Abstracts Brochure - CERN

WEPLS — Poster Session 28-Jun-06 16:00 - 18:00
Undulator-based Production of Polarized Positrons (SLAC E-166)
An experiment at the Final Focus Test Beam
of the Stanford Linear Accelerator Center
has demonstrated the production of polarized
positrons of 4-7 MeV. A 47-GeV electron
beam created a beam of circularly polarized
photons of 9-MeV endpoint energy on passing
through a 1-m-long pulsed helical undulator
with period 2.4 mm and K-factor 0.15.
Photon and positron polarizations were deduced
from measurements of the asymmetry
K.T. McDonald (PU) G. Alexander, E. Reinherz-Aronis (University
of Tel Aviv) Y.K. Batygin, V. Bharadwaj, G.R. Bower, F.-J. Decker, C.
Hast, R.H. Iverson, J. Sheppard, Z. Szalata, D.R. Walz, A.W. Weidemann
(SLAC) T. Behnke, V. Gharibyan, P. Pahl, R. Poeschl, K.P.
Schuler (DESY) S. Berridge, W. Bugg, Y. Efrimenko (UTK) R. Dollan,
H. Kolanoski (Humboldt Universität zu Berlin) J. Kovermann,
A. Stahl (RWTH) K. Laihem, A. Schaelicke (DESY Zeuthen) A.A.
Mikhailichenko (Cornell University, Department of Physics)
in transmission through magnetized iron absorbers (after reconversion to photons in the case of positrons). The results
are in good agreement with simulations, which confirms that this technique is suitable for use in future electron linear
colliders.
Laser Driven Linear Collider
We represent the details of scheme allowing
long term acceleration with >10GeV/m. The A.A. Mikhailichenko (Cornell University, Department of Physics)
basis of the scheme is a fast sweeping device
for laser bunch. After sweeping the laser bunch has a slope with respect to the direction of propagation. So the
every cell of accelerating structure becomes illuminated locally only for the moment, when the particle is there. Self
consistent parameters allow considering this type of collider as a candidate for post-ILC era.
Wiggler for ILC
We represented the concept of a wiggler
with linear piecewise field dependence. This A.A. Mikhailichenko (Cornell University, Department of Physics)
eliminates nonlinearities in wiggler. This
type of wiggler can be recommended for usage in ILC cooler.
The Effect of Vaccum Vessel Permeability on the Field Quality within Dipole and Quadrupole
Magnets at the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory
The Energy Recovery Linac Prototype
(ERLP) is currently under construction at
Daresbury Laboratory in the UK and will
N. Thompson (CCLRC/DL/ASTeC)
serve as a test bed for the investigation of technologies and beam physics issues necessary for the development of
Daresbury Laboratory’s Fourth Generation Light Source (4GLS) proposal. To assist with the material specification of
the vacuum vessels, analyses have been done on the effect of vessel permeability on the magnetic field quality within
quadrupole and dipole magnets. It is found that for dipoles where the specified maximum relative dipole field
variation over the good field region is ± 1x 10 -4 or for quadrupoles where the specified maximum relative gradient
variation is ±1 1x10-3, the transverse size of the good field region decays unacceptably for relative permeability >
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