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1

Ignition feedback regenerative free electron laser (FEL) amplifier  

DOE Patents [OSTI]

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

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

2001-01-01T23:59:59.000Z

2

Scaling relations and parameters for 1 Angstrom FEL. [Free Electron Laser  

SciTech Connect (OSTI)

The Free Electron Laser (FEL) holds great promise as a tunable source of coherent radiation. At the present, the shortest wavelength achieved by an FEL is 2500 {Angstrom}. However, as recent progress in the development of laser driven photocathode electron guns has provided electron beams with lower and lower emittance and higher and higher current, it has become clear that FEL's with much shorter wavelength can be achieved. An FEL operating below 1000 {Angstrom} will yield important advances in fields such as photochemistry, atomic and molecular physics. An FEL with wavelength of 30 {Angstrom} will bring new era to the development of holography of living cells. And, if an FEL with 1 {Angstrom} wavelength can be developed, its impact on solid physics, molecular biology, and many other fields can hardly be exaggerated. We first describe our electron distribution model: a waterbag transverse phase space distribution and a Gaussian energy distribution. This model is widely used in simulations, and is rather close to reality. Then we describe the dispersion relation derived from the Vlasov-Maxwell equations, and its solution, expressed in scaled form. We compare the variational approximation with several simulation codes. Then we compare with exact results which we have derived for a parallel electron beam with finite beam size and energy spread. We explain the scaling relations, and give examples to show how system parameters scale when the FEL wavelength is reduced. Then, applying these scaling relations, we derive a list of preliminary system parameters for a 1 {Angstrom} FEL. As an example, we apply our analytical calculation to optimize one set of parameters derived from the scaling relations. Finally, as a conclusion we discuss the implication of the list of parameters for a 1{Angstrom} FEL. 20 refs., 4 figs.

Yu, L.H.

1990-01-01T23:59:59.000Z

3

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

SciTech Connect (OSTI)

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

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

1983-01-01T23:59:59.000Z

4

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

5

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

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

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

6

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

7

X-ray Free-electron Lasers  

SciTech Connect (OSTI)

In a free-electron laser (FEL) the lasing medium is a high-energy beam of electrons flying with relativistic speed through a periodic magnetic field. The interaction between the synchrotron radiation that is produced and the electrons in the beam induces a periodic bunching of the electrons, greatly increasing the intensity of radiation produced at a particular wavelength. Depending only on a phase match between the electron energy and the magnetic period, the wavelength of the FEL radiation can be continuously tuned within a wide spectral range. The FEL concept can be adapted to produce radiation wavelengths from millimeters to Angstroms, and can in principle produce hard x-ray beams with unprecedented peak brightness, exceeding that of the brightest synchrotron source by ten orders of magnitude or more. This paper focuses on short-wavelength FELs. It reviews the physics and characteristic properties of single-pass FELs, as well as current technical developments aiming for fully coherent x-ray radiation pulses with pulse durations in the 100 fs to 100 as range. First experimental results at wavelengths around 100 nm and examples of scientific applications planned on the new, emerging x-ray FEL facilities are presented.

Feldhaus, J.; /DESY; Arthur, J.; Hastings, J.B.; /SLAC

2007-02-23T23:59:59.000Z

8

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

9

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

E-Print Network [OSTI]

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

Loss, Daniel

10

Simulation of free-electron lasers seeded with broadband radiation  

SciTech Connect (OSTI)

The longitudinal coherence of free-electron laser (FEL) radiation can be enhanced by seeding the FEL with high harmonics of an optical laser pulse. The radiation produced by high-harmonic generation (HHG), however, has a fast-varying temporal profile that can violate the slowly varying envelope approximation and limited frequency window that is employed in conventional free-electron laser simulation codes. Here we investigate the implications of violating this approximation on the accuracy of simulations. On the basis of both analytical considerations and 1D numerical studies, it is concluded that, for most realistic scenarios, conventional FEL codes are capable of accurately simulating the FEL process even when the seed radiation violates the slowly varying envelope approximation. We additionally discuss the significance of filtering the harmonic content of broadband HHG seeds.

Bajlekov, Svetoslav; Fawley, William; Schroeder, Carl; Bartolini, Riccardo; Hooker, Simon

2011-03-10T23:59:59.000Z

11

FREE-ELECTRON LASERS  

E-Print Network [OSTI]

to the electric field of the radiation, this energy-exchangewhere the electric field of the radiation would The energydue to the electric field of the laser radiation, but in

Sessler, A.M.

2008-01-01T23:59:59.000Z

12

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

E-Print Network [OSTI]

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

Loss, Daniel

13

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

E-Print Network [OSTI]

A CW normal-conductive RF gun for free electron laser andincluding state-of-the-art RF guns. High-power RF sourcesand first production RF gun for the DESY TESLA SASE FEL.

Staples, John

2009-01-01T23:59:59.000Z

14

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

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

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

15

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

SciTech Connect (OSTI)

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

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

1993-10-06T23:59:59.000Z

16

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

17

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength  

E-Print Network [OSTI]

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.

Andruszków, J; Ayvazyan, V T; Baboi, N I; Bakker, R; Balakin, V; Barni, D; Bazhan, A; Bernard, M; Bosotti, A; Bourdon, J C; Brefeld, W; Brinkmann, R; Bühler, S; Carneiro, J P; Castellano, M G; Castro, P; Catani, L; Chel, S; Cho, Y; Choroba, S; Colby, E R; Decking, W; Den Hartog, P; Desmons, M; Dohlus, M; Edwards, D; Edwards, H T; Faatz, B; Feldhaus, J; Ferrario, M; Fitch, M J; Flöttmann, K; Fouaidy, M; Gamp, A; Garvey, Terence; Geitz, M A; Gluskin, E S; Gretchko, V; Hahn, U; Hartung, W H; Hubert, D; Hüning, M; Ischebek, R; Jablonka, M; Joly, J M; Juillard, M; Junquera, T; Jurkiewicz, P; Kabel, A C; Kahl, J; Kaiser, H; Kamps, T; Katelev, V V; Kirchgessner, J L; Körfer, M; Kravchuk, L V; Kreps, G; Krzywinski, J; Lokajczyk, T; Lange, R; Leblond, B; Leenen, M; Lesrel, J; Liepe, M; Liero, A; Limberg, T; Lorenz, R; Lu, H H; Lu, F H; Magne, C; Maslov, M A; Materlik, G; Matheisen, A; Menzel, J; Michelato, P; Möller, W D; Mosnier, A; Müller, U C; Napoly, O; Novokhatskii, A V; Omeich, M; Padamsee, H; Pagani, C; Peters, F; Petersen, B; Pierini, P; Pflüger, J; Piot, P; Phung Ngoc, B; Plucinski, L; Proch, D; Rehlich, K; Reiche, S; Reschke, D; Reyzl, I; Rosenzweig, J; Rossbach, J; Roth, S; Saldin, E L; Sandner, W; Sanok, Z; Schlarb, H; Schmidt, G; Schmüser, P; Schneider, J R; Schneidmiller, E A; Schreiber, H J; Schreiber, S; Schütt, P; Sekutowicz, J; Serafini, L; Sertore, D; Setzer, S; Simrock, S; Sonntag, B F; Sparr, B; Stephan, F; Sytchev, V V; Tazzari, S; Tazzioli, F; Tigner, Maury; Timm, M; Tonutti, M; Trakhtenberg, E; Treusch, R; Trines, D; Verzilov, V A; Vielitz, T; Vogel, V; Von Walter, G; Wanzenberg, R; Weiland, T; Weise, H; Weisend, J G; Wendt, M; Werner, M; White, M M; Will, I; Wolff, S; Yurkov, M V; Zapfe, K; Zhogolev, P; Zhou, F

2000-01-01T23:59:59.000Z

18

CONTROL SYSTEM FOR MAGNET POWER SUPPLIES FOR NOVOSIBIRSK FREE ELECTRON LASER  

E-Print Network [OSTI]

- power supplies are very small and do not require water cooling. Therefore it is very convenientCONTROL SYSTEM FOR MAGNET POWER SUPPLIES FOR NOVOSIBIRSK FREE ELECTRON LASER Yu.M.Velikanov, V electron laser (FEL) is described. The characteristics and structure of the power supply system

Kozak, Victor R.

19

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

SciTech Connect (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

20

Inverse free-electron laser accelerator  

SciTech Connect (OSTI)

We first describe the basic physical properties of an inverse free-electron laser and make an estimate of the order of magnitude of the accelerating field obtainable with such a system; then apply the general ideas to the design of an actual device and through this example we give a more accurate evaluation of the fundamental as well as the technical limitations that this acceleration scheme imposes.

Pellegrini, C.; Campisi, R.

1982-01-01T23:59:59.000Z

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.


21

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

SciTech Connect (OSTI)

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

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

2014-04-15T23:59:59.000Z

22

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

23

Ultraviolet Free Electron Laser Facility preliminary design report  

SciTech Connect (OSTI)

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

Ben-Zvi, I. (ed.)

1993-02-01T23:59:59.000Z

24

An inverse free electron laser accelerator experiment  

SciTech Connect (OSTI)

A free electron laser was configured as an autoaccelerator to test the principle of accelerating electrons by stimulated absorption of radiation ([lambda] = 1.65mm) by an electron beam (750kV) traversing an undulator. Radiation is produced in the first section of a constant period undulator (1[sub w1] = 1.43cm) and then absorbed ([approximately] 40%) in a second undulator, having a tapered period (1[sub w2] = 1.8 [minus] 2.25cm), which results in the acceleration of a subgroup ([approximately] 9%) of electrons to [approximately] 1MeV.

Wernick, I.; Marshall, T.C.

1992-01-01T23:59:59.000Z

25

An inverse free electron laser accelerator experiment  

SciTech Connect (OSTI)

A free electron laser was configured as an autoaccelerator to test the principle of accelerating electrons by stimulated absorption of radiation ({lambda} = 1.65mm) by an electron beam (750kV) traversing an undulator. Radiation is produced in the first section of a constant period undulator (1{sub w1} = 1.43cm) and then absorbed ({approximately} 40%) in a second undulator, having a tapered period (1{sub w2} = 1.8 {minus} 2.25cm), which results in the acceleration of a subgroup ({approximately} 9%) of electrons to {approximately} 1MeV.

Wernick, I.; Marshall, T.C.

1992-12-31T23:59:59.000Z

26

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

SciTech Connect (OSTI)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

Schroeder, C. B.; Fawley, W. M.; Gruner, F.; Bakeman, M.; Nakamura, K.; Robinson, K. E.; Toth, Cs.; Esarey, E.; Leemans, W. P.

2008-08-04T23:59:59.000Z

27

The History of X-ray Free-Electron Lasers  

SciTech Connect (OSTI)

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

Pellegrini, C.; /UCLA /SLAC; ,

2012-06-28T23:59:59.000Z

28

Induction linac-driven free-electron lasers: Status and future prospects  

SciTech Connect (OSTI)

The high repetition rate and low single-pass gain inherent in an rf-driven Free Electron Laser (FEL) dictate that the laser system be configured as an oscillator. This allows the laser's electric field to build up over many passes around a high Q cavity. By way of contrast, the high-current capability of the Induction Linac (IL) system permits high single-pass optical gain, but the relatively low duty factor precludes oscillator operation; the pulses are neither long enough nor often enough to permit a field to accumulate in a cavity. The IL is thus configured as a MOPA (master oscillator/power amplifier) with a conventional laser serving as the MO. This report concentrates on the status of IL-driven FEL research at LLNL and gives a description of several applications for the high-peak-power radiation produced by an induction linac FEL.

Prosnitz, D.

1987-01-11T23:59:59.000Z

29

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

30

Reversible electron beam heating for suppression of microbunching instabilities at free-electron lasers  

E-Print Network [OSTI]

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) in front and behind a magnetic bunch compressor chicane. The additional energy spread will be introduced in the first TDS, which suppresses the microbunching instability, and then will be eliminated in the second T...

Behrens, Christopher; Xiang, Dao

2011-01-01T23:59:59.000Z

31

Integrated Numerical Experiments (INEX) and the Free-Electron Laser Physical Process Code (FELPPC)  

SciTech Connect (OSTI)

The strong coupling of subsystem elements, such as the accelerator, wiggler, and optics, greatly complicates the understanding and design of a free electron laser (FEL), even at the conceptual level. Given the requirements for high-performance FELs, the strong coupling between the laser subsystems must be included to obtain a realistic picture of the potential operational capability. To address the strong coupling character of the FEL the concept of an Integrated Numerical Experiment (INEX) was proposed. Unique features of the INEX approach are consistency and numerical equivalence of experimental diagnostics. The equivalent numerical diagnostics mitigates the major problem of misinterpretation that often occurs when theoretical and experimental data are compared. The INEX approach has been applied to a large number of accelerator and FEL experiments. Overall, the agreement between INEX and the experiments is very good. Despite the success of INEX, the approach is difficult to apply to trade-off and initial design studies because of the significant manpower and computational requirements. On the other hand, INEX provides a base from which realistic accelerator, wiggler, and optics models can be developed. The Free Electron Laser Physical Process Code (FELPPC) includes models developed from INEX, provides coupling between the subsystems models and incorporates application models relevant to a specific trade-off or design study.

Thode, L.E.; Chan, K.C.D.; Schmitt, M.J.; McKee, J.; Ostic, J.; Elliott, C.J.; McVey, B.D.

1990-01-01T23:59:59.000Z

32

Laser Phase Errors in Seeded Free Electron Lasers  

SciTech Connect (OSTI)

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

33

Standing-Wave Free-Electron Laser Two-Beam Accelerator  

SciTech Connect (OSTI)

A free-electron laser (FEL) two-beam accelerator (TBA) is proposed, in which the FEL interaction takes place in a series of drive cavities, rather than in a waveguide. Each drive cavity is 'beat-coupled' to a section of the accelerating structure. This standing-wave TBA is investigated theoretically and numerically, with analyses included of microwave extraction, growth of the FEL signal through saturation, equilibrium longitudinal beam dynamics following saturation, and sensitivity of the microwave amplitude and phase to errors in current and energy. It is found that phase errors due to current jitter are substantially reduced from previous versions of the TBA. Analytic scalings and numerical simulations are used to obtain an illustrative TBA parameter set.

Sessler, Andrew M.; Whittum, D.H.; Wurtele, Jonathan S.; Sharp, W.M.; Makowski, M.A.

1991-02-01T23:59:59.000Z

34

Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer  

SciTech Connect (OSTI)

A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5?nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

2014-09-08T23:59:59.000Z

35

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

36

Microsoft PowerPoint - High Gradient Inverse Free Electron Laser...  

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

Hi h G di t Hi h i High Gradient High energy gain Inverse Free Electron Laser at BNL P. Musumeci UCLA Department of Physics and Astronomy ATF user meeting April 2-3 2009 Outline...

37

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

38

Axial interaction free-electron laser  

DOE Patents [OSTI]

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

Carlsten, B.E.

1997-09-02T23:59:59.000Z

39

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

E-Print Network [OSTI]

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

André, Jean-Michel; Jonnard, Philippe

2014-01-01T23:59:59.000Z

40

Slippage effect on energy modulation in seeded free-electron lasers with frequency chirped seed laser pulses  

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

Free-electron lasers (FELs) seeded with external lasers hold great promise for generating high power radiation with nearly transform-limited bandwidth in the soft x-ray region. However, it has been pointed out that the initial seed laser phase error will be amplified by the frequency up-conversion process, which may degrade the quality of the output radiation produced by a harmonic generation scheme. In this paper, theoretical and simulation studies on frequency chirp amplification in seeded FEL schemes with slippage effect taken into account are presented. It is found that the seed laser imperfection experienced by the electron beam can be significantly smoothed by the slippage effect in the modulator when the slippage length is comparable to the seed laser pulse length. This smoothing effect allows one to preserve the excellent temporal coherence of seeded FELs in the presence of large frequency chirp in the seed laser. Our studies show that the tolerance on frequency chirp in the seed laser for generating nearly transform-limited soft x-ray pulses in seeded FELs is much looser than previously thought and fully coherent radiation at nanometer wavelength may be reached with current technologies.

Feng, Chao; Deng, Haixiao; Wang, Guanglei; Wang, Dong; Zhao, Zhentang; Xiang, Dao

2013-06-01T23:59:59.000Z

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

Resonator design for a visible wavelength free-electron laser (*)  

SciTech Connect (OSTI)

Design requirements for a visible wavelength free-electron laser being developed at the Accelerator Test Facility at Brookhaven National Laboratory are presented along with predictions of laser performance from 3-D numerical simulations. The design and construction of the optical resonator, its alignment and control systems are also described. 15 refs., 8 figs., 4 tabs.

Bhowmik, A.; Lordi, N. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.); Ben-Zvi, I.; Gallardo, J. (Brookhaven National Lab., Upton, NY (United States))

1990-01-01T23:59:59.000Z

42

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

43

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

44

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

SciTech Connect (OSTI)

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

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

2014-10-15T23:59:59.000Z

45

High-power rf-pulsed modulators for the Los Alamos free-electron laser  

SciTech Connect (OSTI)

In the rf-driven free-electron laser (FEL) at the Los Alamos National Laboratory, there are two pulsed-power rf modulators as sources for two tandem, side-coupled 20-MeV linear accelerators. The rf power used to control the cavity fields is supplied by two 5.5-MW modulating anode klystrons operating at a center frequency of 1300.2 MHz. The modulation of the 125 kV klystron is achieved by using a triode switch tube that provides a pulse width up to 300 ..mu..s and a pulse repetition rate up to 10 Hz. This paper describes the present configuration of these two duplicate systems and presents plans for meeting the requirements of future rf FEL experiments at Los Alamos. 12 refs., 5 figs.

Johnson, W.J.D.; Lynch, M.T.; Tallerico, P.J.; Keffeler, D.R.; Hornkohl, J.O.

1987-09-01T23:59:59.000Z

46

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

E-Print Network [OSTI]

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

Brandin, M; Ekelöf, T J C; Ferrari, A

2002-01-01T23:59:59.000Z

47

Invited Article: Coherent imaging using seeded free-electron laser pulses with variable polarization: First results and research opportunities  

SciTech Connect (OSTI)

FERMI-Elettra, the first vacuum ultraviolet and soft X-ray free-electron laser (FEL) using by default a 'seeded' scheme, became operational in 2011 and has been opened to users since December 2012. The parameters of the seeded FERMI FEL pulses and, in particular, the superior control of emitted radiation in terms of spectral purity and stability meet the stringent requirements for single-shot and resonant coherent diffraction imaging (CDI) experiments. The advantages of the intense seeded FERMI pulses with variable polarization have been demonstrated with the first experiments performed using the multipurpose experimental station operated at the diffraction and projection imaging (DiProI) beamline. The results reported here were obtained with fixed non-periodic targets during the commissioning period in 2012 using 20-32 nm wavelength range. They demonstrate that the performance of the FERMI FEL source and the experimental station meets the requirements of CDI, holography, and resonant magnetic scattering in both multi- and single-shot modes. Moreover, we present the first magnetic scattering experiments employing the fully circularly polarized FERMI pulses. The ongoing developments aim at pushing the lateral resolution by using shorter wavelengths provided by double-stage cascaded FERMI FEL-2 and probing ultrafast dynamic processes using different pump-probe schemes, including jitter-free seed laser pump or FEL-pump/FEL-probe with two color FEL pulses generated by the same electron bunch.

Capotondi, F.; Pedersoli, E.; Mahne, N.; Menk, R. H.; Passos, G.; Raimondi, L.; Svetina, C.; Sandrin, G.; Kiskinova, M. [FERMI, Elettra-Sincrotrone Trieste, SS 14 - km 163.5, 34149 Basovizza, Trieste (Italy); Zangrando, M. [FERMI, Elettra-Sincrotrone Trieste, SS 14 - km 163.5, 34149 Basovizza, Trieste (Italy); CNR, Istituto Officina dei Materiali - TASC, SS 14 - km 163.5, 34149 Basovizza, Trieste (Italy); Bajt, S.; Barthelmess, M.; Fleckenstein, H.; Chapman, H. N. [CFEL-DESY, Notkestrasse 85, 22607 Hamburg (Germany); Schulz, J. [European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Bach, J.; Froemter, R. [Universitaet Hamburg, Institut fuer Angewandte Physik, 20355 Hamburg (Germany); Schleitzer, S.; Mueller, L.; Gutt, C. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); and others

2013-05-15T23:59:59.000Z

48

Wiggler plane focusing in a linear free electron laser  

DOE Patents [OSTI]

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

Scharlemann, E.T.

1985-11-21T23:59:59.000Z

49

Free electron laser amplifier driven by an induction linac  

SciTech Connect (OSTI)

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

Neil, V.K.

1986-06-03T23:59:59.000Z

50

Inverse free electron laser accelerator for advanced light sources  

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

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

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

2012-06-01T23:59:59.000Z

51

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

SciTech Connect (OSTI)

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

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

1992-07-01T23:59:59.000Z

52

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

SciTech Connect (OSTI)

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

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

1992-07-01T23:59:59.000Z

53

Chirped pulse inverse free-electron laser vacuum accelerator  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

54

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

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

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

55

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

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

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

56

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

57

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

SciTech Connect (OSTI)

The Next Generation Light Source (NGLS) is a high repetition rate free-electron laser facility proposed by Lawrence Berkeley National Laboratory (LBNL). The proposed facility will provide multiple FEL lines with varying spectral characteristics to satisfy a broad soft X-ray physics programme. At this stage of the project a number of FEL technologies and concepts are being investigated for possible implementation on the facility. In this report we consider a free-electron laser seeded by a Higher Harmonic Generation (HHG) source in which a high power (and consequently relatively low repetition rate) laser pulse is injected into a chamber of inert gas. Through a process of ionisation and recombination coherent higher harmonics of the laser are emitted from the gas and can be injected into an FEL system as a seed field. Further harmonic upconversion can be done within the FEL system to enable temporally coherent FEL output at wavelengths much shorter than, and pulse energies orders of magnitude higher than, the HHG source emission. The harmonic conversion within the FEL works in the following way. The seed field induces an energy modulation within the electron bunch at the start of the modulator. This energy modulation grows within the modulator due to the FEL interaction and starts to convert into a density modulation, or bunching, at the seed wavelength. However, this bunching also has components at higher harmonics which retain the longitudinal coherence of the initial seed. The beam passes through a magnetic chicane, which shears the longitudinal phase space to maximise the bunching at the required harmonic, then a further undulator which is tuned to this harmonic. If this second undulator is short it acts as a further modulator, and because the beam is pre-bunched at the modulator resonance there is a strong coherent burst of radiation which acts to modulate the electron beam energy in much the same way the input laser seed field acted in the first modulator. This second modulator is followed by a second bunching chicane and then a final long radiator tuned to a yet higher harmonic of the laser seed - the final output wavelength. Alternatively, the second undulator can be the radiator itself, in which case only one harmonic conversion from seed wavelength to final output is necessary. We initially consider the case of a 400kW peak power HHG seed source at wavelength 12nm (currently considered the cutoff wavelength for sufficient seed power to dominate shot noise in the electron beam) which is converted in either one or two stages or harmonic conversion to FEL emission at 1nm. We then consider the implications of a factor of ten reduction in seed power to 40kW.

Thompson, Neil

2010-10-20T23:59:59.000Z

58

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

SciTech Connect (OSTI)

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

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

2014-07-15T23:59:59.000Z

59

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

60

fel 2005 :: Free Electron Laser Conference and Workshop  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 Industrial Carbon Capture andDeepwater Methane Hydrate MaximizeOctober Home |

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

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

SciTech Connect (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; St& #246; hr, Joachim; Stupakov, Gennady; White, Bill; Xiang, Dao

2009-06-08T23:59:59.000Z

62

Beam conditioner for free electron lasers and synchrotrons  

DOE Patents [OSTI]

A focused optical has been used to introduce an optical pulse, or electromagnetic wave, collinear 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. 4 figs.

Liu, H.; Neil, G.R.

1998-09-08T23:59:59.000Z

63

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

64

Operational Radiation Protection in Synchrotron Light and Free Electron Laser Facilities  

SciTech Connect (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 (< few tens of watts), but extremely high stored beam power ({approx} 1 GW). The 4th generation x-ray free electron laser (FEL) facilities are based on an electron Linac with a long undulator and have high injection beam power (a few kW). Due to its electron and photon beam characteristics and modes of operation, storage ring and photon beamlines have unique safety aspects, which are the main subjects of this paper. The shielding design limits, operational modes, and beam losses are first reviewed. Shielding analysis (source terms and methodologies) and interlocked safety systems for storage ring and photon beamlines (including SR and gas bremsstrahlung) are described. Specific safety issues for storage ring top-off injection operation and FEL facilities are discussed. The operational safety program, e.g., operation authorization, commissioning, training, and 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

65

Efficiency enhancement of a two-beam free-electron laser  

SciTech Connect (OSTI)

A local and nonlinear simulation of two-beam and tapered free-electron laser (FEL) is presented self-consistently. The slippage of the electromagnetic wave with respect to the electron beam is ignored and the relativistic electron beams are assumed to be cold. The fundamental resonance and the third harmonic radiation of the beam with lower energy are considered, in which the third harmonic is at the fundamental resonance of the beam with higher energy. The wiggler field is set to decrease linearly when the radiation of the third harmonic saturates. The optimum starting point of tapering and the slope of the reduction in the amplitude of wiggler are found by successive run of the code. Using the slowly varying envelope approximation, a set of nonlinear equations is derived which describes this system. These equations are solved numerically by the Runge-Kutta method. This method can be used to improve the efficiency of the two-beam FEL in the extreme ultraviolet and x-ray regions of spectrum.

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

2009-12-15T23:59:59.000Z

66

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

SciTech Connect (OSTI)

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

67

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

SciTech Connect (OSTI)

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

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

2012-09-15T23:59:59.000Z

68

Thermal effect on prebunched two-beam free electron laser  

SciTech Connect (OSTI)

A numerical simulation in one-dimension is conducted to study the two-beam free electron laser. The fundamental resonance of the fast electron beam coincides with the fifth harmonic of the slow electron beam in order to generate extreme ultraviolet radiation. Thermal effect in the form of the longitudinal velocity spread is included in the analysis. In order to reduce the length of the wiggler, prebunched slow electron beam is considered. The evaluation of the radiation power, bunching parameter, distribution function of energy, and the distribution function of the pondermotive phase is studied. Sensitivity of the power of the fifth harmonic to the jitter in the energy difference between the two beams is also studied. A phase space is presented that shows the trapped electrons at the saturation point.

Mirian, N. S. [School of Particle and Accelerator Physics, Institute for Research in Fundamental Sciences (IPM), 19395-5531 Tehran (Iran, Islamic Republic of)] [School of Particle and Accelerator Physics, Institute for Research in Fundamental Sciences (IPM), 19395-5531 Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

2013-08-15T23:59:59.000Z

69

A compact x-ray free electron laser  

SciTech Connect (OSTI)

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

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

1988-09-09T23:59:59.000Z

70

Laser Phase Errors in Seeded FELs  

SciTech Connect (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

71

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

SciTech Connect (OSTI)

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

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

2014-08-15T23:59:59.000Z

72

HIGH AVERAGE POWER UV FREE ELECTRON LASER EXPERIMENTS AT JLAB  

SciTech Connect (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

73

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

SciTech Connect (OSTI)

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

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

2006-09-25T23:59:59.000Z

74

LIPSS Free-Electron Laser Searches for Dark Matter  

SciTech Connect (OSTI)

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

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

2011-09-01T23:59:59.000Z

75

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

E-Print Network [OSTI]

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

Emma, Claudio; Wu, Juhao

2014-01-01T23:59:59.000Z

76

Instability of wave modes in a two-stream free-electron laser with a helical wiggler and an axial magnetic field  

SciTech Connect (OSTI)

The dispersion relation of a two-stream free-electron laser (TSFEL) with a one-dimensional helical wiggler and an axial magnetic field is studied. Also, all relativistic effects on the space-charge wave and radiation are considered. This dispersion relation is solved numerically to find the unstable interaction among the all wave modes. Numerical calculations show that the growth rate is considerably enhanced in comparison with single-stream FEL. The effect of the velocity difference of the two electron beams on the two-stream instability and the FEL resonance is investigated. The maximum growth rate of FEL resonance is investigated numerically as a function of the axial magnetic field.

Mohsenpour, Taghi; Mehrabi, Narges [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)] [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)

2013-08-15T23:59:59.000Z

77

Development of free-electron lasers for xuv projection lithography  

SciTech Connect (OSTI)

Future rf-linac-driven FELs, operating in the range from 4 nm to 100 nm, could be excellent exposure tools for extending the resolution limit of projection optical lithography to {le}0.1 {mu}m and with adequate total depth of focus (1 to 2 {mu}m). When operated at a moderate duty rate of {ge}1%, XUV FELs should be able to supply sufficient average power to support high-volume chip production. Recent developments of the electron beam, magnetic undulator, and resonator mirrors are described which raise our expectation that FEL operation below 100 nm is almost ready for demonstration. Included as a supplement is a review of initial design studies of the reflecting XUV projection optics, fabrication of reflection masks, characterization of photoresists, and the first experimental demonstrations of the capability of projection lithography with 14-nm radiation to produce lines and spaces as small as 0.05 {mu}m. 88 refs., 10 figs.

Newnam, B.E.

1990-01-01T23:59:59.000Z

78

Selective Photothermolysis to target Sebaceous Glands: Theoretical Estimation of Parameters and Preliminary Results Using a Free Electron Laser  

SciTech Connect (OSTI)

The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH2 bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH2 vibrational absorption wavelength band. Absorption spectra of natural and artificially prepared sebum were measured from 200 nm to 3000 nm, to determine wavelengths potentially able to target sebaceous glands. The Jefferson National Accelerator superconducting FEL was used to measure photothermal excitation of aqueous gels, artificial sebum, pig skin, human scalp and forehead skin (sebaceous sites). In vitro skin samples were exposed to FEL pulses from 1620 to 1720 nm, spot diameter 7-9.5 mm with exposure through a cold 4C sapphire window in contact with the skin. Exposed and control tissue samples were stained using H and E, and nitroblue tetrazolium chloride staining (NBTC) was used to detect thermal denaturation. Natural and artificial sebum both had absorption peaks near 1210, 1728, 1760, 2306 and 2346 nm. Laser-induced heating of artificial sebum was approximately twice that of water at 1710 and 1720 nm, and about 1.5x higher in human sebaceous glands than in water. Thermal camera imaging showed transient focal heating near sebaceous hair follicles. Histologically, skin samples exposed to {approx}1700 nm, {approx}100-125 ms pulses showed evidence of selective thermal damage to sebaceous glands. Sebaceous glands were positive for NBTC staining, without evidence of selective loss in samples exposed to the laser. Epidermis was undamaged in all samples. Conclusions: SP of sebaceous glands appears to be feasible. Potentially, optical pulses at {approx}1720 nm or {approx}1210 nm delivered with large beam diameter and appropriate skin cooling in approximately 0.1 s may provide an alternative treatment for acne.

Fernanda Sakamoto, Apostolos Doukas, William Farinelli, Zeina Tannous, Michelle D. Shinn, Stephen Benson, Gwyn P. Williams, H. Dylla, Richard Anderson

2011-12-01T23:59:59.000Z

79

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

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

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

80

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

E-Print Network [OSTI]

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

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" from the National Library of EnergyBeta (NLEBeta).
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81

Gamma-ray free-electron lasers: Quantum fluid model  

E-Print Network [OSTI]

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

Silva, H M

2014-01-01T23:59:59.000Z

82

Variable Gap Undulator for 1.5-48 Kev Free Electron Laser at Linac Coherent Light Source  

SciTech Connect (OSTI)

We study the feasibility of generating femtosecond duration Free-Electron Laser with a variable photon energy from 1.5 to 48 keV, using an electron bunch with the same characteristics of the LINAC Coherent Light Source (LCLS) bunch, and a planar undulator with additional focusing. We assume that the electron bunch energy can be changed, and the undulator has a variable gap, allowing a variable undulator parameter. It is assumed to be operated in an ultra-low charge and ultra-short pulse regime. We study the feasibility of a tunable, short pulse, X-ray FEL with photon energy from 1.5 to 48 keV, using an electron beam like the one in the LCLS and a 2:5 cm period, variable gap, planar undulator. The beam energy changes from 4.6 to 13.8 GeV, the electorn charge is kept at 10 pC, and the undulator parameter varies from 1 to 3. The undulator length needed to saturate the 48 keV FEL is about 55 m, with a peak power around 5 GW. At longer wavelength the saturation length is as short as 15 m, and the peak power around 20 GW. The results from the analytical models and the GENESIS simulations show that the system is feasible. The large wavelength range, full tunability and short, few femtosecond pulses, together with the large peak power, would provide a powerful research tool.

Pellegrini, C.; /UCLA; Wu, J.; /SLAC; ,

2011-08-17T23:59:59.000Z

83

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

SciTech Connect (OSTI)

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

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

2014-10-15T23:59:59.000Z

84

Density gradient free electron collisionally excited X-ray laser  

DOE Patents [OSTI]

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

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

1989-01-01T23:59:59.000Z

85

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

86

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

87

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

SciTech Connect (OSTI)

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

Guimei Wang

2011-12-31T23:59:59.000Z

88

Damage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength  

E-Print Network [OSTI]

to the optical components required to utilize XFEL beams, including radiation damage. Theoretical workDamage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength SC were exposed to single 25 fs long pulses of 32.5 nm free-electron-laser radiation at fluences of up

von der Linde, D.

89

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

SciTech Connect (OSTI)

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

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

2011-09-01T23:59:59.000Z

90

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

E-Print Network [OSTI]

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

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

2014-02-27T23:59:59.000Z

91

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

E-Print Network [OSTI]

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

Feng, Chao; Deng, Haixiao; Zhao, Zhentang

2014-01-01T23:59:59.000Z

92

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

SciTech Connect (OSTI)

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

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

2013-12-15T23:59:59.000Z

93

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers  

SciTech Connect (OSTI)

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)] [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Blinne, Alexander [Institute for Theoretical Physics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)] [Institute for Theoretical Physics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Feigl, Torsten [Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Straße 7, 07745 Jena (Germany)] [Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Straße 7, 07745 Jena (Germany); Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany) [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz Institute, Fröbelstieg 3, 07743 Jena (Germany)

2013-09-15T23:59:59.000Z

94

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

95

Design of a free-electron laser driven by the LBNLlaser-plasma-accelerator  

SciTech Connect (OSTI)

We discuss the design and current status of a compactfree-electron laser (FEL), generating ultra-fast, high-peak flux, VUVpulses driven by a high-current, GeV electron beam from the existingLawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator,whose active acceleration length is only a few cm. The proposedultra-fast source would be intrinsically temporally synchronized to thedrive laser pulse, enabling pump-probe studies in ultra-fast science withpulse lengths of tens of fs. Owing to the high current (&10 kA) ofthe laser-plasma-accelerated electron beams, saturated output fluxes arepotentially greater than 1013 photons/pulse. Devices based both on SASEand high-harmonic generated input seeds, to reduce undulator length andfluctuations, are considered.

Schroeder, C.B.; Fawley, W.M.; Montgomery, A.L.; Robinson, K.E.; Gruner, F.; Bakeman, M.; Leemans, W.P.

2007-09-10T23:59:59.000Z

96

Multiple pulse thermal damage thresholds of materials for x-ray free electron laser optics investigated with an ultraviolet laser  

SciTech Connect (OSTI)

Optical elements to be used for x-ray free electron lasers (XFELs) must withstand multiple high-fluence pulses. We have used an ultraviolet laser to study the damage of two candidate materials, crystalline Si and B{sub 4}C-coated Si, emulating the temperature profile expected to occur in optics exposed to XFEL pulses. We found that the damage threshold for 10{sup 5} pulses is {approx}20% to 70% lower than the melting threshold.

Hau-Riege, Stefan P.; London, Richard A.; Bionta, Richard M.; Soufli, Regina; Ryutov, Dmitri; Shirk, Michael; Baker, Sherry L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94539 (United States); Smith, Patrick M.; Nataraj, Pradeep [Kovio, Inc., 1145 Sonora Court, Sunnyvale, California 94086 (United States)

2008-11-17T23:59:59.000Z

97

LUNEX5: A FRENCH FEL TEST FACILITY LIGHT SOURCE PROPOSAL A. Loulergue, C. Benabderrahmane, M. Bessire, P. Betinelli, F. Bouvet, A. Buteau, L. Cassinari,  

E-Print Network [OSTI]

is mandatory for the FEL performance. Although the Solid State Amplifiers (SSA) technology [8] is not yetLUNEX5: A FRENCH FEL TEST FACILITY LIGHT SOURCE PROPOSAL A. Loulergue, C. Benabderrahmane, M is a new Free Electron Laser (FEL) source project aimed at delivering short and coherent X-ray pulses

Boyer, Edmond

98

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

SciTech Connect (OSTI)

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

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

2012-10-01T23:59:59.000Z

99

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

SciTech Connect (OSTI)

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

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

2011-06-15T23:59:59.000Z

100

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

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "free-electron laser fel" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


101

Design of a free-electron laser driven by the LBNL laser-plasma-accelerator  

E-Print Network [OSTI]

plasma accelerator at the LBNL LOASIS facility”, in: Proc.electron laser driven by the LBNL laser-plasma-accelerator ?National Laboratory (LBNL) laser-plasma accelerator, whose

2008-01-01T23:59:59.000Z

102

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

E-Print Network [OSTI]

XPLOTGIN, Technical Report LBNL-49625, Lawrence BerkeleyLASER-PLASMA ACCELERATOR AT THE LBNL LOASIS FACILITY,” inelectron laser driven by the LBNL laser-plasma accelerator

Schroeder, C. B.

2010-01-01T23:59:59.000Z

103

fLasHThe Free-Electron Laser new technologies for new science: Soon X-ray free-electron lasers  

E-Print Network [OSTI]

, how molecular machines really work. Accelerators | photon Science | particle physics Deutsches in the accel- erator tunnel. The photon beam transport system in the hall delivers the FEL pulses ­ as short the feasibility of a superconducting linear electron-positron collider for elementary particle phy- sics

104

IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 27, NO. 12. DECEMBER 1991 2691 Applications of Infrared Free-Electron Lasers: Basic  

E-Print Network [OSTI]

IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 27, NO. 12. DECEMBER 1991 2691 Applications of Infrared. Fayer Invited Paper Abstract-Applications of tunable infrared (IR) picosecond (ps) pulses generated- heating are suggested. I. INTRODUCTION REE-ELECTRON lasers (FEL's) have developed Frapidly in the last 15

Fayer, Michael D.

105

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

SciTech Connect (OSTI)

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

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

2014-05-12T23:59:59.000Z

106

Subnanometer-Scale Measurements of the Interaction of Ultrafast Soft X-Ray Free-Electron-Laser Pulses with Matter  

E-Print Network [OSTI]

lengths greater than 3 A° . This experiment demonstrates that with intense ultrafast pulses, structuralSubnanometer-Scale Measurements of the Interaction of Ultrafast Soft X-Ray Free-Electron-Laser Pulses with Matter Stefan P. Hau-Riege,1,* Henry N. Chapman,1 Jacek Krzywinski,2 Ryszard Sobierajski,2

von der Linde, D.

107

FREE ELECTRON LASERS AND HIGH-ENERGY ELECTRON COOLING* Vladimir N. Litvinenko, BNL, Upton, Long Island, NY, USA#  

E-Print Network [OSTI]

two orders-of-magnitude. Two techniques offering the potential to cool high- energy hadron beamsFREE ELECTRON LASERS AND HIGH-ENERGY ELECTRON COOLING* Vladimir N. Litvinenko, BNL, Upton, Long Island, NY, USA# Yaroslav S. Derbenev, TJNAF, Newport News, VA, USA) Abstract Cooling intense high

108

Evidence of High Harmonics from Echo-Enabled Harmonic Generation for Seeding X-ray Free Electron Lasers  

SciTech Connect (OSTI)

Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science.

Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodle, M.; /SLAC; ,

2012-02-15T23:59:59.000Z

109

Correspondence: Email: shinn@jlab.org; Telephone: 757 269 7565; FAX: 757 269 5519 High Average Power Free-Electron Lasers -A New Laser Source for  

E-Print Network [OSTI]

Power Free-Electron Lasers - A New Laser Source for Materials Processing Michelle D. Shinn Thomas). In general, the processing consists of material removal steps such as drilling, cutting, as well as joining technology provides a scaleable path to laser outputs above 50 kW, rendering these applications economically

110

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

E-Print Network [OSTI]

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

Kozak, Victor R.

111

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

E-Print Network [OSTI]

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

Wurtele, Jonathan

112

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

E-Print Network [OSTI]

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

Wallis, A O G; Emmanouilidou, A

2015-01-01T23:59:59.000Z

113

Damage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength  

SciTech Connect (OSTI)

We exposed samples of B4C, amorphous C, chemical-vapor-deposition (CVD)-diamond C, Si, and SiC to single 25 fs-long pulses of 32.5 nm free-electron-laser radiation at fluences of up to 2.2 J/cm{sup 2}. The samples were chosen as candidate materials for x-ray free electron laser (XFEL) optics. We found that the threshold for surface-damage is on the order of the fluence required for thermal melting. For larger fluences, the crater depths correspond to temperatures on the order of the critical temperature, suggesting that the craters are formed by two-phase vaporization [1]. XFELs have the promise of producing extremely high-intensity ultrashort pulses of coherent, monochromatic radiation in the 1 to 10 keV regime. The expected high output fluence and short pulse duration pose significant challenges to the optical components, including radiation damage. It has not been possible to obtain direct experimental verification of the expected damage thresholds since appropriate x-ray sources are not yet available. FLASH has allowed us to study the interaction of high-fluence short-duration photon pulses with materials at the shortest wavelength possible to date. With these experiments, we have come closer to the extreme conditions expected in XFEL-matter interaction scenarios than previously possible.

Hau-Riege, S; London, R A; Bionta, R M; McKernan, M A; Baker, S L; Krzywinski, J; Sobierajski, R; Nietubyc, R; Pelka, J B; Jurek, M; Klinger, D; Juha, L; Chalupsky, J; Cihelka, J; Hajkova, V; Koptyaev, S; Velyhan, A; Krasa, J; Kuba, J; Tiedtke, K; Toleikis, S; Tschentscher, T; Wabnitz, H; Bergh, M; Caleman, C; Sokolowski-Tinten, K; Stojanovic, N; Zastrau, U; Tronnier, A; Meyer-ter-Vehn, J

2007-12-03T23:59:59.000Z

114

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

SciTech Connect (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. [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

115

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

SciTech Connect (OSTI)

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

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

1987-01-01T23:59:59.000Z

116

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

SciTech Connect (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] [SLAC Director

2011-03-22T23:59:59.000Z

117

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

ScienceCinema (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

2011-06-08T23:59:59.000Z

118

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

SciTech Connect (OSTI)

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

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

1987-06-01T23:59:59.000Z

119

Microbunching Instability Effect Studies and Laser Heater Optimization for the SPARX FEL Accelerator  

SciTech Connect (OSTI)

The effects of microbunching instability for the SPARX accelerator have been analyzed by means of numerical simulations. The laser heater counteracting action has been addressed in order to optimize the parameters of the compression system, either hybrid RF plus magnetic chicane or only magnetic, and possibly enhance the FEL performance.

Vaccarezza, C.; Chiadroni, E.; Ferrario, M.; Giannessi, L.; Quattromini, M.; Ronsivalle, C.; Venturini, C.; Migliorati, M.; Dattoli, G.

2010-05-23T23:59:59.000Z

120

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

SciTech Connect (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

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


121

Status of UCLA Helical Permanent-Magnet Inverse Free Electron Laser  

SciTech Connect (OSTI)

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

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

2009-01-22T23:59:59.000Z

122

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

E-Print Network [OSTI]

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

Schneidmiller, E A

2015-01-01T23:59:59.000Z

123

Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser  

E-Print Network [OSTI]

We present a cylindrically curved GaAs x-ray spectrometer with energy resolution $\\Delta E/E = 1.1\\cdot 10^{-4}$ and wave-number resolution of $\\Delta k/k = 3\\cdot 10^{-3}$, allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to $5.2/$\\AA\\ in 100 separate bins, with only 0.34\\% wavenumber blurring. The dispersion of 0.418~eV/$13.5\\,\\mu$m agrees with predictions within 1.3\\%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic HAPG spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1~eV and a significant range of wavenumbers must be covered in one exposure.

Zastrau, Ulf; Foerster, Eckhart; Galtier, Eric Ch; Gamboa, Eliseo; Glenzer, Siegfried H; Heimann, Philipp; Marschner, Heike; Nagler, Bob; Schropp, Andreas; Wehrhan, Ortrud; Lee, Hae Ja

2014-01-01T23:59:59.000Z

124

Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser  

SciTech Connect (OSTI)

We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ?E/E = 1.1 ×?10{sup ?4} and wave-number resolution of ?k/k = 3 ×?10{sup ?3}, allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to 5.2/Å in 100 separate bins, with only 0.34% wavenumber blurring. The dispersion of 0.418 eV/13.5??m agrees with predictions within 1.3%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic highly annealed pyrolytic graphite spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1 eV and a significant range of wavenumbers must be covered in one exposure.

Zastrau, Ulf, E-mail: ulf.zastrau@uni-jena.de [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Fletcher, Luke B.; Galtier, Eric Ch.; Gamboa, Eliseo; Glenzer, Siegfried H.; Heimann, Philipp; Nagler, Bob; Schropp, Andreas; Lee, Hae Ja [Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Förster, Eckhart [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz Institute Jena, Fröbelstieg 3, 07743 Jena (Germany); Marschner, Heike; Wehrhan, Ortrud [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2014-09-15T23:59:59.000Z

125

Damage Threshold of Platinum Coating used for Optics for Self-Seeding of Soft X-ray Free Electron Laser  

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

We investigated the experimental damage threshold of platinum coating on a silicon substrate illuminated by soft x-ray radiation at grazing incidence angle of 2.1 deg. The coating was the same as the blazed grating used for the soft X-ray self-seeding optics of the Linac Coherent Light Source free electron laser. The irradiation condition was chosen such that the absorbed dose was similar to the maximum dose expected for the grating. The expected dose was simulated by solving the Helmholtz equation in non-homogenous media. The experiment was performed at 900 eV photon energy for both single pulse and multi-shot conditions. We have not observed single shot damage. This corresponds to a single shot damage threshold being higher than 3 J/cm2. The multiple shot damage threshold measured for 10 shots and about 600 shots was determined to be 0.95 J/cm2 and 0.75 J/cm2 respectively. The damage threshold occurred at an instantaneous dose which is higher that the melt dose of platinum.

Krzywinski, Jacek; Cocco, Daniele; Moeller, Stefan; Ratner, Daniel

2015-01-01T23:59:59.000Z

126

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

E-Print Network [OSTI]

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

Geddes, Cameron Guy Robinson

127

Optics-free x-ray FEL oscillator  

SciTech Connect (OSTI)

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

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

2011-03-28T23:59:59.000Z

128

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

SciTech Connect (OSTI)

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

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

2014-03-15T23:59:59.000Z

129

Feedback Requirements for SASE-FELs  

SciTech Connect (OSTI)

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

130

IEEEJOURNAL OF QUANTUMELECTRONICS, VOL. QE-21,NO. 7, JULY 1985 831 High-Gain Free Electron Lasers Using Induction  

E-Print Network [OSTI]

of producing intense cwrents (102-104A) at moderately high energy (1-50 MeV). Experiments using a 500 A, 3.3 Me of Energy under Contracts W- Research Projects Agency under ARPA Order 4856, Program Code 3B10. T. J. Future experi- ments include a high-gain, high-efficiency FEL operating at 10.6 pm using a 50 MeV beam. I

Wurtele, Jonathan

131

Seeded quantum FEL at 478 keV  

SciTech Connect (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

132

Plasma Channel Diagnostic Based on Laser Centroid Oscillations  

E-Print Network [OSTI]

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

Geddes, Cameron Guy Robinson

133

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

E-Print Network [OSTI]

Electron Laser for the LBNL Next Generation Light SourceElectron Laser for the LBNL Next Generation Light SourceBerkeley National Laboratory (LBNL). The proposed facil- ity

Thompson, Neil

2011-01-01T23:59:59.000Z

134

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

SciTech Connect (OSTI)

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

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

2013-04-01T23:59:59.000Z

135

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

E-Print Network [OSTI]

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

Geddes, Cameron Guy Robinson

136

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

137

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

E-Print Network [OSTI]

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

Zhou, Zhongyuan; Chu, Shih-I

2013-02-13T23:59:59.000Z

138

DarkLight: A Search for Dark Forces at the Jefferson Laboratory Free-Electron Laser Facility  

SciTech Connect (OSTI)

We give a short overview of the DarkLight detector concept which is designed to search for a heavy photon A' with a mass in the range 10 MeV/c^2 < m(A') < 90 MeV/c^2 and which decays to lepton pairs. We describe the intended operating environment, the Jefferson Laboratory free electon laser, and a way to extend DarkLight's reach using A' --> invisible decays.

Balewski, Jan; Bernauer, J.; Bertozzi, William; Bessuille, Jason; Buck, B.; Cowan, Ray; Dow, K.; Epstein, C.; Fisher, Peter; Gilad, Shalev; Ihloff, Ernest; Kahn, Yonatan; Kelleher, Aidan; Kelsey, J.; Milner, Richard; Moran, C.; Ou, Longwu; Russell, R.; Schmookler, Barak; Thaler, J.; Tschalar, C.; Vidal, Christopher; Winnebeck, A.; Benson, Stephen [JLAB; Gould, Christopher [JLAB; Biallas, George [JLAB; Boyce, James [JLAB; Coleman, James [JLAB; Douglas, David [JLAB; Ent, Rolf [JLAB; Evtushenko, Pavel [JLAB; Fenker, Howard [JLAB; Gubeli, Joseph [JLAB; Hannon, Fay [JLAB; Huang, Jia [JLAB; Jordan, Kevin [JLAB; Legg, Robert [JLAB; Marchlik, Matthew [JLAB; Moore, Steven [JLAB; Neil, George [JLAB; Shinn, Michelle D [JLAB; Tennant, Christopher [JLAB; Walker, Richard [JLAB; Williams, Gwyn [JLAB; Zhang, Shukui [JLAB; Freytsis, M.; Fiorito, Ralph; O'Shea, P.; Alarcon, Ricardo; Dipert, R.; Ovanesyan, G.; Gunter, Thoth; Kalantarians, Narbe; Kohl, M.; Albayrak, Ibrahim; Horn, Tanja; Gunarathne, D. S.; Martoff, C. J.; Olvitt, D. L.; Surrow, Bernd; Lia, X.; Beck, Reinhard; Schmitz, R.; Walther, D.; Brinkmann, K.; Zaunig, H.

2014-05-01T23:59:59.000Z

139

A 4 to 0.1 nm FEL Based on the SLAC Linac  

SciTech Connect (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

140

FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION  

SciTech Connect (OSTI)

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

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

E-Print Network 3.0 - aps sase fel Sample Search Results  

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

are designed to provide maximum information on the physics of the SASE-FEL... -ray laser 2. However, the experimental proof of SASE-FEL theory has ... Source:...

142

An analysis of the saturation of a high gain FEL  

SciTech Connect (OSTI)

We study the saturated state of an untapered free electron laser in the Compton regime, arising after exponential amplification of an initial low level of radiation by an initially monoenergetic, unbunched electron beam. The saturated state of the FEL is described by oscillations about an equilibrium state. Using the two invariants of the motion, and certain assumptions motivated by computer simulations, we provide approximate analytic descriptions of the radiation field and electron distribution in the saturation regime. We first consider a one-dimensional approximation, and later extend our approach to treat an electron beam of finite radial extent. Of note is a result on the radiated power in the case of an electron beam with small radius.

Gluckstern, R.L.; Okamoto, Hiromi (Maryland Univ., College Park, MD (United States). Dept. of Physics); Krinsky, S. (Brookhaven National Lab., Upton, NY (United States))

1992-12-01T23:59:59.000Z

143

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator  

SciTech Connect (OSTI)

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D. [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)] [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)

2013-09-15T23:59:59.000Z

144

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

E-Print Network [OSTI]

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

Wurtele, Jonathan

145

Experimental Verification of the Chemical Sensitivity of Two-Site Double Core-Hole States Formed by an X-ray FEL  

E-Print Network [OSTI]

We have performed X-ray two-photon photoelectron spectroscopy (XTPPS) using the Linac Coherent Light Source (LCLS) X-ray free-electron laser (FEL) in order to study double core-hole (DCH) states of CO2, N2O and N2. The experiment verifies the theory behind the chemical sensitivity of two-site (ts) DCH states by comparing a set of small molecules with respect to the energy shift of the tsDCH state and by extracting the relevant parameters from this shift.

Salen, P; Schmidt, H T; Thomas, R D; Larsson, M; Feifel, R; Piancastelli, M N; Fang, L; Murphy, B; Osipov, T; Berrah, N; Kukk, E; Ueda, K; Bozek, J D; Bostedt, C; Wada, S; Richter, R; Feyer, V; Prince, K C

2012-01-01T23:59:59.000Z

146

First Results of the LCLS Laser-Heater System  

SciTech Connect (OSTI)

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

147

Hole Coupling Resonator for Free Electron Lasers  

E-Print Network [OSTI]

3. Total round-trip power loss, coupling efficiency and themicron. Total round-trip power loss and coupling efficiencythe total fractional power loss per round trip, the hole

Xie, M.

2011-01-01T23:59:59.000Z

148

Free-Electron Laser | Jefferson Lab  

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

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149

Simple Limits on Achieving A Quasi-Linear Magnetic Compression for an FEL Driver  

SciTech Connect (OSTI)

Free electron lasers (FEL) need a very bright electron beam in three dimensions and a high peak charge density. In order to compress an initially longer electron bunch generated from the photoinjector, magnetic bunch compression systems are widely employed. In this paper, first harmonic RF linearization and its associated requirements are reviewed. Meanwhile it is also briefly discussed what is the relation between a proper initial bunch length and main RF frequency, when a harmonic RF linearization is included. Then given a reasonable bunch compression ratio, a proper initial bunch length as a function of the main RF frequency and RF phase is estimated analytically by several approaches, assuming that no harmonic RF section is needed to linearize the energy modulation introduced during main RF acceleration, and at the same time still linearly compress the bunch length. Next the upper limit of the bunch compression ratio in a single stage is evaluated analytically. The analytical relations derived on choosing a proper initial bunch length as a function of main RF frequency are confirmed by numerical simulation. These simple limit provide rough estimations and may be beneficial for choosing bunch compression ratios in different stages of an FEL driver, especially in a first stage bunch compression where there is usually a harmonic RF linearization applied. It may also be useful in evaluating the possibility of low charge operation mode without any harmonic RF linearization, where a shorter initial bunch length can be achieved from the photoinjector.

Sun, Yipeng; /SLAC

2012-02-16T23:59:59.000Z

150

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

151

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

152

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

153

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

154

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

155

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

156

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

157

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

158

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

159

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

160

Design of an XUV FEL Driven by the Laser-Plasma Accelerator at the LBNL LOASIS Facility  

E-Print Network [OSTI]

A445 (2000) 59. [13] W. M. Fawley, LBNL Technical Report No.LBNL-49625 (2002); see also paper MOPPH073, theseLASER-PLASMA ACCELERATOR AT THE LBNL LOASIS FACILITY ? C. B.

Schroeder, Carl B.; Fawley, W.M.; Esarey, Eric; Leemans, W.P.

2006-01-01T23:59:59.000Z

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


161

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC  

SciTech Connect (OSTI)

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

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

2009-05-04T23:59:59.000Z

162

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

E-Print Network [OSTI]

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

S. Son; S. J. Moon

2012-02-12T23:59:59.000Z

163

A proposed high-power UV industrial demonstration laser at CEBAF  

SciTech Connect (OSTI)

The Laser Processing Consortium, a collaboration of industries, universities, and the Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, Virginia, has proposed building a demonstration industrial processing laser for surface treatment and micro-machining. The laser is a free-electron laser (FEL) with average power output exceeding 1 kW in the ultraviolet (UV). The design calls for a novel driver accelerator that recovers most of the energy of the exhaust electron beam to produce laser light with good wall-plug efficiency. The laser and accelerator design use technologies that are scalable to much higher power. The authors describe the critical design issues in the laser such as the stability, power handling, and losses of the optical resonator, and the quality, power, and reliability of the electron beam. They also describe the calculated laser performance. Finally progress to date on accelerator development and resonator modeling will be reported.

Benson, S.V.; Bisognano, J.J.; Bohn, C.L. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)] [and others

1996-04-01T23:59:59.000Z

164

Laser Assisted Emittance Transfer for Storage Ring Lasing  

SciTech Connect (OSTI)

In modern storage rings the transverse emittance of electron beams can be comparable to that from state-of-art photoinjectors, but the intrinsic low peak current and large energy spread pre-cludes the possibility of realizing short-wavelength high-gain free electron lasers (FELs) in storage rings. In this note I propose a technique to significantly increase beam peak current without greatly increasing beam energy spread, which is achieved by transferring part of the longitudinal emittance to transverse plane. It is shown that by properly repartitioning the emittance in 6-D phase space, the beam from a large storage ring may be used to drive a single-pass high-gain FEL in soft x-ray wavelength range.

Xiang, Dao; /SLAC

2011-06-01T23:59:59.000Z

165

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

166

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

167

Casimir self-energy of a free electron  

E-Print Network [OSTI]

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

Allan Rosencwaig

2006-06-23T23:59:59.000Z

168

High Gradient Inverse Free Electron Laser (IFEL) Accelerator  

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

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169

Part 2: Coherent emission from Free Electron Lasers  

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170

A PLASMA CHANNEL BEAM CONDITIONER FOR A FREE ELECTRON LASER  

E-Print Network [OSTI]

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

Wurtele, Jonathan

171

Free-Electron Laser Targets Fat | Jefferson Lab  

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

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172

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

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

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173

FEL and Optical Klystron Gain for an Electron Beam with Oscillatory Energy Distribution  

SciTech Connect (OSTI)

If the energy spread of a beam is larger then the Pierce parameter, the FEL gain length increases dramatically and the FEL output gets suppressed. We show that if the energy distribution of such a beam is made oscillatory on a small scale, the gain length can be considerably decreased. Such an oscillatory energy distribution is generated by first modulating the beam energy with a laser via the mechanism of inverse FEL, and then sending it through a strong chicane. We show that this approach also works for the optical klystron enhancement scheme. Our analytical results are corroborated by numerical simulations.

Stupakov, G.; Ding, Y.; Huang, Z.; /SLAC

2009-12-09T23:59:59.000Z

174

The GALAXIE all-optical FEL project  

SciTech Connect (OSTI)

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

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

2012-12-21T23:59:59.000Z

175

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

E-Print Network [OSTI]

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

Shyamasundar, R.K.

176

HARMONIC CASCADE FEL DESIGNS FOR LUX G. Penn, M. Reinsch, J. Wurtele  

E-Print Network [OSTI]

HARMONIC CASCADE FEL DESIGNS FOR LUX G. Penn, M. Reinsch, J. Wurtele , J.N. Corlett, W.M. Fawley, A stages of higher harmonic generation, seeded by a 200­250 nm laser of similar duration. This laser mod then produces ra- diation at a higher harmonic after entering a second, differ- ently tuned undulator. Repeated

Wurtele, Jonathan

177

Interactive Video Cubism Sidney Fels  

E-Print Network [OSTI]

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

Fels, Sidney S.

178

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

179

Stability of metallic thin film with free electron model  

SciTech Connect (OSTI)

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

Wu, Biao [ORNL; Zhang, Zhenyu [ORNL

2008-01-01T23:59:59.000Z

180

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

Findley, Gary L.

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

The energy of the quasi-free electron in near critical point nitrogen  

E-Print Network [OSTI]

The energy of the quasi-free electron in near critical point nitrogen Yevgeniy Lushtak a,b , C the density dependent quasi-free electron energy V0() in the strongly absorbing gas N2 for the first time. V0-Seitz model, repulsive fluids, quasi-free electron energy, critical point effects PACS: 79.60.-i, 34.80.-i, 82

Findley, Gary L.

182

Theory of the ion-channel laser  

SciTech Connect (OSTI)

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

Whittum, D.H.

1990-09-01T23:59:59.000Z

183

Beam Line Commissioning of a UV/VUV FEL at Jefferson Lab  

SciTech Connect (OSTI)

Many novel applications in photon sciences require very high brightness and/or short pulses in the vacuum ultra-violet (VUV). Jefferson Lab has commissioned a UV oscillator with high gain and has transported the third harmonic of the UV to a user lab. The experimental performance of the UV FEL is much better than simulated performance in both gain and efficiency. This success is important for efforts to push towards higher gain FELs at short wavelengths where mirrors absorb strongly. We will report on efforts to characterize the UV laser and the VUV coherent harmonics as well as designs to lase directly in the VUV wavelength range.

Benson, Stephen; Blackburn, Keith; Bullard, Daniel; Clavero Perez, Cesar; Coleman, James; Dickover, Cody; Douglas, David; Ellingsworth, Forrest; Evtushenko, Pavel; Hernandez-Garcia, Carlos; Gould, Christopher; Gubeli, Joseph; Hardy, David; Jordan, Kevin; Klopf, John; James, Kortze; Legg, Robert; Marchlik, Matthew; Moore, Steven; Neil, George; Powers, Thomas; Sexton, Daniel; Shinn, Michelle D; Tennant, Christopher; Walker, Richard; Williams, Gwyn; Wilson, Frederick

2011-08-01T23:59:59.000Z

184

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

Findley, Gary L.

185

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

SciTech Connect (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

186

FEL  

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

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187

FEL Design Studies at LBNL: Activities and Plans  

E-Print Network [OSTI]

FEL Design Studies at LBNL: Activities and Plans* J.CA 94720, USA Introduction LBNL staff are currently pursuingRate FEL Facility The LBNL program in R&D toward advanced

Corlett, John N.

2009-01-01T23:59:59.000Z

188

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

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189

Energy of the quasi-free electron in supercritical argon near the critical point C.M. Evans1,  

E-Print Network [OSTI]

Energy of the quasi-free electron in supercritical argon near the critical point C.M. Evans1 to the interaction between argon and the quasi-free electron arising from field ionization of the dopant. The energy by the ionic core, V0(P) is the quasi-free electron energy in the perturbing medium, and P is the perturber

Evans, Cherice M.

190

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.

191

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

SciTech Connect (OSTI)

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

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

2014-07-15T23:59:59.000Z

192

Connecting Lab-Based Attosecond Science with FEL research  

ScienceCinema (OSTI)

In the last few years laboratory-scale femtosecond laser-based research using XUV light has developed dramatically following the successful development of attosecond laser pulses by means of high-harmonic generation. Using attosecond laser pulses, studies of electron dynamics on the natural timescale that electronic processes occur in atoms, molecules and solids can be contemplated, providing unprecedented insight into the fundamental role that electrons play in photo-induced processes. In my talk I will briefly review the present status of the attosecond science research field in terms of present and foreseen capabilities, and discuss a few recent applications, including a first example of the use of attosecond laser pulses in molecular science. In addition, I will discuss very recent results of experiments where photoionization of dynamically aligned molecules is investigated using a high-harmonics XUV source. Photoionization of aligned molecules becomes all the more interesting if the experiment is performed using x-ray photons. Following the absorption of x-rays, ejected photoelectrons can be used as a probe of the (time-evolving) molecular structure, making use of intra-molecular electron diffraction. This amounts, as some have stated, to ?illuminating the molecule from within?. I will present the present status of our experiments on this topic making use of the FLASH free electron laser in Hamburg. Future progress in this research field not only depends on the availability of better and more powerful light sources, but also requires sophisticated detector strategies. In my talk I will explain how we are trying to meet some of the experimental challenges by using the Medipix family of detectors, which we have already used for time- and space-resolved imaging of electrons and ions.

None

2011-10-06T23:59:59.000Z

193

Laser Facilities, Laser-Plasmas & Diagnostics Plasmas Division  

E-Print Network [OSTI]

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

Strathclyde, University of

194

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

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

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

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

2012-09-01T23:59:59.000Z

195

TURKISH ACCELERATOR COMPLEX & STATUS OF TAC SASE FEL  

E-Print Network [OSTI]

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

196

Experimental Demonstration of a Soft X-ray Self-seeded Free-electron Laser  

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

The Linac Coherent Light Source (LCLS) has added self-seeding capability to the soft x-ray range using a grating monochromator system. We report demonstration of soft x-ray self-seeding with a measured resolving power of 2000-5000, wavelength stability of 10-4, and an increase in peak brightness by a factor of 2-5 across the photon energy range of 500-1000 eV. By avoiding the need for a monochromator at the experimental station, the self-seeded beam can deliver as much as 50 fold higher brightness to users.

Ratner, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Abela, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Amann, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Behrens, C. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Bohler, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Bouchard, G. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Bostedt, C. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Boyes, M. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Chow, K. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Cocco, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Decker, F. J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Ding, Y. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Eckman, C. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Emma, P. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Fairley, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Feng, Y. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Field, C. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Flechsig, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Gassner, G. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Hastings, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Heimann, P. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Kelez, N. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Krzywinski, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Lutman, A. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Marinelli, A. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Marcus, G. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Maxwell, T. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Moeller, S. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Morton, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Nuhn, H. D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Rodes, N. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Schlotter, W. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Serkez, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stevens, T. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Turner, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Walz, D. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Welch, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Wu, J. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States)

2015-02-06T23:59:59.000Z

197

Femtosecond dark-field imaging with an X-ray free electron laser (CXIDB ID 19)  

DOE Data Explorer [Office of Scientific and Technical Information (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.

198

Three-dimensional theory of Smith-Purcell free-electron laser with dielectric loaded grating  

SciTech Connect (OSTI)

A dielectric loaded rectangular grating for Smith-Purcell devices is proposed in this paper. Regarding the electron beam as a moving plasma dielectric, a three dimensional (3D) linear theory of beam-wave interaction is developed. The first and second order growth rates are calculated, which are obtained by expanding hot dispersion equation at synchronous point. The results show that the cutoff frequency is affected by grating width. The dispersion curve becomes flatter and shifts towards lower frequency by loading dielectric in grooves. The simulation results, which are obtained by a 3D particle-in-cell code, are in good agreement with theoretical calculations. Compared the first and second order growth rate, it shows that the discrepancy is large when beam parameters are selected with high values. In this case, it is necessary to apply the second order growth rate, which can accurately describe the process of beam-wave interaction.

Cao, Miaomiao, E-mail: mona486@yeah.net; Li, Ke, E-mail: like3714@163.com [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, School of Electronic Science and Technology, Beijing 100049 (China); Liu, Wenxin, E-mail: lwenxin@mail.ie.ac.cn; Wang, Yong, E-mail: wangyong3845@sina.com [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-09-14T23:59:59.000Z

199

Autocorrelation measurements of free-electron laser radiation using a two-photon QWIP  

E-Print Network [OSTI]

]. Besides thermography, the high electrical bandwidth of QWIPs provides interesting opportunities in new

Perera, A. G. Unil

200

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

E-Print Network [OSTI]

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

Placidi, M.

2013-01-01T23:59:59.000Z

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

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

SciTech Connect (OSTI)

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

Hattne, Hattne

2014-03-04T23:59:59.000Z

202

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

SciTech Connect (OSTI)

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

Barends, Thomas, R.M.

2013-11-25T23:59:59.000Z

203

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

E-Print Network [OSTI]

Accelerator Conference, Lucerne, Switzerland (2004) p. 330.Accelerator Conference, Lucerne, Switzerland, July (2004)Proceedings of EPAC 2004, Lucerne, Switzerland. 52. S.

Staples, John

2009-01-01T23:59:59.000Z

204

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

E-Print Network [OSTI]

Accelerator Conference, Lucerne, Switzer- land, July 2004,Accelerator Conference, Lucerne, Switzerland, July 2004,

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

205

Novel adiabatic bifilar helical wiggler entrance for free-electron laser applications  

SciTech Connect (OSTI)

A new adabatic bifilar helical wiggler entrance is presented. This introduction region is obtained by using a liquid shunt resistance to progressively shunt the current circulating in the wiggler helical windings. We have built a prototype wiggler and measured the field profiles obtained with this new scheme. The results agree very well with computer calculations and show that, indeed, one obtains a high quality adiabatic wiggler with this method.

Hartemann, F.; Buzzi, J.M.; Lamain, H.

1988-08-22T23:59:59.000Z

206

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

E-Print Network [OSTI]

end components: GaN JFET transistors, 1GHz fiber optic link and RF micro strip transformers. 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 voltage

Kozak, Victor R.

207

Femtosecond diffractive imaging with a soft-X-ray free-electron laser (CXIDB ID 3)  

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

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

Chapman, H. N.

208

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

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

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

Hattne, Hattne

209

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

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

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

Barends, Thomas, R.M.

210

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

E-Print Network [OSTI]

wavelength seed, and ultrafast pulses. Understanding gainedlasers to produce ultrafast x-ray pulses at the ALS in a “is home to the PULSE Institute for ultrafast energy science,

Staples, John

2009-01-01T23:59:59.000Z

211

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

Office of Science (SC) Website

Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26Germantown Building 1000 Independence...

212

Jefferson Lab's Free-Electron Laser Joins With Others in New...  

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

and magnetic materials (energy transfer); hydrogen and hydrogen-bearing materials (energy storage); and nanophase, composite, and geological materials (novel materials). A...

213

Influence of finite radial geometry on the growth rate of ion-channel free electron laser  

SciTech Connect (OSTI)

The influence of finite radial geometry on the instability of a tenuous relativistic electron beam propagating in an ion-channel in a waveguide is investigated. The instability analysis is based on the linearized Vlasov-Maxwell equations for the perturbation about a self-consistent beam equilibrium. With the help of characteristic method the dispersion relation for the TE-mode is derived and analyzed through the numerical solutions. It is found that the positioning of the beam radius R{sub b} relative to the waveguide radius R{sub c}, and the ion-channel frequency can have a large influence on the maximum growth rate and corresponding wave number.

Bahmani, Mohammad; Hamzehpour, Hossein [Department of Physics, K.N. Toosi University of Technology, Tehran 15875-4416 (Iran, Islamic Republic of)] [Department of Physics, K.N. Toosi University of Technology, Tehran 15875-4416 (Iran, Islamic Republic of); Hasanbeigi, Ali [Department of Physics and Institute for Plasma Research, Kharazmi University, 49 Dr. Mofateh Avenue, Tehran 15614 (Iran, Islamic Republic of)] [Department of Physics and Institute for Plasma Research, Kharazmi University, 49 Dr. Mofateh Avenue, Tehran 15614 (Iran, Islamic Republic of)

2013-11-15T23:59:59.000Z

214

Navy Breaks World Record With Futuristic Free-Electron Laser (FOX News.com)  

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

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215

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of EnergyThe EnergyDepartment of Energy The U.S. andThe

216

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformation for planningto Fuel Cells andEnergy, Office

217

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: Crude OilPublicDNALostPlasmaReviewsOffice ofEnergy,|Office

218

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility of SF(STEO) ï‚·diffractive imaging with a soft-X-ray

219

High-Gain Harmonic Generation Free-Electron Laser at Saturation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas in thein the Assembly ofNa-ionInnovationGain Harmonic

220

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

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

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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

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

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

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222

Microsoft PowerPoint - High Gradient Inverse Free Electron Laser (IFEL.pptx  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fundProject QuarterlyDepartment of Energy FYformulationfeHi h

223

Jefferson Lab's Free-Electron Laser Joins With Others in New Research  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfraredJefferson LabJefferson LabJLab OpenLab ,SOL season

224

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfraredJefferson LabJefferson LabJLab OpenLab ,SOL

225

Jefferson Lab's free-electron laser joins new research venture (Optics.org)  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfraredJefferson LabJefferson LabJLab OpenLab ,SOLDOEJefferson|

226

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

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadoreConnecticut Regions National Science2 FusionSCGF(SC) Free

227

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

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

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228

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

Findley, Gary L.

229

Using pipe with corrugated walls for a sub-terahertz FEL  

E-Print Network [OSTI]

It has been noted in the past, in the study of the wall-roughness impedance, that a metallic pipe with corrugated walls supports propagation of a high-frequency mode that is in resonance with a relativistic beam. This mode can be excited by a beam whose length is a fraction of the wavelength. In this paper, we study another option of excitation of the resonant mode in a metallic pipe with corrugated walls---via the mechanism of the free electron laser instability. This mechanism works if the bunch length is much longer than the wavelength of the radiation.

Stupakov, Gennady

2014-01-01T23:59:59.000Z

230

The Jefferson lab FEL driver ERLs  

SciTech Connect (OSTI)

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

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

2013-11-01T23:59:59.000Z

231

The Jefferson lab FEL driver ERLs  

SciTech Connect (OSTI)

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

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

2013-11-07T23:59:59.000Z

232

High-power, high-intensity laser propagation and interactions  

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

233

Fully QED/relativistic theory of light pressure on free electrons by isotropic radiation  

E-Print Network [OSTI]

A relativistic/QED theory of light pressure on electrons by an isotropic, in particular blackbody radiation predicts thermalization rates of free electrons over entire span of energies available in the lab and the nature. The calculations based on the QED Klein-Nishina theory of electron-photon scattering and relativistic Fokker-Planck equation, show that the transition from classical (Thompson) to QED (Compton) thermalization determined by the product of electron energy and radiation temperature, is reachable under conditions for controlled nuclear fusion, and predicts large acceleration of electron thermalization in the Compton domain.

A. E. Kaplan

2015-02-25T23:59:59.000Z

234

Peculiarities of the Light Absorption and Emission by Free Electrons in Multivalley Semiconductors  

E-Print Network [OSTI]

General expressions are obtained for the coefficient of light absorption by free carriers as well as the intensity of the spontaneous light emission by hot electrons in multivalley semiconductors. These expressions depend on the electron concentration and electron temperature in the individual valleys. An anisotropy of the dispersion law and electron scattering mechanisms is taken into account. Impurity-related and acoustic scattering mechanisms are analyzed. Polarization dependence of the spontaneous emission by hot electrons is found out. At unidirectional pressure applied or high irradiation intensities, the polarization dependence also appears in the coefficient of light absorption by free electrons.

P. M. Tomchuk

2008-11-18T23:59:59.000Z

235

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

SciTech Connect (OSTI)

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

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

1997-10-01T23:59:59.000Z

236

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

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

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

237

aps high power: Topics by E-print Network  

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

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...

238

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

SciTech Connect (OSTI)

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

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

2014-05-19T23:59:59.000Z

239

DEMONSTRATION OF 3D EFFECTS WITH HIGH GAIN AND EFFICIENCY IN A UV FEL OSCILLATOR  

SciTech Connect (OSTI)

We report on the performance of a high gain UV FEL oscillator operating on an energy recovery linac at Jefferson Lab. The high brightness of the electron beam leads to both gain and efficiency that cannot be reconciled with a one-dimensional model. Three-dimensional simulations do predict the performance with reasonable precision. Gain in excess of 100% per pass and an efficiency close to 1/2NW, where NW is the number of wiggler periods, is seen. The laser mirror tuning curves currently permit operation in the wavelength range of 438 to 362 nm. Another mirror set allows operation at longer wavelengths in the red with even higher gain and efficiency.

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

2011-03-01T23:59:59.000Z

240

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

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

ARCHITECTURE AND MAIN HARDWARE COMPONENTS OF THE FEL CONTROL SYSTEM  

E-Print Network [OSTI]

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

Kozak, Victor R.

242

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

Office of Science (SC) Website

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

243

Studies of Resistive Wall Heating at JLAB FEL  

SciTech Connect (OSTI)

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

Li, Rui; Benson, Stephen V.

2013-06-01T23:59:59.000Z

244

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

E-Print Network [OSTI]

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

Geddes, Cameron Guy Robinson

245

Multicolor operation and spectral control in a gain-modulated x-ray free-electron laser  

E-Print Network [OSTI]

PRL 111, 134801 (2013) PHYSICAL REVIEW LETTERS week ending2013 PHYSICAL REVIEW LETTERS PRL 111, 134801 (2013) where uPHYSICAL REVIEW LETTERS PRL 111, 134801 (2013) i u expði u

2013-01-01T23:59:59.000Z

246

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

E-Print Network [OSTI]

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

Dorfman, Konstantin E.

2010-07-14T23:59:59.000Z

247

Longitudinally Coherent Single-Spike Radiation from a Self-Amplified Spontaneous Emission Free-Electron Laser  

E-Print Network [OSTI]

tleties in modern ultrafast pulse measurement techniques.amplitude and phase of ultrafast pulses from the phase-spacephase-space picture of ultrafast pulses is developed with a

Marcus, Gabriel Andrew

2012-01-01T23:59:59.000Z

248

Design considerations for the free-electron laser with the self-seeding and current-enhanced SASE  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape, Density, and MorphologyusingBiomolecularcatalysis5

249

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

E-Print Network [OSTI]

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

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

2006-01-01T23:59:59.000Z

250

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

E-Print Network [OSTI]

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

251

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

252

Beam Halo Measurements at UMER and the JLAB FEL Using an Adaptive Masking Method  

SciTech Connect (OSTI)

Beam halo is a chal­leng­ing issue for in­tense beams since it can cause beam loss, emit­tance growth, nu­cle­ar ac­ti­va­tion and sec­ondary elec­tron emis­sion. Be­cause of the po­ten­tial­ly low num­ber of par­ti­cles in the halo com­pared with beam core, tra­di­tion­al imag­ing meth­ods may not have suf­fi­cient con­trast to de­tect faint halos. We have de­vel­oped a high dy­nam­ic range, adap­tive mask­ing method to mea­sure halo using a dig­i­tal mi­cro-mir­ror array de­vice and demon­strat­ed its ef­fec­tive­ness ex­per­i­men­tal­ly on the Uni­ver­si­ty of Mary­land Elec­tron Ring (UMER). We also re­port on sim­i­lar ex­per­i­ments cur­rent­ly in progress at the Jef­fer­son Lab Free Elec­tron Laser (FEL) using this method.

Zhang, H D; Fiorito, R B; Kishek, R A; O& #x27; Shea, P G; Shkvarunets, A G; Benson, S V; Douglas, D; Wilson, F G

2011-03-01T23:59:59.000Z

253

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect (OSTI)

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

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

2012-12-21T23:59:59.000Z

254

Study of CSR Effects in the Jefferson Laboratory FEL Driver  

SciTech Connect (OSTI)

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

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

2013-08-01T23:59:59.000Z

255

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

E-Print Network [OSTI]

Repetition-Rate FEL Facility at LBNL* A. B ELKACEM , J. M. BBerkeley National Laboratory (LBNL) is working to addressof several divisions at LBNL is working to define the

CORLETT, J.

2009-01-01T23:59:59.000Z

256

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

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

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

257

Design and test of SX-FEL cavity BPM  

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

258

LCLS-II Undulator Tolerance Analysis  

SciTech Connect (OSTI)

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

259

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

SciTech Connect (OSTI)

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

260

Laser Plasma Material Interactions  

SciTech Connect (OSTI)

Surface treatment by means of pulsed laser beams in reactive atmospheres is an attractive technique to enhance the surface features, such as corrosion and wear resistance or the hardness. Many carbides and nitrides play an important role for technological applications, requiring the mentioned property improvements. Here we present a new promising fast, flexible and clean technique for a direct laser synthesis of carbide and nitride surface films by short pulsed laser irradiation in reactive atmospheres (e.g. methane, nitrogen). The corresponding material is treated by short intense laser pulses involving plasma formation just above the irradiated surface. Gas-Plasma-Surface reactions lead to a fast incorporation of the gas species into the material and subsequently the desired coating formation if the treatment parameters are chosen properly. A number of laser types have been used for that (Excimer Laser, Nd:YAG, Ti:sapphire, Free Electron Laser) and a number of different nitride and carbide films have been successfully produced. The mechanisms and some examples will be presented for Fe treated in nitrogen and Si irradiated in methane.

Schaaf, Peter; Carpene, Ettore [Universitaet Goettingen, II. Physikalisches Institut, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

2004-12-01T23:59:59.000Z

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.


261

Using The SLAC Two-Mile Accelerator for Powering an FEL  

SciTech Connect (OSTI)

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

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

2012-06-29T23:59:59.000Z

262

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

E-Print Network [OSTI]

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

263

An Electron Bunch Compressor Based on an FEL Interaction in the Far Infra Red  

E-Print Network [OSTI]

In this note an electron bunch compressor is proposed based on FEL type interaction of the electron bunch with far infrared (FIR) radiation. This mechanism maintains phase space density and thus requires a high quality electron beam to produce bunches of the length of a few ten micrometer.

Gaupp, Andreas

2013-01-01T23:59:59.000Z

264

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

E-Print Network [OSTI]

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

265

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

266

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

SciTech Connect (OSTI)

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

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

2010-08-01T23:59:59.000Z

267

Improvement of classical accelerators by lasers  

E-Print Network [OSTI]

Of the unconventional accelerator techniques those including lasers are reported. After explaining the advances by lasers for classical accelerator techniques, as FELs and other methods for 100 GHz generation of GW pulses, a survey is given of far field and near field laser acceleration. Problems of the beat-wave accelerator are discussed and schemes for particle interaction in vacuum without plasma are elaborated. One scheme is the Boreham experiment and another is the acceleration of "standing" wave fields where charged particles are trapped in the intensity minima. Another scheme uses the relativistic acceleration by half waves where the now available petawatt-picosecond laser pulses should produce GeV electron pulses of high luminosity. Increase of these electron enrgies would need very large lasers in the future.

Hora, Heinrich

1991-01-01T23:59:59.000Z

268

Multidimensional simulation studies of the SELENE FEL oscillator/buncher followed by a radiator/amplifier output scheme  

SciTech Connect (OSTI)

We analyze and present numerical simulations of the so-called electron output scheme [G. I. Erg et al., 15th Int. FEL Conf., The Hague, The Netherlands, 1993, Book of Abstracts p. 50; Preprint Budker INP 93-75] applied to the SELENE proposal of using a high power FEL to illuminate satellite solar cells. In this scheme, a first stage FEL oscillator bunches the electron beam while a second stage ``radiator`` extracts high power radiation. Our analysis suggests only in the case where the radiator employs a long, tapered undulator will the electron output scheme produce a significant increase in extraction efficiency over what is obtainable from a simple, single-stage oscillator. 1- and 2-D numerical simulations of a 1.7{mu}m FEL employing the electron output scheme show reasonably large bunching fractions ({approximately} 0.3--0.4) at the output of the oscillator stage but only {le}2% extraction efficiency from the radiator stage.

Hahn, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Fawley, W.M. [Lawrence Berkeley Lab., CA (United States)

1995-02-01T23:59:59.000Z

269

Simulation studies of a XUV/soft X-ray harmonic-cascade FEL for the proposed LBNL recirculating linac*  

E-Print Network [OSTI]

GINGER and Its Post- Processor XPLOTGIN, LBNL-49625 (2002).CASCADE FEL FOR THE PROPOSED LBNL RECIRCULATING LINCAC £J.N. Corlett, and A. Zholents, LBNL, Berkeley, CA 94720, USA

Fawley, W.M.; Barletta, W.A.; Corlett, J.N.; Zholents, A.

2003-01-01T23:59:59.000Z

270

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

E-Print Network [OSTI]

Bendable Focusing X-Ray Optics for the ALS and the LCLS/FEL:USA 4 Center for X-Ray Optics, Lawrence Berkeley Nationaldevelopment of bendable x-ray optics used for focusing of

Yashchuk, V. V.

2010-01-01T23:59:59.000Z

271

Ultrafast and Nonlinear Spectroscopy of Solids with Small Energy Photons Department of Electrical and Computer Engineering, Rice Quantum Institute, and  

E-Print Network [OSTI]

(FIR) and mid-infrared (MIR) radiation, achievable with free- electron lasers (FELs) and optical and sample damage, lead- ing to extreme nonlinear optical behavior in semiconduc- tors.23,24) Furthermore, Rice University, Houston, Texas 77005, U.S.A. Ultrashort pulses of intense, coherent, and tunable far-infrared

Kono, Junichiro

272

AMPERE AVERAGE CURRENT PHOTOINJECTOR AND ENERGY RECOVERY LINAC*  

E-Print Network [OSTI]

for an ERL based on these units. INTRODUCTION A frontier of very high power Free-Electron Lasers (FEL.) and Jefferson Laboratory to push the frontier of high-brightness ERLs. There are three main elements bunches. Second is a cathode capable of generating high charge electron bunches at the right repetition

Brookhaven National Laboratory

273

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

274

Measurement of the transverse coherence of a VUV Free Electron Laser Rasmus Ischebeck, Manfred Tonutti (RWTH Aachen), Josef Feldhaus, Christopher Gerth  

E-Print Network [OSTI]

-structure in the electron bunch. A large number of electrons emit radiation coherently and the ra- diation intensity grows) Proceedings of EPAC 2004, Lucerne, Switzerland 2580 #12;x / mm y/mm a) -4 -2 0 2 4 -4 -2 0 2 x / mm y/mm b) -4

275

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

E-Print Network [OSTI]

of diluted system, and EIS, dedicated to Elastic Scattering.to the Timer part of the EIS beamline (at whose beginning athe LDM, DIPROI or Timex-EIS beamlines that share a number

Allaria, Enrico

2010-01-01T23:59:59.000Z

276

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

SciTech Connect (OSTI)

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

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

2011-03-01T23:59:59.000Z

277

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

SciTech Connect (OSTI)

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

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

2011-12-13T23:59:59.000Z

278

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

279

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

E-Print Network [OSTI]

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

280

Substrate-Assisted Laser-Initiated Ejection of Proteins Embedded in Water Films Yusheng Dou, Nicholas Winograd, Barbara J. Garrison,*, and Leonid V. Zhigilei  

E-Print Network [OSTI]

. The laser energy is deposited solely into the gold substrate at different heating rates. For fast heating are ejected from the film entraining the enkephalin molecule away from the metal surface. For heating in recent experiments performed with a train of picosecond pulses generated by a mid-infrared free- electron

Zhigilei, Leonid V.

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

Optical techniques for electron-beam characterizations on the APS SASE FEL project  

SciTech Connect (OSTI)

At the Advanced Photon Source (APS) the injector linac`s DC thermionic gun is being supplemented by a low-emittance rf thermionic gun that will support the SASE FEL project. To address the anticipated smaller beam sizes, the standard Chromox beam-profiling screens are being complemented by optical transition radiation (OTR) and Ce-doped YAG single-crystal converters. Direct comparisons of the effective conversion efficiency, spatial resolution, and time response of the three converter screen types have been performed using the DC thermionic gun`s beam accelerated to 400 to 650 MeV. An apparent blurring of observed beam size with increasing incident charge areal density in the YAG crystal was observed for the first time. Only the OTR was prompt enough for the few-ps domain micropulse bunch length measurements performed with a stream camera. Initial beam images of the rf-thermionic gun beam have also been obtained.

Lumpkin, A.H.; Yang, B.X.; Berg, W.J.; White, M.; Lewellen, J.W.; Milton, S.V.

1998-09-01T23:59:59.000Z

282

Impact of the spatial laser distribution on photocathode gun operation  

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

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

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

2012-09-01T23:59:59.000Z

283

Grazing incidence beam expander  

SciTech Connect (OSTI)

A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

1985-01-01T23:59:59.000Z

284

A syncrhronized FIR/VUV light source at Jefferson Lab  

SciTech Connect (OSTI)

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

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

2013-05-31T23:59:59.000Z

285

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

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

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

286

JLAB Electron Driver Capabilities  

SciTech Connect (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

287

A low-neutron background slow-positron source.  

SciTech Connect (OSTI)

The addition of a thermionic rf gun [1] and a photocathode rf gun will allow the Advanced Photon Source (APS) linear accelerator (linac) [2] [3] to become a free-electron laser (FEL) driver [4]. As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low neutron background.

White, M. M.

1998-10-09T23:59:59.000Z

288

Analysis of the microbunching instability in a mid-energy electron linac  

E-Print Network [OSTI]

Microbunching instability usually exists in the linear accelerator (linac) of a free electron laser (FEL) facility. If it is not controlled effectively, the beam quality will be damaged seriously and the machine will not operate properly. In the electron linac of a soft X-Ray FEL device, because the electron energy is not very high, the problem can become even more serious. As a typical example, the microbunching instability in the linac of the proposed Shanghai Soft X-ray Free Electron Laser facility (SXFEL) is investigated in detail by means of both analytical formulae and simulation tools. In the study, a new mechanism of introducing random noise into the beam current profile as the beam passes through a chicane-type bunch compressor is proposed. The higher-order modes that appear in the simulations suggest that further improvement of the current theoretical model of the instability is needed.

Huang, Dazhang; Wang, Zhen; Zhang, Meng; Ng, King Yuen

2014-01-01T23:59:59.000Z

289

SNS Laser Stripping for H- Injection  

SciTech Connect (OSTI)

The ORNL spallation neutron source (SNS) user facility requires a reliable, intense beams of protons. The technique of H- charge exchange injection into a storage ring or synchrotron has the potential to provide the needed beam currents, but it will be limited by intrinsic limitations of carbon and diamond stripping foils. A laser in combination with magnetic stripping has been used to demonstrate a new technique for high intensity proton injection, but several problems need to be solved before a practical system can be realized. Technology developed for use in Free Electron Lasers is being used to address the remaining challenges to practical implementation of laser controlled H- charge exchange injection for the SNS. These technical challenges include (1) operation in vacuum, (2) the control of the UV laser beam to synchronize with the H- beam and to shape the proton beam, (3) the control and stabilization of the Fabry-Perot resonator, and (4) protection of the mirrors from radiation.

V.V. Danilov, Y. Liu, K.B. Beard, V.G. Dudnikov, R.P. Johnson, Michelle D. Shinn

2009-05-01T23:59:59.000Z

290

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

SciTech Connect (OSTI)

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

291

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

E-Print Network [OSTI]

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

Farritor, Shane

292

Laser Telecommunication timeLaser beam  

E-Print Network [OSTI]

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

La Rosa, Andres H.

293

Laser microphone  

DOE Patents [OSTI]

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

Veligdan, James T. (Manorville, NY)

2000-11-14T23:59:59.000Z

294

Rescattering effects in laser-assisted electron-atom bremsstrahlung  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

295

Demonstration of electron beam focusing by a laser-plasma lens  

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

296

Compensating effect of the coherent synchrotron radiation in bunch compressors  

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

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

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

2013-06-01T23:59:59.000Z

297

Coherence properties of the radiation from FLASH  

E-Print Network [OSTI]

FLASH is the first free electron laser user facility operating in the vacuum ultraviolet and soft x-ray wavelength range. Many user experiments require knowledge of the spatial and temporal coherence properties of the radiation. In this paper we present an analysis of the coherence properties of the radiation for the fundamental and for the higher odd frequency harmonics. We show that temporal and spatial coherence reach maximum close to the FEL saturation but may degrade significantly in the post-saturation regime. We also find that the pointing stability of short FEL pulses is limited due to the fact that non-azimuthal FEL eigenmodes are not sufficiently suppressed. We discuss possible ways for improving the degree of transverse coherence and the pointing stability.

Schneidmiller, E A

2015-01-01T23:59:59.000Z

298

Morphology, microstructure, stress and damage properties of thin film coatings for the LCLS x-ray mirrors  

SciTech Connect (OSTI)

The development and properties of reflective coatings for the x-ray offset mirror systems of the Linac Coherent Light Source (LCLS) free-electron laser (FEL) are discussed in this manuscript. The uniquely high instantaneous dose of the LCLS FEL beam translates to strict limits in terms of materials choice, thus leading to an x-ray mirror design consisting of a reflective coating deposited on a silicon substrate. Coherent wavefront preservation requirements for these mirrors result in stringent surface figure and finish specifications. DC-magnetron sputtered B{sub 4}C and SiC thin film coatings with optimized stress, roughness and figure properties for the LCLS x-ray mirrors are presented. The evolution of microstructure, morphology, and stress of these thin films versus deposition conditions is discussed. Experimental results on the performance of these coatings with respect to FEL damage are also presented.

Soufli, R; Baker, S L; Robinson, J C; Gullikson, E M; McCarville, T J; Pivovaroff, M J; Stefan, P; Hau-Riege, S P; Bionta, R

2009-04-23T23:59:59.000Z

299

A SYNCHRONIZED FIR/VUV LIGHT SOURCE AT JEFFERSON LAB  

SciTech Connect (OSTI)

We describe a dual free-electron laser (FEL) configuration on the UV Demo FEL at Jefferson Lab that allows simultaneous lasing at FIR/THz and UV wavelengths. The FIR/THz source would be an FEL oscillator with a short wiggler providing nearly diffraction-limited pulses with pulse energy exceeding 50 microJoules. The FIR source would use the exhaust beam from a UVFEL. The coherent harmonics in the VUV from the UVFEL are out-coupled through a hole. The FIR source uses a shorter resonator with either hole or edge coupling to provide very high power FIR pulses. Simulations indicate excel-lent spectral brightness in the FIR region with over 100 W/cm-1 output.

Stephen Benson, David Douglas, George Neil, Michelle D. Shinn, Gwyn Williams

2012-07-01T23:59:59.000Z

300

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

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

Jefferson Lab News - JLab FEL Wins R&D 100 Award | Jefferson Lab  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfraredJefferson Lab Click onLaser Twinkles inPEM This PEMJeffersonJLab

302

Laser ignition  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

303

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

304

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

305

Multiphoton Ionization of Magnesium in a Ti-Sapphire laser field  

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

306

Laser goniometer  

DOE Patents [OSTI]

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

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

1993-01-01T23:59:59.000Z

307

LASER ACCELERATORS  

E-Print Network [OSTI]

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

Sessler, A.M.

2008-01-01T23:59:59.000Z

308

Laser barometer  

SciTech Connect (OSTI)

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

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

1998-04-01T23:59:59.000Z

309

Laser Optomechanics  

E-Print Network [OSTI]

Cavity optomechanics explores the coupling between the optical field and the mechanical oscillation to induce cooling and regenerative oscillation in a mechanical oscillator. So far, optomechanics relies on the detuning between the cavity and an external pump laser, where the laser acts only as a power supply. Here, we report a new scheme with mutual coupling between a mechanical oscillator that supports a mirror of a vertical-cavity surface-emitting laser (VCSEL) and the optical field, greatly enhancing the light-matter energy transfer. In this work, we used an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror in a VCSEL, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity with > 550 nm self-oscillation amplitude of the micro-mechanical oscillator, two to three orders of magnitude larger than typical. This new scheme not only offers an efficient approach for high-...

Yang, Weijian; Ng, Kar Wei; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J

2015-01-01T23:59:59.000Z

310

Laser EYE SURGERY LASIK and Excimer Lasers  

E-Print Network [OSTI]

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

Fygenson, Deborah Kuchnir

311

Coherent Radiation Effects in the LCLS Undulator  

SciTech Connect (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

312

Local thermodynamic equilibrium in rapidly heated high energy density plasmas  

SciTech Connect (OSTI)

Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance.

Aslanyan, V.; Tallents, G. J. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2014-06-15T23:59:59.000Z

313

Along the Laser Beampath  

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

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

314

Laser Safety Introduction  

E-Print Network [OSTI]

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

McQuade, D. Tyler

315

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

SciTech Connect (OSTI)

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

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

2013-12-01T23:59:59.000Z

316

Laser Cosmology  

E-Print Network [OSTI]

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

Pisin Chen

2014-02-24T23:59:59.000Z

317

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

SciTech Connect (OSTI)

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

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

1988-09-01T23:59:59.000Z

318

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

319

System and method of infrared matrix-assisted laser desorption/ionization mass spectrometry in polyacrylamide gels  

DOE Patents [OSTI]

A system and method for desorption and ionization of analytes in an ablation medium. In one embodiment, the method includes the steps of preparing a sample having analytes in a medium including at least one component, freezing the sample at a sufficiently low temperature so that at least part of the sample has a phase transition, and irradiating the frozen sample with short-pulse radiation to cause medium ablation and desorption and ionization of the analytes. The method further includes the steps of selecting a resonant vibrational mode of at least one component of the medium and selecting an energy source tuned to emit radiation substantially at the wavelength of the selected resonant vibrational mode. The medium is an electrophoresis medium having polyacrylamide. In one embodiment, the energy source is a laser, where the laser can be a free electron laser tunable to generate short-pulse radiation. Alternatively, the laser can be a solid state laser tunable to generate short-pulse radiation. The laser can emit light at various ranges of wavelength.

Haglund Jr., Richard F.; Ermer, David R.; Baltz-Knorr, Michelle Lee

2004-11-30T23:59:59.000Z

320

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

SciTech Connect (OSTI)

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

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

2014-08-15T23:59:59.000Z

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

The CEBAF e{sup +} Footprint  

SciTech Connect (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

322

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

SciTech Connect (OSTI)

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

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

2008-05-05T23:59:59.000Z

323

Accelerator Sources for THz science: A Review  

SciTech Connect (OSTI)

Free Electron Lasers have been around since 1977 providing not only a test bed for the physics of FELs and electron/photon interactions but as a workhorse of scientific research. More than 30 FELs are presently operating around the world spanning a wavelength range from the millimeter region to the hard x-ray using direct current and rf linear accelerators or storage rings as electron sources. The characteristics that have driven the development of these sources are the desire for high peak and average power, high micropulse energies, wavelength tunability, timing flexibility, and wavelengths that are unavailable from more conventional laser sources. Operation of FELs in the far infrared to terahertz regime poses special challenges which have been and are being addressed at a number of facilities around the world. This paper will review a number of former and existing FELs operating in this regime and discuss future efforts. Broadband collective radiation from relativistic electrons also plays a significant role in the production of FIR/THz radiation and several groups are taking advantage of this source for users. Applications for use of the radiation have evolved from simple imaging to complex pump probe tests of insulator/metal transitions and energy flow in organic molecules. We will discuss the technologies for generating the IR/FIR/THz radiation and cover some of the unique applications of such sources.

Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-01-01T23:59:59.000Z

324

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

SciTech Connect (OSTI)

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

Santana Leitner, Mario

2010-09-14T23:59:59.000Z

325

FEL Program | Jefferson Lab  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:Epitaxial ThinFOR IMMEDIATE RELEASE JimFAQs Science Conducting An

326

Laser Roadshow  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs space CombinedValuesRevolutionizingLaser

327

Ionization heating in rare-gas clusters under intense XUV laser pulses  

SciTech Connect (OSTI)

The interaction of intense extreme ultraviolet (XUV) laser pulses ({lambda}=32 nm, I=10{sup 11}-10{sup 14} W/cm{sup 2}) with small rare-gas clusters (Ar{sub 147}) is studied by quasiclassical molecular dynamics simulations. Our analysis supports a very general picture of the charging and heating dynamics in finite samples under short-wavelength radiation that is of relevance for several applications of free-electron lasers. First, up to a certain photon flux, ionization proceeds as a series of direct photoemission events producing a jellium-like cluster potential and a characteristic plateau in the photoelectron spectrum as observed in Bostedt et al. [Phys. Rev. Lett. 100, 133401 (2008)]. Second, beyond the onset of photoelectron trapping, nanoplasma formation leads to evaporative electron emission with a characteristic thermal tail in the electron spectrum. A detailed analysis of this transition is presented. Third, in contrast to the behavior in the infrared or low vacuum ultraviolet range, the nanoplasma energy capture proceeds via ionization heating, i.e., inner photoionization of localized electrons, whereas collisional heating of conduction electrons is negligible up to high laser intensities. A direct consequence of the latter is a surprising evolution of the mean energy of emitted electrons as function of laser intensity.

Arbeiter, Mathias; Fennel, Thomas [Institute of Physics, University of Rostock, D-18051 Rostock (Germany)

2010-07-15T23:59:59.000Z

328

Hypersonic gasdynamic laser system  

SciTech Connect (OSTI)

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

Foreman, K.M.; Maciulaitis, A.

1990-05-22T23:59:59.000Z

329

Analysis of Shot Noise Suppression for Electron Beams  

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

Shot noise can affect the performance of free-electron lasers (FELs) by driving instabilities (e.g., the microbunching instability) or by competing with seeded density modulations. Recent papers have proposed suppressing shot noise to enhance FEL performance. In this paper we use a onedimensional (1D) model to calculate the noise amplification from an energy modulation (e.g., electron interactions from space charge or undulator radiation) followed by a dispersive section. We show that, for a broad class of interactions, selecting the correct dispersive strength suppresses shot noise across a wide range of frequencies. The final noise level depends on the beam’s energy spread and the properties of the interaction potential. We confirm and illustrate our analytical results with 1D simulations.

Ratner, Daniel; Huang, Zhirong; Stupakov, Gennady

2015-02-02T23:59:59.000Z

330

Laser programs highlights 1994  

SciTech Connect (OSTI)

This report provides highlights of the Lawrence Livermore National Laboratories` laser programs. Laser uses and technology assessment and utilization are provided.

NONE

1994-12-31T23:59:59.000Z

331

Laser Desorption Analysis | EMSL  

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

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

332

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

E-Print Network [OSTI]

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

Davidson, Fordyce A.

333

Laser Faraday  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 CERN 73-11LargeLaser Enables InexpensiveFaraday

334

Fiber Lasers  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI HomeTours, Programs and EventsFiber Lasers NIF

335

Narrow gap laser welding  

DOE Patents [OSTI]

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

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

1998-01-01T23:59:59.000Z

336

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

337

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

338

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

339

ablation laser spectrometer  

E-Print Network [OSTI]

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

340

Final Report, Photocathodes for High Repetition Rate Light Sources  

SciTech Connect (OSTI)

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

Ben-Zvi, Ilan [Stony Brook University

2014-04-20T23:59:59.000Z

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

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

SciTech Connect (OSTI)

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

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

2013-12-23T23:59:59.000Z

342

Imaging the ultrafast Kerr effect, free carrier generation, relaxation and ablation dynamics of Lithium Niobate irradiated with femtosecond laser pulses  

SciTech Connect (OSTI)

The interaction of high-power single 130 femtosecond (fs) laser pulses with the surface of Lithium Niobate is experimentally investigated in this work. The use of fs-resolution time-resolved microscopy allows us to separately observe the instantaneous optical Kerr effect induced by the pulse and the generation of a free electron plasma. The maximum electron density is reached 550?fs after the peak of the Kerr effect, confirming the presence of a delayed carrier generation mechanism. We have also observed the appearance of transient Newton rings during the ablation process, related to optical interference of the probe beam reflected at the front and back surface of the ablating layer. Finally, we have analyzed the dynamics of the photorefractive effect on a much longer time scale by measuring the evolution of the transmittance of the irradiated area for different fluences below the ablation threshold.

Garcia-Lechuga, Mario, E-mail: mario@io.cfmac.csic.es; Siegel, Jan, E-mail: j.siegel@io.cfmac.csic.es; Hernandez-Rueda, Javier; Solis, Javier [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain)

2014-09-21T23:59:59.000Z

343

Laser-assisted electrochemistry  

SciTech Connect (OSTI)

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

Glenn, D.F.

1995-05-01T23:59:59.000Z

344

Along the Laser Beampath  

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

9 20 | Next | Last Back to Index NIF Laser Bay Seen from above, each of NIF's two identical laser bays has two clusters of 48 beamlines, one on either side of the utility spine...

345

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

346

Along the Laser Beampath  

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

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

347

Short wavelength laser  

DOE Patents [OSTI]

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

Hagelstein, Peter L. (Livermore, CA)

1986-01-01T23:59:59.000Z

348

Laser bottom hole assembly  

DOE Patents [OSTI]

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

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

2014-01-14T23:59:59.000Z

349

LaserFest Celebration  

SciTech Connect (OSTI)

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

350

X-ray laser  

DOE Patents [OSTI]

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

Nilsen, Joseph (Livermore, CA)

1991-01-01T23:59:59.000Z

351

ORION laser target diagnostics  

SciTech Connect (OSTI)

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

352

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

353

Laser-induced damage of hafnia coatings as a function of pulse duration in the femtosecond to nanosecond range  

SciTech Connect (OSTI)

Laser-damage thresholds and morphologies of hafnia single layers exposed under femtosecond, picosecond, and nanosecond single pulses (1030/1064nm) are reported. The samples were made with different deposition parameters in order to study how the damage behavior of the samples evolves with the pulse duration and how it is linked to the deposition process. In the femtosecond to picosecond regime, the scaling law of the laser-induced damage threshold as a function of pulse duration is in good agreement with the models of photo and avalanche ionization based on the rate equation for free electron generation. However, differences in the damage morphologies between samples are shown. No correlation between the nanosecond and femtosecond/picosecond laser-damage resistance of hafnia coatings could be established. We also report evidence of the transition in damage mechanisms for hafnia, from an ablation process linked to intrinsic properties of the material to a defect-induced process, that exists between a few picoseconds and a few tens of picoseconds.

Gallais, Laurent; Mangote, Benoit; Zerrad, Myriam; Commandre, Mireille; Melninkaitis, Andrius; Mirauskas, Julius; Jeskevic, Maksim; Sirutkaitis, Valdas

2011-03-20T23:59:59.000Z

354

High-peak-power surface high-harmonic generation at extreme ultra-violet wavelengths from a tape  

SciTech Connect (OSTI)

Solid-based surface high-harmonic generation from a tape is experimentally studied. By operating at mildly relativistic normalized laser strengths a{sub 0}?0.2, harmonics up to the 17th order are efficiently produced in the coherent wake emission (CWE) regime. CWE pulse properties, such as divergence, energy, conversion efficiency, and spectrum, are investigated for various tape materials and drive laser conditions. A clear correlation between surface roughness and harmonic beam divergence is found. At the measured pulse properties for the 15th harmonic (conversion efficiency ?6.5×10{sup ?7}, divergence ?7?15 mrad), the 100-mJ-level drive laser produces several MWs of extreme ultra-violet pulses. The spooling tape configuration enables multi-Hz operation over thousands of shots, making this source attractive as a seed to the few-Hz laser-plasma-accelerator-driven free-electron laser (FEL). Models indicate that these CWE pulses with MW level powers are sufficient for seed-induced bunching and FEL gain.

Shaw, B. H. [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States) [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States); Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Tilborg, J. van; Sokollik, T.; Schroeder, C. B.; McKinney, W. R.; Artemiev, N. A.; Yashchuk, V. V.; Gullikson, E. M. [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States); Leemans, W. P. [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States) [Lawrence Berkeley National Lab, Berkeley, California 94720 (United States); Physics Department, University of California, Berkeley, California 94720 (United States)

2013-07-28T23:59:59.000Z

355

LASER SAFETY POLICY Policy Statement  

E-Print Network [OSTI]

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

Vertes, Akos

356

Precision laser aiming system  

DOE Patents [OSTI]

A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.

Ahrens, Brandon R. (Albuquerque, NM); Todd, Steven N. (Rio Rancho, NM)

2009-04-28T23:59:59.000Z

357

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

358

Fluorinated laser dyes  

DOE Patents [OSTI]

A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Hammond, Peter R. (Livermore, CA); Feeman, James F. (Wyomissing, PA)

1992-01-01T23:59:59.000Z

359

ATF CO2 LASER  

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

*Operate at low pressure <<1 atm *Bandwidth P (10 atm supports a picosecond pulse) 4 Ultrafast gas lasers require high pressure Inverse Fourier Transform for discrete spectrum...

360

Novel fluorinated laser dyes  

DOE Patents [OSTI]

A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Hammond, Peter R. (Livermore, CA); Feeman, James F. (Wyomissing, PA)

1991-01-01T23:59:59.000Z

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


361

Laser Program annual report 1987  

SciTech Connect (OSTI)

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

362

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

SciTech Connect (OSTI)

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

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

2012-09-06T23:59:59.000Z

363

Scientific Case and Engineering Design for the BigLight THIR...  

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

(0.3 Broadband (0.3- -3 THz) Terahertz Source (7) 3 THz) Terahertz Source (7) Near Near- -Infrared Free Electron Laser (8) Infrared Free Electron Laser (8) Mid Mid-...

364

Single Particle Laser Ablation | EMSL  

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

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

365

Theoretical investigation of a tunable free-electron light source  

SciTech Connect (OSTI)

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

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

2011-06-15T23:59:59.000Z

366

Free electron gas primary thermometer: The bipolar junction transistor  

SciTech Connect (OSTI)

The temperature of a bipolar transistor is extracted probing its carrier energy distribution through its collector current, obtained under appropriate polarization conditions, following a rigorous mathematical method. The obtained temperature is independent of the transistor physical properties as current gain, structure (Homo-junction or hetero-junction), and geometrical parameters, resulting to be a primary thermometer. This proposition has been tested using off the shelf silicon transistors at thermal equilibrium with water at its triple point, the transistor temperature values obtained involve an uncertainty of a few milli-Kelvin. This proposition has been successfully tested in the temperature range of 77–450?K.

Mimila-Arroyo, J., E-mail: jmimila@cinvestav.mx [Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Dpto. de Ing. Eléctrica-SEES, Av. Instituto Politécnico Nacional No 2508, México D.F. CP 07360 (Mexico)

2013-11-04T23:59:59.000Z

367

Energy Spread Reduction of Electron Beams Produced via Laser Wake  

SciTech Connect (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

368

Longitudinal discharge laser electrodes  

DOE Patents [OSTI]

The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

Warner, B.E.; Miller, J.L.; Ault, E.R.

1994-08-23T23:59:59.000Z

369

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

370

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

371

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

372

Laser Programs Highlight 1995  

SciTech Connect (OSTI)

Our contributions to laser science and technology and corresponding applications range from concept to design of the National Ignition Facility, transfer of Atomic Vapor Laser Isotope Separation technology to the private sector, and from new initiatives in industry and defense to micro-optics for improving human vision.

Jacobs, R.R.

1997-01-31T23:59:59.000Z

373

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

374

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

375

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

376

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

377

Guest Editorial: Laser Damage  

SciTech Connect (OSTI)

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

Vitaly Gruzdev, Michelle D. Shinn

2012-12-01T23:59:59.000Z

378

Commissioning of the LCLS Linac and Bunch Compressors  

SciTech Connect (OSTI)

The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through the first bunch compressor, was commissioned in the spring and summer of 2007. The second phase of commissioning, including the second bunch compressor and various main linac modifications, was completed in January through August of 2008. We report here on experience gained during this second phase of machine commissioning, including the injector, the first and second bunch compressor stages, the linac up to 14 GeV, and beam stability measurements. The final commissioning phase, including the undulator and the long transport line from the linac, is set to begin in December 2008, with first light expected in July 2009.

Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma#, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Limborg-Deprey, C.; Loos, H.; Molloy, S.; Miahnahri, A.; Nuhn, H.-D.; Ratner, D.; Turner, J.; Welch, J.; White, W.; /SLAC

2008-08-20T23:59:59.000Z

379

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

380

The 300 mA SRF ERL  

SciTech Connect (OSTI)

Energy Recovery Linacs (ERL) are important for a variety of applications, from high-power Free-Electron Lasers (FEL) to polarized-electron polarized-proton colliders. The ERL current is arguably the most important characteristic of ERLs for such applications. With that in mind, the Collider-Accelerator Department at Brookhaven National Laboratory embarked on the development of a 300 mA ERL to serve as an R and D test-bed for high-current ERL technologies. These include high-current, extremely well damped superconducting accelerating cavities, high-current superconducting laser-photocathode electron guns and high quantum-efficiency photocathodes. In this presentation I will cover these ERL related developments.

Ben-Zvi, Ilan [Collider-Accelerator Department Brookhaven National Laboratory Upton NY 11973 (United States)

2013-11-07T23:59:59.000Z

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

The Development of the Linac Coherent Light Source RF Gun  

E-Print Network [OSTI]

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

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

2015-01-01T23:59:59.000Z

382

Ab-initio calculations on two-electron ions in strongly coupled plasma environment  

E-Print Network [OSTI]

In this work, the controversy between the interpretations of recent measurements on dense aluminum plasma created with Linac coherent light sources (LCLS) X-ray free electron laser (FEL) and Orion laser has been addressed. In both kind of experiments, helium-like and hydrogen-like spectral lines are used for plasma diagnostics . However, there exist no precise theoretical calculations for He-like ions within dense plasma environment. The strong need for an accurate theoretical estimates for spectral properties of He-like ions in strongly coupled plasma environment leads us to perform ab initio calculations in the framework of Rayleigh-Ritz variation principle in Hylleraas coordinates where ion-sphere potential is used. An approach to resolve the long-drawn problem of numerical instability for evaluating two-electron integrals with extended basis inside a finite domain is presented here. The present values of electron densities corresponding to disappearance of different spectral lines obtained within the fram...

Bhattacharyya, S; Mukherjee, T K

2015-01-01T23:59:59.000Z

383

The Theta Laser A Low Noise Chirped Pulse Laser  

E-Print Network [OSTI]

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

Van Stryland, Eric

384

Effects of e-beam parameters on coherent electron cooling  

SciTech Connect (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

385

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

SciTech Connect (OSTI)

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

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

2014-06-09T23:59:59.000Z

386

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

SciTech Connect (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

387

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

SciTech Connect (OSTI)

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

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

2012-09-05T23:59:59.000Z

388

Quantum electrodynamics in a laser and the electron laser collision  

E-Print Network [OSTI]

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

Qi-Ren Zhang

2014-08-08T23:59:59.000Z

389

1982 laser program annual report  

SciTech Connect (OSTI)

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

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

1983-08-01T23:59:59.000Z

390

Ultra-fast laser system  

DOE Patents [OSTI]

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

Dantus, Marcos; Lozovoy, Vadim V

2014-01-21T23:59:59.000Z

391

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

392

FEL_poster_D4  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:Epitaxial ThinFOR IMMEDIATE RELEASE JimFAQs Science Conducting An

393

Microsoft Word - FEL theory -É  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMappingENVIRONMENTAL IMPACTApproved:GEORGEICReducedITER

394

Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

Laser plasma accelerator, charge diagnostics, Lanex, ICT,Charge Diagnostics for Laser Plasma Accelerators K .CHARGE DIAGNOSTICS CROSS-CALIBRATIONS WITH LASER PLASMA

Nakamura, K.

2011-01-01T23:59:59.000Z

395

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

Broader source: Energy.gov [DOE]

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

396

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

397

Along the Laser Beampath  

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

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

398

Pulsed Laser Deposition | EMSL  

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

is composed of the following: An electro-polished stainless-steel chamber pumped via a turbo molecular pump and backed by a rotary scroll dry pump An excimer laser (KrF) for...

399

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

400

Laser Plasma Interactions  

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

processes. A typical configuration uses a low intensity laser beam (2nd, 3rd, or 4th harmonic of 1054-nm) to probe a plasma volume. The Thomson scattered light is collected by a...

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

Laser cooling of solids  

SciTech Connect (OSTI)

We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

2008-01-01T23:59:59.000Z

402

Insulator for laser housing  

DOE Patents [OSTI]

The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member. 3 figs.

Duncan, D.B.

1992-12-29T23:59:59.000Z

403

Dark Soliton Fiber Laser  

E-Print Network [OSTI]

We report on the experimental observation of stable dark solitons in an all normal dispersion fiber laser. We found experimentally that dark soliton formation is a generic feature of the fiber laser under strong continuous wave (CW) emission. However, only under appropriate pump strength and negative cavity feedback, stable single or multiple dark soliton could be achieved. Furthermore, we show that the features of the observed dark solitons could be well understood based on the nonlinear Schrodinger equation (NLSE).

H. Zhang; D. Y. Tang; L. M. Zhao; X. Wu; Q. L. Bao; K. P. Loh

2009-05-08T23:59:59.000Z

404

Insulator for laser housing  

DOE Patents [OSTI]

The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member.

Duncan, David B. (Auburn, CA)

1992-01-01T23:59:59.000Z

405

Injection-controlled laser resonator  

DOE Patents [OSTI]

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

Chang, J.J.

1995-07-18T23:59:59.000Z

406

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

407

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

408

Controlling molecules with lasers and lasers with molecules  

E-Print Network [OSTI]

I investigate quantum control of spin in molecules using shaped ultrafast lasers and the dynamics of those lasers when their cavities are modified to include programmable molecular masks. The ability to control quantum ...

Taylor, Jason Matthew, 1977-

2007-01-01T23:59:59.000Z

409

Nonlinear laser energy depletion in laser-plasma accelerators  

E-Print Network [OSTI]

Lee- mans, in Advanced Accelerator Concepts, Eleventh Work-in laser-plasma accelerators ? B. A. Shadwick, 1, ‡ C. B.ac- celerators. Laser-plasma accelerators, for example, have

Shadwick, B.A.

2009-01-01T23:59:59.000Z

410

Laser Guiding for GeV Laser-Plasma Accelerators  

E-Print Network [OSTI]

Overview of plasma-based accelerator concepts. IEEE Trans.using laser wake?eld accelerators. Meas. Sci. Technol. 12,for GeV laser-plasma accelerators. In Advanced Accelerator

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

2005-01-01T23:59:59.000Z

411

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 dielectric break ring, and a pair of threaded ring sections is disclosed. 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. 4 figs.

Arnold, P.A.; Anderson, A.T.; Alger, T.W.

1994-09-20T23:59:59.000Z

412

RF laser plasma measurements  

SciTech Connect (OSTI)

One of the major difficulties with excimer lasers has been the presence of impurities, introduced, for example, by the electrodes present in the D.C. discharge approach. Use of microwave excitation makes possible an electrodeless discharge, thereby reducing the risk of introducing impurities into the laser mix. In this approach a tube containing the laser mix is inserted in a waveguide or microwave cavity; the microwaves then break down the laser mix to form a discharge and further interact to heat that discharge. In such microwave discharges, strong fluorescence seems limited to approximately 100 ns. In the same time frame, the fluorescence has also been observed to collapse to the wall. The wall collapse may be related to the reduced fluorescence (reduced radiation area), although burn-up of the lasing components seems more likely. The collapse to the wall reduces the ability to lase by decreasing the active volume. A better understanding of this effect needs to be obtained before a microwave-driven laser can be further developed. This research effort was directed towards obtaining a fundamental understanding of the collapse of the fluorescence to the tube walls. The ultimate goal is to understand the collapse sufficiently to prevent or reduce its effects; to this end, a number of basic plasma physics experiments have been carried out. A complete understanding has not yet been reached.

Bollen, W.M.

1984-08-01T23:59:59.000Z

413

LASER SAFETY MANUAL POLICIES AND PROCEDURES  

E-Print Network [OSTI]

LASER SAFETY MANUAL POLICIES AND PROCEDURES FOR LASER SAFETY AT TEXAS TECH UNIVERSITY LUBBOCK, TEXAS September 2002 #12;V-1 TEXAS TECH UNIVERSITY LASER SAFETY MANUAL TABLE OF CONTENTS SECTION I ­ MANAGEMENT OF LASER LICENSE Introduction A. Laser Safety Program I - 1 B. Radiation Laser Safety Committee I

Zhang, Yuanlin

414

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. 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. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Munich, DE); Boyer, Keith (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

415

Multistable monochromatic laser solitons  

SciTech Connect (OSTI)

We study the spectral properties of stationary laser solitons (LSs) generated in two broad-area vertical cavity surface emitting lasers coupled to each other in face-to-face configuration [P. Genevet et al., Phys. Rev. Lett. 101, 123905 (2008)]. We demonstrate experimentally that LS emission occurs on a single longitudinal mode frequency of the compound cavity. Multistability is reported among differently 'colored' LSs. We also develop a theoretical model beyond the single longitudinal mode approximation whose numerical simulation results are in good agreement with the experimental observations.

Genevet, P.; Columbo, L.; Barland, S.; Giudici, M.; Gil, L.; Tredicce, J. R. [Universite de Nice Sophia Antipolis, Institut Non-Lineaire de Nice, UMR 6618, F-06560 Valbonne (France)

2010-05-15T23:59:59.000Z

416

Laser plasma accelerators  

SciTech Connect (OSTI)

This review article highlights the tremendous evolution of the research on laser plasma accelerators which has, in record time, led to the production of high quality electron beams at the GeV level, using compact laser systems. I will describe the path we followed to explore different injection schemes and I will present the most significant breakthrough which allowed us to generate stable, high peak current and high quality electron beams, with control of the charge, of the relative energy spread and of the electron energy.

Malka, V. [Laboratoire d'Optique Appliquee, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2012-05-15T23:59:59.000Z

417

Laser correcting mirror  

DOE Patents [OSTI]

An improved laser correction mirror (10) for correcting aberrations in a laser beam wavefront having a rectangular mirror body (12) with a plurality of legs (14, 16, 18, 20, 22, 24, 26, 28) arranged into opposing pairs (34, 36, 38, 40) along the long sides (30, 32) of the mirror body (12). Vector force pairs (49, 50, 52, 54) are applied by adjustment mechanisms (42, 44, 46, 48) between members of the opposing pairs (34, 36, 38, 40) for bending a reflective surface 13 of the mirror body 12 into a shape defining a function which can be used to correct for comatic aberrations.

Sawicki, Richard H. (Danville, CA)

1994-01-01T23:59:59.000Z

418

TUFTS UNIVERSITY LASER SAFETY PROGRAM  

E-Print Network [OSTI]

with engineering controls and good work practices. The Tufts University Laser Safety Officer (LSO) along safety liaison to work with the EH&S Office and the LSO to fulfill the requirements outlined operating procedures for these laser installations, and laser safety training for persons working

Dennett, Daniel

419

Single element laser beam shaper  

DOE Patents [OSTI]

A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

2005-09-13T23:59:59.000Z

420

Laser-Induced Breakdown Spectroscopy  

E-Print Network [OSTI]

LIBS-1 Laser-Induced Breakdown Spectroscopy LIBS ANALYSIS OF METAL SURFACES Last updated: June 17, 2014 #12;LIBS-2 Laser­Induced Breakdown Spectroscopy (LIBS) LIBS ANALYSIS OF METAL SURFACES of species at a distance or in hard­to­reach or hazardous environments. Laser­Induced Breakdown Spectroscopy

Nizkorodov, Sergey

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 acceleration of ion beams  

E-Print Network [OSTI]

We consider methods of charged particle acceleration by means of high-intensity lasers. As an application we discuss a laser booster for heavy ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a cascade of crossed laser beams would be necessary to provide additional acceleration to gold ions of the order of GeV/nucleon.

I. A. Egorova; A. V. Filatov; A. V. Prozorkevich; S. A. Smolyansky; D. B. Blaschke; M. Chubaryan

2007-02-01T23:59:59.000Z

422

Laser Cooling of Matter INTRODUCTION  

E-Print Network [OSTI]

- velopment of techniques that have allowed the ion motion to be cooled into the ground state of the confiningLaser Cooling of Matter INTRODUCTION Laser cooling of neutral atoms in the past decades has been a breakthrough in the understanding of their dy- namics and led to the seminal proposals of laser cooling

Kaiser, Robin

423

1 billion times brighter than the sun: Will Jeff Lab's beam lead...  

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

articles.dailypress.com2011-01-17newsdp-nws-cp-jlab-laser-201101161scientists-free-electron-laser-facility-p... Submitted: Thursday, January 20, 2011...

424

How Can X-ray Transient Absorption Spectroscopy Aide Solar Energy...  

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

are from optimized on structural, energetic and dynamic parameters. Intense X-ray pulses from synchrotrons and X-ray free electrons lasers coupled with ultrafast lasers...

425

Laser-Material Interactions: A Study of Laser Energy Coupling with Solids  

E-Print Network [OSTI]

1971) Effects of High-Power Laser Radiation, Academic Presin Effects of High-Power Laser Radiation, (Academic Press,for modeling gas discharge lasers", Boulder, Colo. : Univ.

Shannon, M.A.

2009-01-01T23:59:59.000Z

426

Laser-Generated Shockwaves for the Disruption of Bacterial Biofilms  

E-Print Network [OSTI]

Characterization by modified Laser Spallation Technique (The Basic Laser Spallation Technique (Modified Laser Spallation Technique: “Top-Down”

Navarro, Artemio

2013-01-01T23:59:59.000Z

427

Lucretia: A Matlab-Based Toolbox for the Modellingand Simulation of Single-Pass Electron Beam Transport Systems  

SciTech Connect (OSTI)

We report on Lucretia, a new simulation tool for the study of single-pass electron beam transport systems. Lucretia supports a combination of analytic and tracking techniques to model the tuning and operation of bunch compressors, linear accelerators, and beam delivery systems of linear colliders and linac-driven Free Electron Laser (FEL) facilities. Extensive use of Matlab scripting, graphics, and numerical capabilities maximize the flexibility of the system, and emphasis has been placed on representing and preserving the fixed relationships between elements (common girders, power supplies, etc.) which must be respected in the design of tuning algorithms. An overview of the code organization, some simple examples, and plans for future development are discussed.

Tenenbaum, P.; /SLAC

2005-09-30T23:59:59.000Z

428

X-Ray Microscopy at BESSY: From Nano-Tomography to Fs-Imaging  

SciTech Connect (OSTI)

The BESSY X-ray microscopy group has developed a new full-field x-ray microscope with glass capillary condenser. It permits tomography and spectromicroscopy of cryogenic as well as heated samples. Correlative light and x-ray microscopy is supported by an incorporated high resolution light microscope. Spectromicroscopy with polarized x-rays from a helical undulator can be performed with E/{delta}E = 104. With the planned BESSY High Gain Harmonic Generation Free Electron Laser (HGHG-FEL) x-ray imaging with ultra-short pulses and an integral photon flux of about 1011 photons/pulse in an energy bandwidth of 0.1% will be possible. Single shot imaging with a full field Transmission X-ray Microscope (TXM) employing a beam shaper as a condenser will be feasible with 20 fs pulses.

Schneider, G.; Heim, S.; Rehbein, S.; Eichert, D. [BESSY GmbH, Albert Einstein Strasse 15, 12489 Berlin (Germany); Guttmann, P. [IRP, c/o BESSY m.b.H., Albert Einstein Strasse 15, 12489 Berlin (Germany); Niemann, B. [IRP, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

2007-01-19T23:59:59.000Z

429

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

DOE Patents [OSTI]

A microwiggler assembly produces large magnetic fields for oscillating charged 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. 10 figs.

Warren, R.W.

1992-09-01T23:59:59.000Z

430

Linac Coherent Light Source Undulator RF BPM System  

SciTech Connect (OSTI)

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

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

2007-04-17T23:59:59.000Z

431

Laser Program annual report 1984  

SciTech Connect (OSTI)

The Laser Program Annual Report is part of the continuing series of reports documenting the progress of the unclassified Laser Fusion Program at the Lawrence Livermore National Laboratory (LLNL). As in previous years, the report is organized programmatically. The first section is an overview of the basic goals and directions of the LLNL Inertial Confinement Fusion (ICF) Program, and highlights the year's important accomplishments. Sections 2 through 7 provide the detailed information on the various program elements: Laser Systems and Operations, Target Design, Target Fabrication, Laser Experiments and Advanced Diagnostics, Advanced Laser Development, and Applications of Inertial Confinement Fusion. Individual sections will be indexed separately. 589 refs., 333 figs., 25 tabs.

Rufer, M.L.; Murphy, P.W. (eds.)

1985-06-01T23:59:59.000Z

432

Oxazine laser dyes  

DOE Patents [OSTI]

New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.2 nm copper line to operate in the 700-800 nm range are described by formula I ##STR1##

Hammond, Peter R. (Livermore, CA); Field, George F. (Danville, CA)

1992-01-01T23:59:59.000Z

433

Dye laser amplifier  

DOE Patents [OSTI]

An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

Moses, Edward I. (Livermore, CA)

1992-01-01T23:59:59.000Z

434

Speckle-free laser imaging  

E-Print Network [OSTI]

Many imaging applications require increasingly bright illumination sources, motivating the replacement of conventional thermal light sources with light emitting diodes (LEDs), superluminescent diodes (SLDs) and lasers. Despite their brightness, lasers and SLDs are poorly suited for full-field imaging applications because their high spatial coherence leads to coherent artifacts known as speckle that corrupt image formation. We recently demonstrated that random lasers can be engineered to provide low spatial coherence. Here, we exploit the low spatial coherence of specifically-designed random lasers to perform speckle-free full-field imaging in the setting of significant optical scattering. We quantitatively demonstrate that images generated with random laser illumination exhibit higher resolution than images generated with spatially coherent illumination. By providing intense laser illumination without the drawback of coherent artifacts, random lasers are well suited for a host of full-field imaging applicatio...

Redding, Brandon; Cao, Hui

2011-01-01T23:59:59.000Z

435

2 micron femtosecond fiber laser  

DOE Patents [OSTI]

Methods and systems for generating femtosecond fiber laser pulses are disclose, including generating a signal laser pulse from a seed laser oscillator; using a first amplifier stage comprising an input and an output, wherein the signal laser pulse is coupled into the input of the first stage amplifier and the output of the first amplifier stage emits an amplified and stretched signal laser pulse; using an amplifier chain comprising an input and an output, wherein the amplified and stretched signal laser pulse from the output of the first amplifier stage is coupled into the input of the amplifier chain and the output of the amplifier chain emits a further amplified, stretched signal laser pulse. Other embodiments are described and claimed.

Liu, Jian; Wan, Peng; Yang, Lihmei

2014-07-29T23:59:59.000Z

436

Laser cooling with ultrafast pulse trains  

E-Print Network [OSTI]

We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires vacuum-ultraviolet laser light, while multielectron atoms need laser light at many widely separated frequencies. These restrictions can be eased by laser cooling on two-photon transitions with ultrafast pulse trains. Laser cooling of hydrogen, antihydrogen, and carbon appears feasible, and extension of the technique to molecules may be possible.

David Kielpinski

2003-06-14T23:59:59.000Z

437

Accelerator and Fusion Research Division: 1984 summary of activities  

SciTech Connect (OSTI)

During fiscal 1984, major programmatic activities in AFRD continued in each of five areas: accelerator operations, highlighted by the work of nuclear science users, who produced clear evidence for the formation of compressed nuclear matter during heavy-ion collisions; high-energy physics, increasingly dominated by our participation in the design of the Superconducting Super Collider; heavy-ion fusion accelerator research, which focused on the design of a four-beam experiment as a first step toward assessing the promise of heavy-ion inertial-confinement fusion; and research at the Center for X-Ray Optics, which completed its first year of broadly based activities aimed at the exploitation of x-ray and ultraviolet radiation. At the same time, exploratory studies were under way, aimed at investigating major new programs for the division. During the past year, for example, we took a preliminary look at how we could use the Bevatron as an injector for a pair of colliding-beam rings that might provide the first glimpse of a hitherto unobserved state of matter called the quark-gluon plasma. Together with Livermore scientists, we also conducted pioneering high-gain free-electron laser (FEL) experiments and proposed a new FEL-based scheme (called the two-beam accelerator) for accelerating electrons to very high energies. And we began work on the design of the Coherent XUV Facility (CXF), an advanced electron storage ring for the production of intense coherent radiation from either undulators or free-electron lasers.

Not Available

1985-05-01T23:59:59.000Z

438

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store  

E-Print Network [OSTI]

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store scanners, construction tools, and laser pointers are generally lower powered lasers emit high-intensity, directional light beams that vary in strength, they are a particular hazard

Burke, Peter

439

General Laser Control Measures Operating instructions for a specific laser are found in the manual for that laser.  

E-Print Network [OSTI]

General Laser Control Measures Operating instructions for a specific laser are found in the manual for that laser. There are several procedures that will reduce the potential for exposure to laser beams. 1. The beam from Class IIIB and Class IV lasers should be terminated in highly absorbent, non specular

Huennekens, John

440

Stimulated crystallization of melt-quenched Ge{sub 2}Sb{sub 2}Te{sub 5} films employing femtosecond laser double pulses  

SciTech Connect (OSTI)

The phase transformation of Ge{sub 2}Sb{sub 2}Te{sub 5} films from the melt-quenched amorphous phase into the crystalline phase induced by 800 nm, 100 fs laser pulses has been studied. For partly amorphized films, progressive crystallization could be induced by single pulses, which can be explained by growth of already existing crystalline embryos. For completely amorphized films, it was not possible to induce crystallization with one or two consecutive pulses; three pulses being the threshold for the onset of crystallization. By employing a fs laser double pulse with an adjustable inter-pulse delay, partial crystallization could be triggered for a delay range of 200 fs-100 ps, while for longer delays no crystallization was possible. The time window for stimulated crystallization can be related to the relaxation dynamics of free electrons excited by the first pulse, which are further excited by the second pulse still remaining in the excited state. Our results indicate that the lifetime of excited electrons in melt-quenched amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} is Almost-Equal-To 100 ps.

Cotton, Rebecca L.; Siegel, Jan [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, E-28006 Madrid (Spain)

2012-12-15T23:59:59.000Z

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

Laser beam temporal and spatial tailoring for laser shock processing  

DOE Patents [OSTI]

Techniques are provided for formatting laser pulse spatial shape and for effectively and efficiently delivering the laser energy to a work surface in the laser shock process. An appropriately formatted pulse helps to eliminate breakdown and generate uniform shocks. The invention uses a high power laser technology capable of meeting the laser requirements for a high throughput process, that is, a laser which can treat many square centimeters of surface area per second. The shock process has a broad range of applications, especially in the aerospace industry, where treating parts to reduce or eliminate corrosion failure is very important. The invention may be used for treating metal components to improve strength and corrosion resistance. The invention has a broad range of applications for parts that are currently shot peened and/or require peening by means other than shot peening. Major applications for the invention are in the automotive and aerospace industries for components such as turbine blades, compressor components, gears, etc.

Hackel, Lloyd (Livermore, CA); Dane, C. Brent (Livermore, CA)

2001-01-01T23:59:59.000Z

442

Advances in Laser Science-II  

SciTech Connect (OSTI)

The meeting covered topics on the latest advances in laser technology and applications. The general categories are as follows: advanced lasers and coherent sources; nonlinear optical phenomena and applications; atomic, molecular and ionic spectroscopy; condensed matter, surface and particle spectroscopy; laser photochemistry and photophysics; diagnostic and analytical applications of lasers; and laser research and techniques in medicine and biology. (LSP)

Lapp, M.; Stwalley, W.C.; Kenney-Wallace, G.A.; Lerner, R.G. (eds.)

1987-01-01T23:59:59.000Z

443

Laser Micromachining: Advantages of Liquid Environments  

E-Print Network [OSTI]

Laser Micromachining: Advantages of Liquid Environments Marc J. Palmeri Princeton University Arnold Lab #12;Outline · Motivation ­ Applications of laser micromachining ­ Problems with laser micromachining · How do lasers work? · What is laser micromachining? · Micromachining assembly · Methods

Petta, Jason

444

Laser Fusion Energy The High Average Power  

E-Print Network [OSTI]

Laser Fusion Energy and The High Average Power Program John Sethian Naval Research Laboratory Dec for Inertial Fusion Energy with lasers, direct drive targets and solid wall chambers Lasers DPPSL (LLNL) Kr posters Snead Payne #12;Laser(s) Goals 1. Develop technologies that can meet the fusion energy

445

Laser Safety Manual Scope and Applicability  

E-Print Network [OSTI]

Laser Safety Manual Scope and Applicability This manual applies to all personnel working at or visiting ASU who procure or utilize Class III and Class IV lasers and laser systems. Procurement and user of Class I and Class II laser equipment, such as laser pointers and compact disk players, do not normally

Rhoads, James

446

Laser multiplexing system  

DOE Patents [OSTI]

A plurality of copper lasers, as radiant power sources, emits a beam of power carrying radiation. A plurality of fiber injection assemblies receives power from the plurality of copper lasers and injects such power into a plurality of fibers for individually transmitting the received power to a plurality of power-receiving devices. The power-transmitting fibers of the system are so arranged that power is delivered therethrough to each of the power-receiving devices such that, even if a few of the radiant power sources and/or fibers fail, the power supply to any of the power receiving devices will not completely drop to zero but will drop by the same proportionate amount.

Johnson, Steve A. (Tracy, CA); English, Jr., Ronald Edward (Tracy, CA); White, Ronald K. (Livermore, CA)

2001-01-01T23:59:59.000Z

447

Fusion pumped laser  

DOE Patents [OSTI]

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

Pappas, D.S.

1987-07-31T23:59:59.000Z

448

Laser Safety: A Laser Alignment Practical Training Course  

SciTech Connect (OSTI)

SLAC National Accelerator Laboratory has developed a Laser Alignment Practical Training Course as one of its core laser safety classes. The course is taught to small groups of up to three students and takes 1-3 hours to complete. This practical course is not a substitute for site-specific On-the-Job Training; it does, however, provide a good introduction in core laser safety practices that can be broadly applied. Alignment and diagnostic tasks are performed with low power lasers. Students learn safe alignment and diagnostic techniques and how to avoid common mistakes that might lead to an accident. The class is taught by laser supervisors, enabling them to assess the skill level of new laser personnel and determine the subsequent level of supervision needed. The course has six alignment tasks. For each task, discussion points are given for the instructor to review with the students. The optics setup includes different wavelength lasers, a beam expander, mirrors, irises, a periscope, a beam-splitting polarizer and a diffraction grating. Diagnostic tools include viewing cards, an IR viewer and a ccd camera. Laser eyewear is available to block some laser wavelengths in the setup.

Woods, Michael; Edstrom, Steve; /SLAC; ,

2011-01-26T23:59:59.000Z

449

Ultrafast pulsed laser utilizing broad bandwidth laser glass  

DOE Patents [OSTI]

An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P.sub.2 O.sub.5, Al.sub.2 O.sub.3 and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules.

Payne, Stephen A. (Castro Valley, CA); Hayden, Joseph S. (Clarks Summit, PA)

1997-01-01T23:59:59.000Z

450

Ultrafast pulsed laser utilizing broad bandwidth laser glass  

DOE Patents [OSTI]

An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P{sub 2}O{sub 5}, Al{sub 2}O{sub 3} and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules. 7 figs.

Payne, S.A.; Hayden, J.S.

1997-09-02T23:59:59.000Z

451

Laser fusion neutron source employing compression with short pulse lasers  

DOE Patents [OSTI]

A method and system for achieving fusion is provided. The method includes providing laser source that generates a laser beam and a target that includes a capsule embedded in the target and filled with DT gas. The laser beam is directed at the target. The laser beam helps create an electron beam within the target. The electron beam heats the capsule, the DT gas, and the area surrounding the capsule. At a certain point equilibrium is reached. At the equilibrium point, the capsule implodes and generates enough pressure on the DT gas to ignite the DT gas and fuse the DT gas nuclei.

Sefcik, Joseph A; Wilks, Scott C

2013-11-05T23:59:59.000Z

452

Laser Plasma Interactions  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs space CombinedValuesRevolutionizingLaser Plasma

453

SLAC All Access: Laser Labs  

ScienceCinema (OSTI)

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

Minitti, Mike; Woods Mike

2014-06-03T23:59:59.000Z

454

TLSI W614 laser characterization  

SciTech Connect (OSTI)

The TLSI W614 Laser Trim System, which is a part of the TE5599 Tester, was characterized to find the optimum operating conditions for production trimming of thick and thin film resistors. Operating variables include average laser power, Q-rate, bite size, laser beam focal point, and trim increment start conditions. Operating conditions were found that support a life-stable resistance and a predictable trimming process.

Rector, M.N.

1994-08-01T23:59:59.000Z

455

Hybrid fiber-rod laser  

DOE Patents [OSTI]

Single, or near single transverse mode waveguide definition is produced using a single homogeneous medium to transport both the pump excitation light and generated laser light. By properly configuring the pump deposition and resulting thermal power generation in the waveguide device, a thermal focusing power is established that supports perturbation-stable guided wave propagation of an appropriately configured single or near single transverse mode laser beam and/or laser pulse.

Beach, Raymond J.; Dawson, Jay W.; Messerly, Michael J.; Barty, Christopher P. J.

2012-12-18T23:59:59.000Z

456

Le laser : une brve introduction  

E-Print Network [OSTI]

Le laser : une brève introduction Christian Chardonnet Directeur du Laboratoire Charles Fabry (CNRS Lasers (CNRS/Université Paris 13) Le 9 avril 2010 #12;Les sources de lumière l'ampoule électrique Les;Zoom : x1000 x1000 x1000 x1000 x100 Le spectre du soleil I.R. U.V. Comparaison du rayonnement laser et

van Tiggelen, Bart

457

Laser Atmospheric Studies with VERITAS  

E-Print Network [OSTI]

As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

C. M. Hui; for the VERITAS collaboration

2007-09-25T23:59:59.000Z

458

Coherent instabilities in random lasers  

SciTech Connect (OSTI)

A numerical study is presented of random lasers as a function of the pumping rate above the threshold for lasing. Depending on the leakiness of the system resonances, which is typically larger in random lasers compared to conventional lasers, we observe that the stationary lasing regime becomes unstable above a second threshold. Coherent instabilities are observed as self pulsation at a single frequency of the output intensity, population inversion, as well as the atomic polarization. We find these Rabi oscillations have the same frequency everywhere in the random laser despite the fact that the field intensity strongly depends on the spatial location.

Andreasen, Jonathan; Sebbah, Patrick; Vanneste, Christian [Laboratoire de Physique de la Matiere Condensee, CNRS UMR 6622, Universite de Nice-Sophia Antipolis, Parc Valrose, F-06108, Nice Cedex 02 (France)

2011-08-15T23:59:59.000Z

459

Laser-Based Nondestructive Testing  

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

Laser-Based Nondestructive Testing High speed, non-contact NDT for bridging the gap between traditional nondestructive testing and embedded structural health monitoring. Contact...

460

Single-exciton nanocrystal laser  

DOE Patents [OSTI]

A laser system employing amplification via a single exciton regime and to optical gain media having single exciton amplification is provided.

Klimov, Victor I. (Los Alamos, NM); Ivanov, Sergei A. (Albuquerque, NM)

2012-01-17T23:59:59.000Z

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

EMSL - Single Particle Laser Ablation  

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

single-particle-laser-ablation en Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon http:...

462

Single mode pulsed dye laser oscillator  

DOE Patents [OSTI]

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability.

Hackel, Richard P. (Livermore, CA)

1992-01-01T23:59:59.000Z

463

Single mode pulsed dye laser oscillator  

DOE Patents [OSTI]

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

Hackel, R.P.

1992-11-24T23:59:59.000Z

464

Copper vapor laser modular packaging assembly  

DOE Patents [OSTI]

A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment.

Alger, Terry W. (Tracy, CA); Ault, Earl R. (Dublin, CA); Moses, Edward I. (Castro Valley, CA)

1992-01-01T23:59:59.000Z

465

Laser Spark Distribution and Ignition System  

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

laser spark from a single low power pulse. The system has ap- plications in natural gas fueled reciprocating engines, turbine combustors, explosives, and laser induced...

466

Approaching attometer laser vibrometry  

SciTech Connect (OSTI)

The heterodyne two-beam interferometer has been proven to be the optimal solution for laser-Doppler vibrometry regarding accuracy and signal robustness. The theoretical resolution limit for a two-beam interferometer of laser class 3R (up to 5 mW visible measurement-light) is in the regime of a few femtometer per square-root Hertz and well suited to study vibrations in microstructures. However, some new applications of RF-MEM resonators, nanostructures, and surface-nano-defect detection require resolutions beyond that limit. The resolution depends only on the noise and the sensor sensitivity to specimen displacements. The noise is already defined in nowadays systems by the quantum nature of light for a properly designed optical sensor and more light would lead to an inacceptable influence like heating of a very tiny structure. Thus, noise can only be improved by squeezed-light techniques which require a negligible loss of measurement light which is impossible for almost all technical measurement tasks. Thus, improving the sensitivity is the only possible path which could make attometer laser vibrometry possible. Decreasing the measurement wavelength would increase the sensitivity but would also increase the photon shot noise. In this paper, we discuss an approach to increase the sensitivity by assembling an additional mirror between interferometer and specimen to form an optical cavity. A detailed theoretical analysis of this setup is presented and we derive the resolution limit, discuss the main contributions to the uncertainty budget, and show a first experiment proving the sensitivity amplification of our approach.

Rembe, Christian; Kadner, Lisa; Giesen, Moritz [Research and Development, Polytec GmbH, Polytec Platz 1-7, 76337 Waldbronn (Germany)

2014-05-27T23:59:59.000Z

467

Unidirectional ring lasers  

DOE Patents [OSTI]

Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity is disclosed. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction. 21 figs.

Hohimer, J.P.; Craft, D.C.

1994-09-20T23:59:59.000Z

468

Titan Laser Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System BurstLongTitan Titan is a two-beam laser

469

Jupiter Laser Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region serviceMission Statement Titan TargetInJupiter Laser Facility The

470

BNL | ATF Laser Safety  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformationCenterResearch HighlightsToolsBES Reports EnergyExperiment Start-up AllLaser

471

EMERGING INFRARED LASER ABSORPTION SPECTROSCOPIC  

E-Print Network [OSTI]

CHAPTER 4 EMERGING INFRARED LASER ABSORPTION SPECTROSCOPIC TECHNIQUES FOR GAS ANALYSIS Frank K detection and monitoring of molecular trace gas species in the mid-infrared spectral region be- cause many of the infrared laser source. Well established detection methods include several types of multipass gas absorption

472

Engineering Light: Quantum Cascade Lasers  

ScienceCinema (OSTI)

Quantum cascade lasers are ideal for environmental sensing and medical diagnostic applications. Gmachl discusses how these lasers work, and their applications, including their use as chemical trace gas sensors. As examples of these applications, she briefly presents results from her field campaign at the Beijing Olympics, and ongoing campaigns in Texas, Maryland, and Ghana.

Claire Gmachl

2010-09-01T23:59:59.000Z

473

Laser program annual report 1983  

SciTech Connect (OSTI)

In the 1983 Laser Program Annual Report we present the accomplishments and unclassified activities of the Laser Program at Lawrence Livermore National laboratory (LLNL) for the year 1983. It should be noted that the report, of necessity, is a summary, and more detailed expositions of the research can be found in the many publications and reports authored by staff members in the Laser Program. The purpose of this report is to present our work in a brief form, but with sufficient depth to provide an overview of the analytical and experimental aspects of the LLNL Inertial-Confinement Fusion (ICF) Program. The format of this report is basically the same as that of previous years. Section 1 is an overview and highlights the important accomplishments and directions of the Program. Sections 2 through 7 provide the detailed information on the various major parts of the Program: Laser Systems and Operations, Target Design, Target Fabrication, Fusion Experiments, Laser Research and Development, and Energy Applications.

Hendricks, C.D.; Rufer, M.L.; Murphy, P.W. (eds.)

1984-06-01T23:59:59.000Z

474

Fiber laser development for LISA  

E-Print Network [OSTI]

We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

Kenji Numata; Jeffrey R. Chen; Jordan Camp

2010-03-18T23:59:59.000Z

475

Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum  

SciTech Connect (OSTI)

We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 ?m was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 ?m. The entire probe setup had a spectral resolution of ?1.5 eV, a detection bandwidth of ?24 eV, and an overall photon throughput efficiency of the order of 10{sup ?5}. Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.

Mo, M. Z.; Chen, Z.; Tsui, Y. Y.; Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)] [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Fourmaux, S.; Saraf, A.; Otani, K.; Kieffer, J. C. [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada)] [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada); Ng, A. [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)] [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)

2013-12-15T23:59:59.000Z

476

Levitated droplet dye laser  

E-Print Network [OSTI]

We present the first observation, to our knowledge, of lasing from a levitated, dye droplet. The levitated droplets are created by computer controlled pico-liter dispensing into one of the nodes of a standing ultrasonic wave (100 kHz), where the droplet is trapped. The free hanging droplet forms a high quality optical resonator. Our 750 nL lasing droplets consist of Rhodamine 6G dissolved in ethylene glycol, at a concentration of 0.02 M. The droplets are optically pumped at 532 nm light from a pulsed, frequency doubled Nd:YAG laser, and the dye laser emission is analyzed by a fixed grating spectrometer. With this setup we have achieved reproducible lasing spectra in the visible wavelength range from 610 nm to 650 nm. The levitated droplet technique has previously successfully been applied for a variety of bio-analytical applications at single cell level. In combination with the lasing droplets, the capability of this high precision setup has potential applications within highly sensitive intra-cavity absorban...

Azzouz, H; Balslev, S; Johansson, J; Mortensen, N A; Nilsson, S; Kristensen, A

2006-01-01T23:59:59.000Z

477

Relativistic Laser Plasma Research for Fast Ignition Laser Fusion  

E-Print Network [OSTI]

Reviewed are the present status and future prospects of the laser fusion research at the ILE (Institute of Laser Engineering) Osaka. The Gekko XII and Peta Watt laser system have been operated for investigating the fast ignition, the relativistic laser plasma interactions and so on. In particular, the fast ignition experiments with cone shell target have been in progress as the UK and US-Japan collaboration programs. In the experiments, the imploded high density plasmas are heated by irradiating 500 J level peta watt laser pulse. The thermal neutron yield is found to increase by three orders of magnitude by injecting the peta watt laser into the cone shell target. Transport of relativistic high density electron is the critical issue as the basic physics for understanding the dense plasma heating process. By the theory, simulation and experiment, the collective phenomena in the interactions of intense relativistic electron current with dense plasmas has been investigated to find the formation of self organized flow as the result of filamentation (Weibel) instability. Through the present understanding, the new project, FIREX-I has started recently to prove the principle of the fast ignition scheme. Keywords: fast ignition, peta watt laser, relativistic electron, weibel instability

Mima Kunioki; Tanaka Kazuo. A; Kodama Ryosuke; Johzaki Tomohiro; Nagatomo Hideo; Shiraga Hiroyuki; Miyanaga Noriaki; Azechi Hiroshi; Nakai Mitsuo; Norimatsu Takayoshi; Nagai Keiji; Sunahara Atsushi; Nishihara Katsunobu; Taguchi Toshihiro; Sakagami Hitoshi; Sentoku Yasuhiko; Ruhl Hartmut

2003-01-01T23:59:59.000Z

478

Polarization methods for diode laser excitation of solid state lasers  

DOE Patents [OSTI]

A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

Holtom, Gary R. (Richland, WA)

2008-11-25T23:59:59.000Z

479

Laser Range Finder Objective: Use a forward pointing laser range finder to  

E-Print Network [OSTI]

Laser Range Finder Objective: Use a forward pointing laser range finder to detect and avoid obstacles. Principle Investigators: Randy Beard, Tim McLain Laser Range Finder Opti-Logic RS400 Laser path, laser detects object. 2. Upon detection, insert cylindrical object into world map and plan path

Wirthlin, Michael J.

480

Variable emissivity laser thermal control system  

DOE Patents [OSTI]

A laser thermal control system for a metal vapor laser maintains the wall temperature 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. 8 figs.

Milner, J.R.

1994-10-25T23:59:59.000Z

Note: This page contains sample records for the topic "free-electron laser fel" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


481

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1  

E-Print Network [OSTI]

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 December 2012 #12;LASER SAFETY MANUAL 2012 RICE, and general procedures to aid those individuals working in the laser laboratory environment. It is intended

Natelson, Douglas

482

LASER SAFETY POLICY MANUAL ENVIRONMENTAL HEALTH & SAFETY  

E-Print Network [OSTI]

LASER SAFETY POLICY MANUAL ISSUED BY ENVIRONMENTAL HEALTH & SAFETY OFFICE OF RADIOLOGICAL SAFETY and GEORGIA TECH LASER SAFETY COMMITTEE July 1, 2010 Revised July 31, 2012 #12;Laser Safety Program 1-1 #12;Laser Safety Policy Manual TABLE OF CONTENTS 1. POLICY AND SCOPE

Houston, Paul L.

483

Laser Centre Vrije Universiteit visitors guide  

E-Print Network [OSTI]

Fall 2005 Laser Centre Vrije Universiteit visitors guide #12;Laser Centre Vrije Universiteit De.de.Gijsel@few.vu.nl Website: www.nat.vu.nl/~laser Printing: Drukkerij Ponsen en Looijen, Wageningen © LCVU, Amsterdam great pleasure to present you the Visitors Guide 2005 of the Laser Centre Vrije Universiteit (LCVU

484

Laser transmissionbackscattering through inhomogeneous cirrus clouds  

E-Print Network [OSTI]

Laser transmission­backscattering through inhomogeneous cirrus clouds Szu-Cheng Ou, Yoshihide of the transmission and backscattering of high-energy laser beams. The 2D extinction-coefficient and mean effective and backscattering of high-energy laser beams in realistic atmospheres. The results of laser direct transmission

Takano, Yoshihide

485

Laser Worker Registration Form (LWRF) Surname: Forenames  

E-Print Network [OSTI]

ABCDEFGHI Laser Worker Registration Form (LWRF) Surname: Forenames: School of: Ext No.: Email YY Class of Laser to be Used 1 1M 1E 2 2M 3R 3B 4 Work Location(s) Lab No. Laser Work Currently Undertaken Elsewhere Are you currently engaged in work elsewhere involving laser radiation? YES

Martin, Ralph R.

486

LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1  

E-Print Network [OSTI]

LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 January 2014 #12;LASER SAFETY MANUAL 2014 RICE UNIVERSITY 2 Introduction The objective of the Rice University Laser Safety program is to assist all levels

Natelson, Douglas

487

High precision, rapid laser hole drilling  

DOE Patents [OSTI]

A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

2013-04-02T23:59:59.000Z

488

Surface Science Analysis of GaAs Photocathodes Following Sustained Electron Beam Delivery  

SciTech Connect (OSTI)

Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power Free Electron Lasers (FEL). Several photocathode degradation processes are suspected, including defect formation by ion back bombardment, photochemistry of surface adsorbed species and irradiation-induced surface defect formation. To better understand the mechanisms of photocathode degradation, we have conducted surface and bulk analysis studies of two GaAs photocathodes removed from the FEL photoinjector after delivering electron beam for a few years. The analysis techniques include Helium Ion Microscopy (HIM), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, strained super-lattice GaAs photocathode samples, removed from the CEBAF photoinjector were analyzed using Transmission Electron Microscopy (TEM) and SIMS. This analysis of photocathode degradation during nominal photoinjector operating conditions represents first steps towards developing robust new photocathode designs necessary for generating sub-micron emittance electron beams required for both fourth generation light sources and intense polarized CW electron beams for nuclear and high energy physics facilities.

Shutthanandan, V.; Zhu, Zihua; Stutzman, Marcy L.; Hannon, Fay; Hernandez-Garcia, Carlos; Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Thevuthasan, Suntharampillai; Hess, Wayne P.

2012-06-12T23:59:59.000Z

489

Conditioning of BPM pickup signals for operations of the Duke storage ring with a wide range of single-bunch current  

E-Print Network [OSTI]

The Duke storage ring is a dedicated driver for the storage ring based oscillator free-electron lasers (FELs), and the High Intensity Gamma-ray Source (HIGS). It is operated with a beam current ranging from about 1 mA to 100 mA per bunch for various operations and accelerator physics studies. High performance operations of the FEL and gamma-ray source require a stable electron beam orbit, which has been realized by the global orbit feedback system. As a critical part of the orbit feedback system, the electron beam position monitors (BPMs) are required to be able to precisely measure the electron beam orbit in a wide range of the single-bunch current. However, the high peak voltage of the BPM pickups associated with high single-bunch current degrades the performance of the BPM electronics, and can potentially damage the BPM electronics. A signal conditioning method using low pass filters is developed to reduce the peak voltage to protect the BPM electronics, and to make the BPMs capable of working with a wide ...

Wei, Xu; Sen-Lin, Huang; Wu, W Z; Hao, H; Wang, P; Wu, Y K

2013-01-01T23:59:59.000Z

490

Time-Resolved Imaging of the Microbunching Instability and Energy Spread at the Linac Coherent Light Source  

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

The microbunching instability (MBI) is a well known problem for high brightness electron beams and has been observed at accelerator facilities around the world. Free-electron lasers (FELs) are particularly susceptible to MBI, which can distort the longitudinal phase space and increase the beam’s slice energy spread (SES). Past studies of MBI at the Linac Coherent Light Source (LCLS) relied on optical transition radiation to infer the existence of microbunching. With the development of the x-band transverse deflecting cavity (XTCAV), we can for the first time directly image the longitudinal phase space at the end of the accelerator and complete a comprehensive study of MBI, revealing both detailed MBI behavior as well as insights into mitigation schemes. The fine time resolution of the XTCAV also provides the first LCLS measurements of the final SES, a critical parameter for many advanced FEL schemes. Detailed MBI and SES measurements can aid in understanding MBI mechanisms, benchmarking simulation codes, and designing future high- brightness accelerators.

Ratner, D.; Behrens, C.; Ding, Y.; Huang, Z.; Marinelli, A.; Maxwell, T.; Zhou, F.

2015-03-01T23:59:59.000Z

491

Protective laser beam viewing device  

DOE Patents [OSTI]

A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

Neil, George R.; Jordan, Kevin Carl

2012-12-18T23:59:59.000Z

492

Wick for metal vapor laser  

DOE Patents [OSTI]

An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

Duncan, David B. (Livermore, CA)

1992-01-01T23:59:59.000Z

493

Laser ablation based fuel ignition  

DOE Patents [OSTI]

There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

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

1998-01-01T23:59:59.000Z

494

Laser ablation based fuel ignition  

DOE Patents [OSTI]

There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

Early, J.W.; Lester, C.S.

1998-06-23T23:59:59.000Z

495

Laser Noise Reduction in Air  

E-Print Network [OSTI]

Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuum are strongly correlated. Spectral filtering of the continuum reduces the laser intensity noise by 1.2 dB, showing that fluctuations are rejected to the edges of the spectrum.

Pierre Bejot; Jerome Kasparian; Estelle Salmon; Roland Ackermann; Nicolas Gisin; Jean-Pierre Wolf

2006-08-09T23:59:59.000Z

496

Laser-assisted nuclear photoeffect  

E-Print Network [OSTI]

Proton emission from nuclei via the nuclear photoeffect in the combined electromagnetic fields of a gamma-ray photon and an intense laser wave is studied. An S-matrix approach to the process is developed by utilizing methods known from the theory of nonperturbative laser-atom interactions. As a specific example, photo-proton ejection from halo nuclei is considered. We show that, due to the presence of the laser field, rich sideband structures arise in the photo-proton energy spectra. Their dependence on the parameters and relative orientation of the photon fields is discussed.

Anis Dadi; Carsten Müller