Abstracts Brochure - CERN

TUPLS — Poster Session 27-Jun-06 16:00 - 18:00
of optimizing the impedance characteristics of such devices through the evaluation of loss factors and absorber
effectiveness for specific modes using scattering parameter and wakefield analysis.
Design and Tests of New Fast Kickers for the DAFNE Collider and the ILC Damping
Rings
In this paper we illustrate the design of
new, fast stripline kickers to inject or ex- D. Alesini, S. Guiducci, F. Marcellini, P. Raimondi (INFN/LNF)
tract bunches in electron/positron rings. The
kickers have been designed for the injection upgrade of the Phi-factory DAFNE and as injection/extraction devices
for the International Linear Collider (ILC) damping rings. The design is based on tapering the striplines in order to
simultaneously obtain low impedance and an excellent uniformity of the deflecting field. The design has been done
using 2D and 3D electromagnetic codes such as Superfish and HFSS. High voltage test results on prototypes are also
shown.
New Beam Transport Line from LINAC to Photon Factory in KEK
The e+/e
N. Iida, M. Kikuchi (KEK)
− injector LINAC in KEK usually
injects into four rings which are Low Energy
Ring (LER) of KEKB (3.5GeV/e+), High Energy
Ring (HER) of KEKB(8.0GeV/e-), Photon Factory (PF)(2.5GeV/e-) and Advanced Ring for pulse x-rays (PF-
AR)(3.0GeV/e-). While LINAC continuously injects into LER and HER alternately about every five minutes, both
of the KEKB rings usually store almost full operating currents. Time for PF or PF-AR, which includes switching
time, took about 20 minutes several times a day. During this, the storage currents in KEKB rings decreased, and the
optimum points of luminosity tuning had been lost. It had taken more than two hours to recover the luminosity.
It is so useful for KEKB to shorten the time for switch LINAC KEKB to/from PF or PF-AR. In summer of 2005, the
transport line from LINAC to PF were renewed, in which a DC bending magnet only for PF line apportions electron
beam from the end of LINAC to the new line. We succeeded to reduce the occupancy time for PF injection to about five
minutes. In this paper design of the new PF beam transport line and the practical performance achieved according to
the design are described.
The Beam Screen for the LHC Injection Kicker Magnets
The two LHC injection kicker magnet systems
must produce a kick of 1.3 T.m with a M.J. Barnes, F. Caspers, L. Ducimetière, N. Garrel, T. Kroyer (CERN)
flattop duration variable up to 7860 ns, and
rise and fall times of less than 900 ns and 3000 ns, respectively. Each system is composed of two resonant charging
power supplies and four 5 Ohm transmission line kicker magnets with matching terminating resistors and pulse
forming networks. Because of the high beam intensity, a beam screen is placed in the aperture of the magnets. This
screen consists of a ceramic tube with conducting "stripes" on the inner wall. The stripes provide a path for the image
current of the beam and screen the ferrite against wake fields. The stripes initially foreseen gave adequate low beam
impedance; however inter-stripe discharges were observed during pulsing of the magnet. A new development has
therefore been undertaken and is presented. This paper presents various options considered for the stripes to meet
the often conflicting requirements for low beam impedance, shielding of the ferrite, fast field rise time in the aperture
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