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1

fel 2005 :: Free Electron Laser Conference and Workshop  

NLE Websites -- All DOE Office Websites (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  

Science Conference Proceedings (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

Ultraviolet free-electron laser (uv FEL) facility at Brookhaven National Laboratory  

DOE Green Energy (OSTI)

The proposal for a Ultraviolet Free-Electron Laser Facility UV-FEL grew from the realization that neither existing lasers or synchrotrons, nor the third generation synchrotron radiation sources now under construction address all of the needs of scientists interested in the ultraviolet region of the spectrum, particularly with respect to the combination of continuous wavelength selection, high peak power and short pulse duration. Several workshops have been held at BNL and elsewhere which explored applications and source requirements in the 5 to 30 eV range. A critical requirement determined was is for very high peak power and short wavelength, especially for applications in chemical physics and non-linear optics. The need for wavelength tuning with the ease and agility to which synchrotron radiation users have become accustomed has also been strongly emphasized. With these initial parameters in mind, the accelerator physics staff set about devising ways to produce this radiation. Their design is for an FEL that has unique characteristics both in terms of possible applications, and in the range of radiation it could produce. In addition, the proposed location of the UV-FEL adjacent to the NSLS means that pump-probe experiments involving radiation from both sources will be possible. Each successive design has been reviewed in consultation with potential users in an iterative process to arrive at the present proposal design.

Johnson, E.D.; Sutherland, J.C.

1992-12-31T23:59:59.000Z

4

Ultraviolet free-electron laser (uv FEL) facility at Brookhaven National Laboratory  

DOE Green Energy (OSTI)

The proposal for a Ultraviolet Free-Electron Laser Facility UV-FEL grew from the realization that neither existing lasers or synchrotrons, nor the third generation synchrotron radiation sources now under construction address all of the needs of scientists interested in the ultraviolet region of the spectrum, particularly with respect to the combination of continuous wavelength selection, high peak power and short pulse duration. Several workshops have been held at BNL and elsewhere which explored applications and source requirements in the 5 to 30 eV range. A critical requirement determined was is for very high peak power and short wavelength, especially for applications in chemical physics and non-linear optics. The need for wavelength tuning with the ease and agility to which synchrotron radiation users have become accustomed has also been strongly emphasized. With these initial parameters in mind, the accelerator physics staff set about devising ways to produce this radiation. Their design is for an FEL that has unique characteristics both in terms of possible applications, and in the range of radiation it could produce. In addition, the proposed location of the UV-FEL adjacent to the NSLS means that pump-probe experiments involving radiation from both sources will be possible. Each successive design has been reviewed in consultation with potential users in an iterative process to arrive at the present proposal design.

Johnson, E.D.; Sutherland, J.C.

1992-01-01T23:59:59.000Z

5

Free Electron Laser  

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

Free Electron Laser Building Exterior Top Floor Control Room RF Gallery User Lab Beam Enclosure Injector Linear Accelerator Wiggler Magnet Return Line Free Electron Laser Most...

6

FREE ELECTRON LASERS  

E-Print Network (OSTI)

1984). Colson, W. B. , "Free electron laser theory," Ph.D.M. 0. , Spitzer, R. , editors, Free Electron Generators ofM.D. , Spitzer, R. , editors, Free Electron Generators of

Colson, W.B.

2008-01-01T23:59:59.000Z

7

FREE-ELECTRON LASERS  

E-Print Network (OSTI)

1977. First Operation of a Free-Electron Laser. Phys . __Radiation from a High-Gain Free-Electeon Lasee Amplifier. ~1984. Variable-Wiggler Free-Electron-Laser Oscillat.ion.

Sessler, A.M.

2008-01-01T23:59:59.000Z

8

High average power CW FELs (Free Electron Laser) for application to plasma heating: Designs and experiments  

SciTech Connect

A short period wiggler (period {approximately} 1 cm), sheet beam FEL has been proposed as a low-cost source of high average power (1 MW) millimeter-wave radiation for plasma heating and space-based radar applications. Recent calculation and experiments have confirmed the feasibility of this concept in such critical areas as rf wall heating, intercepted beam ( body'') current, and high voltage (0.5 - 1 MV) sheet beam generation and propagation. Results of preliminary low-gain sheet beam FEL oscillator experiments using a field emission diode and pulse line accelerator have verified that lasing occurs at the predicted FEL frequency. Measured start oscillation currents also appear consistent with theoretical estimates. Finally, we consider the possibilities of using a short-period, superconducting planar wiggler for improved beam confinement, as well as access to the high gain, strong pump Compton regime with its potential for highly efficient FEL operation.

Booske, J.H.; Granatstein, V.L.; Radack, D.J.; Antonsen, T.M. Jr.; Bidwell, S.; Carmel, Y.; Destler, W.W.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Zhang, Z.X. (Maryland Univ., College Park, MD (USA). Lab. for Plasma Research); Freund, H.P. (Science Applications International Corp., McLean, VA (USA))

1989-01-01T23:59:59.000Z

9

Free electron lasers  

SciTech Connect

A review of experimental and theoretical concepts of a free electron laser is given. The possibilities of scaling these lasers to high powers are discussed. (MOW)

Brau, C.A.

1980-01-01T23:59:59.000Z

10

Free-electron laser driven by the LBNL laser-plasma accelerator  

E-Print Network (OSTI)

Free-electron laser driven by the LBNL laser-plasmaA design of a compact free-electron laser (FEL), generatingare considered. Keywords: Free-electron laser, laser-plasma

Schroeder, C. B.

2010-01-01T23:59:59.000Z

11

FREE-ELECTRON LASERS  

SciTech Connect

We can now produce intense, coherent light at wavelengths where no conventional lasers exist. The recent successes of devices known as free-electron lasers mark a striking confluence of two conceptual developments that themselves are only a few decades old. The first of these, the laser, is a product of the fifties and sixties whose essential characteristics have made it a staple resource in almost every field of science and technology. In a practical sense, what defines a laser is its emission of monochromatic, coherent light (that is, light of a single wavelength, with its waves locked in step) at a wavelength in the infrared, visible, or ultraviolet region of the electromagnetic spectrum. A second kind of light, called synchrotron radiation, is a by-product of the age of particle accelerators and was first observed in the laboratory in 1947. As the energies of accelerators grew in the 1960s and 70s, intense, incoherent beams of ultraviolet radiation and x--rays became available at machines built for high-energy physics research. Today, several facilities operate solely as sources of synchrotron light. Unlike the well-collimated monochromatic light emitted by lasers, however, this incoherent radiation is like a sweeping searchlight--more accurately, like the headlight of a train on a circular track--whose wavelengths encompass a wide spectral band. Now, in several laboratories around the world, researchers have exploited the physics of these two light sources and have combined the virtues of both in a single contrivance, the free-electron laser, or FEL (1). The emitted light is laserlike in its narrow, sharply peaked spectral distribution and in its phase coherence, yet it can be of a wavelength unavailable with ordinary lasers. Furthermore, like synchrotron radiation, but unlike the output of most conventional lasers, the radiation emitted by free-electron lasers can be tuned, that is, its wavelength can be easily varied across a wide range. The promise of this new technology extends from the fields of solid-state physics, gas- and liquid-phase photochemistry, and surface catalysis to futuristic schemes for ultrahigh-energy linear accelerators.

Sessler, A.M.; Vaughan, D.

1986-04-01T23:59:59.000Z

12

Catalac free electron laser  

DOE Patents (OSTI)

A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac is described. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator, or as an amplifier in conjunction with a master oscillator laser.

Brau, C.A.; Swenson, D.A.; Boyd, T.J. Jr.

1979-12-12T23:59:59.000Z

13

Catalac free electron laser  

DOE Patents (OSTI)

A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

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

1982-01-01T23:59:59.000Z

14

Progress Toward the Wisconsin Free Electron Laser  

SciTech Connect

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, J; 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

15

Progress toward the Wisconsin Free Electron Laser  

SciTech Connect

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

16

Design Optimization for an X-Ray Free Electron Laser Driven by SLAC Linac  

E-Print Network (OSTI)

FREE ELECTRON LASER DRIVEN BY SLAC LINAC Ming Xie, LawrenceLaser (FEL) driven by the SLAC linac. The study assumes theis carried out for the SLAC FEL over all independent system

Xie, Ming

1994-01-01T23:59:59.000Z

17

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

18

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

E-Print Network (OSTI)

FREE ELECTRON LASER FOR SIBERIAN CENTRE FOR PHOTOCHEMICAL RESEARCH: THE CONTROL SYSTEM of the Siberian Branch of RAS. Abstract. A control system for the magnetic system of the free electron laser (FEL

Kozak, Victor R.

19

Performance study of a soft X-ray harmonic generation FEL seeded with an EUV laser pulse  

E-Print Network (OSTI)

28th International Free Electron Laser Conference (FEL06),26th International Free Electron Laser Conference (FEL04),on the Free Electron Laser Theory and Related Topics, World

Gullans, M.; Wurtele, J.S.; Penn, G.; Zholents, A.A.

2007-01-01T23:59:59.000Z

20

Airborne Tactical Free-Electron Laser  

Science Conference Proceedings (OSTI)

The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

Roy Whitney; George Neil

2007-02-01T23:59:59.000Z

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.


21

Circular free-electron laser  

DOE Patents (OSTI)

A high efficiency, free electron laser is described 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, C.A.; Kurnit, N.A.; Cooper, R.K.

1982-01-26T23:59:59.000Z

22

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

23

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

24

Rf feedback free electron laser  

DOE Patents (OSTI)

A free electron laser system and electron beam system for a free electron laser are provided 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, C.A.; Swenson, D.A.; Boyd, T.J. Jr.

1979-11-02T23:59:59.000Z

25

Free electron laser with masked chicane  

DOE Patents (OSTI)

A free electron laser (FEL) is provided with an accelerator for outputting electron beam pulses; a buncher for modulating each one of the electron beam pulses to form each pulse into longitudinally dispersed bunches of electrons; and a wiggler for generating coherent light from the longitudinally dispersed bunches of electrons. The electron beam buncher is a chicane having a mask for physically modulating the electron beam pulses to form a series of electron beam bunches for input to the wiggler. In a preferred embodiment, the mask is located in the chicane at a position where each electron beam pulse has a maximum dispersion.

Nguyen, Dinh C. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

26

Hybrid free electron laser devices  

Science Conference Proceedings (OSTI)

We consider hybrid free electron laser devices consisting of Cerenkov and undulator sections. We will show that they can in principle be used as segmented devices and also show the possibility of exploiting Cerenkov devices for the generation of nonlinear harmonic coherent power. We discuss both oscillator and amplifier schemes.

Asgekar, Vivek; Dattoli, G. [Department of Physics, University of Pune, Pune 411007 (India); ENEA, Unita Tecnico Scientifica Technologie Fisiche, Avanzate, Centro Ricerche Frascati, C.P. 65-00044 Frascati, Rome (Italy)

2007-03-15T23:59:59.000Z

27

Design Alternatives for a Free Electron Laser Facility  

Science Conference Proceedings (OSTI)

The University of Wisconsin-Madison is continuing design efforts for a vacuum ultraviolet/X-ray Free Electron Laser facility. The design incorporates seeding the FEL to provide fully coherent photon output at energies up to {approx}1 keV. The focus of the present work is to minimize the cost of the facility while preserving its performance. To achieve this we are exploring variations in the electron beam driver for the FEL, in undulator design, and in the seeding mechanism. Design optimizations and trade-offs between the various technologies and how they affect the FEL scientific program will be presented.

Jacobs, K; Bosch, R A; Eisert, D; Fisher, M V; Green, M A; Keil, R G; Kleman, K J; Kulpin, J G; Rogers, G C; Wehlitz, R; Chiang, T; Miller, T J; Lawler, J E; Yavuz, D; Legg, R A

2012-07-01T23:59:59.000Z

28

Puffin: A three dimensional, unaveraged free electron laser simulation code  

SciTech Connect

An unaveraged 3D model of the free electron laser (FEL) is presented which is capable of modelling electron interactions with broad bandwidth radiation that includes electron beam shot-noise and coherent spontaneous emission effects. Non-localised electron transport throughout the beam is modelled self-consistently allowing better modelling of systems where a larger electron energy range is required. The FEL interaction can be modelled with undulator fields of variable polarisation. A modular undulator system allows insertion of other magnetic structures, such as chicanes. A set of working equations that describe the model are derived, the parallel numerical method that solves them described, and some example FEL interactions presented.

Campbell, L. T. [University of Strathclyde (SUPA), Glasgow G4 0NG (United Kingdom); ASTeC, STFC Daresbury Laboratory and Cockcroft Institute, Warrington WA4 4AD (United Kingdom); McNeil, B. W. J. [University of Strathclyde (SUPA), Glasgow G4 0NG (United Kingdom)

2012-09-15T23:59:59.000Z

29

Desktop megawatt superradiant free-electron laser at terahertz frequencies  

SciTech Connect

I present a theoretical and simulation study of a desktop, megawatt (MW), terahertz (THz) superradiance free-electron laser (FEL) driven by a THz-pulse-train photoinjector. With nominal electron parameters from a THz-pulse-train photoinjector, this superradiant FEL is capable of generating more than 5 MW power at THz frequencies from a half-meter, single-pass undulator. Tapering the undulator to a length of 1.5 m can further increase the FEL output power to nearly 15 MW.

Huang, Y.-C. [Department of Electrical Engineering, National Tsinghua University, Hsinchu 30013, Taiwan (China)

2010-06-07T23:59:59.000Z

30

Fifth-Generation Free-Electron Laser Light Sources  

SciTech Connect

During the past few years, the Linac Coherent Light Source (LCLS) and the Free-Electron Laser in Hamburg (FLASH) have demonstrated the outstanding capability of free-electron lasers (FELs) as sources of coherent radiation in the soft and hard x-ray region. The high intensity, tens of GW, short pulses (few to less than 100 femtoseconds, and the unique transverse coherence properties are opening a new window to study the structure and dynamics of atomic and molecular systems. The LCLS, FLASH, and the other FELs now under construction are only the beginning of the development of these light sources. The next generations will reach new levels of performance: terawatt, atto-second, ultra-small line-width, high repetition rate, full longitudinal and transverse coherence. These future developments and the R&D needed to successfully build and operate the next generation of FEL light sources will be discussed.

Pellegrini, Claudio [UCLA

2011-03-02T23:59:59.000Z

31

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

32

Free-Electron Lasers: Present Status and Future Prospects  

E-Print Network (OSTI)

38,892 (1977). C. Brau, "Free-Electron Lasers", Science 239,115 (1988). T. Marshall, "Free-Electron Lasers", MacMillan (1985); C Brau, "Free- Electron Lasers", Academic Press (

Kim, K.-J.

2008-01-01T23:59:59.000Z

33

Free electron laser designs for laser amplification  

DOE Patents (OSTI)

Method for laser beam amplification by means of free electron laser techniques. With wiggler magnetic field strength B.sub.w and wavelength .lambda..sub.w =2.pi./k.sub.w regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B.sub.w /k.sub.w or k.sub.w or B.sub.w and k.sub.w (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space "bucket" area.

Prosnitz, Donald (Walnut Creek, CA); Szoke, Abraham (Fremont, CA)

1985-01-01T23:59:59.000Z

34

X-ray Free-Electron Lasers - Present and Future Capabilities [Invited  

SciTech Connect

The Linac Coherent Light Source is now in operation as an X-ray free-electron laser (FEL) user facility. It produces coherent pulses of 550-10,000 eV X-rays of duration adjustable from <10 fsto500 fs. Typical peak power is in excess of 20 GW. The facility will soon be joined by several X-ray FELs under construction around the world. This article will provide an abridged history of free-electron lasers, a description of some basic physics regarding free-electron laser light amplification, and an overview of the rapidly growing list of examples in which lasers will be used in the control and operation of X-ray FELs.

Galayda, John; Ratner, John Arthur:a Daniel F.; White, William E.; /SLAC

2011-11-16T23:59:59.000Z

35

Beam Conditioning for Free Electron Lasers:Consequences and Methods  

Science Conference Proceedings (OSTI)

The consequences of beam conditioning in four example cases [VISA, a soft x-ray free-electron laser (FEL), LCLS, and a 'Greenfield' FEL] are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse emittance and, furthermore, allows for stronger focusing in the undulator. Simulations show higher saturation power, with gain lengths reduced by a factor of 2 or more. The beam dynamics in a general conditioning system are studied, with 'matching conditions' derived for achieving conditioning without growth in the effective emittance. Various conditioning lattices are considered, and expressions derived for the amount of conditioning provided in each case when the matching conditions are satisfied. These results show that there is no fundamental obstacle to producing beam conditioning, and that the problem can be reduced to one of proper lattice design. Nevertheless, beam conditioning will not be easy to implement in practice.

Wolski, A.; Penn, G.; Sessler, A.; Wurtele, J.; /LBL, Berkeley /UC, Berkeley, Astron. Dept.

2010-12-14T23:59:59.000Z

36

XUV free-electron laser-based projection lithography systems  

SciTech Connect

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

37

Short pulse free electron laser amplifier  

DOE Patents (OSTI)

Method and apparatus for amplification of a laser pulse in a free electron laser amplifier where the laser pulse duration may be a small fraction of the electron beam pulse duration used for amplification. An electron beam pulse is passed through a first wiggler magnet and a short laser pulse to be amplified is passed through the same wiggler so that only the energy of the last fraction, f, (f<1) of the electron beam pulse is consumed in amplifying the laser pulse. After suitable delay of the electron beam, the process is repeated in a second wiggler magnet, a third, . . . , where substantially the same fraction f of the remainder of the electron beam pulse is consumed in amplification of the given short laser pulse in each wiggler magnet region until the useful electron beam energy is substantially completely consumed by amplification of the laser pulse.

Schlitt, Leland G. (Livermore, CA); Szoke, Abraham (Fremont, CA)

1985-01-01T23:59:59.000Z

38

Ultrafast time dynamics studies of periodic lattices with free electron laser radiation  

Science Conference Proceedings (OSTI)

It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

2012-11-01T23:59:59.000Z

39

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

40

Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy  

E-Print Network (OSTI)

Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...

Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

2012-01-01T23:59:59.000Z

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.


41

Ultraviolet Free Electron Laser Facility preliminary design report  

SciTech Connect

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

42

The History of X-ray Free-Electron Lasers  

Science Conference Proceedings (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

43

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

44

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 T{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.

1998-04-21T23:59:59.000Z

45

A setup for resonant inelastic soft x-ray scattering on liquids at free electron laser light sources  

SciTech Connect

We present a flexible and compact experimental setup that combines an in vacuum liquid jet with an x-ray emission spectrometer to enable static and femtosecond time-resolved resonant inelastic soft x-ray scattering (RIXS) measurements from liquids at free electron laser (FEL) light sources. We demonstrate the feasibility of this type of experiments with the measurements performed at the Linac Coherent Light Source FEL facility. At the FEL we observed changes in the RIXS spectra at high peak fluences which currently sets a limit to maximum attainable count rate at FELs. The setup presented here opens up new possibilities to study the structure and dynamics in liquids.

Kunnus, Kristjan; Schreck, Simon; Foehlisch, Alexander [Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam (Germany); Rajkovic, Ivan; Quevedo, Wilson; Gruebel, Sebastian; Scholz, Mirko [IFG Structural Dynamics of (Bio)chemical Systems, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37070 Goettingen (Germany); Eckert, Sebastian; Beye, Martin; Suljoti, Edlira; Weniger, Christian; Wernet, Philippe [Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Kalus, Christian [Abteilung Betrieb Beschleuniger BESSYII, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Zhang, Wenkai; Hartsock, Robert W.; Gaffney, Kelly J. [PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Schlotter, William F.; Turner, Joshua J. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kennedy, Brian [MAX-lab, PO Box 118, 221 00 Lund (Sweden); and others

2012-12-15T23:59:59.000Z

46

Laser Phase Errors in Seeded Free Electron Lasers  

SciTech Connect

Harmonic seeding of free electron lasers has attracted significant attention as a method for producing transform-limited pulses in the soft x-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality and impede production of transform-limited pulses. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.

Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC

2012-04-17T23:59:59.000Z

47

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.

Carlsten, Bruce E. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

48

Wiggler plane focusing in a linear free electron laser  

DOE Patents (OSTI)

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, Ernst T. (Livermore, CA)

1988-01-01T23:59:59.000Z

49

Free electron laser using Rf coupled accelerating and decelerating structures  

DOE Patents (OSTI)

A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

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

1984-01-01T23:59:59.000Z

50

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

51

Free-electron laser driven by the LBNL laser-plasma accelerator  

E-Print Network (OSTI)

OF AN XUV FEL DRIVEN BY THE LASER-PLASMA ACCELERATOR AT THEFree-electron laser driven bythe LBNL laser-plasma accelerator C. B. Schroeder ? , W. M.

Schroeder, C. B.

2010-01-01T23:59:59.000Z

52

Microsoft Word - FEL theory -É  

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

INTEGRAL EQUATION FOR A HIGH GAIN FEL N. A. Vinokurov * Introduction The theory of a high gain free electron laser (FEL) is now well developed (e.g., see 1). In this paper I...

53

Free-electron-laser design for laser amplification  

DOE Patents (OSTI)

A method for laser beam amplification by means of free electron laser techniques is described. With wiggler magnetic field strength B/sub w/ and wavelength lambda/sub w/ = 2..pi../k/sub w/ regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B/sub w//k/sub w/ or k/sub w/ or B/sub w/ and k/sub w/ (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space bucket area.

Prosnitz, D.; Szoke, A.

1982-01-26T23:59:59.000Z

54

FREE ELECTRON LASERS FOR THE PRODUCTION OF INFRARED AND MILLIMETER WAVES  

E-Print Network (OSTI)

S.M. Gold, et. al. , in Free Electron Generators of CoherentThe Hughes Low-Voltage Free-Electron Laser Program," inProc. of the 1985 Free Electron Laser Conference, Lake

Sessler, A.M.

2008-01-01T23:59:59.000Z

55

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

Science Conference Proceedings (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

56

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

57

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

58

High-efficiency free-electron laser results  

Science Conference Proceedings (OSTI)

Results obtained with a tapered-wiggler free-electron laser demonstrate the concepts proposed by Morton for enhanced efficiency and show deceleration of electrons by as much as 7%, and extraction of more than 3% of the total electron-beam energy as laser energy when the laser is operated as an amplifier. The experiment is presently being reconfigured to examine its performance as a laser oscillator.

Boyer, K.; Baru, C.A.; Newnam, B.E.; Stein, W.E.; Warren, R.W.; Winston, J.G.; Young, L.M.

1983-01-01T23:59:59.000Z

59

Multifrequency, single pass free electron laser  

DOE Patents (OSTI)

A method for simultaneous amplification of laser beams with a sequence of frequencies in a single pass, using a relativistic beam of electrons grouped in a sequence of energies corresponding to the sequence of laser beam frequencies. The method allows electrons to pass from one potential well or "bucket" to another adjacent bucket, thus increasing efficiency of trapping and energy conversion.

Szoke, Abraham (Fremont, CA); Prosnitz, Donald (Walnut Creek, CA)

1985-01-01T23:59:59.000Z

60

Physically transparent formulation of a free-electron laser in the linear gain regime  

SciTech Connect

The recent 2-dimensional analytic theories of a free-electron laser (FEL) in the linear regime are reformulated in terms of three dimensionless ratios that describe the degree to which the characteristics of the electron beam deviate from the cold beam limit of a beam with no emittance or energy spread. In terms of these ratios, algebraic model equations of a fit that combines features of both of the 2-dimensional analyses are given as a convenient computational tool. Graphs of the FEL gain eigenvalue computed with the combined 2-D formulation illustrate that the gain and the output power at saturation are reduced from the 1-D value, when any of the ratios is larger than unity.

Barletta, W.A. [Lawrence Livermore National Lab., CA (United States); Sessler, A.M. [Lawrence Berkeley Lab., CA (United States); Yu, L.H. [Brookhaven National Lab., Upton, NY (United States)

1992-08-01T23:59:59.000Z

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

rf modulator design and phase amplitude control for a high-power free-electron-laser linac  

SciTech Connect

The continued interest for building tunable lasers using an electron accelerator as the source of primary energy has resulted in the design of a new accelerator. Earlier work by other members of the Los Alamos team has demonstrated that this design does work in an amplifier mode. The accelerator is to be upgraded for use in an oscillator experiment and the new rf power amplifier system must meet some of the very stringent demands for power and stability placed on the electron beam for the free-electron laser (FEL) interaction to be observed. These demands are particularly stringent because the electron beam energy ultimately will be circulated back through the accelerator so that the electron beam energy not used in the FEL interaction is not wasted. These considerations have to some measure been incorporated into the design of the second FEL system at Los Alamos and are discussed.

Hoeberling, R.F.; Tallerico, P.J.

1981-01-01T23:59:59.000Z

62

Reversible Electron Beam Heating for Suppression of Microbunching Instabilities at Free-Electron Lasers  

SciTech Connect

The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) upstream and downstream of a magnetic bunch compressor chicane. The additional energy spread is introduced in the first TDS, which suppresses the microbunching instability, and then is eliminated in the second TDS. We show the feasibility of the microbunching gain suppression based on calculations and simulations including the effects of coherent synchrotron radiation. Acceptable electron beam and radio-frequency jitter are identified, and inherent options for diagnostics and on-line monitoring of the electron beam's longitudinal phase space are discussed.

Behrens, Christopher; /DESY; Huang, Zhirong; Xiang, Dao; /SLAC

2012-05-30T23:59:59.000Z

63

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

SciTech Connect

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

64

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

SciTech Connect

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

65

Chirped pulse inverse free-electron laser vacuum accelerator  

SciTech Connect

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

66

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

67

Simulation Studies of the X-Ray Free-Electron Laser Oscillator  

SciTech Connect

Simulations of the x-ray free-electron laser (FEL) oscillator are presented that include transverse effects and realistic Bragg crystal properties with the two-dimensional code GINGER. In the present cases considered the radiation divergence is much narrower than the crystal acceptance, and the numerical algorithm can be simplified by ignoring the finite angular bandwidth of the crystal. In this regime GINGER shows that the saturated x-ray pulses have 109 photons and are nearly Fourier-limited with peak powers in excess of 1 MW. Wealso include preliminary results for a four-mirror cavity that can be tuned in wavelength over a few percent, with future plans to incorporate the full transverse response of the Bragg crystals into GINGER to more accurately model this tunable source.

Lindberg, R. R.; Shyd'ko, Y.; Kim, K.-J; Fawley, W. M.

2009-08-14T23:59:59.000Z

68

Investigation of efficiency optimization in free electron lasers  

SciTech Connect

The dynamics of trapped particles in the presence of the wiggler magnetic field and the electromagnetic radiation field in free electron lasers were investigated. From the results of computer simulations, it was found that, for a given set of parameters, the efficiency of energy extraction from the electron beam maximizes at a particular intensity of the electromagnetic radiation. Based on the physical argument of the dynamics of the trapped particles, a criterion which predicts accurately the optimum intensity of the electromagnetic radiation was obtained. (TFD)

Kwan, T.J.T.

1979-01-01T23:59:59.000Z

69

The LLNL/UCLA high gradient inverse free electron laser  

SciTech Connect

We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)

2012-12-21T23:59:59.000Z

70

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

71

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

Science Conference Proceedings (OSTI)

Several recent reports have identified the scientific requirements for a future soft x-ray light source, and a high-repetition-rate free-electron laser (FEL) facility that is responsive to these requirements is now on the horizon. R&D in some critical areas is needed, however, to demonstrate technical performance, thus reducing technical risks and construction costs. Such a facility most likely will be based on a CW superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun operating in CW mode, and on an array of FELs to which the accelerated beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on experimental requirements, the individual FELs can be configured for either self-amplified spontaneous emission (SASE), seeded, or oscillator mode of operation, including the use of high-gain harmonic generation (HGHG), echo-enhanced harmonic generation (EEHG), harmonic cascade, or other configurations. In this White Paper we identify the overall accelerator R&D needs, and highlight the most important pre-construction R&D tasks required to value-engineer the design configuration and deliverables for such a facility. In Section 1.4 we identify the comprehensive R&D ultimately needed. We identify below the highest-priority requirements for understanding machine performance and reduce risk and costs at this pre-conceptual design stage. Details of implementing the required tasks will be the subject of future evaluation. Our highest-priority R&D program is the injector, which must be capable of delivering a beam with bunches up to a nanocoulomb at MHz repetition rate and with normalized emittance {le} 1 mm {center_dot} mrad. This will require integrated accelerating structure, cathode, and laser systems development. Cathode materials will impact the choice of laser technology in wavelength and energy per pulse, as well as vacuum requirements in the accelerating structure. Demonstration experiments in advanced seeding techniques, such as EEHG, and other optical manipulations to enhance the FEL process are required to reduce technical risk in producing temporally coherent and ultrashort x-ray output using optical seed lasers. Success of EEHG in particular would result in reduced development and cost of laser systems and accelerator hardware for seeded FELs. With a 1.5-2.5 GeV linac, FELs could operate in the VUV-soft x-ray range, where the actual beam energy will be determined by undulator technology; for example, to use the lower energy would require the use of advanced designs for which undulator R&D is needed. Significant reductions in both unit costs and accelerator costs resulting from the lower electron beam energy required to achieve lasing at a particular wavelength could be obtained with undulator development. Characterization of the wakefields of the vacuum chambers in narrow-gap undulators will be needed to minimize risk in ability to deliver close to transform limited pulses. CW superconducting RF technology for an FEL facility with short bunches at MHz rate and up to mA average current will require selection of design choices in cavity frequency and geometry, higher order mode suppression and power dissipation, RF power supply and distribution, accelerating gradient, and cryogenics systems. R&D is needed to define a cost and performance optimum. Developments in laser technology are proceeding at rapid pace, and progress in high-power lasers, harmonic generation, and tunable sources will need to be tracked.

Corlett, John; Attwood, David; Byrd, John; Denes, Peter; Falcone, Roger; Heimann, Phil; Leemans, Wim; Padmore, Howard; Prestemon, Soren; Sannibale, Fernando; Schlueter, Ross; Schroeder, Carl; Staples, John; Venturini, Marco; Warwick, Tony; Wells, Russell; Wilcox, Russell; Zholent, Alexander; Adolphsen, Chris; Arthur, John; Bergmann, Uwe; Cai, Yunhai; Colby, Eric; Dowell, David; Emma, Paul; Fox, John; Frisch, Josef; Galayda, John; Hettel, Robert; Huang, Zhirong; Phinney, Nan; Rabedeau, Tom; Raubenheimer, Tor; Reis, David; Schmerge, John; Stöhr, Joachim; Stupakov, Gennady; White, Bill; Xiang, Dao

2009-06-08T23:59:59.000Z

72

Inverse Free Electron Laser Heater for the LCLS  

Science Conference Proceedings (OSTI)

The Linac Coherent Light Source (LCLS) free electron laser employs an RF photocathode gun that yields a 1nC bunch a few picoseconds long, which must be further compressed to yield the high current required for Self Amplified Spontaneous Emission (SASE) gain. The electron beam from the RF photocathode gun is quite sensitive to microbunching instabilities such as coherent synchrotron radiation (CSR) in the compressor chicanes and longitudinal space charge (LSC) in the linac. These effects can be Landau damped by adding energy spread to the electron bunch prior to compression. They propose to do this by co-propagating an infrared laser beam with the electron bunch in an undulator in the LCLS injector beamline. The undulator is placed in a four bend magnet chicane to allow the Ir laser beam to propagate colinearly with the e-beam while it oscillates in the undulator. The IR laser beam is derived from the photocathode gun drive laser, so the two beams are synchronized. Simulations presented elsewhere in these proceedings show that the laser interaction damps the microbunching instabilities to a very great extent. This paper is a description of the design of the laser heater.

Bentson, L.D.; Bolton, P.; Carr, R.; Dowell, D.; Emma, P.; Gilevich, S.; Huang, Z.; Welch, J.J.; Wu, J.; /SLAC

2005-05-11T23:59:59.000Z

73

Beam conditioner for free electron lasers and synchrotrons  

DOE Patents (OSTI)

A focused optical is been used to introduce an optical pulse, or electromagnetic wave, colinearly with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM.sub.10 mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

Liu, Hongxiu (Williamsburg, VA); Neil, George R. (Williamsburg, VA)

1998-01-01T23:59:59.000Z

74

Development of an XUV-IR free-electron laser user facility for scientific research and industrial applications  

Science Conference Proceedings (OSTI)

Los Alamos has designed and proposes to establish an XUV-IR free- electron laser (FEL) user facility for scientific research and industrial applications based on coherent radiation ranging from soft x-rays as short as 1 nm to far-infrared wavelengths as long as 100 {mu}m. As the next-generation light source beyond low-emittance storage rings with undulator insertion devices, this proposed national FEL user facility should make available to researchers broadly tunable, picosecond-pulse, coherent radiation with 10{sup 4} to 10{sup 7} greater spectral flux and brightness. The facility design is based on two series of FEL oscillators including one regenerative amplifier. The primary series of seven FEL oscillators, driven by a single, 1-GeV rf linac, spans the short-wavelength range from 1 to 600 nm. A second 60-MeV rf linac, synchronized with the first, drives a series of three Vis/IR FEL oscillators to cover the 0. 5 to 100-{mu}m range. This paper presents the motivation for such a facility arising from its inherently high power per unit bandwidth and its potential use for an array of scientific and industrial applications, describes the facility design, output parameters, and user laboratories, makes comparisons with synchrotron radiation sources, and summarizes recent technical progress that supports the technical feasibility. 80 refs., 9 figs., 6 tabs.

Newnam, B.E.; Warren, R.W.; Conradson, S.D.; Goldstein, J.C.; McVey, B.D.; Schmitt, M.J.; Elliott, C.J.; Burns, M.J.; Carlsten, B.E.; Chan, K.C.; Johnson, W.J.; Wang, T.S.; Sheffield, R.L.; Meier, K.L.; Olsher, R.H.; Scott, M.L.; Griggs, J.E.

1991-01-01T23:59:59.000Z

75

Free-Electron Lasers: Present Status and Future Prospects  

E-Print Network (OSTI)

is on-going, but no "user facilities" can be expected inbe on constructing user facilities. In the short wavelengthtechnology. IR FEL User Facilities IR FELs have been built

Kim, K.-J.

2008-01-01T23:59:59.000Z

76

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

77

Investigation of the electron trajectories and gain regimes of the whistler pumped free-electron laser  

SciTech Connect

A free-electron laser (FEL) scheme, which employs the whistler wave as a slow electromagnetic wave wiggler, was studied theoretically. Subjected to the transverse fields of whistler wave wiggler, the beam electrons are the source of the energy needed to produce electromagnetic radiation. The strength and the period of the wiggler field depend on the parameters of the magnetoplasma medium. This configuration has a higher tunability by controlling the plasma density, on top of the {gamma}-tunability of the conventional FELs. The theory of linear gain and electron trajectories was presented and four groups (I, II, III, and IV) of electron orbits were found in the presence of an axial guide magnetic field. Using perturbation analysis, it is found that these groups of orbits were stable except small regions of group I and IV orbits. The function {Phi} which determines the rate of change of axial velocity with beam energy was also derived. In the case in which {Phi}<0 represents a negative-mass regime in which the axial velocity accelerates as the electrons lose energy. Numerical solutions showed that by increasing the cyclotron frequency, the gain for group I and III orbits increased, while a gain decrement was obtained for group II and IV orbits.

Jafarinia, F.; Jafari, S. [Department of Physics, University of Guilan, Rasht 41335-1914 (Iran, Islamic Republic of); Mehdian, H. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, Tehran 15614 (Iran, Islamic Republic of)

2013-04-15T23:59:59.000Z

78

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

SciTech Connect

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

79

A wide bandwidth free-electron laser with mode locking using current modulation.  

SciTech Connect

A new scheme for mode locking a free-electron laser amplifier is proposed based on electron beam current modulation. It is found that certain properties of the original concept, based on the energy modulation of electrons, are improved including the spectral brightness of the source and the purity of the series of short pulses. Numerical comparisons are made between the new and old schemes and between a mode-locked free-electron laser and self-amplified spontaneous emission free-electron laser. Illustrative examples using a hypothetical mode-locked free-electron laser amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated.

Kur, E.; Dunning, D. J.; McNeil, B. W. J.; Wurtele, J.; Zholents, A. A. (Accelerator Systems Division (APS)); (Univ. of California at Berkeley); (Univ. of Strathclyde); (STFC Daresbury Lab.); (LBNL)

2011-01-20T23:59:59.000Z

80

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

Office of Science (SC) Website

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...

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,
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81

A Plasma Channel Beam Conditioner for a Free Electron Laser  

E-Print Network (OSTI)

Nature 445, 6741 (2007). [7] LCLS Design Study Group, SLACLinac Coherent Light Source (LCLS) [7]. One example has thefunction in the FEL. For LCLS parameters, the corresponding

Penn, G.; Sessler, A.M.; Wurtele, J.S.

2008-01-01T23:59:59.000Z

82

HIGH AVERAGE POWER UV FREE ELECTRON LASER EXPERIMENTS AT JLAB  

Science Conference Proceedings (OSTI)

Having produced 14 kW of average power at {approx}2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.

Douglas, David; Evtushenko, Pavel; Gubeli, Joseph; Hernandez-Garcia, Carlos; Legg, Robert; Neil, George; Powers, Thomas; Shinn, Michelle D; Tennant, Christopher

2012-07-01T23:59:59.000Z

83

Laser Phase Errors in Seeded FELs  

Science Conference Proceedings (OSTI)

Harmonic seeding of free electron lasers has attracted significant attention from the promise of transform-limited pulses in the soft X-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.

Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC

2012-03-28T23:59:59.000Z

84

Beyond the Standard Model Searches Using a Free Electron Laser  

SciTech Connect

Much of the focus of Beyond the Standard Model physics searches is on the TeV scale, making use of hadron and lepton colliders. Additionally, however, there is the means to make these searches in different regions of parameter space using sub-electron volt photons from a Free Electron Laser, for example. We report on the experimental results of searches for optical-wavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10{sup -5} and 10{sup -2} electron volts for a mixing parameter greater than 10{sup -7}. We also report on the results of a sensitive search for scalar coupling of photons to light neutral bosons in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10{sup -6} GeV{sup -1}. These were generation-regeneration experiments using the 'light shining through a wall' technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The present results indicate no evidence for photon-paraphoton mixing or for scalar couplings of bosons to photons for the range of parameters investigated.

Afanasev, A.; Ramdon, R. [Department of Physics, Hampton University, Hampton, VA 23668 (United States); Baker, O. K.; Slocum, P. [Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520 (United States); Beard, K. B. [Muons, Inc., 552 N. Batavia Avenue, Batavia, IL 60510 (United States); Biallas, G.; Boyce, J.; Shinn, M. [Free Electron Laser Division, Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Minarni, M. [Department of Physics, Universitas Riau (UNRI), Pekanbaru, Riau 28293 (Indonesia)

2010-02-10T23:59:59.000Z

85

LIPSS Free-Electron Laser Searches for Dark Matter  

SciTech Connect

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

86

Beam Conditioning and Harmonic Generation in Free Electron Lasers  

E-Print Network (OSTI)

Meth. A 429, 243 (1999). LCLS Design Study Group, ReportFELs) such as Euro- XFEL and LCLS are to be devices whichproposed at Euro-XFEL or the LCLS, are designed to generate

Charman, A.E.; Penn, G.; Wolski, A.; Wurtele, J.S.

2004-01-01T23:59:59.000Z

87

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

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

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

88

Measurements of the LCLS Laser Heater and its impact on the x-ray FEL Performance  

Science Conference Proceedings (OSTI)

The very bright electron beam required for an x-ray free-electron laser (FEL), such as the Linac Coherent Light Source (LCLS), is susceptible to a microbunching instability in the magnetic bunch compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To this end, a 'laser-heater' system has been installed in the LCLS injector, which modulates the energy of a 135-MeV electron bunch with an IR laser beam in a short undulator, enclosed within a four-dipole chicane. In this paper, we report detailed measurements of laser heater-induced energy spread, including the unexpected self-heating phenomenon when the laser energy is very low. We discuss the suppression of the microbunching instability with the laser heater and its impact on the x-ray FEL performance. We also present the analysis of these experimental results and develop a three-dimensional longitudinal space charge model to explain the self-heating effect.

Huang, Zhirong; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Iverson, R.; Loos, H.; Miahnahri, A.; Nuhn, H.-D.; Ratner, D.; Stupakov, G.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.

2009-12-17T23:59:59.000Z

89

Effects of finite beam and plasma temperature on the growth rate of a two-stream free electron laser with background plasma  

SciTech Connect

A fluid theory is used to derive the dispersion relation of two-stream free electron laser (TSFEL) with a magnetic planar wiggler pump in the presence of background plasma (BP). The effect of finite beams and plasma temperature on the growth rate of a TSFEL has been verified. The twelve order dispersion equation has been solved numerically. Three instabilities, FEL along with the TS and TS-FEL instabilities occur simultaneously. The analysis in the case of cold BP shows that when the effect of the beam temperature is taken into account, both instable bands of wave-number and peak growth rate in the TS instability increase, but peak growth of the FEL and TS-FEL instabilities decreases. Thermal motion of the BP causes to diminish the TS instability and it causes to decrease the FEL and TS-FEL instabilities. By increasing the beam densities and lowering initial velocities (in the collective Raman regime), growth rate of instabilities increases; however, it has opposite behavior in the Campton regime.

Mahdizadeh, N. [Department of Physics, Sabzevar Branch, Islamic Azad University, Sabzevar (Iran, Islamic Republic of); Aghamir, F. M. [Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of)

2013-02-28T23:59:59.000Z

90

Proceedings of the workshop prospects for a 1 angstrom free-electron laser  

Science Conference Proceedings (OSTI)

This report contains papers on the following topics free-electron laser theory, scaling relations and simulations; micro-wigglers; photocathode and switched power gun; applications; and summary of working groups.

Gallardo, J.C. (ed.)

1990-01-01T23:59:59.000Z

91

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

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

The European X-ray Free-Electron Laser: A Progress Report Friday, December 2, 2011 - 2:00pm SLAC, Redtail Conference Room (901-108) M. Altarelli, European XFEL GmbH, Hamburg,...

92

Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator  

SciTech Connect

Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy spread hinders the potential applications for coherent FEL radiation generation. In this paper, we discuss a method to compensate the effects of beam energy spread by introducing a transverse field variation into the FEL undulator. Such a transverse gradient undulator together with a properly dispersed beam can greatly reduce the effects of electron energy spread and jitter on FEL performance. We present theoretical analysis and numerical simulations for SASE and seeded extreme ultraviolet and soft x-ray FELs based on laser plasma accelerators.

Huang, Zhirong; Ding, Yuantao; /SLAC; Schroeder, Carl B.; /LBL, Berkeley

2012-09-13T23:59:59.000Z

93

Bendable Focusing X-Ray Optics for the ALS and the LCLS/FEL: Design, Metrology, and Performance  

E-Print Network (OSTI)

Optics for the ALS and the LCLS/FEL: Design, Metrology, andwas performed in support of the AMO/LCLS project at SLAC. *Coherent Light Source (LCLS) x-ray free electron laser (FEL)

Yashchuk, V. V.

2010-01-01T23:59:59.000Z

94

Preparations for a high gradient inverse free electron laser experiment at Brookhaven national laboratory  

SciTech Connect

Preparations for an inverse free electron laser experiment at Brookhaven National Laboratory's Accelerator Test Facilty are presented. Details of the experimental setup including beam and laser transport optics are first discussed. Next, the driving laser pulse structure is investigated and initial diagnostics are explored and compared to simulations. Finally, planned improvements to the experimental setup are discussed.

Duris, J.; Li, R. K.; Musumeci, P.; Sakai, Y.; Threlkeld, E.; Williams, O.; Fedurin, M.; Kusche, K.; Pogorelsky, I.; Polyanskiy, M.; Yakimenko, V. [UCLA Department of Physics and Astronomy, Los Angeles, CA 90095 (United States); Accelerator Test Facility, Brookhaven National Laboratory, Upton, NY, 11973 (United States)

2012-12-21T23:59:59.000Z

95

X-ray-optical cross-correlator for gas-phase experiments at the Linac Coherent Light Source free-electron laser  

Science Conference Proceedings (OSTI)

X-ray-optical pump-probe experiments at the Linac Coherent Light Source (LCLS) have so far been limited to a time resolution of 280 fs fwhm due to timing jitter between the accelerator-based free-electron laser (FEL) and optical lasers. We have implemented a single-shot cross-correlator for femtosecond x-ray and infrared pulses. A reference experiment relying only on the pulse arrival time information from the cross-correlator shows a time resolution better than 50 fs fwhm (22 fs rms) and also yields a direct measurement of the maximal x-ray pulse length. The improved time resolution enables ultrafast pump-probe experiments with x-ray pulses from LCLS and other FEL sources.

Schorb, S.; Cryan, J. P.; Glownia, J. M.; Bionta, M. R.; Coffee, R. N.; Swiggers, M.; Carron, S.; Castagna, J.-C.; Bozek, J. D.; Messerschmidt, M.; Schlotter, W. F.; Bostedt, C. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309 (United States); Gorkhover, T. [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Erk, B.; Boll, R.; Schmidt, C.; Rudenko, A. [Max-Planck Advanced-Study-Group at CFEL, Notkestr. 85, 22607 Hamburg (Germany); Max-Planck-Institut f. Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Rolles, D. [Max-Planck Advanced-Study-Group at CFEL, Notkestr. 85, 22607 Hamburg (Germany); Max-Planck-Institut f. med. Forschung, Jahnstr. 29, 69120 Heidelberg (Germany); Rouzee, A. [Max-Born-Institut, Max-Born-Str. 2, 12489 Berlin (Germany)

2012-03-19T23:59:59.000Z

96

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

97

Low-Charge, Hard X-Ray Free Electron Laser Driven with an X-Band Injector and Accelerator  

Science Conference Proceedings (OSTI)

After the successful operation of the Free Electron Laser in Hamburg (FLASH) and the Linac Coherent Light Source (LCLS), soft and hard x-ray free electron lasers (FELs) are being built, designed, or proposed at many accelerator laboratories. Acceleration employing lower frequency rf cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic rf system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency rf acceleration process. In this paper, a hard x-ray FEL design using an all X-band accelerator at 11.424 GHz (from photocathode rf gun to linac end) is presented, without the assistance of any harmonic rf linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient, and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (rms), low-charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macroparticle 3D simulation employing several computer codes is presented in this paper, where space charge, wakefields, and incoherent and coherent synchrotron radiation effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low-charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.

Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC

2012-04-17T23:59:59.000Z

98

Mode-Locked Multichromatic X-Rays in a Seeded Free-Electron Laser for Single-Shot X-Ray Spectroscopy  

SciTech Connect

We present the promise of generating gigawatt mode-locked multichromatic x rays in a seeded free-electron laser (FEL). We show that, by using a laser to imprint periodic modulation in electron beam phase space, a single-frequency coherent seed can be amplified and further translated to a mode-locked multichromatic output in an FEL. With this configuration the FEL output consists of a train of mode-locked ultrashort pulses which span a wide frequency gap with a series of equally spaced sharp lines. These gigawatt multichromatic x rays may potentially allow one to explore the structure and dynamics of a large number of atomic states simultaneously. The feasibility of generating mode-locked x rays ranging from carbon K edge ({approx}284 eV) to copper L{sub 3} edge ({approx}931 eV) is confirmed with numerical simulation using the realistic parameters of the linac coherent light source (LCLS) and LCLS-II. We anticipate that the mode-locked multichromatic x rays in FELs may open up new opportunities in x-ray spectroscopy (i.e. resonant inelastic x-ray scattering, time-resolved scattering and spectroscopy, etc.).

Xiang, Dao; Ding, Yuantao; Raubenheimer, Tor; Wu, Juhao; /SLAC

2012-05-10T23:59:59.000Z

99

Aerosol Imaging with a Soft X-ray Free Electron Laser  

SciTech Connect

Lasers have long played a critical role in the advancement of aerosol science. A new regime of ultrafast laser technology has recently be realized, the world's first soft xray free electron laser. The Free electron LASer in Hamburg, FLASH, user facility produces a steady source of 10 femtosecond pulses of 7-32 nm x-rays with 10{sub 12} photons per pulse. The high brightness, short wavelength, and high repetition rate (>500 pulses per second) of this laser offers unique capabilities for aerosol characterization. Here we use FLASH to perform the highest resolution imaging of single PM2.5 aerosol particles in flight to date. We resolve to 35 nm the morphology of fibrous and aggregated spherical carbonaceous nanoparticles that existed for less than two milliseconds in vacuum. Our result opens the possibility for high spatialand time-resolved single particle aerosol dynamics studies, filling a critical technological need in aerosol science.

Bogan, Michael J.; /SLAC /LLNL, Livermore; Boutet, Sebastien; /SLAC; Chapman, Henry N.; /DESY /Hamburg U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry /LLNL, Livermore; Rohner, Urs; /LLNL, Livermore /TOFWERK AG; Frank, Matthias; Hau-Riege, Stefan P.; /LLNL, Livermore; Bajt, Sasa; /DESY; Woods, Bruce; /LLNL, Livermore; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; Hajdu, Janos; /Uppsala U.; Schulz, Joachim; /DESY

2011-08-22T23:59:59.000Z

100

The First Angstrom X-Ray Free-Electron Laser  

SciTech Connect

The Linac Coherent Light Source produced its first x-ray laser beam on 10 April 2009. Today it is routinely producing x-ray pulses with energy >2 mJ across the operating range from 820-8,200 eV. The facility has begun operating for atomic/molecular/optical science experiments. Performance of the facility in its first user run (1 October - 21 December) and current machine development activities will be presented. Early results from the preparations for the start of the second user run is also reported.

Galayda, John; /SLAC

2012-08-24T23:59:59.000Z

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

FEL-accelerator related diagnostics  

SciTech Connect

Free Electron Lasers (FEL) present a unique set of beam parameters to the diagnostics suite. The FEL requires characterization of the full six dimensional phase space of the electron beam at the wiggler and accurate alignment of the electron beam to the optical mode of the laser. In addition to the FEL requirements on the diagnostics suite, the Jefferson Lab FEL is operated as an Energy Recovered Linac (ERL) which imposes additional requirements on the diagnostics. The ERL aspect of the Jefferson Lab FEL requires that diagnostics operate over a unique dynamic range and operate with simultaneous transport of the accelerated and energy recovered beams. This talk will present how these challenges are addressed at the Jefferson Lab FEL.

Kevin Jordan; David Douglas; Stephen V. Benson; Pavel Evtuschenko

2007-08-02T23:59:59.000Z

102

THE SYSTEM OF POWER SUPPLIES, CONTROL AND MODULATION OF ELECTRON GUN FOR FREE ELECTRON LASER  

E-Print Network (OSTI)

. The output of power inverter is connected to input coil of isolated power transformer (300kV). Timer Electric power for part 2 goes from power inverter through isolated power transformer (isolation voltageTHE SYSTEM OF POWER SUPPLIES, CONTROL AND MODULATION OF ELECTRON GUN FOR FREE ELECTRON LASER E

Kozak, Victor R.

103

The “SF” System of Sextupoles for the JLAB 10 KW Free Electron Laser Upgrade  

SciTech Connect

The characteristics of the system of “SF” Sextupoles for the infrared Free Electron Laser Upgrade1 at the Thomas Jefferson National Accelerator Facility (JLab) are described. These eleven sextupoles possess a large field integral (2.15 T/m) with +/- 0.2%

George Biallas, Mark Augustine, Kenneth Baggett, David Douglas, Robin Wines

2009-05-01T23:59:59.000Z

104

X-RAY NONLINEAR OPTICAL PROCESSES IN ATOMS USING A SELF-AMPLIFIED SPONTANEOUS EMISSION FREE-ELECTRON LASER  

SciTech Connect

X-ray free electron lasers (xFEL) will open new avenues to the virtually unexplored territory of non-linear interactions of x rays with matter. Initially xFELs will be based on the principle of self-amplified spontaneous emission (SASE). Each SASE pulse consists of a number of coherent intensity spikes of random amplitude, i.e. the process is chaotic and pulses are irreproducible. The coherence time of SASE xFELs will be a few femtoseconds for a photon energy near 1 keV. The importance of coherence properties of light in non-linear optical processes was theoretically discovered in the early 1960s. In this contribution we will illustrate the impact of field chaoticity on x-ray non-linear optical processes on neon for photon energies around 1 keV and intensities up to 10{sup 18} W/cm{sup 2}. Resonant and non-resonant processes are discussed. The first process to be addressed is the formation of a double-core hole in neon by photoionization with x rays above 1.25 keV energy. In contrast to the long-wavelength regime, non-linear optical processes in the x-ray regime are characterized in general by sequential single-photon single-electron interactions. Despite this fact, the sequential absorption of multiple x-ray photons depends on the statistical properties of the radiation field. Treating the x rays generated by a SASE FEL as fully chaotic, a quantum-mechanical analysis of inner-shell two-photon absorption is performed. By solving a system of time-dependent rate equations, we demonstrate that double-core hole formation in neon via x-ray two-photon absorption is enhanced by chaotic photon statistics. At an intensity of 10{sup 16} W/cm{sup 2}, the statistical enhancement is about 30%, much smaller than typical values in the optical regime. The second part of this presentation discusses the resonant Auger effect of atomic neon at the 1s-3p transition (at 867.1 eV). For low X-ray intensity, the excitation process 1s {yields} 3p in Neon can be treated perturbatively. The core-hole excited 1s{sup -1} 3p state is embedded in the continuum and decays via Auger-process on the timescale of approximately 5 fs. Increasing the x-ray intensity above 1.5 x 10{sup 18} W/cm{sup 2}, a peak intensity accessible with xFEL sources in the near future, x-ray induced emission from 3p back to 1s becomes possible, i.e. Rabi oscillations between these two levels can be induced. For the numerical analysis of this process, an effective two-level model, including a description of the resonant Auger decay process, is employed. The observation of x-ray-driven atomic populations dynamics in the time domain is challenging for chaotic xFEL pulses. In addition to requiring single-shot measurements, sub-femtosecond temporal resolution would be needed. The Rabi oscillations will, however, be imprinted on the kinetic energy distribution of the resonant Auger electron (see Fig. 1). Measuring the resonant Auger-electron line profile will provide information on both atomic population dynamics and x-ray pulse properties.

Rohringer, N

2008-08-08T23:59:59.000Z

105

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

SciTech Connect

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

106

Chorus wave amplification: A free electron laser in the Earth's magnetosphere  

SciTech Connect

A new theoretical model for whistler-mode chorus amplification in the Earth's magnetosphere is presented. We derive, based on the free-electron laser mechanism in a high-gain amplifier, a new closed set of self-consistent relativistic equations that couple the Hamiltonian equations for particles with Maxwell's equations. We demonstrate that these equations predict, through a cubic equation, whistler amplification levels in good agreement with those observed in the Earth's magnetosphere.

Soto-Chavez, A. R.; Bhattacharjee, A. [Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States); Ng, C. S. [Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775 (United States)

2012-01-15T23:59:59.000Z

107

High harmonic attosecond pulse train amplification in a free electron laser  

SciTech Connect

It is shown using three-dimensional simulations that the temporal structure of an attosecond pulse train, such as that generated via high harmonic generation in noble gases, may be retained in a free electron laser amplifier through to saturation using a mode-locked optical klystron configuration. At wavelengths of {approx}12 nm, a train of attosecond pulses of widths {approx}300 as with peak powers in excess of 1 GW are predicted.

McNeil, B.W.; Sheehy, B.; Thompson, N.R.; Dunning, D.J.

2011-03-04T23:59:59.000Z

108

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

SciTech Connect

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

109

Design of a superconducting linear accelerator for an Infrared Free Electron Laser of the proposed Chemical Dynamics Research Laboratory at LBL  

Science Conference Proceedings (OSTI)

An accelerator complex has recently been designed at LBL as part of an Infrared Free Electron Laser facility in support of a proposed Chemical Dynamics Research Laboratory. We will outline the choice of parameters and design philosophy, which are strongly driven by the demand of reliable and spectrally stable operation of the FEL for very special scientific experiments. The design is based on a 500 MHz recirculating superconducting electron linac with highest energy reach of about 60 MeV. The accelerator is injected with beams prepared by a specially designed gun-buncher system and incorporates a near-isochronous and achromatic recirculation line tunable over a wide range of beam energies. The stability issues considered to arrive at the specific design will be outlined.

Chattopadhyay, S.; Byrns, R.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Kim, K.J.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

1992-08-01T23:59:59.000Z

110

Free-electron lasers for strategic defense: the benefits of scientific open scientific exchange  

SciTech Connect

A dominant theme of the Fifth International Seminar on Nuclear War, held at Erice, Sicily, (August 19-24, 1985), was the appeal for openness in science and in technological research. In his address to the seminar, Italian Foreign Minister Giulio Andreotti cited the remarkable achievements at the European Center for Nuclear Research (CERN), as an inspiring example of the benefits of scientific collaboration across national borders - science without frontiers. Dr. Edward Teller eloquently argued that, ''thanks to a nearly complete lack of official secrecy, computer technology has fluorished in the free societies of the United States, Japan, and Western Europe.'' The superiority of this technology, vis-a-vis its status in the Soviet bloc, has enhanced both the national security and the economic vitality of the United States and its allies. A further example of the success of science without secrecy can be found in another technology of major importance to the goals of America's Strategic Defense Initiative (SDI). The technology of note is the free electron-l'Ser (FEL).

Barletta, W.A.

1986-02-24T23:59:59.000Z

111

MaRIE X-Ray Free-Electron Laser Pre-Conceptual Design  

SciTech Connect

The proposed Matter-Radiation Interactions in Extremes (MaRIE) facility at the Los Alamos National Laboratory will include a 50-keV X-Ray Free-Electron Laser (XFEL), a significant extension from planned and existing XFEL facilities. To prevent an unacceptably large energy spread arsing from energy diffusion, the electron beam energy should not exceed 20 GeV, which puts a significant constraint on the beam emittance. A 100-pC baseline design is presented along with advanced technology options to increase the photon flux and to decrease the spectral bandwidth through pre-bunching the electron beam.

Carlsten, Bruce E. [Los Alamos National Laboratory; Barnes, Cris W. [Los Alamos National Laboratory; Bishofberger, Kip A. [Los Alamos National Laboratory; Duffy, Leanne D. [Los Alamos National Laboratory; Heath, Cynthia E. [Los Alamos National Laboratory; Marksteiner, Quinn R. [Los Alamos National Laboratory; Nguyen, Dinh Cong [Los Alamos National Laboratory; Russell, Steven J. [Los Alamos National Laboratory; Ryne, Robert D. [Los Alamos National Laboratory; Sheffield, Richard L. [Los Alamos National Laboratory; Simakov, Evgenya I. [Los Alamos National Laboratory; Yampolsky, Nikolai A. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

112

Femtosecond X-Ray Free Electron Laser Pulse Duration Measurement from Spectral Correlation Function  

SciTech Connect

We present a novel method for measuring the duration of femtosecond x-ray pulses from self-amplified spontaneous emission free electron lasers by performing statistical analysis in the spectral domain. Analytical expressions of the spectral correlation function were derived in the linear regime to extract both the pulse duration and the spectrometer resolution. Numerical simulations confirmed that the method can be also used in the nonlinear regime. The method was demonstrated experimentally at the Linac Coherent Light Source by measuring pulse durations down to 13 fs FWHM.

Lutman, A. A

2012-04-17T23:59:59.000Z

113

Threshold conditions for lasing of a free electron laser oscillator with longitudinal electrostatic wiggler  

Science Conference Proceedings (OSTI)

The system of the nonlinear non-stationary equations describing spatial-temporal dynamics of the amplitudes of an ondulator radiation and a space-charge wave of a relativistic electron beam in the resonator is obtained. A free electron laser resonator with longitudinal electrostatic wiggler is considered. In the linear approximation, the threshold conditions of lasing for Raman and Compton regimes under excitation of forward and backward electromagnetic wave are achieved. In the various physical situations, the variation of the minimum length of the resonator with the amplitude of wiggler, density of electron beam, and with the reflection coefficients of resonator's mirrors is investigated.

Sepehri Javan, N. [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, 56199-11367 (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

114

Chaos in an ion-channel free-electron laser with realistic helical wiggler  

SciTech Connect

Chaotic behavior of an electron motion in a free-electron laser with realistic helical wiggler and ion-channel guiding is studied using Poincare surface-of-section maps. The effects of a realistic electron beam density on chaotic electron dynamics are investigated by considering an electron beam with Gaussian density profile in radial distance. The effects of self-fields on chaotic electron dynamics are investigated for different Gaussian beam parameters, and the results are compared with those of uniform electron beam. It is shown that the electron chaotic behavior can be controlled by changing the Gaussian beam parameter. Also, the chaotic behavior can be controlled by increasing the ion-channel and/or the electron beam densities.

Esmaeilzadeh, Mahdi [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of); Taghavi, Amin [Department of Applied Science, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)

2012-11-15T23:59:59.000Z

115

Analysis of Coherence Properties of 3-rd Generation Synchrotron Sources and Free-Electron Lasers  

E-Print Network (OSTI)

A general theoretical approach based on the results of statistical optics is used for the analysis of the transverse coherence properties of 3-rd generation synchrotron sources and x-ray free-electron lasers (XFEL). Correlation properties of the wavefields are calculated at different distances from an equivalent Gaussian Schell-model source. This model is used to describe coherence properties of the five meter undulator source at the synchrotron storage ring PETRA III. In the case of XFEL sources the decomposition of the statistical fields into a sum of independently propagating transverse modes is used for the analysis of the coherence properties of these new sources. A detailed calculation is performed for the parameters of the SASE1 undulator at the European XFEL. It is demonstrated that only a few modes contribute significantly to the total radiation field of that source.

Vartanyants, I A

2009-01-01T23:59:59.000Z

116

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

SciTech Connect

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

117

Beyond the Standard Model – Searches with a Free-Electron Laser  

SciTech Connect

Much of the focus of Beyond the Standard Model physics searches is on the TeV scale, making use of hadron and lepton colliders. Additionally, however, there is the means to make these searches in different regions of parameter space using sub-electron volt photons from a Free Electron Laser, for example. We report on the experimental results of searches for opticalwavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10^-5 and 10^-2 electron volts for a mixing parameter greater than 10-7. We also report on the results of a sensitive search for scalar coupling of photons to light neutral bosons in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10-6 GeV-1. These were generation-regeneration experiments using the “light shining through a wall” technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The present results indicate no evidence for photon-paraphoton mixing or for scalar couplings of bosons to photons for the range of parameters investigated.

A. Afanasev, O.K. Baker, K.B. Beard, G. Biallas, J. Boyce, M. Minarni, R. Ramdon, Michelle D. Shinn, P. Slocumb

2010-02-01T23:59:59.000Z

118

Design Overview of a Highly Stable Infrared Free Electron Laser at LBL  

E-Print Network (OSTI)

CDRL is an integrated user facility for research in chemicalthird FEL pulses. As a user facility, the lRFEL for CDF mustfor the operation of a user facility. The procedure for the

Kim, K.-J.

2011-01-01T23:59:59.000Z

119

Superlattices and Microstructures, Vol. 21, No. 2, 1997 Free electron laser saturation spectroscopy of neutral donors and  

E-Print Network (OSTI)

for several FEL laser power densities at 12 K. Saturation of the D0 1s-2p+ transition and CR is observable in which an electron excited into the 2p+ state (rate X0) may either relax directly back to the 1s ground state (rate 0), or may be transferred directly to the N = 0 Landau level (LL) (rate X1 times

Kono, Junichiro

120

Influence of diffraction in crystals on the coherence properties of X-ray free-electron laser pulses  

SciTech Connect

The spatial and temporal evolution of the field of random X-ray femtosecond pulses and their coherent properties upon pulse propagation in free space and under dynamical diffraction in perfect crystals in the Bragg and Laue geometries has been analyzed on the basis of the formalism developed in statistical optics. Particular attention is paid to the influence of large pulse propagation distances, which are characteristic of lengthy channels of X-ray free-electron lasers.

Bushuev, V. A., E-mail: vabushuev@yandex.ru [Moscow State University (Russian Federation); Samoylova, L. [European XFEL GmbH (Germany)

2011-09-15T23:59:59.000Z

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.


121

Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers  

SciTech Connect

Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U. [Arizona State University, Tempe, AZ 85287-1504 (United States); Centre for Free-Electron Laser Science, DESY, D-22607 Hamburg (Germany); Arizona State University, Tempe, AZ 85287-1504 (United States)

2012-11-27T23:59:59.000Z

122

Obtaining attosecond X-ray pulses using a self-amplified spontaneous emission free electron laser  

E-Print Network (OSTI)

1369 (2004). [10] W. B. Colson, in Laser Handbook, Volume 6:Free Elec- tron Lasers (North-Holland, Amsterdam, 1990),B. Murphy and C. Pellegrini, in Laser Handbook, Vol- ume 6:

Zholents, A.A.; Penn, G.

2005-01-01T23:59:59.000Z

123

Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser  

SciTech Connect

An amplitude and phase compensation system has been developed and tested at the University of Hawai'i for the optimization of the RF drive system to the Mark V free-electron laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.

Hadmack, M. R.; Kowalczyk, J. M. D.; Lienert, B. R.; Madey, J. M. J.; Szarmes, E. B. [Department of Physics and Astronomy, University of Hawai'i at Manoa, Honolulu, Hawaii 96822 (United States); Jacobson, B. T. [RadiaBeam Technologies, Santa Monica, California 90404 (United States)

2013-06-15T23:59:59.000Z

124

Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser  

E-Print Network (OSTI)

An amplitude and phase compensation system has been developed and tested at the University of Hawai`i for the optimization of the RF drive system to the Mark V Free-Electron Laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.

Hadmack, M R; Kowalczyk, J M D; Lienert, B R; Madey, J M J; Szarmes, E B

2013-01-01T23:59:59.000Z

125

The Turn-on of LCLS: the X-Ray Free Electron Laser at SLAC ( Keynote - 2011 JGI User Meeting)  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. SLAC National Laboratory Director Persis Drell gives a keynote talk on "The Turn-on of LCLS: the X-Ray Free-Electron Laser at SLAC" at the 6th Genomics of Energy & Environment Meeting on March 22, 2011

Drell, Persis [SLAC Director

2011-03-22T23:59:59.000Z

126

The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser  

Science Conference Proceedings (OSTI)

The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480-2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser.

Schlotter, W. F.; Turner, J. J.; Rowen, M.; Holmes, M.; Messerschmidt, M.; Moeller, S.; Krzywinski, J.; Lee, S.; Coffee, R.; Hays, G. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Heimann, P. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Krupin, O. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Soufli, R.; Fernandez-Perea, M.; Hau-Riege, S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kelez, N. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Beye, M.; Gerken, N.; Sorgenfrei, F.; Wurth, W. [Institute for Experimental Physics and CFEL, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); and others

2012-04-15T23:59:59.000Z

127

Lasers without Mirrors, Designed by Supercomputer - NERSC SCience...  

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

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...

128

Abstract FEL Simulations for the LCLS  

E-Print Network (OSTI)

A first Design Study Report has recently been completed [1] for the Linac Coherent Light Source (LCLS), a proposal to build an x-ray Free Electron Laser (FEL) at the Stanford Linear Accelerator Center (SLAC) as a single pass SASE (Self-Amplified Spontaneous Emission) amplifier. The proposal includes the use of a very low emittance electron beam accelerated up to 15 GeV by the last third of the SLAC linac to produce sub-picosecond x-ray pulses with high brightness and full transverse coherence in a 112-meter long undulator. Many aspects of the FEL design have been analyzed with FEL simulation codes. The paper discusses some of the results of these aspects, i.e. temporal x-ray pulse structure and power sprectrum, trajectory

Heinz-dieter Nuhn

1998-01-01T23:59:59.000Z

129

Electron-beam magnetic switch for a plurality of free-electron lasers  

DOE Patents (OSTI)

Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec is described. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

Schlitt, L.G.

1982-01-26T23:59:59.000Z

130

Electron beam magnetic switch for a plurality of free electron lasers  

DOE Patents (OSTI)

Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

Schlitt, Leland G. (Livermore, CA)

1984-01-01T23:59:59.000Z

131

Comment on ''Chaotic electron trajectories in an electromagnetic wiggler free-electron laser with ion-channel guiding'' [Phys. Plasmas 17, 093103 (2010)  

Science Conference Proceedings (OSTI)

The chaotic electron dynamics in a free-electron laser with electromagnetic-wave wiggler and ion-channel has been recently reported by A. Taghavi et al.[Phys. Plasmas 17, 093103 (2010)]. We comment on the authors use of a set of initial condition that is not correct based on the dispersion relation and steady-state orbits.

Nasr, N.; Hasanbeigi, A. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

2011-05-15T23:59:59.000Z

132

Feedback Requirements for SASE-FELs  

SciTech Connect

The operation of a Self Amplified Spontaneous Emission (SASE) Free Electron Lasers (FEL) at soft and hard X-ray wavelengths driven by a high brightness electron beam imposes strong requirements on the stability of the accelerator and feedback systems are necessary to both guarantee saturation of the SASE process as well as a stable photon beam for user experiments. Diagnostics for the relevant transverse and longitudinal beam parameters are presented and various examples of feedback systems for bunches with low repetition rate as well as systems for intra bunch train feedbacks are discussed.

Loos, Henrik; /SLAC

2012-07-06T23:59:59.000Z

133

LCLS CDR Chapter 4 - FEL Physics  

NLE Websites -- All DOE Office Websites (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,

134

Seeded quantum FEL at 478 keV  

Science Conference Proceedings (OSTI)

We present for the first time the concept of a seeded {gamma} quantum Free-Electron-Laser (QFEL) at 478 keV, which has very different properties compared to a classical. The basic concept is to produce a highly brilliant {gamma} beam via SASE. To produce highly intense and coherent {gamma} beam, we intend to use a seeded FEL scheme. Important for the production of such a {gamma} beam are novel refractive {gamma}-lenses for focusing and an efficient monochromator, allowing to generate a very intense and coherent seed beam. The energy of the {gamma} beam is 478 keV, corresponding to a wavelength in the sub-Angstrom regime (1/38 A). To realize a coherent {gamma} beam at 478 keV, it is necessary to use a quantum FEL design. At such high radiation energies a classical description of the {gamma}-FEL becomes wrong.

Guenther, M. M.; Jentschel, M.; Thirolf, P. G.; Seggebrock, T.; Habs, D. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching, Germany and Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

2012-07-09T23:59:59.000Z

135

RF System Upgrades to the Advanced Photon Source Linear Accelerator in Support of the Fel Operation  

E-Print Network (OSTI)

The S-band linear accelerator, which was built to be the source of particles and the front end of the Advanced Photon Source injector, is now also being used to support a low-energy undulator test line (LEUTL) and to drive a free-electron laser (FEL). The more severe rf stability requirements of the FEL have resulted in an effort to identify sources of phase and amplitude instability and implement corresponding upgrades to the rf generation chain and the measurement system. Test data and improvements implemented and planned are described

Smith, T L; Grelick, A E; Pile, G; Nassiri, A; Arnold, N

2000-01-01T23:59:59.000Z

136

FEL potential of eRHIC  

Science Conference Proceedings (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

137

Accelerator Design Study for a Soft X-Ray Free Electron Laser at the Lawrence Berkeley National Laboratory  

E-Print Network (OSTI)

and Phase Diagnostics, SLAC Report LCLS-TN-00-12. Emma P.al. 2009, First Results of the LCLS Laser-Heater System, PACLinac Coherent Light Source (LCLS) Conceptual Design Report,

Kur, E.

2010-01-01T23:59:59.000Z

138

The FERMI@Elettra free-electron-laser source for coherent X-ray physics: photon properties, beam transport system, and applications  

E-Print Network (OSTI)

49625-Rev. 1 (also SLAC Rpt. LCLS-TN-04-3) Fawley W M 2006wavelength FELs (e.g. , FLASH, LCLS, SCSS, XFEL, SPARX) have

Allaria, Enrico

2010-01-01T23:59:59.000Z

139

APS FEL Achieves Ultraviolet Saturation  

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

has achieved "saturation" of self-amplified spontaneous emission in a mirrorless free-electron laser at a wavelength over 1000 times shorter than the previous record. This...

140

Self-seeded injection-locked FEL amplifier  

DOE Patents (OSTI)

A self-seeded free electron laser (FEL) provides a high gain and extraction efficiency for the emitted light. An accelerator outputs a beam of electron pulses to a permanent magnet wiggler having an input end for receiving the electron pulses and an output end for outputting light and the electron pulses. An optical feedback loop collects low power light in a small signal gain regime at the output end of said wiggler and returns the low power light to the input end of the wiggler while outputting high power light in a high signal gain regime.

Sheffield, Richard L.

1998-12-01T23:59:59.000Z

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.


141

Self-seeded injection-locked FEL amplifer  

DOE Patents (OSTI)

A self-seeded free electron laser (FEL) provides a high gain and extraction efficiency for the emitted light. An accelerator outputs a beam of electron pulses to a permanent magnet wiggler having an input end for receiving the electron pulses and an output end for outputting light and the electron pulses. An optical feedback loop collects low power light in a small signal gain regime at the output end of said wiggler and returns the low power light to the input end of the wiggler while outputting high power light in a high signal gain regime.

Sheffield, Richard L. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

142

A 4 to 0.1 nm FEL Based on the SLAC Linac  

Science Conference Proceedings (OSTI)

The author show that using existing electron gun technology and a high energy linac like the one at SLAC, it is possible to build a Free Electron Laser operating around the 4 nm water window. A modest improvement in the gun performance would further allow to extend the FEL to the 0.1 nm region. Such a system would produce radiation with a brightness many order of magnitude above that of any synchrotron radiation source, existing or under construction, with laser power in the multigawatt region and subpicosecond pulse length.

Pellegrini, C.; /UCLA

2012-06-05T23:59:59.000Z

143

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

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

diffractive imaging with a soft-X-ray free-electron laser We have demonstrated flash diffractive imaging of nanostructures using pulses from the first soft-X-ray free-electron...

144

FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION  

SciTech Connect

Numerical electromagnetic simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. A particularly good application for calculation in a boosted frame isthat of short wavelength free-electron lasers (FELs) where a high energy electron beam with small fractional energy spread interacts with a static magnetic undulator. In the optimal boost frame (i.e., the ponderomotive rest frame), the red-shifted FEL radiation and blue-shifted undulator field have identical wavelengths and the number of required longitudinal grid cells and time-steps for fully electromagnetic simulation (relative to the laboratory frame) decrease by factors of gamma^2 each. In theory, boosted frame EM codes permit direct study of FEL problems for which the eikonal approximation for propagation of the radiation field and wiggler-period-averaging for the particle-field interaction may be suspect. We have adapted the WARP code to apply this method to several electromagnetic FEL problems including spontaneous emission, strong exponential gain in a seeded, single pass amplifier configuration, and emission from e-beams in undulators with multiple harmonic components. WARP has a standard relativistic macroparticle mover and a fully 3-D electromagnetic field solver. We discuss our boosted frame results and compare with those obtained using the ?standard? eikonal FEL simulation approach.

Fawley, William; Vay, Jean-Luc

2010-08-16T23:59:59.000Z

145

Optical modeling of the Jefferson Laboratory IR Demo FEL  

Science Conference Proceedings (OSTI)

The Thomas Jefferson National Accelerator Facility (Jefferson Lab) is in the process of building a 1 kW free-electron laser operates at 3 microns. The details of the accelerator driver are given in other papers in these proceedings. The optical cavity consists of a near-concentric resonator with transmissive outcoupling. Though several free-electron lasers have used similar designs, they have not had to confront the high average-power loading present in this laser. It is useful to know the limits of this type of optical cavity design. The optical system of the laser has been modeled using the commercial code GLAD{reg_sign} by using a Beer`s-law region to mimic the FEL interaction. The effects of mirror heating have been calculated and compared with analytical treatments. The magnitude of the distortion for several materials and wave-lengths has been estimated. The model developed here allows one to quickly determine whether the mirror substrates and coatings are adequate for operation at a given optical power level once the absorption of the coatings, substrate, and transmission are known. Results of calculations of the maximum power level expected using several different sets of mirrors will be presented. Measurements of the distortion in calcium fluoride from absorption of carbon dioxide laser light are planned to benchmark the simulations. Multimode simulations using the code ELIXER have been carried out to characterize the saturated optical mode quality. The results will be presented.

Benson, S.V.; Davidson, P.S.; Jain, R.; Kloeppel, P.K.; Neil, G.R.; Shinn, M.D.

1997-11-01T23:59:59.000Z

146

FEL options for power beaming  

DOE Green Energy (OSTI)

The demand for the output power of communication satellites has been increasing exponentially. The satellite power is generated from solar panels which collect the sunlight and convert it to electrical power. The power per satellite is limited due to the limit in the practical size of the solar panel. One way to meet the power demand is to employ multiple satellites (up to 10) per the internationally agreed-upon ``slot`` in the geosynchronous earth orbit (GEO). However, this approach is very expensive due to the high cost of sending a satellite into a GEO orbit. An alternative approach is power beaming, i.e., to illuminate the solar panels with high power, highly-directed laser beams from earth. The power beaming generates more power per satellite for the same area of the solar panel. The minimum optical beam power, interesting for power beaming application, is P{sub L} = 200kW. The wavelength is chosen to be {lambda} = 0.84 {micro}m, so that it is within one of the transmission windows of the air, and at the same time near the peak of the photo-voltaic conversion efficiency of Si, which is the commonly used material for the solar panels. Free electron lasers (FELs) are well suited for the power beaming application because they can provide high power with coherent wavefront, but without high energy density in media. In this article the authors discuss some principal issues, such as the choice of accelerator and electron gun, the choice of beam parameters, radiation hazards, technological availability, and overall efficiency and reliability of the installation. They also attempt to highlight the compromise between the cost of the primary installation, the operation cost, and the choice of technology, and its maturity. They then present several schemes for the accelerator-FEL systems based on RF accelerators. The initial electron beam accelerator up to the energy of a few MeV is more or less common for all these schemes.

Kim, K.J.; Zholents, A.A.; Zolotorev, M.S. [Lawrence Berkeley National Lab., CA (United States); Vinokurov, N.A. [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

1997-10-01T23:59:59.000Z

147

The potential for extending the spectral range accessible to the european X-ray free electron laser in the direction of longer wavelengths  

E-Print Network (OSTI)

The baseline specifications of European XFEL give a range of wavelengths between 0.1 nm and 2 nm. This wavelength range at fixed electron beam energy 17.5 GeV can be covered by operating the SASE FEL with three undulators which have different period and tunable gap. A study of the potential for the extending the spectral range accessible to the XFEL in the direction of longer wavelengths is presented. The extension of the wavelength range to 6 nm would be cover the water window in the VUV region, opening the facility to a new class of experiments. There are at least two possible sources of VUV radiation associated with the X-ray FEL; the "low (2.5 GeV) energy electron beam dedicated" and the " 17.5 GeV spent beam parasitic" (or "after-burner") source modes. The second alternative, "after-burner undulator" is the one we regard as most favorable. It is possible to place an undulator as long as 80 meters after 2 nm undulator. Ultimately, VUV undulator would be able to deliver output power approaching 100 GW. A b...

Saldin, E L; Yurkov, M V

2004-01-01T23:59:59.000Z

148

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

Science Conference Proceedings (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.

2011-08-16T23:59:59.000Z

149

HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS.  

SciTech Connect

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

150

Laser Assisted Emittance Exchange  

Science Conference Proceedings (OSTI)

We describe here the laser assisted emittance exchange (LAEE) technique. A laser operating in the transverse mode (TEM10 or TEM01) is used to interact with the electron beam in a dispersive region and to initiate the transverse-to-longitudinal emittance exchange. It is shown that with the LAEE one can generate an electron beam with ultralow transverse emittance, which allows one to significantly bring down the size of an X-ray free electron laser (FEL) and greatly extend the availability of these light sources. The technique can also be used to enhance the performances of X-ray FELs in storage rings. The timing and energy jitter problems for the standard emittance exchange and LAEE techniques are also discussed.

Xiang, Dao; /SLAC

2012-06-11T23:59:59.000Z

151

2nd FEL Workshop - Methods & Instrumentation  

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

Stanford, California USA March 1-2, 2001 Within the next 5-10 years, free-electron lasers based on high-energy linear accelerators will be producing extremely bright, extremely...

152

Optical modeling of the Jefferson Lab IR Demo FEL  

Science Conference Proceedings (OSTI)

The Thomas Jefferson National Accelerator Facility (formerly known as CEBAF) has embarked on the construction of a 1 kW free-electron laser operating initially at 3 microns that is designed for laser-material interaction experiments and to explore the feasibility of scaling the system in power and wavelength for industrial and Navy defense applications. The superconducting radio-frequency linac, and single-pass transport which accelerates the beam from injector to wiggler, followed by energy-recovery deceleration to a dump. The electron and optical beam time structure in the design consists of a train of pecosecond pulses at a 37.425 MHz pulse repetition rate. The initial optical configuration is a conventional near-concentric resonator with transmissive outcoupling. Future upgrades of the system will increase the power and shorten the operating wavelength, and utilize a more advanced resonator system capable of scaling to high powers. The optical system of the laser has been mode led using the GLAD code by using a Beer's-law region to mimic the FEL interaction. Effects such as mirror heating have been calculated and compared with analytical treatments. The magnitude of the distorium for several materials and wavelengths has been estimated. The advantages as well as the limitations of this approach are discussed.

G. Neil; S. Benson; Michelle D. Shinn; P. Davidson; P. Kloppel

1997-01-01T23:59:59.000Z

153

2002 Free Electron Laser Conference and Workshop  

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

submitted Paper Preparation Instructions Social Events Concert and Prix Fixe Dinner Banquet Vendor Exhibits List of Exhibitors Exhibitor Information Booth Layout and Assignments...

154

Metal Photocathodes for Free Electron Laser Applications  

E-Print Network (OSTI)

and then an appropriate TTL trigger pulse is generated.Detector TDC Start (NIM) Preamp (TTL) PP MIRA Figure 3.21: Aand then an appropriate TTL trigger pulse is generated.

Greaves, Corin Michael Ricardo

2012-01-01T23:59:59.000Z

155

SciTech Connect: "free electron lasers"  

Office of Scientific and Technical Information (OSTI)

Renewable Energy Laboratory (NREL), Golden, CO (United States) Naval Petroleum and Oil Shale Reserves (United States) Navarro Nevada Environmental Services Nevada Field Office,...

156

SciTech Connect: "free electron lasers"  

Office of Scientific and Technical Information (OSTI)

Conference: Entanglement, Holography, and the Quantum Phases of Matter Citation Details In-Document Search Title: Entanglement, Holography, and the Quantum Phases of Matter...

157

Lasers without Mirrors, Designed by Supercomputer - NERSC SCience News  

NLE Websites -- All DOE Office Websites (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

158

First Results of the LCLS Laser-Heater System  

SciTech Connect

The Linac Coherent Light Source (LCLS) is an x-ray Free-Electron Laser (FEL) project that has just achieved its first lasing at 1.5 {angstrom} radiation wavelength. The very bright electron beam required to drive this FEL is susceptible to a microbunching instability in the magnetic bunch compressors that may increase the slice energy spread beyond the FEL tolerance. To control the slice energy spread and to suppress the microbunching instability, a laser heater (LH) system is installed in the LCLS injector area at 135 MeV, right before the RF deflector that is used for the time-resolved electron diagnostics. This unique component is used to add a small level of intrinsic energy spread to the electron beam in order to Landau damp the microbunching instability before it potentially breaks up the high brightness electron beam. The system was fully installed and tested in the fall of 2008, and effects of heating on the electron beam and the x-ray FEL were studied during the 2009 commissioning period. The laser heater system is composed of a 4-dipole chicane; a 9-period, planar, permanent-magnet, adjustable-gap undulator at the center of the chicane; one OTR screen on each side of the undulator for electron/laser spatial alignment; and an IR laser (up to 15-MW power) which co-propagates with the electron beam inside the undulator generating a 758-nm energy modulation along the bunch. The final two dipoles of the 4-dipole chicane time-smear this modulation leaving only a thermal-like intrinsic energy spread within the bunch. Table 1 lists the main parameters for this system. The very bright electron beam required for an x-ray free-electron laser (FEL), such as the LCLS, is susceptible to a microbunching instability in the magnetic bunch compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To this end, a 'laser-heater' system has been installed in the LCLS injector, which modulates the energy of a 135-MeV electron bunch with an IR laser beam in a short undulator, enclosed within a four-dipole chicane. The last half of the chicane time-smears the energy modulation leaving an effective thermal energy spread increase. We present the first commissioning results of this system, its operational issues, its impact on the microbunching instability, and finally its effect on the FEL performance.

Emma, P; Boyce, R.F.; Brachmann, A.; Carr, R.; Decker, F.-J.; Ding, Y.; Dowell, D.; Edstrom, S.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Levashov, Y.; Loos, H.; Miahnahri, A.; Nuhn, H.-D.; Poling, B.; Ratner, D.; Spampinati, S.; /SLAC

2011-12-16T23:59:59.000Z

159

Dielectric Wakefield Accelerator to drive the future FEL Light Source.  

SciTech Connect

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

160

TESLA FEL-Report 1999-03 TESLA FEL-Report 1999-03  

E-Print Network (OSTI)

TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL-Report 1999-03 #12;TESLA FEL

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

TESLA FEL Report 1996-07 TESLA FEL Report 1996-07  

E-Print Network (OSTI)

TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report 1996-07 #12;TESLA FEL Report

162

TESLA FEL-Report 1996-16 TESLA FEL-Report 1996-16  

E-Print Network (OSTI)

#12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL-Report 1996-16 #12;TESLA FEL

163

TESLA FEL-Report 1996-13 TESLA FEL-Report 1996-13  

E-Print Network (OSTI)

TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL-Report 1996-13 #12;TESLA FEL

164

TESLA FEL-Report 1995-02 TESLA FEL-Report 1995-02  

E-Print Network (OSTI)

TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL-Report 1995-02 #12;TESLA FEL

165

TESLA FEL-Report 1995-04 TESLA FEL-Report 1995-04  

E-Print Network (OSTI)

#12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL-Report 1995-04 #12;TESLA FEL

166

TESLA FEL-Report 1997-02 TESLA FEL-Report 1997-02  

E-Print Network (OSTI)

TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL-Report 1997-02 #12;TESLA FEL

167

TESLA FEL Report 1996-06 TESLA FEL Report 1996-06  

E-Print Network (OSTI)

TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report 1996-06 #12;TESLA FEL Report

168

TESLA FEL-Report 2000-02 TESLA FEL-Report 2000-02  

E-Print Network (OSTI)

TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL-Report 2000-02 #12;TESLA FEL

169

TESLA FEL-Report 1996-10 TESLA FEL-Report 1996-10  

E-Print Network (OSTI)

#12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL-Report 1996-10 #12;TESLA FEL

170

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

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

free-electron laser amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated. Introduction As proposed in 1, the concept...

171

TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07  

E-Print Network (OSTI)

TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07 #12;TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07 #12;TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07 #12;TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07 #12;TESLA FEL-Report 1999-04 TESLA FEL-Report 1999-07 #12;TESLA FEL-Report 1999-04 TESLA FEL

172

A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator  

Science Conference Proceedings (OSTI)

After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.

Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC

2012-02-17T23:59:59.000Z

173

SASE FEL at the TESLA Facility, Phase 2 The TESLA Test Facility FEL team  

E-Print Network (OSTI)

SASE FEL at the TESLA Facility, Phase 2 The TESLA Test Facility FEL team June 2002, TESLA-FEL 2002-01 #12;SASE FEL at the TESLA Facility, Phase 2 Abstract The last description of the TESLA Test Facility FEL has been written in 1995 (TESLA- FEL report 95-03). Since then, many changes have developed

174

Optimization for Single-Spike X-Ray FELs at LCLS with a Low Charge Beam  

Science Conference Proceedings (OSTI)

The Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron radiation sources. At the low charge operation mode (20 pC), the x-ray pulse length can be LCLS), the world's first hard x-ray Free electron laser (FEL), has started operation since 2009. With nominal operation charge of 250 pC, the generated x-ray pulse length is from 70 fs to a few hundred fs. This marks the beginning of a new era of ultrashort x-ray sciences. In addition, a low charge (20pC) operation mode has also been established. Since the collective effects are reduced at the low charge mode, we can increase the compression factor and still achieve a few kA peak current. The expected electron beam and x-ray pulses are less than 10 fs. There are growing interests in even shorter x-ray pulses, such as fs to sub-fs regime. One of the simple solutions is going to even lower charge. As discussed, single-spike x-ray pulses can be generated using 1 pC charge. However, this charge level is out of the present LCLS diagnostic range. 20 pC is a reasonable operation charge at LCLS, based on the present diagnostic system. At 20 pC in the soft x-ray wavelength regime, we have experimentally demonstrated that FEL can work at undercompression or over-compression mode, such as 1 degree off the full-compression; at full-compression, however, there is almost no lasing. In hard x-ray wavelength regime, we observed that there are reasonable photons generated even at full-compression mode, although the photon number is less than that from under-compression or over-compression mode. Since we cannot measure the x-ray pulse length at this time scale, the machine is typically optimized for generating maximum photons, not minimum pulse length. In this paper, we study the methods of producing femtosecond (or single-spike) x-ray pulses at LCLS with 20 pC charge, based on start-to-end simulations. Figure 1 shows a layout of LCLS. The compression in the second bunch compressor (BC2) determines the final e-beam bunch length. However, the laser heater, dog-leg after the main linac (DL2) and collective effects also affect the final bunch length. To adjust BC2 compression, we can either change the L2 phase or BC2 R{sub 56}. In this paper we only tune L2 phase while keep BC2 R{sub 56} fixed. For the start-to-end simulations, we used IMPACT-T and ELEGANT tracking from the photocathode to the entrance of the undulator, after that the FEL radiation was simulated with GENESIS. IMPACT-T tracks about 10{sup 6} particles in the injector part until 135 MeV, including 3D space charge force. The output particles from IMPACT-T are smoothed and increased to 12 x 10{sup 6} to reduce high-frequency numerical noise for subsequent ELEGANT simulations, which include linear and nonlinear transport effects, a 1D transient model of CSR, and longitudinal space charge effects, as well as geometric and resistive wake fields in the accelerator. In GENESIS part, the longitudinal wake field from undulator chamber and longitudinal space field are also included.

Wang, L.; Ding, Y.; Huang, Z.; /SLAC

2011-12-14T23:59:59.000Z

175

Jefferson Lab Technology Transfer - Thomas Jefferson National ...  

JSA Invention Disclosure; Technology Transfer Issues (Ombudsman) Programs and Facilities. Free-Electron Laser Program (FEL) Applied Research Center ...

176

The FERMI @ Elettra Technical Optimization Study: General Layout and Parameters and Physics Studies of Longitudinal Space Charge, the Spreader, the Injector, and Preliminary FEL Performance  

E-Print Network (OSTI)

laser systems for a FEL user facility”, M.B Danailov, F. Ö.system intended for a user facility that is operated on a

2005-01-01T23:59:59.000Z

177

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

E-Print Network (OSTI)

laser systems for a FEL user facility”, M.B Danailov, F. Ö.will be the first user facility based on seeded harmonicsystem intended for a user facility that is operated on a

2005-01-01T23:59:59.000Z

178

FERMI@Elettra FEL Design Technical Optimization Final Report  

Science Conference Proceedings (OSTI)

This is the final report of the FEL Design Group for the Technical Optimization Study for the FERMI{at}ELETTRA project. The FERMI{at}ELETTRA project is based on the principle of harmonic upshifting of an initial ''seed'' signal in a single pass, FEL amplifier employing multiple undulators. There are a number of FEL physics principles which underlie this approach to obtaining short wavelength output: (1) the energy modulation of the electron beam via the resonant interaction with an external laser seed (2) the use of a chromatic dispersive section to then develop a strong density modulation with large harmonic overtones (3) the production of coherent radiation by the microbunched beam in a downstream radiator. Within the context of the FERMI project, we discuss each of these elements in turn.

Fawley, William; Penn, Gregory; Allaria, Enrico; De Ninno,Giovanni; Graves, William

2006-07-31T23:59:59.000Z

179

Part 2: Coherent emission from Free Electron Lasers  

NLE Websites -- All DOE Office Websites (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),

180

Advanced Free Electron Laser Facility - Los Alamos National Lab ...  

The AFEL Facility is used for applications requiring high-brightness electron beams or a tunable source of high-energy infrared light pulses in the wavelength range ...

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

Free-Electron Lasers: Present Status and Future Prospects  

E-Print Network (OSTI)

Energy Research, Office of High Energy and Nuclear Physics,Energy Research, Office of High Energy and Nuclear Physics,

Kim, K.-J.

2008-01-01T23:59:59.000Z

182

An Efficient Microwave Power Source: Free-electron Laser Afterburner  

E-Print Network (OSTI)

Office of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High Energy

Wang, C.

2008-01-01T23:59:59.000Z

183

The GALAXIE all-optical FEL project  

SciTech Connect

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

184

SLAC National Accelerator Laboratory - X-ray Laser Helps Fight...  

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

human health. "This is the first new biological structure solved with a free-electron laser," said Henry Chapman of the Center for Free-Electron Laser Science in Hamburg,...

185

Scientific opportunities for FEL amplifier based VUV and X-ray research  

SciTech Connect

It has become increasingly clear to a wide cross section of the synchrotron radiation research community that FELs will be the cornerstone of Fourth Generation Radiation Sources. Through the coherent generation of radiation, they provide as much as 12 orders of magnitude increase in peak power over the third generation storage ring machines of today. Facilities have been proposed which will extend the operating wavelength of these devices well beyond the reach of existing solid state laser technology. In addition, it appears possible to generate pulses of unprecedented brevity, down to a few femtoseconds, with mJ pulse energies. The combination of these attributes has stimulated considerable interest in short wavelength FELs for experiments in chemical, surface, and solid state physics, biology and materials science. This paper provides a brief overview of how the features of these FEL`s relate to the experimental opportunities.

Johnson, E.D.

1994-12-31T23:59:59.000Z

186

Energy of the quasi-free electron in xenon Xianbo Shi a  

E-Print Network (OSTI)

Energy of the quasi-free electron in xenon Xianbo Shi a , Luxi Li a , C.M. Evans a,, G.L. Findley b critical point. The energy of the quasi-free electron, arising from dopant field ionization, in xenon and for the critical isotherm. Key words: supercritical xenon, field ionization, quasi-free electron energy, electron

Evans, Cherice M.

187

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

188

Beam Dynamics Study of X-Band Linac Driven X-Ray FELS  

Science Conference Proceedings (OSTI)

Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to 0.12 nm. Newer XFELs (at Spring8 and PSI) use C-band (5.7 GHz) normal-conducting linac drivers, which can sustain higher acceleration gradients, and hence shorten the linac length, and are more efficient at converting rf energy to bunch energy. The X-band (11.4 GHz) rf technology developed for NLC/GLC offers even higher gradients and efficiencies, and the shorter rf wavelength allows more versatility in longitudinal bunch phase space compression and manipulation. In the following sections, three different configurations of X-band linac driven XFELs are described that operate from 6 to 14 GeV. The first (LOW CHARGE DESIGN) has an electron bunch charge of only 10 pC; the second (OPTICS LINEARIZATION DESIGN) is based on optics linearization of the longitudinal phase space in the first stage bunch compressor and can operate with either a high (250 pC) or low (20 pC) bunch charge; and the third (LCLS INJECTOR DESIGN) is similar to LCLS but uses an X-band linac after the first stage bunch compressor at 250 MeV to achieve a final beam energy up to 14 GeV. Compared with LCLS, these X-band linacs are at least a factor of three shorter.

Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T.O.; Wu, J.; /SLAC; Sun, Y.; /SLAC

2011-12-13T23:59:59.000Z

189

Energy of the Quasi-free Electron in Argon and Krypton C. M. Evans1,  

E-Print Network (OSTI)

Energy of the Quasi-free Electron in Argon and Krypton C. M. Evans1, and G. L. Findley2, 1 these data, a new local Wigner- Seitz model for the density dependent energy V0(P) of a quasi-free electron/medium polarization energy, and includes the thermal kinetic energy of the quasi-free electron. Using this model, V0(P

Evans, Cherice M.

190

Numerical estimation on free electrons generated by shielded radioactive materials under various gaseous environments  

SciTech Connect

We report simulation results on generation of free electrons due to the presence of radioactive materials under controlled pressure and gases using a general Monte Carlo transport code (MCNPX). A radioactive material decays to lower atomic number, simultaneously producing high energy gamma rays that can generate free electrons via various scattering mechanisms. This paper shows detailed simulation works for answering how many free electrons can be generated under the existence of shielded radioactive materials as a function of pressure and types of gases.

Kim, D. S. [Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); Lee, W. S.; So, J. H. [Agency for Defence Development (ADD), Daejeon 305-152 (Korea, Republic of); Choi, E. M. [Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of)

2013-06-15T23:59:59.000Z

191

EXPERIENCE AND PLANS OF THE JLAB FEL FACILITY AS A USER FACILITY  

Science Conference Proceedings (OSTI)

Jefferson Lab's IR Upgrade FEL building was planned from the beginning to be a user facility, and includes an associated 600 m2 area containing seven laboratories. The high average power capability (multikilowatt-level) in the near-infrared (1-3 microns), and many hundreds of watts at longer wavelengths, along with an ultrafast (~ 1 ps) high PRF (10's MHz) temporal structure makes this laser a unique source for both applied and basic research. In addition to the FEL, we have a dedicated laboratory capable of delivering high power (many tens of watts) of broadband THz light. After commissioning the IR Upgrade, we once again began delivering beam to users in 2005. In this presentation, I will give an overview of the FEL facility and its current performance, lessons learned over the last two years, and a synopsis of current and future experiments.

Michelle D. Shinn

2007-08-26T23:59:59.000Z

192

Stability and Performance of CDRL-FEL  

E-Print Network (OSTI)

Laboratory, which would be a user facility and therefore hasBerkeley Laboratory as a user facility serving a communityin Table 1. Being a user facility, the CDRL-FEL must provide

Kim, K.-J.

2010-01-01T23:59:59.000Z

193

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

SciTech Connect

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

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

1993-05-01T23:59:59.000Z

194

Theory of the ion-channel laser  

Science Conference Proceedings (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

195

Slide 1  

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

Synchrotron sources see : http:www.dl.ac.uk A field in expansion Free Electron Lasers (FEL) see : http:www.lightsources.org New technologies + New techniques Better...

196

paper.dvi  

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

is of great interest to those designing accelerators as drivers for free-electron lasers (FELs). Although experimental evidence is incom- plete, CSR is predicted to have...

197

SLAC National Accelerator Laboratory - Small X-band Photoinjector...  

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

when hit by light. Photoinjectors are used to generate electrons for free-electron lasers (FELs) like the Linac Coherent Light Source, among other things, and this development...

198

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

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

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...

199

Accelerator & Detector Research & Development | U.S. DOE Office...  

Office of Science (SC) Website

undulators. Studies on achieving sub-femtosecond (hundreds of attoseconds) free electron laser (FEL) pulses will also be underway. Demonstration experiments will take place...

200

The Operation of the BNL/ATF GUN-IV Photocathode RF Gun at the...  

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

At the Advanced Photon Source (APS) at Argonne National Laboratory (ANL), a free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) process is...

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

Development of a new generation of optical slope measuring profiler  

E-Print Network (OSTI)

Free Electron Laser (FEL), LCLS, National Synchrotron Light1-3]. The beamlines for LCLS, NSLS-II, and planned upgrade

Yashchuk, Valeriy V.

2010-01-01T23:59:59.000Z

202

Latest developments on the Dutch 1MW free electron maser  

SciTech Connect

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

203

Parameter Selection and Longitudinal Phase Space Simulation for a Single Stage X-Band FEL Driver at 250 MeV  

Science Conference Proceedings (OSTI)

Hard x-ray Free electron lasers (FEL) are being built or proposed at many accelerator laboratories as it supports wide range of applications in many aspects. Most of the hard x-ray FEL design is similar with the SLAC Linac Coherent Light Source (LCLS), which features a two (or multiple) stage bunch compression. For the first stage of the bunch compression, usually the beam is accelerated in a lower-frequency RF section (such as S-band for LCLS), and then the longitudinal phase space is linearized by a higher-frequency RF section (harmonic RF, such as X-band for LCLS). In this paper, a compact hard x-ray FEL design is proposed, which is based on X-band RF acceleration and eliminating the need of a harmonic RF. The parameter selection and relation is discussed, and the longitudinal phase space simulation is presented. The FEL coherence condition of the electron beam in the undulators requires a large charge density, a small emittance and small energy spread. The RMS electron bunch length from the injector is in the ps scale, with a bunch charge in the range of hundreds pC to several nC, which means that the current is roughly 0.1 kA. According to the requirement from soft x-ray lasing and hard x-ray lasing, a peak current of 1 kA and 3 kA is needed respectively. Thus the bunch has to be compressed. Usually a two stage bunch compression or multipole stage bunch compression is adopted. The z-correlated energy chirp is normally established by letting the beam pass through a section of RF cavities, with a RF phase off crest. As stated above, S-band RF (3 GHz) acceleration could be applied in this section. Due to the nature of RF acceleration wave, the chirp on the bunch is not linear, but has the RF curvature on it. In order to linearize the energy chirp, a harmonic RF section with higher frequency is needed. For LCLS a short X-band RF section (12 GHz) is used which is a fourth order harmonic. The linearized bunch is then passing by a dispersive region, in which the particles with different energy have different path length. A four dipole chicane is the natural choice for the dispersive region. As the example illustrated in Figure 1, the head of the bunch has smaller energy, and gets a stronger bending kick from the dipole magnet, then has a longer path length in the dispersive region. Similarly, the tail of the bunch has larger energy and shorter path length in the dispersive region. At the exit of the dispersive region, the relative longitudinal position of the head and tail of the bunch both move to the center of the bunch, so the bunch length will be shorter.

Sun, Yipeng

2011-08-19T23:59:59.000Z

204

Measurement and modeling of mirror distortion in a high power FEL  

Science Conference Proceedings (OSTI)

Mirror heating in a high power FEL can alter the optical mode and affect the gain of the laser. This can lead to a large reduction of the laser power from ideal values. Measurements of the power and mode size in the Jefferson Lab IR Demo laser have shown clear evidence of mirror distortion at high average power leading (up to 17 kW incident on the mirrors and over 40 W absorbed per mirror). The measurements and comparisons with modeling will be presented. Both steady state and transient analyses and measurements are considered.

Benson, S.; Neil, G.; Michelle D. Shinn

2000-01-01T23:59:59.000Z

205

Energy of the Quasi-free Electron in Supercritical Krypton near the Critical Point Luxi Li and C. M. Evans  

E-Print Network (OSTI)

Energy of the Quasi-free Electron in Supercritical Krypton near the Critical Point Luxi Li and C. M by the quasi-free electron that arises from field ionization of the dopant, and the zero point kinetic energy of the free electron. The overall decrease in the shift of the dopant ionization energy near the critical

Evans, Cherice M.

206

A kilowatt average power laser for sub-picosecond materials processing  

Science Conference Proceedings (OSTI)

The performance of laser pulses in the sub-picosecond range for materials processing is substantially enhanced over similar fluences delivered in longer pulses. Recent advances in the development of solid state lasers have progressed significantly toward the higher average powers potentially useful for many applications. Nonetheless, prospects remain distant for multi-kilowatt sub-picosecond solid state systems such as would be required for industrial scale surface processing of metals and polymers. The authors present operational results from the world's first kilowatt scale ultra-fast materials processing laser. A Free Electron Laser (FEL) called the IR Demo is operational as a User Facility at Thomas Jefferson National Accelerator Facility in Newport News, Virginia, USA. In its initial operation at high average power it is capable of wavelengths in the 2 to 6 micron range and can produce {approximately}0.7 ps pulses in a continuous train at {approximately}75 MHz. This pulse length has been shown to be nearly optimal for deposition of energy in materials at the surface. Upgrades in the near future will extend operation beyond 10 kW CW average power in the near IR and kilowatt levels of power at wavelengths from 0.3 to 60 microns. This paper will cover the design and performance of this groundbreaking laser and operational aspects of the User Facility.

Stephen V. Benson; George R. Neil; C. Bohn; , G. Biallas; D. Douglas; F. Dylla; J. Fugitt; K. Jordan; G. Krafft; , L. Merminga; , J. Preble; , Michelle D. Shinn; T. Siggins; R. Walker; B. Yunn

1999-11-01T23:59:59.000Z

207

SLAC National Accelerator Laboratory - Ultrafast Lasers at the...  

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

Lasers at the Linac Coherent Light Source By Alan Fry, LCLS Laser Group July 5, 2011 The Linac Coherent Light Source at SLAC is the world's first hard X-ray free-electron laser, or...

208

EDITED--LS-332-DWA_FEL_August16  

NLE Websites -- All DOE Office Websites (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.

209

CRC handbook of laser science and technology. Volume 1. Lasers and masers  

Science Conference Proceedings (OSTI)

This book describes various types of lasers and masers. The following topics are discussed in detail: types and comparisons of laser sources, crystal and glass lasers, semiconductor lasers, organic dye and other liquid lasers, free-electron and x-ray lasers, masers and laser safety.

Weber, M.J.

1982-01-01T23:59:59.000Z

210

FEL Design Studies at LBNL: Activities and Plans  

E-Print Network (OSTI)

needs, we suggest a new user facility equipped with an arraya schematic of a multi-user FEL facility concept. The major

Corlett, John N.

2009-01-01T23:59:59.000Z

211

Generating polarization controllable FELs at Dalian coherent light source  

E-Print Network (OSTI)

The property of the FEL polarization is of great importance to the user community. FEL pulses with ultra-high intensity and flexible polarization control ability will absolutely open up new scientific realms. In this paper, several polarization control approaches are presented to investigate the great potential on Dalian coherent light source, which is a government-approved novel FEL user facility with the capability of wavelength continuously tunable in the EUV regime of 50-150 nm. The numerical simulations show that both circularly polarized FELs with highly modulating frequency and 100 microjoule level pulse energy could be generated at Dalian coherent light source.

Zhang, T; Wang, D; Zhao, Z T; Zhang, W Q; Wu, G R; Dai, D X; Yang, X M

2013-01-01T23:59:59.000Z

212

Superconducting laser photocathode RF gun at BNL | U.S. DOE Office...  

Office of Science (SC) Website

such as electron cooling of hadron colliders, electron-ion colliders, high-power Free-Electron Lasers, high-brightness synchrotron radiation user facilities and much more....

213

Energy of the quasi-free electron in argon, krypton and xenon Xianbo Shi a,b  

E-Print Network (OSTI)

Energy of the quasi-free electron in argon, krypton and xenon Xianbo Shi a,b , Luxi Li a,b , C. M ionization of the dopant, and (iii) the kinetic energy of the quasi-free electron. The polarization terms are determined by a standard statistical mechanical treatment. However, the kinetic energy of the quasi-free

Evans, Cherice M.

214

Femtosecond dark-field imaging with an X-ray free electron laser  

DOE Data Explorer (OSTI)

This data was collected as part of the same experiment as the data deposited in [ID16](id-16.html). Experiment details are given in [Loh, N.D. et al.](http://dx.doi.org/10.1038/nature11222)

Martin, A. V.

215

The Evolution and Limits of Spectral Bandwidth in Free Electron Lasers  

E-Print Network (OSTI)

Dattoli and A. Renieri, Nuovo Cim. 59B (1980) 1; G. Dattoli,is. (1968) A. Renieri, Nuovo Cim. , i l l (1979) 160. For a

Kim, K.-J.

2010-01-01T23:59:59.000Z

216

The Evolution and Limits of Spectral Bandwidth in Free Electron Lasers  

E-Print Network (OSTI)

Dattoli and A. Renieri, Nuovo Cim. 59B (1980) 1; G. Dattoli,is. (1968) A. Renieri, Nuovo Cim. , i l l (1979) 160. For a

Kim, K.-J.

2011-01-01T23:59:59.000Z

217

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 Ă— Cite: MLA Format Close APA Ă— Cite: APA Format Close Chicago Ă— Cite: Chicago Format Close Bibtex Ă— Cite: Bibtex Format Close Export Metadata EndNote Excel Save / Share this Record Save to My Library Send to Email Ă— 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

218

Physically Transparent Formulation of a Free-Electron Laser in the Linear Gain Regime  

E-Print Network (OSTI)

94720 Li-Hua Yu Brookhaven National Laboratory, Upton,Berkeley Laboratory. 3 Brookhaven National Laboratory,

Barletta, W.A.

2008-01-01T23:59:59.000Z

219

OPTIMIZATION OF THE PARAMETERS OF A STORAGE RING FOR A HIGH POWER XUV FREE ELECTRON LASER  

E-Print Network (OSTI)

for Instance. C. Pellegrini. Brookhaven National LaboratoryPellegrini, G. Vignola Brookhaven National Laboratory Upton,and, in part, under Brookhaven National Laboratory DOE

Jackson, A.

2010-01-01T23:59:59.000Z

220

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

E-Print Network (OSTI)

Radiation from the Brookhaven Vacuum-Ultraviolet ElectronArgonne National Laboratory, Brookhaven National Laboratory,Physicist Physics Department Brookhaven National Laboratory

Staples, John

2009-01-01T23:59:59.000Z

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.


221

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

Office of Science (SC) Website

for Teachers and Scientists Small Business Innovation Research and Small Business Technology Transfer Project Assessment Laboratories Ames Laboratory Argonne National...

222

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

E-Print Network (OSTI)

Physical Society, 1996 R&D 100 Award for global feedbackLaboratory, Berkeley, CA R&D Engineer, Lawrence LivermoreLaboratory, Livermore, CA R&D Engineer, Weyerhaeuser

Staples, John

2009-01-01T23:59:59.000Z

223

A NEW VERSION OF A FREE ELECTRON LASER TWO BEAM ACCELERATOR  

E-Print Network (OSTI)

of Energy, Division of Nuclear and High Energy Physics, andEnergy. Division of Nuclear and High Energy Physics. A Newof Energy, Division of Nuclear and High Energy Physics, and

Sessler, A.M.

2008-01-01T23:59:59.000Z

224

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

E-Print Network (OSTI)

S.H. Kim, D. Mangra, ORNL-SNS; D. Barni, C. Pagani, P.for the Spallation Neutron Source (SNS) project,” 50. StuartSpallation Neutron Source (SNS) cavities operate. This may

Staples, John

2009-01-01T23:59:59.000Z

225

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

E-Print Network (OSTI)

Radiation Lightsource (SSRL), Photon Science (PS), andRadiation Laboratory (SSRL) Member of the editorial board ofradiation user facilities SSRL (based on SPEAR3, a third-

Staples, John

2009-01-01T23:59:59.000Z

226

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

E-Print Network (OSTI)

P. Innocenzi, IKNO, a user facility for coherent terahertzAn ultimate experimental user facility will bring additionalgun has to operate in a user facility . Table 2.1 summarizes

Staples, John

2009-01-01T23:59:59.000Z

227

Three-dimensional analysis of free-electron laser performance using brightness scaled variables  

E-Print Network (OSTI)

to the Linac Coherent Light Source (LCLS) design, ESASEon the LCLS, and the optimal gain for a ?xed emittance.The parameters for LCLS used here are a beam energy of 13.64

Gullans, M.

2008-01-01T23:59:59.000Z

228

Obtaining attosecond X-ray pulses using a self-amplified spontaneous emission free electron laser  

E-Print Network (OSTI)

A 429, 243 (1999). [18] LCLS Design Study Group, ReportLinac Coherent Light Source (LCLS) [18], except the electron

Zholents, A.A.; Penn, G.

2005-01-01T23:59:59.000Z

229

Design Studies for a VUV--Soft X-ray Free-Electron Laser Array  

E-Print Network (OSTI)

bunch arrival time in the LCLS, and another system that willFERMI@Elettra and 100 fs for LCLS, both requiring about 200-

Corlett, J.

2010-01-01T23:59:59.000Z

230

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

E-Print Network (OSTI)

2007). 41. P. Emma for the LCLS commissioning team, PAC2009Test Facility for the LCLS”, SLAC-TN-07-005, (2007). John N.Professional/Academic Director, LCLS Strategic Projects

Staples, John

2009-01-01T23:59:59.000Z

231

Exact and variational solutions of 3D Eigenmodes in high gain Free Electron Lasers  

E-Print Network (OSTI)

Phys. Rev. A 41, 1662 [11] LCLS Design Study Report, SLAC-R-radial mode index. Consider LCLS nominal case as an exampleai/a r )2] (Ar/1f(Jx). For the LCLS example, the variational

Xie, M.

2011-01-01T23:59:59.000Z

232

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

DOE Data Explorer (OSTI)

The diffraction pattern of this entry corresponds to the one shown in **figure 2a** of the corresponding citation.

Chapman, H. N.

233

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

E-Print Network (OSTI)

elements, Jan 2000 Invention Disclosure Compact, tunable,field multipole, May 1997 Invention Disclosure Tunable pure

Staples, John

2009-01-01T23:59:59.000Z

234

Operational Radiation Protection in Synchrotron Light and Free Electron Laser Facilities  

Science Conference Proceedings (OSTI)

The 3rd generation synchrotron radiation (SR) facilities are storage ring based facilities with many insertion devices and photon beamlines, and have low injection beam power (radiation measurements, for SR facilities is also presented.

Liu, James C.; Rokni, Sayed H.; /SLAC; Vylet, Vaclav; /Jefferson Lab

2009-12-11T23:59:59.000Z

235

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

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

l aser w ith the s elf---seeding a nd current---enhanced S ASE NGLS T echnical N ote 4 6 Alexander Z holents Argonne N ational L aboratory 6 A ugust 2 013 NGLS Tech. Note 46 3...

236

A unit vector for characterizing the spin polarization of free electron  

E-Print Network (OSTI)

New degrees of freedom having the form of a unit vector are identified for characterizing the spin polarization of free electron. It is shown that when only the spin is considered, the non-commutativity of the Cartesian components of the Pauli vector allows us to use the azimuthal angle of a second direction, denoted by unit vector $\\mathbf I$, with respect to the quantization direction to characterize the spin polarization. The rotation of $\\mathbf I$ through an angle about the quantization axis leads to a rotation of the spin polarization vector through twice the angle about the same axis. Discussions are also made in Heisenberg picture as well. Upon utilizing this approach to a free electron and letting the quantization direction for each plane wave be the wave vector, we arrive at a representation in which the unit vector $\\mathbf I$ functions as an independent index to characterize the spin polarization.

Chun-Fang Li; Yan Wang

2010-08-05T23:59:59.000Z

237

The Emittance Spoiler Foil: A Simple Method to Produce Femtosecond...  

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

doubling time of about 10 months leading to the new Self-Amplified Spontaneous Emission Free-Electron Lasers (SASE FELs or X-Ray Lasers), a source more than ten orders of magnitude...

238

Bound-Free Electron-Positron Pair Production in Relativistic Heavy-Ion Collisions  

E-Print Network (OSTI)

The bound-free electron-positron pair production is considered for relativistic heavy ion collisions. In particular, cross sections are calculated for the pair production with the simultaneous capture of the electron into the 1s ground state of one of the ions and for energies that are relevant for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Colliders (LHC). In the framework of perturbation theory, we applied Monte-Carlo integration techniques to compute the lowest-order Feynman diagrams amplitudes by using Darwin wave functions for the bound states of the elec- trons and Sommerfeld-Maue wave functions for the continuum states of the positrons. Calculations were performed especially for the collision of Au + Au at 100 GeV/nucleon and Pb + Pb at 3400 GeV/nucleon.

M. Y. Sengul; M. C. Guclu; S. Fritzsche

2009-07-30T23:59:59.000Z

239

LCLS CDR Chapter 5 - FEL Parameters and Performance  

NLE Websites -- All DOE Office Websites (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.

240

FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS  

Science Conference Proceedings (OSTI)

We present experimental studies of the gain length and saturation power level from 1.5 nm to 1.5 Angstroms at the Linac Coherent Light Source (LCLS). By disrupting theFEL process with an orbit kick, we are able to measure the X-ray intensity as a function of undulator length. This kick method is cross-checked with the method of removing undulator sections. We also study the FEL-induced electron energy loss after saturation to determine the optimal taper of the undulator K values. The experimental results are compared to theory and simulations.

Ratner, D.; Fawley, W. M.; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, P.; Huang, Z.; Loos, H.; Miahnahri, A.; Nuhn, H.D.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.; Yocky, G.; Fawley, W. M.

2009-08-14T23:59:59.000Z

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

SLAC National Accelerator Laboratory - X-ray Laser Brings Cellular...  

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

a March experiment indicates it has, for the first time, used an X-ray free-electron laser - SLAC's Linac Coherent Light Source - to reconstitute the structure of a G...

242

Lensless imaging  

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

F. Schlotter and J. Sthr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely new classes of...

243

Lensless Imaging of Magnetic Nanostructures by X-ray Spectro...  

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

F. Schlotter and J. Sthr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely new classes of...

244

Characterizations and Diagnostics of Compton Light Source.  

E-Print Network (OSTI)

?? The High Intensity Gamma-ray Source (HIGS) at Duke University is a world class Compton light source facility. At the HIGS, a Free-Electron Laser (FEL)… (more)

Sun, Changchun

2009-01-01T23:59:59.000Z

245

Manual  

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

DOE U.S. Department of Energy ES&H Environment, Safety, and Health FEL Free Electron Laser FM&L Facilities Management and Logistics HSS Office of Health, Safety and Security ISC...

246

Carbon Nanotubes and Nano-Structure Manufacturing at TJNAF |...  

Office of Science (SC) Website

What began in 2001 as an academic investigation of how to make carbon nanotubes with a free-electron laser (FEL) has moved into a new phase. Researchers at NASA's Langley Research...

247

Beam Dynamics Study for TESLA with the Integrated FEL  

E-Print Network (OSTI)

Beam Dynamics Study for TESLA with the Integrated FEL V.M. Tsakanov Yerevan Physics Institute : : : : : : : : : : : : : : : : : : : : : : : 7 2.3 Conclusion 1 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 10 3 The TESLA high based trajectory correction : : : : : : : : : : : : 22 5 Summary 25 1 #12;. 1 Introduction In the TESLA

248

LS Note 280 Benchmark and Comparisons of FEL Simulation Programs  

E-Print Network (OSTI)

60439 June 30, 1999 I. Introduction A low-energy undulator test line (LEUTL) is under construction are reported here. The programs TDA3D and GENESIS solve the paraxial FEL equations with the approximation that the amplitude of the radiation field is slowly varying; d dz k a a f s s w B s = - +sin( ) , (1) d dz k k p

Kemner, Ken

249

BNL | ATF Laser Safety  

NLE Websites -- All DOE Office Websites (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

250

Two-Dimensional Simulation Analysis of the Standing-wave Free-electron Laser Two-Beam Accelerator  

E-Print Network (OSTI)

Office of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High Energy

Wang, C.

2008-01-01T23:59:59.000Z

251

Theoretical Examination of Transfer Cavities in a Standing-wave Free-electron Laser Two-beam Accelerator  

E-Print Network (OSTI)

Office of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High Energy

Govil, R.

2008-01-01T23:59:59.000Z

252

Study of an HHG-Seeded Free-Electron Laser for the LBNL Next Generation Light Source  

E-Print Network (OSTI)

for the LBNL Next Generation Light Source Neil Thompson,for the LBNL Next Generation Light Source Neil Thompson,Introduction The Next Generation Light Source (NGLS) is a

Thompson, Neil

2011-01-01T23:59:59.000Z

253

Optimization of the LCLS X-ray FEL output performance in the presence of strong undulator wakefields  

E-Print Network (OSTI)

Optimization of the LCLS X-ray FEL output performance in the presence of strong undulator wakefields

Reiche, S; Emma, P; Fawley, W M; Huang, Z; Nuhn, H D; Stupakov, G V

2005-01-01T23:59:59.000Z

254

Magnet Design of a Prototype Structure for the X-ray FELs at TESLA  

E-Print Network (OSTI)

Magnet Design of a Prototype Structure for the X-ray FELs at TESLA M. Tischer, J. Pflüger Hamburger Synchrotronstrahlungslabor HASYLAB, DESY, Notkestr. 85, D-22603 Hamburg, Germany Abstract XFEL undulators for the TESLA device is suggested so that both field integrals are trimmed close to zero for all gaps. TESLA­FEL 2000

255

STATISTICAL CORRELATIONS AND INTENSITY SPIKING IN THE SASE FEL.  

SciTech Connect

In the linear regime before saturation, we describe the statistical correlations in the narrow band chaotic output of the SASE FEL. At a fixed position along the undulator axis, we derive joint probability distributions for the intensity in the output pulse to have values I{sub 1} and I{sub 2} at times t{sub 1} and t{sub 2}, and for the spectral intensity to have values {tilde I}{sub 1} and {tilde I}{sub 2} at frequencies {omega}{sub 1} and {omega}{sub 2}. Probability distributions for the peak values of intensity in the time and frequency domains are also determined.

KRINSKY,S.; GLUCKSTERN,R.L.

2001-09-19T23:59:59.000Z

256

Optimisation of An HHG-Seeded Harmonic Cascade FEL Design for the NLS Project  

Science Conference Proceedings (OSTI)

Optimization studies of an HHG-seeded harmonic cascade FEL design for the UK's proposed New Light Source (NLS) facility are presented. Three separate FELs are planned to meet the requirements for continuous coverage of the photon energy range 50-1000 eV with variable polarization, 20 fs pulse widths and good temporal coherence. The design uses an HHG seed source tuneable from 50-100 eV to provide direct FEL seeding in this range, and one or two stage harmonic cascades to reach the higher photon energies. Studies have been carried out to optimize a harmonic cascade FEL operating at 1 keV; topics investigated include modulator configuration, seed power level and ef- fects of the HHG seed structure. FEL simulations using realistic electron beam distributions are presented and tolerance to increased emittance has been considered.

Dunning, David; /Daresbury; Thompson, Neil; /Daresbury; Bartolini, Riccardo; /Oxford U., JAI; Geng, Huiping; /SLAC; Huang, Zhirong; /SLAC; McNeil, Brian; /Strathclyde U.

2012-06-25T23:59:59.000Z

257

A New Approach to Improving the Efficiency of FEL Oscillator Simulations  

SciTech Connect

During the last year we have been benchmarking FEL oscillator simulation codes against the measured performance of the three Jefferson Lab oscillator FELs. While one might think that a full 4D simulation is de facto the best predictor of performance, the simulations are computationally intensive, even when analytical approximations to the electron bunch longitudinal distribution are used. In this presentation we compare the predictions of the 4D FEL interaction codes Genesis and Medusa, in combination with the optical code OPC, with those using a combination of the 2D & 3D versions of these codes, which can be run quickly on a single CPU core desktop computer.

Shinn, Michelle D. [JLAB; Benson, Stephen V. [JLAB; Watson, Anne M. [JLAB; Freund, Henry P. [LANL; Nyugen, Dinh C. [LANL; van der Slot, Peter J.M. [Mesa+, Enschede, The Netherlands

2013-05-01T23:59:59.000Z

258

Electron correlation in two-photon double ionization of helium from attosecond to FEL pulses  

SciTech Connect

We investigate the role of electron correlation in the two-photon double ionization of helium for ultrashort pulses in the extreme ultraviolet (XUV) regime with durations ranging from a hundred attoseconds to a few femtoseconds. We perform time-dependent ab initio calculations for pulses with mean frequencies in the so-called 'sequential' regime ({Dirac_h}{omega} > 54.4 eV). Electron correlation induced by the time correlation between emission events manifests itself in the angular distribution of the ejected electrons, which strongly depends on the energy sharing between them. We show that for ultrashort pulses two-photon double ionization probabilities scale non-uniformly with pulse duration depending on the energy sharing between the electrons. Most interestingly we find evidence for an interference between direct ('nonsequential') and indirect ('sequential') double photoionization with intermediate shake-up states, the strength of which is controlled by the pulse duration. This observation may provide a route towards measuring the pulse duration of x-ray free-electron laser (XFEL) pulses.

Collins, Lee [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

259

Electron correlation in two-photon double ionization of helium from attosecond to FEL pulses  

SciTech Connect

We investigate the role of electron correlation in the two-photon double ionization of helium for ultrashort pulses in the extreme ultraviolet (XUV) regime with durations ranging from a hundred attoseconds to a few femtoseconds. We perform time-dependent ab initio calculations for pulses with mean frequencies in the so-called 'sequential' regime ({Dirac_h}{omega} > 54.4 eV). Electron correlation induced by the time correlation between emission events manifests itself in the angular distribution of the ejected electrons, which strongly depends on the energy sharing between them. We show that for ultrashort pulses two-photon double ionization probabilities scale non-uniformly with pulse duration depending on the energy sharing between the electrons. Most interestingly we find evidence for an interference between direct ('nonsequential') and indirect ('sequential') double photoionization with intermediate shake-up states, the strength of which is controlled by the pulse duration. This observation may provide a route towards measuring the pulse duration of x-ray free-electron laser (XFEL) pulses.

Collins, Lee [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

260

Soft x-ray scattering using FEL radiation for probing near-solid density plasmas at few electronvolt temperatures  

DOE Green Energy (OSTI)

We report on soft x-ray scattering experiments on cryogenic hydrogen and simple metal targets. As a source of intense and ultrashort soft x-ray pulses we have used free-electron laser radiation at 92 eV photon energy from FLASH at DESY, Hamburg. X-ray pulses with energies up to 100 {micro}J and durations below 50 fs provide interaction with the target leading simultaneously to plasma formation and scattering. Experiments exploiting both of these interactions have been carried out, using the same experimental setup. Firstly, recording of soft x-ray inelastic scattering from near-solid density hydrogen plasmas at few electronvolt temperatures confirms the feasibility of this diagnostics technique. Secondly, the soft x-ray excitation of few electronvolt solid-density plasmas in simple metals could be studied by recording soft x-ray line and continuum emission integrated over emission times from fs to ns.

Toleikis, S; Faustlin, R R; Cao, L; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Przystawik, A; Radcliffe, P; Redmer, R; Tavella, F; Thiele, R; Tiggesbaumker, J; Truong, N X; Uschmann, I; Zastrau, U; Tschentscher, T

2009-03-03T23:59:59.000Z

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

Design Studies for a High-Repetition-Rate FEL Facility at LBNL.  

E-Print Network (OSTI)

for a future multi-user facility to meet the scientificabove, we suggest a new user facility equipped with an arraya schematic of a multi-user FEL facility concept. The major

CORLETT, J.

2009-01-01T23:59:59.000Z

262

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect

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

263

RF coupler for high-power CW FEL photoinjector  

SciTech Connect

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. The design presently under way is a 100-mA 2.5-cell {pi}-mode, 700-MHz, normal conducting demonstration CW RF photoinjector. This photoinjector will be capable of accelerating 3 nC per bunch with an emittance at the wiggler less than 10 mm-mrad. The paper presents results for the RF coupling from ridged wave guides to hte photoinjector RF cavity. The LEDA and SNS couplers inspired this 'dog-bone' design. Electromagnetic modeling of the coupler-cavity system has been performed using both 2-D and 3-D frequency-domain calculations, and a novel time-domain approach with MicroWave Studio. These simulations were used to adjust the coupling coefficient and calculate the power-loss distribution on the coupling slot. The cooling of this slot is a rather challenging thermal management project.

Kurennoy, S. (Sergey); Young, L. M. (Lloyd M.)

2003-01-01T23:59:59.000Z

264

  

NLE Websites -- All DOE Office Websites (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

265

LCLS-II Undulator Tolerance Analysis  

SciTech Connect

The SLAC National Accelerator Laboratory is building a new FEL user facility, LCLS-II, as a major upgrade to the Linear Coherent Light Source (LCLS). The upgrade will include two new Free Electron Lasers (FELs), to generate soft (SXR) and hard x-ray (HXR) SASE FEL radiation, based on planar, variable gap hybrid undulators with two different undulator periods (SXU: 55 mm, HXU: 32 mm). An algebraic FEL tolerance analysis for the undulator lines, including tuning, alignment, and phase correction tolerances has been performed. The methods and results are presented in this paper.

Nuhn, H.-D.; /SLAC; Marks, S.; /LBL, Berkeley; Wu, J.; /SLAC

2012-06-06T23:59:59.000Z

266

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, A.

1989-06-20T23:59:59.000Z

267

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

268

Using The SLAC Two-Mile Accelerator for Powering an FEL  

Science Conference Proceedings (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

269

FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS  

E-Print Network (OSTI)

taper mea- surements from LCLS. We ?nd gain lengths of ? 2.9AND TAPER MEASUREMENTS AT LCLS ? D. Ratner † , A. Brachmann,et al. , First Results of the LCLS Laser-Heater Sys- tem,

Ratner, D.

2010-01-01T23:59:59.000Z

270

Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter  

SciTech Connect

Beam diagnostics is an essential constituent of any accelerator, so that it is named as "organs of sense" or "eyes of the accelerator." Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators, viewing screens, ionization chambers; Nuclear or elementary particle physics interactions happen in some other devices, like beam loss monitors, polarimeters, luminosity monitors; Some measure photons emitted by moving charges, such as transition radiation, synchrotron radiation monitors and diffraction radiation-which is the topic of the first part of this thesis; Also, some make use of interaction of particles with photons, such as laser wire and Compton polarimeters-which is the second part of my thesis. Diagnostics let us perceive what properties a beam has and how it behaves in a machine, give us guideline for commissioning, controlling the machine and indispensable parameters vital to physics experiments. In the next two decades, the research highlight will be colliders (TESLA, CLIC, JLC) and fourth-generation light sources (TESLA FEL, LCLS, Spring 8 FEL) based on linear accelerator. These machines require a new generation of accelerator with smaller beam, better stability and greater efficiency. Compared with those existing linear accelerators, the performance of next generation linear accelerator will be doubled in all aspects, such as 10 times smaller horizontal beam size, more than 10 times smaller vertical beam size and a few or more times higher peak power. Furthermore, some special positions in the accelerator have even more stringent requirements, such as the interaction point of colliders and wigglor of free electron lasers. Higher performance of these accelerators increases the difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.

Chuyu Liu

2012-12-31T23:59:59.000Z

271

TESLA-FEL 2004-01 Silica Aerogel Radiators for Bunch Length  

E-Print Network (OSTI)

TESLA-FEL 2004-01 Silica Aerogel Radiators for Bunch Length Measurements J. B¨ahr a , V. Djordjadze aerogel are used to measure the electron bunch length at the photo injector test facility at DESY Zeuthen by the usage of aerogel is calculated analytically and Monte Carlo simulations are performed. It is shown

272

TESLA-FEL 2004-03 Proposed continuous wave energy recovery operation of an XFEL*  

E-Print Network (OSTI)

CEBAF accelerator at JLab [3] are quite encouraging. This combined with continuing progress-FEL 2004-03 FIG. 1. CEBAF Energy Recovery Experiment at JLab. CEBAF - the 6 GeV recirculating of CEBAF with the Energy Recovery experiment is illustrated in Fig. 1. Beam is injected into the North

273

Direct Laser Synthesis of Functional Coatings  

DOE Green Energy (OSTI)

The direct laser synthesis of functional coatings employs the irradiation of materials with short intensive laser pulses in a reactive atmosphere. The material is heated and plasma is ignited in the reactive atmosphere. This leads to an intensive interaction of the material with the reactive species and a coating is directly formed on the materials surface. By that functional coatings can be easily produced a fast way on steel, aluminium, and silicon by irradiation in nitrogen, methane, or even hydrogen. The influence of the processing parameters to the properties of the functional coatings will be presented for titanium nitride coating produced on titanium with the free electron laser.

P. Schaaf; Michelle D. Shinn; E. Carpene; J. Kaspar

2005-06-01T23:59:59.000Z

274

Bendable Focusing X-Ray Optics for the ALS and the LCLS/FEL: Design, Metrology, and Performance  

E-Print Network (OSTI)

Focusing X-Ray Optics for the ALS and the LCLS/FEL: Design,in a vacuum tank on the ALS Long Trace Profiler opticalAdvanced Light Source (ALS) at Lawrence Berkeley National

Yashchuk, V. V.

2010-01-01T23:59:59.000Z

275

LCLS X-Ray FEL Output Performance in the Presence of Highly Time-Dependent Undulator Wakefields  

E-Print Network (OSTI)

resistive-wall wake for a 1-nC LCLS bunch charge propagatingST Accel. Beams, 8, [3] LCLS CDR, SLAC Rpt. SLAC-R-593 (al. , “Optimization of the LCLS X-RAY FEL Performance in the

Bane, Karl L.F.; Emma, Paul; Huang, Heinz-Dieter Nuhn; Stupakov, Gennady; Fawley, William M.; Reiche, Sven

2005-01-01T23:59:59.000Z

276

Coherent terahertz radiation from high-harmonic component of modulated free-electron beam in a tapered two-asymmetric grating structure  

SciTech Connect

Based on the mechanism of incoherent diffraction radiation excited by an electron bunch in a waveguide with periodic structure, this paper presents the concept of coherent terahertz (THz) radiation from the high-harmonic component of a modulated free-electron beam in a tapered two-asymmetric grating structure. The results show that in this mechanism 0.43 THz radiation can be generated with 10 A/cm{sup 2} current density, and the efficiency can reach 0.5%. Because of the low required current density and relative high efficiency, this concept shows the application potential for electron-beam-driven terahertz sources.

Zhang Yaxin; Zhou Yucong; Dong Liang; Liu Shenggang [Terahertz Science and Technology Research Center, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2012-09-17T23:59:59.000Z

277

Microsoft Word - Document1  

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

LASING OF THE LCLS X-RAY FEL AT 1.5 Ă… LASING OF THE LCLS X-RAY FEL AT 1.5 Ă… 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 Ă… 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-Ă… 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

278

OPERATION AND COMMISSIONING OF THE JEFFERSON LAB UV FEL USING AN SRF DRIVER ERL  

Science Conference Proceedings (OSTI)

We describe the operation and commissioning of the Jefferson Lab UV FEL using a CW SRF ERL driver. Based on the same 135 MeV linear accelerator as the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation necessitating a unique set of commissioning and operational procedures. Additionally, a novel technique to initiate lasing is described. To meet these constraints and accommodate a challenging installation schedule, we adopted a staged commissioning plan with alternating installation and operation periods. This report addresses these issues and presents operational results from on-going beam operations.

R. Legg; S. Benson; G. Biallas; K. Blackburn; J. Boyce; D. Bullard; J. Coleman; C. Dickover; D. Douglas; F. Ellingsworth; P. Evtushenko; F. Hannon; C. Hernandez-Garcia; C. Gould; J. Gubeli; D. Hardy; K. Jordan; M. Klopf; J. Kortze; M. Marchlik; W. Moore; G. Neil; T. Powers; D. Sexton; Michelle D. Shinn; C. Tennant; R. Walker; G. Wilson

2011-03-01T23:59:59.000Z

279

Harmonic Generation at Lower Electron Energies for a Hard X-ray FEL  

SciTech Connect

There are several schemes currently being investigated to pre-bunch the electron beam and step the coherent bunching up to higher harmonics, all which require modulator sections which introduce additional energy modulation. X-ray FELs operate in a regime where the FEL parameter, {rho} is equal to or less than the effective energy spread introduced from the emittance in the electron beam. Because of this large effective energy spread, the energy modulation introduced from harmonic generation schemes would seriously degrade FEL performance. This problem can be mitigated by incorporating the harmonic generation scheme at a lower electron kinetic energy than the energy at the final undulator. This will help because the effective energy spread from emittance is reduced at lower energies, and can be further reduced by making the beam transversely large. Then the beam can be squeezed down slowly enough in the subsequent accelerator sections so that geometric debunching is mitigated. The beam size inside the dispersive chicanes and in the accelerator sections must be carefully optimized to avoid debunching, and each subharmonic modulator section must generate enough energy modulation to overcome the SASE noise without significantly increasing the gain length in the final undulator. Here we show analytical results that demonstrate the feasibility of this harmonic pre-bunching scheme.

Marksteiner, Quinn R. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

280

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

SciTech Connect

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

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

2011-12-13T23:59:59.000Z

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

Response to ''Comment on 'Chaotic electron trajectories in an electromagnetic wiggler free-electron laser with ion-channel guiding''' [Phys. Plasmas 17, 093103 (2010)  

Science Conference Proceedings (OSTI)

Nasr and Hasanbeigi in their comment [Phys. Plasmas 17, 093103 (2010)] have claimed that, in our recent paper [Phys. Plasmas 17, 093103 (2010)], incorrect initial conditions have been used based on dispersion relation (or normalized electromagnetic wave frequency {omega}{sub w}) and mean axial velocity {beta}{sub b}. We use a self-consistent method to calculate more accurate values of {omega}{sub w} and {beta}{sub b} and show that all results presented in our recent paper are correct.

Esmaeilzadeh, Mahdi; Taghavi, Amin [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of)

2011-05-15T23:59:59.000Z

282

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

SciTech Connect

A dense electron beam propagating through a laser undulator can radiate a coherent x-ray or gamma ray. This lasing scheme is studied with the Landau damping theory. The analysis suggests that, with currently available physical parameters, coherent gamma rays of up to 50 keV can be generated. The electron quantum diffraction suppresses the free electron laser action, which limits the maximum radiation.

Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Joon Moon, Sung [8 Benjamin Rush Ln., Princeton, New Jersey 08540 (United States)

2012-06-15T23:59:59.000Z

283

Alignment and Magnet Error Tolerances for the LCLS X-Ray FEL  

E-Print Network (OSTI)

We have examined the influence of misalignments and magnet errors on the predicted performance of the Linac Coherent Light Source (LCLS). Due to the extremely large number of wiggler periods (# 10 3 ) and the small optical mode size ( 20 #m), alignment and magnet tolerances will be quite demanding. These demands may increase if the wiggler is split into separate sections by the possible inclusion of diagnostic stations, dispersive sections, etc. We have attempted to quantify such tolerances using the numerical simulation code FRED-3D. 1 INTRODUCTION The LCLS is a multi-institutional proposal for a singlepass x-ray FEL operating in the 1-2 A wavelength region, using electron beams from the SLAC linac at # 15 GeV energy [1]. The effect of field and steering errors on the performance of an X-Ray FEL operating at an optical wavelength of 4 nm based on a 7 GeV electron beam from the SLAC linac has been studied before by Kim et. al. [2]. Since then the proposed target wavelength for t...

H. -d. Nuhn; E. T. Scharlemann; R. Schlüter

1995-01-01T23:59:59.000Z

284

High-Brightness Beams from a Light Source Injector The Advanced Photon Source Low-Energy Undulator Test Line Linac  

E-Print Network (OSTI)

The use of existing linacs, and in particular light source injectors, for free-electron laser (FEL) experiments is becoming more common due to the desire to test FELs at ever shorter wavelengths. The high-brightness, high-current beams required by high-gain FELs impose technical specifications that most existing linacs were not designed to meet. Moreover, the need for specialized diagnostics, especially shot-to-shot data acquisition, demands substantial modification and upgrade of conventional linacs. Improvements have been made to the Advanced Photon Source (APS) injector linac in order to produce and characterize high-brightness beams. Specifically, effort has been directed at generating beams suitable for use in the low-energy undulator test line (LEUTL) FEL in support of fourth-generation light source research. The enhancements to the linac technical and diagnostic capabilities that allowed for self-amplified spontaneous emission (SASE) operation of the FEL at 530 nm are described. Recent results, includi...

Travish, G; Borland, M; Hahne, M; Harkay, K C; Lewellen, J W; Lumpkin, Alex H; Milton, S V; Sereno, N S

2000-01-01T23:59:59.000Z

285

InvenTcl: Making Open Inventor Interpretive with Tcl/[incr Tcl] Sidney Fels, Silvio Esser, Armin Bruderlin, Kenji Mase  

E-Print Network (OSTI)

InvenTcl: Making Open Inventor Interpretive with Tcl/[incr Tcl] Sidney Fels, Silvio Esser, Armin/compile/debug iteration cycle. In this sketch, we introduce InvenTcl which is an interpretive version of Open Inventor. Our interpretive version of Open Inventor uses the interpretive language Tcl, (Tool Command Language

Fels, Sidney S.

286

A Compact X-Band Linac for an X-Ray FEL  

SciTech Connect

With the growing demand for FEL light sources, cost issues are being reevaluated. To make the machines more compact, higher frequency room temperature linacs are being considered, specifically ones using C-band (5.7 GHz) rf technology, for which 40 MV/m gradients are achievable. In this paper, we show that an X-band (11.4 GHz) linac using the technology developed for NLC/GLC can provide an even lower cost solution. In particular, stable operation is possible at gradients of 100 MV/m for single bunch operation and 70 MV/m for multibunch operation. The concern, of course, is whether the stronger wakefields will lead to unacceptable emittance dilution. However, we show that the small emittances produced in a 250 MeV, low bunch charge, LCLS-like S-band injector and bunch compressor can be preserved in a multi-GeV X-band linac with reasonable alignment tolerances. The successful lasing and operation of the LCLS [1] has generated world-wide interest in X-ray FELs. The demand for access to such a light source by researchers eager to harness the capabilities of this new tool far exceeds the numbers that can be accommodated, spurring plans for additional facilities. Along with cost, spatial considerations become increasingly important for a hard X-ray machine driven by a multi-GeV linac. The consequent need for high acceleration gradient focuses attention on higher frequency normal conducting accelerator technology, rather than the superconducting technology of a soft X-ray facility like FLASH. C-band technology, such as used by Spring-8, is a popular option, capable of providing 40 MV/m. However, more than a decade of R&D toward an X-band linear collider, centered at SLAC and KEK, has demonstrated that this frequency option can extend the gradient reach to the 70-100 MV/m range. The following design and beam dynamics calculations show an X-band linac to be an attractive choice on which to base an X-ray FEL.

Adolphsen, Chris; Huang, Zhirong; Bane, Karl L.F.; Li, Zenghai; Zhou, Feng; Wang, Faya; Nantista, Christopher D.; /SLAC

2011-09-12T23:59:59.000Z

287

Potential for ultrafast dynamic chemical imaging with few-cycle infrared lasers  

E-Print Network (OSTI)

We studied the photoelectron spectra generated by an intense few-cycle infrared laser pulse. By focusing on the angular distributions of the back rescattered high energy photoelectrons, we show that accurate differential elastic scattering cross sections of the target ion by free electrons can be extracted. Since the incident direction and the energy of the free electrons can be easily changed by manipulating the laser's polarization, intensity, and wavelength, these extracted elastic scattering cross sections, in combination with more advanced inversion algorithms, may be used to reconstruct the effective single-scattering potential of the molecule, thus opening up the possibility of using few-cycle infrared lasers as powerful table-top tools for imaging chemical and biological transformations, with the desired unprecedented temporal and spatial resolutions.

Morishita, T; Chen, Z; Lin, C D

2007-01-01T23:59:59.000Z

288

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

289

Femtosecond Synchronization of Laser Systems for the LCLS  

SciTech Connect

The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system based on stabilized fiber links has been developed for the LCLS to provide this synchronization. Preliminary results show synchronization of the installed stabilized links at the sub-20-femtosecond level. We present details of the implementation at LCLS and potential for future development.

Byrd, John; /LBL, Berkeley; Doolittle, Lawrence; /LBL, Berkeley; Huang, Gang; /LBL, Berkeley; Staples, John; /LBL, Berkeley; Wilcox, Russell; /LBL, Berkeley; Arthur, John; /SLAC; Frisch, Josef; /SLAC; White, William; /SLAC

2012-08-24T23:59:59.000Z

290

Laser supported solid state absorption fronts in silica  

SciTech Connect

We develop a model based on simulation and experiment that explains the behavior of solid-state laser-supported absorption fronts generated in fused silica during high intensity (up to 5GW/cm{sup 2}) laser exposure. We find that the absorption front velocity is constant in time and is nearly linear in laser intensity. Further, this model can explain the dependence of laser damage site size on these parameters. This behavior is driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. The regime of parameter space critical to this problem spans and extends that measured by other means. It serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

Carr, C W; Bude, J D

2010-02-09T23:59:59.000Z

291

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

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

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

292

Operation of the APS photoinjector drive laser sytem  

NLE Websites -- All DOE Office Websites (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-

293

RF Couplers for Normal-Conducting Photoinjector of High-Power CW FEL  

E-Print Network (OSTI)

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by "dog-bone" irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

Kurennoy, Sergey; Wood, Richard L; Schultheiss, T J; Rathke, John; Young, Lloyd

2004-01-01T23:59:59.000Z

294

RF couplers for normal-conducting photoinjector of high-power CW FEL  

SciTech Connect

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by 'dog-bone' irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

Kurennoy, S. (Sergey)

2004-01-01T23:59:59.000Z

295

A multislit transverse-emittance diagnostic for space-charge-dominated electron beams  

Science Conference Proceedings (OSTI)

Jefferson Lab is developing a 10 MeV injector to provide an electron beam for a high-power free-electron laser (FEL). To characterize the transverse phase space of the space-charged-dominated beam produced by this injector, the authors designed an interceptive multislit emittance diagnostic. It incorporates an algorithm for phase-space reconstruction and subsequent calculation of the Twiss parameters and emittance for both transverse directions at an update rate exceeding 1 Hz, a speed that will facilitate the transverse-phase-space matching between the injector and the FEL`s accelerator that is critical for proper operation. This paper describes issues pertaining to the diagnostic`s design. It also discusses the acquisition system, as well as the software algorithm and its implementation in the FEL control system. First results obtained from testing this diagnostic in Jefferson Lab`s Injector Test Stand are also included.

Piot, P.; Song, J.; Li, R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)] [and others

1997-06-01T23:59:59.000Z

296

Transverse Coherence of the LCLS X-Ray Beam  

Science Conference Proceedings (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

297

JLAB Electron Driver Capabilities  

Science Conference Proceedings (OSTI)

Several schemes have been proposed for adding a positron beam option at the Continuous Electron Beam Facility (CEBAF) at Jefferson Laboratory (JLAB). They involve using a primary beam of electrons or gamma rays striking a target to produce a positron beam. At JLAB electron beams are produced and used in two different accelerators, CEBAF and the JLAB FEL (Free Electron Laser). Both have low emittance and energy spread. The CEBAF beam is polarized. The FEL beam is unpolarized but the injector can produce a higher current electron beam. In this paper we describe the characteristics of these beams and the parameters relevant for positron production.

Kazimi, Reza [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2009-09-02T23:59:59.000Z

298

Suppression of Exponential Electronic Decay in a Charged Environment  

Science Conference Proceedings (OSTI)

Inner-shell ionization of atoms and molecules leads to the creation of highly excited ionic states that often decay by electron emission. The dynamics of the decay is usually assumed to be exponential and the process is characterized by a decay rate. Here we show that in a multiply ionized cluster created by interaction with a high-intensity free-electron laser (FEL) radiation, trapping of the emitted electron by the neighboring ions changes the character of the decay dynamics qualitatively to the extent that it can become oscillatory instead of exponential. Implications of the predicted effect on Coster-Kronig and interatomic Coulombic decay processes induced by FELs are investigated.

Averbukh, Vitali [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Saalmann, Ulf; Rost, Jan Michael [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Max Planck Advanced Study Group at the Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg (Germany)

2010-06-11T23:59:59.000Z

299

Laser Ignition  

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

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...

300

Gutt-111512 - Argonne National Laboratories, Materials Sicence Division  

NLE Websites -- All DOE Office Websites (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

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

Creating intense polarized electron beam via laser stripping and spin-orbit interaction  

DOE Green Energy (OSTI)

The recent advance in laser field make it possible to excite and strip electrons with definite spin from hydrogen atoms. The sources of hydrogen atoms with orders of magnitude higher currents (than that of the conventional polarized electron cathods) can be obtained from H{sup -} sources with good monochromatization. With one electron of H{sup -} stripped by a laser, the remained electron is excited to upper state (2P{sup 3/2} and 2P{sup 1/2}) by a circular polarization laser light from FEL. Then, it is excited to a high quantum number (n=7) with mostly one spin direction due to energy level split of the states with a definite direction of spin and angular momentum in an applied magnetic field and then it is stripped by a strong electric field of an RF cavity. This paper presents combination of lasers and fields to get high polarization and high current electron source.

Danilov, V.; Ptitsyn, V.; Gorlov, T.

2010-12-01T23:59:59.000Z

302

Nonlinear Thomson scattering of an ultrashort laser pulse  

SciTech Connect

The nonlinear scattering of an ultrashort laser pulse by free electrons is considered. The pulse is described in the 'Mexican hat' wavelet basis. The equation of motion for a charged particle in the field of a plane electromagnetic wave has an exact solution allowing, together with the instant spectrum approximation, the calculation of the intensity of nonlinear Thomson scattering for a high-intensity laser pulse. The spectral distribution of scattered radiation for the entire pulse duration is found by integrating with respect to time. The maximum of the emission spectrum of a free electron calculated in 10{sup 19}-10{sup 21} W/cm{sup 2} fields lies in the UV spectral region between 3 and 12 eV. A part of the continuous spectrum achieves high photon energies. One percent of the scattered energy for the field intensity 10{sup 20} W/cm{sup 2} is concentrated in the range h{omega} > 2.7 Multiplication-Sign 10{sup 2} eV, for a field intensity of 10{sup 21} W/cm{sup 2} in the range h{Omega} > 7.9 Multiplication-Sign 10{sup 2} eV, and for an intensity of 10{sup 22} W/cm{sup 2} in the range h{Omega} > 2.45 Multiplication-Sign 10{sup 5} eV. These results allow us to estimate nonlinear scattering as a source of hard X-rays.

Golovinski, P. A., E-mail: golovinski@bk.ru; Mikhin, E. A. [Voronezh State Architectural-Building University (Russian Federation)

2011-10-15T23:59:59.000Z

303

Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts  

SciTech Connect

Previously we have shown that the size of laser induced damage sites in both KDP and SiO{sub 2} is largely governed by the duration of the laser pulse which creates them. Here we present a model based on experiment and simulation that accounts for this behavior. Specifically, we show that solid-state laser-supported absorption fronts are generated during a damage event and that these fronts propagate at constant velocities for laser intensities up to 4 GW/cm{sup 2}. It is the constant absorption front velocity that leads to the dependence of laser damage site size on pulse duration. We show that these absorption fronts are driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport, and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. In addition to the practical application of selecting an optimal laser for pre-initiation of large aperture optics, this work serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

Carr, C W; Bude, J D; Shen, N; Demange, P

2010-10-26T23:59:59.000Z

304

Laser Ignition  

NLE Websites -- All DOE Office Websites (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

305

Laser Radiometry  

Science Conference Proceedings (OSTI)

... over a wide range of powers, energies, and wavelengths. ... the SI units for laser power and energy. ... Novel power meter for high-efficiency laser diode ...

2012-04-18T23:59:59.000Z

306

An empirical model of collective electrostatic effects for laser-beam channeling in long-scale-length relativistic plasmas  

Science Conference Proceedings (OSTI)

This work investigates the capability of ultraintense lasers with irradiance from 10{sup 18} to 10{sup 21} W cm{sup -2} to produce highly energetic electron beams from a Gaussian focus in a low-density plasma. A simple particle simulation code including a physical model of collective electrostatic effects in relativistic plasmas has been developed. Without electrostatic fields, free electrons escape from the Gaussian focal region of a 10-ps petawatt laser pulse very quickly, well before the laser field reaches its maximum amplitude. However, it has been demonstrated that the electrostatic field generated by the electron flow is able to strongly modify the range and direction of the laser-generated MeV electrons by allowing trapped electrons to experience much higher laser-intensity peaks along their trajectories. This modeling predicts some collimation but not enough to meet the requirements of fast ignition.

Yang, Jeong-Hoon; Craxton, R. Stephen [Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623 (United States)

2011-08-15T23:59:59.000Z

307

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

Science Conference Proceedings (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

308

The monochromator beamline at FLASH: performance, capabilities and upgrade plans  

E-Print Network (OSTI)

The monochromator beamline at the FLASH facility at DESY is the worldwide first XUV monochromator beamline operational on a free electron laser (FEL)source. Being a single-user machine, FLASH demands a high flexibility of the instrumentation to fulfil the needs of diverse experiments performed by a multidisciplinary user community. Thus, the beamline has not only been used for high-resolution spectroscopy that it was originally designed for, but also for pump-probe experiments controlling the temporal-spectral properties at moderate resolution, and as a filter for high harmonics of the FEL at very low resolution. The present performance and capabilities of the beamline are discussed with emphasis on particularities arising from the nature of the FEL source, and current developments are presented aiming to enhance its capabilities for accommodating a wide variety of experiments.

Gerasimova, Natalia; Feldhaus, Josef; 10.1080/09500340.2011.588344

2013-01-01T23:59:59.000Z

309

WF-NOTE-238  

NLE Websites -- All DOE Office Websites (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

310

Free Electron Masers for Tokamak Applications  

Science Conference Proceedings (OSTI)

Plasma Heating and System Dynamics / Proceedings of the Seveth Topical Meeting on the Technology of Fusion Energy (Reno, Nevada, June 15–19, 1986)

C.E. Wagner; H. Boehmer; M.Z. Caponi

311

Adjustment of ablation shapes and subwavelength ripples based on electron dynamics control by designing femtosecond laser pulse trains  

SciTech Connect

A quantum model is proposed to investigate femtosecond laser pulse trains processing of dielectrics by including the plasma model with the consideration of laser particle-wave duality. Central wavelengths (400 nm and 800 nm) strongly impact the surface plasmon field distribution, the coupling field intensity distribution (between the absorbed intensity and the surface plasma), and the distribution of transient localized free electron density in the material. This, in turn, significantly changes the localized transient optical/thermal properties during laser materials processing. The effects of central wavelengths on ablation shapes and subwavelength ripples are discussed. The simulation results show that: (1) ablation shapes and the spacing of subwavelength ripples can be adjusted by localized transient electron dynamics control using femtosecond laser pulse trains; (2) the adjustment of the radii of ablation shapes is stronger than that of the periods of subwavelength ripples.

Yuan Yanping; Jiang Lan; Li Xin; Wang Cong [Laser Micro/Nano-Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Lu Yongfeng [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

2012-11-15T23:59:59.000Z

312

Microsoft Word - DWA4XFELsummary_awa_verson.docx  

NLE Websites -- All DOE Office Websites (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,

313

Laser Spectro.  

Science Conference Proceedings (OSTI)

For more information about my work on laser spectroscopy, consult the following papers: Sansonetti, CJ, Gillaspy, JD, and ...

314

The athermal Laser  

E-Print Network (OSTI)

A new laser concept is presented, called the athermal laser, unifying all the hitherto known implementations of radiative laser cooling.

Muys, Peter

2009-01-01T23:59:59.000Z

315

Laser device  

DOE Patents (OSTI)

A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

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

2007-07-10T23:59:59.000Z

316

March OSTI homepage | OSTI, US Dept of Energy, Office of Scientific...  

Office of Scientific and Technical Information (OSTI)

DOE Science Showcase Free-Electron Lasers Free-Electron Lasers, are an innovative technology, opening doors to a vast array of possibilities for manufacturing and basic...

317

The Jefferson Lab High Power Light Source  

Science Conference Proceedings (OSTI)

Jefferson Lab has designed, built and operated two high average power free-electron lasers (FEL) using superconducting RF (SRF) technology and energy recovery techniques. Between 1999-2001 Jefferson Lab operated the IR Demo FEL. This device produced over 2 kW in the mid-infrared, in addition to producing world record average powers in the visible (50 W), ultraviolet (10 W) and terahertz range (50 W) for tunable, short-pulse (power demonstration of an accelerator configuration that is being exploited for a number of new accelerator-driven light source facilities that are currently under design or construction. The driver accelerator for the IR Demo FEL uses an Energy Recovered Linac (ERL) configuration that improves the energy efficiency and lowers both the capital and operating cost of such devices by recovering most of the power in the spent electron beam after optical power is extracted from the beam. The IR Demo FEL was de-commissioned in late 2001 for an upgraded FEL for extending the IR power to over 10 kW and the ultraviolet power to over 1 kW. The FEL Upgrade achieved 10 kW of average power in the mid-IR (6 microns) in July of 2004, and its IR operation currently is being extended down to 1 micron. In addition, we have demonstrated the capability of on/off cycling and recovering over a megawatt of electron beam power without diminishing machine performance. A complementary UV FEL will come on-line within the next year. This paper presents a summary of the FEL characteristics, user community accomplishments with the IR Demo, and planned user experiments.

James R. Boyce

2006-01-01T23:59:59.000Z

318

Femtosecond laser interactions with semiconductor and dielectric materials  

SciTech Connect

Electronic excitation-relaxation processes induced by ultra-short laser pulses are studied numerically for semiconductors and dielectric materials (Si, quartz). A detailed kinetic approach is used in the calculations accounting for electron-photon-phonon, electron-phonon and electron-electron scatterings. In addition, both laser field ionization ranging from multi-photon to tunneling one, and electron impact (avalanche) ionization processes are included in the model. Based on the performed calculations we study the relaxation time as a function of laser parameters. It is shown that this time depends on the density of the created free carriers, which in turn is a nonlinear function of laser intensity. In addition, a simple damage criterion is proposed based on the mean electron energy density rather than on critical free electron density. This criterion gives a reasonable agreement with the available experimental data practically without adjustable parameters. Furthermore, the performed modeling provides energy absorbed in the target, conditions for damage of dielectric materials, as well as conditions for surface plasmon excitation and for periodic surface structure formation on the surface of semiconductor materials.

Shcheblanov, Nikita S.; Derrien, Thibault J. Y.; Itina, Tatiana E. [Laboratoire Hubert Curien, CNRS//Universite Jeann Monnet, 18 rue du Prof. Benoit Lauras, 42000 Saint-Etienne (France); Laboratoire Lasers, Plasmas et Procedes Photoniques, CNRS//Universite de la Mediterranee, 162 avenue de Luminy, 13288, Marseille (France); Laboratoire Hubert Curien, CNRS//Universite Jeann Monnet, 18 rue du Prof. Benoit Lauras, 42000 Saint-Etienne (France)

2012-07-30T23:59:59.000Z

319

LCLS - The X-ray Laser Has Turned On  

SciTech Connect

On April 10, 2009 the Linac Coherent Light Source (LCLS), the world's first hard x-ray free electron laser, was brought to lasing. Producing an x-ray beam with over a billion times higher peak brightness that then most powerful existing syncrotron sources, it marked the beginning of a new era of science. The LCLS pulses arrive at a rate of 60 - 120 Hz in an energy range from 480 eV to 10 keV, with pulse lengths as short as a few fs to about 300 fs. Since October 2009, users have been performing experiments at the LCLS, and currently three of the six planned instruments are available. Although we stand only at the beginning of LCLS science, there is no doubt about the strong sense of early excitement.

Bergmann, Uwe [Linac Coherent Light Source

2010-11-03T23:59:59.000Z

320

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

Science Conference Proceedings (OSTI)

We consider the possibility of experimental verification of vacuum e{sup +}e{sup -} pair creation at the focus of two counter-propagating optical laser beams with intensities 10{sup 20}-10{sup 22} W/cm{sup 2}, achievable with present-day petawatt lasers, and approaching the Schwinger limit: 10{sup 29} W/cm{sup 2} to be reached at ELI. Our approach is based on the collisionless kinetic equation for the evolution of the e{sup +} and e{sup -} distribution functions governed by a non-Markovian source term for pair production. As possible experimental signals of vacuum pair production we consider e{sup +}e{sup -} annihilation into {gamma}-pairs and the refraction of a high-frequency probe laser beam by the produced e{sup +}e{sup -} 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}{sup +}{mu}{sup -} and {pi}{sup +}{pi}{sup -} 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.

Blaschke, D. B.; Prozorkevich, A. V.; Roepke, G.; Roberts, C. D.; Schmidt, S. M.; Shkirmanov, D. S.; Smolyansky, S. A.; Physics; Univ. of Wroclaw; Joint Inst. for Nuclear Research; Univ. Rostock; Saratov State Univ.; Forschungszentrum Juelich GmbH

2009-11-01T23:59:59.000Z

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.


321

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

322

Experimental Studies with Spatial Gaussian-Cut Laser for the LCLS Photocathode Gun  

Science Conference Proceedings (OSTI)

To simplify the LCLS operation and further enhance the injector performances, we are evaluating the various parameters including the photocathode drive laser system. Extensive simulations show that both the projected and time-sliced emittances with spatial Gaussian profiles having reasonable tail-cut are better than those with uniform one. The simulated results are also supported by theoretical analyses. In the LCLS, the spatial uniform or Gaussian-cut laser profiles are conveniently obtained by adjusting the optics of the telescope upstream of an iris, used to define laser size on the cathode. Preliminary beam studies at the LCLS injector show that both the projected and time-sliced emittances with spatial Gaussian-cut laser are almost as good as, although not better than, those with uniform one. In addition, the laser transmission through the iris with the Gaussian-cut profile is twice with uniform one, which can significantly ease LCLS copper cathode/laser operations and thus improve the LCLS operation efficiency. More beam studies are planned to measure FEL performances with the Gaussian-cut in comparison with the uniform one. All simulations and measurements are presented in the paper.

Zhou, F.; Brachmann, A.; Emma, P.; Gilevich, S.; Huang, Z.; /SLAC

2011-12-13T23:59:59.000Z

323

Laser Catalyst  

INL’s Laser Catalyst is a method for removing contaminant matter from a porous material. A polymer material is applied to a contaminated surface and ...

324

Coherent Radiation Effects in the LCLS Undulator  

Science Conference Proceedings (OSTI)

For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting energy losses are significant for the operation of LCLS.

Reiche, S.; /UCLA; Huang, Z.; /SLAC

2010-12-14T23:59:59.000Z

325

MTX final report  

SciTech Connect

The MTX experiment was proposed in 1986 to apply high frequency microwaves generated by a free-electron laser (FEL) to electron cyclotron resonance heating (ECRH) in a high field, high density tokamak. As the absorption of microwaves at the electron cyclotron resonance requires high frequencies, the opportunity of applying a free-electron laser has appeal as the device is not limited to frequencies in the microwave or long millimeter wavelength regions, in contrast to many other sources. In addition, the FEL is inherently a high power source of microwaves, which would permit single units of 10 MW or more, optimum for reactors. Finally, it was recognized early in the study of the application of the FEL based on the induction linear accelerator, that the nonlinear effects associated with the intense pulses of microwaves naturally generated would offer several unique opportunities to apply ECRH to current drive, MHD control, and other plasma effects. It was consequently decided to adapt the induction accelerator based FEL to heating and controlling the tokamak, and to conduct experiments on the associated physics. To this end, the Alcator C tokamak was moved from the Massachusetts Institute of Technology (MIT) to the Lawrence Livermore National Laboratory where it was installed in Building 431 and operated from March, 1989, until the conclusion of the experiment in October, 1992. The FEL, based on the ETA-11 accelerator and IMP wiggler was brought into operation by the LLNL Electron Beam Group and power injected into the tokamak during an experimental run in the Fall, 1989. Following an upgrade by the MTX group, a second experimental run was made lasting from the Winter, 1992 through the end of the experiment. Significant contributions to the ECRH experiments were made by the Japan Atomic Energy Research Institute (JAERI).

Hooper, E.B. [ed.; Allen, S.L.; Brown, M.D.; Byers, J.A.; Casper, T.A.; Cohen, B.I.; Cohen, R.H.; Fenstermacher, M.E.; Foote, J.H.; Hoshino, K. [and others

1994-01-01T23:59:59.000Z

326

NIST Laser Applications Group Homepage  

Science Conference Proceedings (OSTI)

Laser Applications Group. Welcome. The Laser Applications Group advances laser technology for applications in optical ...

2012-05-10T23:59:59.000Z

327

Environmental and industrial applications of pulsed power systems  

SciTech Connect

The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers (FEL`s), and Inertial Confinement Fusion (ICF) drivers from the early 60`s through the late 80`s is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Some of these processes will require very high average beam power levels of hundreds of kilowatts to perhaps megawatts. In this paper we briefly discuss new technology capabilities and then concentrate on specific application areas that may benefit from the high specific energies and high average powers attainable with short-pulse machines.

Neau, E.L.

1993-10-01T23:59:59.000Z

328

Metalworking Lasers  

Science Conference Proceedings (OSTI)

...Several models of metalworking lasers of both domestic and foreign manufacture are commercially available. The majority of these are of either the neodymium yttrium-aluminum garnet (Nd:YAG) solid-state type or the carbon dioxide (CO 2 ) gas type. These lasers may have pulsed or...

329

Observing Structure and Motion in Molecules with Ultrafast Strong Field and Short Wavelength Laser Radiation  

SciTech Connect

The term "molecular movie" has come to describe efforts to track and record Angstrom-scale coherent atomic and electronic motion in a molecule. The relevant time scales for this range cover several orders of magnitude, from sub-femtosecond motion associated with electron-electron correlations, to 100-fs internal vibrations, to multi-picosecond motion associated with the dispersion and quantum revivals of molecular reorientation. Conventional methods of cinematography do not work well in this ultrafast and ultrasmall regime, but stroboscopic "pump and probe" techniques can reveal this motion with high fidelity. This talk will describe some of the methods and recent progress in exciting and controlling this motion, using both laboratory lasers and the SLAC Linac Coherent Light Source x-ray free electron laser, and will further try to relate the date to the goal of molecular movies.

Bucksbaum, Philip H

2011-04-13T23:59:59.000Z

330

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

331

Argonne Accelerator Institute  

NLE Websites -- All DOE Office Websites (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,

332

A Novel Approach for Automatic Control of Piezoelectric Elements Used for Lorentz Force Detuning Compensation  

E-Print Network (OSTI)

Abstract: Linear accelerators such as Free Electron Lasers (FELs) use superconducting (SC) resonant cavities to accelerate electron beam to high energies. TESLA type resonators are extremely sensitive to detuning induced by mechanical deformations – Lorentz force detuning (LFD), mainly due to the extremely high quality factor (Q) of the 1.3 GHz resonance mode, in the range of 1e6. The resulting modulation of a resonance frequency of the cavity makes power consumption and stability performances of the Low-Latency Radio Frequency (LLRF) control more critical. In order to minimize the RF control efforts and desired stabilities, the fast piezoelectric actuators with digital control systems are commonly used. The paper presents a novel approach for automatic control of piezoelectric actuators used for compensation of Lorentz force detuning, the practical application and carried out tests in accelerating module ACC6 in Free-Electron Laser in Hamburg (FLASH).

Przygoda, K; Napieralski, A; Grecki, M

2010-01-01T23:59:59.000Z

333

Laser Beams  

E-Print Network (OSTI)

• Community needs to work together to provide the technical case for funding an IFE program. • IFE program should nurture competition, with judgments made on the basis of technical progress and the potential of the various approaches to IFE. • Direct-drive with lasers looks very attractive for IFE, the physics and needed technologies are mature and advancing. • KrF provides physics advantages for direct drive. • KrF’s demonstrated performance is competitive with solid state lasers as a high-rep-rate durable, efficient IFE driver. (on several important parameters KrF technology leads) Direct Laser Drive is a better choice for Energy

Steve Obenschain

2010-01-01T23:59:59.000Z

334

Gas laser  

SciTech Connect

According to the invention, the gas laser comprises a housing which accommodates two electrodes. One of the electrodes is sectional and has a ballast resistor connected to each section. One of the electrodes is so secured in the housing that it is possible to vary the spacing between the electrodes in the direction of the flow of a gas mixture passed through an active zone between the electrodes where the laser effect is produced. The invention provides for a maximum efficiency of the laser under different operating conditions.

Kosyrev, F. K.; Leonov, A. P.; Pekh, A. K.; Timofeev, V. A.

1980-08-12T23:59:59.000Z

335

Laser barometer  

DOE Patents (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

336

Scientific Needs for Future X-ray Sources in the U.S. -- A White Paper  

E-Print Network (OSTI)

scientific user program at LCLS, the first x-ray laser, toERL SPring-8 Ring ELETTRA LCLS II & III Ring Upgrade SDL SRFERMI FEL ALS Ring Ring FEL LCLS SPARC Upgrade SSRF FEL PAL-

Falcone, Roger

2008-01-01T23:59:59.000Z

337

Single Particle Difraction at FLASH  

SciTech Connect

Single-pulse coherent diffraction patterns have been collected from randomly injected single particles with a soft X-ray free-electron laser (FEL). The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of the object before that object turns into a plasma and explodes. A diffraction pattern of a single particle will only be recorded when the particle arrival into the FEL interaction region coincides with FEL pulse arrival and detector integration. The properties of the experimental apparatus coinciding with these three events set the data acquisition rate. For our single particle FLASH diffraction imaging experiments: (1) an aerodynamic lens stack prepared a particle beam that consisted of particles moving at 150-200 m/s positioned randomly in space and time, (2) the 10 fs long FEL pulses were delivered at a fixed rate, and (3) the detector was set to integrate and readout once every two seconds. The effect of these experimental parameters on the rate of data acquisition using randomly injected particles will be discussed. Overall, the ultrashort FEL pulses do not set the limit of the data acquisition, more important is the effective interaction time of the particle crossing the FEL focus, the pulse sequence structure and the detector readout rate. Example diffraction patterns of randomly injected ellipsoidal iron oxide nanoparticles in different orientations are presented. This is the first single particle diffraction data set of identical particles in different orientations collected on a shot-to-shot basis. This data set will be used to test algorithms for recovering 3D structure from single particle diffraction.

Bogan, M.; Boutet, S.; Starodub, Dmitri; Decorwin-Martin, Philippe; /SLAC; Chapman, H.; Bajt, S.; Schulz, J.; /DESY; Hajdu, Janos; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; /Uppsala U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry; Frank, Matthias; Hau-Riege, Stefan P.; Woods, Bruce; /LLNL, Livermore; Rohner, Urs; /Tofwerk AG, Thun

2010-06-11T23:59:59.000Z

338

Laser-Induced Damage of Calcium Fluoride  

Science Conference Proceedings (OSTI)

Radiation damage of materials has long been of fundamental interest, especially since the growth of laser technology. One such source of damage comes from UV laser light. Laser systems continue to move into shorter wavelength ranges, but unfortunately are limited by the damage threshold of their optical components. For example, semiconductor lithography is making its way into the 157nm range and requires a material that can not only transmit this light (air cannot), but also withstand the highly energetic photons present at this shorter wavelength. CaF2, an alkaline earth halide, is the chosen material for vacuum UV 157 nm excimer radiation. It can transmit light down to 120 nm and is relatively inexpensive. Although it is readily available through natural and synthetic sources, it is often times difficult to find in high purity. Impurities in the crystal can result in occupied states in the band gap that induce photon absorption [2] and ultimately lead to the degradation of the material. In order to predict how well CaF2 will perform under irradiation of short wavelength laser light, one must understand the mechanisms for laser-induced damage. Laser damage is often a two-step process: initial photons create new defects in the lattice and subsequent photons excite these defects. When laser light is incident on a solid surface there is an initial production of electron-hole (e-h) pairs, a heating of free electrons and a generation of local heating around optically absorbing centers [3]. Once this initial excitation converts to the driving energy for nuclear motion, the result is an ejection of atoms, ions and molecules from the surface, known as desorption or ablation [3]. Secondary processes further driving desorption are photoabsorption, successive excitations of self-trapped excitons (STE's) and defects, and ionization of neutrals by incident laser light [3]. The combination of laser-induced desorption and the alterations to the electronic and geometrical structure of the lattice result in defect formation. In the material CaF2 some of these defects take the form of F-centers, an electron trapped at a halogen vacancy [4], and H-centers, a F2- molecular ion at a single lattice site [5]. While the F-centers are stable, the H-centers are transient but can form into aggregates that are stable. There are many different configurations the defects can take based on the relative position of F and H centers in the lattice and this is extensively discussed in literature [1,4,5]. Once these defects have formed they cause further absorption of light, which ultimately induces particle emission and the production of even more defects. Various forms of laser-induced damage of CaF2 have been studied. For example, the mechanism for photon-stimulated desorption (PSD) of F+ from CaF2 (111) is discussed in ref. 6 and the energy threshold, distribution and kinetics governing electron-stimulated desorption (ESD) is investigated in ref. 7. The desorption of neutral Ca and F atoms has also been explored [1]. In this paper I focus on the emission of ions and neutrals from CaF2 under the irradiation of pulsed laser light at 266 nm, in addition to a brief study of its purity and transmittance.

Espana, Aubrey L.; Joly, Alan G.; Hess, Wayne P.; Dickinson, J T.

2004-12-01T23:59:59.000Z

339

A Simple, Low Cost Longitudinal Phase Space Diagnostic  

Science Conference Proceedings (OSTI)

For proper operation of the LCLS [1] x-ray free-electron laser (FEL), and other similar machines, measurement and control of the electron bunch longitudinal phase space is critical. The LCLS accelerator includes two bunch compressor chicanes to magnify the peak current. These magnetic chicanes can generate significant coherent synchrotron radiation (CSR), which can distort the phase space distribution. We propose a diagnostic scheme by exciting a weak skew quadrupole at an energy-chirped, high dispersion point in the first LCLS bunch compressor (BC1) to reconstruct longitudinal phase space on an OTR screen after BC1, allowing a time-resolved characterization of CSR effects.

Bertsche, Kirk; Emma, Paul; /SLAC; Shevchenko, Oleg; /Novosibirsk, IYF

2009-05-15T23:59:59.000Z

340

The CEBAF e{sup +} Footprint  

Science Conference Proceedings (OSTI)

The Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Laboratory (JLAB) is capable of accelerating e{sup -} to 6 GeV in energy. Presently CEBAF is being upgraded to a maximum energy of 12 GeV. In addition to e{sup -} scattering, the user community has expressed interest in performing e{sup +} scattering experiments with the upgraded CEBAF accelerator. This paper describes the existing and planned CEBAF accelerator complex, possible e{sup +} production locations and the expected e{sup +} beam qualities. Possibilities for production of e{sup +} at the JLAB free electron laser (FEL) is also briefly described.

Freyberger, Arne P. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA. 23606 (United States)

2009-09-02T23:59:59.000Z

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

SRF photoinjector for proof-of-principle experiment of coherent electron cooling at RHIC  

SciTech Connect

Coherent Electron Cooling (CEC) based on Free Electron Laser (FEL) amplifier promises to be a very good way to cool protons and ions at high energies. A proof of principle experiment to demonstrate cooling at 40 GeV/u is under construction at BNL. One of possible sources to provide sufficient quality electron beam for this experiment is a SRF photoinjector. In this paper we discuss design and simulated performance of the photoinjector based on existing 112 MHz SRF gun and newly designed single-cavity SRF linac operating at 704 MHz.

Kayran D.; Belomestnykh, S.; Ben-Zvi, I.; Brutus, J.C.; et al

2012-05-20T23:59:59.000Z

342

laser_measurements  

Science Conference Proceedings (OSTI)

Dimensional Measurements. Laser Measurements. Rate our Services. Technical ... Laser Frequency/Wavelength (14510S-14511S). The ...

2013-04-09T23:59:59.000Z

343

Lasers and Optoelectronic Components Used with Lasers  

Science Conference Proceedings (OSTI)

... example, beam profile and relative intensity noise ... for the laser wavelengths and energies for which ... The laser power and energy measurements are ...

2013-06-28T23:59:59.000Z

344

Laser Beam Delivery [Laser Applications Laboratory] - Nuclear...  

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

Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities...

345

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

SciTech Connect

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

346

EA-1534: Final Environmental Assessment | Department of Energy  

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

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

347

EA-1426: Final Environmental Assessment | Department of Energy  

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

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

348

EA-1426: Final Environmental Assessment | Department of Energy  

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

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

349

Ultrasfast Dynamics in Dense Hydrogen Explored at Flash  

DOE Green Energy (OSTI)

The short pulse duration and high intensity of the FLASH (Free-electron LASer in Hamburg) allows us to generate and probe homogeneous warm dense non-equilibrium hydrogen within a single extreme ultraviolet (EUV) light pulse. By analyzing the spectrum of the 13.5 nm Thomson scattered light we determine the plasma temperature and density. We find that classical models of this interaction are in good agreement with our dense plasma conditions. In a FEL-pump FEL-probe experiment droplets of liquid hydrogen and their scattering behavior for different pump-probe setups were observed under 20{sup o} and 90{sup o}. We find that the scattering behavior of the scattered intensity depends on the scattering angle.

Hilbert, V; Zastrau, U; Neumayer, P; Hochhaus, D; Toleikis, S; Harmand, M; Przystawik, A; Tschentscher, T; Glenzer, S H; Doeppner, T; Fortmann, C; White, T; Gregori, G; Gode, S; Tiggesbaumker, J; Skruszewicz, S; Meiwes-Broer, K H; Sperling, P; Redmer, R; Forster, E

2011-08-01T23:59:59.000Z

350

Laser barometer  

DOE Patents (OSTI)

A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

Abercrombie, Kevin R. (Westminster, CO); Shiels, David (Thornton, CO); Rash, Tim (Aurora, CO)

2001-02-06T23:59:59.000Z

351

Laser wavelength effects in ultrafast near-field laser nanostructuring...  

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

Laser wavelength effects in ultrafast near-field laser nanostructuring of Si Title Laser wavelength effects in ultrafast near-field laser nanostructuring of Si Publication Type...

352

EA-1655: Berkeley Lab Laser Accelerator (BELLA) Laser Acquisition...  

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

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

353

Heterodyne laser diagnostic system  

DOE Patents (OSTI)

The heterodyne laser diagnostic system includes, in one embodiment, an average power pulsed laser optical spectrum analyzer for determining the average power of the pulsed laser. In another embodiment, the system includes a pulsed laser instantaneous optical frequency measurement for determining the instantaneous optical frequency of the pulsed laser.

Globig, Michael A. (Antioch, CA); Johnson, Michael A. (Pleasanton, CA); Wyeth, Richard W. (Livermore, CA)

1990-01-01T23:59:59.000Z

354

Microwave Tokamak Experiment: An overview of the construction and checkout phase  

SciTech Connect

At Lawrence Livermore National Laboratory (LLNL) we constructed and presently operate the Microwave Tokamak Experiment (MTX) to demonstrate the feasibility of using microwave pulses produced from a free electron laser (FEL) to provide electron cyclotron heating (ECH) for use in tokamaks, particularly high-field machines. The MTX consists primarily of the ALCATOR C tokamak and power supplies that were documented and disassembled at the Massachusetts Institute of Technology (MIT) and shipped to LLNL in April 1987. We made many additions, including a new primary power system from the magnetic Fusion Test Facility (MFTF) substation, a new commutation system, substantially upgraded seismic support system for earthquake loading, a fast controls system for use with the FEL, a new data-acquisition system, and a new vault facility. We checked out these systems and put them into operation in October 1988; we achieved the first plasma in November 1988. We have also constructed and installed the microwave transmission system and the local microwave system to be used with the FEL. These systems transmit the microwaves to MTX quasi-optically through an evacuated tube. The ongoing plasma operations, both with and without FEL heating, are described in a companion paper. 12 refs., 2 figs., 2 tabs.

Lang, L.L.; Bell, H.H.

1989-09-28T23:59:59.000Z

355

Environment/Health/Safety (EHS): Laser Safety  

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

Laser Safety Home Whom to Call Analysis of Laser Safety Occurrences: 2005-2011 Laser Bio-effects Laser Classification Laser Disposal Guide Laser Forms Laser Newsletter Laser Lab...

356

How do lasers work?  

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

all the way through college physics. Let me try anyway, but first let's define what a laser and laser light are. Laser is an acronym for Light Amplification by Stimulated...

357

Femtosecond Laser Frequency Combs  

Science Conference Proceedings (OSTI)

... to all of these is the continued development of the lasers themselves. We are exploring and comparing different types of fs-laser comb technology ...

358

Physics Out Loud - Laser  

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

Previous Video (Hybrid Meson) Physics Out Loud Main Index Next Video (Matter) Matter Laser Learn all about different types of lasers with Jefferson Lab's Michelle Shinn, a...

359

Laser Music System.  

E-Print Network (OSTI)

?? A Laser Music System has been created, that combines a laser and light sensor system with an infrared distance sensing system that detects the… (more)

Woodruff, Astra

2012-01-01T23:59:59.000Z

360

Laser Propulsion - Quo Vadis  

SciTech Connect

First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community.

Bohn, Willy L. [Institute of Technical Physics, German Aerospace Center (DLR) D-70569 Pfaffenwaldring 38-40, Stuttgart (Germany)

2008-04-28T23:59:59.000Z

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.


361

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

362

Narrow gap laser welding  

SciTech Connect

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

363

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

364

Longitudinal discharge laser baffles  

DOE Patents (OSTI)

The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

1994-01-01T23:59:59.000Z

365

Longitudinal discharge laser baffles  

DOE Patents (OSTI)

The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam. 1 fig.

Warner, B.E.; Ault, E.R.

1994-06-07T23:59:59.000Z

366

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

NLE Websites -- All DOE Office Websites (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

367

Laser Welding of Metals [Laser Applications Laboratory] - Nuclear  

NLE Websites -- All DOE Office Websites (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

368

Laser Guiding for GeV Laser-Plasma Accelerators  

E-Print Network (OSTI)

Light pipe for high intensity laser pulses. Phys. Rev. Lett.and relativistically strong laser pulses in an underdensefrom Thomson scat- tering using laser wake?eld accelerators.

Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

2005-01-01T23:59:59.000Z

369

Nonlinear laser energy depletion in laser-plasma accelerators  

E-Print Network (OSTI)

Nonlinear laser energydepletion in laser-plasma accelerators ? B. A. Shadwick,of intense, short-pulse lasers via excitation of plasma

Shadwick, B.A.

2009-01-01T23:59:59.000Z

370

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  

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

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

371

SciTech Connect: "smart grid"  

Office of Scientific and Technical Information (OSTI)

Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser...

372

LANL | Physics | Trident Laser Facility  

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

science at Trident Laser Facility Several important discoveries and first observations have been made at the Trident Laser Facility, a unique three-beam neodymium-glass laser...

373

Feasibility Study on Laser Microwelding and Laser Shock Peening using Femtosecond Laser Pulses.  

E-Print Network (OSTI)

??Ultrafast lasers of sub-picosecond pulse duration have thus far been investigated for ablation, drilling and cutting processes. Ultrafast lasers also have the potential for laser… (more)

Lee, Dongkyun

2008-01-01T23:59:59.000Z

374

BNL | CO2 Laser  

NLE Websites -- All DOE Office Websites (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

375

Infrared laser system  

DOE Patents (OSTI)

An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

Cantrell, Cyrus D. (Santa Fe, NM); Carbone, Robert J. (Los Alamos, NM); Cooper, Ralph S. (Los Alamos, NM)

1977-01-01T23:59:59.000Z

376

Infrared laser system  

DOE Patents (OSTI)

An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

Cantrell, Cyrus D. (Richardson, TX); Carbone, Robert J. (Johnson City, TN); Cooper, Ralph (Hayward, CA)

1982-01-01T23:59:59.000Z

377

Laser Drilling with Gated High Power Fiber Lasers  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2010. Symposium, Laser Applications in Materials Processing. Presentation Title, Laser Drilling ...

378

Laser Wakefield Acceleration Experiments Using HERCULES Laser  

Science Conference Proceedings (OSTI)

Laser wakefield acceleration (LWFA) in a supersonic gas-jet using a self-guided laser pulse was studied by changing laser power and plasma electron density. The recently upgraded HERCULES laser facility equipped with wavefront correction enables a peak intensity of 6.1x10{sup 19} W/cm{sup 2} at laser power of 80 TW to be delivered to the gas-jet using F/10 focusing optics. We found that electron beam charge was increased significantly with an increase of laser power from 30 TW to 80 TW and showed density threshold behavior at a fixed laser power. We also studied the influence of laser focusing conditions by changing the f-number of the optics to F/15 and found an increase in density threshold for electron production compared to the F/10 configuration. The analysis of different phenomena such as betatron motion of electrons, side scattering of the laser pulse for different focusing conditions, the influence of plasma density down ramp on LWFA are shown.

Matsuoka, T.; McGuffey, C.; Dollar, F.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K. [Center for Ultrafast Optical Science and FOCUS Center, University of Michigan, Ann Arbor, MI 48109 (United States); Horovitz, Y. [Center for Ultrafast Optical Science and FOCUS Center, University of Michigan, Ann Arbor, MI 48109 (United States); Dynamical Experiments Group, Propulsion Division, Soreq NRC, Yavnee 81800 (Israel)

2009-07-25T23:59:59.000Z

379

Ultra-Short Electron Bunch and X-Ray Temporal Diagnostics with an X-Band Transverse Deflector  

Science Conference Proceedings (OSTI)

The measurement of ultra-short electron bunches on the femtosecond time scale constitutes a very challenging problem. In X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS), generation of sub-ten femtosecond X-ray pulses is possible, and some efforts have been put into both ultra-short electron and X-ray beam diagnostics. Here we propose a single-shot method using a transverse rf deflector (X-band) after the undulator to reconstruct both the electron bunch and X-ray temporal profiles. Simulation studies show that about 1 fs (rms) time resolution may be achievable in the LCLS and is applicable to a wide range of FEL wavelengths and pulse lengths. The jitter, resolution and other related issues will be discussed. The successful operation of the Linac Coherent Light Source (LCLS), with its capability of generating free-electron laser (FEL) X-ray pulses from a few femtoseconds (fs) up to a few hundred fs, opens up vast opportunities for studying atoms and molecules on this unprecedented ultrashort time scale. However, tremendous challenges remain in the measurement and control of these ultrashort pulses with femtosecond precision, for both the electron beam (e-beam) and the X-ray pulses. For ultrashort e-beam bunch length measurements, a standard method has been established at LCLS using an S-band radio-frequency (rf) deflector, which works like a streak camera for electrons and is capable of resolving bunch lengths as short as {approx} 10 fs rms. However, the e-beam with low charges of 20 pC at LCLS, which is expected to be less than 10 fs in duration, is too short to be measured using this transverse deflector. The measurement of the electron bunch length is helpful in estimating the FEL X-ray pulse duration. However, for a realistic beam, such as that with a Gaussian shape or even a spiky profile, the FEL amplification varies along the bunch due to peak current or emittance variation. This will cause differences between the temporal shape or duration of the electron bunch and the X-ray pulse. Initial experiments at LCLS have revealed that characterization of the X-ray pulse duration on a shot-by-shot basis is critical for the interpretation of the data. However, a reliable x-ray pulse temporal diagnostic tool is not available so far at the LCLS. We propose a novel method in this paper to characterize the FEL X-ray pulse duration and shape. A transverse rf deflector is used in conjunction with an e-beam energy spectrometer, located after the FEL undulator. By measuring the difference in the e-beam longitudinal phase space between FEL-on and FEL-off, we can obtain the time-resolved energy loss and energy spread induced from the FEL radiation, allowing the FEL X-ray temporal shape to be reconstructed.

Ding, Y.; Emma, P.; Frisch, J.; Huang, Z.; Loos, H.; Krejcik, P.; Wang, M-H.; /SLAC; Behrens, C.; /DESY

2011-12-13T23:59:59.000Z

380

NIST Laser Applications Staff Directory  

Science Conference Proceedings (OSTI)

Laser Applications Staff Directory. Staff. Name, Position, Office Phone. ... Contact. Laser Applications Group Keith Lykke, Group Leader. ...

2012-11-26T23:59:59.000Z

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.


381

General Laser Measurements  

Science Conference Proceedings (OSTI)

General Measurements for Laser Meters. ... 90 to 0 dBm. 0 to 30 dBm. AO 2005, Igor Vayshenker. Laser Dose, 193 nm, SP250-56, David Livigni. ...

2012-11-28T23:59:59.000Z

382

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

383

Laser programs highlights 1993  

SciTech Connect

Over the last two decades, the scope of our laser research has grown immensely. The small, low-power laser systems of our early days have given way to laser systems of record-breaking size and power. Now we are focusing our activities within the target physics and laser science programs to support the ignition and gain goals of the proposed glass-laser National Ignition Facility. In our laser isotope separation work, we completed the most important set of experiments in the history of the AVLIS Program in 1993, which culminated in a spectacularly successful run that met or exceeded all our objectives. We are also developing lasers and laser-related technologies for a variety of energy, commercial, and defense uses. On the horizon are transfers of important technologies for waste treatment, x-ray lithography, communications and security, optical imaging, and remote sensing, among others.

NONE

1995-06-01T23:59:59.000Z

384

Laser induced chemical reactions  

E-Print Network (OSTI)

of Basic Energy Sciences, Chemical Sciences Division of theINFRARED LASER ENHANCEMENT OF CHEMICAL REACTIONS A. B. C. D.Laser Inhibition of Chemical Reaction Effect of Isotopic

Orel, Ann E.

2010-01-01T23:59:59.000Z

385

Atmospheric Laser Communication  

Science Conference Proceedings (OSTI)

Atmospheric laser communication, often referred to as free-space optics (FSO) or free-space laser (FSL) communication, is similar to fiber optic cable in terms of carrier wavelength and bandwidth capability, but data are transmitted directly ...

Kenneth W. Fischer*Michael R. Witiw; Jeffrey A. Baars+; T. R. Oke

2004-05-01T23:59:59.000Z

386

Laser Safety Communiques  

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

Argonne National Laboratory, July 17-19, 2007 Registration Form Workshop Agenda DOE Laser Safety Memo and Final Report, February 28, 2005 APS Laser OJT ANL CHM OJT Example...

387

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

388

Direct nuclear pumped laser  

DOE Patents (OSTI)

There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

Miley, George H. (Champagne, IL); Wells, William E. (Urbana, IL); DeYoung, Russell J. (Hampton, VA)

1978-01-01T23:59:59.000Z

389

Laser Heat Treatment [Laser Applications Laboratory] - Nuclear Engineering  

NLE Websites -- All DOE Office Websites (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

390

Laser Technology and Applications  

Science Conference Proceedings (OSTI)

... Major advances have been made in some areas: ? Specimen preparation using FIB ? Data collection rate ? Laser-assisted field evaporation ...

2013-04-03T23:59:59.000Z

391

Laser Measurements Seminar  

Science Conference Proceedings (OSTI)

Laser Measurements Seminar. June 16, 2005. *. Bookmark and Share. Contact: Michael Baum 301-975-2763. The 20th annual ...

2013-04-23T23:59:59.000Z

392

YAG Laser Weld  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2010. Symposium, Laser Applications in Materials Processing. Presentation Title, The Effects of ...

393

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

SciTech Connect

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

394

LaserFest Celebration  

SciTech Connect

LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

Dr. Alan Chodos; Elizabeth A. Rogan

2011-08-25T23:59:59.000Z

395

ORION laser target diagnostics  

SciTech Connect

The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K. [Plasma Physics Department, Atomic Weapons Establishment, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); and others

2012-10-15T23:59:59.000Z

396

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

397

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

NLE Websites -- All DOE Office Websites (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

398

Effects of e-beam parameters on coherent electron cooling  

Science Conference Proceedings (OSTI)

Coherent Electron Cooling (CeC) requires detailed control of the phase between the hadron an the FEL-amplified wave packet. This phase depends on local electron beam parameters such as the energy spread and the peak current. In this paper, we examine the effects of local density variations on the cooling rates for CeC. Coherent Electron Cooling (CeC) [1] is a new concept in intense, high energy hadron beamcooling, in which the Debye screened charge perturbation calculated in [2] is used to seed a high-gain free electron laser (FEL). Using delays to give the perturbing hadron an energy-dependent longitudinal displacement relative to its frequencymodulated charge perturbation, the hadron receives an energy-dependent kick which reduces its energy variation from the design energy. The equations of motion in [1] assume that the electron bunch is the same physical size as the hadron bunch, and has a homogeneous charge density across the entire bunch. In practice, the electron bunches will be much shorter than the hadron bunch, and this local spacial inhomogeneity in the charge distribution will alter the gain length of the FEL, resulting in both a change in the amplification of the initial signal and a phase shift. In this paper we consider these inhomogeneity effects, determining cooling equations for bunched beam CeC consistent with these effects and determining thresholds for the cooling parameters.

Webb, S.D.; Litvinenko, V.N.; Wang, G.

2011-03-28T23:59:59.000Z

399

Breaking the Attosecond, Angstrom and TV/M Field Barriers with Ultra-Fast Electron Beams  

Science Conference Proceedings (OSTI)

Recent initiatives at UCLA concerning ultra-short, GeV electron beam generation have been aimed at achieving sub-fs pulses capable of driving X-ray free-electron lasers (FELs) in single-spike mode. This use of very low Q beams may allow existing FEL injectors to produce few-100 attosecond pulses, with very high brightness. Towards this end, recent experiments at the LCLS have produced {approx}2 fs, 20 pC electron pulses. We discuss here extensions of this work, in which we seek to exploit the beam brightness in FELs, in tandem with new developments in cryogenic undulator technology, to create compact accelerator-undulator systems that can lase below 0.15 {angstrom}, or be used to permit 1.5 {angstrom} operation at 4.5 GeV. In addition, we are now developing experiments which use the present LCLS fs pulses to excite plasma wakefields exceeding 1 TV/m, permitting a table-top TeV accelerator for frontier high energy physics applications.

Rosenzweig, James; Andonian, Gerard; Fukasawa, Atsushi; Hemsing, Erik; Marcus, Gabriel; Marinelli, Agostino; Musumeci, Pietro; O'Shea, Brendan; O'Shea, Finn; Pellegrini, Claudio; Schiller, David; Travish, Gil; /UCLA; Bucksbaum, Philip; Hogan, Mark; Krejcik, Patrick; /SLAC; Ferrario, Massimo; /INFN, Rome; Full, Steven; /Penn State U.; Muggli, Patric; /Southern California U.

2012-06-22T23:59:59.000Z

400

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

Science Conference Proceedings (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

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

DOE-Funded Research Projects Win 39 R&D Awards for 2010 | Department...  

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

X-ray free electron laser energy monitor non-intrusively measures the energy of ultrahigh intensity X-ray pulses produced by revolutionary X-ray free electron lasers. Grating...

402

Synthetic laser medium  

DOE Patents (OSTI)

A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

Stokowski, S.E.

1987-10-20T23:59:59.000Z

403

Electron acceleration & laser pulse compression using a laser...  

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

acceleration & laser pulse compression using a laser-plasma accelerator Wednesday, August 14, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Andreas Walker, Oxford...

404

LCLS Injector Drive Laser  

SciTech Connect

Requirements for the LCLS injector drive laser present significant challenges to the design of the system. While progress has been demonstrated in spatial shape, temporal shape, UV generation and rep-rate, a laser that meets all of the LCLS specifications simultaneously has yet to be demonstrated. These challenges are compounded by the stability and reliability requirements. The drive laser and transport system has been installed and tested. We will report on the current operational state of the laser and plans for future improvements.

Dowell, D.H.; Castro, J.; Emma, P.; Frisch, J.; Gilevich, A.; Hays, G.; Hering, P.; Limborg-Deprey, C.; Loos, H.; Miahnahri, A.; White, W.; /SLAC

2007-11-02T23:59:59.000Z

405

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.

Jassby, Daniel L. (Princeton, NJ)

1988-01-01T23:59:59.000Z

406

Robot Assisted Laser Osteotomy.  

E-Print Network (OSTI)

??In the scope of this thesis world's first robot system was developed, which facilitates osteotomy using laser in arbitrary geometries with an overall accuracy below… (more)

Burgner, Jessica

2010-01-01T23:59:59.000Z

407

Laser Induced Spectroscopy  

INL’s Laser Induced Spectroscopy technology detects and measures the composition of a material or the molecules in the material. It traces the ...

408

NIST Laser Safety Program  

Science Conference Proceedings (OSTI)

... powered down. 5. Close coolant valves, if chilled water is used; visually check for leaks. 6. Turn off the laser warning light.

2011-09-06T23:59:59.000Z

409

BNL | Nd:YAG Laser  

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

Nd:YAG Laser The Nd:YAG laser is located in a class 1000 clean room (the YAG Room) near the electron gun end of the ATF accelerator. The clean area also includes a separate laser...

410

BNL | CFN Laser System Qualifications  

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

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

411

Laser Program annual report 1987  

SciTech Connect

This report discusses the following topics: target design and experiments; target materials development; laboratory x-ray lasers; laser science and technology; high-average-power solid state lasers; and ICF applications studies.

O'Neal, E.M.; Murphy, P.W.; Canada, J.A.; Kirvel, R.D.; Peck, T.; Price, M.E.; Prono, J.K.; Reid, S.G.; Wallerstein, L.; Wright, T.W. (eds.)

1989-07-01T23:59:59.000Z

412

Energy Spread Reduction of Electron Beams Produced via Laser Wake  

Science Conference Proceedings (OSTI)

Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 10{sup 18} cm{sup -3} in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a limited, defined region. Using this technique a 460 MeV electron beam was produced with an energy spread of 5%. This technique is directly scalable to multi-GeV electron beam generation with sub-percent energy spreads.

Pollock, B

2012-03-19T23:59:59.000Z

413

Laser Power and Energy Calibrations  

Science Conference Proceedings (OSTI)

... calibration services for meters used with the lasers, wavelengths, and power ranges shown in the following table. Other laser wavelengths, power ...

2012-11-28T23:59:59.000Z

414

Laser Ablation: Fundamentals and Applications  

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

90 This seminar will include both experimental and theoretical topics of ultrafast laser ablation. In the first part, fundamental physics of ultrafast laser-material...

415

Laser ultrasonics on moving paper  

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

Laser ultrasonics on moving paper Title Laser ultrasonics on moving paper Publication Type Journal Article LBNL Report Number LBNL-43615 Year of Publication 1999 Authors Ridgway,...

416

Coaxial short pulsed laser  

DOE Patents (OSTI)

This invention relates to a laser system of rugged design suitable for use in a field environment. The laser itself is of coaxial design with a solid potting material filling the space between components. A reservoir is employed to provide a gas lasing medium between an electrode pair, each of which is connected to one of the coaxial conductors. (auth)

Nelson, M.A.; Davies, T.J.

1975-08-01T23:59:59.000Z

417

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

418

Dye laser amplifier  

DOE Patents (OSTI)

An improved dye laser amplifier is disclosed. The efficiency of the dye laser 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. 3 figs.

Moses, E.I.

1992-12-01T23:59:59.000Z

419

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 11 figures.

Warner, B.E.; Duncan, D.B.

1993-12-28T23:59:59.000Z

420

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

1994-01-01T23:59:59.000Z

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.


421

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus is described. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 7 figures.

Warner, B.E.; Duncan, D.B.

1994-02-15T23:59:59.000Z

422

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

1993-01-01T23:59:59.000Z

423

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

424

Much Ado about Microbunching: Coherent Bunching in High Brightness Electron Beams  

Science Conference Proceedings (OSTI)

The push to provide ever brighter coherent radiation sources has led to the creation of correspondingly bright electron beams. With billions of electrons packed into normalized emittances (phase space) below one micron, collective effects may dominate both the preservation and use of such ultra-bright beams. An important class of collective effects is due to density modulations within the bunch, or microbunching. Microbunching may be deleterious, as in the case of the Microbunching Instability (MBI), or it may drive radiation sources of unprecedented intensity, as in the case of Free Electron Lasers (FELs). In this work we begin by describing models of microbunching due to inherent beam shot noise, which sparks both the MBI as well as SLAC's Linac Coherent Light Source, the world's first hard X-ray laser. We first use this model to propose a mechanism for reducing the inherent beam shot noise as well as for predicting MBI effects. We then describe experimental measurements of the resulting microbunching at LCLS, including optical radiation from the MBI, as well as the first gain length and harmonic measurements from a hard X-ray FEL. In the final chapters, we describe schemes that use external laser modulations to microbunch light sources of the future. In these sections we describe coherent light source schemes for both both linacs and storage rings.

Ratner, Daniel; /Stanford U. /SLAC

2012-05-25T23:59:59.000Z

425

Laser controlled flame stabilization  

DOE Patents (OSTI)

A method and apparatus is provided for initiating and stabilizing fuel combustion in applications such as gas turbine electrical power generating engines and jet turbine engines where it is desired to burn lean fuel/air mixtures which produce lower amounts of NO.sub.x. A laser induced spark is propagated at a distance from the fuel nozzle with the laser ignitor being remotely located from the high temperature environment of the combustion chamber. A laser initiating spark generated by focusing high peak power laser light to a sufficiently tight laser spot within the fuel to cause the ionization of air and fuel into a plasma is unobtrusive to the flow dynamics of the combustion chamber of a fuel injector, thereby facilitating whatever advantage can be taken of flow dynamics in the design of the fuel injector.

Early, James W. (Los Alamos, NM); Thomas, Matthew E. (Huntsville, AL)

2001-01-01T23:59:59.000Z

426

Guest Editorial: Laser Damage  

SciTech Connect

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

427

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

428

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

2013-03-28T23:59:59.000Z

429

1982 laser program annual report  

Science Conference Proceedings (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

430

Laser Propulsion Standardization Issues  

SciTech Connect

It is a relevant issue in the research on laser propulsion that experimental results are treated seriously and that meaningful scientific comparison is possible between groups using different equipment and measurement techniques. However, critical aspects of experimental measurements are sparsely addressed in the literature. In addition, few studies so far have the benefit of independent confirmation by other laser propulsion groups. In this paper, we recommend several approaches towards standardization of published laser propulsion experiments. Such standards are particularly important for the measurement of laser ablation pulse energy, laser spot area, imparted impulse or thrust, and mass removal during ablation. Related examples are presented from experiences of an actual scientific cooperation between NU and DLR. On the basis of a given standardization, researchers may better understand and contribute their findings more clearly in the future, and compare those findings confidently with those already published in the laser propulsion literature. Relevant ISO standards are analyzed, and revised formats are recommended for application to laser propulsion studies.

Scharring, Stefan; Eckel, Hans-Albert [Institute of Technical Physics, German Aerospace Center (DLR), D-70569 Stuttgart, Pfaffenwaldring 38-40 (Germany); Roeser, Hans-Peter [Institute of Space Systems, University of Stuttgart, D-70569 Stuttgart, Pfaffenwaldring 31 (Germany); Sinko, John E. [Micro-Nano Global Center of Excellence, Nagoya University (Niue), Nagoya, Aichi, 464-8603 (Japan); Sasoh, Akihiro [Department of Aerospace Engineering, Nagoya University, Nagoya, Aichi, 464-8603 (Japan)

2010-10-08T23:59:59.000Z

431

Laser Spark Plug Development  

Science Conference Proceedings (OSTI)

To meet the ignition system needs of large bore high pressure lean burn natural gas engines a laser diode side pumped passively Q-switched laser igniter was designed and tested. The laser was designed to produce the optical intensities needed to initiate ignition in a lean burn high brake mean effective pressure (BMEP) engine. The experimentation explored a variety of optical and electrical input parameters that when combined produced a robust spark in air. The results show peak power levels exceeding 2 MW and peak focal intensities above 400 GW/cm2. Future research avenues and current progress with the initial prototype are presented and discussed.

McIntyre, D.L.; Richardson, S.W.; Woodruff, S.D.; McMillian, M.H.; Guutam, M. (West Virginia Univ., Morgantown, WV)

2007-04-01T23:59:59.000Z

432

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

433

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

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

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

434

Zig Zag Nd Laser - Industrial Partnerships Office  

The Laser Systems Group at LLNL has developed a high energy, high average power solid state laser system capable of performing production rate laser shot peening.

435

Laser Extinction in Laminar Inverse Diffusion Flames  

E-Print Network (OSTI)

Diagnostics, Chapter 9: Laser-Induced Incandescence,Laser Extinction in Laminar Inverse Diffusion Flames WesternFoundation, Arlington, VA Laser Extinction in Laminar

Macko, Kevin; Mikofski, Mark A; Fernandez-Pello, Carlos; Blevins, Linda G; Davis, Ronald W.

2005-01-01T23:59:59.000Z

436

Terahertz radiation from laser accelerated electron bunches  

E-Print Network (OSTI)

NUMBER 5 MAY 2004 Terahertz radiation from laser acceleratedand millimeter wave radiation from laser acceleratedNo. 5, May 2004 Terahertz radiation from laser accelerated

2004-01-01T23:59:59.000Z

437

Laser having improved windows  

SciTech Connect

A discharge tube for a gaseous laser is terminated with windows made of crystalline quartz which do not fluoresce in the presence of high energy, visible and ultraviolet light radiation.

Alves, R.W.; Costich, V.R.

1976-11-23T23:59:59.000Z

438

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

439

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

440

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

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

Cylindrical laser resonator  

DOE Patents (OSTI)

The properties of an improved class of lasers is presented. In one configuration of these lasers the radiation propagates radially within the amplifying medium, resulting in high fields and symmetric illumination at the resonator axis. Thus there is a strong focusing of energy at the axis of the resonator. In a second configuration the radiation propagates back and forth in a tubular region of space.

Casperson, Lee W. (Los Angeles, CA)

1976-02-24T23:59:59.000Z

442

Pulsed gas laser  

DOE Patents (OSTI)

A pulsed gas laser is constituted by Blumlein circuits wherein space metal plates function both as capacitors and transmission lines coupling high frequency oscillations to a gas filled laser tube. The tube itself is formed by spaced metal side walls which function as connections to the electrodes to provide for a high frequency, high voltage discharge in the tube to cause the gas to lase. Also shown is a spark gap switch having structural features permitting a long life.

Anderson, Louis W. (Madison, WI); Fitzsimmons, William A. (Madison, WI)

1978-01-01T23:59:59.000Z

443

Variable laser attenuator  

SciTech Connect

The disclosure relates to low loss, high power variable attenuators comprng 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.

Foltyn, Stephen R. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

444

Laser cooling of solids  

SciTech Connect

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

445

Laser Initiated Actuator study  

SciTech Connect

The program task was to design and study a laser initiated actuator. The design of the actuator is described, it being comprised of the fiber and body subassemblies. The energy source for all experiments was a Spectra Diode 2200-H2 laser diode. The diode is directly coupled to a 100 micron core, 0.3 numerical aperture fiber optic terminated with an SMA connector. The successful testing results are described and recommendations are made.

Watson, B.

1991-06-27T23:59:59.000Z

446

CRC handbook of laser science and technology. Volume 3. Gas lasers  

Science Conference Proceedings (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

447

ANL/APS/TB-32 Test of Horizontal Field Measurements Using Two-Axis Hall  

NLE Websites -- All DOE Office Websites (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

448

Linac Coherent Light SourCe  

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

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

449

VORPAL Simulations Relevant to Coherent Electron Cooling  

SciTech Connect

Coherent electron cooling (CEC)* combines the best features of electron cooling and stochastic cooling, via free-electron laser technology**, to offer the possibility of cooling high-energy hadron beams with order-of-magnitude shorter cooling times. Many technical difficulties must be resolved via full-scale 3D simulations, before the CEC concept can be validated experimentally. VORPAL is the ideal code for simulating the â modulatorâ and â kickerâ regions, where the electron and hadron beams will co-propagate as in a conventional electron cooling section. Unlike previous VORPAL simulations*** of electron cooling physics, where dynamical friction on the ions was the key metric, it is the details of the electron density wake driven by each ion in the modulator section that must be understood, followed by strong amplification in the FEL. We present some initial simulation results. In particular, we compare the semi-analytic binary collision model with electrostatic particle-in-cell (PIC).

Bell, G.I.; Bruhwiler, D.L.; Sobol, A.V.; Ben-Zvi, Ilan; Litvinenko, Vladimir; Derbenev, Yaroslav

2008-07-01T23:59:59.000Z

450

VORPAL simulations relevant to coherent electron cooling  

Science Conference Proceedings (OSTI)

Coherent electron cooling (CEC) [1] combines the best features of electron cooling and stochastic cooling, via free-electron laser technology [2], to offer the possibility of cooling high-energy hadron beams with order-of-magnitude shorter cooling times. Many technical difficulties must be resolved via full-scale 3D simulations, before the CEC concept can be validated experimentally. VORPAL is the ideal code for simulating the modulator and kicker regions, where the electron and hadron beams will co-propagate as in a conventional electron cooling section. Unlike previous VORPAL simulations [3] of electron cooling physics, where dynamical friction on the ions was the key metric, it is the details of the electron density wake driven by each ion in the modulator section that must be understood, followed by strong amplification in the FEL. We present some initial simulation results.

Bell,G.; Bruhwiler, D.; Sobol, A.; Ben-Zvi, I.; Litvinenko, V.; Derbenev, Y.

2008-06-23T23:59:59.000Z

451

Sub-Picosecond X-Ray Pulses Workshop  

NLE Websites -- All DOE Office Websites (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

452

High Power Electrodynamics (HPE): Accelerator Operations and Technology,  

NLE Websites -- All DOE Office Websites (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.

453

A dynamically polarized hydrogen and deuterium target at Jefferson Lab  

DOE Green Energy (OSTI)

Polarized electron beams have been successfully used at Jefferson Lab for over a year. The authors now report the successful achievement of polarized targets for nuclear and particle physics experiments using the dynamic nuclear polarization (DNP)technique. The technique involves initial irradiation of frozen ammonia crystals (NH{sub 3} and ND{sub 3}) using the electron beam from the new Free Electron Laser (FEL) facility at Jefferson Lab, and transferring the crystals to a special target holder for use in Experimental Halls. By subjecting the still ionized and frozen ammonia crystals to a strong magnetic field and suitably tuned RF, the high electron polarization is transmitted to the nucleus thus achieving target polarization. Details of the irradiation facility, the target holder, irradiation times, ionized crystal shelf life, and achieved polarization are discussed.

Boyce, J.R.; Keith, C.; Mitchell, J.; Seely, M.

1998-07-01T23:59:59.000Z

454

High field pulsed microwiggler comprising a conductive tube with periodically space slots  

DOE Patents (OSTI)

A microwiggler assembly produces large magnetic fields for oscillating ched particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180.degree. relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube.

Warren, Roger W. (Santa Fe, NM)

1992-01-01T23:59:59.000Z

455

Automated Operation of the APS LINAC using the Procedure Execution Manager  

E-Print Network (OSTI)

The Advanced Photon Source (APS) linear accelerator has two thermionic cathode rf guns and one photocathode rf gun. The thermionic guns are used primarily for APS operations while the photocathode gun is used as a free-electron laser (FEL) driver. With each gun requiring a different lattice and timing configuration, the need to change quickly between guns puts great demands on the accelerator operators. Using the Procedure Execution Manager (PEM), a software environment for managing automated procedures, we have made start-up and switch-over of the linac systems both easier and more reliable. The PEM is a graphical user interface written in Tcl/Tk that permits the user to invoke "machine procedures" and control their execution. It allows construction of procedures in a hierarchical, parallel fashion, which makes for efficient execution and development. In this paper, we discuss the features and advantages of the PEM environment as well the specifics of our procedures for the APS linac.

Soliday, R; Borland, M

2000-01-01T23:59:59.000Z

456

Testing and Implementation Progress on the Advanced Photon Source (APS) Linear Accelerator (Linac) High-Power S-band Switching System  

E-Print Network (OSTI)

An S-band linear accelerator is the source of particles and the front end of the Advanced Photon Source injector. In addition, it supports a low-energy undulator test line (LEUTL) and drives a free-electron laser (FEL). A waveguide-switching and distribution system is now under construction. The system configuration was revised to be consistent with the recent change to electron-only operation. There are now six modulator-klystron subsystems, two of which are being configured to act as hot spares for two S-band transmitters each, so that no single failure will prevent injector operation. The two subsystems are also used to support additional LEUTL capabilities and off-line testing. Design considerations for the waveguide-switching subsystem, topology selection, control and protection provisions, high-power test results, and current status are described

Grelick, A E; Berg, S; Dohan, D A; Goeppner, G A; Kang, Y W; Nassiri, A; Pasky, S; Pile, G; Smith, T; Stein, S J

2000-01-01T23:59:59.000Z

457

Requirements and Design of a High Stable Infrared Free Electeron Laser at LBL  

E-Print Network (OSTI)

CDRL). CDRL is an integrated user facility for researc h inthird FEL pulses. As a user facility, the lRFEL must befor the operation of a user facility. The procedure for the

Kim, K.-J.

2010-01-01T23:59:59.000Z

458

Laser fusion pulse shape controller  

DOE Patents (OSTI)

An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

Siebert, Larry D. (Ann Arbor, MI)

1977-01-01T23:59:59.000Z

459

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

460

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 semiconducting laser, e.g., GaAlAs and InGaAlP.

Nguyen, Dinh C.; Faulkner, G.E.

1989-08-25T23:59:59.000Z

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.


461

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

462

Production of high power femtosecond terahertz radiation  

SciTech Connect

The terahertz (THz) region of the electromagnetic spectrum is attracting interest for a broad range of applications ranging from diagnosing electron beams to biological imaging. Most sources of short pulse THz radiation utilize excitation of biased semiconductors or electro-optic crystals by high peak power lasers. For example, this was done by using an un-doped InAs wafer irradiated by a femtosecond free-electron laser (FEL) at the Thomas Jefferson National Accelerator Facility. Microwatt levels of THz radiation were detected when excited with FEL pulses at 1.06 mm wavelength and 10W average power. Recently substantially higher powers of femtosecond THz pulses produced by synchrotron emission were extracted from the electron beamline. Calculations and measurements confirm the production of coherent broadband THz radiation from relativistic electrons with an average power of nearly 20W, a world record in this wavelength range by a factor of 10,000. We describe the source, presenting theoretical calculations and their experimental verification. Potential applications of this exciting new source include driving new non-linear phenomena, performing pump-probe studies of dynamical properties of novel materials, and studying molecular vibrations and rotations, low frequency protein motions, phonons, superconductor band gaps, electronic scattering, collective electronic excitations (e.g., charge density waves), and spintronics.

Neil, George R.; Carr, G.L.; Gubeli III, Joseph F.; Jordan, K.; Martin, Michael C.; McKinney, Wayne R.; Shinn, Michelle; Tani, Masahiko; Williams, G.P.; Zhang, X.-C.

2003-07-11T23:59:59.000Z

463

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

464

Other Projects [Laser Applications Laboratory] - Nuclear Engineering  

NLE Websites -- All DOE Office Websites (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

465

New Advances - Jefferson Lab Technology Transfer  

New Advances Commercial Spin-offs Abound For New Free Electron Laser. The world of laser technology took a giant leap forward recently as researchers ...

466

Laser Materials Processing: Past, Present and Future  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2010. Symposium, Laser Applications in Materials Processing. Presentation Title, Laser Materials ...

467

Comparison of Substrate Processing Via Laser and Laser-Sustained ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2010. Symposium, Laser Applications in Materials Processing. Presentation Title, Comparison of ...

468

Insulative laser shell coupler  

DOE Patents (OSTI)

A segmented coaxial laser shell assembly having at least two water jacket sections, two pairs of interconnection half rings, a dialectric break ring, and a pair of threaded ring sections. Each water jacket section with an inner tubular section that defines an inner laser cavity with water paths adjacent to at least a portion of the exterior of the inner tubular section, and mating faces at the end of the water jacket section through which the inner laser cavity opens and which defines at least one water port therethrough in communication with the water jackets. The water paths also define in their external surface a circumferential notch set back from and in close proximity to the mating face. The dielectric break ring has selected thickness and is placed between, and in coaxial alignment with, the mating faces of two of the adjacent water jacket sections. The break ring also defines an inner laser cavity of the same size and shape as the inner laser cavity of the water jacket sections and at least one water passage through the break ring to communicate with at least one water port through the mating faces of the water jacket sections.

Arnold, Phillip A. (Livermore, CA); Anderson, Andrew T. (Livermore, CA); Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

469

The digital laser  

E-Print Network (OSTI)

It is well-known how to control the spatial output from a laser, with most solutions to date involving customised intra-cavity elements in the form of apertures, diffractive optics and free-form mirrors. These optical elements require considerable design and fabrication effort and suffer from the further disadvantage of being immutably connected to the selection of a particular spatial mode. Consequently, most laser systems are designed for the ubiquitous Gaussian mode, whereas it is clear that there are many instances when a customised mode would be preferable. We overcome these limitations with the first digital laser, comprising an electrically addressed reflective phase-only spatial light modulator as an intra-cavity holographic mirror. The phase and amplitude of the holographic mirror may be controlled as simply as writing a new gray-scale image (computer generated hologram) to the device: on-demand laser modes. We show that we can digitally control the laser modes with ease, albeit with higher round-tri...

Ngcobo, Sandile; Burger, Liesl; Forbes, Andrew

2013-01-01T23:59:59.000Z

470

Robotic laser welding: seam sensor and laser focal frame registration  

Science Conference Proceedings (OSTI)

Robotic laser welding places extreme demands on the spatial accuracy with which the robot must position the focal point of the laser with respect to the joint to be welded. The required level of accuracy is difficult to achieve in a production environment ... Keywords: Calibration, Laser welding, Robots, Seam tracking

J. P. Huissoon

2002-05-01T23:59:59.000Z

471

Chapter 31. Microfluidic Fiber Lasers Microfluidic Fiber Lasers  

E-Print Network (OSTI)

at the water/oil interface. We have shown that in maintaining the same pump beam energy, the fiber laser can based pressure sensors. Custom made hermetic optical coupler oil Pump Light Radially Emitted Laser Light hermetic optical coupler oil Pump Light Radially Emitted Laser Light from R6G-doped water plug Microfluidic

472

Fiber Laser Front Ends for High Energy, Short Pulse Lasers  

SciTech Connect

We are developing a fiber laser system for short pulse (1-10ps), high energy ({approx}1kJ) glass laser systems. Fiber lasers are ideal for these systems as they are highly reliable and enable long term stable operation.

Dawson, J; Messerly, M; Phan, H; Siders, C; Beach, R; Barty, C

2007-06-21T23:59:59.000Z

473

Multi-Photon Laser Cooling  

Science Conference Proceedings (OSTI)

... used traditional cooling beams at 852 nm in the x-y plane, but replaced the usual two beams along z with lasers at 795 nm. This laser only couples ...

2011-10-04T23:59:59.000Z

474

Laser welding of electrical interconnections  

SciTech Connect

Processes and equipment have been developed for welding thin aluminum and copper foils using a Nd : YAG laser. Laser welding provides an alternate technique with improved quality for welding these types of electrical terminations.

Bauer, F.R.

1978-12-01T23:59:59.000Z

475

Stimulated radiative laser cooling  

E-Print Network (OSTI)

Building a refrigerator based on the conversion of heat into optical energy is an ongoing engineering challenge. Under well-defined conditions, spontaneous anti-Stokes fluorescence of a dopant material in a host matrix is capable of lowering the host temperature. The fluorescence is conveying away a part of the thermal energy stored in the vibrational oscillations of the host lattice. In particular, applying this principle to the cooling of (solid-state) lasers opens up many potential device applications, especially in the domain of high-power lasers. In this paper, an alternative optical cooling scheme is outlined, leading to radiative cooling of solid-state lasers. It is based on converting the thermal energy stored in the host, into optical energy by means of a stimulated nonlinear process, rather than a spontaneous process. This should lead to better cooling efficiencies and a higher potential of applying the principle for device applications.

Muys, Peter

2007-01-01T23:59:59.000Z

476

Laser isotope separation  

DOE Patents (OSTI)

A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light is described. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

Robinson, C.P.; Reed, J.J.; Cotter, T.P.; Boyer, K.; Greiner, N.R.

1975-11-26T23:59:59.000Z

477

SOLAR PUMPED LASER MICROTHRUSTER  

DOE Green Energy (OSTI)

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A M; Beach, R; Dawson, J; Siders, C W

2010-02-05T23:59:59.000Z

478

Laser beam alignment system  

DOE Patents (OSTI)

A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

Kasner, William H. (11686 Althea Dr., Pittsburgh, PA 15235); Racki, Daniel J. (712 Union Cemetery Rd., Greensburg, PA 15601); Swenson, Clark E. (228 Scott Dr., Monroeville, PA 15146)

1984-01-01T23:59:59.000Z

479

Laser Application for Material Processing  

Science Conference Proceedings (OSTI)

Oct 10, 2012 ... Advanced Materials, Processes and Applications for Additive Manufacturing: Laser Application for Material Processing Program Organizers: ...

480

Piezoelectric measurement of laser power  

DOE Patents (OSTI)

A method for measuring the energy of individual laser pulses or a series of laser pulses by reading the output of a piezoelectric (PZ) transducer which has received a known fraction of the total laser pulse beam. An apparatus is disclosed that reduces the incident energy on the PZ transducer by means of a beam splitter placed in the beam of the laser pulses. 4 figs.

Deason, V.A.; Johnson, J.A.; Telschow, K.L.

1989-11-20T23:59:59.000Z

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.