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1

fel 2005 :: Free Electron Laser Conference and Workshop  

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

Home | Attendee List | Program | Abstract Submission | Payment | Call for Papers | Exhibitors | Travel 2005 International Free Electron Laser Prize Winner: Avi Gover left to right: John Galayda, Avi Gover (FEL2005 Prize Winner, Alexander Van der Meer This year the FEL Prize Committee awarded the FEL Prize to Avraham (Avi) Gover from Tel-Aviv University for his pioneering work in laying the foundation of FEL theory. Avi Gover, presently head of the FEL Knowledge Center in Israel, has been a member of the FEL community from the very beginning, publishing his first paper on FELs in 1976. In those early years, he played a key role in putting FEL theory on a firm basis by showing the similarities between FELs, 'ordinary' lasers and other free electron radiation devices such as TWTs. In later years he made important contributions to the formulation of a unified theory of superradiant emission in the linear and, more recently, also in the non-linear regime. His deep understanding of the field enabled him to propose conceptually new schemes like stimulated superradiance and post-saturation emission enhancement. In addition to his extensive work and contributions to FEL theory, he also led and contributed to a number of experimental projects aimed at studies of fundamental effects and at the development of new FEL device schemes. Most notably the demonstration of a two-stage BWO FEL and a longitudinal wiggler FEL, demonstration of electron trapping in two counter propagating laser beams and of single-mode locking in a prebunched FEM. He has also been the main driving force behind the international efforts to develop high-average power masers based on electrostatic accelerators in the inverted setup, that is with the undulator at high voltage. Along this line, he also took the initiative for an Israelean FEM user facility and notwithstanding the difficult funding situation in his country, this facility is now operational at the College of Judea and Samaria in Ariel.

2

Ignition feedback regenerative free electron laser (FEL) amplifier  

DOE Patents [OSTI]

An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.

Kim, Kwang-Je (Burr Ridge, IL); Zholents, Alexander (Walnut Creek, CA); Zolotorev, Max (Oakland, CA)

2001-01-01T23:59:59.000Z

3

Free-Electron Laser | Jefferson Lab  

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

Research Inspecting an injector assembly at Jefferson Lab's Free-Electron Laser. A D D I T I O N A L L I N K S: FEL Users FEL Description JLAMP Proposal Applications FEL News...

4

Optical wavelength modulation in free electron lasers  

SciTech Connect (OSTI)

An attribute of the free electron laser (FEL) is the continuous tunability of the optical wavelength by modulation of the electron beam energy. The variation of the wavelength and power of the optical beam is studied as a function of FEL operating parameters. These results will be applied to the Stanford SCA FEL and Boeing FEL.

Mabe, R.M.; Wong, R.K.; Colson, W.B. [Naval Postgraduate School, Monterey, CA (United States)

1995-12-31T23:59:59.000Z

5

rf system for the Los Alamos free-electron laser (FEL)  

SciTech Connect (OSTI)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 ..mu..s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2/sup 0/, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-..mu..s pulses. Each tube has delivered over 3.6-MW, 100-..mu..s pulses in the FEL system.

Friedrichs, C.C.; Tallerico, P.J.; Hoffert, W.J.

1983-01-01T23:59:59.000Z

6

Progress toward the Wisconsin Free Electron Laser  

SciTech Connect (OSTI)

The University of Wisconsin-Madison/Synchrotron Radiation Center is advancing its design for a seeded VUV/soft X-ray Free Electron Laser facility called WiFEL. To support this vision of an ultimate light source, we are pursuing a program of strategic R&D addressing several crucial elements. This includes development of a high repetition rate, VHF superconducting RF electron gun, R&D on photocathode materials by ARPES studies, and evaluation of FEL facility architectures (e.g., recirculation, compressor scenarios, CSR dechirping, undulator technologies) with the specific goal of cost containment. Studies of high harmonic generation for laser seeding are also planned.

Bisognano, Joseph; Eisert, D; Fisher, M V; Green, M A; Jacobs, K; Kleman, K J; Kulpin, J; Rogers, G C; Lawler, J E; Yavuz, D

2011-03-01T23:59:59.000Z

7

Simulations of the rocketdyne free-electron laser  

SciTech Connect (OSTI)

Rocketdyne is assembling a high-brightness 78 MeV free-electron laser (FEL). In this paper performance calculations using the Rocketdyne FELOPT code are presented for a 1.06 {mu}m system.

Cover, R.A.; Bennett, G.T.; Burke, R.J.; Curtin, M.S.; Lampel, M.C.; Rakowsky, G. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.)

1991-12-01T23:59:59.000Z

8

Free-electron laser scientist is one of two newly elected American...  

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

Steve Benson Steve Benson of the Free-Electron Laser (FEL) group was recently selected as a 2002 Fellow of the American Physical Society Free-electron laser scientist is one of two...

9

Free electron laser  

DOE Patents [OSTI]

A high gain, single-pass free electron laser formed of a high brilliance electron injector source, a linear accelerator which imparts high energy to the electron beam, and an undulator capable of extremely high magnetic fields, yet with a very short period. The electron injector source is the first stage (gap) of the linear accelerator or a radial line transformer driven by fast circular switch. The linear accelerator is formed of a plurality of accelerating gaps arranged in series. These gaps are energized in sequence by releasing a single pulse of energy which propagates simultaneously along a plurality of transmission lines, each of which feeds the gaps. The transmission lines are graduated in length so that pulse power is present at each gap as the accelerated electrons pass therethrough. The transmission lines for each gap are open circuited at their ends. The undualtor has a structure similar to the accelerator, except that the transmission lines for each gap are substantially short circuited at their ends, thus converting the electric field into magnetic field. A small amount of resistance is retained in order to generate a small electric field for replenishing the electron bunch with the energy lost as it traverses through the undulator structure.

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

10

Circular free-electron laser  

DOE Patents [OSTI]

A high efficiency, free electron laser utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.

Brau, Charles A. (Los Alamos, NM); Kurnit, Norman A. (Santa Fe, NM); Cooper, Richard K. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

11

Rf Feedback free electron laser  

DOE Patents [OSTI]

A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

12

Femtosecond diffractive imaging with a soft-X-ray free-electron laser  

E-Print Network [OSTI]

LETTERS Femtosecond diffractive imaging with a soft-X-ray free-electron laser HENRY N. CHAPMAN1 of this principle using the FLASH soft-X-ray free-electron laser. An intense 25 fs, 4 Ã? 1013 W cm-2 pulse by one10 . X-ray free-electron lasers (FELs) are expected to permit diffractive imaging at high

Loss, Daniel

13

Injection of harmonics generated in gas in a free-electron laser providing intense and  

E-Print Network [OSTI]

-ultraviolet to X-ray region. Recently, injection of a single-pass FEL by the third laser harmonic of a TiLETTERS Injection of harmonics generated in gas in a free-electron laser providing intense-electron lasers promise to extend this down to femtosecond timescales. The process by which free-electron lasers

Loss, Daniel

14

First operation of the Rocketdyne/Stanford free electron laser  

Science Journals Connector (OSTI)

A near infrared free electron laser (FEL) has been built and installed by Rocketdyne in the Stanford Photon Research Laboratory. The Rocketdyne/Stanford FEL utilizes a very high quality, 2 m long, permanent magnet planar wiggler whose gap may be continuously tuned, and magnetic field axially tapered by varying the gap at one end relative to the other. The laser is operated with an e-beam supplied by the Stanford Mark-III accelerator. A stable resonator with a broadband, dielectric coated element permits transmissive outcoupling over the 2.7–3.7 ?m wavelength range. Results from initial operation of this laser are presented.

Anup Bhowmik; Mark S. Curtin; Wayne A. McMullin; Stephen V. Benson; John M.J. Madey; Bruce A. Richman; Louis Vintro

1988-01-01T23:59:59.000Z

15

INEX (integrated numerical experiment) simulations of the Los Alamos HIBAF (high-brightness accelerator free-electron laser) free-electron laser MOPA (master oscillator power amplifier) experiment  

SciTech Connect (OSTI)

We present results of Integrated Numerical Experiment (INEX) simulations of the performance of a 1-m untapered wiggler FEL oscillator driving a 2-m wiggler FEL amplifier for the new HIBAF (High-Brightness Accelerator Free-Electron Laser) facility at Los Alamos. INEX simulations utilize a numerically-generated electron micropulse, from ISIS/PARMELA calculations of the photoinjector/linac/beam transport system, in the 3-D FEL simulation code FELEX. 13 refs., 10 figs., 1 tab.

Goldstein, J.C.; Carlsten, B.E.; McVey, B.D.

1989-01-01T23:59:59.000Z

16

Two-gigawatt burst-mode operation of the intense microwave prototype (IMP) free-electron laser (FEL) for the microwave tokamak experiment (MTX)  

SciTech Connect (OSTI)

The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the parameter space of the IMP FEL, and finally evaluate transmission and absorption in the MTX. Single-pulse operations were repeatable. After the MTX was shut down burst-mode operations were successful at 2 kHz. This paper will describe the IMP FEL, Microwave Transmission System to MTX, the diagnostics used for calorimetric measurements, and the operations of the entire Microwave system. A discussion of correlated and uncorrelated errors that affect FEL performance will be made Linear and non-linear absorption data of the microwaves in the MTX plasma will be presented.

Felker, B.; Allen, S.; Bell, H. [and others

1993-10-06T23:59:59.000Z

17

Jefferson Lab's Free-Electron Laser explores promise of carbon...  

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

Webs of nanotubes on collector plates Webs of nanotubes form on collector plates during the collaboration's FEL experiment (image not actual size). Jefferson Lab's Free-Electron...

18

Free-Electron Laser Targets Fat | Jefferson Lab  

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

Free-Electron Laser Targets Fat April 10, 2006 Free-Electron Laser Scientists Rox Anderson, right, and Free-Electron Laser Scientist Steve Benson, left, discuss laser beam...

19

Improving electron beam quality of the Boeing free electron laser  

Science Journals Connector (OSTI)

The successful operation of any free electron laser (FEL) is critically dependent upon electron beam quality. In a radiofrequency (rf) accelerator the micropulse or instantaneous beam emittance and peak current is established by the injector, however, it is important to maintain this beam's quality as it is accelerated and transported to the wiggler. In the past year, work has continued to enhance the electron beam of the Boeing FEL. The previous year's improvements in levelling the gun charge during the macropulse and rf power flatness were reported in the 1989 FEL conference. More recent work has concentrated upon the rf master oscillator and electron beam transport, which have lead to reduced macropulse energy spread, as well as decreased position and angle jitter. Also some electron beam diagnostics have been upgraded. The result has been lower macropulse emittance at the entrance to the wiggler.

D.H. Dowell; M.L. Laucks; A.R. Lowrey; M. Bemes; A. Currie; P. Johnson; K. McCrary; J. Adamski; D.R. Shoffstall; A.H. Lumpkin; R.L. Tokar

1991-01-01T23:59:59.000Z

20

Fundamental physics at an X-ray free electron laser  

E-Print Network [OSTI]

X-ray free electron lasers (FELs) have been proposed to be constructed both at SLAC in the form of the so-called Linac Coherent Light Source as well as at DESY, where the so-called XFEL laboratory is part of the design of the electron-positron linear collider TESLA. In addition to the immediate applications in condensed matter physics, chemistry, material science, and structural biology, X-ray FELs may be employed also to study some physics issues of fundamental nature. In this context, one may mention the boiling of the vacuum (Schwinger pair creation in an external field), horizon physics (Unruh effect), and axion production. We review these X-ray FEL opportunities of fundamental physics and discuss the necessary technological improvements in order to achieve these goals.

A. Ringwald

2001-12-19T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Combination free electron and gaseous laser  

DOE Patents [OSTI]

A multiple laser having one or more gaseous laser stages and one or more free electron stages. Each of the free electron laser stages is sequentially pumped by a microwave linear accelerator. Subsequently, the electron beam is directed through a gaseous laser, in the preferred embodiment, and in an alternative embodiment, through a microwave accelerator to lower the energy level of the electron beam to pump one or more gaseous lasers. The combination laser provides high pulse repetition frequencies, on the order of 1 kHz or greater, high power capability, high efficiency, and tunability in the synchronous production of multiple beams of coherent optical radiation.

Brau, Charles A. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Stein, William E. (Los Alamos, NM)

1980-01-01T23:59:59.000Z

22

XUV free-electron laser-based projection lithography systems  

SciTech Connect (OSTI)

Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.

Newnam, B.E.

1990-01-01T23:59:59.000Z

23

Free Electron Laser Program Program at TJNAF| U.S. DOE Office of Science  

Office of Science (SC) Website

Free Electron Laser Program Program at Free Electron Laser Program Program at TJNAF 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 Free Electron Laser Program Program at TJNAF Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Free Electron Laser (FEL) Program Developed at: Thomas Jefferson National Laboratory Developed in: 1990's - 2010

24

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

SciTech Connect (OSTI)

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

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

2014-04-15T23:59:59.000Z

25

Status of the visible Free-Electron Laser at the Brookhaven Accelerator Test Facility  

SciTech Connect (OSTI)

The 500 nm Free-Electron Laser (ATF) of the Brookhaven National Laboratory is reviewed. We present an overview of the ATF, a high-brightness, 50-MeV, electron accelerator and laser complex which is a users' facility for accelerator and beam physics. A number of laser acceleration and FEL experiments are under construction at the ATF. The visible FEL experiment is based on a novel superferric 8.8 mm period undulator. The electron beam parameters, the undulator, the optical resonator, optical and electron beam diagnostics are discussed. The operational status of the experiment is presented. 22 refs., 7 figs.

Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fisher, A.S.; Friedman, A.; Gallardo, J.; Ingold, G.; Kirk, H.; Kramer, S.; Lin, L.; Rogers, J.T.; Sheehan, J.F.; van Steenbergen, A.; Woodle, M.; Xie, J.; Yu, L.H.; Zhang, R. (Brookhaven National Lab., Upton, NY (United States)); Bhowmik, A. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.)

1991-01-01T23:59:59.000Z

26

Ultraviolet Free Electron Laser Facility preliminary design report  

SciTech Connect (OSTI)

This document, the Preliminary Design Report (PDR) for the Brookhaven Ultraviolet Free Electron Laser (UV FEL) facility, describes all the elements of a facility proposed to meet the needs of a research community which requires ultraviolet sources not currently available as laboratory based lasers. Further, for these experiments, the requisite properties are not extant in either the existing second or upcoming third generation synchrotron light sources. This document is the result of our effort at BNL to identify potential users, determine the requirements of their experiments, and to design a facility which can not only satisfy the existing need, but have adequate flexibility for possible future extensions as need dictates and as evolving technology allows. The PDR is comprised of three volumes. In this, the first volume, background for the development of the proposal is given, including descriptions of the UV FEL facility, and representative examples of the science it was designed to perform. Discussion of the limitations and potential directions for growth are also included. A detailed description of the facility design is then provided, which addresses the accelerator, optical, and experimental systems. Information regarding the conventional construction for the facility is contained in an addendum to volume one (IA).

Ben-Zvi, I. (ed.)

1993-02-01T23:59:59.000Z

27

The History of X-ray Free-Electron Lasers  

SciTech Connect (OSTI)

The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.

Pellegrini, C.; /UCLA /SLAC; ,

2012-06-28T23:59:59.000Z

28

Free-Electron Lasers: Status and Applications  

Science Journals Connector (OSTI)

...average power record for an FEL was 11 W (35). An experiment at Boeing (36) demonstrated the ability...power record for an FEL was 11-W (35). An experiment at Boeing (36) demonstrated the ability of photoinjectors to produce...

Patrick G. O'Shea; Henry P. Freund

2001-06-08T23:59:59.000Z

29

Rippled beam free electron laser amplifier  

DOE Patents [OSTI]

A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

Carlsten, Bruce E. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

30

Jefferson Lab's upgraded Free-Electron Laser produces first ligh...  

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

upgraded Free-Electron Laser produces first light June 18, 2003 Researchers at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility have produced first...

31

Free-Electron Lasers: Present Status and Future Prospects  

E-Print Network [OSTI]

US Department of Energy under contract DE-AC03-76SF00098. LBL-29124 Free-Electron Lasers: Present Status

Kim, K.-J.

2008-01-01T23:59:59.000Z

32

Spectral-phase interferometry for direct electric-field reconstruction applied to seeded extreme-ultraviolet free-electron lasers  

E-Print Network [OSTI]

We present a setup for complete characterization of femtosecond pulses generated by seeded free-electron lasers (FEL's) in the extreme-ultraviolet spectral region. Two delayed and spectrally shifted replicas are produced and used for spectral phase interferometry for direct electric field reconstruction (SPIDER). We show that it can be achieved by a simple arrangement of the seed laser. Temporal shape and phase obtained in FEL simulations are well retrieved by the SPIDER reconstruction, allowing to foresee the implementation of this diagnostic on existing and future sources. This will be a significant step towards an experimental investigation and control of FEL spectral phase.

Mahieu, Benoît; De Ninno, Giovanni; Dacasa, Hugo; Lozano, Magali; Rousseau, Jean-Philippe; Zeitoun, Philippe; Garzella, David; Merdji, Hamed

2015-01-01T23:59:59.000Z

33

Initial source of microbunching instability studies in a free electron laser injector  

SciTech Connect (OSTI)

We present the first experimental studies of the initial source of electron beam microbunching instability in a free electron laser (FEL) injector. By utilizing for the studies a transform-limited laser pulse at the photocathode, we eliminated laser-induced microbunching at the National Synchrotron Light Source Source Development Laboratory (SDL). The detailed measurements of the resulting electron beam led us to conclude that, at SDL, microbunching arising from shot noise is not amplified to any significant level, thereby allowing us to set an upper limit on the initial modulation depth of microbunching arising from shot noise. Our analysis demonstrated that the only significant source of microbunching instability under normal operational conditions at SDL is the longitudinal modulation of the photocathode laser pulse. Our work shows that assuring a longitudinally smoothed photocathode laser pulse allows mitigating microbunching instability at a typical FEL injector with a moderate microbunching gain.

Seletskiy, S.; Hidaka, Y; Murphy, J.B.; Podobedov, B.; Qian, H.; Shen, Y.; Wang, X.J.; Yang, X

2011-11-16T23:59:59.000Z

34

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

SciTech Connect (OSTI)

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

35

Single electron beam rf feedback free electron laser  

DOE Patents [OSTI]

A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

Brau, C.A.; Stein, W.E.; Rockwood, S.D.

1981-02-11T23:59:59.000Z

36

INEX modeling of the Boeing ring optical resonator free electron laser  

Science Journals Connector (OSTI)

We present new results from the integrated numerical model of the accelerator/beam transport system and ring optical resonator of the Boeing free electron laser experiment. Modifications of the electron-beam transport have been included in a previously developed PARMELA model and are shown to reduce dramatically emittance growth in the 180° bend. The new numerically generated electron beam is used in the 3D FEL simulation code FELEX to calculate expected laser characteristics with the ring optical resonator and the 5 m untapered THUNDER wiggler. Performance sensitivity to optical cavity misalignments is studied.

J.C. Goldstein; R.L. Tokar; B.D. McVey; C.J. Elliott; D.H. Dowell; M.L. Laucks; A.R. Lowrey

1991-01-01T23:59:59.000Z

37

Axial interaction free-electron laser  

DOE Patents [OSTI]

Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies. 5 figs.

Carlsten, B.E.

1997-09-02T23:59:59.000Z

38

Feasibility considerations of a soft-x-ray distributed feedback laser pumped by an x-ray free electron laser  

E-Print Network [OSTI]

We discuss the feasibility of a soft-x-ray distributed feedback laser (DFL) pumped by an x-ray free electron laser (X-FEL). The DFL under consideration is a Mg/SiC bi-layered Bragg reflector pumped by a single X-FEL bunch at 57.4 eV, stimulating the Mg L2,3 emission at 49 eV corresponding to the 3s-3d â??2p1/2,3/2 transition. Based on a model developed by Yariv and Yeh and an extended coupled-wave theory, we show that it would be possible to obtain a threshold gain compatible with the pumping provided by available X-FEL facilities.

André, Jean-Michel; Jonnard, Philippe

2014-01-01T23:59:59.000Z

39

A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron Laser Experiment at SLAC  

SciTech Connect (OSTI)

With the advent of X-ray Free Electron Lasers (FELs), new methods have been developed to extend capabilities at short wavelengths beyond Self-Amplified Spontaneous Emission (SASE). In particular, seeding of a FEL allows for temporal control of the radiation pulse and increases the peak brightness by orders of magnitude. Most recently, Gennady Stupakov and colleagues at SLAC proposed a new technique: Echo-Enabled Harmonic Generation (EEHG). Here a laser microbunches the beam in an undulator and the beam is sheared in a chicane. This process is repeated with a second laser, undulator and chicane. The interplay between these allows a seeding of the X-ray laser up to the 100th harmonic of the first laser. After introducing the physics of FELs and the EEHG seeding technique, we describe contributions to the experimental effort. We will present detailed studies of the experiment including the choice of parameters and their optimization, the emittance effect, spontaneous emission in the undulators, the second laser phase effect, and measurements of the jitter between RF stations. Finally, the status and preliminary results of the Echo-7 experiment will be outlined.

Pernet, Pierre-Louis; /Ecole Polytechnique, Lausanne /SLAC

2012-01-06T23:59:59.000Z

40

Two-dimensional optimization of free-electron-laser designs  

DOE Patents [OSTI]

Off-axis, two-dimensional designs for free electron lasers are described that maintain correspondence of a light beam with a synchronous electron at an optimal transverse radius r > 0 to achieve increased beam trapping efficiency and enhanced laser beam wavefront control so as to decrease optical beam diffraction and other deleterious effects.

Prosnitz, D.; Haas, R.A.

1982-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Two-dimensional optimization of free electron laser designs  

DOE Patents [OSTI]

Off-axis, two-dimensional designs for free electron lasers that maintain correspondence of a light beam with a "synchronous electron" at an optimal transverse radius r>0 to achieve increased beam trapping efficiency and enhanced laser beam wavefront control so as to decrease optical beam diffraction and other deleterious effects.

Prosnitz, Donald (Walnut Creek, CA); Haas, Roger A. (Pleasanton, CA)

1985-01-01T23:59:59.000Z

42

Spectrometer for X-ray emission experiments at FERMI free-electron-laser  

SciTech Connect (OSTI)

A portable and compact photon spectrometer to be used for photon in-photon out experiments, in particular x-ray emission spectroscopy, is presented. The instrument operates in the 25–800 eV energy range to cover the full emissions of the FEL1 and FEL2 stages of FERMI. The optical design consists of two interchangeable spherical varied-lined-spaced gratings and a CCD detector. Different input sections can be accommodated, with/without an entrance slit and with/without an additional relay mirror, that allow to mount the spectrometer in different end-stations and at variable distances from the target area both at synchrotron and at free-electron-laser beamlines. The characterization on the Gas Phase beamline at ELETTRA Synchrotron (Italy) is presented.

Poletto, L., E-mail: poletto@dei.unipd.it; Frassetto, F.; Miotti, P. [CNR - Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, I-35131 Padova (Italy); Di Cicco, A.; Iesari, F. [Physics Division, School of Science and Technology, Università di Camerino, I-62032 Camerino (Italy); Finetti, P. [ELETTRA - Sincrotrone Trieste, Basovizza Area Science Park, S. S. 14 - km 163,5, I-34149, Basovizza (TS) (Italy); Grazioli, C. [Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy); CNR-Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, I-34149 Trieste (Italy); Kivimäki, A. [CNR-Istituto Officina dei Materiali (CNR-IOM), Laboratorio TASC, I-34149 Trieste (Italy); Stagira, S. [Politecnico di Milano – Department of Physics, I-20133 Milano (Italy); Coreno, M. [ELETTRA - Sincrotrone Trieste, Basovizza Area Science Park, S. S. 14 - km 163,5, I-34149, Basovizza (TS) (Italy); CNR – Istituto di Struttura della Materia (CNR-ISM), UOS Basovizza, I-34149 Trieste (Italy)

2014-10-15T23:59:59.000Z

43

A Far-infrared Undulator for Coherent Synchrotron Radiation and Free Electron Laser at Tohoku University  

SciTech Connect (OSTI)

In order to develop an intense far-infrared radiation source, a high quality electron beam has been studied at Tohoku University, Sendai. The bunch length of the beam expected is very much shorter than terahertz (THz) wavelength, so that coherent spontaneous emission of synchrotron radiation will be a promising high brilliant far-infrared source. An undulator consisting of permanent magnets has been designed in which optional free electron laser (FEL) will be operated in free space mode. Consequently the minimum gap of the undulator is decided to be 54 mm for 0.36 mm radiation to avoid diffraction loss, and then the period length of 10 cm is employed. The undulator may cover a wavelength range from 0.18 to 0.36 mm with the beam energy of 17 MeV. Property of coherent THz radiation from the undulator and possibility of novel pre-bunched THz FEL is discussed.

Hama, Hiroyuki; Hinode, Fujio; Kawai, Masayuki; Nanbu, Kenichi; Miyahara, Fusashi; Yasuda, Mafuyu [Laboratory of Nuclear Science, Tohoku University School of Science, 1-2-1 Mikamine, Taihaku-ku, Sendai 982-0826 (Japan)

2010-06-23T23:59:59.000Z

44

Study of the Feasibility of an X-Ray Free Electron Laser with a 15 GeV CLIC Beam  

E-Print Network [OSTI]

This note presents a study of the feasibility of a Free Electron Laser (FEL) using an electron beam from the Compact Linear Collider (CLIC). We first show that, with the nominal CLIC layout, the energy spread at 15 GeV would be too large to allow FEL saturation in an undulator of reasonable length. An alternative scheme was studied, with a dedicated source, with a by-pass of the damping rings and with magnetic compression between the various acceleration stages. With this scheme, the energy spread of the CLIC beam can be reduced from 1.5% to 0.1%, but the emittance is much larger and, although the power gain is better than in the nominal case, FEL saturation is still not reached. We show that the energy spread or the transverse emittance would have to be reduced by another order of magnitude in order to obtain FEL saturation.

Brandin, M; Ekelöf, T J C; Ferrari, A

2002-01-01T23:59:59.000Z

45

Tests of a grazing-incidence ring resonator free-electron laser  

SciTech Connect (OSTI)

This paper reports on the Boeing free-electron laser (FEL) optical cavity that has been changed from a simple concentric cavity using two spherical mirrors to a larger grazing-incidence ring resonator. The new resonator consists of two mirror telescopes located at each end of the wiggler with a round-trip path length of approximately 133 m. Each telescope is a grazing-incidence hyperboloid followed by a normal-incidence paraboloid. Initial tests showed that poorly positioned ring focus and unreliable pointing alignment resulted in reduced and structured FEL output. (First lasing operation occurred on March 23 and 24, 1990.) Later efforts concentrated on improving the resonator alignment techniques and lowering the single-pass losses. FEL performance and reliability have significantly improved due to better ring alignment. The alignment procedure and recent lasing results are described. The effect the electron beam has on lasing is also discussed. Measurements are presented showing how FEL temporal output and wavelength are sensitive to electron beam energy variations.

Dowell, D.H.; Laucks, M.L.; Lowrey, A.R.; Adamski, J.L.; Pistoresi, D.J.; Shoffstall, D.R. (Boeing Aerospace and Electronics, Seattle, WA (US)); Bentz, M.P.; Burns, R.H.; Guha, J.; Sun, K.; Tomita, W. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.); Lumpkin, A.H.; Bender, S.; Byrd, D.; Tokar, R.L. (Los Alamos National Lab., NM (United States))

1991-12-01T23:59:59.000Z

46

Free electron laser amplifier driven by an induction linac  

SciTech Connect (OSTI)

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

47

Wiggler plane focusing in a linear free electron laser  

DOE Patents [OSTI]

This disclosure describes a free electron laser apparatus that provides a magnetic centering force to turn or focus a non-axial electron toward the longitudinal axis as desired. The focusing effect is provided by wiggler magnet pole faces that are approximately parabolically shaped.

Scharlemann, E.T.

1985-11-21T23:59:59.000Z

48

Initial optical-transition radiation measurements of the electron beam for the Boeing free-electron-laser experiment  

Science Journals Connector (OSTI)

The potential for characterization of electron beams at ? 100 MeV at the Boeing Free Electron Laser (FEL) facility by optical-transition radiation (OTR) techniques has been demonstrated as an important complement to other diagnostic means. Electron beam properties such as spatial profile and position, current intensity, emittance and energy were studied using OTR. Initial examples including transport through the 5 m wiggler and the resolution of Cherenkov radiation and spontaneous-emission radiation competitive sources are discussed.

A.H. Lumpkin; R.B. Fiorito; D.W. Rule; D.H. Dowell; W.C. Sellyey; A.R. Lowrey

1990-01-01T23:59:59.000Z

49

Inverse free electron laser accelerator for advanced light sources  

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

We discuss the inverse free electron laser (IFEL) scheme as a compact high gradient accelerator solution for driving advanced light sources such as a soft x-ray free electron laser amplifier or an inverse Compton scattering based gamma-ray source. In particular, we present a series of new developments aimed at improving the design of future IFEL accelerators. These include a new procedure to optimize the choice of the undulator tapering, a new concept for prebunching which greatly improves the fraction of trapped particles and the final energy spread, and a self-consistent study of beam loading effects which leads to an energy-efficient high laser-to-beam power conversion.

Duris, J. P.; Musumeci, P.; Li, R. K.

2012-06-01T23:59:59.000Z

50

Acceleration of electrons using an inverse free electron laser auto- accelerator  

SciTech Connect (OSTI)

We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW's) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.

Wernick, I.K.; Marshall, T.C.

1992-07-01T23:59:59.000Z

51

Acceleration of electrons using an inverse free electron laser auto- accelerator  

SciTech Connect (OSTI)

We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW`s) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.

Wernick, I.K.; Marshall, T.C.

1992-07-01T23:59:59.000Z

52

Chirped pulse inverse free-electron laser vacuum accelerator  

DOE Patents [OSTI]

A chirped pulse inverse free-electron laser (IFEL) vacuum accelerator for high gradient laser acceleration in vacuum. By the use of an ultrashort (femtosecond), ultrahigh intensity chirped laser pulse both the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large gains in a compact system. In addition, the IFEL resonance condition can be maintained throughout the interaction region by using a chirped drive laser wave. In addition, diffraction can be alleviated by taking advantage of the laser optical bandwidth with negative dispersion focusing optics to produce a chromatic line focus. The combination of these features results in a compact, efficient vacuum laser accelerator which finds many applications including high energy physics, compact table-top laser accelerator for medical imaging and therapy, material science, and basic physics.

Hartemann, Frederic V. (Dublin, CA); Baldis, Hector A. (Pleasanton, CA); Landahl, Eric C. (Walnut Creek, CA)

2002-01-01T23:59:59.000Z

53

E-Print Network 3.0 - alamos free-electron laser Sample Search...  

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

free-electron laser Search Powered by Explorit Topic List Advanced Search Sample search results for: alamos free-electron laser Page: << < 1 2 3 4 5 > >> 1 Applications: Medical...

54

E-Print Network 3.0 - axial free-electron laser Sample Search...  

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

free-electron laser Search Powered by Explorit Topic List Advanced Search Sample search results for: axial free-electron laser Page: << < 1 2 3 4 5 > >> 1 JOURNAL DE PHYSIQUE...

55

George Neil Named to Lead JLab's Free-Electron Laser Program...  

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

George Neil Named to Lead JLab's Free-Electron Laser Program NEWPORT NEWS, Va., Feb.15, 2008 - Dr. George Neil has been named Associate Director of the Free-Electron Laser Division...

56

In the OSTI Collections: Free-Electron Lasers | OSTI, US Dept of Energy,  

Office of Scientific and Technical Information (OSTI)

Free-Electron Lasers Free-Electron Lasers Existing Free-Electron Lasers Using Free-Electron Lasers for Measurement and Defense New Free-Electron Laser Designs References Research Organizations Reports available from OSTI's Information Bridge While most types of laser produce coherent light from electric charges bound within atoms, molecules, or solids, unbound charges are the light source in free-electron lasers. Lasers of this type can operate at higher frequencies than are easily achieved with bound-electron lasers. Various uses and designs of free-electron lasers are the focus of different projects sponsored through the Department of Energy. Lasers, like any source of light or other electromagnetic waves, produce waves when some of the electric charges they contain go from having a

57

Beam energy distribution influences on density modulation efficiency in seeded free-electron lasers  

E-Print Network [OSTI]

The beam energy spread at the entrance of undulator system is of paramount importance for efficient density modulation in high-gain seeded free-electron lasers (FELs). In this paper, the dependences of high harmonic micro-bunching in the high-gain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG) and phase-merging enhanced harmonic generation (PEHG) schemes on the electron energy spread distribution are studied. Theoretical investigations and multi-dimensional numerical simulations are applied to the cases of uniform and saddle beam energy distributions and compared to a traditional Gaussian distribution. It shows that the uniform and saddle electron energy distributions significantly enhance the performance of HGHG-FELs, while they almost have no influence on EEHG and PEHG schemes. A numerical example demonstrates that, with about 84keV RMS uniform and/or saddle slice energy spread, the 30th harmonic radiation can be directly generated by a single-stage seeding scheme for a soft x-ray FEL f...

Wang, Guanglei; Deng, Haixiao; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Wang, Dong; Zhao, Zhentang; Yang, Xueming

2015-01-01T23:59:59.000Z

58

New Laser's "First Light" Shatters Record | Jefferson...  

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

National Accelerator Facility have delivered first light from their Free Electron Laser (FEL). Only 2 years after ground was broken for the FEL, infrared light of more than...

59

Self-field effects on instability of wave modes in a two-stream free-electron laser with an axial magnetic field  

SciTech Connect (OSTI)

Free electron lasers (FEL) play major roles in the Raman Regime, due to the charge and current densities of the beam self-field. The method of perturbation has been applied to study the influence of self-electric and self-magnetic fields. A dispersion relation for two-stream free electron lasers with a helical wiggler and an axial magnetic field has been found. This dispersion relation is solved numerically to investigate the influence of self-fields on the FEL coupling and the two-stream instability. It was found that self-fields can produce very large effects on the FEL coupling, but they have almost negligible effects on two-stream instability.

Mohsenpour, Taghi, E-mail: mohsenpour@umz.ac.ir; Rezaee Rami, Omme Kolsoum [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)

2014-07-15T23:59:59.000Z

60

A high quality permanent-magnet wiggler for the Rocketdyne/Stanford infrared free electron laser  

Science Journals Connector (OSTI)

A high quality, variable gap, variable taper, permanent-magnet wiggler has been built for infrared free electron laser (FEL) experiments to be performed at the Stanford Photon Research Laboratory. The design and characterization procedure used to assemble the wiggler is discussed. A simulated annealing code was used to minimize field errors arising from variations in the individual magnets. The computed electron trajectories associated with the measured magnetic fields are presented for a range of different operating points of the wiggler. These plots indicate a very high quality field over a large range of different wiggler operating regimes. Resultant trajectory wander over the 2 m long wiggler for a 40 MeV electron at a wiggler gap corresponding to 3.3 kG was calculated to be less than 25 ?m. The ability to control trajectory wander and optical phase slip using the simulated annealing code suggests future extensions to extremely long wigglers.

Mark S. Curtin; Anup Bhowmik; Wayne A. McMullin; Stephen V. Benson; John M.J. Madey; Bruce A. Richman; Louis Vintro

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Compact two-beam push-pull free electron laser  

DOE Patents [OSTI]

An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

Hutton, Andrew (Yorktown, VA)

2009-03-03T23:59:59.000Z

62

An infrared free-electron laser for the Chemical Dynamics Research Laboratory. Design report  

SciTech Connect (OSTI)

This document describes a free-electron laser (FEL) proposed as part of the Chemical Dynamics Research Laboratory (CDRL), a user facility that also incorporates several advanced lasers of conventional design and two beamlines for the ALS. The FEL itself addresses the needs of the chemical sciences community for a high-brightness, tunable source covering a broad region of the infrared spectrum -- from 3 to 50 {mu}m. All of these sources, together with a variety of sophisticated experimental stations, will be housed in a new building to be located adjacent to the ALS. The radiation sources can be synchronized to permit powerful two-color, pump-probe experiments that will further our fundamental understanding of chemical dynamics at the molecular level, especially those aspects relevant to practical issues in combustion chemistry. The technical approach adopted in this design makes use of superconducting radiofrequency (SCRF) accelerating structures. The primary motivation for adopting this approach was to meet the user requirement for wavelength stability equal to one part in 10{sup 4}. Previous studies concluded that a wavelength stability of only one part in 10{sup 3} could be achieved with currently available room-temperature technology. In addition, the superconducting design operates in a continuous-wave (cw) mode and hence offers considerably higher average optical output power. It also allows for various pulse-gating configurations that will permit simultaneous multiuser operations. A summary of the comparative performance attainable with room-temperature and superconducting designs is given. The FEL described in this report provides a continuous train of 30-ps micropulses, with 100{mu}J of optical energy per micropulse, at a repetition rate of 6.1 MHz. The device can also deliver pulses at a cw repetition rate of 12.2 MHz, with a peak power of 50 {mu}J per micropulse. 70 ref.

Vaughan, D. [comp.

1992-04-01T23:59:59.000Z

63

An infrared free-electron laser for the Chemical Dynamics Research Laboratory  

SciTech Connect (OSTI)

This document describes a free-electron laser (FEL) proposed as part of the Chemical Dynamics Research Laboratory (CDRL), a user facility that also incorporates several advanced lasers of conventional design and two beamlines for the ALS. The FEL itself addresses the needs of the chemical sciences community for a high-brightness, tunable source covering a broad region of the infrared spectrum -- from 3 to 50 {mu}m. All of these sources, together with a variety of sophisticated experimental stations, will be housed in a new building to be located adjacent to the ALS. The radiation sources can be synchronized to permit powerful two-color, pump-probe experiments that will further our fundamental understanding of chemical dynamics at the molecular level, especially those aspects relevant to practical issues in combustion chemistry. The technical approach adopted in this design makes use of superconducting radiofrequency (SCRF) accelerating structures. The primary motivation for adopting this approach was to meet the user requirement for wavelength stability equal to one part in 10{sup 4}. Previous studies concluded that a wavelength stability of only one part in 10{sup 3} could be achieved with currently available room-temperature technology. In addition, the superconducting design operates in a continuous-wave (cw) mode and hence offers considerably higher average optical output power. It also allows for various pulse-gating configurations that will permit simultaneous multiuser operations. A summary of the comparative performance attainable with room-temperature and superconducting designs is given. The FEL described in this report provides a continuous train of 30-ps micropulses, with 100{mu}J of optical energy per micropulse, at a repetition rate of 6.1 MHz. The device can also deliver pulses at a cw repetition rate of 12.2 MHz, with a peak power of 50 {mu}J per micropulse. 70 ref.

Vaughan, D. (comp.)

1992-04-01T23:59:59.000Z

64

DOE Science Showcase - Free-Electron Lasers | OSTI, US Dept of Energy,  

Office of Scientific and Technical Information (OSTI)

Free-Electron Lasers Free-Electron Lasers Free-Electron Lasers absorb and release energy at any wavelength and can be controlled more precisely than conventional lasers by producing intense powerful light in brief bursts with extreme precision. This innovative technology has opened doors to a vast array of possibilities for manufacturing and for basic research. Read more in the white paper In OSTI Collections: Free-Electron Lasers by Dr. William Watson, Physicist, OSTI staff. Free-Electron Lasers Results in DOE Databases Science.gov Ciencia.Science.gov (Español) WorldWideScience.org Energy Citations Database DOE Information Bridge Relevant Subject Clusters FREE ELECTRON LASERS PARTICLE ACCELERATORS ENGINEERING LASERS ELECTRON BEAMS ACCELERATORS WIGGLER MAGNETS EQUIPMENT ELECTROMAGNETIC RADIATION

65

Efficiency enhancement in a single-pass Raman free electron laser  

SciTech Connect (OSTI)

Efficiency enhancement in free electron laser (FEL) with ion channel and axial magnetic field is compared. By using Maxwell's equations and nonwiggler averaged equation of motion of electron beam, a set of coupled nonlinear differential equations is derived in the slowly varying amplitude and wave number approximation. Because of using nonwiggler averaged equation of motion, it is possible to treat the injection of the beam into the wiggler. The electron beam propagates with a relativistic velocity, ions are assumed immobile and slippage is ignored. The final set of nonlinear first-order differential equations describing the nonlinear evolution of the FEL is solved by the Runge-Kutta method. Efficiency enhancement in group I orbits is almost the same for both ion channel and axial magnetic field cases, with somewhat larger growth rate for the latter. In group II orbits, efficiency enhancement is not possible for the ion-channel guiding; however, the intrinsic efficiency can be larger than that of the axial magnetic field case.

Rouhani, M. H.; Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

2009-09-15T23:59:59.000Z

66

Simulation of a high-gain tapered-wiggler free-electron laser  

SciTech Connect (OSTI)

We present results from a numerical model of a high-gain (electron-beam power > input laser beam power) FEL amplifier.

Fawley, W.M.; Scharlemann, E.T.; Prosnitz, D.

1983-09-27T23:59:59.000Z

67

The analysis of single-electron orbits in a free electron laser based upon a rectangular hybrid wiggler  

SciTech Connect (OSTI)

A three-dimensional analysis of a novel free-electron laser (FEL) based upon a rectangular hybrid wiggler (RHW) is presented. This RHW is designed in a configuration composed of rectangular rings with alternating ferrite and dielectric spacers immersed in a solenoidal magnetic field. An analytic model of RHW is introduced by solution of Laplace's equation for the magnetostatic fields under the appropriate boundary conditions. The single-electron orbits in combined RHW and axial guide magnetic fields are studied when only the first and the third spatial harmonic components of the RHW field are taken into account and the higher order terms are ignored. The results indicate that the third spatial harmonic leads to group III orbits with a strong negative mass regime particularly in large solenoidal magnetic fields. RHW is found to be a promising candidate with favorable characteristics to be used in microwave FEL.

Kordbacheh, A.; Ghahremaninezhad, Roghayeh [Department of Physics, Iran University of Science and Technology, 1684613114 Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 159163411 Tehran (Iran, Islamic Republic of)

2012-09-15T23:59:59.000Z

68

A compact x-ray free electron laser  

SciTech Connect (OSTI)

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be converted to soft x-rays in the range from 2--10 nm by passage through short period, high field strength wigglers as are being designed at Rocketdyne Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitablee for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

Barletta, W.A. (California Univ., Los Angeles, CA (USA). Center for Advanced Accelerators Physics Lawrence Livermore National Lab., CA (USA)); Atac, M.; Cline, D.B.; Kolonko, J. (California Univ., Los Angeles, CA (USA). Center for Advanced Accelerators Physics); Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G. (Rockwell International Corp., Canoga Park, CA (USA). Rocketdyne Div.); Gallardo

1988-01-01T23:59:59.000Z

69

A compact x-ray free electron laser  

SciTech Connect (OSTI)

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

Barletta, W.; Attac, M.; Cline, D.B.; Kolonko, J.; Wang, X.; Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G.; Gallardo, J.; Pellegrini, C.; Westenskow, G.

1988-09-09T23:59:59.000Z

70

following an electron bunch for free electron laser  

SciTech Connect (OSTI)

A video artist's ultra-slow-motion impression of an APEX-style electron gun firing a continuous train of electron bunches into a superconducting linear accelerator (in reality this would happen a million times a second). As they approach the speed of light the bunches contract, maintaining beam quality. After acceleration, the electron bunches are diverted into one or more undulators, the key components of free electron lasers. Oscillating back and forth in the changing magnetic field, they create beams of structured x-ray pulses. Before entering the experimental areas the electron bunches are diverted to a beam dump. (Animation created by Illumina Visual, http://www.illuminavisual.com/, for Lawrence Berkeley National Laboratory. Music for this excerpt, "Feeling Dark (Behind The Mask)" is by 7OOP3D http://ccmixter.org/files/7OOP3D/29126 and is licensed under a Creative Commons license: http://creativecommons.org/licenses/by-nc/3.0/)

None

2012-01-01T23:59:59.000Z

71

Design considerations for the free-electron laser with the self...  

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

5 Design considerations for the free-electron laser with the self-seeding and current-enhanced SASE 1 Alexander Zholents Advanced Photon Source, Argonne National Laboratory...

72

Mode couplings in a two-stream free-electron laser with a helical wiggler and an ion-channel guiding  

SciTech Connect (OSTI)

In this study, the method of perturbation has been applied to obtain the dispersion relation (DR) of a two-stream free-electron laser (FEL) with a helical wiggler and an ion-channel with all relativistic effects on waves. This DR has been solved numerically to find the unstable modes and their growth rate. Numerical solutions of DR show that the growth rate is considerably enhanced in comparison with single-stream free-electron laser. In group II orbits, with relatively large wiggler induced velocities, new couplings are found. The effect of the velocity difference of the two electron beams on the instabilities has also been investigated in this study. Moreover, the effect of the ion-channel density on the maximum growth rate of FEL resonance has been analyzed.

Mohsenpour, Taghi, E-mail: mohsenpour@umz.ac.ir; Alirezaee, Hajar [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)

2014-08-15T23:59:59.000Z

73

High-Gain Harmonic-Generation Free-Electron Laser  

Science Journals Connector (OSTI)

...originally built by STI Optronics for use in a visible FEL at Boeing. 35 Recent theoretical work on generating...originally built by STI Optronics for use in a visible FEL at Boeing. Recent theoretical work on generating hard x-rays by cascading...

L.-H. Yu; M. Babzien; I. Ben-Zvi; L. F. DiMauro; A. Doyuran; W. Graves; E. Johnson; S. Krinsky; R. Malone; I. Pogorelsky; J. Skaritka; G. Rakowsky; L. Solomon; X. J. Wang; M. Woodle; V. Yakimenko; S. G. Biedron; J. N. Galayda; E. Gluskin; J. Jagger; V. Sajaev; I. Vasserman

2000-08-11T23:59:59.000Z

74

XTREME OPTICS: the behavior of cavity optics for the Jefferson Lab free-electron laser  

SciTech Connect (OSTI)

The cavity optics within high power free-electron lasers based on energy-recovering accelerators are subjected to extreme conditions associated with illumination from a broad spectrum of radiation, often at high irradiances. This is especially true for the output coupler, where absorption of radiation by both the mirror substrate and coating places significant design restrictions to properly manage heat load and prevent mirror distortion. Besides the fundamental lasing wavelength, the mirrors are irradiated with light at harmonics of the fundamental, THz radiation generated by the bending magnets downstream of the wiggler, and x-rays produced when the electron beam strikes accelerator diagnostic components (e.g., wire scanners and view screens) or from inadvertent beam loss. The optics must reside within high vacuum at ~ 10-8 Torr and this requirement introduces its own set of complications. This talk discusses the performance of numerous high reflector and output coupler optics assemblies and provides a detailed list of lessons learned gleaned from years of experience operating the Upgrade IR FEL, a 10 kW-class, sub-ps laser with output wavelength from 1 to 6 microns.

Michelle D. Shinn; Christopher Behre; Stephen Benson; David Douglas; Fred Dylla; Christopher Gould; Joseph Gubeli; David Hardy; Kevin Jordan; George Neil; and Shukui Zhanga

2006-09-25T23:59:59.000Z

75

The World's First Free-Electron X-ray Laser | Department of Energy  

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

First Free-Electron X-ray Laser First Free-Electron X-ray Laser The World's First Free-Electron X-ray Laser August 17, 2010 - 6:19pm Addthis The World's First Free-Electron X-ray Laser John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Yesterday, Secretary Chu participated in the dedication of the world's first free-electron and most powerful X-ray laser, the Linac Coherent Light Source (LCLS). In light of this occasion (pun intended), we posted an in-depth look at the innovative nature of this new instrument and its potential to tackle some of life's biggest mysteries. The Secretary seemed just as geeked about the possibilities of the LCLS, stating that "this is a new instrument that will enable us to see the structure of materials that we could not determine by any other means ... Knowing those

76

LIPSS Free-Electron Laser Searches for Dark Matter  

SciTech Connect (OSTI)

A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10{sup -6} - 10{sup -3} eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.

Afanaciev, Andrei; Beard, Kevin; Biallas, George; Boyce, James R; Minarni, M; Ramdon, R; Robinson, Taylor; Shinn, Michelle D

2011-09-01T23:59:59.000Z

77

Transverse pulse shaping and optimization of a tapered hard X-ray free electron laser  

E-Print Network [OSTI]

Multidimensional optimization schemes for TW hard X-Ray free electron lasers are applied to the cases of transversely uniform and parabolic electron beam distributions and compared to examples of transversely Gaussian beams. The optimizations are performed for a $200$m undulator and a resonant wavelength of $\\lambda_r=1.5\\AA $ using the fully 3-dimensional FEL particle code GENESIS. Time dependent simulations showed that the maximum radiation power is larger for flatter transverse distributions due to enhanced optical guiding in the tapered section of the undulator. For a transversely Gaussian beam the maximum output power was found to be $\\text{P}_{max}$=$1.56$ TW compared to $2.26$ TW for the parabolic case and $2.63$ TW for the uniform case. Spectral data also showed a 30-70$\\%$ reduction in energy deposited in the sidebands for the uniform and parabolic beams compared with a Gaussian. An analysis of the maximum power as a function of detuning from resonance shows that redshifting the central wavelength by...

Emma, Claudio; Wu, Juhao

2014-01-01T23:59:59.000Z

78

Toward resistant vacuum-ultraviolet coatings for free-electron lasers down to 150 nm  

SciTech Connect (OSTI)

Research and development are currently trying to run a storage ring free-electron laser down to 150 nm with robust optics. Vacuum-ultraviolet fluoride optics with protected oxide layers and enhanced metallic mirrors are investigated.

Gatto, Alexandre; Yang Minghong; Kaiser, Norbert; Guenster, Stefan; Ristau, Detlev; Trovo, Mauro; Danailov, Miltcho

2006-10-01T23:59:59.000Z

79

A CW normal-conductive RF gun for free electron laser and energy recovery linac applications  

E-Print Network [OSTI]

Todd, State-of-the art electron guns and injector de- signs,7] Summary of working group on guns and injectors, 41st Ad-A CW normal-conductive RF gun for free electron laser and

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

80

The European X-ray Free-Electron Laser: A Progress Report | Stanford...  

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

SLAC, Redtail Conference Room (901-108) M. Altarelli, European XFEL GmbH, Hamburg, Germany The present status of the construction of the European X-ray Free-Electron Laser in...

Note: This page contains sample records for the topic "free-electron laser fel" 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.
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to obtain the most current and comprehensive results.


81

Gamma-ray free-electron lasers: Quantum fluid model  

E-Print Network [OSTI]

A quantum fluid model is used to describe the interacion of a nondegenerate cold relativistic electron beam with an intense optical wiggler taking into account the beam space-charge potential and photon recoil effect. A nonlinear set of coupled equations are obtained and solved numerically. The numerical results shows that in the limit of plasma wave-breaking an ultra-high power radiation pulse are emitted at the$\\gamma$-ray wavelength range which can reach an output intensity near the Schwinger limit depending of the values of the FEL parameters such as detuning and input signal initial phase at the entrance of the interaction region.

Silva, H M

2014-01-01T23:59:59.000Z

82

Study of beam transverse properties of a thermionic electron gun for application to a compact THz free electron laser  

SciTech Connect (OSTI)

A novel thermionic electron gun adopted for use in a high power THz free electron laser (FEL) is proposed in this paper. By optimization of the structural and radiofrequency (RF) parameters, the physical design of the gun is performed using dynamic calculations. Velocity bunching is used to minimize the bunch's energy spread, and the dynamic calculation results indicate that high quality beams can be provided. The transverse properties of the beams generated by the gun are also analyzed. The novel RF focusing effects of the resonance cavity are investigated precisely and are used to establish emittance compensation, which enables the injector length to be reduced. In addition, the causes of the extrema of the beam radius and the normalized transverse emittance are analyzed and interpreted, respectively, and slice simulations are performed to illustrate how the RF focusing varies along the bunch length and to determine the effects of that variation on the emittance compensation. Finally, by observation of the variations of the beam properties in the drift tube behind the electron gun, prospective assembly scenarios for the complete THz-FEL injector are discussed, and a joint-debugging process for the injector is implemented.

Hu, Tongning, E-mail: TongningHu@hust.edu.cn, E-mail: yjpei@ustc.edu.cn; Qin, Bin; Tan, Ping; Chen, Qushan; Yang, Lei [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Pei, Yuanji, E-mail: TongningHu@hust.edu.cn, E-mail: yjpei@ustc.edu.cn; Li, Ji [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)

2014-10-15T23:59:59.000Z

83

Density gradient free electron collisionally excited X-ray laser  

DOE Patents [OSTI]

An operational X-ray laser (30) is provided that amplifies 3p-3s transition X-ray radiation along an approximately linear path. The X-ray laser (30) is driven by a high power optical laser. The driving line focused optical laser beam (32) illuminates a free-standing thin foil (34) that may be associated with a substrate (36) for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the X-ray laser gain medium. The X-ray laser (30) may be driven by more than one optical laser beam (32, 44). The X-ray laser (30) has been successfully demonstrated to function in a series of experimental tests.

Campbell, Edward M. (Pleasanton, CA); Rosen, Mordecai D. (Berkeley, CA)

1989-01-01T23:59:59.000Z

84

Density gradient free electron collisionally excited x-ray laser  

DOE Patents [OSTI]

An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.

Campbell, E.M.; Rosen, M.D.

1984-11-29T23:59:59.000Z

85

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium: a first-principles study  

E-Print Network [OSTI]

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium CEA-DIF, 91297 Arpajon, France (Dated: April 3, 2014) The electronic behavior of various solid metals modelled based on the free electron classical theory, the free electron number is a key parameter. However

Paris-Sud XI, Université de

86

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

SciTech Connect (OSTI)

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

87

Simulations of the Rocketdyne free-electron laser with a 4 m wiggler  

Science Journals Connector (OSTI)

Rocketdyne is assembling a high-brightness 78 MeV FEL. After full development the laser will be capable of an average output of greater than 1 kW. Performance calculations using the Rocketdyne FELOPT code are presented for a 1.06 ?m system.

R.A. Cover; G.T. Bennett; R.J. Burke; M.S. Curtin; M.C. Lampel; G. Rakowsky

1992-01-01T23:59:59.000Z

88

Photon statistics in a free-electron laser with an axial-guide magnetic field  

Science Journals Connector (OSTI)

Starting from an initial state with an electron energy p02/2m+??c/2, a vacuum-laser field, and a coherent wiggler field, I discuss photon statistics in a free-electron laser with an axial-guide magnetic field. It is found that the axial field can weaken the squeezing, enhance the positive (for ?>0) and negative (for ?0) and antibunching (for ?<0).

Gou San-kui

1992-07-15T23:59:59.000Z

89

Characterization and Suppression of the Electromagnetic Interference Induced Phase Shift in the JLab FEL Photo - Injector Advanced Drive Laser System  

SciTech Connect (OSTI)

The drive laser for the photo-cathode gun used in the JLab Free Electron Laser (FEL) facility had been experiencing various phase shifts on the order of tens of degrees (>20{sup o} at 1497 MHz or >40ps) when changing the Advanced Drive Laser (ADL) [2][3][4] micro-pulse frequencies. These phase shifts introduced multiple complications when trying to setup the accelerator for operation, ultimately inhibiting the robustness and overall performance of the FEL. Through rigorous phase measurements and systematic characterizations, we determined that the phase shifts could be attributed to electromagnetic interference (EMI) coupling into the ADL phase control loop, and subsequently resolved the issue of phase shift to within tenths of a degree (<0.5{sup o} at 1497 MHz or <1ps). The diagnostic method developed and the knowledge gained through the entire process will prove to be invaluable for future designs of similar systems.

F. G. Wilson, D. Sexton, S. Zhang

2011-09-01T23:59:59.000Z

90

Dominant Secondary Nuclear Photoexcitation with the X-ray Free Electron Laser  

E-Print Network [OSTI]

The new regime of resonant nuclear photoexcitation rendered possible by x-ray free electron laser beams interacting with solid state targets is investigated theoretically. Our results unexpectedly show that secondary processes coupling nuclei to the atomic shell in the created cold high-density plasma can dominate direct photoexcitation. As an example we discuss the case of $^{93m}$Mo isomer depletion for which nuclear excitation by electron capture as secondary process is shown to be orders of magnitude more efficient than the direct laser-nucleus interaction. General arguments revisiting the role of the x-ray free electron laser in nuclear experiments involving solid-state targets are further deduced.

Jonas Gunst; Yuri A. Litvinov; Christoph H. Keitel; Adriana Pálffy

2014-02-27T23:59:59.000Z

91

Three-dimensional manipulation of electron beam phase space for seeding soft x-ray free-electron lasers  

E-Print Network [OSTI]

In this letter, a simple technique is proposed to induce strong density modulation into the electron beam with small energy modulation. By using the combination of a transversely dispersed electron beam and a wave-front tilted seed laser, three-dimensional manipulation of the electron beam phase space can be utilized to significantly enhance the micro-bunching of seeded free-electron laser schemes, which will improve the performance and extend the short-wavelength range of a single-stage seeded free-electron laser. Theoretical analysis and numerical simulations demonstrate the capability of the proposed technique in a soft x-ray free-electron laser.

Feng, Chao; Deng, Haixiao; Zhao, Zhentang

2014-01-01T23:59:59.000Z

92

Development of Advanced Beam Halo Diagnostics at the Jefferson Lab Free-Electron-Laser Facility  

SciTech Connect (OSTI)

High average current and high brightness electron beams are needed for many applications. At the Jefferson Lab FEL facility, the search for dark matter with the FEL laser beam has produced some interesting results, and a second very promising experiment called ?DarkLight?, using the JLab Energy-recovery-linac (ERL) machine has been put forward. Although the required beam current has been achieved on this machine, one key challenge is the management of beam halo. At the University of Md. (UMD) we have demonstrated a high dynamic range halo measurement method using a digital micro-mirror array device (DMD). A similar system has been established at the JLab FEL facility as a joint effort by UMD and JLab to measure the beam halo on the high current ERL machine. Preliminary experiments to characterize the halo were performed on the new UV FEL. In this paper, the limitations of the present system will be analyzed and a discussion of other approaches (such as an optimized coronagraph) for further extending the dynamic range will be presented. We will also discuss the possibility of performing both longitudinal and transverse (3D) halo measurements together on a single system.

Shukui Zhang, Stephen Benson, Dave Douglas, Frederick Wilson, Hao Zhang, Anatoly Shkvarunets, Ralph Fiorito

2011-03-01T23:59:59.000Z

93

Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field  

SciTech Connect (OSTI)

A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread.

Kheiri, Golshad; Esmaeilzadeh, Mahdi [Department of Physics, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)] [Department of Physics, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)

2013-12-15T23:59:59.000Z

94

Observation of gain in a free-electron laser master oscillator-power amplifier  

SciTech Connect (OSTI)

We report the first operation of a master oscillator-power amplifier in which both devices are free-electron lasers. Gain optimization in the power amplifier was studied. A 35-A electron beam produced up to 60% gain at 3 {mu}m. The gain spectrum was obtained by gap tuning the power amplifier wiggler and evidence was found for violation of the Madey theorem due to high gain effects.

Vintro, L.; Benson, S.V.; Bhowmik, A.; Curtin, M.S.; Madey, J.M.J.; McMullin, W.A.; Richman, R.A. (Stanford Photon Research Laboratory, Stanford University, Stanford, California 94305 (USA) Rocketdyne Division, Rockwell International, 6633 Canoga Avenue, Canoga Park, California 91303 (USA))

1990-04-02T23:59:59.000Z

95

Analysis of saturation phenomena in Cerenkov free-electron lasers with a planar waveguide  

SciTech Connect (OSTI)

In this paper, the operation of the stimulated emission in Cerenkov free-electron laser (CFEL) is studied on the basis of the modulations of electron velocity and density by the electromagnetic (EM) field. The influence of the electron relaxation, due to mutual electrons collisions, on the electron dynamics is taken into account. We investigate the growth characteristics of Cerenkov laser operating in the small-signal and saturation regimes. In the saturation regime, the effect of velocity reduction of the electron beam on the gain dynamics is demonstrated. We also show that our results match with those of other well-known treatments in the small-signal gain limit.

Fares, Hesham; Yamada, Minoru [Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan)

2011-09-15T23:59:59.000Z

96

Toward atomic resolution diffractive imaging of isolated molecules with x-ray free-electron lasers  

E-Print Network [OSTI]

We give a detailed account of the theoretical analysis and the experimental results of an x-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Coherent Light Source [Phys. Rev. Lett. 112, 083002 (2014)]. This experiment is the first step toward coherent diffractive imaging of structures and structural dynamics of isolated molecules at atomic resolution, i. e., picometers and femtoseconds, using x-ray free-electron lasers.

Stern, Stephan; Filsinger, Frank; Rouzée, Arnaud; Rudenko, Artem; Johnsson, Per; Martin, Andrew V; Barty, Anton; Bostedt, Christoph; Bozek, John D; Coffee, Ryan N; Epp, Sascha; Erk, Benjamin; Foucar, Lutz; Hartmann, Robert; Kimmel, Nils; Kühnel, Kai-Uwe; Maurer, Jochen; Messerschmidt, Marc; Rudek, Benedikt; Starodub, Dmitri G; Thøgersen, Jan; Weidenspointner, Georg; White, Thomas A; Stapelfeldt, Henrik; Rolles, Daniel; Chapman, Henry N; Küpper, Jochen

2014-01-01T23:59:59.000Z

97

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

SciTech Connect (OSTI)

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

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

2009-04-15T23:59:59.000Z

98

Transverse-Coherence Properties of the Free-Electron-Laser FLASH at DESY  

SciTech Connect (OSTI)

A general theoretical approach based on the decomposition of statistical fields into a sum of independently propagating transverse modes was used for the analysis of the coherence properties of the new free-electron laser source FLASH operated at 13.7 nm wavelength. The analysis shows that several transverse modes are contributing to the total radiation field of FLASH. The results of theoretical calculations are compared with measurements using Young's double-slit experiment. The coherence lengths in the horizontal and in the vertical directions 20 m downstream from the source are estimated at 300 and 250 {mu}m, respectively.

Singer, A.; Vartanyants, I. A.; Kuhlmann, M.; Duesterer, S.; Treusch, R.; Feldhaus, J. [HASYLAB at DESY, Notkestrasse 85, D-22607 Hamburg (Germany)

2008-12-19T23:59:59.000Z

99

Influence of space charge wave on quasilinear theory of the free-electron laser saturation  

SciTech Connect (OSTI)

A quasilinear theory is presented that describes the self-consistent evolution of the electron beam distribution function and fields in a free-electron laser when the space charge wave is present. In the Raman regime, a high-density electron beam has an appreciable space charge potential. A broad spectrum of waves is assumed in order to have a relatively wide range of resonant particles. A one-dimensional helical magnetic field is considered and the analysis is based on the Vlasov-Maxwell equations. Two coupled differential equations are derived, which, in conjunction with conservation laws, describe the quasilinear development by the diffusion of electrons in the momentum space. This leads to the saturation of the free-electron laser instability by the plateau formation. Analytical expressions for the growth rate and for the diffusion coefficient are derived, which reduced to those in the Compton regime under appropriate conditions. By use of the linear growth rate and diffusion coefficient, an analytical expression for efficiency in Raman regime was derived. A numerical analysis is conducted to study the effects of the spectral width of radiation and the thermal spread of the electron beam on the efficiency.

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

2009-07-15T23:59:59.000Z

100

Multi-range free-electron laser with a pair of dielectric multilayer mirrors  

SciTech Connect (OSTI)

We report the experimental achievement of a free-electron laser in three wavelength regions, mid-infrared, near-infrared, and visible, using a pair of dielectric multilayer mirrors in the storage ring NIJI-IV. Dielectric multilayer mirrors can have high reflectivity at wavelength regions corresponding to higher-diffraction orders of the target wavelength. A narrowing of the relative bandwidth of the dielectric multilayer mirrors was observed in the higher-diffraction orders of the target wavelength and was found to be caused by high diffraction and carbon contamination. Our experimental results will be applied to development of a multi-rang laser that have a gain in a wade wavelength region.

Sei, Norihiro; Ogawa, Hiroshi; Yamada, Kawakatsu [Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Using the X-FEL to photo-pump X-ray laser transitions in He-like Ne  

SciTech Connect (OSTI)

Nearly four decades ago H-like and He-like resonantly photo-pumped laser schemes were proposed for producing X-ray lasers. However, demonstrating these schemes in the laboratory has proved to be elusive because of the difficulty of finding a strong resonant pump line. With the advent of the X-ray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) we now have a tunable X-ray laser source that can be used to replace the pump line in previously proposed laser schemes and allow researchers to study the physics and feasibility of resonantly photo-pumped laser schemes. In this paper we use the X-FEL at 1174 eV to photo-pump the singly excited 1s2p state of He-like Ne to the doubly excited 2p3p state and model gain on the 2p3p-2p2s transition at 175 eV and the 2p3p-1s3p transition at 1017 eV. One motivation for studying this scheme is to explore possible quenching of the gain due to strong non-linear coupling effects from the intense X-FEL beam We compare this scheme with photo-pumping the He-like Ne ground state to the 1s3p singly excited state followed by lasing on the 3p-2s and 3d-2p transitions at 158 and 151 eV. Experiments are being planned at LCLS to study these laser processes and coherent quantum effects.

Nilsen, J; Rohringer, N

2011-08-30T23:59:59.000Z

102

Dissociative multiple ionization of diatomic molecules by extreme-ultraviolet free-electron-laser pulses  

SciTech Connect (OSTI)

Nuclear dynamics in dissociative multiple ionization processes of diatomic molecules exposed to extreme-ultraviolet free-electron-laser pulses is studied theoretically using the Monte Carlo wave packet approach. By simulated detection of the emitted electrons, the model reduces a full propagation of the system to propagations of the nuclear wave packet in one specific electronic charge state at a time. Suggested ionization channels can be examined, and kinetic energy release spectra for the nuclei can be calculated and compared with experiments. Double ionization of O{sub 2} is studied as an example, and good agreement with published experimental data is obtained by simulating the dynamics on ten different electronic Born-Oppenheimer curves.

Leth, Henriette Astrup; Madsen, Lars Bojer [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

2011-06-15T23:59:59.000Z

103

Optical measurements on the Boeing free electron laser ring resonator experiment  

Science Journals Connector (OSTI)

The Boeing free electron laser is presently operating with a stable semiconfocal ring optical cavity surrounding a 5 m wiggler. The resonator consists of two grazing-incidence reflective telescopes each formed by a grazing-incidence hyperboloid and its companion off-axis paraboloid. The resonator is closed by two flats: one used for dynamic jitter correction and the other used to outcouple some of the circulating beam. It is critical to lasing that the alignment of the resonator be maintained, the focus of the optical mode be at the midpoint of the wiggler, and the wavefront quality of the propagating beam be maintained. Measurements of the focus position, power loss, and wavefront quality are made before operation of the electron accelerator to diagnose whether the conditions required for lasing exist.

M.L. Laucks; D.H. Dowell; A.R. Lowrey; M. Bemes; A. Currie; P. Johnson; K. McCrary; J. Adamski; D. Pistoresi; D.R. Shoffstall; M. Bentz; R. Burns; R. Hudyma; K. Sun; W. Mower; S. Bender; J. Goldstein; A. Lumpkin; B. McVey; R. Tokar; D. Shemwell

1991-01-01T23:59:59.000Z

104

Single-Molecule Imaging with X-Ray Free-Electron Lasers: Dream or Reality?  

SciTech Connect (OSTI)

X-ray free-electron lasers (XFEL) are revolutionary photon sources, whose ultrashort, brilliant pulses are expected to allow single-molecule diffraction experiments providing structural information on the atomic length scale of nonperiodic objects. This ultimate goal, however, is currently hampered by several challenging questions basically concerning sample damage, Coulomb explosion, and the role of nonlinearity. By employing an original ab initio approach, we address these issues showing that XFEL-based single-molecule imaging will be only possible with a few-hundred long attosecond pulses, due to significant radiation damage and the formation of preferred multisoliton clusters which reshape the overall electronic density of the molecular system at the femtosecond scale.

Fratalocchi, A. [PRIMALIGHT, Faculty of Electrical Engineering, Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)] [Department of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185, Rome (Italy); Ruocco, G. [Department of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185, Rome (Italy)] [IPCF-CNR, c/o Department of Physics, Sapienza University, P.le Aldo Moro 2, 00185, Rome (Italy)

2011-03-11T23:59:59.000Z

105

Role of multilayer-like interference effects on the transient optical response of Si{sub 3}N{sub 4} films pumped with free-electron laser pulses  

SciTech Connect (OSTI)

X-ray/optical cross-correlation methods are attracting increasing interest for exploring transient states of matter using ultrashort free-electron laser (FEL) pulses. Our paper shows that in such studies the difference in the penetration depth of the FEL-pump and the infrared (IR) probe pulses become important, in particular, when exploring the changes in the optical properties of solid targets. We discuss the role of interference effects, using a phenomenological model with excited and unperturbed slabs. The reliability of this model was experimentally verified by measuring the transient optical response of free-standing and silicon (Si) supported silicon nitride (Si{sub 3}N{sub 4}) films, simultaneously in reflection and transmission, using s- and p-polarized IR light. The changes in the Si{sub 3}N{sub 4} optical refractive index, induced by the FEL pulses, have fully been described in the frame of the proposed model. The experimental results confirm that the differences, observed in the FEL-induced transient reflectance and transmittance of the Si{sub 3}N{sub 4} targets with different thicknesses, arise from multilayer-like interferometric phenomena.

Casolari, F.; Giangrisostomi, E. [Elettra-Sincrotrone Trieste, SS 14 - km 163.5, I-34149 Basovizza, Trieste (Italy); Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, I-34127 Trieste (Italy); Bencivenga, F.; Capotondi, F.; Manfredda, M.; Pedersoli, E.; Principi, E.; Masciovecchio, C.; Kiskinova, M. [Elettra-Sincrotrone Trieste, SS 14 - km 163.5, I-34149 Basovizza, Trieste (Italy); Mincigrucci, R. [Elettra-Sincrotrone Trieste, SS 14 - km 163.5, I-34149 Basovizza, Trieste (Italy); Dipartimento di Fisica, Università degli Studi di Perugia, via A. Pascoli, I-06123 Perugia (Italy)

2014-05-12T23:59:59.000Z

106

Free Electron Laser Program Program at TJNAF| U.S. DOE Office...  

Office of Science (SC) Website

Spin-off examples: accelerator components; nano-material mfg.; anti-missile defense; test bed for high current, high precision, high power SRF accelerators and FELs; energy...

107

Atmospheric propagation simulations and Boeing's high average power free electron laser ; .  

E-Print Network [OSTI]

??The development of a high average power FEL for military applications, whether shipboard or not, represents a significant advancement in technology over present weapons systems… (more)

Ramos, Luis.

1995-01-01T23:59:59.000Z

108

R&D for a Soft X-Ray Free Electron Laser Facility  

E-Print Network [OSTI]

Quantum-degenerate Electron Source, Physical Review LettersHigh brightness electron source, beam instrumentation andFEL Requires high rep-rate electron source Beam switchyard

Staples, John

2009-01-01T23:59:59.000Z

109

Femtosecond x-ray absorption spectroscopy with hard x-ray free electron laser  

SciTech Connect (OSTI)

We have developed a method of dispersive x-ray absorption spectroscopy with a hard x-ray free electron laser (XFEL), generated by a self-amplified spontaneous emission (SASE) mechanism. A transmission grating was utilized for splitting SASE-XFEL light, which has a relatively large bandwidth (?E/E ? 5 × 10{sup ?3}), into several branches. Two primary split beams were introduced into a dispersive spectrometer for measuring signal and reference spectra simultaneously. After normalization, we obtained a Zn K-edge absorption spectrum with a photon-energy range of 210 eV, which is in excellent agreement with that measured by a conventional wavelength-scanning method. From the analysis of the difference spectra, the noise ratio was evaluated to be ?3 × 10{sup ?3}, which is sufficiently small to trace minute changes in transient spectra induced by an ultrafast optical laser. This scheme enables us to perform single-shot, high-accuracy x-ray absorption spectroscopy with femtosecond time resolution.

Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Obara, Yuki; Misawa, Kazuhiko [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)] [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Bhattacharya, Atanu; Kurahashi, Naoya [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)] [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Ogi, Yoshihiro [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)] [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan); Suzuki, Toshinori [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan) [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)

2013-09-23T23:59:59.000Z

110

SciTech Connect: Compact X-ray Free Electron Laser from a Laser...  

Office of Scientific and Technical Information (OSTI)

Gradient Undulator Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large...

111

Generation of ultrashort radiation pulses by injection locking a regenerative free-electron-laser amplifier  

E-Print Network [OSTI]

than a slippage length, with high efficiency. The IRKA configuration can produce such ultra can produce tunable high- power radiation. Another potentially important feature of the FEL is its decades of re- search and development. For example, many scientific appli- cations, such as condensed

Wurtele, Jonathan

112

FREE ELECTRON LASER FOR SIBERIAN CENTRE FOR PHOTOCHEMICAL RESEARCH: THE CONTROL SYSTEM FOR THE  

E-Print Network [OSTI]

phase of the project - the terahertz FEL - was commissioned recently [2]. This article discusses with deep negative feedback and provide across a low-resistance shunt a voltage that is proportional 0.02% 0.01% Relative power source efficiency 80% 92% Cooling system water water Max power

Kozak, Victor R.

113

CW 100 kW radio frequency-free-electron laser design at 10. mu. m  

SciTech Connect (OSTI)

This paper describes the 100 kW CW radio frequency-free-electron last at 10{mu}m to be built at Boeing Defense and Space Group in collaboration with Los Alamos National Laboratory. The authors discuss the criteria which led to the selection of the operating point, the single-accelerator master-oscillator and power-amplifier configuration, the goals of this experiment, and the expected performance.

Parazzoli, C.G.; Rodenburg, R.E.; Romero, J.B.; Adamski, J.L.; Pistoresi, D.J.; Shoffstall, D.R. (Boeing Defense and Space Group, Seattle, WA (US)); Quimby, D.C. (STI Optronics, Inc., Bellevue, WA (US))

1991-12-01T23:59:59.000Z

114

Generation of very high-frequency waves by up-conversion in a plasma-loaded free-electron laser  

Science Journals Connector (OSTI)

A free-electron laser loaded with a plasma is able to resonate at two different frequencies. The two waves are copropagating, one with positive slippage while the other has negative slippage. We deduce the nonlinear partial differential equations describing the interaction between the two waves in the slowly-varying-envelope approximation. By injecting a signal at the low frequency, a strong signal is produced at the harmonically related high frequency, with a lethargy time much smaller than that of the spontaneous vacuum emission. This effect could be applied in the generation of very short wavelength radiation, up to the range of hard x rays.

V. Petrillo and C. Maroli

2000-12-01T23:59:59.000Z

115

Traces on ion yields and electron spectra of Ar inner-shell hollow states with Free-Electron Lasers  

E-Print Network [OSTI]

We explore the formation by Free-Electron-Laser radiation of Ar hollow states with two or three inner-shell holes. We find that even charged Ar ion states can be more populated than odd charged Ar ion states. This depends on the pulse intensity and the number of energetically accessible inner- shell holes. Fully accounting for fine structure, we demonstrate that one electron spectra bare the imprints of Ar hollow states with two inner-shell holes. Moreover, we show how the Auger spectra of these hollow states can be extracted from two-electron coincidence spectra.

Wallis, A O G; Emmanouilidou, A

2015-01-01T23:59:59.000Z

116

Transverse-coherence properties of the FEL at the LCLS  

SciTech Connect (OSTI)

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

117

FEL Program | Jefferson Lab  

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

Science Conducting An Experiment at the Free-Electron Laser A broad range of experiments are conducted at Jefferson Lab's Free-Electron Laser facility. A D D I T I O N A L L I N K...

118

Emittance studies at the Los Alamos National Laboratory Free-Electron Laser  

SciTech Connect (OSTI)

Recent emittance studies at the Los Alamos FEL have indicated several areas of concern in the linac and beamline feeding the wiggler. Four emittance growth mechanisms of special importance have been studied. First, a rapid growth of the electron beam's emittance immediately after the spherical gridded Pierce gun resulted, in part, from the long time required for our pulsing electronics to ramp the grid voltage up at the start and down at the end of the pulse, which created a pulse with a cosine-like current distribution as a function of time. The growth was compounded by the extremely small radial beam size (almost a waist) leaving the gun. In addition, we saw evidence of electrostatic charging of the insulators in the gun, reducing the quality of the electron beam further. Second, the action of the solenoidal focusing fields in the low-voltage bunching region was studied, and criteria for a minimum emittance growth were established. Third, maximum misalignment angles and displacements for various elements of the beamline were calculated for the desired low emittance growth. Finally, emittance growth in the horizontal dimension through the nonisochronous bend caused by varying energy depression on the particles due to longitudinal wake fields was both calculated and observed. In addition, we measured energy depressions caused by the wake fields generated by various other elements in the beamline. Strategies were developed to relieve the magnitude of these wake-field effects. 10 refs., 12 figs.

Carlsten, B.E.; Feldman, D.W.; Lumpkin, A.H.; Stein, W.E.; Warren, R.W.

1987-01-01T23:59:59.000Z

119

High-current-density, high brightness cathodes for free electron laser applications  

SciTech Connect (OSTI)

This report discusses the following topics: brightness and emittance of electron beams and cathodes; general requirements for cathodes in high brightness electron guns; candidate cathode types; plasma and field emission cathodes; true field emission cathodes; oxide cathodes; lanthanum hexaborides cathodes; laser driven thermionic cathodes; laser driven photocathodes; impregnated porous tungsten dispenser cathodes; and choice of best performing cathode types.

Green, M.C. (Varian Associates, Palo Alto, CA (USA). Palo Alto Microwave Tube Div.)

1987-06-01T23:59:59.000Z

120

High-Gain Harmonic Generation Free-Electron Laser at Saturation  

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

shown in Fig. 1. Fig.1. HGHG ATF layout The frequency-quadrupled Nd:YAG photocathode-rf gun drive-laser has a pulse length of 8 ps and an energy of 8 J resulting in a 6-ps FWHM...

Note: This page contains sample records for the topic "free-electron laser fel" 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

Status of UCLA Helical Permanent-Magnet Inverse Free Electron Laser  

SciTech Connect (OSTI)

A helical undulator, utilizing permanent-magnet of cylindrically symmetric (Halbach) geometry is being developed at UCLA's Neptune Facility. The initial prototype is a short 10 cm, 7 periods long helical undulator, designed to test the electron-photon coupling by observing the micro-bunching is currently being constructed. The Neptune IFEL facility utilizes a 15 MeV Photoinjector-generated electron beam of 0.5 nC interacting with CO{sub 2} of peak energy up to 100 J, estimated to have acceleration of 100 MeV/m. An Open Iris-Loaded Waveguide Structure (OILS) scheme which conserves laser mode size and wave fronts throughout the undulator, is utilized to avoid Gouy phase shift caused by focusing of the drive laser. Undulator design was tested by computer simulations Radia and Genesis 1.3. Coherent Transition Radiation and Coherent Cherenkov Radiation will be used for micro-bunching diagnostic. Currently permanent dipoles and their aluminum holders have been built, and the project is in its final state of assembly and undulator testing.

Knyazik, A.; Tikhoplav, R.; Frederico, J. T.; Affolter, M.; Rosenzweig, J. B. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States)

2009-01-22T23:59:59.000Z

122

Statistical properties of the radiation from SASE FEL operating in a post-saturation regime with and without undulator tapering  

E-Print Network [OSTI]

We describe statistical and coherence properties of the radiation from x-ray free electron lasers (XFEL) operating in the post-saturation regime. We consider practical case of the SASE3 FEL at the European XFEL. We perform comparison of the main characteristics of the X-ray FEL operating in the post-saturation regime with and without undulator tapering: efficiency, coherence time and degree of transverse coherence.

Schneidmiller, E A

2015-01-01T23:59:59.000Z

123

Final results of the Boeing and Los Alamos grazing incidence ring-resonator free electron laser experiment  

Science Journals Connector (OSTI)

Initial test results for the Boeing and Los Alamos grazing incidence ring-resonator FEL were presented at the 1990 FEL Conference. This work showed that the resonator pointing alignment accurcy required improvements to the resonator diagnostics to increase the alignment accuracy. The alignment technique was described, but lasing results with the more accurate alignment were not available at that time. This paper discusses more recent and final test results from the grazing-incidence ring-resonator experiment. With the new alignment techniques, the extraction was approximately seven times greater, and the FEL output exhibited much reduced temporal structure. Measurements show that FEL output and wavelength are sensitive to electron beam energy variations.

D.H. Dowell; M.L. Laucks; A.R. Lowrey; J. Adamski; D. Pistoresi; D.R. Shoffstall; A.H. Lumpkin; S. Bender; D. Byrd; R.L. Tokar; K. Sun; M. Bentz; R. Burns; J. Guha; W. Tomita

1992-01-01T23:59:59.000Z

124

The BErkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator  

E-Print Network [OSTI]

used at the world's first x-ray free electron laser (FEL) at the LCLS at SLAC, and the lower energyThe BErkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator W.P. Leemansa,b,c , R, USA Abstract. An overview is presented of the design of a 10 GeV laser plasma accelerator (LPA

Geddes, Cameron Guy Robinson

125

Optics-free x-ray FEL oscillator  

SciTech Connect (OSTI)

There is a need for an Optics-Free FEL Oscillators (OFFELO) to further the advantages of free-electron lasers and turning them in fully coherent light sources. While SASE (Self-Amplified Spontaneous Emission) FELs demonstrated the capability of providing very high gain and short pulses of radiation and scalability to the X-ray range, the spectra of SASE FELs remains rather wide ({approx}0.5%-1%) compared with typical short wavelengths FEL-oscillators (0.01%-0.0003% in OK-4 FEL). Absence of good optics in VUV and X-ray ranges makes traditional oscillator schemes with very high average and peak spectral brightness either very complex or, strictly speaking, impossible. In this paper, we discuss lattice of the X-ray optics-free FEL oscillator and present results of initial computer simulations of the feedback process and the evolution of FEL spectrum in X-ray OFFELO. We also discuss main limiting factors and feasibility of X-ray OFFELO.

Litvinenko, V.N.; Hao, Y.; Kayran, D.; Trbojevic, D.

2011-03-28T23:59:59.000Z

126

Using X-ray free-electron lasers for probing of complex interaction dynamics of ultra-intense lasers with solid matter  

SciTech Connect (OSTI)

We demonstrate the potential of X-ray free-electron lasers (XFEL) to advance the understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. In this paper, we focus on XFEL plasma probing for high power laser matter interactions based on quantitative calculations using synthesized data and evaluate the feasibility of various imaging and scattering techniques with special focus on the small angle X-ray scattering technique.

Kluge, T., E-mail: t.kluge@hzdr.de; Huang, L. G.; Metzkes, J.; Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Gutt, C. [Universität Siegen, D-57068 Siegen (Germany)] [Universität Siegen, D-57068 Siegen (Germany); Schramm, U.; Cowan, T. E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany) [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Technische Universität Dresden, D-01062 Dresden (Germany)

2014-03-15T23:59:59.000Z

127

LCLS CDR Chapter 4 - FEL Physics  

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

4 4 FEL Physics TECHNICAL SYNOPSIS This chapter presents a review of the historical and technological developments of the Free Electron Laser that led to proposals to operate an FEL in the large gain regime, starting from the spontaneous radiation noise, without using an optical cavity. In this mode, called "Self- Amplified-Spontaneous-Emission" (SASE), lasing is produced in a single pass of an electron beam with high phase-space density through a long undulator, eliminating the need for optical cavities, which are difficult to build in the soft x-ray or x-ray spectral region. A discussion of the spontaneous radiation produced in an undulator introduces the concepts and formulae for the radiation intensity, the number of photons produced per electron,

128

The FEL development at the Advanced Photon Source.  

SciTech Connect (OSTI)

Construction of a single-pass free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) mode of operation is nearing completion at the Advanced Photon Source (APS) with initial experiments imminent. The APS SASE FEL is a proof-of-principle fourth-generation light source. As of January 1999 the undulator hall, end-station building, necessary transfer lines, electron and optical diagnostics, injectors, and initial undulatory have been constructed and, with the exception of the undulatory, installed. All preliminary code development and simulations have also been completed. The undulator hall is now ready to accept first beam for characterization of the output radiation. It is the project goal to push towards fill FEL saturation, initially in the visible, but ultimately to W and VUV, wavelengths.

Arnold, N. D.; Benson, C.; Berg, S.; Berg, W.; Biedron, S. G.; Chae, Y. C.; Crosbie, E. A.; Decker, G.; Dejus, R. J.; Den Hartog, P.; Deriy, B.; Dortwegt, R.; Edrmann, M.; Freund, H. P.; Friedsam, H.; Galavda, J. N.; Gluskin, E.; Goeppner, G. A.; Grelick, A.; Huang, Z.; Jones, J.; Kang, Y.; Kim, K.-J.; Kim, S.; Kinoshita, K.; Lewellen, J. W.; Lill, R.; Lumpkin, A. H.; Makarov, O.; Markovich, G. M.; Milton, S. V.; Moog, E. R.; Nassiri, A.; Ogurtsov, V.; Pasky, S.; Power, J.; Tieman, B.; Trakhtenberg, E.; Travish, G.; Vasserman, I.; Walters, D. R.; Wang, J.; Xu, S.; Yang, B.

1999-03-15T23:59:59.000Z

129

Photon Source Capabilities of the Jefferson Lab FEL  

SciTech Connect (OSTI)

Jefferson Lab operates a superconducting energy recovered linac which is operated with CW RF and which powers oscillator-based IR and UV Free Electron Lasers (FELs) with diffraction limited sub-picosecond pulses with >10{sup 13} photons per pulse (1.0%BW) at pulse repetition frequencies up to 75 MHz. Useful harmonics extend into the vacuum ultraviolet (VUV). Based on FEL model calculations validated using this facility, we have designed both an oscillator-based VUV-FEL that would produce 6 ? 10{sup12} coherent (0.5% BW) 100 eV photons per pulse at multi-MHz repetition rates in the fundamental, and a dual FEL configuration that would allow simultaneous lasing lasing at THz and UV wavelengths. The VUV-FEL would utilize a novel high gain, low Q cavity, while the THz source would be an FEL oscillator with a short wiggler providing diffraction limited pulses with pulse energy exceeding 50 microJoules. The THz source would use the exhaust beam from a UVFEL. Such multiphoton capabilities would provide unique opportunities for out of equilibrium dynamical studies at time-scales down to 50 fs. The fully coherent nature of all these sources results in peak and average brightness values that are many orders of magnitude higher than storage rings. * We acknowledge support from the Commonwealth of Virginia. Jefferson Lab is supported by the U.S. DOE under Contract No. DE-AC05-84-ER40150.

Benson, Stephen V.; Douglas, David R.; Evtushenko, Pavel; Hannon, Fay E.; Hernandez-Garcia, Carlos; Klopf, John M.; Legg, Robert A.; Neil, George R.; Shinn, Michelle D.; Tennant, Christopher D.; Zhang, Shukui; Williams, Gwyn P.

2013-03-01T23:59:59.000Z

130

Plasma Channel Diagnostic Based on Laser Centroid Oscillations  

E-Print Network [OSTI]

THz [4] to free electron laser (FEL) x-ray sources [5] and Thomson scattering gamma ray sources [6Plasma Channel Diagnostic Based on Laser Centroid Oscillations A. J. Gonsalves, K. Nakamura, C. Lin for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser

Geddes, Cameron Guy Robinson

131

1.1 Simulations of a Free-Electron Laser Oscillator at Jefferson Lab Lasing in the Vacuum Ultraviolet  

SciTech Connect (OSTI)

The UVFEL at Jefferson Lab has provided a 10 eV photon beam for users by outcoupling the coherent third harmonic of the UVFEL operated at 372 nm. This can provide up to tens of milliwatts of power in the VUV. Operation of the FEL at the fundamental might enhance this power by up to a factor of 1000. With minor upgrades to the accelerator now underway and a new undulator proposed by Calabazas Creek Research, Inc. we show that we can lase in the fundamental at 124 nm. The predicted output is higher by four orders of magnitude on an average power basis and six orders of magnitude on a peak fluence basis than the Advanced Light Source at Lawrence Berkeley National Laboratory.

Shinn, Michelle D. [JLAB; Benson, Stephen V. [JLAB

2013-04-01T23:59:59.000Z

132

FEL potential of eRHIC  

SciTech Connect (OSTI)

Brookhaven National Laboratory plans to build a 5-to-30 GeV energy-recovery linac (ERL) for its future electron-ion collider, eRHIC. In past few months, the Laboratory turned its attention to the potential of this unique machine for free electron lasers (FELS), which we initially assessed earlier. In this paper, we present our current vision of a possible FEL farm, and of narrow-band FEL-oscillators driven by this accelerator. eRHIC, the proposed electron-ion collider at BNL, takes advantage of the existing Relativistic Heavy Ion Collider (RHIC) complex. Plans call for adding a six-pass super-conducting (SRF) ERL to this complex to collide polarized- and unpolarized- electron beams with heavy ions (with energies up to 130 GeV per nucleon) and with polarized protons (with energies up to 325 GeV). RHIC, with a circumference of 3.834 km, has three-fold symmetry and six straight sections each {approx} 250 m long. Two of these straight sections will accommodate 703-MHz SRF linacs. The maximum energy of the electron beam in eRHIC will be reached in stages, from 5 GeV to 30 GeV, by increasing the lengths of its SRF linacs. We plan to install at the start the six-pass magnetic system with small gap magnets. The structure of the eRHIC's electron beam will be identical with that of its hadron beam, viz., 166 bunches will be filled, reserving about a one-microsecond gap for the abort kicker. With modest modifications, we can assure that eRHIC's ERL will become an excellent driver for continuous wave (CW) FELs (see Fig.1). The eRHIC's beam structure will support the operation of several such FELs in parasitic mode.

Litvinenko, V.N.; Ben-Zvi, I.; Hao, Y.; Kao, C-C.; Kayran, D.; Murphy, J.B.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

2010-08-23T23:59:59.000Z

133

A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the  

E-Print Network [OSTI]

for radiation sources ­ ranging from coherent THz to free electron laser (FEL) x-ray sources and ThomsonAbstract A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid

Geddes, Cameron Guy Robinson

134

Multiphoton above-threshold ionization in superintense free-electron x-ray laser fields: Beyond the dipole approximation  

E-Print Network [OSTI]

(k,k?,t)Yl?m?(? ?,??)d#12;d#12;? (17) and Blm,l?m? (k,k?,t) = kk? ? ? Y ?lm(?,?)B(k,k?,t)Yl?m?(? ?,??)d#12;d#12;?, (18) respectively. For the laser pulse given by Eq. (2), Dlm,l?m?(k,k?,t) and Blm,l?m? (k,k?,t) are calculated using Eqs. (B1) and (B2) in Appendix B...†(k?,k,t) = D(k,k?,t) and B†(k?,k,t) = B(k,k?,t). Thus the P-space Hamiltonian given by Eq. (7), H (k,k?,t), is Hermitian. APPENDIX B: P-SPACE PARTIAL-WAVE LASER-ELECTRON INTERACTIONS Substituting Eqs. (A1) and (A2) into Eqs. (17) and (18), respectively, we...

Zhou, Zhongyuan; Chu, Shih-I

2013-02-13T23:59:59.000Z

135

Optical Fibre Dosimeter for SASE FEL Undulators  

E-Print Network [OSTI]

Single pass Free Electron Lasers (FELs) based on self-amplified spontaneous emission (SASE) are developed for high brightness and short wavelength applications. They use permanent magnet undulators which are radiation sensitive devices. During accelerator commissioning beam losses can appear anywhere along the undulator line. To avoid damage of the permanent magnets due to radiation, an optical fibre dosimeter system can be used. The increase of absorption caused by ionizing radiation is measured in radiation sensitive optical fibers. The dose system enables relatively fast particle loss tuning during accelerator operation and allows the monitoring of the accumulated dose. Dose measurements in narrow gaps which are inaccessible for any other (online) dosimeter type become possible. The electromagnetic insensitivity of optical fibre sensor is an advantage of applications in strong magnetic undulator fields. At each location the light absorption is measured by using an optical power-meter. The dynamic range is ...

Körfer, M

2003-01-01T23:59:59.000Z

136

HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS.  

SciTech Connect (OSTI)

Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department.

BEN-ZVI, ILAN, DAYRAN, D.; LITVINENKO, V.

2005-08-21T23:59:59.000Z

137

Availability Performance and Considerations for LCLS X-Ray FEL at SLAC  

SciTech Connect (OSTI)

The Linac Coherent Light Source (LCLS) is an X-ray Free Electron Laser (FEL) facility located at the SLAC National Accelerator Laboratory. LCLS has been in operation since spring 2009, and it has completed its 3rd user run. LCLS is the first in its class of X-ray FEL user facilities, and presents different availability challenges compared to storage ring light sources. This paper presents recent availability performance of the FEL as well as factors to consider when defining the operational availability figure of merit for user runs. During LCLS [1] user runs, an availability of 95% has been set as a goal. In run III, LCLS photon and electron beam systems achieved availabilities of 94.8% and 96.7%, respectively. The total availability goal can be distributed among subsystems to track performance and identify areas that need attention in order to maintain and improve hardware reliability and operational availability. Careful beam time accounting is needed to understand the distribution of down time. The LCLS complex includes multiple experimental hutches for X-ray science, and each user program has different requirements of a set of parameters that the FEL can be configured to deliver. Since each user may have different criteria for what is considered 'acceptable beam', the quality of the beam must be considered to determine the X-ray beam availability.

Allen, W.B.; Brachmann, A.; Colocho, W.; Stanek, M.; Warren, J.; /SLAC; ,

2011-08-16T23:59:59.000Z

138

Improved performance of the Boeing/LANL FEL experiment: Extraction efficiency and cavity-length detuning effects  

Science Journals Connector (OSTI)

We observed significant improvement in the performance of the Boeing/LANL free-electron laser (FEL) experiment in the last year. Some of the more graphic demonstrations of this improved performance are presented in the time-resolved optical spectral measurements (streak/spectrometer) and the electron-beam spectral measurements. We have observed an extraction efficiency of about 14% for the uniform wiggler and nearly 1% for the tapered-wiggler experiment. We also present experimental evidence consistent with a sideband instability and its suppression by cavity-length detuning.

A.H. Lumpkin; R.L. Tokar; D.H. Dowell; A.R. Lowrey; A.D. Yeremian; R.E. Justice

1990-01-01T23:59:59.000Z

139

HARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE  

E-Print Network [OSTI]

-electron laser (FEL) beamlines which use the har- monic cascade approach to produce coherent XUV & soft X-ray for an integrated system of ultrafast x-ray techniques and lasers, using laser-seeded harmonic cascade FEL's, rfHARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE J. Corlett, W. Fawley

Wurtele, Jonathan

140

Lasers without Mirrors, Designed by Supercomputer - NERSC SCience News  

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

Lasers without Lasers without Mirrors, Designed by Supercomputer Lasers without Mirrors, Designed by Supercomputer October 14, 2009 | Tags: Lasers, Life Sciences, Materials Science Contact: Ji Qiang | Lawrence Berkeley National Laboratory | JQiang@lbl.gov John Corlett | Lawrence Berkeley National Laboratory, Center for Beam Physics | JNCorlett@lbl.gov Sometimes it takes a big machine to understand the tiniest details. That's the case with free electron lasers (FELs). The powerful X-rays they generate can probe matter directly at the level of atomic interactions and chemical-bond formation, letting scientists observe such phenomena as chemical reactions in trace elements, electric charges in photosynthesis and the structure of microscopic machines. FELs have the potential to

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141

Time dependence of FEL-induced surface photovoltage on semiconductor interfaces measured with synchroton radiation photoemission spectroscopy  

SciTech Connect (OSTI)

During the last year, the first surface science experiments simultaneously using a Free Electron Laser (FEL) and Synchrotron Radiation (SR) have been performed on SuperACO at LURE (Orsay, France). These {open_quotes}two color{close_quotes} experiments studied the surface photovoltage (SPV) induced on semiconductor surfaces and interfaces by the SuperACO FEL, a storage ring FEL delivering 350 nm photons which am naturally synchronized with the SR; the SPV was measured by synchrotron radiation core-level photoemission spectroscopy on the high-resolution SU3 undulator beamline. We will describe the experimental setup, which allowed us to convey the FEL light onto the samples sitting in the SU3 experimental station by means of a series of mirrors, and show the results we obtained for prototypical systems such as Ag/GaAs(110) and Si(111) 2 x 1. The dependence of the SPV was studied in function of various parameters, changing sample doping and photon flux; but our efforts were mainly devoted to studying its dependence on the time delay between the FEL pump and the SR probe. On SuperACO, such delay can be varied between 1 and 120 ns, the limits being given by the time duration of a SR pulse and by the interval between two consecutive positron bunches, respectively. The results show a clear temporal dependence of the amount of SPV on cleaved Si surfaces, where as the Ag/GaAs(110) does not show any difference on the ns time scale. We will discuss these results in terms of the role of surface recombination in the dynamics of the photoinduced electron-hole pairs. These studies follow the evolution of the density of electrostatic charge at surfaces and interfaces on a nanosecond time scale, and might pave the way for a new series of experiments: for example, one might explore what are the physical mechanisms limiting the time response of Schottky diodes.

Marsi, M. [Ecole Polytechnique Federale de Lausanne (Switzerland); Delboulbe, A.; Garzella, D. [Universite de Paris-Sud, Orsay (France)] [and others

1995-12-31T23:59:59.000Z

142

Dielectric Wakefield Accelerator to drive the future FEL Light Source.  

SciTech Connect (OSTI)

X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall layout, the transform ratio enhancement scheme used to increase the drive to main beam efficiency, main wakefield linac design, cooling of the structure, etc.

Jing, C.; Power, J.; Zholents, A. (Accelerator Systems Division (APS)); ( HEP); (LLC)

2011-04-20T23:59:59.000Z

143

Multiphoton Double Ionization of Ar in Intense Extreme Ultraviolet Laser Fields Studied by Shot-by-Shot Photoelectron Spectroscopy  

SciTech Connect (OSTI)

Photoelectron spectroscopy has been performed to study the multiphoton double ionization of Ar in an intense extreme ultraviolet laser field (h{nu}{approx}21 eV, {approx}5 TW/cm{sup 2}), by using a free electron laser (FEL). Three distinct peaks identified in the observed photoelectron spectra clearly show that the double ionization proceeds sequentially via the formation of Ar{sup +}: Ar+h{nu}{yields}Ar{sup +}+e{sup -} and Ar{sup +}+2h{nu}{yields}Ar{sup 2+}+e{sup -}. Shot-by-shot recording of the photoelectron spectra allows simultaneous monitoring of FEL spectrum and the multiphoton process for each FEL pulse, revealing that the two-photon ionization from Ar{sup +} is significantly enhanced by intermediate resonances in Ar{sup +}.

Hikosaka, Y. [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585 (Japan); RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Fushitani, M.; Hishikawa, A. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585 (Japan); RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602 (Japan); Matsuda, A. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602 (Japan); Tseng, C.-M. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Shigemasa, E. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585 (Japan); RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Nagasono, M.; Tono, K.; Yabashi, M.; Ishikawa, T. [RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Togashi, T.; Ohashi, H.; Kimura, H. [RIKEN, XFEL Project Head Office, Sayo, Hyogo 679-5148 (Japan); Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); Senba, Y. [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan)

2010-09-24T23:59:59.000Z

144

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC  

SciTech Connect (OSTI)

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

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

2009-05-04T23:59:59.000Z

145

Hard x-ray or gamma ray laser by a dense electron beam  

E-Print Network [OSTI]

A coherent x-ray or gamma ray can be created from a dense electron beam propagating through an intense laser undulator. It is analyzed by using the Landau damping theory which suits better than the conventional linear analysis for the free electron laser, as the electron beam energy spread is high. The analysis suggests that the currently available physical parameters would enable the generation of the coherent gamma ray of up to 100 keV. The electron quantum diffraction suppresses the FEL action, by which the maximum radiation energy to be generated is limited.

S. Son; S. J. Moon

2012-02-12T23:59:59.000Z

146

State-of-the-art Thin Film X-ray Optics for Conventional Synchrotrons and FEL Sources  

SciTech Connect (OSTI)

Selected aspects of simulation, preparation and characterization of total reflection and multilayer X-ray optics will be discussed. The best multilayer is found by calculating the optical properties of the coating. Sophisticated improvements in deposition technology allow the precise realisation of the specified parameters when manufacturing the X-ray optics. The quality of the shape of the substrate for the optics is measured with the aid of profilometry. X-ray reflectometry measures both film thickness as well as their lateral gradient. Last but not least we will be showing results of the development of carbon coatings as total reflection mirrors for FEL (free electron laser) sources. Over the past years we have developed optimized optics for the XUV range up to 200 eV. First FEL irradiation tests have shown that carbon coatings offer high reflectivity >95%, high radiation stability, good uniformity in thickness and roughness. An optimized coating of two stripes for different beam energies was produced especially for a tomography beamline, where a Ru/C multilayer was chosen for energies between 10 and 22 keV and a W/Si multilayer for energies between 22 and 45 keV.

Wiesmann, Joerg; Mchaelsen, Carsten; Hertlein, Frank [Incoatec GmbH, Max-Planck-Strasse 2, 21502 Geesthacht (Germany); Stoermer, Michael [GKSS Research Center, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Seifert, Andreas [Carl Zeiss Laser Optics GmbH, Carl-Zeiss-Strasse 22, 73447 Oberkochen (Germany)

2007-01-19T23:59:59.000Z

147

A proposed visible FEL Facility at Boeing  

SciTech Connect (OSTI)

A 1-kW average power, visible wavelength FEL is described, based on a 120-MeV, 0.1. A macropulse average current linac operating at a duty factor of 0. 6% and having average beam power of 70 kW. The accelerator will employ a demonstrated photoinjector, 18-MeV, 433-MHz linac as an injector, followed by a 1300-MHz longitudinal phase space {open_quotes} linearizer,{close_quotes} a magnetic buncher chicane, and seven 1300-MHz, pulsed traveling wave linac sections. The magnets used to transport the beam from the linac to the FEL centerline, the 5-m THUNDER wiggler, and the optical resonator will be reclaimed from previous FEL demonstration experiments. We expect to attain pulse lengths of 7 ps for 3.5 nC, with minimal distortion of the pulse profile and normalized rms emittance of 7.5 {+-} 2.5 {pi} mm-mr. FELEX projects a laser conversion efficiency of 4.3 %, yielding average output of 3 kW.

Dowell, D.H.; Adamski, J.L.; Hayward, T.D. [Boeing Defense & Space Group, Seattle, WA (United States)] [and others

1995-12-31T23:59:59.000Z

148

Echo-Enabled Harmonic Generation for Seeded FELs  

SciTech Connect (OSTI)

In the x-ray wavelengths, the two leading FEL concepts are the self-amplified spontaneous emission (SASE) configuration and the high-gain harmonic generation (HGHG) scheme. While the radiation from a SASE FEL is coherent transversely, it typically has rather limited temporal coherence. Alternatively, the HGHG scheme allows generation of fully coherent radiation by up-converting the frequency of a high-power seed laser. However, due to the relatively low up-frequency conversion efficiency, multiple stages of HGHG FEL are needed in order to generate x-rays from a UV laser. The up-frequency conversion efficiency can be greatly improved with the recently proposed echo-enabled harmonic generation (EEHG) technique. In this work we will present the concept of EEHG, and address some practically important issues that affect the performance of the seeding. We show how the EEHG can be incorporated in the FEL scheme and what is the expected performance of the EEHG seeded FEL. We will then briefly describe the first proof-of-principle EEHG experiment carried out at the Next Linear Collider Test Accelerator (NLCTA) at SLAC. We will also discuss latest advances in the echo-scheme approach, and refer to subsequent modifications of the original concept.

Stupakov, G.; /SLAC

2011-05-19T23:59:59.000Z

149

Casimir self-energy of a free electron  

E-Print Network [OSTI]

We derive the electromagnetic self-energy and the radiative correction to the gyromagnetic ratio of a free electron using a Casimir energy approach. This method provides an attractive and straightforward physical basis for the renormalization process.

Allan Rosencwaig

2006-06-23T23:59:59.000Z

150

Tunable, Nanoscale Free-Electron Source of Photons and Plasmons  

Science Journals Connector (OSTI)

The passage of a free-electron beam through a nano-hole in a periodically layered metal/dielectric structure creates a new type of tuneable, nanoscale radiation source, analogous to...

Adamo, G; MacDonald, K F; Zheludev, N I; Fu, Y H; Wang, C -m; Tsai, D P; García de Abajo, F J

151

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

152

Part 2: Coherent emission from Free Electron Lasers  

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

0 0 Electron beam-based sources of ultrashort x-ray pulses Alexander Zholents Advanced Photon Source, Argonne National Laborator , Argonne, IL 60439 (September 7, 2010) To be published by World Scientific Publishing Co. in Reviews of Accelerator Science and Technology. y 2 Electron beam-based sources of ultrashort x-ray pulses * Alexander Zholents Argonne National Laboratory, Advanced Photon Source, 9700 South Cass Ave., Argonne, IL 60439 Abstract A review of various methods for generation of ultrashort x-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons is considered. Introduction The importance of the time-resolved studies of matter at picosecond (ps),

153

Free-Electron Lasers: Present Status and Future Prospects  

Science Journals Connector (OSTI)

...issue is the plasma response to...operation in the high-frequency range (up...Nonlinear plasma studies Heating...Shanghai (diode, RF linac) IAE...approach is to use radio-frequency (RF) linacs...Repetition 3 MHz 10 Hz 3-10...

Kwang-Je Kim; Andrew Sessler

1990-10-05T23:59:59.000Z

154

Free-Electron Lasers: Present Status and Future Prospects  

Science Journals Connector (OSTI)

...1983-1984) Stanford TRW/Stanford (1977)r (1983) 106-1977) Boeing/STI(1987) Novosibirsk 10o (X.2400 A) UCSB TRW/ 104...Duke (RF linac) Duke (storage ring) Los Alamos (RF linac) Boeing (RF linac) University of California, Santa Barbara (electrostatic...

Kwang-Je Kim; Andrew Sessler

1990-10-05T23:59:59.000Z

155

A PLASMA CHANNEL BEAM CONDITIONER FOR A FREE ELECTRON LASER  

E-Print Network [OSTI]

plasma focusing and plasma accel- eration, but further beam compression is not required. The resulting

Wurtele, Jonathan

156

TEMPERATURE MEASUREMENT SYSTEM OF NOVOSIBIRSK FREE ELECTRON LASER  

E-Print Network [OSTI]

of the accelerator hall. 3. Vacuum "sensors". These sensors are actually control devices for vacuum pumps allows measuring the temperature of the vacuum chamber, cooling water, and windings of the magnetic sensors, it is also used to measure, for instance, vacuum parameters and some parameters of the cooling

Kozak, Victor R.

157

The GALAXIE all-optical FEL project  

SciTech Connect (OSTI)

We describe a comprehensive project, funded under the DARPA AXiS program, to develop an all-optical table-top X-ray FEL based on dielectric acceleration and electromagnetic undulators, yielding a compact source of coherent X-rays for medical and related applications. The compactness of this source demands that high field (>GV/m) acceleration and undulation-inducing fields be employed, thus giving rise to the project's acronym: GV/m AcceLerator And X-ray Integrated Experiment (GALAXIE). There are numerous physics and technical hurdles to surmount in this ambitious scenario, and the integrated solutions include: a biharmonic photonic TW structure, 200 micron wavelength electromagnetic undulators, 5 {mu}m laser development, ultra-high brightness magnetized/asymmetric emittance electron beam generation, and SASE FEL operation. We describe the overall design philosophy of the project, the innovative approaches to addressing the challenges presented by the design, and the significant progress towards realization of these approaches in the nine months since project initialization.

Rosenzweig, J. B.; Arab, E.; Andonian, G.; Cahill, A.; Fitzmorris, K.; Fukusawa, A.; Hoang, P.; Jovanovic, I.; Marcus, G.; Marinelli, A.; Murokh, A.; Musumeci, P.; Naranjo, B.; O'Shea, B.; O'Shea, F.; Ovodenko, A.; Pogorelsky, I.; Putterman, S.; Roberts, K.; Shumail, M. [Dept. of Physics and Astronomy, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90034 (United States); Dept. of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Dept. of Physics and Astronomy, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90034 (United States); and others

2012-12-21T23:59:59.000Z

158

Free-electron induced chemistry Theoretical Chemistry Section, BARC, Mumbai  

E-Print Network [OSTI]

initiated after the resonant capture low energy free-electrons into considerable interest for various fields reactions is the electronic potential energy surface of the electron compound. In the first half of the talk, I shall present the quantum chemical methodologies for computing the potential energy surfaces

Shyamasundar, R.K.

159

Interactive Video Cubism Sidney Fels  

E-Print Network [OSTI]

Interactive Video Cubism Sidney Fels Dept. of Electrical and Computer Engineering University@mic.atr.co.jp ABSTRACT This paper presents an interactive video visualization system. In this visualization video data is considered to be a block of three dimensional data where frames of video data comprise the third dimension

Fels, Sidney S.

160

Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes  

E-Print Network [OSTI]

Design considerations for a laser-plasma linear collider,"E.Esarey, and W.P.Leemans, "Free-electron laser driven bythe LBNL laser-plasma accelerator," in Proc. Adv. Acc. Con.

Geddes, C.G.R.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Stability of metallic thin film with free electron model  

SciTech Connect (OSTI)

The stability of metallic thin lms is studied with free electron model, which is popularly known as model of \\particle in a box". A detailed theoretical framework is presented, along with discussion on typical metals, such as Pb, Al, Ag, Na, and Be. This simple model is found to be able to describe well the oscillation pattern of stability for continuous metallic lms. In particular, it yields even-odd oscillations in the stability of Pb(111) lm, consistent with both experimental observation and ab initio results. However, the free electron model is too crude to predict at what thickness the lm is stable. The lm stability is further examined with a model of \\particle in a corrugated box", where a lattice potential is added along the vertical direction of the lm. The e ect of lattice potential is found not substantial.

Wu, Biao [ORNL; Zhang, Zhenyu [ORNL

2008-01-01T23:59:59.000Z

162

BNL | Nd:YAG Laser  

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

gun.The Nd:YAg laser is operated in a power amplifier mode, giving it a unique Pulse Train Mode. For certain experiments, like the FEL Oscillator Experiment, the YAG laser can...

163

Free electron lifetime achievements in Liquid Argon Imaging TPC  

E-Print Network [OSTI]

A key feature for the success of the Liquid Argon TPC technology is the industrial purification against electro-negative impurities, especially Oxygen and Nitrogen remnants, which have to be initially and continuously kept at an exceptional purity. New purification techniques have been applied to a 120 litres LAr-TPC test facility in the INFN-LNL laboratory. Through-going muon tracks have been used to monitor the LAr purity. The short path length used (30 cm) is compensated by the high accuracy in the observation of the specific ionization of cosmic rays muons at sea level. A free electron lifetime of (21.4+7.3-4.3) ms, namely > 15.8 ms at 90 % C.L. has been observed under stable conditions over several weeks, corresponding to about 15 ppt (part per trillion) of Oxygen equivalent. At 500 V/cm, where the electron speed is approximately of 1.5 mm/us, the free electron lifetime >15 ms corresponds to an attenuation <15 % for a drift path of 5 m, opening the way to reliable operation of LAr TPC for exceptionall...

Baibussinov, B; Calligarich, E; Centro, S; Cieslik, K; Farnese, C; Fava, A; Gibin, D; Guglielmi, A; Meng, G; Pietropaolo, F; Rubbia, C; Varanini, F; Ventura, S

2010-01-01T23:59:59.000Z

164

Theory of the ion-channel laser  

SciTech Connect (OSTI)

A relativistic electron beam propagating through a plasma in the ion-focussed regime exhibits an electromagnetic instability with peak growth rate near a resonant frequency {omega}{approximately}2 {gamma}{sup 2} {omega}{beta}, where {gamma} is the Lorentz factor and {omega}{beta} is the betatron frequency. The physical basis for this instability is that an ensemble of relativistic simple harmonic oscillators, weakly driven by an electromagnetic wave, will lose energy to the wave through axial bunching. This bunching'' corresponds to the development of an rf component in the beam current, and a coherent centroid oscillation. The subject of this thesis is the theory of a laser capitalizing on this electromagnetic instability. A historical perspective is offered. The basic features of relativistic electron beam propagation in the ion-focussed regime are reviewed. The ion-channel laser (ICL) instability is explored theoretically through an eikonal formalism, analgous to the KMR'' formalism for the free-electron laser (FEL). The dispersion relation is derived, and the dependence of growth rate on three key parameters is explored. Finite temperature effects are assessed. From this work it is found that the typical gain length for amplification is longer than the Rayleigh length and we go on to consider three mechanisms which will tend to guide waveguide. First, we consider the effect of the ion channel as a dielectric waveguide. We consider next the use of a conducting waveguide, appropriate for a microwave amplifier. Finally, we examine a form of optical guiding'' analgous to that found in the FEL. The eikonal formalism is used to model numerically the instability through and beyond saturation. Results are compared with the numerical simulation of the full equations of motion, and with the analytic scalings. The analytical requirement on detuning spread is confirmed.

Whittum, D.H.

1990-09-01T23:59:59.000Z

165

Small signal theory of an E×B drifting electron laser  

Science Journals Connector (OSTI)

The concept of the drifting electron laser (DEL), powered by a relativistic beam of E×B drifting electrons in crossed electric and magnetic fields, is introduced. The wiggling motion is generated by adding a periodic modulation in either E or B. In contrast to free electron lasers (FELs) converting kinetic energy and momentum into radiation, the emitted radiation energy and momentum in a DEL come respectively from the change in the electrostatic energy eE0 ?X and vector potential eB0 ?X of the electron, ?X being the quantum recoil of the guiding center (GC) location perpendicular to the drift direction. The difference between stimulated emission and absorption responsible for the gain is provided by the transverse gradient of the wiggler strength, and the gain curve is symmetric relative to the frequency detuning ??. Since the drift velocity and the resonance condition are energy independent, one avoids the low efficiency limits placed on FELs from energy detuning and thermal spreads. Beam energy spreads turn into spreads in the GC location, reducing the gain sensitivity to the beam quality. Saturation in a DEL occurs via the off-axis walk of the emitting electrons. Overlap between the beam and the radiation is maintained by a small tilt of the resonator axis relative to the E×B drift direction.

Spilios Riyopoulos

1997-02-01T23:59:59.000Z

166

The evolution of the radiation field in an FEL undulator is governed...  

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

3 A Wide Bandwidth Free-Electron Laser with Mode Locking Using Current Modulation * E. Kur 1 , D. J. Dunning 2,3 , B.W. J. McNeil 2 , J. Wurtele 1,4 and A. A. Zholents 5 1...

167

The trapped-particle instability in the Boeing 1kW FEL oscillator  

SciTech Connect (OSTI)

The new design for the Boeing High Average Power Free Electron Laser will operate at 1KW average power (0.63 {mu}m) with a peak current of 132A. Simulations are used to investigate the trapped-particle instability and diffraction effects. Incorporating large desynchronism may prove to be a useful method of controlling the trapped-particle instability.

Ramos, L.; Blau, J.; Colson, W.B. [Naval Postgraduate School, Monterey, CA (United States)

1995-12-31T23:59:59.000Z

168

Femtosecond diffractive imaging with a soft-X-ray free-electron...  

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

Synchrotron Radiation Laboratory, Uppsala University, the Deutsches Elektronen-Synchroton (DESY), and Technische Universitt Berlin. The FLASH FEL began operations at DESY...

169

High Power Operation of the JLab IR FEL Driver Accelerator  

SciTech Connect (OSTI)

Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

2007-08-01T23:59:59.000Z

170

Light-Source Facilities  

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

Facility, P.R. China CANDLE, Armenia HSRC - Hiroshima Synchrotron Radiation Center, Japan iFEL - Institute of Free Electron Laser, Japan INDUS 1 INDUS 2, India IR FEL...

171

Laser power beaming applications and technology  

SciTech Connect (OSTI)

Beaming laser energy to spacecraft has important economic potential. It promises significant reduction in the cost of access to space, for commercial and government missions. While the potential payoff is attractive, existing technologies perform the same missions and the keys to market penetration for power beaming are a competitive cost and a schedule consistent with customers` plans. Rocketdyne is considering these questions in the context of a commercial enterprise -- thus, evaluation of the requirements must be done based on market assessments and recognition that significant private funding will be involved. It is in the context of the top level business considerations that the technology requirements are being assessed and the program being designed. These considerations result in the essential elements of the development program. Since the free electron laser is regarded as the ``long pole in the tent``, this paper summarizes Rocketdyne`s approach for a timely, cost-effective program to demonstrate an FEL capable of supporting an initial operating capability (IOC).

Burke, R.J.; Cover, R.A.; Curtin, M.S.; Dinius, R.W.; Lampel, M.C. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Division

1994-12-31T23:59:59.000Z

172

Latest developments on the Dutch 1MW free electron maser  

Science Journals Connector (OSTI)

The FOM Institute (Rijnhuizen Netherlands) as part of their fusion technology program has undertaken the development of a Free Electron Maser with the goal of producing 1MW long pulse to CW microwave output in the range 130 GHz–250GHz with wall plug efficiencies of 60%. This project has been carried out as a collaborative effort with Institute of Applied Physics Nizhny Novgorod Russia Kurchatov Institute Moscow Russia Lawrence Livermore Laboratory U.S.A and CPI U.S.A. The key design features of this FEM consists first of a conventional DC acceleration system at high voltage (2MV) which supplies only the unwanted beam interception current and a depressed collector system at 250kV which provides the main beam power. Low body current interception (usec) testing in an inverted mode with the depressed collector absent. Results to date have demonstrated 98.8% beam transmission (over 5 Meters) at currents as high as 8.4 Amps with 200GHz microwave output at 700kW. There has been good agreement between theory and experiment at the beam current levels tested so far. Details of the most recent experimental results will be presented in particular the output frequency characteristics with detailed comparisons to theory. The immediate future plans are to operate the system at the design value of 12 Amps with at least 1MW output. The system will then be reconfigured with a 3 stage depressed collector to demonstrate in the next year long pulse operation (100 msec) and high wall plug efficiency. Long term future plans call for upgrading the FEM to 2MW and extrapolations up to 5MW are shown to be theoretically possible.

M. Caplan; A. G. A. Verhoeven; W. Urbanus

1999-01-01T23:59:59.000Z

173

Latest developments on the Dutch 1MW free electron maser  

SciTech Connect (OSTI)

The FOM Institute (Rijnhuizen, Netherlands), as part of their fusion technology program, has undertaken the development of a Free Electron Maser with the goal of producing 1MW long pulse to CW microwave output in the range 130 GHz{endash}250GHz with wall plug efficiencies of 60{percent}. This project has been carried out as a collaborative effort with Institute of Applied Physics, Nizhny Novgorod Russia, Kurchatov Institute, Moscow Russia, Lawrence Livermore Laboratory, U.S.A and CPI, U.S.A. The key design features of this FEM consists first of a conventional DC acceleration system at high voltage (2MV) which supplies only the unwanted beam interception current and a depressed collector system at 250kV which provides the main beam power. Low body current interception ({lt}25mA) is ensured by using robust inline beam focussing, a low emittance electron gun with halo suppression and periodic magnet side array focussing in the wiggler. The second key feature is use of a low-loss step corrugated waveguide circuit for broad band CW power handling and beam/RF separation. Finally, the required interaction efficiency and mode control is provided by a two stage stepped wiggler. The FEM has been constructed and recently undergone initial short pulse ({lt}10 usec) testing in an inverted mode with the depressed collector absent. Results to date have demonstrated 98.8{percent} beam transmission (over 5 Meters) at currents as high as 8.4 Amps, with 200GHz microwave output at 700kW. There has been good agreement between theory and experiment at the beam current levels tested so far. Details of the most recent experimental results will be presented, in particular the output frequency characteristics with detailed comparisons to theory. The immediate future plans are to operate the system at the design value of 12 Amps with at least 1MW output. The system will then be reconfigured with a 3 stage depressed collector to demonstrate, in the next year, long pulse operation (100 msec) and high wall plug efficiency. Long term future plans call for upgrading the FEM to 2MW and extrapolations up to 5MW are shown to be theoretically possible. {copyright} {ital 1999 American Institute of Physics.}

Caplan, M. [Lawrence Livermore National Laboratory, 7000 East Ave, L-637 Livermore California, 94551 (United States); Verhoeven, A.G.; Urbanus, W. [FOM Instituut voor Plasma Fysica, Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein (The Netherlands)

1999-05-01T23:59:59.000Z

174

FERMI @ Elettra -- A Seeded Harmonic Cascade FEL for EUV and SoftX-rays  

SciTech Connect (OSTI)

We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FELs, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10nm, with pulse duration from 40 fs to {approx} 1 ps, peak power GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate >40 nm, and a two stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

Bocchetta, C.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D'Auria,G.; DeNinno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; Wilcox, R.; Zholents, A.; Graves, W.; Ilday, F.O.; Kaertner,F.; Wang, D.; Zwart, T.; Cornacchia, M.; Emma, P.; Huang, Z.; Wu, J.

2005-09-01T23:59:59.000Z

175

FERMI@Elettra: A Seeded Harmonic Cascade FEL for EUV and Soft X-Rays  

SciTech Connect (OSTI)

We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10 nm, with pulse duration from 40 fs to {approx} 1ps, peak power {approx}GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate > 40 nm, and a two-stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

Bocchetta, C.J.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D'Auria, G.; De Ninno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; /Sincrotrone Trieste; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; /LBL, Berkeley /MIT /SLAC

2005-12-14T23:59:59.000Z

176

EDITED--LS-332-DWA_FEL_August16  

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

32 32 August 2012 A Compact Soft X-ray Free-Electron Laser Facility based on a Dielectric Wakefield Accelerator C. Jing, P. Schoessow, A. Kanareykin, Euclid Techlabs LLC, Solon, OH 44139 J. G. Power, HEP Division, Argonne National Laboratory, Argonne, IL 60439 R. Lindberg, A. Zholents, APS, Argonne National Laboratory, Argonne, IL 60439 P. Piot, Northern Illinois University, Department of Physics, DeKalb, IL 60115 To be published as a Light Source Technical Notes The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory ("Argonne"). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.

177

Laser-Plasma Acceleration of Electrons and Plasma Diagnostics at High Laser Fields  

E-Print Network [OSTI]

would open the prospect of building x-ray free-electron lasers and linear colliders hundreds of timesLaser-Plasma Acceleration of Electrons and Plasma Diagnostics at High Laser Fields Mike Downer: Laser-plasma acceleration is now entering an era of petawatt lasers, tenuous plasmas and multi

Shvets, Gennady

178

Modeling of free electronic state density in hydrogenic plasmas based on nearest neighbor approximation  

SciTech Connect (OSTI)

Most conventional atomic models in a plasma do not treat the effect of the plasma on the free-electron state density. Using a nearest neighbor approximation, the state densities in hydrogenic plasmas for both bound and free electrons were evaluated and the effect of the plasma on the atomic model (especially for the state density of the free electron) was studied. The model evaluates the electron-state densities using the potential distribution formed by the superposition of the Coulomb potentials of two ions. The potential from one ion perturbs the electronic state density on the other. Using this new model, one can evaluate the free-state density without making any ad-hoc assumptions. The resulting contours of the average ionization degree, given as a function of the plasma temperature and density, are shifted slightly to lower temperatures because of the effect of the increasing free-state density.

Nishikawa, Takeshi, E-mail: nishikawa.takeshi@okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan)

2014-07-15T23:59:59.000Z

179

Laser Facilities, Laser-Plasmas & Diagnostics Plasmas Division  

E-Print Network [OSTI]

of freely moving ions and free electrons. Figure 1: The large NOVA laser at Lawrence Livermore National Facility (NIF) is the world's largest and highest-energy laser (Figure 2). It houses 192 intense laser and of a single wavelength. There are a large number of Figure 2: NIF from above & the target chamber. Figure 4

Strathclyde, University of

180

High-brightness electron beam evolution following laser-based cleaning of a photocathode  

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

Laser-based techniques have been widely used for cleaning metal photocathodes to increase quantum efficiency (QE). However, the impact of laser cleaning on cathode uniformity and thereby on electron beam quality are less understood. We are evaluating whether this technique can be applied to revive photocathodes used for high-brightness electron sources in advanced x-ray free-electron laser (FEL) facilities, such as the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. The laser-based cleaning was applied to two separate areas of the current LCLS photocathode on July 4 and July 26, 2011, respectively. The QE was increased by 8–10 times upon the laser cleaning. Since the cleaning, routine operation has exhibited a slow evolution of the QE improvement and comparatively rapid improvement of transverse emittance, with a factor of 3 QE enhancement over five months, and a significant emittance improvement over the initial 2–3 weeks following the cleaning. Currently, the QE of the LCLS photocathode is holding constant at about 1.2×10?4 , with a normalized injector emittance of about 0.3???m for a 150-pC bunch charge. With the proper procedures, the laser-cleaning technique appears to be a viable tool to revive the LCLS photocathode. We present observations and analyses for the QE and emittance evolution in time following the laser-based cleaning of the LCLS photocathode, and comparison to the previous studies, the measured thermal emittance versus the QE and comparison to the theoretical model.

Zhou, F.; Brachmann, A.; Decker, F-J.; Emma, P.; Gilevich, S.; Iverson, R.; Stefan, P.; Turner, J.

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

TURKISH ACCELERATOR COMPLEX & STATUS OF TAC SASE FEL  

E-Print Network [OSTI]

Facility Study Group (Director: Dr. B. Akku) #12;International collaborations & contacts 8 ATLAS, CMS collaboration & project team Proposed facilities and study groups Committees & collaborations TAC-TARLA Facility TARLA Resonator System TAC SASE-FEL Group Members & Duties TAC SASE-FEL Tentative Parameters

182

SciTech Connect: "free electron lasers"  

Office of Scientific and Technical Information (OSTI)

Conference: How Electron Spectroscopy with Synchrotron Light Can Conference: How Electron Spectroscopy with Synchrotron Light Can Help Us Understand High-Tc Superconductivity and Other Complex States of Matter Citation Details In-Document Search Title: How Electron Spectroscopy with Synchrotron Light Can Help Us Understand High-Tc Superconductivity and Other Complex States of Matter Word Cloud More Like This Have feedback or suggestions for a way to improve these results? Let us know! Citation Formats MLA × Cite: MLA Format Close APA × Cite: APA Format Close Chicago × Cite: Chicago Format Close Bibtex × Cite: Bibtex Format Close Export Metadata EndNote Excel Save / Share this Record Save to My Library Send to Email × Send to Email Email address: Content: Close Send 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document

183

Design Concepts of a Beam Spreader for a Next Generation Free Electron Laser  

E-Print Network [OSTI]

7 0 0 V ) a n d b y the (ESS) magnet fill time assumed to beThe Electrostatic Septum (ESS) A n electrostatic separator Eelectrostatic field E across the ESS between the electrodes

Placidi, M.

2013-01-01T23:59:59.000Z

184

R&D for a Soft X-Ray Free Electron Laser Facility  

E-Print Network [OSTI]

x-ray magnetic linear dichroism spectromicroscop,y” Scienceultrafast magnetic phenomena and materials science [44].Magnet Science & Technology, National High Magnetic Field

Staples, John

2009-01-01T23:59:59.000Z

185

Accurate macromolecular structures using minimal measurements from X-ray free-electron lasers  

SciTech Connect (OSTI)

Diffraction patterns from thermolysin microcrystals and one dark run, collected in December 2011. This data was used for metrology calibration and general cctbx.xfel development.

Hattne, Hattne

2014-03-04T23:59:59.000Z

186

De novo protein crystal structure determination from X-ray free-electron laser data  

SciTech Connect (OSTI)

Serial femtosecond crystallography (SFX) data of microcrystals of a lysozyme gadolinium derivative. The data was used to demonstrate de-novo phasing by single anomalous dispersion.

Barends, Thomas, R.M.

2013-11-25T23:59:59.000Z

187

Accurate macromolecular structures using minimal measurements from X-ray free-electron lasers  

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

Diffraction patterns from thermolysin microcrystals and one dark run, collected in December 2011. This data was used for metrology calibration and general cctbx.xfel development.

Hattne, Hattne

188

De novo protein crystal structure determination from X-ray free-electron laser data  

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

Serial femtosecond crystallography (SFX) data of microcrystals of a lysozyme gadolinium derivative. The data was used to demonstrate de-novo phasing by single anomalous dispersion.

Barends, Thomas, R.M.

189

democrite-00023911,version1-18Mar2005 Analogy between free electron laser  

E-Print Network [OSTI]

is that the entrance angle with respect to the planes be smaller than the critical (Lindhard) angle c = 2U0/ . (3) Fig

Boyer, Edmond

190

The Jefferson lab FEL driver ERLs  

SciTech Connect (OSTI)

Jefferson Lab has - for over a decade - been operating high power IR and UV FELs using CW energy recovering linacs based on DC photocathode electron sources and CEBAF SRF technology. These machines have unique combinations of beam quality, power, and operational flexibility, and thus offer significant opportunity for experiments that use low and medium energy (several tens - few hundreds of MeV) electron beams. We will describe the systems and detail their present and near-term (potential) performance. Recent internal-target analysis and validation testing will be discussed, and schemes for single- and two-pass fixed target operation described. An introduction to subsequent discussions of beam quality and upgrade paths to polarized operation/higher energy will be given.

Douglas, David R. [JLAB; Tennant, Christopher D. [JLAB

2013-11-01T23:59:59.000Z

191

The Jefferson lab FEL driver ERLs  

SciTech Connect (OSTI)

Jefferson Lab has - for over a decade - been operating high power IR and UV FELs using CW energy recovering linacs based on DC photocathode electron sources and CEBAF SRF technology. These machines have unique combinations of beam quality, power, and operational flexibility, and thus offer significant opportunity for experiments that use low and medium energy (several tens - few hundreds of MeV) electron beams. We will describe the systems and detail their present and near-term (potential) performance. Recent internal-target analysis and validation testing will be discussed, and schemes for single- and two-pass fixed target operation described. An introduction to subsequent discussions of beam quality and upgrade paths to polarized operation/higher energy will be given.

Douglas, David R.; Tennant, Christopher D. [Jefferson Lab, Newport News, VA 23606 (United States)

2013-11-07T23:59:59.000Z

192

INEX simulations of the Boeing FEL system  

Science Journals Connector (OSTI)

The INEX (integrated numerical experiment) numerical model is applied to the 0.6 ?m FEL oscillator at the Boeing laboratory in Seattle, WA. This sytem consists of a 110 MeV L-band rf linac, a beam transport line from the accelerator to the entrance of the wiggler, the 5.0 m THUNDER variable-taper wiggler, and a near-concentric two-mirror optical oscillator. Many aspects of the model for the electron beam accelerator and transport line agree with experimental measurements. Predictions for lasing performance are compared with data obtained in May and June 1989, using a mild-tapered wiggler. We obtain good agreement with the achieved extraction efficiency, while ID pulse simulations reproduce the observed sideband instability.

R.L. Tokar; L.M. Young; A.H. Lumpkin; B.D. McVey; L.E. Thode; S.C. Bender; K.C.D. Chan; A.D. Yeremian; D.H. Dowell; A.R. Lowrey; D.C. Quimby

1990-01-01T23:59:59.000Z

193

Front End Loading (FEL) and Process Engineering Workflow  

E-Print Network [OSTI]

Project development for the oil refining industry is typically performed through a process called Front End Loading (FEL). In recent years, the Process and Industrial Division of Burns and McDonnell has performed several ...

Spangler, Ryan

2005-05-20T23:59:59.000Z

194

High-power, high-intensity laser propagation and interactions  

SciTech Connect (OSTI)

This paper presents overviews of a number of processes and applications associated with high-power, high-intensity lasers, and their interactions. These processes and applications include: free electron lasers, backward Raman amplification, atmospheric propagation of laser pulses, laser driven acceleration, atmospheric lasing, and remote detection of radioactivity. The interrelated physical mechanisms in the various processes are discussed.

Sprangle, Phillip [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Electrical and Computer Engineering and Physics, University of Maryland, College Park, Maryland 20740 (United States); Hafizi, Bahman [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2014-05-15T23:59:59.000Z

195

Experimental results from a DC photocathode electron gun for an IR FEL  

SciTech Connect (OSTI)

A 350 keV DC photocathode gun capable of delivering the high-brightness CW electron beam necessary for Jefferson Lab`s infrared free-electron laser is described. The gun is to be used with a superconducting radiofrequency linac operating at 1.497 GHz and is mode-locked to the 40th subharmonic of the fundamental using a Nd:YLF drive laser. The gun provides 20--25 ps bunches at up to 135 pC/bunch. Experimental measurements of transverse and longitudinal beam properties are presented. Transverse emittance is measured using a slit-wire scanner emittance meter, and energy spread is measured using the slit and a spectrometer magnet. Longitudinal emittance is measured using a combination of sampling aperture, kicker cavity, slit and spectrometer. Measurements for bunch charges of 135 pC are described and compared with simulations.

Kehne, D.; Engwall, D.; Legg, R.; Shinn, M.

1997-10-01T23:59:59.000Z

196

E-Print Network 3.0 - alamos advanced fel Sample Search Results  

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

(FEL) for the electric ships of the future. A ship has ten- to thirty seconds... of a potato. That's one of the things the NPS FEL group has been working on in the last fifteen...

197

LCLS CDR Chapter 5 - FEL Parameters and Performance  

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

5 5 FEL Parameters and Performance TECHNICAL SYNOPSIS The FEL parameter optimization and performance characterizations that are described in Chapter 5 are based on three-dimensional theory and computer models. The investigation led to a selection of the best parameters and to a study of the sensitivity to changes in values of accelerator components and beam characteristics and to unavoidable imperfections in the settings of the beam characteristics, magnetic and mechanical components and electron beam monitoring. The focusing of the electron beam plays an important role in the production of the FEL radiation. The LCLS undulator optics has been optimized in terms of its focusing lattice and strength. The electron optics consists of FODO cells; with cell lengths between 7.3 m and 7.5 m.

198

Microsoft Word - WEP93  

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

research and development effort for a 4th generation light source, we have designed a 4-meter long Free-Electron Laser (FEL) undulator. The undulator will be installed at the...

199

Lipidic phase membrane protein serial femtosecond crystallography  

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

crystallography Source: Nature Methods Year: 2012 Volume: 9 Pages: 263-265 ABSTRACT: X-ray free electron laser (X-FEL)-based serial femtosecond crystallography is an emerging...

200

Triangle Universities Nuclear Laboratory : 2011  

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

Proposal Submission| HIGS PAC| HIGS PAC Schedule| HIGS2| High Intensity Gamma-Ray Source (HIGS) is a Free-Electron Laser (FEL) based Compton backscattering gamma-ray source. The...

Note: This page contains sample records for the topic "free-electron laser fel" 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

Computer simulations of the Rocketdyne/Stanford FEL experiment  

SciTech Connect (OSTI)

The Rocketdyne-Stanford FEL experiment is analyzed using Rocketdyne's three-dimensional steady-state wave-optics FEL code FELOPT and the one- and two-dimensional time-dependent codes RAFEL and TWOFEL. The results of simulations based on experimental parameters are presented. The oscillator is a stable near-concentric resonator with an optical waist radius of about 0.07 cm in the center of the 2-m wiggler; the peak current is 25 A, the energy spread is less than 0.5 percent, and the micropulse length is 3 ps. 11 references.

Cover, R.A.; Stone, J.P.; Bhowmik, A.

1987-06-01T23:59:59.000Z

202

Fiber optic probe of free electron evanescent fields in the optical frequency range  

SciTech Connect (OSTI)

We introduce an optical fiber platform which can be used to interrogate proximity interactions between free-electron evanescent fields and photonic nanostructures at optical frequencies in a manner similar to that in which optical evanescent fields are sampled using nanoscale aperture probes in scanning near-field microscopy. Conically profiled optical fiber tips functionalized with nano-gratings are employed to couple electron evanescent fields to light via the Smith-Purcell effect. We demonstrate the interrogation of medium energy (30–50?keV) electron fields with a lateral resolution of a few micrometers via the generation and detection of visible/UV radiation in the 700–300?nm (free-space) wavelength range.

So, Jin-Kyu, E-mail: js1m10@orc.soton.ac.uk; MacDonald, Kevin F. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371 (Singapore)

2014-05-19T23:59:59.000Z

203

Researchers' Hottest New Laser Beams 14.2 kW | Jefferson Lab  

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

Researchers' Hottest New Laser Beams 14.2 kW For more information: Office of Naval Research press release The linear accelerator portion of the FEL. On Thursday, Oct. 26,...

204

ARCHITECTURE AND MAIN HARDWARE COMPONENTS OF THE FEL CONTROL SYSTEM  

E-Print Network [OSTI]

ARCHITECTURE AND MAIN HARDWARE COMPONENTS OF THE FEL CONTROL SYSTEM E.N. Dementiev, V.R. Kozak, E.V. Tararyshkin, A.G. Tribendis, E.N. Shubin, Abstract This article considers the architecture of the control architecture depended on several factors specific to both the facility itself and the control equipment used

Kozak, Victor R.

205

BNL | ATF Laser Safety  

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

ATF Laser Safety ATF Laser Safety To be present in a secured laser area at ATF, a person must either have the required laser training, or be continuously escorted by someone who has such training: The training consists of an eye exam, BNL general laser safety lecture, and formal ATF laser familiarization. Untrained personnel should not be instructed to enter interlocked areas or be escorted into an area and left unattended. If someone without training must enter a secured area, they must be continuously escorted, and are considered spectators, which means they may not perform any work in the area. At ATF, there are 3 classes of personnel authorized to enter secured areas: Experimental operators may secure areas, perform approved experiments with beams from facility lasers (YAG + CO2) or FEL beams, and

206

Making the Old New Again: Measuring Ultrashort X-ray Laser Pulses...  

Office of Science (SC) Website

free-electron lasers using a transverse deflector." Physical Review ST Accelerators and Beams. 14:120701 (2011). DOI: 10.1103PhysRevSTAB.14.120701 External link V. A. Dolgashev...

207

Studies of Resistive Wall Heating at JLAB FEL  

SciTech Connect (OSTI)

When the JLAB FEL is under CW operation, it had been observed that temperature rises over the wiggler vacuum chamber, presumably as the result of the power deposition on the resistive wall of the wiggler chamber. Previous analyses have been done on the resistive wall impedance for various cases, such as DC, AC, and anomalous skin effects*. Here we report an investigation on the beam kinetic energy losses for each of these cases. This study includes the non-ultrarelativistic effect on resistive wall loss, for both round pipe and parallel plates. We will present the comparison of our results with the measured data obtained during CW operation of the JLAB FEL. Other possible factors contributing to the measured heating will also be discussed.

Li, Rui; Benson, Stephen V.

2013-06-01T23:59:59.000Z

208

Nuclear Instruments and Methods in Physics Research A 483 (2002) 326330 A ferroelectric electron gun in a free-electron maser experiment  

E-Print Network [OSTI]

gun in a free-electron maser experiment M. Einat, E. Jerby*, G. Rosenman Faculty of Engineering, Tel Aviv University, University Road, 69978 Ramat Aviv, Israel Abstract An electron-gun based on a ferroelectric cathode is studied in a free-electron maser (FEM) experiment. In this gun, the electrons

Jerby, Eli

209

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities  

E-Print Network [OSTI]

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun ..............................................................................................................................................................19 3.1. DESY GUN 2..................................................................................................................................................19 3.2. DESY GUN 4

210

Plasma channel diagnostic based on laser centroid oscillationsa... A. J. Gonsalves,b  

E-Print Network [OSTI]

for radia- tion sources--ranging from coherent terahertz4 to free elec- tron laser FEL x-ray sources5Plasma channel diagnostic based on laser centroid oscillationsa... A. J. Gonsalves,b K. Nakamura, C the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting

Geddes, Cameron Guy Robinson

211

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

E-Print Network [OSTI]

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

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

2006-01-01T23:59:59.000Z

212

In vivo crystallography at X-ray free-electron lasers: the next generation of structural biology?  

Science Journals Connector (OSTI)

...2-1 Yamadaoka, Suita, Osaka 565-0871, Japan 9 Japan Synchrotron Radiation Research Institute, , Kouto 1-1-1, Sayo...hutch 3 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No...

2014-01-01T23:59:59.000Z

213

Modern problems in Statistical Physics of Bose-Einstein Condensation and in Electrodynamics of Free Electron Lasers  

E-Print Network [OSTI]

(solid lines) for a small number of atoms N? Nc (OAN, there is con- densate) for the trap with a given volume and temperature: the trap-size parameter in Eq. (3.2) is Nv = 100.... . . . . . . . . . . . . . 49 4 Temperature scaling of the mean value of the ground state occu- pation fluctuations for an ideal Bose gas (grey lines) and weakly interacting Bose gas (black lines) for N = 100 obtained from thermodynamic limit expression in Eqs. (2.30) - (2...

Dorfman, Konstantin E.

2010-07-14T23:59:59.000Z

214

Opportunities and challenges for time-resolved studies of protein structural dynamics at X-ray free-electron lasers  

Science Journals Connector (OSTI)

...functional transitions in proteins. Proc. Natl Acad...Woodbury, NW. 2007 Protein dynamics control the...2011 New light on disordered ensembles: ab initio structure...vibrational dynamics of a protein in liquid water by terahertz...

2014-01-01T23:59:59.000Z

215

Methods development for diffraction and spectroscopy studies of metalloenzymes at X-ray free-electron lasers  

Science Journals Connector (OSTI)

...Coherent Light Source, taking...Coherent Light Source (LCLS...radiation energy by the X-ray...developed by us to process...large sample consumption is not sustainable...Coherent Light Source (LCLS...operated for the US Department of Energy Office of...

2014-01-01T23:59:59.000Z

216

Methods development for diffraction and spectroscopy studies of metalloenzymes at X-ray free-electron lasers  

Science Journals Connector (OSTI)

...on electrofocusing, an energy dispersive von Hamos X-ray...spectroscopy data collected by us at the Linac Coherent...deposition of radiation energy by the X-ray pulse was...we review the current status of methods developed in...packages developed by us to process both spectroscopic...

2014-01-01T23:59:59.000Z

217

Contributions to the FEL'99 Conference, August 23-28, 1999 in Hamburg, Germany  

E-Print Network [OSTI]

Contributions to the FEL'99 Conference, August 23-28, 1999 in Hamburg, Germany TESLA FEL-Report 1999-07 #12;Contents M. Dohlus, A. Kabel, T.Limberg DESY, Germany Coherent Effects of a Macrobunch, Germany Efficient Field Calculation of 3D Bunches on General Trajectories

218

Experimental demonstration of mode-selective phonon excitation of 6H-SiC by a mid-infrared laser with anti-Stokes Raman scattering spectroscopy  

SciTech Connect (OSTI)

Mode-selective phonon excitation by a mid-infrared laser (MIR-FEL) is demonstrated via anti-Stokes Raman scattering measurements of 6H-silicon carbide (SiC). Irradiation of SiC with MIR-FEL and a Nd-YAG laser at 14 K produced a peak where the Raman shift corresponds to a photon energy of 119 meV (10.4 ?m). This phenomenon is induced by mode-selective phonon excitation through the irradiation of MIR-FEL, whose photon energy corresponds to the photon-absorption of a particular phonon mode.

Yoshida, Kyohei; Hachiya, Kan; Okumura, Kensuke; Mishima, Kenta; Inukai, Motoharu; Torgasin, Konstantin; Omer, Mohamed [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)] [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Sonobe, Taro [Kyoto University Research Administration Office, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)] [Kyoto University Research Administration Office, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Zen, Heishun; Negm, Hani; Kii, Toshiteru; Masuda, Kai; Ohgaki, Hideaki [Institute of Advanced Energy, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)] [Institute of Advanced Energy, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)

2013-10-28T23:59:59.000Z

219

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-State Studies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary Layout Option Investigation  

E-Print Network [OSTI]

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-Stateinitial studies of the RF gun mode-coupling and potentialas more novel rf photocathode gun configurations – these may

2005-01-01T23:59:59.000Z

220

Development of BPM Electronics at the JLAB FEL  

SciTech Connect (OSTI)

A new version of BPM electronics based on the AD8362 RMS detector, which is a direct RF to DC converter, is under development at the JLAB FEL. Each of these new BPM electronics utilizes an embedded ColdFire Microprocessor for data processing and communication with the EPICS control system via TCP/IP. The ColdFire runs RTEMS, which is an open source real-time operating system. The JLAB FEL is a SRF Energy Recovery LINAC capable of running up to 10 mA CW beam with the micropulse up to 74.85 MHz. For diagnostic reasons and for the machine tune up, the micropulse frequency can be reduced to 1.17 MHz, which corresponds to about 160 ?A of beam current. It is required that the BPM system would be functional for all micropulse frequencies. By taking into account the headroom for the beam steering and current variations the dynamic range of the RF front end is required to be about 60 dB. A BPM resolution of at least 100 ?m is required, whereas better resolution is very desirable to make it possible for more accurate measurements of the electron beam optics. Some results of the RF front end development are presented as well as the first measurements made with an electron beam.

Daniel Sexton; Pavel Evtushenko; Kevin Jordan; Jianxun Yan; Steven Dutton; Steven Moore; Richard Evans; James Coleman

2006-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Light Well: ATunable Free-Electron Light Source on a Chip K. F. MacDonald,1,* Y. H. Fu,2  

E-Print Network [OSTI]

Light Well: ATunable Free-Electron Light Source on a Chip G. Adamo,1 K. F. MacDonald,1,* Y. H. Fu,2 and surface plasmon-polariton sources [1­5]. Electron- beam-induced radiation emission [6­8] is of particular-emitter displays [12]. The light well belongs to a broad family of free-electron- driven radiation sources wherein

Zheludev, Nikolay

222

Polarization Analysis for Seeded FELs in a Crossed-Planar Undulator  

SciTech Connect (OSTI)

The crossed-planar undulator is a promising scheme for full polarization control in x-ray FELs. For SASE FELs, it has been shown a maximum degree of circular polarization of about 80% is achievable at fundamental wavelength just before saturation. In this paper, we study the effectiveness of a crossed undulator for a seeded x-ray FEL. The degree of circular polarization for both the fundamental and the harmonic radiation are considered. Simulations with realistic beam distributions show that a degree of circular polarization of over 90% and 80% is obtainable at the fundamental and 2nd harmonic frequencies, respectively.

Geng, Huiping; /SLAC; Ding, Yuantao; /SLAC; Huang, Zhirong; /SLAC; Bartolini, Riccardo; /Diamond Light Source; Dunning, David; /Daresbury; Thompson, Neil; /Daresbury

2012-06-25T23:59:59.000Z

223

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect (OSTI)

We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.

Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)

2012-12-21T23:59:59.000Z

224

Study of CSR Effects in the Jefferson Laboratory FEL Driver  

SciTech Connect (OSTI)

In a recent experiment conducted on the Jefferson Laboratory IR FEL driver the effects of Coherent Synchrotron Radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR chicane. This experiment also provides a valuable opportunity to benchmark existing CSR models in a system that may not be fully represented by a 1-D CSR model. Here we present results from this experiment and compare to initial simulations of CSR in the magnetic compression chicane of the machine. Finally, we touch upon the possibility for CSR induced microbunching gain in the magnetic compression chicane, and show that parameters in the machine are such that it should be thoroughly damped.

Hall, C. C. [Colorado State U.; Biedron, S. [Colorado State U.; Burleson, Theodore A. [Colorado State U.; Milton, Stephen V. [Colorado State U.; Morin, Auralee L. [Colorado State U.; Benson, Stephen V. [JLAB; Douglas, David R. [JLAB; Evtushenko, Pavel E. [JLAB; Hannon, Fay E. [JLAB; Li, Rui [JLAB; Tennant, Christopher D. [JLAB; Zhang, Shukui [JLAB; Carlsten, Bruce E. [LANL; Lewellen, John W. [LANL

2013-08-01T23:59:59.000Z

225

Optical power evolution in the Boeing 1 kW FEL oscillator  

Science Journals Connector (OSTI)

A four-dimensional simulation in x, y, z, and t, including betatron motion of the electrons, is used to study optical power evolution and the trapped-particle instability in the Boeing 1 kW FEL oscillator.

J. Blau; R.K. Wong; W.B. Colson

1996-01-01T23:59:59.000Z

226

Diffraction and pulse slippage in the Boeing 1 kW FEL oscillator  

SciTech Connect (OSTI)

A four-dimensional simulation in x, y, z, and t, including betatron motion of the electrons, is used to study the combined effects of diffraction, pulse slippage and desynchronism in the Boeing 1 kW FEL oscillator.

Blau, J.; Wong, R.K.; Colson, W.B. [Naval Postgraduate School, Monterey, CA (United States)

1995-12-31T23:59:59.000Z

227

Femtosecond-scale x-ray FEL diagnostics with an X-band transverse...  

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

Femtosecond-scale x-ray FEL diagnostics with an X-band transverse deflector Wednesday, October 22, 2014 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Tim Maxwell,...

228

Pulse energy measurement at the hard x-ray laser in Japan  

SciTech Connect (OSTI)

The pulse energies of a free electron laser have accurately been measured in the hard x-ray spectral range. In the photon energy regime from 4.4 keV to 16.8 keV, pulse energies up to 100 {mu}J were obtained at the hard x-ray laser facility SACLA (SPring-8 Angstrom Compact free-electron LAser). Two independent methods, using a cryogenic radiometer and a gas monitor detector, were applied and agreement within 3.3% was achieved. Based on our validated pulse energy measurement, a SACLA online monitor detector could be calibrated for all future experiments.

Kato, M.; Tanaka, T.; Saito, N. [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kurosawa, T. [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); Richter, M. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany); Sorokin, A. A. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22603 Hamburg (Germany); Ioffe Physico-Technical Institute, RAS, Polytekhnicheskaya 26, 194021 St. Petersburg (Russian Federation); Tiedtke, K. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22603 Hamburg (Germany); Kudo, T.; Yabashi, M. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Tono, K. [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Ishikawa, T. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2012-07-09T23:59:59.000Z

229

Design and test of SX-FEL cavity BPM  

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

230

  

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

1 1 1 Abstract- Research frontiers for future free-electron lasers are discussed. Attention is given to ideas for improving the temporal coherence and obtaining sub-femtosecond x-ray pulses. Improving brightness of the electron bunches is considered to be a major step forward for an electron beam accelerator simultaneously supporting multiple free-electron laser lines. Index Terms-Attosecond, brightness, EEHG, electron gun, emittance, HGHG, FEL, femtosecond, linac, oscillator, SASE, self-seeding, XFELO, x-rays. I. INTRODUCTION free-electron laser (FEL) facility consist of two major components: the FEL itself that contains a chain of undulator magnets plus auxiliary equipment, and the electron beam delivery system that includes the electron gun, linear

231

Fast pulsed excitation wiggler or undulator  

DOE Patents [OSTI]

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

van Steenbergen, Arie (Shoreham, NY)

1990-01-01T23:59:59.000Z

232

Using The SLAC Two-Mile Accelerator for Powering an FEL  

SciTech Connect (OSTI)

A parameter survey is made, employing the recently developed 2D formalism for an FEL, of the characteristics of an FEL using the SLAC accelerator. Attention is focused upon a wavelength of 40 {angstrom} (the water window) and 1 {angstrom} case is also presented. They consider employing the SLAC linac with its present operating parameters and with improved parameters such as would be supplied by a new photo-cathode injector. They find that improved parameters are necessary, but that the parameters presently achieved with present-day photo-cathode guns are adequate to reach the water window.

Barletta, W.A.; /LLNL, Livermore; Sessler, A.M.; /LBL, Berkeley; Yu, L.H.; /Brookhaven

2012-06-29T23:59:59.000Z

233

Lasers as a tool for plasma diagnostics  

SciTech Connect (OSTI)

Lasers can be used as non-perturbative probes to measure many plasma parameters. Plasma refractivity is primarily a function of electron density, and interferometric measurements of phase changes with either pulsed or CW lasers can determine this parameter with spatial or temporal resolution over several orders of magnitude sensitivity by using laser wavelengths from the near uv to the far infrared. Laser scattering from free electrons yields the most fundamental electron temperature measurements in the plasma parameter range where individual scattering events are uncorrelated in phase and ion temperature or plasma wave and turbulence structure in the opposite limit. Laser scattering from bound electrons can be many orders of magnitude larger if the laser is matched to appropriate resonance frequencies and can be used in specialized circumstances for measuring low-ionized impurity or dominant species neutral concentrations and velocities.

Jahoda, F.C.

1981-01-01T23:59:59.000Z

234

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09  

E-Print Network [OSTI]

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09 J. Sekutowicz, J. Iversen, G. Kreps, W Sand Hill Road, Menlo Park, CA 94025, USA We report on the status of an electron RF-gun made of two superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead

235

FEL performance with pure permanent-magnet undulators having optimized ordering  

Science Journals Connector (OSTI)

The degradation of FEL performance by field errors can be greatly mitigated in a pure permanent-magnet undulator by appropriate ordering of magnets. Monte Carlo techniques have been used to obtain such optimized ordering for various systems. The resulting performance improvement has been evaluated using the Rocketdyne simulation code FELOPT.

R.A. Cover; B.L. Bobbs; G. Rakowsky; M.M. Johnson; S.P. Mills

1990-01-01T23:59:59.000Z

236

Contributions to the FEL2001 Conference, August 20-24, 2001 in Darmstadt, Germany  

E-Print Network [OSTI]

Contributions to the FEL2001 Conference, August 20-24, 2001 in Darmstadt, Germany October 2001¨ustefeld , (BESSY, Berlin, Germany), ¡ (DESY, Hamburg, Germany), ¢ (UCLA, Los Angeles, USA), £ (MBI, Berlin, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 V. Balandin, N. Golubeva, M. K¨orfer (DESY, Hamburg, Germany) Studies of Beam Optics

237

TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using  

E-Print Network [OSTI]

1 TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using Passive dosimeters Bhaskar Mukherjee, Radiation dosimetry, Radiation effect, Superconducting Cavities, XFEL 1. INTRODUCTION In April 2006, at DESY-term basis. Conventional radiation monitoring devices are usually bulky and the associated nuclear

238

Use of Multipass Recirculation and Energy Recovery In CW SRF X-FEL Driver Accelerators  

SciTech Connect (OSTI)

We discuss the use of multipass recirculation and energy recovery in CW SRF drivers for short wavelength FELs. Benefits include cost management (through reduced system footprint, required RF and SRF hardware, and associated infrastructure - including high power beam dumps and cryogenic systems), ease in radiation control (low drive beam exhaust energy), ability to accelerate and deliver multiple beams of differing energy to multiple FELs, and opportunity for seamless integration of multistage bunch length compression into the longitudinal matching scenario. Issues include all those associated with ERLs compounded by the challenge of generating and preserving the CW electron drive beam brightness required by short wavelength FELs. We thus consider the impact of space charge, BBU and other environmental wakes and impedances, ISR and CSR, potential for microbunching, intra-beam and beam-residual gas scattering, ion effects, RF transients, and halo, as well as the effect of traditional design, fabrication, installation and operational errors (lattice aberrations, alignment, powering, field quality). Context for the discussion is provided by JLAMP, the proposed VUV/X-ray upgrade to the existing Jefferson Lab FEL.

Douglas, David; Akers, Walt; Benson, Stephen V.; Biallas, George; Blackburn, Keith; Boyce, James; Bullard, Donald; Coleman, James; Dickover, Cody; Ellingsworth, Forrest; Evtushenko, Pavel; Fisk, Sally; Gould, Christopher; Gubeli, Joseph; Hannon, Fay; Hardy, David; Hernandez-Garcia, Carlos; Jordan, Kevin; Klopf, John; Kortze, J.; Legg, Robert; Li, Rui; Marchlik, Matthew; Moore, Steven W.; Neil, George; Powers, Thomas; Sexton, Daniel; Shin, Ilkyoung; Shinn, Michelle D.; Tennant, Christopher; Terzic, Balsa; Walker, Richard; Williams, Gwyn P.; Wilson, G.; Zhang, Shukui

2010-08-01T23:59:59.000Z

239

Microsoft Word - Document1  

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

LASING OF THE LCLS X-RAY FEL AT 1.5 Ã… LASING OF THE LCLS X-RAY FEL AT 1.5 Ã… P. Emma, for the LCLS Commissioning Team; SLAC, Stanford, CA 94309, USA Abstract The Linac Coherent Light Source (LCLS) is a SASE 1.5-15 Ã… x-ray Free-Electron Laser (FEL) facility under construction at SLAC [1], and presently in an advanced phase of commissioning. The injector, linac, and new bunch compressors were commissioned in 2007 [2] and 2008 [3], establishing the necessary electron beam brightness at 14 GeV. The final phase of commissioning, including the FEL undulator and the long transport line from the linac, began in November 2008, with first 1.5-Ã… FEL light and saturation observed in mid-April 2009. We report on the accelerator, undulator, and FEL operations, although prior to the availability of the full x-ray

240

Experimental Observation of Electrons Accelerated in Vacuum to Relativistic Energies by a High-Intensity Laser  

Science Journals Connector (OSTI)

Free electrons have been accelerated in vacuum to MeV energies by a high-intensity subpicosecond laser pulse ( 1019 W/cm2, 300 fs). The experimental data are in good agreement with the relativistic motion of electrons in a spatially and temporally finite electromagnetic field, both in terms of maximum energy and scattering angle.

G. Malka; E. Lefebvre; J. L. Miquel

1997-04-28T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Tapering studies for Terawatt level X-ray FELs with a superconducting undulator  

E-Print Network [OSTI]

We study the tapering optimization scheme for a short period, less than two cm, superconducting undulator, and show that it can generate 4 keV X-ray pulses with peak power in excess of 1 terawatt, using LCLS electron beam parameters. We study the e?ect of undulator module length relative to the FEL gain length for continous and step-wise taper pro?les. For the optimal section length of 1.5m we study the evolution of the FEL process for two di?erent superconducting technologies NbTi and Nb3Sn. We discuss the major factors limiting the maximum output power, particle detrapping around the saturation location and time dependent detrapping due to generation and ampli?cation of sideband modes.

Emma, Claudio; Emma, Paul; Huang, Zhirong; Pellegrini, Claudio

2015-01-01T23:59:59.000Z

242

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

SciTech Connect (OSTI)

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

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

2011-12-13T23:59:59.000Z

243

Design of the SRF Driver ERL for the Jefferson Lab UV FEL  

SciTech Connect (OSTI)

We describe the design of the SRF Energy-Recovering Linac (ERL) providing the CW electron drive beam at the Jefferson Lab UV FEL. Based on the same 135 MeV linear accelerator as ? and sharing portions of the recirculator with ? the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a novel bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation (including correction of RF curvature effects) without the use of magnetic chicanes or harmonic RF. Stringent phase space requirements at the wiggler, low beam energy, high beam current, and use of a pre-existing facility and legacy hardware subject the design to numerous constraints. These are imposed not only by the need for both transverse and longitudinal phase space management, but also by the potential impact of collective phenomena (space charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation (CSR)), and by interactions between the FEL and the accelerator RF system. This report addresses these issues and presents the accelerator design solution that is now in operation.

David R. Douglas; Stephen Benson; George Biallas; Keith Blackburn; James Boyce; Donald Bullard; James Coleman; Cody Dickover; Forrest Ellingsworth; Pavel Evtushenko; Christopher Gould; Joseph Gubeli; Fay Hannon; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; Michael Klopf; James Kortze; Matthew Marchlik; Steven Moore; George Neil; Thomas Powers; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Frederick Wilson; Shukui Zhang

2011-03-01T23:59:59.000Z

244

Laser Roadshow  

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

outreach Laser Roadshow The NIF Laser Roadshow includes a number of interactive laser demonstrations (Laser Light Fountain, Laser DJ, and NIF "3D ride") that have traveled across...

245

Modeling and performance of a single-electron-beam two-FEL system  

Science Journals Connector (OSTI)

The use of a single electron beam to power a master oscillator and power amplifier was demonstrated in the Rocketdyne/Stanford experiment. This article concentrates on the performance of the downstream element under the assumption of higher performance upstream elements such as might be possible for the high-brightness systems being developed in the Los Alamos and Rocketdyne/Duke programs. The modeling covers the performance of the initial high-extraction efficiency system, the filtering, transport, and refocusing of electrons into a second wiggler, and the performance of the second system. The Rocketdyne 3D simulation code FELOPT was used in the FEL calculations.

Ralph A. Cover

1991-01-01T23:59:59.000Z

246

PROPERTIES OF CATHODES USED IN THE PHOTOINJECTOR RF GUN AT THE DESY VUV-FEL  

E-Print Network [OSTI]

nm) laser pulses. The laser, a mode-locked solid-state laser sys- tem based on Nd. An ion pump powered by a battery keeps the vacuum level stable around 1·10-10 mbar. The transport chamber

247

Laser ablative synthesis of carbon nanotubes  

DOE Patents [OSTI]

An improved method for the production of single walled carbon nanotubes that utilizes an RF-induction heated side-pumped synthesis chamber for the production of such. Such a method, while capable of producing large volumes of carbon nanotubes, concurrently permits the use of a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization. The method of the present invention utilizes a free electron laser operating at high average and peak fluence to illuminate a rotating and translating graphite/catalyst target to obtain high yields of SWNTs without the use of a vacuum chamber.

Smith, Michael W. (Newport News, VA); Jordan, Kevin (Newport News, VA); Park, Cheol (Yorktown, VA)

2010-03-02T23:59:59.000Z

248

Laser Ignition  

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

Laser Ignition Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable...

249

Lasers, Electron Beams and New Years Resolutions | Department of Energy  

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

Lasers, Electron Beams and New Years Resolutions Lasers, Electron Beams and New Years Resolutions Lasers, Electron Beams and New Years Resolutions March 2, 2011 - 3:43pm Addthis Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? The electron beam that powers Jefferson Lab's Free-Electron Laser pumped out a record power input of 500 kilvolts using an innovative energy-recovery system that amplifies energy with far less power. A sufficiently powerful laser could make an effective defensive weapon, as well as accurate detection and tracking. The few folks still keeping their New Year's resolutions to work out might be the first to appreciate the recent record-breaking lift by the Energy Department's Jefferson Lab. Take a steel dumbbell. Hoist it up - lift with your legs! - onto a stand. Then add another ...and another

250

Video Navigation with a Personal Viewing History Abir Al-Hajri, Gregor Miller, Sidney Fels, and Matthew Fong  

E-Print Network [OSTI]

Video Navigation with a Personal Viewing History Abir Al-Hajri, Gregor Miller, Sidney Fels, Canada {abira, gregor, ssfels, mfong}@ece.ubc.ca Abstract. We describe a new video interface based previously viewed intervals, highlight segments of video the user found interesting and support other video

Millerm Gregor

251

Experiences with a Virtual Swimming Interface Exhibit Sidney Fels, Steve Yohanan, Sachiyo Takahashi, Yuichiro Kinoshita, Kenji Funahashi, Yasufumi  

E-Print Network [OSTI]

accomplished the artistic endeavour by swimming in the pool of the ocean liner, Queen Elizabeth II, traveling1 Experiences with a Virtual Swimming Interface Exhibit Sidney Fels, Steve Yohanan, Sachiyo based on a new locomotion interface for swimming in a virtual reality ocean environment as part of our

British Columbia, University of

252

Operation of the APS photoinjector drive laser sytem  

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

07 07 Rev. 1, June 2008 Operation of the APS Photoinjector Drive Laser System Yuelin Li Abstract The APS photoinjector drive laser system has been in operation since 1999 and is achieving a performance level exceeding the requirement of stable operation of the LEUTL FEL system. One remarkable number is the UV energy stability of better than 2% rms, sometimes less than 1% rms. This report summarizes the operation experience of the laser system and the improvements made along the way. We also outline the route of upgrade of the system and some frontier laser research and development opportunities in ultrabright electron beam generation. I. Introduction A photoinjector is the only way to generate the high-brightness beams required by fourth-

253

Impact of the spatial laser distribution on photocathode gun operation  

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

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

254

Laser Cladding  

Science Journals Connector (OSTI)

Laser cladding is a surface modification process in which a laser beam is used to melt an addition ... process must be clearly differentiated from that of laser surface alloying ( Laser Surface Al...

Prof. Dr. José L. Ocaña; Prof. Janez Grum

2013-01-01T23:59:59.000Z

255

E-Print Network 3.0 - average power fel Sample Search Results  

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

close Above - A high power femtosecond laser system 2 - Production Of UV And XRay Radiation ... Source: Strathclyde, University of - Department Physics and Applied Physics,...

256

A syncrhronized FIR/VUV light source at Jefferson Lab  

SciTech Connect (OSTI)

This slide show presents an introduction to Free-Electron Lasers (FELs) and what makes the JLab FELs unique. Ways of exploring the nature of matter with the FEL are shown, including applications in the THz, IR, UV, and VUV. The Jefferson Lab FEL Facility is unique in its high average brightness in the THz, and IR -- VUV spectral regions and Sub ps-pulses at MHz repetition rates. With an installation of a rebuilt 'F100' cryomodule the linac energy will increase to > 150MeV. This will permit lasing further into the UV and extend VUV. With the swap of our CEBAF-style cryounit for an improved booster, we could lase in the VUV. Addition of a wiggler and optical cavity slightly canted from the UV beamline would allow simultaneous lasing of UV and THz for high E-field 2 color experiments.

Shinn, Michelle D. [JLAB, Newport News, VA (United States)

2013-05-31T23:59:59.000Z

257

Transverse Coherence of the LCLS X-Ray Beam  

SciTech Connect (OSTI)

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

258

Gutt-111512 - Argonne National Laboratories, Materials Sicence Division  

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

Gutt-111512 Gutt-111512 MATERIALS SCIENCE COLLOQUIUM SPEAKER: Dr. Christian Gutt DESY, Germany TITLE: X-Ray Snapshots of Magnets and Liquids Using X-Ray Free-Electron Lasers DATE: Thursday, November 15, 2012 TIME: 11:00 am PLACE: Building 212 / A-157 HOST: Paul Fuoss Refreshments will be served at 10:45 a.m. ABSTRACT: X-ray free-electron laser sources provide extremely high-intensity and ultashort X-ray pulses which allow to access ultrafast phenomena in condensed matter on the nanoscale. In this talk I will report on results and future challenges of resonant magnetic scattering experiments using the FEL sources FLASH, LCLS and FERMI [1-3]. We investigated via IR pump / FEL probe experiments the ultrafast response of magnetic domain configurations in Co/Pt multilayer systems [4] to an

259

Laser Ignition  

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

Laser Ignition Laser Ignition Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Available for thumbnail of Feynman Center (505) 665-9090 Email Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In two embodiments the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion

260

An asymmetric emittance electron source for the GALAXIE dielectric-laser accelerator injector  

SciTech Connect (OSTI)

The GALAXIE project is a program to develop an all-optical, very high field accelerator and undulator integrated SASE FEL system based on dielectric laser-excited structures that support >GV/m fields. These structures are very wide in one direction to allow adequate charge given beam loading considerations, but also having small (subwavelength) apertures in the narrow direction. Such small vertical dimensions yield strict restrictions on the emittance in this direction, while no such constraint exists in the wide transverse direction. However, the overall beam brightness is restricted by the performance requirements on the FEL. To meet these demands, we are studying a very high field gun with a magnetized cathode, yielding a beam with angular momentum content. This beam is then subject to a skew-quad triplet that splits the emittances; this process is reversed to give a round beam after acceleration. This symmetric emittance beam avoids gain-degrading multiple-transverse-mode operation of the FEL, which also demands that the effects of the angular momentum in the beam be mitigated. In this paper we discuss the RF design of an X-band gun to be operated at {approx}200 MV/m peak field giving a 1 pC magnetized beam with unprecedented brightness. We examine the design of the focusing and skew-quad systems, investigating the associated beam dynamics and efficacy of emittance splitting.

Valloni, A.; Cahill, A.; Fukusawa, A.; Musumeci, P.; Spataro, B.; Yakub, A.; Rosenzweig, J. B. [Dept. of Physics and Astronomy, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90034 (United States); Accelerator Division, Laboratori Nazionali di Frascati (INFN-LNF), Via E. Fermi 40, Frascati (RM) 00044 (Italy); Dept. of Physics and Astronomy, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90034 (United States)

2012-12-21T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Fundamentals of femtosecond laser ablation of dielectric materials  

SciTech Connect (OSTI)

The modeling of laser-excited dielectric materials requires a detailed description of the electronic excitation. Dielectric materials do not absorb visible light by traditional linear absorption, so the dynamical generation of conduction-band electrons strongly couples to the absorption. The generation of free electrons is initiated by strong-field excitation and followed by multiplication through impact ionization by energetic electrons heated by the laser. The present paper describes an approach to solving the coupled problem of electron excitation and one-dimensional light propagation. The electronic excitation is described in the so-called multiple-rate-equation model, and the light is absorbed by a combination of strong-field excitation and linear absorption by the excited electrons, which are assumed to behave as a free-electron gas described by a Drude model. The model is generic and based on a few key parameters: the wavelength and the pulse duration of the light, and the band gap of the dielectric medium. This allows parametric investigations of ablation phenomena.

Byskov-Nielsen, J.; Le, D. Q. S.; Christensen, M. N.; Balling, P. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Christensen, B. H. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Danish Technological Institute, Kongsvang Alle 29, 8000 Aarhus C (Denmark)

2010-10-08T23:59:59.000Z

262

The Model 5000-16C 1000 WATT FEL Lamp Standard pro-vides absolute calibration of spectral irradiance from 250 nm to  

E-Print Network [OSTI]

The Model 5000-16C 1000 WATT FEL Lamp Standard pro- vides absolute calibration of spectral. It has been selected by the National Institute of Standards and Technology to replace the 1000 watt, DXW-pin 1000 watt lamp that is adapted by Gamma Scientific into a bi-post configuration. It is used

263

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

264

Page 1Laser Safety Training Laser Institute of America Laser Safety Laser Institute of America  

E-Print Network [OSTI]

Page 1Laser Safety Training © Laser Institute of America 1 Laser Safety © Laser Institute of America Laser Safety: Hazards, Bioeffects, and Control Measures Laser Institute of America Gus Anibarro Education Manager 2Laser Safety © Laser Institute of America Laser Safety Overview Laser Safety Accidents

Farritor, Shane

265

Laser Telecommunication timeLaser beam  

E-Print Network [OSTI]

Laser Telecommunication Experiment Laser time Laser beam intensity timeLaser beam Laser battery Laser connected to a circuit without a modulator. Bottom graph illustrates what happen when a modulating signal is superimposed to the DC voltage driving the laser Laser beam intensity DC Input voltage DC

La Rosa, Andres H.

266

Laser microphone  

DOE Patents [OSTI]

A microphone for detecting sound pressure waves includes a laser resonator having a laser gain material aligned coaxially between a pair of first and second mirrors for producing a laser beam. A reference cell is disposed between the laser material and one of the mirrors for transmitting a reference portion of the laser beam between the mirrors. A sensing cell is disposed between the laser material and one of the mirrors, and is laterally displaced from the reference cell for transmitting a signal portion of the laser beam, with the sensing cell being open for receiving the sound waves. A photodetector is disposed in optical communication with the first mirror for receiving the laser beam, and produces an acoustic signal therefrom for the sound waves.

Veligdan, James T. (Manorville, NY)

2000-11-14T23:59:59.000Z

267

The Gas Attenuator of FLASH at DESY  

SciTech Connect (OSTI)

FLASH (Free electron LASer at Hamburg) as a part of the Deutsches Elektronen Synchroton DESY is the first Free Electron Laser (FEL) user facility for VUV and soft X-ray coherent light experiments. The SASE (Self Amplification by Stimulated Emission) process generates ultra short coherent radiation pulses on the femtosecond time scale with peak powers in the GW range. Several experiments need reliable means to reduce the FEL intensity over many orders of magnitude without changing the photon beam characteristics. Since a reduction of the FEL intensity by variation of machine parameters is not appropriate, a windowless gas-filled cell in combination with differential pumping units is used for attenuating the FEL radiation. This attenuator is placed in the beamline in outside the experimental hall. The total length of the gas cell is 15 m and the maximum gas pressure, which can be handled by the differential pumping units, is about 0.1 mbar. The attenuation range of Nitrogen covers at least 5 orders of magnitude in the spectral range of 19 to 120 nm due to its large absorption cross section. Between 19 and 9 nm and for shorter wavelengths Xenon and Krypton can be used, respectively.

Hahn, Ulrich; Tiedtke, Kai [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22603 Hamburg (Germany)

2007-01-19T23:59:59.000Z

268

Momentum distributions of sequential ionization generated by an intense laser pulse  

E-Print Network [OSTI]

beam is produced in an EBIT (electron beam ion trap) that is kept at a potential of approximately 5 kV, and which can produce xenon ions with charges ranging from Xe1+ to around Xe20+. Selecting the desired initial charge state with a Wienfilter... that is on the order of its rest energy. Taking into account that the oscillation energy of a free electron is F 2/4?2, one can easily find that relativistic effects occur for radiation of the Ti:Sa laser at the intensity greater than 5? 1018 W/cm2 (see Ref. [2...

Shvetsov-Shilovski, N. I.; Sayler, A. M.; Rathje, T.; Paulus, Gerhard G.

2011-01-01T23:59:59.000Z

269

Rescattering effects in laser-assisted electron-atom bremsstrahlung  

E-Print Network [OSTI]

Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) co...

Zheltukhin, A N; Frolov, M V; Manakov, N L; Starace, Anthony F

2015-01-01T23:59:59.000Z

270

Demonstration of electron beam focusing by a laser-plasma lens  

E-Print Network [OSTI]

Laser-plasma technology promises a drastic reduction of the size of high energy electron accelerators. It could make free electron lasers available to a broad scientific community, and push further the limits of electron accelerators for high energy physics. Furthermore the unique femtosecond nature of the source makes it a promising tool for the study of ultra-fast phenomena. However, applications are hindered by the lack of suitable lens to transport this kind of high-current electron beams, mainly due to their divergence. Here we show that this issue can be solved by using a laser-plasma lens, in which the field gradients are five order of magnitude larger than in conventional optics. We demonstrate a reduction of the divergence by nearly a factor of three, which should allow for an efficient coupling of the beam with a conventional beam transport line.

Thaury, Cédric; Döpp, Andreas; Lehe, Remi; Lifschitz, Agustin; Phuoc, Kim Ta; Gautier, Julien; Goddet, Jean-Philippe; Tafzi, Amar; Flacco, Alessandro; Tissandier, Fabien; Sebban, Stéphane; Rousse, Antoine; Malka, Victor

2014-01-01T23:59:59.000Z

271

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2003-01-01T23:59:59.000Z

272

Compensating effect of the coherent synchrotron radiation in bunch compressors  

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

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

273

WF-NOTE-238  

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

6 6 March 21, 2011 Dielectric Wakefield Accelerator to Drive the Future FEL Light Source C. Jing 1,2 , J. Power 1 , and A. Zholents 3 1. High Energy Physics Division, ANL 2. Euclid Techlabs, LLC 3. Advanced Photon Source, ANL Abstract: X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an

274

Design and Start-to-End Simulation of an X-Band RF Driven Hard X-Ray FEL with LCLS Injector  

SciTech Connect (OSTI)

In this note, it is briefly discussed the accelerator design and start-to-end 3D macro particles simulation (using ELEGANT and GENESIS) of an X-band RF driven hard X-ray FEL with LCLS injector. A preliminary design and LiTrack 1D simulation studies were presented before in an older publication [1]. In numerical simulations this X-band RF driven hard X-ray FEL achieves/exceeds LCLS-like performance in a much shorter overall length of 350 m, compared with 1200 m in the LCLS case. One key feature of this design is that it may achieve a higher final beam current of 5 kA plus a uniform energy profile, mainly due to the employment of stronger longitudinal wake fields in the last X-band RF linac [2].

Sun, Yipeng; /SLAC

2012-08-20T23:59:59.000Z

275

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

276

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

277

Microsoft Word - DWA4XFELsummary_awa_verson.docx  

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

Future X-Ray Lasers Future X-Ray Lasers Article written by J. Power and A. Zholents for the Argonne Management Blog: FOCAL POINT Last week, twenty plus accelerator scientists gathered at Argonne to shape a roadmap to a future x-ray free electron lasers (FELs). Tremendously effective in the production of light, FELs are now actively moving into territory traditionally occupied by machines such as the Advanced Photon Source. They are poised to make a revolution in x-ray research by enabling cutting-edge experiments including time-resolved studies of matter with femtosecond (one femtosecond corresponds to millionth of a billionth second, 10 -15 seconds) resolution and Angstrom scale spatial resolution, a dream of scientists who want to glimpse into the microscopic world of cells,

278

Laser device  

DOE Patents [OSTI]

A laser device includes a virtual source configured to aim laser energy that originates from a true source. The virtual source has a vertical rotational axis during vertical motion of the virtual source and the vertical axis passes through an exit point from which the laser energy emanates independent of virtual source position. The emanating laser energy is collinear with an orientation line. The laser device includes a virtual source manipulation mechanism that positions the virtual source. The manipulation mechanism has a center of lateral pivot approximately coincident with a lateral index and a center of vertical pivot approximately coincident with a vertical index. The vertical index and lateral index intersect at an index origin. The virtual source and manipulation mechanism auto align the orientation line through the index origin during virtual source motion.

Scott, Jill R. (Idaho Falls, ID); Tremblay, Paul L. (Idaho Falls, ID)

2008-08-19T23:59:59.000Z

279

Dynamical Schwinger effect and high-intensity lasers. Realising nonperturbative QED  

E-Print Network [OSTI]

We consider the possibility of experimental verification of vacuum e^+e^- pair creation at the focus of two counter-propagating optical laser beams with intensities 10^{20}-10^{22} W/cm^2, achievable with present-day petawatt lasers, and approaching the Schwinger limit: 10^{29} W/cm^2 to be reached at ELI. Our approach is based on the collisionless kinetic equation for the evolution of the e^+ and e^- distribution functions governed by a non-Markovian source term for pair production. As possible experimental signals of vacuum pair production we consider e^+e^- annihilation into gamma-pairs and the refraction of a high-frequency probe laser beam by the produced e^+e^- plasma. We discuss the dependence of the dynamical pair production process on laser wavelength, with special emphasis on applications in the X-ray domain (X-FEL), as well as the prospects for \\mu^+\\mu^- and \\pi^+\\pi^- pair creation at high-intensity lasers. We investigate perspectives for using high-intensity lasers as ``boosters'' of ion beams in the few-GeV per nucleon range, which is relevant, e.g., to the exploration of the QCD phase transition in laboratory experiments.

D. B. Blaschke; A. V. Prozorkevich; G. Roepke; C. D. Roberts; S. M. Schmidt; D. S. Shkirmanov; S. A. Smolyansky

2008-11-21T23:59:59.000Z

280

Laser goniometer  

DOE Patents [OSTI]

The laser goniometer is an apparatus which permits an operator to sight along a geologic feature and orient a collimated lamer beam to match the attitude of the feature directly. The horizontal orientation (strike) and the angle from horizontal (dip), are detected by rotary incremental encoders attached to the laser goniometer which provide a digital readout of the azimuth and tilt of the collimated laser beam. A microprocessor then translates the square wave signal encoder outputs into an ASCII signal for use by data recording equipment.

Fairer, George M. (Boulder, CO); Boernge, James M. (Lakewood, CO); Harris, David W. (Lakewood, CO); Campbell, DeWayne A. (Littleton, CO); Tuttle, Gene E. (Littleton, CO); McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO)

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Enhanced Nonlinear Double Excitation of He in Intense Extreme Ultraviolet Laser Fields  

SciTech Connect (OSTI)

Nonlinear, three-photon double excitation of He in intense extreme ultraviolet free-electron laser fields ({approx}24.1 eV, {approx}5 TW/cm{sup 2}) is presented. Resonances to the doubly excited states converging to the He{sup +} N=3 level are revealed by the shot-by-shot photoelectron spectroscopy and identified by theoretical calculations based on the time-dependent Schroedinger equation for the two-electron atom under a laser field. It is shown that the three-photon double excitation is enhanced by intermediate Rydberg states below the first ionization threshold, giving a greater contribution to the photoionization yields than the two-photon process by more than 1 order of magnitude.

Hishikawa, A.; Matsuda, A. [Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 (Japan); Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 (Japan); RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); Fushitani, M. [Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 (Japan); RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); Hikosaka, Y. [RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); Department of Environmental Science, Niigata University, Niigata, Niigata 950-2181 (Japan); Liu, C.-N. [Department of Physics, Fu-Jen Catholic University, Taipei 24205, Taiwan (China); Morishita, T. [Department of Engineering Science, University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Shigemasa, E. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 (Japan); RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); Nagasono, M.; Ishikawa, T. [RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); Tono, K.; Togashi, T.; Senba, Y. [JASRI/SPring-8, Sayo, Hyogo 679-5198 (Japan); Ohashi, H.; Kimura, H.; Yabashi, M. [RIKEN/SPring-8, Sayo, Hyogo 679-5148 (Japan); JASRI/SPring-8, Sayo, Hyogo 679-5198 (Japan)

2011-12-09T23:59:59.000Z

282

Multiphoton Ionization of Magnesium in a Ti-Sapphire laser field  

E-Print Network [OSTI]

In this paper we report the theoretical results obtained for partial ionization yields and the above-threshold ionization (ATI) spectra of Magnesium in a Ti:sapphire laser field (804 nm) in the range of short pulse duration (20-120 fs). Ionization yield, with linearly polarized light for a 120 fs laser pulse, is obtained as a function of the peak intensity motivated by recent experimental data \\cite{gillen:2001}. For this, we have solved the time-dependent Schr\\"{o}dinger equation nonperturbatively on a basis of discretized states obtained with two different methods; one with the two-electron wavefunction relaxed at the boundaries, giving a quadratic discretized basis and the other with the two-electron wavefunction expanded in terms of Mg$^+$-orbitals plus one free electron allowing the handling of multiple continua (open channels). Results, obtained with the two methods, are compared and advantages and disadvantages of the open-channel method are discussed.

Nikolopoulos, L A A; Lambropoulos, P; 10.1140/epjd/e2003-00265-7

2013-01-01T23:59:59.000Z

283

Pulsed Laser Deposition | EMSL  

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

Pulsed Laser Deposition Pulsed Laser Deposition EMSL's pulsed laser deposition (PLD) system is designed for epitaxial growth of oxide, ceramic, or synthetic mineral thin films and...

284

Laser barometer  

SciTech Connect (OSTI)

This paper describes an invention of a pressure measuring instrument which uses laser radiation to sense the pressure in an enclosed environment by means of measuring the change in refractive index of a gas - which is pressure dependent.

Abercrombie, K.R.; Shiels, D.; Rash, T.

1998-04-01T23:59:59.000Z

285

LASER ACCELERATORS  

E-Print Network [OSTI]

UNIVERSITY OF CALIFORNIA Accelerator & Fusion Researchat the 1983 Particle Accelerator Conference, Santa Fe, NM,March 21-23, 1983 LASER ACCELERATORS A.M. Sessler TWO-WEEK

Sessler, A.M.

2008-01-01T23:59:59.000Z

286

Laser ignition  

Science Journals Connector (OSTI)

Due to their thermodynamic benefits, second-generation spark-ignition engines with gasoline direct injection systems have ... combination of a spray-guided combustion process with laser-induced ignition allows th...

Bernhard Geringer; Dominikus Klawatsch; Josef Graf; Hans Peter Lenz…

2004-03-01T23:59:59.000Z

287

Laser EYE SURGERY LASIK and Excimer Lasers  

E-Print Network [OSTI]

Laser EYE SURGERY LASIK and Excimer Lasers Michael Hutchins #12;The PROBLEM opia - near sightedness - Laser Assisted in SItu Keratomileusis atomileusis is the procedure of opening the eye and ring the cornea. SIK uses an excimer laser to perform the alterations an er a knife or a femtosecond laser

Fygenson, Deborah Kuchnir

288

Laser Safety Introduction  

E-Print Network [OSTI]

Laser Safety #12;Introduction · A Laser is a device that controls the way energized atoms release photons. · LASER is an acronym for "Light Amplification by Stimulated Emission of Radiation" · The light emitted by a laser is non

McQuade, D. Tyler

289

Along the Laser Beampath  

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

8 20 | Next | Last Back to Index NIF Laser Bay Each NIF laser bay is 122 meters (400 feet) long and contains 96 beamlines. This side view of Laser Bay 2 shows the four-high laser...

290

Micropulse slippage and optical mode distortion in the Boeing APLE amplifier  

Science Journals Connector (OSTI)

In the Boeing Average Power Laser Experiment (APLE), the free electron laser (FEL) oscillator produces short optical pulses for input to the amplifier section. Micropulse slippage can become significant in the amplifier, competing with the effects of high gain and optical mode distortion. A two-dimensional simulation is used to study pulse slippage, and a three-dimensional simulation is used to study mode distortion. A four-dimensional simulation is used to simultaneously study these effects, and to look at the sensitivity of the efficiency to changes in various FEL parameters. We find that high gain and mode distortion effects dominate the pulse slippage effects. The amplifier is fairly insensitice to beam quality degradation and changes in the initial optical field, but a significant improvement in efficiency could be achieved by shortening the electron pulse.

J. Blau; D.J. Frost; W.B. Colson

1993-01-01T23:59:59.000Z

291

Argonne Accelerator Institute  

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

LEUTL: Low Energy Undulator Test Line (operation: 1997-2002) LEUTL: Low Energy Undulator Test Line (operation: 1997-2002) The Low Energy Undulator Test Line (LEUTL) is an experimental hall and associated hardware that was built shortly after the completion of the Advanced Photon Source, and was attached to the APS so that the linac beam could be delivered to the LEUTL hall. LEUTL was configured as a Free Electron Laser (FEL) and was the first experiment to demonstrate Self Amplified Spontaneous Emission in the visible and UV. References - Document Access Guide Description of LEUTL by S. G. Biedron (Argonne National Laboratory Document ) High-Gain Harmonic-Generation Free-Electron Laser, L.-H. Yu, M. Babzien, I. Ben-Zvi, L.F. DiMauro, A. Doyuran, W. Graves, E. Johnson, S. Krinsky, R. Malone, I. Pogorelsky, J. Skaritka, G. Rakowsky, L. Solomon,

292

Non-Invasive Beam Detection in a High-Average Power Electron Accelerator  

SciTech Connect (OSTI)

For a free-electron laser (FEL) to work effectively the electron beam quality must meet exceptional standards. In the case of an FEL operating at infrared wavelengths in an amplifier configuration the critical phase space tends to be in the longitudinal direction. Achieving high enough longitudinal phase space density directly from the electron injector system of such an FEL is difficult due to space charge effects, thus one needs to manipulate the longitudinal phase space once the beam energy reaches a sufficiently high value. However, this is fraught with problems. Longitudinal space charge and coherent synchrotron radiation can both disrupt the overall phase space, furthermore, the phase space disruption is exacerbated by the longitudinal phase space manipulation process required to achieve high peak current. To achieve and maintain good FEL performance one needs to investigate the longitudinal emittance and be able to measure it during operation preferably in a non-invasive manner. Using the electro-optical sampling (EOS) method, we plan to measure the bunch longitudinal profile of a high-energy (~120-MeV), high-power (~10kW or more FEL output power) beam.

Williams, J. [Colorado State U.; Biedron, S. [Colorado State U.; Harris, J. [Colorado State U.; Martinez, J. [Colorado State U.; Milton, S. V. [Colorado State U.; Van Keuren, J. [Colorado State U.; Benson, Steve V. [JLAB; Evtushenko, Pavel [JLAB; Neil, George R. [JLAB; Zhang, Shukui [JLAB

2013-12-01T23:59:59.000Z

293

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

SciTech Connect (OSTI)

Conceptual design of a bright electron injector for the 1 GeV high gradient test experiment. envisaged by the LLNL-SLAC-LBL collaboration on the Relativistic Klystron is presented. The design utilizes a high-brightness laser-driven RF photocathode electron gun, similar to the pioneering LANL early studies in concept (different parametrically however), together with achromatic magnetic bunching and transport systems and diagnostics. The design is performed with attention to possible use in an FEL as well. A simple but realistic analytic model including longitudinal and transverse space-charge and RF effects and extensive computer simulation form the basis of the parametric choice for the source. These parameters are used as guides for the design of the pico-second laser system and magnetic bunching section.

Chattopadhyay, S.; Chen, Y.J.; Hopkins, D.; Kim, K.J.; Kung, A.; Miller, R.; Sessler, a.; Young, T.

1988-09-01T23:59:59.000Z

294

Laser Cosmology  

E-Print Network [OSTI]

Recent years have seen tremendous progress in our understanding of the cosmos, which in turn points to even deeper questions to be further addressed. Concurrently the laser technology has undergone dramatic revolutions, providing exciting opportunity for science applications. History has shown that the symbiosis between direct observations and laboratory investigation is instrumental in the progress of astrophysics. We believe that this remains true in cosmology. Current frontier phenomena related to particle astrophysics and cosmology typically involve one or more of the following conditions: (1) extremely high energy events; (2) very high density, high temperature processes; (3) super strong field environments. Laboratory experiments using high intensity lasers can calibrate astrophysical observations, investigate underlying dynamics of astrophysical phenomena, and probe fundamental physics in extreme limits. In this article we give an overview of the exciting prospect of laser cosmology. In particular, we showcase its unique capability of investigating frontier cosmology issues such as cosmic accelerator and quantum gravity.

Pisin Chen

2014-02-24T23:59:59.000Z

295

Recent Developments on ALICE (Accelerators and Lasers In Combined Experiments) at Daresbury Laboratory  

SciTech Connect (OSTI)

Progress made in ALICE (Accelerators and Lasers In Combined Experiments) commissioning and a summary of the latest experimental results are presented in this paper. After an extensive work on beam loading effects in SC RF linac (booster) and linac cavities conditioning, ALICE can now operate in full energy recovery mode at the bunch charge of 40pC, the beam energy of 30MeV and train lengths of up to 100us. This improved operation of the machine resulted in generation of coherently enhanced broadband THz radiation with the energy of several tens of uJ per pulse and in successful demonstration of the Compton Backscattering x-ray source experiment. The next steps in the ALICE scientific programme are commissioning of the IR FEL and start of the research on the first non-scaling FFAG accelerator EMMA. Results from both projects will be also reported.

Saveliev, Y M; Buckley, R K; Buckley, S R; Clarke, J A; Corlett, P A; Dunning, D J; Goulden, A R; Hill, S F; Jackson, F; Jamison, S P; Jones, J K; Jones, L B; Leonard, S; McIntosh, P A; McKenzie, J W; Middleman, K J; Militsyn, B L; Moss, A J; Muratori, B D; Orrett, J F; Pattalwar, S M; Phillips, P J; Scott, D J; Seddon, E A; Shepherd, B.J.A.; Smith, S L; Thompson, N; Wheelhouse, A E; Williams, P H; Harrison, P; Holder, D J; Holder, G M; Schofield, A L; Weightman, P; Williams, R L; Laundry, D; Powers, T; Priebe, G

2010-05-01T23:59:59.000Z

296

Interferometric and schlieren characterization of the plasmas and shock wave dynamics during laser-triggered discharge in atmospheric air  

SciTech Connect (OSTI)

This paper describes our efforts to reveal the underlying physics of laser-triggered discharges in atmospheric air using a Mach-Zehnder interferometer and schlieren photography. Unlike the hemispherical shock waves that are produced by laser ablation, bell-like morphologies are observed during laser-triggered discharges. Phase shifts are recovered from the interferograms at a time of 1000?ns by the 2D fast Fourier transform method, and then the values of the refractive index are deduced using the Abel inversion. An abundance of free electrons is expected near the cathode surface. The schlieren photographs visualize the formation of stagnation layers at ?600?ns in the interaction zones of the laser- and discharge-produced plasmas. Multiple reflected waves are observed at later times with the development of shock wave propagations. Estimations using the Taylor-Sedov self-similar solution indicated that approximately 45.8% and 51.9% of the laser and electrical energies are transferred into the gas flow motions, respectively. Finally, numerical simulations were performed, which successfully reproduced the main features of the experimental observations, and provided valuable insights into the plasma and shock wave dynamics during the laser-triggered discharge.

Wei, Wenfu; Li, Xingwen, E-mail: xwli@mail.xjtu.edu.cn; Wu, Jian; Yang, Zefeng; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi 710049 (China)

2014-08-15T23:59:59.000Z

297

Demonstration of Successful X-ray Thomson Scattering Using Picosecond K-(alpha) X-ray Sources for the Characterization of Dense Heated Matter  

SciTech Connect (OSTI)

We discuss the first successful K-{alpha} x-ray Thomson scattering experiment from solid density plasmas for use as a diagnostic in determining the temperature, density, and ionization state of warm dense matter with picosecond resolution. The development of this source as a diagnostic and stringent requirements for successful K-{alpha} x-ray Thomson scattering are addressed. Data for the experimental techniques described in this paper [1] suggest the capability of single shot characterization of warm dense matter and the ability to use this scattering source at future Free Electron Lasers (FEL) where comparable scattering signal levels are predicted.

Kritcher, A; Neumayer, P; Lee, H J; Doeppner, T; Falcone, R; Glenzer, S; Morse, E C

2008-05-05T23:59:59.000Z

298

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 (OSTI)

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

299

Jefferson Lab: Laser gun to eventually shoot down missiles (Daily...  

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

articles.dailypress.com2011-02-21newsdp-nws-jefferson-lab-201102211jefferson-lab-researchers-free-electron-l... Submitted: Monday, February 21, 2011...

300

Jupiter Laser Facility  

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

Jupiter Laser Facility The commissioning of the Titan Petawatt-Class laser to LLNL's Jupiter Laser Facility (JLF) has provided a unique platform for the use of petawatt (PW)-class...

Note: This page contains sample records for the topic "free-electron laser fel" 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

Hypersonic gasdynamic laser system  

SciTech Connect (OSTI)

This patent describes a visible, or near to mid infra-red, hypersonic gas dynamic laser system. It comprises: a hypersonic vehicle for carrying the hypersonic gas dynamic laser system, and also providing high energy ram air for thermodynamic excitation and supply of the laser gas; a laser cavity defined within the hypersonic vehicle and having a laser cavity inlet for the laser cavity formed by an opening in the hypersonic vehicle, such that ram air directed through the laser cavity opening supports gas dynamic lasing operations at wavelengths less than 10.6{mu} meters in the laser cavity; and an optical train for collecting the laser radiation from the laser cavity and directing it as a substantially collimated laser beam to an output aperture defined by an opening in the hypersonic vehicle to allow the laser beam to be directed against a target.

Foreman, K.M.; Maciulaitis, A.

1990-05-22T23:59:59.000Z

302

Terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

...Michael Pepper Terahertz quantum cascade lasers Jerome Faist 1 Lassaad Ajili...developments in terahertz quantum cascade lasers are reviewed. Structures...magnetic confinement| Terahertz quantum cascade lasers. | Recent developments in...

2004-01-01T23:59:59.000Z

303

A comparative study of laser ignition and spark ignition with gasoline–air mixtures  

Science Journals Connector (OSTI)

Abstract The ignition probability and minimum ignition energy (MIE) of premixed gasoline–air mixture for different equivalence ratio was experimentally studied using a nanosecond pulse at 532 nm and 1064 nm from a Q-switched Nd:YAG laser in a constant-volume combustion chamber (CVCC) The result was compared with the spark ignition. The initial pressure and temperature of the mixture was 0.1 MP and 363 K, respectively. The research indicates that within the flammable range, the probability increases when the ignition energy increases and the distribution of MIE with the equivalence ratios is U-shape for both laser and spark ignition. For laser ignition with 532 nm, when the incident energy is higher than 110 mJ or the absorbed energy is high than 31 mJ, 100% of ignition could be obtained within equivalence ratios of 0.8–1.6. For 1064 nm it is 235 mJ and 30 mJ. To get the same ignition probability of mixture with identical equivalence ratio, the incident energy of 1064 nm is twice more than the incident energy of 532 nm, while the absorbed energy values are virtually the same. It indicates that significant wavelength dependence is expected for the initial free electrons but irrelevant for the process of absorbing energy. The initial free electrons are produced from impurities in gasoline–air mixture because the intensity in the focus (1012 W/cm2) is too low to ionize gas molecules via the multi-photon ionization process, which requires higher irradiance (?1014 W/cm2). The MIE obtained with a laser-spark ignition is greater than that measured by electrical sparks. The MIE for laser ignition was obtained at equivalence ratio of 1.0 both of 532 nm and 1064 nm, and it was 13.5 mJ and 9.5 mJ, respectively. But for spark ignition, the MIE is 3.76 mJ with equivalence ratio of 1.6. What?s more, laser ignition extends the lean flammability limit from 0.8 to 0.6.

Cangsu Xu; Donghua Fang; Qiyuan Luo; Jian Ma; Yang Xie

2014-01-01T23:59:59.000Z

304

LLE (Laboratory for Laser Energetics) Review: Quarterly report, January--March 1997. Volume 70  

SciTech Connect (OSTI)

This volume of the LLE Review includes an article on the status of the optics on the OMEGA laser system after the first 18 months of operation. A vigorous program to monitor the performance of the optics has been followed since the inception of the OMEGA laser. The article presents results from these observations and defines the various types of possible damage. Many of the optics have not damaged, such as the frequency-conversion crystals, polarizers, calorimeters, and liquid crystal optics. The most significant damage has been sustained by the fused-silica spatial filter lenses. There has been no evidence of any propagation of damage downstream of damage optics. Other highlights of research presented here are: The development of a single-beam, ponderomotive optical trap for energetic free electrons. A description of the new diode-pumped Nd:YLF master oscillator for the OMEGA laser. Simulations of heat transfer from localized absorbing defects to the host coating material in HfO{sub 2}/SiO{sub 2} 351-nm high reflectors. An experimental study of target performance and mixing in titanium-doped target implosions on OMEGA. A theoretical calculation of the dephasing time of an electron accelerated by a laser pulse. Separate abstracts have been indexed into the energy database from articles in this volume.

NONE

1997-06-01T23:59:59.000Z

305

Laser Desorption Analysis | EMSL  

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

Laser Desorption Analysis Laser Desorption Analysis EMSL offers a suite of instrumentation dedicated to understanding photoreactivity in the condensed phase, on surfaces, and at...

306

Laser Desorption Analysis | EMSL  

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

neutral particle detection using a second multiphoton ionization or REMPI laser system; and UHV surface diagnostic equipment (AES, LEED, XPS). User Portal Name: Laser...

307

Laser Safety Management Policy Statement ............................................................................................................1  

E-Print Network [OSTI]

Laser Safety Management Policy Statement...........................................................2 Laser Users.............................................................................................................2 Unit Laser Safety Officer (ULSO

Davidson, Fordyce A.

308

EA-1534: Final Environmental Assessment | Department of Energy  

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

Final Environmental Assessment Final Environmental Assessment EA-1534: Final Environmental Assessment Proposed Upgrade and Operation of the CEBAF and FEL Accelerators and Construction and Use of Buildings Associated with the 2005 Ten-Year Site Plan The U. S. Department of Energy (DOE), in this Environmental Assessment (EA), reports the results of an analysis of the potential environmental impacts from the proposed upgrade and operation of the Continuous Electron Beam Accelerator Facility (CEBAF) and Free-Electron Laser (FEL) accelerators and the construction and use of buildings associated with the 2005 Ten-Year Site Plan at the Thomas Jefferson National Accelerator Facility (TJNAF or Jefferson Lab) in Newport News, Virginia. Environmental Assessment for the Proposed Upgrade and Operation of the

309

EA-1426: Final Environmental Assessment | Department of Energy  

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

6: Final Environmental Assessment 6: Final Environmental Assessment EA-1426: Final Environmental Assessment Linac Coherent Light Source Experimental Facility The 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. The purpose and need for the LCLS is the creation of a new type of x-ray light source from a single pass free electron laser (FEL). The FEL would have a peak brightness 10 orders of magnitude greater and with faster pulses (in the sub-picosecond range), than the most intense synchrotrons currently available. The higher peak brightness would allow examination of much smaller particles, and the faster pulses would allow scientists to evaluate changes within a very short timeframe. As with the

310

EA-1426: Final Environmental Assessment | Department of Energy  

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

426: Final Environmental Assessment 426: Final Environmental Assessment EA-1426: Final Environmental Assessment Linac Coherent Light Source Experimental Facility The 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. The purpose and need for the LCLS is the creation of a new type of x-ray light source from a single pass free electron laser (FEL). The FEL would have a peak brightness 10 orders of magnitude greater and with faster pulses (in the sub-picosecond range), than the most intense synchrotrons currently available. The higher peak brightness would allow examination of much smaller particles, and the faster pulses would allow scientists to evaluate changes within a very short timeframe. As with the

311

Laser Stabilization  

SciTech Connect (OSTI)

This book chapter covers the basics of the field of stabilizing lasers to optical frequency references such as optical cavities and molecular transitions via the application of servo control systems. These discussions are given with reference to the real-life frequency metrology experienced in Hall-Labs (now Ye-Labs), JILA, University of Colorado. The subjects covered include: the basics of control system stability, a discussion of both the theoretical and experimental limitations, an outline of optical cavity susceptibility to environmental noise, and a brief introduction to the use and limitations of molecular transitions as frequency references.

Hall, John L.; Taubman, Matthew S.; Ye, Jun

2010-01-01T23:59:59.000Z

312

Omega Laser Facility - Laboratory for Laser Energetics  

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

- Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE...

313

OMEGA Laser - Laboratory for Laser Energetics  

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

- Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE...

314

OMEGA Laser Drivers - Laboratory for Laser Energetics  

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

Drivers - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE...

315

Nitrogen doping in pulsed laser deposited ZnO thin films using dense plasma focus  

Science Journals Connector (OSTI)

Pulsed laser deposition synthesized ZnO thin films, grown at 400 °C substrate temperature in different oxygen gas pressures, were irradiated with 6 shots of pulsed nitrogen ions obtained from 2.94 kJ dense plasma focus to achieve the nitrogen doping in ZnO. Structural, compositional and optical properties of as-deposited and nitrogen ion irradiated ZnO thin films were investigated to confirm the successful doping of nitrogen in irradiated samples. Spectral changes have been seen in the nitrogen irradiated ZnO thin film samples from the low temperature PL measurements. Free electron to acceptor emissions can be observed from the irradiated samples, which hints towards the successful nitrogen doping in films. Compositional analysis by X-ray photoelectron spectroscopy and corresponding shifts in binding energy core peaks of oxygen and nitrogen confirmed the successful use of plasma focus device as a novel source for nitrogen ion doping in ZnO thin films.

S. Karamat; R.S. Rawat; T.L. Tan; P. Lee; S.V. Springham; E. Ghareshabani; R. Chen; H.D. Sun

2011-01-01T23:59:59.000Z

316

The laser satellites communications and laser noises  

Science Journals Connector (OSTI)

The gain of advanced optical communication systems is reduced by the noise of optical source. Coherent optical communication systems are in particular very sensitive to the noise transmitter and local laser. Optical space communications is on the verge ... Keywords: laser, laser communication, noise limits, optical communication, range loss, satellite communications, satellite systems, signal transfer loss, space channel

Marketa Mazalkova

2008-08-01T23:59:59.000Z

317

ablation laser spectrometer  

E-Print Network [OSTI]

ablation laser mass spectrometer molecular beam REMPI laser NREL has designed and developed a combined laser ablation/ pulsed sample introduction/mass spectrometry platform that integrates pyrolysis and/or laser ablation with resonance- enhanced multiphoton ionization (REMPI) time-of-flight mass

318

Narrow gap laser welding  

DOE Patents [OSTI]

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

Milewski, J.O.; Sklar, E.

1998-06-02T23:59:59.000Z

319

Narrow gap laser welding  

DOE Patents [OSTI]

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

Milewski, John O. (Santa Fe, NM); Sklar, Edward (Santa Fe, NM)

1998-01-01T23:59:59.000Z

320

Short wavelength laser  

DOE Patents [OSTI]

A short wavelength laser is provided that is driven by conventional-laser pulses. A multiplicity of panels, mounted on substrates, are supported in two separated and alternately staggered facing and parallel arrays disposed along an approximately linear path. When the panels are illuminated by the conventional-laser pulses, single pass EUV or soft x-ray laser pulses are produced.

Hagelstein, P.L.

1984-06-25T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Laser Glazing of Railroad Rails [Laser Applications Laboratory] - Nuclear  

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

Laser Glazing of Railroad Laser Glazing of Railroad Rails Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Glazing of Railroad Rails Project description: Laser glazing of rails. Category: Project with industrial partner (American Association of Railroads) Bookmark and Share

322

Laser Welding of Metals [Laser Applications Laboratory] - Nuclear  

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

Laser Welding of Metals Laser Welding of Metals Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Welding of Metals Project description: High-speed laser welding of metals. Category: Project with industrial partner (Delphi Energy and Engine Management Systems) Bookmark and Share

323

PALM - Laser Capture Microdissection | EMSL  

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

PALM - Laser Capture Microdissection PALM - Laser Capture Microdissection This Laser Capture Microdissection system is equipped with 100 x objective lens for enriching distinct...

324

Learn More about Fusion & Lasers  

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

& Lasers How Lasers Work Learn how lasers were developed and how they work. Outreach NIF & Photon Science researchers take learning opportunities on the road. Glossary Don't...

325

BNL | CO2 Laser  

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

CO2 Laser CO2 Laser The ATF is one of the only two facilities worldwide operating picosecond, terawatt-class CO2 lasers. Our laser system consists of a picoseconds pulse-injector based on fast optical switching from the output of a conventional CO2 laser oscillator, and a chain of high-pressure laser amplifiers. It starts with a wavelength converter wherein a near-IR picosecond solid-state laser with l»1 μm produces a mid-IR 10-μm pulse. This process employs two methods; semiconductor optical switching, and the Kerr effect. First, we combine the outputs from a multi-nanosecond CO2 laser oscillator with a picosecond Nd:YAG laser on a germanium Brewster-plate to produce an ~200 ps, 10μm pulse by semiconductor optical switching. Co-propagating this pulse with a Nd:YAG's 2nd harmonic in a

326

BNL | CFN Laser System Qualifications  

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

Laser System Qualification There are multiple laser systems at the CFN. Users who will be working with the following class 3B or 4 laser systems are required to complete the Laser...

327

BUILDING A CHEMICAL LASER WEAPON  

Science Journals Connector (OSTI)

BUILDING A CHEMICAL LASER WEAPON ... Under fire, Airborne Laser program director confronts challenges of revolutionary weapons system ...

WILLIAM G. SCHULZ

2004-12-20T23:59:59.000Z

328

Final Report, Photocathodes for High Repetition Rate Light Sources  

SciTech Connect (OSTI)

This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-antimonide cathodes b) Development and testing of a diamond amplifier for photocathodes c) Tests of both cathodes in superconducting RF photoguns and copper RF photoguns

Ben-Zvi, Ilan [Stony Brook University

2014-04-20T23:59:59.000Z

329

Potential For Laser-Induced Microbunching Studies with the 3-MHZ-Rate Electron Beams at ASTA  

E-Print Network [OSTI]

Investigations of the laser-induced microbunching as it is related to time-sliced electron-beam diagnostics and high-gain-harmonic generation (HGHG) free-electron lasers using bright electron beams are proposed for the ASTA facility. Initial tests at 40-50 MeV with an amplified 800-nm seed laser beam co-propagating with the electron beam through a short undulator (or modulator) tuned for the resonance condition followed by transport through a subsequent chicane will result in energy modulation and z-density modulation (microbunching), respectively. The latter microbunching will result in generation of coherent optical or UV transition radiation (COTR, CUVTR) at a metal converter screen which can reveal slice beam size, centroid, and energy spread. Additionally, direct assessment of the microbunching factors related to HGHG by measurement of the COTR intensity and harmonic content after the chicane as a function of seed laser power and beam parameters will be done. These experiments will be performed using the...

Lumpkin, A H; Byrd, J M; Wilcox, R B

2014-01-01T23:59:59.000Z

330

Along the Laser Beampath  

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

has been installed in the preamplifier modules (PAMs) at the front end of the NIF laser system. The spatial shapers can obscure the laser light at programmed locations within...

331

Laser particle sorter  

DOE Patents [OSTI]

Method and apparatus are provided for sorting particles, such as biological particles. A first laser is used to define an optical path having an intensity gradient which is effective to propel the particles along the path but which is sufficiently weak that the particles are not trapped in an axial direction. A probe laser beam is provided for interrogating the particles to identify predetermined phenotypical characteristics of the particles. A second laser beam is provided to intersect the driving first laser beam, wherein the second laser beam is activated by an output signal indicative of a predetermined characteristic. The second laser beam is switchable between a first intensity and a second intensity, where the first intensity is effective to displace selected particles from the driving laser beam and the second intensity is effective to propel selected particles along the deflection laser beam. The selected particles may then be propelled by the deflection beam to a location effective for further analysis. 2 figs.

Martin, J.C.; Buican, T.N.

1987-11-30T23:59:59.000Z

332

Laser preheat enhanced ignition  

DOE Patents [OSTI]

A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided.

Early, James W. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

333

Laser preheat enhanced ignition  

DOE Patents [OSTI]

A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided. 11 figs.

Early, J.W.

1999-03-02T23:59:59.000Z

334

Laser-assisted electrochemistry  

SciTech Connect (OSTI)

The effect of laser irradiation on electrodeposition processes has been investigated. These studies demonstrated that the addition of laser irradiation to an electroplating process can dramatically enhance plating rates and current efficiencies, as well as improve the morphology of the resultant electrodeposit. During the course of these investigations, the mechanism for the laser enhancement of electrodeposition processes was determined. Experimental evidence was obtained to show that laser irradiation of the substrate results in increased metal ion concentrations at the surface of the electrode due to a laser-induced Soret effect. The laser-induced Soret effect has important implications for laser-assisted electrochemical processing. The increase in the surface concentration of ions allows efficient electrodeposition from dilute solutions. As such, laser- assisted electrodeposition may develop into an environmentally conscious manufacturing process by reducing waste and limiting worker exposure to toxic chemicals.

Glenn, D.F.

1995-05-01T23:59:59.000Z

335

Short wavelength laser  

DOE Patents [OSTI]

A short wavelength laser (28) is provided that is driven by conventional-laser pulses (30, 31). A multiplicity of panels (32), mounted on substrates (34), are supported in two separated and alternately staggered facing and parallel arrays disposed along an approximately linear path (42). When the panels (32) are illuminated by the conventional-laser pulses (30, 31), single pass EUV or soft x-ray laser pulses (44, 46) are produced.

Hagelstein, Peter L. (Livermore, CA)

1986-01-01T23:59:59.000Z

336

Monte Carlo study for optimal conditions in single-shot imaging with femtosecond x-ray laser pulses  

SciTech Connect (OSTI)

Intense x-ray pulses from x-ray free electron lasers (XFELs) enable the unveiling of atomic structure in material and biological specimens via ultrafast single-shot exposures. As the radiation is intense enough to destroy the sample, a new sample must be provided for each x-ray pulse. These single-particle delivery schemes require careful optimization, though systematic study to find such optimal conditions is still lacking. We have investigated two major single-particle delivery methods: particle injection as flying objects and membrane-mount as fixed targets. The optimal experimental parameters were searched for via Monte Carlo simulations to discover that the maximum single-particle hit rate achievable is close to 40%.

Park, Jaehyun; Ishikawa, Tetsuya; Song, Changyong [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Joti, Yasumasa [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2013-12-23T23:59:59.000Z

337

Laser Heat Treatment [Laser Applications Laboratory] - Nuclear Engineering  

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

Heat Treatment Heat Treatment Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Heat Treatment Project description: Optimization of laser beam heat treatment. Category: Project with industrial partner (Caterpillar and USCAR) Bookmark and Share Heat treatment optics

338

Laser-driven fusion  

Science Journals Connector (OSTI)

The use of intense laser light to bring about thermonuclear reactions in a plasma is of considerable current interest. We present detailed analytical and computational studies which show the feasibility of laser-driven fusion. The required laser technology and the presently anticipated practical difficulties are discussed in outline.

Keith A. Brueckner and Siebe Jorna

1974-04-01T23:59:59.000Z

339

Laser bottom hole assembly  

DOE Patents [OSTI]

There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

2014-01-14T23:59:59.000Z

340

X-ray laser  

DOE Patents [OSTI]

An X-ray laser (10) that lases between the K edges of carbon and oxygen, i.e. between 44 and 23 Angstroms, is provided. The laser comprises a silicon (12) and dysprosium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like dysprosium ions (34) are resonantly photo-pumped to their upper X-ray laser state by line emission from hydrogen-like silicon ions (32). The novel X-ray laser should prove especially useful for the microscopy of biological specimens.

Nilsen, Joseph (Livermore, CA)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Ultrafast Laser Facility | Photosynthetic Antenna Research Center  

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

Ultrafast Laser Facility Ultrafast Laser Facility Click for an Overview of the Ultrafast Laser Facility The PARC Ultrafast Laser Facility, under the direction of Associate Director...

342

Laser system using ultra-short laser pulses  

DOE Patents [OSTI]

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

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

2009-10-27T23:59:59.000Z

343

Environmental Assessment for the Proposed Upgrade and Operation of the CEBAF and FEL Accelerators and Construction and Use of Buildings Associated with the 2005 Ten-Year Site Plan  

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

4 4 Environmental Assessment Proposed Upgrade and Operation of the CEBAF and FEL Accelerators and Construction and Use of Buildings Associated with the 2005 Ten-Year Site Plan at the Thomas Jefferson National Accelerator Facility Newport News, Virginia January 2007 U. S. Department of Energy Thomas Jefferson Site Office Newport News, VA DOE/EA-1534 January 2007 C:\TRANSFER\JANUARY 26 Final EA-1534-012607 (2).doc i TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................... 1 1.0 INTRODUCTION ...........................................................................................11 1.1 PREVIOUS ACTIONS....................................................................................11 1.2 SCOPE OF THIS PROPOSED ACTION .......................................................11

344

Searching for plasmas with anomalous dispersion in the soft X-ray regime  

SciTech Connect (OSTI)

Over the last decade the electron density of plasmas has been measured using X-ray laser interferometers in the 14 to 47 nm wavelength regime. With the same formula used in decades of experiments with optical interferometers, the data analysis assumes the index of refraction is due only to the free electrons, which makes the index less than one. Over the last several years, interferometer experiments in C, Al, Ag, and Sn plasmas have observed plasmas with index of refraction greater than one at 14 or 47 nm and demonstrated unequivocally that the usual formula for calculating the index of refraction is not always valid as the contribution from bound electrons can dominate the free electrons in certain cases. In this paper we search for other materials with strong anomalous dispersion that could be used in X-ray laser interferometer experiments to help understand this phenomena. An average atom code is used to calculate the plasma properties. This paper discusses the calculations of anomalous dispersion in Ne and Na plasmas near 47 nm and Xe plasmas near 14 nm. With the advent of the FLASH X-ray free electron laser in Germany and the LCLS X-FEL coming online at Stanford in 2 years the average atom code will be an invaluable tool to explore plasmas at higher X-ray energy to identify potential experiments for the future. During the next decade X-ray free electron lasers and other X-ray sources will be used to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

Nilsen, J; Johnson, W R; Cheng, K T

2007-08-24T23:59:59.000Z

345

LASER SAFETY POLICY Policy Statement  

E-Print Network [OSTI]

LASER SAFETY POLICY Policy Statement Each department that acquires or operates lasers for use in laboratories or research is responsible for reporting laser acquisition to the Office of Laboratory Safety, selecting a departmental deputy laser safety officer, mandating training for its laser operators

Vertes, Akos

346

OMEGA Extended Performance Laser System  

E-Print Network [OSTI]

at UR-LLE is close to that required for ignition to occur. #12;The OMEGA Extended Performance (EP) laserOMEGA Extended Performance Laser System R. L. McCrory University of Rochester Laboratory for Laser­18 February 2008 #12;OMEGA Extended Performance Laser System R.L. McCrory Laboratory for Laser Energetics

347

Laser Safety Inspection Criteria  

SciTech Connect (OSTI)

A responsibility of the Laser Safety Officer (LSO) is to perform laser safety audits. The American National Standard Z136.1 Safe use of Lasers references this requirement in several sections: (1) Section 1.3.2 LSO Specific Responsibilities states under Hazard Evaluation, ''The LSO shall be responsible for hazards evaluation of laser work areas''; (2) Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''; and (3) Appendix D, under Survey and Inspections, it states, ''the LSO will survey by inspection, as considered necessary, all areas where laser equipment is used''. Therefore, for facilities using Class 3B and or Class 4 lasers, audits for laser safety compliance are expected to be conducted. The composition, frequency and rigueur of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms. In many institutions, a sole Laser Safety Officer (LSO) or a number of Deputy LSO's perform these audits. For that matter, there are institutions that request users to perform a self-assessment audit. Many items on the common audit list and the associated findings are subjective because they are based on the experience and interest of the LSO or auditor in particular items on the checklist. Beam block usage is an example; to one set of eyes a particular arrangement might be completely adequate, while to another the installation may be inadequate. In order to provide more consistency, the National Ignition Facility Directorate at Lawrence Livermore National Laboratory (NIF-LLNL) has established criteria for a number of items found on the typical laser safety audit form. These criteria are distributed to laser users, and they serve two broad purposes: first, it gives the user an expectation of what will be reviewed by an auditor, and second, it is an opportunity to explain audit items to the laser user and thus the reasons for some of these items. Some examples are given from the audit criteria handout. As an explanatory key to the reader, an Operational Safety Procedure (OSP) as a formally reviewed safety procedure required for all Class 3B and Class 4 laser installations. An ''OSP Binder'' contains all safety documentation related to a given laser operation and serves as a central repository for documents, such as the OSP, interlock logs, lessons learned, contact information etc. ''Unattended Operation'' refers to approved procedures for unattended operation of the laser installation and may include operation beyond normal working hours. ''L-train'' is the LLNL training tracking system.

Barat, K

2005-02-11T23:59:59.000Z

348

Laser induced nuclear reactions  

SciTech Connect (OSTI)

Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10{sup 19} W/cm{sup 2}. In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that {mu}Ci of {sup 62}Cu can be generated via the ({gamma},n) reaction by a laser with an intensity of about 10{sup 19} Wcm{sup -2}.

Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); European Commission, Institute for Transuranic Elements, Karlsruhe, Postfach 2340, D-76125 (Germany); Scottish Universities Research and Reactor Centre, East Kilbride, Glasgow G75 0QU (United Kingdom); Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom); Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU (United Kingdom)

1998-12-16T23:59:59.000Z

349

Polarization feedback laser stabilization  

DOE Patents [OSTI]

A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

Esherick, P.; Owyoung, A.

1987-09-28T23:59:59.000Z

350

Terahertz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We provide an overview of terahertz quantum cascade lasers based on resonant-phonon depopulation and metal-metal waveguides, including two-phonon resonant-phonon depopulation...

Williams, Benjamin; Kumar, Sushil; Qin, Qi; Lee, Alan Wei Min; Hu, Qing; Reno, John L; Wasilewski, Z R; Liu, H C

351

OMEGA EP Laser Dedication Movie - Laboratory for Laser Energetics  

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

Dedication Movie - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to...

352

Chirped Laser Dispersion Spectroscopy with Directly Modulated Quantum Cascade Laser  

Science Journals Connector (OSTI)

A feasibility study of chirped laser dispersion spectroscopy (CLaDS) with utilizing direct modulation of a quantum cascade laser instead of external modulators is presented....

Hangauer, Andreas; Spinner, Georg; Nikodem, Michal; Wysocki, Gerard

353

Documentation - Laboratory for Laser Energetics  

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

Daily Securing Checklist (S-AB-P-482) EP Bay and OAA Securing Walkthrough (S-AB-P-582) Laser StartupShutdown LOTF Laser Startup (S-AB-P-038) LOTF Laser Shutdown (S-AB-P-039) IRAT...

354

Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources  

SciTech Connect (OSTI)

Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

Chao, Alex; Ratner, Daniel; /SLAC; Jiao, Yi; /Beijing, Inst. High Energy Phys.

2012-09-06T23:59:59.000Z

355

Single Particle Laser Ablation | EMSL  

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

Single Particle Laser Ablation Single Particle Laser Ablation Leads No leads are available at this time. Effect of Solar Radiation on the Optical Properties and Molecular...

356

Plasmonic Quantum Cascade Laser Antenna  

Science Journals Connector (OSTI)

We demonstrate the plasmonic quantum cascade laser antenna, that can confine mid-infrared radiation beyond the diffraction limit, by integrating gold optical antennas on the laser...

Yu, Nanfang; Cubukcu, Ertugrul; Diehl, Laurent; Crozier, Kenneth; Capasso, Federico

357

From Gas Lasers and Tunable Raman Lasers to Quantum Cascade Lasers  

Science Journals Connector (OSTI)

I will describe my involvement in lasers from 1961 to the present, ecompassing high power carbon dioxide lasers, tunable spin-flip Raman lasers, and now high power CW room temperature...

Patel, Kumar

358

Liquid heat capacity lasers  

DOE Patents [OSTI]

The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)

2007-05-01T23:59:59.000Z

359

Explosively pumped laser light  

DOE Patents [OSTI]

A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

360

Laser dividing apparatus  

DOE Patents [OSTI]

A laser beam dividing apparatus (10) having a first beam splitter (14) with an aperture (16) therein positioned in the path of a laser beam (12) such that a portion of the laser beam (12) passes through the aperture (16) onto a second beam splitter (20) and a portion of the laser beam (12) impinges upon the first beam splitter (14). Both the first beam splitter (14) and the second beam splitter (20) are, optionally, made from a dichroic material such that a green component (24) of the laser beam (12) is reflected therefrom and a yellow component (26) is refracted therethrough. The first beam splitter (14) and the second beam splitter (20) further each have a plurality of facets (22) such that the components (24, 26) are reflected and refracted in a number equaling the number of facets (22).

English, Jr., R. Edward (Tracy, CA); Johnson, Steve A. (Tracy, CA)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Guest Editorial: Laser Damage  

SciTech Connect (OSTI)

Laser damage of optical materials, first reported in 1964, continues to limit the output energy and power of pulsed and continuous-wave laser systems. In spite of some 48 years of research in this area, interest from the international laser community to laser damage issues remains at a very high level and does not show any sign of decreasing. Moreover, it grows with the development of novel laser systems, for example, ultrafast and short-wavelength lasers that involve new damage effects and specific mechanisms not studied before. This interest is evident from the high level of attendance and presentations at the annual SPIE Laser Damage Symposium (aka, Boulder Damage Symposium) that has been held in Boulder, Colorado, since 1969. This special section of Optical Engineering is the first one devoted to the entire field of laser damage rather than to a specific part. It is prepared in response to growing interest from the international laser-damage community. Some papers in this special section were presented at the Laser Damage Symposium; others were submitted in response to the general call for papers for this special section. The 18 papers compiled into this special section represent many sides of the broad field of laser-damage research. They consider theoretical studies of the fundamental mechanisms of laser damage including laser-driven electron dynamics in solids (O. Brenk and B. Rethfeld; A. Nikiforov, A. Epifanov, and S. Garnov; T. Apostolova et al.), modeling of propagation effects for ultrashort high-intensity laser pulses (J. Gulley), an overview of mechanisms of inclusion-induced damage (M. Koldunov and A. Manenkov), the formation of specific periodic ripples on a metal surface by femtosecond laser pulses (M. Ahsan and M. Lee), and the laser-plasma effects on damage in glass (Y. Li et al). Material characterization is represented by the papers devoted to accurate and reliable measurements of absorption with special emphasis on thin films (C. Mühlig and S. Bublitz; B. Cho, E. Danielewicz, and J. Rudisill; W. Palm et al; and J. Lu et al.). Statistical treatment of measurements of the laser-damage threshold (J. Arenberg) and the relationship to damage mechanisms (F. Wagner et al.) represent the large subfield of laser-damage measurements. Various aspects of multilayer coating and thin-film characterization are considered in papers by B. Cho, J. Rudisill, and E. Danielewicz (spectral shift in multilayer mirrors) and R. Weber et al. (novel approach to damage studies based on third-harmonic generation microscopy). Of special interest for readers is the paper by C. Stolz that summarizes the results of four “thin-film damage competitions” organized as a part of the Laser Damage Symposium. Another paper is devoted to thermal annealing of damage precursors (N. Shen et al.). Finally, the influence of nano-size contamination on initiation of laser damage by ultrashort pulses is considered in paper of V. Komolov et al.

Vitaly Gruzdev, Michelle D. Shinn

2012-12-01T23:59:59.000Z

362

Theoretical investigation of a tunable free-electron light source  

SciTech Connect (OSTI)

The concept and experimental results of a light source given in a recent paper by Adamo et al.[Phys. Rev. Lett. 103, 113901 (2009)] are very interesting and attractive. Our paper presents detailed theoretical investigations on such a light source, and our results confirm that the mechanism of the light radiation experimentally detected in the published paper is a special kind of diffraction radiation in a waveguide with nanoscale periodic structure excited by an electron beam. The numerical calculations based on our theory and digital simulations agree well with the experimental results. This mechanism of diffraction radiation is of significance in physics and optics, and may bring good opportunities for the generation of electromagnetic waves from terahertz to light frequency regimes.

Liu Shenggang; Hu Min; Zhang Yaxin; Liu Weihao; Zhang Ping; Zhou Jun [Terahertz Research Center, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-06-15T23:59:59.000Z

363

Theoretical investigation of a tunable free-electron light source  

Science Journals Connector (OSTI)

The concept and experimental results of a light source given in a recent paper by Adamo et al. [Phys. Rev. Lett. 103, 113901 (2009)] are very interesting and attractive. Our paper presents detailed theoretical investigations on such a light source, and our results confirm that the mechanism of the light radiation experimentally detected in the published paper is a special kind of diffraction radiation in a waveguide with nanoscale periodic structure excited by an electron beam. The numerical calculations based on our theory and digital simulations agree well with the experimental results. This mechanism of diffraction radiation is of significance in physics and optics, and may bring good opportunities for the generation of electromagnetic waves from terahertz to light frequency regimes.

Shenggang Liu; Min Hu; Yaxin Zhang; Weihao Liu; Ping Zhang; Jun Zhou

2011-06-30T23:59:59.000Z

364

The Theta Laser A Low Noise Chirped Pulse Laser  

E-Print Network [OSTI]

The Theta Laser A Low Noise Chirped Pulse Laser Dimitrios Mandridis dmandrid@creol.ucf.edu April 29, 2011 CREOL Affiliates Day 2011 #12;2 Objective: Frequency Swept (FM) Mode-locked Laser · Develop a frequency swept laser, · linear f-sweep, · uniform-intensity, · low noise, · with long-term stability

Van Stryland, Eric

365

Research | Jefferson Lab  

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

Free-Electron Laser Research Inspecting an injector assembly at Jefferson Lab's Free-Electron Laser. A D D I T I O N A L L I N K S: Read more Nuclear Imaging Research Jefferson...

366

The Next Challenge in X-Ray Science: Control of Resonant Electronic  

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

The Next Challenge in X-Ray Science: Control of Resonant Electronic The Next Challenge in X-Ray Science: Control of Resonant Electronic Processes Wednesday, September 11, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Joachim Stöhr, LCLS My talk will give a historic perspective of the revolutionary science that was enabled by the advent of high power sources of coherent electromagnetic radiation and the implications for future scientific opportunities with x-ray free electron lasers (X-FELs). The historical journey starts with the development of radar microwave sources in the 1940s that fueled the development of nuclear magnetic resonance (NMR) techniques which by now have led to 6 Nobel Prizes. The theoretical description of NMR as coherent processes between nuclear states by Rabi and Bloch also provided the theoretical basis for the optical laser and its applications. Over the last

367

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

368

Quantum electrodynamics in a laser and the electron laser collision  

E-Print Network [OSTI]

Quantum electrodynamics in a laser is formulated, in which the electron-laser interaction is exactly considered, while the interaction of an electron and a single photon is considered by perturbation. The formulation is applied to the electron-laser collisions. The effect of coherence between photons in the laser is therefore fully considered in these collisions. The possibility of $\\gamma-$ray laser generation by use of this kind of collision is discussed.

Qi-Ren Zhang

2014-08-08T23:59:59.000Z

369

Ultra-fast laser system  

DOE Patents [OSTI]

A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

Dantus, Marcos; Lozovoy, Vadim V

2014-01-21T23:59:59.000Z

370

1982 laser program annual report  

SciTech Connect (OSTI)

This annual report covers the following eight sections: (1) laser program review, (2) laser systems and operation, (3) target design, (4) target fabrication, (5) fusion experiments program, (6) Zeus laser project, (7) laser research and development, and (8) energy applications. (MOW)

Hendricks, C.D.; Grow, G.R. (eds.)

1983-08-01T23:59:59.000Z

371

Second and Third Harmonic Measurements at the Linac Coherent Light Source  

SciTech Connect (OSTI)

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

372

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

SciTech Connect (OSTI)

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

373

Infrared Spectroscope for Electron Bunch-length Measurement: Heat Sensor Parameters Analysis  

SciTech Connect (OSTI)

The Linac Coherent Light Source (LCLS) is used for many experiments. Taking advantage of the free electron laser (FEL) process, scientists of various fields perform experiments of all kind. Some for example study protein folding; other experiments are more interested in the way electrons interact with the molecules before they are destroyed. These experiments among many others have very little information about the electrons x-ray produced by the FEL, except that the FEL is using bunches less than 10 femtoseconds long. To be able to interpret the data collected from those experiments, more accurate information is needed about the electron's bunch-length. Existing bunch length measurement techniques are not suitable for the measurement of such small time scales. Hence the need to design a device that will provide more precise information about the electron bunch length. This paper investigates the use of a pyreoelectric heat sensor that has a sensitivity of about 1.34 micro amps per watt for the single cell detector. Such sensitivity, added to the fact that the detector is an array sensor, makes the detector studied the primary candidate to be integrated to an infrared spectrometer designed to better measure the LCLS electron bunch length.

Domgmo-Momo, Gilles; /Towson U. /SLAC

2012-09-05T23:59:59.000Z

374

Fiber optic laser rod  

DOE Patents [OSTI]

A laser rod is formed from a plurality of optical fibers, each forming an individual laser. Synchronization of the individual fiber lasers is obtained by evanescent wave coupling between adjacent optical fiber cores. The fiber cores are dye-doped and spaced at a distance appropriate for evanescent wave coupling at the wavelength of the selected dye. An interstitial material having an index of refraction lower than that of the fiber core provides the optical isolation for effective lasing action while maintaining the cores at the appropriate coupling distance. 2 figs.

Erickson, G.F.

1988-04-13T23:59:59.000Z

375

Anomalous laser-induced ionization rates of molecules and rare-gas atoms  

SciTech Connect (OSTI)

Electron tunnel ionization is considered as the mechanism for producing free electrons in gases under laser radiation. The Keldysh result and the Ammosov-Delone-Krainov (ADK) formulation are amended by considering the excess forces due to the interaction of the electric field of the laser with the electron cloud in a simple mass-on-a-spring approximation. The result of this excess force is a kinetic energy that is directed along the polarization vector of the laser field and an induced potential energy that are proposed as a determining factor in electron tunnel ionization. Relative ionization rates for various pairs of gases are calculated and compared with reported figures. Comparisons were made between several combinations of O{sub 2}, Xe, Ar, N{sub 2}, Cl{sub 2}, H{sub 2}, CO, Kr, NO, F{sub 2}, and D{sub 2}. Predicted ratios of ionization rates between pairs of gases are compared to ADK predictions. Apparently anomalous ionization rates of O{sub 2}, D{sub 2}, and H{sub 2} are explained. A simple expression is developed that reveals why the ionization rate of Xe is about an order of magnitude larger than that of O{sub 2} even though their ionization potentials are nearly identical; why CO is only about half that of Kr even though their ionization potentials are nearly the same; why the ratio of O{sub 2} to O is about ten times larger than predicted by ADK; and why the ratio of NO to Xe is about an order of magnitude less than predicted by ADK.

Bettis, Jerry Ray [5701 Woodlake Drive, Stillwater, Oklahoma 74074 (United States)

2009-12-15T23:59:59.000Z

376

Laser Wakefield Particle Accelerators Project at NERSC  

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

Laser Wakefield Particle Acceleration Laser Wakefield Particle Acceleration Vorpal.jpg Key Challenges: Design of multiple-staged, 10-GeV laser-wakefield plasma accelerated...

377

EA-1655: Berkeley Lab Laser Accelerator (BELLA) Laser Acquisition, Installation and Use for Research and Development  

Broader source: Energy.gov [DOE]

Berkeley Lab Laser Accelerator (BELLA) Laser Acquisition, Installation and Use for Research and Development

378

Terahertz quantum cascade lasers  

E-Print Network [OSTI]

The development of the terahertz frequency range has long been impeded by the relative dearth of compact, coherent radiation sources of reasonable power. This thesis details the development of quantum cascade lasers (QCLs) ...

Williams, Benjamin S. (Benjamin Stanford), 1974-

2003-01-01T23:59:59.000Z

379

Laser Technology: Additive Manufacturing  

Science Journals Connector (OSTI)

Selective Laser Sintering, and in general Additive Manufacturing Processes are becoming mature technologies; in the ... systems that are even utilized for direct parts manufacturing. However, the parts final user...

Srichand Hinduja; Lin Li

2013-01-01T23:59:59.000Z

380

Along the Laser Beampath  

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

from the master oscillator, amplifiy it more than a billion times, and set its spatial profile before injecting it into the main laser beampath. Photo Number: NIF-1107-1416113...

Note: This page contains sample records for the topic "free-electron laser fel" 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

Injection Laser System  

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

Injection Laser System For each of NIF's 192 beams: The pulse shape as a function of time must be generated with a high degree of precision The energy delivered to the target must...

382

Spark and Laser Ignition  

Science Journals Connector (OSTI)

In the context of nonshock initiation of secondary explosives, electric sparks and lasers represent sources of external power that may stimulate exothermic reaction in energetic materials, and generate enough ...

James E. Kennedy

2010-01-01T23:59:59.000Z

383

Fusion reactor pumped laser  

DOE Patents [OSTI]

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

Jassby, D.L.

1987-09-04T23:59:59.000Z

384

Dark Soliton Fiber Laser  

E-Print Network [OSTI]

We report on the experimental observation of stable dark solitons in an all normal dispersion fiber laser. We found experimentally that dark soliton formation is a generic feature of the fiber laser under strong continuous wave (CW) emission. However, only under appropriate pump strength and negative cavity feedback, stable single or multiple dark soliton could be achieved. Furthermore, we show that the features of the observed dark solitons could be well understood based on the nonlinear Schrodinger equation (NLSE).

H. Zhang; D. Y. Tang; L. M. Zhao; X. Wu; Q. L. Bao; K. P. Loh

2009-05-08T23:59:59.000Z

385

Insulator for laser housing  

DOE Patents [OSTI]

The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member.

Duncan, David B. (Auburn, CA)

1992-01-01T23:59:59.000Z

386

Laser surface cleaning  

SciTech Connect (OSTI)

Decontamination of contaminated metal and material recycle, two of 31 priority needs identified by the D&D focus group, are the most promising applications for laser ablation within the DOE complex. F2 Associates has developed a robotic laser ablation system that is capable of high contamination rates, waste volume reduction, surface pore cleaning, and real-time characterization of materials. It is being demonstrated that this system will be the most cost-effective technology for metal decontamination and material recycle.

Crivella, E.C.; Freiwald, J.; Freiwald, D.A.

1996-12-31T23:59:59.000Z

387

Variable laser attenuator  

DOE Patents [OSTI]

The disclosure relates to low loss, high power variable attenuators comprising one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength. 9 figs.

Foltyn, S.R.

1987-05-29T23:59:59.000Z

388

Laser cooling of solids  

SciTech Connect (OSTI)

We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

2008-01-01T23:59:59.000Z

389

Insulator for laser housing  

DOE Patents [OSTI]

The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member. 3 figs.

Duncan, D.B.

1992-12-29T23:59:59.000Z

390

CRC handbook of laser science and technology. Volume 3. Gas lasers  

SciTech Connect (OSTI)

This book describes the fundamentals of gas lasers. It provides information and data on neutral gas lasers, ionized gas lasers, and molecular gas lasers. Concluding this volume is an extensive table of all gas laser wavelengths.

Weber, M.J.

1982-01-01T23:59:59.000Z

391

Injection-controlled laser resonator  

DOE Patents [OSTI]

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

Chang, J.J.

1995-07-18T23:59:59.000Z

392

Blue-green upconversion laser  

DOE Patents [OSTI]

A blue-green laser (450--550 nm) uses a host crystal doped with Tm[sup 3+]. The Tm[sup 3+] is excited through upconversion by a red pumping laser and an IR pumping laser to a state which transitions to a relatively lower energy level through emissions in the blue-green band, e.g., 450.20 nm at 75 K. The exciting laser may be tunable dye lasers or may be solid-state semiconductor laser, e.g., GaAlAs and InGaAlP. 3 figs.

Nguyen, D.C.; Faulkner, G.E.

1990-08-14T23:59:59.000Z

393

Blue-green upconversion laser  

DOE Patents [OSTI]

A blue-green laser (450-550 nm) uses a host crystal doped with Tm.sup.3+. The Tm.sup.+ is excited through upconversion by a red pumping laser and an IR pumping laser to a state which transitions to a relatively lower energy level through emissions in the blue-green band, e.g., 450.20 nm at 75 K. The exciting laser may be tunable dye lasers or may be solid-state semiconductor laser, e.g., GaAlAs and InGaAlP.

Nguyen, Dinh C. (Los Alamos, NM); Faulkner, George E. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

394

Variable emissivity laser thermal control system  

DOE Patents [OSTI]

A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

Milner, Joseph R. (Livermore, CA)

1994-01-01T23:59:59.000Z

395

History of Gas Lasers, Part 2: Pulsed Gas Lasers  

Science Journals Connector (OSTI)

In this second article of a two-part series, Colin Webb explores the origins of pulsed gas lasers, which made possible many critical applications of laser technology, including...

Webb, Colin

2010-01-01T23:59:59.000Z

396

OMEGA EP Laser Sources - Laboratory for Laser Energetics  

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

Sources - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE...

397

Omega Laser Facility Schedule - Laboratory for Laser Energetics  

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

Schedule - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE...

398

Nonlinear laser energy depletion in laser-plasma accelerators  

E-Print Network [OSTI]

Lee- mans, in Advanced Accelerator Concepts, Eleventh Work-in laser-plasma accelerators ? B. A. Shadwick, 1, ‡ C. B.ac- celerators. Laser-plasma accelerators, for example, have

Shadwick, B.A.

2009-01-01T23:59:59.000Z

399

Laser Guiding for GeV Laser-Plasma Accelerators  

E-Print Network [OSTI]

Overview of plasma-based accelerator concepts. IEEE Trans.using laser wake?eld accelerators. Meas. Sci. Technol. 12,for GeV laser-plasma accelerators. In Advanced Accelerator

Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

2005-01-01T23:59:59.000Z

400

Controlling molecules with lasers and lasers with molecules  

E-Print Network [OSTI]

I investigate quantum control of spin in molecules using shaped ultrafast lasers and the dynamics of those lasers when their cavities are modified to include programmable molecular masks. The ability to control quantum ...

Taylor, Jason Matthew, 1977-

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Modeling of laser cladding with diode laser robotized system  

Science Journals Connector (OSTI)

The choice of proper working conditions is a problem for any processing. But for laser processing this procedure is much more serious. ... modeling is accepted. The actual model for laser cladding is developed ba...

Jianhua Yao; V. S. Kovalenko; Qunli Zhang…

2010-06-01T23:59:59.000Z

402

Melt-solid interactions in laser cladding and laser casting  

Science Journals Connector (OSTI)

Experimental data in conjunction with mathematical models are used to explain various aspects of laser casting and laser cladding by the preplaced powder method. For increasing ... the powder bed is analyzed to i...

H. Gedda; A. Kaplan; J. Powell

2005-10-01T23:59:59.000Z

403

Other Projects [Laser Applications Laboratory] - Nuclear Engineering  

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

Other Projects Other Projects Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Other projects Bookmark and Share HIGH POWER LASER BEAM DELIVERY High-power laser-beam delivery with conventional and fiber optics DECONTAMINATION & DECOMMISSIONING Laser processing technology for decontamination of surfaces

404

LASER SAFETY MANUAL POLICIES AND PROCEDURES  

E-Print Network [OSTI]

LASER SAFETY MANUAL POLICIES AND PROCEDURES FOR LASER SAFETY AT TEXAS TECH UNIVERSITY LUBBOCK, TEXAS September 2002 #12;V-1 TEXAS TECH UNIVERSITY LASER SAFETY MANUAL TABLE OF CONTENTS SECTION I ­ MANAGEMENT OF LASER LICENSE Introduction A. Laser Safety Program I - 1 B. Radiation Laser Safety Committee I

Zhang, Yuanlin

405

The Laser as a Weapon  

Science Journals Connector (OSTI)

The laser beam is popularly thought of as a very powerful death ray which can be fired from a hand-held laser gun to vaporize soldiers, demolish buildings, and burn through tanks. This is an immense exaggeration ...

Major General Bengt Anderberg; Dr. Myron L. Wolbarsht

1992-01-01T23:59:59.000Z

406

Laser Additive Manufacturing of Metals  

Science Journals Connector (OSTI)

Laser Additive Manufacturing (LAM) is based on a repeating layer wise manufacturing process which uses a laser beam to ... ) geometries into simpler two-dimensional (2D) manufacturing steps [1, 2...]. Thus LAM of...

Claus Emmelmann; Jannis Kranz; Dirk Herzog; Eric Wycisk

2013-01-01T23:59:59.000Z

407

Solid Solubility in Laser Cladding  

Science Journals Connector (OSTI)

Laser cladding techniques have recently enjoyed attention in preparing ... solid solution formed due to rapid cooling in laser cladding. This model considers a diffusion mechanism for ... one-dimensional semi-inf...

J. Mazumder; A. Kar

1987-02-01T23:59:59.000Z

408

Hybrid laser with CMOS photonics  

E-Print Network [OSTI]

In this thesis, an interesting approach for a photonic laser source is presented. By using integrated photonic resonators with an external gain medium, we are able to build a laser that offers a number of advantages including ...

Chong, Johanna S

2014-01-01T23:59:59.000Z

409

Laser-Induced Breakdown Spectroscopy  

E-Print Network [OSTI]

LIBS-1 Laser-Induced Breakdown Spectroscopy LIBS ANALYSIS OF METAL SURFACES Last updated: June 17, 2014 #12;LIBS-2 Laser­Induced Breakdown Spectroscopy (LIBS) LIBS ANALYSIS OF METAL SURFACES of species at a distance or in hard­to­reach or hazardous environments. Laser­Induced Breakdown Spectroscopy

Nizkorodov, Sergey

410

Laser acceleration of ion beams  

E-Print Network [OSTI]

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

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

2007-02-01T23:59:59.000Z

411

Laser Direct Drive: Scientific Advances,  

E-Print Network [OSTI]

· Simpler targets & physics · Predict Fusion Class Gains (> 140) at lower laser energy (500 kJ - 1 MJ) #12;7 KrF lasers have advantages for fusion energy PHYSICS Deeper UV (248 nm vs 351 for glass): -- Greater · chamber #12;9 Gain for Fusion Energy New Direct Drive Designs: Power plant class gains, much smaller laser

412

TUFTS UNIVERSITY LASER SAFETY PROGRAM  

E-Print Network [OSTI]

with engineering controls and good work practices. The Tufts University Laser Safety Officer (LSO) along safety liaison to work with the EH&S Office and the LSO to fulfill the requirements outlined operating procedures for these laser installations, and laser safety training for persons working

Dennett, Daniel

413

Single element laser beam shaper  

DOE Patents [OSTI]

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

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

2005-09-13T23:59:59.000Z

414

Laser-Material Interactions: A Study of Laser Energy Coupling with Solids  

E-Print Network [OSTI]

1971) Effects of High-Power Laser Radiation, Academic Presin Effects of High-Power Laser Radiation, (Academic Press,for modeling gas discharge lasers", Boulder, Colo. : Univ.

Shannon, M.A.

2009-01-01T23:59:59.000Z

415

Laser-Generated Shockwaves for the Disruption of Bacterial Biofilms  

E-Print Network [OSTI]

Characterization by modified Laser Spallation Technique (The Basic Laser Spallation Technique (Modified Laser Spallation Technique: “Top-Down”

Navarro, Artemio

2013-01-01T23:59:59.000Z

416

HF Chemical Lasers  

Science Journals Connector (OSTI)

The very rapid reaction rate of the H2 + F2 chain reaction coupled with the efficient formation of chain carriers by fast electron beam radiolysis of F2 and SF6 provide laser power of about 1012 watts/liter and q...

Reed J. Jensen

1975-01-01T23:59:59.000Z

417

Quantum dot cascade laser  

Science Journals Connector (OSTI)

We demonstrated an unambiguous quantum dot cascade laser based on InGaAs/GaAs/InAs/InAlAs heterostructure by making use of self-assembled quantum dots in the Stranski-Krastanow growth mode...??~?6.15 ?m and a bro...

Ning Zhuo; Feng Qi Liu; Jin Chuan Zhang; Li Jun Wang…

2014-03-01T23:59:59.000Z

418

US tests antimissile laser  

Science Journals Connector (OSTI)

... It is destined to fly on board a modified Boeing 747 aeroplane as part of a US air defence fleet. The test, which lasted ... Grumman Space Technology, based in Redondo Beach, California, for the Airborne Laser team at Boeing Integrated Defense Systems in St Louis, Missouri. ...

Mark Peplow

2004-11-15T23:59:59.000Z

419

Dye laser amplifier  

DOE Patents [OSTI]

An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

Moses, Edward I. (Livermore, CA)

1992-01-01T23:59:59.000Z

420

2 micron femtosecond fiber laser  

DOE Patents [OSTI]

Methods and systems for generating femtosecond fiber laser pulses are disclose, including generating a signal laser pulse from a seed laser oscillator; using a first amplifier stage comprising an input and an output, wherein the signal laser pulse is coupled into the input of the first stage amplifier and the output of the first amplifier stage emits an amplified and stretched signal laser pulse; using an amplifier chain comprising an input and an output, wherein the amplified and stretched signal laser pulse from the output of the first amplifier stage is coupled into the input of the amplifier chain and the output of the amplifier chain emits a further amplified, stretched signal laser pulse. Other embodiments are described and claimed.

Liu, Jian; Wan, Peng; Yang, Lihmei

2014-07-29T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Laser cooling with ultrafast pulse trains  

E-Print Network [OSTI]

We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires vacuum-ultraviolet laser light, while multielectron atoms need laser light at many widely separated frequencies. These restrictions can be eased by laser cooling on two-photon transitions with ultrafast pulse trains. Laser cooling of hydrogen, antihydrogen, and carbon appears feasible, and extension of the technique to molecules may be possible.

David Kielpinski

2003-06-14T23:59:59.000Z

422

Jefferson Lab - Research  

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

80 en Free-Electron Laser https:www.jlab.orgfree-electron-laser

423

1 billion times brighter than the sun: Will Jeff Lab's beam lead...  

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

articles.dailypress.com2011-01-17newsdp-nws-cp-jlab-laser-201101161scientists-free-electron-laser-facility-p... Submitted: Thursday, January 20, 2011...

424

Sub-Picosecond X-Ray Pulses Workshop  

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

International Workshop on the Interactions of Intense Sub-Picosecond X-Ray International Workshop on the Interactions of Intense Sub-Picosecond X-Ray Pulses with Matter (SLAC, January 23-24, 1997) During the last five years studies have been conducted at the Stanford Linear Accelerator Center (SLAC) and the Deutsches Elektronen-Synchrotron (DESY) in Hamburg concerning the feasibility of driving an Angstrom-wavelength Free-Electron Laser (FEL) with a high energy rf linac. Recent promising advances in linac, rf gun, and insertion device technologies make it seem likely that such a device can be constructed. The output radiation predicted for this type of source will be characterized by full transverse coherence, extreme pulse brevity (~50-100 fs), high peak power (10-100 GW), and very high unfocused peak power density (0.4-4.1013

425

High Power Electrodynamics (HPE): Accelerator Operations and Technology,  

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

CONTACTS CONTACTS Group Leader Bruce Carlsten Deputy Group Leader Ellen Guenette Administrator Josephine (Jo) Torres High-Power Electrodynamics (HPE) The High-Power Electrodynamics (AOT-HPE) Group applies accelerator and beam technologies to national-security-directed energy missions. AOT-HPE has three programmatic thrusts: free-electron lasers (FELs), high-power microwaves (HPM), and compact radiography. To maintain a vigorous and robust technical base for addressing DOE and DoD needs, the group's project portfolio is balanced between exploratory research, infrastructure development, and programmatic deliverables for sponsors. Funding is roughly 25% from the Lab's Directed Research and Development Program, 65% from DoD, and 10% from DOE. Technology Focus Areas AOT-HPE is the Laboratory's main vehicle for applying accelerator-based technologies to directed-energy mission needs. The group recognizes that many directed-energy missions are enabled by compact high-brightness electron accelerators and mm-wave and THz technologies.

426

ANL/APS/TB-32 Test of Horizontal Field Measurements Using Two-Axis Hall  

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

2 2 Test of Horizontal Field Measurements Using Two-Axis Hall Probes at the APS Magnetic Measurement Facility I. Vasserman Advanced Photon Source Argonne National Laboratory Argonne, IL 60439 1. Introduction The free-electron laser (FEL) project at the Advanced Photon Source (APS) will use a 400-MeV particle beam from the APS linac with RMS beam transverse size of 100 µm and requires very high performance of the insertion devices in order to achieve high intensity radiation. Averaged over period, the trajectory must deviate from the ideal on-axis trajectory by not more than 10% of the RMS beam size. Meaning that the second field integral should be straight within ±1300 G-cm 2 over the length of the device for both horizontal and vertical directions for the 400-MeV particle

427

Linac Coherent Light SourCe  

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

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

428

Initial results of operating the rocketdyne undulator in a tapered configuration  

Science Journals Connector (OSTI)

The near-infrared Rocketdyne/Stanford free electron laser (FEL) uses a very-high-quality precision undulator whose field strength and field taper are adjustable. The Rocketdyne undulator has been operated in both an amplifier configuration, as in the master-oscillator power amplifier (MOPA) experiments, and an oscillator configuration, as in the photocathode and tapered-undulator experiments. The tapered-undulator experiment was performed at the Stanford Photon Research Laboratory (SPRL) using an electron beam supplied by the Mark III rf-linac. During the experiment we observed sustained oscillations as the undulator magnetic-field taper was continuously tuned from 0% to 10%. We observed ?1.2% extraction efficiency for a magnetic-field taper of 9.6%. During the same experiment we observed sustained oscillations as the undulator gap was continuously varied over 120 mil. Details of the experiment are presented.

Mark Curtin; Anup Bhowmik; Jeffrey Brown; Wayne McMullin; Philip Metty; Stephen V. Benson; John M.J. Madey

1990-01-01T23:59:59.000Z

429

Lucretia: A Matlab-Based Toolbox for the Modellingand Simulation of Single-Pass Electron Beam Transport Systems  

SciTech Connect (OSTI)

We report on Lucretia, a new simulation tool for the study of single-pass electron beam transport systems. Lucretia supports a combination of analytic and tracking techniques to model the tuning and operation of bunch compressors, linear accelerators, and beam delivery systems of linear colliders and linac-driven Free Electron Laser (FEL) facilities. Extensive use of Matlab scripting, graphics, and numerical capabilities maximize the flexibility of the system, and emphasis has been placed on representing and preserving the fixed relationships between elements (common girders, power supplies, etc.) which must be respected in the design of tuning algorithms. An overview of the code organization, some simple examples, and plans for future development are discussed.

Tenenbaum, P.; /SLAC

2005-09-30T23:59:59.000Z

430

Linac Coherent Light Source Undulator RF BPM System  

SciTech Connect (OSTI)

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

431

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store  

E-Print Network [OSTI]

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store scanners, construction tools, and laser pointers are generally lower powered lasers emit high-intensity, directional light beams that vary in strength, they are a particular hazard

Burke, Peter

432

General Laser Control Measures Operating instructions for a specific laser are found in the manual for that laser.  

E-Print Network [OSTI]

General Laser Control Measures Operating instructions for a specific laser are found in the manual for that laser. There are several procedures that will reduce the potential for exposure to laser beams. 1. The beam from Class IIIB and Class IV lasers should be terminated in highly absorbent, non specular

Huennekens, John

433

Mid–infrared laser applications in medicine and biology  

Science Journals Connector (OSTI)

...diameter wall can be optimized to increase the transmission at a desired...vein treatment and for port wine stain removal. Single- wavelength...or OPAs and FELs. If sensor quality can also be advanced, then...might use multiple passes to increase the signal-to-noise ratio...

2001-01-01T23:59:59.000Z

434

Laser Applications Laboratory - Nuclear Engineering Division (Argonne)  

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

Capabilities > Engineering Capabilities > Engineering Experimentation > Laser Applications Laboratory Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory The Laser Applications Laboratory (LAL) houses two high-power laser systems, complete with diagnostics for materials-processing functions - a 6 kW CO2 laser and a 1.6 kW pulsed Nd:YAG laser.

435

Accelerator and Fusion Research Division: 1984 summary of activities  

SciTech Connect (OSTI)

During fiscal 1984, major programmatic activities in AFRD continued in each of five areas: accelerator operations, highlighted by the work of nuclear science users, who produced clear evidence for the formation of compressed nuclear matter during heavy-ion collisions; high-energy physics, increasingly dominated by our participation in the design of the Superconducting Super Collider; heavy-ion fusion accelerator research, which focused on the design of a four-beam experiment as a first step toward assessing the promise of heavy-ion inertial-confinement fusion; and research at the Center for X-Ray Optics, which completed its first year of broadly based activities aimed at the exploitation of x-ray and ultraviolet radiation. At the same time, exploratory studies were under way, aimed at investigating major new programs for the division. During the past year, for example, we took a preliminary look at how we could use the Bevatron as an injector for a pair of colliding-beam rings that might provide the first glimpse of a hitherto unobserved state of matter called the quark-gluon plasma. Together with Livermore scientists, we also conducted pioneering high-gain free-electron laser (FEL) experiments and proposed a new FEL-based scheme (called the two-beam accelerator) for accelerating electrons to very high energies. And we began work on the design of the Coherent XUV Facility (CXF), an advanced electron storage ring for the production of intense coherent radiation from either undulators or free-electron lasers.

Not Available

1985-05-01T23:59:59.000Z

436

Laser Micromachining: Advantages of Liquid Environments  

E-Print Network [OSTI]

Laser Micromachining: Advantages of Liquid Environments Marc J. Palmeri Princeton University Arnold Lab #12;Outline · Motivation ­ Applications of laser micromachining ­ Problems with laser micromachining · How do lasers work? · What is laser micromachining? · Micromachining assembly · Methods

Petta, Jason

437

Laser Fusion Energy The High Average Power  

E-Print Network [OSTI]

Laser Fusion Energy and The High Average Power Program John Sethian Naval Research Laboratory Dec for Inertial Fusion Energy with lasers, direct drive targets and solid wall chambers Lasers DPPSL (LLNL) Kr posters Snead Payne #12;Laser(s) Goals 1. Develop technologies that can meet the fusion energy

438

Laser Safety Manual Scope and Applicability  

E-Print Network [OSTI]

Laser Safety Manual Scope and Applicability This manual applies to all personnel working at or visiting ASU who procure or utilize Class III and Class IV lasers and laser systems. Procurement and user of Class I and Class II laser equipment, such as laser pointers and compact disk players, do not normally

Rhoads, James

439

CAP2002b_lasers.ppt  

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

Babzien Accelerator Test Facility e - 35 81.6 MHz Nd:YAG LINAC LASER LASER CO 2 x RF GUN e - 35 81.6 MHz Nd:YAG LINAC LASER LASER CO 2 x RF GUN Overview *ATF lasers since 2000...

440

Advances in Laser Science-II  

SciTech Connect (OSTI)

The meeting covered topics on the latest advances in laser technology and applications. The general categories are as follows: advanced lasers and coherent sources; nonlinear optical phenomena and applications; atomic, molecular and ionic spectroscopy; condensed matter, surface and particle spectroscopy; laser photochemistry and photophysics; diagnostic and analytical applications of lasers; and laser research and techniques in medicine and biology. (LSP)

Lapp, M.; Stwalley, W.C.; Kenney-Wallace, G.A.; Lerner, R.G. (eds.)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" 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

Fiber lasers and amplifiers by: Khanh Kieu  

E-Print Network [OSTI]

· Active fibers · Laser performances · Cladding pump technology · Fiber laser research at the College fiber laser: > 1GW peak power! Tünnermann's group #12;What can fiber laser do? #12;Cladding pumpFiber lasers and amplifiers by: Khanh Kieu (02/28/2014) #12;Outlines · Introduction · History

Kieu, Khanh

442

Laser multiplexing system  

DOE Patents [OSTI]

A plurality of copper lasers, as radiant power sources, emits a beam of power carrying radiation. A plurality of fiber injection assemblies receives power from the plurality of copper lasers and injects such power into a plurality of fibers for individually transmitting the received power to a plurality of power-receiving devices. The power-transmitting fibers of the system are so arranged that power is delivered therethrough to each of the power-receiving devices such that, even if a few of the radiant power sources and/or fibers fail, the power supply to any of the power receiving devices will not completely drop to zero but will drop by the same proportionate amount.

Johnson, Steve A. (Tracy, CA); English, Jr., Ronald Edward (Tracy, CA); White, Ronald K. (Livermore, CA)

2001-01-01T23:59:59.000Z

443

Laser pulse sampler  

DOE Patents [OSTI]

The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera. 5 figs.

Vann, C.

1998-03-24T23:59:59.000Z

444

Laser pulse sampler  

DOE Patents [OSTI]

The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera.

Vann, Charles (Fremont, CA)

1998-01-01T23:59:59.000Z

445

Laser ignition studies  

SciTech Connect (OSTI)

The goal of this work is to study the details of laser induced ignition and combustion of high-temperature condensed-phase exothermic reactions. In this work high-speed photography (HSP) and real-time optical pyrometry have been combined to provide a diagnostic tool with a 1 ms temporal resolution for studying laser ignition and combustion wave propagation. Previous experiments have involved the use of HSP for studying combustion wave propagation (1) Real-time pyrometry studies of the ignition process have also been performed previously. The present paper describes how HSP has been expanded to include three-view split-frame photography to allow the ignition and combustion processes to be recorded and studied simultaneously. 2 refs., 3 figs.

Fredin, L.; Hansen, G.P.; Margrave, J.L.; Behrens, R.G.

1985-10-01T23:59:59.000Z

446

Fusion pumped laser  

DOE Patents [OSTI]

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

Pappas, D.S.

1987-07-31T23:59:59.000Z

447

Laser fusion neutron source employing compression with short pulse lasers  

DOE Patents [OSTI]

A method and system for achieving fusion is provided. The method includes providing laser source that generates a laser beam and a target that includes a capsule embedded in the target and filled with DT gas. The laser beam is directed at the target. The laser beam helps create an electron beam within the target. The electron beam heats the capsule, the DT gas, and the area surrounding the capsule. At a certain point equilibrium is reached. At the equilibrium point, the capsule implodes and generates enough pressure on the DT gas to ignite the DT gas and fuse the DT gas nuclei.

Sefcik, Joseph A; Wilks, Scott C

2013-11-05T23:59:59.000Z

448

Ultrafast pulsed laser utilizing broad bandwidth laser glass  

DOE Patents [OSTI]

An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P{sub 2}O{sub 5}, Al{sub 2}O{sub 3} and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules. 7 figs.

Payne, S.A.; Hayden, J.S.

1997-09-02T23:59:59.000Z

449

Accelerated ring laser  

Science Journals Connector (OSTI)

The behavior of a ring laser rotating with nonuniform angular velocity has become of interest, both experimental and theoretical. Within a framework of modest idealizations, we present a classical, relativistically exact theoretical analysis. The beat frequency, we find, is given by an expression of the Sagnac form but with the instantaneous angular velocity in place of the usual constant velocity. One has an "instantaneous Sagnac effect."

Takamasa Takahashi and Ralph Baierlein

1977-02-01T23:59:59.000Z

450

Stimulated crystallization of melt-quenched Ge{sub 2}Sb{sub 2}Te{sub 5} films employing femtosecond laser double pulses  

SciTech Connect (OSTI)

The phase transformation of Ge{sub 2}Sb{sub 2}Te{sub 5} films from the melt-quenched amorphous phase into the crystalline phase induced by 800 nm, 100 fs laser pulses has been studied. For partly amorphized films, progressive crystallization could be induced by single pulses, which can be explained by growth of already existing crystalline embryos. For completely amorphized films, it was not possible to induce crystallization with one or two consecutive pulses; three pulses being the threshold for the onset of crystallization. By employing a fs laser double pulse with an adjustable inter-pulse delay, partial crystallization could be triggered for a delay range of 200 fs-100 ps, while for longer delays no crystallization was possible. The time window for stimulated crystallization can be related to the relaxation dynamics of free electrons excited by the first pulse, which are further excited by the second pulse still remaining in the excited state. Our results indicate that the lifetime of excited electrons in melt-quenched amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} is Almost-Equal-To 100 ps.

Cotton, Rebecca L.; Siegel, Jan [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, E-28006 Madrid (Spain)

2012-12-15T23:59:59.000Z

451

SLAC All Access: Laser Labs  

SciTech Connect (OSTI)

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

Minitti, Mike; Woods Mike

2013-03-01T23:59:59.000Z

452

Hybrid fiber-rod laser  

DOE Patents [OSTI]

Single, or near single transverse mode waveguide definition is produced using a single homogeneous medium to transport both the pump excitation light and generated laser light. By properly configuring the pump deposition and resulting thermal power generation in the waveguide device, a thermal focusing power is established that supports perturbation-stable guided wave propagation of an appropriately configured single or near single transverse mode laser beam and/or laser pulse.

Beach, Raymond J.; Dawson, Jay W.; Messerly, Michael J.; Barty, Christopher P. J.

2012-12-18T23:59:59.000Z

453

Le laser : une brve introduction  

E-Print Network [OSTI]

Le laser : une brève introduction Christian Chardonnet Directeur du Laboratoire Charles Fabry (CNRS Lasers (CNRS/Université Paris 13) Le 9 avril 2010 #12;Les sources de lumière l'ampoule électrique Les;Zoom : x1000 x1000 x1000 x1000 x100 Le spectre du soleil I.R. U.V. Comparaison du rayonnement laser et

van Tiggelen, Bart

454

Laser Atmospheric Studies with VERITAS  

E-Print Network [OSTI]

As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

C. M. Hui; for the VERITAS collaboration

2007-09-25T23:59:59.000Z

455

TLSI W614 laser characterization  

SciTech Connect (OSTI)

The TLSI W614 Laser Trim System, which is a part of the TE5599 Tester, was characterized to find the optimum operating conditions for production trimming of thick and thin film resistors. Operating variables include average laser power, Q-rate, bite size, laser beam focal point, and trim increment start conditions. Operating conditions were found that support a life-stable resistance and a predictable trimming process.

Rector, M.N.

1994-08-01T23:59:59.000Z

456

Laser Catalyst - Energy Innovation Portal  

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

Industrial Technologies Industrial Technologies Find More Like This Return to Search Laser Catalyst Idaho National Laboratory Contact INL About This Technology Technology Marketing...

457

Laser-Based Nondestructive Testing  

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

Laser-Based Nondestructive Testing High speed, non-contact NDT for bridging the gap between traditional nondestructive testing and embedded structural health monitoring. Contact...

458

Single-exciton nanocrystal laser  

DOE Patents [OSTI]

A laser system employing amplification via a single exciton regime and to optical gain media having single exciton amplification is provided.

Klimov, Victor I. (Los Alamos, NM); Ivanov, Sergei A. (Albuquerque, NM)

2012-01-17T23:59:59.000Z

459

EMSL - Single Particle Laser Ablation  

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

single-particle-laser-ablation en Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon http:...

460

Documentation - Laboratory for Laser Energetics  

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

IX Subsystem Startup and Shutdown Procedures Shot Director Operating Procedures (S-AB-P-010) Laser Sources Operating Procedures (S-AB-P-011) Power Conditioning Operating Procedures...

Note: This page contains sample records for the topic "free-electron laser fel" 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

Lasers: The First Fifty Years  

SciTech Connect (OSTI)

This year marks the 50th anniversary of the invention of the laser. The Optical Society of America is publishing this feature issue to celebrate this auspicious birthday.

Boyd, Robert W.; Athale, Ravindra; Onural, Levent; Seka, Wolf

2010-09-01T23:59:59.000Z

462

Laser system using regenerative amplifier  

DOE Patents [OSTI]

High energy laser system using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output.

Emmett, John L. [Pleasanton, CA

1980-03-04T23:59:59.000Z

463

Industry Related Projects [Laser Applications Laboratory] - Nuclear  

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

Industry Related Projects Industry Related Projects Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Industry related projects Bookmark and Share LASER OIL & GAS WELL DRILLING Using high-power lasers to drill and complete gas & oil wells LASER HEAT TREATMENT Optimization of laser beam heat treatment (Caterpillar and USCAR)

464

Mars mission laser tool heads to JPL  

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

Mars mission laser tool Mars mission laser tool heads to JPL Curiosity will carry the newly delivered laser instrument to reveal which elements are present in Mars' rocks and...

465

Martian laser surpasses 100,000 zaps  

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

Martian laser surpasses 100,000 zaps Martian laser surpasses 100,000 zaps ChemCam zaps rocks with a high-powered laser to determine their composition and carries a camera that can...

466

Application of lasers in solar cell technologies  

Science Journals Connector (OSTI)

The possibilities for applying lasers to the fabrication of solar cells (the laser texturing of silicon surfaces and pulsed laser deposition of indium tin oxide (ITO) thin films) are demonstrated.

D. A. Zuev; A. A. Lotin; O. A. Novodvorsky…

2012-10-01T23:59:59.000Z

467

Ignition with Laser Break-Down  

Science Journals Connector (OSTI)

It is considered that ignition with laser break-down is one of the applications of solid-state lasers. This paper shows basic experimental results indicating the advantages of laser...

Furutani, Hirohide; Saito, Takeshi

468

Copper vapor laser modular packaging assembly  

DOE Patents [OSTI]

A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment.

Alger, Terry W. (Tracy, CA); Ault, Earl R. (Dublin, CA); Moses, Edward I. (Castro Valley, CA)

1992-01-01T23:59:59.000Z

469

Laser guiding for GeV laser–plasma accelerators  

Science Journals Connector (OSTI)

...plasma-beat-wave accelerator. Phys. Rev...Singhal2003Applications for nuclear phenomena generated...laser wakefield accelerators. Phys. Plasmas...crossing a plasma-vacuum boundary. Phys...laser wakefield accelerators. Phys. Plasmas...generated at a plasma-vacuum interface. Phys...

2006-01-01T23:59:59.000Z

470

Laser Spark Distribution and Ignition System  

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

partners interested in implement- ing United States Patent Number 7,421,166 entitled "Laser Spark Distribution and Ignition System." Disclosed in this patent is NETL's laser...

471

OMEGA Amplifiers - Laboratory for Laser Energetics  

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

Amplifiers - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE...

472

Laser research shows promise for cancer treatment  

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

Cancer treatment Laser research shows promise for cancer treatment Scientists have observed for the first time how a laser penetrates dense, electron-rich plasma to generate ions....

473

OMEGA EP Construction - Laboratory for Laser Energetics  

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

Construction - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE...

474

OMEGA Experimental Systems - Laboratory for Laser Energetics  

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

Experimental Systems - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map...

475

Laser Decontamination of Metals | The Ames Laboratory  

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

Laser Decontamination of Metals Zapping contamination with lasers may be just the answer for safely and efficiently treating some of the waste awaiting disposal across the country....

476

Laser Crystallization of Phase Change Material  

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

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

477

Laser Cladding of Low Melting Point Alloys  

Science Journals Connector (OSTI)

Laser cladding has been used for some years as ... hardfacing method [1]. The two main laser cladding (and alloying) techniques are: i) ...

M. Ellis; D. C. Xiao; W. M. Steen; C. Lee…

1996-01-01T23:59:59.000Z

478

Achieving laser ignition using zero index metamaterials  

Science Journals Connector (OSTI)

The possibility of laser ignition using zero index metamaterials (ZIM) is investigated theoretically. Using this method, multiple laser beams can be focused automatically regardless of...

Zhai, Tianrui; Shi, Jinwei; Chen, Shujing; Liu, Dahe; Zhang, Xinping

2011-01-01T23:59:59.000Z

479

Laser in situ monitoring of combustion processes  

Science Journals Connector (OSTI)

Several examples of laser in situ monitoring of combustion processes are presented. Using a frequency modulated 13CO2 waveguide laser, in situ concentrations of...

Arnold, A; Becker, H; Hemberger, R; Hentschel, W; Ketterle, W; Kollner, M; Meienburg, W; Monkhouse, P; Neckel, H; Schafer, M; Schindler, K P; Sick, V; Suntz, R; Wolfrum, J

1990-01-01T23:59:59.000Z

480

Rhodamine-doped Aerogel Random Laser  

Science Journals Connector (OSTI)

Random Laser generation can give valuable information on the structure of diffuse materials. The aerogel matrix has knowingly a fractal organization. Here, random laser generation from...

Miranda, Adriana Ramos de; Pecoraro, Édison; Ribeiro, Sidney José L; Giehl, Júlia Maria; Reijn, Saara-Maarit; Wetter, Niklaus U

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


481

Ytterbium-doped borate fluoride laser crystals and lasers  

DOE Patents [OSTI]

A new class of solid state laser crystals and lasers are formed from Yb-doped borate fluoride host crystals. The general formula for the host crystals is MM{prime}(BO{sub 3})F, where M, M{prime} are monovalent, divalent aria trivalent metal cations. A particular embodiment of the invention is Yb-doped BaCaBO{sub 3}F (Yb:BCBF). BCBF and some of the related derivative crystals are capable of nonlinear frequency conversion, whereby the fundamental of the laser is converted to a longer or shorter wavelength. In this way, these new crystals can simultaneously serve as self-frequency doubling crystals and laser materials within the laser resonator. 6 figs.

Schaffers, K.I.; DeLoach, L.D.; Payne, S.A.; Keszler, D.A.

1997-10-14T23:59:59.000Z

482

Engineering Light: Quantum Cascade Lasers  

ScienceCinema (OSTI)

Quantum cascade lasers are ideal for environmental sensing and medical diagnostic applications. Gmachl discusses how these lasers work, and their applications, including their use as chemical trace gas sensors. As examples of these applications, she briefly presents results from her field campaign at the Beijing Olympics, and ongoing campaigns in Texas, Maryland, and Ghana.

Claire Gmachl

2010-09-01T23:59:59.000Z

483

Resonance Ionization Laser Ion Sources  

E-Print Network [OSTI]

The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

Marsh, B

2013-01-01T23:59:59.000Z

484

Laser fusion experiments at LLL  

SciTech Connect (OSTI)

These notes present the experimental basis and status for laser fusion as developed at LLL. Two other chapters, one authored by K.A. Brueckner and the other by C. Max, present the theoretical implosion physics and laser plasma interaction physics. The notes consist of six sections. The first is an introductory section which provides some of the history of inertial fusion and a simple explanation of the concepts involved. The second section presents an extensive discussion of diagnostic instrumentation used in the LLL Laser Fusion Program. The third section is a presentation of laser facilities and capabilities at LLL. The purpose here is to define capability, not to derive how it was obtained. The fourth and fifth sections present the experimental data on laser-plasma interaction and implosion physics. The last chapter is a short projection of the future.

Ahlstrom, H.G.

1980-06-16T23:59:59.000Z

485

Compact Quantum Cascade Laser Transmitter  

SciTech Connect (OSTI)

): In this paper we present design considerations, thermal and optical modeling results, and device performance for a ruggedized, compact laser transmitter that utilizes a room temperature quantum cascade (QC) laser source. The QC laser transmitter is intended for portable mid-infrared (3-12 µm) spectroscopy applications, where the atmospheric transmission window is relatively free of water vapor interference and where the molecular rotational vibration absorption features can be used to detect and uniquely identify chemical compounds of interest. Initial QC laser-based sensor development efforts were constrained by the complications of cryogenic operation. However, improvements in both QC laser designs and fabrication processes have provided room-temperature devices that now enable significant miniaturization and integration potential for national security, environmental monitoring, atmospheric science, and industrial safety applications.

Anheier, Norman C.; Hatchell, Brian K.; Gervais, Kevin L.; Wojcik, Michael D.; Krishnaswami, Kannan; Bernacki, Bruce E.

2009-04-01T23:59:59.000Z

486

Production of extended plasma channels in atmospheric air by amplitude-modulated UV radiation of GARPUN-MTW Ti : sapphire-KrF laser. Part 2. Accumulation of plasma electrons and electric discharge control  

SciTech Connect (OSTI)

The problem of the production of extended ({approx}1 m) plasma channels is studied in atmospheric air by amplitude-modulated laser pulses of UV radiation, which are a superposition of a subpicosecond USP train amplified in a regenerative KrF amplifier with an unstable confocal resonator and a quasi-stationary lasing pulse. The USPs possess a high (0.2-0.3 TW) peak power and efficiently ionise oxygen molecules due to multiphoton ionisation, and the quasi-stationary lasing pulse, which has a relatively long duration ({approx}100 ns), maintains the electron density at a level n{sub e} = (3-5) Multiplication-Sign 10{sup 14} cm{sup -3} by suppressing electron attachment to oxygen. Experiments in laser triggering of high-voltage electric discharges suggest that the use of combined pulses results in a significant lowering of the breakdown threshold and enables controlling the discharge trajectory with a higher efficiency in comparison with smooth pulses. It was shown that controlled breakdowns may develop with a delay of tens of microseconds relative to the laser pulse, which is many orders of magnitude greater than the lifetime of free electrons in the laser-induced plasma. We propose a mechanism for this breakdown, which involves speeding-up of the avalanche ionisation of the air by negative molecular oxygen ions with a low electron binding energy ({approx}0.5 eV) and a long lifetime ({approx}1 ms), which are produced upon cessation of the laser pulse. (extreme light fields and their applications)

Zvorykin, V D; Ionin, Andrei A; Levchenko, A O; Mesyats, Gennadii A; Seleznev, L V; Sinitsyn, D V; Smetanin, Igor V; Sunchugasheva, E S; Ustinovskii, N N; Shutov, A V [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-04-30T23:59:59.000Z

487

Laser surface cleaning  

SciTech Connect (OSTI)

The objective of this work is a laboratory demonstration that red-lead primer and two-part epoxy paints can be stripped from concrete and metal surfaces using surface cleaning systems based on pulsed-repetition CO{sub 2} lasers. The three goals are to: (1) demonstrate coatings removal, including surface pore cleaning; (2) demonstrate that there is negligible release of ablated contaminants to the environment; and (3) demonstrate that the process will generate negligible amounts of additional waste compared to competing technologies. Phase 1 involved site visits to RMI and Fernald to assess the cleaning issues for buildings and parts. In addition, Phase 1 included detailed designs of a more powerful system for industrial cleaning rates, including laser, articulating optics, ablated-material capture suction nozzle attached to a horizontal raster scanner for floor cleaning, and filtration system. Some concept development is also being done for using robots, and for parts cleaning. In Phase 2 a transportable 6 kW system will be built and tested, with a horizontal surface scanner for cleaning paint from floors. The laboratory tests will again be instrumented. Some concept development will continue for using robots, and for parts cleaning. This report describes Phase 1 results.

Freiwald, J.G.; Freiwald, D.A.

1994-12-31T23:59:59.000Z

488

Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel [Laser  

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

Laser Welding of Metals > Laser Welding of Metals > Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Welding of Metals Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel Zhiyue Xu Nuclear Engineering Division of Argonne National Laboratory

489

Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum  

SciTech Connect (OSTI)

We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 ?m was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 ?m. The entire probe setup had a spectral resolution of ?1.5 eV, a detection bandwidth of ?24 eV, and an overall photon throughput efficiency of the order of 10{sup ?5}. Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.

Mo, M. Z.; Chen, Z.; Tsui, Y. Y.; Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)] [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Fourmaux, S.; Saraf, A.; Otani, K.; Kieffer, J. C. [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada)] [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada); Ng, A. [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)] [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)

2013-12-15T23:59:59.000Z

490

Polarization methods for diode laser excitation of solid state lasers  

DOE Patents [OSTI]

A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

Holtom, Gary R. (Richland, WA)

2008-11-25T23:59:59.000Z

491

Manufacturing of Er:ZBLAN ridge waveguides by pulsed laser deposition and ultrafast laser micromachining for green integrated lasers  

Science Journals Connector (OSTI)

Laser radiation is used both for the deposition of the laser active thin films and for the microstructuring to define wave guiding structures for the fabrication of waveguide lasers. Thin films of Er:ZBLAN (a fluoride glass consisting of ZrF4, BaF2, LaF3, AlF3, NaF, ErF3) for green up-conversion lasers (545 nm) are produced by pulsed laser deposition using ArF excimer laser radiation (wavelength 193 nm). Manufacturing of the laser active waveguides by microstructuring is done using fs-laser ablation of the deposited films. The structural and optical properties of the films and the damping losses of the structured waveguides are determined in view of the design and the fabrication of compact and efficient diode pumped waveguide lasers. The resulting waveguides are polished, provided with resonator mirrors, pumped using diode lasers and characterized.

Jens Gottmann; Leonid Moiseev; Ion Vasilief; Dirk Wortmann

2008-01-01T23:59:59.000Z

492

Laser Range Finder Objective: Use a forward pointing laser range finder to  

E-Print Network [OSTI]

Laser Range Finder Objective: Use a forward pointing laser range finder to detect and avoid obstacles. Principle Investigators: Randy Beard, Tim McLain Laser Range Finder Opti-Logic RS400 Laser path, laser detects object. 2. Upon detection, insert cylindrical object into world map and plan path

Wirthlin, Michael J.

493

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1  

E-Print Network [OSTI]

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 December 2012 #12;LASER SAFETY MANUAL 2012 RICE, and general procedures to aid those individuals working in the laser laboratory environment. It is intended

Natelson, Douglas

494

LASER SAFETY POLICY MANUAL ENVIRONMENTAL HEALTH & SAFETY  

E-Print Network [OSTI]

LASER SAFETY POLICY MANUAL ISSUED BY ENVIRONMENTAL HEALTH & SAFETY OFFICE OF RADIOLOGICAL SAFETY and GEORGIA TECH LASER SAFETY COMMITTEE July 1, 2010 Revised July 31, 2012 #12;Laser Safety Program 1-1 #12;Laser Safety Policy Manual TABLE OF CONTENTS 1. POLICY AND SCOPE

Houston, Paul L.

495

Laser Centre Vrije Universiteit visitors guide  

E-Print Network [OSTI]

Fall 2005 Laser Centre Vrije Universiteit visitors guide #12;Laser Centre Vrije Universiteit De.de.Gijsel@few.vu.nl Website: www.nat.vu.nl/~laser Printing: Drukkerij Ponsen en Looijen, Wageningen © LCVU, Amsterdam great pleasure to present you the Visitors Guide 2005 of the Laser Centre Vrije Universiteit (LCVU

496

Laser transmissionbackscattering through inhomogeneous cirrus clouds  

E-Print Network [OSTI]

Laser transmission­backscattering through inhomogeneous cirrus clouds Szu-Cheng Ou, Yoshihide of the transmission and backscattering of high-energy laser beams. The 2D extinction-coefficient and mean effective and backscattering of high-energy laser beams in realistic atmospheres. The results of laser direct transmission

Takano, Yoshihide

497

Laser Worker Registration Form (LWRF) Surname: Forenames  

E-Print Network [OSTI]

ABCDEFGHI Laser Worker Registration Form (LWRF) Surname: Forenames: School of: Ext No.: Email YY Class of Laser to be Used 1 1M 1E 2 2M 3R 3B 4 Work Location(s) Lab No. Laser Work Currently Undertaken Elsewhere Are you currently engaged in work elsewhere involving laser radiation? YES

Martin, Ralph R.

498

LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1  

E-Print Network [OSTI]

LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 January 2014 #12;LASER SAFETY MANUAL 2014 RICE UNIVERSITY 2 Introduction The objective of the Rice University Laser Safety program is to assist all levels

Natelson, Douglas

499

High precision, rapid laser hole drilling  

DOE Patents [OSTI]

A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

2013-04-02T23:59:59.000Z

500

Heterodyne laser instantaneous frequency measurement system  

DOE Patents [OSTI]

A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

Wyeth, Richard W. (Livermore, CA); Johnson, Michael A. (Pleasanton, CA); Globig, Michael A. (Livermore, CA)

1989-01-01T23:59:59.000Z