Abstracts Brochure - CERN

WEPLS — Poster Session 28-Jun-06 16:00 - 18:00
Spin Tracking at the ILC
Polarized beams will play a key role in the
physics programme at the International Linear
Collider (ILC). It is expected that the electron
and positron sources will be able to produce
beams with polarizations of about 90%
and 60% respectively. However, to obtain accurate
measurements it is essential to have
I.R. Bailey, I.R. Bailey, D.P. Barber, J.A. Clarke, J.B. Dainton,
O.B. Malyshev, G.A. Moortgat-Pick, D.J. Scott (Cockcroft Institute)
E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, Y.
Ivanyushenkov, J. Rochford (CCLRC/RAL) P. Cooke, L.I. Malysheva
(Liverpool University, Science Faculty)
precise knowledge and control of the polarization at the interaction point itself. It follows that the theoretical calculations
used for spin tracking must be guaranteed to match the anticipated 0.1% relative measurement uncertainty
of the polarimeters. To meet this need, the heLiCal collaboration is developing a computer simulation to track the
evolution of the polarization of bunches of electrons and positrons from the sources to the interaction point. We have
studied the beam spin dynamics throughout the ILC including spin precession and radiative spin-flip processes in
the positron source, damping rings, beam delivery system and the interaction region. We present the result of these
studies with special emphasis on the impact of new theoretical calculations for the CAIN bunch-bunch simulation
including full spin correlations and higher-order contributions.
Cold Atom Electron Sources
We are developing a completely new
method of producing high-brightness electron
bunches, based on extraction of electrons
from an ultra-cold plasma, created by
O.J. Luiten, M.P. Reijnders, G. Taban, E.J.D. Vredenbregt, S.B. van
der Geer (TUE)
photo-ionization of a cloud of laser-cooled atoms*. In this way extremely low thermal emittances (