Abstracts Brochure - CERN

MOPLS — Poster Session 26-Jun-06 16:00 - 18:00
Status of the HeLiCal Contribution to the Polarised Positron Source for the International
Linear Collider
The baseline positron source for the International
Linear Collider is a helical undulatorbased
design, which can generate unprecedented
quantities of polarised positrons. A
major thrust of the global design in this area
is led by the UK-based HeLiCal collaboration.
The collaboration takes responsibility
J.A. Clarke, O.B. Malyshev, D.J. Scott (CCLRC/DL/ASTeC) I.R.
Bailey, P. Cooke, J.B. Dainton, L.I. Malysheva (Liverpool University,
Science Faculty) D.P. Barber (DESY) E. Baynham, T.W. Bradshaw,
A.J. Brummitt, F.S. Carr, Y. Ivanyushenkov, J. Rochford (CCLRC/
RAL) G.A. Moortgat-Pick (Durham University)
for the design and prototyping of the helical undulator itself, which is a highly demanding short period device with
very small aperture, and also leads the start to end simulations of the polarised particles to ensure that the high
polarisation levels generated are maintained from the source, right through the beam transport systems and up to
the interaction point itself. This paper will provide an update on the work of the collaboration, focusing on these two
topic areas, and will also discuss future plans.
Shower Simulations, Comparison of Fluka, Geant4 and EGS4
Computer simulations with different packages
(Fluka, Geant4 and EGS4) were run in
order to determine the energy deposition of
an ILC bunch in a spoiler of specified geometry
at various depths. The uncertainty in
A. Bungau (Cockcroft Institute) R.J. Barlow (UMAN) L. Fernandez-
Hernando (CCLRC/DL/ASTeC) L. Keller (SLAC) N.K. Watson
(CCLRC/RAL/ASTeC)
these predictions is estimated by comparison of their results. Various candidate spoiler designs (geometry, material)
are studied. These shower simulations can be used as inputs to thermal and mechanical studies using programs such
as ANSYS.
Collimation Optics Optimisation in the ILC Beam Delivery System
The collimation systems of the ILC beam delivery
system must provide efficient removal F. Jackson (CCLRC/DL/ASTeC)
of halo particles which lie outside the acceptable
ranges of energy and spatial spread. The optimisation of the magnet lattice which transports the beam through
the collimation systems to the interaction point is described. Primary considerations are the phase relationships
between collimation systems and the final focus and the overall bandwidth of the system.
Progress towards Crab Cavity Solutions for the ILC
In order to achieve acceptable luminosity for
ILC crossing angles greater than a few mrad,
RF deflection cavities must be used to rotate
electron and position bunches leading up to
the IP. A bunch that passes through a deflec-
G. Burt, A.C. Dexter (Microwave Research Group, Lancaster University)
C.D. Beard, P. Goudket, A. Kalinin, L. Ma (CCLRC/DL/
ASTeC) L. Bellantoni (Fermilab)
tion cavity at a phase where the deflection averages to zero receives a crab kick leading to a finite rotation at the IP.
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