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Sample records for free-electron laser fel

  1. fel 2005 :: Free Electron Laser Conference and Workshop

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

    Submission | Payment | Call for Papers | Exhibitors | Travel 2005 International Free Electron Laser Prize Winner: Avi Gover left to right: John Galayda, Avi Gover (FEL2005...

  2. Ignition feedback regenerative free electron laser (FEL) amplifier

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  3. Free-Electron Laser | Jefferson Lab

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

    Research Inspecting an injector assembly at Jefferson Lab's Free-Electron Laser. A D D I T I O N A L L I N K S: FEL Users FEL Description JLAMP Proposal Applications FEL News Contact top-right bottom-left-corner bottom-right-corner Free-Electron Laser Jefferson Lab's Free-Electron Laser is the world's highest-power tunable infrared laser and was developed using the lab's expertise in superconducting radiofrequency (SRF) accelerators. The FEL also provides ultraviolet laser light, including

  4. Catalac free electron laser

    DOE Patents [OSTI]

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

    1982-01-01

    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.

  5. Efficiency Enhancement in a Tapered Free Electron Laser by Varying...

    Office of Scientific and Technical Information (OSTI)

    public from the National Technical Information Service, Springfield, VA at www.ntis.gov. Energy extraction efficiency of a free electron laser (FEL) can be increased when the...

  6. Design Features of a Planar Hybrid/Permanent Magnet Strong Focusing Undulator for Free Electron Laser (FEL) And Synchrotron Radiation (SR) Applications

    SciTech Connect (OSTI)

    Tatchyn, Roman; /SLAC

    2011-09-09

    Insertion devices for Angstrom-wavelength Free Electron Laser (FEL) amplifiers driven by multi-GeV electron beams generally require distributed focusing substantially stronger than their own natural focusing fields. Over the last several years a wide variety of focusing schemes and configurations have been proposed for undulators of this class, ranging from conventional current-driven quadrupoles external to the undulator magnets to permanent magnet (PM) lattices inserted into the insertion device gap. In this paper we present design studies of a flexible high-field hybrid/PM undulator with strong superimposed planar PM focusing proposed for a 1.5 Angstrom Linac Coherent Light Source (LCLS) driven by an electron beam with a 1 mm-mr normalized emittance. Attainable field parameters, tuning modes, and potential applications of the proposed structure are discussed.

  7. Free electron laser

    DOE Patents [OSTI]

    Villa, Francesco (Alameda, CA)

    1990-01-01

    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.

  8. Airborne Tactical Free-Electron Laser

    SciTech Connect (OSTI)

    Roy Whitney; George Neil

    2007-02-01

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

  9. Circular free-electron laser

    DOE Patents [OSTI]

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

    1984-01-01

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

  10. Rf Feedback free electron laser

    DOE Patents [OSTI]

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

    1981-01-01

    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.

  11. Free electron laser with masked chicane

    DOE Patents [OSTI]

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

    1999-01-01

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

  12. Simulation of free-electron lasers seeded with broadband radiation

    SciTech Connect (OSTI)

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

    2011-03-10

    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.

  13. Efficiency Enhancement in a Tapered Free Electron Laser by Varying the

    Office of Scientific and Technical Information (OSTI)

    Electron Beam Radius (Technical Report) | SciTech Connect Technical Report: Efficiency Enhancement in a Tapered Free Electron Laser by Varying the Electron Beam Radius Citation Details In-Document Search Title: Efficiency Enhancement in a Tapered Free Electron Laser by Varying the Electron Beam Radius Energy extraction efficiency of a free electron laser (FEL) can be increased when the undulator is tapered after the FEL saturation. By use of ray equation approximation to combine the

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

    SciTech Connect (OSTI)

    Felker, B.; Allen, S.; Bell, H.

    1993-10-06

    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.

  15. 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)

    Lab George Neil Named to Lead JLab's Free-Electron Laser Program NEWPORT NEWS, Va., Feb.15, 2008 - Dr. George Neil has been named Associate Director of the Free-Electron Laser Division at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). Neil is responsible for managing the Free-Electron Laser (FEL) operations and research programs. The machine uses superconducting radiofrequency technology to convert electron-beam energy into light that is used to conduct an array of

  16. Crystallographic data processing for free-electron laser sources

    SciTech Connect (OSTI)

    White, Thomas A. Barty, Anton; Stellato, Francesco; Holton, James M.; Kirian, Richard A.; Zatsepin, Nadia A.; Chapman, Henry N.

    2013-07-01

    A processing pipeline for diffraction data acquired using the Ĺserial crystallographyĺ methodology with a free-electron laser source is described with reference to the crystallographic analysis suite CrystFEL and the pre-processing program Cheetah. A processing pipeline for diffraction data acquired using the Ĺserial crystallographyĺ methodology with a free-electron laser source is described with reference to the crystallographic analysis suite CrystFEL and the pre-processing program Cheetah. A detailed analysis of the nature and impact of indexing ambiguities is presented. Simulations of the Monte Carlo integration scheme, which accounts for the partially recorded nature of the diffraction intensities, are presented and show that the integration of partial reflections could be made to converge more quickly if the bandwidth of the X-rays were to be increased by a small amount or if a slight convergence angle were introduced into the incident beam.

  17. Nonlinear study of an ion-channel guiding free-electron laser

    SciTech Connect (OSTI)

    Ouyang, Zhengbiao; Zhang, Shi-Chang

    2015-04-15

    A nonlinear model and simulations of the output power of an ion-channel guiding free-electron laser (FEL) are presented in this paper. Results show that the nonlinear output power of an ion-channel guiding FEL is comparable to that of an axial guide magnetic field FEL. Compared to an axial guide magnetic field FEL, an ion-channel guiding FEL substantially weakens the negative effect of the electron-beam energy spread on the output power due to its advantageous focusing mechanism on the electron motion.

  18. Free electron laser designs for laser amplification

    DOE Patents [OSTI]

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

    1985-01-01

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

  19. Combination free electron and gaseous laser

    DOE Patents [OSTI]

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

    1980-01-01

    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.

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

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

    Jefferson Lab 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 Laser explores promise of carbon nanotubes By James Schultz January 27, 2003 Jefferson Lab's Free-Electron Laser used to explore the fundamental science of how and why nanotubes form, paying close attention to the atomic and molecular details Scientists and technologists of all stripes are working

  1. 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)

    Society Fellows at JLab | Jefferson Lab 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 newly elected American Physical Society Fellows at JLab February 12, 2003 A free-electron laser scientist at the Department of Energy's Jefferson Lab, located in Newport News, Virginia, has earned the distinction of being elected a Fellow of the American Physical Society.

  2. Short pulse free electron laser amplifier

    DOE Patents [OSTI]

    Schlitt, Leland G.; Szoke, Abraham

    1985-01-01

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

  3. Bunch length compression method for free electron lasers to avoid parasitic compressions

    DOE Patents [OSTI]

    Douglas, David R.; Benson, Stephen; Nguyen, Dinh Cong; Tennant, Christopher; Wilson, Guy

    2015-05-26

    A method of bunch length compression method for a free electron laser (FEL) that avoids parasitic compressions by 1) applying acceleration on the falling portion of the RF waveform, 2) compressing using a positive momentum compaction (R.sub.56>0), and 3) compensating for aberration by using nonlinear magnets in the compressor beam line.

  4. Free Electron Lasers Come of Age - Photonics Spectra | Jefferson Lab

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

    Free Electron Lasers Come of Age - Photonics Spectra Submitted: Saturday, August 13, 2005 - 4:35pm

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

    SciTech Connect (OSTI)

    Mirian, N. S.; Maraghechi, B.

    2014-04-15

    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.

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

    SciTech Connect (OSTI)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fisher, A.S.; Friedman, A.; Gallardo, J.; Ingold, G.; Kirk, H.; Kramer, S.; Lin, L.; Rogers, J.T.; Sheehan, J.F.; van Steenbergen, A.; Woodle, M.; Xie, J.; Yu, L.H.; Zhang, R. ); Bhowmik, A. . Rocketdyne Div.)

    1991-01-01

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

  7. Ultraviolet Free Electron Laser Facility preliminary design report

    SciTech Connect (OSTI)

    Ben-Zvi, I.

    1993-02-01

    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).

  8. Distributed seeding for narrow-line width hard x-ray free-electron lasers

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Distributed seeding for narrow-line width hard x-ray free-electron lasers Citation Details In-Document Search Title: Distributed seeding for narrow-line width hard x-ray free-electron lasers We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important

  9. Free-Electron Laser Targets Fat | Jefferson Lab

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

    Free-Electron Laser Targets Fat April 10, 2006 Free-Electron Laser Scientists Rox Anderson, right, and Free-Electron Laser Scientist Steve Benson, left, discuss laser beam parameters while conducting the experiment on pig fat. Image courtesy: Greg Adams, Jefferson Lab Boston, Mass. - Fat may have finally met its match: laser light. Researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital, Harvard Medical School and the Department of Energy's Thomas Jefferson National

  10. An optical parametric chirped-pulse amplifier for seeding high repetition rate free-electron lasers

    SciTech Connect (OSTI)

    H├Âppner, H.; Tanikawa, T.; Schulz, M.; Riedel, R.; Teubner, U.; Faatz, B.; Tavella, F.

    2015-05-15

    High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond lasers for FEL seeding and FEL pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720ÔÇô900 nm, pulse energies up to 1.12 mJ and a pulse duration of 30 fs at a repetition rate of 100 kHz. Since the power scalability of this OPCPA is limited by the OPCPA-pump amplifier, we also demonstrate a 6.7ÔÇô13.7 kW (burst mode) thin-disk OPCPA-pump amplifier, increasing the possible OPCPA output power to many hundreds of watts. Furthermore, third and fourth harmonic generation experiments are performed and the results are used to simulate a seeded FEL with high-gain harmonic generation.

  11. The History of X-ray Free-Electron Lasers

    SciTech Connect (OSTI)

    Pellegrini, C.; ,

    2012-06-28

    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.

  12. Rippled beam free electron laser amplifier

    DOE Patents [OSTI]

    Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01

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

  13. Airborne megawatt class free-electron laser for defense and security

    SciTech Connect (OSTI)

    Roy Whitney; David Douglas; George Neil

    2005-03-01

    An airborne megawatt (MW) average power Free-Electron Laser (FEL) is now a possibility. In the process of shrinking the FEL parameters to fit on ship, a surprisingly lightweight and compact design has been achieved. There are multiple motivations for using a FEL for a high-power airborne system for Defense and Security: Diverse mission requirements can be met by a single system. The MW of light can be made available with any time structure for time periods from microseconds to hours, i.e. there is a nearly unlimited magazine. The wavelength of the light can be chosen to be from the far infrared (IR) to the near ultraviolet (UV) thereby best meeting mission requirements. The FEL light can be modulated for detecting the same pattern in the small fraction of light reflected from the target resulting in greatly enhanced targeting control. The entire MW class FEL including all of its subsystems can be carried by large commercial size airplanes or on an airship. Adequate electrical power can be generated on the plane or airship to run the FEL as long as the plane or airship has fuel to fly. The light from the FEL will work well with relay mirror systems. The required R&D to achieve the MW level is well understood. The coupling of the capabilities of an airborne FEL to diverse mission requirements provides unique opportunities.

  14. Purified self-amplified spontaneous emission free-electron lasers...

    Office of Scientific and Technical Information (OSTI)

    Purified self-amplified spontaneous emission free-electron lasers with slippage-boosted filtering Citation Details In-Document Search Title: Purified self-amplified spontaneous...

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

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

    The Free-Electron Laser upgrade project is funded by the Department of Defense's Office of ... for accelerating electrons to high energy in efficient, cost-effective accelerators. ...

  16. Science Driver Requirements for Seeded Soft X-ray Free Electron Lasers |

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

    Stanford Synchrotron Radiation Lightsource Science Driver Requirements for Seeded Soft X-ray Free Electron Lasers Wednesday, December 2, 2015 - 2:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Fulvio Parmigiani, Elettra-SincrotroneTrieste Program Description Starting from the archetypal FERMI externally seeded FEL, recent theoretical and experimental progress has shown the possibility of producing fully coherent, variable polarization and tunable, soft-X-ray, ultra-short pulses at

  17. FREE ELECTRON LASERS AND HIGH-ENERGY ELECTRON COOLING.

    SciTech Connect (OSTI)

    LITVINENKO,V.N.

    2007-08-31

    Cooling intense high-energy hadron beams remains a major challenge in modern accelerator physics. Synchrotron radiation of such beams is too feeble to provide significant cooling: even in the Large Hadron Collider (LHC) with 7 TeV protons, the longitudinal damping time is about thirteen hours. Decrements of traditional electron cooling decrease rapidly as the high power of beam energy, and an effective electron cooling of protons or antiprotons at energies above 100 GeV seems unlikely. Traditional stochastic cooling still cannot catch up with the challenge of cooling high-intensity bunched proton beams--to be effective, its bandwidth must be increased by about two orders-of-magnitude. Two techniques offering the potential to cool high-energy hadron beams are optical stochastic cooling (OSC) and coherent electron cooling (CEC)--the latter is the focus of this paper. In the early 1980s, CEC was suggested as a possibility for using various instabilities in an electron beam to enhance its interaction with hadrons (i.e., cooling them). The capabilities of present-day accelerator technology, Energy Recovery Linacs (ERLs), and high-gain Free-Electron Lasers (FELs), finally caught up with the idea and provided the all necessary ingredients for realizing such a process. In this paper, we discuss the principles, and the main limitations of the CEC process based on a high-gain FEL driven by an ERL. We also present, and summarize in Table 1, some numerical examples of CEC for ions and protons in RHIC and the LHC.

  18. Flexible control of femtosecond pulse duration and separation using an emittance-spoiling foil in x-ray free-electron lasers

    SciTech Connect (OSTI)

    Ding, Y.; Behrens, C.; Coffee, R.; Decker, F. -J.; Emma, P.; Field, C.; Helml, W.; Huang, Z.; Krejcik, P.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Maxwell, T. J.; Turner, J.

    2015-06-22

    We report experimental studies of generating and controlling femtosecond x-ray pulses in free-electron lasers (FELs) using an emittance spoiling foil. By selectivity spoiling the transverse emittance of the electron beam, the output pulse duration or double-pulse separation is adjusted with a variable size single or double slotted foil. Measurements were performed with an X-band transverse deflector located downstream of the FEL undulator, from which both the FEL lasing and emittance spoiling effects are observed directly.

  19. Axial interaction free-electron laser

    DOE Patents [OSTI]

    Carlsten, Bruce E. (Los Alamos, NM)

    1997-01-01

    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.

  20. Axial interaction free-electron laser

    DOE Patents [OSTI]

    Carlsten, B.E.

    1997-09-02

    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.

  1. Wiggler plane focusing in a linear free electron laser

    DOE Patents [OSTI]

    Scharlemann, Ernst T. (Livermore, CA)

    1988-01-01

    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.

  2. Free electron laser using Rf coupled accelerating and decelerating structures

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  3. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

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

    1981-02-11

    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.

  4. Modeling and Multidimensional Optimization of a Tapered Free Electron Laser

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Modeling and Multidimensional Optimization of a Tapered Free Electron Laser Citation Details In-Document Search Title: Modeling and Multidimensional Optimization of a Tapered Free Electron Laser Authors: Jiao, Y. ; /SLAC /Beijing, Inst. High Energy Phys. ; Wu, J. ; Cai, Y. ; Chao, A.W. ; Fawley, W.M. ; Frisch, J. ; Huang, Z. ; Nuhn, H.D. ; /SLAC ; Pellegrini, C. ; /SLAC /UCLA ; Reiche, S. ; /PSI, Villigen Publication Date: 2013-03-28 OSTI

  5. Enabling X-ray free electron laser crystallography for challenging

    Office of Scientific and Technical Information (OSTI)

    biological systems from a limited number of crystals (Journal Article) | SciTech Connect Enabling X-ray free electron laser crystallography for challenging biological systems from a limited number of crystals Citation Details In-Document Search Title: Enabling X-ray free electron laser crystallography for challenging biological systems from a limited number of crystals Authors: Uervirojnangkoorn, Monarin ; Zeldin, Oliver B. ; Lyubimov, Artem Y. ; Hattne, Johan Search SciTech Connect for

  6. Experiments in sideband suppression on the Los Alamos National Laboratory Free-Electron Laser

    SciTech Connect (OSTI)

    White, C.J.; Coyle, M.R.; Paxton, A.H. (Mission Research Corp., Albuquerque, NM (United States). Laser and Optical R and D Group); O'Shea, P.G.; Bender, S.C.; Byrd, D.A.; Feldman, D.W.; Goldstein, J.C.: Pitcher, E.J.; Zaugg, T.J. (Los Alamos National Lab., NM (United States))

    1993-01-01

    Two versions of the Phase-Step Mirror'' (PSM), a novel optical component that prevents the formation of sidebands in a Free-Electron Laser (FEL) were tested on the Los Alamos National Laboratory (LANL) APEX FEL. Sideband suppression and frequency control with high extraction efficiency and single line, transform limited operation were demonstrated. The results of our LANL experiments and computer simulations showed that for very high gain applications, the first-order sideband is completely suppressed, but the laser gain is so strong that on about pass 300 the sideband at the second-order or next free spectral range of the PSM appears. This second-order sideband may be suppressed by designing a PSM with grooves having two alternating depths, one chosen to suppress the first-order sideband, and the other, the second-order sideband.

  7. Experiments in sideband suppression on the Los Alamos National Laboratory Free-Electron Laser

    SciTech Connect (OSTI)

    White, C.J.; Coyle, M.R.; Paxton, A.H. [Mission Research Corp., Albuquerque, NM (United States). Laser and Optical R and D Group; O`Shea, P.G.; Bender, S.C.; Byrd, D.A.; Feldman, D.W.; Goldstein, J.C.: Pitcher, E.J.; Zaugg, T.J. [Los Alamos National Lab., NM (United States)

    1993-06-01

    Two versions of the ``Phase-Step Mirror`` (PSM), a novel optical component that prevents the formation of sidebands in a Free-Electron Laser (FEL) were tested on the Los Alamos National Laboratory (LANL) APEX FEL. Sideband suppression and frequency control with high extraction efficiency and single line, transform limited operation were demonstrated. The results of our LANL experiments and computer simulations showed that for very high gain applications, the first-order sideband is completely suppressed, but the laser gain is so strong that on about pass 300 the sideband at the second-order or next free spectral range of the PSM appears. This second-order sideband may be suppressed by designing a PSM with grooves having two alternating depths, one chosen to suppress the first-order sideband, and the other, the second-order sideband.

  8. Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

    SciTech Connect (OSTI)

    LehmkŘhler, Felix; Kwa?niewski, Pawe?; Roseker, Wojciech; Fischer, Birgit; Schroer, Martin A.; Tono, Kensuke; Katayama, Tetsuo; Sprung, Michael; Sikorski, Marcin; Song, Sanghoon; Glownia, James; Chollet, Matthieu; Nelson, Silke; Robert, Aymeric; Gutt, Christian; Yabashi, Makina; Ishikawa, Tetsuya; GrŘbel, Gerhard

    2015-11-27

    In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shot based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.

  9. 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)

    Office of Scientific and Technical Information Free-Electron Lasers Existing Free-Electron Lasers Using Free-Electron Lasers for Measurement and Defense New Free-Electron Laser Designs References Research Organizations Reports available from OSTI's Information Bridge While most types of laser produce coherent light from electric charges bound within atoms, molecules, or solids, unbound charges are the light source in free-electron lasers. Lasers of this type can operate at higher frequencies

  10. An optical parametric chirped-pulse amplifier for seeding high repetition rate free-electron lasers

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

    H├Âppner, H.; Hage, A.; Tanikawa, T.; Schulz, M.; Riedel, R.; Teubner, U.; Prandolini, M. J.; Faatz, B.; Tavella, F.

    2015-05-15

    High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond lasers for FEL seeding and FEL pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720ÔÇô900 nm, pulse energies up to 1.12 mJ and a pulse duration of 30 fs at a repetition rate of 100 kHz. Since the power scalability of this OPCPA is limited by the OPCPA-pump amplifier, we also demonstrate a 6.7ÔÇô13.7 kW (burst mode) thin-disk OPCPA-pump amplifier, increasing the possible OPCPA output power to manymore┬á┬╗ hundreds of watts. Furthermore, third and fourth harmonic generation experiments are performed and the results are used to simulate a seeded FEL with high-gain harmonic generation.┬ź┬áless

  11. Multifrequency, single pass free electron laser

    DOE Patents [OSTI]

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

    1985-01-01

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

  12. Two-dimensional optimization of free electron laser designs

    DOE Patents [OSTI]

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

    1985-01-01

    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.

  13. Two-dimensional optimization of free-electron-laser designs

    DOE Patents [OSTI]

    Prosnitz, D.; Haas, R.A.

    1982-05-04

    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.

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

    SciTech Connect (OSTI)

    Bhowmik, A.; Lordi, N. . Rocketdyne Div.); Ben-Zvi, I.; Gallardo, J. )

    1990-01-01

    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.

  15. A spectral unaveraged algorithm for free electron laser simulations

    SciTech Connect (OSTI)

    Andriyash, I.A.; Lehe, R.; Malka, V.

    2015-02-01

    We propose and discuss a numerical method to model electromagnetic emission from the oscillating relativistic charged particles and its coherent amplification. The developed technique is well suited for free electron laser simulations, but it may also be useful for a wider range of physical problems involving resonant fieldÔÇôparticles interactions. The algorithm integrates the unaveraged coupled equations for the particles and the electromagnetic fields in a discrete spectral domain. Using this algorithm, it is possible to perform full three-dimensional or axisymmetric simulations of short-wavelength amplification. In this paper we describe the method, its implementation, and we present examples of free electron laser simulations comparing the results with the ones provided by commonly known free electron laser codes.

  16. A tapered undulator experiment at the ELBE far infrared hybrid-resonator oscillator free electron laser

    SciTech Connect (OSTI)

    Asgekar, V.; Lehnert, U.; Michel, P.

    2012-01-15

    A tapered undulator experiment was carried out at the ELBE far-infrared free electron laser (FEL). The oscillator FEL makes use of a hybrid optical resonator. The main motivation was to see whether the presence of a dispersive medium in the form of a waveguide in the resonator has any effect on the outcome. The FEL saturated power and the wavelength shifts have been measured as a function of both positive as well as negative undulator field amplitude tapering. In contrast to the typical high-gain FELs where positive tapering proves beneficial for the output power we observed an improvement of performance at negative taper. During the same experiments we studied the characteristics of the detuning curves. The width of the curves indicates a maximum small signal gain for zero taper while the output peak power increases with negative taper. The saturated power output, the detuning curve characteristics, and the wavelength shifts agrees with the theoretical predictions. Details of the experiment are presented.

  17. Wiggler plane focusing in a linear free electron laser

    DOE Patents [OSTI]

    Scharlemann, E.T.

    1985-11-21

    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.

  18. Wiggler plane focusing in a linear free electron laser

    DOE Patents [OSTI]

    Scharlemann, E.T.

    1988-02-23

    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. 5 figs.

  19. Chirped pulse inverse free-electron laser vacuum accelerator

    DOE Patents [OSTI]

    Hartemann, Frederic V.; Baldis, Hector A.; Landahl, Eric C.

    2002-01-01

    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.

  20. Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser

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

    Allaria, Enrico; Diviacco, Bruno; Callegari, Carlo; Finetti, Paola; Mahieu, Benoît; Viefhaus, Jens; Zangrando, Marco; De Ninno, Giovanni; Lambert, Guillaume; Ferrari, Eugenio; et al

    2014-12-02

    The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary polarization in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and polarization can be set in less than a minute of routine operations. We report the first demonstration of the full output polarization capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal polarization are set to a series of representative values, and the polarization of the emitted intense pulses is thoroughly characterized by three independentmore┬á┬╗ instruments and methods, expressly developed for the task. The measured radiation polarization is consistently >90% and is not significantly spoiled by the transport optics; differing, relative transport losses for horizontal and vertical polarization become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly polarized state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.┬ź┬áless

  1. Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser

    SciTech Connect (OSTI)

    Allaria, Enrico; Diviacco, Bruno; Callegari, Carlo; Finetti, Paola; Mahieu, Benoţt; Viefhaus, Jens; Zangrando, Marco; De Ninno, Giovanni; Lambert, Guillaume; Ferrari, Eugenio; Buck, Jens; Ilchen, Markus; Vodungbo, Boris; Mahne, Nicola; Svetina, Cristian; Spezzani, Carlo; Di Mitri, Simone; Penco, Giuseppe; Trovˇ, Mauro; Fawley, William M.; Rebernik, Primoz R.; Gauthier, David; Grazioli, Cesare; Coreno, Marcello; Ressel, Barbara; Kivimńki, Antti; Mazza, Tommaso; Glaser, Leif; Scholz, Frank; Seltmann, Joern; Gessler, Patrick; GrŘnert, Jan; De Fanis, Alberto; Meyer, Michael; Knie, AndrÚ; Moeller, Stefan P.; Raimondi, Lorenzo; Capotondi, Flavio; Pedersoli, Emanuele; Plekan, Oksana; Danailov, Miltcho B.; Demidovich, Alexander; Nikolov, Ivaylo; Abrami, Alessandro; Gautier, Julien; LŘning, Jan; Zeitoun, Philippe; Giannessi, Luca

    2014-12-02

    The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary polarization in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and polarization can be set in less than a minute of routine operations. We report the first demonstration of the full output polarization capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal polarization are set to a series of representative values, and the polarization of the emitted intense pulses is thoroughly characterized by three independent instruments and methods, expressly developed for the task. The measured radiation polarization is consistently >90% and is not significantly spoiled by the transport optics; differing, relative transport losses for horizontal and vertical polarization become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly polarized state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.

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

    SciTech Connect (OSTI)

    Thompson, Neil

    2010-10-20

    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.

  3. Toward a Single Mode Free Electron Laser for Coherent Hard X...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Toward a Single Mode Free Electron Laser for Coherent Hard X-Ray Experiments Citation Details In-Document Search Title: Toward a Single Mode Free Electron Laser...

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

    Office of Scientific and Technical Information (OSTI)

    Read more in the white paper In OSTI Collections: Free-Electron Lasers by Dr. William Watson, Physicist, OSTI staff. Free-Electron Lasers Results in DOE Databases Science.gov ...

  5. High Resolution Simulation of Beam Dynamics in Electron Linacs for Free Electron Lasers

    SciTech Connect (OSTI)

    Ryne, R.D.; Venturini, M.; Zholents, A.A.; Qiang, J.

    2009-01-05

    In this paper we report on large scale multi-physics simulation of beam dynamics in electron linacs for next generation free electron lasers (FELs). We describe key features of a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wake fields, longitudinal coherent synchrotron radiation (CSR) wake fields, and treatment of radiofrequency (RF) accelerating cavities using maps obtained from axial field profiles. A macroparticle up-sampling scheme is described that reduces the shot noise from an initial distribution with a smaller number of macroparticles while maintaining the global properties of the original distribution. We present a study of the microbunching instability which is a critical issue for future FELs due to its impact on beam quality at the end of the linac. Using parameters of a planned FEL linac at Lawrence Berkeley National Laboratory (LBNL), we show that a large number of macroparticles (beyond 100 million) is needed to control numerical shot noise that drives the microbunching instability. We also explore the effect of the longitudinal grid on simulation results. We show that acceptable results are obtained with around 2048 longitudinal grid points, and we discuss this in view of the spectral growth rate predicted from linear theory. As an application, we present results from simulations using one billion macroparticles of the FEL linac under design at LBNL. We show that the final uncorrelated energy spread of the beam depends not only on the initial uncorrelated energy spread but also depends strongly on the shape of the initial current profile. By using a parabolic initial current profile, 5 keV initial uncorrelated energy spread at 40 MeV injection energy, and improved linac design, those simulations demonstrate that a reasonable beam quality can be achieved at the end of the linac, with the final distribution having about 100 keV energy spread, 2.4 GeV energy, and 1.2 kA peak current.

  6. Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a

    Office of Scientific and Technical Information (OSTI)

    Transverse Gradient Undulator (Journal Article) | SciTech Connect Journal Article: Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy

  7. Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a

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

    Transverse Gradient Undulator (Journal Article) | SciTech Connect Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy spread hinders

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

    SciTech Connect (OSTI)

    Mohsenpour, Taghi Rezaee Rami, Omme Kolsoum

    2014-07-15

    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.

  9. High-power beam injectors for 100 KW free-electron lasers

    SciTech Connect (OSTI)

    Todd, A. M.; Wood R. L.; Bluem, H.; Young, L. M.; Wiseman, M.; Schultheiss, T.; Schrage, D. L.; Russell, S. J.; Rode, C. H.; Rimmer, R.; Nguyen, D. C.; Kelley, J. P.; Kurennoy, S.; wood, r

    2003-01-01

    A key technology issue on the path to high-power FEL operation is the demonstration of reliable, high-brightness, high-power injector operation. We describe two ongoing programs to produce 100 mA injectors as drivers for 100 kW free-electron lasers. In one approach, in collaboration with the Thomas Jefferson National Accelerator Facility, we are fabricating a 750 MHz superconducting RF cryomodule that will be integrated with a room-temperature DC photocathode gun and tested at the Laboratory. In the other approach, in collaboration with Los Alamos National Laboratory, a high-current 700 MHz, normal-conducting, RF photoinjector is being designed and will undergo thermal management testing at the Laboratory. We describe the design, the projected performance and the status of both injectors.

  10. Compact two-beam push-pull free electron laser

    DOE Patents [OSTI]

    Hutton, Andrew (Yorktown, VA)

    2009-03-03

    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.

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

    SciTech Connect (OSTI)

    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├Âhr, Joachim; Stupakov, Gennady; White, Bill; Xiang, Dao

    2009-06-08

    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.

  12. Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

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

    Lehmk├╝hler, Felix; Kwa┼Ťniewski, Pawe┼é; Roseker, Wojciech; Fischer, Birgit; Schroer, Martin A.; Tono, Kensuke; Katayama, Tetsuo; Sprung, Michael; Sikorski, Marcin; Song, Sanghoon; et al

    2015-11-27

    In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shotmore┬á┬╗ based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.┬ź┬áless

  13. Induction accelerators and free-electron lasers at LLNL: Beam Research Program

    SciTech Connect (OSTI)

    Briggs, R.J.

    1989-02-15

    Linear induction accelerators have been developed to produce pulses of charged particles at voltages exceeding the capabilities of single-stage, diode-type accelerators and at currents too high rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multistage induction machine. The advent of magnetic pulse power systems makes sustained operation at high repetition rates practical, and high-average-power capability is very likely to open up many new applications of induction machines. In Part A of this paper, we survey the US induction linac technology, emphasizing electron machines. We also give a simplified description of how induction machines couple energy to the electron beam to illustrate many general issues that designers of high-brightness and high-average-power induction linacs must consider. We give an example of the application of induction accelerator technology to the relativistic klystron, a power source for high-gradient accelerators. In Part B we address the application of LIAs to free-electron lasers. The multikiloampere peak currents available from linear induction accelerators make high-gain, free-electron laser amplifier configurations feasible. High extraction efficiencies in a single mass of the electron beam are possible if the wiggler parameters are appropriately ''tapered'', as recently demonstrated at millimeter wavelengths on the 4-MeV ELF facility. Key issues involved in extending the technology to shorter wavelengths and higher average powers are described. Current FEL experiments at LLNL are discussed. 5 refs., 16 figs.

  14. Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a

    Office of Scientific and Technical Information (OSTI)

    Transverse-Gradient Undulator (Journal Article) | SciTech Connect Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a Transverse-Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a Transverse-Gradient Undulator Authors: Huang, Zhirong ; Ding, Yuantao ; Schroeder, Carl B. Publication Date: 2012-11-12 OSTI Identifier: 1101325 Type: Publisher's Accepted Manuscript Journal Name: Physical

  15. The European XFEL Free Electron Laser at DESY

    ScienceCinema (OSTI)

    Weise, Hans [Deutsches Elektronen-Synchrotron, Germany

    2009-09-01

    The European X-ray Free-Electron laser Facility (XFEL) is going to be built in an international collaboration at the Deutsches Elektronen-Synchrotron (DESY), Germany, and the Technical Design Report was published in 2006. The official project is expected for summer 2007. This new facility will offer photon beams at wavelengths as short as 1 angstrom with highest peak brilliance being more than 100 million times higher than present day synchrotron radiation sources. The radiation has a high degree of transverse coherence and the pulse duration is reduced from {approx}100 picoseconds (typ. for SR light sources) down to the {approx}10 femtosecond time domain. The overall layout of the XFEL will be described. This includes the envisaged operation parameters for the linear accelerator using superconducting TESLA technology. The complete design is based on the actually operated FLASH free-electron laser at DESY. Experience with the operation during first long user runs at wavelengths from 30 to 13 nm will be described in detail.

  16. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, Hongxiu; Neil, George R.

    1998-01-01

    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.

  17. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, H.; Neil, G.R.

    1998-09-08

    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.

  18. Nonlinear model for thermal effects in free-electron lasers

    SciTech Connect (OSTI)

    Peter, E. Endler, A. Rizzato, F. B.

    2014-11-15

    In the present work, we extend results of a previous paper [Peter et al., Phys. Plasmas 20, 12?3104 (2013)] and develop a semi-analytical model to account for thermal effects on the nonlinear dynamics of the electron beam in free-electron lasers. We relax the condition of a cold electron beam but still use the concept of compressibility, now associated with a warm beam model, to evaluate the time scale for saturation and the peak laser intensity in high-gain regimes. Although vanishing compressibilites and the associated divergent densities are absent in warm models, a series of discontinuities in the electron density precede the saturation process. We show that full wave-particle simulations agree well with the predictions of the model.

  19. A compact x-ray free electron laser

    SciTech Connect (OSTI)

    Barletta, W.A. . Center for Advanced Accelerators Physics Lawrence Livermore National Lab., CA ); Atac, M.; Cline, D.B.; Kolonko, J. . Center for Advanced Accelerators Physics); Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G. . Rocketdyne Div.); Gallardo

    1988-01-01

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

  20. following an electron bunch for free electron laser

    SciTech Connect (OSTI)

    2012-01-01

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

  1. Thermal effect on prebunched two-beam free electron laser

    SciTech Connect (OSTI)

    Mirian, N. S.; Maraghechi, B.

    2013-08-15

    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.

  2. Study of beam loading and its compensation in the Compact Ultrafast Terahertz Free-Electron Laser injector linac

    SciTech Connect (OSTI)

    Lal, Shankar Pant, K. K.

    2014-12-15

    The RF properties of an accelerating structure, and the pulse structure and charge per bunch in the electron beam propagating through it are important parameters that determine the impact of beam loading in the structure. The injector linac of the Compact Ultrafast Terahertz Free-Electron Laser (CUTE-FEL) has been operated with two different pulse structures during initial commissioning experiments and the effect of beam loading on the accelerated electron beam parameters has been studied analytically for these two pulse structures. This paper discusses the analytical study of beam loading in a Standing Wave, Plane Wave Transformer linac employed in the CUTE-FEL setup, and a possible technique for its compensation for the electron beam parameters of the CUTE-FEL. A parametric study has been performed to study beam loading for different beam currents and to optimize injection time of the electron beam to compensate beam loading. Results from the parametric study have also been used to explain previously observed results from acceleration experiments in the CUTE-FEL setup.

  3. Design Considerations for the Free-Electron Laser with Self-Seeding...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Design Considerations for the Free-Electron Laser with Self-Seeding and Current Enhanced SASE Citation Details In-Document Search Title: Design Considerations for...

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

    SciTech Connect (OSTI)

    Kur, E.; Dunning, D. J.; McNeil, B. W. J.; Wurtele, J.; Zholents, A. A. )

    2011-01-20

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

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

    Energy Savers [EERE]

    First Free-Electron X-ray Laser The World's First Free-Electron X-ray Laser August 17, 2010 - 6:19pm Addthis The World's First Free-Electron X-ray Laser John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Yesterday, Secretary Chu participated in the dedication of the world's first free-electron and most powerful X-ray laser, the Linac Coherent Light Source (LCLS). In light of this occasion (pun intended), we posted an in-depth look at the innovative nature of this

  6. Laser Phase Errors in Seeded FELs

    SciTech Connect (OSTI)

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

    2012-03-28

    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.

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

    SciTech Connect (OSTI)

    Mohsenpour, Taghi Alirezaee, Hajar

    2014-08-15

    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.

  8. Compact x-ray free electron laser from a laser-plasma accelerator using a

    Office of Scientific and Technical Information (OSTI)

    transverse gradient undulator (Journal Article) | SciTech Connect Compact x-ray free electron laser from a laser-plasma accelerator using a transverse gradient undulator Citation Details In-Document Search Title: Compact x-ray free electron laser from a laser-plasma accelerator using a transverse gradient undulator Authors: Huang, Zhirong ; Ding, Yuantao ; Schroeder, Carl Publication Date: 2012-09-11 OSTI Identifier: 1172711 Report Number(s): LBNL-5931E DOE Contract Number: DE-AC02-05CH11231

  9. Efficiency enhancement of a harmonic lasing free-electron laser

    SciTech Connect (OSTI)

    Salehi, E.; Maraghechi, B.; Mirian, N. S.

    2015-03-15

    The harmonic lasing free-electron laser amplifier, in which two wigglers is employed in order for the fundamental resonance of the second wiggler to coincide with the third harmonic of the first wiggler to generate ultraviolet radiation, is studied. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system, for a long electron bunch, is solved numerically by CYRUS code. Solutions for the non-averaged and averaged equations are compared. Remarkable agreement is found between the averaged and non-averaged simulations for the evolution of the third harmonic. Thermal effects in the form of longitudinal velocity spread are also investigated. For efficiency enhancement, the second wiggler field is set to decrease linearly and nonlinearly at the point where the radiation of the third harmonic saturates. The optimum starting point and the slope of the tapering of the amplitude of the wiggler are found by a successive run of the code. It is found that tapering can increase the saturated power of the third harmonic considerably. In order to reduce the length of the wiggler, the prebunched electron beam is considered.

  10. Performance of the accelerator driver of Jefferson Laboratory's free-electron laser

    SciTech Connect (OSTI)

    Bohn, C.L.; Benson, S.; Biallas, G.

    1999-04-01

    The driver of Jefferson Lab's kW-level infrared free-electron laser (FEL) is a superconducting, recirculating accelerator that recovers about 75% of the electron-beam power and converts it to radiofrequency power. In achieving first lasing, the accelerator operated straight-ahead to deliver 38 MeV, 1.1 mA cw current through the wiggler for lasing at wavelengths in the vicinity of 5 {mu}m. Just prior to first lasing, measured rms beam properties at the wiggler were 7.5{+-}1.5 mm-mr normalized transverse emittance, 26{+-}7 keV-deg longitudinal emittance, and 0.4{+-}0.1 ps bunch length which yielded a peak current of 60{+-}15A. The waste beam was then sent directly to a dump, bypassing the recirculation loop. Stable operation at up to 311 W cw was achieved in this mode. Commissioning the recirculation loop then proceeded. As of this Conference, the machine has recirculated cw average current up to 4 mA, and has lased cw with energy recover up to 710 W.

  11. The effect of shot noise on the start up of the fundamental and harmonics in free-electron lasers

    SciTech Connect (OSTI)

    Freund, H. P.; Miner, W. H. Jr.; Giannessi, L.

    2008-12-15

    The problem of radiation start up in free-electron lasers (FELs) is important in the simulation of virtually all FEL configurations including oscillators and amplifiers in both seeded master oscillator power amplifier (MOPA) and self-amplified spontaneous emission (SASE) modes. Both oscillators and SASE FELs start up from spontaneous emission due to shot noise on the electron beam, which arises from the random fluctuations in the phase distribution of the electrons. The injected power in a MOPA is usually large enough to overwhelm the shot noise. However, this noise must be treated correctly in order to model the initial start up of the harmonics. In this paper, we discuss and compare two different shot noise models that are implemented in both one-dimensional wiggler-averaged (PERSEO) and non-wiggler-averaged (MEDUSA1D) simulation codes, and a three-dimensional non-wiggler-averaged (MEDUSA) formulation. These models are compared for examples describing both SASE and MOPA configurations in one dimension, in steady-state, and time-dependent simulations. Remarkable agreement is found between PERSEO and MEDUSA1D for the evolution of the fundamental and harmonics. In addition, three-dimensional correction factors have been included in the MEDUSA1D and PERSEO, which show reasonable agreement with MEDUSA for a sample MOPA in steady-state and time-dependent simulations.

  12. Femtosecond all-optical synchronization of an X-ray free-electron laser

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

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; et al

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarilymore┬á┬╗ by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.┬ź┬áless

  13. Femtosecond all-optical synchronization of an X-ray free-electron laser

    SciTech Connect (OSTI)

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; Mazza, T.; Meyer, M.; Pfeiffer, S.; Prędki, P.; Schefer, S.; Schmidt, C.; Wegner, U.; Schlarb, H.; Cavalieri, A. L.

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarily by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.

  14. Focus characterization at an X-ray free-electron laser by coherent...

    Office of Scientific and Technical Information (OSTI)

    Focus characterization at an X-ray free-electron laser by coherent scattering and speckle analysis Citation Details In-Document Search Title: Focus characterization at an X-ray...

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

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

    Free-Electron Laser Joins With Others in New Research Venture NEWPORT NEWS, VA, April 29, ... D.C., under an Energy Frontier Research Center award announced Monday by the White House. ...

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

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

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

  17. Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser

    Office of Scientific and Technical Information (OSTI)

    Fluences (Journal Article) | SciTech Connect Journal Article: Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser Fluences Citation Details In-Document Search Title: Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser Fluences Authors: Schreck, Simon ; Beye, Martin ; Sellberg, Jonas A. ; McQueen, Trevor ; Laksmono, Hartawan ; Kennedy, Brian ; Eckert, Sebastian ; Schlesinger, Daniel ; Nordlund, Dennis ; Ogasawara, Hirohito ; Sierra, Raymond G. ; Segtnan,

  18. Microbunching-Instability-Induced Sidebands in a Seeded Free-Electron Laser

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Microbunching-Instability-Induced Sidebands in a Seeded Free-Electron Laser Citation Details In-Document Search Title: Microbunching-Instability-Induced Sidebands in a Seeded Free-Electron Laser Authors: Zhang, Zhen ; /SLAC /Tsinghua U., Beijing, Dept. Eng. Phys. ; Lindberg, Ryan ; /ANL, APS ; Fawley, William M. ; Huang, Zhirong ; Krzywinski, Jacek ; Lutman, Alberto ; Marcus, Gabriel ; Marinelli, Agostino ; /SLAC Publication Date:

  19. Design Considerations for the Free-Electron Laser with Self-Seeding and

    Office of Scientific and Technical Information (OSTI)

    Current Enhanced SASE (Technical Report) | SciTech Connect Technical Report: Design Considerations for the Free-Electron Laser with Self-Seeding and Current Enhanced SASE Citation Details In-Document Search Title: Design Considerations for the Free-Electron Laser with Self-Seeding and Current Enhanced SASE Authors: Zholents, A. [1] + Show Author Affiliations (Accelerator Systems Division (APS)) Publication Date: 2013-08-06 OSTI Identifier: 1096155 Report Number(s): ANL/APS/LS-335 DOE

  20. Distributed seeding for narrow-line width hard x-ray free-electron...

    Office of Scientific and Technical Information (OSTI)

    Title: Distributed seeding for narrow-line width hard x-ray free-electron lasers We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg ...

  1. Density gradient free electron collisionally excited x-ray laser

    DOE Patents [OSTI]

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

    1984-11-29

    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.

  2. Density gradient free electron collisionally excited X-ray laser

    DOE Patents [OSTI]

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

    1989-01-01

    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.

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

    SciTech Connect (OSTI)

    Hu, Tongning E-mail: yjpei@ustc.edu.cn; Qin, Bin; Tan, Ping; Chen, Qushan; Yang, Lei; Pei, Yuanji E-mail: yjpei@ustc.edu.cn; Li, Ji

    2014-10-15

    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.

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

    SciTech Connect (OSTI)

    Guimei Wang

    2011-12-31

    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.

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

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

    Synchrotron Radiation Lightsource The European X-ray Free-Electron Laser: A Progress Report Friday, December 2, 2011 - 2:00pm SLAC, Redtail Conference Room (901-108) M. Altarelli, European XFEL GmbH, Hamburg, Germany The present status of the construction of the European X-ray Free-Electron Laser in Hamburg will be reviewed, and challenges in the development of the instrumentation, in order to exploit the time-structure of the superconducting linear accelerator, will be described. Programs

  6. Maximizing spectral flux from self-seeding hard x-ray free electron lasers

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Maximizing spectral flux from self-seeding hard x-ray free electron lasers Citation Details In-Document Search Title: Maximizing spectral flux from self-seeding hard x-ray free electron lasers Authors: Yang X. Publication Date: 2013-12-02 OSTI Identifier: 1132380 Report Number(s): BNL--103817-2014-JA 39KC02000 DOE Contract Number: DE-AC02-98CH10886 Resource Type: Journal Article Resource Relation: Journal Name: PHYSICAL REVIEW SPECIAL TOPICS - ACCELERATORS

  7. A single-shot transmissive spectrometer for hard x-ray free electron lasers

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: A single-shot transmissive spectrometer for hard x-ray free electron lasers Citation Details In-Document Search Title: A single-shot transmissive spectrometer for hard x-ray free electron lasers We report hard x-ray single-shot spectral measurements of the Linac Coherent Light Source. The spectrometer is based on a 10 {mu}m thick cylindrically bent Si single crystal operating in the symmetric Bragg geometry

  8. Eigenmode analysis of a high-gain free-electron laser based on a transverse

    Office of Scientific and Technical Information (OSTI)

    gradient undulator (Journal Article) | SciTech Connect Journal Article: Eigenmode analysis of a high-gain free-electron laser based on a transverse gradient undulator Citation Details In-Document Search Title: Eigenmode analysis of a high-gain free-electron laser based on a transverse gradient undulator Authors: Baxevanis, Panagiotis ; Huang, Zhirong ; Ruth, Ronald ; Schroeder, Carl B. Publication Date: 2015-01-27 OSTI Identifier: 1181185 Grant/Contract Number: AC02-05CH11231; AC02-76SF00515

  9. Experimental demonstration of a soft x-ray self-seeded free-electron laser

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Experimental demonstration of a soft x-ray self-seeded free-electron laser Citation Details In-Document Search Title: Experimental demonstration of a soft x-ray self-seeded free-electron laser The Linac Coherent Light Source 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

  10. The First Angstrom X-Ray Free-Electron Laser

    SciTech Connect (OSTI)

    Galayda, John; /SLAC

    2012-08-24

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

  11. FEL Achieves 10 Kilowatts | Jefferson Lab

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

    FEL Achieves 10 Kilowatts Newport News, Va. - The Free-Electron Laser (FEL), supported by the Office of Naval Research and located at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility, achieved 10 kilowatts of infrared laser light in late July, making it the most powerful tunable laser in the world. The recently upgraded laser's new capabilities will enhance defense and manufacturing technologies, and support advanced studies of chemistry, physics, biology, and more.

  12. Single-pulse picking at kHz repetition rates using a Ge plasma switch at the free-electron laser FELBE

    SciTech Connect (OSTI)

    Schmidt, J. Helm, M.; Winnerl, S.; Seidel, W.; Schneider, H.; Bauer, C.; Gensch, M.

    2015-06-15

    We demonstrate a system for picking of mid-infrared and terahertz (THz) radiation pulses from the free-electron laser (FEL) FELBE operating at a repetition rate of 13 MHz. Single pulses are reflected by a dense electron-hole plasma in a Ge slab that is photoexcited by amplified near-infrared (NIR) laser systems operating at repetition rates of 1 kHz and 100 kHz, respectively. The peak intensity of picked pulses is up to 400 times larger than the peak intensity of residual pulses. The required NIR fluence for picking pulses at wavelengths in the range from 5 ?m to 30 ?m is discussed. In addition, we show that the reflectivity of the plasma decays on a time scale from 100 ps to 1 ns dependent on the wavelengths of the FEL and the NIR laser. The plasma switch enables experiments with the FEL that require high peak power but lower average power. Furthermore, the system is well suited to investigate processes with decay times in the ?s to ms regime, i.e., much longer than the 77 ns long pulse repetition period of FELBE.

  13. Distributed seeding for narrow-line width hard x-ray free-electron lasers

    SciTech Connect (OSTI)

    Nguyen, Dinh Cong; Anisimov, Petr Mikhaylovich; Buechler, Cynthia Eileen; Lewellen, IV, John W.; Marksteiner, Quinn R.

    2015-09-09

    We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important aspects. First, DS relies on spectral filtering of the radiation at multiple locations along the undulator, with a monochromator located every few power gain lengths. Second, DS performs filtering early in the exponential gain region before SASE spikes start to appear in the radiation longitudinal profile. Third, DS provides the option to select a wavelength longer than the peak of the SASE gain curve, which leads to improved spectral contrast of the seeded FEL over the SASE background. Timedependent Genesis simulations show the power-vs-z growth curves for DS exhibit behaviors of a seeded FEL amplifier, such as exponential growth region immediately after the filters. Of the seeding approaches considered, the two-stage DS spectra produce the highest contrast of seeded FEL over the SASE background and that the three-stage DS provides the narrowest linewidth with a relative spectral FWHM of 8 X 10-5 .

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

    SciTech Connect (OSTI)

    Kheiri, Golshad; Esmaeilzadeh, Mahdi

    2013-12-15

    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.

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

    SciTech Connect (OSTI)

    Soto-Chavez, A. R.; Bhattacharjee, A.; Ng, C. S.

    2012-01-15

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

  16. VISA: A Milestone on the Path towards X-Ray Free Electron Lasers | Stanford

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

    Synchrotron Radiation Lightsource VISA: A Milestone on the Path towards X-Ray Free Electron Lasers Friday, June 28, 2002 Figure 1. Figure 1 Intensity distribution of a Single SASE radiation pulse as produced by VISA when operating at saturation. Advances in accelerator technology and in the theoretical understanding of collective instabilities and production of coherent radiation, have been the driving forces of the progress toward brighter synchrotron radiation sources, with scientific

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

    Office of Science (SC) Website

    (SC) Free Electron Laser Program Program at TJNAF Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear Science Archives Small Business Innovation / Technology Transfer Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301)

  18. 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)

    Venture | Jefferson Lab Free-Electron Laser Joins With Others in New Research Venture NEWPORT NEWS, VA, April 29, 2009 - The U.S. Department of Energy's Thomas Jefferson National Accelerator Facility will participate in a $777 million federal effort to accelerate scientific breakthroughs. Jefferson Lab will be among nine universities and six DOE labs collaborating with the Carnegie Geophysical Institution of Washington, D.C., under an Energy Frontier Research Center award announced Monday by

  19. Mixing and space-charge effects in free-electron lasers

    SciTech Connect (OSTI)

    Peter, E.; Endler, A.; Rizzato, F. B.; Serbeto, A.

    2013-12-15

    The present work revisits the subjects of mixing, saturation, and space-charge effects in free-electron lasers. Use is made of the compressibility factor, which proves to be a helpful tool in the related systems of charged beams confined by static magnetic fields. The compressibility allows to perform analytical estimates of the elapsed time until the onset of mixing, which in turn allows to estimate the saturated amplitude of the radiation field. In addition, the compressibility helps to pinpoint space-charge effects and the corresponding transition from Compton to Raman regimes.

  20. High-intensity double-pulse X-ray free-electron laser

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

    Marinelli, A.; Ratner, D.; Lutman, A. A.; Turner, J.; Welch, J.; Decker, F. J.; Loos, H.; Behrens, C.; Gilevich, S.; Miahnahri, A. A.; et al

    2015-03-06

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitudemore┬á┬╗ in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion.┬ź┬áless

  1. High-intensity double-pulse X-ray free-electron laser

    SciTech Connect (OSTI)

    Marinelli, A.; Ratner, D.; Lutman, A. A.; Turner, J.; Welch, J.; Decker, F. J.; Loos, H.; Behrens, C.; Gilevich, S.; Miahnahri, A. A.; Vetter, S.; Maxwell, T. J.; Ding, Y.; Coffee, R.; Wakatsuki, S.; Huang, Z.

    2015-03-06

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitude in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion.

  2. A revised partiality model and post-refinement algorithm for X-ray free-electron laser data

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

    Ginn, Helen Mary; Brewster, Aaron S.; Hattne, Johan; Evans, Gwyndaf; Wagner, Armin; Grimes, Jonathan M.; Sauter, Nicholas K.; Sutton, Geoff; Stuart, David Ian

    2015-05-23

    Research towards using X-ray free-electron laser (XFEL) data to solve structures using experimental phasing methods such as sulfur single-wavelength anomalous dispersion (SAD) has been hampered by shortcomings in the diffraction models for X-ray diffraction from FELs. Owing to errors in the orientation matrix and overly simple partiality models, researchers have required large numbers of images to converge to reliable estimates for the structure-factor amplitudes, which may not be feasible for all biological systems. Here, data for cytoplasmic polyhedrosis virus type 17 (CPV17) collected at 1.3 ├ů wavelength at the Linac Coherent Light Source (LCLS) are revisited. A previously published definitionmore┬á┬╗ of a partiality model for reflections illuminated by self-amplified spontaneous emission (SASE) pulses is built upon, which defines a fraction between 0 and 1 based on the intersection of a reflection with a spread of Ewald spheres modelled by a super-Gaussian wavelength distribution in the X-ray beam. A method of post-refinement to refine the parameters of this model is suggested. This has generated a merged data set with an overall discrepancy (by calculating theRsplitvalue) of 3.15% to 1.46 ├ů resolution from a 7225-image data set. The atomic numbers of C, N and O atoms in the structure are distinguishable in the electron-density map. There are 13 S atoms within the 237 residues of CPV17, excluding the initial disordered methionine. These only possess 0.42 anomalous scattering electrons each at 1.3 ├ů wavelength, but the 12 that have single predominant positions are easily detectable in the anomalous difference Fourier map. It is hoped that these improvements will lead towards XFEL experimental phase determination and structure determination by sulfur SAD and will generally increase the utility of the method for difficult cases.┬ź┬áless

  3. A revised partiality model and post-refinement algorithm for X-ray free-electron laser data

    SciTech Connect (OSTI)

    Ginn, Helen Mary; Brewster, Aaron S.; Hattne, Johan; Evans, Gwyndaf; Wagner, Armin; Grimes, Jonathan M.; Sauter, Nicholas K.; Sutton, Geoff; Stuart, David Ian

    2015-05-23

    Research towards using X-ray free-electron laser (XFEL) data to solve structures using experimental phasing methods such as sulfur single-wavelength anomalous dispersion (SAD) has been hampered by shortcomings in the diffraction models for X-ray diffraction from FELs. Owing to errors in the orientation matrix and overly simple partiality models, researchers have required large numbers of images to converge to reliable estimates for the structure-factor amplitudes, which may not be feasible for all biological systems. Here, data for cytoplasmic polyhedrosis virus type 17 (CPV17) collected at 1.3 ┼ wavelength at the Linac Coherent Light Source (LCLS) are revisited. A previously published definition of a partiality model for reflections illuminated by self-amplified spontaneous emission (SASE) pulses is built upon, which defines a fraction between 0 and 1 based on the intersection of a reflection with a spread of Ewald spheres modelled by a super-Gaussian wavelength distribution in the X-ray beam. A method of post-refinement to refine the parameters of this model is suggested. This has generated a merged data set with an overall discrepancy (by calculating theRsplitvalue) of 3.15% to 1.46 ┼ resolution from a 7225-image data set. The atomic numbers of C, N and O atoms in the structure are distinguishable in the electron-density map. There are 13 S atoms within the 237 residues of CPV17, excluding the initial disordered methionine. These only possess 0.42 anomalous scattering electrons each at 1.3 ┼ wavelength, but the 12 that have single predominant positions are easily detectable in the anomalous difference Fourier map. It is hoped that these improvements will lead towards XFEL experimental phase determination and structure determination by sulfur SAD and will generally increase the utility of the method for difficult cases.

  4. Batch crystallization of rhodopsin for structural dynamics using an X-ray free-electron laser

    SciTech Connect (OSTI)

    Wu, Wenting; Nogly, Przemyslaw; Rheinberger, Jan; Kick, Leonhard M.; Gati, Cornelius; Nelson, Garrett; Deupi, Xavier; Standfuss, J÷rg; Schertler, Gebhard; Panneels, ValÚrie

    2015-06-27

    A new batch preparation method is presented for high-density micrometre-sized crystals of the G protein-coupled receptor rhodopsin for use in time-resolved serial femtosecond crystallography at an X-ray free-electron laser using a liquid jet. Rhodopsin is a membrane protein from the G protein-coupled receptor family. Together with its ligand retinal, it forms the visual pigment responsible for night vision. In order to perform ultrafast dynamics studies, a time-resolved serial femtosecond crystallography method is required owing to the nonreversible activation of rhodopsin. In such an approach, microcrystals in suspension are delivered into the X-ray pulses of an X-ray free-electron laser (XFEL) after a precise photoactivation delay. Here, a millilitre batch production of high-density microcrystals was developed by four methodical conversion steps starting from known vapour-diffusion crystallization protocols: (i) screening the low-salt crystallization conditions preferred for serial crystallography by vapour diffusion, (ii) optimization of batch crystallization, (iii) testing the crystal size and quality using second-harmonic generation (SHG) imaging and X-ray powder diffraction and (iv) production of millilitres of rhodopsin crystal suspension in batches for serial crystallography tests; these crystals diffracted at an XFEL at the Linac Coherent Light Source using a liquid-jet setup.

  5. LCLS CDR Chapter 4 - FEL Physics

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

    4 FEL Physics TECHNICAL SYNOPSIS This chapter presents a review of the historical and technological developments of the Free Electron Laser that led to proposals to operate an FEL in the large gain regime, starting from the spontaneous radiation noise, without using an optical cavity. In this mode, called "Self- Amplified-Spontaneous-Emission" (SASE), lasing is produced in a single pass of an electron beam with high phase-space density through a long undulator, eliminating the need for

  6. Improvement of nonlinear harmonics in free electron laser with planar wiggler

    SciTech Connect (OSTI)

    Bazouband, F.; Maraghechi, B.

    2012-11-15

    Spontaneous emission of free electron laser with planar wiggler and ion-channel guiding is calculated analytically and possibility of emission at up-shifted wiggler or ion-channel betatron frequency and their harmonics has been found. To investigate the nonlinear odd harmonics, a set of self-consistent nonlinear differential equations that governs the evolution of radiation and electron beam are derived and solved numerically by Runge-Kutta method. Using the simulation code, gain improvement of third harmonic is studied in the range of microwave frequency by applying ion-channel guiding for a cold beam. It is shown that the combination of the ion-channel and a prebunched electron beam increases the amplitude of the third harmonic of the radiation and decreases its saturation length. The relation between the linear and nonlinear harmonics is discussed.

  7. Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser

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

    Levantino, Matteo; Schir├▓, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; KAIST, Daejeon; Cupane, Antonio; et al

    2015-04-02

    Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ÔÇśproteinquakeÔÇÖ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations withmore┬á┬╗ a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.┬ź┬áless

  8. Applications of free electron lasers and synchrotrons in industry and research

    SciTech Connect (OSTI)

    Barletta, William A. [Dept. of Physics, Massachusetts Institute of Technology Cambridge MA (United States)

    2013-04-19

    Synchrotron radiation sources have had a profound effect on both science and technology from their beginnings decades ago as parasitic operations on accelerators for high energy physics. Now the general area of photon science has opened up new experimental techniques which have become the mainstay tools of materials science, surface physics, protein crystallography, and nanotechnology. With the promise of ultra-bright beams from the latest generation of storage rings and free electron lasers with full coherence, the tools of photon science promise to open a new area of mesoscale science and technology as well as prove to be a disruptive wildcard in the search for sustainable energy technologies. This review will survey a range of applications and explore in greater depth the potential applications to EUV lithography and to technologies for solar energy.

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

    SciTech Connect (OSTI)

    Baptiste, Kenneth; Corlett, John; Kwiatkowski, Slawomir; Lidia, Steven; Qiang, Ji; Sannibale, Fernando; Sonnad, Kiran; Staples, John; Virostek, Steven; Wells, Russell

    2008-10-08

    Currently proposed energy recovery linac and high average power free electron laser projects require electron beam sources that can generate up to {approx} 1 nC bunch charges with less than 1 mmmrad normalized emittance at high repetition rates (greater than {approx} 1 MHz). Proposed sources are based around either high voltage DC or microwave RF guns, each with its particular set of technological limits and system complications. We propose an approach for a gun fully based on mature RF and mechanical technology that greatly diminishes many of such complications. The concepts for such a source as well as the present RF and mechanical design are described. Simulations that demonstrate the beam quality preservation and transport capability of an injector scheme based on such a gun are also presented.

  10. Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser

    SciTech Connect (OSTI)

    Levantino, Matteo; Schir˛, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; KAIST, Daejeon; Cupane, Antonio; Cammarata, Marco

    2015-04-02

    Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such Ĺproteinquakeĺ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations with a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.

  11. Covariance mapping of two-photon double core hole states in C 2 H 2 and C 2 H 6 produced by an x-ray free electron laser

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

    Mucke, M; Zhaunerchyk, V; Frasinski, L J; Squibb, R J; Siano, M; Eland, J H D; Linusson, P; Sal├ęn, P; Meulen, P v d; Thomas, R D; et al

    2015-07-01

    Few-photon ionization and relaxation processes in acetylene (C2H2) and ethane (C2H6) were investigated at the linac coherent light source x-ray free electron laser (FEL) at SLAC, Stanford using a highly efficient multi-particle correlation spectroscopy technique based on a magnetic bottle. The analysis method of covariance mapping has been applied and enhanced, allowing us to identify electron pairs associated with double core hole (DCH) production and competing multiple ionization processes including Auger decay sequences. The experimental technique and the analysis procedure are discussed in the light of earlier investigations of DCH studies carried out at the same FEL and at thirdmore┬á┬╗ generation synchrotron radiation sources. In particular, we demonstrate the capability of the covariance mapping technique to disentangle the formation of molecular DCH states which is barely feasible with conventional electron spectroscopy methods.┬ź┬áless

  12. Covariance mapping of two-photon double core hole states in C 2 H 2 and C 2 H 6 produced by an x-ray free electron laser

    SciTech Connect (OSTI)

    Mucke, M; Zhaunerchyk, V; Frasinski, L J; Squibb, R J; Siano, M; Eland, J H D; Linusson, P; Sal├ęn, P; Meulen, P v d; Thomas, R D; Larsson, M; Foucar, L; Ullrich, J; Motomura, K; Mondal, S; Ueda, K; Osipov, T; Fang, L; Murphy, B F; Berrah, N; Bostedt, C; Bozek, J D; Schorb, S; Messerschmidt, M; Glownia, J M; Cryan, J P; Coffee, R N; Takahashi, O; Wada, S; Piancastelli, M N; Richter, R; Prince, K C; Feifel, R

    2015-07-01

    Few-photon ionization and relaxation processes in acetylene (C2H2) and ethane (C2H6) were investigated at the linac coherent light source x-ray free electron laser (FEL) at SLAC, Stanford using a highly efficient multi-particle correlation spectroscopy technique based on a magnetic bottle. The analysis method of covariance mapping has been applied and enhanced, allowing us to identify electron pairs associated with double core hole (DCH) production and competing multiple ionization processes including Auger decay sequences. The experimental technique and the analysis procedure are discussed in the light of earlier investigations of DCH studies carried out at the same FEL and at third generation synchrotron radiation sources. In particular, we demonstrate the capability of the covariance mapping technique to disentangle the formation of molecular DCH states which is barely feasible with conventional electron spectroscopy methods.

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

    SciTech Connect (OSTI)

    Nilsen, J; Rohringer, N

    2011-08-30

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

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

    SciTech Connect (OSTI)

    Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi; Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina; Obara, Yuki; Misawa, Kazuhiko; Bhattacharya, Atanu; Kurahashi, Naoya; Ogi, Yoshihiro; Suzuki, Toshinori; Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198

    2013-09-23

    We have developed a method of dispersive x-ray absorption spectroscopy with a hard x-ray free electron laser (XFEL), generated by a self-amplified spontaneous emission (SASE) mechanism. A transmission grating was utilized for splitting SASE-XFEL light, which has a relatively large bandwidth (╬öE/E Ôł╝ 5 ├Ś 10{sup Ôłĺ3}), into several branches. Two primary split beams were introduced into a dispersive spectrometer for measuring signal and reference spectra simultaneously. After normalization, we obtained a Zn K-edge absorption spectrum with a photon-energy range of 210 eV, which is in excellent agreement with that measured by a conventional wavelength-scanning method. From the analysis of the difference spectra, the noise ratio was evaluated to be Ôł╝3 ├Ś 10{sup Ôłĺ3}, which is sufficiently small to trace minute changes in transient spectra induced by an ultrafast optical laser. This scheme enables us to perform single-shot, high-accuracy x-ray absorption spectroscopy with femtosecond time resolution.

  15. A revised partiality model and post-refinement algorithm for X-ray free-electron laser data

    SciTech Connect (OSTI)

    Ginn, Helen Mary; Brewster, Aaron S.; Hattne, Johan; Evans, Gwyndaf; Wagner, Armin; Grimes, Jonathan M.; Sauter, Nicholas K.; Sutton, Geoff; Stuart, David Ian

    2015-05-23

    An updated partiality model and post-refinement algorithm for XFEL snapshot diffraction data is presented and confirmed by observing anomalous density for S atoms at an X-ray wavelength of 1.3 ┼. Research towards using X-ray free-electron laser (XFEL) data to solve structures using experimental phasing methods such as sulfur single-wavelength anomalous dispersion (SAD) has been hampered by shortcomings in the diffraction models for X-ray diffraction from FELs. Owing to errors in the orientation matrix and overly simple partiality models, researchers have required large numbers of images to converge to reliable estimates for the structure-factor amplitudes, which may not be feasible for all biological systems. Here, data for cytoplasmic polyhedrosis virus type 17 (CPV17) collected at 1.3 ┼ wavelength at the Linac Coherent Light Source (LCLS) are revisited. A previously published definition of a partiality model for reflections illuminated by self-amplified spontaneous emission (SASE) pulses is built upon, which defines a fraction between 0 and 1 based on the intersection of a reflection with a spread of Ewald spheres modelled by a super-Gaussian wavelength distribution in the X-ray beam. A method of post-refinement to refine the parameters of this model is suggested. This has generated a merged data set with an overall discrepancy (by calculating the R{sub split} value) of 3.15% to 1.46 ┼ resolution from a 7225-image data set. The atomic numbers of C, N and O atoms in the structure are distinguishable in the electron-density map. There are 13 S atoms within the 237 residues of CPV17, excluding the initial disordered methionine. These only possess 0.42 anomalous scattering electrons each at 1.3 ┼ wavelength, but the 12 that have single predominant positions are easily detectable in the anomalous difference Fourier map. It is hoped that these improvements will lead towards XFEL experimental phase determination and structure determination by sulfur SAD and will generally increase the utility of the method for difficult cases.

  16. Soft x-ray free-electron laser induced damage to inorganic scintillators

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

    Burian, Tom├í┼í; H├íjkov├í, V─Ťra; Chalupsk├Ż, Jarom├şr; Vy┼í├şn, Lud─Ťk; Boh├í─Źek, Pavel; P┼Öe─Źek, Martin; Wild, Jan; ├ľzkan, Cigdem; Coppola, Nicola; Farahani, Shafagh Dastjani; et al

    2015-01-07

    An irreversible response of inorganic scintillators to intense soft x-ray laser radiation was investigated at the FLASH (Free-electron LASer in Hamburg) facility. Three ionic crystals, namely, Ce:YAG (cerium-doped yttrium aluminum garnet), PbWO4 (lead tungstate), and ZnO (zinc oxide), were exposed to single 4.6 nm ultra-short laser pulses of variable pulse energy (up to 12 ╬╝J) under normal incidence conditions with tight focus. Damaged areas produced with various levels of pulse fluences, were analyzed on the surface of irradiated samples using differential interference contrast (DIC) and atomic force microscopy (AFM). The effective beam area of 22.2 ┬▒ 2.2 ╬╝m2 was determinedmore┬á┬╗ by means of the ablation imprints method with the use of poly(methyl methacrylate) - PMMA. Applied to the three inorganic materials, this procedure gave almost the same values of an effective area. The single-shot damage threshold fluence was determined for each of these inorganic materials. The Ce:YAG sample seems to be the most radiation resistant under the given irradiation conditions, its damage threshold was determined to be as high as 660.8 ┬▒ 71.2 mJ/cm2. Contrary to that, the PbWO4 sample exhibited the lowest radiation resistance with a threshold fluence of 62.6 ┬▒ 11.9 mJ/cm2. The threshold for ZnO was found to be 167.8 ┬▒ 30.8 mJ/cm2. Both interaction and material characteristics responsible for the damage threshold difference are discussed in the article.┬ź┬áless

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

    SciTech Connect (OSTI)

    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.; ,

    2012-02-15

    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.

  18. VISA: A Milestone on the Path towards X-Ray Free Electron Lasers...

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

    ... One of the properties of a SASE FEL is the generation of nonlinear harmonics, which occurs ... 2nd and the 3rd harmonics. (b) Harmonic Spectra, independently measured at peak VISA gain. ...

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

    Office of Science (SC) Website

    Spin-off examples: accelerator components; nano-material mfg.; anti-missile defense; test ... In addition, the FEL serves as a test bed for SRF linear accelerator technologies, ...

  20. Efficiency enhancement of nonlinear odd harmonics in thermal free electron laser

    SciTech Connect (OSTI)

    Bazouband, F.; Maraghechi, B.

    2013-05-07

    The effect of axial energy spread on the radiation of third harmonic is studied in the free electron laser with planar wiggler and ion-channel guiding. Spread in the longitudinal momentum and so in the initial energy of electron beam, without any spread in the transverse velocity, is assumed in the form of Gaussian distribution function. The technique that is employed is a one-dimensional and steady-state simulation. A set of self consistent nonlinear differential equations that describes the system is solved numerically by Runge-Kutta method. Due to the sensitivity of harmonics to thermal effects, gain improvement of third harmonic radiation is achieved by using ion-channel guiding technique and efficiency enhancement is applied by tapering the magnetic field of wiggler to optimize radiation. The bunching parameter of the electron beam is also studied. It is found that the growth of the magnitude of the bunching parameter that is caused by the ponderomotive wave stops before the saturation point of the radiation. This means that ponderomotive wave saturates at a shorter distance compared to the radiation.

  1. Three-dimensional simulation of efficiency enhancement in free-electron laser with prebunched electron beam

    SciTech Connect (OSTI)

    Chitsazi, Mahboobeh; Maraghechi, B.; Rouhani, M. H.

    2010-10-15

    The effect of prebunching of the electron beam and tapering of the wiggler amplitude on the harmonic upconversion in free-electron laser amplifier is studied in three dimensions. A set of coupled nonlinear first-order differential equations that describe the three-dimensional simulation of the system is solved numerically. This set of equation describes self-consistently the longitudinal spatial dependence of radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. The analysis is related to extreme ultraviolet and x-ray emission. In addition to uniform beam, prebunched electron beam has also been studied. The effect of sinusoidal distribution of entry times for the electron beam on the evolution of radiation is compared with uniform distribution. It is shown that prebunching reduces the saturation length substantially. For efficiency enhancement, the wiggler is set to decrease linearly when the radiation of the third harmonic saturates. The optimum starting point and the slope of tapering of the amplitude of the wiggler are found by a successive run of the code. It was found that tapering can increase the saturated power of the third harmonic considerably.

  2. A Bunch Compression Method for Free Electron Lasers that Avoids Parasitic Compressions

    SciTech Connect (OSTI)

    Benson, Stephen V.; Douglas, David R.; Tennant, Christopher D.; Wilson, Frederick G.; Nguyen, Dinh

    2015-09-01

    Virtually all existing high energy (>few MeV) linac-driven FELs compress the electron bunch length though the use of off-crest acceleration on the rising side of the RF waveform followed by transport through a magnetic chicane. This approach has at least three flaws: 1) it is difficult to correct aberrations- particularly RF curvature, 2) rising side acceleration exacerbates space charge-induced distortion of the longitudinal phase space, and 3) all achromatic "negative compaction" compressors create parasitic compression during the final compression process, increasing the CSR-induced emittance growth. One can avoid these deficiencies by using acceleration on the falling side of the RF waveform and a compressor with M56>0. This approach offers multiple advantages: 1) It is readily achieved in beam lines supporting simple schemes for aberration compensation, 2) Longitudinal space charge (LSC)-induced phase space distortion tends, on the falling side of the RF waveform, to enhance the chirp, and 3) Compressors with M56>0 can be configured to avoid spurious over-compression. We will discuss this bunch compression scheme in detail and give results of a successful beam test in April 2012 using the JLab UV Demo FEL

  3. Focus characterization at an X-ray free-electron laser by coherent scattering and speckle analysis

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

    Sikorski, Marcin; Song, Sanghoon; Schropp, Andreas; Deutsches Elektronen-Synchrotron, Hamburg; Seiboth, Frank; Feng, Yiping; Alonso-Mori, Roberto; Chollet, Matthieu; Lemke, Henrik T.; Sokaras, Dimosthenis; et al

    2015-04-14

    X-ray focus optimization and characterization based on coherent scattering and quantitative speckle size measurements was demonstrated at the Linac Coherent Light Source. Its performance as a single-pulse free-electron laser beam diagnostic was tested for two typical focusing configurations. The results derived from the speckle size/shape analysis show the effectiveness of this technique in finding the focus' location, size and shape. In addition, its single-pulse compatibility enables users to capture pulse-to-pulse fluctuations in focus properties compared with other techniques that require scanning and averaging.

  4. Nonlinear delayed symmetry breaking in a solid excited by hard x-ray free electron laser pulses

    SciTech Connect (OSTI)

    Ferrer, A.; Johnson, J. A. Mariager, S. O.; GrŘbel, S.; Staub, U.; Huber, T.; Trant, M.; Johnson, S. L.; Zhu, D.; Chollet, M.; Robinson, J.; Lemke, H. T.; Ingold, G.; Beaud, P.; Milne, C.

    2015-04-13

    We have studied the ultrafast changes of electronic states in bulk ZnO upon intense hard x-ray excitation from a free electron laser. By monitoring the transient anisotropy induced in an optical probe beam, we observe a delayed breaking of the initial c-plane symmetry of the crystal that lasts for several picoseconds. Interaction with the intense x-ray pulses modifies the electronic state filling in a manner inconsistent with a simple increase in electronic temperature. These results may indicate a way to use intense ultrashort x-ray pulses to investigate high-energy carrier dynamics and to control certain properties of solid-state materials.

  5. 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)

    | Jefferson Lab foxnews.com/scitech/2011/02/18/navy-breaks-world-record-futuristic-laser-getting-real/ Submitted: Sunday, February 20, 2011

  6. Enabling X-ray free electron laser crystallography for challenging biological systems from a limited number of crystals

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

    Uervirojnangkoorn, Monarin; Zeldin, Oliver B.; Lyubimov, Artem Y.; Hattne, Johan; Brewster, Aaron S.; Sauter, Nicholas K.; Brunger, Axel T.; Weis, William I.

    2015-03-17

    There is considerable potential for X-ray free electron lasers (XFELs) to enable determination of macromolecular crystal structures that are difficult to solve using current synchrotron sources. Prior XFEL studies often involved the collection of thousands to millions of diffraction images, in part due to limitations of data processing methods. We implemented a data processing system based on classical post-refinement techniques, adapted to specific properties of XFEL diffraction data. When applied to XFEL data from three different proteins collected using various sample delivery systems and XFEL beam parameters, our method improved the quality of the diffraction data as well as themore┬á┬╗ resulting refined atomic models and electron density maps. Moreover, the number of observations for a reflection necessary to assemble an accurate data set could be reduced to a few observations. These developments will help expand the applicability of XFEL crystallography to challenging biological systems, including cases where sample is limited.┬ź┬áless

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

    ScienceCinema (OSTI)

    Drell, Persis [SLAC Director

    2011-06-08

    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

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

    SciTech Connect (OSTI)

    Drell, Persis [SLAC Director] [SLAC Director

    2011-03-22

    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

  9. High-resolution single-shot spectral monitoring of hard x-ray free-electron laser radiation

    SciTech Connect (OSTI)

    Makita, M.; Karvinen, P.; Zhu, D.; Juranic, P. N.; Gr├╝nert, J.; Cartier, S.; Jungmann-Smith, J. H.; Lemke, H. T.; Mozzanica, A.; Nelson, S.; Patthey, L.; Sikorski, M.; Song, S.; Feng, Y.; David, C.

    2015-10-16

    We have developed an on-line spectrometer for hard x-ray free-electron laser (XFEL) radiation based on a nanostructured diamond diffraction grating and a bent crystal analyzer. Our method provides high spectral resolution, interferes negligibly with the XFEL beam, and can withstand the intense hard x-ray pulses at high repetition rates of >100 Hz. The spectrometer is capable of providing shot-to-shot spectral information for the normalization of data obtained in scientific experiments and optimization of the accelerator operation parameters. We have demonstrated these capabilities of the setup at the Linac Coherent Light Source, in self-amplified spontaneous emission mode at full energy of >1 mJ with a 120 Hz repetition rate, obtaining a resolving power of ╬Ľ/╬┤╬Ľ > 3 ├Ś 104. In conclusion, the device was also used to monitor the effects of pulse duration down to 8 fs by analysis of the spectral spike width.

  10. Enabling X-ray free electron laser crystallography for challenging biological systems from a limited number of crystals

    SciTech Connect (OSTI)

    Uervirojnangkoorn, Monarin; Zeldin, Oliver B.; Lyubimov, Artem Y.; Hattne, Johan; Brewster, Aaron S.; Sauter, Nicholas K.; Brunger, Axel T.; Weis, William I.

    2015-03-17

    There is considerable potential for X-ray free electron lasers (XFELs) to enable determination of macromolecular crystal structures that are difficult to solve using current synchrotron sources. Prior XFEL studies often involved the collection of thousands to millions of diffraction images, in part due to limitations of data processing methods. We implemented a data processing system based on classical post-refinement techniques, adapted to specific properties of XFEL diffraction data. When applied to XFEL data from three different proteins collected using various sample delivery systems and XFEL beam parameters, our method improved the quality of the diffraction data as well as the resulting refined atomic models and electron density maps. Moreover, the number of observations for a reflection necessary to assemble an accurate data set could be reduced to a few observations. These developments will help expand the applicability of XFEL crystallography to challenging biological systems, including cases where sample is limited.

  11. Triple Modulator-Chicane Scheme for Seeding Sub-Nanometer X-Ray Free Electron Lasers

    SciTech Connect (OSTI)

    Xiang, Dao; Stupakov, Gennady; /SLAC

    2011-07-06

    We propose a novel triple modulator-chicane (TMC) scheme to convert external input seed to shorter wavelengths. In the scheme high power seed lasers are used in the first and third modulator while only very low power seed is used in the second modulator. By properly choosing the parameters of the lasers and chicanes, we show that ultrahigh harmonics can be generated in the TMC scheme while simultaneously keeping the energy spread growth much smaller than beam's initial slice energy spread. As an example we show the feasibility of generating significant bunching at 1 nm and below from a low power ({approx} 100 kW) high harmonic generation seed at 20 nm assisted by two high power ({approx} 100 MW) UV lasers at 200 nm while keeping the energy spread growth within 40%. The supreme up-frequency conversion efficiency of the proposed TMC scheme together with its unique advantage in maintaining beam energy spread opens new opportunities for generating fully coherent x-rays at sub-nanometer wavelength from external seeds.

  12. Electron beam magnetic switch for a plurality of free electron lasers

    DOE Patents [OSTI]

    Schlitt, Leland G. (Livermore, CA)

    1984-01-01

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

  13. Analysis of FEL-based CeC amplification at high gain limit

    SciTech Connect (OSTI)

    Wang, G.; Litvinenko, V.; Jing, Y.

    2015-05-03

    An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electronsÔÇÖ energy spread affect the FEL amplification process.

  14. Structural studies of P-type ATPaseÔÇôligand complexes using an X-ray free-electron laser

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

    Bublitz, Maike; Nass, Karol; Drachmann, Nikolaj D.; Markvardsen, Anders J.; Gutmann, Matthias J.; Barends, Thomas R. M.; Mattle, Daniel; Shoeman, Robert L.; Doak, R. Bruce; Boutet, S├ębastien; et al

    2015-06-11

    Membrane proteins are key players in biological systems, mediating signalling events and the specific transport ofe.g.ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX) for the structure determination of membrane proteinÔÇôligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data revealmore┬á┬╗ the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.┬ź┬áless

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

    SciTech Connect (OSTI)

    Zastrau, Ulf; Fletcher, Luke B.; Galtier, Eric Ch.; Gamboa, Eliseo; Glenzer, Siegfried H.; Heimann, Philipp; Nagler, Bob; Schropp, Andreas; Lee, Hae Ja; F÷rster, Eckhart; Marschner, Heike; Wehrhan, Ortrud

    2014-09-15

    We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ?E/E = 1.1 Î?10{sup ?4} and wave-number resolution of ?k/k = 3 Î?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/┼ 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.

  16. 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)

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

    2015-02-23

    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. Wemoreá╗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.źáless

  17. High-resolution single-shot spectral monitoring of hard x-ray free-electron laser radiation

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

    Makita, M.; Karvinen, P.; Zhu, D.; Juranic, P. N.; Gr├╝nert, J.; Cartier, S.; Jungmann-Smith, J. H.; Lemke, H. T.; Mozzanica, A.; Nelson, S.; et al

    2015-10-16

    We have developed an on-line spectrometer for hard x-ray free-electron laser (XFEL) radiation based on a nanostructured diamond diffraction grating and a bent crystal analyzer. Our method provides high spectral resolution, interferes negligibly with the XFEL beam, and can withstand the intense hard x-ray pulses at high repetition rates of >100 Hz. The spectrometer is capable of providing shot-to-shot spectral information for the normalization of data obtained in scientific experiments and optimization of the accelerator operation parameters. We have demonstrated these capabilities of the setup at the Linac Coherent Light Source, in self-amplified spontaneous emission mode at full energy ofmore┬á┬╗ >1 mJ with a 120 Hz repetition rate, obtaining a resolving power of ╬Ľ/╬┤╬Ľ > 3 ├Ś 104. In conclusion, the device was also used to monitor the effects of pulse duration down to 8 fs by analysis of the spectral spike width.┬ź┬áless

  18. Structural studies of P-type ATPaseľligand complexes using an X-ray free-electron laser

    SciTech Connect (OSTI)

    Bublitz, Maike; Nass, Karol; Drachmann, Nikolaj D.; Markvardsen, Anders J.; Gutmann, Matthias J.; Barends, Thomas R. M.; Mattle, Daniel; Shoeman, Robert L.; Doak, R. Bruce; Boutet, SÚbastien; Messerschmidt, Marc; Seibert, Marvin M.; Williams, Garth J.; Foucar, Lutz; Reinhard, Linda; Sitsel, Oleg; Gregersen, Jonas L.; Clausen, Johannes D.; Boesen, Thomas; Gotfryd, Kamil; Wang, Kai -Tuo; Olesen, Claus; M°ller, Jesper V.; Nissen, Poul; Schlichting, Ilme

    2015-06-11

    Membrane proteins are key players in biological systems, mediating signalling events and the specific transport ofe.g.ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX) for the structure determination of membrane proteinľligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data reveal the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.

  19. FEL Program | Jefferson Lab

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

    lab's expertise in superconducting radiofrequency (SRF) accelerators. The FEL uses electrons to produce laser light. The electrons are energized using the lab's superconducting...

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

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

    Laser's "First Light" Shatters Record Researchers at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility have delivered first light from their Free Electron Laser (FEL). Only 2 years after ground was broken for the FEL, infrared light of more than 150 watts (150,000 times more powerful than that of a supermarket scanner or CD player) was delivered today - fifteen times the power of existing free-electron lasers. The Free Electron Laser project was funded by

  1. New Laser's &quot;First Light&quot; Shatters Record | Jefferson Lab

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

    Laser's "First Light" Shatters Record Researchers at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility have delivered first light from their Free Electron Laser (FEL). Only 2 years after ground was broken for the FEL, infrared light of more than 150 watts (150,000 times more powerful than that of a supermarket scanner or CD player) was delivered today - fifteen times the power of existing free-electron lasers. The Free Electron Laser project was funded by

  2. Three-Dimensional Reconstruction of the Giant Mimivirus Particle with an X-Ray Free-Electron Laser

    SciTech Connect (OSTI)

    Ekeberg, Tomas

    2015-05-26

    This dataset contains the diffraction patterns that were used for the first three-dimensional reconstruction of a virus using FEL data. The sample was the giant mimivirus particle, which is one of the largest known viruses with a diameter of 450 nm. The dataset consists of the 198 diffraction patterns that were used in the analysis.

  3. A Comparison of Short Rayleigh Range FEL Performance with Simulations

    SciTech Connect (OSTI)

    Benson, Stephen; Evtushenko, Pavel; Michelle D. Shinn; Neil, George; Blau, Joe; Burggraff, D.; Colson, William; Crooker, P.P.; Sans Aguilar, J.

    2007-08-01

    One approach to attaining very high power in a free-electron laser (FEL) is to operate with a Rayleigh range much smaller than the wiggler length. Previously, 3D simulations of Free-electron laser (FEL) oscillators showed that FEL gain doesn't fall off with Rayleigh range as predicted by one-dimensional simulations*. They also predict that the angular tolerance for the mirrors is much large than simplistic theory predicts. Using the IR Upgrade laser at Jefferson Lab lasing at 935 nm we have studied the performance of an FEL with very short Rayleigh range. We also looked at the angular sensitivity for several different Rayleigh ranges. We find very good agreement between simulations and measured gain and angular sensitivities. Surprisingly the gain continues to rise as the Rayleigh range is shortened and continues to grow even when the resonator becomes geometrically unstable. The same behavior is seen in both the experiment and simulations. We also find that, even for large Rayleigh r

  4. Key Laser Technologies for X-Ray FELs

    SciTech Connect (OSTI)

    Kaertner, Franz

    2013-08-31

    In the final project period, we demonstrated sub femtosecond timing distribution over a 1.2 km polarization-maintaining (PM) fiber-optic link using balanced optical cross-correlators (BOCs) for link stabilization. By eliminating polarization mode dispersion, link operation for 16 days maintained 0.6 fs RMS timing drift and during a 3-day interval only 0.13 fs drift, which corresponds to a stability level of 10-21. To improve the overall system efficiency and robustness, we developed fiber-coupled, hybrid-integrated BOCs using waveguides in periodically-poled KTiOPO4 (PPKTP). The measured second-harmonic conversion efficiency in the waveguides is a factor of 50 higher than that of bulk-optic crystals. Characterization of 1st-generation devices shows performance comparable to free-space BOCs, with the potential for significant improvement in future devices. For optical-to-RF conversion, we developed two balanced optical-microwave phase detectors (BOM-PD) based on the Sagnac and Mach-Zehnder interferometers. RF extraction using BOM-PDs in phase-locked loops yielded sub-10-fs residual timing jitter for locking bandwidths on the order of several hundred kHz. Finally, we characterized the timing jitter of ultralow-noise Ti:Sapphire oscillators, demonstrating an unprecedented 13 as of jitter integrated over the entire Nyquist band. Our measurements agreed well with theory, confirming our models for quantum-limited laser noise. Measurements of commercially available solid-state lasers at 1550 nm showed that there are laser sources already available with sufficiently low noise to achieve sub-femtosecond performance as master oscillators within a timing distribution system.

  5. Method based on atomic photoionization for spot-size measurement on focused soft x-ray free-electron laser beams

    SciTech Connect (OSTI)

    Sorokin, A. A.; Gottwald, A.; Hoehl, A.; Kroth, U.; Schoeppe, H.; Ulm, G.; Richter, M.; Bobashev, S. V.; Domracheva, I. V.; Smirnov, D. N.; Tiedtke, K.; Duesterer, S.; Feldhaus, J.; Hahn, U.; Jastrow, U.; Kuhlmann, M.; Nunez, T.; Ploenjes, E.; Treusch, R.

    2006-11-27

    A method has been developed and applied to measure the beam waist and spot size of a focused soft x-ray beam at the free-electron laser FLASH of the Deutsches Elektronen-Synchrotron in Hamburg. The method is based on a saturation effect upon atomic photoionization and represents an indestructible tool for the characterization of powerful beams of ionizing electromagnetic radiation. At the microfocus beamline BL2 at FLASH, a full width at half maximum focus diameter of (15{+-}2) {mu}m was determined.

  6. First Person -- George Neil Named Head of FEL Program (Inside Business) |

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

    Jefferson Lab first-person-george-neil-named-head-fel-program-inside-business First Person -- George Neil By Lakeshia Artis, Inside Business March 3, 2008 George Neil, head of the Free-Electron Laser Program at Thomas Jefferson National Accelerator Facility has been named associate director of the program. Born April 11, 1948 in Springfield, Mo. 1972-1977 Received Ph. D. in nuclear engineering from the University of Wisconsin in Madison, Wis. 1979-1990 Worked as a staff scientist, FEL

  7. Tunable Laser Reaches Record Power Level | Jefferson Lab

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

    Tunable Laser Reaches Record Power Level Researchers at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) have produced record setting levels of laser power from their Free Electron Laser (FEL). Last summer when the FEL was first turned on, it produced 155 watts of infrared light. On July 15, the FEL exceeded its design goal of 1,000 watts (a million times more powerful than the laser in a supermarket scanner or CD player) by producing 1,720 watts of

  8. FEL potential of eRHIC

    SciTech Connect (OSTI)

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

    2010-08-23

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

  9. Development of an X-ray pixel detector with multi-port charge-coupled device for X-ray free-electron laser experiments

    SciTech Connect (OSTI)

    Kameshima, Takashi; Ono, Shun; Kudo, Togo; Ozaki, Kyosuke; Kirihara, Yoichi; Kobayashi, Kazuo; Inubushi, Yuichi; Yabashi, Makina; Hatsui, Takaki; RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 ; Horigome, Toshio; Holland, Andrew; Holland, Karen; Burt, David; Murao, Hajime

    2014-03-15

    This paper presents development of an X-ray pixel detector with a multi-port charge-coupled device (MPCCD) for X-ray Free-Electron laser experiments. The fabrication process of the CCD was selected based on the X-ray radiation hardness against the estimated annual dose of 1.6 ├Ś 10{sup 14} photon/mm{sup 2}. The sensor device was optimized by maximizing the full well capacity as high as 5 Me- within 50 ╬╝m square pixels while keeping the single photon detection capability for X-ray photons higher than 6 keV and a readout speed of 60 frames/s. The system development also included a detector system for the MPCCD sensor. This paper summarizes the performance, calibration methods, and operation status.

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

    SciTech Connect (OSTI)

    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; Gould, Christopher; Biallas, George; Boyce, James; Coleman, James; Douglas, David; Ent, Rolf; Evtushenko, Pavel; Fenker, Howard; Gubeli, Joseph; Hannon, Fay; Huang, Jia; Jordan, Kevin; Legg, Robert; Marchlik, Matthew; Moore, Steven; Neil, George; Shinn, Michelle D; Tennant, Christopher; Walker, Richard; Williams, Gwyn; Zhang, Shukui; 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.

    2014-05-01

    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.

  11. Self-seeded injection-locked FEL amplifer

    DOE Patents [OSTI]

    Sheffield, Richard L. (Los Alamos, NM)

    1999-01-01

    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.

  12. A 4 to 0.1 nm FEL Based on the SLAC Linac

    SciTech Connect (OSTI)

    Pellegrini, C.; /UCLA

    2012-06-05

    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.

  13. FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION

    SciTech Connect (OSTI)

    Fawley, William; Vay, Jean-Luc

    2010-08-16

    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.

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

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

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

  15. JLab FEL Wins R&D 100 Award | Jefferson Lab

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

    FEL Wins R&D 100 Award Researchers and engineers at the Department of Energy's (DOE) Thomas Jefferson National Accelerator Facility (Jefferson Lab) have been awarded an R&D 100 Award, R&D Magazine's picks for the 100 most technologically significant new products of 2005. This is Jefferson Lab's second R&D 100 award. The 2005 award goes to: The Tunable Energy Recovered High Power Infrared Free-Electron Laser, lead by a team of nine Jefferson Lab scientists and engineers. The

  16. 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)

    JLab FEL Wins R&D 100 Award July 26, 2005 Researchers and engineers at the Department of Energy's (DOE) Thomas Jefferson National Accelerator Facility (Jefferson Lab) have been awarded an R&D 100 Award, R&D Magazine's picks for the 100 most technologically significant new products of 2005. This is Jefferson Lab's second R&D 100 award. The 2005 award goes to: The Tunable Energy Recovered High Power Infrared Free-Electron Laser, lead by a team of nine Jefferson Lab scientists and

  17. An analysis of the saturation of a high gain FEL

    SciTech Connect (OSTI)

    Gluckstern, R.L.; Okamoto, Hiromi; Krinsky, S.

    1992-12-01

    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.

  18. A single-shot transmissive spectrometer for hard x-ray free electron...

    Office of Scientific and Technical Information (OSTI)

    characteristic of a self-amplified spontaneous emission x-ray free electron laser source. ... Resource Relation: Journal Name: Applied Physics Letters; Journal Volume: 101; Journal ...

  19. Maximizing spectral flux from self-seeding hard x-ray free electron...

    Office of Scientific and Technical Information (OSTI)

    Maximizing spectral flux from self-seeding hard x-ray free electron lasers Citation ... TOPICS - ACCELERATORS AND BEAMS; Journal Volume: 16 Research Org: Brookhaven National ...

  20. Researchers' Hottest New Laser Beams 14.2 kW | Jefferson Lab

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

    Researchers' Hottest New Laser Beams 14.2 kW For more information: Office of Naval Research press release The linear accelerator portion of the FEL. On Thursday, Oct. 26, Free-Electron Laser (FEL) team members knew they were within reach of a goal they'd pursued for two years. They were aiming to produce 10 kW of laser light at an infrared wavelength of 1.61 microns. On that day, they blew past the milestone to produce 11.7 kW. But the team didn't stop there. They pushed the machine they had

  1. High Average Brightness Photocathode Development for FEL Applications

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect High Average Brightness Photocathode Development for FEL Applications Citation Details In-Document Search Title: High Average Brightness Photocathode Development for FEL Applications Authors: Rao T. ; Ben-Zvi I. ; Skarita, J. ; Wang, E. Publication Date: 2013-08-26 OSTI Identifier: 1095687 Report Number(s): BNL--101607-2013-CP KA-04 DOE Contract Number: DE-AC02-98CH10886 Resource Type: Conference Resource Relation: Conference: 35th International Free Electron

  2. Serial snapshot crystallography for materials science with SwissFEL

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

    Dejoie, Catherine; Smeets, Stef; Baerlocher, Christian; Tamura, Nobumichi; Pattison, Philip; Abela, Rafael; McCusker, Lynne B.

    2015-04-21

    New opportunities for studying (sub)microcrystalline materials with small unit cells, both organic and inorganic, will open up when the X-ray free electron laser (XFEL) presently being constructed in Switzerland (SwissFEL) comes online in 2017. Our synchrotron-based experiments mimicking the 4%-energy-bandpass mode of the SwissFEL beam show that it will be possible to record a diffraction pattern of up to 10 randomly oriented crystals in a single snapshot, to index the resulting reflections, and to extract their intensities reliably. The crystals are destroyed with each XFEL pulse, but by combining snapshots from several sets of crystals, a complete set of datamore┬á┬╗ can be assembled, and crystal structures of materials that are difficult to analyze otherwise will become accessible. Even with a single shot, at least a partial analysis of the crystal structure will be possible, and with 10ÔÇô50 femtosecond pulses, this offers tantalizing possibilities for time-resolved studies.┬ź┬áless

  3. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

    SciTech Connect (OSTI)

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; Ozkan, C.; St÷rmer, M.; Toleikis, S.; Tschentscher, Th.; Heimann, P. A.; Dorchies, F.

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called ômolecular movieö within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level of the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.

  4. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

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

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; et al

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called ÔÇťmolecular movieÔÇŁ within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level ofmore┬á┬╗ the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.┬ź┬áless

  5. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect (OSTI)

    Luhmann, Jr., N. C.; Alvis, R. M.; Baldis, H. A.; Hartemann, F. V; Heritage, J. P.; Ho, C. H.; Landahl, E. C.; Li, K.; Troha,A. L.; White, W. E.

    1998-12-15

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. When > 100 coherently phased 5 MeV electron bunches are produced in bursts, the photoinjector should be an ideal electron source for a pulsed, pre-bunched free-electron laser (FEL) operating at 100 GHz. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously mode-locked AlGaAs quantum well laser has been achieved using the X0-band gun rf fields. This novel, GHz repetition rate, sub-picosecond laser system is being developed to replace the more conventional femtosecond Ti: Al2O3 system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported.

  6. Generation of femtosecond to sub-femtosecond x-ray pulses in free-electron

    Office of Scientific and Technical Information (OSTI)

    lasers (Journal Article) | SciTech Connect femtosecond to sub-femtosecond x-ray pulses in free-electron lasers Citation Details In-Document Search Title: Generation of femtosecond to sub-femtosecond x-ray pulses in free-electron lasers Abstract is not available Authors: Ding, Yuantao [1] + Show Author Affiliations SLAC National Accelerator Laboratory, Menlo Park, CA (United States) Publication Date: 2015-05-12 OSTI Identifier: 1194669 Resource Type: Journal Article Resource Relation: Journal

  7. A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron Laser Experiment at SLAC Citation Details In-Document Search Title: A Proof-of-Principle...

  8. Science Driver Requirements for Seeded Soft X-ray Free Electron...

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

    Science Driver Requirements for Seeded Soft X-ray Free Electron Lasers Wednesday, December 2, 2015 - 2:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Fulvio Parmigiani,...

  9. Dielectric Wakefield Accelerator to drive the future FEL Light Source.

    SciTech Connect (OSTI)

    Jing, C.; Power, J.; Zholents, A. )

    2011-04-20

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

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

    SciTech Connect (OSTI)

    Sun, Yipeng; /SLAC

    2012-02-16

    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.

  11. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    SciTech Connect (OSTI)

    Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander; Sheffield, Richard L.

    2015-05-04

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  12. Two-Bunch Self-Seeding for Narrow-Bandwidth Hard X-Ray Free-Electron...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Two-Bunch Self-Seeding for Narrow-Bandwidth Hard X-Ray Free-Electron Lasers Citation Details In-Document Search Title: Two-Bunch Self-Seeding for Narrow-Bandwidth...

  13. Proposed UV-FEL user facility at BNL

    SciTech Connect (OSTI)

    Ben-Zvi, I.; Di Mauro, L.F.; Krinsky, S.; White, M.G.; Yu, L.H.

    1990-01-01

    The NSLS at Brookhaven National Laboratory is proposing the construction of a UV-FEL operating in the wavelength range from visible to 1000{angstrom}. Nano-Coulomb electron pulses will be generated at a laser photo-cathode RF gun at a repetition rate of 10 KHz. The 6 ps pulses will be accelerated to 250 MeV in a superconducting linac. The FEL consists of an exponential growth section followed by a tapered section. The amplifier input is a harmonic of a tunable visible laser generated either by nonlinear optical material or the non-linearity of the FEL itself. The FEL output in 10{sup {minus}4} bandwidth is 1 mJ per pulse, resulting in an average power of 10 watts. The availability of radiation with these characteristics would open up new opportunities in photochemistry, biology and non linear optics, as discussed in a recent workshop held at BNL. 10 refs., 4 figs., 1 tab.

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

    SciTech Connect (OSTI)

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

    2012-02-17

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

  15. W-band free-electron masers

    SciTech Connect (OSTI)

    Freund, H. P. [Science Applications International Corp., McLean, Virginia 22102 (United States); Jackson, R. H.; Danly, B. G.; Levush, B. [Naval Research Laboratory, Washington, District of Columbia 20375 (United States)

    1999-05-07

    Theoretical analyses of high power W-band (i.e., {approx_equal}94 GHz) free-electron maser amplifiers are presented for a helical wiggler/cylindrical waveguide configuration using the three-dimensional slow-time-scale ARACHNE simulation code [9]. The geometry treated by ARACHNE is that of an electron beam propagating through the cylindrical waveguide subject to a helical wiggler and an axial guide magnetic field. Two configurations are discussed. The first is the case of a reversed-guide field geometry where the guide field is oriented antiparallel to the helicity of the wiggler field. Using a 330 kV/20 A electron beam, efficiencies of the order of 7% are calculated with a bandwidth (FWHM) of 5 GHz. The second example employs a strong guide field of 20 kG oriented parallel to the helicity of the wiggler. Here, efficiencies of greater than 8% are possible with a FWHM bandwidth of 4.5 GHz using a 300 kV/20 A electron beam. A normalized emittance of 95 mm-mrad is assumed in both cases, and no beam losses are observed for either case. Both cases assume interaction with the fundamental TE{sub 11} mode, which has acceptably low losses in the W-band.

  16. Applications of free electron lasers and synchrotrons in industry...

    Office of Scientific and Technical Information (OSTI)

    Authors: Barletta, William A. 1 + Show Author Affiliations Dept. of Physics, Massachusetts Institute of Technology Cambridge MA (United States) Publication Date: 2013-04-19...

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

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

    and quantum computing and as components for microelectromechanical sensors, or MEMS. The tubes could also function as a "lab on a chip," with attached microelectronics and...

  18. Efficiency Enhancement in a Tapered Free Electron Laser by Varying...

    Office of Scientific and Technical Information (OSTI)

    physical model is built to provide insight to the mechanism of the electron-radiation coherent interaction with variable undulator parameters as well as electron beam radius. ...

  19. 2nd FEL Workshop - Methods & Instrumentation

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

    Visitor Information Need more information? Contact John Arthur 2nd FEL Workshop - Methods and Instrumentation Stanford Linear Accelerator Center Stanford, California USA March...

  20. Single shot polarization characterization of XUV FEL pulses from crossed polarized undulators

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

    Ferrari, E.; Allaria, E.; Buck, J.; De Ninno, G.; Diviacco, B.; Gauthier, D.; Giannessi, L.; Glaser, L.; Huang, Z.; Ilchen, M.; et al

    2015-08-28

    Polarization control is a key feature of light generated by short-wavelength free-electron lasers. In this work, we report the first experimental characterization of the polarization properties of an extreme ultraviolet high gain free-electron laser operated with crossed polarized undulators. We research the average degree of polarization and the shot-to-shot stability and we analyze aspects such as existing possibilities for controlling and switching the polarization state of the emitted light. The results are in agreement with predictions based on Gaussian beams propagation.

  1. FEL

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

  2. Lasers '90: Proceedings of the 13th International Conference on Lasers and Applications, San Diego, CA, Dec. 10-14, 1990

    SciTech Connect (OSTI)

    Harris, D.G.; Herbelin, J. Aerospace Corp., Los Angeles, CA )

    1991-01-01

    The general topics considered are: x-ray lasers; FELs; solid state lasers; techniques and phenomena of ultrafast lasers; optical filters and free space laser communications; discharge lasers; tunable lasers; applications of lasers in medicine and surgery; lasers in materials processing; high power lasers; dynamics gratings, wave mixing, and holography; up-conversion lasers; lidar and laser radar; laser resonators; excimer lasers; laser propagation; nonlinear and quantum optics; blue-green technology; imaging; laser spectroscopy; chemical lasers; dye lasers; and lasers in chemistry.

  3. Seeding Coherent Radiation Sources with Sawtooth Modulation ...

    Office of Scientific and Technical Information (OSTI)

    Contributed to 33rd International Free Electron Laser Conference (FEL 2011), Shanghai, China, 22-26 Aug 2011 Research Org: SLAC National Accelerator Laboratory (SLAC) Sponsoring...

  4. Nuclear Physics: Recent Talks

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks Archived Talks Additional Information Computing at JLab Operations Logbook Physics Topics: ...

  5. Nuclear Physics: Experiment Research - Call for Beam Time Requests

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

    Free-Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks ... Jefferson Lab Users Group From : Nuclear Physics Experiment Scheduling Committee Subject: ...

  6. Nuclear Physics: Experiment Research

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks Archived Talks Additional Information Computing at JLab Operations Logbook Experiment ...

  7. Nuclear Physics: Archived Talks - Accelerator

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks ... Additional Information Computing at JLab Operations Logbook Physics Topics: Archived Talks ...

  8. Nuclear Physics: Campaigns

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

    Free-Electron Laser (FEL) Medical Imaging Physics Topics Campaigns The Structure of the Nuclear Building Blocks The Structure of Nuclei Symmetry Tests in Nuclear Physics Meetings ...

  9. Profile for Nathan Andrew Moody

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

    Accelerators and Electrodynamics High power linear accelerator science and technology Free-electron laser (FEL) High-power radio frequency systems High current particle...

  10. Latest developments on the Dutch 1MW free electron maser

    SciTech Connect (OSTI)

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

    1999-05-01

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

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

    SciTech Connect (OSTI)

    Sun, Yipeng; Raubenheimer, Tor; Wu, Juhao; ,

    2011-08-19

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

  12. Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator...

    Office of Scientific and Technical Information (OSTI)

    Have feedback or suggestions for a way to improve these results? Save Share this Record Citation Formats MLA APA Chicago Bibtex Export Metadata Endnote Excel CSV XML Save to My ...

  13. BELLA World Record Sets Stage for Laser Experiments in Novel...

    Office of Science (SC) Website

    ... The stage is set for the future development of compact particle accelerators for high energy physics and table-top free electron lasers to investigate materials and biological ...

  14. High Average Brightness Photocathode Development for FEL Applications...

    Office of Scientific and Technical Information (OSTI)

    Conference: High Average Brightness Photocathode Development for FEL Applications Citation Details In-Document Search Title: High Average Brightness Photocathode Development for...

  15. High Average Brightness Photocathode Development for FEL Applications...

    Office of Scientific and Technical Information (OSTI)

    High Average Brightness Photocathode Development for FEL Applications Citation Details ... OFFICE OF SCIENCE (SC) Country of Publication: United States Language: English Subject: 46

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

    SciTech Connect (OSTI)

    Nishikawa, Takeshi

    2014-07-15

    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.

  17. Connecting Lab-Based Attosecond Science with FEL research

    ScienceCinema (OSTI)

    None

    2011-10-06

    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.

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

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

    the first demonstration of lasing at harmonics and of multi-kilowatt lasing with an ... Using the IR Demo machine, Benson demonstrated lasing at both the 2nd and 5th harmonics, ...

  19. Goniometer-based femtosecond crystallography with X-ray free electron lasers

    SciTech Connect (OSTI)

    Cohen, Aina E.; Soltis, S. Michael; Gonzßlez, Ana; Aguila, Laura; Alonso-Mori, Roberto; Barnes, Christopher O.; Baxter, Elizabeth L.; Brehmer, Winnie; Brewster, Aaron S.; Brunger, Axel T.; Calero, Guillermo; Chang, Joseph F.; Chollet, Matthieu; Ehrensberger, Paul; Eriksson, Thomas L.; Feng, Yiping; Hattne, Johan; Hedman, Britt; Hollenbeck, Michael; Holton, James M.; Keable, Stephen; Kobilka, Brian K.; Kovaleva, Elena G.; Kruse, Andrew C.; Lemke, Henrik T.; Lin, Guowu; Lyubimov, Artem Y.; Manglik, Aashish; Mathews, Irimpan I.; McPhillips, Scott E.; Nelson, Silke; Peters, John W.; Sauter, Nicholas K.; Smith, Clyde A.; Song, Jinhu; Stevenson, Hilary P.; Tsai, Yingssu; Uervirojnangkoorn, Monarin; Vinetsky, Vladimir; Wakatsuki, Soichi; Weis, William I.; Zadvornyy, Oleg A.; Zeldin, Oliver B.; Zhu, Diling; Hodgson, Keith O.

    2014-10-31

    The emerging method of femtosecond crystallography (FX) may extend the diffraction resolution accessible from small radiation-sensitive crystals and provides a means to determine catalytically accurate structures of acutely radiation-sensitive metalloenzymes. Automated goniometer-based instrumentation developed for use at the Linac Coherent Light Source enabled efficient and flexible FX experiments to be performed on a variety of sample types. In the case of rod-shaped Cpl hydrogenase crystals, only five crystals and about 30 min of beam time were used to obtain the 125 still diffraction patterns used to produce a 1.6-┼ resolution electron density map. With smaller crystals, high-density grids were used to increase sample throughput; 930 myoglobin crystals mounted at random orientation inside 32 grids were exposed, demonstrating the utility of this approach. Screening results from cryocooled crystals of ?2-adrenoreceptor and an RNA polymerase II complex indicate the potential to extend the diffraction resolution obtainable from very radiation-sensitive samples beyond that possible with undulator-based synchrotron sources.

  20. Exploring the Wavefront of Hard X-Ray Free-Electron Laser Radiation...

    Office of Scientific and Technical Information (OSTI)

    Identifier: 1156629 Report Number(s): SLAC-REPRINT-2014-321 DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article Resource Relation: Journal Name: Nature Commun. 3:947...

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

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

    Martin, A. V.

    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)

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

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

    Chapman, H. N.

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

  3. Goniometer-based femtosecond crystallography with X-ray free electron lasers

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

    Cohen, Aina E.; Soltis, S. Michael; González, Ana; Aguila, Laura; Alonso-Mori, Roberto; Barnes, Christopher O.; Baxter, Elizabeth L.; Brehmer, Winnie; Brewster, Aaron S.; Brunger, Axel T.; et al

    2014-10-31

    The emerging method of femtosecond crystallography (FX) may extend the diffraction resolution accessible from small radiation-sensitive crystals and provides a means to determine catalytically accurate structures of acutely radiation-sensitive metalloenzymes. Automated goniometer-based instrumentation developed for use at the Linac Coherent Light Source enabled efficient and flexible FX experiments to be performed on a variety of sample types. In the case of rod-shaped Cpl hydrogenase crystals, only five crystals and about 30 min of beam time were used to obtain the 125 still diffraction patterns used to produce a 1.6-├ů resolution electron density map. With smaller crystals, high-density grids were usedmore┬á┬╗ to increase sample throughput; 930 myoglobin crystals mounted at random orientation inside 32 grids were exposed, demonstrating the utility of this approach. Screening results from cryocooled crystals of ╬▓2-adrenoreceptor and an RNA polymerase II complex indicate the potential to extend the diffraction resolution obtainable from very radiation-sensitive samples beyond that possible with undulator-based synchrotron sources.┬ź┬áless

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

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

    Chapman, H. N.

    2011-02-23

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

  5. Comments on : Proposal for Raman x-ray free electron laser.

    SciTech Connect (OSTI)

    Zholents, A.; Zolotorev, M. (Accelerator Systems Division (APS)); (LBNL)

    2011-05-01

    Equation 13 in this paper defines the force experienced by the electron moving in z direction with velocity v{sub z} due to the X-ray wave propagating in z direction with electric field E{sub 1} pointing in y direction and magnetic field B{sub 1} pointing in x direction as {rvec F}{sub 1}(t) = -eE{sub 1} cos({omega}{sub 1}t - k{sub 1}z){rvec e}{sub y}. In our opinion calculating this force one should also include the impact of the X-ray wave's magnetic field and obtain {rvec F}{sub 1}(t) = -e E{sub 1} = v{sub z}/c B{sub 1} cos({omega}{sub 1}t - k{sub 1}z){rvec e}{sub y} {approx} - eE{sub 1}/2{gamma}{sup 2} cos({omega}{sub 1}t - k{sub 1}z){rvec e}{sub y}. Here c is the speed of light and {gamma} is the electron relativistic factor. In result one would need to change E{sub 1} to E{sub 1}/2{gamma}{sup 2} in all the following equations in the cited paper (except wave propagation equations, Eqs. (23) and (34)). They believe that similar omission in the impact of the magnetic field appears in equation (28). Consequently, the formula for the gaion (Eq. (37) in the cited paper) should also include the factor 1/2{gamma}{sup 2}. This is a rather significant modification considering that relativistic electrons with values of {gamma} ranging from approximately 20 to approximately 300 are used in the numerical examples.

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

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

    Barends, Thomas, R.M.

    2013-11-25

    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.

  7. 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)

    | Jefferson Lab optics.org/article/38950 Submitted: Friday, May 1

  8. Experimental demonstration of a soft x-ray self-seeded free-electron laser

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

    Ratner, D.; Abela, R.; Amann, J.; Behrens, C.; Bohler, D.; Bouchard, G.; Bostedt, C.; Boyes, M.; Chow, K.; Cocco, D.; et al

    2015-02-06

    The Linac Coherent Light Source 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.

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

    SciTech Connect (OSTI)

    Bahmani, Mohammad; Hamzehpour, Hossein; Hasanbeigi, Ali

    2013-11-15

    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.

  10. Eigenmode analysis of a high-gain free-electron laser based on...

    Office of Scientific and Technical Information (OSTI)

    Have feedback or suggestions for a way to improve these results? Save Share this Record Citation Formats MLA APA Chicago Bibtex Export Metadata Endnote Excel CSV XML Save to My ...

  11. Design Considerations for the Free-Electron Laser with Self-Seeding...

    Office of Scientific and Technical Information (OSTI)

    Have feedback or suggestions for a way to improve these results? Save Share this Record Citation Formats MLA APA Chicago Bibtex Export Metadata Endnote Excel CSV XML Save to My ...

  12. Focus characterization at an X-ray free-electron laser by coherent...

    Office of Scientific and Technical Information (OSTI)

    provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this document is also available for sale to...

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

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

    Martin, A. V.

    2012-08-25

    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)

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

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

    Hattne, Hattne

    2014-03-04

    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.

  15. The Jefferson lab FEL driver ERLs

    SciTech Connect (OSTI)

    Douglas, David R.; Tennant, Christopher D.

    2013-11-01

    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.

  16. LCLS CDR Chapter 5 - FEL Parameters and Performance

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

    5 FEL Parameters and Performance TECHNICAL SYNOPSIS The FEL parameter optimization and performance characterizations that are described in Chapter 5 are based on three-dimensional theory and computer models. The investigation led to a selection of the best parameters and to a study of the sensitivity to changes in values of accelerator components and beam characteristics and to unavoidable imperfections in the settings of the beam characteristics, magnetic and mechanical components and electron

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

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

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

  18. Propagation of gamma rays and production of free electrons in air

    SciTech Connect (OSTI)

    Dimant, Y. S.; Nusinovich, G. S.; Romero-Talamas, C. A.; Granatstein, V. L.; Sprangle, P.; Penano, J.

    2012-10-15

    This paper is devoted to the analysis of production of free electrons in air by gamma-rays leaking from radioactive materials. A model based on the Klein-Nishina scattering theory is used to calculate scattering cross sections and approximate the electron production rate. The model includes the effects of primary gamma-quanta radiated by the source as well as that scattered in air. Comparison of the model with the mcnpx kinetic code (http://mcnpx.lanl.gov/) in a sample problem shows excellent agreement. The motivation for this research comes from the recently proposed concept of remote detection of concealed radioactive materials [V. L. Granatstein and G. S. Nusinovich, J. Appl. Phys. 108, 063304 (2010)]. The concept is based on the breakdown in air at the focal point of a high-power beam of electromagnetic waves produced by a THz gyrotron with a 10-20 {mu}s pulse. The presence of a radioactive material can greatly exceed the production rate of free electrons over the natural background rate. Additional electrons act as seeds to initiate the breakdown and create sufficiently dense plasma at the focal region. The dense plasma can then be remotely detected as an unambiguous effect of the concealed radioactive material.

  19. Undulators for the BESSY SASE-FEL Project

    SciTech Connect (OSTI)

    Bahrdt, J.; Frentrup, W.; Gaupp, A.; Kuske, B.; Meseck, A.; Scheer, M.

    2004-05-12

    BESSY plans to build a SASE-FEL facility for the energy range from 20 eV to 1000 eV. The energy range will be covered by three APPLE II type undulators with a magnetic length of about 60 m each. This paper summarizes the basic parameters of the FEL-undulators. The magnetic design will be presented. A modified APPLE II design will be discussed which provides higher fields at the expense of reduced horizontal access. GENESIS simulations give an estimate on the tolerances for the beam wander and for gap errors.

  20. Bound free electron-positron pair production accompanied by giant dipole resonances

    SciTech Connect (OSTI)

    Senguel, M. Y.; Gueclue, M. C.

    2011-01-15

    At the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), for example, virtual photons produce many particles. At small impact parameters where the colliding nuclei make peripheral collisions, photon fluxes are very large and these are responsible for the multiple photonuclear interactions. Free pair productions, bound free pair productions, and nuclear Coulomb excitations are important examples of such interactions, and these processes play important roles in the beam luminosity at RHIC and LHC. Here we obtained the impact parameter dependence of bound free pair production cross sections and by using this probability we obtained bound free electron-positron pair production with nuclear breakup for heavy ion collisions at RHIC and LHC. We also compared our results to the other calculations.

  1. UNCLASSIFIED Institute for Materials ...

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

    PSI: the X-ray free electron laser SwissFEL and its future experimental capabilities. Biography: Prof. Dr. Jol Mesot is, since 2008, director of the Paul Scherrer Institute...

  2. The Linac Coherent Light Source (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a...

  3. Future

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

    Future Future Print Information about the future expansion of research fields for synchrotrons and the growing number of light sources, including free electron lasers (FELs) will be posted here shortly.

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

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

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

  5. Lipidic phase membrane protein serial femtosecond crystallography

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

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

  6. Compound refractive lenses as prefocusing optics for X-ray FEL radiation

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

    Heimann, Philip; MacDonald, Michael; Nagler, Bob; Lee, Hae Ja; Galtier, Eric; Arnold, Brice; Xing, Zhou

    2016-01-27

    The performance of X-ray free-electron laser beamlines may be limited by the angular aperture. Compound refractive lenses (CRLs) can be employed to prefocus the X-ray beam, thereby increasing the beamline transmission. A prefocusing CRL was implemented in the X-ray transport of the Matter under Extreme Conditions Instrument at the Linac Coherent Light Source. A significant improvement in the beamline transmission was calculated over the 3ÔÇô10 keV photon energy range. At 5 keV, the relative X-ray intensity was measured and a factor of four increase was seen in the beamline transmission. As a result, the X-ray focus was also determined bymore┬á┬╗ the ablation imprint method.┬ź┬áless

  7. Studies of Resistive Wall Heating at JLAB FEL

    SciTech Connect (OSTI)

    Li, Rui; Benson, Stephen V.

    2013-06-01

    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.

  8. R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-StateStudies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary LayoutOption Investigation

    SciTech Connect (OSTI)

    Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox Russell; Wurtele, Jonathan; Zholents, Alexander

    2005-10-01

    This report constitutes the third deliverable of LBNLs contracted role in the FERMI {at} Elettra Technical Optimization study. It describes proposed R&D activities for the baseline design of the Technical Optimization Study, initial studies of the RF gun mode-coupling and potential effects on beam dynamics, steady-state studies of FEL-2 performance to 10 nm, preliminary studies of time-dependent FEL-1 performance using electron bunch distribution from the start-to-end studies, and a preliminary investigation of a configuration with FEL sinclined at a small angle from the line of the linac.

  9. Newport News Lab Zaps Record for Laser Power | Jefferson Lab

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

    Newport News Lab Zaps Record for Laser Power Researchers at the Thomas Jefferson National Accelerator Facility vaporized previous records for power produced by a laser. Thursday afternoon and into the night, scientists slowly cranked up the power to Jefferson Lab's free-electron laser and blew away even their own estimates of its capabilities. "We had to pull a few people off the ceiling," said Fred Dylla, director of Jefferson Lab's free-electron laser program. "We're pretty

  10. The Linac Coherent Light Source

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

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-05-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  11. Study of CSR Effects in the Jefferson Laboratory FEL Driver

    SciTech Connect (OSTI)

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

    2013-08-01

    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.

  12. Workshop: New Advances in Crystallography with Synchrotrons and X-FELs |

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

    Stanford Synchrotron Radiation Lightsource New Advances in Crystallography with Synchrotrons and X-FELs Tuesday, October 25, 2011 - 8:00am 2011 SSRL/LCLS Annual Users Conference This workshop, part of the 2011 SSRL/LCLS Annual Users Conference, will describe resources and results from synchrotron-based micro crystallography and X-FEL-based nanocrystallography, and explore the future of these tools in producing important scientific results

  13. Lasers

    SciTech Connect (OSTI)

    1995-01-01

    The scope of our research in laser and related technologies has grown over the years and has attracted a broad user base for applications within DOE, DOD, and private industry. Within the next few years, we expect to begin constructing the National Ignition Facility, to make substantial progress in deploying AVLIS technology for uranium and gadolinium enrichment, and to develop new radar sensing techniques to detect underwater objects. Further, we expect to translate LLNL patent ideas in microlithography into useful industrial products and to successfully apply high-power, diode-based laser technology to industrial and government applications.

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

    Office of Environmental Management (EM)

    Lasers, Electron Beams and New Years Resolutions Lasers, Electron Beams and New Years Resolutions March 2, 2011 - 3:43pm Addthis Charles Rousseaux Charles Rousseaux Senior Communications Specialist (detailee) What are the key facts? The electron beam that powers Jefferson Lab's Free-Electron Laser pumped out a record power input of 500 kilvolts using an innovative energy-recovery system that amplifies energy with far less power. A sufficiently powerful laser could make an effective defensive

  15. Fabrication and characterization of cesium telluride photocathodes: A promising electron source for the Los Alamos Advanced FEL

    SciTech Connect (OSTI)

    Kong, S.H.; Nuguyen, D.C.; Sheffield, R.L.; Sherwood, B.A.

    1994-09-01

    The Advanced FEL at Los Alamos embodies a Y{sub 2}CsSb photocathode as an electron source. The photocathode consists of a K{sub 2}CsSb film deposited on a molybdenum plug that can be inserted into the linac of the FEL. However, because K{sub 2}CsSb is easily contaminated and has a half-life of less than a day when in use, switching to a more rugged high quantum efficiency (QE) material such as Cs{sub 2}Te is considered as a means to lengthen the beam time. Cs{sub 2}Te films were deposited on molybdenum plugs in an ultrahigh-vacuum research chamber. Several Cs{sub 2}Te films were measured in-situ for their spectral responses with a bias voltage of 90V; the resulting QEs were 12-18% at a wavelength of 254 nm, 0.2-1.2% at 334 nm, 10{sup {minus}4}-10{sup {minus}3} at 365 nm, and 10{sup {minus}7}-10{sup {minus}5} at 546 nm. For this cathode to be useful, the authors need to frequency quadruple the 1052 mn line of the Nd:YLF laser to achieve a wavelength of 263 mm. Initial studies showed that the 251-nm QE of Cs{sub 2}Te is much less sensitive to contamination than the 526-nm QE of K{sub 2}CsSb. The authors exposed Cs{sub 2}Te photocathodes to air at 10{sup {minus}4} torr for five minutes. As a result, the QEs dropped from 16-18% to 1-2% at 254 mn. However, heating the cathode to 165{degrees}C revived the QE to about 10%. They conclude that Cs{sub 2}Te is a very rugged photocathode material for use in an rf photoelectron source.

  16. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect (OSTI)

    Landahl, E. C.; Alvis, R. M.; Troha, A. L.; Hartemann, F. V.; Baldis, H. A. [Applied Science Department, University of California, Davis California 95616 (United States); Institute for Laser Science and Applications, LLNL, Livermore, California 94550 (United States); Le Sage, G. P.; White, W. E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bennett, C. V. [Electrical Engineering Department, University of California, Los Angeles, California 90024 (United States); Li, K.; Heritage, J. P. [Electrical and Computer Engineering Department, University of California, Davis, California (United States); Ho, C. H. [Synchrotron Radiation Research Center, Taiwan (China); Luhmann, N. C. Jr. [Applied Science Department, University of California, Davis California 95616 (United States)

    1999-05-07

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously modelocked AlGaAs quantum well laser has been achieved using the X-band gun rf fields. This novel, GHz repetition rate, laser system is being developed to replace the more conventional femtosecond Ti:Al{sub 2}O{sub 3} system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported.

  17. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect (OSTI)

    Landahl, E.C.; Alvis, R.M.; Troha, A.L.; Hartemann, F.V.; Baldis, H.A.; Luhmann, N.C. Jr. [Applied Science Department, University of California, Davis , California 95616 (United States); Landahl, E.C.; Alvis, R.M.; Troha, A.L.; Hartemann, F.V.; Baldis, H.A. [Institute for Laser Science and Applications, LLNL, Livermore, California 94550 (United States); Le Sage, G.P.; White, W.E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bennett, C.V. [Electrical Engineering Department, University of California, Los Angeles, California 90024 (United States); Li, K.; Heritage, J.P. [Electrical and Computer Engineering Department, University of California, Davis, California (United States); Ho, C.H. [Synchrotron Radiation Research Center (Taiwan)

    1999-05-01

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously modelocked AlGaAs quantum well laser has been achieved using the X-band gun rf fields. This novel, GHz repetition rate, laser system is being developed to replace the more conventional femtosecond Ti:Al{sub 2}O{sub 3} system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported. {copyright} {ital 1999 American Institute of Physics.}

  18. A photocathode rf gun design for a mm-wave linac-based FEL

    SciTech Connect (OSTI)

    Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

    1995-07-01

    In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

  19. Using The SLAC Two-Mile Accelerator for Powering an FEL

    SciTech Connect (OSTI)

    Barletta, W.A.; Sessler, A.M.; Yu, L.H.; /Brookhaven

    2012-06-29

    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.

  20. Femtosecond nanocrystallography using X-ray lasers for membrane protein

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

    structure determination Femtosecond nanocrystallography using X-ray lasers for membrane protein structure determination Authors: Fromme, P., and Spence, J. C. H. Title: Femtosecond nanocrystallography using X-ray lasers for membrane protein structure determination Source: Current Opinion in Structural Biology Year: 2011 Volume: 21 Pages: 509-516 ABSTRACT: The invention of free electron X-ray lasers has opened a new era for membrane protein structure determination with the recent first

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

    SciTech Connect (OSTI)

    Kato, M.; Tanaka, T.; Saito, N.; Kurosawa, T.; Richter, M.; Sorokin, A. A.; Tiedtke, K.; Kudo, T.; Yabashi, M.; Tono, K.; Ishikawa, T.

    2012-07-09

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

  2. Fast pulsed excitation wiggler or undulator

    DOE Patents [OSTI]

    van Steenbergen, Arie (Shoreham, NY)

    1990-01-01

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

  3. Ultraviolet radiation induced discharge laser

    DOE Patents [OSTI]

    Gilson, Verle A. (Livermore, CA); Schriever, Richard L. (Livermore, CA); Shearer, James W. (Livermore, CA)

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

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

    SciTech Connect (OSTI)

    Chuyu Liu

    2012-12-31

    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.

  5. LCLS CDR Chapter 1 - Executive Summary

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

    Executive Summary 1.1 Introduction The Stanford Linear Accelerator Center, in collaboration with Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, have collaborated to create a conceptual design for a Free-Electron-Laser (FEL) R&D facility operating in the wavelength range 1.5-15 ├ů. This FEL, called the "Linac Coherent Light Source" (LCLS), utilizes

  6. EA-1534: Final Environmental Assessment | Department of Energy

    Office of Environmental Management (EM)

    Final Environmental Assessment EA-1534: Final Environmental Assessment Proposed Upgrade and Operation of the CEBAF and FEL Accelerators and Construction and Use of Buildings Associated with the 2005 Ten-Year Site Plan The U. S. Department of Energy (DOE), in this Environmental Assessment (EA), reports the results of an analysis of the potential environmental impacts from the proposed upgrade and operation of the Continuous Electron Beam Accelerator Facility (CEBAF) and Free-Electron Laser (FEL)

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

    SciTech Connect (OSTI)

    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

    2011-03-01

    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.

  8. Femtosecond Synchronization of Laser Systems for the LCLS (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Femtosecond Synchronization of Laser Systems for the LCLS Citation Details In-Document Search Title: Femtosecond Synchronization of Laser Systems for the LCLS The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system

  9. Optical laser systems at the Linac Coherent Light Source

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

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; et al

    2015-04-22

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). PumpÔÇôprobe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pumpÔÇôprobe experiments to be performed at┬áLCLS.

  10. Jefferson Lab Laser Twinkles in Rare Color | Jefferson Lab

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

    Laser Twinkles in Rare Color NEWPORT NEWS, VA, Dec. 21 - December is a time for twinkling lights, and scientists at the Department of Energy's Thomas Jefferson National Accelerator Facility are delivering. They've just produced a long-sought, rare color of laser light 100 times brighter than that generated anywhere else. The light was produced by Jefferson Lab's Free-Electron Laser facility. The laser delivered vacuum ultraviolet light in the form of 10 eV photons (a wavelength of 124

  11. Experts at Newport News Lab Develop Powerful New Laser | Jefferson Lab

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

    Experts at Newport News Lab Develop Powerful New Laser By John S. MacNeil, Richmond-Times Dispatch A year after emitting its "first light," a highly focused and powerful experimental laser at the Thomas Jefferson National Accelerator Facility has become the world's most powerful tunable laser. Don't expect this laser on a compact disc player. With just 10 watts, the Jefferson Lab laser, called the Free Electron Laser, can burn holes through metal and pieces of ceramic. With 1,720

  12. THE SECOND STAGE OF FERMI@ELETTRA: A SEEDED FEL IN THE SOFT X-RAY SPECTRAL RANGE

    SciTech Connect (OSTI)

    Allaria, E.; DeNinno, G.; Fawley, W. M.

    2009-08-14

    The second stage of the FERMI FEL, named FEL-2, is based on the principle of high-gain harmonic generation and relies on a double-seeded cascade. Recent developments stimulated a revision of the original setup, which was designed to cover the spectral range between 40 and 10 nm. The numerical simulations we present here show that the nominal (expected) electron-beam performance allows extension of the FEL spectral range down to 4 nm. A significant amount of third harmonic power can be also expected. We also show that the proposed setup is flexible enough for exploiting future developments of new seed sources, e.g., high harmonic generation in gases.

  13. Jefferson Laser Team Meets Goal | Jefferson Lab

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

    Laser Team Meets Goal - Beam Reaches Record 1,720 Watts For a few seconds, it was like a golf ball hovering on the rim of a hole without dropping. Except at the Thomas Jefferson National Accelerator Facility, the ball dropped. Thursday night, the lab's free-electron laser briefly flickered off when the power of its light beam reached 990 watts. As scientists held their breath, it turned back on and passed the 1,000-watt mark - topping the project's goal and prompting one scientist to grab

  14. 2005 | Jefferson Lab

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

    August 2005 Sat, 08/13/2005 - 4:35pm Free Electron Lasers Come of Age - Photonics Spectra July 2005 Tue, 07/26/2005 - 4:26pm JLab FEL Wins R&D 100 Award May 2005 Wed, 05/18/2005 - 4:58pm Jefferson Lab Builds First Single Crystal Single Cell Accelerating Cavity

  15. Space charge field in a FEL with axially symmetric electron beam

    SciTech Connect (OSTI)

    Goncharov, I.A.; Belyavskiy, E.D.

    1995-12-31

    Nonlinear two-dimensional theory of the space charge of an axially symmetric electron beam propagating in combined right-hand polarized wiggler and uniform axial guide fields in a presence of high-frequency electromagnetic wave is presented. The well-known TE{sub 01} mode in a cylindrical waveguide for the model of radiation fields and paraxial approximation for the wiggler field are used. Space charge field components are written in the Lagrange coordinates by the twice averaged Green`s functions of two equally charged infinitely thin discs. For that {open_quotes}compensating charges{close_quotes} method is applied in which an electron ring model is substituted by one with two different radii and signs discs. On this approach the initial Green`s functions peculiarities are eliminated and all calculations are considerably simplified. Coefficients of a twice averaged Green`s function expansion into a Fourier series are obtained by use of corresponding expansion coefficients of longitudinal Green`s functions of equal radii discs and identical rings known from the one-dimensional theory of super HF devices taking into account electron bunches periodicity. This approach permit the space charge field components for an arbitrary stratified stream to be expressed in a simple and strict enough form. The expressions obtained can be employed in a nonlinear two-dimensional FEL theory in order to investigate beam dynamical defocusing and electrons failing on the waveguide walls in the high gain regime. This is especially important for FEL operation in mm and submm.

  16. Laser ablative synthesis of carbon nanotubes

    DOE Patents [OSTI]

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

    2010-03-02

    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.

  17. Lasers, extreme UV and soft X-ray

    SciTech Connect (OSTI)

    Nilsen, Joseph

    2015-09-20

    Three decades ago, large ICF lasers that occupied entire buildings were used as the energy sources to drive the first X-ray lasers. Today X-ray lasers are tabletop, spatially coherent, high-repetition rate lasers that enable many of the standard optical techniques such as interferometry to be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. Over the last decade X-ray laser performance has been improved by the use of the grazing incidence geometry, diode-pumped solid-state lasers, and seeding techniques. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA) laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10 ÔÇô 30 nm range, while the capillary system works best for neon-like argon at 46.9 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors that have peak reflectivity near 13 nm and are used in many applications. As a result, the last decade has seen the birth of the X-ray free electron laser (XFEL) that can reach wavelengths down to 0.15 nm and the inner-shell Ne laser at 1.46 nm.

  18. Lasers, extreme UV and soft X-ray

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

    Nilsen, Joseph

    2015-09-20

    Three decades ago, large ICF lasers that occupied entire buildings were used as the energy sources to drive the first X-ray lasers. Today X-ray lasers are tabletop, spatially coherent, high-repetition rate lasers that enable many of the standard optical techniques such as interferometry to be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. Over the last decade X-ray laser performance has been improved by the use of the grazing incidence geometry, diode-pumped solid-state lasers, and seeding techniques. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA)more┬á┬╗ laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10 ÔÇô 30 nm range, while the capillary system works best for neon-like argon at 46.9 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors that have peak reflectivity near 13 nm and are used in many applications. As a result, the last decade has seen the birth of the X-ray free electron laser (XFEL) that can reach wavelengths down to 0.15 nm and the inner-shell Ne laser at 1.46 nm.┬ź┬áless

  19. Studies Of Coherent Synchrotron Radiation And Longitudinal Space Charge In The Jefferson Lab FEL Driver

    SciTech Connect (OSTI)

    Tennant, Christopher D.; Douglas, David R.; Li, Rui; Tsai, C.-Y.

    2014-12-01

    The Jefferson Laboratory IR FEL Driver provides an ideal test bed for studying a variety of beam dynamical effects. Recent studies focused on characterizing the impact of coherent synchrotron radiation (CSR) with the goal of benchmarking measurements with simulation. Following measurements to characterize the beam, we quantitatively characterized energy extraction via CSR by measuring beam position at a dispersed location as a function of bunch compression. In addition to operating with the beam on the rising part of the linac RF waveform, measurements were also made while accelerating on the falling part. For each, the full compression point was moved along the backleg of the machine and the response of the beam (distribution, extracted energy) measured. Initial results of start-to-end simulations using a 1D CSR algorithm show remarkably good agreement with measurements. A subsequent experiment established lasing with the beam accelerated on the falling side of the RF waveform in conjunction with positive momentum compaction (R56) to compress the bunch. The success of this experiment motivated the design of a modified CEBAF-style arc with control of CSR and microbunching effects.

  20. Waveguide Structures for RF Undulators with Applications to FELs and Storage Rings

    SciTech Connect (OSTI)

    Yeddulla, M.; Geng, H.G.; Huang, Z.; Ma, Z.; Tantawi, S.G.; /SLAC

    2011-11-02

    RF undulators, suggested a long time ago, have the advantage of fast dynamic control of polarization, undulator strength and wavelength. However, RF undulators require very strong RF fields in order to produce radiation of the same order as conventional static devices. Very high power RF energy confined inside a waveguide or a cavity can provide the necessary RF fields to undulate the electron beam. However, the wall losses in the waveguide should be low enough to make it practically feasible as a CW or quasi CW undulator and, hence, competitive with static devices for applications to storage rings and FELs. Here we present various waveguide structures such as smooth walled and corrugated walled waveguides and various RF modes. We will show that there are some advantages in operating with higher order modes and also with hybrid modes in the corrugated guide. We will show that the RF power requirement for some of these modes will permit a quasi CW operation of the undulator, thus permitting its operation in a storage ring.

  1. Industrial Green | Jefferson Lab

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

    Industrial Green Industrial Green - This giant bag may not look green, but it keeps a potent greenhouse gas from being released into the atmosphere. It's part of a system at the Free-Electron Laser that retains sulfur hexafluoride gas when it isn't being used in the FEL's gun test stand. The concept received a 2011 Virginia Governor's Environmental Excellence Program Gold Award. Industrial Green On behalf of work done by Kevin Jordan, a senior engineer in the Free-Electron Laser Division, and

  2. Jefferson Lab Laser Breakthrough Opens Way for Navy Funding | Jefferson Lab

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

    Laser Breakthrough Opens Way for Navy Funding The powerful laser in development at Jefferson Laboratory in Newport News is not "Star Wars" technology, in either the Ronald Reagan or the George Lucas sense. It's more realistic than both the 1980s missile-defense fantasy and the 1990s (and '70s) Jedi space fantasy. The Jefferson Lab's free-electron laser has made believers out of doubters and possibly earned itself federal funding. That could be great economic news for Newport News and

  3. A syncrhronized FIR/VUV light source at Jefferson Lab

    SciTech Connect (OSTI)

    Shinn, Michelle D.

    2013-05-31

    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.

  4. Transverse Coherence of the LCLS X-Ray Beam

    SciTech Connect (OSTI)

    Not Available

    2010-12-01

    Self-amplifying spontaneous radiation free-electron lasers, such as the LCLS or the European X-FEL, rely on the incoherent, spontaneous radiation as the seed for the amplifying process. Though this method overcomes the need for an external seed source one drawback is the incoherence of the effective seed signal. The FEL process allows for a natural growth of the coherence because the radiation phase information is spread out within the bunch due to slippage and diffraction of the radiation field. However, at short wavelengths this spreading is not sufficient to achieve complete coherence. In this presentation we report on the results of numerical simulations of the LCLS X-ray FEL. From the obtained radiation field distribution the coherence properties are extracted to help to characterize the FEL as a light source.

  5. Temporal profile measurements of relativistic electron bunch based on wakefield generation

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

    Bettoni, S.; Craievich, P.; Lutman, A. A.; Pedrozzi, M.

    2016-02-25

    A complete characterization of the time-resolved longitudinal beam phase space is important to optimize the final performances of an accelerator, and in particular this is crucial for Free Electron Laser (FEL) facilities. In this study we propose a novel method to characterize the profile of a relativistic electron bunch by passively streaking the beam using its self-interaction with the transverse wakefield excited by the bunch itself passing off-axis through a dielectric-lined or a corrugated waveguide. Results of a proof-of-principle experiment at the SwissFEL Injector Test Facility are discussed.

  6. Microsoft Word - Document1

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

    FIRST LASING OF THE LCLS X-RAY FEL AT 1.5 ├ů P. Emma, for the LCLS Commissioning Team; SLAC, Stanford, CA 94309, USA Abstract The Linac Coherent Light Source (LCLS) is a SASE 1.5-15 ├ů x-ray Free-Electron Laser (FEL) facility under construction at SLAC [1], and presently in an advanced phase of commissioning. The injector, linac, and new bunch compressors were commissioned in 2007 [2] and 2008 [3], establishing the necessary electron beam brightness at 14 GeV. The final phase of commissioning,

  7. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer

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

    Dell'Angela, M.; Anniyev, T.; Beye, M.; Coffee, R.; F├Âhlisch, A.; Gladh, J.; Kaya, S.; Katayama, T.; Krupin, O.; Nilsson, A.; et al

    2015-03-01

    Vacuum space charge-induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES) have been studied at a free electron laser (FEL) for an oxygen layer on Ru(0001). We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  8. EA-1426: Final Environmental Assessment | Department of Energy

    Office of Environmental Management (EM)

    6: Final Environmental Assessment EA-1426: Final Environmental Assessment Linac Coherent Light Source Experimental Facility The DOE proposes to construct and operate a new research facility at SLAC, the Linac Coherent Light Source (LCLS), as a collaborative effort with other DOE facilities. The purpose and need for the LCLS is the creation of a new type of x-ray light source from a single pass free electron laser (FEL). The FEL would have a peak brightness 10 orders of magnitude greater and with

  9. Procedures for Experiments (PFX)

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

    0 Proposal Submission Guidelines for Proposals Reports Archives Directory of Proposals Membership Summary Workshops Experiment Summaries 6 GeV: pdf 12 GeV: pdf Program Advisory Committee (PAC) Jefferson Lab currently supports research in two broad areas of scientific investigation, the Nuclear Physics program and the Free-Electron Laser (FEL) program. Each program has its own review process for consideration of proposed research. Experiments at JLab are reviewed, approved for beamtime and run

  10. Linac Coherent Light Source (LCLS) Bunch-Length Monitor using Coherent Radiation

    SciTech Connect (OSTI)

    Wu, Juhao; Emma, P.; /SLAC

    2007-03-21

    The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) based on the final kilometer of the Stanford Linear Accelerator. One of the most critical diagnostic devices is the bunch length monitor (BLM), which is to be installed right after each compressor utilizing coherent radiation from the last bending magnet. We describe the components and the optical layout of such a BLM. Based on the setup geometry, we discuss some issues about the coherent radiation signal.

  11. Jefferson Lab Leadership Council - Dr. Andrew Hutton

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

    GEORGE NEIL Associate Director for FEL Division George Neil is Senior Team Lead for the LCLS-II Project at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), a Department of Energy particle accelerator facility run for nuclear physics research. The LCLS-II Project is a new DOE Basic Energy Sciences program centered at Stanford National Accelerator Facility involving the construction of a X-ray Free Electron Laser powered by a 4 GeV continuous wave superconducting accelerator.

  12. Linac Coherent Light SourCe

    Energy Savers [EERE]

    Linac Coherent Light SourCe after the Stanford Linear Accelerator Center (now the SLAC National Accelerator Laboratory) developed its two- mile-long linear accelerator (linac), it received approval from the Department of Energy to construct the Linac Coherent Light Source (LCLS), the first free electron laser (FEL) facility that would be able to produce x-rays short and bright enough that individual molecules could be imaged in their natural states. 40 years Genesis of the idea In 1992, Dr.

  13. Imaging of free carriers in semiconductors via optical feedback in terahertz quantum cascade lasers

    SciTech Connect (OSTI)

    Mezzapesa, F. P. Brambilla, M.; Dabbicco, M.; Scamarcio, G.; Columbo, L. L.; Vitiello, M. S.

    2014-01-27

    To monitor the density of photo-generated charge carriers on a semiconductor surface, we demonstrate a detectorless imaging system based on the analysis of the optical feedback in terahertz quantum cascade lasers. Photo-excited free electron carriers are created in high resistivity n-type silicon wafers via low power (?40 mW/cm{sup 2}) continuous wave pump laser in the near infrared spectral range. A spatial light modulator allows to directly reconfigure and control the photo-patterned intensity and the associated free-carrier density distribution. The experimental results are in good agreement with the numerical simulations.

  14. For laser at Jefferson Lab, it's 'pick a wavelength' | Jefferson Lab

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

    For laser at Jefferson Lab, it's 'pick a wavelength' By Jon W. Glass, The Virginian-Pilot NEWPORT NEWS - The search for a weapon that could knock down an incoming cruise missile drew the Navy. A possible cure for adult acne attracted a Harvard dermatologist. The potential for building lighter, stronger planes and spacecraft brought a NASA engineer. From war to peace, their quests led them to the same place: the free-electron laser lab at the Thomas Jefferson National Accelerator Facility. The

  15. Laser Roadshow

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

    outreach Laser Roadshow The NIF Laser Roadshow includes a number of interactive laser demonstrations (Laser Light Fountain, Laser DJ, and NIF "3D ride") that have traveled across the country to museums and science fairs to bring awareness and education to students and the general public about lasers and how they function. These demonstrations have been presented at the Lawrence Hall of Science, the National Boy Scout Jamboree, meetings of the American Association for the Advancement of

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

    SciTech Connect (OSTI)

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

    2010-10-26

    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.

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

    SciTech Connect (OSTI)

    Sun, Yipeng; /SLAC

    2012-08-20

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

  18. Laser Facilities

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

    Laser Facilities Current Schedule of Experiments Operation Schedule Janus Titan Europa COMET Facility Floorplan

  19. Peculiarities of filamentation of sharply focused ultrashort laser pulses in air

    SciTech Connect (OSTI)

    Geints, Yu. E.; Zemlyanov, A. A.; Ionin, A. A.; Kudryashov, S. I.; Seleznev, L. V. Sinitsyn, D. V.; Sunchugasheva, E. S.

    2010-11-15

    Peculiarities of the self-focusing and filamentation of high-power femtosecond laser pulses in air have been experimentally and theoretically studied under conditions of broad variation of the beam focusing parameter. The influence of the numerical aperture (NA) of the initial radiation focusing on the main characteristics of laser-induced plasma columns (characteristic transverse size, length, and concentration of free electrons) is considered. It is established that, for a rigid (NA > 0.05) initial laser beam focusing, the transverse size of the plasma channel ceases to decrease at a level of R{sub pl} {approx} 2-4 {mu}m as a result of strong refraction of radiation on the plasma formed at the focal waist, which prevents further contraction of the laser beam due to its focusing and self-focusing.

  20. A SYNCHRONIZED FIR/VUV LIGHT SOURCE AT JEFFERSON LAB

    SciTech Connect (OSTI)

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

    2012-07-01

    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.

  1. Absorber for terahertz radiation management

    DOE Patents [OSTI]

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  2. Laser ignition

    DOE Patents [OSTI]

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

    2002-01-01

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

  3. Laser microphone

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2000-11-14

    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.

  4. Laser ignition

    DOE Patents [OSTI]

    Early, James W.; Lester, Charles S.

    2004-01-13

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  5. Laser device

    DOE Patents [OSTI]

    Scott, Jill R.; Tremblay, Paul L.

    2004-11-23

    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.

  6. Laser device

    DOE Patents [OSTI]

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    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.

  7. Laser ignition

    DOE Patents [OSTI]

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

    2003-01-01

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

  8. Second user workshop on high-power lasers at the Linac Coherent Light Source

    SciTech Connect (OSTI)

    Heimann, Phil; Glenzer, Siegfried

    2015-05-28

    The second international workshop on the physics enabled by the unique combination of high-power lasers with the world-class Linac Coherent Light Source (LCLS) free-electron X-ray laser beam was held in Stanford, CA, on October 7ÔÇô8, 2014. The workshop was co-organized by UC Berkeley, Lawrence Berkeley, Lawrence Livermore, and SLAC National Accelerator Laboratories. More than 120 scientists, including 40 students and postdoctoral scientists who are working in high-intensity laser-matter interactions, fusion research, and dynamic high-pressure science came together from North America, Europe, and Asia. The focus of the second workshop was on scientific highlights and the lessons learned from 16 new experiments that were performed on the Matter in Extreme Conditions (MEC) instrument since the first workshop was held one year ago.

  9. Second user workshop on high-power lasers at the Linac Coherent Light Source

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

    Heimann, Phil; Glenzer, Siegfried

    2015-05-28

    The second international workshop on the physics enabled by the unique combination of high-power lasers with the world-class Linac Coherent Light Source (LCLS) free-electron X-ray laser beam was held in Stanford, CA, on October 7ÔÇô8, 2014. The workshop was co-organized by UC Berkeley, Lawrence Berkeley, Lawrence Livermore, and SLAC National Accelerator Laboratories. More than 120 scientists, including 40 students and postdoctoral scientists who are working in high-intensity laser-matter interactions, fusion research, and dynamic high-pressure science came together from North America, Europe, and Asia. The focus of the second workshop was on scientific highlights and the lessons learned from 16 newmore┬á┬╗ experiments that were performed on the Matter in Extreme Conditions (MEC) instrument since the first workshop was held one year ago.┬ź┬áless

  10. Laser ignition

    DOE Patents [OSTI]

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

    2002-01-01

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

  11. Fiber Lasers

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

    Fiber Lasers NIF & Photon Science physicists are exploring the fundamental limits of traditional round fiber structure and developing alternate solutions to allow scaling to higher powers and pulse energies. Comprehensive models of ribbon fiber structures, or waveguides, are also being developed. The goal is to develop ribbon fiber lasers that can amplify light beams to powers well beyond fundamental limits. Joint research efforts with the Lasers and Optics Research Center at the U.S. Air

  12. Laser apparatus

    DOE Patents [OSTI]

    Lewis, Owen (Fairport, NY); Stogran, Edmund M. (North Syracuse, NY)

    1980-01-01

    Laser apparatus is described wherein an active laser element, such as the disc of a face-pumped laser, is mounted in a housing such that the weight of the element is supported by glass spheres which fill a chamber defined in the housing between the walls of the housing and the edges of the laser element. The uniform support provided by the spheres enable the chamber and the pump side of the laser element to be sealed without affecting the alignment or other optical properties of the laser element. Cooling fluid may be circulated through the sealed region by way of the interstices between the spheres. The spheres, and if desired also the cooling fluid may contain material which absorbs radiation at the wavelength of parasitic emissions from the laser element. These parasitic emissions enter the spheres through the interface along the edge surface of the laser element and it is desirable that the index of refraction of the spheres and cooling fluid be near the index of refraction of the laser element. Thus support, cooling, and parasitic suppression functions are all accomplished through the use of the arrangement.

  13. Laser ignition

    DOE Patents [OSTI]

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

    2002-01-01

    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.

  14. Heterodyne laser spectroscopy system

    DOE Patents [OSTI]

    Wyeth, Richard W. (Livermore, CA); Paisner, Jeffrey A. (San Ramon, CA); Story, Thomas (Antioch, CA)

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  15. Heterodyne laser spectroscopy system

    DOE Patents [OSTI]

    Wyeth, Richard W. (Livermore, CA); Paisner, Jeffrey A. (San Ramon, CA); Story, Thomas (Antioch, CA)

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  16. Laser device

    DOE Patents [OSTI]

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

    2008-08-19

    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.

  17. MTX final report

    SciTech Connect (OSTI)

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

    1994-01-01

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

  18. Coherent Radiation Effects in the LCLS Undulator

    SciTech Connect (OSTI)

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

    2010-12-14

    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.

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

    SciTech Connect (OSTI)

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

    2013-12-01

    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.

  20. Laser goniometer

    DOE Patents [OSTI]

    Fairer, George M.; Boernge, James M.; Harris, David W.; Campbell, DeWayne A.; Tuttle, Gene E.; McKeown, Mark H.; Beason, Steven C.

    1993-01-01

    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.

  1. Tunable Laser Reaches Record Power Level | Jefferson Lab

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

    the FEL may have a wide range of applications in manufacturing, including processing of plastics, more durable synthetic fibers, corrosion resistant metals and advanced materials...

  2. Laser applications

    SciTech Connect (OSTI)

    Edelson, M.C. )

    1989-11-01

    The breadth of current applications of laser technology is described. It is used as the basis for extrapolating to future application in such activities as AVLIS, SIS, ICP-MS, and RIMs.

  3. Laser beam monitoring system

    DOE Patents [OSTI]

    Weil, Bradley S. (Knoxville, TN); Wetherington, Jr., Grady R. (Harriman, TN)

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  4. Laser barometer

    DOE Patents [OSTI]

    Abercrombie, Kevin R.; Shiels, David; Rash, Tim

    2001-02-06

    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.

  5. Lensless imaging

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

    4 Lensless Imaging of Magnetic Nanostructures by X-ray Spectro-Holography J. L├╝ning, W. F. Schlotter and J. St├Âhr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely new classes of experiments. The ultra-short time structure of the ultra-bright x-ray pulses will revolutionize the field of femtosecond x-ray science, since it will become possible to obtain sufficient information about a system from probing it

  6. Triangle Universities Nuclear Laboratory : 2011

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

    Proposal Submission| HIGS PAC| HIGS2| High Intensity Gamma-Ray Source (HIGS) is a Free-Electron Laser (FEL) based Compton backscattering gamma-ray source. The HIGS facility is located on the campus of Duke University and operated by Triangle Universities Nuclear Laboratory (TUNL). Currently, HIGS can produce gamma rays between 2 and 100 MeV with linear and circular polarizations. Total gamma-ray intensities can reach over 1 billion photons/second at some energies with few percent energy

  7. Toward TW-Level, Hard X-Ray Pulses at LCLS (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: Toward TW-Level, Hard X-Ray Pulses at LCLS Citation Details In-Document Search Title: Toward TW-Level, Hard X-Ray Pulses at LCLS Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study

  8. Jupiter Laser Facility

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

    Jupiter Laser Facility The commissioning of the Titan Petawatt-Class laser to LLNL's Jupiter Laser Facility (JLF) has provided a unique platform for the use of petawatt (PW)-class lasers to explore laser-matter interactions under extreme conditions. The JLF includes the Janus, Callisto, Europa, Titan, and COMET lasers and associated target chambers (see Laser Facilities). Commissioned in 2007, Titan was the first to offer synchronized operation of both a short-pulse PW beam and a long-pulse

  9. Extreme ultraviolet reflector

    DOE Patents [OSTI]

    Newnam, Brian E. (Los Alamos, NM)

    1990-01-01

    A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

  10. X-ray detectors at the Linac Coherent Light Source

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

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; et al

    2015-04-21

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a newmore┬á┬╗ generation of cameras under development at SLAC, is introduced.┬ź┬áless

  11. Laser Faraday

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

    Faraday rotation measurement of current density fluctuations and electromagnetic torque (invited) W. X. Ding, a) D. L. Brower, and B. H. Deng Electrical Engineering Department, University of California-Los Angeles, Los Angeles, California 90095 D. Craig, S. C. Prager, and V. Svidzinski Physics Department, University of Wisconsin-Madison, Madison, Wisconsin 53706 (Presented on 19 April 2004; published 1 October 2004) Far-infrared laser polarimetry with time response up to ¤│1 ÔÉ«s and spatial

  12. Heterodyne laser diagnostic system

    DOE Patents [OSTI]

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

    1990-01-01

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

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

    DOE Patents [OSTI]

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

    2004-11-30

    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.

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

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

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

  15. Laser programs highlights 1994

    SciTech Connect (OSTI)

    1994-12-31

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

  16. The LCLS variable-energy hard X-ray single-shot spectrometer

    SciTech Connect (OSTI)

    Rich, David; Zhu, Diling; Turner, James; Zhang, Dehong; Hill, Bruce; Feng, Yiping

    2016-01-01

    The engineering design, implementation, operation and performance of the new variable-energy hard X-ray single-shot spectrometer (HXSSS) for the LCLS free-electron laser (FEL) are reported. The HXSSS system is based on a cylindrically bent Si thin crystal for dispersing the incident polychromatic FEL beam. A spatially resolved detector system consisting of a Ce:YAG X-ray scintillator screen, an optical imaging system and a low-noise pixelated optical camera is used to record the spectrograph. The HXSSS provides single-shot spectrum measurements for users whose experiments depend critically on the knowledge of the self-amplified spontaneous emission FEL spectrum. It also helps accelerator physicists for the continuing studies and optimization of self-seeding, various improved mechanisms for lasing mechanisms, and FEL performance improvements. The designed operating energy range of the HXSSS is from 4 to 20 keV, with the spectral range of order larger than 2% and a spectral resolution of 2 Î 10-5or better. Those performance goals have all been achieved during the commissioning of the HXSSS.

  17. The LCLS variable-energy hard X-ray single-shot spectrometer

    SciTech Connect (OSTI)

    Rich, David; Zhu, Diling; Turner, James; Zhang, Dehong; Hill, Bruce; Feng, Yiping

    2016-01-01

    The engineering design, implementation, operation and performance of the new variable-energy hard X-ray single-shot spectrometer (HXSSS) for the LCLS free-electron laser (FEL) are reported. The HXSSS system is based on a cylindrically bent Si thin crystal for dispersing the incident polychromatic FEL beam. A spatially resolved detector system consisting of a Ce:YAG X-ray scintillator screen, an optical imaging system and a low-noise pixelated optical camera is used to record the spectrograph. The HXSSS provides single-shot spectrum measurements for users whose experiments depend critically on the knowledge of the self-amplified spontaneous emission FEL spectrum. It also helps accelerator physicists for the continuing studies and optimization of self-seeding, various improved mechanisms for lasing mechanisms, and FEL performance improvements. The designed operating energy range of the HXSSS is from 4 to 20 keV, with the spectral range of order larger than 2% and a spectral resolution of 2 Î 10-5or better. Those performance goals have all been achieved during the commissioning of the HXSSS.

  18. OMEGA Laser - Laboratory for Laser Energetics

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

    - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser Development and

  19. OMEGA Laser Drivers - Laboratory for Laser Energetics

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

    Drivers - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser Development and

  20. Omega Laser Facility - Laboratory for Laser Energetics

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

    - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser Development and

  1. Transverse Gradient Undulator Huang, Zhirong; Ding, Yuantao;...

    Office of Scientific and Technical Information (OSTI)

    B.; LBL, Berkeley 43 PARTICLE ACCELERATORS; ACCELERATORS; ELECTRON BEAMS; ELECTRONS; FREE ELECTRON LASERS; LASERS; PERFORMANCE; PLASMA GUNS; RADIATIONS; WIGGLER MAGNETS...

  2. Longitudinal discharge laser baffles

    DOE Patents [OSTI]

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

    1994-01-01

    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.

  3. Narrow gap laser welding

    DOE Patents [OSTI]

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

    1998-01-01

    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.

  4. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, J.O.; Sklar, E.

    1998-06-02

    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.

  5. Short wavelength laser

    DOE Patents [OSTI]

    Hagelstein, P.L.

    1984-06-25

    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.

  6. Longitudinal discharge laser baffles

    DOE Patents [OSTI]

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

    1994-06-07

    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.

  7. Laser accelerometer

    SciTech Connect (OSTI)

    Vescial, F.; Aronowitz, F.; Niguel, L.

    1990-04-24

    This patent describes a laser accelerometer. It comprises: an optical cavity characterizing a frame having an input axis (x), a cross axis (y) orthogonal to and co-planar with the input axis and a (z) axis passing through the intersection of the (x) and (y) axes, the (z) axis being orthogonal to the plane of the (x) and (y) axes; and (x) axis proof mass having a predetermined blanking surface; a flexible beam having a first end coupled to the (x) axis proof mass and a second end coupled to the frame, deflection of the flexible beams permitting a predetermined range of movement of the (x) proof mass on the input axis in a direction opposite to sensed acceleration of the frame; a laser light source having a mirror means within the cavity for providing a light ray coaxially aligned with the (z) axis; detector means having at least a first detector on a sensitive plane, the plane being normal to the (z) axis; bias and amplifier means coupled to the detector means for providing a bias current to the first detector and for amplifying the intensity signal; the (x) axis proof mass blanking surface being centrally positioned within and normal to the light ray null intensity region to provide increased blanking of the light ray in response to transverse movement of the mass on the input axis; control means responsive to the intensity signal for applying an (x) axis restoring force to restore the (x) axis proof mass to the central position and for providing an (x) axis output signal proportional to the restoring force.

  8. Laser Plasma Interactions

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

    Laser Plasma Interactions Laser Plasma Interactions Understanding and controlling laser produced plasmas for fusion and basic science Contact David Montgomery (505) 665-7994 Email John Kline (505) 667-7062 Email Thomson scattering is widely used to measure plasma temperature, density, and flow velocity in laser-produced plasmas at Trident, and is also used to detect plasma waves driven by unstable and nonlinear processes. A typical configuration uses a low intensity laser beam (2nd, 3rd, or 4th

  9. Final Report, Photocathodes for High Repetition Rate Light Sources

    SciTech Connect (OSTI)

    Ben-Zvi, Ilan

    2014-04-20

    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

  10. Nanocrystal waveguide (NOW) laser

    DOE Patents [OSTI]

    Simpson, John T.; Simpson, Marcus L.; Withrow, Stephen P.; White, Clark W.; Jaiswal, Supriya L.

    2005-02-08

    A solid state laser includes an optical waveguide and a laser cavity including at least one subwavelength mirror disposed in or on the optical waveguide. A plurality of photoluminescent nanocrystals are disposed in the laser cavity. The reflective subwavelength mirror can be a pair of subwavelength resonant gratings (SWG), a pair of photonic crystal structures (PC), or a distributed feedback structure. In the case of a pair of mirrors, a PC which is substantially transmissive at an operating wavelength of the laser can be disposed in the laser cavity between the subwavelength mirrors to improve the mode structure, coherence and overall efficiency of the laser. A method for forming a solid state laser includes the steps of providing an optical waveguide, creating a laser cavity in the optical waveguide by disposing at least one subwavelength mirror on or in the waveguide, and positioning a plurality of photoluminescent nanocrystals in the laser cavity.

  11. Infrared laser system

    DOE Patents [OSTI]

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

    1982-01-01

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

  12. Laser amplifier and method

    DOE Patents [OSTI]

    Backus, Sterling (Ann Arbor, MI); Kapteyn, Henry C. (Ann Arbor, MI); Murnane, Margaret M. (Ann Arbor, MI)

    1997-01-01

    Laser amplifiers and methods for amplifying a laser beam are disclosed. A representative embodiment of the amplifier comprises first and second curved mirrors, a gain medium, a third mirror, and a mask. The gain medium is situated between the first and second curved mirrors at the focal point of each curved mirror. The first curved mirror directs and focuses a laser beam to pass through the gain medium to the second curved mirror which reflects and recollimates the laser beam. The gain medium amplifies and shapes the laser beam as the laser beam passes therethough. The third mirror reflects the laser beam, reflected from the second curved mirror, so that the laser beam bypasses the gain medium and return to the first curved mirror, thereby completing a cycle of a ring traversed by the laser beam. The mask defines at least one beam-clipping aperture through which the laser beam passes during a cycle. The gain medium is pumped, preferably using a suitable pumping laser. The laser amplifier can be used to increase the energy of continuous-wave or, especially, pulsed laser beams including pulses of femtosecond duration and relatively high pulse rate.

  13. Laser preheat enhanced ignition

    DOE Patents [OSTI]

    Early, J.W.

    1999-03-02

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

  14. Waveguide gas laser

    SciTech Connect (OSTI)

    Zedong, C.

    1982-05-01

    Waveguide gas lasers are described. Transmission loss of hollow tube light waveguides, coupling loss, the calculation of output power, and the width of the oscillation belt are discussed. The structure of a waveguide CO/sub 2/ laser is described.

  15. Direct nuclear pumped laser

    DOE Patents [OSTI]

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

    1978-01-01

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

  16. Slender tip laser scalpel

    DOE Patents [OSTI]

    Veligdan, James T.

    2004-01-06

    A laser scalpel includes a ribbon optical waveguide extending therethrough and terminating at a slender optical cutting tip. A laser beam is emitted along the height of the cutting tip for cutting tissue therealong.

  17. Laser particle sorter

    DOE Patents [OSTI]

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

    1987-11-30

    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.

  18. Laser particle sorter

    DOE Patents [OSTI]

    Martin, John C. (Los Alamos, NM); Buican, Tudor N. (Los Alamos, NM)

    1989-01-01

    Method and apparatus for sorting particles, such as biological particles. A first laser defines 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 interrogates the particles to identify predetermined phenotypical characteristics of the particles. A second laser beam intersects 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.

  19. Laser programs highlights 1993

    SciTech Connect (OSTI)

    1995-06-01

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

  20. Laser cutting system

    DOE Patents [OSTI]

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  1. Short-Pulse Lasers

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

    Short-Pulse Lasers NIF Petawatt Laser Is on Track to Completion The National Ignition Facility's Advanced Radiographic Capability (ARC), a petawatt-class laser with peak power exceeding a quadrillion (1015) watts, is moving rapidly along the path to completion and commissioning. ARC is designed to produce brighter, more penetrating, higher-energy x rays than can be obtained with conventional radiographic techniques. When complete, ARC will be the world's highest-energy short-pulse laser, capable

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

    SciTech Connect (OSTI)

    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)

    2014-09-21

    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.

  3. Laser bottom hole assembly

    SciTech Connect (OSTI)

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

    2014-01-14

    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.

  4. LaserFest Celebration

    SciTech Connect (OSTI)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25

    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.

  5. Polarization feedback laser stabilization

    DOE Patents [OSTI]

    Esherick, Peter (Albuquerque, NM); Owyoung, Adelbert (Albuquerque, NM)

    1988-01-01

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

  6. Laser material processing system

    DOE Patents [OSTI]

    Dantus, Marcos

    2015-04-28

    A laser material processing system and method are provided. A further aspect of the present invention employs a laser for micromachining. In another aspect of the present invention, the system uses a hollow waveguide. In another aspect of the present invention, a laser beam pulse is given broad bandwidth for workpiece modification.

  7. Laser Programs Highlights 1998

    SciTech Connect (OSTI)

    Lowdermilk, H.; Cassady, C.

    1999-12-01

    This report covers the following topics: Commentary; Laser Programs; Inertial Confinement Fusion/National Ignition Facility (ICF/NIF); Atomic Vapor Laser Isotope Separation (AVLIS); Laser Science and Technology (LS&T); Information Science and Technology Program (IS&T); Strategic Materials Applications Program (SMAP); Medical Technology Program (MTP) and Awards.

  8. X-ray laser

    DOE Patents [OSTI]

    Nilsen, Joseph (Livermore, CA)

    1991-01-01

    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.

  9. Trident Laser Facility

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

    Trident Laser Facility Trident Laser Facility Enabling world-class science in high-energy density physics and fundamental laser-matter interactions April 12, 2012 Invisible infrared light from the 200-trillion watt Trident Laser enters from the bottom to interact with a one-micrometer thick foil target in the center of the photo. The laser pulse produces a plasma - an ionized gas - many times hotter than the center of the sun, which lasts for a trillionth of a second. During this time some

  10. FEL_poster_D4

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

  11. Laser system using ultra-short laser pulses

    DOE Patents [OSTI]

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

    2009-10-27

    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.

  12. Technical Design and Optimization Study for the FERMI@Elettra FELPhotoinjector

    SciTech Connect (OSTI)

    Lidia, Steven M.; Penco, Giuseppe; Trovo', Mauro

    2006-06-30

    The FERMI {at} Elettra FEL project will provide a novel, x-ray free electron laser user facility at Sincrotrone Trieste based on seeded and cascade FEL techniques. The electron beam source and injector systems play a crucial role in the success of the facility by providing the highest quality electron beams to the linac and FEL undulators. This Technical Note examines the critical technology components that make up the injector system, and demonstrates optimum beam dynamics solutions to achieve the required high quality electron beams. Section 2 provides an overview of the various systems and subsystems that comprise the photoinjector. The different operating modes of the injector are described as they pertain to the different linac configurations driven by the FEL and experimental design. For each mode, the required electron beam parameters are given. Sections 3 and 4 describe the critical beamline elements in the injector complex: the photocathode and drive laser, and the RF gun. The required drive laser parameters are given at the end of Section 3. Additional details on the design of the photoinjector drive laser systems are presented in a separate Technical Note. Design considerations for the RF gun are extensively presented in Section 4. There, we describe the variation of the cavity geometry to optimize the efficiency of the energy transfer to the electron beam. A study of the power coupling into the various cavity modes that interact within the bandwidth of the RF drive pulse is presented, followed by a study of the transient cavity response under several models and, finally, the effects on extracted beam quality. Section 5 describes the initial design for the low energy, off-axis diagnostic beamline. Beam dynamics simulations using ASTRA, elegant, and MAD are presented. Section 6 presents the optimization studies for the beam dynamics in the various operating modes. The optimized baseline configurations for the beamline and incident drive laser pulse are presented, supported by simulation results from space-charge tracking codes. Optimization of the beam transport through the downstream linac to the FEL undulator entrance requires significant deviations from the canonical ''flat-top'' temporal laser pulse distribution at the photocathode. The physics of nonlinear electron current emission are examined to determine the optimum temporal profile of the drive laser in order to produce the required linear current ramp at the injector exit. Parametric sensitivity studies are performed around the baseline configurations, and jitter studies are presented that analyze the stability of the solutions.

  13. Synthetic laser medium

    DOE Patents [OSTI]

    Stokowski, Stanley E. (Danville, CA)

    1989-01-01

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

  14. Synthetic laser medium

    DOE Patents [OSTI]

    Stokowski, S.E.

    1987-10-20

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

  15. Micro-laser

    DOE Patents [OSTI]

    Hutchinson, Donald P.; Richards, Roger K.

    2003-07-22

    A micro-laser is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide and at least one amplifying medium in the waveguide. PBG features are positioned between the first and second subwavelength resonant gratings and allow introduction of amplifying mediums into the highly resonant guided micro-laser microcavity. The micro-laser may be positioned on a die of a bulk substrate material with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a micro-laser is disclosed. A method for tuning the micro-laser is also disclosed. The micro-laser may be used as an optical regenerator, or a light source for data transfer or for optical computing.

  16. Polarization feedback laser stabilization

    DOE Patents [OSTI]

    Esherick, P.; Owyoung, A.

    1987-09-28

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

  17. Laser cutting plastic materials

    SciTech Connect (OSTI)

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  18. Jupiter Laser Facility

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

    Supporting the broad community of high-energy-density researchers The Jupiter Laser Facility is an institutional user facility in the Physical and Life Sciences Directorate at Lawrence Livermore National Laboratory (LLNL). The facility is designed to provide a high degree of experimental flexibility and high laser shot rates, and to allow direct user operation of experiments. The Jupiter Laser Facilities missions are to support lab-wide research pertinent to LLNL programs (e.g. High Energy

  19. Fluorinated laser dyes

    DOE Patents [OSTI]

    Hammond, Peter R.; Feeman, James F.

    1992-01-01

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

  20. Novel fluorinated laser dyes

    DOE Patents [OSTI]

    Hammond, Peter R.; Feeman, James F.

    1991-01-01

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

  1. Fusion reactor pumped laser

    DOE Patents [OSTI]

    Jassby, Daniel L. (Princeton, NJ)

    1988-01-01

    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.

  2. Gigashot Optical Laser Demonstrator

    SciTech Connect (OSTI)

    Deri, R. J.

    2015-10-13

    The Gigashot Optical Laser Demonstrator (GOLD) project has demonstrated a novel optical amplifier for high energy pulsed lasers operating at high repetition rates. The amplifier stores enough pump energy to support >10 J of laser output, and employs conduction cooling for thermal management to avoid the need for expensive and bulky high-pressure helium subsystems. A prototype amplifier was fabricated, pumped with diode light at 885 nm, and characterized. Experimental results show that the amplifier provides sufficient small-signal gain and sufficiently low wavefront and birefringence impairments to prove useful in laser systems, at repetition rates up to 60 Hz.

  3. Optical amplifiers and lasers

    DOE Patents [OSTI]

    Klimov, Victor I.; Mikhailovski, Alexandre; Hollingsworth, Jennifer A.; Leatherdale, Catherine A.; Bawendi, Moungi G.

    2004-11-16

    An optical amplifier and laser having both broad band and wide range specific band capability can be based on semiconductor nanocrystal solids.

  4. How Lasers Work

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

    How Lasers Work "Laser" is an acronym for light amplification by stimulated emission of radiation. A laser is created when the electrons in atoms in special glasses, crystals, or gases absorb energy from an electrical current or another laser and become "excited." The excited electrons move from a lower-energy orbit to a higher-energy orbit around the atom's nucleus. When they return to their normal or "ground" state, the electrons emit photons (particles of light).

  5. 7 ┼ Resolution in Protein 2-Dimentional-Crystal X-Ray Diffraction at Linac Coherent Light Source

    SciTech Connect (OSTI)

    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

    2014-06-09

    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.

  6. Photon-in photon-out hard X-ray spectroscopy at the Linac Coherent Light Source

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

    Alonso-Mori, Roberto; Sokaras, Dimosthenis; Zhu, Diling; Kroll, Thomas; Chollet, Mathieu; Feng, Yiping; Glownia, James M.; Kern, Jan; Lemke, Henrik T.; Nordlund, Dennis; et al

    2015-04-15

    X-ray free-electron lasers (FELs) have opened unprecedented possibilities to study the structure and dynamics of matter at an atomic level and ultra-fast timescale. Many of the techniques routinely used at storage ring facilities are being adapted for experiments conducted at FELs. In order to take full advantage of these new sources several challenges have to be overcome. They are related to the very different source characteristics and its resulting impact on sample delivery, X-ray optics, X-ray detection and data acquisition. Here it is described how photon-in photon-out hard X-ray spectroscopy techniques can be applied to study the electronic structure andmore┬á┬╗ its dynamics of transition metal systems with ultra-bright and ultra-short FEL X-ray pulses. In particular, some of the experimental details that are different compared with synchrotron-based setups are discussed and illustrated by recent measurements performed at the Linac Coherent Light Source.┬ź┬áless

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

    SciTech Connect (OSTI)

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

    2012-09-05

    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.

  8. Laser Program annual report 1987

    SciTech Connect (OSTI)

    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.

    1989-07-01

    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.

  9. The 300 mA SRF ERL

    SciTech Connect (OSTI)

    Ben-Zvi, Ilan

    2013-11-07

    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.

  10. Laser peening with fiber optic delivery

    DOE Patents [OSTI]

    Friedman, Herbert W.; Ault, Earl R.; Scheibner, Karl F.

    2004-11-16

    A system for processing a workpiece using a laser. The laser produces at least one laser pulse. A laser processing unit is used to process the workpiece using the at least one laser pulse. A fiber optic cable is used for transmitting the at least one laser pulse from the laser to the laser processing unit.

  11. Documentation - Laboratory for Laser Energetics

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

    X Subsystem and Component Maintenance OMEGA Facility Subsystem and Component Maintenance Instructions (S-AA-M-014) Laser Sources Laser Amplifiers Power Conditioning Control System...

  12. Dye laser amplifier

    DOE Patents [OSTI]

    Moses, E.I.

    1992-12-01

    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.

  13. Explosively pumped laser light

    DOE Patents [OSTI]

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

    1991-01-01

    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.

  14. Liquid heat capacity lasers

    DOE Patents [OSTI]

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

    2007-05-01

    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.

  15. Longitudinal discharge laser electrodes

    DOE Patents [OSTI]

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

    1994-08-23

    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.

  16. Laser beam generating apparatus

    DOE Patents [OSTI]

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

    1993-12-28

    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.

  17. Laser beam generating apparatus

    DOE Patents [OSTI]

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

    1994-02-15

    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.

  18. Laser beam generating apparatus

    DOE Patents [OSTI]

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

    1994-01-01

    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).

  19. Laser beam generating apparatus

    DOE Patents [OSTI]

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

    1993-01-01

    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).

  20. Longitudinal discharge laser electrodes

    DOE Patents [OSTI]

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

    1994-01-01

    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.

  1. Laser Programs Highlight 1995

    SciTech Connect (OSTI)

    Jacobs, R.R.

    1997-01-31

    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.

  2. Laser dividing apparatus

    DOE Patents [OSTI]

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

    1995-01-01

    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).

  3. Laser controlled flame stabilization

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  4. Time-resolved protein nanocrystallography using an X-ray free...

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

    Time-resolved protein nanocrystallography using an X-ray free-electron laser Authors: ... protein nanocrystallography using an X-ray free-electron laser Source: OPTICS EXPRESS ...

  5. Influence of irradiation with {gamma}-ray photons on the photoluminescence of Cd{sub 0.9}Zn{sub 0.1}Te crystals preliminarily subjected to the intense radiation of a neodymium laser

    SciTech Connect (OSTI)

    Glinchuk, K. D.; Medvid', A. P.; Mychko, A. M.; Naseka, Yu. M.; Prokhorovich, A. V.; Strilchuk, O. M.

    2013-04-15

    The effect of the preliminary treatment of Cd{sub 0.9}Zn{sub 0.1}Te crystals with high-power pulses of neodymium laser radiation (the power density is {<=}1.8 MW/cm{sup 2}, at a wavelength of 532 nm) on the low-temperature (5 K) photoluminescence induced by {gamma}-ray radiation (the dose was {Phi}{sub {gamma}} = 5 kGy) is studied. The luminescence bands are related to radiation-stimulated donor-acceptor pairs, which include shallow neutral donors and neutral cadmium vacancies stimulated by {gamma}-ray irradiation, the transition of free electrons to neutral cadmium vacancies formed by radiation, and the annihilation of excitons bound to the above vacancies. It is shown that, in the crystals preliminarily treated with laser radiation, the intensity of the {gamma}-ray-stimulated luminescence bands is significantly lower than in crystals not subjected to laser radiation. This fact is accounted for by a decrease in the concentration of cadmium vacancies generated by the {gamma}-ray radiation as a result of their annihilation during the course of their interaction with laser-stimulated defects, in particular, as a consequence of their recombination at laser-stimulated interstitial cadmium atoms.

  6. Piezoelectric measurement of laser power

    DOE Patents [OSTI]

    Deason, Vance A.; Johnson, John A.; Telschow, Kenneth L.

    1991-01-01

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

  7. Laser and infrared (selected articles)

    SciTech Connect (OSTI)

    Not Available

    1992-01-09

    This article reports the author's impressions from a visit to the U.S. in May, 1989. The report describes the rapid deployment in recent years of solid state laser technology in area of application such as high average power, semiconductor laser device pumps, tunability, narrow line width, and other similar solid state laser device, as well as laser materials processing, and so on.

  8. Documentation - Laboratory for Laser Energetics

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

    VII System Description Chapter 1: System Overview Chapter 2: Laser Sources (final draft material) Chapter 3: Laser Amplifiers Chapter 4: Power Conditioning Chapter 5: Optomechanical System Chapter 6: Laser Diagnostics Chapter 7: Experimental System Chapter 8: Control System Chapter 9: Facility and Safety Interlocks Comments Address document comments, questions and corrections to the OMEGA EP Associate Laser Facility Manager

  9. 1982 laser program annual report

    SciTech Connect (OSTI)

    Hendricks, C.D.; Grow, G.R.

    1983-08-01

    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)

  10. Ultra-fast laser system

    DOE Patents [OSTI]

    Dantus, Marcos; Lozovoy, Vadim V

    2014-01-21

    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.

  11. Atomic vapor laser isotope separation

    SciTech Connect (OSTI)

    Stern, R.C.; Paisner, J.A.

    1986-08-15

    The atomic vapor laser isotope separation (AVLIS) process for the enrichment of uranium is evaluated. (AIP)

  12. Fiber optic laser rod

    DOE Patents [OSTI]

    Erickson, G.F.

    1988-04-13

    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.

  13. Laser Spark Plug Development

    SciTech Connect (OSTI)

    McIntyre, D.L.; Richardson, S.W.; Woodruff, S.D.; McMillian, M.H.; Guutam, M.

    2007-04-01

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

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

    SciTech Connect (OSTI)

    Ratner, Daniel; /Stanford U. /SLAC

    2012-05-25

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

  15. 2005 - 08 | Jefferson Lab

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

    August 2005 Sat, 08/13/2005 - 4:35pm Free Electron Lasers Come of Age - Photonics Spectra

  16. Laser cutting nozzle

    DOE Patents [OSTI]

    Ramos, T.J.

    1982-09-30

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece.

  17. Laser cutting nozzle

    DOE Patents [OSTI]

    Ramos, Terry J. (Brentwood, CA)

    1984-01-01

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece. BACKGROUND OF THE INVENTION

  18. Fusion reactor pumped laser

    DOE Patents [OSTI]

    Jassby, D.L.

    1987-09-04

    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.

  19. Laser Plasma Interactions

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

    and controlling laser produced plasmas for fusion and basic science Contact David Montgomery (505) 665-7994 Email John Kline (505) 667-7062 Email Thomson scattering is widely...

  20. Laser dye technology

    SciTech Connect (OSTI)

    Hammond, P R

    1999-09-01

    The author has worked with laser dyes for a number of years. A first interest was in the Navy blue-green program where a flashlamp pumped dye laser was used as an underwater communication and detection device. It made use of the optical window of sea-water--blue for deep ocean, green for coastal water. A major activity however has been with the Atomic Vapor Laser Isotope Separation Program (AVLIS) at the Lawrence Livermore National Laboratory. The aim here has been enriching isotopes for the nuclear fuel cycle. The tunability of the dye laser is utilized to selectively excite one isotope in uranium vapor, and this isotope is collected electrostatically as shown in Figure 1. The interests in the AVLIS program have been in the near ultra-violet, violet, red and deep-red.

  1. Pulsed gas laser

    DOE Patents [OSTI]

    Anderson, Louis W.; Fitzsimmons, William A.

    1978-01-01

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

  2. Laser cooling of solids

    SciTech Connect (OSTI)

    Epstein, Richard I; Sheik-bahae, Mansoor

    2008-01-01

    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.

  3. Variable laser attenuator

    DOE Patents [OSTI]

    Foltyn, S.R.

    1987-05-29

    The disclosure relates to low loss, high power variable attenuators comprising one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength. 9 figs.

  4. Insulator for laser housing

    DOE Patents [OSTI]

    Duncan, D.B.

    1992-12-29

    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.

  5. 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

  6. Tunable dye laser amplifier chain for laser isotope separation

    SciTech Connect (OSTI)

    Grigoriev, Igor' S; D'yachkov, Aleksei B; Labozin, Valerii P; Mironov, Sergei M; Nikulin, Sergei A; Firsov, Valerii A

    2004-05-31

    A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence diffraction grating. Longitudinal pumping of the amplifiers is used. The efficiency of the main amplifiers is 50 % - 55 %. The average power of laser radiation at the output of the last amplifier is 100 W. (lasers. amplifiers)

  7. Generation of very low energy-spread electron beams using low-intensity laser pulses in a low-density plasma

    SciTech Connect (OSTI)

    Upadhyay, Ajay K.; Samant, Sushil Arun; Sarkar, Deepangkar; Krishnagopal, Srinivas; Jha, Pallavi

    2011-03-15

    The possibility of obtaining high-energy electron beams of high quality by using a low-density homogeneous plasma and a low-intensity laser (just above the self-injection threshold in the bubble regime) has been explored. Three-dimensional simulations are used to demonstrate, for the first time, an energy-spread of less than 1%, from self-trapping. More specifically, for a plasma density of 2x10{sup 18} cm{sup -3} and a laser intensity of a{sub 0}=2, a high-energy (0.55 GeV), ultrashort (1.4 fs) electron beam with very low energy-spread (0.55%) and high current (3 kA) is obtained. These parameters satisfy the requirements for drivers of short-wavelength free-electron lasers. It is also found that the quality of the electron beam depends strongly on the plasma length, which therefore needs to be optimized carefully to get the best performance in the experiments.

  8. Blue-green upconversion laser

    DOE Patents [OSTI]

    Nguyen, Dinh C. (Los Alamos, NM); Faulkner, George E. (Los Alamos, NM)

    1990-01-01

    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.

  9. Blue-green upconversion laser

    DOE Patents [OSTI]

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

    1990-08-14

    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.

  10. Injection-controlled laser resonator

    DOE Patents [OSTI]

    Chang, J.J.

    1995-07-18

    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.

  11. Variable emissivity laser thermal control system

    DOE Patents [OSTI]

    Milner, Joseph R. (Livermore, CA)

    1994-01-01

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  12. Longitudinal Diagnostics for Short Electron Beam Bunches

    SciTech Connect (OSTI)

    Loos, H.; ,

    2010-06-11

    Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of the beam mapped onto (optical replicator). The operational needs for bunch length measurements to have fast acquisitions, to be used in feedback systems, to distinguish pulse to pulse changes and to be nondestructive or parasitically have resulted into developing many of the diagnostics into single-shot techniques and in the following the main discussion will emphasize them.

  13. Insulative laser shell coupler

    DOE Patents [OSTI]

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

    1994-09-20

    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.

  14. OMEGA EP Laser Dedication Movie - Laboratory for Laser Energetics

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

    Dedication Movie - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser

  15. OMEGA EP Laser Sources - Laboratory for Laser Energetics

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

    Sources - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser Development and

  16. Omega Laser Facility Schedule - Laboratory for Laser Energetics

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

    Schedule - Laboratory for Laser Energetics Laboratory for Laser Energetics Logo Search Home Around the Lab Past Issues Past Quick Shots About Office of the Director Map to LLE LLE Tours LLE Building Map Partnerships Careers Education Undergraduate Program Graduate Program High School Program Faculty Contacts Computational Astrophysics H-E-D Physics Inertial Confinement Fusion Laser-Plasma Interaction Radiative Hydrodynamics Plasma Astrophysics Organization Director's Office Laser Development and

  17. Antenna coupled photonic wire lasers

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

    Reno, John L.; Kao, Tsung-Kao; Cai, Xiaowei; Lee, Alan W. M.; Hu, Qing

    2015-06-22

    Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to extract power from wire lasers using monolithically integrated antennas. These integrated antennas significantly increase the effective radiation area, and consequently enhance the power extraction efficiency. When applied to wire lasers at THz frequency, we achieved the highest single-side slope efficiency (~450moreá╗mW/A) in pulsed mode for DFB lasers at 4 THz and a ~4x increase in output power at 3 THz compared with a similar structure without antennas. This work demonstrates the versatility of incorporating microwave engineering techniques into laser designs, enabling significant performance enhancements.źáless

  18. Laser isotope separation

    DOE Patents [OSTI]

    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)

    1988-01-01

    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.

  19. SOLAR PUMPED LASER MICROTHRUSTER

    SciTech Connect (OSTI)

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

    2010-02-05

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

  20. Laser pulse detector

    DOE Patents [OSTI]

    Mashburn, D.N.; Akerman, M.A.

    1979-08-13

    A laser pulse detector is provided which is small and inexpensive and has the capability of detecting laser light of any wavelength with fast response (less than 5 nanoseconds rise time). The laser beam is focused onto the receiving end of a graphite rod coaxially mounted within a close-fitting conductive, open-end cylindrical housing so that ablation and electric field breakdown of the resulting plasma occurs due to a bias potential applied between the graphite rod and housing. The pulse produced by the breakdown is transmitted through a matched impedance coaxial cable to a recording device. The cable is connected with its central lead to the graphite rod and its outer conductor to the housing.

  1. Laser pulse detector

    DOE Patents [OSTI]

    Mashburn, Douglas N.; Akerman, M. Alfred

    1981-01-01

    A laser pulse detector is provided which is small and inexpensive and has the capability of detecting laser light of any wavelength with fast response (less than 5 nanoseconds rise time). The laser beam is focused onto the receiving end of a graphite rod coaxially mounted within a close-fitting conductive, open-end cylindrical housing so that ablation and electric field breakdown of the resulting plasma occurs due to a bias potential applied between the graphite rod and housing. The pulse produced by the breakdown is transmitted through a matched impedance coaxial cable to a recording device. The cable is connected with its central lead to the graphite rod and its outer conductor to the housing.

  2. Solar Pumped Laser Microthruster

    SciTech Connect (OSTI)

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

    2010-10-08

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

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

    DOE Patents [OSTI]

    Warren, R.W.

    1992-09-01

    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.

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

    DOE Patents [OSTI]

    Warren, Roger W. (Santa Fe, NM)

    1992-01-01

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

  5. Following the dynamics of matter with femtosecond precision using the X-ray streaking method

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

    David, C.; Karvinen, P.; Sikorski, M.; Song, S.; Vartiainen, I.; Milne, C. J.; Mozzanica, A.; Kayser, Y.; Diaz, A.; Mohacsi, I.; et al

    2015-01-06

    X-ray Free Electron Lasers (FELs) can produce extremely intense and very short pulses, down to below 10 femtoseconds (fs). Among the key applications are ultrafast time-resolved studies of dynamics of matter by observing responses to fast excitation pulses in a pump-probe manner. Detectors with sufficient time resolution for observing these processes are not available. Therefore, such experiments typically measure a sample's full dynamics by repeating multiple pump-probe cycles at different delay times. This conventional method assumes that the sample returns to an identical or very similar state after each cycle. Here we describe a novel approach that can provide amore┬á┬╗ time trace of responses following a single excitation pulse, jitter-free, with fs timing precision. We demonstrate, in an X-ray diffraction experiment, how it can be applied to the investigation of ultrafast irreversible processes.┬ź┬áless

  6. Laser ablation of concrete.

    SciTech Connect (OSTI)

    Savina, M.

    1998-10-05

    Laser ablation is effective both as an analytical tool and as a means of removing surface coatings. The elemental composition of surfaces can be determined by either mass spectrometry or atomic emission spectroscopy of the atomized effluent. Paint can be removed from aircraft without damage to the underlying aluminum substrate, and environmentally damaged buildings and sculptures can be restored by ablating away deposited grime. A recent application of laser ablation is the removal of radioactive contaminants from the surface and near-surface regions of concrete. We present the results of ablation tests on concrete samples using a high power pulsed Nd:YAG laser with fiber optic beam delivery. The laser-surface interaction was studied on various model systems consisting of Type I Portland cement with varying amounts of either fine silica or sand in an effort to understand the effect of substrate composition on ablation rates and mechanisms. A sample of non-contaminated concrete from a nuclear power plant was also studied. In addition, cement and concrete samples were doped with non-radioactive isotopes of elements representative of cooling waterspills, such as cesium and strontium, and analyzed by laser-resorption mass spectrometry to determine the contamination pathways. These samples were also ablated at high power to determine the efficiency with which surface contaminants are removed and captured. The results show that the neat cement matrix melts and vaporizes when little or no sand or aggregate is present. Surface flows of liquid material are readily apparent on the ablated surface and the captured aerosol takes the form of glassy beads up to a few tens of microns in diameter. The presence of sand and aggregate particles causes the material to disaggregate on ablation, with intact particles on the millimeter size scale leaving the surface. Laser resorption mass spectrometric analysis showed that cesium and potassium have similar chemical environments in the matrix, as do strontium and calcium.

  7. Documentation - Laboratory for Laser Energetics

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

    I System Description OMEGA System Operations Manual - Volume I-System Description System Overview Laser Drivers (draft material) Laser Amplifiers Power Conditioning Optomechanical System Laser Diagnostics (draft material available on request) Experimental System Targets and Target Fabrication Target Diagnostics (Refer to Chapter 5 of the Omega Laser Facility Users' Guide) Facility and Safety Interlocks OMEGA Control System (draft material available on request) Target Chamber Tritium Removal

  8. Vacuum ultraviolet laser

    DOE Patents [OSTI]

    Berkowitz, J.; Ruscic, B.M.; Greene, J.P.

    1984-07-06

    Transitions from the 2p/sup 4/(/sup 1/S/sub 0/)3s /sup 2/S/sub 1/2/ state of atomic fluorine to all allowed loser states produces laser emission at six new wavelengths: 680.7A, 682.6A, 3592.7A, 3574.1A, 6089.2A, and 6046.8A. Coherent radiation at these new wavelengths can be generated in an atomic fluorine laser operated as an amplifier or as an oscillator.

  9. Laser pulse stacking method

    DOE Patents [OSTI]

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  10. Injection Laser System

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

    Injection Laser System For each of NIF's 192 beams: The pulse shape as a function of time must be generated with a high degree of precision The energy delivered to the target must be precise The energy must be delivered to the target at exactly the specified time NIF's injection laser system (ILS) plays a key role in meeting these three requirements. The ILS system is responsible for generating a prescribed pulse shape, adjusting the energy in each of the 192 beams, and adjusting the time it

  11. Laser amplifier chain

    DOE Patents [OSTI]

    Hackel, Richard P. (Livermore, CA)

    1992-01-01

    A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain.

  12. Deposition head for laser

    DOE Patents [OSTI]

    Lewis, Gary K. (Los Alamos, NM); Less, Richard M. (Los Alamos, NM)

    1999-01-01

    A deposition head for use as a part of apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. The deposition head delivers the laser beam and powder to a deposition zone, which is formed at the tip of the deposition head. A controller comprised of a digital computer directs movement of the deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which the deposition head moves along the tool path.

  13. Laser amplifier chain

    DOE Patents [OSTI]

    Hackel, R.P.

    1992-10-20

    A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain. 6 figs.

  14. Laser pulse stacking method

    DOE Patents [OSTI]

    Moses, Edward I. (Livermore, CA)

    1992-01-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter.

  15. Single element laser beam shaper

    DOE Patents [OSTI]

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

    2005-09-13

    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.

  16. Oxazine laser dyes

    DOE Patents [OSTI]

    Hammond, Peter R.; Field, George F.

    1992-01-01

    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##

  17. Ring laser scatterometer

    DOE Patents [OSTI]

    Ackermann, Mark; Diels, Jean-Claude

    2005-06-28

    A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a ring laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.

  18. Miniature Laser Tracker

    DOE Patents [OSTI]

    Vann, Charles S. (Fremont, CA)

    2003-09-09

    This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

  19. Dye laser amplifier

    DOE Patents [OSTI]

    Moses, Edward I. (Livermore, CA)

    1992-01-01

    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.

  20. Ultranarrow linewidth waveguide excimer lasers

    SciTech Connect (OSTI)

    Christensen, C.P. ); Feldman, B.J.; Huston, A.

    1989-09-01

    We have constructed a single longitudinal mode XeCl laser using microwave discharge waveguide laser technology. The pulse duration, repetition rate, and simplicity of construction associated with waveguide excimer lasers lend this system unique capabilities and a broad utility for interfacing with other excimer devices. The coherence length of the laser emission has been found to be {similar to}6 m with a corresponding bandwidth of {l brace}22 MHz that is near the transform limit. The laser has been used to demonstrate pulsed UV Doppler velocity measurement in a simple homodyne configuration.

  1. Laser Program annual report 1984

    SciTech Connect (OSTI)

    Rufer, M.L.; Murphy, P.W.

    1985-06-01

    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.

  2. OCDR guided laser ablation device

    DOE Patents [OSTI]

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

    2002-01-01

    A guided laser ablation device. The device includes a mulitmode laser ablation fiber that is surrounded by one or more single mode optical fibers that are used to image in the vicinity of the laser ablation area to prevent tissue damage. The laser ablation device is combined with an optical coherence domain reflectometry (OCDR) unit and with a control unit which initializes the OCDR unit and a high power laser of the ablation device. Data from the OCDR unit is analyzed by the control unit and used to control the high power laser. The OCDR images up to about 3 mm ahead of the ablation surface to enable a user to see sensitive tissue such as a nerve or artery before damaging it by the laser.

  3. 2 micron femtosecond fiber laser

    DOE Patents [OSTI]

    Liu, Jian; Wan, Peng; Yang, Lihmei

    2014-07-29

    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.

  4. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator","Huang, Zhirong; Ding, Yuantao; SLAC; Schroeder, Carl B.; LBL,...

  5. Jefferson Lab - Research

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

    80 en Free-Electron Laser https:www.jlab.orgfree-electron-laser

  6. 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...

  7. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Schroeder Carl B LBL Berkeley PARTICLE ACCELERATORS ACCELERATORS ELECTRON BEAMS ELECTRONS FREE ELECTRON LASERS LASERS PERFORMANCE PLASMA GUNS RADIATIONS WIGGLER MAGNETS...

  8. Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

    Office of Scientific and Technical Information (OSTI)

    Pulsed laser Raman spectroscopy in the laser-heated diamond anvil cell Citation Details In-Document Search Title: Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

  9. Laser frequency modulator for modulating a laser cavity

    DOE Patents [OSTI]

    Erbert, Gaylen V. (Livermore, CA)

    1992-01-01

    The present invention relates to a laser frequency modulator for modulating a laser cavity. It is known in the prior art to utilize a PZT (piezoelectric transducer) element in combination with a mirror to change the cavity length of a laser cavity (which changes the laser frequency). Using a PZT element to drive the mirror directly is adequate at frequencies below 10 kHz. However, in high frequency applications (100 kHz and higher) PZT elements alone do not provide a sufficient change in the cavity length. The present invention utilizes an ultrasonic concentrator with a PZT element and mirror to provide modulation of the laser cavity. With an ultrasonic concentrator, the mirror element at the end of a laser cavity can move at larger amplitudes and higher frequencies.

  10. Laser beam temporal and spatial tailoring for laser shock processing

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  11. Azacoumarin dye lasers

    DOE Patents [OSTI]

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue-green to near ultraviolet region.

  12. Azaquinolone dye lasers

    DOE Patents [OSTI]

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue to near ultraviolet region.

  13. Laser beam guard clamps

    DOE Patents [OSTI]

    Dickson, Richard K. (Stockton, CA)

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  14. Fusion pumped laser

    DOE Patents [OSTI]

    Pappas, D.S.

    1987-07-31

    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.

  15. Fusion pumped laser

    DOE Patents [OSTI]

    Pappas, Daniel S. (Los Alamos, NM)

    1989-01-01

    Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

  16. Laser pulse sampler

    DOE Patents [OSTI]

    Vann, C.

    1998-03-24

    The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera. 5 figs.

  17. Laser pulse sampler

    DOE Patents [OSTI]

    Vann, Charles (Fremont, CA)

    1998-01-01

    The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera.

  18. Laser multiplexing system

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  19. Metal atom oxidation laser

    DOE Patents [OSTI]

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)

  20. Metal atom oxidation laser

    DOE Patents [OSTI]

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.

  1. Nonlinear Laser Spectroscopy

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

    Laser Spectroscopy - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced

  2. Electric motor for laser-mechanical drilling

    DOE Patents [OSTI]

    Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

    2015-07-07

    A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for advancing a borehole. High power laser drilling system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam through the electrical motor.

  3. Ultrafast pulsed laser utilizing broad bandwidth laser glass

    DOE Patents [OSTI]

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

    1997-09-02

    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.

  4. Laser fusion neutron source employing compression with short pulse lasers

    DOE Patents [OSTI]

    Sefcik, Joseph A; Wilks, Scott C

    2013-11-05

    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.

  5. SLAC All Access: Laser Labs

    ScienceCinema (OSTI)

    Minitti, Mike; Woods Mike

    2014-06-03

    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.

  6. Hybrid fiber-rod laser

    DOE Patents [OSTI]

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

    2012-12-18

    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.

  7. Relativistic Laser-Matter Interactions

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

    Relativistic Laser-Matter Interactions Relativistic Laser-Matter Interactions Enabling the next generation of intense particle accelerators Contact Juan Fernandez (505) 667-6575 Email Short-pulse ion acceleration The Trident facility is a world-class performer in the area of ion acceleration from laser-solid target interactions. Trident has demonstrated over 100 MeV protons at intensities of 8x1020 W/cm2 with efficiencies approaching 5%. These intense relativistic interactions can be diagnosed

  8. Documentation - Laboratory for Laser Energetics

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

    VIII System Shot Operations Manual Volume VIII Index (S-AB-P-157) Shot Director Operating Checklists Laser Sources Power Conditioning Beamlines Experimental Systems Experimental Diagnostics Comments Address document comments, questions and corrections to the OMEGA EP Associate Laser Facility Manager. For additional information contact: Director's Administrator University of Rochester - Laboratory for Laser Energetics, 250 E. River Rd, Rochester, NY 14623-1299 Last updated: November 14

  9. Jefferson Lab: Laser gun to eventually shoot down missiles (Daily Press) |

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

    Jefferson Lab articles.dailypress.com/2011-02-21/news/dp-nws-jefferson-lab-20110221_1_jefferson-lab-researchers-free-electron-l... Submitted: Monday, February 21, 2011

  10. Laser system using regenerative amplifier

    DOE Patents [OSTI]

    Emmett, J.L.

    1980-03-04

    High energy laser system is disclosed using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output. 10 figs.

  11. Laser system using regenerative amplifier

    DOE Patents [OSTI]

    Emmett, John L. [Pleasanton, CA

    1980-03-04

    High energy laser system using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output.

  12. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, D.G.; Birx, D.; Cook, E.G.

    1993-01-05

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  13. Documentation - Laboratory for Laser Energetics

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

    III Subsystem and Component Maintenance OMEGA Facility Subsystem and Component Maintenance Instructions (S-AA-M-014) Part 2 - Maintenance Plans Section 1: Laser Drivers Section 2:...

  14. Laser Manufacturing | GE Global Research

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

    Laser Manufacturing at GE Global Research Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Laser Manufacturing at GE Global Research Learn how laser sintering, an additive laser manufacturing process practiced at GE Global Research, makes parts from metal powder. You Might Also Like Munich_interior_V 10 Years ON: From

  15. Uranium molecular laser isotope separation

    SciTech Connect (OSTI)

    Jensen, R.J.; Sullivan, A.

    1982-01-01

    The Molecular Laser Isotope Separation program is moving into the engineering phase, and it is possible to determine in some detail the plant cost terms involved in the process economics. A brief description of the MLIS process physics is given as a motivation to the engineering and economics discussion. Much of the plant cost arises from lasers and the overall optical system. In the paper, the authors discuss lasers as operating units and systems, along with temporal multiplexing and Raman shifting. Estimates of plant laser costs are given.

  16. Single-exciton nanocrystal laser

    DOE Patents [OSTI]

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

    2012-01-17

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

  17. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Birx, Dan (Brentwood, CA); Cook, Edward G. (Livermore, CA)

    1993-01-01

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  18. Laser beam alignment apparatus and method

    DOE Patents [OSTI]

    Gruhn, Charles R.; Hammond, Robert B.

    1981-01-01

    The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  19. Laser beam alignment apparatus and method

    DOE Patents [OSTI]

    Gruhn, C.R.; Hammond, R.B.

    The disclosure related to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  20. Single mode pulsed dye laser oscillator

    DOE Patents [OSTI]

    Hackel, R.P.

    1992-11-24

    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.