1 / 14

Design Considerations of table-top FELs

Design Considerations of table-top FELs. DESY, June 20; recap of FLS 2006, May 15, 2006. LMU: F. Grüner , U. Schramm, S. Becker, R. Sousa, T. Eichner, D. Habs MPQ: S. Karsch, M. Geissler, L. Veisz, J. Meyer-ter-Vehn, F. Krausz UCLA: S. Reiche. laser-plasma accelerators

asta
Download Presentation

Design Considerations of table-top FELs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Design Considerations of table-top FELs DESY, June 20; recap of FLS 2006, May 15, 2006 LMU: F. Grüner, U. Schramm, S. Becker, R. Sousa, T. Eichner, D. HabsMPQ: S. Karsch, M. Geissler, L. Veisz, J. Meyer-ter-Vehn, F. KrauszUCLA: S. Reiche • laser-plasma accelerators • principal possibility of table-top FELs • possible VUV and X-ray scenarios • new experimental status • critical points review • cooperation with DESY…

  2. Laser-Plasma accelerators: “bubble acceleration” electron bunch: e.g. 170 MeV (LOA), 1.2 GeV (Berkeley) TW laser,5-50 fs

  3. M. Geissler PIC code 5fs, a=5

  4. Discharge capillary ~4 cm 300 µm gas-filled capillary electrodes Leemanslaser-plasma-acceleration * presented at Anomalous Absorpt. Conf., June 6, 2006; submitted to Science MPQ: since two weeks 0.35 J in 37 fs, soon 1-2 J future (~2009): 5 J, 5 fs (=1 PW), 1 kHz

  5. Improvement by capillaries de-phasing • discharge introduces parabolic electron density • laser guiding beyond Rayleigh length → higher energies • de-phasing: reducing energy spread • ion-channel: reducing electron beam diameter and divergence • possible scenario: bubble turns into linear wakefield → GeV- energies with ~0.1% energy spread • started cooperation with Simon Hooker (Oxford)

  6. Important feature: ultra-high current typical length scale = plasma wavelength laser pulse ~ 2 µm only!!~ nC charge ~ 100 kA

  7. Principal possibility for table-top FELs simplest estimate: ideal 1d Pierce parameter (no energy spread, emittance, diffraction, time-dependence) : few 100kA (classical: 5 kA) current und. period : few mm (class. few cm) beam diameter (optimal!)

  8. Constraints for table-top FELs saturation length (Xie Ming)for SASE VUV FEL @ ~28nm Λ (Xie Ming) DESY flash (fs mode):λu= 27 mm (462 MeV)εn = 6 mm·mradΔE/E = 0.04 % MPQ (GENESIS)λu= 3 mm (133 MeV)εn = 1 mm·mradΔE/E = 0.5 % • not only table-top size, but sufficient output power: reduction in λu allows a reduction in γ, but needs ultra-high currentfor keeping ρand also saturation power large enough

  9. Start-to-End Simulations electron bunch transport/focusing/filter FEL undulator laser GPT, Geant CSRTrack, Spur;GENESIS 1.3 own 3d PIC code

  10. A possible first VUV case

  11. International competition and a possible first table-top XFEL case

  12. New Experimental Status undulator:60 periods, 5 mm period, 1.6 mm gap~1 T field on axis few days ago: 40 MeV electrons

  13. Critical Points Review • space charge influence due to ultra-dense bunches • - HOMDYN (L. Serafini): for 1 GeV correlated energy spread 0.5 %, no debunching • GPT/CSRtrack runs (see next talk) • simple analytical estimates in agreement with GPT • linear energy chirp can be compensated with tapering • transverse coherence • valid only for spontaneous source, here: gain guiding • calculate growth rate of next higher mode with GENESIS • transverse coherence important for focusing only? • peak brilliance: 1032@ 5 keV - comparable with LCLS! (1012 phts/0.1%BW, θ=15µrad, σx=30µm, τ=10fs)

  14. Cooperation with you… • verify our GPT results with ASTRA • verify entire feasibility study (publishing a joint paper) • discuss beam features in detail (slice energy spread, etc.) • for experiments: diagnostic methods (FROG) • open questions, such as maximum photon energy • what could you learn from us????

More Related