Abstracts Brochure - CERN

MOPLS — Poster Session 26-Jun-06 16:00 - 18:00
to lead to a region of stable collision parameters. Beam and beamstrahlung photon losses are calculated along the
extraction elements. Issues concerning the design of the large bore superconducting final focus magnets, common to
both incoming and outgoing beams, are considered.
Optimization of the e-e − Option at the ILC
The e-e − running mode is one of the interesting
physics options for the International
Linear Collider. The luminosity for e-e − collisions
is reduced by mutual defocusing due
M. Alabau Pons, M. Alabau Pons, A. Faus-Golfe (IFIC) R. Appleby
(UMAN) P. Bambade, X. Dadoun (LAL)
to the strong electromagnetic fields that the bunches experience during collisions. The resulting beamstrahlung
energy loss and beam-beam deflection angles as function of the vertical transverse offset are different compared to
the e + e − collisions. In this paper, the dependence of these observables with the offset for different beam sizes has
been analysed to optimize performances for the e-e − mode, taking into account the requirements of the beam-beam
deflection based intra-train feedback system. A first study of the implications for the final focus and extraction line
optics is also presented for the cases of the 2mrad and 20mrad ILC base line crossing angle geometries.
Investigation of Multipole Errors on the Collimation Efficiency for the ILC Beam Delivery
System
The post-linac collimation system for the future
International Linear Collider is required
to reduce the beam halo by several orders of
magnitude. Multi-stage collimation systems
R. Amirikas, F. Poirier, N.J. Walker (DESY) G.A. Blair, J. Carter
(Royal Holloway, University of London)
are required, whose overall efficiency relies on the optical transfer between them. High-order multipole errors, which
are generally insignificant for the ultra-small emittance core of the beam, can strongly influence the halo particles at
many beam sigma, opening up ’holes’ in the collimation system and reducing the efficiency. We present simulations
of these errors using the GEANT4-based BDSIM code and a fast Monte Carlo scattering implementation in Merlin*.
*http://www.desy.de/∼merlin
Accelerator Component Vibration Studies and Tools
This talk will cover a research program on
accelerator component vibrations. Ground R. Amirikas, A. Bertolini, W. Bialowons, H. Ehrlichmann (DESY)
motion and technical noise, such as vacuum
and refrigeration systems, couple to the beam, mainly via quadrupoles, making the design of their supports, especially,
in the case of the superconducting magnets, critical. This program includes investigation of cold mass vibration of
the superconducting quadrupoles inside an accelerating module and sensor performance in the main or fringe field
of a linear collider detector. Seismometer accuracy limitations in correlated ground motion measurements are also
being investigated.
125
MOPLS061
MOPLS062
MOPLS063