83 research outputs found
Investigation of beam self-polarization in the future circular collider
The use of resonant depolarization has been suggested for precise beam energy
measurements (better than 100 keV) in the Future Circular Collider
(FCC-) for Z and WW physics at 45 and 80 GeV beam energy
respectively. Longitudinal beam polarization would benefit the Z peak physics
program; however it is not essential and therefore it will be not investigated
here. In this paper the possibility of self-polarized leptons is considered.
Preliminary results of simulations in presence of quadrupole misalignments and
beam position monitors (BPMs) errors for a simplified FCC- ring are
presented.Comment: 9 p
FCC-ee: Energy calibration
The FCC-ee aims to improve on electroweak precision measurements, with goals
of 100 keV on the Z mass and width, and a fraction of MeV on the W mass.
Compared to LEP, this implies a much improved knowledge of the centre-of-mass
energy when operating at the Z peak and WW threshold. This can be achieved by
making systematic use of resonant depolarization. A number of issues have been
identified, due in particular to the long polarization times. However the
smaller emittance and energy spread of FCC-ee with respect to LEP should help
achieve a much improved performance.Comment: Poster presented at IPAC'15, Richmond, VA, USA, May 2015. arXiv admin
note: substantial text overlap with arXiv:1501.0685
Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster
The Fermilab Booster - built more than 40 years ago - operates well above the
design proton beam intensity of 4x10**12 ppp. Still, the Fermilab neutrino
experiments call for even higher intensity of 5.5x10**12 ppp. A multitude of
intensity related effects must be overcome in order to meet this goal including
suppression of coherent dipole instabilities of transverse oscillations which
manifest themselves as a sudden drop in the beam current. In this report we
present the results of observation of these instabilities at different tune,
coupling and chromaticity settings and discuss possible cures.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
High Resolution BPM Upgrade for the ATF Damping Ring at KEK
A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility
(ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC
collaboration under the umbrella of the global ILC R&D effort. The upgrade
consists of a high resolution, high reproducibility read-out system, based on
analog and processing, and also implements a new automatic gain error
correction schema. The technical concept and realization as well as results of
beam studies are presented.Comment: 3 pp. 10th European Workshop on Beam Diagnostics and Instrumentation
for Particle Accelerators DIPAC 2011, 16-18 May 2011. Hamburg, German
LHC Abort Gap Cleaning with the Transverse Damper
In the Large Hadron Collider, LHC, particles not captured by the RF system at injection or leaking out of the RF bucket may quench the superconducting magnets during beam abort. The problem, common to other superconducting machines, is particularly serious for the LHC due to the very large stored energy in the beam. For the LHC a way of removing the unbunched beam has been studied and it uses the existing damper kickers to excite resonantly the particles travelling along the abort gap. In this paper we describe the results of simulations performed with MAD X for various LHC optics configurations, including the estimated multipolar errors
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