Abstracts Brochure - CERN

MOPLS018
MOPLS019
MOPLS020
MOPLS021
26-Jun-06 16:00 - 18:00 MOPLS — Poster Session
similar to a dipole first layout option. However, at the same time, the presented solution provides an interesting
alternative to a high gradient triplet layout which requires the new Nb3Ti magnet technology.
High-order Effects and Modeling of the Tevatron
The role and degree of nonlinear contribu-
P. Snopok, M. Berz (MSU) C. Johnstone (Fermilab)
tions to machine performance is a controversial
topic in current collider operations and
in the design of future colliders. A high-order model has been developed of the Tevatron in COSY, which includes
the strongest sources of nonlinearities. Signatures of nonlinear behavior are studied and compared with performance
data. The observed nonlinear effects are compared before and after implemention of nonlinear correction schemes.
Designs for the LHC IR Upgrade
We report on progress on the LHC IR up-
T. Sen, J.A. Johnstone, N.V. Mokhov (Fermilab)
grades made by the US-LARP collaboration.
We discuss quadrupole first and dipole first
designs and introduce a doublet focusing option among the latter set. For each design we present results on the following:
magnet apertures, pole tip fields, required chromaticity and nonlinear correction systems, energy deposition
in the magnets, the impact of beam-beam interactions, and the benefits of reducing L*. These results will highlight
the differences between the designs and help to chosse the upgrade path.
Rad-hard Luminosity Monitoring for the LHC
A. Ratti, J.-F. Beche, J.M. Byrd, K. Chow, P. Denes, B. Ghiorso, M. T.
Monroy, W.C. Turner (LBNL) E. Bravin (CERN) P.F. Manfredi (Pavia
University, Engineering faculty) W. Vandelli (Pavia University)
112
Luminosity measurements at the high luminosity
points of the LHC are very challenging
due to the extremely high radiation levels in
excess of 1 GGy/yr. We have designed an
ionization chamber that uses a flowing gas
mixture and a combination of metals and ceramics. With such a choice, an additonal challenge is achieving the necessary
speed to be able to resolve bunch-by-bunch luminosity data. We present the design, analysis and experimental
results of the early demonstration tests of this device.
Beam Pipe Desorption Rate in RHIC
H. Huang, W. Fischer, P. He, H.-C. Hseuh, U. Iriso, V. Ptitsyn, D.
Trbojevic, J. Wei, S.Y. Zhang (BNL)
Increase of beam intensity in RHIC has
caused several decades of pressure rises in
the warm sections during operation. This
has been a major factor limiting the RHIC lu-
minosity. About 250 meters of NEG coated beam pipes have been installed in many warm sections to ameliorate
this problem. Beam ion induced desorption is one possible cause of pressure rises. A series beam studies in RHIC
has been dedicated to estimate the desorption rate of various beam pipes (regular and NEG coated) at various warm
sections. Correctors were used to generate local beam losses and consequently local pressure rises. The experiment
results are presented and analyzed in this paper.