1
|
Lynn W, Xu T, Andonian G, Doran DS, Ha G, Majernik N, Piot P, Power J, Rosenzweig JB, Whiteford C, Wisniewski E. Observation of Skewed Electromagnetic Wakefields in an Asymmetric Structure Driven by Flat Electron Bunches. PHYSICAL REVIEW LETTERS 2024; 132:165001. [PMID: 38701460 DOI: 10.1103/physrevlett.132.165001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/15/2024] [Indexed: 05/05/2024]
Abstract
Relativistic charged-particle beams that generate intense longitudinal fields in accelerating structures also inherently couple to transverse modes. The effects of this coupling may lead to beam breakup instability and thus must be countered to preserve beam quality in applications such as linear colliders. Beams with highly asymmetric transverse sizes (flat beams) have been shown to suppress the initial instability in slab-symmetric structures. However, as the coupling to transverse modes remains, this solution serves only to delay instability. In order to understand the hazards of transverse coupling in such a case, we describe here an experiment characterizing the transverse effects on a flat beam, traversing near a planar dielectric lined structure. The measurements reveal the emergence of a previously unobserved skew-quadrupolelike interaction when the beam is canted transversely, which is not present when the flat beam travels parallel to the dielectric surface. We deploy a multipole field fitting algorithm to reconstruct the projected transverse wakefields from the data. We generate the effective kick vector map using a simple two-particle theoretical model, with particle-in-cell simulations used to provide further insight for realistic particle distributions.
Collapse
Affiliation(s)
- W Lynn
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - T Xu
- Northern Illinois Center for Accelerator and Detector Development and Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
| | - G Andonian
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - D S Doran
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G Ha
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - N Majernik
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - P Piot
- Northern Illinois Center for Accelerator and Detector Development and Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Power
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J B Rosenzweig
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - C Whiteford
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - E Wisniewski
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| |
Collapse
|
2
|
Pompili R, Chiadroni E, Cianchi A, Curcio A, Del Dotto A, Ferrario M, Galletti M, Romeo S, Scifo J, Shpakov V, Villa F, Zigler A. Time-resolved study of nonlinear photoemission in radio-frequency photoinjectors. OPTICS LETTERS 2021; 46:2844-2847. [PMID: 34129555 DOI: 10.1364/ol.423880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/16/2021] [Indexed: 06/12/2023]
Abstract
Photoemission is one of the fundamental processes that describes the generation of charged particles from materials irradiated by photons. The continuous progress in the development of ultrashort lasers allows investigation into the dynamics of the process at the femtosecond timescale. Here we report about experimental measurements using two ultrashort ultraviolet laser pulses to temporally probe the electrons release from a copper cathode in a radio-frequency photoinjector. By changing their relative delay, we studied how the release mechanism is affected by two-photon photoemission when tens of GW/cm2 intensities are employed. We evaluated the limits it poses on the achievable beam brightness and analyzed the resulting emission yield in terms of the electronic temperature by modeling the cathode as a two-temperature system.
Collapse
|
3
|
Inoue S, Sakabe S, Nakamiya Y, Hashida M. Jitter-free 40-fs 375-keV electron pulses directly accelerated by an intense laser beam and their application to direct observation of laser pulse propagation in a vacuum. Sci Rep 2020; 10:20387. [PMID: 33230177 PMCID: PMC7683604 DOI: 10.1038/s41598-020-77236-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/09/2020] [Indexed: 11/09/2022] Open
Abstract
We report the generation of ultrashort bright electron pulses directly driven by irradiating a solid target with intense femtosecond laser pulses. The duration of electron pulses after compression by a phase rotator composed of permanent magnets was measured as 89 fs via the ponderomotive scattering of electron and laser pulses, which were almost at the compression limit due to the dispersion of the electron optics. The electron pulse compression system consisting of permanent magnets enabled extremely high timing stability between the laser pulse and electron pulse. The long-term RMS arrival time drift was below 14 fs in 4 h, which was limited by the resolution of the current setup. Because there was no time-varying field to generate jitter, the timing jitter was essentially reduced to zero. To demonstrate the capability of the ultrafast electron pulses, we used them to directly visualize laser pulse propagation in a vacuum and perform 2D mapping of the electric fields generated by low-density plasma in real time.
Collapse
Affiliation(s)
- Shunsuke Inoue
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
- Department of Physics, Graduate School of Science, Kyoto University, KitashirakawaKyoto, Sakyo, 606-8502, Japan.
| | - Shuji Sakabe
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
- Department of Physics, Graduate School of Science, Kyoto University, KitashirakawaKyoto, Sakyo, 606-8502, Japan
| | - Yoshihide Nakamiya
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
- Department of Physics, Graduate School of Science, Kyoto University, KitashirakawaKyoto, Sakyo, 606-8502, Japan
| | - Masaki Hashida
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
- Department of Physics, Graduate School of Science, Kyoto University, KitashirakawaKyoto, Sakyo, 606-8502, Japan
| |
Collapse
|
4
|
Zandi O, Sykes AE, Cornelius RD, Alcorn FM, Zerbe BS, Duxbury PM, Reed BW, van der Veen RM. Transient lensing from a photoemitted electron gas imaged by ultrafast electron microscopy. Nat Commun 2020; 11:3001. [PMID: 32532996 PMCID: PMC7293293 DOI: 10.1038/s41467-020-16746-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/18/2020] [Indexed: 11/28/2022] Open
Abstract
Understanding and controlling ultrafast charge carrier dynamics is of fundamental importance in diverse fields of (quantum) science and technology. Here, we create a three-dimensional hot electron gas through two-photon photoemission from a copper surface in vacuum. We employ an ultrafast electron microscope to record movies of the subsequent electron dynamics on the picosecond-nanosecond time scale. After a prompt Coulomb explosion, the subsequent dynamics is characterized by a rapid oblate-to-prolate shape transformation of the electron gas, and periodic and long-lived electron cyclotron oscillations inside the magnetic field of the objective lens. In this regime, the collective behavior of the oscillating electrons causes a transient, mean-field lensing effect and pronounced distortions in the images. We derive an analytical expression for the time-dependent focal length of the electron-gas lens, and perform numerical electron dynamics and probe image simulations to determine the role of Coulomb self-fields and image charges. This work inspires the visualization of cyclotron dynamics inside two-dimensional electron-gas materials and enables the elucidation of electron/plasma dynamics and properties that could benefit the development of high-brightness electron and X-ray sources.
Collapse
Affiliation(s)
- Omid Zandi
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Allan E Sykes
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ryan D Cornelius
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Francis M Alcorn
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Brandon S Zerbe
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Phillip M Duxbury
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Bryan W Reed
- Integrated Dynamic Electron Solutions, Inc. (IDES), Pleasanton, CA, 94588, USA
| | - Renske M van der Veen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| |
Collapse
|
5
|
Kim HW, Baek IH, Shin J, Park S, Bark HS, Oang KY, Jang KH, Lee K, Vinokurov N, Jeong YU. Method for developing a sub-10 fs ultrafast electron diffraction technology. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:034301. [PMID: 32566696 PMCID: PMC7286702 DOI: 10.1063/4.0000012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
The experimental observation of femtosecond dynamics in atoms and molecules by stroboscopic technologies utilizing x ray or electron flashes has attracted much attention and has rapidly developed. We propose a feasible ultrafast electron diffraction (UED) technology with high brightness and a sub-10 fs temporal resolution. We previously demonstrated a UED system with an overall temporal resolution of 31 fs by using an RF photoelectron gun and a 90° achromatic bending structure. This UED structure enabled a bunch duration of 25 fs and a low timing jitter of less than 10 fs while maintaining a high bunch charge of 0.6 pC. In this paper, we demonstrate a simple way to further compress the electron bunch duration to sub-10 fs based on installing an energy filter in the dispersion section of the achromatic bend. The energy filter removes the electrons belonging to nonlinear parts of the phase space. Through numerical simulations, we demonstrate that the electron bunches can be compressed, at the sample position, to a 6.2 fs (rms) duration for a 100 fC charge. This result suggests that the energy filtering approach is more viable and effective than complicated beam-shaping techniques that commonly handle the nonlinear distribution of the electron beam. Furthermore, a gas-filled hollow core fiber compressor and a Ti:sapphire amplifier are used to implement pump laser pulses of less than 5 fs (rms). Thus, we could present the full simulation results of a sub-10 fs UED, and we believe that it will be one of the technical prototypes to challenge the sub-fs time resolution.
Collapse
Affiliation(s)
- Hyun Woo Kim
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - In Hyung Baek
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Junho Shin
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Sunjeong Park
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Hyeon Sang Bark
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Key Young Oang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Kyu-Ha Jang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Kitae Lee
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| | - Nikolay Vinokurov
- Budker Institute of Nuclear Physics, Lavrent'yeva, 11, 630090 Novosibirsk, Russia
| | - Young Uk Jeong
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-gu, Daejeon, South Korea
| |
Collapse
|
6
|
Ischenko AA, Kochikov IV, Miller RJD. The effect of Coulomb repulsion on the space-time resolution limits for ultrafast electron diffraction. J Chem Phys 2019; 150:054201. [PMID: 30736672 DOI: 10.1063/1.5060673] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The development of electron sources capable of temporal resolution on the order of 1 ps or less raises a number of questions associated with the estimation of the physical meaning and accuracy of the dynamic parameters based on the analysis of time-dependent scattering intensity. The use of low brightness ultrashort pulses with few electrons leads to the necessity for increasing the total exposure time and lengthening the time of data acquisition, with attendant problems with the limited sample. The sample restrictions can be mitigated by increasing the charge per pulse, i.e., by going to high brightness sources. Increasing in the number of electrons, however, is limited by the Coulomb repulsion between them, which leads on one hand to distortion of the diffraction pattern and on the other hand to an increase in the duration of the pulse. An analytical technique for estimating the deformation of the diffraction pattern caused by the Coulomb repulsion of the electrons in electron bunches with duration of less than 10 ps and the influence of this effect on the accuracy of determination of the interatomic distances is developed for the non-relativistic and relativistic regimes for electron energies.
Collapse
Affiliation(s)
- A A Ischenko
- Institute of Fine Chemical Technologies named after M.V. Lomonosov, Russian Technological University-MIREA, Prosp. Vernadskogo 86, 119571 Moscow, Russian Federation
| | - I V Kochikov
- Research Computing Center, Lomonosov Moscow State University, 119899 Moscow, Russian Federation
| | - R J Dwayne Miller
- The Max Planck Institute for the Structure and Dynamics of Matter Hamburg, Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| |
Collapse
|
7
|
Conceptual and Technical Design Aspects of Accelerators for External Injection in LWFA. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8050757] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
8
|
Sergeeva DY, Potylitsyn AP, Tishchenko AA, Strikhanov MN. Smith-Purcell radiation from periodic beams. OPTICS EXPRESS 2017; 25:26310-26328. [PMID: 29041289 DOI: 10.1364/oe.25.026310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 10/11/2017] [Indexed: 06/07/2023]
Abstract
Smith-Purcell effect is well known as a source of monochromatic electromagnetic radiation. In this paper we present the generalized theory of Smith-Purcell radiation from periodic beams. The form-factors describing both coherent and incoherent regimes of radiation are calculated. The radiation characteristics are investigated in two practically important frequency ranges, THz and X-ray, for two modulation profiles, most frequently used in practice - a train of microbunches and a Gaussian-shaped one, characterized by sinusoidal modulation with an arbitrary modulation depth. On the base of the theory developed we show that a modulated electron beam consisting of a set of bunches makes it possible to improve significantly the spectral line monochromaticity of the light emitted, reaching values better than 1% for short gratings. We demonstrate as well that Smith-Purcell radiation can be used for non-destructive diagnostics of the depth of modulation for partially modulated beams. These findings not only open up a new way to manipulate the light emission using Smith-Purcell effect but also promise a profound impact for other radiation sources based on charged particle beams, such as undulator radiation in FELs, next-generation X-ray radiation source based on inverse Compton scattering, in a wide range from THz to X-rays.
Collapse
|
9
|
Maxson J, Cesar D, Calmasini G, Ody A, Musumeci P, Alesini D. Direct Measurement of Sub-10 fs Relativistic Electron Beams with Ultralow Emittance. PHYSICAL REVIEW LETTERS 2017; 118:154802. [PMID: 28452517 DOI: 10.1103/physrevlett.118.154802] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Indexed: 05/07/2023]
Abstract
Ultralow emittance (≤20 nm, normalized) electron beams with 10^{5} electrons per bunch are obtained by tightly focusing an ultrafast (∼100 fs) laser pulse on the cathode of a 1.6 cell radio frequency photoinjector. Taking advantage of the small initial longitudinal emittance, a downstream velocity bunching cavity is used to compress the beam to <10 fs rms bunch length. The measurement is performed using a thick high-voltage deflecting cavity which is shown to be well suited to measure ultrashort durations of bunching beams, provided that the beam reaches a ballistic longitudinal focus at the cavity center.
Collapse
Affiliation(s)
- Jared Maxson
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - David Cesar
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - Giacomo Calmasini
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - Alexander Ody
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - Pietro Musumeci
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - David Alesini
- INFN-Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati, Rome, Italy
| |
Collapse
|
10
|
Thompson DJ, Murphy D, Speirs RW, van Bijnen RMW, McCulloch AJ, Scholten RE, Sparkes BM. Suppression of Emittance Growth Using a Shaped Cold Atom Electron and Ion Source. PHYSICAL REVIEW LETTERS 2016; 117:193202. [PMID: 27858456 DOI: 10.1103/physrevlett.117.193202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 05/12/2023]
Abstract
We demonstrate precise control of charged particle bunch shape with a cold atom electron and ion source to create bunches with linear and, therefore, reversible Coulomb expansion. Using ultracold charged particles enables detailed observation of space-charge effects without loss of information from thermal diffusion, unambiguously demonstrating that shaping in three dimensions can result in a marked reduction of Coulomb-driven emittance growth. We show that the emittance growth suppression is accompanied by an increase in bunch focusability and brightness, improvements necessary for the development of sources capable of coherent single-shot ultrafast electron diffraction of noncrystalline objects, with applications ranging from femtosecond chemistry to materials science and rational drug design.
Collapse
Affiliation(s)
- D J Thompson
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - D Murphy
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - R W Speirs
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - R M W van Bijnen
- Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - A J McCulloch
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - R E Scholten
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - B M Sparkes
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
11
|
Cesar D, Maxson J, Musumeci P, Sun Y, Harrison J, Frigola P, O'Shea FH, To H, Alesini D, Li RK. Demonstration of Single-Shot Picosecond Time-Resolved MeV Electron Imaging Using a Compact Permanent Magnet Quadrupole Based Lens. PHYSICAL REVIEW LETTERS 2016; 117:024801. [PMID: 27447510 DOI: 10.1103/physrevlett.117.024801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Indexed: 06/06/2023]
Abstract
We present the results of an experiment where a short focal length (∼1.3 cm), permanent magnet electron lens is used to image micron-size features (of a metal sample) with a single shot from an ultrahigh brightness picosecond-long 4 MeV electron beam emitted by a radio-frequency photoinjector. Magnification ratios in excess of 30× were obtained using a triplet of compact, small gap (3.5 mm), Halbach-style permanent magnet quadrupoles with nearly 600 T/m field gradients. These results pave the way towards single-shot time-resolved electron microscopy and open new opportunities in the applications of high brightness electron beams.
Collapse
Affiliation(s)
- D Cesar
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - J Maxson
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - P Musumeci
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - Y Sun
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | - J Harrison
- Department of Electrical Engineering, UCLA, Los Angeles, California 90095, USA
| | - P Frigola
- RadiaBeam Technologies, 1717 Stewart Street, Santa Monica, California 90404, USA
| | - F H O'Shea
- RadiaBeam Technologies, 1717 Stewart Street, Santa Monica, California 90404, USA
| | - H To
- RadiaBeam Technologies, 1717 Stewart Street, Santa Monica, California 90404, USA
| | - D Alesini
- INFN-LNF, Via E. Fermi, 40-00044 Frascati, Rome, Italy
| | - R K Li
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| |
Collapse
|
12
|
Murphy D, Scholten RE, Sparkes BM. Increasing the Brightness of Cold Ion Beams by Suppressing Disorder-Induced Heating with Rydberg Blockade. PHYSICAL REVIEW LETTERS 2015; 115:214802. [PMID: 26636853 DOI: 10.1103/physrevlett.115.214802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 06/05/2023]
Abstract
A model for the equilibrium coupling of an ion system with varying initial hard-sphere Rydberg blockade correlations is used to quantify the suppression of disorder-induced heating in Coulomb-expanding cold ion bunches. We show that bunches with experimentally achievable blockade parameters have an emittance reduced by a factor of 2.6 and increased focusability and brightness compared to a disordered bunch. Demonstrating suppression of disorder-induced heating is an important step in the development of techniques for the creation of beam sources with sufficient phase-space density for ultrafast, single-shot coherent diffractive imaging.
Collapse
Affiliation(s)
- D Murphy
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - R E Scholten
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - B M Sparkes
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
13
|
Gacheva EI, Zelenogorskii VV, Andrianov AV, Krasilnikov M, Martyanov MA, Mironov SY, Potemkin AK, Syresin EM, Stephan F, Khazanov EA. Disk Yb:KGW amplifier of profiled pulses of laser driver for electron photoinjector. OPTICS EXPRESS 2015; 23:9627-9639. [PMID: 25968999 DOI: 10.1364/oe.23.009627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigated a diode-pumped multipass disk Yb:KGW amplifier intended for amplifying a train of 3D ellipsoidal pulses of a laser driver for a photocathode of a linear electron accelerator. The multipass amplification geometry permitted increasing the energy of broadband (about 10 nm) pulses with a repetition rate of 1 MHz from 0.12 µJ to 39 µJ, despite large losses (two orders of magnitude) introduced by a beam shaper of 3D ellipsoidal beam. The distortions of the pulse train envelope were minimal due to optimal delay between the moment of pump switching on and arrival of the first pulse of the train.
Collapse
|
14
|
Lahme S, Kealhofer C, Krausz F, Baum P. Femtosecond single-electron diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2014; 1:034303. [PMID: 26798778 PMCID: PMC4711605 DOI: 10.1063/1.4884937] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 06/12/2014] [Indexed: 05/06/2023]
Abstract
Ultrafast electron diffraction allows the tracking of atomic motion in real time, but space charge effects within dense electron packets are a problem for temporal resolution. Here, we report on time-resolved pump-probe diffraction using femtosecond single-electron pulses that are free from intra-pulse Coulomb interactions over the entire trajectory from the source to the detector. Sufficient average electron current is achieved at repetition rates of hundreds of kHz. Thermal load on the sample is avoided by minimizing the pump-probe area and by maximizing heat diffusion. Time-resolved diffraction from fibrous graphite polycrystals reveals coherent acoustic phonons in a nanometer-thick grain ensemble with a signal-to-noise level comparable to conventional multi-electron experiments. These results demonstrate the feasibility of pump-probe diffraction in the single-electron regime, where simulations indicate compressibility of the pulses down to few-femtosecond and attosecond duration.
Collapse
Affiliation(s)
- S Lahme
- Max-Planck-Institute of Quantum Optics and Ludwig-Maximilians-Universität München , Am Coulombwall 1, 85748 Garching, Germany
| | - C Kealhofer
- Max-Planck-Institute of Quantum Optics and Ludwig-Maximilians-Universität München , Am Coulombwall 1, 85748 Garching, Germany
| | - F Krausz
- Max-Planck-Institute of Quantum Optics and Ludwig-Maximilians-Universität München , Am Coulombwall 1, 85748 Garching, Germany
| | - P Baum
- Max-Planck-Institute of Quantum Optics and Ludwig-Maximilians-Universität München , Am Coulombwall 1, 85748 Garching, Germany
| |
Collapse
|
15
|
Polyakov A, Senft C, Thompson KF, Feng J, Cabrini S, Schuck PJ, Padmore HA, Peppernick SJ, Hess WP. Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources. PHYSICAL REVIEW LETTERS 2013; 110:076802. [PMID: 25166390 DOI: 10.1103/physrevlett.110.076802] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Indexed: 06/03/2023]
Abstract
In this Letter, we report on the efficient generation of electrons from metals using multiphoton photoemission by use of nanostructured plasmonic surfaces to trap, localize, and enhance optical fields. The plasmonic surface increases absorption over normal metals by more than an order of magnitude, and due to the localization of fields, this results in over 6 orders of magnitude increase in effective nonlinear quantum yield. We demonstrate that the achieved quantum yield is high enough for use in rf photoinjectors operating as electron sources for MHz repetition rate x-ray free electron lasers.
Collapse
Affiliation(s)
- A Polyakov
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - C Senft
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - K F Thompson
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - J Feng
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - S Cabrini
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - P J Schuck
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - H A Padmore
- LBNL, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - S J Peppernick
- PNNL, 902 Batelle Boulevard, Richland, Washington 99352, USA
| | - W P Hess
- PNNL, 902 Batelle Boulevard, Richland, Washington 99352, USA
| |
Collapse
|
16
|
Morrison VR, Chatelain RP, Godbout C, Siwick BJ. Direct optical measurements of the evolving spatio-temporal charge density in ultrashort electron pulses. OPTICS EXPRESS 2013; 21:21-29. [PMID: 23388892 DOI: 10.1364/oe.21.000021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The temporal evolution of the charge density distribution in femtosecond laser produced electron pulses was studied using electron-laser pulse cross correlation techniques and compared to analytical predictions and simulations. The influence of propagation time and weak magnetic focusing were both investigated. Our results show that ultrashort electron pulses develop a relatively uniform internal charge density as they propagate, which is in good agreement with analytical predictions, and that weakly focusing an ultrashort electron pulse results in an increased internal charge density towards the leading edge of the pulse.
Collapse
Affiliation(s)
- Vance R Morrison
- Department of Physics, Center for the Physics of Materials, McGill University, Montreal, Canada
| | | | | | | |
Collapse
|
17
|
Abstract
We discuss recent results on soft and hard X-ray free electron lasers (FELs) and how they can be used to design and optimize the next generation of these sources of high brightness, coherent photons, with femtosecond pulse duration, or very narrow linewidth. In particular, we consider the experimental and theoretical progress in the electron beam generation and manipulation. These results, when combined with the successful development of powerful simulation codes, can be used to design optimized, high intensity sources of coherent photons, and to reduce their size and cost.
Collapse
Affiliation(s)
- Claudio Pellegrini
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
18
|
Carbone F, Musumeci P, Luiten O, Hebert C. A perspective on novel sources of ultrashort electron and X-ray pulses. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.10.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
19
|
Will I, Templin HI, Schreiber S, Sandner W. Photoinjector drive laser of the FLASH FEL. OPTICS EXPRESS 2011; 19:23770-23781. [PMID: 22109402 DOI: 10.1364/oe.19.023770] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The upgraded photoinjector drive laser of the free-electron laser facility FLASH at DESY Hamburg is described in this paper. This laser produces trains of 800 and 2400 ultraviolet picosecond pulses at 1 MHz and 3 MHz repetition rate in the trains, respectively. The amplifying elements of the system are Nd:YLF-rods, which are pumped by fiber-coupled semiconductor diodes. Compared to the flashlamp-pumped photocathode laser previously used at FLASH, the new diode-pumped laser features a better reliability and a significantly improved stability of its pulse parameters.
Collapse
Affiliation(s)
- Ingo Will
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany.
| | | | | | | |
Collapse
|
20
|
van Oudheusden T, Pasmans PLEM, van der Geer SB, de Loos MJ, van der Wiel MJ, Luiten OJ. Compression of subrelativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction. PHYSICAL REVIEW LETTERS 2010; 105:264801. [PMID: 21231672 DOI: 10.1103/physrevlett.105.264801] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Indexed: 05/09/2023]
Abstract
We demonstrate the compression of 95 keV, space-charge-dominated electron bunches to sub-100 fs durations. These bunches have sufficient charge (200 fC) and are of sufficient quality to capture a diffraction pattern with a single shot, which we demonstrate by a diffraction experiment on a polycrystalline gold foil. Compression is realized by means of velocity bunching by inverting the positive space-charge-induced velocity chirp. This inversion is induced by the oscillatory longitudinal electric field of a 3 GHz radio-frequency cavity. The arrival time jitter is measured to be 80 fs.
Collapse
Affiliation(s)
- T van Oudheusden
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | | | | | | | | | | |
Collapse
|
21
|
Musumeci P, Cultrera L, Ferrario M, Filippetto D, Gatti G, Gutierrez MS, Moody JT, Moore N, Rosenzweig JB, Scoby CM, Travish G, Vicario C. Multiphoton photoemission from a copper cathode illuminated by ultrashort laser pulses in an RF photoinjector. PHYSICAL REVIEW LETTERS 2010; 104:084801. [PMID: 20366937 DOI: 10.1103/physrevlett.104.084801] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Indexed: 05/09/2023]
Abstract
In this Letter we report on the use of ultrashort infrared laser pulses to generate a copious amount of electrons by a copper cathode in an rf photoinjector. The charge yield verifies the generalized Fowler-Dubridge theory for multiphoton photoemission. The emission is verified to be prompt using a two pulse autocorrelation technique. The thermal emittance associated with the excess kinetic energy from the emission process is comparable with the one measured using frequency tripled uv laser pulses. In the high field of the rf gun, up to 50 pC of charge can be extracted from the cathode using a 80 fs long, 2 microJ, 800 nm pulse focused to a 140 mum rms spot size. Taking into account the efficiency of harmonic conversion, illuminating a cathode directly with ir laser pulses can be the most efficient way to employ the available laser power.
Collapse
Affiliation(s)
- P Musumeci
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Musumeci P, Moody JT, Scoby CM, Gutierrez MS, Bender HA, Wilcox NS. High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:013306. [PMID: 20113092 DOI: 10.1063/1.3292683] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.
Collapse
Affiliation(s)
- P Musumeci
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | | | | | | | | | | |
Collapse
|
23
|
Musumeci P, Faillace L, Fukasawa A, Moody JT, O'Shea B, Rosenzweig JB, Scoby CM. Novel radio-frequency gun structures for ultrafast relativistic electron diffraction. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2009; 15:290-297. [PMID: 19575830 DOI: 10.1017/s1431927609090412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Radio-frequency (RF) photoinjector-based relativistic ultrafast electron diffraction (UED) is a promising new technique that has the potential to probe structural changes at the atomic scale with sub-100 fs temporal resolution in a single shot. We analyze the limitations on the temporal and spatial resolution of this technique considering the operating parameters of a standard 1.6 cell RF gun (which is the RF photoinjector used for the first experimental tests of relativistic UED at Stanford Linear Accelerator Center; University of California, Los Angeles; Brookhaven National Laboratory), and study the possibility of employing novel RF structures to circumvent some of these limits.
Collapse
Affiliation(s)
- P Musumeci
- University of California, Los Angeles, Department of Physics and Astronomy, 475 Portola Plaza, Los Angeles, CA 90095-1547, USA.
| | | | | | | | | | | | | |
Collapse
|
24
|
Reed BW, Armstrong MR, Browning ND, Campbell GH, Evans JE, LaGrange T, Masiel DJ. The evolution of ultrafast electron microscope instrumentation. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2009; 15:272-281. [PMID: 19575828 DOI: 10.1017/s1431927609090394] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Extrapolating from a brief survey of the literature, we outline a vision for the future development of time-resolved electron probe instruments that could offer levels of performance and flexibility that push the limits of physical possibility. This includes a discussion of the electron beam parameters (brightness and emittance) that limit performance, the identification of a dimensionless invariant figure of merit for pulsed electron guns (the number of electrons per lateral coherence area, per pulse), and calculations of how this figure of merit determines the trade-off of spatial against temporal resolution for different imaging modes. Modern photonics' ability to control its fundamental particles at the quantum level, while enjoying extreme flexibility and a very large variety of operating modes, is held up as an example and a goal. We argue that this goal may be approached by combining ideas already in the literature, suggesting the need for large-scale collaborative development of next-generation time-resolved instruments.
Collapse
Affiliation(s)
- B W Reed
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA.
| | | | | | | | | | | | | |
Collapse
|
25
|
Musumeci P, Moody JT, Scoby CM, Gutierrez MS, Tran T. rf streak camera based ultrafast relativistic electron diffraction. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:013302. [PMID: 19191429 DOI: 10.1063/1.3072883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We theoretically and experimentally investigate the possibility of using a rf streak camera to time resolve in a single shot structural changes at the sub-100 fs time scale via relativistic electron diffraction. We experimentally tested this novel concept at the UCLA Pegasus rf photoinjector. Time-resolved diffraction patterns from thin Al foil are recorded. Averaging over 50 shots is required in order to get statistics sufficient to uncover a variation in time of the diffraction patterns. In the absence of an external pump laser, this is explained as due to the energy chirp on the beam out of the electron gun. With further improvements to the electron source, rf streak camera based ultrafast electron diffraction has the potential to yield truly single shot measurements of ultrafast processes.
Collapse
Affiliation(s)
- P Musumeci
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
| | | | | | | | | |
Collapse
|
26
|
Relativistic electron diffraction at the UCLA Pegasus photoinjector laboratory. Ultramicroscopy 2008; 108:1450-3. [PMID: 18640780 DOI: 10.1016/j.ultramic.2008.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 03/27/2008] [Indexed: 11/23/2022]
Abstract
Electron diffraction holds the promise to yield real-time resolution of atomic motion in an easily accessible environment like a university laboratory at a fraction of the cost of fourth-generation X-ray sources. Currently the limit in time-resolution for conventional electron diffraction is set by how short an electron pulse can be made. A very promising solution to maintain the highest possible beam intensity without excessive pulse broadening from space charge effects is to increase the electron energy to the MeV level where relativistic effects significantly reduce the space charge forces. Rf photoinjectors can in principle deliver up to 10(7)-10(8) electrons packed in bunches of approximately 100-fs length, allowing an unprecedented time resolution and enabling the study of irreversible phenomena by single-shot diffraction patterns. The use of rf photoinjectors as sources for ultrafast electron diffraction has been recently at the center of various theoretical and experimental studies. The UCLA Pegasus laboratory, commissioned in early 2007 as an advanced photoinjector facility, is the only operating system in the country, which has recently demonstrated electron diffraction using a relativistic beam from an rf photoinjector. Due to the use of a state-of-the-art ultrashort photoinjector driver laser system, the beam has been measured to be sub-100-fs long, at least a factor of 5 better than what measured in previous relativistic electron diffraction setups. Moreover, diffraction patterns from various metal targets (titanium and aluminum) have been obtained using the Pegasus beam. One of the main laboratory goals in the near future is to fully develop the rf photoinjector-based ultrafast electron diffraction technique with particular attention to the optimization of the working point of the photoinjector in a low-charge ultrashort pulse regime, and to the development of suitable beam diagnostics.
Collapse
|