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Sample records for electron laser conference

  1. Tenth international free electron laser conference, kibbutz Ramat Rachel, Jerusalem, Israel, August 29 - September 2, 1988

    International Nuclear Information System (INIS)

    1988-01-01

    The volume contains over a hundred abstracts of lectures covering a wide variety of subjects in the field of free electron lasers. Many features of lasing were observed over a range of problems, and experiments which resulted in finding ideal or near-ideal techniques for gaining better and more efficient optical power have been carried out

  2. Free electron laser

    International Nuclear Information System (INIS)

    Ortega, J.M.; Billardon, M.

    1986-01-01

    Operation principle of a laser and an oscillator are recalled together with the klystron one. In the free electron laser, electrons go through an undulator or an optical klystron. Principles of the last one are given. The two distinct ways of producing coherent radiation with an undulator and an optical klystron are presented. The first one is the use of the free electron laser, the second is to make use of the spontaneous emission generation (harmonics generation). The different current types of free electron lasers are presented (Stanford, Los Alamos, Aco at Orsay). Prospects and applications are given in conclusion [fr

  3. High-quality electron beam generation and bright betatron radiation from a cascaded laser wakefield accelerator (Conference Presentation)

    Science.gov (United States)

    Liu, Jiansheng; Wang, Wentao; Li, Wentao; Qi, Rong; Zhang, Zhijun; Yu, Changhai; Wang, Cheng; Liu, Jiaqi; Qing, Zhiyong; Ming, Fang; Xu, Yi; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2017-05-01

    One of the major goals of developing laser wakefiled accelerators (LWFAs) is to produce compact high-energy electron beam (e-beam) sources, which are expected to be applied in developing compact x-ray free-electron lasers and monoenergetic gamma-ray sources. Although LWFAs have been demonstrated to generate multi-GeV e-beams, to date they are still failed to produce high quality e beams with several essential properties (narrow energy spread, small transverse emittance and high beam charge) achieved simultaneously. Here we report on the demonstration of a high-quality cascaded LWFA experimentally via manipulating electron injection, seeding in different periods of the wakefield, as well as controlling energy chirp for the compression of energy spread. The cascaded LWFA was powered by a 1-Hz 200-TW femtosecond laser facility at SIOM. High-brightness e beams with peak energies in the range of 200-600 MeV, 0.4-1.2% rms energy spread, 10-80 pC charge, and 0.2 mrad rms divergence are experimentally obtained. Unprecedentedly high 6-dimensional (6-D) brightness B6D,n in units of A/m2/0.1% was estimated at the level of 1015-16, which is very close to the typical brightness of e beams from state-of-the-art linac drivers and several-fold higher than those of previously reported LWFAs. Furthermore, we propose a scheme to minimize the energy spread of an e beam in a cascaded LWFA to the one-thousandth-level by inserting a stage to compress its longitudinal spatial distribution via velocity bunching. In this scheme, three-segment plasma stages are designed for electron injection, e-beam length compression, and e-beam acceleration, respectively. A one-dimensional theory and two-dimensional particle-in-cell simulations have demonstrated this scheme and an e beam with 0.2% rms energy spread and low transverse emittance could be generated without loss of charge. Based on the high-quality e beams generated in the LWFA, we have experimentally realized a new scheme to enhance the

  4. Sixteenth International Laser Radar Conference, Part 2

    International Nuclear Information System (INIS)

    Mccormick, M.P.

    1992-07-01

    Given here are extended abstracts of papers presented at the 16th International Laser Radar Conference, held in Cambridge, Massachusetts, July 20-24, 1992. Topics discussed include the Mt. Pinatubo volcanic dust laser observations, global change, ozone measurements, Earth mesospheric measurements, wind measurements, imaging, ranging, water vapor measurements, and laser devices and technology

  5. Proceedings of the conference on lasers and electro-optics

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book presents the papers discussed at a conference on the subject of electro-optics and lasers. Some of the topics discussed were: laser fusion and interactions; implosion experiments; tunable integrated Bragg lasers, CO 2 lasers; present status of integrated lasers; DFB lasers; transition metal lasers-solid state lasers, mirror laser resonators, multiquantumwell lasers; fusion laser technology; and dynamics and characteristics of diode lasers

  6. PREFACE AND CONFERENCE INFORMATION: Eighth International Conference on Laser Ablation

    Science.gov (United States)

    Hess, Wayne P.; Herman, Peter R.; Bäuerle, Dieter; Koinuma, Hideomi

    2007-04-01

    Laser ablation encompasses a wide range of delicate to extreme light interactions with matter that present considerably challenging problems for scientists to study and understand. At the same time, laser ablation also represents a basic process of significant commercial importance in laser material processing—defining a multi-billion dollar industry today. These topics were widely addressed at the 8th International Conference on Laser Ablation (COLA), held in Banff, Canada on 11-16 September 2005. The meeting took place amongst the majestic and natural beauty of the Canadian Rocky Mountains at The Banff Centre, where delegates enjoyed many inspiring presentations and discussions in a unique campus learning environment. The conference brought together world leading scientists, students and industry representatives to examine the basic science of laser ablation and improve our understanding of the many physical, chemical and/or biological processes driven by the laser. The multi-disciplinary research presented at the meeting underlies some of our most important trends at the forefront of science and technology today that are represented in the papers collected in this volume. Here you will find new processes that are producing novel types of nanostructures and nano-materials with unusual and promising properties. Laser processes are described for delicately manipulating living cells or modifying their internal structure with unprecedented degrees of control and precision. Learn about short-pulse lasers that are driving extreme physical processes on record-fast time scales and opening new directions from material processing applications. The conference papers further highlight forefront application areas in pulsed laser deposition, nanoscience, analytical methods, materials, and microprocessing applications. Laser ablation continues to grow and evolve, touching forefront areas in science and driving new technological trends in laser processing applications. Please

  7. Abstracts of 2. International conference on lasers and their applications

    International Nuclear Information System (INIS)

    1993-01-01

    The following topics are presented at 2. international conference on lasers and their applications in Iran: laser principle and technology, laser applications in spectroscopy; nonlinear optics; industry; medicine; and laser related techniques

  8. 14th International Conference on X-Ray Lasers

    CERN Document Server

    Menoni, Carmen; Marconi, Mario

    2016-01-01

    These proceedings comprise invited and contributed papers presented at the 14th International Conference on X-Ray Lasers (ICXRL 2014). This conference is part of a continuing series dedicated to recent developments and applications of x-ray lasers and other coherent x-ray sources with attention to supporting technologies and instrumentation. New results in the generation of intense, coherent x-rays and progress toward practical devices and their applications in numerous fields are reported. Areas of research in plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generation, and other x-ray generation schemes are covered.  The scope of ICXRL 2014 included, but was not limited to: Laser-pumped X-ray lasers Discharge excitation and other X-ray laser pumping methods Injection/seeding of X-ray amplifiers New lasing transitions and novel X-ray laser schemes High Harmonic sources-Free-electron laser generation in the XUV and X-ray range Novel schemes for coherent XUV and X-ray ge...

  9. Sixteenth International Laser Radar Conference, Part 1

    International Nuclear Information System (INIS)

    Mccormick, M.P.

    1992-07-01

    This publication contains extended abstracts of papers presented at the 16th International Laser Radar Conference. One-hundred ninety-five papers were presented in both oral and poster sessions. The topics of the conference sessions were: (1) Mt. Pinatubo Volcanic Dust Layer Observations; (2) Global Change/Ozone Measurements; (3) GLOBE/LAWS/LITE; (4) Mesospheric Measurements and Measurement Systems; (5) Middle Atmosphere; (6) Wind Measurements and Measurement Systems; (7) Imaging and Ranging; (8) Water Vapor Measurements; (9) Systems and Facilities; and (10) Laser Devices and Technology. This conference reflects the breadth of research activities being conducted in the lidar field. These abstracts address subjects from lidar-based atmospheric investigations relating to global change to the development of new lidar systems and technology

  10. Laser Spectroscopy : XII International Conference

    CERN Document Server

    Allegrini, Maria; Sasso, Antonio

    1996-01-01

    This text includes all the recent advances in the field of laser spectroscopy. Major results span from the control of matter by electromagnetic fields (trapping and coding) to high precision measurements on simple atomic systems and to quantum optics with single atoms. It includes a report of the Bose-Einstein condensation achieved by laser-cooling of rubidium atoms. Achievements in the technology of tunable sources, in particular of miniaturized solid state devices, are also reported. Most recent advances in molecular spectroscopy are illustrated with emphasis on "cooled" spectra, clusters and high accuracy frequency references. Topics such as atomic interferometry and microcavity quantum optics are also covered.

  11. 18th International Laser Radar Conference

    CERN Document Server

    Neuber, Roland; Rairoux, Patrick; Wandinger, Ulla

    1997-01-01

    Lidar or laser radar, the depth-resolved remote measurement of atmospheric parameters with optical means, has become an important tool in the field of atmospheric and environmental remote sensing. In this volume the latest progress in the development of lidar methods, experiments, and applications is described. The content is based on selected and thoroughly refereed papers presented at the 18th International Laser Radar Conference, Berlin, 22-26 July 1996. The book is divided into six parts which cover the topics of tropospheric aerosols and clouds, lidar in space, wind, water vapor, troposheric trace gases and plumes, and stratospheric and mesospheric profiling. As a supplement to fundamental lidar textbooks this volume may serve as a guide for scientists, engineers, and graduate students through the blossoming field of modern lidar techniques and their contribution to atmospheric and environmental research.

  12. Free-electron laser results

    International Nuclear Information System (INIS)

    Stein, W.E.; Brau, C.A.; Newnam, B.E.; Warren, R.W.; Winston, J.; Young, L.M.

    1981-01-01

    The Los Alamos free-electron laser (FEL) amplifier experiment was designed to demonstrate high efficiency for transfer of energy from an electron beam to a light beam in the magnetic field of a tapered wiggler. Initial results indicate an energy transfer consistent with theory. Distinct groups of decelerated electrons as well as accelerated electrons are clearly present in the energy spectrum of electrons emerging from the wiggler when the laser light is present. The observed energy decrease for the electrons captured in the decelerating bucket is approx. 6% and the average decrease of the entire energy distribution is approx. 2% for the conditions of these initial measurements

  13. Photonic Free-Electron Lasers

    NARCIS (Netherlands)

    van der Slot, Petrus J.M.; Denis, T.; Lee, J.H.H.; van Dijk, M.W.; Boller, Klaus J.

    2012-01-01

    A photonic free-electron laser (pFEL) produces coherent Cerenkov radiation from a set of parallel electron beams streaming through a photonic crystal. The function of the crystal is to slow down the phase velocity of a copropagating electromagnetic wave, such that also mildly relativistic electrons

  14. Tenth Biennial Coherent Laser Radar Technology and Applications Conference

    Science.gov (United States)

    Kavaya, Michael J. (Compiler)

    1999-01-01

    The tenth conference on coherent laser radar technology and applications is the latest in a series beginning in 1980 which provides a forum for exchange of information on recent events current status, and future directions of coherent laser radar (or lidar or lader) technology and applications. This conference emphasizes the latest advancement in the coherent laser radar field, including theory, modeling, components, systems, instrumentation, measurements, calibration, data processing techniques, operational uses, and comparisons with other remote sensing technologies.

  15. 2nd International Conference on Photonics, Optics and Laser Technology

    CERN Document Server

    Raposo, Maria

    2016-01-01

    This collection of the selected papers presented to the Second International Conference on Photonics, Optics and laser technology PHOTOPTICS 2014 covers the three main conference scientific areas of “Optics”, “Photonics” and “Lasers”. The selected papers, in two classes full and short, result from a double blind review carried out by conference Program Committee members who are highly qualified experts in the conference topic areas.

  16. 3rd International Conference on Photonics, Optics and Laser Technology

    CERN Document Server

    Raposo, Maria

    2016-01-01

    The book provides a collection of selected papers presented to the third International Conference on Photonics, Optics and Laser Technology PHOTOPTICS 2015, covering the three main conference scientific areas of “Optics”, “Photonics” and “Lasers”. The selected papers, in two classes full and short, result from a double blind review carried out by the conference program committee members which are highly qualified experts in conference topic areas.

  17. Laser-driven electron accelerators

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1981-01-01

    The following possibilities are discussed: inverse free electron laser (wiggler accelerator); inverse Cerenkov effect; plasma accelerator; dielectric tube; and grating linac. Of these, the grating acceleraton is considered the most attractive alternative

  18. 18th International Conference on Electronic Publishing

    CERN Document Server

    Dobreva, Milena

    2014-01-01

    The ways in which research data is used and handled continue to capture public attention and are the focus of increasing interest. Electronic publishing is intrinsic to digital data management, and relevant to the fields of data mining, digital publishing and social networks, with their implications for scholarly communication, information services, e-learning, e-business and the cultural heritage sector. This book presents the proceedings of the 18th International Conference on Electronic Publishing (ELPUB), held in Thessaloniki, Greece, in June 2014. The conference brings together researchers and practitioners to discuss the many aspects of electronic publishing, and the theme this year is 'Let's put data to use: digital scholarship for the next generation'. As well as examining the role of cultural heritage and service organisations in the creation, accessibility, duration and long-term preservation of data, it provides a discussion forum for the appraisal, citation and licensing of research data and the n...

  19. International Conference on Laser Physics and Quantum Optics

    CERN Document Server

    Xie, Shengwu; Zhu, Shi-Yao; Scully, Marlan

    2000-01-01

    Since the advent of the laser about 40 years ago, the field of laser physics and quantum optics have evolved into a major discipline. The early studies included the optical coherence theory and the semiclassical and quantum mechanical theories of the laser. More recently many new and interesting effects have been predicted. These include the role of coherent atomic effects in lasing without inversion and electromagnetically induced transparency, atom optics, laser cooling and trapping, teleportation, the single-atom micromaser and its role in quantum measurement theory, to name a few. The International Conference on Laser Physics and Quantum Optics was held in Shanghai from August 25 to August 28, 1999, to discuss these and many other exciting developments in laser physics and quantum optics. The international character of the conference was manifested by the fact that scientists from over 13 countries participated and lectured at the conference. There were four keynote lectures delivered by Nobel laureate Wi...

  20. Electrons and atoms in intense laser fields

    International Nuclear Information System (INIS)

    Davidovich, L.

    1982-01-01

    Several non-linear effects that show up when electrons and atoms interact with strong laser fields are considered. Thomson scattering, electron potential scattering in the presence of a laser beam, atomic ionization by strong laser fields, the refraction of electrons by laser beams and the Kapitza-Dirac effect are discussed. (Author) [pt

  1. Electrons and atoms in intense laser fields

    International Nuclear Information System (INIS)

    Davidovich, L.

    1982-11-01

    Several non-linear effects that show up when electrons and atoms interact with strong laser fields are considered. Thomson scattering, electron potential scattering in the presence of a laser beam, atomic ionization by strong laser fields, the refraction of electrons by laser beams and the Kapitza-Dirac effect are discussed. (Author) [pt

  2. Laser control of electron matter waves

    NARCIS (Netherlands)

    Jones, E.; Becker, M.; Luiten, O.J.; Batelaan, H.

    2016-01-01

    In recent years laser light has been used to control the motion of electron waves. Electrons can now be diffracted by standing waves of light. Laser light in the vicinity of nanostructures is used to affect free electrons, for example, femto-second and atto-second laser-induced electrons are emitted

  3. Free-electron lasers 2

    International Nuclear Information System (INIS)

    Petroff, Y.

    1989-01-01

    This book presents papers on free-electron laser technology. The authors cover technological developments on existing FELs, new FEL research, and the use of FELs in experimental investigations. Among the studies reported are lasing in the visible and UV on the Novosibirsk VEPP-3 storage ring, description of Japanese FEL research, and Mark III FEL, and the Paladin results

  4. Free Electron Lasers in 2005

    CERN Document Server

    Colson, W B; Voughs, T

    2005-01-01

    Twenty-eight years after the first operation of the short wavelength free electron laser (FEL) at Stanford University, there continue to be many important experiments, proposed experiments, and user facilities around the world. Properties of FELs in the infrared, visible, UV, and x-ray wavelength regimes are listed and discussed.

  5. Free Electron Lasers in 2004

    CERN Document Server

    Colson, William B

    2004-01-01

    Twenty-seven years after the first operation of the short wavelength free electron laser (FEL) at Stanford University, there continue to be many important experiments, proposed experiments, and user facilities around the world. Properties of FELs operating in the infrared, visible, UV, and x-ray wavelength regimes are listed and discussed.

  6. Nuclear Electronics. Proceedings of a Conference on Nuclear Electronics

    International Nuclear Information System (INIS)

    1966-01-01

    The science of electronics, which is playing a decisive role in the modern world, is particularly important in the development of the nuclear sciences, both in fundamental research on the structure of matter and in the production of power from fission. It is impractical, however, to deal with this vast and varied subject at one time. The Agency's first conference on the subject, at Belgrade in May 1961, was restricted to just a few aspects of nuclear electronics. The second conference, organized by the Agency in co-operation with the Indian Atomic Energy Commission and held at Bombay from 22 to 26 November 1965, was limited, for all practical purposes, to the use of nuclear electronics in reactor control and safety. The importance of this subject is self-evident, for the number of power reactors throughout the world is increasing every year and the economics of their operation depends just as much on optimum functioning as on improved safety. The Bombay conference, at which 48 papers were presented, was attended by a large number of participants, representing 12 countries and two international organizations. The main topics were power and neutron-flux measurements, reactor control, safety devices, and data processing to ensure optimum operation. The Proceedings, which contain both the texts and discussions of the papers presented, are of immediate interest to specialists in these fields and should form a valuable source of information

  7. Electron beam cooling by laser

    CERN Document Server

    Urakawa, J; Terunuma, N; Taniguchi, T; Yamazaki, Y; Hirano, K; Nomura, M; Sakai, I; Takano, M; Sasao, N; Honda, Y; Noda, A; Bulyak, E; Gladkikh, P; Mystykov, A; Zelinsky, A; Zimmermann, Frank

    2004-01-01

    In 1997, Z.Huang and R.Ruth proposed a compact laser-electron storage ring (LESR) for electron beam cooling or x-ray generation. Because the laser-wire monitor in the ATF storage ring has worked well and demonstrated the achievement of the world's smallest transverse emittance for a circulating electron beam, we have started the design of a small storage ring with about 10 m circumference and the development of basic technologies for the LESR. In this paper, we describe the design and experimental results of pulse stacking in a 42-cm long optical cavity. Since our primary purpose is demonstrating the proof-of-principle of the LESR, we will then discuss the future experimental plan at the KEK-ATF for the generation of high average-brilliance gamma-rays.

  8. Free-electron laser theory

    International Nuclear Information System (INIS)

    Dattoli, G.; Torre, A.

    1989-01-01

    The essential features of the theory of the free electron laser (FEL) are given in some detail. Beginning with an explanation of the basic gain mechanism, the lectures continue with a discussion of the problems associated with single-passage and recirculated (storage-ring) operation. Pulse propagation effects and the so-called 'lethargic' behaviour are analysed more completely. Finally, elements of FEL quantum theory are reported, in order to clarify the laser process from the microscopic point of view. Appendices give a fuller treatment of optical cavities and undulator magnets. (orig.)

  9. III International Conference on Laser and Plasma Researches and Technologies

    Science.gov (United States)

    2017-12-01

    A.P. Kuznetsov and S.V. Genisaretskaya III Conference on Plasma and Laser Research and Technologies took place on January 24th until January 27th, 2017 at the National Research Nuclear University "MEPhI" (NRNU MEPhI). The Conference was organized by the Institute for Laser and Plasma Technologies and was supported by the Competitiveness Program of NRNU MEPhI. The conference program consisted of nine sections: • Laser physics and its application • Plasma physics and its application • Laser, plasma and radiation technologies in industry • Physics of extreme light fields • Controlled thermonuclear fusion • Modern problems of theoretical physics • Challenges in physics of solid state, functional materials and nanosystems • Particle accelerators and radiation technologies • Modern trends of quantum metrology. The conference is based on scientific fields as follows: • Laser, plasma and radiation technologies in industry, energetic, medicine; • Photonics, quantum metrology, optical information processing; • New functional materials, metamaterials, “smart” alloys and quantum systems; • Ultrahigh optical fields, high-power lasers, Mega Science facilities; • High-temperature plasma physics, environmentally-friendly energetic based on controlled thermonuclear fusion; • Spectroscopic synchrotron, neutron, laser research methods, quantum mechanical calculation and computer modelling of condensed media and nanostructures. More than 250 specialists took part in the Conference. They represented leading Russian scientific research centers and universities (National Research Centre "Kurchatov Institute", A.M. Prokhorov General Physics Institute, P.N. Lebedev Physical Institute, Troitsk Institute for Innovation and Fusion Research, Joint Institute for Nuclear Research, Moscow Institute of Physics and Tecnology and others) and leading scientific centers and universities from Germany, France, USA, Canada, Japan. We would like to thank heartily all of

  10. Free Electron Laser in Poland

    CERN Document Server

    Romaniuk, Ryszard

    2009-01-01

    The idea of building a new IVth generation of light sources of high luminosity, which use accelerators, arose in the 80ties of XXth century. Now, in a numerable synchrotron and laser laboratories in Europe, there is carried out, since a couple of years, intense applied research on free electron lasers (FEL) [17,18]. Similarly, in this country, free electron laser in Poland – POLFEL [9] is, in a design, a coherent light source of the IVth generation, characterized by very short pulses in the range of 10-100fs, of big power 0,2GW and UV wavelength of 27nm, of average power 1W, with effective high power third harmonic of 9nm. The laser consists of a linear superconducting accelerator 100m in length, undulator and experimental lines. It generates a monochromatic and coherent radiation and can be tuned from THz range via IR, visible to UV, and potentially to X-rays. The linac works in quasi-CW or real-CW mode. It is planned by IPJ [9,10] and XFEL-Poland Consortium [16] as a part of the ESFRI [1] priority EuroFEL...

  11. Inverse Free Electron Laser accelerator

    International Nuclear Information System (INIS)

    Fisher, A.; Gallardo, J.; van Steenbergen, A.; Sandweiss, J.

    1992-09-01

    The study of the INVERSE FREE ELECTRON LASER, as a potential mode of electron acceleration, is being pursued at Brookhaven National Laboratory. Recent studies have focussed on the development of a low energy, high gradient, multi stage linear accelerator. The elementary ingredients for the IFEL interaction are the 50 MeV Linac e - beam and the 10 11 Watt CO 2 laser beam of BNL's Accelerator Test Facility (ATF), Center for Accelerator Physics (CAP) and a wiggler. The latter element is designed as a fast excitation unit making use of alternating stacks of Vanadium Permendur (VaP) ferromagnetic laminations, periodically interspersed with conductive, nonmagnetic laminations, which act as eddy current induced field reflectors. Wiggler parameters and field distribution data will be presented for a prototype wiggler in a constant period and in a ∼ 1.5 %/cm tapered period configuration. The CO 2 laser beam will be transported through the IFEL interaction region by means of a low loss, dielectric coated, rectangular waveguide. Short waveguide test sections have been constructed and have been tested using a low power cw CO 2 laser. Preliminary results of guide attenuation and mode selectivity will be given, together with a discussion of the optical issues for the IFEL accelerator. The IFEL design is supported by the development and use of 1D and 3D simulation programs. The results of simulation computations, including also wiggler errors, for a single module accelerator and for a multi-module accelerator will be presented

  12. II International Conference on Plasma and Laser Research and Technologies

    International Nuclear Information System (INIS)

    Kurnaev, V A; Dodulad, E I

    2016-01-01

    II Conference on Plasma and Laser Research and Technologies took place on January 25 th until January 27 th , 2016 at National Research Nuclear University “MEPhI” (NRNU MEPhI). It was organized by the Institute of Laser and Plasma Technologies and was supported by the Competitiveness Program of NRNU MEPhI. The Conference consisted of four sections: Plasma physics and controlled nuclear fusion, Laser physics, Modern aspects of solid state matter physics and Charged particle accelerators. The Conference provided participants an opportunity to present their research results for the consideration of a wide audience from the sidelines of science. The main topics of the Conference were: • Controlled nuclear fusion with magnetic and inertial confinement; • Low-temperature plasma and its application in modern technology; • Laser physics and technologies for industry, environmental control and precise measurements; • Optical information control, holography, spintronics and photonics; • Modern aspects of solid state matter physics and nanophysics; • Charged particle accelerators. More than 200 specialists on plasma, laser and solid state physics took part in the II Conference. They represented leading Russian scientific research centres and universities (such as Troitsk Institute of Innovative and Thermonuclear Research, Institute of Crystallography, National Research Centre 'Kurchatov Institute', Institute of Physical Chemistry and Electrochemistry and others) and universities from Belarus, Ukraine, Germany, USA, Canada, Belgium, and Sweden. All report presentations were broadcasted online on the NRNU MEPhI official site. The translation was watched by viewers from Moscow, Prague, St. Petersburgh and other cities, who could not attend the Conference. We would like to thank heartily all of the speakers, participants and organizing committee members for their contribution to the conference. (paper)

  13. 10th International Conference on X-Ray Lasers

    CERN Document Server

    Nickles, P.V; X-Ray Lasers 2006

    2007-01-01

    The search for table-top and repetitive pump schemes during the last decade has been the driving force behind the spectacular advances demonstrated during the 10th International Conference on X-Ray Lasers, organized in 2006 in Berlin. Since 1986, international experts have gathered every two years at this established conference to discuss the progress in theory, experiment and application of plasma-based soft X-ray lasers. Traditionally, the conference sessions devoted to complementary and alternative sources of short wavelength radiation, such as high harmonics, XFEL or incoherent X-rays are organized so as to emphasize the role of X-ray laser research in relation to the other short wavelength sources. Grazing incidence pumping (GRIP) and seeding with high harmonics were the dominant topics of the conference. High repetition rate and portable X-ray lasers were reported to have been applied in metrology and photochemistry for the first time. The proceedings of this series of conferences constitute a comprehen...

  14. International Free Electron Laser Conference (15th) Held in The Hague, Netherland on August 23-27, 1993. Book of Abstracts

    Science.gov (United States)

    1993-08-27

    missioning and service for: nology, extending from research and development, design, c( nstruction and El Synchrotron radiation facilities...Experiment Using the Coherent Synchrotron Radiation Emitted From Electron Bunches M. AsaKawa, N. Sakamoto, N. Inoue, T. Yamamoto, K. Mima, S. Nakai, J...Netherlands 12:30 Lunch Session Poster I 14:00 Th3-01 Magnetic Bunching Experiments on ELSA S. Joly, D.H. Dowell, ELSA -FEL Team CEN/SPTN, France Th3-03

  15. Electron-beam initiated HF lasers

    International Nuclear Information System (INIS)

    Gerber, R.A.; Patterson, E.L.

    1975-01-01

    Electron beams were used to ignite hydrogen/fluorine mixtures, producing laser energies up to 4.2 kJ, and giving hope that this approach may soon produce energy levels suitable for laser-fusion studies. (auth)

  16. Laser frequency modulation with electron plasma

    Science.gov (United States)

    Burgess, T. J.; Latorre, V. R.

    1972-01-01

    When laser beam passes through electron plasma its frequency shifts by amount proportional to plasma density. This density varies with modulating signal resulting in corresponding modulation of laser beam frequency. Necessary apparatus is relatively inexpensive since crystals are not required.

  17. Mobile terawatt laser propagation facility (Conference Presentation)

    Science.gov (United States)

    Shah, Lawrence; Roumayah, Patrick; Bodnar, Nathan; Bradford, Joshua D.; Maukonen, Douglas; Richardson, Martin C.

    2017-03-01

    This presentation will describe the design and construction status of a new mobile high-energy femtosecond laser systems producing 500 mJ, 100 fs pulses at 10 Hz. This facility is built into a shipping container and includes a cleanroom housing the laser system, a separate section for the beam director optics with a retractable roof, and the environmental control equipment necessary to maintain stable operation. The laser system includes several innovations to improve the utility of the system for "in field" experiments. For example, this system utilizes a fiber laser oscillator and a monolithic chirped Bragg grating stretcher to improve system robustness/size and employs software to enable remote monitoring and system control. Uniquely, this facility incorporates a precision motion-controlled gimbal altitude-azimuth mount with a coudé path to enable aiming of the beam over a wide field of view. In addition to providing the ability to precisely aim at multiple targets, it is also possible to coordinate the beam with separate tracking/diagnostic sensing equipment as well as other laser systems. This mobile platform will be deployed at the Townes Institute Science and Technology Experimental Facility (TISTEF) located at the Kennedy Space Center in Florida, to utilize the 1-km secured laser propagation range and the wide array of meteorological instrumentation for atmospheric and turbulence characterization. This will provide significant new data on the propagation of high peak power ultrashort laser pulses and detailed information on the atmospheric conditions in a coastal semi-tropical environment.

  18. Electronic Conference Tracking and Approval System

    Data.gov (United States)

    US Agency for International Development — eCTAS tracks information relevant to attendance and hosting conferences of USAID's Washington offices and Missions worldwide including cost, numbers attending,...

  19. 2012 International Conference on Mechanical and Electronic Engineering

    CERN Document Server

    Lin, Sally; ICMEE2012; Advances in Mechanical and Electronic Engineering v.2

    2012-01-01

    This book includes the volume 2 of the proceedings of the 2012 International Conference on Mechanical and Electronic Engineering(ICMEE2012), held at June 23-24,2012 in Hefei, China. The conference provided a rare opportunity to bring together worldwide researchers who are working in the fields. This volume 2 is focusing on Mechatronic Engineering and Technology,  Electronic Engineering and Electronic Information Technology .

  20. Free-electron laser beam

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    2003-01-01

    The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7μm FEL beam. Cancer cells are considered diagnosed by FEL beam of far-infrared-THz range. The FEL beam CT is expected to have a wide variety of application without the radiation exposure and its resolution is equal or superior to that of usual imaging techniques. (N.I.)

  1. Electron-beam-excited gas laser research

    International Nuclear Information System (INIS)

    Johnson, A.W.; Gerardo, J.B.; Patterson, E.L.; Gerber, R.A.; Rice, J.K.; Bingham, F.W.

    1975-01-01

    Net energy gain in laser fusion places requirements on the laser that are not realized by any existing laser. Utilization of relativistic electron beams (REB's), a relatively new source for the excitation of gas laser media, may lead to new lasers that could satisfy these requirements. Already REB's have been utilized to excite gas laser media and produce gas lasers that have not been produced as successfully any other way. Electron-beam-excitation has produced electronic-transition dimer lasers that have not yet been produced by any other excitation scheme (for example, Xe 2 / sup *(1)/, Kr:O(2 1 S)/sup 2/, KrF/sup *(3)/). In addition, REB's have initiated chemical reactions to produce HF laser radiation with unique and promising results. Relativistic-electron-beam gas-laser research is continuing to lead to new lasers with unique properties. Results of work carried out at Sandia Laboratories in this pioneering effort of electron-beam-excited-gas lasers are reviewed. (U.S.)

  2. 2012 International Conference on Electrical and Electronics Engineering

    CERN Document Server

    Chen, Suting; Wei, Zhanming; Xia, Jingming

    2014-01-01

    Unifying Electrical Engineering and Electronics Engineering is based on the Proceedings of the 2012 International Conference on Electrical and Electronics Engineering (ICEE 2012). This book collects the peer reviewed papers presented at the conference. The aim of the conference is to unify the two areas of Electrical and Electronics Engineering. The book examines trends and techniques in the field as well as theories and applications. The editors have chosen to include the following topics; biotechnology, power engineering, superconductivity circuits, antennas technology, system architectures and telecommunication.

  3. High frequency free-electron laser results

    International Nuclear Information System (INIS)

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

    1983-01-01

    By looking at the free-electron laser as a particle accelerator working backwards, Morton realized that the techniques used to accelerate particles could be used to improve the performance of free-electron lasers. In particular, he predicted the capture of electrons in ''stable-phase'' regions, or ''buckets'' in the electron phase space, and proposed that by decelerating the buckets, the trapped electrons could be decelerated to extract significant amounts of their energy as optical radiation. In fact, since electrons not trapped in the stable regions are forever excluded from them--at least in the adiabatic approximation--displacement techniques could also be used to accelerate or decelerate electrons in a free-electron laser. This paper explains the principle behind ''phase-displacement'' acceleration and details an experiment carried out with a 20-MeV electron beam to test these predictions. Results obtained with a tapered-wiggler free-electron laser demonstrate the concepts proposed by Morton for enhanced efficiency. They show deceleration of electrons by as much as 7% and extraction of more than 3% of the total electron-beam energy as laser energy when the laser is operated as an amplifier. The experiment is presently being reconfigured to examine its performance as a laser oscillator

  4. Proceedings of the 4. International Conference on Lasers and their Applications

    International Nuclear Information System (INIS)

    400 scientists from 19 countries participated in the 4. international conference on lasers and their applications, held at Leipzig, GDR, in October 1981. The conference focused on problems of gas lasers, high-power lasers for materials working, and laser spectroscopy, on optoelectronics considering communications systems, and on laser-controlled thermonuclear fusion with special regard to the laser plant 'Delphin 1'. 186 summaries are included

  5. Free-electron lasers considered for CEBAF

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Spinoff development of industrial free-electron lasers is in prospect for an industry-universitylaboratory consortium centred at the Continuous Electron Beam Accelerator Facility in Newport News, Virginia, site of the CEBAF 4 GeV superconducting radiofrequency (SRF) accelerator, now being commissioned (see page 42). Together with several US corporations and universities, the Laboratory is now also addressing the potential of smaller SRF electron accelerators for ''driving'' free-electron lasers (FELs)

  6. 13th International Conference on X-Ray Lasers

    CERN Document Server

    Gautier, Julien; Ros, David; Zeitoun, Philippe

    2014-01-01

    These proceedings comprise of invited and contributed papers presented at the 13th International Conference on X-Ray Lasers (ICXRL 2012) which was held 11–15 June 2012 in Paris, in the famous Quartier Latin, inside the historical Center of Cordeliers. This conference is part of a continuing series dedicated to recent developments and applications of x-ray lasers and other coherent x-ray sources with attention to supporting technologies and instrumentation. New results in the generation of intense, coherent x-rays and progress towards practical devices and their applications are reported in these proceedings, including areas of research in plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generation. Recent achievements related to the increase of the repetition rate up to 100 Hz and shorter wavelength collisional plasma-based soft x-ray lasers down to about 7 nm are presented. Seeding the amplifying plasma with a femtosecond high-order harmonic of infrared laser was fore...

  7. International Conference on Nano-electronics, Circuits & Communication Systems

    CERN Document Server

    2017-01-01

    This volume comprises select papers from the International Conference on Nano-electronics, Circuits & Communication Systems(NCCS). The conference focused on the frontier issues and their applications in business, academia, industry, and other allied areas. This international conference aimed to bring together scientists, researchers, engineers from academia and industry. The book covers technological developments and current trends in key areas such as VLSI design, IC manufacturing, and applications such as communications, ICT, and hybrid electronics. The contents of this volume will prove useful to researchers, professionals, and students alike.

  8. PREFACE: 21st International Conference on Laser Spectroscopy - ICOLS 2013

    Science.gov (United States)

    Budker, Dmitry; Häffner, Hartmut; Müller, Holger

    2013-12-01

    The 21st International Conference on Laser Spectroscopy (ICOLS) took place at Berkeley, California on 9-14 June 2013. Following the tradition of previous meetings in this series, the conference featured about thirty invited talks broadly covering this burgeoning field of science that refuses to show any sign of saturation after more than half a century of continuous boom. In addition to the invited talks, there were two informative poster sessions, where the more than 300 ICOLS participants had an opportunity to exchange the latest scientific news and ideas while enjoying the gorgeous view of the San Francisco Bay from the vista of the Claremont Hotel, the meeting's venue. The heights of the cultural program of the meeting were excursions to several of the Bay Area gems (including the Lick observatory), as well as the conference banquet where the participants were treated to addresses by an inventor of the laser Professor Charles H Townes, a nonlinear optics pioneer Professor Erwin L Hahn, and one of the previous ICOLS chairs Professor Y R Shen. While the field of Laser Spectroscopy and the series of the bi-annual ICOLS meetings are as 'healthy' as one could imagine, the same cannot be said about the concept of published conference proceedings. With new ways to publish scientific articles and preprints, submitting papers to conference proceedings seems to be rapidly losing popularity. For this meeting, the great interest in attendance and opportunities to present is sharply contrasted with a somewhat sluggish response to the call for submission of the proceedings papers. The present collection represents a dozen or so contributions from the 'hero' invited speakers, to whom we are deeply grateful for submitting their work. We hope that this selection will faithfully convey to the readers the excitement of modern laser spectroscopy. In addition to these papers, we draw the reader's attention to the audio recordings and selected viewgraphs from the invited talks, and

  9. Proceedings of 10. Conference on Electron Microscopy of Solids

    International Nuclear Information System (INIS)

    1999-01-01

    The new technical solutions and methodical variants of electron microscopy i. e. transmission electron microscopy and scanning electron microscopy have been presented. Development of new methods and microscope constructions which became more and more sophisticated causes the progress in possible applications. The broad spectrum of such applications in metallurgy, materials science, chemical engineering, electronics, physical chemistry, solid state physics, mineralogy and other branches of science and technique have been performed and discussed at the conference

  10. High-intensity-laser-electron scattering

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.

    1997-01-01

    In the field of an intense laser, photon-electron scattering becomes nonlinear when the oscillatory energy of the electron approaches its rest mass. The electron wave function is dressed by the field with a concomitant increase in the effective electron mass. When the photon energy in the electron rest frame is comparable to the electron rest mass, multiphoton Compton scattering occurs. When the photon energy is significantly lower than the electron rest mass, the electron acquires momentum from the photon field and emits harmonics. This paper reviews nonlinear photon-electron scattering processes and results from two recent experiments where they have been observed

  11. XXIII International Conference on Nonlinear Dynamics of Electronic Systems

    CERN Document Server

    Stoop, Ruedi; Stramaglia, Sebastiano

    2017-01-01

    This book collects contributions to the XXIII international conference “Nonlinear dynamics of electronic systems”. Topics range from non-linearity in electronic circuits to synchronisation effects in complex networks to biological systems, neural dynamics and the complex organisation of the brain. Resting on a solid mathematical basis, these investigations address highly interdisciplinary problems in physics, engineering, biology and biochemistry.

  12. Free electron laser and superconductivity

    CERN Document Server

    Iwata, A

    2003-01-01

    The lasing of the first free-electron laser (FEL) in the world was successfully carried out in 1977, so the history of FELs as a light source is not so long. But FELs are now utilized for research in many scientific and engineering fields owing to such characteristics as tunability of the wavelength, and short pulse and high peak power, which is difficult utilizing a common light source. Research for industrial applications has also been carried out in some fields, such as life sciences, semiconductors, nano-scale measurement, and others. The task for the industrial use of FEL is the realization of high energy efficiency and high optical power. As a means of promoting realization, the combining of an FEL and superconducting linac is now under development in order to overcome the thermal limitations of normal-conducting linacs. Further, since tuning the wavelength is carried out by changing the magnetic density of the undulator, which is now induced by moving part of the stack of permanent magnets, there is un...

  13. Third International Electronic Conference on Medicinal Chemistry (ECMC-3

    Directory of Open Access Journals (Sweden)

    Annie Mayence

    2018-02-01

    Full Text Available The third International Electronic Conference on Medicinal Chemistry, organized and sponsored by MDPI AG, publisher, and the journal Pharmaceuticals, took place in November 2017 on the SciForum website (www.sciforum.net/conference/ecmc-3. Around 300 authors from 34 different countries participated at the event, which hosted more than 70 presentations, keynotes, videos, and posters. A short description of some works presented during that scientific meeting is disclosed in this report.

  14. Free electron laser as a fusion driver

    International Nuclear Information System (INIS)

    Prosnitz, D.; Schlitt, L.

    1981-01-01

    The Free Electron Laser (FEL) is shown to be a potentially attractive solution to the problem of finding a suitable short wavelength fusion driver. The design of a 3 MJ, 250 nm FEL fusion driver is discussed

  15. Book of abstracts of the second Uzbekistan physical electronics conference

    International Nuclear Information System (INIS)

    1999-11-01

    The second Uzbekistan Physical Electronics Conference on was held on 3-5 November, 1999 in Tashkent, Uzbekistan. The specialists discussed both theoretical and experimental research results in the field of interaction of corpuscular beams with solid state surface: fundamental problem of adsorption; surface ionization; electron, ion, photon emission; scattering of the particles on the surface; action of ion and electron irradiation, plasma treatment of material surface and also the problems of solid state electronics and applications of fundamental problems of physical electronics to surface diagnostics, ecology, technology and agriculture. More than 300 talks were presented in the meeting on the subjects mentioned above(A.A.D.)

  16. 1st International Conference on Advancements of Medical Electronics

    CERN Document Server

    Bag, Sandip; Ganguly, Karabi; Sarkar, Indranath; Biswas, Papun

    2015-01-01

    The book is a collection of peer-reviewed scientific papers submitted by active researchers in the 1st International Conference on Advancements of Medical Electronics (ICAME2015). The conference is organized jointly by the Department of Biomedical Engineering and Electronics and Communication Engineering, JIS College of Engineering, West Bengal, India. The primary objective of the conference is to strengthen interdisciplinary research and its applications for the welfare of humanity. A galaxy of academicians, professionals, scientists, statesman and researchers from different parts of the country and abroad got together and shared their knowledge. The book presents research articles of medical image processing & analysis, biomedical instrumentation & measurements, DSP & clinical applications, embedded systems & its applications in healthcare. The book can be referred as a tool for further research.

  17. Control system for JAERI Free Electron Laser

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1992-01-01

    A control system comprising of the personal computers network and the CAMAC stations for the JAERI Free Electron Laser is designed and is in the development stage. It controls the equipment and analyzes the electron and optical beam experiments. The concept and the prototype of the control system are described. (author)

  18. Laser-assisted electron-atom collisions

    International Nuclear Information System (INIS)

    Mason, N.J.

    1989-01-01

    New developments in our understanding of the electron-atom collision process have been made possible by combining the use of highly monochromatic electron beams and intense CO 2 lasers. This paper reviews such experiments and discusses possible future progress in what is a new field in atomic collision physics. (author)

  19. 2015 Applications in Electronics Pervading Industry, Environment and Society Conference

    CERN Document Server

    2017-01-01

    This book provides a thorough overview of cutting-edge research on electronics applications relevant to industry, the environment, and society at large. It covers a broad spectrum of application domains, from automotive to space and from health to security, while devoting special attention to the use of embedded devices and sensors for imaging, communication and control. The book is based on the 2015 ApplePies Conference, held in Rome, which brought together researchers and stakeholders to consider the most significant current trends in the field of applied electronics and to debate visions for the future. Areas addressed by the conference included information communication technology; biotechnology and biomedical imaging; space; secure, clean and efficient energy; the environment; and smart, green and integrated transport. As electronics technology continues to develop apace, constantly meeting previously unthinkable targets, further attention needs to be directed toward the electronics applications and the ...

  20. International Conference on Strongly Correlated Electron Systems 2017 (SCES2017)

    Science.gov (United States)

    2018-05-01

    The 2017 International Conference on Strongly Correlated Electron Systems, SCES 2017, took place at the Clarion Congress Hotel in Prague, Czech Republic from July 17 to 21, 2017. The meeting was held under the auspices of the Department of Condensed Matter Physics of the Faculty of Mathematics and Physics of the Charles University.

  1. 2nd International Conference on Electric and Electronics (EEIC 2012)

    CERN Document Server

    Advances in Electric and Electronics

    2012-01-01

    This volume contains 108 full length papers presented at the 2nd International Conference on Electric and Electronics (EEIC 2012), held on April 21-22 in Sanya, China, which brings together researchers working in many different areas of education and learning to foster international collaborations and exchange of new ideas. This volume can be divided into two sections on the basis of the classification of manuscripts considered: the first section deals with Electric and the second section with Electronics.

  2. International Conference on Power Electronics and Renewable Energy Systems

    CERN Document Server

    Suresh, L; Dash, Subhransu; Panigrahi, Bijaya

    2015-01-01

    The book is a collection of high-quality peer-reviewed research papers presented in Proceedings of International Conference on Power Electronics and Renewable Energy Systems (ICPERES 2014) held at Rajalakshmi Engineering College, Chennai, India. These research papers provide the latest developments in the broad area of Power Electronics and Renewable Energy. The book discusses wide variety of industrial, engineering and scientific applications of the emerging techniques. It presents invited papers from the inventors/originators of new applications and advanced technologies.

  3. Conferences on electronic waste in Costa Rica

    International Nuclear Information System (INIS)

    Roa Gutierrez, Floria

    2006-01-01

    The management system of electronic waste is a project organized and financed by the bilateral agreement Costa Rica - Holanda, it is integrated by governmental and non-governmental enterprises. It was divided in two phases, first performed in 2003 which provided a diagnosis on the management of electronic resources, based on the diagnosis a propose of strategy for recycling was made. The second phase is given in 2005 with the implementation and realization of the project including two pilots plans located one at the Instituto Tecnologico de Costa Rica and another in the community of Escazu, at the end some recommendations were given to strengthen the system. The electronic waste were divided in white line, gray and brown line; those with pollutants such as phosphorus, chromium, cadmium, barium, lead, beryllium, mercury are toxic and have different effects on human health. The project in Costa Rica has taken as examples several recycling plants in different countries, among them one installed in Belgica. As an outstanding figure of the diagnosis made it was determined that Costa Rica has no legal support regarding the handling of such materials. It has been accumulated in 2007 more than 24 260 tonnes and is growing rapidly year after year. Within the achieved progress in the implementation of the project are: the creation of a legal support, the organization of the compliance unit of the project, the valuation of environmental costs and the increase of enterprises offering the service of primary treatment [es

  4. Linac technology for free-electron lasers

    International Nuclear Information System (INIS)

    Cooper, R.K.; Morton, P.L.; Wilson, P.B.; Keefe, D.; Faltens, A.

    1983-01-01

    The purpose of this paper is to concentrate on the properties of high-energy electron linear accelerators for use in free-electron lasers operating principally in the Compton regime. To fix our focus somewhat, we shall consider electron energies in the 20- to 200-MeV range and consider requirements for high-power free-electron lasers operating in the 0.5- to 10-μm range. Preliminary remarks are made on high-power free-electron laser amplifiers and oscillators and some desirable characteristics of the linacs that deliver electron beams for these devices. Both the high peak-current requirements of the amplifier and the high pulse-repetition frequency requirements of the oscillator can be met by present-day linac technology, although not necessarily by the same machine. In this papers second and third section, the technology of two rather different types of linear accelerators, the rf linac and the induction linac, is reviewed. In conclusion, applications to the Free Electron Lasers are stated

  5. Long range coherence in free electron lasers

    Science.gov (United States)

    Colson, W. B.

    1984-01-01

    The simple free electron laser (FEL) design uses a static, periodic, transverse magnetic field to undulate relativistic electrons traveling along its axis. This allows coupling to a co-propagating optical wave and results in bunching to produce coherent radiation. The advantages of the FEL are continuous tunability, operation at wavelengths ranging from centimeters to angstroms, and high efficiency resulting from the fact that the interaction region only contains light, relativistic electrons, and a magnetic field. Theoretical concepts and operational principles are discussed.

  6. Laser Interaction and Related Plasma Phenomena: 13th International Conference. Proceedings

    International Nuclear Information System (INIS)

    Miley, G.H.; Campbell, E.M.; Hogan, W.J.; Maille-Petersen, C.; Coppedge, H.; Montoya, E.

    1997-01-01

    These proceedings contain papers presented at the Thirteenth International Conference on Laser Interaction and Related Plasma Phenomena held in Monterey, California in April, 1997. Topics covered in the conference included laser design, alternate concepts in volume ignition and advance fuels, beam/plasma interactions, nuclear-pumped lasers, alternate fast ignitors, heavy ion fusions, laser-ion beam interactions, extreme short-pulse interactions, high-energy-density plasma physics, and hydrodynamic instabilities. The conference was sponsored in part by the Lawrence Livermore National Laboratory of the United States Department of Energy. There were 80 papers presented and 23 have been abstracted for the Energy Science and Technology database

  7. 2nd International Conference on Measurement Instrumentation and Electronics

    International Nuclear Information System (INIS)

    2017-01-01

    Preface It is our great pleasure to welcome you to 2017 2nd International Conference on Measurement Instrumentation and Electronics which has been held in Prague, Czech Republic during June 9-11, 2017. ICMIE 2017 is dedicated to issues related to measurement instrumentation and electronics. The major goal and feature of the conference is to bring academic scientists, engineers, industry researchers together to exchange and share their experiences and research results, and discuss the practical challenges encountered and the solutions adopted. Professors from Czech Republic, Germany and Italy are invited to deliver keynote speeches regarding latest information in their respective expertise areas. It is a golden opportunity for the students, researchers and engineers to interact with the experts and specialists to get their advice or consultation on technical matters, teaching methods and strategies. These proceedings present a selection from papers submitted to the conference from universities, research institutes and industries. All of the papers were subjected to peer-review by conference committee members and international reviewers. The papers selected depended on their quality and their relevancy to the conference. The volume tends to present to the readers the recent advances in the field of computer and communication system, system design and measurement and control technology, power electronics and electrical engineering, materials science and engineering, power machinery and equipment maintenance, architectural design and project management, environmental analysis and detection etc. We would like to thank all the authors who have contributed to this volume and also to the organizing committee, reviewers, speakers, chairpersons, and all the conference participants for their support to ICMIE 2017. ICMIE 2017 Organizing Committee June 20th, 2017 (paper)

  8. Electron distribution function in laser heated plasmas

    International Nuclear Information System (INIS)

    Fourkal, E.; Bychenkov, V. Yu.; Rozmus, W.; Sydora, R.; Kirkby, C.; Capjack, C. E.; Glenzer, S. H.; Baldis, H. A.

    2001-01-01

    A new electron distribution function has been found in laser heated homogeneous plasmas by an analytical solution to the kinetic equation and by particle simulations. The basic kinetic model describes inverse bremsstrahlung absorption and electron--electron collisions. The non-Maxwellian distribution function is comprised of a super-Gaussian bulk of slow electrons and a Maxwellian tail of energetic particles. The tails are heated due to electron--electron collisions and energy redistribution between superthermal particles and light absorbing slow electrons from the bulk of the distribution function. A practical fit is proposed to the new electron distribution function. Changes to the linear Landau damping of electron plasma waves are discussed. The first evidence for the existence of non-Maxwellian distribution functions has been found in the interpretation, which includes the new distribution function, of the Thomson scattering spectra in gold plasmas [Glenzer , Phys. Rev. Lett. 82, 97 (1999)

  9. Increasing Laser Stability with Improved Electronic Instruments

    Science.gov (United States)

    Troxel, Daylin; Bennett, Aaron; Erickson, Christopher J.; Jones, Tyler; Durfee, Dallin S.

    2010-03-01

    We present several electronic instruments developed to implement an ultra-stable laser lock. These instruments include a high speed, low noise homodyne photo-detector; an ultrahigh stability, low noise current driver with high modulation bandwidth and digital control; a high-speed, low noise PID controller; a low-noise piezo driver; and a laser diode temperature controller. We will present the theory of operation for these instruments, design and construction techniques, and essential characteristics for each device.

  10. 8th international conference on electronic spectroscopy and structure

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Art

    2000-10-16

    Gathering from 33 countries around the world, 408 registrants and a number of local drop-in participants descended on the Clark Kerr Campus of the University of California, Berkeley, from Monday, August 7 through Saturday, August 12, 2000 for the Eighth International Conference on Electronic Structure and Spectroscopy (ICESS8). At the conference, participants benefited from an extensive scientific program comprising more than 100 oral presentations (plenary lectures and invited and contributed talks) and 330 poster presentations, as well as ample time for socializing and a tour of the Advanced Light Source (ALS) at the nearby Lawrence Berkeley National Laboratory.

  11. PREFACE: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19)

    Science.gov (United States)

    González, T.; Martín-Martínez, M. J.; Mateos, J.

    2015-10-01

    The 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19) was held at the Hospedería Fonseca (Universidad de Salamanca, Spain), on 29 June - 2 July, 2015, and was organized by the Electronics Area from the University of Salamanca. The Conference is held biannually and covers the recent progress in the field of electron dynamics in solid-state materials and devices. This was the 19th meeting of the international conference series formerly named Hot Carriers in Semiconductors (HCIS), first held in Modena in 1973. In the edition of 1997 in Berlin the name of the conference changed to International Conference on Nonequilibrium Carrier Dynamics in Semiconductors, keeping the same acronym, HCIS; and finally in the edition of Montpellier in 2009 the name was again changed to the current one, International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON). The latest editions took place in Santa Barbara, USA, in 2011 and Matsue, Japan, in 2013. Research work on electron dynamics involves quite different disciplines, and requires both fundamental and technological scientific efforts. Attendees to the conference come mostly from academic institutions, belonging to both theoretical and experimental groups working in a variety of fields, such as solid-state physics, electronics, optics, electrical engineering, material science, laser physics, etc. In this framework, events like the EDISON conference become a basic channel for the progress in the field. Here, researchers working in different areas can meet, present their latest advances and exchange their ideas. The program of EDISON'19 included 13 invited papers, 61 oral contributions and 73 posters. These contributions originated from scientists in more than 30 different countries. The Conference gathered 140 participants, coming from 24 different countries, most from Europe, but also with a significant participation

  12. Proceedings of 11. Conference on Electron Microscopy of Solids

    International Nuclear Information System (INIS)

    2002-01-01

    The conference is the cyclically organised discussion forum on problems connected with application of different electron microscopy techniques for the study of solid state materials. The main topics of 11 conference on Electron Microscopy of Solids held in Krynica (PL) in 2002 was: application of TEM in materials science; analytical techniques and orientation imaging in materials science; high resolution TEM in electronic materials; TEM and SEM application in ceramic and composites; advanced TEM techniques; advanced analytical and orientation imaging techniques; application of TEM in investigations of amorphous and nanocrystalline material; Intermetallic and superalloys; TEM application in martensite alloys; TEM and SEM application in research of iron base alloys; TEM studies of deformed alloys; TEM application in thin films and surface layer studies; TEM and SEM application in materials science

  13. Undulators and free-electron lasers

    CERN Document Server

    Luchini, P

    1990-01-01

    This book is a reference text for all those working in free-electron laser research as well as being a learning aid for physicists and graduate students who wish an introduction to this field. Only a basic understanding of relativistic mechanics and electromagnetism is presupposed. After an overview of early developments and general principles of operation, the different models that can be used to describe free-electron lasers are presented, organized according to their range of applicability. The relevent conceptual and mathematical constructs are built up from first principles with attention to obtaining the practically important results in a simple but rigorous way. Interaction of the undulator with the driving electron accelerator and the laser cavity and design of undulator magnets are treated and an overview is given of some typical experiments.

  14. Laser-pulsed relativistic electron gun

    International Nuclear Information System (INIS)

    Sherman, N.K.

    1986-01-01

    A relativistic (β ≅ 0.8) electron gun with good emittance and subnanosecond pulse duration which can be synchronized to picosecond laser pulses is being developed at NRC for use in studies of particle acceleration by lasers. Bursts of electron pulses exceeding 280 keV in energy have been extracted into air form a laser-driven vacuum photodiode. Trains of 5 ps pulses of ultraviolet UV light illuminate a magnesium cathode. Photoelectrons emitted from the cathode are accelerated in a graded electrostatic potential set up by a 360 kV Marx-generator. The UV pulses are obtained by doubling the frequency of a 606 nm dye laser modelocked at 160 MHz. Electron energies were measured by residual range in an echelon of Al foils. Total charge per burst was measured by picoammeter. Time structure of the bursts has been examined with plastic scintillator and a fast photomultiplier. Tests on a low voltage photodiode achieved a current density of 180 A/cm/sup 2/ from an Mg cathode, with quantum efficiency of 2.4 x 10/sup -6/ electron per UV photon. The brevity and intensity of the laser pulses cause the electric charge collected per pulse to increase linearly with bias voltage rather than according to the Langmuir-Child law. Gun emittance is about 150 mm-msr and beam brightness is about 1A/cm/sup 2/-sr. Estimated duration of individual electron pulses of a burst is about 400 ps with instantaneous current of about 0.1 mA. Energy spread within one pulse is expected to be about 15%. This gun has the potential to be a useful source of relativistic electrons for laser acceleration studies

  15. 5th International Conference on Electronics, Communications and Networks

    CERN Document Server

    2016-01-01

    This book comprises peer-reviewed contributions presented at the 5th International Conference on Electronics, Communications and Networks (CECNet 2015), held in Shanghai, China, 12-15 December, 2015. It includes new multi-disciplinary topics spanning a unique depth and breadth of cutting-edge research areas in Electronic Engineering, Communications and Networks, and Computer Technology. More generally, it is of interest to academics, students and professionals involved in Consumer Electronics Technology, Communication Engineering and Technology, Wireless Communication Systems and Technology, and Computer Engineering and Technology.

  16. Progress toward the Wisconsin Free Electron Laser

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  17. An inverse free electron laser accelerator experiment

    International Nuclear Information System (INIS)

    Wernick, I.; Marshall, T.C.

    1992-01-01

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

  18. Quantum aspects of the free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Gaiba, R.

    2007-03-15

    We study the role of Quantum Mechanics in the physics of Free Electron Lasers. While the Free Electron Laser (FEL) is usually treated as a classical device, we review the advantages of a quantum formulation of the FEL. We then show the existence of a regime of operation of the FEL that can only be described using Quantum Mechanics: if the dimensionless quantum parameter anti {rho} is smaller than 1, then in the 1-dimensional approximation the Hamiltonian that describes the FEL becomes equivalent to the Hamiltonian of a two-level system coupled to a radiation field. We give analytical and numerical solutions for the photon statistics of a Free Electron Laser operating in the quantum regime under various approximations. Since in the quantum regime the momentum of the electrons is discrete, we give a description of the electrons in phase space by introducing the Discrete Wigner Function. We then drop the assumption of a mono-energetic electron beam and describe the general case of a initial electron energy spread G({gamma}). Numerical analysis shows that the FEL quantum regime is observed only when the width of the initial momentum distribution is smaller than the momentum of the emitted photons. Both the analytical results in the linear approximation and the numerical simulations show that only the electrons close to a certain resonant energy start to emit photons. This generates the so-called Hole-burning effect in the electrons energy distribution, as it can be seen in the simulations we provide. Finally, we present a brief discussion about a fundamental uncertainty relation that ties the electron energy spread and the electron bunching. (orig.)

  19. Rippled beam free electron laser amplifier

    Science.gov (United States)

    Carlsten, Bruce E.

    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.

  20. Laser printed interconnects for flexible electronics

    Science.gov (United States)

    Pique, Alberto; Beniam, Iyoel; Mathews, Scott; Charipar, Nicholas

    Laser-induced forward transfer (LIFT) can be used to generate microscale 3D structures for interconnect applications non-lithographically. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or dispersed metallic nanoparticles. However, the resulting 3D structures do not achieve the bulk conductivity of metal interconnects of the same cross-section and length as those formed by wire bonding or tab welding. It is possible, however, to laser transfer entire structures using a LIFT technique known as lase-and-place. Lase-and-place allows whole components and parts to be transferred from a donor substrate onto a desired location with one single laser pulse. This talk will present the use of LIFT to laser print freestanding solid metal interconnects to connect individual devices into functional circuits. Furthermore, the same laser can bend or fold the thin metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief due to flexing or thermal mismatch. Examples of these laser printed 3D metallic bridges and their role in the development of next generation flexible electronics by additive manufacturing will be presented. This work was funded by the Office of Naval Research (ONR) through the Naval Research Laboratory Basic Research Program.

  1. Proceedings of the International Conference on Lasers 󈨜 Held in Lake Tahoe, Nevada on 4-9 December 1988.

    Science.gov (United States)

    1989-01-01

    Multiphoton Double Ionization of Ba T. F. Gallagher, R. R. Jones, Y. Ziiu, U. Eichmann +, and W. Sandner + Department of Physics University of Virginia... Eichmann , Y. Zhu and T. F. Gallagher J. Phys. B 20 4461 tions, not necessarily at the shortest wavelengths. This is contrary (1987). to much of our...and J. M. Watson; Abstract 13.18, 10th International Free-Electron Laser Conference, Jerusalem , Israel, August 29-September 2, 1988. 2. "High-Extraction

  2. Electron acceleration in a plane laser beam

    Czech Academy of Sciences Publication Activity Database

    Petržílka, Václav; Krlín, Ladislav; Tataronis, J. A.

    2002-01-01

    Roč. 52, supplement D (2002), s. 279-282 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : electron acceleration, laser beam Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  3. Electronic Subsystems For Laser Communication System

    Science.gov (United States)

    Long, Catherine; Maruschak, John; Patschke, Robert; Powers, Michael

    1992-01-01

    Electronic subsystems of free-space laser communication system carry digital signals at 650 Mb/s over long distances. Applicable to general optical communications involving transfer of great quantities of data, and transmission and reception of video images of high definition.

  4. Applications for Energy Recovering Free Electron Lasers

    Energy Technology Data Exchange (ETDEWEB)

    George Neil

    2007-08-01

    The availability of high-power, high-brilliance sources of tunable photons from energy-recovered Free Electron Lasers is opening up whole new fields of application of accelerators in industry. This talk will review some of the ideas that are already being put into production, and some of the newer ideas that are still under development.

  5. PREFACE: Plasma Physics by Laser and Applications 2013 Conference (PPLA2013)

    Science.gov (United States)

    Nassisi, V.; Giulietti, D.; Torrisi, L.; Delle Side, D.

    2014-04-01

    , Professor V Nassisi of Salento University, Professor D Giulietti of Pisa University and Professor L Torrisi of Messina University. The Scientific Committee was constituted by colleagues coming from different European laboratories: Dr F Belloni from European Commission, Bruxell, Belgium; Professor M Borghesi from the Queens University of Belfast, United Kingdom; Professor L Calcagno from Catania University, Italy; Professor D Giulietti from Pisa University, Italy; Dr J Krása from Academy of Science of Czech Republic, Prague; Professor V Malka from Laboratoire d'Optique Appliquée, Palaiseau, France; Professor V Nassisi from Salento University, Italy; Professor L Palladino from L'Aquila University, Italy; Professor L Torrisi from Messina University, Italy; Professor Ullschmied from Academy of Science of Czech Republic, Prague; Professor J Wolowski from Institute of Plasma Physics and Laser Microfusion of Warsaw, Poland and Dr J. Badziak from Institute of Plasma Physics and Laser Microfusion of Warsaw, Poland. The Local Organizing team was composed by: Dr G Buccolieri, Dr D Delle Side, Dr F Paladini and Dr L Velardi from Salento University and Dr M Cutroneo from Messina University. The Scientific secretariat was coordinated by Dr D. Dell'Anna from Salento University. The Topics discussed in the conference were: ·Laser-Matter interactions; ·Laser ion sources; ·Electron beam generation; ·Physics of non-equilibrium plasmas; ·Theoretical models in plasmas; ·Photons and particles emission from pulsed plasmas; ·Ion acceleration from plasma; ·Fs laser pulses; ·Pulsed laser deposition; ·Applications of laser beams and pulsed plasmas; ·Techniques of characterization of plasmas. The colleagues attending the conference were about 80. The Chairmen and Presidents of the different Conference sessions were: Professor V Nassisi, Professor D Giulietti, Professor L Torrisi, Professor M Borghesi, Dr K Rohlena (ASCR of Prague, Czech Republic), Professor D Neely (RAL, Oxon, UK), Dr J

  6. Los Alamos advanced free-electron laser

    Science.gov (United States)

    Chan, K. C. D.; Kraus, R. H.; Ledford, J.; Meier, K. L.; Meyer, R. E.; Nguyen, D.; Sheffield, R. L.; Sigler, F. L.; Young, L. M.; Wang, T. S.; Wilson, W. L.; Wood, R. L.

    1992-07-01

    Los Alamos researchers are building a free-electron laser (FEL) for industrial, medical, and research applications. This FEL, which will incorporate many of the new technologies developed over the last decade, will be compact, robust, and user-friendly. Electrons produced by a photocathode will be accelerated to 20 MeV by a high-brightness accelerator and transported by permanent-magnet quadrupoles and dipoles. The resulting electron beam will have an excellent instantaneous beam quality of 10πmm mrad in transverse emittance and 0.3% in energy spread at a peak current up to 300 A. Including operation at higher harmonics, the laser wavelength extends from 3.7 μm to 0.4 μm.

  7. Simulations of free electron laser

    International Nuclear Information System (INIS)

    Kwan, T.; Godfrey, B.B.

    1979-01-01

    The generation of coherent electromagnetic radiation by the interaction of a relativistic electron beam with a static helical magnetic field is investigated using one- and two-dimensional relativistic electromagnetic plasma simulation codes. In the one-dimensional simulations, we observed the coupling between the negative energy beam mode and the positive energy electromagnetic wave. Substantial growth rate (omega 1 approx. 0.1 omega/sub pe/) of the unstable electromagnetic wave has been observed and efficiency of radiation production is found to be between 25 to 30% depending on various parameters. In the two-dimensional simulations, we observed a decrease in the growth rate, but increased efficiency due to the decrease in the phase velocity of the unstable electrostatic wave. In addition, we also observed waves propagating at an angle with respect to the electron beam. Consequently, the beam is bunched in the radial as well as the axial directions. These waves are believed to be generated by another instability which saturates at relatively low level

  8. PREFACE: XXVIth International Conference on Photonic, Electronic and Atomic Collisions

    Science.gov (United States)

    Orel, Ann; Starace, Anthony F.; Nikolić, Dragan; Berrah, Nora; Gorczyca, Thomas W.; Kamber, Emanuel Y.; Tanis, John A.

    2009-12-01

    The XXVIth International Conference on Photonic, Electronic and Atomic Collisions was held on the campus of Western Michigan University (WMU) in Kalamazoo during 22-28 July 2009. Kalamazoo, the home of a major state university amid pleasant surroundings, was a delightful place for the conference. The 473 scientific participants, 111 of whom were students, had many fruitful discussions and exchanges that contributed to the success of the conference. Participants from 43 countries made the conference truly international in scope. The 590 abstracts that were presented on the first four days formed the heart of the conference and provided ample opportunity for discussion. This change, allowing the conference to end with invited talks, was a departure from the format used at previous ICPEAC gatherings in which the conferences ended with a poster session. The abstracts were split almost equally between the three main conference areas, i.e., photonic, electronic, and atomic collisions, and the posters were distributed across the days of the conference so that approximately equal numbers of abstracts in the different areas were scheduled for each day. Of the total number of presented abstracts, 517 of these are included in this proceedings volume, the first time that abstracts have been published by ICPEAC. There were 5 plenary lectures covering the different areas of the conference: Paul Corkum (University of Ottawa) talked on attosecond physics with atoms and molecules, Serge Haroche (Collège de France) on non-destructive photon counting, Toshiyuki Azuma (Tokyo Metropolitan University) on resonant coherent excitation of highly-charged ions in crystals, Eva Lindroth (Stockholm University) on atomic structure effects, and Alfred Müller (Justus Liebig University) on resonance phenomena in electron- and photon-ion collisions. Two speakers gave very illuminating public lectures that drew many people from the local area, as well as conference participants: Patricia Dehmer

  9. Two-stage free electron laser research

    Science.gov (United States)

    Segall, S. B.

    1984-10-01

    KMS Fusion, Inc. began studying the feasibility of two-stage free electron lasers for the Office of Naval Research in June, 1980. At that time, the two-stage FEL was only a concept that had been proposed by Luis Elias. The range of parameters over which such a laser could be successfully operated, attainable power output, and constraints on laser operation were not known. The primary reason for supporting this research at that time was that it had the potential for producing short-wavelength radiation using a relatively low voltage electron beam. One advantage of a low-voltage two-stage FEL would be that shielding requirements would be greatly reduced compared with single-stage short-wavelength FEL's. If the electron energy were kept below about 10 MeV, X-rays, generated by electrons striking the beam line wall, would not excite neutron resonance in atomic nuclei. These resonances cause the emission of neutrons with subsequent induced radioactivity. Therefore, above about 10 MeV, a meter or more of concrete shielding is required for the system, whereas below 10 MeV, a few millimeters of lead would be adequate.

  10. Contributions to the 1st Int. Conference on new laser technologies and applications

    International Nuclear Information System (INIS)

    1988-01-01

    The report contains ten papers contributing to the first International conference on new laser technologies held in Olympia from 19 to 23 June 1988. They represent the activities in this field carried out by the ENEA Department of Basic Technologies

  11. Smith-Purcell free-electron laser

    International Nuclear Information System (INIS)

    Woods, K.J.; Walsh, J.E.

    1995-01-01

    The term Smith-Purcell free electron laser can be employed generally to describe any coherent radiation source in which a diffraction grating is used to couple an electron beam with the electromagnetic field. To date, most practical developments of this concept have focused on devices which operate in the millimeter spectral regime. In this paper construction of a Smith-Purcell free-electron laser operating in the far-infrared (FIR) region using a novel resonator cavity design and the electron beam from a low energy (0.5-5 MeV) radio-frequency accelerator will be discussed. A tunable source in this region would have many applications and since the beam energy is low, the small size and low overall cost of such a device would make it a laboratory instrument. Current projects which are progressing towards developing a FIR source are the programs at Stanford and CREOL. Both of these projects are using permanent magnet undulators to couple the electron beam with the electromagnetic field. An alternative approach is to use an electron beam passing over a diffraction grating as the radiating mechanism. This phenomenon is known as Smith-Purcell radiation and was first demonstrated for incoherent emission at visible wavelengths. The addition of feedback enhances the stimulated component of the emission which leads to the growth of coherence. Recent calculations for spontaneous emission have shown that the wiggler parameter and the grating efficiency are analogous. This result has important implications for the development of a Smith-Purcell FEL because a grating based free-electron laser would offer a greater range of tunability at a lower cost than its wiggler based counterpart

  12. Polarization in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    1995-12-31

    Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.

  13. International Conference on NextGen Electronic Technologies

    CERN Document Server

    Thalmann, Nadia; Bhaaskaran, V

    2017-01-01

    This book is a collection of keynote lectures from international experts presented at International Conference on NextGen Electronic Technologies (ICNETS2-2016). ICNETS2 encompasses six symposia covering all aspects of electronics and communications domains, including relevant nano/micro materials and devices . This volume comprises of recent research in areas like computational signal processing analysis, intelligent embedded systems, nanoelectronic materials and devices, optical and microwave technologies, VLSI design: circuits systems and application, and wireless communication networks, and the internet of things. The contents of this book will be useful to researchers, professionals, and students working in the core areas of electronics and their applications, especially to signal processing, embedded systems, and networking.

  14. 31. European Conference on Laser Interaction with Matter. Book of abstracts

    International Nuclear Information System (INIS)

    2010-01-01

    The ECLIM conferences on the field of high intensity laser-matter interactions. In this year has the 50th anniversary of Maiman's first laser. ECLIM is a conference for all types of laser-matter interactions, especially for those occurring at high power. New lasers, new ideas are traditionally welcome. Applications as inertial fusion energy have been the driving force in the last decades towards increasing laser intensity, and toward the discovery of new, nonlinear interactions. This time the organizers want to open the doors even broader toward short-pulse laser-plasma interactions and attophysics, organizing even special session for the Extreme Light Infrastructure (ELI). ECLIM is this time hosted the first time in Hungary, one of the sites of the future's great undertaking, the ELI laser. (S.I.)

  15. Inverse free-electron laser accelerator development

    International Nuclear Information System (INIS)

    Fisher, A.; Gallardo, J.; Steenbergen, A. van; Sandweiss, J.; Fang, J.M.

    1994-06-01

    The study of the Inverse Free-Electron Laser, as a potential mode of electron acceleration, has been pursued at Brookhaven National Laboratory for a number of years. More recent studies focused on the development of a low energy (few GeV), high gradient, multistage linear accelerator. The authors are presently designing a short accelerator module which will make use of the 50 MeV linac beam and high power (2 x 10 11 W) CO 2 laser beam of the Accelerator Test Facility (ATF) at the Center for Accelerator Physics (CAP), Brookhaven National Laboratory. These elements will be used in conjunction with a fast excitation (300 μsec pulse duration) variable period wiggler, to carry out an accelerator demonstration stage experiment

  16. Elsa: an infrared free electron laser

    International Nuclear Information System (INIS)

    Guimbal, P.; Chaix, P.

    1998-01-01

    Since the first experiments, twenty years ago, free-electron lasers (FEL) have known a strong development because of their promise: broadband tunability from X-rays to microwaves and high (peak or average) power, limited only by technological issues. ELSA has been designed as a research tool to investigate the physics of high-power FELs. After a brief introduction of the FEL field of research, we point out the unique characteristics of ELSA and why it is a valuable tool for the study of FEL interaction in the strong electron-photon coupling. The main experimental results are reviewed. We conclude on the concept of Two-Frequency-Wiggler. (author)

  17. Laser system for a subpicosecond electron linac

    International Nuclear Information System (INIS)

    Crowell, R. A.

    1998-01-01

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions

  18. The waveguide Free-Electron Laser. 14

    International Nuclear Information System (INIS)

    Walsh, J.E.

    1990-01-01

    The general characteristics of free-electron lasers (FELs) which employ a waveguiding structure to confine electromagnetic fields and to couple them to the electron beam is discussed. The mode structure of the basic parallel plate waveguide and its adaptation via quasi-optical techniques to FEL resonator design are considered in detail. A summary of the theory of FEL systems which depend intrinsically on a guide structure (micro-undulator, Cerenkov and metal-grating FELs) and a review of progress on waveguide FEL experiments are also presented. (author). 44 refs.; 16 figs

  19. The laser-matter interaction. Press conference wednesday 17 november 1999; L'interaction laser-matiere. Conference de presse mercredi 17 novembre 1999

    Energy Technology Data Exchange (ETDEWEB)

    Cohen-Tannoudji, C. [Ecole Normale Superieure, Dept. de Physique, 75 - Paris (France); Mons, M.; Schmidt, M.; Salieres, P. [CEA/Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, DRECAM, 91 - Gif-sur-Yvette (France); Chieze, J.P. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee, DAPNIA, 91 - Gif-sur-Yvette (France)

    1999-11-01

    During the press conference of wednesday 17 november 1999, scientists of the CEA presented the knowledge and the researches in the domain of the laser-matter interactions. The possibilities of the new ultra-short pulses laser offer to study in real time the molecular dynamic, the molecules and chemical reactions vibrations. The texts of the five speeches form this paper. The CEA missions are also recalled. (A.L.B.)

  20. High-efficiency free-electron laser results

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  1. PREFACE: ISEC 2005: The 10th International Superconductive Electronics Conference

    Science.gov (United States)

    Rogalla, Horst

    2006-05-01

    The 10th International Superconductive Electronics Conference took place in Noordwijkerhout in the Netherlands, 5-9 September 2005, not far from the birthplace of superconductivity in Leiden nearly 100 years ago. There have been many reasons to celebrate the 10th ISEC: not only was it the 20th anniversary, but also the achievements since the first conference in Tokyo in 1987 are tremendous. We have seen whole new groups of superconductive materials come into play, such as oxide superconductors with maximum Tc in excess of 100 K, carbon nanotubes, as well as the realization of new digital concepts from saturation logic to the ultra-fast RSFQ-logic. We have learned that superconductors not only show s-wave symmetries in the spatial arrangement of the order parameter, but also that d-wave dependence in oxide superconductors is now well accepted and can even be successfully applied to digital circuits. We are now used to operating SQUIDs in liquid nitrogen; fT sensitivity of SQUID magnetometers is not surprising anymore and can even be reached with oxide-superconductor based SQUIDs. Even frequency discriminating wide-band single photon detection with superconductive devices, and Josephson voltage standards with tens of thousands of junctions, nowadays belong to the daily life of advanced laboratories. ISEC has played a very important role in this development. The first conferences were held in 1987 and 1989 in Tokyo, and subsequently took place in Glasgow (UK), Boulder (USA), Nagoya (Japan), Berlin (Germany), Berkeley (USA), Osaka (Japan), Sydney (Australia), and in 2005 for the first time in the Netherlands. These conferences have provided platforms for the presentation of the research and development results of this community and for the vivid discussion of achievements and strategies for the further development of superconductive electronics. The 10th conference has played a very important role in this context. The results in laboratories show great potential and

  2. Request for Support for the Conference on Super Intense Laser Atom Physics

    International Nuclear Information System (INIS)

    Todd Ditmire

    2004-01-01

    The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions

  3. First International Conference on Electrical, Electronic and Communications Engineering

    CERN Document Server

    Vyas, Nalinaksh; Sanei, Saeid; Deb, Kalyanmoy

    2017-01-01

    The book reports on advanced theories and methods in two related engineering fields: electrical and electronic engineering, and communications engineering and computing. It highlights areas of global and growing importance, such as renewable energy, power systems, mobile communications, security and the Internet of Things (IoT). The contributions cover a number of current research issues, including smart grids, photovoltaic systems, wireless power transfer, signal processing, 4G and 5G technologies, IoT applications, mobile cloud computing and many more. Based on the proceedings of the first International Conference on Emerging Trends in Electrical, Electronic and Communications Engineering (ELECOM 2016), held in Voila Bagatelle, Mauritius from November 25 to 27, 2016, the book provides graduate students, researchers and professionals with a snapshot of the state-of-the-art and a source of new ideas for future research and collaborations.

  4. Wave function of free electron in a strong laser plasma

    International Nuclear Information System (INIS)

    Zhu Shitong; Shen Wenda; Guo Qizhi

    1993-01-01

    The wave function of free electron in a strong laser plasma is obtained by solving exactly the Dirac equation in a curved space-time with optical metric for the laser plasma. When the laser field is diminished to zero, the wave function is naturally reduced to relativistic wave function of free electron. The possible application of the wave function is discussed

  5. Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies

    Science.gov (United States)

    Bhatia, Anand

    2012-01-01

    We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.

  6. An Inverse Free-Electron-Laser accelerator

    International Nuclear Information System (INIS)

    Fisher, A.S.; Gallardo, J.C.; van Steenbergen, A.; Ulc, S.; Woodle, M.; Sandweiss, J.; Fang, Jyan-Min

    1993-01-01

    Recent work at BNL on electron acceleration using the Inverse Free-Electron Laser (IFEL) has considered a low-energy, high-gradient, multi-stage linear accelerator. Experiments are planned at BNL's Accelerator Test Facility using its 50-MeV linac and 100-GW CO 2 laser. We have built and tested a fast-excitation wiggler magnet with constant field, tapered period, and overall length of 47 cm. Vanadium-Permendur ferromagnetic laminations are stacked in alternation with copper, eddy-current-induced, field reflectors to achieve a 1.4-T peak field with a 4-mm gap and a typical period of 3 cm. The laser beam will pass through the wiggler in a low-loss, dielectric-coated stainless-steel, rectangular waveguide. The attenuation and transverse mode has been measured in waveguide sections of various lengths, with and without the dielectric. Results of 1-D and 3-D IFEL simulations, including wiggler errors, will be presented for several cases: the initial, single-module experiment with ΔE = 39 MeV, a four-module design giving ΔE = 100 MeV in a total length of 2 m, and an eight-module IFEL with ΔE = 210 MeV

  7. High gain free electron laser at ETA

    International Nuclear Information System (INIS)

    Orzechowski, T.J.; Prosnitz, D.; Halbach, K.

    1983-01-01

    A single pass, tapered electron wiggler and associated beam transport has been constructed at the Experimental Test Accelerator (ETA) at Lawrence Livermore National Laboratory (LLNL). The system is designed to transport 1 kA of 4.5 MeV electrons with an emittance of 30 millirad-cm. The planar wiggler is provided by a pulsed electromagnet. The interaction region is an oversized rectangular waveguide. Quadrupole fields stabilize the beam in the plane parallel to the wiggler field. The 3 meter long wiggler has a 9.8 cm period. The Free Electron Laser (FEL) will serve as an amplifier for input frequencies of 35 GHz and 140 GHz. The facility is designed to produce better than 500 Megawatts peak power

  8. Free-electron lasers in ultraviolet photobiology

    International Nuclear Information System (INIS)

    Coohill, T.P.; Sutherland, J.C.

    1989-01-01

    The potential uses for a free-electron laser (FEL), tunable in wavelength from 10 to 400 nm, for photobiological experiments is discussed. Inherent problems of cell and molecular absorption, especially in certain regions of the ultraviolet (UV), are addressed. Absorption values for living cells and viruses at selected wavelengths in the UV are tabulated, and a calculation of the flux needed to inactivate mammalian cells is included. A comparison is made of the UV output of a proposed rf-linac FEL with those of a monochromator, a tunable dye laser, and a synchrotron. The advantages of a UV FEL are apparent, especially in the wavelength regions where the cross section for absorption by biological molecules is low, i.e., 300 to 400 nm and 10 to 200 nm. It is apparent that a UV FEL would be an ideal source for a variety of biological studies that use both intact organisms and isolated cells and viruses

  9. Free electron laser and fundamental physics

    Science.gov (United States)

    Dattoli, Giuseppe; Nguyen, Federico

    2018-03-01

    This review paper is devoted to the understanding of free-electron lasers (FEL) as devices for fundamental physics (FP) studies. After clarifying what FP stands for, we select some aspects of the FEL physics which can be viewed as fundamental. Furthermore, we discuss the perspective uses of the FEL in FP experiments. Regarding the FP aspects of the FEL, we analyze the quantum electrodynamics (QED) nature of the underlying laser mechanism. We look for the truly quantum signature in a process whose phenomenology is dominated by classical effects. As to the use of FEL as a tool for FP experiments we discuss the realization of a device dedicated to the study of non-linear effects in QED such as photon-photon scattering and shining-through-the-wall experiments planned to search for dark matter candidates like axions.

  10. DISCOURSE AND PARTICIPATION IN ESL FACE-TO-FACE AND WRITTEN ELECTRONIC CONFERENCES

    Directory of Open Access Journals (Sweden)

    Michael Fitze

    2006-01-01

    Full Text Available This study was a comparative investigation of face-to-face and written electronic conferences. The participants were advanced English as a second language (hereafter: ESL students. The two types of conferences were compared in terms of textual features and participation. There was no statistically significant difference in the total number of words that students produced in an equivalent amount of time in the two types of conferences. The discourse in written electronic conferences displayed greater lexical range, and students in these conferences produced more discourse demonstrating interactive competence. The statistically significant finding of increased lexical range in written electronic conferences persisted even when the interactive discourse was eliminated from the conference transcripts and the transcripts were reanalyzed. This finding suggests that, during written electronic conferences, students were better able to use and practice a wider range of vocabulary related to the topics. For one of the groups, participation in written electronic conferences was more balanced among students, while for the other group participation was about equally balanced regardless of the conference setting. This last finding came as a surprise and points to a need for further research into variables that might mediate balanced participation in face-to-face and written electronic conferences.

  11. PREFACE: XXIX International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC2015)

    Science.gov (United States)

    Díaz, C.; Rabadán, I.; García, G.; Méndez, L.; Martín, F.

    2015-09-01

    The 29th International Conference on Photonic, Electronic and Atomic Collisions (XXIX ICPEAC) was held at the Palacio de Congresos ''El Greco'', Toledo, Spain, on 22-28 July, 2015, and was organized by the Universidad Autónoma de Madrid (UAM) and the Consejo Superior de Investigaciones Científicas (CSIC). ICPEAC is held biannually and is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, and atomic collisions with matter. With a history back to 1958, ICPEAC came to Spain in 2015 for the very first time. UAM and CSIC had been preparing the conference for six years, ever since the ICPEAC International General Committee made the decision to hold the XXIX ICPEAC in Toledo. The conference gathered 670 participants from 52 countries and attracted 854 contributed papers for presentation in poster sessions. Among the latter, 754 are presented in issues 2-12 of this volume of the Journal of Physics Conference Series. In addition, five plenary lectures, including the opening one by the Nobel laureate Prof. Ahmed H. Zewail and the lectures by Prof. Maciej Lewenstein, Prof. Paul Scheier, Prof. Philip H. Bucksbaum, and Prof. Stephen J. Buckman, 62 progress reports and 26 special reports were presented following the decision of the ICPEAC International General Committee. Detailed write-ups of most of the latter are presented in issue 1 of this volume, constituting a comprehensive tangible record of the meeting. On the occasion of the International Year of Light (IYL2015) and with the support of the Fundación Española para la Ciencia y la Tecnología (FECYT), the program was completed with two public lectures delivered by the Nobel laureate Prof. Serge Haroche and the Príncipe de Asturias laureate Prof. Pedro M. Echenique on, respectively, ''Fifty years of laser revolutions in physics'rquot; and ''The sublime usefulness of useless science''. Also a

  12. Kinetic theory of free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Hafizi, B. [Naval Research Lab., Washington, DC (United States); Roberson, C.W. [Office of Naval Research, Arlington, VA (United States)

    1995-12-31

    We have developed a relativistic kinetic theory of free electron lasers (FELs). The growth rate, efficiency, filling factor and radius of curvature of the radiation wave fronts are determined. We have used the theory to examine the effects of beam compression on growth rate. The theory has been extended to include self field effects on FEL operation. These effects are particularly important in compact, low voltage FELs. The surprising result is that the self field contribution to the beam quality is opposite to the emittance contribution. Hence self fields can improve beam quality, particularly in compact, low voltage FELs.

  13. Free electron lasers on superconducting linac

    International Nuclear Information System (INIS)

    Lapierrre, Y.

    1986-01-01

    Analysing the results of several Free Electron Laser experiments, we show that the best accelerator should be a superconducting linear accelerator: it can provide a c.w. high quality beam (energy spread and emittance). The technology of RF superconductivity provide the opportunity to build such an accelerator. In this paper, we present the foreseen results one can expect from a FEL based on such a machine: - Average power > 1 Kw, - Total efficiency > 2.5%, - Tunability between 0.6 and 5 μm [fr

  14. The free electron laser: conceptual history

    International Nuclear Information System (INIS)

    Madey, John; Scully, Marlan O; Sprangle, Phillip

    2016-01-01

    The free electron laser (FEL) has lived up to its promise as given in (Madey 1971 J. Appl. Phys. 42 1906) to wit: ‘As shall be seen, finite gain is available …from the far-infrared through the visible region …with the further possibility of partially coherent radiation sources in the x-ray region’. In the present paper we review the history of the FEL drawing liberally (and where possible literally) from the original sources. Coauthors, Madey, Scully and Sprangle were involved in the early days of the subject and give a first hand account of the subject with an eye to the future. (invited comment)

  15. X-ray Free-electron Lasers

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-23

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

  16. Externally Controlled Injection of Electrons by a Laser Pulse in a Laser Wakefield Electron Accelerator

    CERN Document Server

    Chen Szu Yuan; Chen Wei Ting; Chien, Ting-Yei; Lee, Chau-Hwang; Lin, Jiunn-Yuan; Wang, Jyhpyng

    2005-01-01

    Spatially and temporally localized injection of electrons is a key element for development of plasma-wave electron accelerator. Here we report the demonstration of two different schemes for electron injection in a self-modulated laser wakefield accelerator (SM-LWFA) by using a laser pulse. In the first scheme, by implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. We found that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the pump pulse. In the second scheme, by using a transient density ramp we achieve self-injection of electrons in a SM-LWFA with spatial localization. The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated wi...

  17. Short Rayleigh Length Free Electron Lasers

    CERN Document Server

    Crooker, P P; Armstead, R L; Blau, J

    2004-01-01

    Conventional free electron laser (FEL) oscillators minimize the optical mode volume around the electron beam in the undulator by making the resonator Rayleigh length about one third of the undulator length. This maximizes gain and beam-mode coupling. In compact configurations of high-power infrared FELs or moderate power UV FELs, the resulting optical intensity can damage the resonator mirrors. To increase the spot size and thereby reduce the optical intensity at the mirrors below the damage threshold, a shorter Rayleigh length can be used, but the FEL interaction is significantly altered. A new FEL interaction is described and analyzed with a Rayleigh length that is only one tenth the undulator length, or less. The effect of mirror vibration and positioning are more critical in the short Rayleigh length design, but we find that they are still within normal design tolerances.

  18. Free electron laser variable bridge coupler

    International Nuclear Information System (INIS)

    Spalek, G.; Billen, J.H.; Garcia, J.A.; McMurry, D.E.; Harnsborough, L.D.; Giles, P.M.; Stevens, S.B.

    1985-01-01

    The Los Alamos free-electron laser (FEL) is being modified to test a scheme for recovering most of the power in the residual 20-MeV electron beam by decelerating the microbunches in a linear standing-wave accelerator and using the recovered energy to accelerate new beam. A variable-coupler low-power model that resonantly couples the accelerator and decelerator structures has been built and tested. By mixing the TE 101 and TE 102 modes, this device permits continuous variation of the decelerator fields relative to the accelerator fields through a range of 1:1 to 1:2.5. Phase differences between the two structures are kept below 1 0 and are independent of power-flow direction. The rf power is also fed to the two structures through this coupling device. Measurements were also made on a three-post-loaded variable coupler that is a promising candidate for the same task

  19. Workshop on scientific and industrial applications of free electron lasers

    International Nuclear Information System (INIS)

    Difilippo, F.C.; Perez, R.B.

    1990-05-01

    A Workshop on Scientific and Industrial Applications of Free Electron Lasers was organized to address potential uses of a Free Electron Laser in the infrared wavelength region. A total of 13 speakers from national laboratories, universities, and the industry gave seminars to an average audience of 30 persons during June 12 and 13, 1989. The areas covered were: Free Electron Laser Technology, Chemistry and Surface Science, Atomic and Molecular Physics, Condensed Matter, and Biomedical Applications, Optical Damage, and Optoelectronics

  20. EDITORIAL: Electron Microscopy and Analysis Group Conference 2011 (EMAG 2011)

    Science.gov (United States)

    Moebus, Guenter; Walther, Thomas; Brydson, Rik; Ozkaya, Dogan; MacLaren, Ian; Donnelly, Steve; Nellist, Pete; Li, Ziyou; Baker, Richard; Chiu, YuLung

    2012-07-01

    The biennial EMAG conference has established a strong reputation as a key event for the national and international electron microscopy community. In 2011 the meeting was held at The University of Birmingham, and I must first take this opportunity of thanking Birmingham for hosting the conference and for the excellent support we received from the local organisers. As a committee, we are delighted to see that enthusiasm for the EMAG conference series continues to be strong. We received more than 160 submitted abstracts, and 157 delegates attended the meeting. The scientific programme organiser, Ian MacLaren, put together an exciting programme. Plenary lectures were presented by Professor Knut Urban, Dr Frances Ross and Dr Richard Henderson. There were a further 10 invited speakers, from the UK, Continental Europe, Australia, the USA and Japan. The quality of the contributed oral and poster presentations was also very high. EMAG is keen to encourage student participation, and a winner and two runners-up were presented with prizes for the best oral and poster presentations from a student. I am always struck by the scientific quality of the oral and poster contributions and the vibrant discussions that occur both in the formal sessions and in the exhibition space at EMAG. I am convinced that a crucial part of maintaining that scientific quality is the opportunity that is offered of having a paper fully reviewed by two internationally selected referees and published in the Journal of Physics: Conference Series. For many students, this is the first fully reviewed paper they publish. I hope that you, like me, will be struck by the scientific quality of the 87 papers that follow, and that you will find them interesting and informative. Finally I must thank the platinum sponsors for their support of the meeting. These were Gatan, Zeiss, FEI, JEOL and Hitachi. I must also thank the European Microscopy Society for their generous sponsorship and support for the travel costs of

  1. Applications of laser printing for organic electronics

    Science.gov (United States)

    Delaporte, Ph.; Ainsebaa, A.; Alloncle, A.-P.; Benetti, M.; Boutopoulos, C.; Cannata, D.; Di Pietrantonio, F.; Dinca, V.; Dinescu, M.; Dutroncy, J.; Eason, R.; Feinaugle, M.; Fernández-Pradas, J.-M.; Grisel, A.; Kaur, K.; Lehmann, U.; Lippert, T.; Loussert, C.; Makrygianni, M.; Manfredonia, I.; Mattle, T.; Morenza, J.-L.; Nagel, M.; Nüesch, F.; Palla-Papavlu, A.; Rapp, L.; Rizvi, N.; Rodio, G.; Sanaur, S.; Serra, P.; Shaw-Stewart, J.; Sones, C. L.; Verona, E.; Zergioti, I.

    2013-03-01

    The development of organic electronic requires a non contact digital printing process. The European funded e-LIFT project investigated the possibility of using the Laser Induced Forward Transfer (LIFT) technique to address this field of applications. This process has been optimized for the deposition of functional organic and inorganic materials in liquid and solid phase, and a set of polymer dynamic release layer (DRL) has been developed to allow a safe transfer of a large range of thin films. Then, some specific applications related to the development of heterogeneous integration in organic electronics have been addressed. We demonstrated the ability of LIFT process to print thin film of organic semiconductor and to realize Organic Thin Film Transistors (OTFT) with mobilities as high as 4 10-2 cm2.V-1.s-1 and Ion/Ioff ratio of 2.8 105. Polymer Light Emitting Diodes (PLED) have been laser printed by transferring in a single step process a stack of thin films, leading to the fabrication of red, blue green PLEDs with luminance ranging from 145 cd.m-2 to 540 cd.m-2. Then, chemical sensors and biosensors have been fabricated by printing polymers and proteins on Surface Acoustic Wave (SAW) devices. The ability of LIFT to transfer several sensing elements on a same device with high resolution allows improving the selectivity of these sensors and biosensors. Gas sensors based on the deposition of semiconducting oxide (SnO2) and biosensors for the detection of herbicides relying on the printing of proteins have also been realized and their performances overcome those of commercial devices. At last, we successfully laser-printed thermoelectric materials and realized microgenerators for energy harvesting applications.

  2. Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities

    International Nuclear Information System (INIS)

    Chen, H.; Shepherd, R.; Chung, H. K.; Kemp, A.; Hansen, S. B.; Wilks, S. C.; Ping, Y.; Widmann, K.; Fournier, K. B.; Beiersdorfer, P.; Dyer, G.; Faenov, A.; Pikuz, T.

    2007-01-01

    We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10 17 , 10 18 , and 10 19 W/cm 2 , using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kα generation, collisional coupling, and plasma expansion

  3. Synchronization of sub-picosecond electron and laser pulses

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Le Sage, G.P.

    1999-01-01

    Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is sub-picosecond, with tens of femtosecond synchronization implied for next generation experiments. The design of a microwave timing modulator system is now being investigated in more detail. (AIP) copyright 1999 American Institute of Physics

  4. Laser applications in the electronics and optoelectronics industry in Japan

    Science.gov (United States)

    Washio, Kunihiko

    1999-07-01

    This paper explains current status and technological trends in laser materials processing applications in electronics and optoelectronics industry in Japan. Various laser equipment based on solid state lasers or gas lasers such as excimer lasers or CO2 lasers has been developed and applied in manufacturing electronic and optoelectronic devices to meet the strong demands for advanced device manufacturing technologies for high-performance, lightweight, low power-consumption portable digital electronic appliances, cellular mobile phones, personal computers, etc. Representative applications of solid-state lasers are, opaque and clear defects repairing of photomasks for LSIs and LCDs, trimming of thick-film chip resistors and low resistance metal resistors, laser cutting and drilling of thin films for high-pin count semiconductor CSP packages, laser patterning of thin-film amorphous silicon solar cells, and laser welding of electronic components such as hard-disk head suspensions, optical modules, miniature relays and lithium ion batteries. Compact and highly efficient diode- pumped and Q-switched solid-state lasers in second or third harmonic operation mode are now being increasingly incorporated in various laser equipment for fine material processing. Representative applications of excimer lasers are, sub-quarter micron design-rule LSI lithography and low- temperature annealing of poly-silicon TFT LCD.

  5. Short Rayleigh length free electron lasers

    Directory of Open Access Journals (Sweden)

    W. B. Colson

    2006-03-01

    Full Text Available Conventional free electron laser (FEL oscillators minimize the optical mode volume around the electron beam in the undulator by making the resonator Rayleigh length about one third to one half of the undulator length. This maximizes gain and beam-mode coupling. In compact configurations of high-power infrared FELs or moderate power UV FELs, the resulting optical intensity can damage the resonator mirrors. To increase the spot size and thereby reduce the optical intensity at the mirrors below the damage threshold, a shorter Rayleigh length can be used, but the FEL interaction is significantly altered. We model this interaction using a coordinate system that expands with the rapidly diffracting optical mode from the ends of the undulator to the mirrors. Simulations show that the interaction of the strongly focused optical mode with a narrow electron beam inside the undulator distorts the optical wave front so it is no longer in the fundamental Gaussian mode. The simulations are used to study how mode distortion affects the single-pass gain in weak fields, and the steady-state extraction in strong fields.

  6. The Two-Beam Free Electron Laser Oscillator

    CERN Document Server

    Thompson, Neil R

    2004-01-01

    A one-dimensional model of a free-electron laser operating simultaneously with two electron beams of different energies [1] is extended to an oscillator configuration. The electron beam energies are chosen so that an harmonic of the lower energy beam is at the fundamental radiation wavelength of the higher energy beam. Potential benefits over a single-beam free-electron laser oscillator are discussed.

  7. Ultrafast magnetodynamics with free-electron lasers

    Science.gov (United States)

    Malvestuto, Marco; Ciprian, Roberta; Caretta, Antonio; Casarin, Barbara; Parmigiani, Fulvio

    2018-02-01

    The study of ultrafast magnetodynamics has entered a new era thanks to the groundbreaking technological advances in free-electron laser (FEL) light sources. The advent of these light sources has made possible unprecedented experimental schemes for time-resolved x-ray magneto-optic spectroscopies, which are now paving the road for exploring the ultimate limits of out-of-equilibrium magnetic phenomena. In particular, these studies will provide insights into elementary mechanisms governing spin and orbital dynamics, therefore contributing to the development of ultrafast devices for relevant magnetic technologies. This topical review focuses on recent advancement in the study of non-equilibrium magnetic phenomena from the perspective of time-resolved extreme ultra violet (EUV) and soft x-ray spectroscopies at FELs with highlights of some important experimental results.

  8. Imaging femtosecond laser-induced electronic excitation in glass

    International Nuclear Information System (INIS)

    Mao Xianglei; Mao, Samuel S.; Russo, Richard E.

    2003-01-01

    While substantial progress has been achieved in understanding laser ablation on the nanosecond and picosecond time scales, it remains a considerable challenge to elucidate the underlying mechanisms during femtosecond laser material interactions. We present experimental observations of electronic excitation inside a wide band gap glass during single femtosecond laser pulse (100 fs, 800 nm) irradiation. Using a femtosecond time-resolved imaging technique, we measured the evolution of a laser-induced electronic plasma inside the glass and calculated the electron number density to be on the order of 10 19 cm -3

  9. Nonlinear theory of the free-electron laser

    International Nuclear Information System (INIS)

    Chian, A.C.-L.; Padua Brito Serbeto, A. de.

    1984-01-01

    A theory of Raman free-electron laser using a circularly polarized electromagnetic pump is investigated. Coupled wave equations that describe both linear and nonlinear evolution of stimulated Raman scattering are derived. The dispersion relation and the growth rate for the parametric instability are obtained. Nonlinear processes that may lead to saturation of the free-electron laser are discussed. (Author) [pt

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

    Science.gov (United States)

    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.

  11. CERN's web application updates for electron and laser beam technologies

    CERN Document Server

    Sigas, Christos

    2017-01-01

    This report describes the modifications at CERN's web application for electron and laser beam technologies. There are updates at both the front and the back end of the application. New electron and laser machines were added and also old machines were updated. There is also a new feature for printing needed information.

  12. Optimizing chirped laser pulse parameters for electron acceleration in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Akhyani, Mina; Jahangiri, Fazel; Niknam, Ali Reza; Massudi, Reza, E-mail: r-massudi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983969411 (Iran, Islamic Republic of)

    2015-11-14

    Electron dynamics in the field of a chirped linearly polarized laser pulse is investigated. Variations of electron energy gain versus chirp parameter, time duration, and initial phase of laser pulse are studied. Based on maximizing laser pulse asymmetry, a numerical optimization procedure is presented, which leads to the elimination of rapid fluctuations of gain versus the chirp parameter. Instead, a smooth variation is observed that considerably reduces the accuracy required for experimentally adjusting the chirp parameter.

  13. Proceedings of 8. national conference on nuclear electronic and nuclear detection technology: Pt.1

    International Nuclear Information System (INIS)

    1996-01-01

    The 8th National Conference on Nuclear Electronics and Nuclear Detection Technology was held during 2-7, 12, 1996 in Zhuhai, Guangdong, China. 184 pieces of papers were collected in the conference proceedings. The contents of the conference proceedings are: nuclear electronics, nuclear detectors, nuclear instruments and its application, nuclear medical electronics, computer applications in nuclear sciences and technology, measurement of nuclear monitoring and nuclear explosion, radiation hardened electronics, liquid scintillation counting techniques and miscellaneous. Reported hereafter is the first part of the proceedings

  14. PREFACE: International Conference on Strongly Correlated Electron Systems (SCES 2011)

    Science.gov (United States)

    Littlewood, P. B.; Lonzarich, G. G.; Saxena, S. S.; Sutherland, M. L.; Sebastian, S. E.; Artacho, E.; Grosche, F. M.; Hadzibabic, Z.

    2012-11-01

    The Strongly Correlated Electron Systems Conference (SCES) 2011, was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 was dedicated to 100 years of superconductivity and covered a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The meeting welcomed to Cambridge 657 participants from 23 countries, who presented 127 talks (including 16 plenary, 57 invited, and 54 contributed) and 736 posters in 40 sessions over five full days of meetings. This proceedings volume contains papers reporting on the science presented at the meeting. This work deepens our understanding of the rich physical phenomena that arise from correlation effects. Strongly correlated systems are known for their remarkable array of emergent phenomena: the traditional subjects of superconductivity, magnetism and metal-insulator transitions have been joined by non-Fermi liquid phenomena, topologically protected quantum states, atomic and photonic gases, and quantum phase transitions. These are some of the most challenging and interesting phenomena in science. As well as the science driver, there is underlying interest in energy-dense materials, which make use of 'small' electrons packed to the highest possible density. These are by definition 'strongly correlated'. For example: good photovoltaics must be efficient optical absorbers, which means that photons will generate tightly bound electron-hole pairs (excitons) that must then be ionised at a heterointerface and transported to contacts; efficient solid state refrigeration depends on substantial entropy changes in a unit cell, with large local electrical or magnetic moments; efficient lighting is in a real sense the inverse of photovoltaics; the limit of an efficient battery is a supercapacitor employing mixed valent ions; fuel cells and solar to fuel conversion

  15. 11th International Conference on X-Ray Lasers

    CERN Document Server

    Lewis, Ciaran L. S; X-Ray Lasers 2008

    2009-01-01

    This book provides a thorough account of the current status of achievements made in the area of soft X-ray laser source development and of the increasingly diverse applications being demonstrated using such radiation sources. There is significant effort worldwide to develop very bright, short duration radiation sources in the X-ray spectral region – driven by the multitude of potential applications in all branches of science. This book contains updates on several different approaches for comparative purposes but concentrates on developments in the area of laser-produced plasmas, whereby transient population inversion and gain between ion states is pumped by optical lasers interacting with pre-formed plasmas. The most significant development here is the demonstrated increasing feasibility to produce useful soft X-ray laser beams with high repetition rates in a typical, small, university-class laboratory – as opposed to the requirement of access to a national facility some 20 years ago. Experimental progres...

  16. Chaotic behaviour and controlling chaos in free electron lasers

    International Nuclear Information System (INIS)

    Wang Wenjie; Chen Shigang; Du Xiangwan; Wang Guangrui

    1995-01-01

    Chaos in free electron lasers (FEL) is reviewed. Special attention has been paid to the chaotic behaviour of the electrons and the laser field. The problem of controlling and utilizing chaotic motion of the electrons and the laser field has also been discussed. In order to find out the rules of instability and chaos in FEL, some typical methods of the chaotic theory are used. These methods include making the Poincare surface of section, drawing the phase space diagrams of the electron orbits, calculating the Liapunov exponents, and computing the power spectrum, etc. Finally, some problems in FEL research are discussed (103 refs., 54 figs.)

  17. Electronic properties of asymmetrical quantum dots dressed by laser field

    Energy Technology Data Exchange (ETDEWEB)

    Kibis, O.V. [Department of Applied and Theoretical Physics, Novosibirsk State Technical University, Karl Marx Avenue 20, 630092 Novosibirsk (Russian Federation); Slepyan, G.Ya.; Maksimenko, S.A. [Institute for Nuclear Problems, Belarus State University, Bobruyskaya St. 11, 220050 Minsk (Belarus); Hoffmann, A. [Institut fuer Festkoerperphysik, Technische Universitaet Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany)

    2012-05-15

    In the present paper, we demonstrate theoretically that the strong non-resonant interaction between asymmetrical quantum dots (QDs) and a laser field results in harmonic oscillations of their band gap. It is shown that such oscillations change the spectrum of elementary electron excitations in QDs: in the absence of the laser pumping there is only one resonant electron frequency, but QDs dressed by the laser field have a set of electron resonant frequencies. One expects that this modification of elementary electron excitations in QDs can be observable in optical experiments. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Electron beam pumped KrF lasers for fusion energy

    International Nuclear Information System (INIS)

    Sethian, J.D.; Friedman, M.; Giuliani, J.L. Jr.; Lehmberg, R.H.; Obenschain, S.P.; Kepple, P.; Wolford, M.; Hegeler, F.; Swanekamp, S.B.; Weidenheimer, D.; Welch, D.; Rose, D.V.; Searles, S.

    2003-01-01

    In this paper, we describe the development of electron beam pumped KrF lasers for inertial fusion energy. KrF lasers are an attractive driver for fusion, on account of their demonstrated very high beam quality, which is essential for reducing imprint in direct drive targets; their short wavelength (248 nm), which mitigates the growth of plasma instabilities; and their modular architecture, which reduces development costs. In this paper we present a basic overview of KrF laser technology as well as current research and development in three key areas: electron beam stability and transport; KrF kinetics and laser propagation; and pulsed power. The work will be cast in context of the two KrF lasers at the Naval Research Laboratory, The Nike Laser (5 kJ, single shot), and The Electra Laser (400-700 J repetitively pulsed)

  19. In situ laser processing in a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Nicholas A.; Magel, Gregory A.; Hartfield, Cheryl D.; Moore, Thomas M.; Fowlkes, Jason D.; Rack, Philip D. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States) and Omniprobe, Inc., an Oxford Instruments Company, 10410 Miller Rd., Dallas, Texas 75238 (United States); Omniprobe, Inc., an Oxford Instruments Company, 10410 Miller Rd., Dallas, Texas 75238 (United States); Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States) and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2012-07-15

    Laser delivery probes using multimode fiber optic delivery and bulk focusing optics have been constructed and used for performing materials processing experiments within scanning electron microscope/focused ion beam instruments. Controlling the current driving a 915-nm semiconductor diode laser module enables continuous or pulsed operation down to sub-microsecond durations, and with spot sizes on the order of 50 {mu}m diameter, achieving irradiances at a sample surface exceeding 1 MW/cm{sup 2}. Localized laser heating has been used to demonstrate laser chemical vapor deposition of Pt, surface melting of silicon, enhanced purity, and resistivity via laser annealing of Au deposits formed by electron beam induced deposition, and in situ secondary electron imaging of laser induced dewetting of Au metal films on SiO{sub x}.

  20. High energy gain electron beam acceleration by 100TW laser

    International Nuclear Information System (INIS)

    Kotaki, Hideyuki; Kando, Masaki; Kondo, Shuji; Hosokai, Tomonao; Kanazawa, Shuhei; Yokoyama, Takashi; Matoba, Toru; Nakajima, Kazuhisa

    2001-01-01

    A laser wakefield acceleration experiment using a 100TW laser is planed at JAERI-Kansai. High quality and short pulse electron beams are necessary to accelerate the electron beam by the laser. Electron beam - laser synchronization is also necessary. A microtron with a photocathode rf-gun was prepared as a high quality electron injector. The quantum efficiency (QE) of the photocathode of 2x10 -5 was obtained. A charge of 100pC from the microtron was measured. The emittance and pulse width of the electron beam was 6π mm-mrad and 10ps, respectively. In order to produce a short pulse electron beam, and to synchronize between the electron beam and the laser pulse, an inverse free electron laser (IFEL) is planned. One of problems of LWFA is the short acceleration length. In order to overcome the problem, a Z-pinch plasma waveguide will be prepared as a laser wakefield acceleration tube for 1 GeV acceleration. (author)

  1. Nonlinear optics with coherent free electron lasers

    Science.gov (United States)

    Bencivenga, F.; Capotondi, F.; Mincigrucci, R.; Cucini, R.; Manfredda, M.; Pedersoli, E.; Principi, E.; Simoncig, A.; Masciovecchio, C.

    2016-12-01

    We interpreted the recent construction of free electron laser (FELs) facilities worldwide as an unprecedented opportunity to bring concepts and methods from the scientific community working with optical lasers into the domain of x-ray science. This motivated our efforts towards the realization of FEL-based wave-mixing applications. In this article we present new extreme ultraviolet transient grating (X-TG) data from vitreous SiO2, collected using two crossed FEL pulses (photon frequency 38 eV) to generate the X-TG and a phase matched optical probing pulse (photon frequency 3.1 eV). This experiment extends our previous investigation, which was carried out on a nominally identical sample using a different FEL photon frequency (45 eV) to excite the X-TG. The present data are featured by a peak intensity of the X-TG signal substantially larger than that previously reported and by slower modulations of the X-TG signal at positive delays. These differences could be ascribed to the different FEL photon energy used in the two experiments or to differences in the sample properties. A systematic X-TG study on the same sample as a function of the FEL wavelength is needed to draw a consistent conclusion. We also discuss how the advances in the performance of the FELs, in terms of generation of fully coherent photon pulses and multi-color FEL emission, may push the development of original experimental strategies to study matter at the femtosecond-nanometer time-length scales, with the unique option of element and chemical state specificity. This would allow the development of advanced experimental tools based on wave-mixing processes, which may have a tremendous impact in the study of a large array of phenomena, ranging from nano-dynamics in complex materials to charge and energy transfer processes.

  2. Laser Assisted Free-Free Transition in Electron - Atom Collision

    Science.gov (United States)

    Sinha, C.; Bhatia, A. K.

    2011-01-01

    Free-free transition is studied for electron-Hydrogen atom system in ground state at very low incident energies in presence of an external homogeneous, monochromatic and linearly polarized laser field. The incident electron is considered to be dressed by the laser in a non perturbative manner by choosing the Volkov solutions in both the channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the effect of electron exchange, short range as well as of the long range interactions. Laser assisted differential as well as elastic total cross sections are calculated for single photon absorption/emission in the soft photon limit, the laser intensity being much less than the atomic field intensity. A strong suppression is noted in the laser assisted cross sections as compared to the field free situations. Significant difference is noted in the singlet and the triplet cross sections.

  3. Biomedical Studies with the Free Electron Laser

    Science.gov (United States)

    1989-05-15

    and Berns. Mi. W. User pitotora- 26. Kestel. D.. And Chou. T. C. Tumer -localizing components of the ptirph% rin diation therapy of cancer following... cancer , (2) laser tissue interactions for the study of atherosclerosis, (3) pulsed laser effects on the eye, (4) laser application in genetic...these studies. Please refer to the appropriate article/abstract for further detail. 1. Dye plus laser photosensitization of cancer . Significant

  4. Vitamin C for stabilising biological lasers (Conference Presentation)

    Science.gov (United States)

    Kar, Ajoy K.; Mackenzie, Mark D.; Cialowicz, Katarzyna I.; Saleeb, Rebecca S.; Duncan, Rory R.

    2016-04-01

    We report on efforts to improve the lifetime of biological lasers through the use of ascorbic acid (also commonly known as vitamin C). Fluorescent proteins and dyes, used in biological lasers, suffer from photobleaching due to the build-up of reactive oxygen species (ROS) which causes damage leading to a decrease in emission over time. This is an issue both for laser lifetime and cell health. It has previously been shown that ascorbic acid can be effective in reducing ROS levels in a variety of applications. For our experiments human embryonic kidney cells (HEK293), containing the fluorescent dye Calcein AM, were placed between two dielectric plane mirrors to form a laser cavity. The cells were pumped using the output of a Ti:Sapphire femtosecond OPO system, frequency doubled twice in BBO crystals, giving an output of 474 nm. Initial results have shown an increase in laser lifetime when ascorbic acid is added to cells indicating a reduction in the build-up of ROS.

  5. Laser nano-surgery for neuronal manipulation (Conference Presentation)

    Science.gov (United States)

    Sarker, Hori Pada; Chudal, Lalit; Mahapatra, Vasu; Kim, Young-tae; Mohanty, Samarendra K.

    2016-03-01

    Optical manipulation has enabled study of bio-chemical and bio-mechanical properties of the cells. Laser nanosurgery by ultrafast laser beam with appropriate laser parameters provides spatially-targeted manipulation of neurons in a minimal invasiveness manner with high efficiency. We utilized femto-second laser nano-surgery for both axotomy and sub-axotomy of rat cortical neurons. Degeneration and regeneration after axotomy was studied with and without external growth-factor(s) and biochemical(s). Further, axonal injury was studied as a function of pulse energy, exposure and site of injury. The ability to study the response of neurons to localized injury opens up opportunities for screening potential molecules for repair and regeneration after nerve injury. Sub-axotomy enabled transient opening of axonal membrane for optical delivery of impermeable molecules to the axoplasm. Fast resealing of the axonal membrane after sub-axotomy without significant long-term damage to axon (monitored by its growth) was observed. We will present these experimental results along with theoretical simulation of injury due to laser nano-surgery and delivery via the transient pore. Targeted delivery of proteins such as antibodies, genes encoding reporter proteins, ion-channels and voltage indicators will allow visualization, activation and detection of the neuronal structure and function.

  6. Laser-Electron-Gamma-Source. Progress report, July 1986

    International Nuclear Information System (INIS)

    Dowell, D.H.; Fineman, B.; Giordano, G.; Kistner, OC.; Matone, G.; Sandorfi, A.M.; Schaerf, C.; Thorn, C.E.; Ziegler, W.

    1986-07-01

    When completed, the Laser Electron Gamma Source (LEGS) is expected to provide intense beams of monochromatic and polarized (circular or linear) gamma rays with energies up to 500 MeV. The gamma-ray beams will be produced by Compton backscattering uv laser light from the electrons circulating in a storage ring. Progress with installation of the facility is described, particularly the Ar-ion laser and tagging spectrometer. Tests of the tagging spectrometer coponents is reported, and a second laser is described for higher energy operation. Estimates are given of expected beam parameters. Experimental equipment for the planned research projects to be carried out at the LEGS facility is discussed

  7. 1988 linear accelerator conference proceedings

    International Nuclear Information System (INIS)

    1989-06-01

    This report contains papers presented at the 1988 Linear Accelerator Conference. A few topics covered are beam dynamics; beam transport; superconducting components; free electron lasers; ion sources; and klystron research

  8. High-power fiber lasers for photocathode electron injectors

    Directory of Open Access Journals (Sweden)

    Zhi Zhao

    2014-05-01

    Full Text Available Many new applications for electron accelerators require high-brightness, high-average power beams, and most rely on photocathode-based electron injectors as a source of electrons. To achieve such a photoinjector, one requires both a high-power laser system to produce the high average current beam, and also a system at reduced repetition rate for electron beam diagnostics to verify high beam brightness. Here we report on two fiber laser systems designed to meet these specific needs, at 50 MHz and 1.3 GHz repetition rate, together with pulse pickers, second harmonic generation, spatiotemporal beam shaping, intensity feedback, and laser beam transport. The performance and flexibility of these laser systems have allowed us to demonstrate electron beam with both low emittance and high average current for the Cornell energy recovery linac.

  9. Spin effects in strong-field laser-electron interactions

    International Nuclear Information System (INIS)

    Ahrens, S; Bauke, H; Müller, T-O; Villalba-Chávez, S; Müller, C

    2013-01-01

    The electron spin degree of freedom can play a significant role in relativistic scattering processes involving intense laser fields. In this contribution we discuss the influence of the electron spin on (i) Kapitza-Dirac scattering in an x-ray laser field of high intensity, (ii) photo-induced electron-positron pair production in a strong laser wave and (iii) multiphoton electron-positron pair production on an atomic nucleus. We show that in all cases under consideration the electron spin can have a characteristic impact on the process properties and their total probabilities. To this end, spin-resolved calculations based on the Dirac equation in the presence of an intense laser field are performed. The predictions from Dirac theory are also compared with the corresponding results from the Klein-Gordon equation.

  10. Laser vacuum acceleration of a relativistic electron bunch

    Energy Technology Data Exchange (ETDEWEB)

    Glazyrin, I V; Karpeev, A V; Kotova, O G; Nazarov, K S [E.I. Zababakhin All-Russian Scientific-Research Institute of Technical Physics, Russian Federal Nuclear Centre, Snezhinsk, Chelyabinsk region (Russian Federation); Bychenkov, V Yu [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-06-30

    With regard to the problem of laser acceleration of a relativistic electron bunch we present a scheme of its vacuum acceleration directly by a relativistic intensity laser pulse. The energy of the electron bunch injected into the laser pulse leading edge increases during its coaxial movement to a thin, pulse-reflecting target. The laser-accelerated electrons continue to move free forward, passing through the target. The study of this acceleration scheme in the three-dimensional geometry is verified in a numerical simulation by the particle-in-cell method, which showed that the energy of a part of the electrons can increase significantly compared to the initial one. Restrictions are discussed, which impose limiting values of energy and total charge of accelerated electrons. (superstrong light fields)

  11. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    International Nuclear Information System (INIS)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.

    2017-01-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μm. In conclusion, our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  12. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    Science.gov (United States)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.; Gilevich, S.; Huang, Z.; Miahnahri, A.; Ratner, D.; Robinson, J.; Zhou, F.

    2017-08-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μ m . Our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  13. Commissioning of the JAERI free electron laser

    International Nuclear Information System (INIS)

    Minehara, E.J.; Nagai, R.; Sawamura, M.

    1993-01-01

    We have developed, and constructed a prototype for a quasi-cw, and high-average power free electron laser driven by a 15MeV superconducting rf linac at Tokai, JAERI. In designing a high power FEL, there are many available design options to generate the required power output. By applying the superconducting rf linac driver, some of the options relating to the FEL itself may be relaxed by transferring design difficulties to the driver. Because wall losses become minimal in the superconducting accelerator cavity, very long pulse or quasi-cw, and resultant high average power may be readily attained at the JAERI superconducting rf linac FEL. In 1992 Japanese fiscal year, we have successfully demonstrated better cryogenic (stand-by loss<3.5W at 4.5K) and accelerating fields' performances (Eacc=7-9.4MV/m and Q=1-2x10+9) of four JAERI superconducting accelerator modules, and installed them in the FEL accelerator vault. In 1993, Optical resonators and beam transport systems, which have been already assembled, are now under commissioning. A description and the latest results of the JAERI super-conducting rf linac FEL will be discussed in comparison with a normal-conducting one, and reported in the symposium. (author)

  14. Biological applications of ultraviolet free-electron lasers

    International Nuclear Information System (INIS)

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated

  15. The suppression of radiation reaction and laser field depletion in laser-electron beam interaction

    Science.gov (United States)

    Ong, J. F.; Moritaka, T.; Takabe, H.

    2018-03-01

    The effects of radiation reaction (RR) have been studied extensively by using the interaction of ultraintense lasers with a counter-propagating relativistic electron. At the laser intensity at the order of 1023 W/cm2, the effects of RR are significant in a few laser periods for a relativistic electron. However, a laser at such intensity is tightly focused and the laser energy is usually assumed to be fixed. Then, the signal of RR and energy conservation cannot be guaranteed. To assess the effects of RR in a tightly focused laser pulse and the evolution of the laser energy, we simulated this interaction with a beam of 109 electrons by means of a Particle-In-Cell method. We observe that the effects of RR are suppressed due to the ponderomotive force and accompanied by a non-negligible amount of laser field energy reduction. This is because the ponderomotive force prevents the electrons from approaching the center of the laser pulse and leads to an interaction at the weaker field region. At the same time, the laser energy is absorbed through ponderomotive acceleration. Thus, the kinetic energy of the electron beam has to be carefully selected such that the effects of RR become obvious.

  16. Electron acceleration via high contrast laser interacting with submicron clusters

    International Nuclear Information System (INIS)

    Zhang Lu; Chen Liming; Wang Weiming; Yan Wenchao; Yuan Dawei; Mao Jingyi; Wang Zhaohua; Liu Cheng; Shen Zhongwei; Li Yutong; Dong Quanli; Lu Xin; Ma Jinglong; Wei Zhiyi; Faenov, Anatoly; Pikuz, Tatiana; Li Dazhang; Sheng Zhengming; Zhang Jie

    2012-01-01

    We experimentally investigated electron acceleration from submicron size argon clusters-gas target irradiated by a 100 fs, 10 TW laser pulses having a high-contrast. Electron beams are observed in the longitudinal and transverse directions to the laser propagation. The measured energy of the longitudinal electron reaches 600 MeV and the charge of the electron beam in the transverse direction is more than 3 nC. A two-dimensional particle-in-cell simulation of the interaction has been performed and it shows an enhancement of electron charge by using the cluster-gas target.

  17. Laser-electron Compton interaction in plasma channels

    International Nuclear Information System (INIS)

    Pogorelsky, I.V.; Ben-Zvi, I.; Hirose, T.

    1998-10-01

    A concept of high intensity femtosecond laser synchrotron source (LSS) is based on Compton backscattering of focused electron and laser beams. The short Rayleigh length of the focused laser beam limits the length of interaction to a few picoseconds. However, the technology of the high repetition rate high-average power picosecond lasers required for high put through LSS applications is not developed yet. Another problem associated with the picosecond laser pulses is undesirable nonlinear effects occurring when the laser photons are concentrated in a short time interval. To avoid the nonlinear Compton scattering, the laser beam has to be split, and the required hard radiation flux is accumulated over a number of consecutive interactions that complicates the LSS design. In order to relieve the technological constraints and achieve a practically feasible high-power laser synchrotron source, the authors propose to confine the laser-electron interaction region in the extended plasma channel. This approach permits to use nanosecond laser pulses instead of the picosecond pulses. That helps to avoid the nonlinear Compton scattering regime and allows to utilize already existing technology of the high-repetition rate TEA CO 2 lasers operating at the atmospheric pressure. They demonstrate the advantages of the channeled LSS approach by the example of the prospective polarized positron source for Japan Linear Collider

  18. Two-pulse laser control of nuclear and electronic motion

    DEFF Research Database (Denmark)

    Grønager, Michael; Henriksen, Niels Engholm

    1997-01-01

    We discuss an explicitly time-dependent two-pulse laser scheme for controlling where nuclei and electrons are going in unimolecular reactions. We focus on electronic motion and show, with HD+ as an example, that one can find non-stationary states where the electron (with some probability...

  19. Nuclear Electronics I. Proceedings of the Conference on Nuclear Electronics. Vol. I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-04-15

    Nuclear instruments are used in almost every phase of atomic energy work, from assessing health hazards and prospecting for nuclear materials to plant control and nuclear physics experiments. The demands on nucleonic instrumentation are growing steadily. High-energy particle physics need such instruments for measuring extremely short times; in various research experiments most advanced electronic systems are required; and routine applications of radioisotopes call for more reliable instruments for automated counting facilities. In order to give designers and users of nuclear instrumentation an opportunity to discuss the research results and to exchange information on recent developments and new designs, the International Atomic Energy Agency, in co-operation with the Federal Nuclear Energy Commission of Yugoslavia, organized a Conference on Nuclear Electronics which was held in Belgrade from 15-20 May 1961. It was attended by more than 300 scientists from nearly 30 countries and five international organizations. Over 150 papers were read and discussed. As the field of nuclear electronics has expanded considerably, it was impossible to discuss all aspects of nuclear electronics in one series of meetings. Included in the main topics were radiation detectors, electronic circuitry in conventional and fast-pulse techniques and advanced electronic systems used in nuclear research. The Proceedings presented in these volumes contain the full records of the Conference, including discussions. The present state of technique, together with current trends and developments, are outlined. Of particular value should be the world-wide survey on progress recently made in such fields as those connected with semiconductor detectors, spark counters, luminescence chambers and fast electronic facilities for nuclear physics research. Together with the Proceedings of the Symposium on the same subject held in Paris and also published by the International Atomic Energy Agency, these volumes

  20. Nuclear Electronics II. Proceedings of the Conference on Nuclear Electronics. V. II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-04-15

    Nuclear instruments are used in almost every phase of atomic energy work, from assessing health hazards and prospecting for nuclear materials to plant control and nuclear physics experiments. The demands on nucleonic instrumentation are growing steadily. High-energy particle physics need such instruments for measuring extremely short times; in various research experiments most advanced electronic systems are required; and routine applications of radioisotopes call for more reliable instruments for automated counting facilities. In order to give designers and users of nuclear instrumentation an opportunity to discuss the research results and to exchange information on recent developments and new designs, the International Atomic Energy Agency, in co-operation with the Federal Nuclear Energy Commission of Yugoslavia, organized a Conference on Nuclear Electronics which was held in Belgrade from 15-20 May 1961. It was attended by more than 300 scientists from nearly 30 countries and five international organizations. Over 150 papers were read and discussed. As the field of nuclear electronics has expanded considerably, it was impossible to discuss all aspects of nuclear electronics in one series of meetings. Included in the main topics were radiation detectors, electronic circuitry in conventional and fast-pulse techniques and advanced electronic systems used in nuclear research. The Proceedings presented in these volumes contain the full records of the Conference, including discussions. The present state of technique, together with current trends and developments, are outlined. Of particular value should be the world-wide survey on progress recently made in such fields as those connected with semiconductor detectors, spark counters, luminescence chambers and fast electronic facilities for nuclear physics research. Together with the Proceedings of the Symposium on the same subject held in Paris and also published by the International Atomic Energy Agency, these volumes

  1. Nuclear Electronics III. Proceedings of the Conference on Nuclear Electronics. V. III

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-04-15

    Nuclear instruments are used in almost every phase of atomic energy work, from assessing health hazards and prospecting for nuclear materials to plant control and nuclear physics experiments. The demands on nucleonic instrumentation are growing steadily. High-energy particle physics need such instruments for measuring extremely short times; in various research experiments most advanced electronic systems are required; and routine applications of radioisotopes call for more reliable instruments for automated counting facilities. In order to give designers and users of nuclear instrumentation an opportunity to discuss the research results and to exchange information on recent developments and new designs, the International Atomic Energy Agency, in co-operation with the Federal Nuclear Energy Commission of Yugoslavia, organized a Conference on Nuclear Electronics which was held in Belgrade from 15-20 May 1961. It was attended by more than 300 scientists from nearly 30 countries and five international organizations. Over 150 papers were read and discussed. As the field of nuclear electronics has expanded considerably, it was impossible to discuss all aspects of nuclear electronics in one series of meetings. Included in the main topics were radiation detectors, electronic circuitry in conventional and fast-pulse techniques and advanced electronic systems used in nuclear research. The Proceedings presented in these volumes contain the full records of the Conference, including discussions. The present state of technique, together with current trends and developments, are outlined. Of particular value should be the world-wide survey on progress recently made in such fields as those connected with semiconductor detectors, spark counters, luminescence chambers and fast electronic facilities for nuclear physics research. Together with the Proceedings of the Symposium on the same subject held in Paris and also published by the International Atomic Energy Agency, these volumes

  2. Recombinational laser employing electron transitions of diatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Biriukov, A S; Prokhorov, A M; Shelepin, L A; Shirokov, N N

    1974-12-01

    Conditions are established for obtaining laser action in the visible and uv regions of the spectrum, using transitions between electronic states of diatomic molecules during recombination of a dissociated gas. The mechanism of population inversion was studied for the oxygen molecule, and gain estimates were obtained for laser action at a wavelength of 4881 A. The feasibility of laser action at other wavelengths was examined.

  3. Peculiarities of laser phase behavior associated with the accelerated electron in a chirped laser pulse

    International Nuclear Information System (INIS)

    Song, Q.; Wu, X. Y.; Wang, J. X.; Kawata, S.; Wang, P. X.

    2014-01-01

    In this paper, we qualitatively analyzed peculiarities of laser phase behavior associated with the accelerated electron in a chirped laser pulse. We unveiled the relationship between the changes in the orientation of the electron trajectory and the cusps in magnitude of the phase velocity of the optical field along the electron trajectory in a chirped laser pulse. We also explained how the chirp effect induced the singular point of the phase velocity. Finally, we discussed the phase velocity and phase witnessed by the electron in the particle's moving instantaneous frame

  4. ADVISOR Users Conference Proceedings 2000 - Final Electronic version

    Energy Technology Data Exchange (ETDEWEB)

    NREL

    2000-09-26

    This is a compilation of papers presented at the ADVISOR (ADvanced Vehicle SimulatOR) Users Conference held in Costa Mesa, California, August 24-25, 2000. Major topics of the conference included modeling and simulation; partnering with the auto industry; co-simulation: partnering with the software industry in optimization and thermal modeling and geometric and mechanical modeling; forward-looking simulations coupled with ADVISOR; new concepts from universities; validation, vehicle development and applications.

  5. Novel aspects of direct laser acceleration of relativistic electrons

    Science.gov (United States)

    Arefiev, Alexey

    2015-11-01

    Production of energetic electrons is a keystone aspect of ultraintense laser-plasma interactions that underpins a variety of topics and applications, including fast ignition inertial confinement fusion and compact particle and radiation sources. There is a wide range of electron acceleration regimes that depend on the duration of the laser pulse and the plasma density. This talk focuses on the regime in which the plasma is significantly underdense and the laser pulse duration is longer than the electron response time, so that, in contrast to the wakefield acceleration regime, the pulse creates a quasi-static channel in the electron density. Such a regime is of particular interest, since it can naturally arise in experiments with solid density targets where the pre-pulse of an ultraintense laser produces an extended sub-critical pre-plasma. This talk examines the impact of several key factors on electron acceleration by the laser pulse and the resulting electron energy gain. A detailed consideration is given to the role played by: (1) the static longitudinal electric field, (2) the static transverse electric field, (3) the electron injection into the laser pulse, (4) the electromagnetic dispersion, and (5) the static longitudinal magnetic field. It is shown that all of these factors lead, under conditions outlined in the talk, to a considerable electron energy gain that greatly exceeds the ponderomotive limit. The static fields do not directly transfer substantial energy to electrons. Instead, they alter the longitudinal dephasing between the electrons and the laser pulse, which then allows the electrons to gain extra energy from the pulse. The talk will also outline a time-resolution criterion that must be satisfied in order to correctly reproduce these effects in particle-in-cell simulations. Supported by AFOSR Contract No. FA9550-14-1-0045, National Nuclear Security Administration Contract No. DE-FC52-08NA28512, and US Department of Energy Contract No. DE-FG02

  6. Development of laser heated high current DC electron gun

    International Nuclear Information System (INIS)

    Banerjee, Srutarshi; Bhattacharjee, Dhruva; Kandaswamy, E.; Ghodke, S.R.; Tiwari, Rajnish; Bakhtsingh, R.I.

    2015-01-01

    The paper deals with the development of a Laser heated cathode for Electron Accelerator. The electron gun is meant for Megawatt-class DC Accelerator for Electron Beam Flue Gas Treatment applications. Conventionally, LaB 6 cathode is indirectly heated by tungsten filaments whereas in the newly proposed gun, Laser is utilized for heating. A Nd:YAG Laser is used to heat the LaB 6 cathode to emission temperatures. The characterization of cathode heating at various Laser powers has been carried out. In initial trials, it has been observed that with 125 W of Laser power, the LaB 6 pellet was heated to 1315 ° C. Based on these experimental results, an electron gun rated for 30 kV, 350 mA CW has been designed. The optimization of gun electrode geometry has been done using CST Particle Studio in order to tune the various electron gun parameters. The beam diameter obtained in simulation is 8 mm at 100 mm from the LaB 6 cathode. The perveance obtained is 7.1 x 10 -8 A/V 3/2 . The Laser heated cathode has the advantages of eliminating the magnetic field effects of filament on the electron beam, electrical isolation needed for gun filament power supplies and better electron beam emittances. (author)

  7. 2012 Gordon Research Conference, Electron donor-acceptor interactions, August 5-10 2012

    Energy Technology Data Exchange (ETDEWEB)

    McCusker, James [Michigan State Univ., East Lansing, MI (United States)

    2012-08-10

    The upcoming incarnation of the Gordon Research Conference on Electron Donor Acceptor Interactions will feature sessions on classic topics including proton-coupled electron transfer, dye-sensitized solar cells, and biological electron transfer, as well as emerging areas such as quantum coherence effects in donor-acceptor interactions, spintronics, and the application of donor-acceptor interactions in chemical synthesis.

  8. 2008 Electron Donor Acceptor Interactions Gordon Research Conference-August 3-8, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, Malcolm [Univ. of North Carolina, Chapel Hill, NC (United States); Gray, Nancy Ryan [Gordon Research Conferences, West Kingston, RI (United States)

    2009-09-19

    The conference presents and advances the current frontiers in experimental and theoretical studies of Electron Transfer and Transport in Molecular and Nano-scale Systems. The program includes sessions on coupled electron transfers, molecular solar energy conversion, biological and biomimetic systems, spin effects, ultrafast reactions and technical frontiers as well as electron transport in single molecules and devices.

  9. Scaling electron acceleration in the bubble regime for upcoming lasers

    International Nuclear Information System (INIS)

    Jansen, O.; Tueckmantel, T.; Pukhov, A.

    2014-01-01

    Electron acceleration in the laser-plasma bubble appeared to be the most successful regime of laser wake field acceleration in the last decade. The laser technology became mature enough to generate short and relativistically intense pulses required to reach the bubble regime naturally delivering quasi-monoenergetic bunches of relativistic electrons. The upcoming laser technology projects are promising short pulses with many times more energy than the existing ones. The natural question is how will the bubble regime scale with the available laser energy. We present here a parametric study of laser-plasma acceleration in the bubble regime using full three dimensional particle-in-cell simulations and compare numerical results with the analytical scalings from the relativistic laser-plasma similarity theory. Our simulations and the theory match almost perfectly for spot sizes above R = 2λ and laser amplitudes above a 0 = 4. We also studied the emission of synchrotron radiation by the accelerated electrons. Both classical and a QED model were applied. We found borders, at which theory and simulations stopped matching. With small spot radii (R < 2λ) we almost never observed the formation of a bubble structure or any form of mono-energetic acceleration. Low laser amplitudes lead to higher energies than predicted by the theory

  10. The quantum mechanical analysis of the free electron laser

    International Nuclear Information System (INIS)

    Dattoli, G.; Renieri, A.

    1985-01-01

    A quantum analysis of the Free Electron Laser is presented. The theory is developed both in single and longitudinal multimode regimes. Finally a self-consistent procedure to study the growth of the laser signal from the vacuum to the macroscopic level is presented

  11. Electron acceleration by a self-diverging intense laser pulse

    International Nuclear Information System (INIS)

    Singh, K.P.; Gupta, D.N.; Tripathi, V.K.; Gupta, V.L.

    2004-01-01

    Electron acceleration by a laser pulse having a Gaussian radial and temporal profile of intensity has been studied. The interaction region is vacuum followed by a gas. The starting point of the gas region has been chosen around the point at which the peak of the pulse interacts with the electron. The tunnel ionization of the gas causes a defocusing of the laser pulse and the electron experiences the action of a ponderomotive deceleration at the trailing part of the pulse with a lower intensity rather than an acceleration at the rising part of the laser pulse with a high intensity, and thus gains net energy. The initial density of the neutral gas atoms should be high enough to properly defocus the pulse; otherwise the electron experiences some deceleration during the trailing part of the pulse and the net energy gain is reduced. The rate of tunnel ionization increases with the increase in the laser intensity and the initial density of neutral gas atoms, and with the decreases in the laser spot size, which causes more defocusing of the laser pulse. The required initial density of neutral gas atoms decreases with the increase in the laser intensity and also with the decrease in the laser spot size

  12. International Conference on Emerging Research in Electronics, Computer Science and Technology

    CERN Document Server

    Sheshadri, Holalu; Padma, M

    2014-01-01

    PES College of Engineering is organizing an International Conference on Emerging Research in Electronics, Computer Science and Technology (ICERECT-12) in Mandya and merging the event with Golden Jubilee of the Institute. The Proceedings of the Conference presents high quality, peer reviewed articles from the field of Electronics, Computer Science and Technology. The book is a compilation of research papers from the cutting-edge technologies and it is targeted towards the scientific community actively involved in research activities.

  13. PREFACE: Electron Microscopy and Analysis Group Conference (EMAG2015)

    Science.gov (United States)

    MacLaren, Ian

    2015-10-01

    2015 marked a new venture for the EMAG group of the Institute of Physics in that the conference was held in conjunction with the MMC2015 conference at the wonderful Manchester Central conference centre. As anyone who was there would be able to confirm, this went exceptionally well and was a really vibrant and top quality conference. The oral sessions were filled with good talks, the poster sessions were very lively, and there was a good balance between oral sessions with a specifically "EMAG" identity, and the integration into a larger conference with the ability to switch between up to six parallel sessions covering physical sciences, techniques, and life sciences. The large conference also attracted a wide range of exhibitors, and this is essential for the ongoing success of all of our work, in a field that is very dependent on continued technical innovation and on collaborations between academic researchers and commercial developers of microscopes, holders, detectors, spectrometers, sample preparation equipment, and software, among other things. As has long been the case at EMAG, all oral and poster presenters were invited to submit papers for consideration for the proceedings. As ever, these papers were independently reviewed by other conference attendees, with the aim of continuing the long tradition of the EMAG proceedings being a top quality, peer-reviewed publication, worthy of reference in future years. Whilst I recognise that not all presenters were able to submit papers to the proceedings (for instance due to the need not to prejudice publication in some other journals, or due to avoiding duplicate publication of data), we are gratified that our presenters submitted as many papers as they did. The 41 papers included provide an interesting snapshot of many of the areas covered in the conference presentations, including functional materials, coatings, 3D microscopy, FIB and SEM, nanomaterials, magnetic and structural materials, advances in EM techniques

  14. A control system for a free electron laser experiment

    International Nuclear Information System (INIS)

    Giove, D.

    1992-01-01

    The general layout of a control and data acquisition system for a Free Electron Laser experiment will be discussed. Some general considerations about the requirements and the architecture of the whole system will be developed. (author)

  15. Electron-beam pumping of visible and ultraviolet gas lasers

    International Nuclear Information System (INIS)

    Bradley, L.P.

    1975-01-01

    Several techniques for using direct electron-pumping of gas lasers are reviewed. The primary objective is to categorize pump geometries and to give guidelines for gun selection and pulser design. Examples and application of pump technology are given

  16. Direct longitudinal laser acceleration of electrons in free space

    Directory of Open Access Journals (Sweden)

    Sergio Carbajo

    2016-02-01

    Full Text Available Compact laser-driven accelerators are pursued heavily worldwide because they make novel methods and tools invented at national laboratories widely accessible in science, health, security, and technology [V. Malka et al., Principles and applications of compact laser-plasma accelerators, Nat. Phys. 4, 447 (2008]. Current leading laser-based accelerator technologies [S. P. D. Mangles et al., Monoenergetic beams of relativistic electrons from intense laser-plasma interactions, Nature (London 431, 535 (2004; T. Toncian et al., Ultrafast laser-driven microlens to focus and energy-select mega-electron volt protons, Science 312, 410 (2006; S. Tokita et al. Single-shot ultrafast electron diffraction with a laser-accelerated sub-MeV electron pulse, Appl. Phys. Lett. 95, 111911 (2009] rely on a medium to assist the light to particle energy transfer. The medium imposes material limitations or may introduce inhomogeneous fields [J. R. Dwyer et al., Femtosecond electron diffraction: “Making the molecular movie,”, Phil. Trans. R. Soc. A 364, 741 (2006]. The advent of few cycle ultraintense radially polarized lasers [S. Carbajo et al., Efficient generation of ultraintense few-cycle radially polarized laser pulses, Opt. Lett. 39, 2487 (2014] has ushered in a novel accelerator concept [L. J. Wong and F. X. Kärtner, Direct acceleration of an electron in infinite vacuum by a pulsed radially polarized laser beam, Opt. Express 18, 25035 (2010; F. Pierre-Louis et al. Direct-field electron acceleration with ultrafast radially polarized laser beams: Scaling laws and optimization, J. Phys. B 43, 025401 (2010; Y. I. Salamin, Electron acceleration from rest in vacuum by an axicon Gaussian laser beam, Phys. Rev. A 73, 043402 (2006; C. Varin and M. Piché, Relativistic attosecond electron pulses from a free-space laser-acceleration scheme, Phys. Rev. E 74, 045602 (2006; A. Sell and F. X. Kärtner, Attosecond electron bunches accelerated and

  17. Second harmonic generation in Te crystal using free electron laser

    CERN Document Server

    Yamauchi, T; Minehara, E J

    2002-01-01

    The second harmonic generation signal converted from the fundamental wavelength of 22 mu m of a free electron laser was observed for the first time using a birefringent Te crystal. The experimental conversion efficiency of Te crystal for second harmonic generation is 0.53%, which is equivalent to the theoretical value within a factor of 2. The Te crystal has been incorporated into an autocorrelator system to measure the micro-pulse width of infrared free electron laser successfully. (author)

  18. Laser wakefield electron acceleration. A novel approach employing supersonic microjets and few-cycle laser pulses

    International Nuclear Information System (INIS)

    Schmid, Karl

    2011-01-01

    This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams. (orig.)

  19. Free-electron lasers with magnetized ion-wiggler

    International Nuclear Information System (INIS)

    Mehdian, H.; Jafari, S.; Hasanbeigi, A.; Ebrahimi, F.

    2009-01-01

    Significant progress has been made using laser ionized channels to guide electron beams in the ion focus regime in a free-electron laser. Propagation of an electron beam in the ion focusing regime (IFR) allows the beam to propagate without expanding from space-charge repulsion. The ninth-degree polynomial dispersion relation for electromagnetic and space-charge waves is derived analytically by solving the electron momentum transfer and wave equations. The variation of resonant frequencies and peak growth rates with axial magnetic field strength has been demonstrated. Substantial enhancement in peak growth rate is obtained as the axial field frequency approaches the gyroresonance frequency.

  20. High energy electron acceleration with PW-class laser system

    International Nuclear Information System (INIS)

    Nakanii, N.; Kondo, K.; Yabuuchi, T.; Tsuji, K.; Kimura, K.; Fukumochi, S.; Kashihara, M.; Tanimoto, T.; Nakamura, H.; Ishikura, T.; Kodama, R.; Mima, K.; Tanaka, K. A.; Mori, Y.; Miura, E.; Suzuki, S.; Asaka, T.; Yanagida, K.; Hanaki, H.; Kobayashi, T.

    2008-01-01

    We performed electron acceleration experiment with PW-class laser and a plasma tube, which was created by imploding a hollow polystyrene cylinder. In this experiment, electron energies in excess of 600 MeV have been observed. Moreover, the spectra of a comparatively high-density plasma ∼10 19 cm -3 had a bump around 10 MeV. Additionally, we performed the absolute sensitivity calibration of imaging plate for 1 GeV electrons from the injector Linac of Spring-8 in order to evaluate absolute number of GeV-class electrons in the laser acceleration experiment

  1. Investigation of longitudinal dynamic in laser electron storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Karnaukhov, I.; Zelinsky, A. E-mail: zelinsky@kipt.kharkov.ua; Telegin, Yu

    2001-09-01

    Longitudinal dynamic of electron beam due to radiation damping and quantum fluctuations in the storage ring with a laser-electron interaction section (Compton scattering) is investigated. This investigation was carried out by numerical simulations using the Monte Carlo method. The dependence of the steady-state energy spread of electron beam due to the Compton back scattering of photons on the electron beam energy and photon flash density were obtained. Simulation findings are compared with the analytical estimations by Z. Huang.

  2. Investigation of longitudinal dynamic in laser electron storage ring

    CERN Document Server

    Karnaukhov, I; Telegin, Yu P

    2001-01-01

    Longitudinal dynamic of electron beam due to radiation damping and quantum fluctuations in the storage ring with a laser-electron interaction section (Compton scattering) is investigated. This investigation was carried out by numerical simulations using the Monte Carlo method. The dependence of the steady-state energy spread of electron beam due to the Compton back scattering of photons on the electron beam energy and photon flash density were obtained. Simulation findings are compared with the analytical estimations by Z. Huang.

  3. Staged electron laser accelerator (STELLA) experiment at brookhaven ATF

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelsky, I V; Steenbergen, A van; Gallardo, J C [Brookhaven National Lab., Upton, NY (United States); and others

    1998-03-01

    The STELLA experiment is being prepared at the BNL Accelerator Test Facility (STF). The goal of the experiment is to demonstrate quasi-monochromatic inverse Cherenkov acceleration (ICA) of electrons bunched to the laser wavelength period. Microbunches on the order of 2 {mu}m in length separated by 10.6 {mu}m will be produced using an inverse free electron laser (IFEL) accelerator driven by a CO{sub 2} laser. The design and simulations for two phases of this experiment including demonstration of 10 MeV and 100 MeV acceleration are presented. (author)

  4. Structural defects in laser- and electron-beam annealed silicon

    International Nuclear Information System (INIS)

    Narayan, J.

    1979-01-01

    Laser and electron beam pulses provide almost an ideal source of heat by which thin layers of semiconductors can be rapidly melted and solidified with heating and cooling rates exceeding 10 80 C/sec. Microstructural modifications obtained as a function of laser parameters are examined and it is shown that both laser and electron beam pulses can be used to remove displacement damage, dislocations, dislocation loops and precipitates. Annealing of defects underneath the oxide layers in silicon is possible within a narrow energy window. The formation of cellular structure provides a rather clear evidence of melting which leads to segregation and supercooling, and subsequent cell formation

  5. Magnetic Field Generation and Electron Acceleration in Relativistic Laser Channel

    International Nuclear Information System (INIS)

    Kostyukov, I.Yu.; Shvets, G.; Fisch, N.J.; Rax, J.M.

    2001-01-01

    The interaction between energetic electrons and a circularly polarized laser pulse inside an ion channel is studied. Laser radiation can be resonantly absorbed by electrons executing betatron oscillations in the ion channel and absorbing angular momentum from the laser. The absorbed angular momentum manifests itself as a strong axial magnetic field (inverse Faraday effect). The magnitude of this magnetic field is calculated and related to the amount of the absorbed energy. Absorbed energy and generated magnetic field are estimated for the small and large energy gain regimes. Qualitative comparisons with recent experiments are also made

  6. Laser-Compton Scattering as a Potential Electron Beam Monitor

    International Nuclear Information System (INIS)

    Chouffani, K.; Wells, D.; Harmon, F.; Lancaster, G.; Jones, J.

    2002-01-01

    LCS experiments were carried out at the Idaho Accelerator Center (IAC); sharp monochromatic x-ray lines were observed. These are produced using the so-called inverse Compton effect, whereby optical laser photons are collided with a relativistic electron beam. The back-scattered photons are then kinematically boosted to keV x-ray energies. We have first demonstrated these beams using a 20 MeV electron beam collided with a 100 MW, 7 ns Nd; YAG laser. We observed narrow LCS x-ray spectral peaks resulting from the interaction of the electron beam with the Nd; YAG laser second harmonic (532 nm). The LCS x-ray energy lines and energy deviations were measured as a function of the electron beam energy and energy-spread respectively. The results showed good agreement with the predicted valves. LCS could provide an excellent probe of electron beam energy, energy spread, transverse and longitudinal distribution and direction

  7. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y.; Li, M. H.; Li, Y. F.; Wang, J. G.; Tao, M. Z.; Han, Y. J.; Zhao, J. R.; Huang, K.; Yan, W. C.; Ma, J. L.; Li, Y. T. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, D. Z. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Chen, Z. Y. [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621999 (China); Sheng, Z. M. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, J. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-08-15

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble.

  8. Development of broadband free electron laser technology

    International Nuclear Information System (INIS)

    Lee, B. C.; Jeong, Y. W.; Joe, S. O.; Park, S. H.; Ryu, J. K.; Kazakevich, G.; Cha, H. J.; Sohn, S. C.; Han, S. J.

    2003-02-01

    Layer cladding technology was developed to mitigate the fretting wear damages occurred at fuel spacers in Hanaro reactor. The detailed experimental procedures are as follows. 1) Analyses of fretting wear damages and fabrication process of fuel spacers 2) Development and analysis of spherical Al 6061 T-6 alloy powders for the laser cladding 3) Analysis of parameter effects on laser cladding process for clad bids, and optimization of laser cladding process 4) Analysis on the changes of cladding layers due to overlapping factor change 5) Microstructural observation and phase analysis 6) Characterization of materials properties (hardness wear tests) 7) Development of a vision system and revision of its related software 8) Manufacture of prototype fuel spacers. As a result, it was confirmed that the laser cladding technology could increased considerably the wear resistance of Al 6061 alloy which is the raw material of fuel spacers.

  9. Compact electron accelerator for pumping gas lasers

    International Nuclear Information System (INIS)

    Duncan, C.V.; Bradley, L.P.

    1976-01-01

    A description is given of the design and application of a simple e-beam generator for the repetitive pulse pumping of gas lasers. The circuit uses a low inductance Marx and series tuned pulse forming elements

  10. Escaping Electrons from Intense Laser-Solid Interactions as a Function of Laser Spot Size

    OpenAIRE

    Rusby, Dean; Gray, Ross; Butler, Nick; Dance, Rachel; Scott, Graeme; Bagnoud, Vincent; Zielbauer, Bernhard; McKenna, Paul; Neely, David

    2018-01-01

    The interaction of a high-intensity laser with a solid target produces an energetic distribution of electrons that pass into the target. These electrons reach the rear surface of the target creating strong electric potentials that act to restrict the further escape of additional electrons. The measurement of the angle, flux and spectra of the electrons that do escape gives insights to the initial interaction. Here, the escaping electrons have been measured using a differentially filtered imag...

  11. The chirped-pulse inverse free-electron laser: A high-gradient vacuum laser accelerator

    International Nuclear Information System (INIS)

    Hartemann, F.V.; Landahl, E.C.; Troha, A.L.; Van Meter, J.R.; Baldis, H.A.; Freeman, R.R.; Luhmann, N.C. Jr.; Song, L.; Kerman, A.K.; Yu, D.U.

    1999-01-01

    The inverse free-electron laser (IFEL) interaction is studied theoretically and computationally in the case where the drive laser intensity approaches the relativistic regime, and the pulse duration is only a few optical cycles long. The IFEL concept has been demonstrated as a viable vacuum laser acceleration process; it is shown here that by using an ultrashort, ultrahigh-intensity drive laser pulse, the IFEL interaction bandwidth and accelerating gradient are increased considerably, thus yielding large energy gains. Using a chirped pulse and negative dispersion focusing optics allows one to take further advantage of the laser optical bandwidth and produce a chromatic line focus maximizing the gradient. The combination of these novel ideas results in a compact vacuum laser accelerator capable of accelerating picosecond electron bunches with a high gradient (GeV/m) and very low energy spread. copyright 1999 American Institute of Physics

  12. The theoretical study of the optical klystron free electron laser

    International Nuclear Information System (INIS)

    Yang Zhenhua

    2001-01-01

    The work of the theoretical study and numerical simulation of optical klystron free electron laser is supported by National 863 Research Development Program and National Science Foundation of China. The object of studying UV band free electron laser (FEL) is to understand the physical law of optical klystron FEL and to gain experience for design. A three-dimensional code OPFEL are made and it is approved that the code is correct completely. The magnetic field of the optical klystron, the energy modulation of the electron beam, the density modulation of the electron beam, spontaneous emission of the electron beam in optical klystron, the harmonic super-radiation of the electron beam, and the effects of the undulator magnetic field error on modulation of the electron beam energy are simulated. These results are useful for the future experiments

  13. Atomic electron correlations in intense laser fields

    International Nuclear Information System (INIS)

    DiMauro, L.F.; Sheehy, B.; Walker, B.; Agostini, P.A.

    1998-01-01

    This talk examines two distinct cases in strong optical fields where electron correlation plays an important role in the dynamics. In the first example, strong coupling in a two-electron-like system is manifested as an intensity-dependent splitting in the ionized electron energy distribution. This two-electron phenomenon (dubbed continuum-continuum Autler-Townes effect) is analogous to a strongly coupled two-level, one-electron atom but raises some intriguing questions regarding the exact nature of electron-electron correlation. The second case examines the evidence for two-electron ionization in the strong-field tunneling limit. Although their ability to describe the one-electron dynamics has obtained a quantitative level of understanding, a description of the two (multiple) electron ionization remains unclear

  14. Precision laser processing for micro electronics and fiber optic manufacturing

    Science.gov (United States)

    Webb, Andrew; Osborne, Mike; Foster-Turner, Gideon; Dinkel, Duane W.

    2008-02-01

    The application of laser based materials processing for precision micro scale manufacturing in the electronics and fiber optic industry is becoming increasingly widespread and accepted. This presentation will review latest laser technologies available and discuss the issues to be considered in choosing the most appropriate laser and processing parameters. High repetition rate, short duration pulsed lasers have improved rapidly in recent years in terms of both performance and reliability enabling flexible, cost effective processing of many material types including metal, silicon, plastic, ceramic and glass. Demonstrating the relevance of laser micromachining, application examples where laser processing is in use for production will be presented, including miniaturization of surface mount capacitors by applying a laser technique for demetalization of tracks in the capacitor manufacturing process and high quality laser machining of fiber optics including stripping, cleaving and lensing, resulting in optical quality finishes without the need for traditional polishing. Applications include telecoms, biomedical and sensing. OpTek Systems was formed in 2000 and provide fully integrated systems and sub contract services for laser processes. They are headquartered in the UK and are establishing a presence in North America through a laser processing facility in South Carolina and sales office in the North East.

  15. Theory and Simulation of an Inverse Free Electron Laser Experiment

    Science.gov (United States)

    Guo, S. K.; Bhattacharjee, A.; Fang, J. M.; Marshall, T. C.

    1996-11-01

    An experimental demonstration of the acceleration of electrons using a high power CO2 laser in an inverse free electron laser (IFEL) is underway at the Brookhaven National Laboratory. This experiment has generated data, which we are attempting to simulate. Included in our studies are such effects as: a low-loss metallic waveguide with a dielectric coating on the walls; multi-mode coupling due to self-consistent interaction between the electrons and the optical wave; space charge (which is significant at lower laser power); energy-spread of the electrons; arbitrary wiggler field profile; and slippage. Two types of wiggler profile have been considered: a linear taper of the period, and a step-taper of the period (the period is ~ 3cm, the field is ~ 1T, and the wiggler length is 47cm). The energy increment of the electrons ( ~ 1-2%) is analyzed in detail as a function of laser power, wiggler parameters, and the initial beam energy (40MeV). For laser power ~ 0.5GW, the predictions of the simulations are in good accord with experimental results. A matter currently under study is the discrepancy between theory and observations for the electron energy distribution observed at the end of the IFEL. This work is supported by the Department of Energy.

  16. Electron acceleration by CO/sub 2/ laser

    International Nuclear Information System (INIS)

    Fujita, H.; Kitagawa, Y.; Daido, H.

    1986-01-01

    Experiments on electron acceleration have been performed by LEKKO VIII CO/sub 2/ laser system. The laser light was focused by an off-axis parabolic mirror with the F-number of 1.5 and irradiated to thin foil and pipe targets in order to obtain uniform underdense plasmas. Energy spectrum of electrons was measured by an electron spectrometer in the range of 0.3-1.1 MeV. In the single frequency case, electrons up to 1 MeV were observed in the direction of the laser axis for the laser intensity above 1.6 x 10/sup 14/ W/cm/sup 2/ which was equal to the estimated threshold for forward Raman scattering. Amount of high energy electrons depended on the interaction length and the background hot electron temperature. More electrons could resonate with the plasma wave for the higher hot electron temperature. This was confirmed by particle simulation. In most experiments, the plasma density was estimated of about 0.1 n/sub c/. When the plasma density was reduced to 0.01 n/sub c/ using pre-pulse, high energy electrons were not observed because of the low background hot electron temperature and the higher instability threshold. In the two frequency case, energetic electron beam injection is planned for efficient coupling with fast plasma wave. Pipe target seems to be hopeful because 1) the laser light is confined by the plasma fiber and 2) the phase velocity of the plasma wave is controlled by the transverse mode

  17. High-efficiency free-electron-laser experiments

    International Nuclear Information System (INIS)

    Boyer, K.; Brau, C.A.; Goldstein, J.C.; Hohla, K.L.; Newnam, B.E.; Stein, W.E.; Warren, R.W.; Winston, J.G.

    1983-01-01

    Experiments with a tapered-wiggler free-electron laser have demonstrated extraction of about 3% of the energy from the electron beam and measured the corresponding optical emission. These results are in excellent agreement with theory and represent an order-of-magnitude improvement over all previous results

  18. Coherent Startup of an Infrared Free-Electron Laser

    NARCIS (Netherlands)

    Jaroszynski, D. A.; Bakker, R. J.; van der Meer, A. F. G.; Oepts, D.; van Amersfoort, P. W.

    1993-01-01

    Coherent enhancement of the spontaneous undulator radiation by several orders of magnitude has been observed in a free-electron laser at wavelengths from 40 to 100 mum. The coherent emission can be explained by details of the electron-beam micropulse structure. Furthermore, it has been found that

  19. Linac-driven XUV free-electron laser

    International Nuclear Information System (INIS)

    Newnam, B.E.; Goldstein, J.C.; Fraser, J.S.; Cooper, R.K.

    1983-01-01

    Use of an rf linear accelerator as the electron source for a free-electron laser operating in the extreme ultraviolet wavelength range from 100 nm to at least as low as 50 nm appears feasible. Peak and average power outputs of greater than 100 kW and 50W, respectively, are predicted

  20. Free electron laser amplifier driven by an induction linac

    International Nuclear Information System (INIS)

    Neil, V.K.

    1986-01-01

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

  1. XUV/VUV free-electron laser oscillator

    International Nuclear Information System (INIS)

    Goldstein, J.C.; Newnam, B.E.; Cooper, R.K.; Comly, J.C. Jr.

    1984-04-01

    It is shown, from computations based on a detailed theoretical model, that modest improvements in electron beam and optical mirror technologies will enable a free-electron laser, driven by an rf linear accelerator, to operate in the 50 to 200-nm range of optical wavelengths. 10 references

  2. Photonuclear fission with quasimonoenergetic electron beams from laser wakefields

    International Nuclear Information System (INIS)

    Reed, S. A.; Chvykov, V.; Kalintchenko, G.; Matsuoka, T.; Rousseau, P.; Yanovsky, V.; Vane, C. R.; Beene, J. R.; Stracener, D.; Schultz, D. R.; Maksimchuk, A.

    2006-01-01

    Recent advancements in laser wakefield accelerators have resulted in the generation of low divergence, hundred MeV, quasimonoenergetic electron beams. The bremsstrahlung produced by these highly energetic electrons in heavy converters includes a large number of MeV γ rays that have been utilized to induce photofission in natural uranium. Analysis of the measured delayed γ emission demonstrates production of greater than 3x10 5 fission events per joule of laser energy, which is more than an order of magnitude greater than that previously achieved. Monte Carlo simulations model the generated bremsstrahlung spectrum and compare photofission yields as a function of target depth and incident electron energy

  3. Laser plasma acceleration of electrons with multi-PW laser beams in the frame of CILEX

    Energy Technology Data Exchange (ETDEWEB)

    Cros, B., E-mail: brigitte.cros@u-psud.fr [LPGP, CNRS and Université Paris Sud, Orsay (France); Paradkar, B.S. [LPGP, CNRS and Université Paris Sud, Orsay (France); Davoine, X. [CEA DAM DIF, Arpajon F-91297 (France); Chancé, A. [CEA IRFU-SACM, Gif-Sur-Yvette (France); Desforges, F.G. [LPGP, CNRS and Université Paris Sud, Orsay (France); Dobosz-Dufrénoy, S. [CEA DSM-IRAMIS-SPAM, Gif-sur-Yvette (France); Delerue, N. [LAL, CNRS and Universit Paris Sud, Orsay (France); Ju, J.; Audet, T.L.; Maynard, G. [LPGP, CNRS and Université Paris Sud, Orsay (France); Lobet, M.; Gremillet, L. [CEA DAM DIF, Arpajon F-91297 (France); Mora, P. [CPhT, CNRS and Ecole Polytechnique, Palaiseau (France); Schwindling, J.; Delferrière, O. [CEA IRFU-SACM, Gif-Sur-Yvette (France); Bruni, C.; Rimbault, C.; Vinatier, T. [LAL, CNRS and Universit Paris Sud, Orsay (France); Di Piazza, A. [Max-Planck-Institut für Kernphysik, Heidelberg (Germany); Grech, M. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Palaiseau (France); and others

    2014-03-11

    Laser plasma acceleration of electrons has progressed along with advances in laser technology. It is thus expected that the development in the near-future of multi-PW-class laser and facilities will enable a vast range of scientific opportunities for laser plasma acceleration research. On one hand, high peak powers can be used to explore the extremely high intensity regime of laser wakefield acceleration, producing for example large amounts of electrons in the GeV range or generating high energy photons. On the other hand, the available laser energy can be used in the quasi-linear regime to create accelerating fields in large volumes of plasma and study controlled acceleration in a plasma stage of externally injected relativistic particles, either electrons or positrons. In the frame of the Centre Interdisciplinaire de la Lumière EXtrême (CILEX), the Apollon-10P laser will deliver two beams at the 1 PW and 10 PW levels, in ultra-short (>15fs) pulses, to a target area dedicated to electron acceleration studies, such as the exploration of the non-linear regimes predicted theoretically, or multi-stage laser plasma acceleration.

  4. European Power Electronic conference in Aalborg, Denmark - 1000 participants discussing the future energy technologies

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Munk-Nielsen, Stig

    2007-01-01

    The European Power Electronics and Adjustable Speed Drives conference with technical sponsorship of IEEE Industrial Electronic Society has been held in Aalborg, Denmark, during the first days of September 2007 with an overwhelming success and participation. It was hosted by Aalborg University's I...

  5. An inverse free electron laser accelerator: Experiment and theoretical interpretation

    International Nuclear Information System (INIS)

    Fang, Jyan-Min.

    1997-01-01

    Experimental and numerical studies of the Inverse Free Electron Laser using a GW-level 10.6 μm CO 2 laser have been carried out at Brookhaven's Accelerator Test Facility. An energy gain of 2.5 % (ΔE/E) on a 40 MeV electron beam has been observed E which compares well with theory. The effects on IFEL acceleration with respect to the variation of the laser electric field, the input electron beam energy, and the wiggler magnetic field strength were studied, and show the importance of matching the resonance condition in the IFEL. The numerical simulations were performed under various conditions and the importance of the electron bunching in the IFEL is shown. The numerical interpretation of our IFEL experimental results was examined. Although good numerical agreement with the experimental results was obtained, there is a discrepancy between the level of the laser power measured in the experiment and used in the simulation, possibly due to the non-Gaussian profile of the input high power laser beam. The electron energy distribution was studied numerically and a smoothing of the energy spectrum by the space charge effect at the location of the spectrometer was found, compared with the spectrum at the exit of the wiggler. The electron bunching by the IFEL and the possibility of using the IFEL as an electron prebuncher for another laser-driven accelerator were studied numerically. We found that bunching of the electrons at 1 meter downstream from the wiggler can be achieved using the existing facility. The simulation shows that there is a fundamental difference between the operating conditions for using the IFEL as a high gradient accelerator, and as a prebuncher for another accelerator

  6. Beam conditioner for free electron lasers and synchrotrons

    International Nuclear Information System (INIS)

    Liu, H.; Neil, G.R.

    1998-01-01

    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 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

  7. Guiding-center equations for electrons in ultraintense laser fields

    International Nuclear Information System (INIS)

    Moore, J.E.; Fisch, N.J.

    1994-01-01

    The guiding-center equations are derived for electrons in arbitrarily intense laser fields also subject to external fields and ponderomotive forces. Exhibiting the relativistic mass increase of the oscillating electrons, a simple frame-invariant equation is shown to govern the behavior of the electrons for sufficiently weak background fields and ponderomotive forces. The parameter regime for which such a formulation is valid is made precise, and some predictions of the equation are checked by numerical simulation

  8. High power electron beam accelerators for gas laser excitation

    International Nuclear Information System (INIS)

    Kelly, J.G.; Martin, T.H.; Halbleib, J.A.

    1976-06-01

    A preliminary parameter investigation has been used to determine a possible design of a high-power, relativistic electron beam, transversely excited laser. Based on considerations of present and developing pulsed power technology, broad area diode physics and projected laser requirements, an exciter is proposed consisting of a Marx generator, pulse shaping transmission lines, radially converging ring diodes and a laser chamber. The accelerator should be able to deliver approximately 20 kJ of electron energy at 1 MeV to the 10 4 cm 2 cylindrical surface of a laser chamber 1 m long and 0.3 m in diameter in 24 ns with very small azimuthal asymmetry and uniform radial deposition

  9. Electron in the ultrashort laser pulse

    Czech Academy of Sciences Publication Activity Database

    Pardy, Miroslav

    2003-01-01

    Roč. 42, č. 1 (2003), s. 99-110 ISSN 0020-7748 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z2043910 Keywords : laser pulse, Volkov solution, compton effect Subject RIV: BE - The oretical Physics Impact factor: 0.476, year: 2003

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

    Science.gov (United States)

    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. Intense pulsed sources of ions and electrons produced by lasers

    International Nuclear Information System (INIS)

    Bourrabier, G.; Consoli, T.; Slama, L.

    1966-11-01

    We describe a device for the acceleration of the plasma burst produced by focusing a laser beam into a metal target. We extract the electrons and the ions from the plasma. The maximum current is around 2000 amperes during few microseconds. The study of the effect of the kind of the target on the characteristics of the current shows the great importance of the initial conditions that is the ionisation potential of the target and the energy laser. (authors) [fr

  12. Pulse propagation in tapered wiggler free electron lasers

    International Nuclear Information System (INIS)

    Goldstein, J.C.; Colson, W.B.

    1981-01-01

    The one-dimensional theory of short pulse propagation in free electron lasers is extended to tapered wiggler devices and is used to study the behavior of an oscillator with parameter values close to those expected in forthcoming experiments. It is found that stable laser output is possible only over a small range of optical cavity lengths. Optical pulse characteristcs are presented and are found to change considerably over this range

  13. Solid state lasers: a major direction in quantum electronics

    International Nuclear Information System (INIS)

    Shcherbakov, I.A.

    2004-01-01

    The aim of the report is to analyze development of solid-state lasers (SSL) as one of the most important avenues of the quantum electronics. The obtained intensity of a laser radiation at the focus equal to 5x10 1 0 W/cm 2 (the field intensity equal to about 5x10 1 0 V/cm 2 ) is noted to enable to observe nonlinear quantum- electrodynamic effects. Besides, one managed to increase the SSL efficiency conventionally equal to maximum 3% up to 48-50%. Paper describes new types of SSLs, namely, the crystalline fiber lasers with the lateral gradient of the index of refraction [ru

  14. Ultrafast molecular imaging by laser-induced electron diffraction

    International Nuclear Information System (INIS)

    Peters, M.; Nguyen-Dang, T. T.; Cornaggia, C.; Saugout, S.; Charron, E.; Keller, A.; Atabek, O.

    2011-01-01

    We address the feasibility of imaging geometric and orbital structures of a polyatomic molecule on an attosecond time scale using the laser-induced electron diffraction (LIED) technique. We present numerical results for the highest molecular orbitals of the CO 2 molecule excited by a near-infrared few-cycle laser pulse. The molecular geometry (bond lengths) is determined within 3% of accuracy from a diffraction pattern which also reflects the nodal properties of the initial molecular orbital. Robustness of the structure determination is discussed with respect to vibrational and rotational motions with a complete interpretation of the laser-induced mechanisms.

  15. Diode laser spectroscopy of oxygen electronic band at 760 nm

    International Nuclear Information System (INIS)

    Lucchesini, A.; De Rosa, M.; Gozzini, S.

    1998-01-01

    Collisional broadening and shift coefficients have been obtained by analyzing the line shapes of oxygen absorptions in the 760 nm electronic band. By using a diode laser spectrometer with commercially available etherostructure Al x Ga 1-x As diode lasers operating in 'free-running mode', line shape parameters have been collected at room temperature by varying the gas pressure. A systematic study has been carried on seven absorption lines by scanning the diode laser emission wavelength around the gas resonances. The weak absorption lines have been detected by using the wavelength modulation (WM) spectroscopy technique with second-harmonic detection

  16. A spectral unaveraged algorithm for free electron laser simulations

    International Nuclear Information System (INIS)

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

    2015-01-01

    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 field–particles 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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    We discuss the design and current status of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, VUV pulses driven by a high-current, GeV electron beam from the existing Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few cm. The proposed ultra-fast source would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science with pulse lengths of tens of fs. Owing to the high current ( and 10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 1013 photons/pulse. Devices based both on SASE and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered

  19. Multi-GeV electron-positron beam generation from laser-electron scattering.

    Science.gov (United States)

    Vranic, Marija; Klimo, Ondrej; Korn, Georg; Weber, Stefan

    2018-03-16

    The new generation of laser facilities is expected to deliver short (10 fs-100 fs) laser pulses with 10-100 PW of peak power. This opens an opportunity to study matter at extreme intensities in the laboratory and provides access to new physics. Here we propose to scatter GeV-class electron beams from laser-plasma accelerators with a multi-PW laser at normal incidence. In this configuration, one can both create and accelerate electron-positron pairs. The new particles are generated in the laser focus and gain relativistic momentum in the direction of laser propagation. Short focal length is an advantage, as it allows the particles to be ejected from the focal region with a net energy gain in vacuum. Electron-positron beams obtained in this setup have a low divergence, are quasi-neutral and spatially separated from the initial electron beam. The pairs attain multi-GeV energies which are not limited by the maximum energy of the initial electron beam. We present an analytical model for the expected energy cutoff, supported by 2D and 3D particle-in-cell simulations. The experimental implications, such as the sensitivity to temporal synchronisation and laser duration is assessed to provide guidance for the future experiments.

  20. Optimization and application of electron acceleration in relativistic laser plasmas

    International Nuclear Information System (INIS)

    Koenigstein, Thomas

    2013-01-01

    This thesis describes experiments and simulations of the acceleration of electrons to relativistic energies (toward γ e ∼ 10 3 ) by structures in plasmas which are generated by ultrashort (pulse length < 10 -14 s) laser pulses. The first part of this work discusses experiments in a parameter space where quasimonoenergetic electron bunches are generated in subcritical (gaseous) plasmas and compares them to analytical scalings. A primary concern in this work is to optimize the stability of the energy and the pointing of the electrons. The second part deals with acceleration of electrons along the surface of solid substrates by laser-plasma interaction. The measurements show good agreement with existing analytical scalings and dedicated numerical simulations. In the third part, two new concepts for multi-stage acceleration will be presented and parameterised by analytical considerations and numerical simulations. The first method uses electron pairs, as produced in the first part, to transfer energy from the first bunch to the second by means of a plasma wave. The second method utilizes a low intensity laser pulse in order to inject electrons from a neutral gas into the accelerating phase of a plasma wave. The final chapter proposes and demonstrates a first application that has been developed in collaboration with ESA. The use of electron beams with exponential energy distribution, as in the second part of this work, offers the potential to investigate the resistance of electronic components against space radiation exposure.

  1. Free electron lasers for transmission of energy in space

    Science.gov (United States)

    Segall, S. B.; Hiddleston, H. R.; Catella, G. C.

    1981-01-01

    A one-dimensional resonant-particle model of a free electron laser (FEL) is used to calculate laser gain and conversion efficiency of electron energy to photon energy. The optical beam profile for a resonant optical cavity is included in the model as an axial variation of laser intensity. The electron beam profile is matched to the optical beam profile and modeled as an axial variation of current density. Effective energy spread due to beam emittance is included. Accelerators appropriate for a space-based FEL oscillator are reviewed. Constraints on the concentric optical resonator and on systems required for space operation are described. An example is given of a space-based FEL that would produce 1.7 MW of average output power at 0.5 micrometer wavelength with over 50% conversion efficiency of electrical energy to laser energy. It would utilize a 10 m-long amplifier centered in a 200 m-long optical cavity. A 3-amp, 65 meV electrostatic accelerator would provide the electron beam and recover the beam after it passes through the amplifier. Three to five shuttle flights would be needed to place the laser in orbit.

  2. Electron acceleration using laser produced plasmas

    CERN Multimedia

    CERN. Geneva; Landua, Rolf

    2005-01-01

    Low density plasmas have long been of interest as a potential medium for particle acceleration since relativistic plasma waves are capable of supporting electric fields greater than 100 GeV/m. The physics of particle acceleration using plasmas will be reviewed, and new results will be discussed which have demonstrated that relatively narrow energy spread (<3%) beams having energies greater than 100 MeV can be produced from femtosecond laser plasma interactions. Future experiments and potential applications will also be discussed.

  3. ICTEI-2015: International Conference on Telecommunications, Electronics and Informatics. Proceedings

    International Nuclear Information System (INIS)

    Kantser, V.; Andronic, S.

    2015-01-01

    This book includes articles which cover a vast range of subjects, such as: telecommunications networks and technologies; electronic, optoelectronic, photonic and information systems and devices; materials, components and equipment in electronics and communications; informatics and computer science; software development and testing etc.

  4. Observation of second harmonics in laser-electron scattering using low energy electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Iinuma, Masataka [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan)]. E-mail: iinuma@hiroshima-u.ac.jp; Matsukado, Koji [Venture Business Laboratory, Hiroshima University, 1-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527 (Japan); Endo, Ichita [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Hashida, Masaki [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, Kenji [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Kohara, Akitsugu [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Matsumoto, Fumihiko [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Nakanishi, Yoshitaka [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Sakabe, Shuji [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Shimizu, Seiji [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Tauchi, Toshiaki [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yamamoto, Ken [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Takahashi, Tohru [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan)

    2005-10-17

    We observed photon generation in the second harmonic region in collisions of 10 keV free electrons and the intense laser beam with the peak intensity of 4.0x10{sup 15} W/cm{sup 2}. Observed photon yield was 3 orders of magnitude higher than expectation from the nonlinear Compton scattering. The observation indicates necessity of further investigation for the interaction between the intense laser field and the low energy electron beam.

  5. 2005 Laser Diagnostics in Combustion Gordon Conference July 31-August 5, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Mark G. Allen

    2005-08-01

    The Gordon Research Conference (GRC) on LASER DIAGNOSTICS IN COMBUSTION was held at Mount Holyoke College from 7/31/2005 thru 8/5/2005. The Conference was well-attended with 121 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field. I want to personally thank you for your support of this Conference. As you know, in the interest of promoting the presentation of unpublished and frontier-breaking research, Gordon Research Conferences does not permit publication of meeting proceedings. If you wish any further details, please feel free to contact me.

  6. Short wavelength optics for future free electron lasers

    International Nuclear Information System (INIS)

    Attwood, D.T.

    1984-04-01

    Although much free-electron laser work is directed toward achieving sufficient single-pass gain to be useful for research purposes, the availability of mirrors of high reflectance for the vacuum ultraviolet and soft x-ray regime would make resonant cavities a possibility. In addition, as in ordinary synchrotron radiation work, mirrors are required for the construction of realistic experiments and for beam manipulation purposes such as folding and extraction. The Working Group discussed a number of approaches to reflecting optics for free electron lasers, which are summarized here, and described in some detail. 16 references, 2 figures

  7. A laser printing based approach for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Hu, M.; Guo, Q.; Zhang, W.; Yang, J., E-mail: jyang@eng.uwo.ca [Department of Mechanical and Materials Engineering, Western University, London N6A 3K7 (Canada); Liu, Y.; Lau, W. [Chengdu Green Energy and Green Manufacturing Technology R& D Center, 355 Tengfei Road, 620107 Chengdu (China); Wang, X. [Department of Mechanical and Materials Engineering, Western University, London N6A 3K7 (Canada); Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-03-07

    Here we report a study of printing of electronics using an office use laser printer. The proposed method eliminates those critical disadvantages of solvent-based printing techniques by taking the advantages of electroless deposition and laser printing. The synthesized toner acts as a catalyst for the electroless copper deposition as well as an adhesion-promoting buffer layer between the substrate and deposited copper. The easy metallization of printed patterns and strong metal-substrate adhesion make it an especially effective method for massive production of flexible printed circuits. The proposed process is a high throughput, low cost, efficient, and environmentally benign method for flexible electronics manufacturing.

  8. Free electron laser on the ACO storage ring

    International Nuclear Information System (INIS)

    Elleaume, P.

    1984-06-01

    This dissertation presents the design and characteristics of a Free Electron Laser built on the electron storage ring ACO at Orsay. The weak optical gain available (approximately 0.1% per pass) necessitated the use of an optical klystron instead of an undulator and the use of mirror with extremely high reflectivity. The laser characteristics: spectra, micro and macro-temporal structures, transverse structure and power are presented. They are in very good agreement with a classical theory based on the Lorentz force and Maxwell equations [fr

  9. A laser printing based approach for printed electronics

    International Nuclear Information System (INIS)

    Zhang, T.; Hu, M.; Guo, Q.; Zhang, W.; Yang, J.; Liu, Y.; Lau, W.; Wang, X.

    2016-01-01

    Here we report a study of printing of electronics using an office use laser printer. The proposed method eliminates those critical disadvantages of solvent-based printing techniques by taking the advantages of electroless deposition and laser printing. The synthesized toner acts as a catalyst for the electroless copper deposition as well as an adhesion-promoting buffer layer between the substrate and deposited copper. The easy metallization of printed patterns and strong metal-substrate adhesion make it an especially effective method for massive production of flexible printed circuits. The proposed process is a high throughput, low cost, efficient, and environmentally benign method for flexible electronics manufacturing.

  10. Beamline for X-ray Free Electron Laser of SACLA

    International Nuclear Information System (INIS)

    Tono, K; Togashi, T; Ohashi, H; Kimura, H; Takahashi, S; Takeshita, K; Tomizawa, H; Goto, S; Inubushi, Y; Sato, T; Yabashi, M

    2013-01-01

    A beamline for X-ray free electron laser (XFEL) has been developed at SACLA, SPring-8 Angstrom Compact free electron LAser. The beamline delivers and diagnoses an XFEL beam without degrading the beam quality. The transport optics are applicable in the range of 4–30 keV with a double-crystal monochromator or 4–15 keV with either of two double-mirror systems. A photon diagnostic system of the beamline monitors intensity, photon energy, center-of-mass position, and spatial profile in shot-by-shot and non-destructive manners.

  11. Proceedings of 2011 International Conference on Electronic Engineering, Communication and Management

    CERN Document Server

    Lin, Sally

    2012-01-01

      This volume presents the main results of 2011 International Conference on Electronic  Engineering, Communication and Management (EECM2011) held December 24-25, 2011, Beijing China. The EECM2011 is an integrated conference providing a valuable opportunity for researchers, scholars and scientists to exchange their ideas face to face together. The main focus of the EECM 2011 and the present 2 volumes “Advances in Electronic Engineering, Communication and Management” is on Power Engineering, Electrical engineering applications, Electrical machines, as well as Communication and Information Systems Engineering.

  12. Proceedings of 2011 International Conference on Electronic Engineering, Communication and Management

    CERN Document Server

    Lin, Sally

    2012-01-01

    This volume presents the main results of 2011 International Conference on Electronic  Engineering, Communication and Management (EECM2011) held December 24-25, 2011, Beijing China. The EECM2011 is an integrated conference providing a valuable opportunity for researchers, scholars and scientists to exchange their ideas face to face together. The main focus of the EECM 2011 and the present 2 volumes “Advances in Electronic Engineering, Communication and Management” is on Power Engineering, Electrical engineering applications, Electrical machines, as well as Communication and Information Systems Engineering.

  13. Automatic tuning of free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, Ilya; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL, Schenefeld (Germany); Tomin, Sergey [European XFEL, Schenefeld (Germany); NRC Kurchatov Institute, Moscow (Russian Federation)

    2017-04-07

    Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various components. The tuning procedures typically employed in operation are often manual and lengthy. We have been developing a combination of model-free and model-based automatic tuning methods to meet the needs of present and upcoming XFEL facilities. Our approach has been implemented at FLASH to achieve automatic SASE tuning using empirical control of orbit, electron optics and bunch compression. In this paper we describe our approach to empirical tuning, the software which implements it, and the results of using it at FLASH.We also discuss the potential of using machine learning and model-based techniques in tuning methods.

  14. Automatic tuning of free electron lasers

    International Nuclear Information System (INIS)

    Agapov, Ilya; Zagorodnov, Igor; Geloni, Gianluca; Tomin, Sergey

    2017-01-01

    Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various components. The tuning procedures typically employed in operation are often manual and lengthy. We have been developing a combination of model-free and model-based automatic tuning methods to meet the needs of present and upcoming XFEL facilities. Our approach has been implemented at FLASH to achieve automatic SASE tuning using empirical control of orbit, electron optics and bunch compression. In this paper we describe our approach to empirical tuning, the software which implements it, and the results of using it at FLASH.We also discuss the potential of using machine learning and model-based techniques in tuning methods.

  15. Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse

    International Nuclear Information System (INIS)

    Wang Xiaofang; Saleh, Ned; Krishnan, Mohan; Wang Haiwen; Backus, Sterling; Murnane, Margaret; Kapteyn, Henry; Umstadter, Donald; Wang Quandong; Shen Baifei

    2003-01-01

    Mega-electron-volt (MeV) electron emission from the interaction of an ultrafast (τ∼29 fs), intense (>10 18 W/cm 2 ) laser pulse with underdense plasmas has been studied. A beam of MeV electrons with a divergence angle as small as 1 deg. is observed in the forward direction, which is correlated with relativistic filamentation of the laser pulse in plasmas. A novel net-energy-gain mechanism is proposed for electron acceleration resulting from the relativistic filamentation and beam breakup. These results suggest an approach for generating a beam of femtosecond, MeV electrons at a kilohertz repetition rate with a compact ultrafast intense laser system

  16. 2nd Biennial Conference on Refrigeration for Cryogenic Sensors and Electronic Systems

    CERN Document Server

    1983-01-01

    This proceedings documents the output of the Second Biennial Conference on Refrigeration for Cryogenic Sensors and Electronic Systems held at the National Aeronautics and Space Administration's Goddard Space Flight Center, Greenbelt, Maryland, on December 7-8, 1982. Building on the first open meeting hosted by the National Bureau of Standards in 1980, the focus of this second meeting was again on low-temperature, closed-cycle cooler technology. However, higher temperature coolers (77 K), with technology applicable to the low temperature coolers, were considered to be within the scope of this meeting. This second conference consisted of 30 papers presented by representatives of industry, government, and academia. The conference proceedings reproduced here was published by the NASA Goddard Space Flight Center in Greenbelt Maryland as NASA Conference Publication 2287.

  17. Electron acceleration by laser produced wake field: Pulse shape effect

    Science.gov (United States)

    Malik, Hitendra K.; Kumar, Sandeep; Nishida, Yasushi

    2007-12-01

    Analytical expressions are obtained for the longitudinal field (wake field: Ex), density perturbations ( ne') and the potential ( ϕ) behind a laser pulse propagating in a plasma with the pulse duration of the electron plasma period. A feasibility study on the wake field is carried out with Gaussian-like (GL) pulse, rectangular-triangular (RT) pulse and rectangular-Gaussian (RG) pulse considering one-dimensional weakly nonlinear theory ( ne'/n0≪1), and the maximum energy gain acquired by an electron is calculated for all these three types of the laser pulse shapes. A comparative study infers that the RT pulse yields the best results: In its case maximum electron energy gain is 33.5 MeV for a 30 fs pulse duration whereas in case of GL (RG) pulse of the same duration the gain is 28.6 (28.8)MeV at the laser frequency of 1.6 PHz and the intensity of 3.0 × 10 18 W/m 2. The field of the wake and hence the energy gain get enhanced for the higher laser frequency, larger pulse duration and higher laser intensity for all types of the pulses.

  18. Emittance Measurements from a Laser Driven Electron Injector

    Energy Technology Data Exchange (ETDEWEB)

    Reis, David A

    2003-07-28

    The Gun Test Facility (GTF) at the Stanford Linear Accelerator Center was constructed to develop an appropriate electron beam suitable for driving a short wavelength free electron laser (FEL) such as the proposed Linac Coherent Light Source (LCLS). For operation at a wavelength of 1.5 {angstrom}, the LCLS requires an electron injector that can produce an electron beam with approximately 1 {pi} mm-mrad normalized rms emittance with at least 1 nC of charge in a 10 ps or shorter bunch. The GTF consists of a photocathode rf gun, emittance-compensation solenoid, 3 m linear accelerator (linac), drive laser, and diagnostics to measure the beam. The rf gun is a symmetrized 1.6 cell, s-band high gradient, room temperature, photocathode structure. Simulations show that this gun when driven by a temporally and spatially shaped drive laser, appropriately focused with the solenoid, and further accelerated in linac can produce a beam that meets the LCLS requirements. This thesis describes the initial characterization of the laser and electron beam at the GTF. A convolved measurement of the relative timing between the laser and the rf phase in the gun shows that the jitter is less than 2.5 ps rms. Emittance measurements of the electron beam at 35 MeV are reported as a function of the (Gaussian) pulse length and transverse profile of the laser as well as the charge of the electron beam at constant phase and gradient in both the gun and linac. At 1 nC the emittance was found to be {approx} 13 {pi} mm-mrad for 5 ps and 8 ps long laser pulses. At 0.5 nC the measured emittance decreased approximately 20% in the 5 ps case and 40% in the 8 ps case. These measurements are between 40-80% higher than simulations for similar experimental conditions. In addition, the thermal emittance of the electron beam was measured to be 0.5 {pi} mm-mrad.

  19. Bunch decompression for laser-plasma driven free-electron laser demonstration schemes

    Directory of Open Access Journals (Sweden)

    T. Seggebrock

    2013-07-01

    Full Text Available X-ray free-electron lasers (FELs require a very high electron beam quality in terms of emittance and energy spread. Since 2004 high quality electrons produced by laser-wakefield accelerators have been demonstrated, but the electron quality up to now did not allow the operation of a compact x-ray FEL using these electrons. Maier et al. [Phys. Rev. X 2, 031019 (2012PRXHAE2160-330810.1103/PhysRevX.2.031019] suggested a concept for a proof-of-principle experiment allowing FEL operation in the vacuum ultraviolet range based on an optimized undulator and bunch decompression using electron bunches from a laser-plasma accelerator as currently available. In this paper we discuss in more detail how a chicane can be used as a bunch stretcher instead of a bunch compressor to allow the operation of a laser-wakefield accelerator driven FEL using currently available electrons. A scaling characterizing the impact of bunch decompression on the gain length is derived and the feasibility of the concept is tested numerically in a demanding scenario.

  20. Inhomogeneous effects in the quantum free electron laser

    International Nuclear Information System (INIS)

    Piovella, N.; Bonifacio, R.

    2006-01-01

    We include inhomogeneous effects in the quantum model of a free electron laser taking into account the initial energy spread of the electron beam. From a linear analysis, we obtain a generalized dispersion relation, from which the exponential gain can be explicitly calculated. We determine the maximum allowed initial energy spread in the quantum exponential regime and we discuss the limit of large energy spread

  1. Vibrational analysis of a shipboard free electron laser beam path

    OpenAIRE

    Gallant, Bryan M.

    2011-01-01

    This thesis explores the deployment of a free electron laser (FEL) weapon system in a shipboard vibration environment. A concept solid model of a shipboard FEL is developed and used as a basis for a finite element model which is subjected to vibration simulation in MATLAB. Vibration input is obtained from ship shock trials data and wave excited motion data from ship motion simulation software. Emphasis is placed on the motion of electron beam path components of the FEL and the feasibility of ...

  2. Desorption by Femtosecond Laser Pulses : An Electron-Hole Effect?

    OpenAIRE

    D. M., NEWNS; T. F., HEINZ; J. A., MISEWICH; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center

    1992-01-01

    Desorption of molecules from metal surfaces induced by femtosecond visible laser pulses has been reported. Since the lattice temperature rise is insufficient to explain desorption, an electronic mechanism is clearly responsible. It is shown that a theory based on direct coupling between the center-of-mass degree of freedom of the adsorbate and the electron-hole excitations of the substrate provides a satisfactory explanation of the various experimental findings.

  3. Channeling of electrons in a crossed laser field

    Directory of Open Access Journals (Sweden)

    S. B. Dabagov

    2015-06-01

    Full Text Available In this article a new analytical description of the effective interaction potential for a charged particle with the field of two interfering laser beams is presented. The potential dependence on the lasers intensities, orientation and parameters of the particle entering the considered system is analyzed. For the first time the phenomenon of effective potential inversion (or “relativistic reversal” is described for arbitrary lasers crossing angle. Threshold electron velocity values for the phenomenon are introduced and its extended illustration based on numerical simulations for two laser beams polarizations is presented. In addition the projectile radiation spectral distribution is given and general estimations on the expected beam radiation yield are outlined.

  4. Microlens Array Laser Transverse Shaping Technique for Photoemission Electron Source

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Northern Illinois Univ., DeKalb, IL (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ha, G. [Argonne National Lab. (ANL), Argonne, IL (United States); Pohang Univ. of Science and Technology (POSTECH) (Korea, Republic of); Qiang, G. [Argonne National Lab. (ANL), Argonne, IL (United States); Tsinghua Univ., Beijing (China); Gai, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Power, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Piot, P. [Northern Illinois Univ., DeKalb, IL (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wisniewski, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Edstrom, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ruan, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Santucci, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-09-06

    A common issue encountered in photoemission electron sources used in electron accelerators is distortion of the laser spot due to non ideal conditions at all stages of the amplification. Such a laser spot at the cathode may produce asymmetric charged beams that will result in degradation of the beam quality due to space charge at early stages of acceleration and fail to optimally utilize the cathode surface. In this note we study the possibility of using microlens arrays to dramatically improve the transverse uniformity of the drive laser pulse on UV photocathodes at both Fermilab Accelerator Science \\& Technology (FAST) facility and Argonne Wakefield Accelerator (AWA). In particular, we discuss the experimental characterization of the homogeneity and periodic patterned formation at the photocathode. Finally, we compare the experimental results with the paraxial analysis, ray tracing and wavefront propagation software.

  5. Inverse free electron laser accelerator for advanced light sources

    Directory of Open Access Journals (Sweden)

    J. P. Duris

    2012-06-01

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

  6. Electronic dynamics induced by laser in (D)KDP crystals

    International Nuclear Information System (INIS)

    Duchateau, G.; Geoffroy, G.; Dyan, A.; Piombini, H.; Geoffroy, G.; Guizard, S.

    2011-01-01

    DKDP (KD 2 PO 4 ) and KDP (KH 2 PO 4 ) crystals that are used in frequency conversion systems have a damage threshold that limits the development of power lasers. It is assumed that laser-induced damage (LID) stems for a precursor defect present in the crystal or quickly generated by the laser-radiation. The Socrate bench has been useful for studying the evolution of LID but the understanding of the very beginning of the LID requires a new method. We have performed femtosecond interferometric measures to study the behaviour of charge carriers. We show that the valence electrons are excited through multi-photon absorption and their relaxation time depends on the isotope (hydrogen or deuterium). The various electron populations are computed through an adequate simulation and the comparison with experimental data has allowed us to get values for multi-photon absorption cross-sections and relaxation times

  7. Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

    International Nuclear Information System (INIS)

    Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2013-01-01

    The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA

  8. XI Scientific Conference Selected Issues of Electrical Engineering and Electronics (WZEE)

    CERN Document Server

    Mazur, Damian; Analysis and Simulation of Electrical and Computer Systems

    2015-01-01

    This book presents the selected results of the XI Scientific Conference Selected Issues of Electrical Engineering and Electronics (WZEE) which was held in Rzeszów and Czarna, Poland on September 27-30, 2013. The main aim of the Conference was to provide academia and industry to discuss and present the latest technological advantages and research results and to integrate the new interdisciplinary scientific circle in the field of electrical engineering, electronics and mechatronics. The Conference was organized by the Rzeszów Division of Polish Association of Theoretical and Applied Electrical Engineering (PTETiS) in cooperation with Rzeszów University of Technology, the Faculty of Electrical and Computer Engineering and Rzeszów University, the Faculty of Mathematics and Natural Sciences.  

  9. Synchrotron radiation and free electron laser activities in Novosibirsk

    International Nuclear Information System (INIS)

    Korchuganov, V.N.; Kulipanov, G.N.; Mezentsev, N.A.; Oreshkov, A.D.; Panchenko, V.E.; Pindyurin, V.F.; Skrinskij, A.N.; Sheromov, M.A.; Vinokurov, N.A.; Zolotarev, K.V.

    1994-01-01

    The results of studies realized in the Siberian synchrotron radiation centre within the frameworks of wide program of synchrotron radiation and free electron laser research are summarized. The technical information on the VEPP-2M, VEPP-3 and VEPP-4M storage rings used as synchrotron radiation sources is given. 10 refs.; 8 figs.; 12 tabs

  10. Emittance growth in laser-driven RF electron guns

    International Nuclear Information System (INIS)

    Kim, K.J.

    1989-01-01

    A simple analysis for the evolution of the electron-beam phase space distribution in laser-driven rf guns is presented. In particular, formulas are derived for the transverse and longitudinal emittances at the exit of the gun. The results are compared and found to agree well with those from simulation. (Author). 9 refs.; 4 figs

  11. Three-dimensional simulations of free-electron laser physics

    International Nuclear Information System (INIS)

    McVey, B.D.

    1985-09-01

    A computer code has been developed to simulate three-dimensional free-electron laser physics. A mathematical formulation of the FEL equations is presented, and the numerical solution of the problem is described. Sample results from the computer code are discussed. 23 refs., 6 figs., 2 tabs

  12. Modeling paraxial wave propagation in free-electron laser oscillators

    NARCIS (Netherlands)

    Karssenberg, J.G.; van der Slot, Petrus J.M.; Volokhine, I.; Verschuur, Jeroen W.J.; Boller, Klaus J.

    2006-01-01

    Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the light propagation outside the undulator. We have developed a paraxial optical propagation code that can be combined with various existing models of gain media, for

  13. Mechanisms for the production of harmonics in free electron lasers

    NARCIS (Netherlands)

    Elgin, J.N.; Penman, C.

    1991-01-01

    Harmonics in the radiation of a free electron laser are useful for extending the range of tuning, may originate in spontaneous or parametric processes, and can take part in stimulated emission or amplification. These mechanisms exhibit interesting analogies with those of nonlinear optics. Apart from

  14. Electron laser acceleration in vacuum by a quadratically chirped laser pulse

    International Nuclear Information System (INIS)

    Salamin, Yousef I; Jisrawi, Najeh M

    2014-01-01

    Single MeV electrons in vacuum subjected to single high-intensity quadratically chirped laser pulses are shown to gain multi-GeV energies. The laser pulses are modelled by finite-duration trapezoidal and cos  2 pulse-shapes and the equations of motion are solved numerically. It is found that, typically, the maximum energy gain from interaction with a quadratic chirp is about half of what would be gained from a linear chirp. (paper)

  15. Green development within product families, Electronics goes green 2000+ conference

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Willum, Ole; Frees, Niels

    2001-01-01

    , based on environ-mental and economical importance as well as the existence of several producers. Using this method, five families have been selected, namely mobile phones, vacuum cleaners, industrial valves with electronic controls, lighting and ventilation. Collaboration with 5 industrial companies has...

  16. Electron beam requirements for soft x-ray/XUV free-electron lasers

    International Nuclear Information System (INIS)

    Goldstein, J.C.

    1987-01-01

    A discussion of the electron beam quality (peak current, energy spread, and transverse emittance) required to drive short wavelength free-electron lasers in the XUV (10-100 nm) and soft x-ray (<10 nm) optical wavelength ranges is presented

  17. Intensity dependence of electron gas kinetics in a laser corona

    Directory of Open Access Journals (Sweden)

    Mašek Martin

    2013-11-01

    Full Text Available In various experimental situations relevant to the laser fusion, such as plasma near the light entrance holes of hohlraum in the indirect drive experiments or more recently in the shock ignition direct drive a relatively long underdense plasma of corona type is encountered, which is subject to an intense nanosecond laser beam. The plasma is only weakly collisional and thus in the electron phase space a complicated kinetic evolution is going on, which is taking the electron gas fairly far from the thermal equilibrium and contributes to its unstable behaviour. These phenomena impede the absorption and thermalization of the incoming laser energy, create groups of fast electrons and also may lead to a non-linear reflection of the heating laser beam. One of the key processes leading to the electron acceleration is the stimulated Raman scattering (SRS in its non-linear phase. The SRS in the presence of electron-ion collisions requires a certain threshold intensity above which the mentioned non-dissipative phenomena can occur and develop to the stage, where they may become unpleasant for the fusion experiments. To assess this intensity limit a computational model has been developed based on the Vlasov-Maxwell kinetics describing such a plasma in 1D geometry. At a relatively high intensity of 1016 W/cm2 a number of non-linear phenomena are predicted by the code such as a saturation of Landau damping, which is then translated in an unfavourable time dependence of the reflected light intensity and formation of accelerated electron groups due to the electron trapping. The purpose of the present contribution is to map the intensity dependence of this non-linear development with the aim of assessing its weight in fusion relevant situations.

  18. The free electron laser: a system capable of determining the gold standard in laser vision correction

    International Nuclear Information System (INIS)

    Fowler, W. Craig; Rose, John G.; Chang, Daniel H.; Proia, Alan D.

    1999-01-01

    Introduction. In laser vision correction surgery, lasers are generally utilized based on their beam-tissue interactions and corneal absorption characteristics. Therefore, the free electron laser, with its ability to provide broad wavelength tunability, is a unique research tool for investigating wavelengths of possible corneal ablation. Methods. Mark III free electron laser wavelengths between 2.94 and 6.7 μm were delivered in serial 0.1 μm intervals to corneas of freshly enucleated porcine globes. Collateral damage, ablation depth, and ablation diameter were measured in histologic sections. Results. The least collateral damage (12-13 μm) was demonstrated at three wavelengths: 6.0, 6.1 (amide I), and 6.3 μm. Minimal collateral damage (15 μm) was noted at 2.94 μm (OH-stretch) and at 6.2 μm. Slightly greater collateral damage was noted at 6.45 μm (amide II), as well as at the 5.5-5.7 μm range, but this was still substantially less than the collateral damage noted at the other wavelengths tested. Conclusions. Our results suggest that select mid-infrared wavelengths have potential for keratorefractive surgery and warrant additional study. Further, the free electron laser's ability to allow parameter adjustment in the far-ultraviolet spectrum may provide unprecedented insights toward establishing the gold-standard parameters for laser vision correction surgery

  19. Electron energy and electron trajectories in an inverse free-electron laser accelerator based on a novel electrostatic wiggler

    Science.gov (United States)

    Nikrah, M.; Jafari, S.

    2016-06-01

    We expand here a theory of a high-gradient laser-excited electron accelerator based on an inverse free-electron laser (inverse-FEL), but with innovations in the structure and design. The electrostatic wiggler used in our scheme, namely termed the Paul wiggler, is generated by segmented cylindrical electrodes with applied oscillatory voltages {{V}\\text{osc}}(t) over {{90}\\circ} segments. The inverse-FEL interaction can be described by the equations that govern the electron motion in the combined fields of both the laser pulse and Paul wiggler field. A numerical study of electron energy and electron trajectories has been made using the fourth-order Runge-Kutta method. The results indicate that the electron attains a considerable energy at short distances in this device. It is found that if the electron has got sufficient suitable wiggler amplitude intensities, it can not only gain higher energy in longer distances, but also can retain it even after the passing of the laser pulse. In addition, the results reveal that the electron energy gains different peaks for different initial axial velocities, so that a suitable small initial axial velocity of e-beam produces substantially high energy gain. With regard to the transverse confinement of the electron beam in a Paul wiggler, there is no applied axial guide magnetic field in this device.

  20. Improvement of the quality of laser-wakefield accelerators: towards a compact free-electron laser

    International Nuclear Information System (INIS)

    Lehe, R.

    2014-01-01

    When an intense and short laser pulse propagates through an underdense gas, it can accelerate a fraction of the electrons of the gas, and thereby generate an electron bunch with an energy of a few hundreds of MeV. This phenomenon, which is referred to as laser-wakefield acceleration, has many potential applications, including the design of ultra-bright X-ray sources known as free electron lasers (FEL). However, these applications require the electron bunch to have an excellent quality (low divergence, emittance and energy spread). In this thesis, different solutions to improve the quality of the electron bunch are developed, both analytically and through the use of Particle-In-Cell (PIC) simulations. It is first shown however that PIC simulations tend to erroneously overestimate the emittance of the bunch, due to the numerical Cherenkov effect. Thus, in order to correctly estimate the emittance, a modified PIC algorithm is proposed, which is not subject to this unphysical Cherenkov effect. Using this algorithm, we have observed and studied a new mechanism to generate the electron bunch: optical transverse injection. This mechanism can produce bunches with a high charge, a low emittance and a low energy spread. In addition, we also proposed an experimental setup - the laser-plasma lens - which can strongly reduce the final divergence of the bunch. Finally, these results are put into context by discussing the properties required for the design of a compact FEL. It is shown in particular that laser-wakefield accelerator could be advantageously combined with innovative laser-plasma undulators, in order to produce bright X-rays sources. (author)

  1. Property Investigation of Laser Cladded, Laser Melted and Electron Beam Melted Ti-Al6-V4

    Science.gov (United States)

    2006-05-01

    UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Figure 3: Examples of electron beam melted net shape parts; powder bed [3]. 1.4 Laser Cladding ...description, www.arcam.com. [4] K.-H. Hermann, S. Orban, S. Nowotny, Laser Cladding of Titanium Alloy Ti6242 to Restore Damaged Blades, Proceedings...Property Investigation of Laser Cladded , Laser Melted and Electron Beam Melted Ti-Al6-V4 Johannes Vlcek EADS Deutschland GmbH Corporate Research

  2. Attosecond Electron Wave Packet Dynamics in Strong Laser Fields

    International Nuclear Information System (INIS)

    Johnsson, P.; Remetter, T.; Varju, K.; L'Huillier, A.; Lopez-Martens, R.; Valentin, C.; Balcou, Ph.; Kazamias, S.; Mauritsson, J.; Gaarde, M. B.; Schafer, K. J.; Mairesse, Y.; Wabnitz, H.; Salieres, P.

    2005-01-01

    We use a train of sub-200 attosecond extreme ultraviolet (XUV) pulses with energies just above the ionization threshold in argon to create a train of temporally localized electron wave packets. We study the energy transfer from a strong infrared (IR) laser field to the ionized electrons as a function of the delay between the XUV and IR fields. When the wave packets are born at the zero crossings of the IR field, a significant amount of energy (∼20 eV) is transferred from the field to the electrons. This results in dramatically enhanced above-threshold ionization in conditions where the IR field alone does not induce any significant ionization. Because both the energy and duration of the wave packets can be varied independently of the IR laser, they are valuable tools for studying and controlling strong-field processes

  3. A new far infrared free-electron laser

    CERN Document Server

    Walsh, J E; Swartz, J C; Urata, J; Kimmitt, M F

    1999-01-01

    The operation of a new ultra compact diffraction grating coupled free-electron laser (FEL) has been demonstrated. The basic elements of the device which is termed a grating coupled oscillator (GCO) are the beam in a scanning electron microscope (SEM) and a diffraction grating which is mounted in the e-beam focal region of the SEM. The e-beam is controlled by the SEM's electron optical system and distributed feed back is provided by the grating itself. Recent experimental results are presented and techniques for extending the wavelength and power coverage are discussed.

  4. A new far infrared free-electron laser

    International Nuclear Information System (INIS)

    Walsh, J.E.; Brownell, J.H.; Swartz, J.C.; Urata, J.; Kimmitt, M.F.

    1999-01-01

    The operation of a new ultra compact diffraction grating coupled free-electron laser (FEL) has been demonstrated. The basic elements of the device which is termed a grating coupled oscillator (GCO) are the beam in a scanning electron microscope (SEM) and a diffraction grating which is mounted in the e-beam focal region of the SEM. The e-beam is controlled by the SEM's electron optical system and distributed feed back is provided by the grating itself. Recent experimental results are presented and techniques for extending the wavelength and power coverage are discussed

  5. A new far infrared free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, J.E.; Brownell, J.H.; Swartz, J.C.; Urata, J.; Kimmitt, M.F

    1999-06-01

    The operation of a new ultra compact diffraction grating coupled free-electron laser (FEL) has been demonstrated. The basic elements of the device which is termed a grating coupled oscillator (GCO) are the beam in a scanning electron microscope (SEM) and a diffraction grating which is mounted in the e-beam focal region of the SEM. The e-beam is controlled by the SEM's electron optical system and distributed feed back is provided by the grating itself. Recent experimental results are presented and techniques for extending the wavelength and power coverage are discussed.

  6. Transient analysis of a bunched beam free electron laser

    International Nuclear Information System (INIS)

    Wang, J.M.; Yu, L.H.

    1985-01-01

    The problem of the bunched beam operation of a free electron laser was studied. Assuming the electron beam to be initially monoenergetic, the Maxwell-Vlasov equations describing the system reduce to a third order partial differential equation for the envelope of the emitted light. The Green's function corresponding to an arbitrary shape of the electron bunch, which describes the transient behavior of the system, is obtained. The Green's function was used to discuss the start up problem as well as the power output and the power specrum of a self-amplified spontaneous emission

  7. High-energy inverse free-electron laser accelerator

    International Nuclear Information System (INIS)

    Courant, E.D.; Pellegrini, C.; Zakowicz, W.

    1985-01-01

    We study the inverse free electron laser (IFEL) accelerator and show that it can accelerate electrons to the few hundred GeV region with average acceleration rates of the order of 200 meV/m. Several possible accelerating structures are analyzed, and the effect of synchrotron radiation losses is studied. The longitudinal phase stability of accelerated particles is also analyzed. A Hamiltonian description, which takes into account the dissipative features of the IFEL accelerator, is introduced to study perturbations from the resonant acceleration. Adiabatic invariants are obtained and used to estimate the change of the electron phase space density during the acceleration process

  8. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Bradley Bolt [Univ. of California, San Diego, CA (United States)

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  9. Large area electron beam pumped krypton fluoride laser amplifier

    International Nuclear Information System (INIS)

    Sethian, J.D.; Obenschain, S.P.; Gerber, K.A.; Pawley, C.J.; Serlin, V.; Sullivan, C.A.; Webster, W.; Deniz, A.V.; Lehecka, T.; McGeoch, M.W.; Altes, R.A.; Corcoran, P.A.; Smith, I.D.; Barr, O.C.

    1997-01-01

    Nike is a recently completed multi-kilojoule krypton fluoride (KrF) laser that has been built to study the physics of direct drive inertial confinement fusion. This paper describes in detail both the pulsed power and optical performance of the largest amplifier in the Nike laser, the 60 cm amplifier. This is a double pass, double sided, electron beam-pumped system that amplifies the laser beam from an input of 50 J to an output of up to 5 kJ. It has an optical aperture of 60 cm x 60 cm and a gain length of 200 cm. The two electron beams are 60 cm high x 200 cm wide, have a voltage of 640 kV, a current of 540 kA, and a flat top power pulse duration of 250 ns. A 2 kG magnetic field is used to guide the beams and prevent self-pinching. Each electron beam is produced by its own Marx/pulse forming line system. The amplifier has been fully integrated into the Nike system and is used on a daily basis for laser-target experiments. copyright 1997 American Institute of Physics

  10. Laser-assisted electron emission from gated field-emitters

    CERN Document Server

    Ishizuka, H; Yokoo, K; Mimura, H; Shimawaki, H; Hosono, A

    2002-01-01

    Enhancement of electron emission by illumination of gated field-emitters was studied using a 100 mW cw YAG laser at a wavelength of 532 nm, intensities up to 10 sup 7 W/m sup 2 and mechanically chopped with a rise time of 4 mu s. When shining an array of 640 silicon emitters, the emission current responded quickly to on-off of the laser. The increase of the emission current was proportional to the basic emission current at low gate voltages, but it was saturated at approx 3 mu A as the basic current approached 100 mu A with the increase of gate voltage. The emission increase was proportional to the square root of laser power at low gate voltages and to the laser power at elevated gate voltages. For 1- and 3-tip silicon emitters, the rise and fall of the current due to on-off of the laser showed a significant time lag. The magnitude of emission increase was independent of the position of laser spot on the emitter base and reached 2 mu A at a basic current of 5 mu A without showing signs of saturation. The mech...

  11. Nonlinear electron transport in magnetized laser plasmas

    International Nuclear Information System (INIS)

    Kho, T.H.; Haines, M.G.

    1986-01-01

    Electron transport in a magnetized plasma heated by inverse bremsstrahlung is studied numerically using a nonlinear Fokker--Planck model with self-consistent E and B fields. The numerical scheme is described. Nonlocal transport is found to alter many of the transport coefficients derived from linear transport theory, in particular, the Nernst and Righi--Leduc effects, in addition to the perpendicular heat flux q/sub perpendicular/, are substantially reduced near critical surface. The magnetic field, however, remains strongly coupled to the nonlinear q/sub perpendicular/ and, as has been found in hydrosimulations, convective amplification of the magnetic field occurs in the overdense plasma

  12. High-current electron accelerator for gas-laser pumping

    Energy Technology Data Exchange (ETDEWEB)

    Badaliants, G R; Mamikonian, V A; Nersisian, G Ts; Papanian, V O

    1978-11-26

    A high-current source of pulsed electron beams has been developed for the pumping of UV gas lasers. The parameters of the device are: energy of 0.3-0.7 MeV pulse duration of 30 ns and current density (in a high-pressure laser chamber) of 40-100 A/sq cm. The principal feature of the device is the use of a rectangular cold cathode with incomplete discharge along the surface of the high-permittivity dielectric. Cathodes made of stainless steel, copper, and graphite were investigated.

  13. Investigation of electron heating in laser-plasma interaction

    Directory of Open Access Journals (Sweden)

    A Parvazian

    2013-03-01

    Full Text Available  In this paper, stimulated Raman scattering (SRS and electron heating in laser plasma propagating along the plasma fusion is investigated by particle-in cell simulation. Applying an external magnetic field to plasma, production of whistler waves and electron heating associated with whistler waves in the direction perpendicular to external magnetic field was observed in this simulation. The plasma waves with low phase velocities, generated in backward-SRS and dominateing initially in time and space, accelerated the backward electrons by trapping them. Then these electrons promoted to higher energies by the forward-SRS plasma waves with high phase velocities. This tow-stage electron acceleration is more efficient due to the coexistence of these two instabilities.

  14. Investigation of electron heating in laser-plasma interaction

    International Nuclear Information System (INIS)

    Parvazian, A.; Haji Sharifi, K.

    2013-01-01

    In this paper, stimulated Raman scattering and electron heating in laser plasma propagating along the plasma fusion is investigated by particle-in cell simulation. Applying an external magnetic field to plasma, production of whistler waves and electron heating associated with whistler waves in the direction perpendicular to external magnetic field was observed in this simulation. The plasma waves with low phase velocities, generated in backward-stimulated Raman scattering and dominating initially in time and space, accelerated the backward electrons by trapping them. Then these electrons promoted to higher energies by the forward-stimulated Raman scattering plasma waves with high phase velocities. This two-stage electron acceleration is more efficient due to the coexistence of these two instabilities.

  15. Laser pulse control of bridge mediated heterogeneous electron transfer

    International Nuclear Information System (INIS)

    Wang Luxia; May, Volkhard

    2009-01-01

    Ultrafast heterogeneous electron transfer from surface attached dye molecules into semiconductor band states is analyzed. The focus is on systems where the dye is separated from the surface by different bridge anchor groups. To simulate the full quantum dynamics of the transfer process a model of reduced dimensionality is used. It comprises the electronic levels of the dye, the bridge anchor group electronic levels and the continuum of semiconductor band states, all defined versus a single intramolecular vibrational coordinate. The effect of the bridge states is demonstrated, firstly, in studying the injection dynamics following an impulsive excitation of the dye. Then, by discussing different control tasks it is demonstrate in which way the charge injection process can be influenced by tailored laser pulses. To highlight the importance of electron wave function interference emphasis is put on asymmetric two-bridge molecule systems which are also characterized by different and complex valued electronic transfer matrix elements.

  16. Beam manipulation for compact laser wakefield accelerator based free-electron lasers

    International Nuclear Information System (INIS)

    Loulergue, A; Labat, M; Benabderrahmane, C; Couprie, M E; Evain, C; Malka, V

    2015-01-01

    Free-electron lasers (FELs) are a unique source of light, particularly in the x-ray domain. After the success of FELs based on conventional acceleration using radio-frequency cavities, an important challenge is the development of FELs based on electron bunching accelerated by a laser wakefield accelerator (LWFA). However, the present LWFA electron bunch properties do not permit use directly for a significant FEL amplification. It is known that longitudinal decompression of electron beams delivered by state-of-the-art LWFA eases the FEL process. We propose here a second order transverse beam manipulation turning the large inherent transverse chromatic emittances of LWFA beams into direct FEL gain advantage. Numerical simulations are presented showing that this beam manipulation can further enhance by orders of magnitude the peak power of the radiation. (paper)

  17. Emittance Measurements from a Laser Driven Electron Injector

    CERN Document Server

    Reis, D

    2003-01-01

    The Gun Test Facility (GTF) at the Stanford Linear Accelerator Center was constructed to develop an appropriate electron beam suitable for driving a short wavelength free electron laser (FEL) such as the proposed Linac Coherent Light Source (LCLS). For operation at a wavelength of 1.5 (angstrom), the LCLS requires an electron injector that can produce an electron beam with approximately 1 pi mm-mrad normalized rms emittance with at least 1 nC of charge in a 10 ps or shorter bunch. The GTF consists of a photocathode rf gun, emittance-compensation solenoid, 3 m linear accelerator (linac), drive laser, and diagnostics to measure the beam. The rf gun is a symmetrized 1.6 cell, s-band high gradient, room temperature, photocathode structure. Simulations show that this gun when driven by a temporally and spatially shaped drive laser, appropriately focused with the solenoid, and further accelerated in linac can produce a beam that meets the LCLS requirements. This thesis describes the initial characterization of the ...

  18. High quality electron beams from a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, S M; Issac, R C; Welsh, G H; Brunetti, E; Shanks, R P; Anania, M P; Cipiccia, S; Manahan, G G; Aniculaesei, C; Ersfeld, B; Islam, M R; Burgess, R T L; Vieux, G; Jaroszynski, D A [SUPA, Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Gillespie, W A [SUPA, Division of Electronic Engineering and Physics, University of Dundee, Dundee (United Kingdom); MacLeod, A M [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee (United Kingdom); Van der Geer, S B; De Loos, M J, E-mail: m.wiggins@phys.strath.ac.u [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands)

    2010-12-15

    High quality electron beams have been produced in a laser-plasma accelerator driven by femtosecond laser pulses with a peak power of 26 TW. Electrons are produced with an energy up to 150 MeV from the 2 mm gas jet accelerator and the measured rms relative energy spread is less than 1%. Shot-to-shot stability in the central energy is 3%. Pepper-pot measurements have shown that the normalized transverse emittance is {approx}1{pi} mm mrad while the beam charge is in the range 2-10 pC. The generation of high quality electron beams is understood from simulations accounting for beam loading of the wakefield accelerating structure. Experiments and self-consistent simulations indicate that the beam peak current is several kiloamperes. Efficient transportation of the beam through an undulator is simulated and progress is being made towards the realization of a compact, high peak brilliance free-electron laser operating in the vacuum ultraviolet and soft x-ray wavelength ranges.

  19. Multiple purpose research complex on the basis of electron accelerators and terahertz free electron laser

    International Nuclear Information System (INIS)

    Kulipanov, G.N.

    2009-01-01

    In this report the basic positioning parameters of multiple purpose research complex are presented, the list of potential experiments and technological uses on the example of results received in the multiuser center of G.I. Budker Institut of nuclear physics Siberian department of the Russian Academy of Sciences is discussed. This research complex is directed on work in the big universities and nano technology centers. Electron accelerators is intended for development of electron-beam technologies different material modification, for production of nano powder, nano materials and solution of ecological tasks. In this work the project of multiple purpose research complex on the basis of new generation electron accelerator Il-14 and workable terahertz free electron laser is suggested. Terahertz free electron laser will be used for researches in the sphere of physics and chemistry, biology and medicine, nanotechnology engineering and different methods of nanodiagnostics.

  20. Accelerator for medical applications and electron acceleration by laser plasma

    International Nuclear Information System (INIS)

    Hosokai, Tomonao; Uesaka, Mitsuru

    2006-01-01

    In this article, the current status of radiation therapies in Japan and updated medical accelerators are reviewed. For medical use, there is a strong demand of a compact and flexible accelerator. At present, however, we have only two choices of the S-band linac with one or two rotation axis combined with the multi leaf collimator, or the X-band linac with a rather flexible robotic arm. In addition, the laser plasma cathode that is the second generation of the laser wake-field accelerator (LWFA) is studied as a high-quality electron source for medical use though it is still at the stage of the basic research. The potential of LWFA as medical accelerator near future is discussed based on updated results of laser plasma cathode experiment in Univ. of Tokyo. (author)

  1. Relativistic electron mirrors from high intensity laser nanofoil interactions

    International Nuclear Information System (INIS)

    Kiefer, Daniel

    2012-01-01

    The reflection of a laser pulse from a mirror moving close to the speed of light could in principle create an X-ray pulse with unprecedented high brightness owing to the increase in photon energy and accompanying temporal compression by a factor of 4γ 2 , where γ is the Lorentz factor of the mirror. While this scheme is theoretically intriguingly simple and was first discussed by A. Einstein more than a century ago, the generation of a relativistic structure which acts as a mirror is demanding in many different aspects. Recently, the interaction of a high intensity laser pulse with a nanometer thin foil has raised great interest as it promises the creation of a dense, attosecond short, relativistic electron bunch capable of forming a mirror structure that scatters counter-propagating light coherently and shifts its frequency to higher photon energies. However, so far, this novel concept has been discussed only in theoretical studies using highly idealized interaction parameters. This thesis investigates the generation of a relativistic electron mirror from a nanometer foil with current state-of-the-art high intensity laser pulses and demonstrates for the first time the reflection from those structures in an experiment. To achieve this result, the electron acceleration from high intensity laser nanometer foil interactions was studied in a series of experiments using three inherently different high power laser systems and free-standing foils as thin as 3nm. A drastic increase in the electron energies was observed when reducing the target thickness from the micrometer to the nanometer scale. Quasi-monoenergetic electron beams were measured for the first time from ultrathin (≤5nm) foils, reaching energies up to ∝35MeV. The acceleration process was studied in simulations well-adapted to the experiments, indicating the transition from plasma to free electron dynamics as the target thickness is reduced to the few nanometer range. The experience gained from those

  2. Relativistic electron mirrors from high intensity laser nanofoil interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Daniel

    2012-12-21

    The reflection of a laser pulse from a mirror moving close to the speed of light could in principle create an X-ray pulse with unprecedented high brightness owing to the increase in photon energy and accompanying temporal compression by a factor of 4γ{sup 2}, where γ is the Lorentz factor of the mirror. While this scheme is theoretically intriguingly simple and was first discussed by A. Einstein more than a century ago, the generation of a relativistic structure which acts as a mirror is demanding in many different aspects. Recently, the interaction of a high intensity laser pulse with a nanometer thin foil has raised great interest as it promises the creation of a dense, attosecond short, relativistic electron bunch capable of forming a mirror structure that scatters counter-propagating light coherently and shifts its frequency to higher photon energies. However, so far, this novel concept has been discussed only in theoretical studies using highly idealized interaction parameters. This thesis investigates the generation of a relativistic electron mirror from a nanometer foil with current state-of-the-art high intensity laser pulses and demonstrates for the first time the reflection from those structures in an experiment. To achieve this result, the electron acceleration from high intensity laser nanometer foil interactions was studied in a series of experiments using three inherently different high power laser systems and free-standing foils as thin as 3nm. A drastic increase in the electron energies was observed when reducing the target thickness from the micrometer to the nanometer scale. Quasi-monoenergetic electron beams were measured for the first time from ultrathin (≤5nm) foils, reaching energies up to ∝35MeV. The acceleration process was studied in simulations well-adapted to the experiments, indicating the transition from plasma to free electron dynamics as the target thickness is reduced to the few nanometer range. The experience gained from those

  3. PREFACE: XXVIII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2013)

    Science.gov (United States)

    Xiao, Guoqing; Cai, Xiaohong; Ding, Dajun; Ma, Xinwen; Zhao, Yongtao

    2014-04-01

    The 28th International Conference on Photonic, Electronic and Atomic Collisions (XXVIII ICPEAC) was held by the Institute of Modern Physics, Chinese Academy of Sciences (IMP) on 24-30 July, 2013 in Lanzhou, China. The 444 conference participants came from 37 countries and/or regions. Five plenary lectures, more than 80 progress reports and special reports had been arranged according to the decision of the ICPEAC International General Committee. Meanwhile, more than 650 abstracts were selected as poster presentations. Before the conference, three highly distinguished scientists, Professor Joachim Burgdöorfer, Professor Hossein Sadeghpour and Professor Yasunori Yamazaki, presented tutorial lectures with the support of the IMP Branch of Youth Innovation Promotion Association, CAS (IMP-YIPA). During the conference, Professor Jianwei Pan from University of Sciences and Technology in China presented an enlightening public lecture on quantum communication. Furthermore, 2013 IUPAP Young Scientist Prize was awarded to Dr T Jahnke from Johann Wolfgang Goethe University of Germany. The Sheldon Datz Prize for an Outstanding Young Scientist Attending ICPEAC was awarded to Dr Diogo Almeida from University of Fribourg of Switzerland. As a biannual academic conference, ICPEAC is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, atomic, ionic, molecular, cluster collisions with matter. With a history back to 1958, ICPEAC came to China for the very first time. IMP has been preparing the conference six years before, ever since the ICPEAC International General Committee made the decision to hold the XXVIII ICPEAC in Lanzhou. This proceedings includes the papers of the two plenary lectures, 40 progress reports, 17 special reports and 337 posters, which were reviewed and revised according to the comments of the referees. The Local Organizing Committee would like to

  4. High-speed ultrafast laser machining with tertiary beam positioning (Conference Presentation)

    Science.gov (United States)

    Yang, Chuan; Zhang, Haibin

    2017-03-01

    For an industrial laser application, high process throughput and low average cost of ownership are critical to commercial success. Benefiting from high peak power, nonlinear absorption and small-achievable spot size, ultrafast lasers offer advantages of minimal heat affected zone, great taper and sidewall quality, and small via capability that exceeds the limits of their predecessors in via drilling for electronic packaging. In the past decade, ultrafast lasers have both grown in power and reduced in cost. For example, recently, disk and fiber technology have both shown stable operation in the 50W to 200W range, mostly at high repetition rate (beyond 500 kHz) that helps avoid detrimental nonlinear effects. However, to effectively and efficiently scale the throughput with the fast-growing power capability of the ultrafast lasers while keeping the beneficial laser-material interactions is very challenging, mainly because of the bottleneck imposed by the inertia-related acceleration limit and servo gain bandwidth when only stages and galvanometers are being used. On the other side, inertia-free scanning solutions like acoustic optics and electronic optical deflectors have small scan field, and therefore not suitable for large-panel processing. Our recent system developments combine stages, galvanometers, and AODs into a coordinated tertiary architecture for high bandwidth and meanwhile large field beam positioning. Synchronized three-level movements allow extremely fast local speed and continuous motion over the whole stage travel range. We present the via drilling results from such ultrafast system with up to 3MHz pulse to pulse random access, enabling high quality low cost ultrafast machining with emerging high average power laser sources.

  5. Femtosecond laser ablation of gold interdigitated electrodes for electronic tongues

    Science.gov (United States)

    Manzoli, Alexandra; de Almeida, Gustavo F. B.; Filho, José A.; Mattoso, Luiz H. C.; Riul, Antonio; Mendonca, Cleber R.; Correa, Daniel S.

    2015-06-01

    Electronic tongue (e-tongue) sensors based on impedance spectroscopy have emerged as a potential technology to evaluate the quality and chemical composition of food, beverages, and pharmaceuticals. E-tongues usually employ transducers based on metal interdigitated electrodes (IDEs) coated with a thin layer of an active material, which is capable of interacting chemically with several types of analytes. IDEs are usually produced by photolithographic methods, which are time-consuming and costly, therefore, new fabrication technologies are required to make it more affordable. Here, we employed femtosecond laser ablation with pulse duration of 50 fs to microfabricate gold IDEs having finger width from 2.3 μm up to 3.2 μm. The parameters used in the laser ablation technique, such as light intensity, scan speed and beam spot size have been optimized to achieve uniform IDEs, which were characterized by optical and scanning electron microscopy. The electrical properties of gold IDEs fabricated by laser ablation were evaluated by impedance spectroscopy, and compared to those produced by conventional photolithography. The results show that femtosecond laser ablation is a promising alternative to conventional photolithography for fabricating metal IDEs for e-tongue systems.

  6. Harmonic operation of high gain harmonic generation free electron laser

    International Nuclear Information System (INIS)

    Deng Haixiao; Chinese Academy of Sciences, Beijing; Dai Zhimin

    2008-01-01

    In high gain harmonic generation (HGHG) free electron laser (FEL), with the right choice of parameters of the modulator undulator, the dispersive section and the seed laser, one may make the spatial bunching of the electron beam density distribution correspond to one of the harmonic frequencies of the radiator radiation, instead of the fundamental frequency of the radiator radiation in conventional HGHG, thus the radiator undulator is in harmonic operation (HO) mode. In this paper, we investigate HO of HGHG FEL. Theoretical analyses with universal method are derived and numerical simulations in ultraviolet and deep ultraviolet spectral regions are given. It shows that the power of the 3rd harmonic radiation in the HO of HGHG may be as high as 18.5% of the fundamental power level. Thus HO of HGHG FEL may obtain short wavelength by using lower beam energy. (authors)

  7. Laser-driven injector of electrons for IOTA

    Science.gov (United States)

    Romanov, Aleksandr

    2017-03-01

    Fermilab is developing the Integrable Optics Test Accelerator (IOTA) ring for experiments on nonlinear integrable optics. The machine will operate with either electron beams of 150 MeV or proton beams of 2.5 MeV energies, respectively. The stability of integrable optics depends critically on the precision of the magnetic lattice, which demands the use of beam-based lattice measurements for optics correction. In the proton mode, the low-energy proton beam does not represent a good probe for this application; hence we consider the use of a low-intensity reverse-injected electron beam of matched momentum (70 MeV). Such an injector could be implemented with the use of laser-driven acceleration techniques. This report presents the consideration for a laser-plasma injector for IOTA and discusses the requirements determined by the ring design.

  8. Applications of Free Electron Lasers in Biology and Medicine

    International Nuclear Information System (INIS)

    Pelka, J.B.; Tybor, K.R.; Nietubyc, R.; Wrochna, G.

    2010-01-01

    The advent of free electron lasers opens up new opportunities to probe the dynamics of ultrafast processes and the structure of matter with unprecedented spatial and temporal resolution. New methods inaccessible with other known types of radiation sources can be developed, resulting in a breakthrough in deep understanding the fundamentals of life as well as in numerous medical and biological applications. In the present work the properties of free electron laser radiation that make the sources excellent for probing biological matter at an arbitrary wavelength, in a wide range of intensities and pulse durations are briefly discussed. A number of biophysical and biomedical applications of the new sources, currently considered among the most promising in the field, are presented. (author)

  9. Charged beam dynamics, particle accelerators and free electron lasers

    CERN Document Server

    Dattoli, Giuseppe; Sabia, Elio; Artioli, Marcello

    2017-01-01

    Charged Beam Dynamics, Particle Accelerators and Free Electron Lasers summarises different topics in the field of accelerators and of Free Electron Laser (FEL) devices. It is intended as a reference manual for the different aspects of FEL devices, explaining how to design both a FEL device and the accelerator providing the driving beam. It covers both theoretical and experimental aspects, allowing researchers to attempt a first design of a FEL device in different operating conditions. It provides an analysis of what is already available, what is needed, and what the challenges are to determine new progress in this field. All chapters contain complements and exercises that are designed in such a way that the reader will gradually acquire self-confidence with the matter treated in the book.

  10. Electron injection by evolution of self-modulated laser wakefields

    International Nuclear Information System (INIS)

    Kim, Changbum; Kim, Guang-Hoon; Kim, Jong-Uk; Lee, Hae June; Suk, Hyyong; Ko, In Soo

    2003-01-01

    Self-injection mechanisms in the self-modulated laser wakefield acceleration (SM-LWFA) are investigated. Two-dimensional (2D) particle-in-cell (PIC) simulations show that a significant amount of plasma electrons can be self-injected into the acceleration phase of a laser wakefield by a dynamic increase in the wake wavelength in the longitudinal direction. In this process, it is found that the wake wavelength increases due to the relativistic effect and this leads to a large amount of electron injection into the wakefields. In this paper, the injection phenomena are studied with 2D simulations and a brief explanation of the new self-injection mechanism is presented. (author)

  11. High-brightness electron source driven by laser

    International Nuclear Information System (INIS)

    Zhao Kui; Geng Rongli; Wang Lifang

    1996-01-01

    A DC high-brightness laser driven by photo emissive electron gun is being developed at Beijing University, in order to produce 50∼100 ps electron bunches of high quality. The gun consists of a photocathode preparation chamber and a DC acceleration cavity. Different ways of fabricating photocathode, such as chemical vapor deposition, ion beam implantation and ion beam enhanced deposition, can be adopted. The acceleration gap is designed with the aid of simulation codes EGUN and POISSON. 100 kV DC high voltage is fed to the anode through a careful designed ceramic insulator. The laser system is a mode locked Nd-YAG oscillator proceeded by an amplifier at 10 Hz repetition rate, which can deliver three different wavelength (1064/532/266 nm). The combination of a superconducting cavity with the photocathode preparation chamber is discussed

  12. Free-electron laser system with Raman amplifier outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Linford, G.J.

    1988-05-03

    A free-electron laser system is described comprising: a free-electron laser pump beam generator producing a high-power optical output beam in a vacuum environement; a Raman amplifier cell located in the path of the output beam from the pump beam generator; means for generating and introducing a Stokes seed beam into the Raman amplifier cell, a pair of gaseous windows through which the output beam enters and leaves the Raman amplifier cell, each window having a stream of gas moving continuously in a direction generally perpendicular to the beam; and a mirror positioned in the path of the output beam from the Raman amplifier, the mirror functioning to reflect and further direct the output beam, but not the unwanted spectral components.

  13. The stability of free-electron lasers against filamentation

    International Nuclear Information System (INIS)

    Barnard, J.J.; Scharlemann, E.T.; Yu, S.S.

    1987-01-01

    In inertial confinement fusion (ICF) experiments, the high electromagnetic fields propagating through a relatively dense plasma can result in a transverse instability, causing the matter and light to form filaments oriented parallel to the light beam. We examine whether a similar instability exists in the electron beam of a free-electron laser, where such an instability could interfere with the transfer of beam kinetic energy into optical wave energy. We heuristically examine the instability in a relativistic beam through which an intense laser beam is propagating. We ignore the FEL effects. We estimate how the altered index of refraction in an FEL affects the dispersion relation. Finally, we estimate the effect that the instability could have on the phase coherence of a particle as it transits an FEL. 10 refs., 2 tabs

  14. Crystallographic data processing for free-electron laser sources

    International Nuclear Information System (INIS)

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

    2013-01-01

    A processing pipeline for diffraction data acquired using the ‘serial crystallography’ 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 ‘serial crystallography’ 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

  15. Crystallographic data processing for free-electron laser sources

    Energy Technology Data Exchange (ETDEWEB)

    White, Thomas A., E-mail: taw@physics.org; Barty, Anton; Stellato, Francesco [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Holton, James M. [University of California, San Francisco, CA 94158 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kirian, Richard A. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Arizona State University, Tempe, AZ 85287 (United States); Zatsepin, Nadia A. [Arizona State University, Tempe, AZ 85287 (United States); Chapman, Henry N. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

    2013-07-01

    A processing pipeline for diffraction data acquired using the ‘serial crystallography’ 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 ‘serial crystallography’ 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.

  16. Electron dynamics in RF sources with a laser controlled emission

    CERN Document Server

    Khodak, I V; Metrochenko, V V

    2001-01-01

    Photoemission radiofrequency (RF) electron sources are sources of electron beams with extremely high brightness. Beam bunching processes in such devices are well studied in case when laser pulse duration is much lower of rf oscillation period.At the same time photoemission RF guns have some merits when operating in 'long-pulse' mode. In this case the laser pulse duration is much higher of rf oscillation period but much lower of rise time of oscillations in a gun cavity. Beam parameters at the gun output are compared for photoemission and thermoemission cathode applications. The paper presents results of a beam dynamics simulation in such guns with different resonance structures. Questions connected with defining of the current pulse peak value that can be obtained in such guns are discussed.

  17. Advanced laser technologies for high-brightness photocathode electron gun

    International Nuclear Information System (INIS)

    Tomizawa, Hiromitsu

    2012-01-01

    A laser-excited photocathode RF gun is one of the most reliable high-brightness electron beam sources for XFELs. Several 3D laser shaping methods have been developed as ideal photocathode illumination sources at SPring-8 since 2001. To suppress the emittance growth caused by nonlinear space-charge forces, the 3D cylindrical UV-pulse was optimized spatially as a flattop and temporally as squarely stacked chirped pulses. This shaping system is a serial combination of a deformable mirror that adaptively shapes the spatial profile with a genetic algorithm and a UV-pulse stacker that consists of four birefringent α-BBO crystal rods for temporal shaping. Using this 3D-shaped pulse, a normalized emittance of 1.4 πmm mrad was obtained in 2006. Utilizing laser's Z-polarization, Schottky-effect-gated photocathode gun was proposed in 2006. The cathode work functions are reduced by a laser-induced Schottky effect. As a result of focusing a radially polarized laser pulse with a hollow lens in vacuum, the Z-field (Z-polarization) is generated at the cathode. (author)

  18. Electron heating enhancement by frequency-chirped laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, E.; Afarideh, H., E-mail: hafarideh@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Sadighi-Bonabi, R., E-mail: Sadighi@sharif.ir [Department of Physics, Sharif University of Technology, P.O. Box 11365-9567, Tehran (Iran, Islamic Republic of); Riazi, Z. [Physics and Accelerator School, Tehran (Iran, Islamic Republic of); Hora, H. [Department of Theoretical Physics, University of New South Wales, Sydney 2052 (Australia)

    2014-09-14

    Propagation of a chirped laser pulse with a circular polarization through an uprising plasma density profile is studied by using 1D-3V particle-in-cell simulation. The laser penetration depth is increased in an overdense plasma compared to an unchirped pulse. The induced transparency due to the laser frequency chirp results in an enhanced heating of hot electrons as well as increased maximum longitudinal electrostatic field at the back side of the solid target, which is very essential in target normal sheath acceleration regime of proton acceleration. For an applied chirp parameter between 0.008 and 0.01, the maximum amount of the electrostatic field is improved by a factor of 2. Furthermore, it is noticed that for a chirped laser pulse with a₀=5, because of increasing the plasma transparency length, the laser pulse can penetrate up to about n{sub e}≈6n{sub c}, where n{sub c} is plasma critical density. It shows 63% increase in the effective critical density compared to the relativistic induced transparency regime for an unchirped condition.

  19. Advanced Laser Technologies for High-brightness Photocathode Electron Gun

    Science.gov (United States)

    Tomizawa, Hiromitsu

    A laser-excited photocathode RF gun is one of the most reliable high-brightness electron beam sources for XFELs. Several 3D laser shaping methods have been developed as ideal photocathode illumination sources at SPring-8 since 2001. To suppress the emittance growth caused by nonlinear space-charge forces, the 3D cylindrical UV-pulse was optimized spatially as a flattop and temporally as squarely stacked chirped pulses. This shaping system is a serial combination of a deformable mirror that adaptively shapes the spatial profile with a genetic algorithm and a UV-pulse stacker that consists of four birefringent α-BBO crystal rods for temporal shaping. Using this 3D-shaped pulse, a normalized emittance of 1.4 π mm mrad was obtained in 2006. Utilizing laser's Z-polarization, Schottky-effect-gated photocathode gun was proposed in 2006. The cathode work functions are reduced by a laser-induced Schottky effect. As a result of focusing a radially polarized laser pulse with a hollow lens in vacuum, the Z-field (Z-polarization) is generated at the cathode.

  20. Heat transfer between adsorbate and laser-heated hot electrons

    International Nuclear Information System (INIS)

    Ueba, H; Persson, B N J

    2008-01-01

    Strong short laser pulses can give rise to a strong increase in the electronic temperature at metal surfaces. Energy transfer from the hot electrons to adsorbed molecules may result in adsorbate reactions, e.g. desorption or diffusion. We point out the limitations of an often used equation to describe the heat transfer process in terms of a friction coupling. We propose a simple theory for the energy transfer between the adsorbate and hot electrons using a newly introduced heat transfer coefficient, which depends on the adsorbate temperature. We calculate the transient adsorbate temperature and the reaction yield for a Morse potential as a function of the laser fluency. The results are compared to those obtained using a conventional heat transfer equation with temperature-independent friction. It is found that our equation of energy (heat) transfer gives a significantly lower adsorbate peak temperature, which results in a large modification of the reaction yield. We also consider the heat transfer between different vibrational modes excited by hot electrons. This mode coupling provides indirect heating of the vibrational temperature in addition to the direct heating by hot electrons. The formula of heat transfer through linear mode-mode coupling of two harmonic oscillators is applied to the recent time-resolved study of carbon monoxide and atomic oxygen hopping on an ultrafast laser-heated Pt(111) surface. It is found that the maximum temperature of the frustrated translation mode can reach high temperatures for hopping, even when direct friction coupling to the hot electrons is not strong enough

  1. Help system for control of JAERI FEL (Free Electron laser)

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1993-01-01

    The control system of JAERI FEL (Free Electron Laser) has a help system to provide the information necessary to operate the machine and to develop the new user interface. As the control software is constructed on the MS-Windows 3.x, the hyper-text feature of the Windows help system can be accessed. It consists of three major parts: (1) on-line help, (2) full document, and (3) tutorial system. (author)

  2. Storage ring free electron lasers and saw-tooth instability

    CERN Document Server

    Dattoli, Giuseppe; Migliorati, M; Palumbo, L; Renieri, A

    1999-01-01

    We show that Free Electron Lasers (FEL) operating with storage rings may counteract beam instabilities of the Saw Tooth (STI) type. We use a model based on a set of equations that couple those describing the FEL evolution to those accounting for the STI dynamics. The analysis provides a clear picture of the FEL-STI mutual feedback and clarifies the mechanisms of the instability inhibition. The reliability of the results is supported by a comparison with fully numerical codes.

  3. Unlimited electron acceleration in laser-driven plasma waves

    International Nuclear Information System (INIS)

    Katsouleas, T.; Dawson, J.M.

    1983-01-01

    It is shown that the limitation to the energy gain of 2(ω/ω/sub p/) 2 mc 2 of an electron in the laser-plasma beat-wave accelerator can be overcome by imposing a magnetic field of appropriate strength perpendicular to the plasma wave. This accelerates particles parallel to the phase fronts of the accelerating wave which keeps them in phase with it. Arbitrarily large energy is theoretically possible

  4. Acceleration of laser-injected electron beams in an electron-beam driven plasma wakefield accelerator

    International Nuclear Information System (INIS)

    Knetsch, Alexander

    2018-03-01

    Plasma wakefields deliver accelerating fields that are approximately a 100 times higher than those in conventional radiofrequency or even superconducting radiofrequency cavities. This opens a transformative path towards novel, compact and potentially ubiquitous accelerators. These prospects, and the increasing demand for electron accelerator beamtime for various applications in natural, material and life sciences, motivate the research and development on novel plasma-based accelerator concepts. However, these electron beam sources need to be understood and controlled. The focus of this thesis is on electron beam-driven plasma wakefield acceleration (PWFA) and the controlled injection and acceleration of secondary electron bunches in the accelerating wake fields by means of a short-pulse near-infrared laser. Two laser-triggered injection methods are explored. The first one is the Trojan Horse Injection, which relies on very good alignment and timing control between electron beam and laser pulse and then promises electron bunches with hitherto unprecedented quality as regards emittance and brightness. The physics of electron injection in the Trojan Horse case is explored with a focus on the final longitudinal bunch length. Then a theoretical and numerical study is presented that examines the physics of Trojan Horse injection when performed in an expanding wake generated by a smooth density down-ramp. The benefits are radically decreased drive-electron bunch requirements and a unique bunch-length control that enables longitudinal electron-bunch shaping. The second laser-triggered injection method is the Plasma Torch Injection, which is a versatile, all-optical laser-plasma-based method capable to realize tunable density downramp injection. At the SLAC National Laboratory, the first proof-of-principle was achieved both for Trojan Horse and Plasma Torch injection. Setup details and results are reported in the experimental part of the thesis along with the commissioning

  5. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    International Nuclear Information System (INIS)

    Matlis, N.H.; Bakeman, M.; Geddes, C.G.R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G.R.; Schroeder, C.B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W.P.

    2010-01-01

    We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable electron bunches from LPAs.

  6. Investigation of metal coatings for the free electron laser

    International Nuclear Information System (INIS)

    Scott, M.L.; Arendt, P.N.; Springer, R.W.; Cordi, R.C.; McCreary, W.J.

    1985-01-01

    We are investigating the deposition and characteristics of metal coatings for use in environments such as the Free Electron Laser where the radiation resistance of metal coatings could prove to be of great benefit. We have concentrated our initial efforts on silver laminate coatings due to the high reflectance of silver at 1 micron wavelength. Our initial laminate coatings have utilized thin layers of titanium oxide to break up the columnar structure of the silver during electron-beam deposition on fused silica substrates. Our initial results on equal coating thickness samples indicate an improvement in damage threshold that ranges from 1.07 to 1.71 at 351 nm

  7. Runaway electron beam control for longitudinally pumped metal vapor lasers

    Science.gov (United States)

    Kolbychev, G. V.; Kolbycheva, P. D.

    1995-08-01

    Physics and techniques for producing of the pulsed runaway electron beams are considered. The main obstacle for increasing electron energies in the beams is revealed to be a self- breakdown of the e-gun's gas-filled diode. Two methods to suppress the self-breakdown and enhance the volumetric discharge producing the e-beam are offered and examined. Each of them provides 1.5 fold increase of the ceiling potential on the gun. The methods also give the ways to control several guns simultaneously. Resulting in the possibility of realizing the powerful longitudinal pumping of metal-vapor lasers on self-terminated transitions of atoms or ions.

  8. The LLNL/UCLA high gradient inverse free electron laser

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-21

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

  9. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G. R.; Schroeder, C. B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W. P.

    2010-06-01

    We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable electron bunches from LPAs.

  10. ETL linac facility and free-electron lasers

    International Nuclear Information System (INIS)

    Yamazaki, T.; Noguchi, T.; Mikado, T.; Sugiyama, S.; Yamada, K.; Chiwaki, M.; Ohgaki, H.; Suzuki, R.; Sei, N.

    1993-01-01

    An outline is presented of the recent development on the ETL (Electro-technical Laboratory) electron-linac facility and storage-ring FELs (free-electron lasers). Some modifications including the injection system have been made to the linac. Four storage rings are working very well. The TERAS FEL system has been shut down after the successful oscillation around 590 nm. The new NIJI-IV FEL system has been proven to work well, and the current tunable wavelength range is over 100 nm (488-595 nm). Preparatory experiments on the FEL at shorter wavelength are underway. (author)

  11. Research on high performance mirrors for free electron lasers

    International Nuclear Information System (INIS)

    Kitatani, Fumito

    1996-01-01

    For the stable functioning of free electron laser, high performance optical elements are required because of its characteristics. In particular in short wavelength free electron laser, since its gain is low, the optical elements having very high reflectivity are required. Also in free electron laser, since high energy noise light exists, the optical elements must have high optical breaking strength. At present in Power Reactor and Nuclear Fuel Development Corporation, the research for heightening the performance of dielectric multi-layer film elements for short wavelength is carried out. For manufacturing such high performance elements, it is necessary to develop the new materials for vapor deposition, new vapor deposition process, and the techniques of accurate substrate polishing and inspection. As the material that satisfies the requirements, there is diamond-like carbon (DLC) film, of which the properties are explained. As for the manufacture of the DLC films for short wavelength optics, the test equipment for forming the DLC films, the test of forming the DLC films, the change of the film quality due to gas conditions, discharge conditions and substrate materials, and the measurement of the optical breaking strength are reported. (K.I.)

  12. Development of superconducting acceleration cavity technology for free electron lasers

    International Nuclear Information System (INIS)

    Lee, Jong Min; Lee, Byung Cheol; Kim, Sun Kook; Jeong, Young Uk; Cho, Sung Oh

    2000-10-01

    As a result of the cooperative research between the KAERI and Peking University, the key technologies of superconducting acceleration cavity and photoelectron gun have been developed for the application to high power free electron lasers. A 1.5-GHz, 1-cell superconducting RF cavity has been designed and fabricated by using pure Nb sheets. The unloaded Q values of the fabricated superconducting cavity has been measured to be 2x10 9 at 2.5K, and 8x10 9 at 1.8K. The maximum acceleration gradient achieved was 12 MeV/m at 2.5K, and 20MV/m at 1.8 K. A cryostat for the 1-cell superconducting cavity has been designed. As a source of electron beam, a DC photocathode electron gun has been designed and fabricated, which is composed of a photocathode evaporation chamber and a 100-keV acceleration chamber. The efficiency of the Cs2Te photocathode is 3% nominally at room temperature, 10% at 290 deg C. The superconducting photoelectron gun system developed has been estimated to be a good source of high-brightness electron beam for high-power free electron lasers

  13. Development of superconducting acceleration cavity technology for free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Min; Lee, Byung Cheol; Kim, Sun Kook; Jeong, Young Uk; Cho, Sung Oh

    2000-10-01

    As a result of the cooperative research between the KAERI and Peking University, the key technologies of superconducting acceleration cavity and photoelectron gun have been developed for the application to high power free electron lasers. A 1.5-GHz, 1-cell superconducting RF cavity has been designed and fabricated by using pure Nb sheets. The unloaded Q values of the fabricated superconducting cavity has been measured to be 2x10{sup 9} at 2.5K, and 8x10{sup 9} at 1.8K. The maximum acceleration gradient achieved was 12 MeV/m at 2.5K, and 20MV/m at 1.8 K. A cryostat for the 1-cell superconducting cavity has been designed. As a source of electron beam, a DC photocathode electron gun has been designed and fabricated, which is composed of a photocathode evaporation chamber and a 100-keV acceleration chamber. The efficiency of the Cs2Te photocathode is 3% nominally at room temperature, 10% at 290 deg C. The superconducting photoelectron gun system developed has been estimated to be a good source of high-brightness electron beam for high-power free electron lasers.

  14. The Livermore Free-Electron Laser Program Magnet Test Laboratory

    International Nuclear Information System (INIS)

    Burns, M.J.; Kulke, B.; Deis, G.A.; Frye, R.W.; Kallman, J.S.; Ollis, C.W.; Tyler, G.C.; Van Maren, R.D.; Weiss, W.C.

    1987-01-01

    The Lawrence Livermore National Laboratory (LLNL) Free-Electron Laser Program Magnet Test Laboratory supports the ongoing development of the Induction Linac Free Electron Laser (IFEL) and uses magnetic field measurement systems that are useful in the testing of long periodic magnetic structures, electron-beam transport magnets, and spectrometer magnets. The major systems described include two computer-controlled, three-axis Hall probe-and-search coil transports with computer-controlled data acquisition; a unique, automated-search coil system used to detect very small inaccuracies in wiggler fields; a nuclear magnetic resonance (NMR)-based Hall probe-calibration facility; and a high-current DC ion source using heavy ions of variable momentum to model the transport of high-energy electrons. Additionally, a high-precision electron-beam-position monitor for use within long wigglers that has a positional resolution of less than 100 μm is under development in the laboratory and will be discussed briefly. Data transfer to LLNL's central computing facility and on-line graphics enable us to analyze large data sets quickly. 3 refs

  15. Search for nuclear excitation by laser-driven electron motion

    International Nuclear Information System (INIS)

    Bounds, J.A.; Dyer, P.

    1992-01-01

    It has been proposed that a nucleus may be excited by first exciting the atom's electrons with UV photons. The incident photons couple to the electrons, which would then couple via a virtual photon to the nucleus. As a test case, experiments with 235 U have been performed. A pulsed infrared laser produces an atomic vapor of 235 U which is then bombarded by a high-brightness UV laser beam. The resulting ions are collected. The first excited nuclear state of 235 U has a 26-min half-life and decays by internal conversion, resulting in emission of an atomic electron. These conversion electrons are detected by a channel electron multiplier. An upper limit of 4.0x10 -5 has been obtained for the probability of exciting the nucleus of a 235 U atom that is in the 248-nm UV beam for 700 fs at an irradiance in the range of 1.0x10 15 to 2.5x10 15 W/cm 2

  16. UV laser ionization and electron beam diagnostics for plasma lenses

    International Nuclear Information System (INIS)

    Govil, R.; Volfbeyn, P.; Leemans, W.

    1995-04-01

    A comprehensive study of focusing of relativistic electron beams with overdense and underdense plasma lenses requires careful control of plasma density and scale lengths. Plasma lens experiments are planned at the Beam Test Facility of the LBL Center for Beam Physics, using the 50 MeV electron beam delivered by the linac injector from the Advanced Light Source. Here we present results from an interferometric study of plasmas produced in tri-propylamine vapor with a frequency quadrupled Nd:YAG laser at 266 nm. To study temporal dynamics of plasma lenses we have developed an electron beam diagnostic using optical transition radiation to time resolve beam size and divergence. Electron beam ionization of the plasma has also been investigated

  17. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    International Nuclear Information System (INIS)

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich; Byrne, Warren; Leemans, Wim

    2011-01-01

    A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm 2 and 0.4 pC/(ps mm 2 ), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within ±8%, showing that they all can provide accurate charge measurements for LPAs.

  18. 2010 Electron Donor-Acceptor Interactions Gordon Research Conference, August 8 - 13, 2010.

    Energy Technology Data Exchange (ETDEWEB)

    Gerald Meyer

    2010-08-18

    The Gordon Research Conference on Electron Donor Acceptor Interactions (GRC EDAI) presents and advances the current frontiers in experimental and theoretical studies of Electron Transfer Processes and Energy Conversion. The fundamental concepts underpinning the field of electron transfer and charge transport phenomena are understood, but fascinating experimental discoveries and novel applications based on charge transfer processes are expanding the discipline. Simultaneously, global challenges for development of viable and economical alternative energy resources, on which many researchers in the field focus their efforts, are now the subject of daily news headlines. Enduring themes of this conference relate to photosynthesis, both natural and artificial, and solar energy conversion. More recent developments include molecular electronics, optical switches, and nanoscale charge transport structures of both natural (biological) and man-made origin. The GRC EDAI is one of the major international meetings advancing this field, and is one of the few scientific meetings where fundamental research in solar energy conversion has a leading voice. The program includes sessions on coupled electron transfers, molecular solar energy conversion, biological and biomimetic systems, spin effects, ultrafast reactions and technical frontiers as well as electron transport in single molecules and devices. In addition to disseminating the latest advances in the field of electron transfer processes, the conference is an excellent forum for scientists from different disciplines to meet and initiate new directions; for scientists from different countries to make contacts; for young scientists to network and establish personal contacts with other young scientists and with established scientists who, otherwise, might not have the time to meet young people. The EDAI GRC also features an interactive atmosphere with lively poster sessions, a few of which are selected for oral presentations.

  19. Commissioning of Japanese x-ray free electron laser, SACLA and achieved laser performance

    International Nuclear Information System (INIS)

    Tanaka, Hitoshi; Amselem, Arnaud; Aoyagi, Hideki

    2012-01-01

    After 8 months of beam commissioning of SPring-8 Angstrom Compact free electron LAser, SACLA reached the primary target performance, i.e., a shortest laser wavelength of ∼0.6 Angstrom and a laser pulse energy value of sub-mJ at a wavelength of 1.2 Angstrom. This success was due to the following four factors; (1) performance estimation of each component of SACLA required for the target laser performance and its achievement, (2) elaboration of beam diagnostics and control systems enabling precise accelerator and undulator tuning, (3) a rational and strategic commissioning plan, (4) most adequate response to various accidental events during the beam commissioning period. This article, in order to light up the above four factors leading us to the success, starts with the features of SACLA and critical tolerance for the sub-system components, and then, explains our approach to achieve the target laser performance and how the beam commissioning of SACLA proceeded. At last, the article summarizes the present laser and operational status. (author)

  20. Self-amplified spontaneous emission free electron laser devices and nonideal electron beam transport

    Directory of Open Access Journals (Sweden)

    L. L. Lazzarino

    2014-11-01

    Full Text Available We have developed, at the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL device performance control. We describe an actual FEL, including electron and optical beam transport, through a set of analytical formulas, allowing a fast and reliable on-line “simulation” of the experiment. The system is designed in such a way that the characteristics of the transport elements and the laser intensity are measured and adjusted, via a real time computation, during the experimental run, to obtain an on-line feedback of the laser performances. The detail of the procedure and the relevant experimental results are discussed.

  1. Electron scattering from atoms in the presence of a laser field. III

    International Nuclear Information System (INIS)

    Mittleman, M.H.

    1977-01-01

    The development of the theory of the effect of a laser on electron-atom scattering is continued by the derivation of explicit relations between the observed electron-atom scattering cross sections in the presence of a laser and exact electron-atom scattering cross sections with no laser present. No approximation concerning the scattering interaction is made. The only approximations concerning the laser are that (1) the laser-atom interaction energy is small compared to atomic energies, (2) the Rabi frequency times the collision time is small, and (3) the laser intensity in appropriate units is small

  2. Present status of the NIJI-IV storage-ring free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, T.; Yamada, K.; Sei, N. [Electrotechnical Lab., Ibaraki (Japan)] [and others

    1995-12-31

    The tunable region of the free-electron-laser (FEL) wavelength with the NIJI-IV system is now 348{approximately}595 nm. After the lasing at 352 nm in 1994, the quality of the electron beam stored in the ring has been improved further, and the highest peak intensity of the laser obtained so far is more than 300 times as high as that of the resonated spontaneous emission. The macro-temporal structure of the lasing has been greatly improved. Recently, a single-bunch injection system was completed, and the system has been installed in the injector linac, which is expected to increase the peak stored-beam current. The commissioning and the test of the new system is under way. The beam transporting system from the linac to the ring is also being modified by increasing the number of quadrupole magnets. The experiments related to the FEL in the ultraviolet wavelength region will be begun in this coming May. The results and the status of the FEL experiments will be presented at the Conference.

  3. Microwave free-electron laser applications for electron cyclotron heating of plasmas

    International Nuclear Information System (INIS)

    Thomassen, K.

    1990-01-01

    Millimeter wave power may be the ideal source of heat for the plasma, but advances in technology are needed to meet requirements of next generation fusion devices. Free electron lasers (FEL) are one candidate for such sources, and this paper reviews the progress, issues of physics and technology, and potential benefits for fusion from these devices

  4. Microwave free-electron laser applications for electron cyclotron heating of plasmas

    International Nuclear Information System (INIS)

    Thomassen, K.I.

    1990-01-01

    Millimeter wave power may be the ideal source of heat for a plasma, but advances in technology are needed to meet requirements of next generation fusion devices. Free electron lasers (FEL) are one candidate for such sources, and this paper reviews the progress, issues of physics and technology, and potential benefits for fusion from these devices. 15 refs., 13 figs

  5. Electro-optics/Laser International '80 UK Proceedings of the Conference, Brighton, England, March 25-27, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Jerrard, H G [ed.

    1980-01-01

    Papers are presented concerning recent developments in the fields of electro-optics, particularly as it relates to the use of lasers, and other laser applications. Specific topics include loss measurements in graded index compound glass optical fibers, coherent optical two-dimensional signal analysis for picture deblurring applications, applications of the high-resolution holography of large volumes, laser speckle vibrometry for measurements of microscopic motions at audio frequencies, laser hazard control under field conditions, laser coupling to a gaseous medium through resonance saturations, a time-of-flight laser anemometer for remote wind velocity measurement, an electron-beam-pumped excimer laser system, the evaluation of thermal imaging systems, and a flat-plate capacitor discharge N/sub 2/ laser.

  6. GaSb-based single-mode distributed feedback lasers for sensing (Conference Presentation)

    Science.gov (United States)

    Gupta, James A.; Bezinger, Andrew; Lapointe, Jean; Poitras, Daniel; Aers, Geof C.

    2017-02-01

    GaSb-based tunable single-mode diode lasers can enable rapid, highly-selective and highly-sensitive absorption spectroscopy systems for gas sensing. In this work, single-mode distributed feedback (DFB) laser diodes were developed for the detection of various trace gases in the 2-3.3um range, including CO2, CO, HF, H2S, H2O and CH4. The lasers were fabricated using an index-coupled grating process without epitaxial regrowth, making the process significantly less expensive than conventional DFB fabrication. The devices are based on InGaAsSb/AlGaAsSb separate confinement heterostructures grown on GaSb by molecular beam epitaxy. DFB lasers were produced using a two step etch process. Narrow ridge waveguides were first defined by optical lithography and etched into the semiconductor. Lateral gratings were then defined on both sides of the ridge using electron-beam lithography and etched to produce the index-grating. Effective index modeling was used to optimize the ridge width, etch depths and the grating pitch to ensure single-lateral-mode operation and adequate coupling strength. The effective index method was further used to simulate the DFB laser emission spectrum, based on a transfer matrix model for light transmission through the periodic structure. The fabricated lasers exhibit single-mode operation which is tunable through the absorption features of the various target gases by adjustment of the drive current. In addition to the established open-path sensing applications, these devices have great potential for optoelectronic integrated gas sensors, making use of integrated photodetectors and possibly on-chip Si photonics waveguide structures.

  7. A high power gain switched diode laser oscillator and amplifier for the CEBAF polarized electron injector

    International Nuclear Information System (INIS)

    Poelker, M.; Hansknecht, J.

    1996-01-01

    The photocathode in the polarized electron source at Jefferson Lab is illuminated with pulsed laser light from a gain switched diode laser and diode optical amplifier. Laser pulse repetition rates up to 2,000 MHz, optical pulsewidths between 31 and 123 ps, and average power > 100 mW are demonstrated. The laser system is highly reliable and completely remotely controlled

  8. Development of a high power free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Min; Lee, Byung Chul; Kim, Sun Kook; Jung, Yung Wook; Cho, Sung Oh [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-01-01

    A millimeter-wave free electron laser (FEL) driven by a recirculating electrostatic accelerator has been developed. The wavelength of the FEL is tunable in the range of 3 - 12 mm by tuning the energy of the electron beam. The output power is estimated to be 1 kW. The electrostatic accelerator is composed of high-current electron gun, acceleration tube, high-voltage generator, high-voltage terminal, deceleration tube, electron collator, and vacuum pumps. Two types of LaB{sub 6}-based thermionic electron guns (triode gun and diode gun) and their power supplies have been developed. The voltage of the guns is 30 kV and the output current is - 2 A. A beam-focusing planar undulator and a permanent-magnet helical undulator have been developed and 3D trajectories of electron beam in the undulators have been calculated to find optimal input condition of electron beam. 135 figs, 15 pix, 17 tabs, 98 refs. (Author).

  9. Development of a high power free-electron laser

    International Nuclear Information System (INIS)

    Lee, Jong Min; Lee, Byung Chul; Kim, Sun Kook; Jung, Yung Wook; Cho, Sung Oh

    1995-01-01

    A millimeter-wave free electron laser (FEL) driven by a recirculating electrostatic accelerator has been developed. The wavelength of the FEL is tunable in the range of 3 - 12 mm by tuning the energy of the electron beam. The output power is estimated to be 1 kW. The electrostatic accelerator is composed of high-current electron gun, acceleration tube, high-voltage generator, high-voltage terminal, deceleration tube, electron collator, and vacuum pumps. Two types of LaB 6 -based thermionic electron guns (triode gun and diode gun) and their power supplies have been developed. The voltage of the guns is 30 kV and the output current is - 2 A. A beam-focusing planar undulator and a permanent-magnet helical undulator have been developed and 3D trajectories of electron beam in the undulators have been calculated to find optimal input condition of electron beam. 135 figs, 15 pix, 17 tabs, 98 refs. (Author)

  10. Molecular electron recollision dynamics in intense circularly polarized laser pulses

    Science.gov (United States)

    Bandrauk, André D.; Yuan, Kai-Jun

    2018-04-01

    Extreme UV and x-ray table top light sources based on high-order harmonic generation (HHG) are focused now on circular polarization for the generation of circularly polarized attosecond pulses as new tools for controlling electron dynamics, such as charge transfer and migration and the generation of attosecond quantum electron currents for ultrafast magneto-optics. A fundamental electron dynamical process in HHG is laser induced electron recollision with the parent ion, well established theoretically and experimentally for linear polarization. We discuss molecular electron recollision dynamics in circular polarization by theoretical analysis and numerical simulation. The control of the polarization of HHG with circularly polarized ionizing pulses is examined and it is shown that bichromatic circularly polarized pulses enhance recollision dynamics, rendering HHG more efficient, especially in molecules because of their nonspherical symmetry. The polarization of the harmonics is found to be dependent on the compatibility of the rotational symmetry of the net electric field created by combinations of bichromatic circularly polarized pulses with the dynamical symmetry of molecules. We show how the field and molecule symmetry influences the electron recollision trajectories by a time-frequency analysis of harmonics. The results, in principle, offer new unique controllable tools in the study of attosecond molecular electron dynamics.

  11. Extremely short relativistic-electron-bunch generation in the laser wakefield via novel bunch injection scheme

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.; Reitsma, A.J.W.; Jaroszynski, D.A.

    2004-01-01

    Recently a new electron-bunch injection scheme for the laser wakefield accelerator has been proposed [JETP Lett. 74, 371 (2001); Phys. Rev. E 65, 046504 (2002)]. In this scheme, a low energy electron bunch, sent in a plasma channel just before a high-intensity laser pulse, is trapped in the laser

  12. Electron momentum spectroscopy of H2+ in the presence of laser radiation

    International Nuclear Information System (INIS)

    Bulychev, A.A.; Kouzakov, K.A.

    2017-01-01

    Theoretical analysis of laser-assisted electron impact ionization of a hydrogen molecular ion H 2 + at high impact energy and large momentum transfer is carried out. The laser-field effects on the incoming and outgoing electrons are taken into account using the Volkov functions. The field-dressing of the target electron is treated with a quasistatic state approach. Calculations for laser radiation with frequency ω = 1.55 eV and intensity I = 5 * 10 11 W/cm 2 exhibit strong laser influence on the molecular bond oscillation in laser-assisted electron momentum distributions. (authors)

  13. Electronic packaging: new results in singulation by Laser Microjet

    Science.gov (United States)

    Wagner, Frank; Sibailly, Ochelio; Richerzhagen, Bernold

    2004-07-01

    Cutting electronic packages that are produced in a matrix array fashion is an important process and deals with the ready-to-use devices. Thus an increase in the singulation yield is directly correlated to an increase in benefit. Due to the usage of different substrate materials, the saws encounter big problems in terms of lifetime and constancy of cut quality in these applications. Today"s equipment manufacturers are not yet in the position to propose an adequate solution for all types of packages. Compared to classical laser cutting, the water-jet guided laser technology minimizes the heat damages in any kind of sample. This new material processing method consists in guiding a laser beam inside a hair thin, lowpressure water-jet by total internal reflection, and is applied to package singulation since two years approximately. Using a frequency doubled Nd:YAG laser guided by a water jet, an LTCC-ceramics based package is singulated according to a scribe and break process. Speeds of 2-10 mm/s are reached in the LTTC and 40 mm/s in the mold compound. The process is wear-free and provides very good edge quality of the LTCC and the mold compound as well as reliable separation of the packages.

  14. Injection of electrons by colliding laser pulses in a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, M., E-mail: martin.hansson@fysik.lth.se; Aurand, B.; Ekerfelt, H.; Persson, A.; Lundh, O.

    2016-09-01

    To improve the stability and reproducibility of laser wakefield accelerators and to allow for future applications, controlling the injection of electrons is of great importance. This allows us to control the amount of charge in the beams of accelerated electrons and final energy of the electrons. Results are presented from a recent experiment on controlled injection using the scheme of colliding pulses and performed using the Lund multi-terawatt laser. Each laser pulse is split into two parts close to the interaction point. The main pulse is focused on a 2 mm diameter gas jet to drive a nonlinear plasma wave below threshold for self-trapping. The second pulse, containing only a fraction of the total laser energy, is focused to collide with the main pulse in the gas jet under an angle of 150°. Beams of accelerated electrons with low divergence and small energy spread are produced using this set-up. Control over the amount of accelerated charge is achieved by rotating the plane of polarization of the second pulse in relation to the main pulse. Furthermore, the peak energy of the electrons in the beams is controlled by moving the collision point along the optical axis of the main pulse, and thereby changing the acceleration length in the plasma. - Highlights: • Compact colliding pulse injection set-up used to produce low energy spread e-beams. • Beam charge controlled by rotating the polarization of injection pulse. • Peak energy controlled by point of collision to vary the acceleration length.

  15. Electron density interferometry measurement in laser-matter interaction

    International Nuclear Information System (INIS)

    Popovics-Chenais, C.

    1981-05-01

    This work is concerned with the laser-interferometry measurement of the electronic density in the corona and the conduction zone external part. Particularly, it is aimed at showing up density gradients and at their space-time localization. The first chapter recalls the density profile influence on the absorption principal mechanisms and the laser energy transport. In chapter two, the numerical and analytical hydrodynamic models describing the density profile are analysed. The influence on the density profile of the ponderomotive force associated to high oscillating electric fields is studied, together with the limited thermal conduction and suprathermal electron population. The mechanism action, in our measurement conditions, is numerically simulated. Calculations are made with experimental parameters. The measurement interaction conditions, together with the diagnostic method by high resolution laser interferometry are detailed. The results are analysed with the help of numerical simulation which is the experiment modeling. An overview of the mechanisms shown up by interferometric measurements and their correlation with other diagnostics is the conclusion of this work [fr

  16. Femtosecond electron-bunch dynamics in laser wakefields and vacuum

    Directory of Open Access Journals (Sweden)

    A. G. Khachatryan

    2007-12-01

    Full Text Available Recent advances in laser wakefield acceleration demonstrated the generation of extremely short (with a duration of a few femtoseconds relativistic electron bunches with relatively low (of the order of couple of percent energy spread. In this article we study the dynamics of such bunches in drift space (vacuum and in channel-guided laser wakefields. Analytical solutions were found for the transverse coordinate of an electron and for the bunch envelope in the wakefield in the case of arbitrary change in the energy. Our results show strong bunch dynamics already on a millimeter scale propagation distance both in plasma and in vacuum. When the bunch propagates in vacuum, its transverse sizes grow considerably; the same is observed for the normalized bunch emittance that worsens the focusability of the bunch. A scheme of two-stage laser wakefield accelerator with small drift space between the stages is proposed. It is found that fast longitudinal betatron phase mixing occurs in a femtosecond bunch when it propagates along the wakefield axis. When bunch propagates off axis, strong bunch decoherence and fast emittance degradation due to the finite bunch length was observed.

  17. Electron-atom collisions in a laser field

    International Nuclear Information System (INIS)

    Ehlotzky, F.

    1998-01-01

    The present work is a report on recent progress made in our understanding of electron-atom collisions in a laser field. To some extent it is a continuation of a previous review covering a somewhat larger subject (Can. J. Phys. 63 (1985)). We shall discuss the present status of investigations in this field from the theoretical as well as experimental point of view but most of the report will be devoted to an analysis of the various approximation schemes used at present in this field to describe the different aspects of laser-assisted electron-atom interactions. As the table of contents shows, most of the work done so far is treating the atom as a spectator, described by a potential and only very little has been achieved over the years to include the atomic structure into consideration since the inclusion of these structure effects poses considerable computational problems. Since, for example, multiphoton ionization and its inverse process laser-assisted recombination may be considered as one half of a scattering process, it is quite natural that some of the theoretical techniques described here are also of interest for the treatment of other multiphoton processes not considered here since there are several other recent reviews available on these topics. (orig.)

  18. The electron beam dynamics simulation in the laser-electron storage ring involving compton and intrabeam scattering

    International Nuclear Information System (INIS)

    Gladkikh, P.I.; Telegin, Yu.N.; Karnaukhov, I.M.

    2002-01-01

    The feasibility of the development of intense X-ray sources based on Compton scattering in laser-electron storage rings is discussed. The results of the electron beam dynamics simulation involving Compton and intrabeam scattering are presented

  19. The electron beam dynamics simulation in the laser-electron storage ring involving compton and intrabeam scattering

    CERN Document Server

    Gladkikh, P I; Karnaukhov, I M

    2002-01-01

    The feasibility of the development of intense X-ray sources based on Compton scattering in laser-electron storage rings is discussed. The results of the electron beam dynamics simulation involving Compton and intrabeam scattering are presented.

  20. Conceptual design of industrial free electron laser using superconducting accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

    1995-12-31

    Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths ({lambda} = 0.3...20 {mu}m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

  1. A compact x-ray free electron laser

    International Nuclear Information System (INIS)

    Barletta, W.; Attac, M.; Cline, D.B.

    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 concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs

  2. Hemostatic properties of the free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Cram, G.P. Jr.; Copeland, M.L. [Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN 37235 (United States)

    1998-09-02

    We have investigated the hemostatic properties of the free-electron laser (FEL) and compared these properties to the most commonly used commercial lasers in neurosurgery, CO{sub 2} and Nd:YAG, using an acute canine model. Arterial and venous vessels, of varying diameters from 0.1 to 1.0 mm, were divided with all three lasers. Analysis of five wavelengths of the FEL (3.0, 4.5, 6.1, 6.45, and 7.7 microns) resulted in bleeding without evidence of significant coagulation, regardless of whether the vessel was an artery or vein. Hemorrhage from vessels less than 0.4 mm diameter was subsequently easily controlled with Gelfoam registered (topical hemostatic agent) alone, whereas larger vessels required bipolar electrocautery. No significant charring, or contraction of the surrounding parenchyma was noted with any of the wavelengths chosen from FEL source. The CO{sub 2} laser, in continuous mode, easily coagulated vessels with diameters of 4 mm and less, while larger vessels displayed significant bleeding requiring bipolar electrocautery for control. Tissue charring was noted with application of the CO{sub 2} laser. In super pulse mode, the CO{sub 2} laser exhibited similar properties, including significant charring of the surrounding parenchyma. The Nd:YAG coagulated all vessels tested up to 1.4 mm, which was the largest diameter cortical artery found, however this laser displayed significant and extensive contraction and retraction of the surrounding parenchyma. In conclusion, the FEL appears to be a poor hemostatic agent. Our results did not show any benefit of the FEL over current conventional means of achieving hemostasis. However, control of hemorrhage was easily achieved with currently used methods of hemostasis, namely Gelfoam registered or bipolar electrocuatery. Although only cortical vessels in dogs were tested, we feel this data can be applied to all animals, including humans, and the peripheral, as well as central, vasculature, as our data on the CO{sub 2} and

  3. Hemostatic properties of the free-electron laser

    International Nuclear Information System (INIS)

    Cram, G.P. Jr.; Copeland, M.L.

    1998-01-01

    We have investigated the hemostatic properties of the free-electron laser (FEL) and compared these properties to the most commonly used commercial lasers in neurosurgery, CO 2 and Nd:YAG, using an acute canine model. Arterial and venous vessels, of varying diameters from 0.1 to 1.0 mm, were divided with all three lasers. Analysis of five wavelengths of the FEL (3.0, 4.5, 6.1, 6.45, and 7.7 microns) resulted in bleeding without evidence of significant coagulation, regardless of whether the vessel was an artery or vein. Hemorrhage from vessels less than 0.4 mm diameter was subsequently easily controlled with Gelfoam registered (topical hemostatic agent) alone, whereas larger vessels required bipolar electrocautery. No significant charring, or contraction of the surrounding parenchyma was noted with any of the wavelengths chosen from FEL source. The CO 2 laser, in continuous mode, easily coagulated vessels with diameters of 4 mm and less, while larger vessels displayed significant bleeding requiring bipolar electrocautery for control. Tissue charring was noted with application of the CO 2 laser. In super pulse mode, the CO 2 laser exhibited similar properties, including significant charring of the surrounding parenchyma. The Nd:YAG coagulated all vessels tested up to 1.4 mm, which was the largest diameter cortical artery found, however this laser displayed significant and extensive contraction and retraction of the surrounding parenchyma. In conclusion, the FEL appears to be a poor hemostatic agent. Our results did not show any benefit of the FEL over current conventional means of achieving hemostasis. However, control of hemorrhage was easily achieved with currently used methods of hemostasis, namely Gelfoam registered or bipolar electrocuatery. Although only cortical vessels in dogs were tested, we feel this data can be applied to all animals, including humans, and the peripheral, as well as central, vasculature, as our data on the CO 2 and Nd:YAG appear to closely

  4. Effects of laser-polarization and wiggler magnetic fields on electron acceleration in laser-cluster interaction

    Science.gov (United States)

    Singh Ghotra, Harjit; Kant, Niti

    2018-06-01

    We examine the electron dynamics during laser-cluster interaction. In addition to the electrostatic field of an individual cluster and laser field, we consider an external transverse wiggler magnetic field, which plays a pivotal role in enhancing the electron acceleration. Single-particle simulation has been presented with a short pulse linearly polarized as well as circularly polarized laser pulses for electron acceleration in a cluster. The persisting Coulomb field allows the electron to absorb energy from the laser field. The stochastically heated electron finds a weak electric field at the edge of the cluster from where it is ejected. The wiggler magnetic field connects the regions of the stochastically heated, ejected electron from the cluster and high energy gain by the electron from the laser field outside the cluster. This increases the field strength and hence supports the electron to meet the phase of the laser field for enhanced acceleration. A long duration resonance appears with an optimized magnetic wiggler field of about 3.4 kG. Hence, the relativistic energy gain by the electron is enhanced up to a few 100 MeV with an intense short pulse laser with an intensity of about 1019 W cm‑2 in the presence of a wiggler magnetic field.

  5. Electron Bunch Timing with Femtosecond Precision in a Superconducting Free-Electron Laser

    Science.gov (United States)

    Löhl, F.; Arsov, V.; Felber, M.; Hacker, K.; Jalmuzna, W.; Lorbeer, B.; Ludwig, F.; Matthiesen, K.-H.; Schlarb, H.; Schmidt, B.; Schmüser, P.; Schulz, S.; Szewinski, J.; Winter, A.; Zemella, J.

    2010-04-01

    High-gain free-electron lasers (FELs) are capable of generating femtosecond x-ray pulses with peak brilliances many orders of magnitude higher than at other existing x-ray sources. In order to fully exploit the opportunities offered by these femtosecond light pulses in time-resolved experiments, an unprecedented synchronization accuracy is required. In this Letter, we distributed the pulse train of a mode-locked fiber laser with femtosecond stability to different locations in the linear accelerator of the soft x-ray FEL FLASH. A novel electro-optic detection scheme was applied to measure the electron bunch arrival time with an as yet unrivaled precision of 6 fs (rms). With two beam-based feedback systems we succeeded in stabilizing both the arrival time and the electron bunch compression process within two magnetic chicanes, yielding a significant reduction of the FEL pulse energy jitter.

  6. Relativistic electronic dressing in laser-assisted ionization of atomic hydrogen by electron impact

    International Nuclear Information System (INIS)

    Attaourti, Y.; Taj, S.

    2004-01-01

    Within the framework of the coplanar binary geometry where it is justified to use plane wave solutions for the study of the (e,2e) reaction and in the presence of a circularly polarized laser field, we introduce as a first step the Dirac-Volkov plane wave Born approximation 1 where we take into account only the relativistic dressing of the incident and scattered electrons. Then, we introduce the Dirac-Volkov plane wave Born approximation 2 where we take totally into account the relativistic dressing of the incident, scattered, and ejected electrons. We then compare the corresponding triple differential cross sections for laser-assisted ionization of atomic hydrogen by electron impact both for the nonrelativistic and the relativistic regime

  7. Two electron response to an intense x-ray free electron laser pulse

    International Nuclear Information System (INIS)

    Moore, L R; Parker, J S; Meharg, K J; Armstrong, G S J; Taylor, K T

    2009-01-01

    New x-ray free electron lasers (FELs) promise an ultra-fast ultra-intense regime in which new physical phenomena, such as double core hole formation in at atom, should become directly observable. Ahead of x-ray FEL experiments, an initial key task is to theoretically explore such fundamental laser-atom interactions and processes. To study the response of a two-electron positive ion to an intense x-ray FEL pulse, our theoretical approach is a direct numerical integration, incorporating non-dipole Hamiltonian terms, of the full six-dimensional time-dependent Schroedinger equation. We present probabilities of double K-shell ionization in the two-electron positive ions Ne 8+ and Ar 16+ exposed to x-ray FEL pulses with frequencies in the range 50 au to 300 au and intensities in the range 10 17 to 10 22 W/cm 2 .

  8. Two electron response to an intense x-ray free electron laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Moore, L R; Parker, J S; Meharg, K J; Armstrong, G S J; Taylor, K T, E-mail: l.moore@qub.ac.u [DAMTP, David Bates Building, Queen' s University Belfast, Belfast, BT7 1NN (United Kingdom)

    2009-11-01

    New x-ray free electron lasers (FELs) promise an ultra-fast ultra-intense regime in which new physical phenomena, such as double core hole formation in at atom, should become directly observable. Ahead of x-ray FEL experiments, an initial key task is to theoretically explore such fundamental laser-atom interactions and processes. To study the response of a two-electron positive ion to an intense x-ray FEL pulse, our theoretical approach is a direct numerical integration, incorporating non-dipole Hamiltonian terms, of the full six-dimensional time-dependent Schroedinger equation. We present probabilities of double K-shell ionization in the two-electron positive ions Ne{sup 8+} and Ar{sup 16+} exposed to x-ray FEL pulses with frequencies in the range 50 au to 300 au and intensities in the range 10{sup 17} to 10{sup 22} W/cm{sup 2}.

  9. Electron Bunch Timing with Femtosecond Precision in a Superconducting Free-Electron Laser

    International Nuclear Information System (INIS)

    Loehl, F.; Arsov, V.; Felber, M.; Hacker, K.; Lorbeer, B.; Ludwig, F.; Matthiesen, K.-H.; Schlarb, H.; Schmidt, B.; Winter, A.; Jalmuzna, W.; Schmueser, P.; Schulz, S.; Zemella, J.; Szewinski, J.

    2010-01-01

    High-gain free-electron lasers (FELs) are capable of generating femtosecond x-ray pulses with peak brilliances many orders of magnitude higher than at other existing x-ray sources. In order to fully exploit the opportunities offered by these femtosecond light pulses in time-resolved experiments, an unprecedented synchronization accuracy is required. In this Letter, we distributed the pulse train of a mode-locked fiber laser with femtosecond stability to different locations in the linear accelerator of the soft x-ray FEL FLASH. A novel electro-optic detection scheme was applied to measure the electron bunch arrival time with an as yet unrivaled precision of 6 fs (rms). With two beam-based feedback systems we succeeded in stabilizing both the arrival time and the electron bunch compression process within two magnetic chicanes, yielding a significant reduction of the FEL pulse energy jitter.

  10. Electron beam properties and impedance characterization for storage rings used for free electron lasers

    International Nuclear Information System (INIS)

    Dattoli, G.; Mezi, L.; Renieri, A.; Migliorati, M.; Walker, R.

    2000-01-01

    Good electron beam qualities and stability are the crucial features of Storage Rings dedicated to synchrotron radiation sources or to Free Electron Laser. Most of these characteristics depends on the coupling of the e-beam with the machine environment, which can be in turn modelled in terms of a characteristic impedance, whose absolute value and structure can be used to specify both the stability (longitudinal and transverse) of the beam and its qualities (energy spread, bunch length, peak current ...). In this paper are considered two specific examples of Storage Rings used for FEL operation and analyze their performances by means of semi analytical and numerical methods. The analysis is aimed at clarifying the dependence of beam energy spread and bunch length on beam current and at providing a set of parameters useful for the optimization of Free Electron Laser or synchrotron radiation sources [it

  11. Achromatic and isochronous electron beam transport for tunable free electron lasers

    International Nuclear Information System (INIS)

    Bengtsson, J.; Kim, K.J.

    1991-09-01

    We have continued the study of a suitable electron beam transport line, which is both isochronous and achromatic, for the free electron laser being designed at Lawrence Berkeley Laboratory. A refined version of the beam transport optics is discussed that accommodates two different modes of FEL wavelength tuning. For the fine tuning involving a small change of the electron beam energy, sextupoles are added to cancel the leading nonlinear dispersion. For the main tuning involving the change of the undulator gap, a practical solution of maintaining the beam matching condition is presented. Calculation of the higher order aberrations is facilitated by a newly developed code. 11 refs., 4 figs., 3 tabs

  12. Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas

    Science.gov (United States)

    2016-11-01

    Free Electron Density in Laser-Produced Plasmas by Anthony R Valenzuela Approved for public release; distribution is...AND SUBTITLE Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas 5a...SUPPLEMENTARY NOTES 14. ABSTRACT The Shack-Hartmann Electron Densitometer is a novel method to diagnose ultrashort pulse laser–produced plasmas

  13. User issues at the Stanford picosecond free electron laser center

    International Nuclear Information System (INIS)

    Smith, T.I.

    1995-01-01

    Assembling a productive user facility around a Free Electron Laser (FEL) is a complex task. Reliable operation of the FEL is a necessary, but by no means sufficient, condition to ensure that the center will be able to attract and keep the interest of first rate researchers. Some other issues which are important include: center wavelength stability and ease of tuning, bandwidth control, amplitude and position stability, ability to select arbitrary sequences of micropulses, and real time availability of information of the FEL's important parameters (spectral width, center wavelength, micropulse length and energy, etc.). In addition, at the Stanford Center we have found that providing additional systems (conventional picosecond lasers synchronized to the FEL, an FTIR spectrometer, a confocal microscopy, ...) has been important. (author)

  14. Electron acceleration by a radially polarized laser pulse during ionization of low density gases

    Directory of Open Access Journals (Sweden)

    Kunwar Pal Singh

    2011-03-01

    Full Text Available The acceleration of electrons by a radially polarized intense laser pulse has been studied. The axial electric field of the laser is responsible for electron acceleration. The axial electric field increases with decreasing laser spot size; however, the laser pulse gets defocused sooner for smaller values and the electrons do not experience high electric field for long, reducing the energy they can reach. The electron remains confined in the electric field of the laser for longer and the electron energy peaks for the normalized laser spot size nearly equal to the normalized laser intensity parameter. Electron energy peaks for initial laser phase ϕ_{0}=π due to accelerating laser phase and decreases with transverse initial position of the electrons. The energy and angle of the emittance spectrum of the electrons generated during ionization of krypton and argon at low densities have been obtained and a right choice of laser parameters has been suggested to obtain high energy quasimonoenergetic collimated electron beams. It has been found that argon is more suitable than krypton to obtain high energy electron beams due to higher ionization potential of inner shells for the former.

  15. Gain of a Smith-Purcell free-electron laser

    Directory of Open Access Journals (Sweden)

    H. L. Andrews

    2004-07-01

    Full Text Available A formula is derived for the small-signal gain of a Smith-Purcell free-electron laser. The theory describes the electron beam as a moving plasma dielectric, and assumes that the electron beam interacts with an evanescent mode traveling along the surface of a periodic waveguide with a rectangular profile. The phase velocity of the evanescent wave is synchronous with the electron velocity, but the group velocity is actually negative. The electron beam amplifies the evanescent wave, which does not itself radiate. According to this picture, the radiation observed emanating from the grating is Smith-Purcell radiation enhanced by the bunching of the electrons due to the interaction with the evanescent mode. There will also be radiation from the part of the evanescent mode that is outcoupled from the ends of the grating. This radiation appears at a lower frequency than the Smith-Purcell radiation. The new results explain both the gain and the radiation observed in the experiments of Urata and Walsh, and the cube-root current dependence of the gain inferred by Bakhtyari, Walsh, and Brownell.

  16. A high-repetition rate LWFA for studies of laser propagation and electron generation

    Science.gov (United States)

    He, Zhaohan; Easter, James; Hou, Bixue; Krushelnick, Karl; Nees, John; Thomas, Alec

    2010-11-01

    Advances in ultrafast optics today have enabled laser systems to deliver ever shorter and more intense pulses. When focused, such laser pulses can easily exceed relativistic intensities where the wakefield created by the strong laser electric field can be used to accelerate electrons. Laser wakefield acceleration of electrons holds promise for future compact electron accelerators or drivers of other radiation sources in many scientific, medical and engineering applications. We present experimental studies of laser wakefield acceleration using the λ-cubed laser at the University of Michigan -- a table-top high-power laser system operating at 500 Hz repetition rate. The high repetition rate allows statistical studies of laser propagation and electron acceleration which are not accessible with typical sub-0.1 Hz repetition rate systems. In addition, we compare the experiments with particle-in-cell simulations using the code OSIRIS.

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

    International Nuclear Information System (INIS)

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

    1992-07-01

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

  18. An XUV/VUV free-electron laser oscillator

    Science.gov (United States)

    Goldstein, J. C.; Newnam, B. E.; Cooper, R. K.; Comly, J. C., Jr.

    Problems regarding the extension of free-electron laser technology from the visible and near infrared region, where such devices are currently operating, to the ultraviolet have recently been extensively discussed. It was found that significant technical problems must be overcome before free-electron lasers (FELs) can be operated in the VUV (100-200 nm) and the XUV (50-100). However, the present lack of other intense and tunable sources of coherent radiation at these wavelengths together with the intrinsic properties of FELs make the development of such devices potentially very rewarding. The properties of FELs include continuous tunability in wavelength and output in the form of a train of picosecond pulses. An investigation is conducted regarding the feasibility of an operation of a FEL in the XUV/VUV regions, taking into account a theoretical model. It is found that modest improvements in electron beam and optical mirror technologies will make the design of a FEL for operation in the 50-200-nm range of optical wavelength possible.

  19. Bone Ablation at 2.94 mm Using the Free-Electron Laser and Er:YAG Laser

    Science.gov (United States)

    Ivanov, Borislav; Hakimian, Arman; Peavy, G. M.; Haglund, Richard

    2002-03-01

    Bone Ablation at 2.94 microns Using the Free-Electron Laser and Er:YAG Laser in Perfluorocarbon Compounds B. Ivanov^1, A. M. Hakimian^1, G. M. Peavy^2, R. F. Haglund, Jr.1 1Department of Physics and Astronomy, W. M. Keck Foundation Free-Electron Laser Center, Vanderbilt University, Nashville, TN 37235 2Beckman Laser Institute and Medical Clinic, College of Medicine, University of California, Irvine, CA 92612 We report studies on the efficiency of mid-IR laser ablation of cow cortical bone using the Vanderbilt free-electron laser (FEL), when irrigating the ablation zone with an inert and biocompatible perfluorocarbon compounds (PFC). At 2.94 microns, the bone matrix (mainly by water) absorbs the radiation while the PFCs transmit this wavelength, dissipate heat and acoustical stress, and prevent carbonization of the bone sample. The ablation rate, as a function of laser fluence, scanning speed and the type of PFC, was investigated. The laser fluence was estimated to be 5 J/cm^2 - 100 J/cm^2 with a laser focal spot diameter of 160 microns 500 microns and a scanning speed of 40 microns/s 2960 microns/s. The ablation rate was estimated from scanning electron microscopy to be 0.5 mm/s 2.4 mm/s. Comparisons of ablation rates with the FEL and a Er:YAG laser at 2.94 microns are being evaluated.

  20. Laser annealed in-situ P-doped Ge for on-chip laser source applications (Conference Presentation)

    Science.gov (United States)

    Srinivasan, Ashwyn; Pantouvaki, Marianna; Shimura, Yosuke; Porret, Clement; Van Deun, Rik; Loo, Roger; Van Thourhout, Dries; Van Campenhout, Joris

    2016-05-01

    (1620nm) of the setup. Therefore, the 18× enhancement is a lower limit estimation. In this contribution, an extensive study of laser annealing conditions and their impact on material properties will be discussed. A major concern in using highly doped Ge as an active medium is the increase in free-carrier absorption (FCA). However, results reported in [4] suggest that FCA is significantly dominated by holes due to larger absorption cross-section of holes compared to electrons. The FCA results in [4] and JDOS modeling were used to calculate the gain spectrum for the highest doped Ge samples, including the typical 0.25% biaxial tensile strain of epitaxial Ge on Si. A carrier lifetime of 3 ns is required as shown in Fig. 3 for a target threshold current density of sub-20 kA/cm2 which represents at least tenfold reduction when compared to active P-doping level of 6×1019 cm-3. As a result, laser annealed highly doped Ge layers grown with Ge2H6 precursors are a promising approach for realizing a power efficient on-chip Ge laser source.

  1. IEEE conference record -- Abstracts

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This conference covers the following areas: computational plasma physics; vacuum electronic; basic phenomena in fully ionized plasmas; plasma, electron, and ion sources; environmental/energy issues in plasma science; space plasmas; plasma processing; ball lightning/spherical plasma configurations; plasma processing; fast wave devices; magnetic fusion; basic phenomena in partially ionized plasma; dense plasma focus; plasma diagnostics; basic phenomena in weakly ionized gases; fast opening switches; MHD; fast z-pinches and x-ray lasers; intense ion and electron beams; laser-produced plasmas; microwave plasma interactions; EM and ETH launchers; solid state plasmas and switches; intense beam microwaves; and plasmas for lighting. Separate abstracts were prepared for 416 papers in this conference

  2. A numerical study of the integral equations for the laser fields in free-electron lasers

    International Nuclear Information System (INIS)

    Yoo, J. G.; Park, S. H.; Jeong, Y. U.; Lee, B. C.; Rhee, Y. J.; Cho, S. O.

    2004-01-01

    The dynamics of the radiation fields in free-electron lasers is investigated on the basis of the integro-differential equations in the one-dimensional formulation. For simple cases we solved the integro-differential equations analytically and numerically to test our numerical procedures developed on the basis of the Filon method. The numerical results showed good agreement with the analytical solutions. To confirm the legitimacy of the numerical package, we carried out numerical studies on the inhomogeneous broadening effects, where no analytic solutions are available, due to the energy spread and the emittance of the electron beam.

  3. Program to Research Laser-Driven Thermionic Electron Sources for Free Electron Lasers.

    Science.gov (United States)

    1988-01-01

    by sinal I lengths of coaxial cable. With the ’. corresponding charge to the diode also reduced, a series of temporall y sho rter -Ioctron pulse-s was...e combination of approximately 1.6 eV. With the Nd:glass laser beam pulse heating the cathode " and the charge supplied by 0.5/ F capacitor, a series ...available charge stored in the h-arg ing ’apar i tor. A series of experiments was performed wilh lowetr capacitances of sevoral tens of picofarads furnished

  4. 1st International Conference on Opto-Electronics and Applied Optics

    CERN Document Server

    Bhattacharya, Indrani

    2015-01-01

    The Proceedings of First International Conference on Opto-Electronics and Applied Optics 2014, IEM OPTRONIX 2014 presents the research contributions presented in the conference by researchers from both India and abroad. Contributions from established scientists as well as students are included. The book is organized to enable easy access to various topics of interest.   The first part includes the Keynote addresses by Phillip Russell, Max Planck Institute of the Light Sciences, Erlangen, Germany and Lorenzo Pavesi, University of Trento, Italy.   The second part focuses on the Plenary Talks given by eminent scientists, namely, Azizur Rahman, City University London, London; Bishnu Pal, President, The Optical Society of India; Kamakhya Ghatak, National Institute of Technology, Agartala; Kehar Singh, Former Professor, India Institute of Technology Delhi; Mourad Zghal, SUPCOM, University of Carthage, Tunisia; Partha Roy Chaudhuri, IIT Kharagpur; S K. Bhadra, CSIR-Central Glass and Ceramic Research Institute, Kol...

  5. Upgrade of laser and electron beam welding database

    CERN Document Server

    Furman, Magdalena

    2014-01-01

    The main purpose of this project was to fix existing issues and update the existing database holding parameters of laser-beam and electron-beam welding machines. Moreover, the database had to be extended to hold the data for the new machines that arrived recently at the workshop. As a solution - the database had to be migrated to Oracle framework, the new user interface (using APEX) had to be designed and implemented with the integration with the CERN web services (EDMS, Phonebook, JMT, CDD and EDH).

  6. Scaling of electron beam sources for laser fusion applications

    International Nuclear Information System (INIS)

    Schlitt, L.G.; Bradley, L.P.

    1975-01-01

    The purpose of this study is to develop a scheme for constructing electron beam machines capable of pumping large volumes of gas, to analyze their performance within the framework of existing knowledge of the physical mechanisms involved, to use this analysis to assess the viability of the overall concept, pinpoint weaknesses in the understanding of the physics, identify the most important limiting physical processes, and hence to propose a program to prepare for the eventual construction of a large scale gas laser system. (auth)

  7. Deep saturated Free Electron Laser oscillators and frozen spikes

    Energy Technology Data Exchange (ETDEWEB)

    Ottaviani, P.L. [ENEA - Centro Ricerche Bologna, via Martiri di Monte Sole, 4, IT 40129, Bologna (Italy); Pagnutti, S., E-mail: simonetta.pagnutti@enea.it [ENEA - Centro Ricerche Bologna, via Martiri di Monte Sole, 4, IT 40129, Bologna (Italy); Dattoli, G., E-mail: giuseppe.dattoli@enea.it [ENEA - Centro Ricerche Frascati, via E. Fermi, 45, IT 00044, Frascati, Roma (Italy); Sabia, E., E-mail: elio.sabia@enea.it [ENEA - Centro Ricerche Frascati, via E. Fermi, 45, IT 00044, Frascati, Roma (Italy); Petrillo, V., E-mail: vittoria.petrillo@mi.infn.it [Universita' degli Studi di Milano, via Celoria 16, IT 20133, Milano (Italy); INFN - Mi, via Celoria 16, IT 20133, Milano (Italy); Slot, P.J.M. van der, E-mail: p.j.m.vanderslot@utwente.nl [Mesa+ Institute for Nanotechnology, University of Twente, P.O.Box 217, 7500 AE, Enschede (Netherlands); Biedron, S., E-mail: sandra.biedron@colostate.edu [Department of Electrical and Computer Engineering Colorado State University (United States); Milton, S., E-mail: milton@engr.colostate.edu [Department of Electrical and Computer Engineering Colorado State University (United States)

    2016-10-21

    We analyze the behavior of Free Electron Laser (FEL) oscillators operating in the deep saturated regime and point out the formation of sub-peaks of the optical pulse. These are very stable configurations and the sub-peaks are found to have a duration corresponding to the coherence length. We speculate on the physical mechanisms underlying their growth and attempt an identification with natural mode-locked structures in FEL oscillators. Their impact on the intra-cavity nonlinear harmonic generation is also discussed along with the possibility of exploiting them as cavity out-coupler.

  8. Inverse free electron laser beat-wave accelerator research

    International Nuclear Information System (INIS)

    Marshall, T.C.; Bhattacharjee, A.

    1993-09-01

    A calculation on the stabilization of the sideband instability in the free electron laser (FEL) and inverse FEL (IFEL) was completed. The issue arises in connection with the use of a tapered (''variable-parameter'') undulator of extended length, such as might be used in an ''enhanced efficiency'' traveling-wave FEL or an IFEL accelerator. In addition, the FEL facility at Columbia was configured as a traveling wave amplifier for a 10-kW signal from a 24-GHz magnetron. The space charge field in the bunches of the FEL was measured. Completed work has been published

  9. Free-Electron Lasers Push Into New Frontiers

    International Nuclear Information System (INIS)

    Benson, Stephen V.

    2003-01-01

    From the early days of the development of free-electron lasers (FELs) the promise of high power and short wavelengths has tantalized physicists and other scientists. Recent developments in accelerator technologies and some new discoveries about the physics of FELs have allowed researchers to push the performance of FELs into new frontiers of high power, short wavelength, and ultra-short pulses. Spin-offs from the FELs have also opened up new radiation sources in the THz, X-ray and gamma ray wavelength ranges

  10. Electron emission from laser irradiating target normal sheath acceleration (TNSA)

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Cutroneo, Mariapompea

    2016-01-01

    Roč. 171, 9-10 (2016), s. 754-765 ISSN 1042-0150. [12th Workshop on European Collaboration for Higher Education and Research in Nuclear Engineering and Radiological Protection. Bologna, Catania, Milan, 30.05.2016-01.06.2016] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : electron emission from plasma * TNSA * TOF * SiC * plastic scintillator * Thomson parabola spectrometer Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.443, year: 2016

  11. Free-electron laser experiments in the microwave tokamak experiment

    International Nuclear Information System (INIS)

    Allen, S.L.; Brown, M.D.; Byers, J.A.; Casper, T.A.; Cohen, B.I.; Cohen, R.H.; Cummings, J.C.; Fenstermacher, M.E.; Foote, J.H.; Hooper, E.B.; Jong, R.A.; Langdon, A.B.; Lasinski, B.F.; Lasnier, C.J.; Matsuda, Y.; Meyer, W.H.; Moller, J.M.; Nexsen, W.E.; Rice, B.W.; Rognlien, T.D.; Smith, G.R.; Stallard, B.W.; Thomassen, K.I.; Throop, A.L.; Turner, W.C.; Wood, R.D.; Cook, D.R.; Makowski, M.A.; Oasa, K.; Ogawa, T.

    1990-08-01

    Microwave pulses have been injected from a free electron-laser (FEL) into the Microwave Tokamak Experiment (MTX) at up to 0.2 GW at 140 GHz in short pulses (10-ns duration) with O-mode polarization. The power transmitted through the plasma was measured in a first experimental study of high power pulse propagation in the plasma; no nonlinear effects were found at this power level. Calculations indicate that nonlinear effects may be found at the higher power densities expected in future experiments. 9 refs., 2 figs

  12. Longitudinal space charge assisted echo seeding of a free-electron laser with laser-spoiler noise suppression

    Directory of Open Access Journals (Sweden)

    Kirsten Hacker

    2014-09-01

    Full Text Available Seed lasers are employed to improve the temporal coherence of free-electron laser (FEL light. However, when these seed pulses are short relative to the particle bunch, the noisy, temporally incoherent radiation from the unseeded electrons can overwhelm the coherent, seeded radiation. In this paper, a technique to seed a particle bunch with an external laser is presented in which a new mechanism to improve the contrast between coherent and incoherent free electron laser radiation is employed together with a novel, simplified echo-seeding method. The concept relies on a combination of longitudinal space charge wakes and an echo-seeding technique to make a short, coherent pulse of FEL light together with noise background suppression. Several different simulation codes are used to illustrate the concept with conditions at the soft x-ray free-electron laser in Hamburg, FLASH.

  13. A Low-Energy-Spread Rf Accelerator for a Far-Infrared Free-Electron Laser

    NARCIS (Netherlands)

    van der Geer, C. A. J.; Bakker, R. J.; van der Meer, A. F. G.; van Amersfoort, P. W.; Gillespie, W. A.; Saxon, G.; Poole, M. W.

    1993-01-01

    A high electron current and a small energy spread are essential for the operation of a free electron laser (FEL). In this paper we discuss the design and performance of the accelerator for FELIX, the free electron laser for infrared experiments. The system consists of a thermionic gun, a prebuncher,

  14. Free electron laser and coherent radiation. Working group summary

    International Nuclear Information System (INIS)

    Gover, A.; Csonka, P.; Deacon, D.

    1984-01-01

    The planned development of a new storage ring at SSRL gives hope for the exciting possibility that an x-ray laser may become available in a users facility. Such a device would certainly be a unique and revolutionary tool for scientific research and industrial applications, which may take advantage of the spatial and temporal coherence, high power and high brightness of this device in a wavelength regime where no alternative coherent radiation sources exist. The feasibility of implementing such a device in the new ring should be examined carefully by the ring designers. If conclusions are positive, the ring design should take into account the special requirements which are set by the x-ray laser design parameters. Our working group made the first step in this examination process. Most of the emphasis was put on the consideration of an X-Ray Free Electron Laser (XR FEL). FEL technology has developed in the last few years and was recently demonstrated to operate successfully in the visible wavelength regime in the ACO storage ring in Orsay

  15. XUV free-electron laser-based projection lithography systems

    Energy Technology Data Exchange (ETDEWEB)

    Newnam, B.E.

    1990-01-01

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

  16. Introduction to the theory of free electron lasers

    International Nuclear Information System (INIS)

    Krinsky, S.

    1985-01-01

    We present an introduction to some fundamental aspects of the theory of free electron lasers. Spontaneous radiation emitted by electrons traversing a wiggler magnet is briefly reviewed, and stimulated emission in the low-gain regime is discussed using Colson's pendulum equations and Madey's theorems. The high-gain regime is treated by an extention of the work of Bonifacio, Pellegrini, and Narducci. We introduce dynamical variables to describe the radiation field, and a Hamiltonian formulation of Maxwell's equations is employed. A canonical transformation to the interaction representation factors out the fast time variation of the radiation field, and the slow time dependence is determined by linearized equations for the appropriate collective variables. As an application of this technique we consider self-amplified spontaneous radiation, and we comment upon the relationship between our approach and the use of coupled Vlasov-Maxwell equations

  17. Introduction to free electron lasers (1/3)

    CERN Multimedia

    CERN. Geneva

    2002-01-01

    The Free-electron laser (FEL) is a source of coherent electromagnetic radiation based on a relativistic electron beam. First operated 25 years ago, the FEL has now reached a stage of maturity for operation in the infra-red region of the spectrum and several facilities provide intense FEL radiation beams for research covering a wide range of disciplines. Several projects both underway and proposed aim at pushing the minimum wavelength from its present limit around 100 nm progressively down to the 1 Angstrom region where the X-ray FEL would open up many new and exciting research possibilities. Other developments aim at increasing power levels to the 10's of kW level. In this series of lectures we give an introduction to the basic principles of FELs and their different modes of operation, and summarise their applications and current state of development.

  18. Introduction to free electron lasers (3/3)

    CERN Multimedia

    CERN. Geneva

    2002-01-01

    The Free-electron laser (FEL) is a source of coherent electromagnetic radiation based on a relativistic electron beam. First operated 25 years ago, the FEL has now reached a stage of maturity for operation in the infra-red region of the spectrum and several facilities provide intense FEL radiation beams for research covering a wide range of disciplines. Several projects both underway and proposed aim at pushing the minimum wavelength from its present limit around 100 nm progressively down to the 1 Angstrom region where the X-ray FEL would open up many new and exciting research possibilities. Other developments aim at increasing power levels to the 10's of kW level. In this series of lectures we give an introduction to the basic principles of FELs and their different modes of operation, and summarise their applications and current state of development.

  19. Introduction to free electron lasers (2/3)

    CERN Multimedia

    CERN. Geneva

    2002-01-01

    The Free-electron laser (FEL) is a source of coherent electromagnetic radiation based on a relativistic electron beam. First operated 25 years ago, the FEL has now reached a stage of maturity for operation in the infra-red region of the spectrum and several facilities provide intense FEL radiation beams for research covering a wide range of disciplines. Several projects both underway and proposed aim at pushing the minimum wavelength from its present limit around 100 nm progressively down to the 1 Angstrom region where the X-ray FEL would open up many new and exciting research possibilities. Other developments aim at increasing power levels to the 10's of kW level. In this series of lectures we give an introduction to the basic principles of FELs and their different modes of operation, and summarise their applications and current state of development.

  20. International Conference on the Interaction of atoms, molecules and plasmas with intense ultrashort laser pulses. Book of abstracts

    International Nuclear Information System (INIS)

    2006-01-01

    International Conference on the Interaction of atoms, molecules and plasmas with intense ultrashort laser pulses was held in Hungary in 2006. This conference which joined the ULTRA COST activity ('Laser-matter interactions with ultra-short pulses, high-frequency pulses and ultra-intense pulses. From attophysics to petawatt physics') and the XTRA ('Ultrashort XUV Pulses for Time-Resolved and Non-Linear Applications') Marie-Curie Research Training Network, intends to offer a possibility to the members of both of these activities to exchange ideas on recent theoretical and experimental results on the interaction of ultrashort laser pulses with matter giving a broad view from theoretical models to practical and technical applications. Ultrashort laser pulses reaching extra high intensities open new windows to obtain information about molecular and atomic processes. These pulses are even able to penetrate into atomic scalelengths not only by generating particles of ultrahigh energy but also inside the spatial and temporal atomic scalelengths. New regimes of laser-matter interaction were opened in the last decade with an increasing number of laboratories and researchers in these fields. (S.I.)

  1. Basic design considerations for free-electron lasers driven by electron beams from RF accelerators

    Science.gov (United States)

    Gover, A.; Freund, H.; Granatstein, V. L.; McAdoo, J. H.; Tang, C.-M.

    A design procedure and design criteria are derived for free-electron lasers driven by electron beams from RF accelerators. The procedure and criteria permit an estimate of the oscillation-buildup time and the laser output power of various FEL schemes: with waveguide resonator or open resonator, with initial seed-radiation injection or with spontaneous-emission radiation source, with a linear wiggler or with a helical wiggler. Expressions are derived for computing the various FEL parameters, allowing for the design and optimization of the FEL operational characteristics under ideal conditions or with nonideal design parameters that may be limited by technological or practical constraints. The design procedure enables one to derive engineering curves and scaling laws for the FEL operating parameters. This can be done most conveniently with a computer program based on flowcharts given in the appendices.

  2. PREFACE: International Conference on Strongly Correlated Electron Systems 2014 (SCES2014)

    Science.gov (United States)

    2015-03-01

    The 2014 International Conference on Strongly Correlated Electron Systems (SCES) was held in Grenoble from the 7th to 11th of July on the campus of the University of Grenoble. It was a great privilege to have the conference in Grenoble after the series of meetings in Sendai (1992), San Diego (1993), Amsterdam (1994), Goa (1995), Zürich (1996), Paris (1998), Nagano (1999), Ann Arbor (2001), Krakow (2002), Karlsruhe (2004), Vienna (2005), Houston (2007), Buzios (2008), Santa Fe (2010), Cambridge (2011) and Tokyo (2013). Every three years, SCES joins the triennial conference on magnetism ICM. In 2015, ICM will take place in Barcelona. The meeting gathered an audience of 875 participants who actively interacted inside and outside of conference rooms. A large number of posters (530) was balanced with four parallel oral sessions which included 86 invited speakers and 141 short oral contributions. A useful arrangement was the possibility to put poster presentations on the website so participants could see them all through the conference week. Each morning two plenary sessions were held, ending on Friday with experimental and theoretical summaries delivered by Philipp Gegenwart (Augsburg) and Andrew Millis (Columbia). The plenary sessions were given by Gabriel Kotliar (Rutgers), Masashi Kawasaki (Tokyo), Jennifer Hoffman (Harvard), Mathias Vojta (Dresden), Ashvin Vishwanath (Berkeley), Andrea Cavalleri (Hamburg), Marc-Henri Julien (Grenoble), Neil Mathur (Cambridge), Giniyat Khaliullin (Stuttgart), and Toshiro Sakakibara (Tokyo). The parallel oral sessions were prepared by 40 symposium organizers selected by the chairman (Antoine Georges) and co-chairman (Kamran Behnia) of the Program Committee with the supplementary rule that speakers had not delivered an invited talk at the previous SCES conference held in 2013 in Tokyo. Special attention was given to help young researchers via grants to 40 overseas students. Perhaps due to the additional possibility of cheap

  3. Escaping Electrons from Intense Laser-Solid Interactions as a Function of Laser Spot Size

    Directory of Open Access Journals (Sweden)

    Rusby Dean

    2018-01-01

    Full Text Available The interaction of a high-intensity laser with a solid target produces an energetic distribution of electrons that pass into the target. These electrons reach the rear surface of the target creating strong electric potentials that act to restrict the further escape of additional electrons. The measurement of the angle, flux and spectra of the electrons that do escape gives insights to the initial interaction. Here, the escaping electrons have been measured using a differentially filtered image plate stack, from interactions with intensities from mid 1020-1017 W/cm2, where the intensity has been reduced by defocussing to increase the size of the focal spot. An increase in electron flux is initially observed as the intensity is reduced from 4x1020 to 6x1018 W/cm2. The temperature of the electron distribution is also measured and found to be relatively constant. 2D particle-in-cell modelling is used to demonstrate the importance of pre-plasma conditions in understanding these observations.

  4. Simulations of Electron Transport in Laser Hot Spots

    International Nuclear Information System (INIS)

    Brunner, S.; Valeo, E.

    2001-01-01

    Simulations of electron transport are carried out by solving the Fokker-Planck equation in the diffusive approximation. The system of a single laser hot spot, with open boundary conditions, is systematically studied by performing a scan over a wide range of the two relevant parameters: (1) Ratio of the stopping length over the width of the hot spot. (2) Relative importance of the heating through inverse Bremsstrahlung compared to the thermalization through self-collisions. As for uniform illumination [J.P. Matte et al., Plasma Phys. Controlled Fusion 30 (1988) 1665], the bulk of the velocity distribution functions (VDFs) present a super-Gaussian dependence. However, as a result of spatial transport, the tails are observed to be well represented by a Maxwellian. A similar dependence of the distributions is also found for multiple hot spot systems. For its relevance with respect to stimulated Raman scattering, the linear Landau damping of the electron plasma wave is estimated for such VD Fs. Finally, the nonlinear Fokker-Planck simulations of the single laser hot spot system are also compared to the results obtained with the linear non-local hydrodynamic approach [A.V. Brantov et al., Phys. Plasmas 5 (1998) 2742], thus providing a quantitative limit to the latter method: The hydrodynamic approach presents more than 10% inaccuracy in the presence of temperature variations of the order delta T/T greater than or equal to 1%, and similar levels of deformation of the Gaussian shape of the Maxwellian background

  5. A polarized look at nucleons: Laser electron gamma source

    International Nuclear Information System (INIS)

    1991-01-01

    As the title suggests we are going to look at reactions induced on nucleons by polarized photons. The results I am going to show today are from the Laser Electron Gamma Source, or ''LEGS'' facility, at Brookhaven National Laboratory. At LEGS, gamma ray beams are produced by backscattering laser light from relativistic electrons. I will only summarize the main characteristics of this facility, and leave an in depth description to Dr. Schaerf who will discuss LEGS and other similar backscattering facilities on Wednesday. Reactions with polarized photons inevitably reflect interference terms that for the most part remain hidden in spin-averaged unpolarized measurements. This provides a tool for probing interactions that depend upon spin. In particular, we are going to look today at two cases where the polarization is used to probe the tensor interaction. First, we will examine the tensor force between a proton-neutron pair in deuterium. Secondly, we will examine the tensor force between quarks in a proton that produces a small E2 component that is mixed with the predominantly M1 excitation of the delta resonance.The magnitude of this E2 components provides a sensitive probe of the structure of the Nucleon

  6. Numerical Simulations of X-Ray Free Electron Lasers (XFEL)

    KAUST Repository

    Antonelli, Paolo

    2014-11-04

    We study a nonlinear Schrödinger equation which arises as an effective single particle model in X-ray free electron lasers (XFEL). This equation appears as a first principles model for the beam-matter interactions that would take place in an XFEL molecular imaging experiment in [A. Fratalocchi and G. Ruocco, Phys. Rev. Lett., 106 (2011), 105504]. Since XFEL are more powerful by several orders of magnitude than more conventional lasers, the systematic investigation of many of the standard assumptions and approximations has attracted increased attention. In this model the electrons move under a rapidly oscillating electromagnetic field, and the convergence of the problem to an effective time-averaged one is examined. We use an operator splitting pseudospectral method to investigate numerically the behavior of the model versus that of its time-averaged version in complex situations, namely the energy subcritical/mass supercritical case and in the presence of a periodic lattice. We find the time-averaged model to be an effective approximation, even close to blowup, for fast enough oscillations of the external field. This work extends previous analytical results for simpler cases [P. Antonelli, A. Athanassoulis, H. Hajaiej, and P. Markowich, Arch. Ration. Mech. Anal., 211 (2014), pp. 711--732].

  7. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO 2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  8. Laser-induced electron--ion recombination used to study enhanced spontaneous recombination during electron cooling

    International Nuclear Information System (INIS)

    Schramm, U.; Wolf, A.; Schuess ler, T.; Habs, D.; Schwalm, D.; Uwira, O.; Linkemann, J.; Mueller, A.

    1997-01-01

    Spontaneous recombination of highly charged ions with free electrons in merged velocity matched electron and ion beams has been observed in earlier experiments to occur at rates significantly higher than predicted by theoretical estimates. To study this enhanced spontaneous recombination, laser induced recombination spectra were measured both in velocity matched beams and in beams with well defined relative velocities, corresponding to relative electron-ion detuning energies ranging from 1 meV up to 6.5 meV where the spontaneous recombination enhancement was found to be strongly reduced. Based on a comparison with simplified calculations, the development of the recombination spectra for decreasing detuning energies indicates additional contributions at matched velocities which could be related to the energy distribution of electrons causing the spontaneous recombination rate enhancement

  9. A multi-frequency approach to free electron lasers driven by short electron bunches

    International Nuclear Information System (INIS)

    Piovella, Nicola

    1997-01-01

    A multi-frequency model for free electron lasers (FELs), based on the Fourier decomposition of the radiation field coupled with the beam electrons, is discussed. We show that the multi-frequency approach allows for an accurate description of the evolution of the radiation spectrum, also when the FEL is driven by short electron bunches, of arbitrary longitudinal profile. We derive from the multi-frequency model, by averaging over one radiation period, the usual FEL equations modelling the slippage between radiation and particles and describing the super-radiant regime in high-gain FELs. As an example of application of the multi-frequency model, we discuss the coherent spontaneous emission (CSE) from short electron bunches

  10. International Conference on Microtechnology and Thermal Problems in Electronics (MicroTherm'2015) and International Conference on Smart Engineering of New Materials (SENM'2015)

    International Nuclear Information System (INIS)

    2016-01-01

    The issue covers selected papers presented during the Joint Event of two International Cyclic Conferences: MicroTherm – Microtechnology and Thermal Problems in Electronics and SENM – Smart Engineering of New Materials. The Duoconference was held in Lodz, Poland on 23-25 June 2015. It gathered almost 200 participants from 20 countries. MicroTherm is an International Conference on Microtechnology and Thermal Problems in Electronics that is organised every two years, since 1996. The success of the first seminar devoted to thermal management aspects, and the successive conferences have led us to the eleventh edition. Since the first meeting, the scope of the Conference has expanded, following the progress of electronics. Now, it covers subjects connected with extreme temperature, electronics, sensors and measurement techniques, modelling, simulation, wide band-gap materials, packaging and reliability, renewable energy sources and photonics with special emphasis on microelectronic technologies. The tradition of SENM dates back to 1985 when the First International Conference on Diamond Crystallization under Reduced Pressure was held in Jabłonna, Poland. Since then, the Conference is organised regularly every five years. From the early beginning the main aim of this event was the creation of an international forum of scientists for the presentation of the newest achievements and investigation results in vacuum and plasma techniques, synthesis, characterisation and application of diamond, its derivatives and other wide bandgap materials. Over time, the scope of the conference has expanded to include nanomaterials, biomaterials and new functional materials, in the range of production, design and optimisation of the synthesis and modification technologies. Traditionally, the programme of MicroTherm’2015 and SENM’2015 is comprised of invited talks and regular sessions in the form of planar discussions and poster presentations, which also include a Students’ Session

  11. Modeling and multidimensional optimization of a tapered free electron laser

    Directory of Open Access Journals (Sweden)

    Y. Jiao

    2012-05-01

    Full Text Available Energy extraction efficiency of a free electron laser (FEL can be greatly increased using a tapered undulator and self-seeding. However, the extraction rate is limited by various effects that eventually lead to saturation of the peak intensity and power. To better understand these effects, we develop a model extending the Kroll-Morton-Rosenbluth, one-dimensional theory to include the physics of diffraction, optical guiding, and radially resolved particle trapping. The predictions of the model agree well with that of the GENESIS single-frequency numerical simulations. In particular, we discuss the evolution of the electron-radiation interaction along the tapered undulator and show that the decreasing of refractive guiding is the major cause of the efficiency reduction, particle detrapping, and then saturation of the radiation power. With this understanding, we develop a multidimensional optimization scheme based on GENESIS simulations to increase the energy extraction efficiency via an improved taper profile and variation in electron beam radius. We present optimization results for hard x-ray tapered FELs, and the dependence of the maximum extractable radiation power on various parameters of the initial electron beam, radiation field, and the undulator system. We also study the effect of the sideband growth in a tapered FEL. Such growth induces increased particle detrapping and thus decreased refractive guiding that together strongly limit the overall energy extraction efficiency.

  12. Field Emitter Arrays for a Free Electron Laser Application

    CERN Document Server

    Shing-Bruce-Li, Kevin; Ganter, Romain; Gobrecht, Jens; Raguin, Jean Yves; Rivkin, Leonid; Wrulich, Albin F

    2004-01-01

    The development of a new electron gun with the lowest possible emittance would help reducing the total length and cost of a free electron laser. Field emitter arrays (FEAs) are an attractive technology for electron sources of ultra high brightness. Indeed, several thousands of microscopic tips can be deposited on a 1 mm diameter area. Electrons are then extracted by applying voltage to a first grid layer close to the tip apexes, the so called gate layer, and focused by a second grid layer one micrometer above the tips. The typical aperture diameter of the gate and the focusing layer is in the range of one micrometer. One challenge for such cathodes is to produce peak currents in the ampere range since the usual applications of FEAs require less than milliampere. Encouraging peak current performances have been obtained by applying voltage pulses at low frequency between gate and tips. In this paper we report on different tip materials available on the market: diamond FEAs from Extreme Devices Inc., ZrC single ...

  13. Optical guiding and beam bending in free-electron lasers

    International Nuclear Information System (INIS)

    Scharlemann, E.T.

    1987-01-01

    The electron beam in a free-electron laser (FEL) can act as an optical fiber, guiding or bending the optical beam. The refractive and gain effects of the bunched electron beam can compensate for diffraction, making possible wigglers that are many Rayleigh ranges (i.e., characteristic diffraction lengths) long. The origin of optical guiding can be understood by examining gain and refractive guiding in a fiber with a complex index of refraction, providing a mathematical description applicable also to the FEL, with some extensions. In the exponential gain regime of the FEL, the electron equations of motion must be included, but a self-consistent description of exponential gain with diffraction fully included becomes possible. The origin of the effective index of refraction of an FEL is illustrated with a simple example of bunched, radiating dipoles. Some of the properties of the index of refraction are described. The limited experimental evidence for optical beam bending is summarized. The evidence does not yet provide conclusive proof of the existence of optical guiding, but supports the idea. Finally, the importance of refractive guiding for the performance of a high-gain tapered-wiggler FEL amplifier is illustrated with numerical simulations

  14. Electron beam charge diagnostics for laser plasma accelerators

    Directory of Open Access Journals (Sweden)

    K. Nakamura

    2011-06-01

    Full Text Available A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs. First, a scintillating screen (Lanex was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160  pC/mm^{2} and 0.4  pC/(ps  mm^{2}, respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within ±8%, showing that they all can provide accurate charge measurements for LPAs.

  15. Radial electron beam laser excitation: the REBLE report

    International Nuclear Information System (INIS)

    Ramirez, J.J.; Prestwich, K.R.

    1978-10-01

    The results of an investigation of techniques to generate high-power radially converging electron beams and the application of these beams to gas lasers is discussed. The design and performance of the REBLE accelerator that was developed for this program is presented. Reliable operation of the radial diode has been obtained at levels up to 1 MV, 200 kA, and 20 ns. It has been demonstrated that the anode current density can be made uniform to better than 15% over 1000 cm 2 areas with 100 to 250 A/cm 2 intensities. The measured total and spatially resolved energy deposition of this radial electron beam in various gases is compared with Monte Carlo calculations. In most cases, these codes give an accurate description of the beam transport and energy deposition. With the electron beam pumping xenon gas, the amplitude of xenon excimer radiation (1720 A 0 ) was radially uniform to within the experimental uncertainty. The efficiency of converting deposited electron beam energy to xenon excimer radiation was 20%

  16. Electron ionization and spin polarization control of Fe atom adsorbed graphene irradiated by a femtosecond laser

    International Nuclear Information System (INIS)

    Yu, Dong; Jiang, Lan; Wang, Feng; Li, Xin; Qu, Liangti; Lu, Yongfeng

    2015-01-01

    We investigate the structural properties and ionized spin electrons of an Fe–graphene system, in which the time-dependent density functional theory (TDDFT) within the generalized gradient approximation is used. The electron dynamics, including electron ionization and ionized electron spin polarization, is described for Fe atom adsorbed graphene under femtosecond laser irradiation. The theoretical results show that the electron ionization and ionized electron spin polarization are sensitive to the laser parameters, such as the incident angle and the peak intensity. The spin polarization presents the maximum value under certain laser parameters, which may be used as a source of spin-polarized electrons. - Highlights: • The structural properties of Fe–graphene system are investigated. • The electron dynamics of Fe–graphene system under laser irradiation are described. • The Fe–graphene system may be used as a source of spin-polarized electrons

  17. Structural and electronic characterization of 355 nm laser-crystallized silicon: Interplay of film thickness and laser fluence

    International Nuclear Information System (INIS)

    Semler, Matthew R.; Swenson, Orven F.; Hoey, Justin M.; Guruvenket, Srinivasan; Gette, Cody R.; Hobbie, Erik K.

    2014-01-01

    We present a detailed study of the laser crystallization of amorphous silicon thin films as a function of laser fluence and film thickness. Silicon films grown through plasma-enhanced chemical vapor deposition were subjected to a Q-switched, diode-pumped solid-state laser operating at 355 nm. The crystallinity, morphology, and optical and electronic properties of the films are characterized through transmission and reflectance spectroscopy, resistivity measurements, Raman spectroscopy, X-ray diffraction, atomic force microscopy, and optical and scanning-electron microscopy. Our results reveal a unique surface morphology that strongly couples to the electronic characteristics of the films, with a minimum laser fluence at which the film properties are optimized. A simple scaling model is used to relate film morphology to conductivity in the laser-processed films

  18. Characterization of electron-deficient chemical bonding of diborane with attosecond electron wavepacket dynamics and laser response

    International Nuclear Information System (INIS)

    Yonehara, Takehiro; Takatsuka, Kazuo

    2009-01-01

    We report a theoretical study of non-adiabatic electrons-nuclei coupled dynamics of diborane H 2 BH 2 BH 2 under several types of short pulse lasers. This molecule is known to have particularly interesting geometrical and electronic structures, which originate from the electron-deficient chemical bondings. We revisit the chemical bonding of diborane from the view point of electron wavepacket dynamics coupled with nuclear motions, and attempt to probe the characteristics of it by examining its response to intense laser fields. We study in the following three aspects, (i) bond formation of diborane by collision between two monoboranes, (ii) attosecond electron wavepacket dynamics in the ground state and first excited state by circularly polarized laser pulse, and (iii) induced fragmentation back to monoborane molecules by linearly polarized laser. The wave lengths of two types of laser field employed are 200 nm (in UV range) and 800 nm (in IR range), and we track the dynamics from hundreds of attoseconds up to few tens of femtoseconds. To this end, we apply the ab initio semiclassical Ehrenfest theory, into which the classical vector potential of a laser field is introduced. Basic features of the non-adiabatic response of electrons to the laser fields is elucidated in this scheme. To analyze the electronic wavepackets thus obtained, we figure out bond order density that is a spatial distribution of the bond order and bond order flux density arising only from the bonding regions, and so on. Main findings in this work are: (i) dimerization of monoboranes to diborane is so efficient that even intense laser is hard to prevent it; (ii) collective motions of electron flux emerge in the central BHHB bonding area in response to the circularly polarized laser fields; (iii) laser polarization with the direction of central two BH bonding vector is efficient for the cleavage of BH 3 -BH 3 ; and (iv) nuclear derivative coupling plays a critical role in the field induced

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

    International Nuclear Information System (INIS)

    Harris, D.G.; Herbelin, J.

    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

  20. Material Processing Opportunites Utilizing a Free Electron Laser

    Science.gov (United States)

    Todd, Alan

    1996-11-01

    Many properties of photocathode-driven Free Electron Lasers (FEL) are extremely attractive for material processing applications. These include: 1) broad-band tunability across the IR and UV spectra which permits wavelength optimization, depth deposition control and utilization of resonance phenomena; 2) picosecond pulse structure with continuous nanosecond spacing for optimum deposition efficiency and minimal collateral damage; 3) high peak and average radiated power for economic processing in quantity; and 4) high brightness for spatially defined energy deposition and intense energy density in small spots. We discuss five areas: polymer, metal and electronic material processing, micromachining and defense applications; where IR or UV material processing will find application if the economics is favorable. Specific examples in the IR and UV, such as surface texturing of polymers for improved look and feel, and anti-microbial food packaging films, which have been demonstrated using UV excimer lamps and lasers, will be given. Unfortunately, although the process utility is readily proven, the power levels and costs of lamps and lasers do not scale to production margins. However, from these examples, application specific cost targets ranging from 0.1=A2/kJ to 10=A2/kJ of delivered radiation at power levels from 10 kW to 500 kW, have been developed and are used to define strawman FEL processing systems. Since =46EL radiation energy extraction from the generating electron beam is typically a few percent, at these high average power levels, economic considerations dictate the use of a superconducting RF accelerator with energy recovery to minimize cavity and beam dump power loss. Such a 1 kW IR FEL, funded by the US Navy, is presently under construction at the Thomas Jefferson National Accelerator Facility. This dual-use device, scheduled to generate first light in late 1997, will test both the viability of high-power FELs for shipboard self-defense against cruise

  1. First observations of acceleration of injected electrons in a laser plasma beatwave experiment

    International Nuclear Information System (INIS)

    Ebrahim, N.A.; Martin, F.; Bordeur, P.; Heighway, E.A.; Matte, J.P.; Pepin, H.; Lavigne, P.

    1986-01-01

    The first experimental observations of acceleration of injected electrons in a laser driven plasma beatwave are presented. The plasma waves were excited in an ionized gas jet, using a short pulse high intensity CO 2 laser with two collinearly propagating beams (at λ = 9.6 μm and 10.6 μm) to excite a fast wave (v/sub p/ = c). The source of electrons was a laser plasma produced on an aluminum slab target by a third, synchronized CO 2 laser beam. A double-focusing dipole magnet was used to energy select and inject electrons into the beatwave, and a second magnetic spectrograph was used to analyze the accelerated electrons. Electron acceleration was only observed when the appropriate resonant plasma density was produced (∼ 10 17 cm -3 ), the two laser lines were incident on the plasma, and electrons were injected into this plasma from an external source

  2. Electrons trajectories around a bubble regime in intense laser plasma interaction

    International Nuclear Information System (INIS)

    Lu, Ding; Xie, Bai-Song; Ali Bake, Muhammad; Sang, Hai-Bo; Zhao, Xue-Yan; Wu, Hai-Cheng

    2013-01-01

    Some typical electrons trajectories around a bubble regime in intense laser plasma interaction are investigated theoretically. By considering a modification of the fields and ellipsoid bubble shape due to the presence of residual electrons in the bubble regime, we study in detail the electrons nonlinear dynamics with or without laser pulse. To examine the electron dynamical behaviors, a set of typical electrons, which locate initially at the front of the bubble, on the transverse edge and at the bottom of the bubble respectively, are chosen for study. It is found that the range of trapped electrons in the case with laser pulse is a little narrower than that without laser pulse. The partial phase portraits for electrons around the bubble are presented numerically and their characteristic behaviors are discussed theoretically. Implication of our results on the high quality electron beam generation is also discussed briefly

  3. Abstracts of the 5. International Conference on Lasers and their Applications

    International Nuclear Information System (INIS)

    1985-01-01

    New results have been presented in the fields of laser physics and laser applications including the development of new laser light sources, new laser frequencies in the UV and VUV spectral regions using anti-Stokes Raman scattering, nonlinear optical effects for the formation of ultrashort optical pulses, laser spectroscopy, collisionless multiphoton excitation processes using molecular beams, selective generation of free radicals by laser, laser applications in medicine, plasma diagnostics analysing X-ray spectra for studying laser fusion problems, coherence properties in phase-sampling interferometric techniques, and fundamental problems in quantum physics and nonlinear processes

  4. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    International Nuclear Information System (INIS)

    Behrens, Christopher

    2012-11-01

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  5. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2012-11-15

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  6. Conceptual design of a laser-plasma accelerator driven free-electron laser demonstration experiment

    International Nuclear Information System (INIS)

    Seggebrock, Thorben

    2015-01-01

    Up to now, short-wavelength free-electron lasers (FEL) have been systems on the scale of hundreds of meters up to multiple kilometers. Due to the advancements in laser-plasma acceleration in the recent years, these accelerators have become a promising candidate for driving a fifth-generation synchrotron light source - a lab-scale free-electron laser. So far, demonstration experiments have been hindered by the broad energy spread typical for this type of accelerator. This thesis addresses the most important challenges of the conceptual design for a first lab-scale FEL demonstration experiment using analytical considerations as well as simulations. The broad energy spread reduces the FEL performance directly by weakening the microbunching and indirectly via chromatic emittance growth, caused by the focusing system. Both issues can be mitigated by decompressing the electron bunch in a magnetic chicane, resulting in a sorting by energies. This reduces the local energy spread as well as the local chromatic emittance growth and also lowers performance degradations caused by the short bunch length. Moreover, the energy dependent focus position leads to a focus motion within the bunch, which can be synchronized with the radiation pulse, maximizing the current density in the interaction region. This concept is termed chromatic focus matching. A comparison shows the advantages of the longitudinal decompression concept compared to the alternative approach of transverse dispersion. When using typical laser-plasma based electron bunches, coherent synchrotron radiation and space-charge contribute in equal measure to the emittance growth during decompression. It is shown that a chicane for this purpose must not be as weak and long as affordable to reduce coherent synchrotron radiation, but that an intermediate length is required. Furthermore, the interplay of the individual concepts and components is assessed in a start-to-end simulation, confirming the feasibility of the

  7. Conceptual design of a laser-plasma accelerator driven free-electron laser demonstration experiment

    Energy Technology Data Exchange (ETDEWEB)

    Seggebrock, Thorben

    2015-07-08

    Up to now, short-wavelength free-electron lasers (FEL) have been systems on the scale of hundreds of meters up to multiple kilometers. Due to the advancements in laser-plasma acceleration in the recent years, these accelerators have become a promising candidate for driving a fifth-generation synchrotron light source - a lab-scale free-electron laser. So far, demonstration experiments have been hindered by the broad energy spread typical for this type of accelerator. This thesis addresses the most important challenges of the conceptual design for a first lab-scale FEL demonstration experiment using analytical considerations as well as simulations. The broad energy spread reduces the FEL performance directly by weakening the microbunching and indirectly via chromatic emittance growth, caused by the focusing system. Both issues can be mitigated by decompressing the electron bunch in a magnetic chicane, resulting in a sorting by energies. This reduces the local energy spread as well as the local chromatic emittance growth and also lowers performance degradations caused by the short bunch length. Moreover, the energy dependent focus position leads to a focus motion within the bunch, which can be synchronized with the radiation pulse, maximizing the current density in the interaction region. This concept is termed chromatic focus matching. A comparison shows the advantages of the longitudinal decompression concept compared to the alternative approach of transverse dispersion. When using typical laser-plasma based electron bunches, coherent synchrotron radiation and space-charge contribute in equal measure to the emittance growth during decompression. It is shown that a chicane for this purpose must not be as weak and long as affordable to reduce coherent synchrotron radiation, but that an intermediate length is required. Furthermore, the interplay of the individual concepts and components is assessed in a start-to-end simulation, confirming the feasibility of the

  8. Laser - assisted multiphoton ionization of ground state Li{sup +} by electron and positron impact

    Energy Technology Data Exchange (ETDEWEB)

    Deb, S Ghosh; Sinha, C, E-mail: srabanti.ghosh@gmail.co, E-mail: chand_sin@hotmail.co [Theoretical Physics Department, Indian Association for the Cultivation of Science, Kolkata - 700032 (India)

    2009-11-01

    The influence of the laser field on the dynamics of (e, 2e) process of Li{sup +} ion by electron / positron impact is studied for coplanar geometry with laser polarization parallel to the incident momentum. The laser dressed projectile wavefunctions are chosen as Coulomb Volkov (CV) while for ejected electron, modified CV is considered. The target dressing is constructed using the time dependent perturbation theory. Laser field suppresses the FF cross-sections significantly for single photon exchange while for multiple photon exchanges the cross-sections are enhanced. TDCS is quite sensitive with respect to the initial phase of the laser field.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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. Efficiency enhancement of a harmonic lasing free-electron laser

    Science.gov (United States)

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

    2015-03-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  12. Millimeter wave free electron laser amplifiers: Experiments and designs

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Zhang, Z.X.; Antonsen, T.M. Jr.; Bensen, D.M.; Destler, W.W.; Granatstein, V.L.; Lantham, P.E.; Levush, B.; Rodgers, J.

    1991-01-01

    Free electron laser amplifies are investigated as sources of high- average-power (1 MW) millimeter to submillimeter wave radiation (200 GHz - 600 GHz) for application to electron cyclotron resonance heating of magnetically confined fusion plasmas. As a stepping-stone to higher frequencies and cw operation a pulsed amplifier (τ pulse ≅ 80 ns) at 98 GHz is being developed. Status is reported on this experiment which investigates linear gain amplification with use of sheet electron beam (transverse cross section = 0.1 cm x 2.0 cm, V beam = 440 keV, I beam ≅ 10 A) and short-period wiggler (ell w = 0.96 cm) and with expected output of 140 W. Predictions of gain and efficiency from a 1-D universal formulation are presented. Beam propagation results, with wiggler focusing as a means of sheet beam confinement in both transverse dimensions, through the 54 cm (56 period) pulsed electromagnet wiggler are discussed. Peak wiggler fields of 5.1 kG on-axis have been achieved

  13. Higher-order harmonics coupling in different free-electron laser codes

    Science.gov (United States)

    Giannessi, L.; Freund, H. P.; Musumeci, P.; Reiche, S.

    2008-08-01

    The capability for simulation of the dynamics of a free-electron laser including the higher-order harmonics in linear undulators exists in several existing codes as MEDUSA [H.P. Freund, S.G. Biedron, and S.V. Milton, IEEE J. Quantum Electron. 27 (2000) 243; H.P. Freund, Phys. Rev. ST-AB 8 (2005) 110701] and PERSEO [L. Giannessi, Overview of Perseo, a system for simulating FEL dynamics in Mathcad, , in: Proceedings of FEL 2006 Conference, BESSY, Berlin, Germany, 2006, p. 91], and has been recently implemented in GENESIS 1.3 [See ]. MEDUSA and GENESIS also include the dynamics of even harmonics induced by the coupling through the betatron motion. In addition MEDUSA, which is based on a non-wiggler averaged model, is capable of simulating the generation of even harmonics in the transversally cold beam regime, i.e. when the even harmonic coupling arises from non-linear effects associated with longitudinal particle dynamics and not to a finite beam emittance. In this paper a comparison between the predictions of the codes in different conditions is given.

  14. Laser-driven electron beam and radiation sources for basic, medical and industrial sciences

    Science.gov (United States)

    NAKAJIMA, Kazuhisa

    2015-01-01

    To date active research on laser-driven plasma-based accelerators have achieved great progress on production of high-energy, high-quality electron and photon beams in a compact scale. Such laser plasma accelerators have been envisaged bringing a wide range of applications in basic, medical and industrial sciences. Here inheriting the groundbreaker’s review article on “Laser Acceleration and its future” [Toshiki Tajima, (2010)],1) we would like to review recent progress of producing such electron beams due to relativistic laser-plasma interactions followed by laser wakefield acceleration and lead to the scaling formulas that are useful to design laser plasma accelerators with controllability of beam energy and charge. Lastly specific examples of such laser-driven electron/photon beam sources are illustrated. PMID:26062737

  15. Research Area 4.1 Nano- and Bio-Electronics: Lester Eastman Conference on High-Performance Devices

    Science.gov (United States)

    2017-06-02

    significantly lower. Moreover, wells containing MoS2 on the polyimide film had a large amount of cells growing on the material, further indicating high ...SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6...Research Area 4.1 Nano- and Bio-Electronics: Lester Eastman Conference on High -Performance Devices The 2016 IEEE Lester Eastman Conference of High

  16. Electron structure of atoms in laser plasma: The Debye shielding model

    International Nuclear Information System (INIS)

    Sako, Tokuei; Okutsu, Hiroshi; Yamanouchi, Kaoru

    2005-01-01

    The electronic structure and the energy spectra of multielectron atoms in laser plasmas are examined by the Debye shielding model. The effect of the plasma environment on the electrons bound in an atom is taken into account by introducing the screened Coulomb-type potentials into the electronic Hamiltonian of an atom in place of the standard nuclear attraction and electron repulsion potentials. The capabilities of this new Hamiltonian are demonstrated for He and Li in laser plasmas. (author)

  17. The electron accelerator for FELIX [Free Electron Laser for Infrared eXperiments

    International Nuclear Information System (INIS)

    Amersfoort, P.W. van; Geer, C.A.J. van der; Meer, A.F.G. van der; Bruinsma, P.J.T.; Hoekstra, R.; Kroes, F.B.; Luyckx, G.; Noomen, J.G.; Poole, M.W.; Saxon, G.

    1989-01-01

    The authors discuss the design of the electron accelerator for the Free Electron Laser for Infrared eXperiments (FELIX), which is meant to provide the Dutch science community with a rapidly tunable source of infrared radiation. The first stage of the project will (at least) cover the wavelength range between 8 and 80 μm. The accelerator consists of a triode with a grid modulated at 1 GHz, a 3.8-MeV buncher, and two travelling-wave S-band linac structures, with which 70-A, 3-ps bunches are accelerated to an energy between 15 and 4-5 MeV. The system has been designed to minimize the energy spread in the electron beam. 8 refs., 2 figs., 1 tab

  18. Electron beam halo monitor for a compact x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Hideki Aoyagi

    2013-03-01

    Full Text Available An electron beam halo monitor using diamond-based detectors, which are operated in the ionization mode, has been developed for the SPring-8 Angstrom compact free-electron laser (SACLA to protect its undulator magnets from radiation damage. Diamond-based detectors are inserted in a beam duct to measure the intensity of the beam halo directly. To suppress the degradation of the electron beam due to the installation of the beam halo monitor, rf fingers with aluminum windows are newly employed. We evaluated the effect of radiation from the Al windows on the output signal both experimentally and by simulation. The operational results of the beam halo monitor employed in SACLA are presented.

  19. Marangoni Convection during Free Electron Laser Nitriding of Titanium

    Science.gov (United States)

    Höche, Daniel; Müller, Sven; Rapin, Gerd; Shinn, Michelle; Remdt, Elvira; Gubisch, Maik; Schaaf, Peter

    2009-08-01

    Pure titanium was treated by free electron laser (FEL) radiation in a nitrogen atmosphere. As a result, nitrogen diffusion occurs and a TiN coating was synthesized. Local gradients of interfacial tension due to the local heating lead to a Marangoni convection, which determines the track properties. Because of the experimental inaccessibility of time-dependent occurrences, finite element calculations were performed, to determine the physical processes such as heat transfer, melt flow, and mass transport. In order to calculate the surface deformation of the gas-liquid interface, the level set approach was used. The equations were modified and coupled with heat-transfer and diffusion equations. The process was characterized by dimensionless numbers such as the Reynolds, Peclet, and capillary numbers, to obtain more information about the acting forces and the coating development. Moreover, the nitrogen distribution was calculated using the corresponding transport equation. The simulations were compared with cross-sectional micrographs of the treated titanium sheets and checked for their validity. Finally, the process presented is discussed and compared with similar laser treatments.

  20. Ultraviolet Free Electron Laser Facility preliminary design report

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, I. (ed.)

    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).

  1. Cartilage ablation studies using mid-IR free electron laser

    Science.gov (United States)

    Youn, Jong-In; Peavy, George M.; Venugopalan, Vasan

    2005-04-01

    The ablation rate of articular cartilage and fibrocartilage (meniscus), were quantified to examine wavelength and tissue-composition dependence of ablation efficiency for selected mid-infrared wavelengths. The wavelengths tested were 2.9 um (water dominant absorption), 6.1 (protein and water absorption) and 6.45 um (protein dominant absorption) generated by the Free Electron Laser (FEL) at Vanderbilt University. The measurement of tissue mass removal using a microbalance during laser ablation was conducted to determine the ablation rates of cartilage. The technique can be accurate over methods such as profilometer and histology sectioning where tissue surface and the crater morphology may be affected by tissue processing. The ablation efficiency was found to be dependent upon the wavelength. Both articular cartilage and meniscus (fibrocartilage) ablations at 6.1 um were more efficient than those at the other wavelengths evaluated. We observed the lowest ablation efficiency of both types of cartilage with the 6.45 um wavelength, possibly due to the reduction in water absorption at this wavelength in comparison to the other wavelengths that were evaluated.

  2. Nuclear fission fragment excitation of electronic transition laser media

    International Nuclear Information System (INIS)

    Lorents, D.C.; McCusker, M.V.; Rhodes, C.K.

    1976-01-01

    The properties of high energy electronic transition lasers excited by fission fragments are expanded. Specific characteristics of the media including density, excitation rates, wavelength, kinetics, fissile material, scale size, and medium uniformity are assessed. The use of epithermal neutrons, homogeneously mixed fissile material, and special high cross section nuclear isotopes to optimize coupling of the energy to the medium are shown to be important considerations maximizing the scale size, energy deposition, and medium uniformity. A performance limit point of approximately 1000 J/l in approximately 100 μs pulses is established for a large class of systems operating in the near ultraviolet and visible spectral regions. It is demonstrated that e-beam excitation can be used to simulate nuclear pumping conditions to facilitate the search for candidate media. Experimental data for the kinetics of a XeF* laser operating in Ar/Xe/F 2 /UF 6 mixtures are given. These reactor-pumped systems are suitable for scaling to volumes on the order of (meters) 3

  3. Ultraviolet Free Electron Laser Facility preliminary design report

    International Nuclear Information System (INIS)

    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)

  4. Optical klystron and harmonic generation free electron laser

    Directory of Open Access Journals (Sweden)

    Qika Jia

    2005-06-01

    Full Text Available The optical field evolution of an optical klystron free electron laser is analytically described for both low gain and high gain cases. The harmonic optical klystron (HOK in which the second undulator is resonant on the higher harmonic of the first undulator is analyzed as a harmonic amplifier. The optical field evolution equation of the HOK is derived analytically for both the CHG mode (coherent harmonic generation, the quadratic gain regime and the HGHG mode (high gain harmonic generation, the exponential gain regime, the effects of energy spread, energy modulation, and dispersion in the whole process are taken into account. The linear theory is given and discussed for the HGHG mode. The analytical formula is given for the CHG mode.

  5. Test of models for electron transport in laser produced plasmas

    International Nuclear Information System (INIS)

    Colombant, D.G.; Manheimer, W.M.; Busquet, M.

    2005-01-01

    This paper examines five different models of electron thermal transport in laser produced spherical implosions. These are classical, classical with a flux limit f, delocalization, beam deposition model, and Fokker-Planck solutions. In small targets, the results are strongly dependent on f for flux limit models, with small f's generating very steep temperature gradients. Delocalization models are characterized by large preheat in the center of the target. The beam deposition model agrees reasonably well with the Fokker-Planck simulation results. For large, high gain fusion targets, the delocalization model shows the gain substantially reduced by the preheat. However, flux limitation models show gain largely independent of f, with the beam deposition model also showing the same high gain

  6. Free Electron Laser as Energy Driver for Inertial Confinement Fusion

    International Nuclear Information System (INIS)

    Saldin, E.L.; Shnejdmiller, E.A.; Ul'yanov, Yu.N.; Sarantsev, V.P.; Yurkov, M.V.

    1994-01-01

    A FEL based energy driver for Inertial Confinement Fusion (ICF) is proposed. The key element of the scheme is free electron laser system. Novel technical solutions reveal a possibility to construct the FEL system operating at radiation wavelength λ = 0.5 μm and providing flash energy E = 1 MJ and brightness 4 x 10 22 W cm -2 sr -1 within steering pulse duration 0.1-2 ns. Total energy efficiency of the proposed ICF energy driver is about of 11% and repetition rate is 40 Hz. Dimensions of such an ICF driver are comparable with those of heavy-ion ICF driver, while the problem of technical realization seems to be more realistic. It is shown that the FEL based ICF energy driver may be constructed at the present level of accelerator technique R and D. 27 refs., 10 figs., 3 tabs

  7. Los Alamos free-electron laser (FEL) rf system

    International Nuclear Information System (INIS)

    Tallerico, P.J.; Lynch, M.T.

    1985-01-01

    The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements

  8. Red Shift and Broadening of Backward Harmonic Radiation from Electron Oscillations Driven by Femtosecond Laser Pulse

    International Nuclear Information System (INIS)

    Tian Youwei; Yu Wei; Lu Peixiang; Senecha, Vinod K; Han, Xu; Deng Degang; Li Ruxin; Xu Zhizhan

    2006-01-01

    The characteristics of backward harmonic radiation due to electron oscillations driven by a linearly polarized fs laser pulse are analysed considering a single electron model. The spectral distributions of the electron's backward harmonic radiation are investigated in detail for different parameters of the driver laser pulse. Higher order harmonic radiations are possible for a sufficiently intense driving laser pulse. We have shown that for a realistic pulsed photon beam, the spectrum of the radiation is red shifted as well as broadened because of changes in the longitudinal velocity of the electrons during the laser pulse. These effects are more pronounced at higher laser intensities giving rise to higher order harmonics that eventually leads to a continuous spectrum. Numerical simulations have further shown that by increasing the laser pulse width the broadening of the high harmonic radiations can be controlled

  9. Electron accelerator with a laser ignition for investigation of beam plasma by optical methods

    International Nuclear Information System (INIS)

    Kabanov, S.N.; Korolev, A.A.; Kul'beda, V.E.; Razumovskij, A.I.; Trukhin, V.A.

    1990-01-01

    Facility to conduct investigations into dense gas beam plasma is described. Facility comprises: electron accelerator (200-300 keV, 5kA, 20ns), OGM-40 ignition ruby laser LZhI-501 diagnostic laser (with 0.55-0.66 μm tunable wave length), Michelson interferometer and diagnostic equipment for optical measurements. Laser ignition of spark gap is introduced to strong synchronization (±10ns) of radiation pulse of diagnostic laser with beam current pulse

  10. Harmonic lasing in x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    E. A. Schneidmiller

    2012-08-01

    Full Text Available Harmonic lasing in a free electron laser with a planar undulator (under the condition that the fundamental frequency is suppressed might be a cheap and efficient way of extension of wavelength ranges of existing and planned x-ray free electron laser (FEL facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide much more intense, stable, and narrow-band FEL beam which is easier to handle due to the suppressed fundamental frequency. In this paper we perform a parametrization of the solution of the eigenvalue equation for lasing at odd harmonics, and present an explicit expression for FEL gain length, taking into account all essential effects. We propose and discuss methods for suppression of the fundamental harmonic. We also suggest a combined use of harmonic lasing and lasing at the retuned fundamental wavelength in order to reduce bandwidth and to increase brilliance of x-ray beam at saturation. Considering 3rd harmonic lasing as a practical example, we come to the conclusion that it is much more robust than usually thought, and can be widely used in the existing or planned x-ray FEL (XFEL facilities. In particular, Linac Coherent Light Source (LCLS after a minor modification can lase to saturation at the 3rd harmonic up to the photon energy of 25–30 keV providing multigigawatt power level and narrow bandwidth. As for the European XFEL, harmonic lasing would allow one to extend operating range (ultimately up to 100 keV, to reduce FEL bandwidth and to increase brilliance, to enable two-color operation for pump-probe experiments, and to provide more flexible operation at different electron energies. Similar improvements can be realized in other x-ray FEL facilities with gap-tunable undulators like FLASH II, SACLA, LCLS II, etc. Harmonic lasing can be an attractive option for compact x-ray FELs (driven by electron beams with a relatively low energy, allowing the use of the standard undulator technology instead of

  11. First-principles electron dynamics control simulation of diamond under femtosecond laser pulse train irradiation

    International Nuclear Information System (INIS)

    Wang Cong; Jiang Lan; Wang Feng; Li Xin; Yuan Yanping; Xiao Hai; Tsai, Hai-Lung; Lu Yongfeng

    2012-01-01

    A real-time and real-space time-dependent density functional is applied to simulate the nonlinear electron-photon interactions during shaped femtosecond laser pulse train ablation of diamond. Effects of the key pulse train parameters such as the pulse separation, spatial/temporal pulse energy distribution and pulse number per train on the electron excitation and energy absorption are discussed. The calculations show that photon-electron interactions and transient localized electron dynamics can be controlled including photon absorption, electron excitation, electron density, and free electron distribution by the ultrafast laser pulse train. (paper)

  12. Electron transport phenomena and dense plasmas produced by ultra-short pulse laser interaction

    International Nuclear Information System (INIS)

    More, R.M.

    1994-01-01

    Recent experiments with femtosecond lasers provide a test bed for theoretical ideas about electron processes in hot dense plasmas. We briefly review aspects of electron conduction theory likely to prove relevant to femtosecond laser absorption. We show that the Mott-Ioffe-Regel limit implies a maximum inverse bremsstrahlung absorption of about 50% at temperatures near the Fermi temperature. We also propose that sheath inverse bremsstrahlung leads to a minimum absorption of 7-10% at high laser intensity

  13. Nuclear excitation via the motion of electrons in a strong laser field

    International Nuclear Information System (INIS)

    Berger, J.F.; Gogny, D.; Weiss, M.S.

    1987-12-01

    A method of switching from a nuclear isomeric state to a lasing state is examined. A semi-classical model of laser-electron-nuclear coupling is developed. In it the electrons are treated as free in the external field of the laser, but with initial conditions corresponding to their atomic orbits. Application is made to testing this model in 235 U and to the design criteria of a gamma-ray laser. 14 refs., 2 tabs

  14. Laser based analysis using a passively Q-switched laser employing analysis electronics and a means for detecting atomic optical emission of the laser media

    Science.gov (United States)

    Woodruff, Steven D.; Mcintyre, Dustin L.

    2016-03-29

    A device for Laser based Analysis using a Passively Q-Switched Laser comprising an optical pumping source optically connected to a laser media. The laser media and a Q-switch are positioned between and optically connected to a high reflectivity mirror (HR) and an output coupler (OC) along an optical axis. The output coupler (OC) is optically connected to the output lens along the optical axis. A means for detecting atomic optical emission comprises a filter and a light detector. The optical filter is optically connected to the laser media and the optical detector. A control system is connected to the optical detector and the analysis electronics. The analysis electronics are optically connected to the output lens. The detection of the large scale laser output production triggers the control system to initiate the precise timing and data collection from the detector and analysis.

  15. Relativistic electron kinetic effects on laser diagnostics in burning plasmas

    Science.gov (United States)

    Mirnov, V. V.; Den Hartog, D. J.

    2018-02-01

    Toroidal interferometry/polarimetry (TIP), poloidal polarimetry (PoPola), and Thomson scattering systems (TS) are major optical diagnostics being designed and developed for ITER. Each of them relies upon a sophisticated quantitative understanding of the electron response to laser light propagating through a burning plasma. Review of the theoretical results for two different applications is presented: interferometry/polarimetry (I/P) and polarization of Thomson scattered light, unified by the importance of relativistic (quadratic in vTe/c) electron kinetic effects. For I/P applications, rigorous analytical results are obtained perturbatively by expansion in powers of the small parameter τ = Te/me c2, where Te is electron temperature and me is electron rest mass. Experimental validation of the analytical models has been made by analyzing data of more than 1200 pulses collected from high-Te JET discharges. Based on this validation the relativistic analytical expressions are included in the error analysis and design projects of the ITER TIP and PoPola systems. The polarization properties of incoherent Thomson scattered light are being examined as a method of Te measurement relevant to ITER operational regimes. The theory is based on Stokes vector transformation and Mueller matrices formalism. The general approach is subdivided into frequency-integrated and frequency-resolved cases. For each of them, the exact analytical relativistic solutions are presented in the form of Mueller matrix elements averaged over the relativistic Maxwellian distribution function. New results related to the detailed verification of the frequency-resolved solutions are reported. The precise analytic expressions provide output much more rapidly than relativistic kinetic numerical codes allowing for direct real-time feedback control of ITER device operation.

  16. Measurement of the electron quenching rate in an electron beam pumped KrF* laser

    International Nuclear Information System (INIS)

    Nishioka, Hajime; Kurashima, Toshio; Kuranishi, Hideaki; Ueda, Kenichi; Takuma, Hiroshi; Sasaki, Akira; Kasuya, Koichi.

    1988-01-01

    The electron quenching rate of KrF * in an electron beam pumped laser has been studied by accurately measuring the saturation intensity in a mixture of Ar/Kr/F 2 = 94/6/0.284. The input intensity of the measurements was widely varied from 100 W cm -2 (small signal region) to 100 MW cm -2 (absorption dominant region) in order to separate laser parameters which are small signal gain coefficient, absorption coefficient, and saturation intensity from the measured net gain coefficients. The gas pressure and the pump rate were varied in the range of 0.5 to 2.5 atm and 0.3 to 1.4 MW cm -3 , respectively. The electron quenching rate constant of 4.5 x 10 -7 cm 3 s -1 was obtained from the pressure and the pump rate dependence of the KrF * saturation intensity with the temperature dependence of the rate gas 3-body quenching rate as a function of gas temperature to the -3rd power. The small signal gain coefficients calculated with the determined quenching rate constants shows excellent agreement with the measurements. (author)

  17. Measurement of the electron quenching rate in an electron beam pumped KrF/sup */ laser

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, Hajime; Kurashima, Toshio; Kuranishi, Hideaki; Ueda, Kenichi; Takuma, Hiroshi; Sasaki, Akira; Kasuya, Koichi.

    1988-09-01

    The electron quenching rate of KrF/sup */ in an electron beam pumped laser has been studied by accurately measuring the saturation intensity in a mixture of Ar/Kr/F/sub 2/ = 94/6/0.284. The input intensity of the measurements was widely varied from 100 W cm/sup -2/ (small signal region) to 100 MW cm/sup -2/ (absorption dominant region) in order to separate laser parameters which are small signal gain coefficient, absorption coefficient, and saturation intensity from the measured net gain coefficients. The gas pressure and the pump rate were varied in the range of 0.5 to 2.5 atm and 0.3 to 1.4 MW cm/sup -3/, respectively. The electron quenching rate constant of 4.5 x 10/sup -7/ cm/sup 3/s/sup -1/ was obtained from the pressure and the pump rate dependence of the KrF/sup */ saturation intensity with the temperature dependence of the rate gas 3-body quenching rate as a function of gas temperature to the -3rd power. The small signal gain coefficients calculated with the determined quenching rate constants shows excellent agreement with the measurements.

  18. Relativistic electron drift in overdense plasma produced by a superintense femtosecond laser pulse

    International Nuclear Information System (INIS)

    Rastunkov, V.S.; Krainov, V.P.

    2004-01-01

    The general peculiarities of electron motion in the skin layer at the irradiation of overdense plasma by a superintense linearly polarized laser pulse of femtosecond duration are considered. The quiver electron energy is assumed to be a relativistic quantity. Relativistic electron drift along the propagation of laser radiation produced by a magnetic part of a laser field remains after the end of the laser pulse, unlike the relativistic drift of a free electron in underdense plasma. As a result, the penetration depth is much larger than the classical skin depth. The conclusion has been made that the drift velocity is a nonrelativistic quantity even at the peak laser intensity of 10 21 W/cm 2 . The time at which an electron penetrates into field-free matter from the skin layer is much less than the pulse duration

  19. Proceedings of the International Conference on Lasers 󈨝 (12th), Held in New Orleans, Louisiana on December 3-8, 1989.

    Science.gov (United States)

    1990-01-01

    divides them corresponds to the vertex of the porro prism . This pattern can be explained by realizing that the resonator is optically equivalent to one...1c). The porro prism folds the resonator back on itself and places the two beams adjacent and parallel to each other (Fig. ld). They are, however...Symposia on Aerospace Sensing Conference, 1989. PORRO OUTPUT PRISM LASER ROD COUPLER Fig. la. Mallet Laser Resonator . Fig. lb. Mallet Laser Near Field

  20. Effect of the temporal laser pulse asymmetry on pair production processes during intense laser-electron scattering

    Science.gov (United States)

    Hojbota, C. I.; Kim, Hyung Taek; Kim, Chul Min; Pathak, V. B.; Nam, Chang Hee

    2018-06-01

    We investigate the effects of laser pulse shape on strong-field quantum electrodynamics (QED) processes during the collision between a relativistic electron beam and an intense laser pulse. The interplay between high-energy photon emission and two pair production processes, i.e. nonlinear Breit–Wheeler (BW) and Trident, was investigated using particle-in-cell simulations. We found that the temporal evolution of these two processes could be controlled by using laser pulses with different degrees of asymmetry. The temporal envelope of the laser pulse can significantly affect the number of pairs coming from the Trident process, while the nonlinear BW process is less sensitive to it. This study shows that the two QED processes can be examined with state-of-the-art petawatt lasers and the discrimination of the two pair creation processes is feasible by adjusting the temporal asymmetry of the colliding laser pulse.

  1. The effect of laser pulse parameters and initial phase on the acceleration of electrons in a vacuum

    International Nuclear Information System (INIS)

    Singh, Kunwar Pal; Gupta, Devki Nandan; Malik, Hitendra K

    2008-01-01

    Laser driven acceleration of electrons lying along the axis of the laser has been studied. We have considered a linearly polarized laser pulse. The quiver amplitude causes electrons to escape from the pulse. The energy gained by the electrons peaks for a suitable value of laser spot size. The value of a suitable laser spot size increases with laser intensity and initial electron energy. The energy gained by the electron depends upon its initial position with respect to the laser pulse. The electrons close to the pulse peak with initial phase π/2 are scattered least and gain higher energy. The electrons close to the leading edge of the pulse gain sufficient energy for a short laser pulse and the effect of initial phase is not important. A suitable value of laser spot size can be estimated from this study

  2. Design of an electron injector for multi-stages laser wakefield acceleration

    International Nuclear Information System (INIS)

    Audet, T.

    2016-01-01

    Laser wakefield acceleration (LWFA) is a particle acceleration process relying on the interaction between high intensity laser pulses, of the order of 10 18 W/cm 2 and a plasma. The plasma wave generated in the laser wake sustain high amplitude electric fields (1- 100 GV/m). Those electric fields are 3 orders of magnitude higher than maximum electric fields in radio frequency cavities and represent the main benefit of LWFA, allowing more compact acceleration. However improvements of the LWFA-produced electron bunches properties, stability and repetition rate are mandatory for LWFA to be usable for applications. A scheme to improve electron bunches properties and to potentially increase the repetition rate is multi-stage LWFA. The laser plasma electron source, called the injector, has to produce relatively low energy (50 - 100 MeV), but high charge, small size and low divergence electron bunches. Produced electron bunches then have to be transported and injected into a second stage to increase electron kinetic energy. The subject of this thesis is to study and design a laser wakefield electron injector for multistage LWFA. In the frame of CILEX and the two-stages LWFA program, a prototype of the injector was built : ELISA consisting in a variable length gas cell. The plasma electronic density, which is a critical parameter for the control of the electron bunches properties, was characterized both experimentally and numerically. ELISA was used at 2 different laser facilities and physical mechanisms linked to electron bunches properties were studied in function of experimental parameters. A range of experimental parameters suitable for a laser wakefield injector was determined. A magnetic transport and diagnostic line was also built, implemented and tested at the UHI100 laser facility of the CEA Saclay. It allowed a more precise characterization of electron bunches generated with ELISA as well as an estimation of the quality of transported electron bunches for their

  3. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Science.gov (United States)

    He, Z.-H.; Thomas, A. G. R.; Beaurepaire, B.; Nees, J. A.; Hou, B.; Malka, V.; Krushelnick, K.; Faure, J.

    2013-02-01

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  4. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d' Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

    2013-02-11

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  5. Electron Hole Plasma in Solids Induced by Ultrashort XUV Laser Pulses

    International Nuclear Information System (INIS)

    Rethfeld, B.; Medvedev, N.

    2013-01-01

    Irradiation of solids with ultrashort XUV laser pulses leads to an excitation of electrons from the valence band and deeper shells to the conduction band leading to a nonequilibrium highly energetic electron hole plasma. We investigate the transient electron dynamics in a solid semiconductor and metal (silicon and aluminum, respectively) under irradiation with a femtosecond VUV to XUV laser pulse as used in experiments with the Free Electron Laser FLASH at DESY in Hamburg, Germany. Applying the Asymptotical Trajectory Monte-Carlo technique, we obtain the transient energy distribution of the excited and ionized electrons within the solid. Photon absorption by electrons in different bands and secondary excitation and ionization processes are simulated event by event. The method was extended in order to take into account the electronic band structure and Pauli's principle for electrons in the conduction band. In this talk we review our results on the dynamics of the transient electron-hole plasma, in particular its transient density and energy distribution in dependence on laser and material parameters. For semiconductors we introduce the concept of an ''effective energy gap'' for collective electronic excitation, which can be applied to estimate the free electron density after high-intensity ultrashort XUV laser pulse irradiation. For aluminum we demonstrate that the electronic spectra depend on the relaxation kinetics of the excited electronic subsystem. Experimentally observed spectra of emitted photons from irradiated aluminum can be explained well with our results. (author)

  6. Cold cathode electron guns in the LASL high power short-pulse CO2 laser program

    International Nuclear Information System (INIS)

    Singer, S.; Ladish, J.S.; Nutter, M.J.

    1975-01-01

    The Electron Beam Controlled Discharge CO 2 Laser is now firmly established as the only high power short pulse laser amplifier that has been demonstrated to have scaling capabilities to large apertures and energies much greater than 100 J. These devices require a beam of energetic electrons to control the gas discharge that produces the required population inversion. Until recently, the electron source was usually a thermionic emitter, even for rather large lasers, whose heater requirements dwarfed the pulsed energies associated with the transient operation of the laser. With the advent of reliable cold-cathode electron guns, the operation of these lasers has been greatly simplified. At LASL, there are four electron beam controlled laser systems which are in operation, under construction, or in design: the 1 kJ system, now operational; the 2.5 kJ system; the 10 kJ system; and the 100 kJ system. Only the first uses thermionic-emitter electron guns; the remainder use or will use cold cathode sources. The operation of the 200 x 35 cm 2 two sided cold cathode electron gun used in the 2.5 kJ laser system and to be used in the 10 kJ laser is described

  7. Development of terahertz laser diagnostics for electron density measurements.

    Science.gov (United States)

    Kawahata, K; Akiyama, T; Tanaka, K; Nakayama, K; Okajima, S

    2008-10-01

    A two color laser interferometer using terahertz laser sources is under development for high performance operation on the large helical device and for future burning plasma experiments such as ITER. Through investigation of terahertz laser sources, we have achieved high power simultaneous oscillations at 57.2 and 47.6 microm of a CH(3)OD laser pumped by a cw 9R(8) CO(2) laser line. The laser wavelength around 50 microm is the optimum value for future fusion devices from the consideration of the beam refraction effect and signal-to-noise ratio for an expected phase shift due to plasma. In this article, recent progress of the terahertz laser diagnostics, especially in mechanical vibration compensation by using a two color laser operation and terahertz laser beam transmission through a dielectric waveguide, will be presented.

  8. Free-electron laser and related quantum beams

    International Nuclear Information System (INIS)

    Minehara, Eisuke J.

    2003-01-01

    Past, present and future development programs of the JAERI super-conducting rf linac-based FELs and light sources with and without energy recovery have been discussed and introduced briefly. The JAERI FEL group has successfully discovered, and realized the brand-new FEL lasing mode of 255 fs ultra fast pulse, 6-9% high-efficiency, one GW high peak power, a few kW average power, and wide tunability of medium and far infrared wavelength regions at the same time. Using the new lasing, we could realize a powerful and efficient free-electron laser (FEL) for industrial uses near future. In order to realize such a tunable, ultra-short-pulse, high averaged-power FEL, we have needed the efficient and powerful CW FEL driver of the JAERI compact, stand-alone and zero-boil-off super-conducting rf linac with an energy-recovery geometry. The JAERI energy-recovery and/or super-conducting rf linac driver has been developed to use as an industrial electron irradiator, and millimeter-wave, far-infrared, mid-infrared, near-infrared and shorter wavelength quantum beam sources. (author)

  9. Determination of molecular parameters by electron collisions and laser techniques

    International Nuclear Information System (INIS)

    Colon, C.

    1989-01-01

    In this work a general procedure to study diatomic molecules in intermediate coupling scheme has been developed. This study allows to obtain expressions to calculate molecular line strengths and rotational transition intensities. These results are used in a numerical program to synthetize vibrational and rotational band spectra of any diatomic molecule. With this technique the experimental spectra of the first negative system of N 2 + and the fist positive system of N 2 are reproduced theoretically and it is possible to deduce its electronic transition moments values by comparison. Also the method has been applied to compare the synthetized bands with the experimental spectra of the B O u + -- x 1 Σ g + system of Au 2 and the A 2 Σ--- x 2 π system of OH. From these comparison band intensities and electronic moments can be deduced. The branching ratio method to measure the relative spectral response in the 1100-1560 A o =wavelength range of a vacuum uv monochromator has been used. Relative intensity of rotational lines with origine in a common upper vibrational-rotational level of Warner and Lyman systems of H 2 , have been measured. Also in this work, the deexcitation of the B 3 π + (0 + u ), v'=14 level of I 2 after pulsed laser excitation has been studied. The quenching cross sections by collisions with I 2 , H 2 , CO 2 and CH 4 have been determin-ed. (Author)

  10. Free-electron laser and related quantum beams

    Energy Technology Data Exchange (ETDEWEB)

    Minehara, Eisuke J [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-07-01

    Past, present and future development programs of the JAERI super-conducting rf linac-based FELs and light sources with and without energy recovery have been discussed and introduced briefly. The JAERI FEL group has successfully discovered, and realized the brand-new FEL lasing mode of 255 fs ultra fast pulse, 6-9% high-efficiency, one GW high peak power, a few kW average power, and wide tunability of medium and far infrared wavelength regions at the same time. Using the new lasing, we could realize a powerful and efficient free-electron laser (FEL) for industrial uses near future. In order to realize such a tunable, ultra-short-pulse, high averaged-power FEL, we have needed the efficient and powerful CW FEL driver of the JAERI compact, stand-alone and zero-boil-off super-conducting rf linac with an energy-recovery geometry. The JAERI energy-recovery and/or super-conducting rf linac driver has been developed to use as an industrial electron irradiator, and millimeter-wave, far-infrared, mid-infrared, near-infrared and shorter wavelength quantum beam sources. (author)

  11. Structural enzymology using X-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    Christopher Kupitz

    2017-07-01

    Full Text Available Mix-and-inject serial crystallography (MISC is a technique designed to image enzyme catalyzed reactions in which small protein crystals are mixed with a substrate just prior to being probed by an X-ray pulse. This approach offers several advantages over flow cell studies. It provides (i room temperature structures at near atomic resolution, (ii time resolution ranging from microseconds to seconds, and (iii convenient reaction initiation. It outruns radiation damage by using femtosecond X-ray pulses allowing damage and chemistry to be separated. Here, we demonstrate that MISC is feasible at an X-ray free electron laser by studying the reaction of M. tuberculosis ß-lactamase microcrystals with ceftriaxone antibiotic solution. Electron density maps of the apo-ß-lactamase and of the ceftriaxone bound form were obtained at 2.8 Å and 2.4 Å resolution, respectively. These results pave the way to study cyclic and non-cyclic reactions and represent a new field of time-resolved structural dynamics for numerous substrate-triggered biological reactions.

  12. Free electron laser experiments using a long pulse induction linac

    International Nuclear Information System (INIS)

    Pasour, J.A.; Lucey, R.

    1983-01-01

    The NRL Long Pulse Induction Linac is being employed in a Free Electron Laser (FEL) experiment. The authors present results of beam transport and focusing experiments as well as measurements of the output radiation generated by various magnetic wigglers. The electron gun of the accelerator presently has a 17-cmdiam. cold cathode which is located in a nearly zero magnetic field (B /SUB z/ less than or equal to 5 G). The gun voltage is flat to within approx. = + or - 5% for 1.5 μsec with this graphite brush cathode. The beam is focused by a series of solenoidal coils as it propagates through the 4-m-long accelerator. 2 A solenoidal field which can be varied from 1-10 kG confines the beam in the FEL interaction region. Previous experiments were limited by poor beam transport, focusing, and matching into the relatively large solenoidal field in the FEL region. By smoothing the axial magnetic field profile in the accelerator and making a more adiabatic transition from the low field in the accelerator to the high field in the FEL, beam transport into the wiggler has been substantially improved. Currently, a 700 kV beam with I > 500 A and r /SUB b/ < 0.75 cm is transported through the FEL region. Beam transport is in qualitative agreement with envelope code calculations

  13. Energy modulation of nonrelativistic electrons with a CO2 laser using a metal microslit

    OpenAIRE

    Jongsuck, Bae; Ryo, Ishikawa; Sumio, Okuyama; Takashi, Miyajima; Taiji, Akizuki; Tatsuya, Okamoto; Koji, Mizuno

    2000-01-01

    A metal microslit has been used as an interaction circuit between a CO2 laser beam and nonrelativistic free electrons. Evanescent waves which are induced on the slit by illumination of the laser light modulate the energy of electrons passing close to the surface of the slit. The electron-energy change of more than ±5 eV for the 80 keV electron beam has been observed using the 7 kW laser beam at the wavelength of 10.6 μm.

  14. Energy modulation of nonrelativistic electrons with a CO2 laser using a metal microslit

    Science.gov (United States)

    Bae, Jongsuck; Ishikawa, Ryo; Okuyama, Sumio; Miyajima, Takashi; Akizuki, Taiji; Okamoto, Tatsuya; Mizuno, Koji

    2000-04-01

    A metal microslit has been used as an interaction circuit between a CO2 laser beam and nonrelativistic free electrons. Evanescent waves which are induced on the slit by illumination of the laser light modulate the energy of electrons passing close to the surface of the slit. The electron-energy change of more than ±5 eV for the 80 keV electron beam has been observed using the 7 kW laser beam at the wavelength of 10.6 μm.

  15. GeV electron beams from centimeter-scale channel guided laser wakefield

    International Nuclear Information System (INIS)

    Gonsalves, A.; Nakamura, K.; Panasenko, D.; Toth, Cs.; Esarey, E.; Schroeder; Hooker, S.M.; Leemans, W.P.; Hooker, S.M.

    2007-01-01

    Results are presented on the generation of quasi-monoenergetic electron beams with energy up to 1 GeV using a 40TW laser and a 3.3 cm-long hydrogen-filled capillary discharge waveguide. Electron beams were not observed without a plasma channel, indicating that self-focusing alone could not be relied upon for effective guiding of the laser pulse. Results are presented of the electron beam spectra, and the dependence of the reliability of producing electron beams as a function of laser and plasma parameters

  16. Studies of harmonic generation in free electron lasers

    International Nuclear Information System (INIS)

    Goldammer, K.

    2007-01-01

    Nonlinear harmonic generation is one of the most interesting aspects of Free Electron Lasers under study today. It provides for coherent, high intensity radiation at higher harmonics of the FEL resonant frequency. The sources, numerical simulation and applications of harmonic radiation in cascaded High Gain Harmonic Generation FELs were the subject of this thesis. Harmonic emission in FELs originates from harmonic microbunching of the particles and the particular electron trajectory during FEL interaction. Numerical FEL simulation codes model these analytical equations and predict the performance of Free Electron Lasers with good accuracy. This thesis has relied heavily upon the FEL simulation code Genesis 1.3 which has been upgraded in the framework of this thesis to compute harmonic generation in a self-consistent manner. Tests against analytical predictions suggest that the harmonic power levels as well as harmonic gain lengths are simulated correctly. A benchmark with the FEL simulation code GINGER yields excellent agreement of the harmonic saturation length and saturation power. The new version of the simulation code Genesis was also tested against measurements from the VUV-FEL FLASH at DESY. The spectral power distributions of fundamental and third harmonic radiation were recorded at 25.9 nm and 8.6 nm, respectively. The relative bandwidths (FWHM) were in the range of 2 % for both the fundamental as well as the third harmonic, which was accurately reproduced by time-dependent simulations with Genesis. The new code was also used to propose and evaluate a new design for the BESSY Soft X-Ray FEL, a cascaded High Gain Harmonic Generation FEL proposed by BESSY in Berlin. The original design for the BESSY High Energy FEL line requires four HGHG stages to convert the initial seed laser wavelength of 297.5 nm down to 1.24 nm. A new scheme is proposed that makes use of fifth harmonic radiation from the first stage and reduces the number of HGHG stages to three. It

  17. Studies of harmonic generation in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Goldammer, K.

    2007-11-12

    Nonlinear harmonic generation is one of the most interesting aspects of Free Electron Lasers under study today. It provides for coherent, high intensity radiation at higher harmonics of the FEL resonant frequency. The sources, numerical simulation and applications of harmonic radiation in cascaded High Gain Harmonic Generation FELs were the subject of this thesis. Harmonic emission in FELs originates from harmonic microbunching of the particles and the particular electron trajectory during FEL interaction. Numerical FEL simulation codes model these analytical equations and predict the performance of Free Electron Lasers with good accuracy. This thesis has relied heavily upon the FEL simulation code Genesis 1.3 which has been upgraded in the framework of this thesis to compute harmonic generation in a self-consistent manner. Tests against analytical predictions suggest that the harmonic power levels as well as harmonic gain lengths are simulated correctly. A benchmark with the FEL simulation code GINGER yields excellent agreement of the harmonic saturation length and saturation power. The new version of the simulation code Genesis was also tested against measurements from the VUV-FEL FLASH at DESY. The spectral power distributions of fundamental and third harmonic radiation were recorded at 25.9 nm and 8.6 nm, respectively. The relative bandwidths (FWHM) were in the range of 2 % for both the fundamental as well as the third harmonic, which was accurately reproduced by time-dependent simulations with Genesis. The new code was also used to propose and evaluate a new design for the BESSY Soft X-Ray FEL, a cascaded High Gain Harmonic Generation FEL proposed by BESSY in Berlin. The original design for the BESSY High Energy FEL line requires four HGHG stages to convert the initial seed laser wavelength of 297.5 nm down to 1.24 nm. A new scheme is proposed that makes use of fifth harmonic radiation from the first stage and reduces the number of HGHG stages to three. It

  18. Electron acceleration by femtosecond laser interaction with micro-structured plasmas

    Science.gov (United States)

    Goers, Andy James

    Laser-driven accelerators are a promising and compact alternative to RF accelerator technology for generating relativistic electron bunches for medical, scientific, and security applications. This dissertation presents three experiments using structured plasmas designed to advance the state of the art in laser-based electron accelerators, with the goal of reducing the energy of the drive laser pulse and enabling higher repetition rate operation with current laser technology. First, electron acceleration by intense femtosecond laser pulses in He-like nitrogen plasma waveguides is demonstrated. Second, significant progress toward a proof of concept realization of quasi-phasematched direct acceleration (QPM-DLA) is presented. Finally, a laser wakefield accelerator at very high plasma density is studied, enabling relativistic electron beam generation with ˜10 mJ pulse energies. Major results from these experiments include: • Acceleration of electrons up to 120 MeV from an ionization injected wakefield accelerator driven in a 1.5 mm long He-like nitrogen plasma waveguide • Guiding of an intense, quasi-radially polarized femtosecond laser pulse in a 1 cm plasma waveguide. This pulse provides a strong drive field for the QPM-DLA concept. • Wakefield acceleration of electrons up to ˜10 MeV with sub-terawatt, ˜10 mJ pulses interacting with a thin (˜200 mum), high density (>1020 cm-3) plasma. • Observation of an intense, coherent, broadband wave breaking radiation flash from a high plasma density laser wakefield accelerator. The flash radiates > 1% of the drive laser pulse energy in a bandwidth consistent with half-cycle (˜1 fs) emission from violent unidirectional acceleration of electron bunches from rest. These results open the way to high repetition rate (>˜kHz) laser-driven generation of relativistic electron beams with existing laser technology.

  19. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  20. On the physics of electron ejection from laser-irradiated overdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Thévenet, M.; Vincenti, H.; Faure, J. [Laboratoire d' Optique Appliquée, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France)

    2016-06-15

    Using 1D and 2D PIC simulations, we describe and model the backward ejection of electron bunches when a laser pulse reflects off an overdense plasma with a short density gradient on its front side. The dependence on the laser intensity and gradient scale length is studied. It is found that during each laser period, the incident laser pulse generates a large charge-separation field, or plasma capacitor, which accelerates an attosecond bunch of electrons toward vacuum. This process is maximized for short gradient scale lengths and collapses when the gradient scale length is comparable to the laser wavelength. We develop a model that reproduces the electron dynamics and the dependence on laser intensity and gradient scale length. This process is shown to be strongly linked with high harmonic generation via the Relativistic Oscillating Mirror mechanism.

  1. High efficiency, multiterawatt x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    C. Emma

    2016-02-01

    Full Text Available In this paper we present undulator magnet tapering methods for obtaining high efficiency and multiterawatt peak powers in x-ray free electron lasers (XFELs, a key requirement for enabling 3D atomic resolution single molecule imaging and nonlinear x-ray science. The peak power and efficiency of tapered XFELs is sensitive to time dependent effects, like synchrotron sideband growth. To analyze this dependence in detail we perform a comparative numerical optimization for the undulator magnetic field tapering profile including and intentionally disabling these effects. We show that the solution for the magnetic field taper profile obtained from time independent optimization does not yield the highest extraction efficiency when time dependent effects are included. Our comparative optimization is performed for a novel undulator designed specifically to obtain TW power x-ray pulses in the shortest distance: superconducting, helical, with short period and built-in strong focusing. This design reduces the length of the breaks between modules, decreasing diffraction effects, and allows using a stronger transverse electron focusing. Both effects reduce the gain length and the overall undulator length. We determine that after a fully time dependent optimization of a 100 m long Linac coherent light source-like XFEL we can obtain a maximum efficiency of 7%, corresponding to 3.7 TW peak radiation power. Possible methods to suppress the synchrotron sidebands, and further enhance the FEL peak power, up to about 6 TW by increasing the seed power and reducing the electron beam energy spread, are also discussed.

  2. Electron emission from a double-layer metal under femtosecond laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuchang; Li, Suyu; Jiang, Yuanfei; Chen, Anmin, E-mail: amchen@jlu.edu.cn; Ding, Dajun; Jin, Mingxing, E-mail: mxjin@jlu.edu.cn

    2015-01-01

    In this paper we theoretically investigate electron emission during femtosecond laser ablation of single-layer metal (copper) and double-layer structures. The double-layer structure is composed of a surface layer (copper) and a substrate layer (gold or chromium). The calculated results indicate that the double-layer structure brings a change to the electron emission from the copper surface. Compared with the ablation of a single-layer, a double-layer structure may be helpful to decrease the relaxation time of the electron temperature, and optimize the electron emission by diminishing the tailing phenomenon under the same absorbed laser fluence. With the increase of the absorbed laser fluence, the effect of optimization becomes significant. This study provides a way to optimize the electron emission which can be beneficial to generate laser induced ultrafast electron pulse sources.

  3. Enhancement of the Number of Fast Electrons Generated in a Laser Inverse Cone Interaction

    International Nuclear Information System (INIS)

    Yan-Ling, Ji; Gang, Jiang; Wei-Dong, Wu; Ji-Cheng, Zhang; Yong-Jian, Tang

    2010-01-01

    Enhancement of the energy-conversion efficiency from laser to target electrons is demonstrated by two-dimensional particle-in-cell simulations in a laser-inverse cone interaction. When an intense short-pulse laser illuminates the inverse cone target, the electrons at the cone end are accelerated by the ponderomotive force. Then these electrons are guided and confined to transport along the inverse cone walls by the induced electromagnetic fields. A device consisting of inverse hollow-cone and multihole array plasma is proposed in order to increase the energy-conversion efficiency from laser to electrons. Particle-in-cell simulations present that the multiholes transpiercing the cone end help to enhance the number of fast electrons and the maximum electron energy significantly. (physics of gases, plasmas, and electric discharges)

  4. 5th International Conference on Optics Within Life Sciences

    CERN Document Server

    Papazoglou, Theodore; Kalpouzos, Costas

    2000-01-01

    Following to previous OWLS conferences devoted to widespread applications of optics in life sciences, this 5th OWLS Conference focuses on recent achievements in applying lasers and optics in biomedicine and the preservation of our cultural heritage. Particular attention is paid to laser diagnostics in medicine, interaction of laser radiation with biological tissue, aspects of the preservation of cultural heritage, and the development of new systems for these studies. The contributors to this volume cover international research activities in the following areas: Laser-tissue interactions and tissue optics - photon migration in tissue; Medical sensors - fiber optics; Clinical use of lasers (dermatology, ENT, cardiology, etc.); Laser-based techniques in art conservation (cleaning, diagnostics, analytical applications); Imaging techniques and lasers in archaeology; Laser technologies in contemporary art (holography, marking, etc.); and New laser and opto-electronic systems for biomedical and art-related studies.

  5. Measurements of plasma temperature and electron density in laser ...

    Indian Academy of Sciences (India)

    of 6 ns focussed onto a copper solid sample in air at atmospheric pressure is studied spectroscopically. ... Pulsed laser-induced plasmas (LIPs) of metals and alloys formed at laser pulse ir- radiances near the .... fibre-based collection system.

  6. Transient thermal and nonthermal electron and phonon relaxation after short-pulsed laser heating of metals

    International Nuclear Information System (INIS)

    Giri, Ashutosh; Hopkins, Patrick E.

    2015-01-01

    Several dynamic thermal and nonthermal scattering processes affect ultrafast heat transfer in metals after short-pulsed laser heating. Even with decades of measurements of electron-phonon relaxation, the role of thermal vs. nonthermal electron and phonon scattering on overall electron energy transfer to the phonons remains unclear. In this work, we derive an analytical expression for the electron-phonon coupling factor in a metal that includes contributions from equilibrium and nonequilibrium distributions of electrons. While the contribution from the nonthermal electrons to electron-phonon coupling is non-negligible, the increase in the electron relaxation rates with increasing laser fluence measured by thermoreflectance techniques cannot be accounted for by only considering electron-phonon relaxations. We conclude that electron-electron scattering along with electron-phonon scattering have to be considered simultaneously to correctly predict the transient nature of electron relaxation during and after short-pulsed heating of metals at elevated electron temperatures. Furthermore, for high electron temperature perturbations achieved at high absorbed laser fluences, we show good agreement between our model, which accounts for d-band excitations, and previous experimental data. Our model can be extended to other free electron metals with the knowledge of the density of states of electrons in the metals and considering electronic excitations from non-Fermi surface states

  7. The chirped-pulse free-electron laser: Final technical report, September 1987--October 1988

    International Nuclear Information System (INIS)

    Moore, G.T.

    1989-01-01

    This is the final report of a theoretical and numerical investigation into the operation of pulsed free-electron lasers in which the electron energy depends on the time of injection into the wiggler. Such energy ''chirping'' over each of a train of electron micropulses injected into an FEL oscillator is expected to give rise to a laser pulse inside the optical resonator with a chirped carrier frequency ω/sub s/(/tau/). 8 refs., 7 figs

  8. Hot electron effects on the satellite spectrum of laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, J. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM (United States); Faenov, A.Y.; Pikuz, T.A. [MISDC, NPO ' VNIIFTRI' , Mendeleevo, Moscow Region, 141570 (Russian Federation); Wilke, M.D.; Kyrala, G.A.; Clark, R.E.H. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM (United States)

    1999-05-01

    In laser-produced plasmas, the interaction of the intense laser light with plasma electrons can produce high-energy superthermal electrons with energies in the keV range. These hot electrons can influence the level populations which determine spectral line structure. In the present paper, the effect of hot electrons on the X-ray satellite spectrum of laser-produced plasmas is studied. Calculated spectra are compared with experimental observations. Magnesium targets irradiated by three different types of laser pulses are considered. These include, a high-intensity 600 fs Nd-glass laser, a 1 ns Nd-glass laser, and a 2ns CO{sub 2} laser. The Nd-glass laser experiments were conducted recently at the Los Alamos Trident Facility and the CO{sub 2} data were recorded by MISDC. High-resolution spectra were measured near the He-like resonance line of magnesium. The calculations employ an electron energy distribution which includes a thermal and a hot electron component, as part of a detailed collisional-radiative model. Plasma parameters including electron temperature, density, and hot electron fraction are estimated by choosing best fits to the experimental measurements. The calculations show that hot electrons can cause several anomalous effects. The Li-like jkl, abcd, and qr satellites can show intensities which are generally attributed to electron densities in excess of 10{sup 23} cm{sup -3}. In addition, the relative amplitude of the intercombination line can be unusually large even at high electron densities due to enhanced collisional excitation of the 1s2p{sup 3}P state by hot electrons. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Double-sided electron-beam generator for KrF laser excitation

    International Nuclear Information System (INIS)

    Schlitt, L.; Swingle, J.

    1980-05-01

    Several laser systems excited by electron beam have been identified as candidates for pump sources for laser fusion applications. The electron beam generators required must be compact, reliable and capable of synchronization with other system components. A KrF laser producing a minimum output of 25 J was needed for the RAPIER (Raman Amplifier Pumped by Intensified Excimer Radiation) system. A double-sided electron beam system was designed and constructed specifically for this purpose and has produced > 35 J of KrF output. Each of the two electron beam machines in the system operates with an rms jitter of 0.4 ns and together occupy approx. 3.5 m 2 of floor space. The successful operation of this laser has engendered requests for a description of the engineering details of this system. This document contains a brief description of the design issues and a full set of engineering drawings for this KrF laser amplifier

  10. 5th International Conference LACONA V (Lasers in the Conservation of Artworks)

    CERN Document Server

    Dickmann, Klaus; Asmus, John F; Lasers in the Conservation of Artworks

    2005-01-01

    Since 1995, when Costas Fotakis first brought together restorers and scientists to discuss the potential of lasers in art conservation, the field has grown enormously in importance, and today restorers and laser scientists work together to develop new applications. This book presents the more than six dozen research papers prepared for LACONA V (Lasers in Art Conservation), held in Osnabrueck/Germany in September 2003. The fifth congress once again gathers restorers, art historians, museum staff, laser scientists and laser manufacturers. The topics include, among others: laser cleaning of artworks (case studies and side effects), removal of former conservation layers, fundamentals of laser-artwork interaction, online monitoring and process control, laser diagnostics, spectroscopy for monitoring and identification, networks and co-operation projects.

  11. Multidisciplinary approaches to radiation-balanced lasers (MARBLE): a MURI program by AFOSR (Conference Presentation)

    Science.gov (United States)

    Sheik-Bahae, Mansoor

    2017-02-01

    An overview of the diverse research activities under the newly funded MURI project by AFOSR will be presented. The main goal is to advance the science of radiation-balanced lasers, also known as athermal lasers, in order to mitigate the thermal degradation of the high-power laser beams. The MARBLE project involves researchers from four universities and spans research activities in rare-earth doped crystals and fibers to semiconductor disc lasers.

  12. All-optical time-resolved measurement of laser energy modulation in a relativistic electron beam

    Directory of Open Access Journals (Sweden)

    D. Xiang

    2011-11-01

    Full Text Available We propose and demonstrate an all-optical method to measure laser energy modulation in a relativistic electron beam. In this scheme the time-dependent energy modulation generated from the electron-laser interaction in an undulator is converted into time-dependent density modulation with a chicane, which is measured to infer the laser energy modulation. The method, in principle, is capable of simultaneously providing information on femtosecond time scale and 10^{-5} energy scale not accessible with conventional methods. We anticipate that this method may have wide applications in many laser-based advanced beam manipulation techniques.

  13. Laser pulse guiding and electron acceleration in the ablative capillary discharge plasma

    International Nuclear Information System (INIS)

    Kameshima, T.; Kotaki, H.; Kando, M.; Daito, I.; Kawase, K.; Fukuda, Y.; Homma, T.; Esirkepov, T. Zh.; Chen, L. M.; Kondo, S.; Bobrova, N. A.; Sasorov, P. V.; Bulanov, S. V.

    2009-01-01

    The results of experiments are presented for the laser electron acceleration in the ablative capillary discharge plasma. The plasma channel is formed by the discharge inside the ablative capillary. The intense short laser pulse is guided over a 4 cm length. The generated relativistic electrons show both the quasimonoenergetic and quasi-Maxwellian energy spectra, depending on laser and plasma parameters. The analysis of the inner walls of the capillaries that underwent several tens of shots shows that the wall deformation and blistering resulted from the discharge and laser pulse effects.

  14. Laser-driven relativistic electron dynamics in a cylindrical plasma channel

    Science.gov (United States)

    Geng, Pan-Fei; Lv, Wen-Juan; Li, Xiao-Liang; Tang, Rong-An; Xue, Ju-Kui

    2018-03-01

    The energy and trajectory of the electron, which is irradiated by a high-power laser pulse in a cylindrical plasma channel with a uniform positive charge and a uniform negative current, have been analyzed in terms of a single-electron model of direct laser acceleration. We find that the energy and trajectory of the electron strongly depend on the positive charge density, the negative current density, and the intensity of the laser pulse. The electron can be accelerated significantly only when the positive charge density, the negative current density, and the intensity of the laser pulse are in suitable ranges due to the dephasing rate between the wave and electron motion. Particularly, when their values satisfy a critical condition, the electron can stay in phase with the laser and gain the largest energy from the laser. With the enhancement of the electron energy, strong modulations of the relativistic factor cause a considerable enhancement of the electron transverse oscillations across the channel, which makes the electron trajectory become essentially three-dimensional, even if it is flat at the early stage of the acceleration. Project supported by the National Natural Science Foundation of China (Grant Nos. 11475027, 11765017, 11764039, 11305132, and 11274255), the Natural Science Foundation of Gansu Province, China (Grant No. 17JR5RA076), and the Scientific Research Project of Gansu Higher Education, China (Grant No. 2016A-005).

  15. Research on heightening quality of free electron laser using superconducting linear accelerator

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    1996-01-01

    In this paper, the superconducting high frequency linear accelerator technology using low temperature superconductor is introduced, and its application to the heightening of quality of free electron laser is discussed. The high frequency application of superconductivity is a relatively new technology, and the first superconducting high frequency linear accelerator was made at the middle of 1960s. The invention of free electron laser and the development so far are described. In free electron laser, the variation of wavelength, high efficiency and high power output are possible as compared with conventional type lasers. The price and the size are two demerits of free electron laser that remain to the last. In Japan Atomic Energy Research Institute, the adjustment experiment is carried out for the prototype free electron laser. About this prototype, injection system, superconducting accelerator, helium refrigerator, whole solid element high frequency power source, control system, electron beam transport system, undulator system and optical resonator are described. The application of high mean power output free electron laser and its future are discussed. (K.I.)

  16. Ultra-High-Contrast Laser Acceleration of Relativistic Electrons in Solid Targets

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, Drew Pitney [Univ. of California, San Diego, CA (United States)

    2013-01-01

    The cone-guided fast ignition approach to Inertial Con nement Fusion requires laser-accelerated relativistic electrons to deposit kilojoules of energy within an imploded fuel core to initiate fusion burn. One obstacle to coupling electron energy into the core is the ablation of material, known as preplasma, by laser energy proceeding nanoseconds prior to the main pulse. This causes the laser-absorption surface to be pushed back hundreds of microns from the initial target surface; thus increasing the distance that electrons must travel to reach the imploded core. Previous experiments have shown an order of magnitude decrease in coupling into surrogate targets when intentionally increasing the amount of preplasma. Additionally, for electrons to deposit energy within the core, they should have kinetic energies on the order of a few MeV, as less energetic electrons will be stopped prior to the core and more energetic electrons will pass through the core without depositing much energy. Thus a quantitative understanding of the electron energy spectrum and how it responds to varied laser parameters is paramount for fast ignition. For the rst time, this dissertation quantitatively investigates the acceleration of electrons using an ultra-high-contrast laser. Ultra-high-contrast lasers reduce the laser energy that reaches the target prior to the main pulse; drastically reducing the amount of preplasma. Experiments were performed in a cone-wire geometry relevant to fast ignition. These experiments irradiated the inner-tip of a Au cone with the laser and observed electrons that passed through a Cu wire attached to the outer-tip of the cone. The total emission of K x-rays is used as a diagnostic to infer the electron energy coupled into the wire. Imaging the x-ray emission allowed an e ective path-length of electrons within the wire to be determined, which constrained the electron energy spectrum. Experiments were carried out on the ultra-high-contrast Trident laser at Los

  17. Laser-driven wakefield electron acceleration and associated radiation sources

    International Nuclear Information System (INIS)

    Davoine, X.

    2009-10-01

    The first part of this research thesis introduces the basic concepts needed for the understanding of the laser-driven wakefield acceleration. It describes the properties of the used laser beams and plasmas, presents some notions about laser-plasma interactions for a better understanding of the physics of laser-driven acceleration. The second part deals with the numerical modelling and the presentation of simulation tools needed for the investigation of laser-induced wakefield acceleration. The last part deals with the optical control of the injection, a technique analogous to the impulsion collision scheme

  18. En Route: next-generation laser-plasma-based electron accelerators

    International Nuclear Information System (INIS)

    Hidding, Bernhard

    2008-05-01

    Accelerating electrons to relativistic energies is of fundamental interest, especially in particle physics. Today's accelerator technology, however, is limited by the maximum electric fields which can be created. This thesis presents results on various mechanisms aiming at exploiting the fields in focussed laser pulses and plasma waves for electron acceleration, which can be orders of magnitude higher than with conventional accelerators. With relativistic, underdense laser-plasma-interaction, quasimonoenergetic electron bunches with energies up to ∼50 MeV and normalized emittances of the order of 5mmmrad have been generated. This was achieved by focussing the ∼80 fs, 1 J pulses of the JETI-laser at the FSU Jena to intensities of several 10 19 W=cm 2 into gas jets. The experimental observations could be explained via ''bubble acceleration'', which is based on self-injection and acceleration of electrons in a highly nonlinear breaking plasma wave. For the rst time, this bubble acceleration was achieved explicitly in the self-modulated laser wakefield regime (SMLWFA). This quasimonoenergetic SMLWFA-regime stands out by relaxing dramatically the requirements on the driving laser pulse necessary to trigger bubble acceleration. This is due to self-modulation of the laser pulse in high-density gas jets, leading to ultrashort laser pulse fragments capable of initiating bubble acceleration. Electron bunches with durations < or similar 5 fs can thus be created, which is at least an order of magnitude shorter than with conventional accelerator technology. In addition, more than one laser pulse fragment can be powerful enough to drive a bubble. Distinct double peaks have been observed in the electron spectra, indicating that two quasimonoenergetic electron bunches separated by only few tens of fs have formed. This is backed up by PIC-Simulations (Particle-in-Cell). These results underline the feasibility of the construction of small table-top accelerators, while at the

  19. Reduction of secondary electron yield for E-cloud mitigation by laser ablation surface engineering

    Energy Technology Data Exchange (ETDEWEB)

    Valizadeh, R., E-mail: reza.valizadeh@stfc.ac.uk [ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Malyshev, O.B. [ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Wang, S. [ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Department of Physics, Loughborough University, Loughborough LE11 3TU (United Kingdom); Sian, T. [ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); The Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom); Cropper, M.D. [Department of Physics, Loughborough University, Loughborough LE11 3TU (United Kingdom); Sykes, N. [Micronanics Ltd., Didcot, Oxon OX11 0QX (United Kingdom)

    2017-05-15

    Highlights: • SEY below 1 can be achieved with Laser ablation surface engineering. • SEY <1 surface can be produced with different types of nanosecond lasers. • Both microstructure (groves) and nano-structures are playing a role in reducing SEY. - Abstract: Developing a surface with low Secondary Electron Yield (SEY) is one of the main ways of mitigating electron cloud and beam-induced electron multipacting in high-energy charged particle accelerators. In our previous publications, a low SEY < 0.9 for as-received metal surfaces modified by a nanosecond pulsed laser was reported. In this paper, the SEY of laser-treated blackened copper has been investigated as a function of different laser irradiation parameters. We explore and study the influence of micro- and nano-structures induced by laser surface treatment in air of copper samples as a function of various laser irradiation parameters such as peak power, laser wavelength (λ = 355 nm and 1064 nm), number of pulses per point (scan speed and repetition rate) and fluence, on the SEY. The surface chemical composition was determined by x-ray photoelectron spectroscopy (XPS) which revealed that heating resulted in diffusion of oxygen into the bulk and induced the transformation of CuO to sub-stoichiometric oxide. The surface topography was examined with high resolution scanning electron microscopy (HRSEM) which showed that the laser-treated surfaces are dominated by microstructure grooves and nanostructure features.

  20. Laser ablation under different electron heat conduction models in inertial confinement fusion

    Science.gov (United States)

    Li, Shuanggui; Ren, Guoli; Huo, Wen Yi

    2018-06-01

    In this paper, we study the influence of three different electron heat conduction models on the laser ablation of gold plane target. Different from previous studies, we concentrate on the plasma conditions, the conversion efficiency from laser into soft x rays and the scaling relation of mass ablation, which are relevant to hohlraum physics study in indirect drive inertial confinement fusion. We find that the simulated electron temperature in corona region is sensitive to the electron heat conduction models. For different electron heat conduction models, there are obvious differences in magnitude and spatial profile of electron temperature. For the flux limit model, the calculated conversion efficiency is sensitive to flux limiters. In the laser ablation of gold, most of the laser energies are converted into x rays. So the scaling relation of mass ablation rate is quite different from that of low Z materials.

  1. First experimental results of the BNL inverse free electron laser accelerator

    International Nuclear Information System (INIS)

    Steenbergen, A. van; Gallardo, J.; Babzien, M.; Skaritka, J.; Wang, X.J.; Sandweiss, J.; Fang, J.M.; Qiu, X.

    1996-10-01

    A 40 MeV electron beam, using the inverse3e free-electron laser interaction, has been accelerated by ΔE/E = 2.5% over a distance of 0.47 m. The electrons interact with a 1--2 GW CO 2 laser beam bounded by a 2.8 mm ID sapphire circular waveguide in the presence of a tapered wiggler with Bmax ∼ 1 T and a period 2.89 cm ≤ λ w ≤ 3.14 cm. The experimental results of ΔE/E as a function of electron energy E, peak magnetic field Bw and laser power W 1 compare well with analytical and 1-D numerical simulations and permit scaling to higher laser power and electron energy

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  3. Intense pulsed sources of ions and electrons produced by lasers; Sources pulsees intenses d'ions et d'electrons produites par laser

    Energy Technology Data Exchange (ETDEWEB)

    Bourrabier, G [Centre de Recherche de la C.S.F., Corbeville (France); Consoli, T; Slama, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-11-01

    We describe a device for the acceleration of the plasma burst produced by focusing a laser beam into a metal target. We extract the electrons and the ions from the plasma. The maximum current is around 2000 amperes during few microseconds. The study of the effect of the kind of the target on the characteristics of the current shows the great importance of the initial conditions that is the ionisation potential of the target and the energy laser. (authors) [French] On decrit un dispositif destine a accelerer la bouffee de plasma produite par focalisation d'un faisceau laser sur une cible solide. On extrait du plasma les electrons et les ions. Le courant maximum atteint pres de 2000 amperes pendant quelques microsecondes. L'etude de l'effet de la nature de la cible sur les caracteristiques du courant collecte, met en evidence l'importance des conditions initiales (potentiel d'ionisation de la cible, energie du laser). (auteurs)

  4. Proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices

    International Nuclear Information System (INIS)

    Singh, R.; Messick, L.J.

    1989-01-01

    This book contains the proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices. Topics covered include: Growth and characterization of bulk and epitaxial films, Passivation technology, Processing technology, High speed optoelectronic integrated circuits, and Solar cells

  5. Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator

    International Nuclear Information System (INIS)

    Chang, C.-L.; Hsieh, C.-T.; Ho, Y.-C.; Chen, Y.-S.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

    2007-01-01

    Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the plasma column and then accelerated with an acceleration gradient exceeding 2 GeV/cm. The injection position shifts with the position of pump-pulse focus, and no significant deceleration is observed for the monoenergetic electron bunch after it reaches the maximum energy. The results are consistent with the model of transverse wave breaking and beam loading for the injection of monoenergetic electrons. The tomographic method adds a crucial dimension to the whole array of existing diagnostics for laser beams, plasma waves, and electron beams. With this method the details of the underlying physical processes in laser-plasma interactions can be resolved and compared directly to particle-in-cell simulations

  6. Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

    International Nuclear Information System (INIS)

    Li, X. F.; Yu, Q.; Qu, J. F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

    2016-01-01

    In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

  7. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  8. A microwave FEL [free electron laser] code using waveguide modes

    International Nuclear Information System (INIS)

    Byers, J.A.; Cohen, R.H.

    1987-08-01

    A free electron laser code, GFEL, is being developed for application to the LLNL tokamak current drive experiment, MTX. This single frequency code solves for the slowly varying complex field amplitude using the usual wiggler-averaged equations of existing codes, in particular FRED, except that it describes the fields by a 2D expansion in the rectangular waveguide modes, using coupling coefficients similar to those developed by Wurtele, which include effects of spatial variations in the fields seen by the wiggler motion of the particles. Our coefficients differ from those of Wurtele in two respects. First, we have found a missing √2γ/a/sub w/ factor in his C/sub z/; when corrected this increases the effect of the E/sub z/ field component and this in turn reduces the amplitude of the TM mode. Second, we have consistently retained all terms of second order in the wiggle amplitude. Both corrections are necessary for accurate computation. GFEL has the capability of following the TE/sub 0n/ and TE(M)/sub m1/ modes simultaneously. GFEL produces results nearly identical to those from FRED if the coupling coefficients are adjusted to equal those implied by the algorithm in FRED. Normally, the two codes produce results that are similar but different in detail due to the different treatment of modes higher than TE/sub 01/. 5 refs., 2 figs., 1 tab

  9. Extreme-Ultraviolet Vortices from a Free-Electron Laser

    Directory of Open Access Journals (Sweden)

    Primož Rebernik Ribič

    2017-08-01

    Full Text Available Extreme-ultraviolet vortices may be exploited to steer the magnetic properties of nanoparticles, increase the resolution in microscopy, and gain insight into local symmetry and chirality of a material; they might even be used to increase the bandwidth in long-distance space communications. However, in contrast to the generation of vortex beams in the infrared and visible spectral regions, production of intense, extreme-ultraviolet and x-ray optical vortices still remains a challenge. Here, we present an in-situ and an ex-situ technique for generating intense, femtosecond, coherent optical vortices at a free-electron laser in the extreme ultraviolet. The first method takes advantage of nonlinear harmonic generation in a helical undulator, producing vortex beams at the second harmonic without the need for additional optical elements, while the latter one relies on the use of a spiral zone plate to generate a focused, micron-size optical vortex with a peak intensity approaching 10^{14}  W/cm^{2}, paving the way to nonlinear optical experiments with vortex beams at short wavelengths.

  10. SATURNUS: the UCLA infrared free-electron laser project

    International Nuclear Information System (INIS)

    Dodd, J.W.; Hartman, S.C.; Park, S.; Pellegrini, C.; Rosenzweig, J.B.; Smolin, J.A.; Hairapetian, G.; Kolonko, J.; Barletta, W.A.; Cline, D.B.; Favis, J.G.; Joshi, C.J.; Luhmann, N.C. Jr.; Ivanchenkov, S.N.; Khlebnikov, A.S.; Lachin, Y.Y.; Varfolomeev, A.A.

    1991-01-01

    A compact 20 MeV linac with an RF laser-driven electron gun will be used to drive a high-gain (10cm gain length), 10.6 μm wavelength FEL amplifier, operating in the SASE mode. Saturnus will mainly study FEL physics in the high-gain regime, including start-up from noise, optical guiding, sidebands, saturation, and superradiance, with emphasis on the effects important for future short wavelength operation of FEL's. The hybrid undulator was designed and built at the Kurchatov Inst. of Atomic Energy in the USSR. The primary magnetic flux is provided by C-shaped iron yokes, where between the poles thin blocks of neodymium-iron-boron magnets are placed to provide additional magnetic flux along the undulator axis. The field strength is adjusted by moving the thin Nd-Fe-B blocks on a set screw mount. The initial assembly will have forty periods, each 1.5 cm long. The gap distance between the yoke pole-pieces is fixed at 5 mm. The undulator field has been measured, yielding on an axis peak value of 6.6kGauss, which closely matches computer simulations

  11. Reflection of attosecond x-ray free electron laser pulses

    International Nuclear Information System (INIS)

    Hau-Riege, Stefan P.; Chapman, Henry N.

    2007-01-01

    In order to utilize hard x-ray free electron lasers (XFEL's) when they are extended to attosecond pulse lengths, it is necessary to choose optical elements with minimal response time. Specular grazing-incidence optics made of low-Z materials are popular candidates for reflectors since they are likely to withstand x-ray damage and provide sufficiently large reflectivities. Using linear-optics reflection theory, we calculated the transient reflectivity of a delta-function electric pulse from a homogenous semi-infinite medium as a function of angle of incidence for s- and p-polarized light. We specifically considered the pulse response of beryllium, diamond, silicon carbide, and silicon, all of which are of relevance to the XFEL's that are currently being built. We found that the media emit energy in a damped oscillatory way, and that the impulse-response times are shorter than 0.3 fs for normal incidence. For grazing incidence, the impulse-response time is substantially shorter, making grazing-incidence mirrors a good choice for deep subfemtosecond reflective optics

  12. Electron trajectory evaluation in laser-plasma interaction for effective output beam

    Science.gov (United States)

    Zobdeh, P.; Sadighi-Bonabi, R.; Afarideh, H.

    2010-06-01

    Using the ellipsoidal cavity model, the quasi-monoenergetic electron output beam in laser-plasma interaction is described. By the cavity regime the quality of electron beam is improved in comparison with those generated from other methods such as periodic plasma wave field, spheroidal cavity regime and plasma channel guided acceleration. Trajectory of electron motion is described as hyperbolic, parabolic or elliptic paths. We find that the self-generated electron bunch has a smaller energy width and more effective gain in energy spectrum. Initial condition for the ellipsoidal cavity is determined by laser-plasma parameters. The electron trajectory is influenced by its position, energy and cavity electrostatic potential.

  13. Control of electron injection and acceleration in laser-wakefield accelerators

    International Nuclear Information System (INIS)

    Guillaume, E.

    2015-01-01

    Laser-plasma accelerators provide a promising compact alternative to conventional accelerators. Plasma waves with extremely strong electric fields are generated when a high intensity laser is focused into an underdense gas target. Electrons that are trapped in these laser-driven plasma waves can be accelerated up to energies of a few GeVs. Despite their great potential, laser-wakefield accelerators face some issues, regarding notably the stability and reproducibility of the beam when electrons are injected in the accelerating structure. In this manuscript, different techniques of electron injection are presented and compared, notably injection in a sharp density gradient and ionization injection. It is shown that combining these two methods allows for the generation of stable and tunable electron beams. We have also studied a way to manipulate the electron bunch in the phase-space in order to accelerate the bunch beyond the dephasing limit. Such a technique was used with quasi-monoenergetic electron beams to enhance their energy. Moreover, the origin of the evolution of the angular momentum of electrons observed experimentally was investigated. Finally, we demonstrated experimentally a new method - the laser-plasma lens - to strongly reduce the divergence of the electron beam. This laser-plasma lens consists of a second gas jet placed at the exit of the accelerator. The laser pulse drives a wakefield in this second jet whose focusing forces take advantage to reduce the divergence of the trailing electron bunch. A simple analytical model describing the principle is presented, underlining the major importance of the second jet length, density and distance from the first jet. Experimental demonstration of the laser-plasma lens shows a divergence reduction by a factor of 2.6 for electrons up to 300 MeV, in accordance with the model predictions

  14. Laser-assisted electron scattering in strong-field ionization of dense water vapor by ultrashort laser pulses

    International Nuclear Information System (INIS)

    Wilke, M; Al-Obaidi, R; Moguilevski, A; Kothe, A; Engel, N; Metje, J; Kiyan, I Yu; Aziz, E F

    2014-01-01

    We report on strong-field ionization of dense water gas in a short infrared laser pulse. By employing a unique combination of photoelectron spectroscopy with a liquid micro-jet technique, we observe how the character of electron emission at high kinetic energies changes with the increase of the medium density. This change is associated with the process of laser-assisted electron scattering (LAES) on neighboring particles, which becomes a dominant mechanism of hot electron emission at higher medium densities. The manifestation of this mechanism is found to require densities that are orders of magnitude lower than those considered for heating the laser-generated plasmas via the LAES process. The experimental results are supported by simulations of the LAES yield with the use of the Kroll–Watson theory. (paper)

  15. Pulse forming networks for fast pumping of high power electron-beam-controlled CO2 lasers

    International Nuclear Information System (INIS)

    Riepe, K.B.

    1975-01-01

    The transverse electric discharge is a widely used technique for pumping CO 2 lasers at high pressures for the generation, simply and efficiently, of very high power laser pulses. The development of the electron-beam-controlled discharge has allowed the application of the transverse discharge to large aperture, very high energy systems. LASL is now in the process of assembly and checkout of a CO 2 laser which is designed to generate a one nanosecond pulse containing 10 kilojoules, for use in laser fusion experiments. The front end of this laser consists of a set of preamplifiers and a mode locked oscillator with electro-optic single pulse switchout. The final amplifier stage consists of four parallel modules, each one consisting of a two-sided electron gun, and two 35 x 35 x 200 cm gas pumping regions operating at a pressure of 1800 torr with a 3/ 1 / 4 /1 (He/N 2 /CO 2 ) laser mix. (auth)

  16. Electron-hydrogen collisions with dressed target and Volkov projectile states in a laser field

    International Nuclear Information System (INIS)

    Smith, P.H.G.; Flannery, M.R.

    1992-01-01

    Cross sections for the 1S-2S and 1S-2P O transitions in laser-assisted e - -H(1S) collisions are calculated in both the multi-channel eikonal treatment and the Born wave approximation, as a function of impact energy and laser field intensity. The laser considered is a monotonic, plane-polarized CO 2 laser (photon energy = 0.117 eV) with the polarization direction parallel to the initial projectile velocity. The first part of this paper confines the laser perturbation to the bound electrons of the atom. The second part extends the laser perturbation to the projectile electron, and the familiar Volkov dressed states are used. (author)

  17. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    Science.gov (United States)

    Scisciò, M.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Papaphilippou, Y.; Antici, P.

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  18. Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients

    International Nuclear Information System (INIS)

    Gray, R J; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Quinn, M N; Tresca, O; McKenna, P; Burza, M; Wahlström, C-G; Lancaster, K L; Neely, D; Lin, X X; Li, Y T

    2014-01-01

    Laser energy absorption to fast electrons during the interaction of an ultra-intense (10 20 W cm −2 ), picosecond laser pulse with a solid is investigated, experimentally and numerically, as a function of the plasma density scale length at the irradiated surface. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient. (paper)

  19. Conductors, semiconductors and insulators irradiated with short-wavelength free-electron laser

    Czech Academy of Sciences Publication Activity Database

    Krzywinski, J.; Sobierajski, R.; Jurek, M.; Nietubyc, R.; Pelka, J. B.; Juha, Libor; Bittner, Michal; Létal, V.; Vorlíček, Vladimír; Andrejczuk, A.; Feldhaus, J.; Keitel, B.; Saldin, E.; Schneidmiller, E.A.; Treusch, R.; Yurkov, M. V.

    2007-01-01

    Roč. 101, č. 4 (2007), 043107/1-043107/4 ISSN 0021-8979 R&D Projects: GA MŠk 1P04LA235; GA MŠk LC510; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523 Keywords : free-electron laser * extreme ultraviolet * ablation * laser-matter interaction Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.171, year: 2007

  20. Self-focusing of laser beams in magnetized relativistic electron beams

    International Nuclear Information System (INIS)

    Whang, M.H.; Ho, A.Y.; Kuo, S.P.

    1989-01-01

    Recently, there is considerable interest in radiation focusing and optical guiding using the resonant interaction between the radiation field and electron beam. The result of radiation focusing has been shown to play a central role in the practical utilization of the FEL. This result allows the device to use longer interaction length for achieving higher output power. Likewise, the possibility of self-focusing of the laser beam in cyclotron resonance with a relativistic electron beam is also an important issue in the laser acceleration concepts for achieving high-gradient electron acceleration. The effectiveness of the acceleration process relies strongly on whether the laser intensity can be maintained at the desired level throughout the interaction. In this work, the authors study the problem concerning the self-focusing of laser beam in the relativistic electron beams under the cyclotron auto-resonance interaction. They assume that there is no electron density perturbation prohibited from the background magnetic field for the time scale of interest. The nonlinearity responsible for self-focusing process is introduced by the energy dependence of the relativistic mass of electrons. The plasma frequency varies with the electron energy which is proportional to the radiation amplitude. They then examine such a relativistic nonlinear effect on the propagation of a Gaussian beam in the electron beam. A parametric study of the dependence of the laser beam width on the axial position for various electron beam density has been performed