the positron beam of the DA$\\Phi$NE linac at the Laboratori Nazionali di Frascati, INFN. In one year of running a sensitivity in the relative interaction strength down to $\\sim10^{-6}$ is achievable, in the mass region from 2.5 MeV$

Mauro Raggi; Venelin Kozhuharov

2014-03-12T23:59:59.000Z

365

Beam Measurement of 11.424 GHz X-Band Linac for Compton Scattering X-ray Source  

SciTech Connect

An inverse Compton scattering X-ray source for medical applications, consisting of an X-band (11.424 GHz) linac and Q-switched Nd:YAG laser, is currently being developed at the University of Tokyo. This system uses an X-band 3.5-cell thermionic cathode RF gun for electron beam generation. We can obtain a multi-bunch electron beam with this gun. The beam is accelerated to 30 MeV by a traveling-wave accelerating tube. So far, we have verified stable beam generation (around 2.3 MeV) by using the newly designed RF gun and we have succeeded in beam transportation to a beam dump.

Natsui, Takuya; Mori, Azusa; Masuda, Hirotoshi; Uesaka, Mitsuru [Nuclear Professional School, School of Engineering, University of Tokyo, 22-2 Shirane-shirakata, Tokai, Naka, Ibaraki 319-1188 (Japan); Sakamoto, Fumito [Akita National College of Technology, 1-1 Iijima-bunkyo, Akita city, Akita 011-8511 (Japan)

2010-11-04T23:59:59.000Z

366

OECD-International Platform on Policy Coherence for Development | Open  

Open Energy Info (EERE)

International Platform on Policy Coherence for Development International Platform on Policy Coherence for Development Jump to: navigation, search Tool Summary Name: OECD-International Platform on Policy Coherence for Development Agency/Company /Organization: Organisation for Economic Co-Operation and Development (OECD) Focus Area: Economic Development Topics: Co-benefits assessment Resource Type: Guide/manual, Lessons learned/best practices, Technical report User Interface: Website Website: community.oecd.org/community/pcd Cost: Free Language: English OECD-International Platform on Policy Coherence for Development Screenshot References: OECD-International Platform on Policy Coherence for Development[1] "The "International Platform on Policy Coherence for Development"" is intended as an interactive tool to be built up over time. It contains four

367

Preparation and probing of the ground state coherence in Rubidium  

E-Print Network (OSTI)

We demonstrate the preparation and probing of the coherence between the hyperfine ground states |5S_{1/2}, F=1> and |5S_{1/2}, F=2> of the Rubidium 87 isotope. The effect of various coherence control techniques, i.e. fractional Stimulated Raman Adiabatic Passage and Coherent Population Return on the coherence are investigated. These techniques are implemented using nearly degenerate pump and Stokes lasers at 795nm (Rubidium D1 transition) which couple the two hyperfine ground states via the excited state |5P_{1/2}, F=1> through a resonant two-photon process, in which a coherent superposition of the two hyperfine ground states is established. The medium is probed by an additional weak laser, which generates a four-wave mixing signal proportional to the ground state coherence, and allows us to monitor its evolution in time. The experimental data are compared with numerical simulations.

Martin Oberst; Frank Vewinger; A. I. Lvovsky

2007-01-31T23:59:59.000Z

368

Eddy impacts on the Florida Current E. Frajka-Williams,1  

E-Print Network (OSTI)

Eddy impacts on the Florida Current E. Frajka-Williams,1 W. E. Johns,2 C. S. Meinen,3 L. M. Beal,2. Meinen, L. M. Beal, and S. A. Cunningham (2013), Eddy impacts on the Florida Current, Geophys. Res. Lett, the FC is coherent with local winds [Schott et al., 1988; Atkinson et al., 2010; Rousset and Beal, 2011

369

Panama City 2003 Acoustic Coherence Experiments: Environmental Characterization  

Science Journals Connector (OSTI)

During June 2003 the Naval Research Laboratory conducted a series of acoustic propagation experiments to measure both high (20 to 150 kHz) and low (1 to 10 kHz) frequency spatial and temporal coherence in very shallow water. Environmental data collected to support the acoustic measurements included water column current bottom current sea?surface wave height tide height CTD water column profiles and mid?water time series two?dimensional micro?scale seawater temperature and weather parameters. Wave periods varied from 3 to 7 seconds and wind speeds ranged from 4 to 35 knots throughout the experiment. Temperature and salinity profiles characterized periods when the water column was isovelocity and periods when the water column was stratified with a strong depth dependence of temperature and salinity. Current magnitudes were always less than 25 cm/s. Experimental geometry and methods of environmental data collection are briefly described and environmental conditions and their impact on the propagation environment are emphasized.

Roger Meredith; Robert Fisher; Steve Stanic; Edgar Kennedy; Dexter Malley; Bob Brown

2004-01-01T23:59:59.000Z

370

Measuring plasma turbulence using low coherence microwave radiation  

SciTech Connect

Low coherence backscattering (LCBS) is a proposed diagnostic technique for measuring plasma turbulence and fluctuations. LCBS is an adaptation of optical coherence tomography, a biomedical imaging technique. Calculations and simulations show LCBS measurements can achieve centimeter-scale spatial resolution using low coherence microwave radiation. LCBS measurements exhibit several advantages over standard plasma turbulence measurement techniques including immunity to spurious reflections and measurement access in hollow density profiles. Also, LCBS is scalable for 1-D profile measurements and 2-D turbulence imaging.

Smith, D. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2012-02-20T23:59:59.000Z

371

Tematea: Issue Based Modules for Coherent Implementation of Biodiversi...  

Open Energy Info (EERE)

Tematea: Issue Based Modules for Coherent Implementation of Biodiversity Conventions Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Tematea: Issue Based Modules for...

372

KS0 regeneration on nuclei and the coherent production model  

Science Journals Connector (OSTI)

We use the coherent production model to calculate the energy dependence of the forward KS0 regeneration amplitude on nuclear targets. The agreement with experiment is satisfactory.

Fumiyo Uchiyama

1974-02-01T23:59:59.000Z

373

Coherent Carbon Cryogel-Ammonia Borane Nanocomposites for Improved...  

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

Carbon Cryogel-Ammonia Borane Nanocomposites for Improved Hydrogen Storage. Coherent Carbon Cryogel-Ammonia Borane Nanocomposites for Improved Hydrogen Storage. Abstract: Ammonia...

374

Coherence and Entanglement in a Stern-Gerlach experiment  

E-Print Network (OSTI)

We give a simple example of the tight connection between entanglement and coherence for pure bipartite systems showing the double role played by entanglement; it allows for the creation of superpositions of macroscopic objects but at the same time makes subsystems lose their quantum mechanical coherence. For this we study the time evolution of the spin coherence in the Stern-Gerlach (SG) experiment. We also show that, contrary to the naive intuition, the spin coherence is lost before the two beams become separated in the spatial coordinates.

Thiago R. de Oliveira; A. O. Caldeira

2006-08-24T23:59:59.000Z

375

Witnessing quantum coherence in the presence of noise  

E-Print Network (OSTI)

We address the problem of assessing the coherent character of physical evolution. We take the quantum Zeno effect (QZE) as a characteristic trait of quantum dynamics, and derive relations among transfer rates as a function of the strength of a measurement. These relations support the intuition that only quantum dynamics is susceptible to QZE. With the derived bounds on the magnitude of coherent dynamics, we propose an experimentally accessible coherence witness. Our results have potential application in assessing coherence of quantum transport in biological and other complex many-body systems.

Alex Monras; Agata Ch?ci?ska; Artur Ekert

2013-12-19T23:59:59.000Z

376

Quantitative studies of x-ray optical coherence.  

E-Print Network (OSTI)

??Over the past 15 years, there has been a development of non-interferometric methods of coherence measurement which seek to obtain a full characterisation of the… (more)

Flewett, Samuel

2010-01-01T23:59:59.000Z

377

Increasing photocell power by quantum coherence induced by external source  

SciTech Connect

We show that photocell power can be substantially enhanced by quantum coherence in the model proposed by [M. O. Scully Phys. Rev. Lett. 104, 207701 (2010)]. Here coherence is induced by an external microwave drive. We show that although such coherence requires an extra energy input, the amount of extra input power can be much smaller than produced enhancement of the photovoltaic power. We demonstrate that for certain parameters power enhancement is governed by quantum coherence and is not just a result of population transfer due to the driving field. This corroborates and extends the earlier work of Scully.

Dorfman, Konstantin E.; Kim, Moochan B. [Texas A and M University, College Station, Texas 77843 (United States); Svidzinsky, Anatoly A. [Texas A and M University, College Station, Texas 77843 (United States); Princeton University, Princeton NJ 08544 (United States)

2011-11-15T23:59:59.000Z

378

Role of pump coherence in two-photon interferometry  

SciTech Connect

We use a parametric down-conversion source pumped by a short-coherence-length continuous-wave (CW) diode laser to perform two-photon interferometry in an intermediate regime between the more familiar Franson-type experiments with a long-coherence-length pump laser, and the short pulsed pump ''time-bin'' experiments pioneered by Gisin's group. The use of a time-bin-like Mach-Zehnder interferometer in the CW pumping beam induces coherence between certain two-photon amplitudes, while the CW nature of the experiment prevents the elimination of remaining incoherent ones. The experimental results highlight the role of pump coherence in two-photon interferometry.

Liang, J.; Hendrickson, S. M.; Pittman, T. B. [Physics Department, University of Maryland Baltimore County, Baltimore, Maryland 21250 (United States)

2011-03-15T23:59:59.000Z

379

The role of pump coherence in two-photon interferometry  

E-Print Network (OSTI)

We use a parametric down-conversion source pumped by a short coherence-length continuous-wave (CW) diode laser to perform two-photon interferometry in an intermediate regime between the more familiar Franson-type experiments with a long coherence-length pump laser, and the short pulsed pump "time-bin" experiments pioneered by Gisin's group. The use of a time-bin-like Mach-Zehnder interferometer in the CW pumping beam induces coherence between certain two-photon amplitudes, while the CW nature of the experiment prevents the elimination of remaining incoherent ones. The experimental results highlight the role of pump coherence in two-photon interferometry.

J. Liang; S. M. Hendrickson; T. B. Pittman

2010-12-20T23:59:59.000Z

380

Coherence Length of Cold Exciton Gases in Coupled Quantum Wells  

Science Journals Connector (OSTI)

A Mach-Zehnder interferometer with spatial and spectral resolution was used to probe spontaneous coherence in cold exciton gases, which are implemented experimentally in the ring of indirect excitons in coupled quantum wells. A strong enhancement of the exciton coherence length is observed at temperatures below a few Kelvin. The increase of the coherence length is correlated with the macroscopic spatial ordering of excitons. The coherence length at the lowest temperature corresponds to a very narrow spread of the exciton momentum distribution, much smaller than that for a classical exciton gas.

Sen Yang, A. T. Hammack, M. M. Fogler, L. V. Butov, and A. C. Gossard

2006-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Nuclear morphology measurements using Fourier domain low coherence interferometry  

Science Journals Connector (OSTI)

We present a new common path configuration Fourier domain low coherence interferometry (fLCI) optical system and demonstrate its capabilities by presenting results which determine the...

Graf, Robert; Wax, Adam

2005-01-01T23:59:59.000Z

382

Serial optical coherence scanner for brain imaging and mapping  

Science Journals Connector (OSTI)

The serial optical coherence scanner reconstructs macroscopic tissues at microscopic resolution using intrinsic optical contrasts. The anatomy, nerve fiber architectures and fiber...

Akkin, Taner; Wang, Hui

383

Temporal Coherence of Normal Modes in an Ocean Waveguide  

Science Journals Connector (OSTI)

The coherence time of acoustic signals is derived using coupled mode equation to the first order of sound speed perturbation squared. It is found that mode coupling induced by internal waves in a waveguide changes the temporal coherence of the acoustic field. For a typical shallow water environment numerical results show that the coherence time of acoustic field decreases as ?3/2 power of frequency and ?1/2 power of range at high frequencies in accord with experimental data. Ignoring the mode coupling the coherence time of acoustic field decreases as ?1 power of frequency and ?1/2 power of range same as that predicted for acoustic rays.

T. C. Yang

2010-01-01T23:59:59.000Z

384

The coordinate coherent states approach revisited  

SciTech Connect

We revisit the coordinate coherent states approach through two different quantization procedures in the quantum field theory on the noncommutative Minkowski plane. The first procedure, which is based on the normal commutation relation between an annihilation and creation operators, deduces that a point mass can be described by a Gaussian function instead of the usual Dirac delta function. However, we argue this specific quantization by adopting the canonical one (based on the canonical commutation relation between a field and its conjugate momentum) and show that a point mass should still be described by the Dirac delta function, which implies that the concept of point particles is still valid when we deal with the noncommutativity by following the coordinate coherent states approach. In order to investigate the dependence on quantization procedures, we apply the two quantization procedures to the Unruh effect and Hawking radiation and find that they give rise to significantly different results. Under the first quantization procedure, the Unruh temperature and Unruh spectrum are not deformed by noncommutativity, but the Hawking temperature is deformed by noncommutativity while the radiation specturm is untack. However, under the second quantization procedure, the Unruh temperature and Hawking temperature are untack but the both spectra are modified by an effective greybody (deformed) factor. - Highlights: Black-Right-Pointing-Pointer Suggest a canonical quantization in the coordinate coherent states approach. Black-Right-Pointing-Pointer Prove the validity of the concept of point particles. Black-Right-Pointing-Pointer Apply the canonical quantization to the Unruh effect and Hawking radiation. Black-Right-Pointing-Pointer Find no deformations in the Unruh temperature and Hawking temperature. Black-Right-Pointing-Pointer Provide the modified spectra of the Unruh effect and Hawking radiation.

Miao, Yan-Gang, E-mail: miaoyg@nankai.edu.cn; Zhang, Shao-Jun, E-mail: sjzhang@mail.nankai.edu.cn

2013-02-15T23:59:59.000Z

385

Coherent Perfect Absorption of Single Photons  

E-Print Network (OSTI)

We examine the question of coherent perfect absorption (CPA) of single photons, and more generally, of the quantum fields. We show the CPA of path entangled single photons in a Fabry-Perot interferometer containing an absorptive medium. The frequency of perfect absorption can be controlled by changing the interferometer parameters like the reflectivity and the complex dielectric constant of the material. We exhibit similar results for path entangled photons in micro-ring resonators. For entangled fields like the ones produced by a down converter the CPA aspect is evident in phase sensitive detection schemes such as in measurements of the squeezing spectrum.

Huang, Sumei

2014-01-01T23:59:59.000Z

386

Self-Similar Modes of Coherent Diffusion  

E-Print Network (OSTI)

Self-similar solutions of the coherent diffusion equation are derived and measured. The set of real similarity solutions is generalized by the introduction of a nonuniform phase surface, based on the elegant Gaussian modes of optical diffraction. In an experiment of light storage in a gas of diffusing atoms, a complex initial condition is imprinted, and its diffusion dynamics is monitored. The self-similarity of both the amplitude and the phase pattern is demonstrated, and an algebraic decay associated with the mode order is measured. Notably, as opposed to a regular diffusion spreading, a self-similar contraction of a special subset of the solutions is predicted and observed.

O. Firstenberg; P. London; D. Yankelev; R. Pugatch; M. Shuker; N. Davidson

2010-08-16T23:59:59.000Z

387

Coherence Scale of the Kondo Lattice  

Science Journals Connector (OSTI)

It is shown that the large- N approach yields two energy scales for the Kondo lattice model. The single-impurity Kondo temperature, TK, signals the onset of local singlet formation, while Fermi-liquid coherence sets in only below a lower scale, T?. At low conduction electron density nc (“exhaustion” limit), the ratio T?/TK is much smaller than unity, and is shown to depend only on nc and not on the Kondo coupling. The physical meaning of these two scales is demonstrated by computing several quantities as a function of nc and temperature.

S. Burdin; A. Georges; D. R. Grempel

2000-07-31T23:59:59.000Z

388

Coherence properties of the stochastic oscillator  

Science Journals Connector (OSTI)

An oscillator with stochastic frequency is discussed as a model for evaluating the quantum coherence properties of a physical system. It is found that the choice of jump statistics has to be considered with care if unphysical consequences are to be avoided. We investigate one such model, evaluate the damping it causes, the decoherence rate and the correlations it results in, and the properties of the state for asymptotically long times. Also the choice of initial state and its effect on the time evolution of the correlations are discussed.

Martti Havukainen and Stig Stenholm

1999-07-01T23:59:59.000Z

389

Optical coherence tomography guided dental drill  

DOE Patents (OSTI)

A dental drill that has one or multiple single mode fibers that can be used to image in the vicinity of the drill tip. It is valuable to image below the surface being drilled to minimize damage to vital or normal tissue. Identifying the boundary between decayed and normal enamel (or dentine) would reduce the removal of viable tissue, and identifying the nerve before getting too close with the drill could prevent nerve damage. By surrounding a drill with several optical fibers that can be used by an optical coherence domain reflectometry (OCDR) to image several millimeters ahead of the ablation surface will lead to a new and improved dental treatment device.

DaSilva, Luiz B. (Danville, CA); Colston, Jr., Bill W. (Livermore, CA); James, Dale L. (Tracy, CA)

2002-01-01T23:59:59.000Z

390

Spontaneous coherence, kinetics and pattern formation in cold exciton gases in GaAs/AlGaAs coupled quantum wells  

E-Print Network (OSTI)

Chapter 6 Coherence . . . . . . . . . . . . .way to measure spatial coherence . . . . . . . . . 6.5exciton and optical coherence lengths 6.3.2 Geometrical

Yang, Sen

2009-01-01T23:59:59.000Z

391

Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography  

E-Print Network (OSTI)

J. G. Fujimoto, “Optical coherence tomography,” Science 254(and imaging using optical coherence tomography,” Nat. Med.J. G. Fujimoto, “Optical coherence tomography for optical

Kim, Chang Soo; Ahn, Yeh-Chan; Wilder-Smith, Petra; Oh, Seajin; Chen, Zhongping; Kwon, Young Jik

2010-01-01T23:59:59.000Z

392

Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement  

E-Print Network (OSTI)

lymphoid tissue . MALT . Optical coherence tomography . OCTdo not include ocular coherence tomography (OCT). We presentSpectral-domain optical coherence tomography of conjunctival

Williams, Basil K.; Tsui, Irena; McCannel, Tara A.

2010-01-01T23:59:59.000Z

393

Phase Coherence Analysis of Solar Magnetic Activity  

E-Print Network (OSTI)

Over 24 years of synoptic data from the NSO Kitt Peak Vacuum Telescope is used to investigate the coherency and source of the 27-day (synodic) periodicity that is observed over multiple solar cycles in various solar-related time series. A strong 27.03-day period signal, recently reported by Neugebauer et al. (2000), is clearly detected in power spectra of time series from integrated full-disk measurements of the magnetic flux in the 868.8 nm Fe I line and the line equivalent width in the 1083.0 nm He I line. Using spectral analysis of synoptic maps of photospheric magnetic fields, in addition to constructing maps of the surface distribution of activity, we find that the origin of the 27.03-day signal is long-lived complexes of active regions in the northern hemisphere at a latitude of approximately 18 degrees. In addition, using a new time series analysis technique which utilizes the phase variance of a signal, the coherency of the 27.03-day period signal is found to be significant for the past two decades. However, using the past 120 years of the sunspot number time series, the 27.03-day period signal is found to be a short-lived, no longer than two 11-year solar cycles, quasi-stationary signal.

Carl J. Henney; John W. Harvey

2006-12-20T23:59:59.000Z

394

Progress on the Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source  

E-Print Network (OSTI)

IHEP, China is constructing a 100 MeV / 100 kW electron Linac for NSC KIPT, Ukraine. This linac will be used as the driver of a neutron source based on a subcritical assembly. In 2012, the injector part of the accelerator was pre-installed as a testing facility in the experimental hall #2 of IHEP. The injector beam and key hardware testing results were met the design goal. Recently, the injector testing facility was disassembled and all of the components for the whole accelerator have been shipped to Ukraine from China by ocean shipping. The installation of the whole machine in KIPT will be started in June, 2013. The construction progress, the design and testing results of the injector beam and key hardware are presented.

Yun-Long, Chi; Guo-Xi, Pei; Shu-Hong, Wang; Jian-She, Cao; Mi, Hou; Wei-Bin, Liu; Zu-Sheng, Zhou; Feng-Li, Zhao; Rong, Liu; Xiang-Cheng, Kong; Jing-Xia, Zhao; Chang-Dong, Deng; Hong, Song; Jin-Tong, Liu; Xu-Wen, Dai; Jun-Hui, Yue; Qi, Yang; Da-Yong, He; Xiang, He; Qi, Le; Xiao-Ping, Li; Lin, Wang; Xiang-Jian, Wang; Hui-Zhou, Ma; Xiao-Yan, Zhao; Yan-Feng, Sui; Hai-Sheng, Guo; Chuang-Xin, Ma; Jian-Bing, Zhao; Peng, Chen

2013-01-01T23:59:59.000Z

395

Radio-Frequency Beam Conditioner for Fast-Wave Free-Electron Generators of Coherent Radiation  

E-Print Network (OSTI)

for Fast-Wave Free-Electron Generators of Coherent RadiationFAST-WAVE FREE-ELECTRON GENERATORS OF COHERENT RADIATION'OFOR FAST-WAVE FREE-ELECTRON GENERATORS OF COHERENT RADIATION

Sessler, Andrew M.

2008-01-01T23:59:59.000Z

396

Evaluating the coherence of Take-the-best in structured environments  

E-Print Network (OSTI)

to the special is- sue: Coherence and correspondence inPsy- chology, 50, 488–494. Coherence of Take-the-best Lee,are good process- or coherence-based Judgment and Decision

Lee, M. D.; Zhang, S. A.

2012-01-01T23:59:59.000Z

397

Coherence and Linewidth Studies of a 4-nm High Power FEL  

E-Print Network (OSTI)

published in the Proceedings Coherence and Linewidth StudiesLBL-33285 HIFAN-570 Coherence and Linewidth Studies of a 4-No. DE-AC03-76SFOO098. Coherence and Linewidth Studies of a

Fawley, W.M.

2008-01-01T23:59:59.000Z

398

Coherence in nervous system design: the visual system of Pantodon buchholzi  

Science Journals Connector (OSTI)

...by S. P. Collin and N. J. Marshall Coherence in nervous system design: the visual...fusiform cell|Pantodon buchholzi | Coherence in nervous system design: the visual...Relationship Vision, Ocular physiology Coherence in nervous system design: the visual...

2000-01-01T23:59:59.000Z

399

Exciton coherence length fluctuations in chromophore aggregates probed by multidimensional optical spectroscopy  

E-Print Network (OSTI)

Exciton coherence length fluctuations in chromophore aggregates probed by multidimensional optical 10 May 2010; published online 2 July 2010 The coherent third order optical response of molecular integral over stochastic bath paths described by the stochastic Liouville equations. Coherent two

Mukamel, Shaul

400

Remark on the coherent information saturating its upper bound  

E-Print Network (OSTI)

Coherent information is a useful concept in quantum information theory. It connects with other notions in data processing. In this short remark, we discuss the coherent information saturating its upper bound. A necessary and sufficient condition for this saturation is derived.

Lin Zhang

2012-08-25T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Optical quantum swapping in a coherent atomic medium  

E-Print Network (OSTI)

We propose to realize a passive optical quantum swapping device which allows for the exchange of the quantum fluctuations of two bright optical fields interacting with a coherent atomic medium in an optical cavity. The device is based on a quantum interference process between the fields within the cavity bandwidth arising from coherent population trapping in the atomic medium.

Aurelien Dantan

2011-10-03T23:59:59.000Z

402

Coherent Quantum-Noise Cancellation for Optomechanical Sensors  

E-Print Network (OSTI)

Using a flowchart representation of quantum optomechanical dynamics, we design coherent quantum-noise-cancellation schemes that can eliminate the back-action noise induced by radiation pressure at all frequencies and thus overcome the standard quantum limit of force sensing. The proposed schemes can be regarded as novel examples of coherent feedforward quantum control.

Mankei Tsang; Carlton M. Caves

2010-08-17T23:59:59.000Z

403

Light polarization control during free-space propagation using coherence  

SciTech Connect

We report an experimental demonstration of light polarization degree control during free propagation via manipulation of the coherent properties of the source. These experimental results corroborate the theory that polarization and coherence are both related to the same statistical properties of the electromagnetic field.

Vidal, Itamar; Fonseca, Eduardo J. S.; Hickmann, Jandir M. [Optics and Materials Group-Optma, Universidade Federal de Alagoas, Caixa Postal 2051, Maceio, AL, 57061-970 (Brazil)

2011-09-15T23:59:59.000Z

404

Mode coherence at megameter ranges in the North Pacific Ocean  

E-Print Network (OSTI)

Mode coherence at megameter ranges in the North Pacific Ocean Kathleen E. Wage, Matthew A and the Acoustical Society of America. #12;Mode coherence at megameter ranges in the North Pacific Ocean Kathleen E Thermometry of Ocean Climate ATOC and Alternate Source Test AST experiments. Vertical line arrays at Hawaii

Wage, Kathleen

405

Generation of Coherent Institute for Perception Research (IPO)  

E-Print Network (OSTI)

Generation of Coherent Monologues Jan Odijk Institute for Perception Research (IPO) P.O.Box 513 for generating coherent texts is de- scribed. In this method only local conditions associated with sentences any form of planning and it concentrates on maximizing the amount of variation of the texts generated

Theune, Mariët

406

The feasibility of coherent energy transfer in microtubules  

Science Journals Connector (OSTI)

...1004 30 39 44 The feasibility of coherent energy transfer in microtubules Travis John Adrian...theoretical analyses have shown that thermal energy may assist, rather than disrupt, quantum...necessary involvement of quantum coherent energy transfer between uniquely arranged chromophores...

2014-01-01T23:59:59.000Z

407

The use the a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy  

E-Print Network (OSTI)

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

Baussan, E; Ekelof, T; Martinez, E Fernandez; Ohman, H; Vassilopoulos, N

2012-01-01T23:59:59.000Z

408

The use of a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy  

E-Print Network (OSTI)

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

E. Baussan; M. Dracos; T. Ekelof; E. Fernandez Martinez; H. Ohman; N. Vassilopoulos

2013-02-09T23:59:59.000Z

409

Tematea: Issue Based Modules for Coherent Implementation of Biodiversity  

Open Energy Info (EERE)

Tematea: Issue Based Modules for Coherent Implementation of Biodiversity Tematea: Issue Based Modules for Coherent Implementation of Biodiversity Conventions Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Tematea: Issue Based Modules for Coherent Implementation of Biodiversity Conventions Agency/Company /Organization: United Nations Environment Programme, International Union for Conservation of Nature Sector: Land Topics: Implementation, Co-benefits assessment, - Environmental and Biodiversity Resource Type: Guide/manual, Training materials, Lessons learned/best practices Website: www.tematea.org Tematea: Issue Based Modules for Coherent Implementation of Biodiversity Conventions Screenshot References: Tematea[1] Summary "The TEMATEA Project on Issue-Based Modules supports a better and more coherent national implementation of biodiversity-related conventions

410

Polaron Coherence Condensation in Layered Colossal Resistive Manganites  

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

Polaron Coherence Condensation Polaron Coherence Condensation in Layered Colossal Resistive Manganites Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Wednesday, 30 July 2008 00:00 Novel quantum phenomena, such as high-temperature superconductivity (HTSC) and colossal magnetoresistance (CMR), arise in certain materials where the interactions between electrons are very strong, but the mechanism driving their appearance remains a major puzzle. Now, angle-resolved photoemission findings from an international team led by researchers from Stanford University and the ALS provide the first direct spectroscopic evidence that the transition from insulator to metal in CMR manganese oxides (manganites) results from coherent "polaron condensation." The new findings also suggest that coherence-driven transitions are a generic controlling factor for novel quantum phenomena in doped transition-metal oxides.

411

Coherence area profiling in multi-spatial-mode squeezed states  

E-Print Network (OSTI)

The presence of multiple bipartite entangled modes in squeezed states generated by four wave mixing in atomic vapors enables ultra-trace sensing, imaging, and metrology applications that are impossible to achieve with single-spatial-mode squeezed states. For Gaussian seed beams, the spatial distribution of bipartite entangled modes, or coherence areas, across each beam is largely dependent on the spatial modes present in the pump beam, but it has proven difficult to map the distribution of these coherence areas in frequency and space. We demonstrate an accessible method to map the distribution of the coherence areas within these twin beams. We also show that the pump shape can impart different noise properties to each coherence area, and that it is possible to select and detect coherence areas with optimal squeezing with this approach.

Lawrie, B J; Otterstrom, N

2014-01-01T23:59:59.000Z

412

Coherence theory of a laser beam passing through a moving diffuser  

Science Journals Connector (OSTI)

Abstract: We present the general coherence theory for laser beams passing through a moving diffuser. The temporal coherence of laser beams passing through a moving diffuser depends on...

Li, Gaoming; Qiu, Yishen; Li, Hui

2013-01-01T23:59:59.000Z

413

Coherence and persistent currents in mesoscopic rings  

Science Journals Connector (OSTI)

We calculate, to first order in the screened electron-electron interaction, the grand potential and the equilibrium current in a mesoscopic normal-metal ring threaded by a magnetic flux. The average current in an ensemble of such rings is found to be periodic in the flux with period h/2e, and to be given at zero temperature in order of magnitude by I?evFl/L2, where l is the mean free path and L the circumference of the ring. Interference between time-reversed paths, as in the theory of weak localization, is the crucial ingredient. The effect decreases exponentially with temperature on a scale determined by the coherence energy ?hD/L2, where D is the electronic diffusion constant. The results are in good agreement with recent measurements.

Vinay Ambegaokar and Ulrich Eckern

1990-07-16T23:59:59.000Z

414

Birefringence insensitive optical coherence domain reflectometry system  

DOE Patents (OSTI)

A birefringence insensitive fiber optic optical coherence domain reflectometry (OCDR) system is provided containing non-polarization maintaining (non-PM) fiber in the sample arm and the reference arm without suffering from signal degradation caused by birefringence. The use of non-PM fiber significantly reduces the cost of the OCDR system and provides a disposable or multiplexed section of the sample arm. The dispersion in the reference arm and sample arm of the OCDR system are matched to achieve high resolution imaging. This system is useful in medical applications or for non-medical in situ probes. The disposable section of non-PM fiber in the sample arm can be conveniently replaced when contaminated by a sample or a patient.

Everett, Matthew J. (Livermore, CA); Davis, Joseph G. (Lafayette, CA)

2002-01-01T23:59:59.000Z

415

Economic Impacts  

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

Impacts Annual federal research budget 399.4 million American Recovery and Reinvestment stimulus an additional 8,000 Employees * Total 1,945 * Living in Fox Valley or western...

416

Fabrication, Tuning, Treatment and Testing of Two 3.5 Cell Photo-Injector Cavities for the ELBE Linac  

SciTech Connect

As part of a CRADA (Cooperative Research and Development Agreement) between Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Thomas Jefferson Lab National Accelerator Facility (TJNAF) we have fabricated and tested two 1.3 GHz 3.5 cell photo-injector cavities from polycrystalline RRR niobium and large grain RRR niobium, respectively. The cavity with the better performance will replace the presently used injector cavity in the ELBE linac. The cavities have been fabricated and pre-tuned at TJNAF, while the more sophisticated final field tuning, the adjustment of the external couplings and the field profile measurement of transverse electric modes for RF focusing was done at HZDR. The following standard surface treatment and the vertical test was carried out at TJNAF's production facilities. A major challenge turned out to be the rinsing of the cathode cell, which has small opening (O-slash10mm) to receive the cathode stalk. Another unexpected problem encountered after etching, since large visible defects appeared in the least accessible cathode cell. This contribution reports about our experiences, initial results and the on-going diagnostic work to understand and fix the problems.

Arnold, A. [HZDR, Dresden (Germany); Murcek, P. [HZDR, Dresden (Germany); Teichert, J. [HZDR, Dresden (Germany); Xiang, R. [HZDR, Dresden (Germany); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kneisel, P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Stirbet, M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Turlington, L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2011-07-01T23:59:59.000Z

417

Effect of depolarization on temporal coherence within a focused supercontinuum  

SciTech Connect

Under the conditions of vectorial diffraction, an increase in refraction at the extremities of the lens rotates the incident polarization state which transfers energy from the initial state to the orthogonal transverse field and the longitudinal field, which is known as depolarization. Since the field is a vectorial field containing three polarization components, the theory for the degree of coherence is first extended to incorporate cross-correlation effects within these vectorial components which are calculated through a coherency matrix. The use of this matrix provides an insight into interesting correlation effects between copropagating vectorial fields such as the coupled modes (linear polarized modes) of the supercontinuum generated by a photonic crystal fiber. An investigation is presented on the coherence times for the supercontinuum field generated by cross coupling into the photonic crystal fiber. The coherence times under cross-coupling conditions show that the degree of coherence of the two coupled modes from the fiber are different, which is due to the differences in phase. For a supercontinuum with a linear polarization state, the coherence times along the x, y, and z axes are different, with the most significant change occurring along the optical axis (z) where the coherence time changes by an order of magnitude when the numerical aperture is increased from 0.1 to 1.

Chick, Brendan J.; Chon, James W. M.; Gu Min [Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Post Office Box 218, Hawthorn 3122, Victoria (Australia)

2010-08-15T23:59:59.000Z

418

Impact of the spatial laser distribution on photocathode gun operation  

It is widely believed that a drive laser with uniform temporal and spatial laser profiles is required to generate the lowest emittance beam at the photoinjector. However, for a given 3 ps smooth-Gaussian laser temporal profile, our recent simulations indicate that a truncated-Gaussian laser spatial profile produces an electron beam with smaller emittance. The simulation results are qualitatively confirmed by later analytical calculation, and also confirmed by measurements: emittance reduction of ?25% was observed at the linac coherent light source (LCLS) injector with a truncated-Gaussian laser spatial profile at the nominal operating bunch charge of 150 pC. There was a significant secondary benefit—laser transmission through the iris for the truncated-Gaussian profile was about twice that compared to the nearly uniform distribution, which significantly loosens the laser power and quantum efficiency requirements for drive laser system and photocathode. Since February 9, 2012, the drive laser with the truncated-Gaussian spatial distribution has been used for LCLS routine user operations and the corresponding free electron laser power is at least the same as the one when using the nearly uniform spatial profile.

Zhou, Feng; Brachmann, Axel; Emma, Paul; Gilevich, Sasha; Huang, Zhirong

2012-09-01T23:59:59.000Z

419

Coherent structures in compressible free-shear-layer flows  

SciTech Connect

Large scale coherent structures are intrinsic fluid mechanical characteristics of all free-shear flows, from incompressible to compressible, and laminar to fully turbulent. These quasi-periodic fluid structures, eddies of size comparable to the thickness of the shear layer, dominate the mixing process at the free-shear interface. As a result, large scale coherent structures greatly influence the operation and efficiency of many important commercial and defense technologies. Large scale coherent structures have been studied here in a research program that combines a synergistic blend of experiment, direct numerical simulation, and analysis. This report summarizes the work completed for this Sandia Laboratory-Directed Research and Development (LDRD) project.

Aeschliman, D.P.; Baty, R.S. [Sandia National Labs., Albuquerque, NM (United States). Engineering Sciences Center; Kennedy, C.A.; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion and Physical Sciences Center

1997-08-01T23:59:59.000Z

420

Coherent states and holomorphic representations for multilevel atoms  

Science Journals Connector (OSTI)

The notion of atomic coherent states is extended to the multilevel case. Since the representation based on coherent states is convenient in treating collective interactions of atoms with photons, and since many optical processes involve atoms of three or more levels, it is expected that this extension will play a role in the theory of such processes as cascade superfluorescence and superradiant lasing. Like their bosonic counterparts, atomic coherent states may be used to define a holomorphic representation for atomic states and operators. We discuss this in detail and give examples to illustrate applications.

Cao Chang-qi and Fritz Haake

1995-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "impact linac coherent" 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

Temporal coherence length of light in semiclassical field theory models  

SciTech Connect

The following work is motivated by the conceptual problems associated with the wave-particle duality and the notion of the photon. Two simple classical models for radiation from individual emitters are compared, one based on sines with random phasejumps, another based on pulse trains. The sum signal is calculated for a varying number of emitters. The focus lies on the final signal's statistical features quantified by means of the temporal coherence function and the temporal coherence length. We show how these features might be used to experimentally differentiate between the models. We also point to ambiguities in the definition of the temporal coherence length.

Jagielski, Borys; Lein, Johanne; Inge Vistnes, Arnt [Quantum Optics Laboratory, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316 Oslo (Norway)

2011-03-28T23:59:59.000Z

422

Coherence of Four-Particle Correlations in Semiconductors  

Science Journals Connector (OSTI)

We report direct investigations of the coherence of four-particle (exciton-exciton) correlations by ultrafast four-wave mixing experiments. We determine the sensitivity of the coherence of the four-particle correlations to temperature and excitation density, comparing it to the coherence of the two-particle correlations. We discuss our results in terms of numerical solutions of the general kinetic equations, treating the four-particle correlations in the second order Born approximation. We introduce a simple model deduced from these kinetic equations that provides an intuitive interpretation of our results.

P. Kner; W. Schäfer; R. Lövenich; D. S. Chemla

1998-12-14T23:59:59.000Z

423

TAO: Impact  

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

Impact Impact Home Download Documentation Publications Referencing TAO Impact Who We Are Acknowledgements License Contact Us Research and Publications that make use of TAO Dressed TDDFT study of low-lying electronic excited states in selected linear polyenes and diphenylopolyenes, Mazur, G., Makowski, M., Włodarczyk, R., and Aoki, Y., International Journal of Quantum Chemistry, 111, 4, 819--825, 2011. BibTeX Secondary thermal cracks in EGS: a variational approach, Bourdin, B., Knepley, M., and Maurini, C., Proceedings of the 34th annual meeting of the Geothermal resources council, 2010. BibTeX Adaptive Real-Time Bioheat Transfer Models for Computer Driven MR-guided Laser Induced Thermal Therapy, Fuentes, D., Feng, Y., Elliott, A., Shetty, A., McNichols, R. J., Oden, J. T., and Stafford, R. J., IEEE Trans. Biomed. Eng., 5, 1024--1030, 2010. BibTeX

424

Polaron Coherence Condensation in Layered Colossal Resistive Manganites  

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

Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Novel quantum phenomena, such as high-temperature superconductivity (HTSC) and colossal magnetoresistance (CMR), arise in certain materials where the interactions between electrons are very strong, but the mechanism driving their appearance remains a major puzzle. Now, angle-resolved photoemission findings from an international team led by researchers from Stanford University and the ALS provide the first direct spectroscopic evidence that the transition from insulator to metal in CMR manganese oxides (manganites) results from coherent "polaron condensation." The new findings also suggest that coherence-driven transitions are a generic controlling factor for novel quantum phenomena in doped transition-metal oxides.

425

Polaron Coherence Condensation in Layered Colossal Resistive Manganites  

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

Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Novel quantum phenomena, such as high-temperature superconductivity (HTSC) and colossal magnetoresistance (CMR), arise in certain materials where the interactions between electrons are very strong, but the mechanism driving their appearance remains a major puzzle. Now, angle-resolved photoemission findings from an international team led by researchers from Stanford University and the ALS provide the first direct spectroscopic evidence that the transition from insulator to metal in CMR manganese oxides (manganites) results from coherent "polaron condensation." The new findings also suggest that coherence-driven transitions are a generic controlling factor for novel quantum phenomena in doped transition-metal oxides.

426

Covariant Wave Function Reduction and Coherent Decays of Kaon Pair  

E-Print Network (OSTI)

The recently developed relativistically covariant formulation of wave function reduction is illustrated for Lipkin's proposal to study CP violation in the coherent decay of kaon pairs. Covariant results are obtained in agreement with an amplitude approach proposed in the literature.

Bernd A. Berg

1998-09-12T23:59:59.000Z

427

From local to macroscopic coherence in systems with composite quasiparticles  

Science Journals Connector (OSTI)

Strongly interacting systems are characterized by heavily dressed entities with internal degrees of freedom, which, on a local level, can be described in terms of coherent quantum states. We examine the modification of these local coherent quantum states when such entities condense into a macroscopic coherent quantum state, such as superfluidity. As an example, we consider a system of electrons coupled to local lattice deformations. Significant changes in the phonon clouds surrounding the charge carriers occur when the system develops into a spatially phase-locked state. The question of localized self-trapped charge carriers (bipolarons) in the normal state becoming delocalized upon entering the superconducting phase is discussed in terms of squeezing of the local coherent phonon states. Suggestions for experimental verifications of these features associated with the lattice dynamics are made.

J. Ranninger and A. Romano

2002-09-11T23:59:59.000Z

428

Development of Molecular Contrast in Coherence Domain Optical Imaging  

E-Print Network (OSTI)

spectrally resolved two color pump-probe Optical Coherence Microscopy (SRPPOCM). We showed the prototype system on a red hair and a black hair. Our preliminary results show that the SRPPOCM technique could provide a contrast between pheomelanin and eumelanin...

Wan, Qiujie

2012-02-14T23:59:59.000Z

429

Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium  

E-Print Network (OSTI)

Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium niobate M of the photorefractive light-induced scattering (beam fanning) in Sr0.61Ba0.39Nb2O6 (strontium barium niobate) doped

Osnabrück, Universität

430

Water Window Ptychographic Imaging with Characterized Coherent X-rays  

E-Print Network (OSTI)

We report on a ptychographical coherent diffractive imaging experiment in the water window with focused soft X-rays at $500~\\mathrm{eV}$. An X-ray beam with high degree of coherence was selected for ptychography at the P04 beamline of the PETRA III synchrotron radiation source. We measured the beam coherence with the newly developed non-redundant array method. A pinhole $2.6~\\mathrm{\\mu m}$ in size selected the coherent part of the beam and was used for ptychographic measurements of a lithographically manufactured test sample and fossil diatom. The achieved resolution was $53~\\mathrm{nm}$ for the test sample and only limited by the size of the detector. The diatom was imaged at a resolution better than $90~\\mathrm{nm}$.

Rose, Max; Dzhigaev, Dmitry; Gorobtsov, Oleg; Senkbeil, Tobias; von Gundlach, Andreas; Gorniak, Thomas; Shabalin, Anatoly; Viefhaus, Jens; Rosenhahn, Axel; Vartanyants, Ivan

2015-01-01T23:59:59.000Z

431

Thickness Estimation with Optical Coherence Tomography and Statistical Decision Theory  

Science Journals Connector (OSTI)

We implement a maximum-likelihood (ML) estimator to interpret Optical Coherence Tomography (OCT) data, based on a Fourier-Domain OCT and a two-interface tear film model. We use the...

Huang, Jinxin; Clarkson, Eric; Kupinski, Matthew; Rolland, Jannick P

432

Magnetism studies using resonant, coherent, x-ray scattering...  

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

Magnetism studies using resonant, coherent, x-ray scattering Monday, September 10, 2012 - 10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron...

433

Quantum coherence, time-translation symmetry and thermodynamics  

E-Print Network (OSTI)

The first law of thermodynamics imposes not just a constraint on the energy-content of systems in extreme quantum regimes, but also symmetry-constraints related to the thermodynamic processing of quantum coherence. Harmonic analysis allows any density operator to be decomposed in terms of mode operators which quantify the coherence present in a state in a natural way. We establish upper and lower bounds for the evolution of such modes under arbitrary thermal operations, and analyse primitive coherence manipulations. Well-studied thermo-majorization relations on block-diagonal quantum states correspond to constraints only on the zero-mode of a state, governing energy transfers. A complete set of constraints for non-zero modes, governing coherence transfers, is at present unknown, but these modes are found to display similar irreversibility, which demands greater study.

Matteo Lostaglio; Kamil Korzekwa; David Jennings; Terry Rudolph

2014-10-16T23:59:59.000Z

434

Comparison of 2- and 10-µm Coherent Doppler Lidar Performance  

Science Journals Connector (OSTI)

The performance of 2- and 10-µm coherent Doppler lidar is presented in terms of the statistical distribution of the maximum-likelihood velocity estimator from simulations for fixed range resolution and fixed velocity search space as a function of ...

Rod Frehlich

1995-04-01T23:59:59.000Z

435

Doppler optical coherence microscopy for studies of cochlear mechanics  

E-Print Network (OSTI)

The possibility of measuring subnanometer motions with micron scale spatial resolution in the intact mammalian cochlea using Doppler optical coherence microscopy (DOCM) is demonstrated. A novel DOCM system is described ...

Hong, Stanley S.

436

The minimum-uncertainty coherent states for Landau levels  

SciTech Connect

The Glauber minimum-uncertainty coherent states with two variables for Landau levels, based on the representation of Weyl-Heisenberg algebra by two different modes, have been studied about four decades ago. Here, we introduce new two-variable coherent states with minimum uncertainty relationship for Landau levels in three different methods: the infinite unitary representation of su(1, 1) is realized in two different methods, first, by consecutive levels with the same energy gaps and also with the same value for z-angular momentum quantum number, then, by shifting z-angular momentum mode number by two units while the energy level remaining the same. Besides, for su(2), whether by lowest Landau levels or Landau levels with lowest z-angular momentum, just one finite unitary representation is introduced. Having constructed the generalized Klauder-Perelomov coherent states, for any of the three representations, we obtain their Glauber coherency by displacement operator of Weyl-Heisenberg algebra.

Dehghani, A. [Physics Department, Payame Noor University, P. O. Box 19395-4697 Tehran (Iran, Islamic Republic of); Fakhri, H. [Department of Theoretical Physics and Astrophysics, Faculty of Physics, University of Tabriz, P. O. Box 51666-16471 Tabriz (Iran, Islamic Republic of); Mojaveri, B. [Department of Physics, Azarbaijan Shahid Madani University, P. O. Box 51745-406 Tabriz (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

437

Documentation Integrity for Safety-Critical Applications: The COHERE Project  

E-Print Network (OSTI)

. Keywords Authoring interface, documentation integrity, consistency 1. INTRODUCTION This paper reportsDocumentation Integrity for Safety-Critical Applications: The COHERE Project David G. Novick-critical systems. Following a set of documentation integrity maxims, the project developed two generations

Novick, David G.

438

Frequency comb swept lasers for optical coherence tomography  

E-Print Network (OSTI)

We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep ...

Tsai, Tsung-Han

439

Cache coherence strategies in a many-core processor  

E-Print Network (OSTI)

Caches are frequently employed in memory systems, exploiting memory locality to gain advantages in high-speed performance and low latency. However, as computer processor core counts increase, maintaining coherence between ...

Celio, Christopher P

2009-01-01T23:59:59.000Z

440

Computational imaging for 3D phase and coherence retrieval |...  

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

Computational imaging for 3D phase and coherence retrieval Wednesday, December 10, 2014 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Laura Waller (UC Berkeley) Program...

Note: This page contains sample records for the topic "impact linac coherent" 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

Ultrahigh speed optical coherence tomography for ophthalmic imaging applications  

E-Print Network (OSTI)

Optical coherence tomography (OCT) is a non-contact, non-invasive, micron-scale optical imaging technology that has become a standard clinical tool in ophthalmology. Fourier domain OCT detection methods have enabled higher ...

Liu, Jonathan Jaoshin

2014-01-01T23:59:59.000Z

442

Polaron Coherence Condensation in Layered Colossal Resistive Manganites  

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

Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Polaron Coherence Condensation in Layered Colossal Resistive Manganites Print Novel quantum phenomena, such as high-temperature superconductivity (HTSC) and colossal magnetoresistance (CMR), arise in certain materials where the interactions between electrons are very strong, but the mechanism driving their appearance remains a major puzzle. Now, angle-resolved photoemission findings from an international team led by researchers from Stanford University and the ALS provide the first direct spectroscopic evidence that the transition from insulator to metal in CMR manganese oxides (manganites) results from coherent "polaron condensation." The new findings also suggest that coherence-driven transitions are a generic controlling factor for novel quantum phenomena in doped transition-metal oxides.

443

Studying coherence in ultra-cold atomic gases  

E-Print Network (OSTI)

This thesis will discuss the study of coherence properties of ultra-cold atomic gases. The atomic systems investigated include a thermal cloud of atoms, a Bose-Einstein condensate and a fermion pair condensate. In each ...

Miller, Daniel E. (Daniel Edward)

2007-01-01T23:59:59.000Z

444

Coherence and decoherence of a polariton condensate  

Science Journals Connector (OSTI)

We formulate a Langevin-Gross-Pitaevski equation for spatially homogeneous systems together with the semiclassical Boltzmann equations for the excited states of polaritons in a microcavity. The gain of the coherent amplitude is due to the polariton-polariton scattering from the excited states to the ground state and has been obtained by an adiabatic elimination the corresponding three-point polarization. The Langevin-Gross-Pitaevski equation contains in addition to the gain the cavity losses as well as the fluctuations from the cavity losses and from the eliminated polarization. In analogy to the semiconductor laser theory the homogeneously broadened linewidth of the condensate amplitude can be evaluated analytically above threshold using the dissipation-fluctuation theorem. A linewidth enhancement is found because of the changes in the dispersive part of the gain function with the number of excited states and of the blueshift of the ground state. The latter mechanism causes well above threshold the homogeneously broadened linewidth to increase again after a remarkably narrow linewidth is reached. This decoherence mechanisms is inherent to all nonequilibrium condensates due to the Gross-Pitaevski nonlinearity and the fluctuations of the condensate population

H. Haug; H. Thien Cao; D. B. Tran Thoai

2010-06-10T23:59:59.000Z

445

Coherence theory of the ring laser  

Science Journals Connector (OSTI)

Expressions for the fluctuations and correlations of the light emitted by a ring laser with counter-rotating traveling wave modes are derived theoretically. It is shown that the competition of the two modes for the excited atomic population leads to negative correlations between their intensity fluctuations, whose magnitude depends on the detuning of the laser cavity from the atomic line center. As a result of the mode competition, the relative intensity fluctuations do not die out in general as the working point of the laser is raised above threshold at line center, and the emitted light does not become fully coherent as in a conventional laser. The two-time amplitude and intensity correlation functions of the light are calculated at line center, and are shown to be expressible in terms of the eigenfunctions and eigenvalues of a certain Schrödinger equation, in complete analogy with the theory of the single-mode laser. However, the intensity correlation time increases with pump parameter above threshold, unlike that for the single-mode laser.

M. M- Tehrani and L. Mandel

1978-02-01T23:59:59.000Z

446

Coherent testing and simulation of composite blade repair  

E-Print Network (OSTI)

COHERENT TESTING AND SIMULATION OF COMPOSITE BLADE REPAIR A Thesis by BRIAN GLENN MCNICHOLS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1997 Major Subject: Mechanical Engineering COHERENT TESTING AND SIMULATION OF COMPOSITE BLADE REPAIR A Thesis by BRIAN GLENN MCNICHOLS Submitted to Texas A&M University In partial fulfillment of the requirements for the degree of MASTER...

McNichols, Brian Glenn

2012-06-07T23:59:59.000Z

447

Wide-band coherent receiver development for enhanced surveillance  

SciTech Connect

Oak Ridge National Laboratory (ORNL) has been developing advanced coherent IR heterodyne receivers for plasma diagnostics in fusion reactors for over 20 years. Recent progress in wide band IR detectors and high speed electronics has significantly enhanced the measurement capabilities of coherent receivers. In addition, developments in new HgCdTe and quantum well IR photodetector (QWIP) focal plane arrays are providing the possibility of both active and passive coherent imaging. In this paper the authors discuss the implications of these new enabling technologies to the IR remote sensing community for enhanced surveillance. Coherent receivers, as opposed to direct or thermal detection, provide multiple dimensions of information about a scene or target in a single detector system. Combinations of range, velocity, temperature, and chemical species information are all available from a coherent heterodyne receiver. They present laboratory data showing measured noise equivalent power (NEP) of new QWIP detectors with heterodyne bandwidths greater than 7 GHz. For absorption measurements, a wide band coherent receiver provides the capability of looking between CO{sub 2} lines at off-resonance peaks and thus the measurement of lines normally inaccessible with conventional heterodyne or direct detection systems. Also described are differential absorption lidar (DIAL) and Doppler laboratory measurements using an 8 x 8 HgCdTe focal plane array demonstrating the snapshot capability of coherent receiver detector arrays for enhanced chemical plume and moving hardbody capture. Finally they discuss a variety of coherent receiver configurations that can suppress (or enhance) sensitivity of present active remote sensing systems to speckle, glint, and other measurement anomalies.

Simpson, M.L.; Richards, R.K.; Hutchinson, D.P.

1998-03-01T23:59:59.000Z

448

Self-Organized Transition to Coherent Activity in Disordered Media  

Science Journals Connector (OSTI)

Synchronized oscillations are of critical functional importance in many biological systems. We show that such oscillations can arise without centralized coordination in a disordered system of electrically coupled excitable and passive cells. Increasing the coupling strength results in waves that lead to coherent periodic activity, exhibiting cluster, local and global synchronization under different conditions. Our results may explain the self-organized transition in a pregnant uterus from transient, localized activity initially to system-wide coherent excitations just before delivery.

Rajeev Singh; Jinshan Xu; Nicolas G. Garnier; Alain Pumir; Sitabhra Sinha

2012-02-09T23:59:59.000Z

449

Femtosecond time-resolved spectroscopy of coherent oscillations in nanomaterials  

E-Print Network (OSTI)

FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY May 2007 Major Subject: Physics FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial...

Jerebtsov, Serguei Nikolaevich

2009-05-15T23:59:59.000Z

450

Comment on 'Coherence measures for heralded single-photon sources'  

SciTech Connect

A recent Brief Report [Phys. Rev. A 79, 035801 (2009)] investigates two figures of merit for heralded photon sources based on spontaneous parametric down-conversion with a continuous pump, namely, the time-averaged temporal coherence between the signal and idler beams and the time-averaged conditioned second-order degree of coherence for photons in the heralded arm. However, contrary to what is claimed, no one-arm second-order effect is actually measured.

Bettelli, Stefano [Romanogasse 29/15, 1200 Vienna (Austria)

2010-03-15T23:59:59.000Z

451

Electron Beam Diagnostics using Coherent Cherenkov Radiation in Aerogel  

SciTech Connect

The use of coherent Cherenkov radiation as a diagnostic tool for longitudinal distribution of an electron beam is studied in this paper. Coherent Cherenkov radiation is produced in an aerogel with an index of refraction close to unity. An aerogel spectral properties are experimentally studied and analyzed. This method will be employed for the helical IFEL bunching experiment at Neptune linear accelerator facility at UCLA.

Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B. [UCLA Physics Dept., Los Angeles, CA 90066 (United States); Ruelas, M. [RadiaBeam Technologies, Marina Del Ray, CA 90292 (United States)

2009-01-22T23:59:59.000Z

452

Phase-dependent coherent population trapping and optical switching  

SciTech Connect

We propose a scheme for achieving phase-dependent coherent population trapping, showing that both the dark state of the atoms and light propagation dynamics depend on the relative phase of the fields. The atomic coherence prepared via adiabatic process plays a key role in the interaction of light with matter. And an optical switching based on the phase-controlled quantum interference is implemented, which may have potential application in high-speed optical communications and quantum information systems.

Kou, J. [College of Physics, Jilin University, Changchun 130023 (China); Quantum Engineering Center, Beijing Institute of Control Device, Beijing 100854 (China); Wan, R. G.; Kang, Z. H.; Jiang, L.; Wang, L.; Jiang, Y.; Gao, J. Y. [College of Physics, Jilin University, Changchun 130023 (China)

2011-12-15T23:59:59.000Z

453

The Diamond Beamline I13L for Imaging and Coherence  

SciTech Connect

I13L is the first long beamline at Diamond dedicated to imaging and coherence. Two independent branches will operate in the energy range of 6-30 keV with spatial resolution on the micro- to nano-lengthscale. The Imaging branch is dedicated to imaging and tomography with In-line phase contrast and full-field microscopy on the micron to nano-length scale. Ultimate resolution will be achieved on the Coherence branch at I13L with imaging techniques in the reciprocal space. The experimental stations will be located about 250 m from the source, taking advantage of the coherence properties of the source. The beamline has some outstanding features such as the mini-beta layout of the storage ring's straight section. The optical layout is optimized for beam stability and high optical quality to preserve the coherent radiation. In the experimental stations several methods will be available, starting for the first user with in-line phase contrast imaging on the imaging branch and Coherent X-ray Diffraction (CXRD) on the coherence branch.

Rau, C. [Diamond Light Source Ltd., Chilton, Oxfordshire (United Kingdom); Feinberg School of Medicine, Northwestern University, Chicago, Illinois (United States); Wagner, U.; Peach, A.; Singh, B.; Wilkin, G.; Jones, C. [Diamond Light Source Ltd., Chilton, Oxfordshire (United Kingdom); Robinson, I. K. [Diamond Light Source Ltd., Chilton, Oxfordshire (United Kingdom); Laboratory for Nanomaterials, University College London, London, London (United Kingdom)

2010-06-23T23:59:59.000Z

454

Improvement of dose distribution in breast radiotherapy using a reversible transverse magnetic field Linac-MR unit  

SciTech Connect

Purpose: To investigate the improvement in dose distribution in tangential breast radiotherapy using a reversible transverse magnetic field that maintains the same direction of Lorentz force between two fields. The investigation has a potential application in future Linac-MR units. Methods: Computed tomography images of four patients and magnetic fields of 0.25–1.5 Tesla (T) were used for Monte Carlo simulation. Two patients had intact breast while the other two had mastectomy. Simulations of planning and chest wall irradiation were similar to the actual clinical process. The direction of superior-inferior magnetic field for the medial treatment beam was reversed for the lateral beam. Results: For the ipsilateral lung and heart mean doses were reduced by a mean (range) of 45.8% (27.6%–58.6%) and 26.0% (20.2%–38.9%), respectively, depending on various treatment plan setups. The mean V{sub 20} for ipsilateral lung was reduced by 55.0% (43.6%–77.3%). In addition acceptable results were shown after simulation of 0.25 T magnetic field demonstrated in dose-volume reductions of the heart, ipsilateral lung, and noninvolved skin. Conclusions: Applying a reversible magnetic field during breast radiotherapy, not only reduces the dose to the lung and heart but also produces a sharp drop dose volume histogram for planning target volume, because of bending of the path of secondary charged particles toward the chest wall by the Lorentz force. The simulations have shown that use of the magnetic field at 1.5 T is not feasible for clinical applications due to the increase of ipsilateral chest wall skin dose in comparison to the conventional planning while 0.25 T is suitable for all patients due to dose reduction to the chest wall skin.

Esmaeeli, A. D., E-mail: ali-esmaeeli-d@yahoo.com [Department of Physics, Rasht Branch, Islamic Azad University, Rasht, 41476-54919 (Iran, Islamic Republic of); Mahdavi, S. R. [Department of Medical Physics, Tehran University of Medical Sciences, Tehran, 14174 (Iran, Islamic Republic of)] [Department of Medical Physics, Tehran University of Medical Sciences, Tehran, 14174 (Iran, Islamic Republic of); Pouladian, M.; Bagheri, S. [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, 14778-93855 (Iran, Islamic Republic of)] [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, 14778-93855 (Iran, Islamic Republic of); Monfared, A. S. [Department of Medical Physics, Babol University of Medical Sciences, Babol, 47148-71167 (Iran, Islamic Republic of)] [Department of Medical Physics, Babol University of Medical Sciences, Babol, 47148-71167 (Iran, Islamic Republic of)

2014-01-15T23:59:59.000Z

455

Optimization of a coherent soft x-ray beamline for coherent scattering experiments at NSLS-II  

SciTech Connect

The coherent soft x-ray and full polarization control (CSX) beamline at the National Synchrotron Light Source - II (NSLS-II) will deliver 1013 coherent photons per second in the energy range of 0.2-2 keV with a resolving power of 2000. The source, a dual elliptically polarizing undulator (EPU), and beamline optics should be optimized to deliver the highest possible coherent flux in a 10-30 {micro}m spot for use in coherent scattering experiments. Using the computer code Synchrotron Radiation Workshop (SRW), we simulate the photon source and focusing optics in order to investigate the conditions which provide the highest usable coherent intensity on the sample. In particular, we find that an intermediate phasing magnet is needed to correct for the relative phase between the two EPUs and that the optimum phase setting produces a spectrum in which the desired wavelength is slightly red-shifted thus requiring a larger aperture than originally anticipated. This setting is distinct from that which produces an on-axis spectrum similar to a single long undulator. Furthermore, partial coherence calculations, utilizing a multiple electron approach, indicate that a high degree of spatial coherence is still obtained at the sample location when such an aperture is used. The aperture size which maximizes the signal-to-noise ratio of a double-slit experiment is explored. This combination of high coherence and intensity is ideally suited for x-ray ptychography experiments which reconstruct the scattering density from micro-diffraction patterns. This technique is briefly reviewed and the effects on the image quality of proximity to the beamline focus are explored.

Shapiro D.; Chubar, O.; Kaznatcheev, K.; Reininger, R.; Sanchez-Hanke, C.; Wang, S.

2011-08-21T23:59:59.000Z

456

Theory of coherent neutron scattering by hydrogen-bonded ferroelectrics at low temperatures. I. General expression for inelastic coherent scattering of slow neutrons and effective thermal factors  

Science Journals Connector (OSTI)

The differential cross section for inelastic coherent scattering of slow neutrons scattered by hydrogen-bonded ferroelectrics at low temperatures...

S. Stamenkovi?

1972-12-01T23:59:59.000Z

457

HOM damping properties of fundamental power couplers in the superconducting electron gun of the energy recovery LINAC at Brookhaven National Laboratory  

SciTech Connect

Among the accelerator projects under construction at the Relativistic Heavy Ion Collider (RHIC) is an R and D energy recovery LINAC (ERL) test facility. The ERL includes both a five-cell superconducting cavity as well as a superconducting, photoinjector electron gun. Because of the high-charge and high-current demands, effective higher-order mode (HOM) damping is essential, and several strategies are being pursued. Among these is the use of the fundamental power couplers as a means for damping some HOMs. Simulation studies have shown that the power couplers can play a substantial role in damping certain HOMs, and this presentation discusses these studies along with measurements.

Hammons, L.; Hahn, H.

2011-03-28T23:59:59.000Z

458

Inhomogeneous dephasing masks coherence lifetimes in ensemble measurements  

SciTech Connect

An open question at the forefront of modern physical sciences is what role, if any, quantum effects may play in biological sensing and energy transport mechanisms. One area of such research concerns the possibility of coherent energy transport in photosynthetic systems. Spectroscopic evidence of long-lived quantum coherence in photosynthetic light-harvesting pigment protein complexes (PPCs), along with theoretical modeling of PPCs, has indicated that coherent energy transport might boost efficiency of energy transport in photosynthesis. Accurate assessment of coherence lifetimes is crucial for modeling the extent to which quantum effects participate in this energy transfer, because such quantum effects can only contribute to mechanisms proceeding on timescales over which the coherences persist. While spectroscopy is a useful way to measure coherence lifetimes, inhomogeneity in the transition energies across the measured ensemble may lead to underestimation of coherence lifetimes from spectroscopic experiments. Theoretical models of antenna complexes generally model a single system, and direct comparison of single system models to ensemble averaged experimental data may lead to systematic underestimation of coherence lifetimes, distorting much of the current discussion. In this study, we use simulations of the Fenna-Matthews-Olson complex to model single complexes as well as averaged ensembles to demonstrate and roughly quantify the effect of averaging over an inhomogeneous ensemble on measured coherence lifetimes. We choose to model the Fenna-Matthews-Olson complex because that system has been a focus for much of the recent discussion of quantum effects in biology, and use an early version of the well known environment-assisted quantum transport model to facilitate straightforward comparison between the current model and past work. Although ensemble inhomogeneity is known to lead to shorter lifetimes of observed oscillations (simply inhomogeneous spectral broadening in the time domain), this important fact has been left out of recent discussions of spectroscopic measurements of energy transport in photosynthesis. In general, these discussions have compared single-system theoretical models to whole-ensemble laboratory measurements without addressing the effect of inhomogeneous dephasing. Our work addresses this distinction between single system and ensemble averaged observations, and shows that the ensemble averaging inherent in many experiments leads to an underestimation of coherence lifetimes in individual systems.

Pelzer, Kenley M.; Griffin, Graham B.; Engel, Gregory S. [James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); Gray, Stephen K. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2012-04-28T23:59:59.000Z

459

Economic Impact Reporting Framework  

E-Print Network (OSTI)

Economic Impact Reporting Framework 2007/08 November 2008 #12;#12;Economic Impact Reporting Framework 2007/08 #12;STFC Economic Impact Reporting Framework 2007/08 Contents: Introduction..............................................................................................................................................2 1: Overall Economic Impacts

460

Economic Impact Reporting Framework  

E-Print Network (OSTI)

Economic Impact Reporting Framework 2008/09 #12;#12;Economic Impact Reporting Framework 2008/09 #12;STFC Economic Impact Reporting Framework 2008/09 Contents: Introduction..............................................................................................................................................2 1: Overall Economic Impacts

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


461

Quantification of airway thickness changes in smoke-inhalation injury using in-vivo 3-D endoscopic frequency-domain optical coherence tomography  

E-Print Network (OSTI)

J. G. Fujimoto, “Optical coherence tomography,” Science 254(endomicroscopy using optical coherence tomography,” Nat.Fourier domain optical coherence tomography,” Opt. Express

2011-01-01T23:59:59.000Z

462

500 MW X-Band RF System of a 0.25 GeV Electron LINAC for Advanced Compton Scattering Source Application  

SciTech Connect

A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with the SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

Chu, Tak Sum; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Marsh, Roark; /LLNL, Livermore; Siders, Craig; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

2012-07-03T23:59:59.000Z

463

Intrinsic Noise Induced Coherence Resonance in a Glow discharge Plasma  

E-Print Network (OSTI)

Experimental evidence of intrinsic noise induced coherence resonance in a glow discharge plasma is being reported. Initially the system is started at a discharge voltage (DV) where it exhibited fixed point dynamics, and then with the subsequent increase in the DV spikes were excited which were few in number and with further increase of DV the number of spikes as well as their regularity increased. The regularity in the interspike interval of the spikes is estimated using normalized variance (NV). Coherence resonance was determined using normalized variance curve and also corroborated by Hurst exponent and power spectrum plots. We show that the regularity of the excitable spikes in the floating potential fluctuation increases with the increase in the DV, upto a particular value of DV. Using a Wiener filter, we separated the noise component which was observed to increase with DV and hence conjectured that noise can be playing an important role in the generation of the coherence resonance. From an anharmonic osc...

Shaw, Pankaj Kumar; Ghosh, S; Janaki, M S; Iyengar, A N S

2014-01-01T23:59:59.000Z

464

Probing angular momentum coherence in a twin-atom interferometer  

E-Print Network (OSTI)

We propose to use a double longitudinal Stern-Gerlach atom interferometer in order to investigate quantitatively the angular momentum coherence of molecular fragments. Assuming that the dissociated molecule has a null total angular momentum, we investigate the propagation of the corresponding atomic fragments in the apparatus. We show that the envisioned interferometer enables one to distinguish unambiguously a spin-coherent from a spin-incoherent dissociation, as well as to estimate the purity of the angular momentum density matrix associated with the fragments. This setup, which may be seen as an atomic analogue of a twin-photon interferometer, can be used to investigate the suitability of molecule dissociation processes -- such as the metastable hydrogen atoms H($2^2 S$)-H($2^2 S$) dissociation - for coherent twin-atom optics.

de Carvalho, Carlos R; Impens, François; Robert, J; Medina, Aline; Zappa, F; Faria, N V de Castro

2014-01-01T23:59:59.000Z

465

Color coherence in multi-jet final states  

E-Print Network (OSTI)

We discuss coherent QCD radiation from space-like parton branching and its effects on multi-jet final states at high-energy hadron colliders. Coherence effects for small longitudinal momentum fractions x are not included in the branching algorithms of standard shower Monte Carlo event generators. On the other hand, they are taken into account only partially in perturbative next-to-leading-order calculations for multi-jets. Such effects are present to all orders in alpha_s and can become logarithmically enhanced with \\sqrt{s} / E_T, where E_T is the hardest jet transverse energy. We present results of summing coherence effects to all orders by parton-branching Monte Carlo methods based on transverse-momentum dependent matrix elements.

F. Hautmann; H. Jung

2008-12-16T23:59:59.000Z

466

Transverse Coherence of the LCLS X-Ray Beam  

SciTech Connect

Self-amplifying spontaneous radiation free-electron lasers, such as the LCLS or the European X-FEL, rely on the incoherent, spontaneous radiation as the seed for the amplifying process. Though this method overcomes the need for an external seed source one drawback is the incoherence of the effective seed signal. The FEL process allows for a natural growth of the coherence because the radiation phase information is spread out within the bunch due to slippage and diffraction of the radiation field. However, at short wavelengths this spreading is not sufficient to achieve complete coherence. In this presentation we report on the results of numerical simulations of the LCLS X-ray FEL. From the obtained radiation field distribution the coherence properties are extracted to help to characterize the FEL as a light source.

Not Available

2010-12-01T23:59:59.000Z

467

Method and apparatus for coherent imaging of infrared energy  

DOE Patents (OSTI)

A coherent camera system performs ranging, spectroscopy, and thermal imaging. Local oscillator radiation is combined with target scene radiation to enable heterodyne detection by the coherent camera's two-dimensional photodetector array. Versatility enables deployment of the system in either a passive mode (where no laser energy is actively transmitted toward the target scene) or an active mode (where a transmitting laser is used to actively illuminate the target scene). The two-dimensional photodetector array eliminates the need to mechanically scan the detector. Each element of the photodetector array produces an intermediate frequency signal that is amplified, filtered, and rectified by the coherent camera's integrated circuitry. By spectroscopic examination of the frequency components of each pixel of the detector array, a high-resolution, three-dimensional or holographic image of the target scene is produced for applications such as air pollution studies, atmospheric disturbance monitoring, and military weapons targeting.

Hutchinson, Donald P. (Knoxville, TN)

1998-01-01T23:59:59.000Z

468

Method and apparatus for coherent imaging of infrared energy  

DOE Patents (OSTI)

A coherent camera system performs ranging, spectroscopy, and thermal imaging. Local oscillator radiation is combined with target scene radiation to enable heterodyne detection by the coherent camera`s two-dimensional photodetector array. Versatility enables deployment of the system in either a passive mode (where no laser energy is actively transmitted toward the target scene) or an active mode (where a transmitting laser is used to actively illuminate the target scene). The two-dimensional photodetector array eliminates the need to mechanically scan the detector. Each element of the photodetector array produces an intermediate frequency signal that is amplified, filtered, and rectified by the coherent camera`s integrated circuitry. By spectroscopic examination of the frequency components of each pixel of the detector array, a high-resolution, three-dimensional or holographic image of the target scene is produced for applications such as air pollution studies, atmospheric disturbance monitoring, and military weapons targeting. 8 figs.

Hutchinson, D.P.

1998-05-12T23:59:59.000Z

469

ON THE SUITABILITY OF LONGITUDINAL PROFILE MEASUREMENTS USING COHERENT SMITH-PURCELL RADIATION  

E-Print Network (OSTI)

Kittelmann, C. Thomas, ESS, Lund, Sweden Abstract The use of Smith-Purcell radiation to measure electrons power, it is mandatory to understand the beam dynamics and to determine the beam size and profile with precision. In high power proton Linacs, such under- standing would allow a full characterization of the beam

Boyer, Edmond

470

High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues  

E-Print Network (OSTI)

We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T

2014-01-01T23:59:59.000Z

471

Coherent Oscillations in an Exciton-Polariton Josephson Junction  

SciTech Connect

We report on the observation of spontaneous coherent oscillations in a microcavity polariton bosonic Josephson junction. Condensation of exciton polaritons here takes place under incoherent excitation in a double potential well naturally formed in the disorder. Coherent oscillations set on at an excitation power well above the condensation threshold. The time resolved population and phase dynamics reveal the analogy with the ac Josephson effect. A theoretical two-mode model describes the observed effects, explaining how the different realizations of the pulsed experiment can be in phase.

Lagoudakis, K. G.; Pietka, B.; Deveaud-Pledran, B. [ICMP, Ecole Polytechnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Wouters, M. [ITP, Ecole Polytechnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Andre, R. [Institut Neel, CNRS, Grenoble (France)

2010-09-17T23:59:59.000Z

472

Uncertainties of coherent states for a generalized supersymmetric annihilation operator  

SciTech Connect

This study presents supersymmetric coherent states that are eigenstates of a general four-parameter family of annihilation operators. The elements of this family are defined as operators in Fock space that transform a subspace of a definite number of particles into a subspace with one particle removed. The emphasis is on classifying parameter space in various regions according to the uncertainty bounds of the corresponding coherent states. Specifically, the uncertainty in position-momentum is analyzed, with specific focus on characterizing regions of minimum uncertainty states, regions where the uncertainties are bounded from above, and where they grow unbound.

Kornbluth, Mordechai; Zypman, Fredy [Physics Department, Yeshiva University, 500 W 185th Street, New York, New York 10033 (United States)] [Physics Department, Yeshiva University, 500 W 185th Street, New York, New York 10033 (United States)

2013-01-15T23:59:59.000Z

473

Single-wall carbon nanotubes as coherent plasmon generators  

Science Journals Connector (OSTI)

The possibility of low-energy surface plasmon amplification by optically excited excitons in small-diameter single-wall carbon nanotubes is theoretically demonstrated. The nonradiative exciton-plasmon energy transfer causes the buildup of macroscopic population numbers of coherent localized surface plasmons associated with high-intensity coherent local fields formed at nanoscale throughout the nanotube surface. These strong local fields can be used in a variety of new optoelectronic applications of carbon nanotubes, including near-field nonlinear-optical probing and sensing, optical switching, enhanced electromagnetic absorption, and materials nanoscale modification.

I. V. Bondarev

2012-01-30T23:59:59.000Z

474

Behavior of sigma(gamma p) at Large Coherence Lengths  

E-Print Network (OSTI)

Various parametrizations of sigma(gamma p) are tried out on the small-x fixed target and HERA data. A two-Pomeron type parametrization is found to give the best reproduction of the data. The data indicate that the value of lambda(eff) for parametrizations of the form sigma(gamma p)~l^lambda(eff) approaches a constant value at high Q^2. The extrapolated values of sigma(gamma p) to very long coherence lengths are found to cross in some parametrizations for l>10^7 fm, indicating the possibility that sigma(gamma p) becomes Q^2 independent at large values of the coherence length l.

Allen Caldwell

2008-02-06T23:59:59.000Z

475

N-mode coherence in collective neutrino oscillations  

SciTech Connect

We study two-flavor neutrino oscillations in a homogeneous and isotropic ensemble under the influence of neutrino-neutrino interactions. For any density there exist forms of collective oscillations that show self-maintained coherence. They can be classified by a number N of linearly independent functions that describe all neutrino modes as linear superpositions. What is more, the dynamics is equivalent to another ensemble with the same effective density, consisting of N modes with discrete energies E{sub i} with i=1,...,N. We use this equivalence to derive the analytic solution for two-mode (bimodal) coherence, relevant for spectral-split formation in supernova neutrinos.

Raffelt, Georg G. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)

2011-05-15T23:59:59.000Z

476

Spatial coherence measurement of sound in the northwest Pacific Ocean  

Science Journals Connector (OSTI)

An experiment on the transverse horizontal spatial coherence of sound propagating in the ocean was performed jointly by Chinese and Russian acousticians in the northwest Pacific Ocean in June 1990. Three hydrophones with spacings of 270 and 130 m were put in the water at a 30?m depth. The acoustic source with four cw (from 109 to 860 Hz) and a broadband pseudorandom noise signal was drifted at a depth of 100 m. Part of the measurement results of up to 140 km are presented in this paper. It seems that the spatial coherence was related to the amplitude of the received signals and rises considerably in convergence zones.

Dinghua Guan; Ruichao Zhu; Renhe Zhang; Yaoming Chen

1993-01-01T23:59:59.000Z

477

Coulomb Interaction and Quantum Transport through a Coherent Scatterer  

Science Journals Connector (OSTI)

An interplay between charge discreteness, coherent scattering, and Coulomb interaction yields nontrivial effects in quantum transport. We derive a real-time effective action and an equivalent quantum Langevin equation for an arbitrary coherent scatterer and evaluate its current-voltage characteristics in the presence of interactions. Within our model, at large conductances G0 and low T (but outside the instanton-dominated regime), the interaction correction to G0 saturates and causes conductance suppression by a universal factor which depends only on the type of the conductor.

Dmitrii S. Golubev and Andrei D. Zaikin

2001-05-21T23:59:59.000Z

478

Scattering of coherent pulses on a two-level system  

E-Print Network (OSTI)

In this work, we consider a two-level system (TLS) coupled to a one-dimensional continuum of bosonic modes in a transmission line. Using the master equation approach, a method for determining the photon number distribution of the scattered field is outlined. Specifically, results for the reflected field when driving the TLS with a coherent pulse are given. While the one-photon probability is enhanced compared to the incident coherent field, the system is still not a good deterministic single-photon source. Extending the system to contain two separate transmission lines, however, output fields with one-photon probabilities close to unity can be reached.

Joel Lindkvist; Göran Johansson

2014-01-15T23:59:59.000Z

479

Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon, L. Liu, E.J. Blain, A.M. Daskalakis, B.J. McDermott, K. Ramic, C.R. Wendorff  

E-Print Network (OSTI)

Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon . As the energy of the neutrons increases to the keV region neutron resonance scattering becomes dominant compared to capture, and scattered neutrons can penetrate the 10 B4C liner of the NaI capture detector and get

Danon, Yaron

480

Limitations for detecting small-scale faults using the coherency analysis of seismic data  

E-Print Network (OSTI)

Coherency analyzes the trace to trace amplitude similarities recorded by seismic waves. Coherency algorithms have been used to identify the structural or stratigraphic features of an area but the limitations for detecting small-scale features...

Barnett, David Benjamin

2006-08-16T23:59:59.000Z

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481

Detecting and analyzing coherent structures in two-dimensional dynamical systems  

E-Print Network (OSTI)

The identification of coherent structures enhances the understanding of transport by complex flows such as those found at the ocean surface. The rapidly developing approach of Lagrangian Coherent Structures (LCSs) is based ...

Allshouse, Michael R

2013-01-01T23:59:59.000Z

482

Chirality dependence of coherent phonon amplitudes in single-wall carbon nanotubes  

E-Print Network (OSTI)

We simulate the ultrafast dynamics of laser-induced coherent phonons in single-wall carbon nanotubes (SWNTs). In particular, we examine the coherent phonon amplitude of the radial breathing mode (RBM) as a function of ...

Dresselhaus, Mildred

483

Optical measurement of neural action potentials using low coherence heterodyne interferometry  

E-Print Network (OSTI)

We present a novel non-invasive optical method for detection of neural action potentials using low coherence interferometry. The dual beam heterodyne interferometer (DBHI) is a modified Michelson with a low coherence source ...

Chu, Mark Changhao, 1978-

2004-01-01T23:59:59.000Z

484

Cellular resolution ex vivo imaging of gastrointestinal tissues with coherence microscopy  

E-Print Network (OSTI)

Optical coherence microscopy (OCM) combines confocal microscopy and optical coherence tomography (OCT) to improve imaging depth and contrast, enabling cellular imaging in human tissues. We aim to investigate OCM for ex ...

Fujimoto, James G.

485

Klystron-linac combination  

DOE Patents (OSTI)

A combination klystron-linear accelerator which utilizes anti-bunch electrons generated in the klystron section as a source of electrons to be accelerated in the accelerator section. Electron beam current is controlled by second harmonic bunching, constrictor aperture size and magnetic focusing. Rf coupling is achieved by internal and external coupling.

Stein, W.E.

1980-04-24T23:59:59.000Z

486

REVIEW OF INDUCTION LINACS  

E-Print Network (OSTI)

1 Induction Acceleration Cavity and Voitage Generator INPUTgenerator become paramount. Because almost all of the inductiongenerator to pulse both an ion-diode - to supply the protons - and a downstream induction

Faltens, A.

2010-01-01T23:59:59.000Z

487

Pulse power linac  

DOE Patents (OSTI)

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

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

488

Induction Linac Pulsers  

E-Print Network (OSTI)

50 ? transmission lines charged to ~30 kV to produce~15 kV pulses into smaller transmission lines (coax cables)

Faltens, Andris

2011-01-01T23:59:59.000Z

489

PUBLISHED ONLINE: 15 MARCH 2009 | DOI: 10.1038/NPHYS1219 Observation of terahertz radiation coherently  

E-Print Network (OSTI)

coherently generated by acoustic waves Michael R. Armstrong1 *, Evan J. Reed1 , Ki-Yong Kim2 , James H

Loss, Daniel

490

Final report: high resolution lensless 3D imaging of nanostructures with coherent x-rays  

SciTech Connect

Final report on the project "High resolution lensless 3D imaging of nanostructures with coherent x-rays"

Jacobsen, Chris

2014-12-07T23:59:59.000Z

491

E-Print Network 3.0 - anatomical optical coherence Sample Search...  

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

Laryngoscope Lippincott Williams & Wilkins Summary: Imaged With Optical Coherence Tomography by Anatomic Regions and Subsites. Anatomic Regions Locations... and Otological...

492

Coherent transport of electron spin in a ferromagnetically contacted carbon nanotube  

Science Journals Connector (OSTI)

... -08361999Macmillian Magazines Ltd.10.1038/44108 Coherent transport of electron spin in a ferromagnetically contacted carbon nanotube

Kazuhito Tsukagoshi; Bruce W. Alphenaar; Hiroki Ago

1999-10-07T23:59:59.000Z

493

The Variational Ising Classifier (VIC) algorithm for coherently contaminated data  

E-Print Network (OSTI)

The Variational Ising Classifier (VIC) algorithm for coherently contaminated data Oliver Williams) in test images which have not explicitly been encountered in training data. The Variational Ising-dimension, for image contours [5], the Variational Ising Classi- fier (VIC) models contamination explicitly as switches

Martin, Ralph R.

494

Phased laser array with tailored spectral and coherence properties  

DOE Patents (OSTI)

Architectures for coherently combining an array of fiber-based lasers are provided. By matching their lengths to within a few integer multiples of a wavelength, the spatial and temporal properties of a single large laser are replicated, while extending the average or peak pulsed power limit.

Messerly, Michael J; Dawson, Jay W; Beach, Raymond J

2014-05-20T23:59:59.000Z

495

Holographic optical coherence imaging of rat osteogenic sarcoma tumor spheroids  

E-Print Network (OSTI)

rates. The technical drawbacks of this approach are the need for P. Yu is with the Department of Physics that passes coherent structure-bearing light to the camera during holographic readout while preferentially video-rate movies.9 The smart-pixel arrays currently operate at 58 58 pixels.10 A direct en face imaging

Nolte, David D.

496

Tuning a short coherence length Josephson junction through a  

E-Print Network (OSTI)

Tuning a short coherence length Josephson junction through a metal-insulator transition J. K University, Josephson Junction talk, 2001 #12;Josephson Tunnel Junctions · A Superconductor maintaining nonhysteretic behavior. J. K. Freericks, Georgetown University, Josephson Junction talk, 2001 S N

Freericks, Jim

497

Adaptive coherent interferometric imaging for sensor networks Gregoire Derveauxa)  

E-Print Network (OSTI)

with distributed sensor networks is presented. The sensors record the impulse response of the unknown background imaging when the background is known is considered in Ref.8. The sensors record an approximate impulseAdaptive coherent interferometric imaging for sensor networks Gr´egoire Derveauxa) INRIA Domaine de

Papanicolaou, George C.

498

Towards a more coherent oil policy in Russia? S. Boussena,  

E-Print Network (OSTI)

Towards a more coherent oil policy in Russia? S. Boussena, Professor, University of Grenoble II of Russia on the world oil scene. The first is the development of its oil production (over 9 Mb/d in 2004. Will Russia be a key variable in world energy balances? Could Russia ­ as some suggest and even desire

Paris-Sud XI, Université de

499

Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities  

DOE Patents (OSTI)

A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

Harrison, Neil (Santa Fe, NM); Singleton, John (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

2008-08-05T23:59:59.000Z

500

CONTROL OF COHERENT STRUCTURE IN COAXIAL SWIRLING TURBULENT JETS  

E-Print Network (OSTI)

stronger effect than the pilot jet itself, leading to an almost entire removal of coherent structures. 2.2. Flow Instability Swirl is naturally presented in the exhaust from a turbine or an axial flow pump, and may be deliberately generated... ............................................................................................. 1 2. REVIEW OF LITERATURE............................................................................. 6 2.1. Turbulent Jets with Swirl................................................................................ 7 2.2. Flow Instability...

Lee, Wonjoong

2008-01-01T23:59:59.000Z