IPAC2011 - List of Authors (Schmidt, F.)

Paper	Title	Page
TUPZ006	Aperture Determination in the LHC Based on an Emittance Blowup Technique with Collimator Position Scan	1810
	R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, S. Redaelli, F. Schmidt, R. Tomás, J. Wenninger, D. Wollmann CERN, Geneva, Switzerland M. Alabau IFIC, Valencia, Spain
	A new method to determine the LHC aperture was proposed. The new component is a collimator scan technique that refers the globally measured aperture limit to the shadow of the primary collimator, expressed in σs of rms beam size. As a by-product the BLM response to beam loss is quantified. The method is described and LHC measurement results are presented.

WEPC032	First Measurements of Higher Order Optics Parameters in the LHC	2073
	G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands M. Aiba PSI, Villigen, Switzerland R. Bartolini Diamond, Oxfordshire, United Kingdom R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA M. Giovannozzi, F. Schmidt, R. Tomás CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom
	Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

WEPC078	Non-linear Chromaticity Studies of the LHC at Injection	2199
	E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland R. Bartolini JAI, Oxford, United Kingdom
	The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

WEPC079	Beta-beating in the Effective Model of the LHC Using PTC	2202
	M.C. Alabau Pons, F. Schmidt, R. Tomás CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom
	An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code with MAD-X as front-end to allow the inclusion of harmonics to an arbitrary order in thick lattice elements. Beta-beating calculations have been performed with this model at injection optics and at 3.5 TeV squeezed optics to 3.5 m beta-function at the interaction point. The model predictions are in remarkable agreement with the measurements performed in the 2010 LHC commissioning run.

Paper

Title

Page

Aperture Determination in the LHC Based on an Emittance Blowup Technique with Collimator Position Scan

1810

R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, S. Redaelli, F. Schmidt, R. Tomás, J. Wenninger, D. Wollmann
CERN, Geneva, Switzerland
M. Alabau
IFIC, Valencia, Spain

A new method to determine the LHC aperture was proposed. The new component is a collimator scan technique that refers the globally measured aperture limit to the shadow of the primary collimator, expressed in σs of rms beam size. As a by-product the BLM response to beam loss is quantified. The method is described and LHC measurement results are presented.

WEPC032

First Measurements of Higher Order Optics Parameters in the LHC

2073

G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands
M. Aiba
PSI, Villigen, Switzerland
R. Bartolini
Diamond, Oxfordshire, United Kingdom
R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
M. Giovannozzi, F. Schmidt, R. Tomás
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom

Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

WEPC078

Non-linear Chromaticity Studies of the LHC at Injection

2199

E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
R. Bartolini
JAI, Oxford, United Kingdom

The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

WEPC079

Beta-beating in the Effective Model of the LHC Using PTC

2202

M.C. Alabau Pons, F. Schmidt, R. Tomás
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom

An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code with MAD-X as front-end to allow the inclusion of harmonics to an arbitrary order in thick lattice elements. Beta-beating calculations have been performed with this model at injection optics and at 3.5 TeV squeezed optics to 3.5 m beta-function at the interaction point. The model predictions are in remarkable agreement with the measurements performed in the 2010 LHC commissioning run.