Abstracts Brochure - CERN

MOPCH — Poster Session 26-Jun-06 16:00 - 18:00
on the seeding chambers presented in this paper have been realised at the CEA (Saclay, France). The experiment is
based on three vacuum chambers. In the first one, a Ti: Sa laser (800 nm, 2.5 mJ, 50 fs, 10 Hz) is focussed in a 10 Hz
pulsed gas jet (Argon or Xenon), producing harmonics of the fundamental. Filters in the second chamber enable the
selection of the harmonic (3rd or 5th). Finally, a telescope focuses the harmonic beam at a given position. The whole
module is to be moved to the SPARC facility. Appropriate tuning of the undulator gaps will amplify the 3rd and 5th
harmonics seeded, as well as non-linear harmonics of those wavelengths, allowing the perspective of producing a
FEL at 53 nm
Coherent Harmonic Generation Experiment on UVSOR-II Storage Ring
Harmonic Generation schemes on Free Electron
Laser devices are very promising. The
injection of a traditional laser source inside
the first undulator leads to an efficient energy
modulation of the electron bunch, and
M. Labat, M.-E. Couprie, G. Lambert (CEA) T. Hara (RIKEN Spring-
8 Harima) M. Hosaka, M. Katoh, A. Mochihashi (UVSOR) D.
Nutarelli (LAC) Y. Takashima (Nagoya University)
therefore, its spatial modulation, resulting in a more coherent light emission along the second undulator. Experiments
have been performed on the UVSOR-II Storage Ring at Okazaki (Japan) with electrons stored at an energy of 600 MeV,
and using a 2.5 mJ Ti:Sa laser at 800 nm wavelength, 1 kHz repetition rate, and 100 fs up to 2 ps pulse duration. The
experimental setup is presented, including the transport alignment and synchronisation between the laser and the
electron beam. The third harmonic at 266 nm has been characterised versus various parameters: current, RF cavity
voltage, undulator gap, magnetic functions of the storage ring, and laser pulse duration. Those results are compared
with theory via analytical models and simulations.
The ARC-EN-CIEL FEL Proposal
ARC-EN-CIEL (Accelerator-Radiation Complex
for Enhanced Coherent Intense Extended
Light), the French project of a fourth
generation light source aims at providing the
user community with coherent femtosecond
light pulses covering from UV to soft X ray.
M.-E. Couprie, B. Carré, D. Garzella, M. Jablonka, M. Labat, G.
Lambert, F. Meot, P. Monot, A. Mosnier (CEA) O.V. Chubar, A.
Loulergue, L. Nahon (SOLEIL) J.-R. Marquès (LULI) D. Nutarelli
(LAC) J.-M. Ortega (CLIO/ELYSE/LCP) A. Rousse (LOA)
It is based on a CW 1 GeV superconducting linear accelerator delivering high charge, subpicosecond, low emittance
electron bunches with a high repetition rate (1 kHz). Electron beam calculations will be presented. The FEL is based
on the injection of High Harmonics Generated in Gases (HHG) in a High Gain Harmonic Generation scheme, leading
to a rather compact solution. The produced radiation extending down to 0.8 nm with the Non Linear Harmonics
reproduces the good longitudinal and transverse coherence of the harmonics in gas. Calculations are preformed with
PERSEO, taking into account the proper transverse overlap between HHG and the electron beam, and with SRW.
Optional beam loops are foreseen to increase the beam current or the energy. They will accommodate fs synchrotron
infrared Coherent Synchrotron Radiation sources, VUV and X ray ranges and a FEL oscillator in the 10 nm range. An
important synergy is expected between accelerat
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