Abstracts Brochure - CERN

THPLS — Poster Session 29-Jun-06 16:00 - 18:00
device sources and for damping wigglers to reduce emittance. The dispersive regions can be designed to minimize
the strength of the chromatic correction sextupoles. A key constraint is the imposition of a limit on circumference
which is closely tied to cost. We discuss optimization of the dynamic aperture by minimizing the non-linear driving
terms using high-order achromatic cancellation in the non-linear lattice.
Control of Dynamic Aperture with Insertion Devices
It is well known that insertion devices (IDs)
perturb the linear optics in the vertical plane. T.V. Shaftan, J. Bengtsson, S.L. Kramer (BNL)
In particular, that the effect can be corrected
locally by a symmetric arrangement of four quadrupoles on each side of the IDs. We show how to control an arbitrary
set of IDs in this configuration with the response matrix for the beta-beat and perturbation of the phase advance and
SVD, i.e., to maintain the dynamic aperture. We also evaluate the residual impact on the dynamic aperture from the
nonlinear terms and outline how to control these. As an example, we discuss an impact of some ID models on the
NSLS-2 dynamic aperture. Results for a single ID and a set of 20 IDs with random field strengths are presented.
Nb-Pb Superconducting RF Gun
We report on the status of an electron RF-gun
made of two superconductors: niobium and
lead. The presented design combines the advantages
of the RF performance of bulk niobium
superconducting cavities and the reasonably
high quantum efficiency of lead, as
compared to other superconducting metals.
The concept, mentioned in a previous paper,
J.S. Sekutowicz, J.I. Iversen, D. Klinke, D. Kostin, W.-D. Möller
(DESY) I. Ben-Zvi, T. Rao, J. Smedley (BNL) M. Ferrario (INFN/
LNF) P. Kneisel (Jefferson Lab) K. Ko, L. Xiao (SLAC) J. Langner,
P.S. Strzyzewski (The Andrzej Soltan Institute for Nuclear Studies,
Centre Swierk) A.R. Lipski (SBUNSL) J.B. Rosenzweig (UCLA) K.
Szalowski (University of Lodz)
follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group.
Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photonbroken
Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.
Status of the Photocathode RF Gun System at Tsinghua University
An S-band high gradient photocathode RF
gun test stand is in construction process at
Tsinghua University. The photocathode RF
gun test stand is a primary step of a femtosec-
X. He, Cheng. Cheng. Cheng, Q. Du, Du.Taibin. Du, Y.-C. Du,
W.-H. Huang, Y. Lin, C.-X. Tang, S. Zheng (TUB)
ond hard x-ray source based on Thomson scattering. The photocathode RF gun system adopts Ti:Sap laser, BNL IV
type 1.6 cell RF gun, compact compensation solenoid. We foresee to conduct investigations on the thermal emittance
contribution of surface roughness, the emittance compensation technique under various laser shape and its application
to Thomson scattering x-ray source. Except for the transportation of laser, correction of laser front for glazing
incidence and laser pulse shaping system, other parts of the photocathode RF gun test stand have been constructed,
and we can start very primary experiment on the RF gun test stand, such as measurements of dark current, QE and
energy of the beam. The experimental results are reported.
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THPLS091
THPLS092
THPLS093