Abstracts Brochure - CERN

WEPLS023
WEPLS024
WEPLS025
28-Jun-06 16:00 - 18:00 WEPLS — Poster Session
m downstream of the spectrometer magnets permit to determine the beam energy with required resolution. The
main principles of the beam energy measurements based on SR, the numerical simulations of SR performed by the
GEANT code and proposal of SR monitors with submicron resolution are discussed.
The Two-beam Test-stand in CTF3
V.G. Ziemann, T. J. C. Ekelof (UU/ISV) H.-H. Braun, S. Doebert, G.
Geschonke, J.P.H. Sladen, W. Wuensch (CERN)
338
The acceleration concept for CLIC, based on
the two-beam acceleration scheme, where
the 30 GHz RF power needed to accelerate
the high energy beam is generated by a high-
intensity but rather low energy drive beam, will be for the first time tested with realistic parameters in the two-beam
test-stand in CTF3. The extreme power levels of up to 600 MW warrant a careful diagnostic system to analyze RF
breakdown by observing the effect on both probe − and drive-beam but also the RF signals and secondary effects
such as emitted light, vibrations, vacuum, and temperatures. We describe the experimental setup and the diagnostic
system planned to be installed in CTF3 for 2007.
Linear Laser Wakefield Acceleration with External Injection
W. van Dijk, G.J.H. Brussaard, W.H. Urbanus, M.J. Van der Wiel,
S.B. van der Geer (TUE)
The Laser Wakefield project at Eindhoven
University seeks to separate three processes
needed for controlled LWFA: Creation of a
plasma channel, injection of electrons and
acceleration of these electrons. This enables control over and optimization of the individual components of the
accelerator. It also removes the need to operate in the non-linear wakefield regime. This allows the use of lower density
plasma regimes without requiring enormous laser intensities. Using front-to-end particle tracking simulations, a
setup has been designed consisting of a RF-photogun, a ’modest’ 2 TW tabletop laser and a pulsed capillary discharge
plasma. Together, these enable the creation of 100 MeV, 1pC bunches with a duration of 10fs. The capabilities of the
setup under construction will be presented. Also the outlook of laser wakefield acceleration with external injection
will be discussed.
Multi-bunch Plasma Wakefield Experiments at the Brookhaven National Laboratory Accelerator
Test Facility
P. Muggli, E.K. Kallos, T.C. Katsouleas (USC) M. Babzien, I. Ben-Zvi,
K. Kusche, P.I. Pavlishin, I. Pogorelsky, D. Stolyarov, V. Yakimenko
(BNL) W.D. Kimura (STI) F. Zhou (UCLA)
In the plasma wakefield accelerator (PWFA),
a short particle bunch or train of bunches
drives a large amplitude relativistic plasma
wave or wake. The wake has both transverse,
focusing fields, and longitudinal fields that
can accelerate trailing particles or a trailing bunch. In this experiment conducted at BNL-ATF, a CO2 laser driven
IFEL modulates the energy of the 65 MeV, 1.5 ps electron bunch, which after a drift creates a train of bunches
approximately 3 fs long, separated by the laser wavelength (10.6 µm or about 30 fs). The largest wake amplitude is
reached when the plasma wavelength is equal to the bunch spacing: n=1·10 19 e-/cc. In this case, the bunch train
drives a wake with an amplitude of approximately 7 GV/m in an ablative capillary discharge plasma. This wake
amplitude is much larger than that previously observed with the un-bunched beam*. With this multi-bunch PWFA