Narrow spread electron beams from a laser-plasma wakefield accelerator

S. M. Wiggins, M. P. Anania, E. Brunetti, S. Cipiccia, B. Ersfeld, M. R. Islam, R. C. Issac, G. Raj, R. P. Shanks, G. Vieux, G. H. Welsh, W. A. Gillespie, A. M. MacLeod, D. A. Jaroszynski

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    7 Citations (Scopus)

    Abstract

    The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme is developing laser-plasma accelerators for the production of ultra-short electron bunches with subsequent generation of incoherent radiation pulses from plasma and coherent short-wavelength radiation pulses from a free-electron laser (FEL). The first quantitative measurements of the electron energy spectra have been made on the University of Strathclyde ALPHA-X wakefield acceleration beam line. A high peak power laser pulse (energy 900 mJ, duration 35 fs) is focused into a gas jet (nozzle length 2 mm) using an F/16 spherical mirror. Electrons from the laser-induced plasma are self-injected into the accelerating potential of the plasma density wake behind the laser pulse. Electron beams emitted from the plasma have been imaged downstream using a series of Lanex screens positioned along the beam line axis and the divergence of the electron beam has been measured to be typically in the range 1-3 mrad. Measurements of the electron energy spectrum, obtained using the ALPHA-X high resolution magnetic dipole spectrometer, are presented. The maximum central energy of the monoenergetic beam is 90 MeV and r.m.s. relative energy spreads as low as 0.8% are measured. The mean central energy is 82 MeV and mean relative energy spread is 1.1%. A theoretical analysis of this unexpectedly high electron beam quality is presented and the potential impact on the viability of FELs driven by electron beams from laser wakefield accelerators is examined.

    Original languageEnglish
    Title of host publicationHarnessing Relativistic Plasma Waves as Novel Radiation Sources from Terahertz to X-Rays and Beyond
    EditorsDino A. Jaroszynski, Antoine Rousse
    Place of PublicationBellingham
    PublisherSPIE-International Society for Optical Engineering
    ISBN (Print)9780819476333
    DOIs
    Publication statusPublished - 2009
    EventSPIE Europe Optics + Optoelectronics 2009: Harnessing Relativistic Plasma Waves as Novel Radiation Sources From Terahertz to X-Rays and Beyond - Prague Congress Centre, Prague, Czech Republic
    Duration: 22 Apr 200923 Apr 2009
    http://spie.org/x34921.xml

    Publication series

    NameProceedings of SPIE
    PublisherSPIE
    Volume7359

    Conference

    ConferenceSPIE Europe Optics + Optoelectronics 2009: Harnessing Relativistic Plasma Waves as Novel Radiation Sources From Terahertz to X-Rays and Beyond
    CountryCzech Republic
    CityPrague
    Period22/04/0923/04/09
    Internet address

    Keywords

    • wakefield acceleration
    • energy spread
    • laser-plasma interaction
    • relativistic electron beams
    • SYNCHROTRON-RADIATION
    • GENERATION
    • REGIME
    • PULSES

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