Abstracts Brochure - CERN

THPCH153
THPCH154
29-Jun-06 16:00 - 18:00 THPCH — Poster Session
efficiency for KrF is ascribed to higher photon energy and to Schottky effect. Several electron-beam simulations using
OPERA 3-D were carried out to analyze the influence of the geometrical characteristics of the diode. Simulating the
photoemission by cathodes with micro-structures the output current was dependent on cathode roughness.
*L. Martina et al. Rev. Sci. Instrum., 73, 2552 (2002).
Production of Temporally Flat Top UV SPARC Photoinjector
M. Petrarca, P. Musumeci (INFN-Roma) I. Boscolo, S. Cialdi (INFN-
Milano) G. Gatti, A. Ghigo, C. Vicario (INFN/LNF)
432
In the SPARC photoinjector, the amplified
Ti:Sa laser system is conceived to produce an
UV flat top pulse profile designed in order
to reduce the beam emittance by minimizing
the non-linear space charge effects in the photoelectrons pulse. Beam dynamic simulations indicate that the optimal
pulse distribution has to be flat top in space and time with 10 ps FWHM duration, 1 ps of rise and fall time and a
limited ripple on the plateau. In previous work it was demonstrated the possibility to use a programmable dispersive
acousto-optics (AO) filter to achieve pulse profile close to the optimal one*. The AO filter is inserted at low energy
level at the fundamental wavelength of the laser, centered at 800 nm. In this paper we report the characterization of
the effects of amplification and third harmonics conversion on the pulse temporal profile. The measurements and
simulations in the temporal and spectral domain at the fundamental laser wavelength and at the second and third
harmonics are presented.
*H. Loos et al. "Temporal E-Beam Shaping in an S-Band Accelerator", Proc. Particle Accelerator Conference, p.642,
2005, Knoxville, TN, USA.
Development of Pulsed-laser Super-cavity for Compact High Flux X-ray Source
K. Sakaue, M. Washio (RISE) S. Araki, Y. Higashi, Y. Honda, T.
Taniguchi, J.U. Urakawa (KEK) M.K. Fukuda, M. Takano (NIRS) H.
Sakai (ISSP/SRL) N. Sasao (Kyoto University)
Pulsed-laser super-cavity is being developed
at KEK-ATF for the application of a compact
high brightness x-ray source based on Laser
Compton Scattering. We use a Fabry-Perot
optical cavity with a pulsed laser. The cavity
increases a laser effective power, and at the same time, stably makes a small laser spot in side the cavity. In addition,
the pulsed-laser gives much higher peak power. Thus, this scheme will open up a new possibility for building a
compact high-brightness x-ray source, when collided with an intense bunched electron beam. We are now planning
to build such an x-ray source with a 50MeV multi-bunch linac and a 42cm Fabry-Perot cavity using pulse stacking
technology. We actually finished construction of the 50MeV linac and will start its operation in the spring, 2006.
Development of the pulsed-laser super-cavity and future plan of our compact x-ray source will be presented at the
conference.